iommu sg: powerpc: convert iommu to use the IOMMU helper

This patch converts PPC's IOMMU to use the IOMMU helper functions.  The IOMMU
doesn't allocate a memory area spanning LLD's segment boundary anymore.

iseries_hv_alloc and iseries_hv_map don't have proper device
struct. 4GB boundary is used for them.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 34 insertions, 36 deletions

diff --git a/arch/powerpc/kernel/dma_64.c b/arch/powerpc/kernel/dma_64.c
index f9de2fddf4d..3a317cb0636 100644
--- a/arch/powerpc/kernel/dma_64.c
+++ b/arch/powerpc/kernel/dma_64.c
@@ -31,8 +31,8 @@ static inline unsigned long device_to_mask(struct device *dev)
 static void *dma_iommu_alloc_coherent(struct device *dev, size_t size,
                                       dma_addr_t *dma_handle, gfp_t flag)
 {
-        return iommu_alloc_coherent(dev->archdata.dma_data, size, dma_handle,
-                                    device_to_mask(dev), flag,
+        return iommu_alloc_coherent(dev, dev->archdata.dma_data, size,
+                                    dma_handle, device_to_mask(dev), flag,
                                     dev->archdata.numa_node);
 }
 
@@ -52,7 +52,7 @@ static dma_addr_t dma_iommu_map_single(struct device *dev, void *vaddr,
                                        size_t size,
                                        enum dma_data_direction direction)
 {
-        return iommu_map_single(dev->archdata.dma_data, vaddr, size,
+        return iommu_map_single(dev, dev->archdata.dma_data, vaddr, size,
                                 device_to_mask(dev), direction);
 }
 
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index d0e6fac4ef4..c42219c0afd 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -31,6 +31,7 @@
 #include <linux/string.h>
 #include <linux/dma-mapping.h>
 #include <linux/bitops.h>
+#include <linux/iommu-helper.h>
 #include <asm/io.h>
 #include <asm/prom.h>
 #include <asm/iommu.h>
@@ -81,17 +82,19 @@ static int __init setup_iommu(char *str)
 __setup("protect4gb=", setup_protect4gb);
 __setup("iommu=", setup_iommu);
 
-static unsigned long iommu_range_alloc(struct iommu_table *tbl,
+static unsigned long iommu_range_alloc(struct device *dev,
+                                       struct iommu_table *tbl,
                                        unsigned long npages,
                                        unsigned long *handle,
                                        unsigned long mask,
                                        unsigned int align_order)
 { 
-        unsigned long n, end, i, start;
+        unsigned long n, end, start;
         unsigned long limit;
         int largealloc = npages > 15;
         int pass = 0;
         unsigned long align_mask;
+        unsigned long boundary_size;
 
         align_mask = 0xffffffffffffffffl >> (64 - align_order);
 
@@ -136,14 +139,17 @@ static unsigned long iommu_range_alloc(struct iommu_table *tbl,
                         start &= mask;
         }
 
-        n = find_next_zero_bit(tbl->it_map, limit, start);
-
-        /* Align allocation */
-        n = (n + align_mask) & ~align_mask;
-
-        end = n + npages;
+        if (dev)
+                boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
+                                      1 << IOMMU_PAGE_SHIFT);
+        else
+                boundary_size = ALIGN(1UL << 32, 1 << IOMMU_PAGE_SHIFT);
+        /* 4GB boundary for iseries_hv_alloc and iseries_hv_map */
 
-        if (unlikely(end >= limit)) {
+        n = iommu_area_alloc(tbl->it_map, limit, start, npages,
+                             tbl->it_offset, boundary_size >> IOMMU_PAGE_SHIFT,
+                             align_mask);
+        if (n == -1) {
                 if (likely(pass < 2)) {
                         /* First failure, just rescan the half of the table.
                          * Second failure, rescan the other half of the table.
@@ -158,14 +164,7 @@ static unsigned long iommu_range_alloc(struct iommu_table *tbl,
                 }
         }
 
-        for (i = n; i < end; i++)
-                if (test_bit(i, tbl->it_map)) {
-                        start = i+1;
-                        goto again;
-                }
-
-        for (i = n; i < end; i++)
-                __set_bit(i, tbl->it_map);
+        end = n + npages;
 
         /* Bump the hint to a new block for small allocs. */
         if (largealloc) {
@@ -184,16 +183,17 @@ static unsigned long iommu_range_alloc(struct iommu_table *tbl,
         return n;
 }
 
