Merge tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - The series "Enable strict percpu address space checks" from Uros
   Bizjak uses x86 named address space qualifiers to provide
   compile-time checking of percpu area accesses.

   This has caused a small amount of fallout - two or three issues were
   reported. In all cases the calling code was found to be incorrect.

 - The series "Some cleanup for memcg" from Chen Ridong implements some
   relatively monir cleanups for the memcontrol code.

 - The series "mm: fixes for device-exclusive entries (hmm)" from David
   Hildenbrand fixes a boatload of issues which David found then using
   device-exclusive PTE entries when THP is enabled. More work is
   needed, but this makes thins better - our own HMM selftests now
   succeed.

 - The series "mm: zswap: remove z3fold and zbud" from Yosry Ahmed
   remove the z3fold and zbud implementations. They have been deprecated
   for half a year and nobody has complained.

 - The series "mm: further simplify VMA merge operation" from Lorenzo
   Stoakes implements numerous simplifications in this area. No runtime
   effects are anticipated.

 - The series "mm/madvise: remove redundant mmap_lock operations from
   process_madvise()" from SeongJae Park rationalizes the locking in the
   madvise() implementation. Performance gains of 20-25% were observed
   in one MADV_DONTNEED microbenchmark.

 - The series "Tiny cleanup and improvements about SWAP code" from
   Baoquan He contains a number of touchups to issues which Baoquan
   noticed when working on the swap code.

 - The series "mm: kmemleak: Usability improvements" from Catalin
   Marinas implements a couple of improvements to the kmemleak
   user-visible output.

 - The series "mm/damon/paddr: fix large folios access and schemes
   handling" from Usama Arif provides a couple of fixes for DAMON's
   handling of large folios.

 - The series "mm/damon/core: fix wrong and/or useless damos_walk()
   behaviors" from SeongJae Park fixes a few issues with the accuracy of
   kdamond's walking of DAMON regions.

 - The series "expose mapping wrprotect, fix fb_defio use" from Lorenzo
   Stoakes changes the interaction between framebuffer deferred-io and
   core MM. No functional changes are anticipated - this is preparatory
   work for the future removal of page structure fields.

 - The series "mm/damon: add support for hugepage_size DAMOS filter"
   from Usama Arif adds a DAMOS filter which permits the filtering by
   huge page sizes.

 - The series "mm: permit guard regions for file-backed/shmem mappings"
   from Lorenzo Stoakes extends the guard region feature from its
   present "anon mappings only" state. The feature now covers shmem and
   file-backed mappings.

 - The series "mm: batched unmap lazyfree large folios during
   reclamation" from Barry Song cleans up and speeds up the unmapping
   for pte-mapped large folios.

 - The series "reimplement per-vma lock as a refcount" from Suren
   Baghdasaryan puts the vm_lock back into the vma. Our reasons for
   pulling it out were largely bogus and that change made the code more
   messy. This patchset provides small (0-10%) improvements on one
   microbenchmark.

 - The series "Docs/mm/damon: misc DAMOS filters documentation fixes and
   improves" from SeongJae Park does some maintenance work on the DAMON
   docs.

 - The series "hugetlb/CMA improvements for large systems" from Frank
   van der Linden addresses a pile of issues which have been observed
   when using CMA on large machines.

 - The series "mm/damon: introduce DAMOS filter type for unmapped pages"
   from SeongJae Park enables users of DMAON/DAMOS to filter my the
   page's mapped/unmapped status.

 - The series "zsmalloc/zram: there be preemption" from Sergey
   Senozhatsky teaches zram to run its compression and decompression
   operations preemptibly.

 - The series "selftests/mm: Some cleanups from trying to run them" from
   Brendan Jackman fixes a pile of unrelated issues which Brendan
   encountered while runnimg our selftests.

 - The series "fs/proc/task_mmu: add guard region bit to pagemap" from
   Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to
   determine whether a particular page is a guard page.

 - The series "mm, swap: remove swap slot cache" from Kairui Song
   removes the swap slot cache from the allocation path - it simply
   wasn't being effective.

 - The series "mm: cleanups for device-exclusive entries (hmm)" from
   David Hildenbrand implements a number of unrelated cleanups in this
   code.

