Merge tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - "Add folio_mk_pte()" from Matthew Wilcox simplifies the act of
   creating a pte which addresses the first page in a folio and reduces
   the amount of plumbing which architecture must implement to provide
   this.

 - "Misc folio patches for 6.16" from Matthew Wilcox is a shower of
   largely unrelated folio infrastructure changes which clean things up
   and better prepare us for future work.

 - "memory,x86,acpi: hotplug memory alignment advisement" from Gregory
   Price adds early-init code to prevent x86 from leaving physical
   memory unused when physical address regions are not aligned to memory
   block size.

 - "mm/compaction: allow more aggressive proactive compaction" from
   Michal Clapinski provides some tuning of the (sadly, hard-coded (more
   sadly, not auto-tuned)) thresholds for our invokation of proactive
   compaction. In a simple test case, the reduction of a guest VM's
   memory consumption was dramatic.

 - "Minor cleanups and improvements to swap freeing code" from Kemeng
   Shi provides some code cleaups and a small efficiency improvement to
   this part of our swap handling code.

 - "ptrace: introduce PTRACE_SET_SYSCALL_INFO API" from Dmitry Levin
   adds the ability for a ptracer to modify syscalls arguments. At this
   time we can alter only "system call information that are used by
   strace system call tampering, namely, syscall number, syscall
   arguments, and syscall return value.

   This series should have been incorporated into mm.git's "non-MM"
   branch, but I goofed.

 - "fs/proc: extend the PAGEMAP_SCAN ioctl to report guard regions" from
   Andrei Vagin extends the info returned by the PAGEMAP_SCAN ioctl
   against /proc/pid/pagemap. This permits CRIU to more efficiently get
   at the info about guard regions.

 - "Fix parameter passed to page_mapcount_is_type()" from Gavin Shan
   implements that fix. No runtime effect is expected because
   validate_page_before_insert() happens to fix up this error.

 - "kernel/events/uprobes: uprobe_write_opcode() rewrite" from David
   Hildenbrand basically brings uprobe text poking into the current
   decade. Remove a bunch of hand-rolled implementation in favor of
   using more current facilities.

 - "mm/ptdump: Drop assumption that pxd_val() is u64" from Anshuman
   Khandual provides enhancements and generalizations to the pte dumping
   code. This might be needed when 128-bit Page Table Descriptors are
   enabled for ARM.

 - "Always call constructor for kernel page tables" from Kevin Brodsky
   ensures that the ctor/dtor is always called for kernel pgtables, as
   it already is for user pgtables.

   This permits the addition of more functionality such as "insert hooks
   to protect page tables". This change does result in various
   architectures performing unnecesary work, but this is fixed up where
   it is anticipated to occur.

 - "Rust support for mm_struct, vm_area_struct, and mmap" from Alice
   Ryhl adds plumbing to permit Rust access to core MM structures.

 - "fix incorrectly disallowed anonymous VMA merges" from Lorenzo
   Stoakes takes advantage of some VMA merging opportunities which we've
   been missing for 15 years.

 - "mm/madvise: batch tlb flushes for MADV_DONTNEED and MADV_FREE" from
   SeongJae Park optimizes process_madvise()'s TLB flushing.

   Instead of flushing each address range in the provided iovec, we
   batch the flushing across all the iovec entries. The syscall's cost
   was approximately halved with a microbenchmark which was designed to
   load this particular operation.

 - "Track node vacancy to reduce worst case allocation counts" from
   Sidhartha Kumar makes the maple tree smarter about its node
   preallocation.

   stress-ng mmap performance increased by single-digit percentages and
   the amount of unnecessarily preallocated memory was dramaticelly
   reduced.

 - "mm/gup: Minor fix, cleanup and improvements" from Baoquan He removes
   a few unnecessary things which Baoquan noted when reading the code.

