commit 685ca577b408ffd9c5a4057a2acc0cd3e6978b36 upstream.
The arm_smmu_attach_commit() updates master->ats_enabled before calling
arm_smmu_remove_master_domain() that is supposed to clean up everything
in the old domain, including the old domain's nr_ats_masters. So, it is
supposed to use the old ats_enabled state of the device, not an updated
state.
This isn't a problem if switching between two domains where:
- old ats_enabled = false; new ats_enabled = false
- old ats_enabled = true; new ats_enabled = true
but can fail cases where:
- old ats_enabled = false; new ats_enabled = true
(old domain should keep the counter but incorrectly decreased it)
- old ats_enabled = true; new ats_enabled = false
(old domain needed to decrease the counter but incorrectly missed it)
Update master->ats_enabled after arm_smmu_remove_master_domain() to fix
this.
Fixes: 7497f4211f ("iommu/arm-smmu-v3: Make changing domains be hitless for ATS")
Cc: stable@vger.kernel.org
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Acked-by: Will Deacon <will@kernel.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Link: https://lore.kernel.org/r/20250801030127.2006979-1-nicolinc@nvidia.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
9efa1a429c