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authorJean-Philippe Brucker <jean-philippe@linaro.org>2021-04-01 17:47:12 +0200
committerJoerg Roedel <jroedel@suse.de>2021-04-07 10:54:28 +0200
commit34b48c704d194738eef0893aa06e412bdc8a972f (patch)
tree1dda798acf14d87c1f3358c6202e5311158eba13 /include
parentiommu/arm-smmu-v3: Use device properties for pasid-num-bits (diff)
downloadlinux-34b48c704d194738eef0893aa06e412bdc8a972f.tar.xz
linux-34b48c704d194738eef0893aa06e412bdc8a972f.zip
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>
Diffstat (limited to 'include')
-rw-r--r--include/linux/iommu.h20
1 files changed, 17 insertions, 3 deletions
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 16ce75693d83..45c4eb372f56 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -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)