driver should implement both set_dev_pasid and remove_dev_pasid op, otherwise it is a problem how to detach pasid. In reality, it is impossible that an iommu driver implements set_dev_pasid() but no remove_dev_pasid() op. However, it is better to check it. Move the group check to be the first as dev_iommu_ops() may fail when there is no valid group. Also take the chance to remove the dev_has_iommu() check as it is duplicated to the group check. Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx> Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx> --- drivers/iommu/iommu.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 9bc0c74cca3c..38c3f67e441f 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -3368,16 +3368,19 @@ int iommu_attach_device_pasid(struct iommu_domain *domain, /* Caller must be a probed driver on dev */ struct iommu_group *group = dev->iommu_group; struct group_device *device; + const struct iommu_ops *ops; int ret; - if (!domain->ops->set_dev_pasid) - return -EOPNOTSUPP; - if (!group) return -ENODEV; - if (!dev_has_iommu(dev) || dev_iommu_ops(dev) != domain->owner || - pasid == IOMMU_NO_PASID) + ops = dev_iommu_ops(dev); + + if (!domain->ops->set_dev_pasid || + !ops->remove_dev_pasid) + return -EOPNOTSUPP; + + if (ops != domain->owner || pasid == IOMMU_NO_PASID) return -EINVAL; mutex_lock(&group->mutex); -- 2.34.1
