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| author | Robin Murphy <robin.murphy@arm.com> | 2023-05-10 16:38:43 +0100 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2023-06-08 21:58:12 +0100 |
| commit | f322e8af35c7f23a8c08b595c38d6c855b2d836f (patch) | |
| tree | 1a91a9fdb93761f0c8e29f693ff22337bf847c3e | |
| parent | 44c026a73be8038f03dbdeef028b642880cf1511 (diff) | |
| download | lwn-f322e8af35c7f23a8c08b595c38d6c855b2d836f.tar.gz lwn-f322e8af35c7f23a8c08b595c38d6c855b2d836f.zip | |
iommu/arm-smmu-v3: Work around MMU-600 erratum 1076982
MMU-600 versions prior to r1p0 fail to correctly generate a WFE wakeup
event when the command queue transitions fom full to non-full. We can
easily work around this by simply hiding the SEV capability such that we
fall back to polling for space in the queue - since MMU-600 implements
MSIs we wouldn't expect to need SEV for sync completion either, so this
should have little to no impact.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/08adbe3d01024d8382a478325f73b56851f76e49.1683731256.git.robin.murphy@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
| -rw-r--r-- | Documentation/arm64/silicon-errata.rst | 2 | ||||
| -rw-r--r-- | drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 29 | ||||
| -rw-r--r-- | drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 6 |
3 files changed, 37 insertions, 0 deletions
diff --git a/Documentation/arm64/silicon-errata.rst b/Documentation/arm64/silicon-errata.rst index 9e311bc43e05..951d8d42c248 100644 --- a/Documentation/arm64/silicon-errata.rst +++ b/Documentation/arm64/silicon-errata.rst @@ -140,6 +140,8 @@ stable kernels. +----------------+-----------------+-----------------+-----------------------------+ | ARM | MMU-500 | #841119,826419 | N/A | +----------------+-----------------+-----------------+-----------------------------+ +| ARM | MMU-600 | #1076982 | N/A | ++----------------+-----------------+-----------------+-----------------------------+ +----------------+-----------------+-----------------+-----------------------------+ | Broadcom | Brahma-B53 | N/A | ARM64_ERRATUM_845719 | +----------------+-----------------+-----------------+-----------------------------+ 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 3fd83fb75722..667e7a90706e 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -3429,6 +3429,33 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass) return 0; } +#define IIDR_IMPLEMENTER_ARM 0x43b +#define IIDR_PRODUCTID_ARM_MMU_600 0x483 + +static void arm_smmu_device_iidr_probe(struct arm_smmu_device *smmu) +{ + u32 reg; + unsigned int implementer, productid, variant, revision; + + reg = readl_relaxed(smmu->base + ARM_SMMU_IIDR); + implementer = FIELD_GET(IIDR_IMPLEMENTER, reg); + productid = FIELD_GET(IIDR_PRODUCTID, reg); + variant = FIELD_GET(IIDR_VARIANT, reg); + revision = FIELD_GET(IIDR_REVISION, reg); + + switch (implementer) { + case IIDR_IMPLEMENTER_ARM: + switch (productid) { + case IIDR_PRODUCTID_ARM_MMU_600: + /* Arm erratum 1076982 */ + if (variant == 0 && revision <= 2) + smmu->features &= ~ARM_SMMU_FEAT_SEV; + break; + } + break; + } +} + static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu) { u32 reg; @@ -3635,6 +3662,8 @@ static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu) smmu->ias = max(smmu->ias, smmu->oas); + arm_smmu_device_iidr_probe(smmu); + if (arm_smmu_sva_supported(smmu)) smmu->features |= ARM_SMMU_FEAT_SVA; 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 b574c58a3487..5ce47f2e3402 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h @@ -69,6 +69,12 @@ #define IDR5_VAX GENMASK(11, 10) #define IDR5_VAX_52_BIT 1 +#define ARM_SMMU_IIDR 0x18 +#define IIDR_PRODUCTID GENMASK(31, 20) +#define IIDR_VARIANT GENMASK(19, 16) +#define IIDR_REVISION GENMASK(15, 12) +#define IIDR_IMPLEMENTER GENMASK(11, 0) + #define ARM_SMMU_CR0 0x20 #define CR0_ATSCHK (1 << 4) #define CR0_CMDQEN (1 << 3) |