Yi,
On 7/12/20 1:20 PM, Liu Yi L wrote:
> This patch is added as instead of returning a boolean for DOMAIN_ATTR_NESTING,
> iommu_domain_get_attr() should return an iommu_nesting_info handle.
you may add in the commit message you return an empty nesting info
struct for now as true nesting is not yet supported by the SMMUs.
Besides:
Reviewed-by: Eric Auger <eric.auger@xxxxxxxxxx>
Thanks
Eric
>
> Cc: Will Deacon <will@xxxxxxxxxx>
> Cc: Robin Murphy <robin.murphy@xxxxxxx>
> Cc: Eric Auger <eric.auger@xxxxxxxxxx>
> Cc: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
> Suggested-by: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
> Signed-off-by: Liu Yi L <yi.l.liu@xxxxxxxxx>
> Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
> ---
> v4 -> v5:
> *) address comments from Eric Auger.
> ---
> drivers/iommu/arm-smmu-v3.c | 29 +++++++++++++++++++++++++++--
> drivers/iommu/arm-smmu.c | 29 +++++++++++++++++++++++++++--
> 2 files changed, 54 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index f578677..ec815d7 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -3019,6 +3019,32 @@ 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->size < size) {
> + info->size = size;
> + return 0;
> + }
> +
> + /* report an empty iommu_nesting_info for now */
> + memset(info, 0x0, size);
> + info->size = size;
> + return 0;
> +}
> +
> static int arm_smmu_domain_get_attr(struct iommu_domain *domain,
> enum iommu_attr attr, void *data)
> {
> @@ -3028,8 +3054,7 @@ 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;
> }
> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
> index 243bc4c..09e2f1b 100644
> --- a/drivers/iommu/arm-smmu.c
> +++ b/drivers/iommu/arm-smmu.c
> @@ -1506,6 +1506,32 @@ 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->size < size) {
> + info->size = size;
> + return 0;
> + }
> +
> + /* report an empty iommu_nesting_info for now */
> + memset(info, 0x0, size);
> + info->size = size;
> + return 0;
> +}
> +
> static int arm_smmu_domain_get_attr(struct iommu_domain *domain,
> enum iommu_attr attr, void *data)
> {
> @@ -1515,8 +1541,7 @@ 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;
> }
>
