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. For now, return an empty nesting info struct for now as true nesting is not yet supported by the SMMUs. Note: this patch just ensure no compiling issue, to be functional ready fro ARM platform, needs to apply patches from Vivek Gautam in below link. https://lore.kernel.org/linux-iommu/20210212105859.8445-1-vivek.gautam@xxxxxxx/ 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> Reviewed-by: Eric Auger <eric.auger@xxxxxxxxxx> --- v5 -> v6: *) add review-by from Eric Auger. v4 -> v5: *) address comments from Eric Auger. --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 29 +++++++++++++++++++-- drivers/iommu/arm/arm-smmu/arm-smmu.c | 29 +++++++++++++++++++-- 2 files changed, 54 insertions(+), 4 deletions(-) diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index 8594b4a83043..99ea3ee35826 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -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; } diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c index d8c6bfde6a61..d874c580ea80 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c @@ -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; -- 2.25.1
