Use WRITE_ONCE() to make sure that the SMMU doesn't read incomplete stream table descriptors. Refer to the comment about 64-bit accesses, and add the comment to the equivalent context descriptor code. Signed-off-by: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx> --- drivers/iommu/arm-smmu-v3.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index 6b76df37025e..068a16d0eabe 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -1531,6 +1531,7 @@ static void arm_smmu_write_cd_l1_desc(__le64 *dst, u64 val = (l1_desc->l2ptr_dma & CTXDESC_L1_DESC_L2PTR_MASK) | CTXDESC_L1_DESC_V; + /* See comment in arm_smmu_write_ctx_desc() */ WRITE_ONCE(*dst, cpu_to_le64(val)); } @@ -1726,7 +1727,8 @@ arm_smmu_write_strtab_l1_desc(__le64 *dst, struct arm_smmu_strtab_l1_desc *desc) val |= FIELD_PREP(STRTAB_L1_DESC_SPAN, desc->span); val |= desc->l2ptr_dma & STRTAB_L1_DESC_L2PTR_MASK; - *dst = cpu_to_le64(val); + /* See comment in arm_smmu_write_ctx_desc() */ + WRITE_ONCE(*dst, cpu_to_le64(val)); } static void arm_smmu_sync_ste_for_sid(struct arm_smmu_device *smmu, u32 sid) -- 2.25.0
