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-rw-r--r--Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt3
-rw-r--r--drivers/iommu/arm-smmu-v3.c32
2 files changed, 34 insertions, 1 deletions
diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt
index c03eec116872..3443e0f838df 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 29cba3280af7..da902baaa794 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)