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[ARM] dma: fix dmabounce dma_sync_xxx() implementations

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The dmabounce dma_sync_xxx() implementation have been broken for
quite some time; they all copy data between the DMA buffer and
the CPU visible buffer no irrespective of the change of ownership.
(IOW, a DMA_FROM_DEVICE mapping copies data from the DMA buffer
to the CPU buffer during a call to dma_sync_single_for_device().)

Fix it by getting rid of sync_single(), moving the contents into
the recently created dmabounce_sync_for_xxx() functions and adjusting
appropriately.

This also makes it possible to properly support the DMA range sync
functions.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King
2008-09-25 22:16:22 +01:00
committed by Russell King
parent 8c8a0ec57e
commit 125ab12acf
2 changed files with 69 additions and 101 deletions
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26
arch/arm/include/asm/dma-mapping.h
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@@ -241,6 +241,15 @@ extern void dmabounce_unregister_dev(struct device *);
*/
extern int dma_needs_bounce(struct device*, dma_addr_t, size_t);
/*
* The DMA API, implemented by dmabounce.c. See below for descriptions.
*/
extern dma_addr_t dma_map_single(struct device *,void *, size_t, enum dma_data_direction);
extern dma_addr_t dma_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction dir);
extern void dma_unmap_single(struct device *, dma_addr_t, size_t, enum dma_data_direction);
/*
* Private functions
*/
@@ -251,7 +260,6 @@ int dmabounce_sync_for_device(struct device *, dma_addr_t, unsigned long,
#else
#define dmabounce_sync_for_cpu(dev,dma,off,sz,dir) (1)
#define dmabounce_sync_for_device(dev,dma,off,sz,dir) (1)
#endif /* CONFIG_DMABOUNCE */
/**
@@ -268,7 +276,6 @@ int dmabounce_sync_for_device(struct device *, dma_addr_t, unsigned long,
* can regain ownership by calling dma_unmap_single() or
* dma_sync_single_for_cpu().
*/
#ifndef CONFIG_DMABOUNCE
static inline dma_addr_t
dma_map_single(struct device *dev, void *cpu_addr, size_t size,
enum dma_data_direction dir)
@@ -278,9 +285,7 @@ dma_map_single(struct device *dev, void *cpu_addr, size_t size,
return virt_to_dma(dev, cpu_addr);
}
#else
extern dma_addr_t dma_map_single(struct device *,void *, size_t, enum dma_data_direction);
#endif
/**
* dma_map_page - map a portion of a page for streaming DMA
@@ -297,7 +302,6 @@ extern dma_addr_t dma_map_single(struct device *,void *, size_t, enum dma_data_d
* can regain ownership by calling dma_unmap_page() or
* dma_sync_single_for_cpu().
*/
#ifndef CONFIG_DMABOUNCE
static inline dma_addr_t
dma_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size,
@@ -308,11 +312,6 @@ dma_map_page(struct device *dev, struct page *page,
return page_to_dma(dev, page) + offset;
}
#else
extern dma_addr_t dma_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction dir);
#endif
/**
* dma_unmap_single - unmap a single buffer previously mapped
@@ -328,16 +327,13 @@ extern dma_addr_t dma_map_page(struct device *dev, struct page *page,
* After this call, reads by the CPU to the buffer are guaranteed to see
* whatever the device wrote there.
*/
#ifndef CONFIG_DMABOUNCE
static inline void
dma_unmap_single(struct device *dev, dma_addr_t handle, size_t size,
enum dma_data_direction dir)
{
/* nothing to do */
}
#else
extern void dma_unmap_single(struct device *, dma_addr_t, size_t, enum dma_data_direction);
#endif
#endif /* CONFIG_DMABOUNCE */
/**
* dma_unmap_page - unmap a buffer previously mapped through dma_map_page()