lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

ARM: dma-mapping: push buffer ownership down into dma-mapping.c

Browse Source 
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-By: Santosh Shilimkar <santosh.shilimkar@ti.com>
This commit is contained in:
Russell King
2009-11-24 16:27:17 +00:00
parent 18eabe2347
commit 4ea0d7371e
2 changed files with 55 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

39
arch/arm/include/asm/dma-mapping.h
View File

@ -56,47 +56,58 @@ static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
}
#endif
/*
* Private support functions: these are not part of the API and are
* liable to change. Drivers must not use these.
*/
extern void dma_cache_maint(const void *kaddr, size_t size, int rw);
extern void dma_cache_maint_page(struct page *page, unsigned long offset,
size_t size, int rw);
/*
* 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.
*
* As above, these are private support functions and not part of the API.
* Drivers must not use these.
* 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_cache_maint(kaddr, size, dir);
___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)
{
/* nothing to do */
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_cache_maint_page(page, off, size, dir);
___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)
{
/* nothing to do */
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);
}
/*