From 5e92946c39ca6abc65e34775a93cc1d1a819c0e3 Mon Sep 17 00:00:00 2001 From: Zhen Lei Date: Tue, 7 Jul 2015 04:30:18 +0100 Subject: [PATCH] iommu/arm-smmu: Skip the execution of CMD_PREFETCH_CONFIG Hisilicon SMMUv3 devices treat CMD_PREFETCH_CONFIG as a illegal command, execute it will trigger GERROR interrupt. Although the gerror code manage to turn the prefetch into a SYNC, and the system can continue to run normally, but it's ugly to print error information. Signed-off-by: Zhen Lei [will: extended binding documentation] Signed-off-by: Will Deacon --- .../devicetree/bindings/iommu/arm,smmu-v3.txt | 3 ++ drivers/iommu/arm-smmu-v3.c | 32 +++++++++++++++++++++- 2 files changed, 34 insertions(+), 1 deletion(-) diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt index c03eec1..3443e0f 100644 --- a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt +++ b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt @@ -35,3 +35,6 @@ the PCIe specification. NOTE: this only applies to the SMMU itself, not masters connected upstream of the SMMU. + +- hisilicon,broken-prefetch-cmd + : Avoid sending CMD_PREFETCH_* commands to the SMMU. diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index 29cba32..da902ba 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -543,6 +543,9 @@ struct arm_smmu_device { #define ARM_SMMU_FEAT_HYP (1 << 12) u32 features; +#define ARM_SMMU_OPT_SKIP_PREFETCH (1 << 0) + u32 options; + struct arm_smmu_cmdq cmdq; struct arm_smmu_evtq evtq; struct arm_smmu_priq priq; @@ -603,11 +606,35 @@ struct arm_smmu_domain { static DEFINE_SPINLOCK(arm_smmu_devices_lock); static LIST_HEAD(arm_smmu_devices); +struct arm_smmu_option_prop { + u32 opt; + const char *prop; +}; + +static struct arm_smmu_option_prop arm_smmu_options[] = { + { ARM_SMMU_OPT_SKIP_PREFETCH, "hisilicon,broken-prefetch-cmd" }, + { 0, NULL}, +}; + static struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom) { return container_of(dom, struct arm_smmu_domain, domain); } +static void parse_driver_options(struct arm_smmu_device *smmu) +{ + int i = 0; + + do { + if (of_property_read_bool(smmu->dev->of_node, + arm_smmu_options[i].prop)) { + smmu->options |= arm_smmu_options[i].opt; + dev_notice(smmu->dev, "option %s\n", + arm_smmu_options[i].prop); + } + } while (arm_smmu_options[++i].opt); +} + /* Low-level queue manipulation functions */ static bool queue_full(struct arm_smmu_queue *q) { @@ -1037,7 +1064,8 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_device *smmu, u32 sid, arm_smmu_sync_ste_for_sid(smmu, sid); /* It's likely that we'll want to use the new STE soon */ - arm_smmu_cmdq_issue_cmd(smmu, &prefetch_cmd); + if (!(smmu->options & ARM_SMMU_OPT_SKIP_PREFETCH)) + arm_smmu_cmdq_issue_cmd(smmu, &prefetch_cmd); } static void arm_smmu_init_bypass_stes(u64 *strtab, unsigned int nent) @@ -2575,6 +2603,8 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev) if (irq > 0) smmu->gerr_irq = irq; + parse_driver_options(smmu); + /* Probe the h/w */ ret = arm_smmu_device_probe(smmu); if (ret) -- 2.7.4