110 files changed, 870 insertions, 597 deletions

diff --git a/Documentation/DMA-mapping.txt b/Documentation/DMA-mapping.txt
index 8efe12d74268..3c8ae020b6a7 100644
--- a/Documentation/DMA-mapping.txt
+++ b/Documentation/DMA-mapping.txt
@@ -514,7 +514,7 @@ With scatterlists, you map a region gathered from several regions by:
         int i, count = pci_map_sg(dev, sglist, nents, direction);
         struct scatterlist *sg;
 
-        for (i = 0, sg = sglist; i < count; i++, sg++) {
+        for_each_sg(sglist, sg, count, i) {
                 hw_address[i] = sg_dma_address(sg);
                 hw_len[i] = sg_dma_len(sg);
         }
diff --git a/arch/ia64/hp/common/sba_iommu.c b/arch/ia64/hp/common/sba_iommu.c
index e980e7aa2306..4338f4123f31 100644
--- a/arch/ia64/hp/common/sba_iommu.c
+++ b/arch/ia64/hp/common/sba_iommu.c
@@ -396,7 +396,7 @@ sba_dump_sg( struct ioc *ioc, struct scatterlist *startsg, int nents)
                 printk(KERN_DEBUG " %d : DMA %08lx/%05x CPU %p\n", nents,
                        startsg->dma_address, startsg->dma_length,
                        sba_sg_address(startsg));
-                startsg++;
+                startsg = sg_next(startsg);
         }
 }
 
@@ -409,7 +409,7 @@ sba_check_sg( struct ioc *ioc, struct scatterlist *startsg, int nents)
         while (the_nents-- > 0) {
                 if (sba_sg_address(the_sg) == 0x0UL)
                         sba_dump_sg(NULL, startsg, nents);
-                the_sg++;
+                the_sg = sg_next(the_sg);
         }
 }
 
@@ -1201,7 +1201,7 @@ sba_fill_pdir(
                         u32 pide = startsg->dma_address & ~PIDE_FLAG;
                         dma_offset = (unsigned long) pide & ~iovp_mask;
                         startsg->dma_address = 0;
-                        dma_sg++;
+                        dma_sg = sg_next(dma_sg);
                         dma_sg->dma_address = pide | ioc->ibase;
                         pdirp = &(ioc->pdir_base[pide >> iovp_shift]);
                         n_mappings++;
@@ -1228,7 +1228,7 @@ sba_fill_pdir(
                                 pdirp++;
                         } while (cnt > 0);
                 }
-                startsg++;
+                startsg = sg_next(startsg);
         }
         /* force pdir update */
         wmb();
@@ -1297,7 +1297,7 @@ sba_coalesce_chunks( struct ioc *ioc,
                 while (--nents > 0) {
                         unsigned long vaddr;    /* tmp */
 
-                        startsg++;
+                        startsg = sg_next(startsg);
 
                         /* PARANOID */
                         startsg->dma_address = startsg->dma_length = 0;
@@ -1407,7 +1407,7 @@ int sba_map_sg(struct device *dev, struct scatterlist *sglist, int nents, int di
 #ifdef ALLOW_IOV_BYPASS_SG
         ASSERT(to_pci_dev(dev)->dma_mask);
         if (likely((ioc->dma_mask & ~to_pci_dev(dev)->dma_mask) == 0)) {
-                for (sg = sglist ; filled < nents ; filled++, sg++){
+                for_each_sg(sglist, sg, nents, filled) {
                         sg->dma_length = sg->length;
                         sg->dma_address = virt_to_phys(sba_sg_address(sg));
                 }
@@ -1501,7 +1501,7 @@ void sba_unmap_sg (struct device *dev, struct scatterlist *sglist, int nents, in
         while (nents && sglist->dma_length) {
 
                 sba_unmap_single(dev, sglist->dma_address, sglist->dma_length, dir);
-                sglist++;
+                sglist = sg_next(sglist);
                 nents--;
         }
 
diff --git a/arch/ia64/hp/sim/simscsi.c b/arch/ia64/hp/sim/simscsi.c
index d62fa76e5a7d..a3a558a06757 100644
--- a/arch/ia64/hp/sim/simscsi.c
+++ b/arch/ia64/hp/sim/simscsi.c
@@ -360,6 +360,7 @@ static struct scsi_host_template driver_template = {
         .max_sectors            = 1024,
         .cmd_per_lun            = SIMSCSI_REQ_QUEUE_LEN,
         .use_clustering         = DISABLE_CLUSTERING,
+        .use_sg_chaining        = ENABLE_SG_CHAINING,
 };
 
 static int __init
diff --git a/arch/ia64/sn/pci/pci_dma.c b/arch/ia64/sn/pci/pci_dma.c
index d79ddacfba2d..ecd8a52b9b9e 100644
--- a/arch/ia64/sn/pci/pci_dma.c
+++ b/arch/ia64/sn/pci/pci_dma.c
@@ -218,16 +218,17 @@ EXPORT_SYMBOL(sn_dma_unmap_single);
  *
  * Unmap a set of streaming mode DMA translations.
  */
-void sn_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
+void sn_dma_unmap_sg(struct device *dev, struct scatterlist *sgl,
                      int nhwentries, int direction)
 {
         int i;
         struct pci_dev *pdev = to_pci_dev(dev);
         struct sn_pcibus_provider *provider = SN_PCIDEV_BUSPROVIDER(pdev);
+        struct scatterlist *sg;
 
         BUG_ON(dev->bus != &pci_bus_type);
 
-        for (i = 0; i < nhwentries; i++, sg++) {
+        for_each_sg(sgl, sg, nhwentries, i) {
                 provider->dma_unmap(pdev, sg->dma_address, direction);
                 sg->dma_address = (dma_addr_t) NULL;
                 sg->dma_length = 0;
@@ -244,11 +245,11 @@ EXPORT_SYMBOL(sn_dma_unmap_sg);
  *
  * Maps each entry of @sg for DMA.
  */
-int sn_dma_map_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
+int sn_dma_map_sg(struct device *dev, struct scatterlist *sgl, int nhwentries,
                   int direction)
 {
         unsigned long phys_addr;
-        struct scatterlist *saved_sg = sg;
+        struct scatterlist *saved_sg = sgl, *sg;
         struct pci_dev *pdev = to_pci_dev(dev);
         struct sn_pcibus_provider *provider = SN_PCIDEV_BUSPROVIDER(pdev);
         int i;
@@ -258,7 +259,7 @@ int sn_dma_map_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
         /*
          * Setup a DMA address for each entry in the scatterlist.
          */
-        for (i = 0; i < nhwentries; i++, sg++) {
+        for_each_sg(sgl, sg, nhwentries, i) {
                 phys_addr = SG_ENT_PHYS_ADDRESS(sg);
                 sg->dma_address = provider->dma_map(pdev,
                                                     phys_addr, sg->length,
diff --git a/arch/powerpc/kernel/dma_64.c b/arch/powerpc/kernel/dma_64.c
index 7b0e754383cf..9001104b56b0 100644
--- a/arch/powerpc/kernel/dma_64.c
+++ b/arch/powerpc/kernel/dma_64.c
@@ -154,12 +154,13 @@ static void dma_direct_unmap_single(struct device *dev, dma_addr_t dma_addr,
 {
 }
 
-static int dma_direct_map_sg(struct device *dev, struct scatterlist *sg,
+static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
                              int nents, enum dma_data_direction direction)
 {
+        struct scatterlist *sg;
         int i;
 
-        for (i = 0; i < nents; i++, sg++) {
+        for_each_sg(sgl, sg, nents, i) {
                 sg->dma_address = (page_to_phys(sg->page) + sg->offset) |
                         dma_direct_offset;
                 sg->dma_length = sg->length;
diff --git a/arch/powerpc/kernel/ibmebus.c b/arch/powerpc/kernel/ibmebus.c
index 53bf64623bd8..2e16ca5778a3 100644
--- a/arch/powerpc/kernel/ibmebus.c
+++ b/arch/powerpc/kernel/ibmebus.c
@@ -87,15 +87,16 @@ static void ibmebus_unmap_single(struct device *dev,
 }
 
 static int ibmebus_map_sg(struct device *dev,
-                          struct scatterlist *sg,
+                          struct scatterlist *sgl,
                           int nents, enum dma_data_direction direction)
 {
+        struct scatterlist *sg;
         int i;
 
-        for (i = 0; i < nents; i++) {
-                sg[i].dma_address = (dma_addr_t)page_address(sg[i].page)
-                        + sg[i].offset;
-                sg[i].dma_length = sg[i].length;
+        for_each_sg(sgl, sg, nents, i) {
+                sg->dma_address = (dma_addr_t)page_address(sg->page)
+                        + sg->offset;
+                sg->dma_length = sg->length;
         }
 
         return nents;
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index e4ec6eee81a8..306a6f75b6c5 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -277,7 +277,7 @@ int iommu_map_sg(struct iommu_table *tbl, struct scatterlist *sglist,
         dma_addr_t dma_next = 0, dma_addr;
         unsigned long flags;
         struct scatterlist *s, *outs, *segstart;
-        int outcount, incount;
+        int outcount, incount, i;
         unsigned long handle;
 
         BUG_ON(direction == DMA_NONE);
@@ -297,7 +297,7 @@ int iommu_map_sg(struct iommu_table *tbl, struct scatterlist *sglist,
 
         spin_lock_irqsave(&(tbl->it_lock), flags);
 
-        for (s = outs; nelems; nelems--, s++) {
+        for_each_sg(sglist, s, nelems, i) {
                 unsigned long vaddr, npages, entry, slen;
 
                 slen = s->length;
@@ -341,7 +341,8 @@ int iommu_map_sg(struct iommu_table *tbl, struct scatterlist *sglist,
                         if (novmerge || (dma_addr != dma_next)) {
                                 /* Can't merge: create a new segment */
                                 segstart = s;
-                                outcount++; outs++;
+                                outcount++;
+                                outs = sg_next(outs);
                                 DBG("    can't merge, new segment.\n");
                         } else {
                                 outs->dma_length += s->length;
@@ -374,7 +375,7 @@ int iommu_map_sg(struct iommu_table *tbl, struct scatterlist *sglist,
          * next entry of the sglist if we didn't fill the list completely
          */
         if (outcount < incount) {
-                outs++;
+                outs = sg_next(outs);
                 outs->dma_address = DMA_ERROR_CODE;
                 outs->dma_length = 0;
         }
@@ -385,7 +386,7 @@ int iommu_map_sg(struct iommu_table *tbl, struct scatterlist *sglist,
         return outcount;
 
  failure:
-        for (s = &sglist[0]; s <= outs; s++) {
+        for_each_sg(sglist, s, nelems, i) {
                 if (s->dma_length != 0) {
                         unsigned long vaddr, npages;
 
@@ -395,6 +396,8 @@ int iommu_map_sg(struct iommu_table *tbl, struct scatterlist *sglist,
                         s->dma_address = DMA_ERROR_CODE;
                         s->dma_length = 0;
                 }
+                if (s == outs)
+                        break;
         }
         spin_unlock_irqrestore(&(tbl->it_lock), flags);
         return 0;
@@ -404,6 +407,7 @@ int iommu_map_sg(struct iommu_table *tbl, struct scatterlist *sglist,
 void iommu_unmap_sg(struct iommu_table *tbl, struct scatterlist *sglist,
                 int nelems, enum dma_data_direction direction)
 {
+        struct scatterlist *sg;
         unsigned long flags;
 
         BUG_ON(direction == DMA_NONE);
@@ -413,15 +417,16 @@ void iommu_unmap_sg(struct iommu_table *tbl, struct scatterlist *sglist,
 
         spin_lock_irqsave(&(tbl->it_lock), flags);
 
+        sg = sglist;
         while (nelems--) {
                 unsigned int npages;
-                dma_addr_t dma_handle = sglist->dma_address;
+                dma_addr_t dma_handle = sg->dma_address;
 
-                if (sglist->dma_length == 0)
+                if (sg->dma_length == 0)
                         break;
-                npages = iommu_num_pages(dma_handle,sglist->dma_length);
+                npages = iommu_num_pages(dma_handle, sg->dma_length);
                 __iommu_free(tbl, dma_handle, npages);
-                sglist++;
+                sg = sg_next(sg);
         }
 
         /* Flush/invalidate TLBs if necessary. As for iommu_free(), we
diff --git a/arch/powerpc/platforms/ps3/system-bus.c b/arch/powerpc/platforms/ps3/system-bus.c
index 190ff4b59a55..07e64b48e7fc 100644
--- a/arch/powerpc/platforms/ps3/system-bus.c
+++ b/arch/powerpc/platforms/ps3/system-bus.c
@@ -616,17 +616,18 @@ static void ps3_unmap_single(struct device *_dev, dma_addr_t dma_addr,
         }
 }
 
-static int ps3_sb_map_sg(struct device *_dev, struct scatterlist *sg, int nents,
-        enum dma_data_direction direction)
+static int ps3_sb_map_sg(struct device *_dev, struct scatterlist *sgl,
+        int nents, enum dma_data_direction direction)
 {
 #if defined(CONFIG_PS3_DYNAMIC_DMA)
         BUG_ON("do");
         return -EPERM;
 #else
         struct ps3_system_bus_device *dev = ps3_dev_to_system_bus_dev(_dev);
+        struct scatterlist *sg;
         int i;
 
-        for (i = 0; i < nents; i++, sg++) {
+        for_each_sg(sgl, sg, nents, i) {
                 int result = ps3_dma_map(dev->d_region,
                         page_to_phys(sg->page) + sg->offset, sg->length,
                                          &sg->dma_address, 0);
diff --git a/arch/sparc/kernel/ioport.c b/arch/sparc/kernel/ioport.c
index 62182d2d7b0d..9c3ed88853f3 100644
--- a/arch/sparc/kernel/ioport.c
+++ b/arch/sparc/kernel/ioport.c
@@ -35,6 +35,7 @@
 #include <linux/slab.h>
 #include <linux/pci.h>          /* struct pci_dev */
 #include <linux/proc_fs.h>
+#include <linux/scatterlist.h>
 
 #include <asm/io.h>
 #include <asm/vaddrs.h>
@@ -717,19 +718,19 @@ void pci_unmap_page(struct pci_dev *hwdev,
  * Device ownership issues as mentioned above for pci_map_single are
  * the same here.
  */
-int pci_map_sg(struct pci_dev *hwdev, struct scatterlist *sg, int nents,
+int pci_map_sg(struct pci_dev *hwdev, struct scatterlist *sgl, int nents,
     int direction)
 {
+        struct scatterlist *sg;
         int n;
 
         BUG_ON(direction == PCI_DMA_NONE);
         /* IIep is write-through, not flushing. */
-        for (n = 0; n < nents; n++) {
+        for_each_sg(sgl, sg, nents, n) {
                 BUG_ON(page_address(sg->page) == NULL);
                 sg->dvma_address =
                         virt_to_phys(page_address(sg->page)) + sg->offset;
                 sg->dvma_length = sg->length;
-                sg++;
         }
         return nents;
 }
@@ -738,19 +739,19 @@ int pci_map_sg(struct pci_dev *hwdev, struct scatterlist *sg, int nents,
  * Again, cpu read rules concerning calls here are the same as for
  * pci_unmap_single() above.
  */
-void pci_unmap_sg(struct pci_dev *hwdev, struct scatterlist *sg, int nents,
+void pci_unmap_sg(struct pci_dev *hwdev, struct scatterlist *sgl, int nents,
     int direction)
 {
+        struct scatterlist *sg;
         int n;
 
         BUG_ON(direction == PCI_DMA_NONE);
         if (direction != PCI_DMA_TODEVICE) {
-                for (n = 0; n < nents; n++) {
+                for_each_sg(sgl, sg, nents, n) {
                         BUG_ON(page_address(sg->page) == NULL);
                         mmu_inval_dma_area(
                             (unsigned long) page_address(sg->page),
                             (sg->length + PAGE_SIZE-1) & PAGE_MASK);
-                        sg++;
                 }
         }
 }
@@ -789,34 +790,34 @@ void pci_dma_sync_single_for_device(struct pci_dev *hwdev, dma_addr_t ba, size_t
  * The same as pci_dma_sync_single_* but for a scatter-gather list,
  * same rules and usage.
  */
-void pci_dma_sync_sg_for_cpu(struct pci_dev *hwdev, struct scatterlist *sg, int nents, int direction)
+void pci_dma_sync_sg_for_cpu(struct pci_dev *hwdev, struct scatterlist *sgl, int nents, int direction)
 {
+        struct scatterlist *sg;
         int n;
 
         BUG_ON(direction == PCI_DMA_NONE);
         if (direction != PCI_DMA_TODEVICE) {
-                for (n = 0; n < nents; n++) {
+                for_each_sg(sgl, sg, nents, n) {
                         BUG_ON(page_address(sg->page) == NULL);
                         mmu_inval_dma_area(
                             (unsigned long) page_address(sg->page),
                             (sg->length + PAGE_SIZE-1) & PAGE_MASK);
-                        sg++;
                 }
         }
 }
 
-void pci_dma_sync_sg_for_device(struct pci_dev *hwdev, struct scatterlist *sg, int nents, int direction)
+void pci_dma_sync_sg_for_device(struct pci_dev *hwdev, struct scatterlist *sgl, int nents, int direction)
 {
+        struct scatterlist *sg;
         int n;
 
         BUG_ON(direction == PCI_DMA_NONE);
         if (direction != PCI_DMA_TODEVICE) {
-                for (n = 0; n < nents; n++) {
+                for_each_sg(sgl, sg, nents, n) {
                         BUG_ON(page_address(sg->page) == NULL);
                         mmu_inval_dma_area(
                             (unsigned long) page_address(sg->page),
                             (sg->length + PAGE_SIZE-1) & PAGE_MASK);
-                        sg++;
                 }
         }
 }
diff --git a/arch/sparc/mm/io-unit.c b/arch/sparc/mm/io-unit.c
index 7c89893b1fe8..375b4db63704 100644
--- a/arch/sparc/mm/io-unit.c
+++ b/arch/sparc/mm/io-unit.c
@@ -11,8 +11,8 @@
 #include <linux/mm.h>
 #include <linux/highmem.h>      /* pte_offset_map => kmap_atomic */
 #include <linux/bitops.h>
+#include <linux/scatterlist.h>
 
-#include <asm/scatterlist.h>
 #include <asm/pgalloc.h>
 #include <asm/pgtable.h>
 #include <asm/sbus.h>
@@ -144,8 +144,9 @@ static void iounit_get_scsi_sgl(struct scatterlist *sg, int sz, struct sbus_bus
         spin_lock_irqsave(&iounit->lock, flags);
         while (sz != 0) {
                 --sz;
-                sg[sz].dvma_address = iounit_get_area(iounit, (unsigned long)page_address(sg[sz].page) + sg[sz].offset, sg[sz].length);
-                sg[sz].dvma_length = sg[sz].length;
+                sg->dvma_address = iounit_get_area(iounit, (unsigned long)page_address(sg->page) + sg->offset, sg->length);
+                sg->dvma_length = sg->length;
+                sg = sg_next(sg);
         }
         spin_unlock_irqrestore(&iounit->lock, flags);
 }
@@ -173,11 +174,12 @@ static void iounit_release_scsi_sgl(struct scatterlist *sg, int sz, struct sbus_
         spin_lock_irqsave(&iounit->lock, flags);
         while (sz != 0) {
                 --sz;
-                len = ((sg[sz].dvma_address & ~PAGE_MASK) + sg[sz].length + (PAGE_SIZE-1)) >> PAGE_SHIFT;
-                vaddr = (sg[sz].dvma_address - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
+                len = ((sg->dvma_address & ~PAGE_MASK) + sg->length + (PAGE_SIZE-1)) >> PAGE_SHIFT;
+                vaddr = (sg->dvma_address - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
                 IOD(("iounit_release %08lx-%08lx\n", (long)vaddr, (long)len+vaddr));
                 for (len += vaddr; vaddr < len; vaddr++)
                         clear_bit(vaddr, iounit->bmap);
+                sg = sg_next(sg);
         }
         spin_unlock_irqrestore(&iounit->lock, flags);
 }
diff --git a/arch/sparc/mm/iommu.c b/arch/sparc/mm/iommu.c
index 52e907af9d29..283656d9f6ea 100644
--- a/arch/sparc/mm/iommu.c
+++ b/arch/sparc/mm/iommu.c
@@ -12,8 +12,8 @@
 #include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/highmem.h>      /* pte_offset_map => kmap_atomic */
+#include <linux/scatterlist.h>
 
-#include <asm/scatterlist.h>
 #include <asm/pgalloc.h>
 #include <asm/pgtable.h>
 #include <asm/sbus.h>
@@ -240,7 +240,7 @@ static void iommu_get_scsi_sgl_noflush(struct scatterlist *sg, int sz, struct sb
                 n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
                 sg->dvma_address = iommu_get_one(sg->page, n, sbus) + sg->offset;
                 sg->dvma_length = (__u32) sg->length;
-                sg++;
+                sg = sg_next(sg);
         }
 }
 
@@ -254,7 +254,7 @@ static void iommu_get_scsi_sgl_gflush(struct scatterlist *sg, int sz, struct sbu
                 n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
                 sg->dvma_address = iommu_get_one(sg->page, n, sbus) + sg->offset;
                 sg->dvma_length = (__u32) sg->length;
-                sg++;
+                sg = sg_next(sg);
         }
 }
 
@@ -285,7 +285,7 @@ static void iommu_get_scsi_sgl_pflush(struct scatterlist *sg, int sz, struct sbu
 
                 sg->dvma_address = iommu_get_one(sg->page, n, sbus) + sg->offset;
                 sg->dvma_length = (__u32) sg->length;
-                sg++;
+                sg = sg_next(sg);
         }
 }
 
@@ -325,7 +325,7 @@ static void iommu_release_scsi_sgl(struct scatterlist *sg, int sz, struct sbus_b
                 n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
                 iommu_release_one(sg->dvma_address & PAGE_MASK, n, sbus);
                 sg->dvma_address = 0x21212121;
-                sg++;
+                sg = sg_next(sg);
         }
 }
 
diff --git a/arch/sparc/mm/sun4c.c b/arch/sparc/mm/sun4c.c
index 005a3e72d4f2..ee6708fc4492 100644
--- a/arch/sparc/mm/sun4c.c
+++ b/arch/sparc/mm/sun4c.c
@@ -17,8 +17,8 @@
 #include <linux/highmem.h>
 #include <linux/fs.h>
 #include <linux/seq_file.h>
+#include <linux/scatterlist.h>
 
-#include <asm/scatterlist.h>
 #include <asm/page.h>
 #include <asm/pgalloc.h>
 #include <asm/pgtable.h>
@@ -1228,8 +1228,9 @@ static void sun4c_get_scsi_sgl(struct scatterlist *sg, int sz, struct sbus_bus *
 {
         while (sz != 0) {
                 --sz;
-                sg[sz].dvma_address = (__u32)sun4c_lockarea(page_address(sg[sz].page) + sg[sz].offset, sg[sz].length);
-                sg[sz].dvma_length = sg[sz].length;
+                sg->dvma_address = (__u32)sun4c_lockarea(page_address(sg->page) + sg->offset, sg->length);
+                sg->dvma_length = sg->length;
+                sg = sg_next(sg);
         }
 }
 
@@ -1244,7 +1245,8 @@ static void sun4c_release_scsi_sgl(struct scatterlist *sg, int sz, struct sbus_b
 {
         while (sz != 0) {
                 --sz;
-                sun4c_unlockarea((char *)sg[sz].dvma_address, sg[sz].length);
+                sun4c_unlockarea((char *)sg->dvma_address, sg->length);
+                sg = sg_next(sg);
         }
 }
 
diff --git a/arch/sparc64/kernel/iommu.c b/arch/sparc64/kernel/iommu.c
index b35a62167e9c..db3ffcf7a120 100644
--- a/arch/sparc64/kernel/iommu.c
+++ b/arch/sparc64/kernel/iommu.c
@@ -10,6 +10,7 @@
 #include <linux/device.h>
 #include <linux/dma-mapping.h>
 #include <linux/errno.h>
+#include <linux/scatterlist.h>
 