 - The series "mm: Rework generic PTDUMP configs" from Anshuman Khandual
   implements a number of preparatoty cleanups to the GENERIC_PTDUMP
   Kconfig logic.

 - The series "mm/damon: auto-tune aggregation interval" from SeongJae
   Park implements a feedback-driven automatic tuning feature for
   DAMON's aggregation interval tuning.

 - The series "Fix lazy mmu mode" from Ryan Roberts fixes some issues in
   powerpc, sparc and x86 lazy MMU implementations. Ryan did this in
   preparation for implementing lazy mmu mode for arm64 to optimize
   vmalloc.

 - The series "mm/page_alloc: Some clarifications for migratetype
   fallback" from Brendan Jackman reworks some commentary to make the
   code easier to follow.

 - The series "page_counter cleanup and size reduction" from Shakeel
   Butt cleans up the page_counter code and fixes a size increase which
   we accidentally added late last year.

 - The series "Add a command line option that enables control of how
   many threads should be used to allocate huge pages" from Thomas
   Prescher does that. It allows the careful operator to significantly
   reduce boot time by tuning the parallalization of huge page
   initialization.

 - The series "Fix calculations in trace_balance_dirty_pages() for cgwb"
   from Tang Yizhou fixes the tracing output from the dirty page
   balancing code.

 - The series "mm/damon: make allow filters after reject filters useful
   and intuitive" from SeongJae Park improves the handling of allow and
   reject filters. Behaviour is made more consistent and the documention
   is updated accordingly.

 - The series "Switch zswap to object read/write APIs" from Yosry Ahmed
   updates zswap to the new object read/write APIs and thus permits the
   removal of some legacy code from zpool and zsmalloc.

 - The series "Some trivial cleanups for shmem" from Baolin Wang does as
   it claims.

 - The series "fs/dax: Fix ZONE_DEVICE page reference counts" from
   Alistair Popple regularizes the weird ZONE_DEVICE page refcount
   handling in DAX, permittig the removal of a number of special-case
   checks.

 - The series "refactor mremap and fix bug" from Lorenzo Stoakes is a
   preparatoty refactoring and cleanup of the mremap() code.

 - The series "mm: MM owner tracking for large folios (!hugetlb) +
   CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in
   which we determine whether a large folio is known to be mapped
   exclusively into a single MM.

 - The series "mm/damon: add sysfs dirs for managing DAMOS filters based
   on handling layers" from SeongJae Park adds a couple of new sysfs
   directories to ease the management of DAMON/DAMOS filters.

 - The series "arch, mm: reduce code duplication in mem_init()" from
   Mike Rapoport consolidates many per-arch implementations of
   mem_init() into code generic code, where that is practical.

 - The series "mm/damon/sysfs: commit parameters online via
   damon_call()" from SeongJae Park continues the cleaning up of sysfs
   access to DAMON internal data.

 - The series "mm: page_ext: Introduce new iteration API" from Luiz
   Capitulino reworks the page_ext initialization to fix a boot-time
   crash which was observed with an unusual combination of compile and
   cmdline options.

 - The series "Buddy allocator like (or non-uniform) folio split" from
   Zi Yan reworks the code to split a folio into smaller folios. The
   main benefit is lessened memory consumption: fewer post-split folios
   are generated.

 - The series "Minimize xa_node allocation during xarry split" from Zi
   Yan reduces the number of xarray xa_nodes which are generated during
   an xarray split.

 - The series "drivers/base/memory: Two cleanups" from Gavin Shan
   performs some maintenance work on the drivers/base/memory code.

 - The series "Add tracepoints for lowmem reserves, watermarks and
   totalreserve_pages" from Martin Liu adds some more tracepoints to the
   page allocator code.

 - The series "mm/madvise: cleanup requests validations and
   classifications" from SeongJae Park cleans up some warts which
   SeongJae observed during his earlier madvise work.

 - The series "mm/hwpoison: Fix regressions in memory failure handling"
   from Shuai Xue addresses two quite serious regressions which Shuai
   has observed in the memory-failure implementation.

