From 43377453af83b8ff8c1c731da1508bd6b84ebfea Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Thu, 12 Mar 2009 22:52:09 -0400 Subject: [ARM] introduce dma_cache_maint_page() This is a helper to be used by the DMA mapping API to handle cache maintenance for memory identified by a page structure instead of a virtual address. Those pages may or may not be highmem pages, and when they're highmem pages, they may or may not be virtually mapped. When they're not mapped then there is no L1 cache to worry about. But even in that case the L2 cache must be processed since unmapped highmem pages can still be L2 cached. Signed-off-by: Nicolas Pitre --- arch/arm/include/asm/dma-mapping.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'arch/arm/include/asm/dma-mapping.h') diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index 22cb14ec3438..59fa762e9c66 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -57,6 +57,8 @@ static inline dma_addr_t virt_to_dma(struct device *dev, void *addr) * Use the driver DMA support - see dma-mapping.h (dma_sync_*) */ 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); /* * Return whether the given device DMA address mask can be supported @@ -316,7 +318,7 @@ static inline dma_addr_t dma_map_page(struct device *dev, struct page *page, BUG_ON(!valid_dma_direction(dir)); if (!arch_is_coherent()) - dma_cache_maint(page_address(page) + offset, size, dir); + dma_cache_maint_page(page, offset, size, dir); return page_to_dma(dev, page) + offset; } -- cgit v1.2.3 From 58edb515724f9e63e569536d01ac8d8f8ddb367a Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Tue, 9 Sep 2008 15:54:13 -0400 Subject: [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 --- arch/arm/include/asm/dma-mapping.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'arch/arm/include/asm/dma-mapping.h') 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) { -- cgit v1.2.3