Commit 34b48c70 authored by Jean-Philippe Brucker's avatar Jean-Philippe Brucker Committed by Joerg Roedel
Browse files

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: default avatarEric Auger <eric.auger@redhat.com>
Reviewed-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: default avatarJean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20210401154718.307519-4-jean-philippe@linaro.org


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 434b73e6

include/linux/iommu.h

+17 −3
Original line number Diff line number Diff line
@@ -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)