 - The series "mm: reliable huge page allocator" from Johannes Weiner
   makes huge page allocations cheaper and more reliable by reducing
   fragmentation.

 - The series "Minor memcg cleanups & prep for memdescs" from Matthew
   Wilcox is preparatory work for the future implementation of memdescs.

 - The series "track memory used by balloon drivers" from Nico Pache
   introduces a way to track memory used by our various balloon drivers.

 - The series "mm/damon: introduce DAMOS filter type for active pages"
   from Nhat Pham permits users to filter for active/inactive pages,
   separately for file and anon pages.

 - The series "Adding Proactive Memory Reclaim Statistics" from Hao Jia
   separates the proactive reclaim statistics from the direct reclaim
   statistics.

 - The series "mm/vmscan: don't try to reclaim hwpoison folio" from
   Jinjiang Tu fixes our handling of hwpoisoned pages within the reclaim
   code.

* tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (431 commits)
  mm/page_alloc: remove unnecessary __maybe_unused in order_to_pindex()
  x86/mm: restore early initialization of high_memory for 32-bits
  mm/vmscan: don't try to reclaim hwpoison folio
  mm/hwpoison: introduce folio_contain_hwpoisoned_page() helper
  cgroup: docs: add pswpin and pswpout items in cgroup v2 doc
  mm: vmscan: split proactive reclaim statistics from direct reclaim statistics
  selftests/mm: speed up split_huge_page_test
  selftests/mm: uffd-unit-tests support for hugepages > 2M
  docs/mm/damon/design: document active DAMOS filter type
  mm/damon: implement a new DAMOS filter type for active pages
  fs/dax: don't disassociate zero page entries
  MM documentation: add "Unaccepted" meminfo entry
  selftests/mm: add commentary about 9pfs bugs
  fork: use __vmalloc_node() for stack allocation
  docs/mm: Physical Memory: Populate the "Zones" section
  xen: balloon: update the NR_BALLOON_PAGES state
  hv_balloon: update the NR_BALLOON_PAGES state
  balloon_compaction: update the NR_BALLOON_PAGES state
  meminfo: add a per node counter for balloon drivers
  mm: remove references to folio in __memcg_kmem_uncharge_page()
  ...

1 files changed, 265 insertions, 28 deletions

diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index 683a04088f3f..6b82b618846e 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -13,6 +13,7 @@
 #include <linux/highmem.h>
 #include <linux/pagemap.h>
 #include <linux/memremap.h>
+#include <linux/bit_spinlock.h>
 
 /*
  * The anon_vma heads a list of private "related" vmas, to scan if
@@ -173,6 +174,214 @@ static inline void anon_vma_merge(struct vm_area_struct *vma,
 
 struct anon_vma *folio_get_anon_vma(const struct folio *folio);
 