 - ""Enhance sysfs handling for memory hotplug in weighted interleave"
   from Rakie Kim "enhances the weighted interleave policy in the memory
   management subsystem by improving sysfs handling, fixing memory
   leaks, and introducing dynamic sysfs updates for memory hotplug
   support". Fixes things on error paths which we are unlikely to hit.

 - "mm/damon: auto-tune DAMOS for NUMA setups including tiered memory"
   from SeongJae Park introduces new DAMOS quota goal metrics which
   eliminate the manual tuning which is required when utilizing DAMON
   for memory tiering.

 - "mm/vmalloc.c: code cleanup and improvements" from Baoquan He
   provides cleanups and small efficiency improvements which Baoquan
   found via code inspection.

 - "vmscan: enforce mems_effective during demotion" from Gregory Price
   changes reclaim to respect cpuset.mems_effective during demotion when
   possible. because presently, reclaim explicitly ignores
   cpuset.mems_effective when demoting, which may cause the cpuset
   settings to violated.

   This is useful for isolating workloads on a multi-tenant system from
   certain classes of memory more consistently.

 - "Clean up split_huge_pmd_locked() and remove unnecessary folio
   pointers" from Gavin Guo provides minor cleanups and efficiency gains
   in in the huge page splitting and migrating code.

 - "Use kmem_cache for memcg alloc" from Huan Yang creates a slab cache
   for `struct mem_cgroup', yielding improved memory utilization.

 - "add max arg to swappiness in memory.reclaim and lru_gen" from
   Zhongkun He adds a new "max" argument to the "swappiness=" argument
   for memory.reclaim MGLRU's lru_gen.

   This directs proactive reclaim to reclaim from only anon folios
   rather than file-backed folios.

 - "kexec: introduce Kexec HandOver (KHO)" from Mike Rapoport is the
   first step on the path to permitting the kernel to maintain existing
   VMs while replacing the host kernel via file-based kexec. At this
   time only memblock's reserve_mem is preserved.

 - "mm: Introduce for_each_valid_pfn()" from David Woodhouse provides
   and uses a smarter way of looping over a pfn range. By skipping
   ranges of invalid pfns.

 - "sched/numa: Skip VMA scanning on memory pinned to one NUMA node via
   cpuset.mems" from Libo Chen removes a lot of pointless VMA scanning
   when a task is pinned a single NUMA mode.

   Dramatic performance benefits were seen in some real world cases.

 - "JFS: Implement migrate_folio for jfs_metapage_aops" from Shivank
   Garg addresses a warning which occurs during memory compaction when
   using JFS.

 - "move all VMA allocation, freeing and duplication logic to mm" from
   Lorenzo Stoakes moves some VMA code from kernel/fork.c into the more
   appropriate mm/vma.c.

 - "mm, swap: clean up swap cache mapping helper" from Kairui Song
   provides code consolidation and cleanups related to the folio_index()
   function.

 - "mm/gup: Cleanup memfd_pin_folios()" from Vishal Moola does that.

 - "memcg: Fix test_memcg_min/low test failures" from Waiman Long
   addresses some bogus failures which are being reported by the
   test_memcontrol selftest.

 - "eliminate mmap() retry merge, add .mmap_prepare hook" from Lorenzo
   Stoakes commences the deprecation of file_operations.mmap() in favor
   of the new file_operations.mmap_prepare().

   The latter is more restrictive and prevents drivers from messing with
   things in ways which, amongst other problems, may defeat VMA merging.

 - "memcg: decouple memcg and objcg stocks"" from Shakeel Butt decouples
   the per-cpu memcg charge cache from the objcg's one.

   This is a step along the way to making memcg and objcg charging
   NMI-safe, which is a BPF requirement.

 - "mm/damon: minor fixups and improvements for code, tests, and
   documents" from SeongJae Park is yet another batch of miscellaneous
   DAMON changes. Fix and improve minor problems in code, tests and
   documents.

 - "memcg: make memcg stats irq safe" from Shakeel Butt converts memcg
   stats to be irq safe. Another step along the way to making memcg
   charging and stats updates NMI-safe, a BPF requirement.

