This is a note to let you know that I've just added the patch titled
iommu/arm-smmu-v3: Work around MMU-600 erratum 1076982
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iommu-arm-smmu-v3-work-around-mmu-600-erratum-1076982.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From stable-owner@xxxxxxxxxxxxxxx Wed Aug 2 19:21:17 2023
From: Easwar Hariharan <eahariha@xxxxxxxxxxxxxxxxxxx>
Date: Wed, 2 Aug 2023 17:20:57 +0000
Subject: iommu/arm-smmu-v3: Work around MMU-600 erratum 1076982
To: stable@xxxxxxxxxxxxxxx
Cc: easwar.hariharan@xxxxxxxxxxxxx, Robin Murphy <robin.murphy@xxxxxxx>, Nicolin Chen <nicolinc@xxxxxxxxxx>, Will Deacon <will@xxxxxxxxxx>, Catalin Marinas <catalin.marinas@xxxxxxx>, Jonathan Corbet <corbet@xxxxxxx>, Joerg Roedel <joro@xxxxxxxxxx>, Yicong Yang <yangyicong@xxxxxxxxxxxxx>, Vladimir Oltean <vladimir.oltean@xxxxxxx>, Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>, linux-arm-kernel@xxxxxxxxxxxxxxxxxxx (moderated list:ARM64 PORT (AARCH64 ARCHITECTURE)), linux-doc@xxxxxxxxxxxxxxx (open list:DOCUMENTATION), linux-kernel@xxxxxxxxxxxxxxx (open list), iommu@xxxxxxxxxxxxxxx (open list:IOMMU SUBSYSTEM)
Message-ID: <20230802172100.1599164-2-eahariha@xxxxxxxxxxxxxxxxxxx>
From: Robin Murphy <robin.murphy@xxxxxxx>
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@xxxxxxx>
Reviewed-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
Tested-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
Link: https://lore.kernel.org/r/08adbe3d01024d8382a478325f73b56851f76e49.1683731256.git.robin.murphy@xxxxxxx
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Easwar Hariharan <eahariha@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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)
Patches currently in stable-queue which might be from stable-owner@xxxxxxxxxxxxxxx are
queue-6.1/iommu-arm-smmu-v3-document-nesting-related-errata.patch
queue-6.1/iommu-arm-smmu-v3-add-explicit-feature-for-nesting.patch
queue-6.1/iommu-arm-smmu-v3-document-mmu-700-erratum-2812531.patch
queue-6.1/iommu-arm-smmu-v3-work-around-mmu-600-erratum-1076982.patch
