[PATCH v3 3/9] iommu/vt-d: Let intel_pasid_tear_down_entry() return pasid entry

[Yi Liu <yi.l.liu@xxxxxxxxx>]

intel_pasid_tear_down_entry() finds the pasid entry and tears it down.
There are paths that need to get the pasid entry, tear it down and
re-configure it. Letting intel_pasid_tear_down_entry() return the pasid
entry can avoid duplicate codes to get the pasid entry. No functional
change is intended.

Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx>
---
 drivers/iommu/intel/pasid.c | 11 ++++++++---
 drivers/iommu/intel/pasid.h |  5 +++--
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
index 2898e7af2cf4..336f9425214c 100644
--- a/drivers/iommu/intel/pasid.c
+++ b/drivers/iommu/intel/pasid.c
@@ -239,9 +239,12 @@ devtlb_invalidation_with_pasid(struct intel_iommu *iommu,
 /*
  * Caller can request to drain PRQ in this helper if it hasn't done so,
  * e.g. in a path which doesn't follow remove_dev_pasid().
+ * Return the pasid entry pointer if the entry is found or NULL if no
+ * entry found.
  */
-void intel_pasid_tear_down_entry(struct intel_iommu *iommu, struct device *dev,
-				 u32 pasid, u32 flags)
+struct pasid_entry *
+intel_pasid_tear_down_entry(struct intel_iommu *iommu, struct device *dev,
+			    u32 pasid, u32 flags)
 {
 	struct pasid_entry *pte;
 	u16 did, pgtt;
@@ -250,7 +253,7 @@ void intel_pasid_tear_down_entry(struct intel_iommu *iommu, struct device *dev,
 	pte = intel_pasid_get_entry(dev, pasid);
 	if (WARN_ON(!pte) || !pasid_pte_is_present(pte)) {
 		spin_unlock(&iommu->lock);
-		return;
+		goto out;
 	}
 
 	did = pasid_get_domain_id(pte);
@@ -273,6 +276,8 @@ void intel_pasid_tear_down_entry(struct intel_iommu *iommu, struct device *dev,
 
 	if (flags & INTEL_PASID_TEARDOWN_DRAIN_PRQ)
 		intel_drain_pasid_prq(dev, pasid);
+out:
+	return pte;
 }
 
 /*
diff --git a/drivers/iommu/intel/pasid.h b/drivers/iommu/intel/pasid.h
index 7dc9e4dfbd88..9b2351325b0e 100644
--- a/drivers/iommu/intel/pasid.h
+++ b/drivers/iommu/intel/pasid.h
@@ -306,8 +306,9 @@ int intel_pasid_setup_nested(struct intel_iommu *iommu, struct device *dev,
 
 #define INTEL_PASID_TEARDOWN_IGNORE_FAULT	BIT(0)
 #define INTEL_PASID_TEARDOWN_DRAIN_PRQ		BIT(1)
-void intel_pasid_tear_down_entry(struct intel_iommu *iommu, struct device *dev,
-				 u32 pasid, u32 flags);
+struct pasid_entry *
+intel_pasid_tear_down_entry(struct intel_iommu *iommu, struct device *dev,
+			    u32 pasid, u32 flags);
 void intel_pasid_setup_page_snoop_control(struct intel_iommu *iommu,
 					  struct device *dev, u32 pasid);
 int intel_pasid_setup_sm_context(struct device *dev);
-- 
2.34.1