49 lines
2.0 KiB
Diff
49 lines
2.0 KiB
Diff
From 901e269fd5b5d6868b4055f4b8afcf876cf5c8bd Mon Sep 17 00:00:00 2001
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From: Nicolin Chen <nicolinc@nvidia.com>
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Date: Thu, 31 Jul 2025 20:01:27 -0700
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Subject: iommu/arm-smmu-v3: Fix smmu_domain->nr_ats_masters decrement
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The arm_smmu_attach_commit() updates master->ats_enabled before calling
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arm_smmu_remove_master_domain() that is supposed to clean up everything
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in the old domain, including the old domain's nr_ats_masters. So, it is
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supposed to use the old ats_enabled state of the device, not an updated
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state.
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This isn't a problem if switching between two domains where:
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- old ats_enabled = false; new ats_enabled = false
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- old ats_enabled = true; new ats_enabled = true
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but can fail cases where:
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- old ats_enabled = false; new ats_enabled = true
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(old domain should keep the counter but incorrectly decreased it)
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- old ats_enabled = true; new ats_enabled = false
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(old domain needed to decrease the counter but incorrectly missed it)
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Update master->ats_enabled after arm_smmu_remove_master_domain() to fix
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this.
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Fixes: 7497f4211f4f ("iommu/arm-smmu-v3: Make changing domains be hitless for ATS")
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Cc: stable@vger.kernel.org
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Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
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Acked-by: Will Deacon <will@kernel.org>
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Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
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Reviewed-by: Pranjal Shrivastava <praan@google.com>
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Link: https://lore.kernel.org/r/20250801030127.2006979-1-nicolinc@nvidia.com
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Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
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---
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drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 2 +-
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1 file changed, 1 insertion(+), 1 deletion(-)
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--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
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+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
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@@ -2997,9 +2997,9 @@ void arm_smmu_attach_commit(struct arm_s
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/* ATS is being switched off, invalidate the entire ATC */
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arm_smmu_atc_inv_master(master, IOMMU_NO_PASID);
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}
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- master->ats_enabled = state->ats_enabled;
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arm_smmu_remove_master_domain(master, state->old_domain, state->ssid);
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+ master->ats_enabled = state->ats_enabled;
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}
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static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
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