Re: [PATCH v3 2/4] iommu/arm-smmu: Workaround for Marvell Armada-AP806 SoC erratum #582743
On 03.07.2020 11:03, Robin Murphy wrote: On 2020-07-02 21:16, Tomasz Nowicki wrote: From: Hanna Hawa Due to erratum #582743, the Marvell Armada-AP806 can't access 64bit to ARM SMMUv2 registers. Provide implementation relevant hooks: - split the writeq/readq to two accesses of writel/readl. - mask the MMU_IDR2.PTFSv8 fields to not use AArch64 format (but only AARCH32_L) since with AArch64 format 32 bits access is not supported. Note that separate writes/reads to 2 is not problem regards to atomicity, because the driver use the readq/writeq while initialize the SMMU, report for SMMU fault, and use spinlock in one case (iova_to_phys). The comment about the spinlock seems to be out of date, and TBH that whole sentence is a bit unclear - how about something like: "Note that most 64-bit registers like TTBRn can be accessed as two 32-bit halves without issue, and AArch32 format ensures that the register writes which must be atomic (for TLBI etc.) need only be 32-bit." Signed-off-by: Hanna Hawa Signed-off-by: Gregory CLEMENT Signed-off-by: Tomasz Nowicki --- Documentation/arm64/silicon-errata.rst | 3 ++ drivers/iommu/arm-smmu-impl.c | 52 ++ 2 files changed, 55 insertions(+) diff --git a/Documentation/arm64/silicon-errata.rst b/Documentation/arm64/silicon-errata.rst index 936cf2a59ca4..157214d3abe1 100644 --- a/Documentation/arm64/silicon-errata.rst +++ b/Documentation/arm64/silicon-errata.rst @@ -125,6 +125,9 @@ stable kernels. | Cavium | ThunderX2 Core | #219 | CAVIUM_TX2_ERRATUM_219 | ++-+-+-+ ++-+-+-+ +| Marvell | ARM-MMU-500 | #582743 | N/A | +++-+-+-+ +++-+-+-+ | Freescale/NXP | LS2080A/LS1043A | A-008585 | FSL_ERRATUM_A008585 | ++-+-+-+ ++-+-+-+ diff --git a/drivers/iommu/arm-smmu-impl.c b/drivers/iommu/arm-smmu-impl.c index c75b9d957b70..c1fc5e1b8193 100644 --- a/drivers/iommu/arm-smmu-impl.c +++ b/drivers/iommu/arm-smmu-impl.c @@ -147,6 +147,53 @@ static const struct arm_smmu_impl arm_mmu500_impl = { .reset = arm_mmu500_reset, }; +static u64 mrvl_mmu500_readq(struct arm_smmu_device *smmu, int page, int off) +{ + u64 val; + + /* + * Marvell Armada-AP806 erratum #582743. + * Split all the readq to double readl + */ + val = (u64)readl_relaxed(arm_smmu_page(smmu, page) + off + 4) << 32; + val |= readl_relaxed(arm_smmu_page(smmu, page) + off); Even though io-64-nonatomic-hi-lo.h doesn't override readq() etc. for 64-bit builds, you can still use hi_lo_readq_relaxed() directly. + + return val; +} + +static void mrvl_mmu500_writeq(struct arm_smmu_device *smmu, int page, int off, + u64 val) +{ + /* + * Marvell Armada-AP806 erratum #582743. + * Split all the writeq to double writel + */ + writel_relaxed(upper_32_bits(val), arm_smmu_page(smmu, page) + off + 4); + writel_relaxed(lower_32_bits(val), arm_smmu_page(smmu, page) + off); Similarly, hi_lo_writeq_relaxed(). +} + +static u32 mrvl_mmu500_cfg_id2_fixup(u32 id) +{ + + /* + * Armada-AP806 erratum #582743. + * Hide the SMMU_IDR2.PTFSv8 fields to sidestep the AArch64 + * formats altogether and allow using 32 bits access on the + * interconnect. + */ + id &= ~(ARM_SMMU_ID2_PTFS_4K | ARM_SMMU_ID2_PTFS_16K | + ARM_SMMU_ID2_PTFS_64K); + + return id; +} + +static const struct arm_smmu_impl mrvl_mmu500_impl = { + .read_reg64 = mrvl_mmu500_readq, + .write_reg64 = mrvl_mmu500_writeq, + .cfg_id2_fixup = mrvl_mmu500_cfg_id2_fixup, + .reset = arm_mmu500_reset, +}; + struct arm_smmu_device *arm_smmu_impl_init(struct arm_smmu_device *smmu) { @@ -160,6 +207,11 @@ struct arm_smmu_device *arm_smmu_impl_init(struct arm_smmu_device *smmu) */ switch (smmu->model) { case ARM_MMU500: + if (of_device_is_compatible(smmu->dev->of_node, Nit: there's a local "np" variable now. + "marvell,ap806-smmu-500")) { + smmu->impl = _mmu500_impl; + return smmu; + } Please put this with the other integration checks below the switch statement. Yes, it means we'll end up assigning smmu->impl twice for this particular case, but that's the intended pattern. Thanks, all above comments do make sense and will be fixed in next spin. Thanks, Tomasz ___ iommu mailing list iommu@lists.linux-foundation.org
