From f7219a5300ba753b0c762d631763bd878b8bb00c Mon Sep 17 00:00:00 2001 From: Alessandro Rubini Date: Wed, 4 Apr 2012 19:40:10 +0200 Subject: [PATCH] x86: Introduce CONFIG_X86_DMA_REMAP The default functions phys_to_dma, dma_to_phys implement identity mapping as fast inline functions. Some systems, however, may need a custom function to implement its own mapping between CPU addresses and device addresses. This new configuration option allows the functions to be external when needed (such as for the ConneXt device) Signed-off-by: Alessandro Rubini Link: http://lkml.kernel.org/r/6e4329b772df675f1c442f68e59e844e4dd8c965.1333560789.git.rubini@gnudd.com Acked-by: Giancarlo Asnaghi Cc: Alan Cox Signed-off-by: H. Peter Anvin --- arch/x86/Kconfig | 3 +++ arch/x86/include/asm/dma-mapping.h | 7 +++++++ 2 files changed, 10 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 07b412aed38b..95ca56036030 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2220,6 +2220,9 @@ config X86_DEV_DMA_OPS bool depends on X86_64 +config X86_DMA_REMAP + bool + source "net/Kconfig" source "drivers/Kconfig" diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h index 09aa473e2917..61c0bd25845a 100644 --- a/arch/x86/include/asm/dma-mapping.h +++ b/arch/x86/include/asm/dma-mapping.h @@ -62,6 +62,12 @@ extern void *dma_generic_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_addr, gfp_t flag, struct dma_attrs *attrs); +#ifdef CONFIG_X86_DMA_REMAP /* Platform code defines bridge-specific code */ +extern bool dma_capable(struct device *dev, dma_addr_t addr, size_t size); +extern dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr); +extern phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr); +#else + static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size) { if (!dev->dma_mask) @@ -79,6 +85,7 @@ static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr) { return daddr; } +#endif /* CONFIG_X86_DMA_REMAP */ static inline void dma_cache_sync(struct device *dev, void *vaddr, size_t size, -- 2.34.1