+#ifdef CONFIG_MM_ID
+static __always_inline void folio_lock_large_mapcount(struct folio *folio)
+{
+	bit_spin_lock(FOLIO_MM_IDS_LOCK_BITNUM, &folio->_mm_ids);
+}
+
+static __always_inline void folio_unlock_large_mapcount(struct folio *folio)
+{
+	__bit_spin_unlock(FOLIO_MM_IDS_LOCK_BITNUM, &folio->_mm_ids);
+}
+
+static inline unsigned int folio_mm_id(const struct folio *folio, int idx)
+{
+	VM_WARN_ON_ONCE(idx != 0 && idx != 1);
+	return folio->_mm_id[idx] & MM_ID_MASK;
+}
+
+static inline void folio_set_mm_id(struct folio *folio, int idx, mm_id_t id)
+{
+	VM_WARN_ON_ONCE(idx != 0 && idx != 1);
+	folio->_mm_id[idx] &= ~MM_ID_MASK;
+	folio->_mm_id[idx] |= id;
+}
+
+static inline void __folio_large_mapcount_sanity_checks(const struct folio *folio,
+		int diff, mm_id_t mm_id)
+{
+	VM_WARN_ON_ONCE(!folio_test_large(folio) || folio_test_hugetlb(folio));
+	VM_WARN_ON_ONCE(diff <= 0);
+	VM_WARN_ON_ONCE(mm_id < MM_ID_MIN || mm_id > MM_ID_MAX);
+
+	/*
+	 * Make sure we can detect at least one complete PTE mapping of the
+	 * folio in a single MM as "exclusively mapped". This is primarily
+	 * a check on 32bit, where we currently reduce the size of the per-MM
+	 * mapcount to a short.
+	 */
+	VM_WARN_ON_ONCE(diff > folio_large_nr_pages(folio));
+	VM_WARN_ON_ONCE(folio_large_nr_pages(folio) - 1 > MM_ID_MAPCOUNT_MAX);
+
+	VM_WARN_ON_ONCE(folio_mm_id(folio, 0) == MM_ID_DUMMY &&
+			folio->_mm_id_mapcount[0] != -1);
+	VM_WARN_ON_ONCE(folio_mm_id(folio, 0) != MM_ID_DUMMY &&
+			folio->_mm_id_mapcount[0] < 0);
+	VM_WARN_ON_ONCE(folio_mm_id(folio, 1) == MM_ID_DUMMY &&
+			folio->_mm_id_mapcount[1] != -1);
+	VM_WARN_ON_ONCE(folio_mm_id(folio, 1) != MM_ID_DUMMY &&
+			folio->_mm_id_mapcount[1] < 0);
+	VM_WARN_ON_ONCE(!folio_mapped(folio) &&
+			folio_test_large_maybe_mapped_shared(folio));
+}
+
+static __always_inline void folio_set_large_mapcount(struct folio *folio,
+		int mapcount, struct vm_area_struct *vma)
+{
+	__folio_large_mapcount_sanity_checks(folio, mapcount, vma->vm_mm->mm_id);
+
+	VM_WARN_ON_ONCE(folio_mm_id(folio, 0) != MM_ID_DUMMY);
+	VM_WARN_ON_ONCE(folio_mm_id(folio, 1) != MM_ID_DUMMY);
+
+	/* Note: mapcounts start at -1. */
+	atomic_set(&folio->_large_mapcount, mapcount - 1);
+	folio->_mm_id_mapcount[0] = mapcount - 1;
+	folio_set_mm_id(folio, 0, vma->vm_mm->mm_id);
+}
+
+static __always_inline int folio_add_return_large_mapcount(struct folio *folio,
+		int diff, struct vm_area_struct *vma)
+{
+	const mm_id_t mm_id = vma->vm_mm->mm_id;
+	int new_mapcount_val;
+
+	folio_lock_large_mapcount(folio);
+	__folio_large_mapcount_sanity_checks(folio, diff, mm_id);
+
+	new_mapcount_val = atomic_read(&folio->_large_mapcount) + diff;
+	atomic_set(&folio->_large_mapcount, new_mapcount_val);
+
+	/*
+	 * If a folio is mapped more than once into an MM on 32bit, we
+	 * can in theory overflow the per-MM mapcount (although only for
+	 * fairly large folios), turning it negative. In that case, just
+	 * free up the slot and mark the folio "mapped shared", otherwise
+	 * we might be in trouble when unmapping pages later.
+	 */
+	if (folio_mm_id(folio, 0) == mm_id) {
+		folio->_mm_id_mapcount[0] += diff;
+		if (!IS_ENABLED(CONFIG_64BIT) && unlikely(folio->_mm_id_mapcount[0] < 0)) {
+			folio->_mm_id_mapcount[0] = -1;
+			folio_set_mm_id(folio, 0, MM_ID_DUMMY);
+			folio->_mm_ids |= FOLIO_MM_IDS_SHARED_BIT;
+		}
+	} else if (folio_mm_id(folio, 1) == mm_id) {
+		folio->_mm_id_mapcount[1] += diff;
+		if (!IS_ENABLED(CONFIG_64BIT) && unlikely(folio->_mm_id_mapcount[1] < 0)) {
+			folio->_mm_id_mapcount[1] = -1;
+			folio_set_mm_id(folio, 1, MM_ID_DUMMY);
+			folio->_mm_ids |= FOLIO_MM_IDS_SHARED_BIT;
+		}
+	} else if (folio_mm_id(folio, 0) == MM_ID_DUMMY) {
