[PATCH 6/8] iommu/vt-d: Use intel_pasid_write() for second-stage setup

[Lu Baolu]

Refactor intel_pasid_setup_second_level() to utilize the
intel_pasid_write() helper. Similar to the first-stage setup, moves the
second stage setup logic to the entry_sync library by constructing the
target PASID entry in a local buffer and committing it via
intel_pasid_write().

Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
 drivers/iommu/intel/iommu.c | 19 ++++---------------
 drivers/iommu/intel/pasid.c | 26 ++++----------------------
 2 files changed, 8 insertions(+), 37 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index db5e8dad50dc..b98020ac9de2 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -1248,17 +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_second_level(struct intel_iommu *iommu,
-				     struct dmar_domain *domain,
-				     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_second_level(iommu, domain, dev, pasid);
-}
-
 static int domain_setup_passthrough(struct intel_iommu *iommu,
 				    struct device *dev, ioasid_t pasid,
 				    struct iommu_domain *old)
@@ -1323,8 +1312,8 @@ static int dmar_domain_attach_device(struct dmar_domain *domain,
 		ret = domain_setup_first_level(iommu, domain, dev,
 					       IOMMU_NO_PASID, NULL);
 	else if (intel_domain_is_ss_paging(domain))
-		ret = domain_setup_second_level(iommu, domain, dev,
-						IOMMU_NO_PASID, NULL);
+		ret = intel_pasid_setup_second_level(iommu, domain,
+						     dev, IOMMU_NO_PASID);
 	else if (WARN_ON(true))
 		ret = -EINVAL;
 
@@ -3634,8 +3623,8 @@ static int intel_iommu_set_dev_pasid(struct iommu_domain *domain,
 		ret = domain_setup_first_level(iommu, dmar_domain,
 					       dev, pasid, old);
 	else if (intel_domain_is_ss_paging(dmar_domain))
-		ret = domain_setup_second_level(iommu, dmar_domain,
-						dev, pasid, old);
+		ret = intel_pasid_setup_second_level(iommu, dmar_domain,
+						     dev, pasid);
 	else if (WARN_ON(true))
 		ret = -EINVAL;
 
diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
index 8ea1ac8cbf5e..3084afb3d4a1 100644
--- a/drivers/iommu/intel/pasid.c
+++ b/drivers/iommu/intel/pasid.c
@@ -590,10 +590,7 @@ static void pasid_pte_config_second_level(struct intel_iommu *iommu,
 {
 	struct pt_iommu_vtdss_hw_info pt_info;
 
-	lockdep_assert_held(&iommu->lock);
-
 	pt_iommu_vtdss_hw_info(&domain->sspt, &pt_info);
-	pasid_clear_entry(pte);
 	pasid_set_domain_id(pte, did);
 	pasid_set_slptr(pte, pt_info.ssptptr);
 	pasid_set_address_width(pte, pt_info.aw);
@@ -611,9 +608,10 @@ int intel_pasid_setup_second_level(struct intel_iommu *iommu,
 				   struct dmar_domain *domain,
 				   struct device *dev, u32 pasid)
 {
-	struct pasid_entry *pte;
+	struct pasid_entry new_pte = {0};
 	u16 did;
 
+	iommu_group_mutex_assert(dev);
 
 	/*
 	 * If hardware advertises no support for second level
@@ -626,25 +624,9 @@ int intel_pasid_setup_second_level(struct intel_iommu *iommu,
 	}
 
 	did = domain_id_iommu(domain, iommu);
+	pasid_pte_config_second_level(iommu, &new_pte, domain, did);
 
-	spin_lock(&iommu->lock);
-	pte = intel_pasid_get_entry(dev, pasid);
-	if (!pte) {
-		spin_unlock(&iommu->lock);
-		return -ENODEV;
-	}
-
-	if (pasid_pte_is_present(pte)) {
-		spin_unlock(&iommu->lock);
-		return -EBUSY;
-	}
-
-	pasid_pte_config_second_level(iommu, pte, domain, 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