tree b2eb9bedbf954e9301722f1cad5ddd7c426021a8
parent 4af9027d3f4061992c0b065102a0a666b72f073b
author Guo Ren <ren_guo@c-sky.com> 1564478188 +0800
committer Guo Ren <ren_guo@c-sky.com> 1565075734 +0800

csky: Optimize arch_sync_dma_for_cpu/device with dma_inv_range

DMA_FROM_DEVICE only need to read dma data of memory into CPU cache,
so there is no need to clear cache before. Also clear + inv for
DMA_FROM_DEVICE won't cause problem, because the memory range for dma
won't be touched by software during dma working.

Changes for V2:
 - Remove clr cache and ignore the DMA_TO_DEVICE in _for_cpu.
 - Change inv to wbinv cache with DMA_FROM_DEVICE in _for_device.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>