On Fri, 8 Jan 2021 15:52:13 +0100 Jean-Philippe Brucker <[email protected]> wrote:
> The IOPF (I/O Page Fault) feature is now enabled independently from the > SVA feature, because some IOPF implementations are device-specific and > do not require IOMMU support for PCIe PRI or Arm SMMU stall. > > Enable IOPF unconditionally when enabling SVA for now. In the future, if > a device driver implementing a uacce interface doesn't need IOPF > support, it will need to tell the uacce module, for example with a new > flag. > > Signed-off-by: Jean-Philippe Brucker <[email protected]> Hi Jean-Philippe, A minor suggestion inline but I'm not that bothered so either way looks good to me. > --- > Cc: Arnd Bergmann <[email protected]> > Cc: Greg Kroah-Hartman <[email protected]> > Cc: Zhangfei Gao <[email protected]> > Cc: Zhou Wang <[email protected]> > --- > drivers/misc/uacce/uacce.c | 32 +++++++++++++++++++++++++------- > 1 file changed, 25 insertions(+), 7 deletions(-) > > diff --git a/drivers/misc/uacce/uacce.c b/drivers/misc/uacce/uacce.c > index d07af4edfcac..41ef1eb62a14 100644 > --- a/drivers/misc/uacce/uacce.c > +++ b/drivers/misc/uacce/uacce.c > @@ -385,6 +385,24 @@ static void uacce_release(struct device *dev) > kfree(uacce); > } > > +static unsigned int uacce_enable_sva(struct device *parent, unsigned int > flags) > +{ > + if (!(flags & UACCE_DEV_SVA)) > + return flags; > + > + flags &= ~UACCE_DEV_SVA; > + > + if (iommu_dev_enable_feature(parent, IOMMU_DEV_FEAT_IOPF)) > + return flags; > + > + if (iommu_dev_enable_feature(parent, IOMMU_DEV_FEAT_SVA)) { > + iommu_dev_disable_feature(parent, IOMMU_DEV_FEAT_IOPF); > + return flags; > + } > + > + return flags | UACCE_DEV_SVA; > +} I'm a great fan of paired enable / disable functions. Whilst it would be trivial, maybe it is worth introducing uacce_disable_sva()? Also make that do the flags check internally to make it match up with the enable path. > + > /** > * uacce_alloc() - alloc an accelerator > * @parent: pointer of uacce parent device > @@ -404,11 +422,7 @@ struct uacce_device *uacce_alloc(struct device *parent, > if (!uacce) > return ERR_PTR(-ENOMEM); > > - if (flags & UACCE_DEV_SVA) { > - ret = iommu_dev_enable_feature(parent, IOMMU_DEV_FEAT_SVA); > - if (ret) > - flags &= ~UACCE_DEV_SVA; > - } > + flags = uacce_enable_sva(parent, flags); > > uacce->parent = parent; > uacce->flags = flags; > @@ -432,8 +446,10 @@ struct uacce_device *uacce_alloc(struct device *parent, > return uacce; > > err_with_uacce: > - if (flags & UACCE_DEV_SVA) > + if (flags & UACCE_DEV_SVA) { > iommu_dev_disable_feature(uacce->parent, IOMMU_DEV_FEAT_SVA); > + iommu_dev_disable_feature(uacce->parent, IOMMU_DEV_FEAT_IOPF); > + } > kfree(uacce); > return ERR_PTR(ret); > } > @@ -487,8 +503,10 @@ void uacce_remove(struct uacce_device *uacce) > mutex_unlock(&uacce->queues_lock); > > /* disable sva now since no opened queues */ > - if (uacce->flags & UACCE_DEV_SVA) > + if (uacce->flags & UACCE_DEV_SVA) { > iommu_dev_disable_feature(uacce->parent, IOMMU_DEV_FEAT_SVA); > + iommu_dev_disable_feature(uacce->parent, IOMMU_DEV_FEAT_IOPF); > + } > > if (uacce->cdev) > cdev_device_del(uacce->cdev, &uacce->dev); _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
