On Fri, Apr 05, 2019 at 05:55:37AM -1000, Linus Torvalds wrote: > On Fri, Apr 5, 2019 at 3:59 AM Will Deacon <will.deacon@xxxxxxx> wrote: > > > > I've also pushed this series out here: > > > > git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/mmiowb > > > > and I would like to get it into -next once the first patch has been acked. > > Ack on it all. Thanks. > With the afore-mentioned slight worry about non-spinlocked IO > ordering, but I _think_ it's purely limited to ia64 and wmb() and > friends should work elsewhere? > > Or did I miss something? I think the ia64() mb/rmb/wmb stuff only > works on normal memory on ia64. I was worried about RISC-V, but actually their wmb() is "fence ow,ow" which I think is stronger than their mmiowb() "fence o,w" implementation. Everybody else should be fine with wmb() afaict, so if a driver writer is smart enough to want this ordering outside of spinlocks, they can do that for everybody apart from ia64. Will
