Commit 5e92946c authored by Zhen Lei's avatar Zhen Lei Committed by Will Deacon
Browse files

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: default avatarZhen Lei <thunder.leizhen@huawei.com>
[will: extended binding documentation]
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent e2f4c233

Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt

+3 −0
Original line number Diff line number Diff line
@@ -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.

drivers/iommu/arm-smmu-v3.c

+31 −1
Original line number Diff line number Diff line
@@ -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)

{
@@ -1037,6 +1064,7 @@ 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 */

	if (!(smmu->options & ARM_SMMU_OPT_SKIP_PREFETCH))

		arm_smmu_cmdq_issue_cmd(smmu, &prefetch_cmd);

}
@@ -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)

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