 #ifdef CONFIG_PCI
 #include <linux/pci.h>
@@ -480,7 +481,7 @@ static inline void fill_sg(iopte_t *iopte, struct scatterlist *sg,
                            unsigned long iopte_protection)
 {
         struct scatterlist *dma_sg = sg;
-        struct scatterlist *sg_end = sg + nelems;
+        struct scatterlist *sg_end = sg_last(sg, nelems);
         int i;
 
         for (i = 0; i < nused; i++) {
@@ -515,7 +516,7 @@ static inline void fill_sg(iopte_t *iopte, struct scatterlist *sg,
                                         len -= (IO_PAGE_SIZE - (tmp & (IO_PAGE_SIZE - 1UL)));
                                         break;
                                 }
-                                sg++;
+                                sg = sg_next(sg);
                         }
 
                         pteval = iopte_protection | (pteval & IOPTE_PAGE);
@@ -528,24 +529,24 @@ static inline void fill_sg(iopte_t *iopte, struct scatterlist *sg,
                         }
 
                         pteval = (pteval & IOPTE_PAGE) + len;
-                        sg++;
+                        sg = sg_next(sg);
 
                         /* Skip over any tail mappings we've fully mapped,
                          * adjusting pteval along the way.  Stop when we
                          * detect a page crossing event.
                          */
-                        while (sg < sg_end &&
+                        while (sg != sg_end &&
                                (pteval << (64 - IO_PAGE_SHIFT)) != 0UL &&
                                (pteval == SG_ENT_PHYS_ADDRESS(sg)) &&
                                ((pteval ^
                                  (SG_ENT_PHYS_ADDRESS(sg) + sg->length - 1UL)) >> IO_PAGE_SHIFT) == 0UL) {
                                 pteval += sg->length;
-                                sg++;
+                                sg = sg_next(sg);
                         }
                         if ((pteval << (64 - IO_PAGE_SHIFT)) == 0UL)
                                 pteval = ~0UL;
                 } while (dma_npages != 0);
-                dma_sg++;
+                dma_sg = sg_next(dma_sg);
         }
 }
 
@@ -606,7 +607,7 @@ static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist,
         sgtmp = sglist;
         while (used && sgtmp->dma_length) {
                 sgtmp->dma_address += dma_base;
-                sgtmp++;
+                sgtmp = sg_next(sgtmp);
                 used--;
         }
         used = nelems - used;
@@ -642,6 +643,7 @@ static void dma_4u_unmap_sg(struct device *dev, struct scatterlist *sglist,
         struct strbuf *strbuf;
         iopte_t *base;
         unsigned long flags, ctx, i, npages;
+        struct scatterlist *sg, *sgprv;
         u32 bus_addr;
 
         if (unlikely(direction == DMA_NONE)) {
@@ -654,11 +656,14 @@ static void dma_4u_unmap_sg(struct device *dev, struct scatterlist *sglist,
 
         bus_addr = sglist->dma_address & IO_PAGE_MASK;
 
-        for (i = 1; i < nelems; i++)
-                if (sglist[i].dma_length == 0)
+        sgprv = NULL;
+        for_each_sg(sglist, sg, nelems, i) {
+                if (sg->dma_length == 0)
                         break;
-        i--;
-        npages = (IO_PAGE_ALIGN(sglist[i].dma_address + sglist[i].dma_length) -
+                sgprv = sg;
+        }
+
+        npages = (IO_PAGE_ALIGN(sgprv->dma_address + sgprv->dma_length) -
                   bus_addr) >> IO_PAGE_SHIFT;
 
         base = iommu->page_table +
@@ -730,6 +735,7 @@ static void dma_4u_sync_sg_for_cpu(struct device *dev,
         struct iommu *iommu;
         struct strbuf *strbuf;
         unsigned long flags, ctx, npages, i;
+        struct scatterlist *sg, *sgprv;
         u32 bus_addr;
 
         iommu = dev->archdata.iommu;
@@ -753,11 +759,14 @@ static void dma_4u_sync_sg_for_cpu(struct device *dev,
 
         /* Step 2: Kick data out of streaming buffers. */
         bus_addr = sglist[0].dma_address & IO_PAGE_MASK;
-        for(i = 1; i < nelems; i++)
-                if (!sglist[i].dma_length)
+        sgprv = NULL;
+        for_each_sg(sglist, sg, nelems, i) {
+                if (sg->dma_length == 0)
                         break;
-        i--;
-        npages = (IO_PAGE_ALIGN(sglist[i].dma_address + sglist[i].dma_length)
+                sgprv = sg;
+        }
+
+        npages = (IO_PAGE_ALIGN(sgprv->dma_address + sgprv->dma_length)
                   - bus_addr) >> IO_PAGE_SHIFT;
         strbuf_flush(strbuf, iommu, bus_addr, ctx, npages, direction);
 
diff --git a/arch/sparc64/kernel/pci_sun4v.c b/arch/sparc64/kernel/pci_sun4v.c
index 95de1444ee67..cacacfae5451 100644
--- a/arch/sparc64/kernel/pci_sun4v.c
+++ b/arch/sparc64/kernel/pci_sun4v.c
@@ -13,6 +13,7 @@
 #include <linux/irq.h>
 #include <linux/msi.h>
 #include <linux/log2.h>
+#include <linux/scatterlist.h>
 
 #include <asm/iommu.h>
 #include <asm/irq.h>
@@ -373,7 +374,7 @@ static inline long fill_sg(long entry, struct device *dev,
                            int nused, int nelems, unsigned long prot)
 {
         struct scatterlist *dma_sg = sg;
-        struct scatterlist *sg_end = sg + nelems;
+        struct scatterlist *sg_end = sg_last(sg, nelems);
         unsigned long flags;
         int i;
 
@@ -413,7 +414,7 @@ static inline long fill_sg(long entry, struct device *dev,
                                         len -= (IO_PAGE_SIZE - (tmp & (IO_PAGE_SIZE - 1UL)));
                                         break;
                                 }
-                                sg++;
+                                sg = sg_next(sg);
                         }
 
                         pteval = (pteval & IOPTE_PAGE);
@@ -431,24 +432,25 @@ static inline long fill_sg(long entry, struct device *dev,
                         }
 
                         pteval = (pteval & IOPTE_PAGE) + len;
-                        sg++;
+                        sg = sg_next(sg);
 
                         /* Skip over any tail mappings we've fully mapped,
                          * adjusting pteval along the way.  Stop when we
                          * detect a page crossing event.
                          */
-                        while (sg < sg_end &&
-                               (pteval << (64 - IO_PAGE_SHIFT)) != 0UL &&
+                        while ((pteval << (64 - IO_PAGE_SHIFT)) != 0UL &&
                                (pteval == SG_ENT_PHYS_ADDRESS(sg)) &&
                                ((pteval ^
                                  (SG_ENT_PHYS_ADDRESS(sg) + sg->length - 1UL)) >> IO_PAGE_SHIFT) == 0UL) {
                                 pteval += sg->length;
-                                sg++;
+                                if (sg == sg_end)
+                                        break;
+                                sg = sg_next(sg);
                         }
                         if ((pteval << (64 - IO_PAGE_SHIFT)) == 0UL)
                                 pteval = ~0UL;
                 } while (dma_npages != 0);
-                dma_sg++;
+                dma_sg = sg_next(dma_sg);
         }
 
         if (unlikely(iommu_batch_end() < 0L))
@@ -510,7 +512,7 @@ static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist,
         sgtmp = sglist;
         while (used && sgtmp->dma_length) {
                 sgtmp->dma_address += dma_base;
-                sgtmp++;
+                sgtmp = sg_next(sgtmp);
                 used--;
         }
         used = nelems - used;
@@ -545,6 +547,7 @@ static void dma_4v_unmap_sg(struct device *dev, struct scatterlist *sglist,
         struct pci_pbm_info *pbm;
         struct iommu *iommu;
         unsigned long flags, i, npages;
+        struct scatterlist *sg, *sgprv;
         long entry;
         u32 devhandle, bus_addr;
 
@@ -558,12 +561,15 @@ static void dma_4v_unmap_sg(struct device *dev, struct scatterlist *sglist,
         devhandle = pbm->devhandle;
         
         bus_addr = sglist->dma_address & IO_PAGE_MASK;
-
-        for (i = 1; i < nelems; i++)
-                if (sglist[i].dma_length == 0)
+        sgprv = NULL;
+        for_each_sg(sglist, sg, nelems, i) {
+                if (sg->dma_length == 0)
                         break;
-        i--;
-        npages = (IO_PAGE_ALIGN(sglist[i].dma_address + sglist[i].dma_length) -
+
+                sgprv = sg;
+        }
+
+        npages = (IO_PAGE_ALIGN(sgprv->dma_address + sgprv->dma_length) -
                   bus_addr) >> IO_PAGE_SHIFT;
 
         entry = ((bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
diff --git a/arch/x86/kernel/pci-calgary_64.c b/arch/x86/kernel/pci-calgary_64.c
index 71da01e73f03..a50b787b3bfa 100644
--- a/arch/x86/kernel/pci-calgary_64.c
+++ b/arch/x86/kernel/pci-calgary_64.c
@@ -35,6 +35,7 @@
 #include <linux/pci_ids.h>
 #include <linux/pci.h>
 #include <linux/delay.h>
+#include <linux/scatterlist.h>
 #include <asm/iommu.h>
 #include <asm/calgary.h>
 #include <asm/tce.h>
@@ -384,31 +385,32 @@ static void calgary_unmap_sg(struct device *dev,
         struct scatterlist *sglist, int nelems, int direction)
 {
         struct iommu_table *tbl = find_iommu_table(dev);
+        struct scatterlist *s;
+        int i;
 
         if (!translate_phb(to_pci_dev(dev)))
                 return;
 
-        while (nelems--) {
+        for_each_sg(sglist, s, nelems, i) {
                 unsigned int npages;
-                dma_addr_t dma = sglist->dma_address;
-                unsigned int dmalen = sglist->dma_length;
+                dma_addr_t dma = s->dma_address;
+                unsigned int dmalen = s->dma_length;
 
                 if (dmalen == 0)
                         break;
 
                 npages = num_dma_pages(dma, dmalen);
                 iommu_free(tbl, dma, npages);
-                sglist++;
         }
 }
 
 static int calgary_nontranslate_map_sg(struct device* dev,
         struct scatterlist *sg, int nelems, int direction)
 {
+        struct scatterlist *s;
         int i;
 
-        for (i = 0; i < nelems; i++ ) {
-                struct scatterlist *s = &sg[i];
+        for_each_sg(sg, s, nelems, i) {
                 BUG_ON(!s->page);
                 s->dma_address = virt_to_bus(page_address(s->page) +s->offset);
                 s->dma_length = s->length;
@@ -420,6 +422,7 @@ static int calgary_map_sg(struct device *dev, struct scatterlist *sg,
         int nelems, int direction)
 {
         struct iommu_table *tbl = find_iommu_table(dev);
+        struct scatterlist *s;
         unsigned long vaddr;
         unsigned int npages;
         unsigned long entry;
@@ -428,8 +431,7 @@ static int calgary_map_sg(struct device *dev, struct scatterlist *sg,
         if (!translate_phb(to_pci_dev(dev)))
                 return calgary_nontranslate_map_sg(dev, sg, nelems, direction);
 
-        for (i = 0; i < nelems; i++ ) {
-                struct scatterlist *s = &sg[i];
+        for_each_sg(sg, s, nelems, i) {
                 BUG_ON(!s->page);
 
                 vaddr = (unsigned long)page_address(s->page) + s->offset;
@@ -454,9 +456,9 @@ static int calgary_map_sg(struct device *dev, struct scatterlist *sg,
         return nelems;
 error:
         calgary_unmap_sg(dev, sg, nelems, direction);
-        for (i = 0; i < nelems; i++) {
-                sg[i].dma_address = bad_dma_address;
-                sg[i].dma_length = 0;
+        for_each_sg(sg, s, nelems, i) {
+                sg->dma_address = bad_dma_address;
+                sg->dma_length = 0;
         }
         return 0;
 }
diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c
index 4918c575d582..cfcc84e6c350 100644
--- a/arch/x86/kernel/pci-gart_64.c
+++ b/arch/x86/kernel/pci-gart_64.c
@@ -23,6 +23,7 @@
 #include <linux/interrupt.h>
 #include <linux/bitops.h>
 #include <linux/kdebug.h>
+#include <linux/scatterlist.h>
 #include <asm/atomic.h>
 #include <asm/io.h>
 #include <asm/mtrr.h>
@@ -278,10 +279,10 @@ static void gart_unmap_single(struct device *dev, dma_addr_t dma_addr,
  */
 static void gart_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, int dir)
 {
+        struct scatterlist *s;
         int i;
 
-        for (i = 0; i < nents; i++) {
-                struct scatterlist *s = &sg[i];
+        for_each_sg(sg, s, nents, i) {
                 if (!s->dma_length || !s->length)
                         break;
                 gart_unmap_single(dev, s->dma_address, s->dma_length, dir);
@@ -292,14 +293,14 @@ static void gart_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
 static int dma_map_sg_nonforce(struct device *dev, struct scatterlist *sg,
                                int nents, int dir)
 {
+        struct scatterlist *s;
         int i;
 
 #ifdef CONFIG_IOMMU_DEBUG
         printk(KERN_DEBUG "dma_map_sg overflow\n");
 #endif
 
-        for (i = 0; i < nents; i++ ) {
-                struct scatterlist *s = &sg[i];
+        for_each_sg(sg, s, nents, i) {
                 unsigned long addr = page_to_phys(s->page) + s->offset; 
                 if (nonforced_iommu(dev, addr, s->length)) { 
                         addr = dma_map_area(dev, addr, s->length, dir);
@@ -319,23 +320,23 @@ static int dma_map_sg_nonforce(struct device *dev, struct scatterlist *sg,
 }
 
 /* Map multiple scatterlist entries continuous into the first. */
-static int __dma_map_cont(struct scatterlist *sg, int start, int stopat,
+static int __dma_map_cont(struct scatterlist *start, int nelems,
                       struct scatterlist *sout, unsigned long pages)
 {
         unsigned long iommu_start = alloc_iommu(pages);
         unsigned long iommu_page = iommu_start; 
+        struct scatterlist *s;
         int i;
 
         if (iommu_start == -1)
                 return -1;
-        
-        for (i = start; i < stopat; i++) {
-                struct scatterlist *s = &sg[i];
+
+        for_each_sg(start, s, nelems, i) {
                 unsigned long pages, addr;
                 unsigned long phys_addr = s->dma_address;
                 
-                BUG_ON(i > start && s->offset);
-                if (i == start) {
+                BUG_ON(s != start && s->offset);
+                if (s == start) {
                         *sout = *s; 
                         sout->dma_address = iommu_bus_base;
                         sout->dma_address += iommu_page*PAGE_SIZE + s->offset;
@@ -357,17 +358,17 @@ static int __dma_map_cont(struct scatterlist *sg, int start, int stopat,
         return 0;
 }
 
-static inline int dma_map_cont(struct scatterlist *sg, int start, int stopat,
+static inline int dma_map_cont(struct scatterlist *start, int nelems,
                       struct scatterlist *sout,
                       unsigned long pages, int need)
 {
-        if (!need) { 
-                BUG_ON(stopat - start != 1);
-                *sout = sg[start]; 
-                sout->dma_length = sg[start].length; 
+        if (!need) {
+                BUG_ON(nelems != 1);
+                *sout = *start;
+                sout->dma_length = start->length;
                 return 0;
-        } 
-        return __dma_map_cont(sg, start, stopat, sout, pages);
+        }
+        return __dma_map_cont(start, nelems, sout, pages);
 }
                 
 /*
@@ -381,6 +382,7 @@ int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents, int dir)
         int start;
         unsigned long pages = 0;
         int need = 0, nextneed;
+        struct scatterlist *s, *ps, *start_sg, *sgmap;
 
         if (nents == 0) 
                 return 0;
@@ -390,8 +392,9 @@ int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents, int dir)
 
         out = 0;
         start = 0;
-        for (i = 0; i < nents; i++) {
-                struct scatterlist *s = &sg[i];
+        start_sg = sgmap = sg;
+        ps = NULL; /* shut up gcc */
+        for_each_sg(sg, s, nents, i) {
                 dma_addr_t addr = page_to_phys(s->page) + s->offset;
                 s->dma_address = addr;
                 BUG_ON(s->length == 0); 
@@ -400,29 +403,33 @@ int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents, int dir)
 
                 /* Handle the previous not yet processed entries */
                 if (i > start) {
-                        struct scatterlist *ps = &sg[i-1];
                         /* Can only merge when the last chunk ends on a page 
                            boundary and the new one doesn't have an offset. */
                         if (!iommu_merge || !nextneed || !need || s->offset ||
-                            (ps->offset + ps->length) % PAGE_SIZE) { 
-                                if (dma_map_cont(sg, start, i, sg+out, pages,
-                                                 need) < 0)
+                            (ps->offset + ps->length) % PAGE_SIZE) {
+                                if (dma_map_cont(start_sg, i - start, sgmap,
+                                                  pages, need) < 0)
                                         goto error;
                                 out++;
+                                sgmap = sg_next(sgmap);
                                 pages = 0;
-                                start = i;      
+                                start = i;
+                                start_sg = s;
                         }
                 }
 
                 need = nextneed;
                 pages += to_pages(s->offset, s->length);
+                ps = s;
         }
-        if (dma_map_cont(sg, start, i, sg+out, pages, need) < 0)
+        if (dma_map_cont(start_sg, i - start, sgmap, pages, need) < 0)
                 goto error;
         out++;
         flush_gart();
-        if (out < nents) 
-                sg[out].dma_length = 0; 
+        if (out < nents) {
+                sgmap = sg_next(sgmap);
+                sgmap->dma_length = 0;
+        }
         return out;
 
 error:
@@ -437,8 +444,8 @@ error:
         if (panic_on_overflow)
                 panic("dma_map_sg: overflow on %lu pages\n", pages);
         iommu_full(dev, pages << PAGE_SHIFT, dir);
-        for (i = 0; i < nents; i++)
-                sg[i].dma_address = bad_dma_address;
+        for_each_sg(sg, s, nents, i)
+                s->dma_address = bad_dma_address;
         return 0;
 } 
 
diff --git a/arch/x86/kernel/pci-nommu_64.c b/arch/x86/kernel/pci-nommu_64.c
index 2a34c6c025a9..e85d4360360c 100644
--- a/arch/x86/kernel/pci-nommu_64.c
+++ b/arch/x86/kernel/pci-nommu_64.c
@@ -5,6 +5,7 @@
 #include <linux/pci.h>
 #include <linux/string.h>
 #include <linux/dma-mapping.h>
+#include <linux/scatterlist.h>
 
 #include <asm/iommu.h>
 #include <asm/processor.h>
@@ -57,10 +58,10 @@ static void nommu_unmap_single(struct device *dev, dma_addr_t addr,size_t size,
 static int nommu_map_sg(struct device *hwdev, struct scatterlist *sg,
                int nents, int direction)
 {
+        struct scatterlist *s;
         int i;
 
-        for (i = 0; i < nents; i++ ) {
-                struct scatterlist *s = &sg[i];
+        for_each_sg(sg, s, nents, i) {
                 BUG_ON(!s->page);
                 s->dma_address = virt_to_bus(page_address(s->page) +s->offset);
                 if (!check_addr("map_sg", hwdev, s->dma_address, s->length))
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 4df7d027eb06..527bd8d4db50 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -30,6 +30,7 @@
 #include <linux/cpu.h>
 #include <linux/blktrace_api.h>
 #include <linux/fault-inject.h>
+#include <linux/scatterlist.h>
 
 /*
  * for max sense size
@@ -1318,9 +1319,10 @@ static int blk_hw_contig_segment(struct request_queue *q, struct bio *bio,
  * must make sure sg can hold rq->nr_phys_segments entries
  */
 int blk_rq_map_sg(struct request_queue *q, struct request *rq,
-                  struct scatterlist *sg)
+                  struct scatterlist *sglist)
 {
         struct bio_vec *bvec, *bvprv;
+        struct scatterlist *next_sg, *sg;
         struct req_iterator iter;
         int nsegs, cluster;
 
@@ -1331,11 +1333,12 @@ int blk_rq_map_sg(struct request_queue *q, struct request *rq,
          * for each bio in rq
          */
         bvprv = NULL;
+        sg = next_sg = &sglist[0];
         rq_for_each_segment(bvec, rq, iter) {
                 int nbytes = bvec->bv_len;
 
                 if (bvprv && cluster) {
-                        if (sg[nsegs - 1].length + nbytes > q->max_segment_size)
+                        if (sg->length + nbytes > q->max_segment_size)
                                 goto new_segment;
 
                         if (!BIOVEC_PHYS_MERGEABLE(bvprv, bvec))
@@ -1343,14 +1346,15 @@ int blk_rq_map_sg(struct request_queue *q, struct request *rq,
                         if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bvec))
                                 goto new_segment;
 
-                        sg[nsegs - 1].length += nbytes;
+                        sg->length += nbytes;
                 } else {
 new_segment:
-                        memset(&sg[nsegs],0,sizeof(struct scatterlist));
-                        sg[nsegs].page = bvec->bv_page;
-                        sg[nsegs].length = nbytes;
-                        sg[nsegs].offset = bvec->bv_offset;
+                        sg = next_sg;
+                        next_sg = sg_next(sg);
 
+                        sg->page = bvec->bv_page;
+                        sg->length = nbytes;
+                        sg->offset = bvec->bv_offset;
                         nsegs++;
                 }
                 bvprv = bvec;
@@ -4068,7 +4072,23 @@ static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
         return queue_var_show(max_hw_sectors_kb, (page));
 }
 
+static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
+{
+        return queue_var_show(q->max_phys_segments, page);
+}
+
+static ssize_t queue_max_segments_store(struct request_queue *q,
+                                        const char *page, size_t count)
+{
+        unsigned long segments;
+        ssize_t ret = queue_var_store(&segments, page, count);
 
+        spin_lock_irq(q->queue_lock);
+        q->max_phys_segments = segments;
+        spin_unlock_irq(q->queue_lock);
+
+        return ret;
+}
 static struct queue_sysfs_entry queue_requests_entry = {
         .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
         .show = queue_requests_show,
@@ -4092,6 +4112,12 @@ static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
         .show = queue_max_hw_sectors_show,
 };
 
+static struct queue_sysfs_entry queue_max_segments_entry = {
+        .attr = {.name = "max_segments", .mode = S_IRUGO | S_IWUSR },
+        .show = queue_max_segments_show,
+        .store = queue_max_segments_store,
+};
+
 static struct queue_sysfs_entry queue_iosched_entry = {
         .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
         .show = elv_iosched_show,
@@ -4103,6 +4129,7 @@ static struct attribute *default_attrs[] = {
         &queue_ra_entry.attr,
         &queue_max_hw_sectors_entry.attr,
         &queue_max_sectors_entry.attr,
+        &queue_max_segments_entry.attr,
         &queue_iosched_entry.attr,
         NULL,
 };
diff --git a/crypto/digest.c b/crypto/digest.c
index 1bf7414aeb9e..e56de6748b15 100644
--- a/crypto/digest.c
+++ b/crypto/digest.c
@@ -77,7 +77,7 @@ static int update2(struct hash_desc *desc,
 
                 if (!nbytes)
                         break;
-                sg = sg_next(sg);
+                sg = scatterwalk_sg_next(sg);
         }
 
         return 0;
diff --git a/crypto/scatterwalk.c b/crypto/scatterwalk.c
index 3052f6507f53..d6852c33cfb7 100644
--- a/crypto/scatterwalk.c
+++ b/crypto/scatterwalk.c
@@ -62,7 +62,7 @@ static void scatterwalk_pagedone(struct scatter_walk *walk, int out,
                 walk->offset += PAGE_SIZE - 1;
                 walk->offset &= PAGE_MASK;
                 if (walk->offset >= walk->sg->offset + walk->sg->length)
-                        scatterwalk_start(walk, sg_next(walk->sg));
+                        scatterwalk_start(walk, scatterwalk_sg_next(walk->sg));
         }
 }
 
diff --git a/crypto/scatterwalk.h b/crypto/scatterwalk.h
index 500a220ad908..9c73e37a42ce 100644
--- a/crypto/scatterwalk.h
+++ b/crypto/scatterwalk.h
@@ -20,7 +20,7 @@
 