+		folio_set_mm_id(folio, 0, mm_id);
+		folio->_mm_id_mapcount[0] = diff - 1;
+		/* We might have other mappings already. */
+		if (new_mapcount_val != diff - 1)
+			folio->_mm_ids |= FOLIO_MM_IDS_SHARED_BIT;
+	} else if (folio_mm_id(folio, 1) == MM_ID_DUMMY) {
+		folio_set_mm_id(folio, 1, mm_id);
+		folio->_mm_id_mapcount[1] = diff - 1;
+		/* Slot 0 certainly has mappings as well. */
+		folio->_mm_ids |= FOLIO_MM_IDS_SHARED_BIT;
+	}
+	folio_unlock_large_mapcount(folio);
+	return new_mapcount_val + 1;
+}
+#define folio_add_large_mapcount folio_add_return_large_mapcount
+
+static __always_inline int folio_sub_return_large_mapcount(struct folio *folio,
+		int diff, struct vm_area_struct *vma)
+{
+	const mm_id_t mm_id = vma->vm_mm->mm_id;
+	int new_mapcount_val;
+
+	folio_lock_large_mapcount(folio);
+	__folio_large_mapcount_sanity_checks(folio, diff, mm_id);
+
+	new_mapcount_val = atomic_read(&folio->_large_mapcount) - diff;
+	atomic_set(&folio->_large_mapcount, new_mapcount_val);
+
+	/*
+	 * There are valid corner cases where we might underflow a per-MM
+	 * mapcount (some mappings added when no slot was free, some mappings
+	 * added once a slot was free), so we always set it to -1 once we go
+	 * negative.
+	 */
+	if (folio_mm_id(folio, 0) == mm_id) {
+		folio->_mm_id_mapcount[0] -= diff;
+		if (folio->_mm_id_mapcount[0] >= 0)
+			goto out;
+		folio->_mm_id_mapcount[0] = -1;
+		folio_set_mm_id(folio, 0, MM_ID_DUMMY);
+	} else if (folio_mm_id(folio, 1) == mm_id) {
+		folio->_mm_id_mapcount[1] -= diff;
+		if (folio->_mm_id_mapcount[1] >= 0)
+			goto out;
+		folio->_mm_id_mapcount[1] = -1;
+		folio_set_mm_id(folio, 1, MM_ID_DUMMY);
+	}
+
+	/*
+	 * If one MM slot owns all mappings, the folio is mapped exclusively.
+	 * Note that if the folio is now unmapped (new_mapcount_val == -1), both
+	 * slots must be free (mapcount == -1), and we'll also mark it as
+	 * exclusive.
+	 */
+	if (folio->_mm_id_mapcount[0] == new_mapcount_val ||
+	    folio->_mm_id_mapcount[1] == new_mapcount_val)
+		folio->_mm_ids &= ~FOLIO_MM_IDS_SHARED_BIT;
+out:
+	folio_unlock_large_mapcount(folio);
+	return new_mapcount_val + 1;
+}
+#define folio_sub_large_mapcount folio_sub_return_large_mapcount
+#else /* !CONFIG_MM_ID */
+/*
+ * See __folio_rmap_sanity_checks(), we might map large folios even without
+ * CONFIG_TRANSPARENT_HUGEPAGE. We'll keep that working for now.
+ */
+static inline void folio_set_large_mapcount(struct folio *folio, int mapcount,
+		struct vm_area_struct *vma)
+{
+	/* Note: mapcounts start at -1. */
+	atomic_set(&folio->_large_mapcount, mapcount - 1);
+}
+
+static inline void folio_add_large_mapcount(struct folio *folio,
+		int diff, struct vm_area_struct *vma)
+{
+	atomic_add(diff, &folio->_large_mapcount);
+}
+
+static inline int folio_add_return_large_mapcount(struct folio *folio,
+		int diff, struct vm_area_struct *vma)
+{
+	BUILD_BUG();
+}
+
+static inline void folio_sub_large_mapcount(struct folio *folio,
+		int diff, struct vm_area_struct *vma)
+{
+	atomic_sub(diff, &folio->_large_mapcount);
+}
+
+static inline int folio_sub_return_large_mapcount(struct folio *folio,
+		int diff, struct vm_area_struct *vma)
+{
+	BUILD_BUG();
+}
+#endif /* CONFIG_MM_ID */
+
+#define folio_inc_large_mapcount(folio, vma) \
+	folio_add_large_mapcount(folio, 1, vma)
+#define folio_inc_return_large_mapcount(folio, vma) \
+	folio_add_return_large_mapcount(folio, 1, vma)
+#define folio_dec_large_mapcount(folio, vma) \
+	folio_sub_large_mapcount(folio, 1, vma)
+#define folio_dec_return_large_mapcount(folio, vma) \
+	folio_sub_return_large_mapcount(folio, 1, vma)
+
 /* RMAP flags, currently only relevant for some anon rmap operations. */
 typedef int __bitwise rmap_t;
 
