[PATCH 7/8] iommu/vt-d: Use intel_pasid_write() for pass-through setup

[Lu Baolu <baolu.lu@linux.intel.com>]

Refactor intel_pasid_setup_pass_through() to utilize
the intel_pasid_write() helper. Move the pass-through setup implementation
to the entry_sync library, where the target PASID entry is constructed
locally and committed via the centralized intel_pasid_write() wrapper.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/intel/iommu.c | 12 +-----------
 drivers/iommu/intel/pasid.c | 26 ++++----------------------
 2 files changed, 5 insertions(+), 33 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index b98020ac9de2..f1f9fafd3984 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -1248,16 +1248,6 @@ static void domain_context_clear_one(struct device_domain_info *info, u8 bus, u8
 	__iommu_flush_cache(iommu, context, sizeof(*context));
 }
 
-static int domain_setup_passthrough(struct intel_iommu *iommu,
-				    struct device *dev, ioasid_t pasid,
-				    struct iommu_domain *old)
-{
-	if (old)
-		intel_pasid_tear_down_entry(iommu, dev, pasid, false);
-
-	return intel_pasid_setup_pass_through(iommu, dev, pasid);
-}
-
 static int domain_setup_first_level(struct intel_iommu *iommu,
 				    struct dmar_domain *domain,
 				    struct device *dev,
@@ -3848,7 +3838,7 @@ static int identity_domain_set_dev_pasid(struct iommu_domain *domain,
 	if (ret)
 		return ret;
 
-	ret = domain_setup_passthrough(iommu, dev, pasid, old);
+	ret = intel_pasid_setup_pass_through(iommu, dev, pasid);
 	if (ret) {
 		iopf_for_domain_replace(old, domain, dev);
 		return ret;
diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
index 3084afb3d4a1..cb55ff422d7d 100644
--- a/drivers/iommu/intel/pasid.c
+++ b/drivers/iommu/intel/pasid.c
@@ -704,9 +704,6 @@ int intel_pasid_setup_dirty_tracking(struct intel_iommu *iommu,
 static void pasid_pte_config_pass_through(struct intel_iommu *iommu,
 					  struct pasid_entry *pte, u16 did)
 {
-	lockdep_assert_held(&iommu->lock);
-
-	pasid_clear_entry(pte);
 	pasid_set_domain_id(pte, did);
 	pasid_set_address_width(pte, iommu->agaw);
 	pasid_set_translation_type(pte, PASID_ENTRY_PGTT_PT);
@@ -718,27 +715,12 @@ static void pasid_pte_config_pass_through(struct intel_iommu *iommu,
 int intel_pasid_setup_pass_through(struct intel_iommu *iommu,
 				   struct device *dev, u32 pasid)
 {
-	u16 did = FLPT_DEFAULT_DID;
-	struct pasid_entry *pte;
+	struct pasid_entry new_pte = {0};
 
-	spin_lock(&iommu->lock);
-	pte = intel_pasid_get_entry(dev, pasid);
-	if (!pte) {
-		spin_unlock(&iommu->lock);
-		return -ENODEV;
-	}
+	iommu_group_mutex_assert(dev);
+	pasid_pte_config_pass_through(iommu, &new_pte, FLPT_DEFAULT_DID);
 
-	if (pasid_pte_is_present(pte)) {
-		spin_unlock(&iommu->lock);
-		return -EBUSY;
-	}
-
-	pasid_pte_config_pass_through(iommu, pte, did);
-	spin_unlock(&iommu->lock);
-
-	pasid_flush_caches(iommu, pte, pasid, did);
-
-	return 0;
+	return intel_pasid_write(iommu, dev, pasid, (u128 *)&new_pte);
 }
 
 /*
-- 
2.43.0