[PATCH 2/6] iommu/qcom: Write TCR before TTBRs to fix ASID access behavior

Konrad Dybcio
2022-05-27T21:39:07Z

From: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>

As also stated in the arm-smmu driver, we must write the TCR before
writing the TTBRs, since the TCR determines the access behavior of
some fields.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
Signed-off-by: Konrad Dybcio <konrad.dybcio@somainline.org>
---
drivers/iommu/arm/arm-smmu/qcom_iommu.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu/qcom_iommu.c b/drivers/iommu/arm/arm-smmu/qcom_iommu.c
index 1728d4d7fe25..75f353866c40 100644
--- a/drivers/iommu/arm/arm-smmu/qcom_iommu.c
+++ b/drivers/iommu/arm/arm-smmu/qcom_iommu.c
@@ -273,18 +273,18 @@ static int qcom_iommu_init_domain(struct iommu_domain *domain,
ctx->secure_init = true;
}

- /* TTBRs */
- iommu_writeq(ctx, ARM_SMMU_CB_TTBR0,
- pgtbl_cfg.arm_lpae_s1_cfg.ttbr |
- FIELD_PREP(ARM_SMMU_TTBRn_ASID, ctx->asid));
- iommu_writeq(ctx, ARM_SMMU_CB_TTBR1, 0);
-
/* TCR */
iommu_writel(ctx, ARM_SMMU_CB_TCR2,
arm_smmu_lpae_tcr2(&pgtbl_cfg));
iommu_writel(ctx, ARM_SMMU_CB_TCR,
arm_smmu_lpae_tcr(&pgtbl_cfg) | ARM_SMMU_TCR_EAE);

+ /* TTBRs */
+ iommu_writeq(ctx, ARM_SMMU_CB_TTBR0,
+ pgtbl_cfg.arm_lpae_s1_cfg.ttbr |
+ FIELD_PREP(ARM_SMMU_TTBRn_ASID, ctx->asid));
+ iommu_writeq(ctx, ARM_SMMU_CB_TTBR1, 0);
+
/* MAIRs (stage-1 only) */
iommu_writel(ctx, ARM_SMMU_CB_S1_MAIR0,
pgtbl_cfg.arm_lpae_s1_cfg.mair);
--
2.36.1