[PATCH 1/4] iommu/arm-smmu-v3: Work around MMU-600 erratum 1076982

[Nicolin Chen]

On Wed, May 10, 2023 at 10:40:42AM -0700, Nicolin Chen wrote:
> On Wed, May 10, 2023 at 04:38:43PM +0100, Robin Murphy wrote:
> 
> > MMU-600 versions prior to r1p0 fail to correctly generate a WFE wakeup
> > event when the command queue transitions fom full to non-full. We can
> > easily work around this by simply hiding the SEV capability such that we
> > fall back to polling for space in the queue - since MMU-600 implements
> > MSIs we wouldn't expect to need SEV for sync completion either, so this
> > should have little to no impact.
> > 
> > Signed-off-by: Robin Murphy <robin.murphy at arm.com>
> 
> Reviewed-by: Nicolin Chen <nicolinc at nvidia.com>

It happens that I have a simulation environment where the
IIDR value hits the errata, i.e. the NESTING feature bit
gets canceled by this patch. So,

Tested-by: Nicolin Chen <nicolinc at nvidia.com>

Hopefully we can get this series merged soon.

Thanks!
Nic