 - "Let unmap_hugepage_range() and several related functions take folio
   instead of page" from Fan Ni provides folio conversions in the
   hugetlb code.

* tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (285 commits)
  mm: pcp: increase pcp->free_count threshold to trigger free_high
  mm/hugetlb: convert use of struct page to folio in __unmap_hugepage_range()
  mm/hugetlb: refactor __unmap_hugepage_range() to take folio instead of page
  mm/hugetlb: refactor unmap_hugepage_range() to take folio instead of page
  mm/hugetlb: pass folio instead of page to unmap_ref_private()
  memcg: objcg stock trylock without irq disabling
  memcg: no stock lock for cpu hot-unplug
  memcg: make __mod_memcg_lruvec_state re-entrant safe against irqs
  memcg: make count_memcg_events re-entrant safe against irqs
  memcg: make mod_memcg_state re-entrant safe against irqs
  memcg: move preempt disable to callers of memcg_rstat_updated
  memcg: memcg_rstat_updated re-entrant safe against irqs
  mm: khugepaged: decouple SHMEM and file folios' collapse
  selftests/eventfd: correct test name and improve messages
  alloc_tag: check mem_profiling_support in alloc_tag_init
  Docs/damon: update titles and brief introductions to explain DAMOS
  selftests/damon/_damon_sysfs: read tried regions directories in order
  mm/damon/tests/core-kunit: add a test for damos_set_filters_default_reject()
  mm/damon/paddr: remove unused variable, folio_list, in damon_pa_stat()
  mm/damon/sysfs-schemes: fix wrong comment on damons_sysfs_quota_goal_metric_strs
  ...

8 files changed, 383 insertions, 113 deletions

diff --git a/drivers/acpi/numa/srat.c b/drivers/acpi/numa/srat.c
index 0a725e46d017..53816dfab645 100644
--- a/drivers/acpi/numa/srat.c
+++ b/drivers/acpi/numa/srat.c
@@ -14,6 +14,7 @@
 #include <linux/errno.h>
 #include <linux/acpi.h>
 #include <linux/memblock.h>
+#include <linux/memory.h>
 #include <linux/numa.h>
 #include <linux/nodemask.h>
 #include <linux/topology.h>
@@ -429,13 +430,23 @@ static int __init acpi_parse_cfmws(union acpi_subtable_headers *header,
 {
 	struct acpi_cedt_cfmws *cfmws;
 	int *fake_pxm = arg;
-	u64 start, end;
+	u64 start, end, align;
 	int node;
+	int err;
 
 	cfmws = (struct acpi_cedt_cfmws *)header;
 	start = cfmws->base_hpa;
 	end = cfmws->base_hpa + cfmws->window_size;
 
+	/* Align memblock size to CFMW regions if possible */
+	align = 1UL << __ffs(start | end);
+	if (align >= SZ_256M) {
+		err = memory_block_advise_max_size(align);
+		if (err)
+			pr_warn("CFMWS: memblock size advise failed (%d)\n", err);
+	} else
+		pr_err("CFMWS: [BIOS BUG] base/size alignment violates spec\n");
+
 	/*
 	 * The SRAT may have already described NUMA details for all,
 	 * or a portion of, this CFMWS HPA range. Extend the memblks
@@ -453,7 +464,7 @@ static int __init acpi_parse_cfmws(union acpi_subtable_headers *header,
 		return -EINVAL;
 	}
 
-	if (numa_add_memblk(node, start, end) < 0) {
+	if (numa_add_reserved_memblk(node, start, end) < 0) {
 		/* CXL driver must handle the NUMA_NO_NODE case */
 		pr_warn("ACPI NUMA: Failed to add memblk for CFMWS node %d [mem %#llx-%#llx]\n",
 			node, start, end);
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 19469e7f88c2..ed3e69dc785c 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -110,6 +110,57 @@ static void memory_block_release(struct device *dev)
 	kfree(mem);
 }
 
