From mboxrd@z Thu Jan 1 00:00:00 1970 From: kraxel@redhat.com (Gerd Hoffmann) Date: Tue, 7 Jun 2016 13:05:41 +0200 Subject: [PATCH v3 03/10] arm64: Allow for different DMA and CPU bus offsets In-Reply-To: <1465297548-17182-1-git-send-email-kraxel@redhat.com> References: <1465297548-17182-1-git-send-email-kraxel@redhat.com> Message-ID: <1465297548-17182-4-git-send-email-kraxel@redhat.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Alexander Graf On arm64, all SoCs we supported so far either have an IOMMU or have bus addresses equal to CPU addresses. However, with the Raspberry Pi 3 coming up, this is no longer true. To allow DMA to work with an AArch64 kernel on those devices, let's allow devices to have DMA offsets again. Signed-off-by: Alexander Graf Acked-by: Arnd Bergmann Acked-by: Catalin Marinas --- arch/arm64/include/asm/dma-mapping.h | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/dma-mapping.h b/arch/arm64/include/asm/dma-mapping.h index 7dbea6c..ccea82c 100644 --- a/arch/arm64/include/asm/dma-mapping.h +++ b/arch/arm64/include/asm/dma-mapping.h @@ -66,12 +66,16 @@ static inline bool is_device_dma_coherent(struct device *dev) static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr) { - return (dma_addr_t)paddr; + dma_addr_t dev_addr = (dma_addr_t)paddr; + + return dev_addr - ((dma_addr_t)dev->dma_pfn_offset << PAGE_SHIFT); } static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dev_addr) { - return (phys_addr_t)dev_addr; + phys_addr_t paddr = (phys_addr_t)dev_addr; + + return paddr + ((phys_addr_t)dev->dma_pfn_offset << PAGE_SHIFT); } static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size) @@ -86,5 +90,14 @@ static inline void dma_mark_clean(void *addr, size_t size) { } +/* Override for dma_max_pfn() */ +static inline unsigned long dma_max_pfn(struct device *dev) +{ + dma_addr_t dma_max = (dma_addr_t)*dev->dma_mask; + + return (ulong)dma_to_phys(dev, dma_max) >> PAGE_SHIFT; +} +#define dma_max_pfn(dev) dma_max_pfn(dev) + #endif /* __KERNEL__ */ #endif /* __ASM_DMA_MAPPING_H */ -- 1.8.3.1