@@ -192,6 +401,7 @@ typedef int __bitwise rmap_t;
 enum rmap_level {
 	RMAP_LEVEL_PTE = 0,
 	RMAP_LEVEL_PMD,
+	RMAP_LEVEL_PUD,
 };
 
 static inline void __folio_rmap_sanity_checks(const struct folio *folio,
@@ -228,6 +438,14 @@ static inline void __folio_rmap_sanity_checks(const struct folio *folio,
 		VM_WARN_ON_FOLIO(folio_nr_pages(folio) != HPAGE_PMD_NR, folio);
 		VM_WARN_ON_FOLIO(nr_pages != HPAGE_PMD_NR, folio);
 		break;
+	case RMAP_LEVEL_PUD:
+		/*
+		 * Assume that we are creating a single "entire" mapping of the
+		 * folio.
+		 */
+		VM_WARN_ON_FOLIO(folio_nr_pages(folio) != HPAGE_PUD_NR, folio);
+		VM_WARN_ON_FOLIO(nr_pages != HPAGE_PUD_NR, folio);
+		break;
 	default:
 		VM_WARN_ON_ONCE(true);
 	}
@@ -251,12 +469,16 @@ void folio_add_file_rmap_ptes(struct folio *, struct page *, int nr_pages,
 	folio_add_file_rmap_ptes(folio, page, 1, vma)
 void folio_add_file_rmap_pmd(struct folio *, struct page *,
 		struct vm_area_struct *);
+void folio_add_file_rmap_pud(struct folio *, struct page *,
+		struct vm_area_struct *);
 void folio_remove_rmap_ptes(struct folio *, struct page *, int nr_pages,
 		struct vm_area_struct *);
 #define folio_remove_rmap_pte(folio, page, vma) \
 	folio_remove_rmap_ptes(folio, page, 1, vma)
 void folio_remove_rmap_pmd(struct folio *, struct page *,
 		struct vm_area_struct *);
+void folio_remove_rmap_pud(struct folio *, struct page *,
+		struct vm_area_struct *);
 
 void hugetlb_add_anon_rmap(struct folio *, struct vm_area_struct *,
 		unsigned long address, rmap_t flags);
@@ -322,7 +544,8 @@ static inline void hugetlb_remove_rmap(struct folio *folio)
 }
 
 static __always_inline void __folio_dup_file_rmap(struct folio *folio,
-		struct page *page, int nr_pages, enum rmap_level level)
+		struct page *page, int nr_pages, struct vm_area_struct *dst_vma,
+		enum rmap_level level)
 {
 	const int orig_nr_pages = nr_pages;
 
@@ -335,14 +558,17 @@ static __always_inline void __folio_dup_file_rmap(struct folio *folio,
 			break;
 		}
 
