1 files changed, 34 insertions, 21 deletions

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index c24721a33b4c..0977317c6835 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -134,7 +134,8 @@ struct dma_map_ops {
         int is_phys;
 };
 
-extern struct dma_map_ops dma_noop_ops;
+extern const struct dma_map_ops dma_noop_ops;
+extern const struct dma_map_ops dma_virt_ops;
 
 #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))
 
@@ -171,14 +172,26 @@ int dma_mmap_from_coherent(struct device *dev, struct vm_area_struct *vma,
 
 #ifdef CONFIG_HAS_DMA
 #include <asm/dma-mapping.h>
+static inline const struct dma_map_ops *get_dma_ops(struct device *dev)
+{
+        if (dev && dev->dma_ops)
+                return dev->dma_ops;
+        return get_arch_dma_ops(dev ? dev->bus : NULL);
+}
+
+static inline void set_dma_ops(struct device *dev,
+                               const struct dma_map_ops *dma_ops)
+{
+        dev->dma_ops = dma_ops;
+}
 #else
 /*
  * Define the dma api to allow compilation but not linking of
  * dma dependent code.  Code that depends on the dma-mapping
  * API needs to set 'depends on HAS_DMA' in its Kconfig
  */
-extern struct dma_map_ops bad_dma_ops;
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+extern const struct dma_map_ops bad_dma_ops;
+static inline const struct dma_map_ops *get_dma_ops(struct device *dev)
 {
         return &bad_dma_ops;
 }
@@ -189,7 +202,7 @@ static inline dma_addr_t dma_map_single_attrs(struct device *dev, void *ptr,
                                               enum dma_data_direction dir,
                                               unsigned long attrs)
 {
-        struct dma_map_ops *ops = get_dma_ops(dev);
+        const struct dma_map_ops *ops = get_dma_ops(dev);
         dma_addr_t addr;
 
         kmemcheck_mark_initialized(ptr, size);
@@ -208,7 +221,7 @@ static inline void dma_unmap_single_attrs(struct device *dev, dma_addr_t addr,
                                           enum dma_data_direction dir,
                                           unsigned long attrs)
 {
-        struct dma_map_ops *ops = get_dma_ops(dev);
+        const struct dma_map_ops *ops = get_dma_ops(dev);
 
         BUG_ON(!valid_dma_direction(dir));
         if (ops->unmap_page)
@@ -224,7 +237,7 @@ static inline int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
                                    int nents, enum dma_data_direction dir,
                                    unsigned long attrs)
 {
-        struct dma_map_ops *ops = get_dma_ops(dev);
+        const struct dma_map_ops *ops = get_dma_ops(dev);
         int i, ents;
         struct scatterlist *s;
 
@@ -242,7 +255,7 @@ static inline void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg
                                       int nents, enum dma_data_direction dir,
                                       unsigned long attrs)
 {
-        struct dma_map_ops *ops = get_dma_ops(dev);
+        const struct dma_map_ops *ops = get_dma_ops(dev);
 
         BUG_ON(!valid_dma_direction(dir));
         debug_dma_unmap_sg(dev, sg, nents, dir);
@@ -256,7 +269,7 @@ static inline dma_addr_t dma_map_page_attrs(struct device *dev,
                                             enum dma_data_direction dir,
                                             unsigned long attrs)
 {
-        struct dma_map_ops *ops = get_dma_ops(dev);
+        const struct dma_map_ops *ops = get_dma_ops(dev);
         dma_addr_t addr;
 
         kmemcheck_mark_initialized(page_address(page) + offset, size);
@@ -272,7 +285,7 @@ static inline void dma_unmap_page_attrs(struct device *dev,
                                         enum dma_data_direction dir,
                                         unsigned long attrs)
 {
-        struct dma_map_ops *ops = get_dma_ops(dev);
+        const struct dma_map_ops *ops = get_dma_ops(dev);
 
         BUG_ON(!valid_dma_direction(dir));
         if (ops->unmap_page)
@@ -286,7 +299,7 @@ static inline dma_addr_t dma_map_resource(struct device *dev,
                                           enum dma_data_direction dir,
                                           unsigned long attrs)
 {
-        struct dma_map_ops *ops = get_dma_ops(dev);
+        const struct dma_map_ops *ops = get_dma_ops(dev);
         dma_addr_t addr;
 
