Re: [PATCH RESEND v3] iommu/tegra-smmu: Add missing locks around mapping operations

[Joerg Roedel]

On Fri, Aug 14, 2020 at 07:22:52PM +0300, Dmitry Osipenko wrote:
> The mapping operations of the Tegra SMMU driver are subjected to a race
> condition issues because SMMU Address Space isn't allocated and freed
> atomically, while it should be. This patch makes the mapping operations
> atomic, it fixes an accidentally released Host1x Address Space problem
> which happens while running multiple graphics tests in parallel on
> Tegra30, i.e. by having multiple threads racing with each other in the
> Host1x's submission and completion code paths, performing IOVA mappings
> and unmappings in parallel.
> 
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>

Thierry, does this change look good to you?