On 10/09/18 16:47, Christoph Hellwig wrote:
--- a/kernel/dma/Kconfig
+++ b/kernel/dma/Kconfig
@@ -13,6 +13,9 @@ config NEED_DMA_MAP_STATE
config ARCH_DMA_ADDR_T_64BIT
def_bool 64BIT || PHYS_ADDR_T_64BIT
+config ARCH_HAS_DMA_COHERENCE_H
+ bool
This seems a little crude - is it unbearably churny to make an
asm-generic/dma-coherence.h implementation for everyone else?
The case of having something else than the per-device flag is rather
odd, and I hope we don't grow any new user in addition to mips.
In fact I'm already thinking of ways to get rid of it for mips by
e.g. iterating over all devices and just setting dma_coherent,
but for now I wanted to solve the more urgen issues and tackle this
later, as this unification blocks a few other things
Ah, somehow I started thinking that arm(64) would need to implement
their own as well, but I see the point now. In that case, TBH I'd be
quite happy with just a simple #ifdef CONFIG_MIPS in
linux/dma-noncoherent.h - plus then it looks even more like something
nobody else is expected to do.
Nits aside, this otherwise looks sane to me for factoring out the
equivalent Xen and arm64 DMA ops cases.
Like this? :)
http://git.infradead.org/users/hch/misc.git/shortlog/refs/heads/dma-maybe-coherent
Man, that's going to take me a *lot* of time to pick through. All those
horrendous subtleties that I barely remember!
Robin.
