ARM: dma-mapping: move all dma bounce code to separate dma ops structure

This patch removes dma bounce hooks from the common dma mapping
implementation on ARM architecture and creates a separate set of
dma_map_ops for dma bounce devices.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Tested-By: Subash Patel <subash.ramaswamy@linaro.org>

1 files changed, 69 insertions, 10 deletions

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index b50fa578df81..c94966891dee 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -29,6 +29,75 @@
 
 #include "mm.h"
 
+/*
+ * The DMA API is built upon the notion of "buffer ownership".  A buffer
+ * is either exclusively owned by the CPU (and therefore may be accessed
+ * by it) or exclusively owned by the DMA device.  These helper functions
+ * represent the transitions between these two ownership states.
+ *
+ * Note, however, that on later ARMs, this notion does not work due to
+ * speculative prefetches.  We model our approach on the assumption that
+ * the CPU does do speculative prefetches, which means we clean caches
+ * before transfers and delay cache invalidation until transfer completion.
+ *
+ * Private support functions: these are not part of the API and are
+ * liable to change.  Drivers must not use these.
+ */
+static inline void __dma_single_cpu_to_dev(const void *kaddr, size_t size,
+        enum dma_data_direction dir)
+{
+        extern void ___dma_single_cpu_to_dev(const void *, size_t,
+                enum dma_data_direction);
+
+        if (!arch_is_coherent())
+                ___dma_single_cpu_to_dev(kaddr, size, dir);
+}
+
+static inline void __dma_single_dev_to_cpu(const void *kaddr, size_t size,
+        enum dma_data_direction dir)
+{
+        extern void ___dma_single_dev_to_cpu(const void *, size_t,
+                enum dma_data_direction);
+
+        if (!arch_is_coherent())
+                ___dma_single_dev_to_cpu(kaddr, size, dir);
+}
+
+static inline void __dma_page_cpu_to_dev(struct page *page, unsigned long off,
+        size_t size, enum dma_data_direction dir)
+{
+        extern void ___dma_page_cpu_to_dev(struct page *, unsigned long,
+                size_t, enum dma_data_direction);
+
+        if (!arch_is_coherent())
+                ___dma_page_cpu_to_dev(page, off, size, dir);
+}
+
+static inline void __dma_page_dev_to_cpu(struct page *page, unsigned long off,
+        size_t size, enum dma_data_direction dir)
+{
+        extern void ___dma_page_dev_to_cpu(struct page *, unsigned long,
+                size_t, enum dma_data_direction);
+
+        if (!arch_is_coherent())
+                ___dma_page_dev_to_cpu(page, off, size, dir);
+}
+
+
+static inline dma_addr_t __dma_map_page(struct device *dev, struct page *page,
+             unsigned long offset, size_t size, enum dma_data_direction dir)
+{
+        __dma_page_cpu_to_dev(page, offset, size, dir);
+        return pfn_to_dma(dev, page_to_pfn(page)) + offset;
+}
+
+static inline void __dma_unmap_page(struct device *dev, dma_addr_t handle,
+                size_t size, enum dma_data_direction dir)
+{
+        __dma_page_dev_to_cpu(pfn_to_page(dma_to_pfn(dev, handle)),
+                handle & ~PAGE_MASK, size, dir);
+}
+
 /**
  * arm_dma_map_page - map a portion of a page for streaming DMA
  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
@@ -76,9 +145,6 @@ static inline void arm_dma_sync_single_for_cpu(struct device *dev,
 {
         unsigned int offset = handle & (PAGE_SIZE - 1);
         struct page *page = pfn_to_page(dma_to_pfn(dev, handle-offset));
-        if (!dmabounce_sync_for_cpu(dev, handle, size, dir))
-                return;
-
         __dma_page_dev_to_cpu(page, offset, size, dir);
 }
 
@@ -87,9 +153,6 @@ static inline void arm_dma_sync_single_for_device(struct device *dev,
 {
         unsigned int offset = handle & (PAGE_SIZE - 1);
         struct page *page = pfn_to_page(dma_to_pfn(dev, handle-offset));
-        if (!dmabounce_sync_for_device(dev, handle, size, dir))
-                return;
-
         __dma_page_cpu_to_dev(page, offset, size, dir);
 }
 
@@ -599,7 +662,6 @@ void ___dma_page_cpu_to_dev(struct page *page, unsigned long off,
         }
         /* FIXME: non-speculating: flush on bidirectional mappings? */
 }
-EXPORT_SYMBOL(___dma_page_cpu_to_dev);
 
 void ___dma_page_dev_to_cpu(struct page *page, unsigned long off,
         size_t size, enum dma_data_direction dir)
@@ -619,7 +681,6 @@ void ___dma_page_dev_to_cpu(struct page *page, unsigned long off,
         if (dir != DMA_TO_DEVICE && off == 0 && size >= PAGE_SIZE)
                 set_bit(PG_dcache_clean, &page->flags);
 }
-EXPORT_SYMBOL(___dma_page_dev_to_cpu);
 
 /**
  * arm_dma_map_sg - map a set of SG buffers for streaming mode DMA
@@ -737,9 +798,7 @@ static int arm_dma_set_mask(struct device *dev, u64 dma_mask)
         if (!dev->dma_mask || !dma_supported(dev, dma_mask))
                 return -EIO;
 
-#ifndef CONFIG_DMABOUNCE
         *dev->dma_mask = dma_mask;
-#endif
 
         return 0;
 }