+
+/* Max block size to be set by memory_block_advise_max_size */
+static unsigned long memory_block_advised_size;
+static bool memory_block_advised_size_queried;
+
+/**
+ * memory_block_advise_max_size() - advise memory hotplug on the max suggested
+ *				    block size, usually for alignment.
+ * @size: suggestion for maximum block size. must be aligned on power of 2.
+ *
+ * Early boot software (pre-allocator init) may advise archs on the max block
+ * size. This value can only decrease after initialization, as the intent is
+ * to identify the largest supported alignment for all sources.
+ *
+ * Use of this value is arch-defined, as is min/max block size.
+ *
+ * Return: 0 on success
+ *	   -EINVAL if size is 0 or not pow2 aligned
+ *	   -EBUSY if value has already been probed
+ */
+int __init memory_block_advise_max_size(unsigned long size)
+{
+	if (!size || !is_power_of_2(size))
+		return -EINVAL;
+
+	if (memory_block_advised_size_queried)
+		return -EBUSY;
+
+	if (memory_block_advised_size)
+		memory_block_advised_size = min(memory_block_advised_size, size);
+	else
+		memory_block_advised_size = size;
+
+	return 0;
+}
+
+/**
+ * memory_block_advised_max_size() - query advised max hotplug block size.
+ *
+ * After the first call, the value can never change. Callers looking for the
+ * actual block size should use memory_block_size_bytes. This interface is
+ * intended for use by arch-init when initializing the hotplug block size.
+ *
+ * Return: advised size in bytes, or 0 if never set.
+ */
+unsigned long memory_block_advised_max_size(void)
+{
+	memory_block_advised_size_queried = true;
+	return memory_block_advised_size;
+}
+
 unsigned long __weak memory_block_size_bytes(void)
 {
 	return MIN_MEMORY_BLOCK_SIZE;
diff --git a/drivers/base/node.c b/drivers/base/node.c
index 618712071a1e..c19094481630 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -7,6 +7,7 @@
 #include <linux/init.h>
 #include <linux/mm.h>
 #include <linux/memory.h>
+#include <linux/mempolicy.h>
 #include <linux/vmstat.h>
 #include <linux/notifier.h>
 #include <linux/node.h>
@@ -214,6 +215,14 @@ void node_set_perf_attrs(unsigned int nid, struct access_coordinate *coord,
 			break;
 		}
 	}
+
+	/* When setting CPU access coordinates, update mempolicy */
+	if (access == ACCESS_COORDINATE_CPU) {
+		if (mempolicy_set_node_perf(nid, coord)) {
+			pr_info("failed to set mempolicy attrs for node %d\n",
+				nid);
+		}
+	}
 }
 EXPORT_SYMBOL_GPL(node_set_perf_attrs);
 
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index fda7d8624889..94e6e9b80bf0 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -734,114 +734,19 @@ static void read_from_bdev_async(struct zram *zram, struct page *page,
 	submit_bio(bio);
 }
 
