Merge branch 'for-linus' of git://git.kernel.dk/data/git/linux-2.6-block

* 'for-linus' of git://git.kernel.dk/data/git/linux-2.6-block: (63 commits)
  Fix memory leak in dm-crypt
  SPARC64: sg chaining support
  SPARC: sg chaining support
  PPC: sg chaining support
  PS3: sg chaining support
  IA64: sg chaining support
  x86-64: enable sg chaining
  x86-64: update pci-gart iommu to sg helpers
  x86-64: update nommu to sg helpers
  x86-64: update calgary iommu to sg helpers
  swiotlb: sg chaining support
  i386: enable sg chaining
  i386 dma_map_sg: convert to using sg helpers
  mmc: need to zero sglist on init
  Panic in blk_rq_map_sg() from CCISS driver
  remove sglist_len
  remove blk_queue_max_phys_segments in libata
  revert sg segment size ifdefs
  Fixup u14-34f ENABLE_SG_CHAINING
  qla1280: enable use_sg_chaining option
  ...

16 files changed, 167 insertions, 127 deletions

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))