diff options
| -rw-r--r-- | arch/tile/include/asm/dma-mapping.h | 4 | ||||
| -rw-r--r-- | arch/tile/kernel/pci-dma.c | 18 |
2 files changed, 22 insertions, 0 deletions
diff --git a/arch/tile/include/asm/dma-mapping.h b/arch/tile/include/asm/dma-mapping.h index 4a60059876e..6f522d56913 100644 --- a/arch/tile/include/asm/dma-mapping.h +++ b/arch/tile/include/asm/dma-mapping.h @@ -20,6 +20,10 @@ #include <linux/cache.h> #include <linux/io.h> +#ifdef __tilegx__ +#define ARCH_HAS_DMA_GET_REQUIRED_MASK +#endif + extern struct dma_map_ops *tile_dma_map_ops; extern struct dma_map_ops *gx_pci_dma_map_ops; extern struct dma_map_ops *gx_legacy_pci_dma_map_ops; diff --git a/arch/tile/kernel/pci-dma.c b/arch/tile/kernel/pci-dma.c index adc369d8c77..9fef64d70c5 100644 --- a/arch/tile/kernel/pci-dma.c +++ b/arch/tile/kernel/pci-dma.c @@ -607,3 +607,21 @@ int dma_set_coherent_mask(struct device *dev, u64 mask) } EXPORT_SYMBOL(dma_set_coherent_mask); #endif + +#ifdef ARCH_HAS_DMA_GET_REQUIRED_MASK +/* + * The generic dma_get_required_mask() uses the highest physical address + * (max_pfn) to provide the hint to the PCI drivers regarding 32-bit or + * 64-bit DMA configuration. Since TILEGx has I/O TLB/MMU, allowing the + * DMAs to use the full 64-bit PCI address space and not limited by + * the physical memory space, we always let the PCI devices use + * 64-bit DMA if they have that capability, by returning the 64-bit + * DMA mask here. The device driver has the option to use 32-bit DMA if + * the device is not capable of 64-bit DMA. + */ +u64 dma_get_required_mask(struct device *dev) +{ + return DMA_BIT_MASK(64); +} +EXPORT_SYMBOL_GPL(dma_get_required_mask); +#endif |