@@ -2449,6 +2449,32 @@ static struct iommu_group *arm_smmu_device_group(struct device *dev)
return group;
}
+static int arm_smmu_domain_nesting_info(struct arm_smmu_domain *smmu_domain,
+ void *data)
+{
+ struct iommu_nesting_info *info = (struct iommu_nesting_info *)data;
+ unsigned int size;
+
+ if (!info || smmu_domain->stage != ARM_SMMU_DOMAIN_NESTED)
+ return -ENODEV;
+
+ size = sizeof(struct iommu_nesting_info);
+
+ /*
+ * if provided buffer size is smaller than expected, should
+ * return 0 and also the expected buffer size to caller.
+ */
+ if (info->argsz < size) {
+ info->argsz = size;
+ return 0;
+ }
+
+ /* report an empty iommu_nesting_info for now */
+ memset(info, 0x0, size);
+ info->argsz = size;
+ return 0;
+}
+
static int arm_smmu_domain_get_attr(struct iommu_domain *domain,
enum iommu_attr attr, void *data)
{
@@ -2458,8 +2484,7 @@ static int arm_smmu_domain_get_attr(struct iommu_domain *domain,
case IOMMU_DOMAIN_UNMANAGED:
switch (attr) {
case DOMAIN_ATTR_NESTING:
- *(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED);
- return 0;
+ return arm_smmu_domain_nesting_info(smmu_domain, data);
default:
return -ENODEV;
}
@@ -1481,6 +1481,32 @@ static struct iommu_group *arm_smmu_device_group(struct device *dev)
return group;
}
+static int arm_smmu_domain_nesting_info(struct arm_smmu_domain *smmu_domain,
+ void *data)
+{
+ struct iommu_nesting_info *info = (struct iommu_nesting_info *)data;
+ unsigned int size;
+
+ if (!info || smmu_domain->stage != ARM_SMMU_DOMAIN_NESTED)
+ return -ENODEV;
+
+ size = sizeof(struct iommu_nesting_info);
+
+ /*
+ * if provided buffer size is smaller than expected, should
+ * return 0 and also the expected buffer size to caller.
+ */
+ if (info->argsz < size) {
+ info->argsz = size;
+ return 0;
+ }
+
+ /* report an empty iommu_nesting_info for now */
+ memset(info, 0x0, size);
+ info->argsz = size;
+ return 0;
+}
+
static int arm_smmu_domain_get_attr(struct iommu_domain *domain,
enum iommu_attr attr, void *data)
{
@@ -1490,8 +1516,7 @@ static int arm_smmu_domain_get_attr(struct iommu_domain *domain,
case IOMMU_DOMAIN_UNMANAGED:
switch (attr) {
case DOMAIN_ATTR_NESTING:
- *(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED);
- return 0;
+ return arm_smmu_domain_nesting_info(smmu_domain, data);
case DOMAIN_ATTR_IO_PGTABLE_CFG: {
struct io_pgtable_domain_attr *pgtbl_cfg = data;
*pgtbl_cfg = smmu_domain->pgtbl_cfg;