 #include "internal.h"
 
-static inline struct scatterlist *sg_next(struct scatterlist *sg)
+static inline struct scatterlist *scatterwalk_sg_next(struct scatterlist *sg)
 {
         return (++sg)->length ? sg : (void *)sg->page;
 }
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 68699b3e7998..bbaa545ea999 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -1410,7 +1410,7 @@ static void ata_qc_complete_internal(struct ata_queued_cmd *qc)
  */
 unsigned ata_exec_internal_sg(struct ata_device *dev,
                               struct ata_taskfile *tf, const u8 *cdb,
-                              int dma_dir, struct scatterlist *sg,
+                              int dma_dir, struct scatterlist *sgl,
                               unsigned int n_elem, unsigned long timeout)
 {
         struct ata_link *link = dev->link;
@@ -1472,11 +1472,12 @@ unsigned ata_exec_internal_sg(struct ata_device *dev,
         qc->dma_dir = dma_dir;
         if (dma_dir != DMA_NONE) {
                 unsigned int i, buflen = 0;
+                struct scatterlist *sg;
 
-                for (i = 0; i < n_elem; i++)
-                        buflen += sg[i].length;
+                for_each_sg(sgl, sg, n_elem, i)
+                        buflen += sg->length;
 
-                ata_sg_init(qc, sg, n_elem);
+                ata_sg_init(qc, sgl, n_elem);
                 qc->nbytes = buflen;
         }
 
@@ -4292,7 +4293,7 @@ void ata_sg_clean(struct ata_queued_cmd *qc)
                 if (qc->n_elem)
                         dma_unmap_sg(ap->dev, sg, qc->n_elem, dir);
                 /* restore last sg */
-                sg[qc->orig_n_elem - 1].length += qc->pad_len;
+                sg_last(sg, qc->orig_n_elem)->length += qc->pad_len;
                 if (pad_buf) {
                         struct scatterlist *psg = &qc->pad_sgent;
                         void *addr = kmap_atomic(psg->page, KM_IRQ0);
@@ -4547,6 +4548,7 @@ void ata_sg_init_one(struct ata_queued_cmd *qc, void *buf, unsigned int buflen)
         qc->orig_n_elem = 1;
         qc->buf_virt = buf;
         qc->nbytes = buflen;
+        qc->cursg = qc->__sg;
 
         sg_init_one(&qc->sgent, buf, buflen);
 }
@@ -4572,6 +4574,7 @@ void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg,
         qc->__sg = sg;
         qc->n_elem = n_elem;
         qc->orig_n_elem = n_elem;
+        qc->cursg = qc->__sg;
 }
 
 /**
@@ -4661,7 +4664,7 @@ static int ata_sg_setup(struct ata_queued_cmd *qc)
 {
         struct ata_port *ap = qc->ap;
         struct scatterlist *sg = qc->__sg;
-        struct scatterlist *lsg = &sg[qc->n_elem - 1];
+        struct scatterlist *lsg = sg_last(qc->__sg, qc->n_elem);
         int n_elem, pre_n_elem, dir, trim_sg = 0;
 
         VPRINTK("ENTER, ata%u\n", ap->print_id);
@@ -4825,7 +4828,6 @@ void ata_data_xfer_noirq(struct ata_device *adev, unsigned char *buf,
 static void ata_pio_sector(struct ata_queued_cmd *qc)
 {
         int do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
-        struct scatterlist *sg = qc->__sg;
         struct ata_port *ap = qc->ap;
         struct page *page;
         unsigned int offset;
@@ -4834,8 +4836,8 @@ static void ata_pio_sector(struct ata_queued_cmd *qc)
         if (qc->curbytes == qc->nbytes - qc->sect_size)
                 ap->hsm_task_state = HSM_ST_LAST;
 
-        page = sg[qc->cursg].page;
-        offset = sg[qc->cursg].offset + qc->cursg_ofs;
+        page = qc->cursg->page;
+        offset = qc->cursg->offset + qc->cursg_ofs;
 
         /* get the current page and offset */
         page = nth_page(page, (offset >> PAGE_SHIFT));
@@ -4863,8 +4865,8 @@ static void ata_pio_sector(struct ata_queued_cmd *qc)
         qc->curbytes += qc->sect_size;
         qc->cursg_ofs += qc->sect_size;
 
-        if (qc->cursg_ofs == (&sg[qc->cursg])->length) {
-                qc->cursg++;
+        if (qc->cursg_ofs == qc->cursg->length) {
+                qc->cursg = sg_next(qc->cursg);
                 qc->cursg_ofs = 0;
         }
 }
@@ -4950,16 +4952,18 @@ static void __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)
 {
         int do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
         struct scatterlist *sg = qc->__sg;
+        struct scatterlist *lsg = sg_last(qc->__sg, qc->n_elem);
         struct ata_port *ap = qc->ap;
         struct page *page;
         unsigned char *buf;
         unsigned int offset, count;
+        int no_more_sg = 0;
 
         if (qc->curbytes + bytes >= qc->nbytes)
                 ap->hsm_task_state = HSM_ST_LAST;
 
 next_sg:
-        if (unlikely(qc->cursg >= qc->n_elem)) {
+        if (unlikely(no_more_sg)) {
                 /*
                  * The end of qc->sg is reached and the device expects
                  * more data to transfer. In order not to overrun qc->sg
@@ -4982,7 +4986,7 @@ next_sg:
                 return;
         }
 
-        sg = &qc->__sg[qc->cursg];
+        sg = qc->cursg;
 
         page = sg->page;
         offset = sg->offset + qc->cursg_ofs;
@@ -5021,7 +5025,10 @@ next_sg:
         qc->cursg_ofs += count;
 
         if (qc->cursg_ofs == sg->length) {
-                qc->cursg++;
+                if (qc->cursg == lsg)
+                        no_more_sg = 1;
+
+                qc->cursg = sg_next(qc->cursg);
                 qc->cursg_ofs = 0;
         }
 
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index d63c81ed084f..ba62d534f32b 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -801,8 +801,6 @@ int ata_scsi_slave_config(struct scsi_device *sdev)
 
         ata_scsi_sdev_config(sdev);
 
-        blk_queue_max_phys_segments(sdev->request_queue, LIBATA_MAX_PRD);
-
         sdev->manage_start_stop = 1;
 
         if (dev)
diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index a895228f3d70..3fb7e8bc436d 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -2569,6 +2569,7 @@ static void do_cciss_request(struct request_queue *q)
                (int)creq->nr_sectors);
 #endif                          /* CCISS_DEBUG */
 
+        memset(tmp_sg, 0, sizeof(tmp_sg));
         seg = blk_rq_map_sg(q, creq, tmp_sg);
 
         /* get the DMA records for the setup */
diff --git a/drivers/ide/cris/ide-cris.c b/drivers/ide/cris/ide-cris.c
index 2b4d2a0ae5c2..c306c9f534ab 100644
--- a/drivers/ide/cris/ide-cris.c
+++ b/drivers/ide/cris/ide-cris.c
@@ -939,7 +939,8 @@ static int cris_ide_build_dmatable (ide_drive_t *drive)
                 /* group sequential buffers into one large buffer */
                 addr = page_to_phys(sg->page) + sg->offset;
                 size = sg_dma_len(sg);
-                while (sg++, --i) {
+                while (--i) {
+                        sg = sg_next(sg);
                         if ((addr + size) != page_to_phys(sg->page) + sg->offset)
                                 break;
                         size += sg_dma_len(sg);
diff --git a/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c
index b453211ee0fc..a4cbbbaccde9 100644
--- a/drivers/ide/ide-dma.c
+++ b/drivers/ide/ide-dma.c
@@ -280,7 +280,7 @@ int ide_build_dmatable (ide_drive_t *drive, struct request *rq)
                         }
                 }
 
-                sg++;
+                sg = sg_next(sg);
                 i--;
         }
 
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index f36ff5962af6..04273d3c147c 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -846,7 +846,8 @@ void ide_init_sg_cmd(ide_drive_t *drive, struct request *rq)
         ide_hwif_t *hwif = drive->hwif;
 
         hwif->nsect = hwif->nleft = rq->nr_sectors;
-        hwif->cursg = hwif->cursg_ofs = 0;
+        hwif->cursg_ofs = 0;
+        hwif->cursg = NULL;
 }
 
 EXPORT_SYMBOL_GPL(ide_init_sg_cmd);
diff --git a/drivers/ide/ide-probe.c b/drivers/ide/ide-probe.c
index d1011712601c..34b1fb65bc79 100644
--- a/drivers/ide/ide-probe.c
+++ b/drivers/ide/ide-probe.c
@@ -1349,7 +1349,7 @@ static int hwif_init(ide_hwif_t *hwif)
         if (!hwif->sg_max_nents)
                 hwif->sg_max_nents = PRD_ENTRIES;
 
-        hwif->sg_table = kmalloc(sizeof(struct scatterlist)*hwif->sg_max_nents,
+        hwif->sg_table = kzalloc(sizeof(struct scatterlist)*hwif->sg_max_nents,
                                  GFP_KERNEL);
         if (!hwif->sg_table) {
                 printk(KERN_ERR "%s: unable to allocate SG table.\n", hwif->name);
diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c
index aa06dafb74ac..2a3c8d498343 100644
--- a/drivers/ide/ide-taskfile.c
+++ b/drivers/ide/ide-taskfile.c
@@ -45,6 +45,7 @@
 #include <linux/hdreg.h>
 #include <linux/ide.h>
 #include <linux/bitops.h>
+#include <linux/scatterlist.h>
 
 #include <asm/byteorder.h>
 #include <asm/irq.h>
@@ -263,6 +264,7 @@ static void ide_pio_sector(ide_drive_t *drive, unsigned int write)
 {
         ide_hwif_t *hwif = drive->hwif;
         struct scatterlist *sg = hwif->sg_table;
+        struct scatterlist *cursg = hwif->cursg;
         struct page *page;
 #ifdef CONFIG_HIGHMEM
         unsigned long flags;
@@ -270,8 +272,14 @@ static void ide_pio_sector(ide_drive_t *drive, unsigned int write)
         unsigned int offset;
         u8 *buf;
 
-        page = sg[hwif->cursg].page;
-        offset = sg[hwif->cursg].offset + hwif->cursg_ofs * SECTOR_SIZE;
+        cursg = hwif->cursg;
+        if (!cursg) {
+                cursg = sg;
+                hwif->cursg = sg;
+        }
+
+        page = cursg->page;
+        offset = cursg->offset + hwif->cursg_ofs * SECTOR_SIZE;
 
         /* get the current page and offset */
         page = nth_page(page, (offset >> PAGE_SHIFT));
@@ -285,8 +293,8 @@ static void ide_pio_sector(ide_drive_t *drive, unsigned int write)
         hwif->nleft--;
         hwif->cursg_ofs++;
 
-        if ((hwif->cursg_ofs * SECTOR_SIZE) == sg[hwif->cursg].length) {
-                hwif->cursg++;
+        if ((hwif->cursg_ofs * SECTOR_SIZE) == cursg->length) {
+                hwif->cursg = sg_next(hwif->cursg);
                 hwif->cursg_ofs = 0;
         }
 
@@ -367,6 +375,8 @@ static ide_startstop_t task_error(ide_drive_t *drive, struct request *rq,
 
 static void task_end_request(ide_drive_t *drive, struct request *rq, u8 stat)
 {
+        HWIF(drive)->cursg = NULL;
+
         if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
                 ide_task_t *task = rq->special;
 
diff --git a/drivers/ide/mips/au1xxx-ide.c b/drivers/ide/mips/au1xxx-ide.c
index aebde49365d1..892d08f61dc0 100644
--- a/drivers/ide/mips/au1xxx-ide.c
+++ b/drivers/ide/mips/au1xxx-ide.c
@@ -296,7 +296,7 @@ static int auide_build_dmatable(ide_drive_t *drive)
                         cur_addr += tc;
                         cur_len -= tc;
                 }
-                sg++;
+                sg = sg_next(sg);
                 i--;
         }
 
diff --git a/drivers/ide/pci/sgiioc4.c b/drivers/ide/pci/sgiioc4.c
index 85ffaaa39b1b..c74fef6bbc91 100644
--- a/drivers/ide/pci/sgiioc4.c
+++ b/drivers/ide/pci/sgiioc4.c
@@ -29,6 +29,7 @@
 #include <linux/mm.h>
 #include <linux/ioport.h>
 #include <linux/blkdev.h>
+#include <linux/scatterlist.h>
 #include <linux/ioc4.h>
 #include <asm/io.h>
 
@@ -537,7 +538,7 @@ sgiioc4_build_dma_table(ide_drive_t * drive, struct request *rq, int ddir)
                         }
                 }
 
-                sg++;
+                sg = sg_next(sg);
                 i--;
         }
 
diff --git a/drivers/ide/ppc/pmac.c b/drivers/ide/ppc/pmac.c
index 7d8873839e21..9e86406bf44b 100644
--- a/drivers/ide/ppc/pmac.c
+++ b/drivers/ide/ppc/pmac.c
@@ -1539,7 +1539,7 @@ pmac_ide_build_dmatable(ide_drive_t *drive, struct request *rq)
                         cur_len -= tc;
                         ++table;
                 }
-                sg++;
+                sg = sg_next(sg);
                 i--;
         }
 
diff --git a/drivers/infiniband/hw/ipath/ipath_dma.c b/drivers/infiniband/hw/ipath/ipath_dma.c
index f87f003e3ef8..22709a4f8fc8 100644
--- a/drivers/infiniband/hw/ipath/ipath_dma.c
+++ b/drivers/infiniband/hw/ipath/ipath_dma.c
@@ -30,6 +30,7 @@
  * SOFTWARE.
  */
 
+#include <linux/scatterlist.h>
 #include <rdma/ib_verbs.h>
 
 #include "ipath_verbs.h"
@@ -96,17 +97,18 @@ static void ipath_dma_unmap_page(struct ib_device *dev,
         BUG_ON(!valid_dma_direction(direction));
 }
 
-static int ipath_map_sg(struct ib_device *dev, struct scatterlist *sg, int nents,
-                        enum dma_data_direction direction)
+static int ipath_map_sg(struct ib_device *dev, struct scatterlist *sgl,
+                        int nents, enum dma_data_direction direction)
 {
+        struct scatterlist *sg;
         u64 addr;
         int i;
         int ret = nents;
 
         BUG_ON(!valid_dma_direction(direction));
 
-        for (i = 0; i < nents; i++) {
-                addr = (u64) page_address(sg[i].page);
+        for_each_sg(sgl, sg, nents, i) {
+                addr = (u64) page_address(sg->page);
                 /* TODO: handle highmem pages */
                 if (!addr) {
                         ret = 0;
diff --git a/drivers/infiniband/ulp/iser/iser_memory.c b/drivers/infiniband/ulp/iser/iser_memory.c
index e05690e3592f..f3529b6f0a33 100644
--- a/drivers/infiniband/ulp/iser/iser_memory.c
+++ b/drivers/infiniband/ulp/iser/iser_memory.c
@@ -124,17 +124,19 @@ static int iser_start_rdma_unaligned_sg(struct iscsi_iser_cmd_task *iser_ctask,
 
         if (cmd_dir == ISER_DIR_OUT) {
                 /* copy the unaligned sg the buffer which is used for RDMA */
-                struct scatterlist *sg = (struct scatterlist *)data->buf;
+                struct scatterlist *sgl = (struct scatterlist *)data->buf;
+                struct scatterlist *sg;
                 int i;
                 char *p, *from;
 
-                for (p = mem, i = 0; i < data->size; i++) {
-                        from = kmap_atomic(sg[i].page, KM_USER0);
+                p = mem;
+                for_each_sg(sgl, sg, data->size, i) {
+                        from = kmap_atomic(sg->page, KM_USER0);
                         memcpy(p,
-                               from + sg[i].offset,
-                               sg[i].length);
+                               from + sg->offset,
+                               sg->length);
                         kunmap_atomic(from, KM_USER0);
-                        p += sg[i].length;
+                        p += sg->length;
                 }
         }
 
@@ -176,7 +178,7 @@ void iser_finalize_rdma_unaligned_sg(struct iscsi_iser_cmd_task *iser_ctask,
 
         if (cmd_dir == ISER_DIR_IN) {
                 char *mem;
-                struct scatterlist *sg;
+                struct scatterlist *sgl, *sg;
                 unsigned char *p, *to;
                 unsigned int sg_size;
                 int i;
@@ -184,16 +186,17 @@ void iser_finalize_rdma_unaligned_sg(struct iscsi_iser_cmd_task *iser_ctask,
                 /* copy back read RDMA to unaligned sg */
                 mem     = mem_copy->copy_buf;
 
-                sg      = (struct scatterlist *)iser_ctask->data[ISER_DIR_IN].buf;
+                sgl     = (struct scatterlist *)iser_ctask->data[ISER_DIR_IN].buf;
                 sg_size = iser_ctask->data[ISER_DIR_IN].size;
 
-                for (p = mem, i = 0; i < sg_size; i++){
-                        to = kmap_atomic(sg[i].page, KM_SOFTIRQ0);
-                        memcpy(to + sg[i].offset,
+                p = mem;
+                for_each_sg(sgl, sg, sg_size, i) {
+                        to = kmap_atomic(sg->page, KM_SOFTIRQ0);
+                        memcpy(to + sg->offset,
                                p,
-                               sg[i].length);
+                               sg->length);
                         kunmap_atomic(to, KM_SOFTIRQ0);
-                        p += sg[i].length;
+                        p += sg->length;
                 }
         }
 
@@ -224,7 +227,8 @@ static int iser_sg_to_page_vec(struct iser_data_buf *data,
                                struct iser_page_vec *page_vec,
                                struct ib_device *ibdev)
 {
-        struct scatterlist *sg = (struct scatterlist *)data->buf;
+        struct scatterlist *sgl = (struct scatterlist *)data->buf;
+        struct scatterlist *sg;
         u64 first_addr, last_addr, page;
         int end_aligned;
         unsigned int cur_page = 0;
@@ -232,24 +236,25 @@ static int iser_sg_to_page_vec(struct iser_data_buf *data,
         int i;
 
         /* compute the offset of first element */
-        page_vec->offset = (u64) sg[0].offset & ~MASK_4K;
+        page_vec->offset = (u64) sgl[0].offset & ~MASK_4K;
 
-        for (i = 0; i < data->dma_nents; i++) {
-                unsigned int dma_len = ib_sg_dma_len(ibdev, &sg[i]);
+        for_each_sg(sgl, sg, data->dma_nents, i) {
+                unsigned int dma_len = ib_sg_dma_len(ibdev, sg);
 
                 total_sz += dma_len;
 
-                first_addr = ib_sg_dma_address(ibdev, &sg[i]);
+                first_addr = ib_sg_dma_address(ibdev, sg);
                 last_addr  = first_addr + dma_len;
 
                 end_aligned   = !(last_addr  & ~MASK_4K);
 
                 /* continue to collect page fragments till aligned or SG ends */
                 while (!end_aligned && (i + 1 < data->dma_nents)) {
+                        sg = sg_next(sg);
                         i++;
-                        dma_len = ib_sg_dma_len(ibdev, &sg[i]);
+                        dma_len = ib_sg_dma_len(ibdev, sg);
                         total_sz += dma_len;
-                        last_addr = ib_sg_dma_address(ibdev, &sg[i]) + dma_len;
+                        last_addr = ib_sg_dma_address(ibdev, sg) + dma_len;
                         end_aligned = !(last_addr  & ~MASK_4K);
                 }
 
@@ -284,25 +289,26 @@ static int iser_sg_to_page_vec(struct iser_data_buf *data,
 static unsigned int iser_data_buf_aligned_len(struct iser_data_buf *data,
                                               struct ib_device *ibdev)
 {
-        struct scatterlist *sg;
+        struct scatterlist *sgl, *sg;
         u64 end_addr, next_addr;
         int i, cnt;
         unsigned int ret_len = 0;
 
-        sg = (struct scatterlist *)data->buf;
+        sgl = (struct scatterlist *)data->buf;
 
-        for (cnt = 0, i = 0; i < data->dma_nents; i++, cnt++) {
+        cnt = 0;
+        for_each_sg(sgl, sg, data->dma_nents, i) {
                 /* iser_dbg("Checking sg iobuf [%d]: phys=0x%08lX "
                    "offset: %ld sz: %ld\n", i,
-                   (unsigned long)page_to_phys(sg[i].page),
-                   (unsigned long)sg[i].offset,
-                   (unsigned long)sg[i].length); */
-                end_addr = ib_sg_dma_address(ibdev, &sg[i]) +
-                           ib_sg_dma_len(ibdev, &sg[i]);
+                   (unsigned long)page_to_phys(sg->page),
+                   (unsigned long)sg->offset,
+                   (unsigned long)sg->length); */
+                end_addr = ib_sg_dma_address(ibdev, sg) +
+                           ib_sg_dma_len(ibdev, sg);
                 /* iser_dbg("Checking sg iobuf end address "
                        "0x%08lX\n", end_addr); */
                 if (i + 1 < data->dma_nents) {
-                        next_addr = ib_sg_dma_address(ibdev, &sg[i+1]);
+                        next_addr = ib_sg_dma_address(ibdev, sg_next(sg));
                         /* are i, i+1 fragments of the same page? */
                         if (end_addr == next_addr)
                                 continue;
@@ -322,15 +328,16 @@ static unsigned int iser_data_buf_aligned_len(struct iser_data_buf *data,
 static void iser_data_buf_dump(struct iser_data_buf *data,
                                struct ib_device *ibdev)
 {
-        struct scatterlist *sg = (struct scatterlist *)data->buf;
+        struct scatterlist *sgl = (struct scatterlist *)data->buf;
+        struct scatterlist *sg;
         int i;
 
-        for (i = 0; i < data->dma_nents; i++)
+        for_each_sg(sgl, sg, data->dma_nents, i)
                 iser_err("sg[%d] dma_addr:0x%lX page:0x%p "
                          "off:0x%x sz:0x%x dma_len:0x%x\n",
-                         i, (unsigned long)ib_sg_dma_address(ibdev, &sg[i]),
-                         sg[i].page, sg[i].offset,
-                         sg[i].length, ib_sg_dma_len(ibdev, &sg[i]));
+                         i, (unsigned long)ib_sg_dma_address(ibdev, sg),
+                         sg->page, sg->offset,
+                         sg->length, ib_sg_dma_len(ibdev, sg));
 }
 
 static void iser_dump_page_vec(struct iser_page_vec *page_vec)
diff --git a/drivers/message/fusion/mptscsih.c b/drivers/message/fusion/mptscsih.c
index bdff950a54a1..3918ebf01e8d 100644
--- a/drivers/message/fusion/mptscsih.c
+++ b/drivers/message/fusion/mptscsih.c
@@ -293,7 +293,7 @@ nextSGEset:
         for (ii=0; ii < (numSgeThisFrame-1); ii++) {
                 thisxfer = sg_dma_len(sg);
                 if (thisxfer == 0) {
-                        sg ++; /* Get next SG element from the OS */
+                        sg = sg_next(sg); /* Get next SG element from the OS */
                         sg_done++;
                         continue;
                 }
@@ -301,7 +301,7 @@ nextSGEset:
                 v2 = sg_dma_address(sg);
                 mptscsih_add_sge(psge, sgflags | thisxfer, v2);
 