Re: [PATCH v3 2/4] iommu/arm-smmu: Workaround for Marvell Armada-AP806 SoC erratum #582743
On 2020-07-02 21:16, Tomasz Nowicki wrote: From: Hanna Hawa Due to erratum #582743, the Marvell Armada-AP806 can't access 64bit to ARM SMMUv2 registers. Provide implementation relevant hooks: - split the writeq/readq to two accesses of writel/readl. - mask the MMU_IDR2.PTFSv8 fields to not use AArch64 format (but only AARCH32_L) since with AArch64 format 32 bits access is not supported. Note that separate writes/reads to 2 is not problem regards to atomicity, because the driver use the readq/writeq while initialize the SMMU, report for SMMU fault, and use spinlock in one case (iova_to_phys). The comment about the spinlock seems to be out of date, and TBH that whole sentence is a bit unclear - how about something like: "Note that most 64-bit registers like TTBRn can be accessed as two 32-bit halves without issue, and AArch32 format ensures that the register writes which must be atomic (for TLBI etc.) need only be 32-bit." Signed-off-by: Hanna Hawa Signed-off-by: Gregory CLEMENT Signed-off-by: Tomasz Nowicki --- Documentation/arm64/silicon-errata.rst | 3 ++ drivers/iommu/arm-smmu-impl.c | 52 ++ 2 files changed, 55 insertions(+) diff --git a/Documentation/arm64/silicon-errata.rst b/Documentation/arm64/silicon-errata.rst index 936cf2a59ca4..157214d3abe1 100644 --- a/Documentation/arm64/silicon-errata.rst +++ b/Documentation/arm64/silicon-errata.rst @@ -125,6 +125,9 @@ stable kernels. | Cavium | ThunderX2 Core | #219| CAVIUM_TX2_ERRATUM_219 | ++-+-+-+ ++-+-+-+ +| Marvell| ARM-MMU-500 | #582743 | N/A | +++-+-+-+ +++-+-+-+ | Freescale/NXP | LS2080A/LS1043A | A-008585| FSL_ERRATUM_A008585 | ++-+-+-+ ++-+-+-+ diff --git a/drivers/iommu/arm-smmu-impl.c b/drivers/iommu/arm-smmu-impl.c index c75b9d957b70..c1fc5e1b8193 100644 --- a/drivers/iommu/arm-smmu-impl.c +++ b/drivers/iommu/arm-smmu-impl.c @@ -147,6 +147,53 @@ static const struct arm_smmu_impl arm_mmu500_impl = { .reset = arm_mmu500_reset, }; +static u64 mrvl_mmu500_readq(struct arm_smmu_device *smmu, int page, int off) +{ + u64 val; + + /* +* Marvell Armada-AP806 erratum #582743. +* Split all the readq to double readl +*/ + val = (u64)readl_relaxed(arm_smmu_page(smmu, page) + off + 4) << 32; + val |= readl_relaxed(arm_smmu_page(smmu, page) + off); Even though io-64-nonatomic-hi-lo.h doesn't override readq() etc. for 64-bit builds, you can still use hi_lo_readq_relaxed() directly. + + return val; +} + +static void mrvl_mmu500_writeq(struct arm_smmu_device *smmu, int page, int off, + u64 val) +{ + /* +* Marvell Armada-AP806 erratum #582743. +* Split all the writeq to double writel +*/ + writel_relaxed(upper_32_bits(val), arm_smmu_page(smmu, page) + off + 4); + writel_relaxed(lower_32_bits(val), arm_smmu_page(smmu, page) + off); Similarly, hi_lo_writeq_relaxed(). +} + +static u32 mrvl_mmu500_cfg_id2_fixup(u32 id) +{ + + /* +* Armada-AP806 erratum #582743. +* Hide the SMMU_IDR2.PTFSv8 fields to sidestep the AArch64 +* formats altogether and allow using 32 bits access on the +* interconnect. +*/ + id &= ~(ARM_SMMU_ID2_PTFS_4K | ARM_SMMU_ID2_PTFS_16K | + ARM_SMMU_ID2_PTFS_64K); + + return id; +} + +static const struct arm_smmu_impl mrvl_mmu500_impl = { + .read_reg64 = mrvl_mmu500_readq, + .write_reg64 = mrvl_mmu500_writeq, + .cfg_id2_fixup = mrvl_mmu500_cfg_id2_fixup, + .reset = arm_mmu500_reset, +}; + struct arm_smmu_device *arm_smmu_impl_init(struct arm_smmu_device *smmu) { @@ -160,6 +207,11 @@ struct arm_smmu_device *arm_smmu_impl_init(struct arm_smmu_device *smmu) */ switch (smmu->model) { case ARM_MMU500: + if (of_device_is_compatible(smmu->dev->of_node, Nit: there's a local "np" variable now. + "marvell,ap806-smmu-500")) { + smmu->impl = _mmu500_impl; + return smmu; + } Please put this with the other integration checks below the switch statement. Yes, it means we'll end up assigning smmu->impl twice for this particular case, but that's the intended pattern. Robin. smmu->impl = _mmu500_impl; break; case
