1 files changed, 52 insertions, 0 deletions

diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index 2ed3594f384e..7ac4907235c3 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
@@ -2071,6 +2071,54 @@ err_reset_platform_ops: __maybe_unused;
 	return err;
 }
 
+static void arm_smmu_rmr_install_bypass_smr(struct arm_smmu_device *smmu)
+{
+	struct list_head rmr_list;
+	struct iommu_resv_region *e;
+	int idx, cnt = 0;
+	u32 reg;
+
+	INIT_LIST_HEAD(&rmr_list);
+	iort_get_rmr_sids(dev_fwnode(smmu->dev), &rmr_list);
+
+	/*
+	 * Rather than trying to look at existing mappings that
+	 * are setup by the firmware and then invalidate the ones
+	 * that do no have matching RMR entries, just disable the
+	 * SMMU until it gets enabled again in the reset routine.
+	 */
+	reg = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_sCR0);
+	reg |= ARM_SMMU_sCR0_CLIENTPD;
+	arm_smmu_gr0_write(smmu, ARM_SMMU_GR0_sCR0, reg);
+
+	list_for_each_entry(e, &rmr_list, list) {
+		struct iommu_iort_rmr_data *rmr;
+		int i;
+
+		rmr = container_of(e, struct iommu_iort_rmr_data, rr);
+		for (i = 0; i < rmr->num_sids; i++) {
+			idx = arm_smmu_find_sme(smmu, rmr->sids[i], ~0);
+			if (idx < 0)
+				continue;
+
+			if (smmu->s2crs[idx].count == 0) {
+				smmu->smrs[idx].id = rmr->sids[i];
+				smmu->smrs[idx].mask = 0;
+				smmu->smrs[idx].valid = true;
+			}
+			smmu->s2crs[idx].count++;
+			smmu->s2crs[idx].type = S2CR_TYPE_BYPASS;
+			smmu->s2crs[idx].privcfg = S2CR_PRIVCFG_DEFAULT;
+
+			cnt++;
+		}
+	}
+
+	dev_notice(smmu->dev, "\tpreserved %d boot mapping%s\n", cnt,
+		   cnt == 1 ? "" : "s");
+	iort_put_rmr_sids(dev_fwnode(smmu->dev), &rmr_list);
+}
+
 static int arm_smmu_device_probe(struct platform_device *pdev)
 {
 	struct resource *res;
@@ -2191,6 +2239,10 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
 	}
 
 	platform_set_drvdata(pdev, smmu);
+
+	/* Check for RMRs and install bypass SMRs if any */
+	arm_smmu_rmr_install_bypass_smr(smmu);
+
 	arm_smmu_device_reset(smmu);
 	arm_smmu_test_smr_masks(smmu);