iommu/arm-smmu-qcom: Skip the TTBR1 quirk for db820c.

[ Upstream commit a242f42 ]

db820c wants to use the qcom smmu path to get HUPCF set (which keeps
the GPU from wedging and then sometimes wedging the kernel after a
page fault), but it doesn't have separate pagetables support yet in
drm/msm so we can't go all the way to the TTBR1 path.

Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20210326231303.3071950-1-eric@anholt.net
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c

@@ -130,6 +130,16 @@ static int qcom_adreno_smmu_alloc_context_bank(struct arm_smmu_domain *smmu_doma
 	return __arm_smmu_alloc_bitmap(smmu->context_map, start, count);
 }
 
+static bool qcom_adreno_can_do_ttbr1(struct arm_smmu_device *smmu)
+{
+	const struct device_node *np = smmu->dev->of_node;
+
+	if (of_device_is_compatible(np, "qcom,msm8996-smmu-v2"))
+		return false;
+
+	return true;
+}
+
 static int qcom_adreno_smmu_init_context(struct arm_smmu_domain *smmu_domain,
 		struct io_pgtable_cfg *pgtbl_cfg, struct device *dev)
 {
@@ -144,7 +154,8 @@ static int qcom_adreno_smmu_init_context(struct arm_smmu_domain *smmu_domain,
 	 * be AARCH64 stage 1 but double check because the arm-smmu code assumes
 	 * that is the case when the TTBR1 quirk is enabled
 	 */
-	if ((smmu_domain->stage == ARM_SMMU_DOMAIN_S1) &&
+	if (qcom_adreno_can_do_ttbr1(smmu_domain->smmu) &&
+	    (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) &&
 	    (smmu_domain->cfg.fmt == ARM_SMMU_CTX_FMT_AARCH64))
 		pgtbl_cfg->quirks |= IO_PGTABLE_QUIRK_ARM_TTBR1;