[PATCH] iommu/arm-smmu-v3: Add rmb after reading event queue prod_reg

[Will Deacon]

On Mon, 28 Sep 2020 16:32:02 +0800, Zhou Wang wrote:
> In arm_smmu_evtq_thread, reading event queue is from consumer pointer,
> which has no address dependency on producer pointer, prog_reg(MMIO) and
> event queue memory(Normal memory) can disorder. So the load for event queue
> can be done before the load of prod_reg, then perhaps wrong event entry
> value will be got.
> 
> Add rmb to make sure to get correct event queue entry value.

Applied to will (for-joerg/arm-smmu/updates), thanks!

[1/1] iommu/arm-smmu-v3: Add rmb after reading event queue prod_reg
      https://git.kernel.org/will/c/a76a37777f2c 

(please note that I changed the patch to use readl() instead of an rmb()
in conjunction with the _relaxed() accessor, and then adjusted the cons
side to match in terms of DMB vs DSB).

Cheers,
-- 
Will

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