Merge tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of
   switching from a user process to a kernel thread.

 - More folio conversions from Kefeng Wang, Zhang Peng and Pankaj
   Raghav.

 - zsmalloc performance improvements from Sergey Senozhatsky.

 - Yue Zhao has found and fixed some data race issues around the
   alteration of memcg userspace tunables.

 - VFS rationalizations from Christoph Hellwig:
     - removal of most of the callers of write_one_page()
     - make __filemap_get_folio()'s return value more useful

 - Luis Chamberlain has changed tmpfs so it no longer requires swap
   backing. Use `mount -o noswap'.

 - Qi Zheng has made the slab shrinkers operate locklessly, providing
   some scalability benefits.

 - Keith Busch has improved dmapool's performance, making part of its
   operations O(1) rather than O(n).

 - Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd,
   permitting userspace to wr-protect anon memory unpopulated ptes.

 - Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive
   rather than exclusive, and has fixed a bunch of errors which were
   caused by its unintuitive meaning.

 - Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature,
   which causes minor faults to install a write-protected pte.

 - Vlastimil Babka has done some maintenance work on vma_merge():
   cleanups to the kernel code and improvements to our userspace test
   harness.

 - Cleanups to do_fault_around() by Lorenzo Stoakes.

 - Mike Rapoport has moved a lot of initialization code out of various
   mm/ files and into mm/mm_init.c.

 - Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for
   DRM, but DRM doesn't use it any more.

 - Lorenzo has also coverted read_kcore() and vread() to use iterators
   and has thereby removed the use of bounce buffers in some cases.

 - Lorenzo has also contributed further cleanups of vma_merge().

 - Chaitanya Prakash provides some fixes to the mmap selftesting code.

 - Matthew Wilcox changes xfs and afs so they no longer take sleeping
   locks in ->map_page(), a step towards RCUification of pagefaults.

 - Suren Baghdasaryan has improved mmap_lock scalability by switching to
   per-VMA locking.

 - Frederic Weisbecker has reworked the percpu cache draining so that it
   no longer causes latency glitches on cpu isolated workloads.

 - Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig
   logic.

 - Liu Shixin has changed zswap's initialization so we no longer waste a
   chunk of memory if zswap is not being used.

 - Yosry Ahmed has improved the performance of memcg statistics
   flushing.

 - David Stevens has fixed several issues involving khugepaged,
   userfaultfd and shmem.

 - Christoph Hellwig has provided some cleanup work to zram's IO-related
   code paths.

 - David Hildenbrand has fixed up some issues in the selftest code's
   testing of our pte state changing.

 - Pankaj Raghav has made page_endio() unneeded and has removed it.

 - Peter Xu contributed some rationalizations of the userfaultfd
   selftests.

 - Yosry Ahmed has fixed an issue around memcg's page recalim
   accounting.

 - Chaitanya Prakash has fixed some arm-related issues in the
   selftests/mm code.

 - Longlong Xia has improved the way in which KSM handles hwpoisoned
   pages.

 - Peter Xu fixes a few issues with uffd-wp at fork() time.

 - Stefan Roesch has changed KSM so that it may now be used on a
   per-process and per-cgroup basis.

* tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits)
  mm,unmap: avoid flushing TLB in batch if PTE is inaccessible
  shmem: restrict noswap option to initial user namespace
  mm/khugepaged: fix conflicting mods to collapse_file()
  sparse: remove unnecessary 0 values from rc
  mm: move 'mmap_min_addr' logic from callers into vm_unmapped_area()
  hugetlb: pte_alloc_huge() to replace huge pte_alloc_map()
  maple_tree: fix allocation in mas_sparse_area()
  mm: do not increment pgfault stats when page fault handler retries
  zsmalloc: allow only one active pool compaction context
  selftests/mm: add new selftests for KSM
  mm: add new KSM process and sysfs knobs
  mm: add new api to enable ksm per process
  mm: shrinkers: fix debugfs file permissions
  mm: don't check VMA write permissions if the PTE/PMD indicates write permissions
  migrate_pages_batch: fix statistics for longterm pin retry
  userfaultfd: use helper function range_in_vma()
  lib/show_mem.c: use for_each_populated_zone() simplify code
  mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list()
  fs/buffer: convert create_page_buffers to folio_create_buffers
  fs/buffer: add folio_create_empty_buffers helper
  ...

