diff options
| -rw-r--r-- | arch/arm/Kconfig | 4 | ||||
| -rw-r--r-- | arch/arm/include/asm/types.h | 17 |
2 files changed, 19 insertions, 2 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index e668994..9851065 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -7,6 +7,10 @@ config SYS_ARCH config ARM64 bool +config DMA_ADDR_T_64BIT + bool + default y if ARM64 + config HAS_VBAR bool diff --git a/arch/arm/include/asm/types.h b/arch/arm/include/asm/types.h index 388058e..d108915 100644 --- a/arch/arm/include/asm/types.h +++ b/arch/arm/include/asm/types.h @@ -46,16 +46,29 @@ typedef unsigned long long u64; #endif /* CONFIG_ARM64 */ #ifdef CONFIG_PHYS_64BIT -typedef unsigned long long dma_addr_t; typedef unsigned long long phys_addr_t; typedef unsigned long long phys_size_t; #else /* DMA addresses are 32-bits wide */ -typedef u32 dma_addr_t; typedef unsigned long phys_addr_t; typedef unsigned long phys_size_t; #endif +/* + * A dma_addr_t can hold any valid DMA address, i.e., any address returned + * by the DMA API. + * + * If the DMA API only uses 32-bit addresses, dma_addr_t need only be 32 + * bits wide. Bus addresses, e.g., PCI BARs, may be wider than 32 bits, + * but drivers do memory-mapped I/O to ioremapped kernel virtual addresses, + * so they don't care about the size of the actual bus addresses. + */ +#ifdef CONFIG_DMA_ADDR_T_64BIT +typedef unsigned long long dma_addr_t; +#else +typedef u32 dma_addr_t; +#endif + #endif /* __KERNEL__ */ typedef unsigned long resource_size_t; |