-                sg++;           /* Get next SG element from the OS */
+                sg = sg_next(sg);       /* Get next SG element from the OS */
                 psge += (sizeof(u32) + sizeof(dma_addr_t));
                 sgeOffset += (sizeof(u32) + sizeof(dma_addr_t));
                 sg_done++;
@@ -322,7 +322,7 @@ nextSGEset:
                 v2 = sg_dma_address(sg);
                 mptscsih_add_sge(psge, sgflags | thisxfer, v2);
                 /*
-                sg++;
+                sg = sg_next(sg);
                 psge += (sizeof(u32) + sizeof(dma_addr_t));
                 */
                 sgeOffset += (sizeof(u32) + sizeof(dma_addr_t));
diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index b0abc7d92805..a5d0354bbbda 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -153,14 +153,14 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock
                         blk_queue_max_hw_segments(mq->queue, bouncesz / 512);
                         blk_queue_max_segment_size(mq->queue, bouncesz);
 
-                        mq->sg = kmalloc(sizeof(struct scatterlist),
+                        mq->sg = kzalloc(sizeof(struct scatterlist),
                                 GFP_KERNEL);
                         if (!mq->sg) {
                                 ret = -ENOMEM;
                                 goto cleanup_queue;
                         }
 
-                        mq->bounce_sg = kmalloc(sizeof(struct scatterlist) *
+                        mq->bounce_sg = kzalloc(sizeof(struct scatterlist) *
                                 bouncesz / 512, GFP_KERNEL);
                         if (!mq->bounce_sg) {
                                 ret = -ENOMEM;
@@ -177,7 +177,7 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock
                 blk_queue_max_hw_segments(mq->queue, host->max_hw_segs);
                 blk_queue_max_segment_size(mq->queue, host->max_seg_size);
 
-                mq->sg = kmalloc(sizeof(struct scatterlist) *
+                mq->sg = kzalloc(sizeof(struct scatterlist) *
                         host->max_phys_segs, GFP_KERNEL);
                 if (!mq->sg) {
                         ret = -ENOMEM;
diff --git a/drivers/s390/scsi/zfcp_def.h b/drivers/s390/scsi/zfcp_def.h
index 16e5563e0c65..57cac7008e0b 100644
--- a/drivers/s390/scsi/zfcp_def.h
+++ b/drivers/s390/scsi/zfcp_def.h
@@ -34,6 +34,7 @@
 #include <linux/slab.h>
 #include <linux/mempool.h>
 #include <linux/syscalls.h>
+#include <linux/scatterlist.h>
 #include <linux/ioctl.h>
 #include <scsi/scsi.h>
 #include <scsi/scsi_tcq.h>
diff --git a/drivers/s390/scsi/zfcp_qdio.c b/drivers/s390/scsi/zfcp_qdio.c
index 3f105fdcf239..51d92b196ee7 100644
--- a/drivers/s390/scsi/zfcp_qdio.c
+++ b/drivers/s390/scsi/zfcp_qdio.c
@@ -590,7 +590,7 @@ zfcp_qdio_sbals_from_segment(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
  */
 int
 zfcp_qdio_sbals_from_sg(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
-                        struct scatterlist *sg, int sg_count, int max_sbals)
+                        struct scatterlist *sgl, int sg_count, int max_sbals)
 {
         int sg_index;
         struct scatterlist *sg_segment;
@@ -606,9 +606,7 @@ zfcp_qdio_sbals_from_sg(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
         sbale->flags |= sbtype;
 
         /* process all segements of scatter-gather list */
-        for (sg_index = 0, sg_segment = sg, bytes = 0;
-             sg_index < sg_count;
-             sg_index++, sg_segment++) {
+        for_each_sg(sgl, sg_segment, sg_count, sg_index) {
                 retval = zfcp_qdio_sbals_from_segment(
                                 fsf_req,
                                 sbtype,
diff --git a/drivers/scsi/3w-9xxx.c b/drivers/scsi/3w-9xxx.c
index efd9d8d3a890..fb14014ee16e 100644
--- a/drivers/scsi/3w-9xxx.c
+++ b/drivers/scsi/3w-9xxx.c
@@ -1990,6 +1990,7 @@ static struct scsi_host_template driver_template = {
         .max_sectors            = TW_MAX_SECTORS,
         .cmd_per_lun            = TW_MAX_CMDS_PER_LUN,
         .use_clustering         = ENABLE_CLUSTERING,
+        .use_sg_chaining        = ENABLE_SG_CHAINING,
         .shost_attrs            = twa_host_attrs,
         .emulated               = 1
 };
diff --git a/drivers/scsi/3w-xxxx.c b/drivers/scsi/3w-xxxx.c
index c7995fc216e8..a64153b96034 100644
--- a/drivers/scsi/3w-xxxx.c
+++ b/drivers/scsi/3w-xxxx.c
@@ -2261,6 +2261,7 @@ static struct scsi_host_template driver_template = {
         .max_sectors            = TW_MAX_SECTORS,
         .cmd_per_lun            = TW_MAX_CMDS_PER_LUN,  
         .use_clustering         = ENABLE_CLUSTERING,
+        .use_sg_chaining        = ENABLE_SG_CHAINING,
         .shost_attrs            = tw_host_attrs,
         .emulated               = 1
 };
diff --git a/drivers/scsi/BusLogic.c b/drivers/scsi/BusLogic.c
index 9b206176f717..49e1ffa4b2ff 100644
--- a/drivers/scsi/BusLogic.c
+++ b/drivers/scsi/BusLogic.c
@@ -3575,6 +3575,7 @@ static struct scsi_host_template Bus_Logic_template = {
         .unchecked_isa_dma = 1,
         .max_sectors = 128,
         .use_clustering = ENABLE_CLUSTERING,
+        .use_sg_chaining = ENABLE_SG_CHAINING,
 };
 
 /*
diff --git a/drivers/scsi/NCR53c406a.c b/drivers/scsi/NCR53c406a.c
index eda8c48f6be7..3168a1794849 100644
--- a/drivers/scsi/NCR53c406a.c
+++ b/drivers/scsi/NCR53c406a.c
@@ -1066,7 +1066,8 @@ static struct scsi_host_template driver_template =
      .sg_tablesize              = 32                    /*SG_ALL*/ /*SG_NONE*/, 
      .cmd_per_lun               = 1                     /* commands per lun */, 
      .unchecked_isa_dma         = 1                     /* unchecked_isa_dma */,
-     .use_clustering            = ENABLE_CLUSTERING                               
+     .use_clustering            = ENABLE_CLUSTERING,
+     .use_sg_chaining           = ENABLE_SG_CHAINING,
 };
 
 #include "scsi_module.c"
diff --git a/drivers/scsi/a100u2w.c b/drivers/scsi/a100u2w.c
index f608d4a1d6da..d3a6d15fb77a 100644
--- a/drivers/scsi/a100u2w.c
+++ b/drivers/scsi/a100u2w.c
@@ -1071,6 +1071,7 @@ static struct scsi_host_template inia100_template = {
         .sg_tablesize           = SG_ALL,
         .cmd_per_lun            = 1,
         .use_clustering         = ENABLE_CLUSTERING,
+        .use_sg_chaining        = ENABLE_SG_CHAINING,
 };
 
 static int __devinit inia100_probe_one(struct pci_dev *pdev,
diff --git a/drivers/scsi/aacraid/linit.c b/drivers/scsi/aacraid/linit.c
index a7f42a17b5c7..038980be763d 100644
--- a/drivers/scsi/aacraid/linit.c
+++ b/drivers/scsi/aacraid/linit.c
@@ -944,6 +944,7 @@ static struct scsi_host_template aac_driver_template = {
         .cmd_per_lun                    = AAC_NUM_IO_FIB, 
 #endif  
         .use_clustering                 = ENABLE_CLUSTERING,
+        .use_sg_chaining                = ENABLE_SG_CHAINING,
         .emulated                       = 1,
 };
 
diff --git a/drivers/scsi/aha1542.c b/drivers/scsi/aha1542.c
index cbbfbc9f3e0f..961a1882cb7e 100644
--- a/drivers/scsi/aha1542.c
+++ b/drivers/scsi/aha1542.c
@@ -61,15 +61,15 @@ static void BAD_DMA(void *address, unsigned int length)
 }
 
 static void BAD_SG_DMA(Scsi_Cmnd * SCpnt,
-                       struct scatterlist *sgpnt,
+                       struct scatterlist *sgp,
                        int nseg,
                        int badseg)
 {
         printk(KERN_CRIT "sgpnt[%d:%d] page %p/0x%llx length %u\n",
                badseg, nseg,
-               page_address(sgpnt[badseg].page) + sgpnt[badseg].offset,
-               (unsigned long long)SCSI_SG_PA(&sgpnt[badseg]),
-               sgpnt[badseg].length);
+               page_address(sgp->page) + sgp->offset,
+               (unsigned long long)SCSI_SG_PA(sgp),
+               sgp->length);
 
         /*
          * Not safe to continue.
@@ -691,7 +691,7 @@ static int aha1542_queuecommand(Scsi_Cmnd * SCpnt, void (*done) (Scsi_Cmnd *))
         memcpy(ccb[mbo].cdb, cmd, ccb[mbo].cdblen);
 
         if (SCpnt->use_sg) {
-                struct scatterlist *sgpnt;
+                struct scatterlist *sg;
                 struct chain *cptr;
 #ifdef DEBUG
                 unsigned char *ptr;
@@ -699,23 +699,21 @@ static int aha1542_queuecommand(Scsi_Cmnd * SCpnt, void (*done) (Scsi_Cmnd *))
                 int i;
                 ccb[mbo].op = 2;        /* SCSI Initiator Command  w/scatter-gather */
                 SCpnt->host_scribble = kmalloc(512, GFP_KERNEL | GFP_DMA);
-                sgpnt = (struct scatterlist *) SCpnt->request_buffer;
                 cptr = (struct chain *) SCpnt->host_scribble;
                 if (cptr == NULL) {
                         /* free the claimed mailbox slot */
                         HOSTDATA(SCpnt->device->host)->SCint[mbo] = NULL;
                         return SCSI_MLQUEUE_HOST_BUSY;
                 }
-                for (i = 0; i < SCpnt->use_sg; i++) {
-                        if (sgpnt[i].length == 0 || SCpnt->use_sg > 16 ||
-                            (((int) sgpnt[i].offset) & 1) || (sgpnt[i].length & 1)) {
+                scsi_for_each_sg(SCpnt, sg, SCpnt->use_sg, i) {
+                        if (sg->length == 0 || SCpnt->use_sg > 16 ||
+                            (((int) sg->offset) & 1) || (sg->length & 1)) {
                                 unsigned char *ptr;
                                 printk(KERN_CRIT "Bad segment list supplied to aha1542.c (%d, %d)\n", SCpnt->use_sg, i);
-                                for (i = 0; i < SCpnt->use_sg; i++) {
+                                scsi_for_each_sg(SCpnt, sg, SCpnt->use_sg, i) {
                                         printk(KERN_CRIT "%d: %p %d\n", i,
-                                               (page_address(sgpnt[i].page) +
-                                                sgpnt[i].offset),
-                                               sgpnt[i].length);
+                                               (page_address(sg->page) +
+                                                sg->offset), sg->length);
                                 };
                                 printk(KERN_CRIT "cptr %x: ", (unsigned int) cptr);
                                 ptr = (unsigned char *) &cptr[i];
@@ -723,10 +721,10 @@ static int aha1542_queuecommand(Scsi_Cmnd * SCpnt, void (*done) (Scsi_Cmnd *))
                                         printk("%02x ", ptr[i]);
                                 panic("Foooooooood fight!");
                         };
-                        any2scsi(cptr[i].dataptr, SCSI_SG_PA(&sgpnt[i]));
-                        if (SCSI_SG_PA(&sgpnt[i]) + sgpnt[i].length - 1 > ISA_DMA_THRESHOLD)
-                                BAD_SG_DMA(SCpnt, sgpnt, SCpnt->use_sg, i);
-                        any2scsi(cptr[i].datalen, sgpnt[i].length);
+                        any2scsi(cptr[i].dataptr, SCSI_SG_PA(sg));
+                        if (SCSI_SG_PA(sg) + sg->length - 1 > ISA_DMA_THRESHOLD)
+                                BAD_SG_DMA(SCpnt, sg, SCpnt->use_sg, i);
+                        any2scsi(cptr[i].datalen, sg->length);
                 };
                 any2scsi(ccb[mbo].datalen, SCpnt->use_sg * sizeof(struct chain));
                 any2scsi(ccb[mbo].dataptr, SCSI_BUF_PA(cptr));
diff --git a/drivers/scsi/aha1740.c b/drivers/scsi/aha1740.c
index e4a4f3a965d9..f6722fd46008 100644
--- a/drivers/scsi/aha1740.c
+++ b/drivers/scsi/aha1740.c
@@ -563,6 +563,7 @@ static struct scsi_host_template aha1740_template = {
         .sg_tablesize     = AHA1740_SCATTER,
         .cmd_per_lun      = AHA1740_CMDLUN,
         .use_clustering   = ENABLE_CLUSTERING,
+        .use_sg_chaining  = ENABLE_SG_CHAINING,
         .eh_abort_handler = aha1740_eh_abort_handler,
 };
 
diff --git a/drivers/scsi/aic7xxx/aic79xx_osm.c b/drivers/scsi/aic7xxx/aic79xx_osm.c
index a055a96e3ad3..42c0f14a262c 100644
--- a/drivers/scsi/aic7xxx/aic79xx_osm.c
+++ b/drivers/scsi/aic7xxx/aic79xx_osm.c
@@ -766,6 +766,7 @@ struct scsi_host_template aic79xx_driver_template = {
         .max_sectors            = 8192,
         .cmd_per_lun            = 2,
         .use_clustering         = ENABLE_CLUSTERING,
+        .use_sg_chaining        = ENABLE_SG_CHAINING,
         .slave_alloc            = ahd_linux_slave_alloc,
         .slave_configure        = ahd_linux_slave_configure,
         .target_alloc           = ahd_linux_target_alloc,
diff --git a/drivers/scsi/aic7xxx/aic7xxx_osm.c b/drivers/scsi/aic7xxx/aic7xxx_osm.c
index 2e9c38f2e8a6..7770befbf50c 100644
--- a/drivers/scsi/aic7xxx/aic7xxx_osm.c
+++ b/drivers/scsi/aic7xxx/aic7xxx_osm.c
@@ -747,6 +747,7 @@ struct scsi_host_template aic7xxx_driver_template = {
         .max_sectors            = 8192,
         .cmd_per_lun            = 2,
         .use_clustering         = ENABLE_CLUSTERING,
+        .use_sg_chaining        = ENABLE_SG_CHAINING,
         .slave_alloc            = ahc_linux_slave_alloc,
         .slave_configure        = ahc_linux_slave_configure,
         .target_alloc           = ahc_linux_target_alloc,
diff --git a/drivers/scsi/aic7xxx_old.c b/drivers/scsi/aic7xxx_old.c
index 1a71b0236c97..4025608d6964 100644
--- a/drivers/scsi/aic7xxx_old.c
+++ b/drivers/scsi/aic7xxx_old.c
@@ -11142,6 +11142,7 @@ static struct scsi_host_template driver_template = {
         .max_sectors            = 2048,
         .cmd_per_lun            = 3,
         .use_clustering         = ENABLE_CLUSTERING,
+        .use_sg_chaining        = ENABLE_SG_CHAINING,
 };
 
 #include "scsi_module.c"
diff --git a/drivers/scsi/aic94xx/aic94xx_task.c b/drivers/scsi/aic94xx/aic94xx_task.c
index f2b23e01401a..ee0a98bffcd4 100644
--- a/drivers/scsi/aic94xx/aic94xx_task.c
+++ b/drivers/scsi/aic94xx/aic94xx_task.c
@@ -94,7 +94,7 @@ static inline int asd_map_scatterlist(struct sas_task *task,
                         res = -ENOMEM;
                         goto err_unmap;
                 }
-                for (sc = task->scatter, i = 0; i < num_sg; i++, sc++) {
+                for_each_sg(task->scatter, sc, num_sg, i) {
                         struct sg_el *sg =
                                 &((struct sg_el *)ascb->sg_arr->vaddr)[i];
                         sg->bus_addr = cpu_to_le64((u64)sg_dma_address(sc));
@@ -103,7 +103,7 @@ static inline int asd_map_scatterlist(struct sas_task *task,
                                 sg->flags |= ASD_SG_EL_LIST_EOL;
                 }
 
-                for (sc = task->scatter, i = 0; i < 2; i++, sc++) {
+                for_each_sg(task->scatter, sc, 2, i) {
                         sg_arr[i].bus_addr =
                                 cpu_to_le64((u64)sg_dma_address(sc));
                         sg_arr[i].size = cpu_to_le32((u32)sg_dma_len(sc));
@@ -115,7 +115,7 @@ static inline int asd_map_scatterlist(struct sas_task *task,
                 sg_arr[2].bus_addr=cpu_to_le64((u64)ascb->sg_arr->dma_handle);
         } else {
                 int i;
-                for (sc = task->scatter, i = 0; i < num_sg; i++, sc++) {
+                for_each_sg(task->scatter, sc, num_sg, i) {
                         sg_arr[i].bus_addr =
                                 cpu_to_le64((u64)sg_dma_address(sc));
                         sg_arr[i].size = cpu_to_le32((u32)sg_dma_len(sc));
diff --git a/drivers/scsi/arcmsr/arcmsr_hba.c b/drivers/scsi/arcmsr/arcmsr_hba.c
index cfcf40159eab..f81777586b8f 100644
--- a/drivers/scsi/arcmsr/arcmsr_hba.c
+++ b/drivers/scsi/arcmsr/arcmsr_hba.c
@@ -122,6 +122,7 @@ static struct scsi_host_template arcmsr_scsi_host_template = {
         .max_sectors            = ARCMSR_MAX_XFER_SECTORS,
         .cmd_per_lun            = ARCMSR_MAX_CMD_PERLUN,
         .use_clustering         = ENABLE_CLUSTERING,
+        .use_sg_chaining        = ENABLE_SG_CHAINING,
         .shost_attrs            = arcmsr_host_attrs,
 };
 #ifdef CONFIG_SCSI_ARCMSR_AER
diff --git a/drivers/scsi/dc395x.c b/drivers/scsi/dc395x.c
index 1591824cf4b3..fd42d4789202 100644
--- a/drivers/scsi/dc395x.c
+++ b/drivers/scsi/dc395x.c
@@ -4765,6 +4765,7 @@ static struct scsi_host_template dc395x_driver_template = {
         .eh_bus_reset_handler   = dc395x_eh_bus_reset,
         .unchecked_isa_dma      = 0,
         .use_clustering         = DISABLE_CLUSTERING,
+        .use_sg_chaining        = ENABLE_SG_CHAINING,
 };
 
 
diff --git a/drivers/scsi/dpt_i2o.c b/drivers/scsi/dpt_i2o.c
index bea9d659af15..8258506ba7d7 100644
--- a/drivers/scsi/dpt_i2o.c
+++ b/drivers/scsi/dpt_i2o.c
@@ -3295,6 +3295,7 @@ static struct scsi_host_template adpt_template = {
         .this_id                = 7,
         .cmd_per_lun            = 1,
         .use_clustering         = ENABLE_CLUSTERING,
+        .use_sg_chaining        = ENABLE_SG_CHAINING,
 };
 
 static s32 adpt_scsi_register(adpt_hba* pHba)
diff --git a/drivers/scsi/eata.c b/drivers/scsi/eata.c
index ec2233114bc9..7ead5210de96 100644
--- a/drivers/scsi/eata.c
+++ b/drivers/scsi/eata.c
@@ -523,7 +523,8 @@ static struct scsi_host_template driver_template = {
         .slave_configure = eata2x_slave_configure,
         .this_id = 7,
         .unchecked_isa_dma = 1,
-        .use_clustering = ENABLE_CLUSTERING
+        .use_clustering = ENABLE_CLUSTERING,
+        .use_sg_chaining = ENABLE_SG_CHAINING,
 };
 
