arm: make SWIOTLB available

IOMMU_HELPER is needed because SWIOTLB calls iommu_is_span_boundary,
provided by lib/iommu_helper.c.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
CC: will.deacon@arm.com
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Changes in v9:
- remove uneeded include asm/cacheflush.h;
- just return 0 if !dev->dma_mask in dma_capable.

Changes in v8:
- use __phys_to_pfn and __pfn_to_phys.

Changes in v7:
- dma_mark_clean: empty implementation;
- in dma_capable use coherent_dma_mask if dma_mask hasn't been
  allocated.

Changes in v6:
- check for dev->dma_mask being NULL in dma_capable.

Changes in v5:
- implement dma_mark_clean using dmac_flush_range.

Changes in v3:
- dma_capable: do not treat dma_mask as a limit;
- remove SWIOTLB dependency on NEED_SG_DMA_LENGTH.

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 3f7714d8d2d216bf3bbd7b4a5b227ea982997554..180c1321dbfbb1e53a2b648389ff2cd4836e89f0 100644 (file)
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1872,6 +1872,12 @@ config CC_STACKPROTECTOR
          neutralized via a kernel panic.
          This feature requires gcc version 4.2 or above.
 
+config SWIOTLB
+       def_bool y
+
+config IOMMU_HELPER
+       def_bool SWIOTLB
+
 config XEN_DOM0
        def_bool y
        depends on XEN

diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index 5b579b951503e51a436683d6fb0be964d983bf67..1ad2c171054b96e20ac562effdce2d608117489a 100644 (file)
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -86,6 +86,39 @@ static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
 }
 #endif
 
+static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
+{
+       unsigned int offset = paddr & ~PAGE_MASK;
+       return pfn_to_dma(dev, __phys_to_pfn(paddr)) + offset;
+}
+
+static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dev_addr)
+{
+       unsigned int offset = dev_addr & ~PAGE_MASK;
+       return __pfn_to_phys(dma_to_pfn(dev, dev_addr)) + offset;
+}
+
+static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
+{
+       u64 limit, mask;
+
+       if (!dev->dma_mask)
+               return 0;
+
+       mask = *dev->dma_mask;
+
+       limit = (mask + 1) & ~mask;
+       if (limit && size > limit)
+               return 0;
+
+       if ((addr | (addr + size - 1)) & ~mask)
+               return 0;
+
+       return 1;
+}
+
+static inline void dma_mark_clean(void *addr, size_t size) { }
+
 /*
  * DMA errors are defined by all-bits-set in the DMA address.
  */