-#define PAGE_WB_SIG "page_index="
-
-#define PAGE_WRITEBACK			0
-#define HUGE_WRITEBACK			(1<<0)
-#define IDLE_WRITEBACK			(1<<1)
-#define INCOMPRESSIBLE_WRITEBACK	(1<<2)
-
-static int scan_slots_for_writeback(struct zram *zram, u32 mode,
-				    unsigned long nr_pages,
-				    unsigned long index,
-				    struct zram_pp_ctl *ctl)
+static int zram_writeback_slots(struct zram *zram, struct zram_pp_ctl *ctl)
 {
-	for (; nr_pages != 0; index++, nr_pages--) {
-		bool ok = true;
-
-		zram_slot_lock(zram, index);
-		if (!zram_allocated(zram, index))
-			goto next;
-
-		if (zram_test_flag(zram, index, ZRAM_WB) ||
-		    zram_test_flag(zram, index, ZRAM_SAME))
-			goto next;
-
-		if (mode & IDLE_WRITEBACK &&
-		    !zram_test_flag(zram, index, ZRAM_IDLE))
-			goto next;
-		if (mode & HUGE_WRITEBACK &&
-		    !zram_test_flag(zram, index, ZRAM_HUGE))
-			goto next;
-		if (mode & INCOMPRESSIBLE_WRITEBACK &&
-		    !zram_test_flag(zram, index, ZRAM_INCOMPRESSIBLE))
-			goto next;
-
-		ok = place_pp_slot(zram, ctl, index);
-next:
-		zram_slot_unlock(zram, index);
-		if (!ok)
-			break;
-	}
-
-	return 0;
-}
-
-static ssize_t writeback_store(struct device *dev,
-		struct device_attribute *attr, const char *buf, size_t len)
-{
-	struct zram *zram = dev_to_zram(dev);
-	unsigned long nr_pages = zram->disksize >> PAGE_SHIFT;
-	struct zram_pp_ctl *ctl = NULL;
+	unsigned long blk_idx = 0;
+	struct page *page = NULL;
 	struct zram_pp_slot *pps;
-	unsigned long index = 0;
-	struct bio bio;
 	struct bio_vec bio_vec;
-	struct page *page = NULL;
-	ssize_t ret = len;
-	int mode, err;
-	unsigned long blk_idx = 0;
-
-	if (sysfs_streq(buf, "idle"))
-		mode = IDLE_WRITEBACK;
-	else if (sysfs_streq(buf, "huge"))
-		mode = HUGE_WRITEBACK;
-	else if (sysfs_streq(buf, "huge_idle"))
-		mode = IDLE_WRITEBACK | HUGE_WRITEBACK;
-	else if (sysfs_streq(buf, "incompressible"))
-		mode = INCOMPRESSIBLE_WRITEBACK;
-	else {
-		if (strncmp(buf, PAGE_WB_SIG, sizeof(PAGE_WB_SIG) - 1))
-			return -EINVAL;
-
-		if (kstrtol(buf + sizeof(PAGE_WB_SIG) - 1, 10, &index) ||
-				index >= nr_pages)
-			return -EINVAL;
-
-		nr_pages = 1;
-		mode = PAGE_WRITEBACK;
-	}
-
-	down_read(&zram->init_lock);
-	if (!init_done(zram)) {
-		ret = -EINVAL;
-		goto release_init_lock;
-	}
-
-	/* Do not permit concurrent post-processing actions. */
-	if (atomic_xchg(&zram->pp_in_progress, 1)) {
-		up_read(&zram->init_lock);
-		return -EAGAIN;
-	}
-
-	if (!zram->backing_dev) {
-		ret = -ENODEV;
-		goto release_init_lock;
-	}
+	struct bio bio;
+	int ret = 0, err;
+	u32 index;
 
 	page = alloc_page(GFP_KERNEL);
-	if (!page) {
-		ret = -ENOMEM;
-		goto release_init_lock;
-	}
-
-	ctl = init_pp_ctl();
-	if (!ctl) {
-		ret = -ENOMEM;
-		goto release_init_lock;
-	}
-
-	scan_slots_for_writeback(zram, mode, nr_pages, index, ctl);
+	if (!page)
+		return -ENOMEM;
 
 	while ((pps = select_pp_slot(ctl))) {
 		spin_lock(&zram->wb_limit_lock);
@@ -929,10 +834,215 @@ next:
 
