diff --git a/include/linux/iommu.h b/include/linux/iommu.h index a1a815bb13b10cd8f6e04b8fba5f5a65867f880a..d58613d902b520901dac85b2f90bcafa07ff84aa 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -155,10 +155,24 @@ struct iommu_resv_region { enum iommu_resv_type type; }; -/* Per device IOMMU features */ +/** + * enum iommu_dev_features - Per device IOMMU features + * @IOMMU_DEV_FEAT_AUX: Auxiliary domain feature + * @IOMMU_DEV_FEAT_SVA: Shared Virtual Addresses + * @IOMMU_DEV_FEAT_IOPF: I/O Page Faults such as PRI or Stall. Generally + * enabling %IOMMU_DEV_FEAT_SVA requires + * %IOMMU_DEV_FEAT_IOPF, but some devices manage I/O Page + * Faults themselves instead of relying on the IOMMU. When + * supported, this feature must be enabled before and + * disabled after %IOMMU_DEV_FEAT_SVA. + * + * Device drivers query whether a feature is supported using + * iommu_dev_has_feature(), and enable it using iommu_dev_enable_feature(). + */ enum iommu_dev_features { - IOMMU_DEV_FEAT_AUX, /* Aux-domain feature */ - IOMMU_DEV_FEAT_SVA, /* Shared Virtual Addresses */ + IOMMU_DEV_FEAT_AUX, + IOMMU_DEV_FEAT_SVA, + IOMMU_DEV_FEAT_IOPF, }; #define IOMMU_PASID_INVALID (-1U)