5 files changed, 80 insertions, 65 deletions

diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index d4c1d96f85cd8..8535e19062f65 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -271,18 +271,17 @@ config ARCH_SPARSEMEM_DEFAULT
 	def_bool y if SPARC64
 
 config ARCH_FORCE_MAX_ORDER
-	int "Maximum zone order"
-	default "13"
+	int "Order of maximal physically contiguous allocations"
+	default "12"
 	help
-	  The kernel memory allocator divides physically contiguous memory
-	  blocks into "zones", where each zone is a power of two number of
-	  pages.  This option selects the largest power of two that the kernel
-	  keeps in the memory allocator.  If you need to allocate very large
-	  blocks of physically contiguous memory, then you may need to
-	  increase this value.
-
-	  This config option is actually maximum order plus one. For example,
-	  a value of 13 means that the largest free memory block is 2^12 pages.
+	  The kernel page allocator limits the size of maximal physically
+	  contiguous allocations. The limit is called MAX_ORDER and it
+	  defines the maximal power of two of number of pages that can be
+	  allocated as a single contiguous block. This option allows
+	  overriding the default setting when ability to allocate very
+	  large blocks of physically contiguous memory is required.
+
+	  Don't change if unsure.
 
 if SPARC64 || COMPILE_TEST
 source "kernel/power/Kconfig"
diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index 2dc8d46417346..5563efa1a19f9 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -357,6 +357,42 @@ static inline pgprot_t pgprot_noncached(pgprot_t prot)
  */
 #define pgprot_noncached pgprot_noncached
 
+static inline unsigned long pte_dirty(pte_t pte)
+{
+	unsigned long mask;
+
+	__asm__ __volatile__(
+	"\n661:	mov		%1, %0\n"
+	"	nop\n"
+	"	.section	.sun4v_2insn_patch, \"ax\"\n"
+	"	.word		661b\n"
+	"	sethi		%%uhi(%2), %0\n"
+	"	sllx		%0, 32, %0\n"
+	"	.previous\n"
+	: "=r" (mask)
+	: "i" (_PAGE_MODIFIED_4U), "i" (_PAGE_MODIFIED_4V));
+
+	return (pte_val(pte) & mask);
+}
+
+static inline unsigned long pte_write(pte_t pte)
+{
+	unsigned long mask;
+
+	__asm__ __volatile__(
+	"\n661:	mov		%1, %0\n"
+	"	nop\n"
+	"	.section	.sun4v_2insn_patch, \"ax\"\n"
+	"	.word		661b\n"
+	"	sethi		%%uhi(%2), %0\n"
+	"	sllx		%0, 32, %0\n"
+	"	.previous\n"
+	: "=r" (mask)
+	: "i" (_PAGE_WRITE_4U), "i" (_PAGE_WRITE_4V));
+
+	return (pte_val(pte) & mask);
+}
+
 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
 pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags);
 #define arch_make_huge_pte arch_make_huge_pte
@@ -418,28 +454,43 @@ static inline bool is_hugetlb_pte(pte_t pte)
 }
 #endif
 
+static inline pte_t __pte_mkhwwrite(pte_t pte)
+{
+	unsigned long val = pte_val(pte);
+
+	/*
+	 * Note: we only want to set the HW writable bit if the SW writable bit
+	 * and the SW dirty bit are set.
+	 */
+	__asm__ __volatile__(
+	"\n661:	or		%0, %2, %0\n"
+	"	.section	.sun4v_1insn_patch, \"ax\"\n"
+	"	.word		661b\n"
+	"	or		%0, %3, %0\n"
+	"	.previous\n"
+	: "=r" (val)
+	: "0" (val), "i" (_PAGE_W_4U), "i" (_PAGE_W_4V));
+
+	return __pte(val);
+}
+
 static inline pte_t pte_mkdirty(pte_t pte)
 {
-	unsigned long val = pte_val(pte), tmp;
+	unsigned long val = pte_val(pte), mask;
 
 	__asm__ __volatile__(
-	"\n661:	or		%0, %3, %0\n"
-	"	nop\n"
-	"\n662:	nop\n"
+	"\n661:	mov		%1, %0\n"
 	"	nop\n"
 	"	.section	.sun4v_2insn_patch, \"ax\"\n"
 	"	.word		661b\n"
-	"	sethi		%%uhi(%4), %1\n"
-	"	sllx		%1, 32, %1\n"
-	"	.word		662b\n"
-	"	or		%1, %%lo(%4), %1\n"
-	"	or		%0, %1, %0\n"
+	"	sethi		%%uhi(%2), %0\n"
+	"	sllx		%0, 32, %0\n"
 	"	.previous\n"
-	: "=r" (val), "=r" (tmp)
-	: "0" (val), "i" (_PAGE_MODIFIED_4U | _PAGE_W_4U),
-	  "i" (_PAGE_MODIFIED_4V | _PAGE_W_4V));
+	: "=r" (mask)
+	: "i" (_PAGE_MODIFIED_4U), "i" (_PAGE_MODIFIED_4V));
 