 	if (blk_idx)
 		free_block_bdev(zram, blk_idx);
-
-release_init_lock:
 	if (page)
 		__free_page(page);
+
+	return ret;
+}
+
+#define PAGE_WRITEBACK			0
+#define HUGE_WRITEBACK			(1 << 0)
+#define IDLE_WRITEBACK			(1 << 1)
+#define INCOMPRESSIBLE_WRITEBACK	(1 << 2)
+
+static int parse_page_index(char *val, unsigned long nr_pages,
+			    unsigned long *lo, unsigned long *hi)
+{
+	int ret;
+
+	ret = kstrtoul(val, 10, lo);
+	if (ret)
+		return ret;
+	if (*lo >= nr_pages)
+		return -ERANGE;
+	*hi = *lo + 1;
+	return 0;
+}
+
+static int parse_page_indexes(char *val, unsigned long nr_pages,
+			      unsigned long *lo, unsigned long *hi)
+{
+	char *delim;
+	int ret;
+
+	delim = strchr(val, '-');
+	if (!delim)
+		return -EINVAL;
+
+	*delim = 0x00;
+	ret = kstrtoul(val, 10, lo);
+	if (ret)
+		return ret;
+	if (*lo >= nr_pages)
+		return -ERANGE;
+
+	ret = kstrtoul(delim + 1, 10, hi);
+	if (ret)
+		return ret;
+	if (*hi >= nr_pages || *lo > *hi)
+		return -ERANGE;
+	*hi += 1;
+	return 0;
+}
+
+static int parse_mode(char *val, u32 *mode)
+{
+	*mode = 0;
+
+	if (!strcmp(val, "idle"))
+		*mode = IDLE_WRITEBACK;
+	if (!strcmp(val, "huge"))
+		*mode = HUGE_WRITEBACK;
+	if (!strcmp(val, "huge_idle"))
+		*mode = IDLE_WRITEBACK | HUGE_WRITEBACK;
+	if (!strcmp(val, "incompressible"))
+		*mode = INCOMPRESSIBLE_WRITEBACK;
+
+	if (*mode == 0)
+		return -EINVAL;
+	return 0;
+}
+
+static int scan_slots_for_writeback(struct zram *zram, u32 mode,
+				    unsigned long lo, unsigned long hi,
+				    struct zram_pp_ctl *ctl)
+{
+	u32 index = lo;
+
+	while (index < hi) {
+		bool ok = true;
+
+		zram_slot_lock(zram, index);
+		if (!zram_allocated(zram, index))
+			goto next;
+
+		if (zram_test_flag(zram, index, ZRAM_WB) ||
+		    zram_test_flag(zram, index, ZRAM_SAME))
+			goto next;
+
+		if (mode & IDLE_WRITEBACK &&
+		    !zram_test_flag(zram, index, ZRAM_IDLE))
+			goto next;
+		if (mode & HUGE_WRITEBACK &&
+		    !zram_test_flag(zram, index, ZRAM_HUGE))
+			goto next;
+		if (mode & INCOMPRESSIBLE_WRITEBACK &&
+		    !zram_test_flag(zram, index, ZRAM_INCOMPRESSIBLE))
+			goto next;
+
+		ok = place_pp_slot(zram, ctl, index);
+next:
+		zram_slot_unlock(zram, index);
+		if (!ok)
+			break;
+		index++;
+	}
+
+	return 0;
+}
+
+static ssize_t writeback_store(struct device *dev,
+			       struct device_attribute *attr,
+			       const char *buf, size_t len)
+{
+	struct zram *zram = dev_to_zram(dev);
+	u64 nr_pages = zram->disksize >> PAGE_SHIFT;
+	unsigned long lo = 0, hi = nr_pages;
+	struct zram_pp_ctl *ctl = NULL;
+	char *args, *param, *val;
+	ssize_t ret = len;
+	int err, mode = 0;
+
+	down_read(&zram->init_lock);
+	if (!init_done(zram)) {
+		up_read(&zram->init_lock);
+		return -EINVAL;
+	}
+
+	/* Do not permit concurrent post-processing actions. */
+	if (atomic_xchg(&zram->pp_in_progress, 1)) {
+		up_read(&zram->init_lock);
+		return -EAGAIN;
+	}
+
+	if (!zram->backing_dev) {
+		ret = -ENODEV;
+		goto release_init_lock;
+	}
+
+	ctl = init_pp_ctl();
+	if (!ctl) {
+		ret = -ENOMEM;
+		goto release_init_lock;
+	}
+
+	args = skip_spaces(buf);
+	while (*args) {
+		args = next_arg(args, &param, &val);
+
+		/*
+		 * Workaround to support the old writeback interface.
+		 *
+		 * The old writeback interface has a minor inconsistency and
+		 * requires key=value only for page_index parameter, while the
+		 * writeback mode is a valueless parameter.
+		 *
+		 * This is not the case anymore and now all parameters are
+		 * required to have values, however, we need to support the
+		 * legacy writeback interface format so we check if we can
+		 * recognize a valueless parameter as the (legacy) writeback
+		 * mode.
+		 */
+		if (!val || !*val) {
+			err = parse_mode(param, &mode);
+			if (err) {
+				ret = err;
+				goto release_init_lock;
+			}
+
+			scan_slots_for_writeback(zram, mode, lo, hi, ctl);
+			break;
+		}
+
+		if (!strcmp(param, "type")) {
+			err = parse_mode(val, &mode);
+			if (err) {
+				ret = err;
+				goto release_init_lock;
+			}
+
+			scan_slots_for_writeback(zram, mode, lo, hi, ctl);
+			break;
+		}
+
+		if (!strcmp(param, "page_index")) {
+			err = parse_page_index(val, nr_pages, &lo, &hi);
+			if (err) {
+				ret = err;
+				goto release_init_lock;
+			}
+
+			scan_slots_for_writeback(zram, mode, lo, hi, ctl);
+			continue;
+		}
+
+		if (!strcmp(param, "page_indexes")) {
+			err = parse_page_indexes(val, nr_pages, &lo, &hi);
+			if (err) {
+				ret = err;
+				goto release_init_lock;
+			}
+
+			scan_slots_for_writeback(zram, mode, lo, hi, ctl);
+			continue;
+		}
+	}
+
+	err = zram_writeback_slots(zram, ctl);
+	if (err)
+		ret = err;
+
+release_init_lock:
 	release_pp_ctl(zram, ctl);
 	atomic_set(&zram->pp_in_progress, 0);
 	up_read(&zram->init_lock);
@@ -1694,7 +1804,7 @@ static int write_incompressible_page(struct zram *zram, struct page *page,
 	 */
 	handle = zs_malloc(zram->mem_pool, PAGE_SIZE,
 			   GFP_NOIO | __GFP_NOWARN |
-			   __GFP_HIGHMEM | __GFP_MOVABLE);
+			   __GFP_HIGHMEM | __GFP_MOVABLE, page_to_nid(page));
 	if (IS_ERR_VALUE(handle))
 		return PTR_ERR((void *)handle);
 
