sparc: use dma_map_page instead of dma_map_single

This patch converts dma_map_single and dma_unmap_single to use
map_page and unmap_page respectively and removes unnecessary
map_single and unmap_single. map_page can be used to implement
map_single but the opposite is impossible. Having only dma_map_page in
struct dma_ops is enough.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Tested-by: Robert Reif <reif@earthlink.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 28 insertions, 25 deletions

diff --git a/arch/sparc/include/asm/dma-mapping_64.h b/arch/sparc/include/asm/dma-mapping_64.h
index 0c4fb1f81caf..579757e00a25 100644
--- a/arch/sparc/include/asm/dma-mapping_64.h
+++ b/arch/sparc/include/asm/dma-mapping_64.h
@@ -9,12 +9,12 @@ struct dma_ops {
                                 dma_addr_t *dma_handle, gfp_t flag);
         void (*free_coherent)(struct device *dev, size_t size,
                               void *cpu_addr, dma_addr_t dma_handle);
-        dma_addr_t (*map_single)(struct device *dev, void *cpu_addr,
-                                 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);
+        dma_addr_t (*map_page)(struct device *dev, struct page *page,
+                               unsigned long offset, size_t size,
+                               enum dma_data_direction direction);
+        void (*unmap_page)(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,
@@ -51,29 +51,30 @@ static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr,
                                         size_t size,
                                         enum dma_data_direction direction)
 {
-        return dma_ops->map_single(dev, cpu_addr, size, direction);
+        return dma_ops->map_page(dev, virt_to_page(cpu_addr),
+                                 (unsigned long)cpu_addr & ~PAGE_MASK, size,
+                                 direction);
 }
 
 static inline void dma_unmap_single(struct device *dev, dma_addr_t dma_addr,
                                     size_t size,
                                     enum dma_data_direction direction)
 {
-        dma_ops->unmap_single(dev, dma_addr, size, direction);
+        dma_ops->unmap_page(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)
 {
-        return dma_ops->map_single(dev, page_address(page) + offset,
-                                   size, direction);
+        return dma_ops->map_page(dev, page, offset, size, direction);
 }
 
 static inline void dma_unmap_page(struct device *dev, dma_addr_t dma_address,
                                   size_t size,
                                   enum dma_data_direction direction)
 {
-        dma_ops->unmap_single(dev, dma_address, size, direction);
+        dma_ops->unmap_page(dev, dma_address, size, direction);
 }
 
 static inline int dma_map_sg(struct device *dev, struct scatterlist *sg,
diff --git a/arch/sparc/kernel/iommu.c b/arch/sparc/kernel/iommu.c
index d8900e1d5aad..0aeaefe696b9 100644
--- a/arch/sparc/kernel/iommu.c
+++ b/arch/sparc/kernel/iommu.c
@@ -351,8 +351,9 @@ static void dma_4u_free_coherent(struct device *dev, size_t size,
                 free_pages((unsigned long)cpu, order);
 }
 
-static dma_addr_t dma_4u_map_single(struct device *dev, void *ptr, size_t sz,
-                                    enum dma_data_direction direction)
+static dma_addr_t dma_4u_map_page(struct device *dev, struct page *page,
+                                  unsigned long offset, size_t sz,
+                                  enum dma_data_direction direction)
 {
         struct iommu *iommu;
         struct strbuf *strbuf;
@@ -368,7 +369,7 @@ static dma_addr_t dma_4u_map_single(struct device *dev, void *ptr, size_t sz,
         if (unlikely(direction == DMA_NONE))
                 goto bad_no_ctx;
 
-        oaddr = (unsigned long)ptr;
+        oaddr = (unsigned long)(page_address(page) + offset);
         npages = IO_PAGE_ALIGN(oaddr + sz) - (oaddr & IO_PAGE_MASK);
         npages >>= IO_PAGE_SHIFT;
 
@@ -472,8 +473,8 @@ do_flush_sync:
                        vaddr, ctx, npages);
 }
 
-static void dma_4u_unmap_single(struct device *dev, dma_addr_t bus_addr,
-                                size_t sz, enum dma_data_direction direction)
+static void dma_4u_unmap_page(struct device *dev, dma_addr_t bus_addr,
+                              size_t sz, enum dma_data_direction direction)
 {
         struct iommu *iommu;
         struct strbuf *strbuf;
@@ -824,8 +825,8 @@ static void dma_4u_sync_sg_for_cpu(struct device *dev,
 static const struct dma_ops sun4u_dma_ops = {
         .alloc_coherent         = dma_4u_alloc_coherent,
         .free_coherent          = dma_4u_free_coherent,
-        .map_single             = dma_4u_map_single,
-        .unmap_single           = dma_4u_unmap_single,
+        .map_page               = dma_4u_map_page,
+        .unmap_page             = dma_4u_unmap_page,
         .map_sg                 = dma_4u_map_sg,
         .unmap_sg               = dma_4u_unmap_sg,
         .sync_single_for_cpu    = dma_4u_sync_single_for_cpu,
diff --git a/arch/sparc/kernel/pci_sun4v.c b/arch/sparc/kernel/pci_sun4v.c
index 5db5ebed35da..2485eaa23101 100644
--- a/arch/sparc/kernel/pci_sun4v.c
+++ b/arch/sparc/kernel/pci_sun4v.c
@@ -230,8 +230,9 @@ static void dma_4v_free_coherent(struct device *dev, size_t size, void *cpu,
                 free_pages((unsigned long)cpu, order);
 }
 
-static dma_addr_t dma_4v_map_single(struct device *dev, void *ptr, size_t sz,
-                                    enum dma_data_direction direction)
+static dma_addr_t dma_4v_map_page(struct device *dev, struct page *page,
+                                  unsigned long offset, size_t sz,
+                                  enum dma_data_direction direction)
 {
         struct iommu *iommu;
         unsigned long flags, npages, oaddr;
@@ -245,7 +246,7 @@ static dma_addr_t dma_4v_map_single(struct device *dev, void *ptr, size_t sz,
         if (unlikely(direction == DMA_NONE))
                 goto bad;
 
-        oaddr = (unsigned long)ptr;
+        oaddr = (unsigned long)(page_address(page) + offset);
         npages = IO_PAGE_ALIGN(oaddr + sz) - (oaddr & IO_PAGE_MASK);
         npages >>= IO_PAGE_SHIFT;
 
@@ -294,8 +295,8 @@ iommu_map_fail:
         return DMA_ERROR_CODE;
 }
 
-static void dma_4v_unmap_single(struct device *dev, dma_addr_t bus_addr,
-                                size_t sz, enum dma_data_direction direction)
+static void dma_4v_unmap_page(struct device *dev, dma_addr_t bus_addr,
+                              size_t sz, enum dma_data_direction direction)
 {
         struct pci_pbm_info *pbm;
         struct iommu *iommu;
@@ -537,8 +538,8 @@ static void dma_4v_sync_sg_for_cpu(struct device *dev,
 static const struct dma_ops sun4v_dma_ops = {
         .alloc_coherent                 = dma_4v_alloc_coherent,
         .free_coherent                  = dma_4v_free_coherent,
-        .map_single                     = dma_4v_map_single,
-        .unmap_single                   = dma_4v_unmap_single,
+        .map_page                       = dma_4v_map_page,
+        .unmap_page                     = dma_4v_unmap_page,
         .map_sg                         = dma_4v_map_sg,
         .unmap_sg                       = dma_4v_unmap_sg,
         .sync_single_for_cpu            = dma_4v_sync_single_for_cpu,