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authorHaavard Skinnemoen <hskinnemoen@atmel.com>2007-03-20 14:41:13 +0100
committerHaavard Skinnemoen <hskinnemoen@atmel.com>2007-05-09 08:48:39 +0200
commita492dbb9e3d04db138f2841648d1904d38a5295d (patch)
tree6b2b433941c8a97c175b827796d47824831a7506 /arch/avr32/mm/dma-coherent.c
parente89b064a4fd18b9c57b7aecbe7101d782759cf81 (diff)
downloadlinux-a492dbb9e3d04db138f2841648d1904d38a5295d.tar.gz
[AVR32] Implement dma_{alloc,free}_writecombine()
Implement dma_alloc_writecombine() and its dma_free_writecombine() counterpart. These will do basically the same thing as dma_alloc_coherent() except that the virtual mapping will allow write buffering, causing better performance for certain use cases like frame buffers. The same API is already available on ARM. Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Diffstat (limited to 'arch/avr32/mm/dma-coherent.c')
-rw-r--r--arch/avr32/mm/dma-coherent.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/arch/avr32/mm/dma-coherent.c b/arch/avr32/mm/dma-coherent.c
index b68d669..099212d 100644
--- a/arch/avr32/mm/dma-coherent.c
+++ b/arch/avr32/mm/dma-coherent.c
@@ -112,16 +112,21 @@ void dma_free_coherent(struct device *dev, size_t size,
}
EXPORT_SYMBOL(dma_free_coherent);
-#if 0
void *dma_alloc_writecombine(struct device *dev, size_t size,
dma_addr_t *handle, gfp_t gfp)
{
struct page *page;
+ dma_addr_t phys;
page = __dma_alloc(dev, size, handle, gfp);
+ if (!page)
+ return NULL;
+
+ phys = page_to_phys(page);
+ *handle = phys;
/* Now, map the page into P3 with write-combining turned on */
- return __ioremap(page_to_phys(page), size, _PAGE_BUFFER);
+ return __ioremap(phys, size, _PAGE_BUFFER);
}
EXPORT_SYMBOL(dma_alloc_writecombine);
@@ -132,8 +137,7 @@ void dma_free_writecombine(struct device *dev, size_t size,
iounmap(cpu_addr);
- page = bus_to_page(handle);
+ page = phys_to_page(handle);
__dma_free(dev, size, page, handle);
}
EXPORT_SYMBOL(dma_free_writecombine);
-#endif