[PATCH v4 1/2] asm-generic: Add memory barrier dma_mb()

[Catalin Marinas]

On Fri, Jun 17, 2022 at 12:18:41PM +0200, Marco Elver wrote:
> On Fri, 17 Jun 2022 at 01:13, Paul E. McKenney <paulmck at kernel.org> wrote:
> > On Mon, May 23, 2022 at 01:35:27PM +0200, Marco Elver wrote:
> > > On Mon, 23 May 2022 at 13:21, Kefeng Wang <wangkefeng.wang at huawei.com> wrote:
> > > >
> > > > The memory barrier dma_mb() is introduced by commit a76a37777f2c
> > > > ("iommu/arm-smmu-v3: Ensure queue is read after updating prod pointer"),
> > > > which is used to ensure that prior (both reads and writes) accesses
> > > > to memory by a CPU are ordered w.r.t. a subsequent MMIO write.
> > > >
> > > > Reviewed-by: Arnd Bergmann <arnd at arndb.de> # for asm-generic
> > > > Signed-off-by: Kefeng Wang <wangkefeng.wang at huawei.com>
> > >
> > > Reviewed-by: Marco Elver <elver at google.com>
> >
> > Just checking...  Did these ever get picked up?  It was suggested
> > that they go up via the arm64 tree, if I remember correctly.
> 
> I don't see them in -next, and as far as I can tell, they're not in
> the arm64 tree.

Since v4 was posted during the merging window, it hasn't been queued for
5.19-rc1. I normally only merge patches with a Fixes tag during the -rc
period (though there are some exceptions). Mark commented in v1 that
such tag isn't necessary, so I thought I'd leave it for the 5.20 merging
window.

That said, the diffstat is small, so if it helps having this in 5.19, I
can queue it for -rc4.

-- 
Catalin