-static dma_addr_t iommu_alloc(struct iommu_table *tbl, void *page,
-                       unsigned int npages, enum dma_data_direction direction,
-                       unsigned long mask, unsigned int align_order)
+static dma_addr_t iommu_alloc(struct device *dev, struct iommu_table *tbl,
+                              void *page, unsigned int npages,
+                              enum dma_data_direction direction,
+                              unsigned long mask, unsigned int align_order)
 {
         unsigned long entry, flags;
         dma_addr_t ret = DMA_ERROR_CODE;
 
         spin_lock_irqsave(&(tbl->it_lock), flags);
 
-        entry = iommu_range_alloc(tbl, npages, NULL, mask, align_order);
+        entry = iommu_range_alloc(dev, tbl, npages, NULL, mask, align_order);
 
         if (unlikely(entry == DMA_ERROR_CODE)) {
                 spin_unlock_irqrestore(&(tbl->it_lock), flags);
@@ -224,7 +224,6 @@ static void __iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
                          unsigned int npages)
 {
         unsigned long entry, free_entry;
-        unsigned long i;
 
         entry = dma_addr >> IOMMU_PAGE_SHIFT;
         free_entry = entry - tbl->it_offset;
@@ -246,9 +245,7 @@ static void __iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
         }
 
         ppc_md.tce_free(tbl, entry, npages);
-        
-        for (i = 0; i < npages; i++)
-                __clear_bit(free_entry+i, tbl->it_map);
+        iommu_area_free(tbl->it_map, free_entry, npages);
 }
 
 static void iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
@@ -317,7 +314,7 @@ int iommu_map_sg(struct device *dev, struct scatterlist *sglist,
                 if (IOMMU_PAGE_SHIFT < PAGE_SHIFT && slen >= PAGE_SIZE &&
                     (vaddr & ~PAGE_MASK) == 0)
                         align = PAGE_SHIFT - IOMMU_PAGE_SHIFT;
-                entry = iommu_range_alloc(tbl, npages, &handle,
+                entry = iommu_range_alloc(dev, tbl, npages, &handle,
                                           mask >> IOMMU_PAGE_SHIFT, align);
 
                 DBG("  - vaddr: %lx, size: %lx\n", vaddr, slen);
@@ -574,9 +571,9 @@ void iommu_free_table(struct iommu_table *tbl, const char *node_name)
  * need not be page aligned, the dma_addr_t returned will point to the same
  * byte within the page as vaddr.
  */
-dma_addr_t iommu_map_single(struct iommu_table *tbl, void *vaddr,
-                size_t size, unsigned long mask,
-                enum dma_data_direction direction)
+dma_addr_t iommu_map_single(struct device *dev, struct iommu_table *tbl,
+                            void *vaddr, size_t size, unsigned long mask,
+                            enum dma_data_direction direction)
 {
         dma_addr_t dma_handle = DMA_ERROR_CODE;
         unsigned long uaddr;
@@ -593,7 +590,7 @@ dma_addr_t iommu_map_single(struct iommu_table *tbl, void *vaddr,
                     ((unsigned long)vaddr & ~PAGE_MASK) == 0)
                         align = PAGE_SHIFT - IOMMU_PAGE_SHIFT;
 
-                dma_handle = iommu_alloc(tbl, vaddr, npages, direction,
+                dma_handle = iommu_alloc(dev, tbl, vaddr, npages, direction,
                                          mask >> IOMMU_PAGE_SHIFT, align);
                 if (dma_handle == DMA_ERROR_CODE) {
                         if (printk_ratelimit())  {
@@ -625,8 +622,9 @@ void iommu_unmap_single(struct iommu_table *tbl, dma_addr_t dma_handle,
  * Returns the virtual address of the buffer and sets dma_handle
  * to the dma address (mapping) of the first page.
  */
-void *iommu_alloc_coherent(struct iommu_table *tbl, size_t size,
-                dma_addr_t *dma_handle, unsigned long mask, gfp_t flag, int node)
+void *iommu_alloc_coherent(struct device *dev, struct iommu_table *tbl,
+                           size_t size, dma_addr_t *dma_handle,
+                           unsigned long mask, gfp_t flag, int node)
 {
         void *ret = NULL;
         dma_addr_t mapping;
@@ -660,7 +658,7 @@ void *iommu_alloc_coherent(struct iommu_table *tbl, size_t size,
         /* Set up tces to cover the allocated range */
         nio_pages = size >> IOMMU_PAGE_SHIFT;
         io_order = get_iommu_order(size);
-        mapping = iommu_alloc(tbl, ret, nio_pages, DMA_BIDIRECTIONAL,
+        mapping = iommu_alloc(dev, tbl, ret, nio_pages, DMA_BIDIRECTIONAL,
                               mask >> IOMMU_PAGE_SHIFT, io_order);
         if (mapping == DMA_ERROR_CODE) {
                 free_pages((unsigned long)ret, order);