| Message ID | 20210127154322.3959196-4-jean-philippe@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | iommu: I/O page faults for SMMUv3 | expand |
Hi Jean, On 1/27/21 4:43 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. > > Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Eric > --- > 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) >
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)
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 <jean-philippe@linaro.org> --- 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(-) -- 2.30.0