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| author | Nicolas Pitre <nico@cam.org> | 2008-09-09 15:54:13 -0400 |
|---|---|---|
| committer | Nicolas Pitre <nico@cam.org> | 2009-03-15 21:01:21 -0400 |
| commit | 58edb515724f9e63e569536d01ac8d8f8ddb367a (patch) | |
| tree | 627d3eafefd38b031e776b48d8d04d764912ec92 /arch/arm/include/asm/dma-mapping.h | |
| parent | 43377453af83b8ff8c1c731da1508bd6b84ebfea (diff) | |
| download | lwn-58edb515724f9e63e569536d01ac8d8f8ddb367a.tar.gz lwn-58edb515724f9e63e569536d01ac8d8f8ddb367a.zip | |
[ARM] make page_to_dma() highmem aware
If a machine class has a custom __virt_to_bus() implementation then it
must provide a __arch_page_to_dma() implementation as well which is
_not_ based on page_address() to support highmem.
This patch fixes existing __arch_page_to_dma() and provide a default
implementation otherwise. The default implementation for highmem is
based on __pfn_to_bus() which is defined only when no custom
__virt_to_bus() is provided by the machine class.
That leaves only ebsa110 and footbridge which cannot support highmem
until they provide their own __arch_page_to_dma() implementation.
But highmem support on those legacy platforms with limited memory is
certainly not a priority.
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Diffstat (limited to 'arch/arm/include/asm/dma-mapping.h')
| -rw-r--r-- | arch/arm/include/asm/dma-mapping.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index 59fa762e9c66..ff46dfa68a97 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -15,10 +15,20 @@ * must not be used by drivers. */ #ifndef __arch_page_to_dma + +#if !defined(CONFIG_HIGHMEM) static inline dma_addr_t page_to_dma(struct device *dev, struct page *page) { return (dma_addr_t)__virt_to_bus((unsigned long)page_address(page)); } +#elif defined(__pfn_to_bus) +static inline dma_addr_t page_to_dma(struct device *dev, struct page *page) +{ + return (dma_addr_t)__pfn_to_bus(page_to_pfn(page)); +} +#else +#error "this machine class needs to define __arch_page_to_dma to use HIGHMEM" +#endif static inline void *dma_to_virt(struct device *dev, dma_addr_t addr) { |