Refactor intel_pasid_setup_nested() to utilize the intel_pasid_write()
helper. Move the implementation to the entry_sync infrastructure, where
the nested PASID entry is constructed in a local buffer and committed
via the centralized intel_pasid_write() wrapper.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/intel/nested.c | 13 +------------
 drivers/iommu/intel/pasid.c  | 27 +++++----------------------
 2 files changed, 6 insertions(+), 34 deletions(-)

diff --git a/drivers/iommu/intel/nested.c b/drivers/iommu/intel/nested.c
index 2b979bec56ce..1cebc1232f70 100644
--- a/drivers/iommu/intel/nested.c
+++ b/drivers/iommu/intel/nested.c
@@ -131,17 +131,6 @@ static int intel_nested_cache_invalidate_user(struct iommu_domain *domain,
 	return ret;
 }
 
-static int domain_setup_nested(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_nested(iommu, dev, pasid, domain);
-}
-
 static int intel_nested_set_dev_pasid(struct iommu_domain *domain,
 				      struct device *dev, ioasid_t pasid,
 				      struct iommu_domain *old)
@@ -170,7 +159,7 @@ static int intel_nested_set_dev_pasid(struct iommu_domain *domain,
 	if (ret)
 		goto out_remove_dev_pasid;
 
-	ret = domain_setup_nested(iommu, dmar_domain, dev, pasid, old);
+	ret = intel_pasid_setup_nested(iommu, dev, pasid, dmar_domain);
 	if (ret)
 		goto out_unwind_iopf;
 
diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
index cb55ff422d7d..5e0548dd8388 100644
--- a/drivers/iommu/intel/pasid.c
+++ b/drivers/iommu/intel/pasid.c
@@ -754,12 +754,8 @@ static void pasid_pte_config_nestd(struct intel_iommu *iommu,
 {
 	struct pt_iommu_vtdss_hw_info pt_info;
 
-	lockdep_assert_held(&iommu->lock);
-
 	pt_iommu_vtdss_hw_info(&s2_domain->sspt, &pt_info);
 
-	pasid_clear_entry(pte);
-
 	if (s1_cfg->addr_width == ADDR_WIDTH_5LEVEL)
 		pasid_set_flpm(pte, 1);
 
@@ -806,7 +802,9 @@ int intel_pasid_setup_nested(struct intel_iommu *iommu, struct device *dev,
 	struct iommu_hwpt_vtd_s1 *s1_cfg = &domain->s1_cfg;
 	struct dmar_domain *s2_domain = domain->s2_domain;
 	u16 did = domain_id_iommu(domain, iommu);
-	struct pasid_entry *pte;
+	struct pasid_entry new_pte = {0};
+
+	iommu_group_mutex_assert(dev);
 
 	/* Address width should match the address width supported by hardware */
 	switch (s1_cfg->addr_width) {
@@ -837,23 +835,8 @@ int intel_pasid_setup_nested(struct intel_iommu *iommu, struct device *dev,
 		return -EINVAL;
 	}
 
-	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_nestd(iommu, pte, s1_cfg, s2_domain, did);
-	spin_unlock(&iommu->lock);
-
-	pasid_flush_caches(iommu, pte, pasid, did);
-
-	return 0;
+	pasid_pte_config_nestd(iommu, &new_pte, s1_cfg, s2_domain, did);
+	return intel_pasid_write(iommu, dev, pasid, (u128 *)&new_pte);
 }
 
 /*
-- 
2.43.0