Messages in this thread | | | Date | Fri, 5 Apr 2019 17:09:19 +0100 | From | Will Deacon <> | Subject | Re: [PATCH v2 00/21] Remove Mysterious Macro Intended to Obscure Weird Behaviours (mmiowb()) |
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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@arm.com> 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
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