 #if !defined(__BIG_ENDIAN_BITFIELD) && !defined(__LITTLE_ENDIAN_BITFIELD)
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index adc9559cb6f4..112ab6abe62b 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -343,6 +343,7 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
         shost->use_clustering = sht->use_clustering;
         shost->ordered_tag = sht->ordered_tag;
         shost->active_mode = sht->supported_mode;
+        shost->use_sg_chaining = sht->use_sg_chaining;
 
         if (sht->max_host_blocked)
                 shost->max_host_blocked = sht->max_host_blocked;
diff --git a/drivers/scsi/hptiop.c b/drivers/scsi/hptiop.c
index 8b384fa7f048..8515054cdf70 100644
--- a/drivers/scsi/hptiop.c
+++ b/drivers/scsi/hptiop.c
@@ -655,6 +655,7 @@ static struct scsi_host_template driver_template = {
         .unchecked_isa_dma          = 0,
         .emulated                   = 0,
         .use_clustering             = ENABLE_CLUSTERING,
+        .use_sg_chaining            = ENABLE_SG_CHAINING,
         .proc_name                  = driver_name,
         .shost_attrs                = hptiop_attrs,
         .this_id                    = -1,
diff --git a/drivers/scsi/ibmmca.c b/drivers/scsi/ibmmca.c
index 1a924e9b0271..714e6273a70d 100644
--- a/drivers/scsi/ibmmca.c
+++ b/drivers/scsi/ibmmca.c
@@ -1501,6 +1501,7 @@ static struct scsi_host_template ibmmca_driver_template = {
           .sg_tablesize   = 16,
           .cmd_per_lun    = 1,
           .use_clustering = ENABLE_CLUSTERING,
+          .use_sg_chaining = ENABLE_SG_CHAINING,
 };
 
 static int ibmmca_probe(struct device *dev)
diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
index cda0cc3d182f..22d91ee173c5 100644
--- a/drivers/scsi/ibmvscsi/ibmvscsi.c
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -1548,6 +1548,7 @@ static struct scsi_host_template driver_template = {
         .this_id = -1,
         .sg_tablesize = SG_ALL,
         .use_clustering = ENABLE_CLUSTERING,
+        .use_sg_chaining = ENABLE_SG_CHAINING,
         .shost_attrs = ibmvscsi_attrs,
 };
 
diff --git a/drivers/scsi/ide-scsi.c b/drivers/scsi/ide-scsi.c
index d81bb076a15a..d297f64cd432 100644
--- a/drivers/scsi/ide-scsi.c
+++ b/drivers/scsi/ide-scsi.c
@@ -70,6 +70,7 @@ typedef struct idescsi_pc_s {
         u8 *buffer;                             /* Data buffer */
         u8 *current_position;                   /* Pointer into the above buffer */
         struct scatterlist *sg;                 /* Scatter gather table */
+        struct scatterlist *last_sg;            /* Last sg element */
         int b_count;                            /* Bytes transferred from current entry */
         struct scsi_cmnd *scsi_cmd;             /* SCSI command */
         void (*done)(struct scsi_cmnd *);       /* Scsi completion routine */
@@ -173,12 +174,6 @@ static void idescsi_input_buffers (ide_drive_t *drive, idescsi_pc_t *pc, unsigne
         char *buf;
 
         while (bcount) {
-                if (pc->sg - scsi_sglist(pc->scsi_cmd) >
-                                                 scsi_sg_count(pc->scsi_cmd)) {
-                        printk (KERN_ERR "ide-scsi: scatter gather table too small, discarding data\n");
-                        idescsi_discard_data (drive, bcount);
-                        return;
-                }
                 count = min(pc->sg->length - pc->b_count, bcount);
                 if (PageHighMem(pc->sg->page)) {
                         unsigned long flags;
@@ -197,10 +192,17 @@ static void idescsi_input_buffers (ide_drive_t *drive, idescsi_pc_t *pc, unsigne
                 }
                 bcount -= count; pc->b_count += count;
                 if (pc->b_count == pc->sg->length) {
-                        pc->sg++;
+                        if (pc->sg == pc->last_sg)
+                                break;
+                        pc->sg = sg_next(pc->sg);
                         pc->b_count = 0;
                 }
         }
+
+        if (bcount) {
+                printk (KERN_ERR "ide-scsi: scatter gather table too small, discarding data\n");
+                idescsi_discard_data (drive, bcount);
+        }
 }
 
 static void idescsi_output_buffers (ide_drive_t *drive, idescsi_pc_t *pc, unsigned int bcount)
@@ -209,12 +211,6 @@ static void idescsi_output_buffers (ide_drive_t *drive, idescsi_pc_t *pc, unsign
         char *buf;
 
         while (bcount) {
-                if (pc->sg - scsi_sglist(pc->scsi_cmd) >
-                                                 scsi_sg_count(pc->scsi_cmd)) {
-                        printk (KERN_ERR "ide-scsi: scatter gather table too small, padding with zeros\n");
-                        idescsi_output_zeros (drive, bcount);
-                        return;
-                }
                 count = min(pc->sg->length - pc->b_count, bcount);
                 if (PageHighMem(pc->sg->page)) {
                         unsigned long flags;
@@ -233,10 +229,17 @@ static void idescsi_output_buffers (ide_drive_t *drive, idescsi_pc_t *pc, unsign
                 }
                 bcount -= count; pc->b_count += count;
                 if (pc->b_count == pc->sg->length) {
-                        pc->sg++;
+                        if (pc->sg == pc->last_sg)
+                                break;
+                        pc->sg = sg_next(pc->sg);
                         pc->b_count = 0;
                 }
         }
+
+        if (bcount) {
+                printk (KERN_ERR "ide-scsi: scatter gather table too small, padding with zeros\n");
+                idescsi_output_zeros (drive, bcount);
+        }
 }
 
 static void hexdump(u8 *x, int len)
@@ -804,6 +807,7 @@ static int idescsi_queue (struct scsi_cmnd *cmd,
         memcpy (pc->c, cmd->cmnd, cmd->cmd_len);
         pc->buffer = NULL;
         pc->sg = scsi_sglist(cmd);
+        pc->last_sg = sg_last(pc->sg, cmd->use_sg);
         pc->b_count = 0;
         pc->request_transfer = pc->buffer_size = scsi_bufflen(cmd);
         pc->scsi_cmd = cmd;
diff --git a/drivers/scsi/initio.c b/drivers/scsi/initio.c
index d9dfb69ae031..22d40fd5845b 100644
--- a/drivers/scsi/initio.c
+++ b/drivers/scsi/initio.c
@@ -2831,6 +2831,7 @@ static struct scsi_host_template initio_template = {
         .sg_tablesize           = SG_ALL,
         .cmd_per_lun            = 1,
         .use_clustering         = ENABLE_CLUSTERING,
+        .use_sg_chaining        = ENABLE_SG_CHAINING,
 };
 
 static int initio_probe_one(struct pci_dev *pdev,
diff --git a/drivers/scsi/ips.c b/drivers/scsi/ips.c
index 2ed099e2c20d..edaac2714c5a 100644
--- a/drivers/scsi/ips.c
+++ b/drivers/scsi/ips.c
@@ -3252,7 +3252,7 @@ ips_done(ips_ha_t * ha, ips_scb_t * scb)
                  */
                 if ((scb->breakup) || (scb->sg_break)) {
                         struct scatterlist *sg;
-                        int sg_dma_index, ips_sg_index = 0;
+                        int i, sg_dma_index, ips_sg_index = 0;
 
                         /* we had a data breakup */
                         scb->data_len = 0;
@@ -3261,20 +3261,22 @@ ips_done(ips_ha_t * ha, ips_scb_t * scb)
 
                         /* Spin forward to last dma chunk */
                         sg_dma_index = scb->breakup;
+                        for (i = 0; i < scb->breakup; i++)
+                                sg = sg_next(sg);
 
                         /* Take care of possible partial on last chunk */
                         ips_fill_scb_sg_single(ha,
-                                               sg_dma_address(&sg[sg_dma_index]),
+                                               sg_dma_address(sg),
                                                scb, ips_sg_index++,
-                                               sg_dma_len(&sg[sg_dma_index]));
+                                               sg_dma_len(sg));
 
                         for (; sg_dma_index < scsi_sg_count(scb->scsi_cmd);
-                             sg_dma_index++) {
+                             sg_dma_index++, sg = sg_next(sg)) {
                                 if (ips_fill_scb_sg_single
                                     (ha,
-                                     sg_dma_address(&sg[sg_dma_index]),
+                                     sg_dma_address(sg),
                                      scb, ips_sg_index++,
-                                     sg_dma_len(&sg[sg_dma_index])) < 0)
+                                     sg_dma_len(sg)) < 0)
                                         break;
                         }
 
diff --git a/drivers/scsi/lpfc/lpfc_scsi.c b/drivers/scsi/lpfc/lpfc_scsi.c
index cd674938ccd5..c0755565fae9 100644
--- a/drivers/scsi/lpfc/lpfc_scsi.c
+++ b/drivers/scsi/lpfc/lpfc_scsi.c
@@ -1438,6 +1438,7 @@ struct scsi_host_template lpfc_template = {
         .scan_finished          = lpfc_scan_finished,
         .this_id                = -1,
         .sg_tablesize           = LPFC_SG_SEG_CNT,
+        .use_sg_chaining        = ENABLE_SG_CHAINING,
         .cmd_per_lun            = LPFC_CMD_PER_LUN,
         .use_clustering         = ENABLE_CLUSTERING,
         .shost_attrs            = lpfc_hba_attrs,
@@ -1460,6 +1461,7 @@ struct scsi_host_template lpfc_vport_template = {
         .sg_tablesize           = LPFC_SG_SEG_CNT,
         .cmd_per_lun            = LPFC_CMD_PER_LUN,
         .use_clustering         = ENABLE_CLUSTERING,
+        .use_sg_chaining        = ENABLE_SG_CHAINING,
         .shost_attrs            = lpfc_vport_attrs,
         .max_sectors            = 0xFFFF,
 };
diff --git a/drivers/scsi/mac53c94.c b/drivers/scsi/mac53c94.c
index b12ad7c7c673..a035001f4438 100644
--- a/drivers/scsi/mac53c94.c
+++ b/drivers/scsi/mac53c94.c
@@ -402,6 +402,7 @@ static struct scsi_host_template mac53c94_template = {
         .sg_tablesize   = SG_ALL,
         .cmd_per_lun    = 1,
         .use_clustering = DISABLE_CLUSTERING,
+        .use_sg_chaining = ENABLE_SG_CHAINING,
 };
 
 static int mac53c94_probe(struct macio_dev *mdev, const struct of_device_id *match)
diff --git a/drivers/scsi/megaraid.c b/drivers/scsi/megaraid.c
index e7e11f282c8f..10d1aff9938a 100644
--- a/drivers/scsi/megaraid.c
+++ b/drivers/scsi/megaraid.c
@@ -4492,6 +4492,7 @@ static struct scsi_host_template megaraid_template = {
         .sg_tablesize                   = MAX_SGLIST,
         .cmd_per_lun                    = DEF_CMD_PER_LUN,
         .use_clustering                 = ENABLE_CLUSTERING,
+        .use_sg_chaining                = ENABLE_SG_CHAINING,
         .eh_abort_handler               = megaraid_abort,
         .eh_device_reset_handler        = megaraid_reset,
         .eh_bus_reset_handler           = megaraid_reset,
diff --git a/drivers/scsi/megaraid/megaraid_mbox.c b/drivers/scsi/megaraid/megaraid_mbox.c
index c6a53dccc16a..e4e4c6a39ed6 100644
--- a/drivers/scsi/megaraid/megaraid_mbox.c
+++ b/drivers/scsi/megaraid/megaraid_mbox.c
@@ -361,6 +361,7 @@ static struct scsi_host_template megaraid_template_g = {
         .eh_host_reset_handler          = megaraid_reset_handler,
         .change_queue_depth             = megaraid_change_queue_depth,
         .use_clustering                 = ENABLE_CLUSTERING,
+        .use_sg_chaining                = ENABLE_SG_CHAINING,
         .sdev_attrs                     = megaraid_sdev_attrs,
         .shost_attrs                    = megaraid_shost_attrs,
 };
diff --git a/drivers/scsi/megaraid/megaraid_sas.c b/drivers/scsi/megaraid/megaraid_sas.c
index ebb948c016bb..e3c5c5282203 100644
--- a/drivers/scsi/megaraid/megaraid_sas.c
+++ b/drivers/scsi/megaraid/megaraid_sas.c
@@ -1110,6 +1110,7 @@ static struct scsi_host_template megasas_template = {
         .eh_timed_out = megasas_reset_timer,
         .bios_param = megasas_bios_param,
         .use_clustering = ENABLE_CLUSTERING,
+        .use_sg_chaining = ENABLE_SG_CHAINING,
 };
 
 /**
diff --git a/drivers/scsi/mesh.c b/drivers/scsi/mesh.c
index 651d09b08f2a..7470ff39ab22 100644
--- a/drivers/scsi/mesh.c
+++ b/drivers/scsi/mesh.c
@@ -1843,6 +1843,7 @@ static struct scsi_host_template mesh_template = {
         .sg_tablesize                   = SG_ALL,
         .cmd_per_lun                    = 2,
         .use_clustering                 = DISABLE_CLUSTERING,
+        .use_sg_chaining                = ENABLE_SG_CHAINING,
 };
 
 static int mesh_probe(struct macio_dev *mdev, const struct of_device_id *match)
diff --git a/drivers/scsi/nsp32.c b/drivers/scsi/nsp32.c
index 7fed35372150..28161dc95e0d 100644
--- a/drivers/scsi/nsp32.c
+++ b/drivers/scsi/nsp32.c
@@ -281,6 +281,7 @@ static struct scsi_host_template nsp32_template = {
         .cmd_per_lun                    = 1,
         .this_id                        = NSP32_HOST_SCSIID,
         .use_clustering                 = DISABLE_CLUSTERING,
+        .use_sg_chaining                = ENABLE_SG_CHAINING,
         .eh_abort_handler               = nsp32_eh_abort,
         .eh_bus_reset_handler           = nsp32_eh_bus_reset,
         .eh_host_reset_handler          = nsp32_eh_host_reset,
diff --git a/drivers/scsi/pcmcia/sym53c500_cs.c b/drivers/scsi/pcmcia/sym53c500_cs.c
index 961839ecfe86..190e2a7d7067 100644
--- a/drivers/scsi/pcmcia/sym53c500_cs.c
+++ b/drivers/scsi/pcmcia/sym53c500_cs.c
@@ -694,6 +694,7 @@ static struct scsi_host_template sym53c500_driver_template = {
      .sg_tablesize              = 32,
      .cmd_per_lun               = 1,
      .use_clustering            = ENABLE_CLUSTERING,
+     .use_sg_chaining           = ENABLE_SG_CHAINING,
      .shost_attrs               = SYM53C500_shost_attrs
 };
 
diff --git a/drivers/scsi/qla1280.c b/drivers/scsi/qla1280.c
index fba8aa8a81b5..76089cf55f4e 100644
--- a/drivers/scsi/qla1280.c
+++ b/drivers/scsi/qla1280.c
@@ -2775,7 +2775,7 @@ qla1280_64bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
         struct device_reg __iomem *reg = ha->iobase;
         struct scsi_cmnd *cmd = sp->cmd;
         cmd_a64_entry_t *pkt;
-        struct scatterlist *sg = NULL;
+        struct scatterlist *sg = NULL, *s;
         __le32 *dword_ptr;
         dma_addr_t dma_handle;
         int status = 0;
@@ -2889,13 +2889,16 @@ qla1280_64bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
          * Load data segments.
          */
         if (seg_cnt) {  /* If data transfer. */
+                int remseg = seg_cnt;
                 /* Setup packet address segment pointer. */
                 dword_ptr = (u32 *)&pkt->dseg_0_address;
 
                 if (cmd->use_sg) {      /* If scatter gather */
                         /* Load command entry data segments. */
-                        for (cnt = 0; cnt < 2 && seg_cnt; cnt++, seg_cnt--) {
-                                dma_handle = sg_dma_address(sg);
+                        for_each_sg(sg, s, seg_cnt, cnt) {
+                                if (cnt == 2)
+                                        break;
+                                dma_handle = sg_dma_address(s);
 #if defined(CONFIG_IA64_GENERIC) || defined(CONFIG_IA64_SGI_SN2)
                                 if (ha->flags.use_pci_vchannel)
                                         sn_pci_set_vchan(ha->pdev,
@@ -2906,12 +2909,12 @@ qla1280_64bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
                                         cpu_to_le32(pci_dma_lo32(dma_handle));
                                 *dword_ptr++ =
                                         cpu_to_le32(pci_dma_hi32(dma_handle));
-                                *dword_ptr++ = cpu_to_le32(sg_dma_len(sg));
-                                sg++;
+                                *dword_ptr++ = cpu_to_le32(sg_dma_len(s));
                                 dprintk(3, "S/G Segment phys_addr=%x %x, len=0x%x\n",
                                         cpu_to_le32(pci_dma_hi32(dma_handle)),
                                         cpu_to_le32(pci_dma_lo32(dma_handle)),
-                                        cpu_to_le32(sg_dma_len(sg)));
+                                        cpu_to_le32(sg_dma_len(sg_next(s))));
+                                remseg--;
                         }
                         dprintk(5, "qla1280_64bit_start_scsi: Scatter/gather "
                                 "command packet data - b %i, t %i, l %i \n",
@@ -2926,7 +2929,9 @@ qla1280_64bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
                         dprintk(3, "S/G Building Continuation...seg_cnt=0x%x "
                                 "remains\n", seg_cnt);
 
-                        while (seg_cnt > 0) {
+                        while (remseg > 0) {
+                                /* Update sg start */
+                                sg = s;
                                 /* Adjust ring index. */
                                 ha->req_ring_index++;
                                 if (ha->req_ring_index == REQUEST_ENTRY_CNT) {
@@ -2952,9 +2957,10 @@ qla1280_64bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
                                         (u32 *)&((struct cont_a64_entry *) pkt)->dseg_0_address;
 
                                 /* Load continuation entry data segments. */
-                                for (cnt = 0; cnt < 5 && seg_cnt;
-                                     cnt++, seg_cnt--) {
-                                        dma_handle = sg_dma_address(sg);
+                                for_each_sg(sg, s, remseg, cnt) {
+                                        if (cnt == 5)
+                                                break;
+                                        dma_handle = sg_dma_address(s);
 #if defined(CONFIG_IA64_GENERIC) || defined(CONFIG_IA64_SGI_SN2)
                                 if (ha->flags.use_pci_vchannel)
                                         sn_pci_set_vchan(ha->pdev, 
@@ -2966,13 +2972,13 @@ qla1280_64bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
                                         *dword_ptr++ =
                                                 cpu_to_le32(pci_dma_hi32(dma_handle));
                                         *dword_ptr++ =
-                                                cpu_to_le32(sg_dma_len(sg));
+                                                cpu_to_le32(sg_dma_len(s));
                                         dprintk(3, "S/G Segment Cont. phys_addr=%x %x, len=0x%x\n",
                                                 cpu_to_le32(pci_dma_hi32(dma_handle)),
                                                 cpu_to_le32(pci_dma_lo32(dma_handle)),
-                                                cpu_to_le32(sg_dma_len(sg)));
-                                        sg++;
+                                                cpu_to_le32(sg_dma_len(s)));
                                 }
+                                remseg -= cnt;
                                 dprintk(5, "qla1280_64bit_start_scsi: "
                                         "continuation packet data - b %i, t "
                                         "%i, l %i \n", SCSI_BUS_32(cmd),
@@ -3062,7 +3068,7 @@ qla1280_32bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
         struct device_reg __iomem *reg = ha->iobase;
         struct scsi_cmnd *cmd = sp->cmd;
         struct cmd_entry *pkt;
-        struct scatterlist *sg = NULL;
+        struct scatterlist *sg = NULL, *s;
         __le32 *dword_ptr;
         int status = 0;
         int cnt;
@@ -3188,6 +3194,7 @@ qla1280_32bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
          * Load data segments.
          */
         if (seg_cnt) {
+                int remseg = seg_cnt;
                 /* Setup packet address segment pointer. */
                 dword_ptr = &pkt->dseg_0_address;
 
@@ -3196,22 +3203,25 @@ qla1280_32bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
                         qla1280_dump_buffer(1, (char *)sg, 4 * 16);
 
                         /* Load command entry data segments. */
-                        for (cnt = 0; cnt < 4 && seg_cnt; cnt++, seg_cnt--) {
+                        for_each_sg(sg, s, seg_cnt, cnt) {
+                                if (cnt == 4)
+                                        break;
                                 *dword_ptr++ =
-                                        cpu_to_le32(pci_dma_lo32(sg_dma_address(sg)));
-                                *dword_ptr++ =
-                                        cpu_to_le32(sg_dma_len(sg));
+                                        cpu_to_le32(pci_dma_lo32(sg_dma_address(s)));
+                                *dword_ptr++ = cpu_to_le32(sg_dma_len(s));
                                 dprintk(3, "S/G Segment phys_addr=0x%lx, len=0x%x\n",
-                                        (pci_dma_lo32(sg_dma_address(sg))),
-                                        (sg_dma_len(sg)));
-                                sg++;
+                                        (pci_dma_lo32(sg_dma_address(s))),
+                                        (sg_dma_len(s)));
+                                remseg--;
                         }
                         /*
                          * Build continuation packets.
                          */
                         dprintk(3, "S/G Building Continuation"
                                 "...seg_cnt=0x%x remains\n", seg_cnt);
-                        while (seg_cnt > 0) {
+                        while (remseg > 0) {
+                                /* Continue from end point */
+                                sg = s;
                                 /* Adjust ring index. */
                                 ha->req_ring_index++;
                                 if (ha->req_ring_index == REQUEST_ENTRY_CNT) {
@@ -3239,19 +3249,20 @@ qla1280_32bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
                                         &((struct cont_entry *) pkt)->dseg_0_address;
 
                                 /* Load continuation entry data segments. */
-                                for (cnt = 0; cnt < 7 && seg_cnt;
-                                     cnt++, seg_cnt--) {
+                                for_each_sg(sg, s, remseg, cnt) {
+                                        if (cnt == 7)
+                                                break;
                                         *dword_ptr++ =
-                                                cpu_to_le32(pci_dma_lo32(sg_dma_address(sg)));
+                                                cpu_to_le32(pci_dma_lo32(sg_dma_address(s)));
                                         *dword_ptr++ =
-                                                cpu_to_le32(sg_dma_len(sg));
+                                                cpu_to_le32(sg_dma_len(s));
                                         dprintk(1,
                                                 "S/G Segment Cont. phys_addr=0x%x, "
                                                 "len=0x%x\n",
-                                                cpu_to_le32(pci_dma_lo32(sg_dma_address(sg))),
-                                                cpu_to_le32(sg_dma_len(sg)));
-                                        sg++;
+                                                cpu_to_le32(pci_dma_lo32(sg_dma_address(s))),
+                                                cpu_to_le32(sg_dma_len(s)));
                                 }
+                                remseg -= cnt;
                                 dprintk(5, "qla1280_32bit_start_scsi: "
                                         "continuation packet data - "
                                         "scsi(%i:%i:%i)\n", SCSI_BUS_32(cmd),
@@ -4248,6 +4259,7 @@ static struct scsi_host_template qla1280_driver_template = {
         .sg_tablesize           = SG_ALL,
         .cmd_per_lun            = 1,
         .use_clustering         = ENABLE_CLUSTERING,
+        .use_sg_chaining        = ENABLE_SG_CHAINING,
 };
 
 
diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index a6bb8d0ecf13..0351d380c2d7 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -132,6 +132,7 @@ struct scsi_host_template qla2x00_driver_template = {
         .this_id                = -1,
         .cmd_per_lun            = 3,
         .use_clustering         = ENABLE_CLUSTERING,
+        .use_sg_chaining        = ENABLE_SG_CHAINING,
         .sg_tablesize           = SG_ALL,
 
         /*
@@ -163,6 +164,7 @@ struct scsi_host_template qla24xx_driver_template = {
         .this_id                = -1,
         .cmd_per_lun            = 3,
         .use_clustering         = ENABLE_CLUSTERING,
+        .use_sg_chaining        = ENABLE_SG_CHAINING,
         .sg_tablesize           = SG_ALL,
 
         .max_sectors            = 0xFFFF,
diff --git a/drivers/scsi/qla4xxx/ql4_os.c b/drivers/scsi/qla4xxx/ql4_os.c
index b1d565c12c5b..03b68d4f3bd0 100644
--- a/drivers/scsi/qla4xxx/ql4_os.c
+++ b/drivers/scsi/qla4xxx/ql4_os.c
@@ -94,6 +94,7 @@ static struct scsi_host_template qla4xxx_driver_template = {
         .this_id                = -1,
         .cmd_per_lun            = 3,
         .use_clustering         = ENABLE_CLUSTERING,
+        .use_sg_chaining        = ENABLE_SG_CHAINING,
         .sg_tablesize           = SG_ALL,
 
         .max_sectors            = 0xFFFF,
diff --git a/drivers/scsi/qlogicfas.c b/drivers/scsi/qlogicfas.c
index 1e874f1fb5c6..1769f965eedf 100644
--- a/drivers/scsi/qlogicfas.c
+++ b/drivers/scsi/qlogicfas.c
@@ -197,6 +197,7 @@ static struct scsi_host_template qlogicfas_driver_template = {
         .sg_tablesize           = SG_ALL,
         .cmd_per_lun            = 1,
         .use_clustering         = DISABLE_CLUSTERING,
+        .use_sg_chaining        = ENABLE_SG_CHAINING,
 };
 
 static __init int qlogicfas_init(void)
diff --git a/drivers/scsi/qlogicpti.c b/drivers/scsi/qlogicpti.c
index e93f80316a19..7a2e7986b038 100644
--- a/drivers/scsi/qlogicpti.c
+++ b/drivers/scsi/qlogicpti.c
@@ -868,7 +868,7 @@ static inline int load_cmd(struct scsi_cmnd *Cmnd, struct Command_Entry *cmd,
                            struct qlogicpti *qpti, u_int in_ptr, u_int out_ptr)
 {
         struct dataseg *ds;
-        struct scatterlist *sg;
+        struct scatterlist *sg, *s;
         int i, n;
 
         if (Cmnd->use_sg) {
@@ -884,11 +884,12 @@ static inline int load_cmd(struct scsi_cmnd *Cmnd, struct Command_Entry *cmd,
                 n = sg_count;
                 if (n > 4)
                         n = 4;
-                for (i = 0; i < n; i++, sg++) {
-                        ds[i].d_base = sg_dma_address(sg);
-                        ds[i].d_count = sg_dma_len(sg);
+                for_each_sg(sg, s, n, i) {
+                        ds[i].d_base = sg_dma_address(s);
+                        ds[i].d_count = sg_dma_len(s);
                 }
                 sg_count -= 4;
+                sg = s;
                 while (sg_count > 0) {
                         struct Continuation_Entry *cont;
 
