iommu: Separate IOMMU_DEV_FEAT_IOPF from IOMMU_DEV_FEAT_SVA

Some devices manage I/O Page Faults (IOPF) themselves instead of relying
on PCIe PRI or Arm SMMU stall. Allow their drivers to enable SVA without
mandating IOMMU-managed IOPF. The other device drivers now need to first
enable IOMMU_DEV_FEAT_IOPF before enabling IOMMU_DEV_FEAT_SVA. Enabling
IOMMU_DEV_FEAT_IOPF on its own doesn't have any effect visible to the
device driver, it is used in combination with other features.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20210401154718.307519-4-jean-philippe@linaro.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Jean-Philippe Brucker 2021-04-01 17:47:12 +02:00 committed by Joerg Roedel
parent 434b73e61c
commit 34b48c704d

View file

@ -156,10 +156,24 @@ 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)