[v6 2/3] iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #74
Shameerali Kolothum Thodi
shameerali.kolothum.thodi at huawei.com
Wed May 17 03:13:01 PDT 2017
Hi Geetha,
> -----Original Message-----
> From: linux-arm-kernel [mailto:linux-arm-kernel-
> bounces at lists.infradead.org] On Behalf Of Geetha sowjanya
> Sent: Friday, May 12, 2017 1:41 PM
> To: will.deacon at arm.com; robin.murphy at arm.com;
> lorenzo.pieralisi at arm.com; hanjun.guo at linaro.org; sudeep.holla at arm.com;
> iommu at lists.linux-foundation.org
> Cc: Charles.Garcia-Tobin at arm.com; Geetha Sowjanya;
> geethasowjanya.akula at gmail.com; jcm at redhat.com;
> linu.cherian at cavium.com; rjw at rjwysocki.net; robert.moore at intel.com;
> linux-kernel at vger.kernel.org; linux-acpi at vger.kernel.org;
> robert.richter at cavium.com; lv.zheng at intel.com; catalin.marinas at arm.com;
> sgoutham at cavium.com; linux-arm-kernel at lists.infradead.org;
> devel at acpica.org
> Subject: [v6 2/3] iommu/arm-smmu-v3: Add workaround for Cavium
> ThunderX2 erratum #74
>
> From: Linu Cherian <linu.cherian at cavium.com>
>
> Cavium ThunderX2 SMMU implementation doesn't support page 1 register
> space and PAGE0_REGS_ONLY option is enabled as an errata workaround.
> This option when turned on, replaces all page 1 offsets used for
> EVTQ_PROD/CONS, PRIQ_PROD/CONS register access with page 0 offsets.
>
> SMMU resource size checks are now based on SMMU option
> PAGE0_REGS_ONLY, since resource size can be either 64k/128k.
> For this, arm_smmu_device_dt_probe/acpi_probe has been moved before
> platform_get_resource call, so that SMMU options are set beforehand.
>
> Signed-off-by: Linu Cherian <linu.cherian at cavium.com>
> Signed-off-by: Geetha Sowjanya <geethasowjanya.akula at cavium.com>
> ---
> Documentation/arm64/silicon-errata.txt | 1 +
> .../devicetree/bindings/iommu/arm,smmu-v3.txt | 6 ++
> drivers/iommu/arm-smmu-v3.c | 64 +++++++++++++++++-----
> 3 files changed, 56 insertions(+), 15 deletions(-)
>
> diff --git a/Documentation/arm64/silicon-errata.txt
> b/Documentation/arm64/silicon-errata.txt
> index 10f2ddd..4693a32 100644
> --- a/Documentation/arm64/silicon-errata.txt
> +++ b/Documentation/arm64/silicon-errata.txt
> @@ -62,6 +62,7 @@ stable kernels.
> | Cavium | ThunderX GICv3 | #23154 | CAVIUM_ERRATUM_23154
> |
> | Cavium | ThunderX Core | #27456 | CAVIUM_ERRATUM_27456
> |
> | Cavium | ThunderX SMMUv2 | #27704 | N/A |
> +| Cavium | ThunderX2 SMMUv3| #74 | N/A |
> | | | | |
> | Freescale/NXP | LS2080A/LS1043A | A-008585 |
> FSL_ERRATUM_A008585 |
> | | | | |
> diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt
> b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt
> index be57550..e6da62b 100644
> --- a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt
> +++ b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt
> @@ -49,6 +49,12 @@ the PCIe specification.
> - hisilicon,broken-prefetch-cmd
> : Avoid sending CMD_PREFETCH_* commands to the SMMU.
>
> +- cavium-cn99xx,broken-page1-regspace
> + : Replaces all page 1 offsets used for EVTQ_PROD/CONS,
> + PRIQ_PROD/CONS register
> access with page 0 offsets.
> + Set for Caviun ThunderX2
> silicon that doesn't support
> + SMMU page1 register space.
