iommu/amd: Handle race between registration and device probe

As for the Intel driver, make sure the AMD driver can cope with seeing
.probe_device calls without having to wait for all known instances to
register first.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/a8d8ebe12b411d28972f1ab928c6db92e8913cf5.1660572783.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 94220eb5bff3f103ade5e0a0917e30a06bf9b478..85c4122b5d61dadc58d9ab59d5b77ff4c4159e7e 100644 (file)
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -1851,6 +1851,10 @@ static struct iommu_device *amd_iommu_probe_device(struct device *dev)
        if (!iommu)
                return ERR_PTR(-ENODEV);
 
+       /* Not registered yet? */
+       if (!iommu->iommu.ops)
+               return ERR_PTR(-ENODEV);
+
        if (dev_iommu_priv_get(dev))
                return &iommu->iommu;