[PATCH v3 14/15] iommu/amd: Refactor logic to program the host page table in DTE

[Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>]

Introduce the set_dte_v1() helper function to configure IOMMU host (v1)
page table into DTE.

There is no functional change.

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
 drivers/iommu/amd/iommu.c | 54 +++++++++++++++++++++------------------
 1 file changed, 29 insertions(+), 25 deletions(-)

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index ffb1adfd75c0..2a536d02aeab 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -2044,6 +2044,32 @@ static void set_dte_gcr3_table(struct amd_iommu *iommu,
 		target->data[2] |= FIELD_PREP(DTE_GPT_LEVEL_MASK, GUEST_PGTABLE_4_LEVEL);
 }
 
+static void set_dte_v1(struct iommu_dev_data *dev_data,
+		       struct protection_domain *domain, u16 domid,
+		       struct dev_table_entry *new)
+{
+	/*
+	 * When SNP is enabled, we can only support TV=1 with non-zero domain ID.
+	 * This is prevented by the SNP-enable and IOMMU_DOMAIN_IDENTITY check in
+	 * do_iommu_domain_alloc().
+	 */
+	WARN_ON(amd_iommu_snp_en && (domid == 0));
+
+	if (domain->iop.mode != PAGE_MODE_NONE)
+		new->data[0] |= iommu_virt_to_phys(domain->iop.root);
+
+	new->data[0] |= FIELD_PREP(DTE_MODE_MASK, domain->iop.mode);
+	new->data[0] |= DTE_FLAG_IR | DTE_FLAG_IW | DTE_FLAG_TV;
+
+	if (domain->dirty_tracking)
+		new->data[0] |= DTE_FLAG_HAD;
+
+	if (dev_data->ats_enabled)
+		new->data[1] |= DTE_FLAG_IOTLB;
+
+	new->data[1] |= domid;
+}
+
 static void set_dte_entry(struct amd_iommu *iommu,
 			  struct iommu_dev_data *dev_data)
 {
@@ -2061,36 +2087,14 @@ static void set_dte_entry(struct amd_iommu *iommu,
 
 	amd_iommu_make_clear_dte(dev_data, &new);
 
-	if (domain->iop.mode != PAGE_MODE_NONE)
-		new.data[0] |= iommu_virt_to_phys(domain->iop.root);
-
-	new.data[0] |= (domain->iop.mode & DEV_ENTRY_MODE_MASK)
-		    << DEV_ENTRY_MODE_SHIFT;
-
-	new.data[0] |= DTE_FLAG_IR | DTE_FLAG_IW;
+	old_domid = READ_ONCE(dte->data[1]) & DTE_DOMID_MASK;
 
-	/*
-	 * When SNP is enabled, we can only support TV=1 with non-zero domain ID.
-	 * This is prevented by the SNP-enable and IOMMU_DOMAIN_IDENTITY check in
-	 * do_iommu_domain_alloc().
-	 */
-	WARN_ON(amd_iommu_snp_en && (domid == 0));
-	new.data[0] |= DTE_FLAG_TV;
+	set_dte_v1(dev_data, domain, domid, &new);
+	set_dte_gcr3_table(iommu, dev_data, &new);
 
 	if (dev_data->ppr)
 		new.data[0] |= 1ULL << DEV_ENTRY_PPR;
 
-	if (domain->dirty_tracking)
-		new.data[0] |= DTE_FLAG_HAD;
-
-	if (dev_data->ats_enabled)
-		new.data[1] |= DTE_FLAG_IOTLB;
-
-	old_domid = READ_ONCE(dte->data[1]) & DTE_DOMID_MASK;
-	new.data[1] |= domid;
-
-	set_dte_gcr3_table(iommu, dev_data, &new);
-
 	amd_iommu_update_dte256(iommu, dev_data, &new);
 
 	/*
-- 
2.34.1