-		do {
-			atomic_inc(&page->_mapcount);
-		} while (page++, --nr_pages > 0);
-		atomic_add(orig_nr_pages, &folio->_large_mapcount);
+		if (IS_ENABLED(CONFIG_PAGE_MAPCOUNT)) {
+			do {
+				atomic_inc(&page->_mapcount);
+			} while (page++, --nr_pages > 0);
+		}
+		folio_add_large_mapcount(folio, orig_nr_pages, dst_vma);
 		break;
 	case RMAP_LEVEL_PMD:
+	case RMAP_LEVEL_PUD:
 		atomic_inc(&folio->_entire_mapcount);
-		atomic_inc(&folio->_large_mapcount);
+		folio_inc_large_mapcount(folio, dst_vma);
 		break;
 	}
 }
@@ -352,45 +578,47 @@ static __always_inline void __folio_dup_file_rmap(struct folio *folio,
  * @folio:	The folio to duplicate the mappings of
  * @page:	The first page to duplicate the mappings of
  * @nr_pages:	The number of pages of which the mapping will be duplicated
+ * @dst_vma:	The destination vm area
  *
  * The page range of the folio is defined by [page, page + nr_pages)
  *
  * The caller needs to hold the page table lock.
  */
 static inline void folio_dup_file_rmap_ptes(struct folio *folio,
-		struct page *page, int nr_pages)
+		struct page *page, int nr_pages, struct vm_area_struct *dst_vma)
 {
-	__folio_dup_file_rmap(folio, page, nr_pages, RMAP_LEVEL_PTE);
+	__folio_dup_file_rmap(folio, page, nr_pages, dst_vma, RMAP_LEVEL_PTE);
 }
 
 static __always_inline void folio_dup_file_rmap_pte(struct folio *folio,
-		struct page *page)
+		struct page *page, struct vm_area_struct *dst_vma)
 {
-	__folio_dup_file_rmap(folio, page, 1, RMAP_LEVEL_PTE);
+	__folio_dup_file_rmap(folio, page, 1, dst_vma, RMAP_LEVEL_PTE);
 }
 
 /**
  * folio_dup_file_rmap_pmd - duplicate a PMD mapping of a page range of a folio
  * @folio:	The folio to duplicate the mapping of
  * @page:	The first page to duplicate the mapping of
+ * @dst_vma:	The destination vm area
  *
  * The page range of the folio is defined by [page, page + HPAGE_PMD_NR)
  *
  * The caller needs to hold the page table lock.
  */
 static inline void folio_dup_file_rmap_pmd(struct folio *folio,
-		struct page *page)
+		struct page *page, struct vm_area_struct *dst_vma)
 {
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-	__folio_dup_file_rmap(folio, page, HPAGE_PMD_NR, RMAP_LEVEL_PTE);
+	__folio_dup_file_rmap(folio, page, HPAGE_PMD_NR, dst_vma, RMAP_LEVEL_PTE);
 #else
 	WARN_ON_ONCE(true);
 #endif
 }
 
 static __always_inline int __folio_try_dup_anon_rmap(struct folio *folio,
-		struct page *page, int nr_pages, struct vm_area_struct *src_vma,
-		enum rmap_level level)
+		struct page *page, int nr_pages, struct vm_area_struct *dst_vma,
+		struct vm_area_struct *src_vma, enum rmap_level level)
 {
 	const int orig_nr_pages = nr_pages;
 	bool maybe_pinned;
@@ -432,18 +660,20 @@ static __always_inline int __folio_try_dup_anon_rmap(struct folio *folio,
 		do {
 			if (PageAnonExclusive(page))
 				ClearPageAnonExclusive(page);
-			atomic_inc(&page->_mapcount);
+			if (IS_ENABLED(CONFIG_PAGE_MAPCOUNT))
+				atomic_inc(&page->_mapcount);
 		} while (page++, --nr_pages > 0);
-		atomic_add(orig_nr_pages, &folio->_large_mapcount);
+		folio_add_large_mapcount(folio, orig_nr_pages, dst_vma);
 		break;
 	case RMAP_LEVEL_PMD:
+	case RMAP_LEVEL_PUD:
 		if (PageAnonExclusive(page)) {
 			if (unlikely(maybe_pinned))
 				return -EBUSY;
 			ClearPageAnonExclusive(page);
 		}
 		atomic_inc(&folio->_entire_mapcount);
-		atomic_inc(&folio->_large_mapcount);
+		folio_inc_large_mapcount(folio, dst_vma);
 		break;
 	}
 	return 0;
@@ -455,6 +685,7 @@ static __always_inline int __folio_try_dup_anon_rmap(struct folio *folio,
  * @folio:	The folio to duplicate the mappings of
  * @page:	The first page to duplicate the mappings of
  * @nr_pages:	The number of pages of which the mapping will be duplicated
+ * @dst_vma:	The destination vm area
  * @src_vma:	The vm area from which the mappings are duplicated
  *
  * The page range of the folio is defined by [page, page + nr_pages)
@@ -473,16 +704,18 @@ static __always_inline int __folio_try_dup_anon_rmap(struct folio *folio,
  * Returns 0 if duplicating the mappings succeeded. Returns -EBUSY otherwise.
  */
 static inline int folio_try_dup_anon_rmap_ptes(struct folio *folio,
-		struct page *page, int nr_pages, struct vm_area_struct *src_vma)
+		struct page *page, int nr_pages, struct vm_area_struct *dst_vma,
+		struct vm_area_struct *src_vma)
 {
-	return __folio_try_dup_anon_rmap(folio, page, nr_pages, src_vma,
-					 RMAP_LEVEL_PTE);
+	return __folio_try_dup_anon_rmap(folio, page, nr_pages, dst_vma,
+					 src_vma, RMAP_LEVEL_PTE);
 }
 
 static __always_inline int folio_try_dup_anon_rmap_pte(struct folio *folio,
-		struct page *page, struct vm_area_struct *src_vma)
+		struct page *page, struct vm_area_struct *dst_vma,
+		struct vm_area_struct *src_vma)
 {
-	return __folio_try_dup_anon_rmap(folio, page, 1, src_vma,
+	return __folio_try_dup_anon_rmap(folio, page, 1, dst_vma, src_vma,
 					 RMAP_LEVEL_PTE);
 }
 
@@ -491,6 +724,7 @@ static __always_inline int folio_try_dup_anon_rmap_pte(struct folio *folio,
  *				 of a folio
  * @folio:	The folio to duplicate the mapping of
  * @page:	The first page to duplicate the mapping of
+ * @dst_vma:	The destination vm area
  * @src_vma:	The vm area from which the mapping is duplicated
  *
  * The page range of the folio is defined by [page, page + HPAGE_PMD_NR)
@@ -509,11 +743,12 @@ static __always_inline int folio_try_dup_anon_rmap_pte(struct folio *folio,
  * Returns 0 if duplicating the mapping succeeded. Returns -EBUSY otherwise.
  */
 static inline int folio_try_dup_anon_rmap_pmd(struct folio *folio,
-		struct page *page, struct vm_area_struct *src_vma)
+		struct page *page, struct vm_area_struct *dst_vma,
+		struct vm_area_struct *src_vma)
 {
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-	return __folio_try_dup_anon_rmap(folio, page, HPAGE_PMD_NR, src_vma,
-					 RMAP_LEVEL_PMD);
+	return __folio_try_dup_anon_rmap(folio, page, HPAGE_PMD_NR, dst_vma,
+					 src_vma, RMAP_LEVEL_PMD);
 #else
 	WARN_ON_ONCE(true);
 	return -EBUSY;
@@ -663,9 +898,8 @@ int folio_referenced(struct folio *, int is_locked,
 void try_to_migrate(struct folio *folio, enum ttu_flags flags);
 void try_to_unmap(struct folio *, enum ttu_flags flags);
 
-int make_device_exclusive_range(struct mm_struct *mm, unsigned long start,
-				unsigned long end, struct page **pages,
-				void *arg);
+struct page *make_device_exclusive(struct mm_struct *mm, unsigned long addr,
+		void *owner, struct folio **foliop);
 
 /* Avoid racy checks */
 #define PVMW_SYNC		(1 << 0)
@@ -739,6 +973,9 @@ unsigned long page_address_in_vma(const struct folio *folio,
  */
 int folio_mkclean(struct folio *);
 
+int mapping_wrprotect_range(struct address_space *mapping, pgoff_t pgoff,
+		unsigned long pfn, unsigned long nr_pages);
+
 int pfn_mkclean_range(unsigned long pfn, unsigned long nr_pages, pgoff_t pgoff,
 		      struct vm_area_struct *vma);