diff options
author | Jean-Philippe Brucker <jean-philippe@linaro.org> | 2020-09-18 12:18:50 +0200 |
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committer | Will Deacon <will@kernel.org> | 2020-09-28 23:48:06 +0100 |
commit | d744f9e6c222c8086376bc56c86e4380595350bd (patch) | |
tree | 7d321bd8985731609a9733e8cfa299bb230674a9 /drivers | |
parent | 3e63033675c9b1e79b14655481a8c4ecaf23821f (diff) | |
download | linux-d744f9e6c222c8086376bc56c86e4380595350bd.tar.bz2 |
iommu/arm-smmu-v3: Check for SVA features
Aggregate all sanity-checks for sharing CPU page tables with the SMMU
under a single ARM_SMMU_FEAT_SVA bit. For PCIe SVA, users also need to
check FEAT_ATS and FEAT_PRI. For platform SVA, they will have to check
FEAT_STALLS.
Introduce ARM_SMMU_FEAT_BTM (Broadcast TLB Maintenance), but don't
enable it at the moment. Since the entire VMID space is shared with the
CPU, enabling DVM (by clearing SMMU_CR2.PTM) could result in
over-invalidation and affect performance of stage-2 mappings.
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20200918101852.582559-11-jean-philippe@linaro.org
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 45 | ||||
-rw-r--r-- | drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 3 | ||||
-rw-r--r-- | drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 10 |
3 files changed, 58 insertions, 0 deletions
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c index ef3fcfa72187..cb94c0924196 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c @@ -152,3 +152,48 @@ static void arm_smmu_free_shared_cd(struct arm_smmu_ctx_desc *cd) kfree(cd); } } + +bool arm_smmu_sva_supported(struct arm_smmu_device *smmu) +{ + unsigned long reg, fld; + unsigned long oas; + unsigned long asid_bits; + u32 feat_mask = ARM_SMMU_FEAT_BTM | ARM_SMMU_FEAT_COHERENCY; + + if (vabits_actual == 52) + feat_mask |= ARM_SMMU_FEAT_VAX; + + if ((smmu->features & feat_mask) != feat_mask) + return false; + + if (!(smmu->pgsize_bitmap & PAGE_SIZE)) + return false; + + /* + * Get the smallest PA size of all CPUs (sanitized by cpufeature). We're + * not even pretending to support AArch32 here. Abort if the MMU outputs + * addresses larger than what we support. + */ + reg = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1); + fld = cpuid_feature_extract_unsigned_field(reg, ID_AA64MMFR0_PARANGE_SHIFT); + oas = id_aa64mmfr0_parange_to_phys_shift(fld); + if (smmu->oas < oas) + return false; + + /* We can support bigger ASIDs than the CPU, but not smaller */ + fld = cpuid_feature_extract_unsigned_field(reg, ID_AA64MMFR0_ASID_SHIFT); + asid_bits = fld ? 16 : 8; + if (smmu->asid_bits < asid_bits) + return false; + + /* + * See max_pinned_asids in arch/arm64/mm/context.c. The following is + * generally the maximum number of bindable processes. + */ + if (arm64_kernel_unmapped_at_el0()) + asid_bits--; + dev_dbg(smmu->dev, "%d shared contexts\n", (1 << asid_bits) - + num_possible_cpus() - 2); + + return true; +} 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 14108f1cd2ea..cc02d6d815e6 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -3274,6 +3274,9 @@ static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu) smmu->ias = max(smmu->ias, smmu->oas); + if (arm_smmu_sva_supported(smmu)) + smmu->features |= ARM_SMMU_FEAT_SVA; + dev_info(smmu->dev, "ias %lu-bit, oas %lu-bit (features 0x%08x)\n", smmu->ias, smmu->oas, smmu->features); return 0; diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h index 1529714ce006..454a935de445 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h @@ -602,6 +602,8 @@ struct arm_smmu_device { #define ARM_SMMU_FEAT_STALL_FORCE (1 << 13) #define ARM_SMMU_FEAT_VAX (1 << 14) #define ARM_SMMU_FEAT_RANGE_INV (1 << 15) +#define ARM_SMMU_FEAT_BTM (1 << 16) +#define ARM_SMMU_FEAT_SVA (1 << 17) u32 features; #define ARM_SMMU_OPT_SKIP_PREFETCH (1 << 0) @@ -684,4 +686,12 @@ int arm_smmu_write_ctx_desc(struct arm_smmu_domain *smmu_domain, int ssid, void arm_smmu_tlb_inv_asid(struct arm_smmu_device *smmu, u16 asid); bool arm_smmu_free_asid(struct arm_smmu_ctx_desc *cd); +#ifdef CONFIG_ARM_SMMU_V3_SVA +bool arm_smmu_sva_supported(struct arm_smmu_device *smmu); +#else /* CONFIG_ARM_SMMU_V3_SVA */ +static inline bool arm_smmu_sva_supported(struct arm_smmu_device *smmu) +{ + return false; +} +#endif /* CONFIG_ARM_SMMU_V3_SVA */ #endif /* _ARM_SMMU_V3_H */ |