@@ -907,9 +908,9 @@ static inline int load_cmd(struct scsi_cmnd *Cmnd, struct Command_Entry *cmd,
                         n = sg_count;
                         if (n > 7)
                                 n = 7;
-                        for (i = 0; i < n; i++, sg++) {
-                                ds[i].d_base = sg_dma_address(sg);
-                                ds[i].d_count = sg_dma_len(sg);
+                        for_each_sg(sg, s, n, i) {
+                                ds[i].d_base = sg_dma_address(s);
+                                ds[i].d_count = sg_dma_len(s);
                         }
                         sg_count -= n;
                 }
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 4947dfe625a6..72ee4c9cfb1a 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -38,6 +38,7 @@
 #include <linux/proc_fs.h>
 #include <linux/vmalloc.h>
 #include <linux/moduleparam.h>
+#include <linux/scatterlist.h>
 
 #include <linux/blkdev.h>
 #include "scsi.h"
@@ -600,7 +601,7 @@ static int fill_from_dev_buffer(struct scsi_cmnd * scp, unsigned char * arr,
         int k, req_len, act_len, len, active;
         void * kaddr;
         void * kaddr_off;
-        struct scatterlist * sgpnt;
+        struct scatterlist * sg;
 
         if (0 == scp->request_bufflen)
                 return 0;
@@ -619,16 +620,16 @@ static int fill_from_dev_buffer(struct scsi_cmnd * scp, unsigned char * arr,
                         scp->resid = req_len - act_len;
                 return 0;
         }
-        sgpnt = (struct scatterlist *)scp->request_buffer;
         active = 1;
-        for (k = 0, req_len = 0, act_len = 0; k < scp->use_sg; ++k, ++sgpnt) {
+        req_len = act_len = 0;
+        scsi_for_each_sg(scp, sg, scp->use_sg, k) {
                 if (active) {
                         kaddr = (unsigned char *)
-                                kmap_atomic(sgpnt->page, KM_USER0);
+                                kmap_atomic(sg->page, KM_USER0);
                         if (NULL == kaddr)
                                 return (DID_ERROR << 16);
-                        kaddr_off = (unsigned char *)kaddr + sgpnt->offset;
-                        len = sgpnt->length;
+                        kaddr_off = (unsigned char *)kaddr + sg->offset;
+                        len = sg->length;
                         if ((req_len + len) > arr_len) {
                                 active = 0;
                                 len = arr_len - req_len;
@@ -637,7 +638,7 @@ static int fill_from_dev_buffer(struct scsi_cmnd * scp, unsigned char * arr,
                         kunmap_atomic(kaddr, KM_USER0);
                         act_len += len;
                 }
-                req_len += sgpnt->length;
+                req_len += sg->length;
         }
         if (scp->resid)
                 scp->resid -= act_len;
@@ -653,7 +654,7 @@ static int fetch_to_dev_buffer(struct scsi_cmnd * scp, unsigned char * arr,
         int k, req_len, len, fin;
         void * kaddr;
         void * kaddr_off;
-        struct scatterlist * sgpnt;
+        struct scatterlist * sg;
 
         if (0 == scp->request_bufflen)
                 return 0;
@@ -668,13 +669,14 @@ static int fetch_to_dev_buffer(struct scsi_cmnd * scp, unsigned char * arr,
                 memcpy(arr, scp->request_buffer, len);
                 return len;
         }
-        sgpnt = (struct scatterlist *)scp->request_buffer;
-        for (k = 0, req_len = 0, fin = 0; k < scp->use_sg; ++k, ++sgpnt) {
-                kaddr = (unsigned char *)kmap_atomic(sgpnt->page, KM_USER0);
+        sg = scsi_sglist(scp);
+        req_len = fin = 0;
+        for (k = 0; k < scp->use_sg; ++k, sg = sg_next(sg)) {
+                kaddr = (unsigned char *)kmap_atomic(sg->page, KM_USER0);
                 if (NULL == kaddr)
                         return -1;
-                kaddr_off = (unsigned char *)kaddr + sgpnt->offset;
-                len = sgpnt->length;
+                kaddr_off = (unsigned char *)kaddr + sg->offset;
+                len = sg->length;
                 if ((req_len + len) > max_arr_len) {
                         len = max_arr_len - req_len;
                         fin = 1;
@@ -683,7 +685,7 @@ static int fetch_to_dev_buffer(struct scsi_cmnd * scp, unsigned char * arr,
                 kunmap_atomic(kaddr, KM_USER0);
                 if (fin)
                         return req_len + len;
-                req_len += sgpnt->length;
+                req_len += sg->length;
         }
         return req_len;
 }
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 207f1aa08869..aac8a02cbe80 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -17,6 +17,7 @@
 #include <linux/pci.h>
 #include <linux/delay.h>
 #include <linux/hardirq.h>
+#include <linux/scatterlist.h>
 
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>
@@ -33,35 +34,34 @@
 #define SG_MEMPOOL_NR           ARRAY_SIZE(scsi_sg_pools)
 #define SG_MEMPOOL_SIZE         2
 
+/*
+ * The maximum number of SG segments that we will put inside a scatterlist
+ * (unless chaining is used). Should ideally fit inside a single page, to
+ * avoid a higher order allocation.
+ */
+#define SCSI_MAX_SG_SEGMENTS    128
+
 struct scsi_host_sg_pool {
         size_t          size;
-        char            *name; 
+        char            *name;
         struct kmem_cache       *slab;
         mempool_t       *pool;
 };
 
-#if (SCSI_MAX_PHYS_SEGMENTS < 32)
-#error SCSI_MAX_PHYS_SEGMENTS is too small
-#endif
-
-#define SP(x) { x, "sgpool-" #x } 
+#define SP(x) { x, "sgpool-" #x }
 static struct scsi_host_sg_pool scsi_sg_pools[] = {
         SP(8),
         SP(16),
+#if (SCSI_MAX_SG_SEGMENTS > 16)
         SP(32),
-#if (SCSI_MAX_PHYS_SEGMENTS > 32)
+#if (SCSI_MAX_SG_SEGMENTS > 32)
         SP(64),
-#if (SCSI_MAX_PHYS_SEGMENTS > 64)
+#if (SCSI_MAX_SG_SEGMENTS > 64)
         SP(128),
-#if (SCSI_MAX_PHYS_SEGMENTS > 128)
-        SP(256),
-#if (SCSI_MAX_PHYS_SEGMENTS > 256)
-#error SCSI_MAX_PHYS_SEGMENTS is too large
-#endif
 #endif
 #endif
 #endif
-};      
+};
 #undef SP
 
 static void scsi_run_queue(struct request_queue *q);
@@ -289,14 +289,16 @@ static int scsi_req_map_sg(struct request *rq, struct scatterlist *sgl,
         struct request_queue *q = rq->q;
         int nr_pages = (bufflen + sgl[0].offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
         unsigned int data_len = bufflen, len, bytes, off;
+        struct scatterlist *sg;
         struct page *page;
         struct bio *bio = NULL;
         int i, err, nr_vecs = 0;
 
-        for (i = 0; i < nsegs; i++) {
-                page = sgl[i].page;
-                off = sgl[i].offset;
-                len = sgl[i].length;
+        for_each_sg(sgl, sg, nsegs, i) {
+                page = sg->page;
+                off = sg->offset;
+                len = sg->length;
+                data_len += len;
 
                 while (len > 0 && data_len > 0) {
                         /*
@@ -695,56 +697,170 @@ static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int uptodate,
         return NULL;
 }
 
-struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask)
-{
-        struct scsi_host_sg_pool *sgp;
-        struct scatterlist *sgl;
+/*
+ * Like SCSI_MAX_SG_SEGMENTS, but for archs that have sg chaining. This limit
+ * is totally arbitrary, a setting of 2048 will get you at least 8mb ios.
+ */
+#define SCSI_MAX_SG_CHAIN_SEGMENTS      2048
 
-        BUG_ON(!cmd->use_sg);
+static inline unsigned int scsi_sgtable_index(unsigned short nents)
+{
+        unsigned int index;
 
-        switch (cmd->use_sg) {
+        switch (nents) {
         case 1 ... 8:
-                cmd->sglist_len = 0;
+                index = 0;
                 break;
         case 9 ... 16:
-                cmd->sglist_len = 1;
+                index = 1;
                 break;
+#if (SCSI_MAX_SG_SEGMENTS > 16)
         case 17 ... 32:
-                cmd->sglist_len = 2;
+                index = 2;
                 break;
-#if (SCSI_MAX_PHYS_SEGMENTS > 32)
+#if (SCSI_MAX_SG_SEGMENTS > 32)
         case 33 ... 64:
-                cmd->sglist_len = 3;
+                index = 3;
                 break;
-#if (SCSI_MAX_PHYS_SEGMENTS > 64)
+#if (SCSI_MAX_SG_SEGMENTS > 64)
         case 65 ... 128:
-                cmd->sglist_len = 4;
-                break;
-#if (SCSI_MAX_PHYS_SEGMENTS  > 128)
-        case 129 ... 256:
-                cmd->sglist_len = 5;
+                index = 4;
                 break;
 #endif
 #endif
 #endif
         default:
-                return NULL;
+                printk(KERN_ERR "scsi: bad segment count=%d\n", nents);
+                BUG();
         }
 
-        sgp = scsi_sg_pools + cmd->sglist_len;
-        sgl = mempool_alloc(sgp->pool, gfp_mask);
-        return sgl;
+        return index;
+}
+
+struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask)
+{
+        struct scsi_host_sg_pool *sgp;
+        struct scatterlist *sgl, *prev, *ret;
+        unsigned int index;
+        int this, left;
+
+        BUG_ON(!cmd->use_sg);
+
+        left = cmd->use_sg;
+        ret = prev = NULL;
+        do {
+                this = left;
+                if (this > SCSI_MAX_SG_SEGMENTS) {
+                        this = SCSI_MAX_SG_SEGMENTS - 1;
+                        index = SG_MEMPOOL_NR - 1;
+                } else
+                        index = scsi_sgtable_index(this);
+
+                left -= this;
+
+                sgp = scsi_sg_pools + index;
+
+                sgl = mempool_alloc(sgp->pool, gfp_mask);
+                if (unlikely(!sgl))
+                        goto enomem;
+
+                memset(sgl, 0, sizeof(*sgl) * sgp->size);
+
+                /*
+                 * first loop through, set initial index and return value
+                 */
+                if (!ret)
+                        ret = sgl;
+
+                /*
+                 * chain previous sglist, if any. we know the previous
+                 * sglist must be the biggest one, or we would not have
+                 * ended up doing another loop.
+                 */
+                if (prev)
+                        sg_chain(prev, SCSI_MAX_SG_SEGMENTS, sgl);
+
+                /*
+                 * don't allow subsequent mempool allocs to sleep, it would
+                 * violate the mempool principle.
+                 */
+                gfp_mask &= ~__GFP_WAIT;
+                gfp_mask |= __GFP_HIGH;
+                prev = sgl;
+        } while (left);
+
+        /*
+         * ->use_sg may get modified after dma mapping has potentially
+         * shrunk the number of segments, so keep a copy of it for free.
+         */
+        cmd->__use_sg = cmd->use_sg;
+        return ret;
+enomem:
+        if (ret) {
+                /*
+                 * Free entries chained off ret. Since we were trying to
+                 * allocate another sglist, we know that all entries are of
+                 * the max size.
+                 */
+                sgp = scsi_sg_pools + SG_MEMPOOL_NR - 1;
+                prev = ret;
+                ret = &ret[SCSI_MAX_SG_SEGMENTS - 1];
+
+                while ((sgl = sg_chain_ptr(ret)) != NULL) {
+                        ret = &sgl[SCSI_MAX_SG_SEGMENTS - 1];
+                        mempool_free(sgl, sgp->pool);
+                }
+
+                mempool_free(prev, sgp->pool);
+        }
+        return NULL;
 }
 
 EXPORT_SYMBOL(scsi_alloc_sgtable);
 
-void scsi_free_sgtable(struct scatterlist *sgl, int index)
+void scsi_free_sgtable(struct scsi_cmnd *cmd)
 {
+        struct scatterlist *sgl = cmd->request_buffer;
         struct scsi_host_sg_pool *sgp;
 
-        BUG_ON(index >= SG_MEMPOOL_NR);
+        /*
+         * if this is the biggest size sglist, check if we have
+         * chained parts we need to free
+         */
+        if (cmd->__use_sg > SCSI_MAX_SG_SEGMENTS) {
+                unsigned short this, left;
+                struct scatterlist *next;
+                unsigned int index;
+
+                left = cmd->__use_sg - (SCSI_MAX_SG_SEGMENTS - 1);
+                next = sg_chain_ptr(&sgl[SCSI_MAX_SG_SEGMENTS - 1]);
+                while (left && next) {
+                        sgl = next;
+                        this = left;
+                        if (this > SCSI_MAX_SG_SEGMENTS) {
+                                this = SCSI_MAX_SG_SEGMENTS - 1;
+                                index = SG_MEMPOOL_NR - 1;
+                        } else
+                                index = scsi_sgtable_index(this);
+
+                        left -= this;
+
+                        sgp = scsi_sg_pools + index;
+
+                        if (left)
+                                next = sg_chain_ptr(&sgl[sgp->size - 1]);
+
+                        mempool_free(sgl, sgp->pool);
+                }
+
+                /*
+                 * Restore original, will be freed below
+                 */
+                sgl = cmd->request_buffer;
+                sgp = scsi_sg_pools + SG_MEMPOOL_NR - 1;
+        } else
+                sgp = scsi_sg_pools + scsi_sgtable_index(cmd->__use_sg);
 
-        sgp = scsi_sg_pools + index;
         mempool_free(sgl, sgp->pool);
 }
 
@@ -770,7 +886,7 @@ EXPORT_SYMBOL(scsi_free_sgtable);
 static void scsi_release_buffers(struct scsi_cmnd *cmd)
 {
         if (cmd->use_sg)
-                scsi_free_sgtable(cmd->request_buffer, cmd->sglist_len);
+                scsi_free_sgtable(cmd);
 
         /*
          * Zero these out.  They now point to freed memory, and it is
@@ -984,7 +1100,6 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
 static int scsi_init_io(struct scsi_cmnd *cmd)
 {
         struct request     *req = cmd->request;
-        struct scatterlist *sgpnt;
         int                count;
 
         /*
@@ -997,14 +1112,13 @@ static int scsi_init_io(struct scsi_cmnd *cmd)
         /*
          * If sg table allocation fails, requeue request later.
          */
-        sgpnt = scsi_alloc_sgtable(cmd, GFP_ATOMIC);
-        if (unlikely(!sgpnt)) {
+        cmd->request_buffer = scsi_alloc_sgtable(cmd, GFP_ATOMIC);
+        if (unlikely(!cmd->request_buffer)) {
                 scsi_unprep_request(req);
                 return BLKPREP_DEFER;
         }
 
         req->buffer = NULL;
-        cmd->request_buffer = (char *) sgpnt;
         if (blk_pc_request(req))
                 cmd->request_bufflen = req->data_len;
         else
@@ -1529,8 +1643,25 @@ struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost,
         if (!q)
                 return NULL;
 
+        /*
+         * this limit is imposed by hardware restrictions
+         */
         blk_queue_max_hw_segments(q, shost->sg_tablesize);
-        blk_queue_max_phys_segments(q, SCSI_MAX_PHYS_SEGMENTS);
+
+        /*
+         * In the future, sg chaining support will be mandatory and this
+         * ifdef can then go away. Right now we don't have all archs
+         * converted, so better keep it safe.
+         */
+#ifdef ARCH_HAS_SG_CHAIN
+        if (shost->use_sg_chaining)
+                blk_queue_max_phys_segments(q, SCSI_MAX_SG_CHAIN_SEGMENTS);
+        else
+                blk_queue_max_phys_segments(q, SCSI_MAX_SG_SEGMENTS);
+#else
+        blk_queue_max_phys_segments(q, SCSI_MAX_SG_SEGMENTS);
+#endif
+
         blk_queue_max_sectors(q, shost->max_sectors);
         blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost));
         blk_queue_segment_boundary(q, shost->dma_boundary);
@@ -2193,18 +2324,19 @@ EXPORT_SYMBOL_GPL(scsi_target_unblock);
  *
  * Returns virtual address of the start of the mapped page
  */
-void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
+void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count,
                           size_t *offset, size_t *len)
 {
         int i;
         size_t sg_len = 0, len_complete = 0;
+        struct scatterlist *sg;
         struct page *page;
 
         WARN_ON(!irqs_disabled());
 
-        for (i = 0; i < sg_count; i++) {
+        for_each_sg(sgl, sg, sg_count, i) {
                 len_complete = sg_len; /* Complete sg-entries */
-                sg_len += sg[i].length;
+                sg_len += sg->length;
                 if (sg_len > *offset)
                         break;
         }
@@ -2218,10 +2350,10 @@ void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
         }
 
         /* Offset starting from the beginning of first page in this sg-entry */
-        *offset = *offset - len_complete + sg[i].offset;
+        *offset = *offset - len_complete + sg->offset;
 
         /* Assumption: contiguous pages can be accessed as "page + i" */
-        page = nth_page(sg[i].page, (*offset >> PAGE_SHIFT));
+        page = nth_page(sg->page, (*offset >> PAGE_SHIFT));
         *offset &= ~PAGE_MASK;
 
         /* Bytes in this sg-entry from *offset to the end of the page */
diff --git a/drivers/scsi/scsi_tgt_lib.c b/drivers/scsi/scsi_tgt_lib.c
index 66c692ffa305..a91761c3645f 100644
--- a/drivers/scsi/scsi_tgt_lib.c
+++ b/drivers/scsi/scsi_tgt_lib.c
@@ -332,7 +332,7 @@ static void scsi_tgt_cmd_done(struct scsi_cmnd *cmd)
         scsi_tgt_uspace_send_status(cmd, tcmd->itn_id, tcmd->tag);
 
         if (cmd->request_buffer)
-                scsi_free_sgtable(cmd->request_buffer, cmd->sglist_len);
+                scsi_free_sgtable(cmd);
 
         queue_work(scsi_tgtd, &tcmd->work);
 }
@@ -373,7 +373,7 @@ static int scsi_tgt_init_cmd(struct scsi_cmnd *cmd, gfp_t gfp_mask)
         }
 
         eprintk("cmd %p cnt %d\n", cmd, cmd->use_sg);
-        scsi_free_sgtable(cmd->request_buffer, cmd->sglist_len);
+        scsi_free_sgtable(cmd);
         return -EINVAL;
 }
 
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index f6f5fc7d0cee..7238b2dfc497 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1165,7 +1165,7 @@ sg_vma_nopage(struct vm_area_struct *vma, unsigned long addr, int *type)
         sg = rsv_schp->buffer;
         sa = vma->vm_start;
         for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
-             ++k, ++sg) {
+             ++k, sg = sg_next(sg)) {
                 len = vma->vm_end - sa;
                 len = (len < sg->length) ? len : sg->length;
                 if (offset < len) {
@@ -1209,7 +1209,7 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma)
         sa = vma->vm_start;
         sg = rsv_schp->buffer;
         for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
-             ++k, ++sg) {
+             ++k, sg = sg_next(sg)) {
                 len = vma->vm_end - sa;
                 len = (len < sg->length) ? len : sg->length;
                 sa += len;
@@ -1840,7 +1840,7 @@ sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
         }
         for (k = 0, sg = schp->buffer, rem_sz = blk_size;
              (rem_sz > 0) && (k < mx_sc_elems);
-             ++k, rem_sz -= ret_sz, ++sg) {
+             ++k, rem_sz -= ret_sz, sg = sg_next(sg)) {
                 
                 num = (rem_sz > scatter_elem_sz_prev) ?
                       scatter_elem_sz_prev : rem_sz;
@@ -1913,7 +1913,7 @@ sg_write_xfer(Sg_request * srp)
                 if (res)
                         return res;
 
-                for (; p; ++sg, ksglen = sg->length,
+                for (; p; sg = sg_next(sg), ksglen = sg->length,
                      p = page_address(sg->page)) {
                         if (usglen <= 0)
                                 break;
@@ -1992,7 +1992,7 @@ sg_remove_scat(Sg_scatter_hold * schp)
                         int k;
 
                         for (k = 0; (k < schp->k_use_sg) && sg->page;
-                             ++k, ++sg) {
+                             ++k, sg = sg_next(sg)) {
                                 SCSI_LOG_TIMEOUT(5, printk(
                                     "sg_remove_scat: k=%d, pg=0x%p, len=%d\n",
                                     k, sg->page, sg->length));
@@ -2045,7 +2045,7 @@ sg_read_xfer(Sg_request * srp)
                 if (res)
                         return res;
 
-                for (; p; ++sg, ksglen = sg->length,
+                for (; p; sg = sg_next(sg), ksglen = sg->length,
                      p = page_address(sg->page)) {
                         if (usglen <= 0)
                                 break;
@@ -2092,7 +2092,7 @@ sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
         if ((!outp) || (num_read_xfer <= 0))
                 return 0;
 
-        for (k = 0; (k < schp->k_use_sg) && sg->page; ++k, ++sg) {
+        for (k = 0; (k < schp->k_use_sg) && sg->page; ++k, sg = sg_next(sg)) {
                 num = sg->length;
                 if (num > num_read_xfer) {
                         if (__copy_to_user(outp, page_address(sg->page),
@@ -2142,7 +2142,7 @@ sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
         rem = size;
 
-        for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sg) {
+        for (k = 0; k < rsv_schp->k_use_sg; ++k, sg = sg_next(sg)) {
                 num = sg->length;
                 if (rem <= num) {
                         sfp->save_scat_len = num;
diff --git a/drivers/scsi/stex.c b/drivers/scsi/stex.c
index 72f6d8015358..e3fab3a6aed7 100644
--- a/drivers/scsi/stex.c
+++ b/drivers/scsi/stex.c
@@ -1123,6 +1123,7 @@ static struct scsi_host_template driver_template = {
         .this_id                        = -1,
         .sg_tablesize                   = ST_MAX_SG,
         .cmd_per_lun                    = ST_CMD_PER_LUN,
+        .use_sg_chaining                = ENABLE_SG_CHAINING,
 };
 
 static int stex_set_dma_mask(struct pci_dev * pdev)
diff --git a/drivers/scsi/sym53c416.c b/drivers/scsi/sym53c416.c
index 92bfaeafe30d..8befab7e9839 100644
--- a/drivers/scsi/sym53c416.c
+++ b/drivers/scsi/sym53c416.c
@@ -854,5 +854,6 @@ static struct scsi_host_template driver_template = {
         .cmd_per_lun =          1,
         .unchecked_isa_dma =    1,
         .use_clustering =       ENABLE_CLUSTERING,
+        .use_sg_chaining =      ENABLE_SG_CHAINING,
 };
 #include "scsi_module.c"
diff --git a/drivers/scsi/sym53c8xx_2/sym_glue.c b/drivers/scsi/sym53c8xx_2/sym_glue.c
index 3db22325ea2c..db03c4c8ec1e 100644
--- a/drivers/scsi/sym53c8xx_2/sym_glue.c
+++ b/drivers/scsi/sym53c8xx_2/sym_glue.c
@@ -1808,6 +1808,7 @@ static struct scsi_host_template sym2_template = {
         .eh_host_reset_handler  = sym53c8xx_eh_host_reset_handler,
         .this_id                = 7,
         .use_clustering         = ENABLE_CLUSTERING,
+        .use_sg_chaining        = ENABLE_SG_CHAINING,
         .max_sectors            = 0xFFFF,
 #ifdef SYM_LINUX_PROC_INFO_SUPPORT
         .proc_info              = sym53c8xx_proc_info,
diff --git a/drivers/scsi/u14-34f.c b/drivers/scsi/u14-34f.c
index fc9f51818e8f..7edd6ceb13b2 100644
--- a/drivers/scsi/u14-34f.c
+++ b/drivers/scsi/u14-34f.c
@@ -450,7 +450,8 @@ static struct scsi_host_template driver_template = {
                 .slave_configure         = u14_34f_slave_configure,
                 .this_id                 = 7,
                 .unchecked_isa_dma       = 1,
-                .use_clustering          = ENABLE_CLUSTERING
+                .use_clustering          = ENABLE_CLUSTERING,
+                .use_sg_chaining         = ENABLE_SG_CHAINING,
                 };
 