[PATCH v3 2/4] iommu/arm-smmu: Workaround for Marvell Armada-AP806 SoC erratum #582743
From: Hanna Hawa Due to erratum #582743, the Marvell Armada-AP806 can't access 64bit to ARM SMMUv2 registers. Provide implementation relevant hooks: - split the writeq/readq to two accesses of writel/readl. - mask the MMU_IDR2.PTFSv8 fields to not use AArch64 format (but only AARCH32_L) since with AArch64 format 32 bits access is not supported. Note that separate writes/reads to 2 is not problem regards to atomicity, because the driver use the readq/writeq while initialize the SMMU, report for SMMU fault, and use spinlock in one case (iova_to_phys). Signed-off-by: Hanna Hawa Signed-off-by: Gregory CLEMENT Signed-off-by: Tomasz Nowicki --- Documentation/arm64/silicon-errata.rst | 3 ++ drivers/iommu/arm-smmu-impl.c | 52 ++ 2 files changed, 55 insertions(+) diff --git a/Documentation/arm64/silicon-errata.rst b/Documentation/arm64/silicon-errata.rst index 936cf2a59ca4..157214d3abe1 100644 --- a/Documentation/arm64/silicon-errata.rst +++ b/Documentation/arm64/silicon-errata.rst @@ -125,6 +125,9 @@ stable kernels. | Cavium | ThunderX2 Core | #219| CAVIUM_TX2_ERRATUM_219 | ++-+-+-+ ++-+-+-+ +| Marvell| ARM-MMU-500 | #582743 | N/A | +++-+-+-+ +++-+-+-+ | Freescale/NXP | LS2080A/LS1043A | A-008585| FSL_ERRATUM_A008585 | ++-+-+-+ ++-+-+-+ diff --git a/drivers/iommu/arm-smmu-impl.c b/drivers/iommu/arm-smmu-impl.c index c75b9d957b70..c1fc5e1b8193 100644 --- a/drivers/iommu/arm-smmu-impl.c +++ b/drivers/iommu/arm-smmu-impl.c @@ -147,6 +147,53 @@ static const struct arm_smmu_impl arm_mmu500_impl = { .reset = arm_mmu500_reset, }; +static u64 mrvl_mmu500_readq(struct arm_smmu_device *smmu, int page, int off) +{ + u64 val; + + /* +* Marvell Armada-AP806 erratum #582743. +* Split all the readq to double readl +*/ + val = (u64)readl_relaxed(arm_smmu_page(smmu, page) + off + 4) << 32; + val |= readl_relaxed(arm_smmu_page(smmu, page) + off); + + return val; +} + +static void mrvl_mmu500_writeq(struct arm_smmu_device *smmu, int page, int off, + u64 val) +{ + /* +* Marvell Armada-AP806 erratum #582743. +* Split all the writeq to double writel +*/ + writel_relaxed(upper_32_bits(val), arm_smmu_page(smmu, page) + off + 4); + writel_relaxed(lower_32_bits(val), arm_smmu_page(smmu, page) + off); +} + +static u32 mrvl_mmu500_cfg_id2_fixup(u32 id) +{ + + /* +* Armada-AP806 erratum #582743. +* Hide the SMMU_IDR2.PTFSv8 fields to sidestep the AArch64 +* formats altogether and allow using 32 bits access on the +* interconnect. +*/ + id &= ~(ARM_SMMU_ID2_PTFS_4K | ARM_SMMU_ID2_PTFS_16K | + ARM_SMMU_ID2_PTFS_64K); + + return id; +} + +static const struct arm_smmu_impl mrvl_mmu500_impl = { + .read_reg64 = mrvl_mmu500_readq, + .write_reg64 = mrvl_mmu500_writeq, + .cfg_id2_fixup = mrvl_mmu500_cfg_id2_fixup, + .reset = arm_mmu500_reset, +}; + struct arm_smmu_device *arm_smmu_impl_init(struct arm_smmu_device *smmu) { @@ -160,6 +207,11 @@ struct arm_smmu_device *arm_smmu_impl_init(struct arm_smmu_device *smmu) */ switch (smmu->model) { case ARM_MMU500: + if (of_device_is_compatible(smmu->dev->of_node, + "marvell,ap806-smmu-500")) { + smmu->impl = _mmu500_impl; + return smmu; + } smmu->impl = _mmu500_impl; break; case CAVIUM_SMMUV2: -- 2.17.1 ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu