mm/debug_vm_pgtable: add tests for __HAVE_ARCH_PTE_SWP_EXCLUSIVE

Let's test that __HAVE_ARCH_PTE_SWP_EXCLUSIVE works as expected.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Don Dutile <[email protected]>
Cc: Gerald Schaefer <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Liang Zhang <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Nadav Amit <[email protected]>
Cc: Oded Gabbay <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Pedro Demarchi Gomes <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

1 files changed, 15 insertions, 0 deletions

diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index 30fd11a2ed32..1ab091f49fc0 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;
@@ -1295,6 +1308,8 @@ 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);