Subject: [PATCH v2 2/8] mm/debug_vm_pgtable: add tests for __HAVE_ARCH_PTE_SWP_EXCLUSIVE

From: David Hildenbrand <[email-masked]>
Date: Tue, 29 Mar 2022 18:43:23 +0200

Let's test that __HAVE_ARCH_PTE_SWP_EXCLUSIVE works as expected.

Signed-off-by: David Hildenbrand <[email-masked]>
---
 mm/debug_vm_pgtable.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index db2abd9e415b..55f1a8dc716f 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -837,6 +837,19 @@ static void __init pmd_soft_dirty_tests(struct pgtable_debug_args *args) { }
 static void __init pmd_swap_soft_dirty_tests(struct pgtable_debug_args *args) { }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
+static void __init pte_swap_exclusive_tests(struct pgtable_debug_args *args)
+{
+#ifdef __HAVE_ARCH_PTE_SWP_EXCLUSIVE
+	pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
+
+	pr_debug("Validating PTE swap exclusive\n");
+	pte = pte_swp_mkexclusive(pte);
+	WARN_ON(!pte_swp_exclusive(pte));
+	pte = pte_swp_clear_exclusive(pte);
+	WARN_ON(pte_swp_exclusive(pte));
+#endif /* __HAVE_ARCH_PTE_SWP_EXCLUSIVE */
+}
+
 static void __init pte_swap_tests(struct pgtable_debug_args *args)
 {
 	swp_entry_t swp;
@@ -1288,6 +1301,8 @@ static int __init debug_vm_pgtable(void)
 	pte_swap_soft_dirty_tests(&args);
 	pmd_swap_soft_dirty_tests(&args);
 
+	pte_swap_exclusive_tests(&args);
+
 	pte_swap_tests(&args);
 	pmd_swap_tests(&args);
 
-- 
2.35.1