         BUG_ON(!valid_dma_direction(dir));
@@ -307,7 +320,7 @@ static inline void dma_unmap_resource(struct device *dev, dma_addr_t addr,
                                       size_t size, enum dma_data_direction dir,
                                       unsigned long attrs)
 {
-        struct dma_map_ops *ops = get_dma_ops(dev);
+        const struct dma_map_ops *ops = get_dma_ops(dev);
 
         BUG_ON(!valid_dma_direction(dir));
         if (ops->unmap_resource)
@@ -319,7 +332,7 @@ static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr,
                                            size_t size,
                                            enum dma_data_direction dir)
 {
-        struct dma_map_ops *ops = get_dma_ops(dev);
+        const struct dma_map_ops *ops = get_dma_ops(dev);
 
         BUG_ON(!valid_dma_direction(dir));
         if (ops->sync_single_for_cpu)
@@ -331,7 +344,7 @@ static inline void dma_sync_single_for_device(struct device *dev,
                                               dma_addr_t addr, size_t size,
                                               enum dma_data_direction dir)
 {
-        struct dma_map_ops *ops = get_dma_ops(dev);
+        const struct dma_map_ops *ops = get_dma_ops(dev);
 
         BUG_ON(!valid_dma_direction(dir));
         if (ops->sync_single_for_device)
@@ -371,7 +384,7 @@ static inline void
 dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
                     int nelems, enum dma_data_direction dir)
 {
-        struct dma_map_ops *ops = get_dma_ops(dev);
+        const struct dma_map_ops *ops = get_dma_ops(dev);
 
         BUG_ON(!valid_dma_direction(dir));
         if (ops->sync_sg_for_cpu)
@@ -383,7 +396,7 @@ static inline void
 dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
                        int nelems, enum dma_data_direction dir)
 {
-        struct dma_map_ops *ops = get_dma_ops(dev);
+        const struct dma_map_ops *ops = get_dma_ops(dev);
 
         BUG_ON(!valid_dma_direction(dir));
         if (ops->sync_sg_for_device)
@@ -428,7 +441,7 @@ static inline int
 dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma, void *cpu_addr,
                dma_addr_t dma_addr, size_t size, unsigned long attrs)
 {
-        struct dma_map_ops *ops = get_dma_ops(dev);
+        const struct dma_map_ops *ops = get_dma_ops(dev);
         BUG_ON(!ops);
         if (ops->mmap)
                 return ops->mmap(dev, vma, cpu_addr, dma_addr, size, attrs);
@@ -446,7 +459,7 @@ dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt, void *cpu_addr,
                       dma_addr_t dma_addr, size_t size,
                       unsigned long attrs)
 {
-        struct dma_map_ops *ops = get_dma_ops(dev);
+        const struct dma_map_ops *ops = get_dma_ops(dev);
         BUG_ON(!ops);
         if (ops->get_sgtable)
                 return ops->get_sgtable(dev, sgt, cpu_addr, dma_addr, size,
@@ -464,7 +477,7 @@ static inline void *dma_alloc_attrs(struct device *dev, size_t size,
                                        dma_addr_t *dma_handle, gfp_t flag,
                                        unsigned long attrs)
 {
-        struct dma_map_ops *ops = get_dma_ops(dev);
+        const struct dma_map_ops *ops = get_dma_ops(dev);
         void *cpu_addr;
 
         BUG_ON(!ops);
@@ -486,7 +499,7 @@ static inline void dma_free_attrs(struct device *dev, size_t size,
                                      void *cpu_addr, dma_addr_t dma_handle,
                                      unsigned long attrs)
 {
-        struct dma_map_ops *ops = get_dma_ops(dev);
+        const struct dma_map_ops *ops = get_dma_ops(dev);
 
         BUG_ON(!ops);
         WARN_ON(irqs_disabled());
@@ -544,7 +557,7 @@ static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 #ifndef HAVE_ARCH_DMA_SUPPORTED
 static inline int dma_supported(struct device *dev, u64 mask)
 {
-        struct dma_map_ops *ops = get_dma_ops(dev);
+        const struct dma_map_ops *ops = get_dma_ops(dev);
 
         if (!ops)
                 return 0;
@@ -557,7 +570,7 @@ static inline int dma_supported(struct device *dev, u64 mask)
 #ifndef HAVE_ARCH_DMA_SET_MASK
 static inline int dma_set_mask(struct device *dev, u64 mask)
 {
-        struct dma_map_ops *ops = get_dma_ops(dev);
+        const struct dma_map_ops *ops = get_dma_ops(dev);
 
         if (ops->set_dma_mask)
                 return ops->set_dma_mask(dev, mask);