iommu/amd: Improve amd_iommu_release_device()

JIRA: https://issues.redhat.com/browse/RHEL-78701

Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

commit 18f5a6b
Author: Vasant Hegde <[email protected]>
Date:   Wed Oct 30 06:35:56 2024 +0000

    iommu/amd: Improve amd_iommu_release_device()

    Previous patch added ops->release_domain support. Core will attach
    devices to release_domain->attach_dev() before calling this function.
    Devices are already detached their current domain and attached to
    blocked domain.

    This is mostly dummy function now. Just throw warning if device is still
    attached to domain.

    Suggested-by: Jason Gunthorpe <[email protected]>
    Signed-off-by: Vasant Hegde <[email protected]>
    Reviewed-by: Jason Gunthorpe <[email protected]>
    Link: https://lore.kernel.org/r/[email protected]
    Signed-off-by: Joerg Roedel <[email protected]>

Signed-off-by: Eder Zulian <[email protected]>

Author: efzrh

drivers/iommu/amd/iommu.c

@@ -77,8 +77,6 @@ DEFINE_IDA(pdom_ids);
 
 struct kmem_cache *amd_iommu_irq_cache;
 
-static void detach_device(struct device *dev);
-
 static int amd_iommu_attach_device(struct iommu_domain *dom,
 				   struct device *dev);
 
@@ -563,22 +561,6 @@ static void iommu_ignore_device(struct amd_iommu *iommu, struct device *dev)
 	setup_aliases(iommu, dev);
 }
 
-static void amd_iommu_uninit_device(struct device *dev)
-{
-	struct iommu_dev_data *dev_data;
-
-	dev_data = dev_iommu_priv_get(dev);
-	if (!dev_data)
-		return;
-
-	if (dev_data->domain)
-		detach_device(dev);
-
-	/*
-	 * We keep dev_data around for unplugged devices and reuse it when the
-	 * device is re-plugged - not doing so would introduce a ton of races.
-	 */
-}
 
 /****************************************************************************
  *
@@ -2249,17 +2231,14 @@ static struct iommu_device *amd_iommu_probe_device(struct device *dev)
 
 static void amd_iommu_release_device(struct device *dev)
 {
-	struct amd_iommu *iommu;
-
-	if (!check_device(dev))
-		return;
+	struct iommu_dev_data *dev_data = dev_iommu_priv_get(dev);
 
-	iommu = rlookup_amd_iommu(dev);
-	if (!iommu)
-		return;
+	WARN_ON(dev_data->domain);
 
-	amd_iommu_uninit_device(dev);
-	iommu_completion_wait(iommu);
+	/*
+	 * We keep dev_data around for unplugged devices and reuse it when the
+	 * device is re-plugged - not doing so would introduce a ton of races.
+	 */
 }
 
 static struct iommu_group *amd_iommu_device_group(struct device *dev)