 #if !defined(__BIG_ENDIAN_BITFIELD) && !defined(__LITTLE_ENDIAN_BITFIELD)
diff --git a/drivers/scsi/ultrastor.c b/drivers/scsi/ultrastor.c
index c08235d5afc9..ea72bbeb8f9d 100644
--- a/drivers/scsi/ultrastor.c
+++ b/drivers/scsi/ultrastor.c
@@ -1197,5 +1197,6 @@ static struct scsi_host_template driver_template = {
         .cmd_per_lun       = ULTRASTOR_MAX_CMDS_PER_LUN,
         .unchecked_isa_dma = 1,
         .use_clustering    = ENABLE_CLUSTERING,
+        .use_sg_chaining   = ENABLE_SG_CHAINING,
 };
 #include "scsi_module.c"
diff --git a/drivers/scsi/wd7000.c b/drivers/scsi/wd7000.c
index d6fd4259c56b..255c611e78b8 100644
--- a/drivers/scsi/wd7000.c
+++ b/drivers/scsi/wd7000.c
@@ -1671,6 +1671,7 @@ static struct scsi_host_template driver_template = {
         .cmd_per_lun            = 1,
         .unchecked_isa_dma      = 1,
         .use_clustering         = ENABLE_CLUSTERING,
+        .use_sg_chaining        = ENABLE_SG_CHAINING,
 };
 
 #include "scsi_module.c"
diff --git a/drivers/usb/storage/alauda.c b/drivers/usb/storage/alauda.c
index 4d3cbb12b713..8d3711a7ff06 100644
--- a/drivers/usb/storage/alauda.c
+++ b/drivers/usb/storage/alauda.c
@@ -798,12 +798,13 @@ static int alauda_read_data(struct us_data *us, unsigned long address,
 {
         unsigned char *buffer;
         u16 lba, max_lba;
-        unsigned int page, len, index, offset;
+        unsigned int page, len, offset;
         unsigned int blockshift = MEDIA_INFO(us).blockshift;
         unsigned int pageshift = MEDIA_INFO(us).pageshift;
         unsigned int blocksize = MEDIA_INFO(us).blocksize;
         unsigned int pagesize = MEDIA_INFO(us).pagesize;
         unsigned int uzonesize = MEDIA_INFO(us).uzonesize;
+        struct scatterlist *sg;
         int result;
 
         /*
@@ -827,7 +828,8 @@ static int alauda_read_data(struct us_data *us, unsigned long address,
         max_lba = MEDIA_INFO(us).capacity >> (blockshift + pageshift);
 
         result = USB_STOR_TRANSPORT_GOOD;
-        index = offset = 0;
+        offset = 0;
+        sg = NULL;
 
         while (sectors > 0) {
                 unsigned int zone = lba / uzonesize; /* integer division */
@@ -873,7 +875,7 @@ static int alauda_read_data(struct us_data *us, unsigned long address,
 
                 /* Store the data in the transfer buffer */
                 usb_stor_access_xfer_buf(buffer, len, us->srb,
-                                &index, &offset, TO_XFER_BUF);
+                                &sg, &offset, TO_XFER_BUF);
 
                 page = 0;
                 lba++;
@@ -891,11 +893,12 @@ static int alauda_write_data(struct us_data *us, unsigned long address,
                 unsigned int sectors)
 {
         unsigned char *buffer, *blockbuffer;
-        unsigned int page, len, index, offset;
+        unsigned int page, len, offset;
         unsigned int blockshift = MEDIA_INFO(us).blockshift;
         unsigned int pageshift = MEDIA_INFO(us).pageshift;
         unsigned int blocksize = MEDIA_INFO(us).blocksize;
         unsigned int pagesize = MEDIA_INFO(us).pagesize;
+        struct scatterlist *sg;
         u16 lba, max_lba;
         int result;
 
@@ -929,7 +932,8 @@ static int alauda_write_data(struct us_data *us, unsigned long address,
         max_lba = MEDIA_INFO(us).capacity >> (pageshift + blockshift);
 
         result = USB_STOR_TRANSPORT_GOOD;
-        index = offset = 0;
+        offset = 0;
+        sg = NULL;
 
         while (sectors > 0) {
                 /* Write as many sectors as possible in this block */
@@ -946,7 +950,7 @@ static int alauda_write_data(struct us_data *us, unsigned long address,
 
                 /* Get the data from the transfer buffer */
                 usb_stor_access_xfer_buf(buffer, len, us->srb,
-                                &index, &offset, FROM_XFER_BUF);
+                                &sg, &offset, FROM_XFER_BUF);
 
                 result = alauda_write_lba(us, lba, page, pages, buffer,
                         blockbuffer);
diff --git a/drivers/usb/storage/datafab.c b/drivers/usb/storage/datafab.c
index c87ad1bae1d6..579e9f52053a 100644
--- a/drivers/usb/storage/datafab.c
+++ b/drivers/usb/storage/datafab.c
@@ -98,7 +98,8 @@ static int datafab_read_data(struct us_data *us,
         unsigned char  thistime;
         unsigned int totallen, alloclen;
         int len, result;
-        unsigned int sg_idx = 0, sg_offset = 0;
+        unsigned int sg_offset = 0;
+        struct scatterlist *sg = NULL;
 
         // we're working in LBA mode.  according to the ATA spec, 
         // we can support up to 28-bit addressing.  I don't know if Datafab
@@ -155,7 +156,7 @@ static int datafab_read_data(struct us_data *us,
 
                 // Store the data in the transfer buffer
                 usb_stor_access_xfer_buf(buffer, len, us->srb,
-                                 &sg_idx, &sg_offset, TO_XFER_BUF);
+                                 &sg, &sg_offset, TO_XFER_BUF);
 
                 sector += thistime;
                 totallen -= len;
@@ -181,7 +182,8 @@ static int datafab_write_data(struct us_data *us,
         unsigned char thistime;
         unsigned int totallen, alloclen;
         int len, result;
-        unsigned int sg_idx = 0, sg_offset = 0;
+        unsigned int sg_offset = 0;
+        struct scatterlist *sg = NULL;
 
         // we're working in LBA mode.  according to the ATA spec, 
         // we can support up to 28-bit addressing.  I don't know if Datafab
@@ -217,7 +219,7 @@ static int datafab_write_data(struct us_data *us,
 
                 // Get the data from the transfer buffer
                 usb_stor_access_xfer_buf(buffer, len, us->srb,
-                                &sg_idx, &sg_offset, FROM_XFER_BUF);
+                                &sg, &sg_offset, FROM_XFER_BUF);
 
                 command[0] = 0;
                 command[1] = thistime;
diff --git a/drivers/usb/storage/jumpshot.c b/drivers/usb/storage/jumpshot.c
index 003fcf545888..61097cbb1585 100644
--- a/drivers/usb/storage/jumpshot.c
+++ b/drivers/usb/storage/jumpshot.c
@@ -119,7 +119,8 @@ static int jumpshot_read_data(struct us_data *us,
         unsigned char  thistime;
         unsigned int totallen, alloclen;
         int len, result;
-        unsigned int sg_idx = 0, sg_offset = 0;
+        unsigned int sg_offset = 0;
+        struct scatterlist *sg = NULL;
 
         // we're working in LBA mode.  according to the ATA spec, 
         // we can support up to 28-bit addressing.  I don't know if Jumpshot
@@ -170,7 +171,7 @@ static int jumpshot_read_data(struct us_data *us,
 
                 // Store the data in the transfer buffer
                 usb_stor_access_xfer_buf(buffer, len, us->srb,
-                                 &sg_idx, &sg_offset, TO_XFER_BUF);
+                                 &sg, &sg_offset, TO_XFER_BUF);
 
                 sector += thistime;
                 totallen -= len;
@@ -195,7 +196,8 @@ static int jumpshot_write_data(struct us_data *us,
         unsigned char  thistime;
         unsigned int totallen, alloclen;
         int len, result, waitcount;
-        unsigned int sg_idx = 0, sg_offset = 0;
+        unsigned int sg_offset = 0;
+        struct scatterlist *sg = NULL;
 
         // we're working in LBA mode.  according to the ATA spec, 
         // we can support up to 28-bit addressing.  I don't know if Jumpshot
@@ -225,7 +227,7 @@ static int jumpshot_write_data(struct us_data *us,
 
                 // Get the data from the transfer buffer
                 usb_stor_access_xfer_buf(buffer, len, us->srb,
-                                &sg_idx, &sg_offset, FROM_XFER_BUF);
+                                &sg, &sg_offset, FROM_XFER_BUF);
 
                 command[0] = 0;
                 command[1] = thistime;
diff --git a/drivers/usb/storage/protocol.c b/drivers/usb/storage/protocol.c
index 9ad30428d2dd..cc8f7c52c729 100644
--- a/drivers/usb/storage/protocol.c
+++ b/drivers/usb/storage/protocol.c
@@ -157,7 +157,7 @@ void usb_stor_transparent_scsi_command(struct scsi_cmnd *srb,
  * pick up from where this one left off. */
 
 unsigned int usb_stor_access_xfer_buf(unsigned char *buffer,
-        unsigned int buflen, struct scsi_cmnd *srb, unsigned int *index,
+        unsigned int buflen, struct scsi_cmnd *srb, struct scatterlist **sgptr,
         unsigned int *offset, enum xfer_buf_dir dir)
 {
         unsigned int cnt;
@@ -184,16 +184,17 @@ unsigned int usb_stor_access_xfer_buf(unsigned char *buffer,
          * located in high memory -- then kmap() will map it to a temporary
          * position in the kernel's virtual address space. */
         } else {
-                struct scatterlist *sg =
-                                (struct scatterlist *) srb->request_buffer
-                                + *index;
+                struct scatterlist *sg = *sgptr;
+
+                if (!sg)
+                        sg = (struct scatterlist *) srb->request_buffer;
 
                 /* This loop handles a single s-g list entry, which may
                  * include multiple pages.  Find the initial page structure
                  * and the starting offset within the page, and update
                  * the *offset and *index values for the next loop. */
                 cnt = 0;
-                while (cnt < buflen && *index < srb->use_sg) {
+                while (cnt < buflen) {
                         struct page *page = sg->page +
                                         ((sg->offset + *offset) >> PAGE_SHIFT);
                         unsigned int poff =
@@ -209,8 +210,7 @@ unsigned int usb_stor_access_xfer_buf(unsigned char *buffer,
 
                                 /* Transfer continues to next s-g entry */
                                 *offset = 0;
-                                ++*index;
-                                ++sg;
+                                sg = sg_next(sg);
                         }
 
                         /* Transfer the data for all the pages in this
@@ -234,6 +234,7 @@ unsigned int usb_stor_access_xfer_buf(unsigned char *buffer,
                                 sglen -= plen;
                         }
                 }
+                *sgptr = sg;
         }
 
         /* Return the amount actually transferred */
@@ -245,9 +246,10 @@ unsigned int usb_stor_access_xfer_buf(unsigned char *buffer,
 void usb_stor_set_xfer_buf(unsigned char *buffer,
         unsigned int buflen, struct scsi_cmnd *srb)
 {
-        unsigned int index = 0, offset = 0;
+        unsigned int offset = 0;
+        struct scatterlist *sg = NULL;
 
-        usb_stor_access_xfer_buf(buffer, buflen, srb, &index, &offset,
+        usb_stor_access_xfer_buf(buffer, buflen, srb, &sg, &offset,
                         TO_XFER_BUF);
         if (buflen < srb->request_bufflen)
                 srb->resid = srb->request_bufflen - buflen;
diff --git a/drivers/usb/storage/protocol.h b/drivers/usb/storage/protocol.h
index 845bed4b8031..8737a36891ca 100644
--- a/drivers/usb/storage/protocol.h
+++ b/drivers/usb/storage/protocol.h
@@ -52,7 +52,7 @@ extern void usb_stor_transparent_scsi_command(struct scsi_cmnd*,
 enum xfer_buf_dir       {TO_XFER_BUF, FROM_XFER_BUF};
 
 extern unsigned int usb_stor_access_xfer_buf(unsigned char *buffer,
-        unsigned int buflen, struct scsi_cmnd *srb, unsigned int *index,
+        unsigned int buflen, struct scsi_cmnd *srb, struct scatterlist **,
         unsigned int *offset, enum xfer_buf_dir dir);
 
 extern void usb_stor_set_xfer_buf(unsigned char *buffer,
diff --git a/drivers/usb/storage/sddr09.c b/drivers/usb/storage/sddr09.c
index b2ed2a3e6fca..b12202c5da2d 100644
--- a/drivers/usb/storage/sddr09.c
+++ b/drivers/usb/storage/sddr09.c
@@ -705,7 +705,8 @@ sddr09_read_data(struct us_data *us,
         unsigned char *buffer;
         unsigned int lba, maxlba, pba;
         unsigned int page, pages;
-        unsigned int len, index, offset;
+        unsigned int len, offset;
+        struct scatterlist *sg;
         int result;
 
         // Figure out the initial LBA and page
@@ -730,7 +731,8 @@ sddr09_read_data(struct us_data *us,
         // contiguous LBA's. Another exercise left to the student.
 
         result = 0;
-        index = offset = 0;
+        offset = 0;
+        sg = NULL;
 
         while (sectors > 0) {
 
@@ -777,7 +779,7 @@ sddr09_read_data(struct us_data *us,
 
                 // Store the data in the transfer buffer
                 usb_stor_access_xfer_buf(buffer, len, us->srb,
-                                &index, &offset, TO_XFER_BUF);
+                                &sg, &offset, TO_XFER_BUF);
 
                 page = 0;
                 lba++;
@@ -931,7 +933,8 @@ sddr09_write_data(struct us_data *us,
         unsigned int pagelen, blocklen;
         unsigned char *blockbuffer;
         unsigned char *buffer;
-        unsigned int len, index, offset;
+        unsigned int len, offset;
+        struct scatterlist *sg;
         int result;
 
         // Figure out the initial LBA and page
@@ -968,7 +971,8 @@ sddr09_write_data(struct us_data *us,
         }
 
         result = 0;
-        index = offset = 0;
+        offset = 0;
+        sg = NULL;
 
         while (sectors > 0) {
 
@@ -987,7 +991,7 @@ sddr09_write_data(struct us_data *us,
 
                 // Get the data from the transfer buffer
                 usb_stor_access_xfer_buf(buffer, len, us->srb,
-                                &index, &offset, FROM_XFER_BUF);
+                                &sg, &offset, FROM_XFER_BUF);
 
                 result = sddr09_write_lba(us, lba, page, pages,
                                 buffer, blockbuffer);
diff --git a/drivers/usb/storage/sddr55.c b/drivers/usb/storage/sddr55.c
index 0b1b5b59ca7b..d43a3415e12f 100644
--- a/drivers/usb/storage/sddr55.c
+++ b/drivers/usb/storage/sddr55.c
@@ -167,7 +167,8 @@ static int sddr55_read_data(struct us_data *us,
         unsigned long address;
 
         unsigned short pages;
-        unsigned int len, index, offset;
+        unsigned int len, offset;
+        struct scatterlist *sg;
 
         // Since we only read in one block at a time, we have to create
         // a bounce buffer and move the data a piece at a time between the
@@ -178,7 +179,8 @@ static int sddr55_read_data(struct us_data *us,
         buffer = kmalloc(len, GFP_NOIO);
         if (buffer == NULL)
                 return USB_STOR_TRANSPORT_ERROR; /* out of memory */
-        index = offset = 0;
+        offset = 0;
+        sg = NULL;
 
         while (sectors>0) {
 
@@ -255,7 +257,7 @@ static int sddr55_read_data(struct us_data *us,
 
                 // Store the data in the transfer buffer
                 usb_stor_access_xfer_buf(buffer, len, us->srb,
-                                &index, &offset, TO_XFER_BUF);
+                                &sg, &offset, TO_XFER_BUF);
 
                 page = 0;
                 lba++;
@@ -287,7 +289,8 @@ static int sddr55_write_data(struct us_data *us,
 
         unsigned short pages;
         int i;
-        unsigned int len, index, offset;
+        unsigned int len, offset;
+        struct scatterlist *sg;
 
         /* check if we are allowed to write */
         if (info->read_only || info->force_read_only) {
@@ -304,7 +307,8 @@ static int sddr55_write_data(struct us_data *us,
         buffer = kmalloc(len, GFP_NOIO);
         if (buffer == NULL)
                 return USB_STOR_TRANSPORT_ERROR;
-        index = offset = 0;
+        offset = 0;
+        sg = NULL;
 
         while (sectors > 0) {
 
@@ -322,7 +326,7 @@ static int sddr55_write_data(struct us_data *us,
 
                 // Get the data from the transfer buffer
                 usb_stor_access_xfer_buf(buffer, len, us->srb,
-                                &index, &offset, FROM_XFER_BUF);
+                                &sg, &offset, FROM_XFER_BUF);
 
                 US_DEBUGP("Write %02X pages, to PBA %04X"
                         " (LBA %04X) page %02X\n",
diff --git a/drivers/usb/storage/shuttle_usbat.c b/drivers/usb/storage/shuttle_usbat.c
index 17ca4d73577b..cb22a9ad1694 100644
--- a/drivers/usb/storage/shuttle_usbat.c
+++ b/drivers/usb/storage/shuttle_usbat.c
@@ -993,7 +993,8 @@ static int usbat_flash_read_data(struct us_data *us,
         unsigned char  thistime;
         unsigned int totallen, alloclen;
         int len, result;
-        unsigned int sg_idx = 0, sg_offset = 0;
+        unsigned int sg_offset = 0;
+        struct scatterlist *sg = NULL;
 
         result = usbat_flash_check_media(us, info);
         if (result != USB_STOR_TRANSPORT_GOOD)
@@ -1047,7 +1048,7 @@ static int usbat_flash_read_data(struct us_data *us,
         
                 /* Store the data in the transfer buffer */
                 usb_stor_access_xfer_buf(buffer, len, us->srb,
-                                         &sg_idx, &sg_offset, TO_XFER_BUF);
+                                         &sg, &sg_offset, TO_XFER_BUF);
 
                 sector += thistime;
                 totallen -= len;
@@ -1083,7 +1084,8 @@ static int usbat_flash_write_data(struct us_data *us,
         unsigned char  thistime;
         unsigned int totallen, alloclen;
         int len, result;
-        unsigned int sg_idx = 0, sg_offset = 0;
+        unsigned int sg_offset = 0;
+        struct scatterlist *sg = NULL;
 
         result = usbat_flash_check_media(us, info);
         if (result != USB_STOR_TRANSPORT_GOOD)
@@ -1122,7 +1124,7 @@ static int usbat_flash_write_data(struct us_data *us,
 
                 /* Get the data from the transfer buffer */
                 usb_stor_access_xfer_buf(buffer, len, us->srb,
-                                         &sg_idx, &sg_offset, FROM_XFER_BUF);
+                                         &sg, &sg_offset, FROM_XFER_BUF);
 
                 /* ATA command 0x30 (WRITE SECTORS) */
                 usbat_pack_ata_sector_cmd(command, thistime, sector, 0x30);
@@ -1162,8 +1164,8 @@ static int usbat_hp8200e_handle_read10(struct us_data *us,
         unsigned char *buffer;
         unsigned int len;
         unsigned int sector;
-        unsigned int sg_segment = 0;
         unsigned int sg_offset = 0;
+        struct scatterlist *sg = NULL;
 
         US_DEBUGP("handle_read10: transfersize %d\n",
                 srb->transfersize);
@@ -1220,9 +1222,6 @@ static int usbat_hp8200e_handle_read10(struct us_data *us,
         sector |= short_pack(data[7+5], data[7+4]);
         transferred = 0;
 
-        sg_segment = 0; /* for keeping track of where we are in */
-        sg_offset = 0;  /* the scatter/gather list */
-
         while (transferred != srb->request_bufflen) {
 
                 if (len > srb->request_bufflen - transferred)
@@ -1255,7 +1254,7 @@ static int usbat_hp8200e_handle_read10(struct us_data *us,
 
                 /* Store the data in the transfer buffer */
                 usb_stor_access_xfer_buf(buffer, len, srb,
-                                 &sg_segment, &sg_offset, TO_XFER_BUF);
+                                 &sg, &sg_offset, TO_XFER_BUF);
 
                 /* Update the amount transferred and the sector number */
 
diff --git a/include/asm-ia64/dma-mapping.h b/include/asm-ia64/dma-mapping.h
index 3ca6d5c14b2e..f1735a22d0ea 100644
--- a/include/asm-ia64/dma-mapping.h
+++ b/include/asm-ia64/dma-mapping.h
@@ -6,7 +6,7 @@
  *      David Mosberger-Tang <davidm@hpl.hp.com>
  */
 #include <asm/machvec.h>
-#include <asm/scatterlist.h>
+#include <linux/scatterlist.h>
 
 #define dma_alloc_coherent      platform_dma_alloc_coherent
 /* coherent mem. is cheap */
diff --git a/include/asm-ia64/scatterlist.h b/include/asm-ia64/scatterlist.h
index a452ea24205a..7d5234d50312 100644
--- a/include/asm-ia64/scatterlist.h
+++ b/include/asm-ia64/scatterlist.h
@@ -30,4 +30,6 @@ struct scatterlist {
 #define sg_dma_len(sg)          ((sg)->dma_length)
 #define sg_dma_address(sg)      ((sg)->dma_address)
 
