Re: [PATCH v13 03/10] iommu: Separate IOMMU_DEV_FEAT_IOPF from IOMMU_DEV_FEAT_SVA

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 3/2/21 5:26 PM, Jean-Philippe Brucker wrote:
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@xxxxxxxxxx>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
---
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Joerg Roedel <joro@xxxxxxxxxx>
Cc: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Zhangfei Gao <zhangfei.gao@xxxxxxxxxx>
Cc: Zhou Wang <wangzhou1@xxxxxxxxxxxxx>
---
  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 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)


Reviewed-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>

Best regards,
baolu




[Index of Archives]     [Linux IBM ACPI]     [Linux Power Management]     [Linux Kernel]     [Linux Laptop]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Video 4 Linux]     [Device Mapper]     [Linux Resources]

  Powered by Linux