From: Isaac J. Manjarres isaacm@codeaurora.org
commit dead723e6f049e9fb6b05e5b93456982798ea961 upstream.
When extracting the mask for a SMR that was programmed by the bootloader, the SMR's valid bit is also extracted and is treated as part of the mask, which is not correct. Consider the scenario where an SMMU master whose context is determined by a bootloader programmed SMR is removed (omitting parts of device/driver core):
->iommu_release_device() -> arm_smmu_release_device() -> arm_smmu_master_free_smes() -> arm_smmu_free_sme() /* Assume that the SME is now free */ -> arm_smmu_write_sme() -> arm_smmu_write_smr() /* Construct SMR value using mask and SID */
Since the valid bit was considered as part of the mask, the SMR will be programmed as valid.
Fix the SMR mask extraction step for bootloader programmed SMRs by masking out the valid bit when we know that we're already working with a valid SMR.
Fixes: 07a7f2caaa5a ("iommu/arm-smmu-qcom: Read back stream mappings") Signed-off-by: Isaac J. Manjarres isaacm@codeaurora.org Cc: stable@vger.kernel.org Reviewed-by: Robin Murphy robin.murphy@arm.com Link: https://lore.kernel.org/r/1611611545-19055-1-git-send-email-isaacm@codeauror... Signed-off-by: Will Deacon will@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c @@ -65,6 +65,8 @@ static int qcom_smmu_cfg_probe(struct ar smr = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_SMR(i));
if (FIELD_GET(ARM_SMMU_SMR_VALID, smr)) { + /* Ignore valid bit for SMR mask extraction. */ + smr &= ~ARM_SMMU_SMR_VALID; smmu->smrs[i].id = FIELD_GET(ARM_SMMU_SMR_ID, smr); smmu->smrs[i].mask = FIELD_GET(ARM_SMMU_SMR_MASK, smr); smmu->smrs[i].valid = true;