On Thu, Mar 24, 2016 at 04:02:00PM +0530, Lokesh Vutla wrote:
dma_addr_t holds any valid DMA address. 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. Also 32 bit ARM systems with LPAE enabled can use 64bit address space, but DMA still use 32bit address like in case of DRA7 and Keystone platforms.
This is inspired from the Linux kernel types implementation[1]
[1] https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/include...
Acked-by: Lukasz Majewski l.majewski@samsung.com Signed-off-by: Lokesh Vutla lokeshvutla@ti.com
Reviewed-by: Tom Rini trini@konsulko.com