diff options
| author | Nicolin Chen <nicolinc@nvidia.com> | 2025-07-31 20:01:27 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-08-28 16:31:05 +0200 |
| commit | 9efa1a429cc2736187e04c32e482940f46ff0f9b (patch) | |
| tree | bc96bd7a6026f05c058f1d5951c9bed6a65f1600 | |
| parent | 4652d0b6f7e67fee22f1a1e172efb85368acac24 (diff) | |
iommu/arm-smmu-v3: Fix smmu_domain->nr_ats_masters decrement
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: 7497f4211f4f ("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>
| -rw-r--r-- | drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index 780e2d9e4ea8..172ce2030197 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -2778,9 +2778,9 @@ static void arm_smmu_attach_commit(struct arm_smmu_attach_state *state) /* ATS is being switched off, invalidate the entire ATC */ arm_smmu_atc_inv_master(master, IOMMU_NO_PASID); } - master->ats_enabled = state->ats_enabled; arm_smmu_remove_master_domain(master, state->old_domain, state->ssid); + master->ats_enabled = state->ats_enabled; } static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) |