> +
> ** Example
>
> smmu at 2b400000 {
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index 380969a..c519927c 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -412,6 +412,9 @@
> #define MSI_IOVA_BASE 0x8000000
> #define MSI_IOVA_LENGTH 0x100000
>
> +#define ARM_SMMU_PAGE0_REGS_ONLY(smmu) \
> + ((smmu)->options & ARM_SMMU_OPT_PAGE0_REGS_ONLY)
> +
> static bool disable_bypass;
> module_param_named(disable_bypass, disable_bypass, bool, S_IRUGO);
> MODULE_PARM_DESC(disable_bypass, @@ -597,6 +600,7 @@ struct
> arm_smmu_device {
> u32 features;
>
> #define ARM_SMMU_OPT_SKIP_PREFETCH (1 << 0)
> +#define ARM_SMMU_OPT_PAGE0_REGS_ONLY (1 << 1)
> u32 options;
>
> struct arm_smmu_cmdq cmdq;
> @@ -663,9 +667,19 @@ struct arm_smmu_option_prop {
>
> static struct arm_smmu_option_prop arm_smmu_options[] = {
> { ARM_SMMU_OPT_SKIP_PREFETCH, "hisilicon,broken-prefetch-
> cmd" },
> + { ARM_SMMU_OPT_PAGE0_REGS_ONLY,
> +"cavium-cn99xx,broken-page1-regspace"},
> { 0, NULL},
> };
>
> +static inline void __iomem *arm_smmu_page1_fixup(unsigned long offset,
> + struct arm_smmu_device
> *smmu)
> +{
> + if (offset > SZ_64K && ARM_SMMU_PAGE0_REGS_ONLY(smmu))
> + offset -= SZ_64K;
> +
> + return smmu->base + offset;
> +}
> +
> static struct arm_smmu_domain *to_smmu_domain(struct iommu_domain
> *dom) {
> return container_of(dom, struct arm_smmu_domain, domain); @@ -
> 1961,8 +1975,8 @@ static int arm_smmu_init_one_queue(struct
> arm_smmu_device *smmu,
> return -ENOMEM;
> }
>
> - q->prod_reg = smmu->base + prod_off;
> - q->cons_reg = smmu->base + cons_off;
> + q->prod_reg = arm_smmu_page1_fixup(prod_off, smmu);
> + q->cons_reg = arm_smmu_page1_fixup(cons_off, smmu);
> q->ent_dwords = dwords;
>
> q->q_base = Q_BASE_RWA;
> @@ -2363,8 +2377,10 @@ static int arm_smmu_device_reset(struct
> arm_smmu_device *smmu, bool bypass)
>
> /* Event queue */
> writeq_relaxed(smmu->evtq.q.q_base, smmu->base +
> ARM_SMMU_EVTQ_BASE);
> - writel_relaxed(smmu->evtq.q.prod, smmu->base +
> ARM_SMMU_EVTQ_PROD);
> - writel_relaxed(smmu->evtq.q.cons, smmu->base +
> ARM_SMMU_EVTQ_CONS);
> + writel_relaxed(smmu->evtq.q.prod,
> + arm_smmu_page1_fixup(ARM_SMMU_EVTQ_PROD,
> smmu));
> + writel_relaxed(smmu->evtq.q.cons,
> + arm_smmu_page1_fixup(ARM_SMMU_EVTQ_CONS,
> smmu));
>
> enables |= CR0_EVTQEN;
> ret = arm_smmu_write_reg_sync(smmu, enables,
> ARM_SMMU_CR0, @@ -2379,9 +2395,9 @@ static int
> arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass)
> writeq_relaxed(smmu->priq.q.q_base,
> smmu->base + ARM_SMMU_PRIQ_BASE);
> writel_relaxed(smmu->priq.q.prod,
> - smmu->base + ARM_SMMU_PRIQ_PROD);
> +
> arm_smmu_page1_fixup(ARM_SMMU_PRIQ_PROD, smmu));
> writel_relaxed(smmu->priq.q.cons,
> - smmu->base + ARM_SMMU_PRIQ_CONS);
> +
> arm_smmu_page1_fixup(ARM_SMMU_PRIQ_CONS, smmu));
>
> enables |= CR0_PRIQEN;
> ret = arm_smmu_write_reg_sync(smmu, enables,
> ARM_SMMU_CR0, @@ -2605,6 +2621,14 @@ static int
> arm_smmu_device_hw_probe(struct arm_smmu_device *smmu) }
>
> #ifdef CONFIG_ACPI
> +static void acpi_smmu_get_options(u32 model, struct arm_smmu_device
> +*smmu) {
> + if (model == ACPI_IORT_SMMU_CAVIUM_CN99XX)
> + smmu->options |= ARM_SMMU_OPT_PAGE0_REGS_ONLY;
HiSIlicon hip06/07 boards have a similar existing option to enable,
ARM_SMMU_OPT_SKIP_PREFETCH. I have just sent out a similar patch to enable
It-" [PATCH] iommu/arm-smmu-v3: Enable ACPI based HiSilicon CMD_PREFETCH
quirk(erratum 161010701)". May be it can be merged here, if this series goes through.
Not sure about the protocol though.
Thanks,
Shameer
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