@@ -1761,7 +1871,7 @@ static int zram_write_page(struct zram *zram, struct page *page, u32 index)
 
 	handle = zs_malloc(zram->mem_pool, comp_len,
 			   GFP_NOIO | __GFP_NOWARN |
-			   __GFP_HIGHMEM | __GFP_MOVABLE);
+			   __GFP_HIGHMEM | __GFP_MOVABLE, page_to_nid(page));
 	if (IS_ERR_VALUE(handle)) {
 		zcomp_stream_put(zstrm);
 		return PTR_ERR((void *)handle);
@@ -1981,10 +2091,15 @@ static int recompress_slot(struct zram *zram, u32 index, struct page *page,
 	 * We are holding per-CPU stream mutex and entry lock so better
 	 * avoid direct reclaim.  Allocation error is not fatal since
 	 * we still have the old object in the mem_pool.
+	 *
+	 * XXX: technically, the node we really want here is the node that holds
+	 * the original compressed data. But that would require us to modify
+	 * zsmalloc API to return this information. For now, we will make do with
+	 * the node of the page allocated for recompression.
 	 */
 	handle_new = zs_malloc(zram->mem_pool, comp_len_new,
 			       GFP_NOIO | __GFP_NOWARN |
-			       __GFP_HIGHMEM | __GFP_MOVABLE);
+			       __GFP_HIGHMEM | __GFP_MOVABLE, page_to_nid(page));
 	if (IS_ERR_VALUE(handle_new)) {
 		zcomp_stream_put(zstrm);
 		return PTR_ERR((void *)handle_new);
diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c
index e97d47f42ee2..584c70a34b52 100644
--- a/drivers/dax/kmem.c
+++ b/drivers/dax/kmem.c
@@ -13,6 +13,7 @@
 #include <linux/mman.h>
 #include <linux/memory-tiers.h>
 #include <linux/memory_hotplug.h>
+#include <linux/string_helpers.h>
 #include "dax-private.h"
 #include "bus.h"
 
