From: Robin Murphy robin.murphy@arm.com
commit f322e8af35c7f23a8c08b595c38d6c855b2d836f upstream
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/08adbe3d01024d8382a478325f73b56851f76e49.168373125... Signed-off-by: Will Deacon will@kernel.org Signed-off-by: Easwar Hariharan eahariha@linux.microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- Documentation/arm64/silicon-errata.rst | 2 + drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 29 ++++++++++++++++++++++++++++ drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 6 +++++ 3 files changed, 37 insertions(+)
--- a/Documentation/arm64/silicon-errata.rst +++ b/Documentation/arm64/silicon-errata.rst @@ -141,6 +141,8 @@ stable kernels. +----------------+-----------------+-----------------+-----------------------------+ | ARM | MMU-500 | #841119,826419 | N/A | +----------------+-----------------+-----------------+-----------------------------+ +| ARM | MMU-600 | #1076982 | N/A | ++----------------+-----------------+-----------------+-----------------------------+ +----------------+-----------------+-----------------+-----------------------------+ | Broadcom | Brahma-B53 | N/A | ARM64_ERRATUM_845719 | +----------------+-----------------+-----------------+-----------------------------+ --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -3410,6 +3410,33 @@ static int arm_smmu_device_reset(struct 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; @@ -3615,6 +3642,8 @@ static int arm_smmu_device_hw_probe(stru
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;
--- 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)