+#define ARCH_HAS_SG_CHAIN
+
 #endif /* _ASM_IA64_SCATTERLIST_H */
diff --git a/include/asm-powerpc/dma-mapping.h b/include/asm-powerpc/dma-mapping.h
index d05891608f74..2af321f36aba 100644
--- a/include/asm-powerpc/dma-mapping.h
+++ b/include/asm-powerpc/dma-mapping.h
@@ -6,149 +6,6 @@
  */
 #ifndef _ASM_DMA_MAPPING_H
 #define _ASM_DMA_MAPPING_H
-#ifdef __KERNEL__
-
-#include <linux/types.h>
-#include <linux/cache.h>
-/* need struct page definitions */
-#include <linux/mm.h>
-#include <asm/scatterlist.h>
-#include <asm/io.h>
-
-#define DMA_ERROR_CODE          (~(dma_addr_t)0x0)
-
-#ifdef CONFIG_NOT_COHERENT_CACHE
-/*
- * DMA-consistent mapping functions for PowerPCs that don't support
- * cache snooping.  These allocate/free a region of uncached mapped
- * memory space for use with DMA devices.  Alternatively, you could
- * allocate the space "normally" and use the cache management functions
- * to ensure it is consistent.
- */
-extern void *__dma_alloc_coherent(size_t size, dma_addr_t *handle, gfp_t gfp);
-extern void __dma_free_coherent(size_t size, void *vaddr);
-extern void __dma_sync(void *vaddr, size_t size, int direction);
-extern void __dma_sync_page(struct page *page, unsigned long offset,
-                                 size_t size, int direction);
-
-#else /* ! CONFIG_NOT_COHERENT_CACHE */
-/*
- * Cache coherent cores.
- */
-
-#define __dma_alloc_coherent(gfp, size, handle) NULL
-#define __dma_free_coherent(size, addr)         ((void)0)
-#define __dma_sync(addr, size, rw)              ((void)0)
-#define __dma_sync_page(pg, off, sz, rw)        ((void)0)
-
-#endif /* ! CONFIG_NOT_COHERENT_CACHE */
-
-#ifdef CONFIG_PPC64
-/*
- * DMA operations are abstracted for G5 vs. i/pSeries, PCI vs. VIO
- */
-struct dma_mapping_ops {
-        void *          (*alloc_coherent)(struct device *dev, size_t size,
-                                dma_addr_t *dma_handle, gfp_t flag);
-        void            (*free_coherent)(struct device *dev, size_t size,
-                                void *vaddr, dma_addr_t dma_handle);
-        dma_addr_t      (*map_single)(struct device *dev, void *ptr,
-                                size_t size, enum dma_data_direction direction);
-        void            (*unmap_single)(struct device *dev, dma_addr_t dma_addr,
-                                size_t size, enum dma_data_direction direction);
-        int             (*map_sg)(struct device *dev, struct scatterlist *sg,
-                                int nents, enum dma_data_direction direction);
-        void            (*unmap_sg)(struct device *dev, struct scatterlist *sg,
-                                int nents, enum dma_data_direction direction);
-        int             (*dma_supported)(struct device *dev, u64 mask);
-        int             (*set_dma_mask)(struct device *dev, u64 dma_mask);
-};
-
-static inline struct dma_mapping_ops *get_dma_ops(struct device *dev)
-{
-        /* We don't handle the NULL dev case for ISA for now. We could
-         * do it via an out of line call but it is not needed for now. The
-         * only ISA DMA device we support is the floppy and we have a hack
-         * in the floppy driver directly to get a device for us.
-         */
-        if (unlikely(dev == NULL || dev->archdata.dma_ops == NULL))
-                return NULL;
-        return dev->archdata.dma_ops;
-}
-
-static inline int dma_supported(struct device *dev, u64 mask)
-{
-        struct dma_mapping_ops *dma_ops = get_dma_ops(dev);
-
-        if (unlikely(dma_ops == NULL))
-                return 0;
-        if (dma_ops->dma_supported == NULL)
-                return 1;
-        return dma_ops->dma_supported(dev, mask);
-}
-
-static inline int dma_set_mask(struct device *dev, u64 dma_mask)
-{
-        struct dma_mapping_ops *dma_ops = get_dma_ops(dev);
-
-        if (unlikely(dma_ops == NULL))
-                return -EIO;
-        if (dma_ops->set_dma_mask != NULL)
-                return dma_ops->set_dma_mask(dev, dma_mask);
-        if (!dev->dma_mask || !dma_supported(dev, dma_mask))
-                return -EIO;
-        *dev->dma_mask = dma_mask;
-        return 0;
-}
-
-static inline void *dma_alloc_coherent(struct device *dev, size_t size,
-                                       dma_addr_t *dma_handle, gfp_t flag)
-{
-        struct dma_mapping_ops *dma_ops = get_dma_ops(dev);
-
-        BUG_ON(!dma_ops);
-        return dma_ops->alloc_coherent(dev, size, dma_handle, flag);
-}
-
-static inline void dma_free_coherent(struct device *dev, size_t size,
-                                     void *cpu_addr, dma_addr_t dma_handle)
-{
-        struct dma_mapping_ops *dma_ops = get_dma_ops(dev);
-
-        BUG_ON(!dma_ops);
-        dma_ops->free_coherent(dev, size, cpu_addr, dma_handle);
-}
-
-static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr,
-                                        size_t size,
-                                        enum dma_data_direction direction)
-{
-        struct dma_mapping_ops *dma_ops = get_dma_ops(dev);
-
-        BUG_ON(!dma_ops);
-        return dma_ops->map_single(dev, cpu_addr, size, direction);
-}
-
-static inline void dma_unmap_single(struct device *dev, dma_addr_t dma_addr,
-                                    size_t size,
-                                    enum dma_data_direction direction)
-{
-        struct dma_mapping_ops *dma_ops = get_dma_ops(dev);
-
-        BUG_ON(!dma_ops);
-        dma_ops->unmap_single(dev, dma_addr, size, direction);
-}
-
-static inline dma_addr_t dma_map_page(struct device *dev, struct page *page,
-                                      unsigned long offset, size_t size,
-                                      enum dma_data_direction direction)
-{
-        struct dma_mapping_ops *dma_ops = get_dma_ops(dev);
-
-        BUG_ON(!dma_ops);
-        return dma_ops->map_single(dev, page_address(page) + offset, size,
-                        direction);
-}
 
 static inline void dma_unmap_page(struct device *dev, dma_addr_t dma_address,
                                   size_t size,
@@ -276,14 +133,15 @@ static inline void dma_unmap_page(struct device *dev, dma_addr_t dma_address,
 }
 
 static inline int
-dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
+dma_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
            enum dma_data_direction direction)
 {
+        struct scatterlist *sg;
         int i;
 
         BUG_ON(direction == DMA_NONE);
 
-        for (i = 0; i < nents; i++, sg++) {
+        for_each_sg(sgl, sg, nents, i) {
                 BUG_ON(!sg->page);
                 __dma_sync_page(sg->page, sg->offset, sg->length, direction);
                 sg->dma_address = page_to_bus(sg->page) + sg->offset;
@@ -318,26 +176,28 @@ static inline void dma_sync_single_for_device(struct device *dev,
 }
 
 static inline void dma_sync_sg_for_cpu(struct device *dev,
-                struct scatterlist *sg, int nents,
+                struct scatterlist *sgl, int nents,
                 enum dma_data_direction direction)
 {
+        struct scatterlist *sg;
         int i;
 
         BUG_ON(direction == DMA_NONE);
 
-        for (i = 0; i < nents; i++, sg++)
+        for_each_sg(sgl, sg, nents, i)
                 __dma_sync_page(sg->page, sg->offset, sg->length, direction);
 }
 
 static inline void dma_sync_sg_for_device(struct device *dev,
-                struct scatterlist *sg, int nents,
+                struct scatterlist *sgl, int nents,
                 enum dma_data_direction direction)
 {
+        struct scatterlist *sg;
         int i;
 
         BUG_ON(direction == DMA_NONE);
 
-        for (i = 0; i < nents; i++, sg++)
+        for_each_sg(sgl, sg, nents, i)
                 __dma_sync_page(sg->page, sg->offset, sg->length, direction);
 }
 
diff --git a/include/asm-powerpc/scatterlist.h b/include/asm-powerpc/scatterlist.h
index 8c992d1491d4..b075f619c3b7 100644
--- a/include/asm-powerpc/scatterlist.h
+++ b/include/asm-powerpc/scatterlist.h
@@ -41,5 +41,7 @@ struct scatterlist {
 #define ISA_DMA_THRESHOLD       (~0UL)
 #endif
 
+#define ARCH_HAS_SG_CHAIN
+
 #endif /* __KERNEL__ */
 #endif /* _ASM_POWERPC_SCATTERLIST_H */
diff --git a/include/asm-sparc/scatterlist.h b/include/asm-sparc/scatterlist.h
index a4fcf9ac9649..4055af90ad7e 100644
--- a/include/asm-sparc/scatterlist.h
+++ b/include/asm-sparc/scatterlist.h
@@ -19,4 +19,6 @@ struct scatterlist {
 
 #define ISA_DMA_THRESHOLD (~0UL)
 
+#define ARCH_HAS_SG_CHAIN
+
 #endif /* !(_SPARC_SCATTERLIST_H) */
diff --git a/include/asm-sparc64/scatterlist.h b/include/asm-sparc64/scatterlist.h
index 048fdb40e81d..703c5bbe6c8c 100644
--- a/include/asm-sparc64/scatterlist.h
+++ b/include/asm-sparc64/scatterlist.h
@@ -20,4 +20,6 @@ struct scatterlist {
 
 #define ISA_DMA_THRESHOLD       (~0UL)
 
+#define ARCH_HAS_SG_CHAIN
+
 #endif /* !(_SPARC64_SCATTERLIST_H) */
diff --git a/include/asm-x86/dma-mapping_32.h b/include/asm-x86/dma-mapping_32.h
index f1d72d177f68..6a2d26cb5da6 100644
--- a/include/asm-x86/dma-mapping_32.h
+++ b/include/asm-x86/dma-mapping_32.h
@@ -2,10 +2,10 @@
 #define _ASM_I386_DMA_MAPPING_H
 
 #include <linux/mm.h>
+#include <linux/scatterlist.h>
 
 #include <asm/cache.h>
 #include <asm/io.h>
-#include <asm/scatterlist.h>
 #include <asm/bug.h>
 
 #define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
@@ -35,18 +35,19 @@ dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
 }
 
 static inline int
-dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
+dma_map_sg(struct device *dev, struct scatterlist *sglist, int nents,
            enum dma_data_direction direction)
 {
+        struct scatterlist *sg;
         int i;
 
         BUG_ON(!valid_dma_direction(direction));
-        WARN_ON(nents == 0 || sg[0].length == 0);
+        WARN_ON(nents == 0 || sglist[0].length == 0);
 
-        for (i = 0; i < nents; i++ ) {
-                BUG_ON(!sg[i].page);
+        for_each_sg(sglist, sg, nents, i) {
+                BUG_ON(!sg->page);
 
-                sg[i].dma_address = page_to_phys(sg[i].page) + sg[i].offset;
+                sg->dma_address = page_to_phys(sg->page) + sg->offset;
         }
 
         flush_write_buffers();
diff --git a/include/asm-x86/dma-mapping_64.h b/include/asm-x86/dma-mapping_64.h
index 6897e2a436e5..ecd0f6125ba3 100644
--- a/include/asm-x86/dma-mapping_64.h
+++ b/include/asm-x86/dma-mapping_64.h
@@ -6,8 +6,7 @@
  * documentation.
  */
 
-
-#include <asm/scatterlist.h>
+#include <linux/scatterlist.h>
 #include <asm/io.h>
 #include <asm/swiotlb.h>
 
diff --git a/include/asm-x86/scatterlist_32.h b/include/asm-x86/scatterlist_32.h
index d7e45a8f1aae..bd5164aa8f63 100644
--- a/include/asm-x86/scatterlist_32.h
+++ b/include/asm-x86/scatterlist_32.h
@@ -10,6 +10,8 @@ struct scatterlist {
     unsigned int        length;
 };
 
+#define ARCH_HAS_SG_CHAIN
+
 /* These macros should be used after a pci_map_sg call has been done
  * to get bus addresses of each of the SG entries and their lengths.
  * You should only work with the number of sg entries pci_map_sg
diff --git a/include/asm-x86/scatterlist_64.h b/include/asm-x86/scatterlist_64.h
index eaf7ada27e14..ef3986ba4b79 100644
--- a/include/asm-x86/scatterlist_64.h
+++ b/include/asm-x86/scatterlist_64.h
@@ -11,6 +11,8 @@ struct scatterlist {
     unsigned int        dma_length;
 };
 
+#define ARCH_HAS_SG_CHAIN
+
 #define ISA_DMA_THRESHOLD (0x00ffffff)
 
 /* These macros should be used after a pci_map_sg call has been done
diff --git a/include/linux/i2o.h b/include/linux/i2o.h
index 9752307d16ba..7da5b98d90e6 100644
--- a/include/linux/i2o.h
+++ b/include/linux/i2o.h
@@ -32,6 +32,7 @@
 #include <linux/workqueue.h>    /* work_struct */
 #include <linux/mempool.h>
 #include <linux/mutex.h>
+#include <linux/scatterlist.h>
 
 #include <asm/io.h>
 #include <asm/semaphore.h>      /* Needed for MUTEX init macros */
@@ -837,7 +838,7 @@ static inline int i2o_dma_map_sg(struct i2o_controller *c,
                 if ((sizeof(dma_addr_t) > 4) && c->pae_support)
                         *mptr++ = cpu_to_le32(i2o_dma_high(sg_dma_address(sg)));
 #endif
-                sg++;
+                sg = sg_next(sg);
         }
         *sg_ptr = mptr;
 
diff --git a/include/linux/ide.h b/include/linux/ide.h
index 234fa3df24f6..30a1931466a6 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -772,7 +772,7 @@ typedef struct hwif_s {
 
         unsigned int nsect;
         unsigned int nleft;
-        unsigned int cursg;
+        struct scatterlist *cursg;
         unsigned int cursg_ofs;
 
         int             rqsize;         /* max sectors per request */
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 229a9ff9f924..377e6d4d9be3 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -29,7 +29,7 @@
 #include <linux/delay.h>
 #include <linux/interrupt.h>
 #include <linux/dma-mapping.h>
-#include <asm/scatterlist.h>
+#include <linux/scatterlist.h>
 #include <linux/io.h>
 #include <linux/ata.h>
 #include <linux/workqueue.h>
@@ -416,6 +416,7 @@ struct ata_queued_cmd {
         unsigned long           flags;          /* ATA_QCFLAG_xxx */
         unsigned int            tag;
         unsigned int            n_elem;
+        unsigned int            n_iter;
         unsigned int            orig_n_elem;
 
         int                     dma_dir;
@@ -426,7 +427,7 @@ struct ata_queued_cmd {
         unsigned int            nbytes;
         unsigned int            curbytes;
 
-        unsigned int            cursg;
+        struct scatterlist      *cursg;
         unsigned int            cursg_ofs;
 
         struct scatterlist      sgent;
@@ -1043,7 +1044,7 @@ ata_sg_is_last(struct scatterlist *sg, struct ata_queued_cmd *qc)
                 return 1;
         if (qc->pad_len)
                 return 0;
-        if (((sg - qc->__sg) + 1) == qc->n_elem)
+        if (qc->n_iter == qc->n_elem)
                 return 1;
         return 0;
 }
@@ -1051,6 +1052,7 @@ ata_sg_is_last(struct scatterlist *sg, struct ata_queued_cmd *qc)
 static inline struct scatterlist *
 ata_qc_first_sg(struct ata_queued_cmd *qc)
 {
+        qc->n_iter = 0;
         if (qc->n_elem)
                 return qc->__sg;
         if (qc->pad_len)
@@ -1063,8 +1065,8 @@ ata_qc_next_sg(struct scatterlist *sg, struct ata_queued_cmd *qc)
 {
         if (sg == &qc->pad_sgent)
                 return NULL;
-        if (++sg - qc->__sg < qc->n_elem)
-                return sg;
+        if (++qc->n_iter < qc->n_elem)
+                return sg_next(sg);
         if (qc->pad_len)
                 return &qc->pad_sgent;
         return NULL;
@@ -1309,9 +1311,11 @@ static inline void ata_qc_reinit(struct ata_queued_cmd *qc)
         qc->dma_dir = DMA_NONE;
         qc->__sg = NULL;
         qc->flags = 0;
-        qc->cursg = qc->cursg_ofs = 0;
+        qc->cursg = NULL;
+        qc->cursg_ofs = 0;
         qc->nbytes = qc->curbytes = 0;
         qc->n_elem = 0;
+        qc->n_iter = 0;
         qc->err_mask = 0;
         qc->pad_len = 0;
         qc->sect_size = ATA_SECT_SIZE;
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index 4efbd9c445f5..2dc7464cce52 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -20,4 +20,88 @@ static inline void sg_init_one(struct scatterlist *sg, const void *buf,
         sg_set_buf(sg, buf, buflen);
 }
 
+/*
+ * We overload the LSB of the page pointer to indicate whether it's
+ * a valid sg entry, or whether it points to the start of a new scatterlist.
+ * Those low bits are there for everyone! (thanks mason :-)
+ */
+#define sg_is_chain(sg)         ((unsigned long) (sg)->page & 0x01)
+#define sg_chain_ptr(sg)        \
+        ((struct scatterlist *) ((unsigned long) (sg)->page & ~0x01))
+
+/**
+ * sg_next - return the next scatterlist entry in a list
+ * @sg:         The current sg entry
+ *
+ * Usually the next entry will be @sg@ + 1, but if this sg element is part
+ * of a chained scatterlist, it could jump to the start of a new
+ * scatterlist array.
+ *
+ * Note that the caller must ensure that there are further entries after
+ * the current entry, this function will NOT return NULL for an end-of-list.
+ *
+ */
+static inline struct scatterlist *sg_next(struct scatterlist *sg)
+{
+        sg++;
+
+        if (unlikely(sg_is_chain(sg)))
+                sg = sg_chain_ptr(sg);
+
+        return sg;
+}
+
+/*
+ * Loop over each sg element, following the pointer to a new list if necessary
+ */
+#define for_each_sg(sglist, sg, nr, __i)        \
+        for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))
+
+/**
+ * sg_last - return the last scatterlist entry in a list
+ * @sgl:        First entry in the scatterlist
+ * @nents:      Number of entries in the scatterlist
+ *
+ * Should only be used casually, it (currently) scan the entire list
+ * to get the last entry.
+ *
+ * Note that the @sgl@ pointer passed in need not be the first one,
+ * the important bit is that @nents@ denotes the number of entries that
+ * exist from @sgl@.
+ *
+ */
+static inline struct scatterlist *sg_last(struct scatterlist *sgl,
+                                          unsigned int nents)
+{
+#ifndef ARCH_HAS_SG_CHAIN
+        struct scatterlist *ret = &sgl[nents - 1];
+#else
+        struct scatterlist *sg, *ret = NULL;
+        int i;
+
+        for_each_sg(sgl, sg, nents, i)
+                ret = sg;
+
+#endif
+        return ret;
+}
+
+/**
+ * sg_chain - Chain two sglists together
+ * @prv:        First scatterlist
+ * @prv_nents:  Number of entries in prv
+ * @sgl:        Second scatterlist
+ *
+ * Links @prv@ and @sgl@ together, to form a longer scatterlist.
+ *
+ */
+static inline void sg_chain(struct scatterlist *prv, unsigned int prv_nents,
+                            struct scatterlist *sgl)
+{
+#ifndef ARCH_HAS_SG_CHAIN
+        BUG();
+#endif
+        prv[prv_nents - 1].page = (struct page *) ((unsigned long) sgl | 0x01);
+}
+
 #endif /* _LINUX_SCATTERLIST_H */
diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h
index 9f8f80ab0c8b..702fcfeb37f1 100644
--- a/include/scsi/scsi.h
+++ b/include/scsi/scsi.h
@@ -11,13 +11,6 @@
 #include <linux/types.h>
 
 /*
- *      The maximum sg list length SCSI can cope with
- *      (currently must be a power of 2 between 32 and 256)
- */
-#define SCSI_MAX_PHYS_SEGMENTS  MAX_PHYS_SEGMENTS
-
-
-/*
  *      SCSI command lengths
  */
 
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index 65ab5145a09b..3f47e522a1ec 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -5,6 +5,7 @@
 #include <linux/list.h>
 #include <linux/types.h>
 #include <linux/timer.h>
+#include <linux/scatterlist.h>
 
 struct request;
 struct scatterlist;
@@ -68,7 +69,7 @@ struct scsi_cmnd {
 
         /* These elements define the operation we ultimately want to perform */
         unsigned short use_sg;  /* Number of pieces of scatter-gather */
-        unsigned short sglist_len;      /* size of malloc'd scatter-gather list */
+        unsigned short __use_sg;
 
         unsigned underflow;     /* Return error if less than
                                    this amount is transferred */
@@ -128,7 +129,7 @@ extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
 extern void scsi_kunmap_atomic_sg(void *virt);
 
 extern struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *, gfp_t);
-extern void scsi_free_sgtable(struct scatterlist *, int);
+extern void scsi_free_sgtable(struct scsi_cmnd *);
 
 extern int scsi_dma_map(struct scsi_cmnd *cmd);
 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
@@ -148,6 +149,6 @@ static inline int scsi_get_resid(struct scsi_cmnd *cmd)
 }
 
 #define scsi_for_each_sg(cmd, sg, nseg, __i)                    \
-        for (__i = 0, sg = scsi_sglist(cmd); __i < (nseg); __i++, (sg)++)
+        for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
 
 #endif /* _SCSI_SCSI_CMND_H */
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 7d210cd6c38d..0fd4746ee39d 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -39,6 +39,9 @@ struct blk_queue_tags;
 #define DISABLE_CLUSTERING 0
 #define ENABLE_CLUSTERING 1
 
+#define DISABLE_SG_CHAINING 0
+#define ENABLE_SG_CHAINING 1
+
 enum scsi_eh_timer_return {
         EH_NOT_HANDLED,
         EH_HANDLED,
@@ -443,6 +446,15 @@ struct scsi_host_template {
         unsigned ordered_tag:1;
 
         /*
+         * true if the low-level driver can support sg chaining. this
+         * will be removed eventually when all the drivers are
+         * converted to support sg chaining.
+         *
+         * Status: OBSOLETE
+         */
+        unsigned use_sg_chaining:1;
+
+        /*
          * Countdown for host blocking with no commands outstanding
          */
         unsigned int max_host_blocked;
@@ -586,6 +598,7 @@ struct Scsi_Host {
         unsigned unchecked_isa_dma:1;
         unsigned use_clustering:1;
         unsigned use_blk_tcq:1;
+        unsigned use_sg_chaining:1;
 
         /*
          * Host has requested that no further requests come through for the
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 30c1400e749e..c419ecf334c3 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -677,16 +677,17 @@ swiotlb_sync_single_range_for_device(struct device *hwdev, dma_addr_t dev_addr,
  * same here.
  */
 int
-swiotlb_map_sg(struct device *hwdev, struct scatterlist *sg, int nelems,
+swiotlb_map_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
                int dir)
 {
+        struct scatterlist *sg;
         void *addr;
         dma_addr_t dev_addr;
         int i;
 
         BUG_ON(dir == DMA_NONE);
 
-        for (i = 0; i < nelems; i++, sg++) {
+        for_each_sg(sgl, sg, nelems, i) {
                 addr = SG_ENT_VIRT_ADDRESS(sg);
                 dev_addr = virt_to_bus(addr);
                 if (swiotlb_force || address_needs_mapping(hwdev, dev_addr)) {
@@ -696,7 +697,7 @@ swiotlb_map_sg(struct device *hwdev, struct scatterlist *sg, int nelems,
                                    to do proper error handling. */
                                 swiotlb_full(hwdev, sg->length, dir, 0);
                                 swiotlb_unmap_sg(hwdev, sg - i, i, dir);
-                                sg[0].dma_length = 0;
+                                sgl[0].dma_length = 0;
                                 return 0;
                         }
                         sg->dma_address = virt_to_bus(map);
@@ -712,19 +713,21 @@ swiotlb_map_sg(struct device *hwdev, struct scatterlist *sg, int nelems,
  * concerning calls here are the same as for swiotlb_unmap_single() above.
  */
 void
-swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sg, int nelems,
+swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
                  int dir)
 {
+        struct scatterlist *sg;
         int i;
 
         BUG_ON(dir == DMA_NONE);
 
-        for (i = 0; i < nelems; i++, sg++)
+        for_each_sg(sgl, sg, nelems, i) {
                 if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg))
                         unmap_single(hwdev, bus_to_virt(sg->dma_address),
                                      sg->dma_length, dir);
                 else if (dir == DMA_FROM_DEVICE)
                         dma_mark_clean(SG_ENT_VIRT_ADDRESS(sg), sg->dma_length);
+        }
 }
 
 /*
@@ -735,19 +738,21 @@ swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sg, int nelems,
  * and usage.
  */
 static void
-swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sg,
+swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl,
                 int nelems, int dir, int target)
 {
+        struct scatterlist *sg;
         int i;
 
         BUG_ON(dir == DMA_NONE);
 
-        for (i = 0; i < nelems; i++, sg++)
+        for_each_sg(sgl, sg, nelems, i) {
                 if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg))
                         sync_single(hwdev, bus_to_virt(sg->dma_address),
                                     sg->dma_length, dir, target);
                 else if (dir == DMA_FROM_DEVICE)
                         dma_mark_clean(SG_ENT_VIRT_ADDRESS(sg), sg->dma_length);
+        }
 }
 
 void