[PATCH 2/6] iommu/vt-d: Add attach_deferred() helper

[Tim Gardner]

From: Joerg Roedel <jroedel at suse.de>

BugLink: https://bugs.launchpad.net/bugs/1922738

Implement a helper function to check whether a device's attach process
is deferred.

Fixes: 1ee0186b9a12 ("iommu/vt-d: Refactor find_domain() helper")
Cc: stable at vger.kernel.org # v5.5
Reviewed-by: Jerry Snitselaar <jsnitsel at redhat.com>
Acked-by: Lu Baolu <baolu.lu at linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel at suse.de>
(cherry picked from commit 1d4615978f525b769990a4a4ef22fb1b9a04cdf1)
Signed-off-by: Tim Gardner <tim.gardner at canonical.com>
---
 drivers/iommu/intel-iommu.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index ebdccc72dc46..9828f5167332 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -738,6 +738,11 @@ static int iommu_dummy(struct device *dev)
 	return dev->archdata.iommu == DUMMY_DEVICE_DOMAIN_INFO;
 }
 
+static bool attach_deferred(struct device *dev)
+{
+	return dev->archdata.iommu == DEFER_DEVICE_DOMAIN_INFO;
+}
+
 /**
  * is_downstream_to_pci_bridge - test if a device belongs to the PCI
  *				 sub-hierarchy of a candidate PCI-PCI bridge
@@ -2431,8 +2436,7 @@ static struct dmar_domain *find_domain(struct device *dev)
 {
 	struct device_domain_info *info;
 
-	if (unlikely(dev->archdata.iommu == DEFER_DEVICE_DOMAIN_INFO ||
-		     dev->archdata.iommu == DUMMY_DEVICE_DOMAIN_INFO))
+	if (unlikely(attach_deferred(dev) || iommu_dummy(dev)))
 		return NULL;
 
 	/* No lock here, assumes no domain exit in normal case */
@@ -2445,7 +2449,7 @@ static struct dmar_domain *find_domain(struct device *dev)
 
 static struct dmar_domain *deferred_attach_domain(struct device *dev)
 {
-	if (unlikely(dev->archdata.iommu == DEFER_DEVICE_DOMAIN_INFO)) {
+	if (unlikely(attach_deferred(dev))) {
 		struct iommu_domain *domain;
 
 		dev->archdata.iommu = NULL;
@@ -5971,7 +5975,7 @@ intel_iommu_aux_get_pasid(struct iommu_domain *domain, struct device *dev)
 static bool intel_iommu_is_attach_deferred(struct iommu_domain *domain,
 					   struct device *dev)
 {
-	return dev->archdata.iommu == DEFER_DEVICE_DOMAIN_INFO;
+	return attach_deferred(dev);
 }
 
 /*
-- 
2.17.1