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authorNicolas Pitre <nico@cam.org>2008-09-09 21:54:13 +0200
committerNicolas Pitre <nico@cam.org>2009-03-16 02:01:21 +0100
commit58edb515724f9e63e569536d01ac8d8f8ddb367a (patch)
tree627d3eafefd38b031e776b48d8d04d764912ec92 /arch/arm/include/asm/dma-mapping.h
parent[ARM] introduce dma_cache_maint_page() (diff)
downloadlinux-58edb515724f9e63e569536d01ac8d8f8ddb367a.tar.xz
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[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.h10
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)
{