[PATCH v6 7/9] iommu/arm-smmu-v3: Get associated RMR info and install bypass STE
From: Shameer Kolothum <hidden>
Date: 2021-07-16 08:39:35
Also in:
linux-acpi, linux-iommu
Subsystem:
arm smmu drivers, iommu subsystem, the rest · Maintainers:
Will Deacon, Joerg Roedel, Linus Torvalds
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(). Signed-off-by: Shameer Kolothum <redacted> --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 31 +++++++++++++++++++++ 1 file changed, 31 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 34f84641dc6a..71a682fb375b 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c@@ -3759,6 +3759,34 @@ 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; + int ret; + + INIT_LIST_HEAD(&rmr_list); + if (iommu_dma_get_rmrs(dev_fwnode(smmu->dev), &rmr_list)) + return; + + list_for_each_entry(e, &rmr_list, list) { + __le64 *step; + u32 sid = e->fw_data.rmr.sid; + + ret = arm_smmu_init_sid_strtab(smmu, sid); + if (ret) { + dev_err(smmu->dev, "RMR SID(0x%x) bypass failed\n", + sid); + continue; + } + + step = arm_smmu_get_step_for_sid(smmu, sid); + arm_smmu_init_bypass_stes(step, 1, true); + } + + iommu_dma_put_rmrs(dev_fwnode(smmu->dev), &rmr_list); +} + static int arm_smmu_device_probe(struct platform_device *pdev) { int irq, ret;
@@ -3840,6 +3868,9 @@ 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)
--
2.17.1
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