-	return __pte(val);
+	pte = __pte(val | mask);
+	return pte_write(pte) ? __pte_mkhwwrite(pte) : pte;
 }
 
 static inline pte_t pte_mkclean(pte_t pte)
@@ -481,7 +532,8 @@ static inline pte_t pte_mkwrite(pte_t pte)
 	: "=r" (mask)
 	: "i" (_PAGE_WRITE_4U), "i" (_PAGE_WRITE_4V));
 
-	return __pte(val | mask);
+	pte = __pte(val | mask);
+	return pte_dirty(pte) ? __pte_mkhwwrite(pte) : pte;
 }
 
 static inline pte_t pte_wrprotect(pte_t pte)
@@ -584,42 +636,6 @@ static inline unsigned long pte_young(pte_t pte)
 	return (pte_val(pte) & mask);
 }
 
-static inline unsigned long pte_dirty(pte_t pte)
-{
-	unsigned long mask;
-
-	__asm__ __volatile__(
-	"\n661:	mov		%1, %0\n"
-	"	nop\n"
-	"	.section	.sun4v_2insn_patch, \"ax\"\n"
-	"	.word		661b\n"
-	"	sethi		%%uhi(%2), %0\n"
-	"	sllx		%0, 32, %0\n"
-	"	.previous\n"
-	: "=r" (mask)
-	: "i" (_PAGE_MODIFIED_4U), "i" (_PAGE_MODIFIED_4V));
-
-	return (pte_val(pte) & mask);
-}
-
-static inline unsigned long pte_write(pte_t pte)
-{
-	unsigned long mask;
-
-	__asm__ __volatile__(
-	"\n661:	mov		%1, %0\n"
-	"	nop\n"
-	"	.section	.sun4v_2insn_patch, \"ax\"\n"
-	"	.word		661b\n"
-	"	sethi		%%uhi(%2), %0\n"
-	"	sllx		%0, 32, %0\n"
-	"	.previous\n"
-	: "=r" (mask)
-	: "i" (_PAGE_WRITE_4U), "i" (_PAGE_WRITE_4V));
-
-	return (pte_val(pte) & mask);
-}
-
 static inline unsigned long pte_exec(pte_t pte)
 {
 	unsigned long mask;
diff --git a/arch/sparc/kernel/pci_sun4v.c b/arch/sparc/kernel/pci_sun4v.c
index 3844809718052..7d91ca6aa675c 100644
--- a/arch/sparc/kernel/pci_sun4v.c
+++ b/arch/sparc/kernel/pci_sun4v.c
@@ -193,7 +193,7 @@ static void *dma_4v_alloc_coherent(struct device *dev, size_t size,
 
 	size = IO_PAGE_ALIGN(size);
 	order = get_order(size);
-	if (unlikely(order >= MAX_ORDER))
+	if (unlikely(order > MAX_ORDER))
 		return NULL;
 
 	npages = size >> IO_PAGE_SHIFT;
diff --git a/arch/sparc/kernel/traps_64.c b/arch/sparc/kernel/traps_64.c
index 5b4de4a89decb..08ffd17d5ec34 100644
--- a/arch/sparc/kernel/traps_64.c
+++ b/arch/sparc/kernel/traps_64.c
@@ -897,7 +897,7 @@ void __init cheetah_ecache_flush_init(void)
 
 	/* Now allocate error trap reporting scoreboard. */
 	sz = NR_CPUS * (2 * sizeof(struct cheetah_err_info));
-	for (order = 0; order < MAX_ORDER; order++) {
+	for (order = 0; order <= MAX_ORDER; order++) {
 		if ((PAGE_SIZE << order) >= sz)
 			break;
 	}
diff --git a/arch/sparc/mm/tsb.c b/arch/sparc/mm/tsb.c
index 9122057871610..5e2931a184094 100644
--- a/arch/sparc/mm/tsb.c
+++ b/arch/sparc/mm/tsb.c
@@ -402,8 +402,8 @@ void tsb_grow(struct mm_struct *mm, unsigned long tsb_index, unsigned long rss)
 	unsigned long new_rss_limit;
 	gfp_t gfp_flags;
 
-	if (max_tsb_size > (PAGE_SIZE << MAX_ORDER))
-		max_tsb_size = (PAGE_SIZE << MAX_ORDER);
+	if (max_tsb_size > PAGE_SIZE << MAX_ORDER)
+		max_tsb_size = PAGE_SIZE << MAX_ORDER;
 
 	new_cache_index = 0;
 	for (new_size = 8192; new_size < max_tsb_size; new_size <<= 1UL) {