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>
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index b50fa57..c9496689 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 @@
{
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 @@
{
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 @@
}
/* 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 @@
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 @@
if (!dev->dma_mask || !dma_supported(dev, dma_mask))
return -EIO;
-#ifndef CONFIG_DMABOUNCE
*dev->dma_mask = dma_mask;
-#endif
return 0;
}