Merge branch 'for-next/mm' into for-next/core

* for-next/mm:
  arm64: enable THP_SWAP for arm64

Author: willdeacon

arch/arm64/Kconfig

@@ -101,6 +101,7 @@ config ARM64
 	select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
 	select ARCH_WANT_LD_ORPHAN_WARN
 	select ARCH_WANTS_NO_INSTR
+	select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
 	select ARCH_HAS_UBSAN_SANITIZE_ALL
 	select ARM_AMBA
 	select ARM_ARCH_TIMER

arch/arm64/include/asm/pgtable.h

@@ -45,6 +45,12 @@
 	__flush_tlb_range(vma, addr, end, PUD_SIZE, false, 1)
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
+static inline bool arch_thp_swp_supported(void)
+{
+	return !system_supports_mte();
+}
+#define arch_thp_swp_supported arch_thp_swp_supported
+
 /*
  * Outside of a few very special situations (e.g. hibernation), we always
  * use broadcast TLB invalidation instructions, therefore a spurious page

include/linux/huge_mm.h

@@ -461,4 +461,16 @@ static inline int split_folio_to_list(struct folio *folio,
 	return split_huge_page_to_list(&folio->page, list);
 }
 
+/*
+ * archs that select ARCH_WANTS_THP_SWAP but don't support THP_SWP due to
+ * limitations in the implementation like arm64 MTE can override this to
+ * false
+ */
+#ifndef arch_thp_swp_supported
+static inline bool arch_thp_swp_supported(void)
+{
+	return true;
+}
+#endif
+
 #endif /* _LINUX_HUGE_MM_H */

mm/swap_slots.c

@@ -307,7 +307,7 @@ swp_entry_t folio_alloc_swap(struct folio *folio)
 	entry.val = 0;
 
 	if (folio_test_large(folio)) {
-		if (IS_ENABLED(CONFIG_THP_SWAP))
+		if (IS_ENABLED(CONFIG_THP_SWAP) && arch_thp_swp_supported())
 			get_swap_pages(1, &entry, folio_nr_pages(folio));
 		goto out;
 	}