[PATCH v10 03/10] iommu: Separate IOMMU_DEV_FEAT_IOPF from IOMMU_DEV_FEAT_SVA
From: Jean-Philippe Brucker <hidden>
Date: 2021-01-21 12:44:02
Also in:
linux-acpi, linux-arm-kernel, linux-iommu
Subsystem:
iommu subsystem, the rest · Maintainers:
Joerg Roedel, Will Deacon, Linus Torvalds
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. Signed-off-by: Jean-Philippe Brucker <redacted> --- Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Joerg Roedel <joro@8bytes.org> Cc: Lu Baolu <baolu.lu@linux.intel.com> Cc: Will Deacon <will@kernel.org> Cc: Zhangfei Gao <zhangfei.gao@linaro.org> Cc: Zhou Wang <wangzhou1@hisilicon.com> --- include/linux/iommu.h | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-)
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index b7ea11fc1a93..00348e4c3c26 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)
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2.30.0