linux-kernel - [PATCH 07/13] iommu: amd: Restructure code for freeing page table

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Date:   Wed, 23 Sep 2020 10:14:36 +0000
From:   Suravee Suthikulpanit <suravee.suthikulpanit@....com>
To:     linux-kernel@...r.kernel.org, iommu@...ts.linux-foundation.org
Cc:     joro@...tes.org,
        Suravee Suthikulpanit <suravee.suthikulpanit@....com>
Subject: [PATCH 07/13] iommu: amd: Restructure code for freeing page table

Introduce amd_iommu_free_pgtable helper function, which consolidates
logic for freeing page table.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@....com>
---
 drivers/iommu/amd/amd_iommu.h  |  2 +-
 drivers/iommu/amd/io_pgtable.c | 12 +++++++++++-
 drivers/iommu/amd/iommu.c      | 19 ++-----------------
 3 files changed, 14 insertions(+), 19 deletions(-)

diff --git a/drivers/iommu/amd/amd_iommu.h b/drivers/iommu/amd/amd_iommu.h
index ee7ff4d827e1..8dff7d85be79 100644
--- a/drivers/iommu/amd/amd_iommu.h
+++ b/drivers/iommu/amd/amd_iommu.h
@@ -123,7 +123,6 @@ static inline void amd_iommu_apply_ivrs_quirks(void) { }
 #endif
 
 /* TODO: These are temporary and will be removed once fully transition */
-extern void free_pagetable(struct domain_pgtable *pgtable);
 extern int iommu_map_page(struct protection_domain *dom,
 			  unsigned long bus_addr,
 			  unsigned long phys_addr,
@@ -140,4 +139,5 @@ extern void amd_iommu_domain_get_pgtable(struct protection_domain *domain,
 					 struct domain_pgtable *pgtable);
 extern void amd_iommu_domain_set_pgtable(struct protection_domain *domain,
 					 u64 *root, int mode);
+extern void amd_iommu_free_pgtable(struct amd_io_pgtable *pgtable);
 #endif
diff --git a/drivers/iommu/amd/io_pgtable.c b/drivers/iommu/amd/io_pgtable.c
index 7e4154e26757..8ce2f0325123 100644
--- a/drivers/iommu/amd/io_pgtable.c
+++ b/drivers/iommu/amd/io_pgtable.c
@@ -167,14 +167,24 @@ static struct page *free_sub_pt(unsigned long root, int mode,
 	return freelist;
 }
 
-void free_pagetable(struct domain_pgtable *pgtable)
+void amd_iommu_free_pgtable(struct amd_io_pgtable *pgtable)
 {
+	struct protection_domain *dom;
 	struct page *freelist = NULL;
 	unsigned long root;
 
 	if (pgtable->mode == PAGE_MODE_NONE)
 		return;
 
+	dom = container_of(pgtable, struct protection_domain, iop);
+
+	/* Update data structure */
+	amd_iommu_domain_clr_pt_root(dom);
+
+	/* Make changes visible to IOMMUs */
+	amd_iommu_domain_update(dom);
+
+	/* Page-table is not visible to IOMMU anymore, so free it */
 	BUG_ON(pgtable->mode < PAGE_MODE_NONE ||
 	       pgtable->mode > PAGE_MODE_6_LEVEL);
 
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 4d65f64236b6..cbbea7b952fb 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -1882,17 +1882,13 @@ static void cleanup_domain(struct protection_domain *domain)
 
 static void protection_domain_free(struct protection_domain *domain)
 {
-	struct domain_pgtable pgtable;
-
 	if (!domain)
 		return;
 
 	if (domain->id)
 		domain_id_free(domain->id);
 
-	amd_iommu_domain_get_pgtable(domain, &pgtable);
-	amd_iommu_domain_clr_pt_root(domain);
-	free_pagetable(&pgtable);
+	amd_iommu_free_pgtable(&domain->iop);
 
 	kfree(domain);
 }
@@ -2281,22 +2277,11 @@ EXPORT_SYMBOL(amd_iommu_unregister_ppr_notifier);
 void amd_iommu_domain_direct_map(struct iommu_domain *dom)
 {
 	struct protection_domain *domain = to_pdomain(dom);
-	struct domain_pgtable pgtable;
 	unsigned long flags;
 
 	spin_lock_irqsave(&domain->lock, flags);
 
-	/* First save pgtable configuration*/
-	amd_iommu_domain_get_pgtable(domain, &pgtable);
-
-	/* Remove page-table from domain */
-	amd_iommu_domain_clr_pt_root(domain);
-
-	/* Make changes visible to IOMMUs */
-	amd_iommu_domain_update(domain);
-
-	/* Page-table is not visible to IOMMU anymore, so free it */
-	free_pagetable(&pgtable);
+	amd_iommu_free_pgtable(&domain->iop);
 
 	spin_unlock_irqrestore(&domain->lock, flags);
 }
-- 
2.17.1