[PATCH v3 7/8] iommu/arm-smmu: Provide helper for allocating identity domain
From: Bjorn Andersson <hidden>
Date: 2020-09-04 15:55:52
Also in:
linux-arm-msm, linux-iommu, lkml
Subsystem:
arm smmu drivers, iommu subsystem, the rest · Maintainers:
Will Deacon, Joerg Roedel, Linus Torvalds
Some platform implementations needs to be able to allocate a domain for emulating identity mappings using a context bank without translation. Provide a helper function to allocate such a domain. Signed-off-by: Bjorn Andersson <redacted> --- Changes since v2: - Extracted from previous arm_smmu_setup_identity() implementation drivers/iommu/arm/arm-smmu/arm-smmu.c | 25 +++++++++++++++++++++++++ drivers/iommu/arm/arm-smmu/arm-smmu.h | 2 ++ 2 files changed, 27 insertions(+)
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index 4c4d302cd747..3c06146dfdb9 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c@@ -1924,6 +1924,31 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu) return 0; } +struct iommu_domain *arm_smmu_alloc_identity_domain(struct arm_smmu_device *smmu) +{ + struct iommu_domain *identity; + int ret; + + /* Create a IDENTITY domain to use for all inherited streams */ + identity = arm_smmu_domain_alloc(IOMMU_DOMAIN_IDENTITY); + if (!identity) { + dev_err(smmu->dev, "failed to create identity domain\n"); + return ERR_PTR(-ENOMEM); + } + + identity->pgsize_bitmap = smmu->pgsize_bitmap; + identity->type = IOMMU_DOMAIN_IDENTITY; + identity->ops = &arm_smmu_ops; + + ret = arm_smmu_init_domain_context(identity, smmu, NULL); + if (ret < 0) { + dev_err(smmu->dev, "failed to initialize identity domain: %d\n", ret); + return ERR_PTR(ret); + } + + return identity; +} + struct arm_smmu_match_data { enum arm_smmu_arch_version version; enum arm_smmu_implementation model;
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.h b/drivers/iommu/arm/arm-smmu/arm-smmu.h
index f58164976e74..fbdf3d7ca70d 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.h
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.h@@ -537,4 +537,6 @@ struct arm_smmu_device *qcom_adreno_smmu_impl_init(struct arm_smmu_device *smmu) void arm_smmu_write_context_bank(struct arm_smmu_device *smmu, int idx); int arm_mmu500_reset(struct arm_smmu_device *smmu); +struct iommu_domain *arm_smmu_alloc_identity_domain(struct arm_smmu_device *smmu); + #endif /* _ARM_SMMU_H */
--
2.28.0
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