From: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Date: Wed, 15 Jun 2022 11:10:43 +0100
Subject: iommu/arm-smmu-v3: Get associated RMR info and install bypass STE
Git-commit: 9bdbdaa3c44ea97c8e97e51dd503a7061bd676a0
Patch-mainline: v6.0-rc1
References: bsc#1205701

Check if there is any RMR info associated with the devices behind
the SMMUv3 and if any, install bypass STEs for them. This is to
keep any ongoing traffic associated with these devices alive
when we enable/reset SMMUv3 during probe().

Tested-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20220615101044.1972-9-shameerali.kolothum.thodi@huawei.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 33 +++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 09723861a08a..448e7b7ce0f2 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -3754,6 +3754,36 @@ static void __iomem *arm_smmu_ioremap(struct device *dev, resource_size_t start,
 	return devm_ioremap_resource(dev, &res);
 }
 
+static void arm_smmu_rmr_install_bypass_ste(struct arm_smmu_device *smmu)
+{
+	struct list_head rmr_list;
+	struct iommu_resv_region *e;
+
+	INIT_LIST_HEAD(&rmr_list);
+	iort_get_rmr_sids(dev_fwnode(smmu->dev), &rmr_list);
+
+	list_for_each_entry(e, &rmr_list, list) {
+		__le64 *step;
+		struct iommu_iort_rmr_data *rmr;
+		int ret, i;
+
+		rmr = container_of(e, struct iommu_iort_rmr_data, rr);
+		for (i = 0; i < rmr->num_sids; i++) {
+			ret = arm_smmu_init_sid_strtab(smmu, rmr->sids[i]);
+			if (ret) {
+				dev_err(smmu->dev, "RMR SID(0x%x) bypass failed\n",
+					rmr->sids[i]);
+				continue;
+			}
+
+			step = arm_smmu_get_step_for_sid(smmu, rmr->sids[i]);
+			arm_smmu_init_bypass_stes(step, 1, true);
+		}
+	}
+
+	iort_put_rmr_sids(dev_fwnode(smmu->dev), &rmr_list);
+}
+
 static int arm_smmu_device_probe(struct platform_device *pdev)
 {
 	int irq, ret;
@@ -3837,6 +3867,9 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
 	/* Record our private device structure */
 	platform_set_drvdata(pdev, smmu);
 
+	/* Check for RMRs and install bypass STEs if any */
+	arm_smmu_rmr_install_bypass_ste(smmu);
+
 	/* Reset the device */
 	ret = arm_smmu_device_reset(smmu, bypass);
 	if (ret)