arm-smmu= arm-smmu driver option
off Disable arm-smmu driver (ie. ignore available SMMUs)
force_isolation
Try to attach each master device on every SMMU to a
separate iommu_domain.
Default is that driver detects SMMUs but no translation is configured
(transactions just bypass translation process).
Signed-off-by: Andreas Herrmann <[email protected]>
---
drivers/iommu/arm-smmu.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 3eb2259..251564e 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -399,6 +399,9 @@ struct arm_smmu_domain {
static DEFINE_SPINLOCK(arm_smmu_devices_lock);
static LIST_HEAD(arm_smmu_devices);
+static bool arm_smmu_disabled;
+static bool arm_smmu_force_isolation;
+
static struct arm_smmu_master *find_smmu_master(struct arm_smmu_device *smmu,
struct device_node *dev_node)
{
@@ -1837,6 +1840,9 @@ static int arm_smmu_device_dt_probe(struct
platform_device *pdev)
struct of_phandle_args masterspec;
int num_irqs, i, err;
+ if (arm_smmu_disabled)
+ return -ENODEV;
+
smmu = devm_kzalloc(dev, sizeof(*smmu), GFP_KERNEL);
if (!smmu) {
dev_err(dev, "failed to allocate arm_smmu_device\n");
@@ -2022,6 +2028,23 @@ static struct platform_driver arm_smmu_driver = {
.remove = arm_smmu_device_remove,
};
+static int __init arm_smmu_parse_options(char *str)
+{
+ if (*str) {
+ str++;
+ if (!strncmp(str, "off", 3))
+ arm_smmu_disabled = true;
+ else if(!strncmp(str, "force_isolation", 15))
+ arm_smmu_force_isolation = true;
+ else {
+ pr_warn("arm_smmu: invalid parameter (\"%s\")\n", str);
+ return 0;
+ }
+ }
+ return 1;
+}
+__setup("arm-smmu", arm_smmu_parse_options);
+
static int __init arm_smmu_init(void)
{
int ret;
@@ -2037,6 +2060,9 @@ static int __init arm_smmu_init(void)
if (!iommu_present(&amba_bustype))
bus_set_iommu(&amba_bustype, &arm_smmu_ops);
+ if (arm_smmu_force_isolation)
+ arm_smmu_isolate_devices();
+
return 0;
}
--
1.7.9.5
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