@@ -68,7 +69,7 @@ static void kmem_put_memory_types(void)
 static int dev_dax_kmem_probe(struct dev_dax *dev_dax)
 {
 	struct device *dev = &dev_dax->dev;
-	unsigned long total_len = 0;
+	unsigned long total_len = 0, orig_len = 0;
 	struct dax_kmem_data *data;
 	struct memory_dev_type *mtype;
 	int i, rc, mapped = 0;
@@ -97,6 +98,7 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax)
 	for (i = 0; i < dev_dax->nr_range; i++) {
 		struct range range;
 
+		orig_len += range_len(&dev_dax->ranges[i].range);
 		rc = dax_kmem_range(dev_dax, i, &range);
 		if (rc) {
 			dev_info(dev, "mapping%d: %#llx-%#llx too small after alignment\n",
@@ -109,6 +111,12 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax)
 	if (!total_len) {
 		dev_warn(dev, "rejecting DAX region without any memory after alignment\n");
 		return -EINVAL;
+	} else if (total_len != orig_len) {
+		char buf[16];
+
+		string_get_size(orig_len - total_len, 1, STRING_UNITS_2,
+				buf, sizeof(buf));
+		dev_warn(dev, "DAX region truncated by %s due to alignment\n", buf);
 	}
 
 	init_node_memory_type(numa_node, mtype);
diff --git a/drivers/gpu/drm/i915/i915_mm.c b/drivers/gpu/drm/i915/i915_mm.c
index 76e2801619f0..c33bd3d83069 100644
--- a/drivers/gpu/drm/i915/i915_mm.c
+++ b/drivers/gpu/drm/i915/i915_mm.c
@@ -100,7 +100,7 @@ int remap_io_mapping(struct vm_area_struct *vma,
 
 	GEM_BUG_ON((vma->vm_flags & EXPECTED_FLAGS) != EXPECTED_FLAGS);
 
-	/* We rely on prevalidation of the io-mapping to skip track_pfn(). */
+	/* We rely on prevalidation of the io-mapping to skip pfnmap tracking. */
 	r.mm = vma->vm_mm;
 	r.pfn = pfn;
 	r.prot = __pgprot((pgprot_val(iomap->prot) & _PAGE_CACHE_MASK) |
@@ -140,7 +140,7 @@ int remap_io_sg(struct vm_area_struct *vma,
 	};
 	int err;
 
-	/* We rely on prevalidation of the io-mapping to skip track_pfn(). */
+	/* We rely on prevalidation of the io-mapping to skip pfnmap tracking. */
 	GEM_BUG_ON((vma->vm_flags & EXPECTED_FLAGS) != EXPECTED_FLAGS);
 
 	while (offset >= r.sgt.max >> PAGE_SHIFT) {
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index aedd0e2dcd89..0edd639898a6 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -25,6 +25,7 @@
 #include <linux/serial_core.h>
 #include <linux/sysfs.h>
 #include <linux/random.h>
+#include <linux/kexec_handover.h>
 
 #include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
 #include <asm/page.h>
@@ -875,6 +876,36 @@ void __init early_init_dt_check_for_usable_mem_range(void)
 		memblock_add(rgn[i].base, rgn[i].size);
 }
 
+/**
+ * early_init_dt_check_kho - Decode info required for kexec handover from DT
+ */
+static void __init early_init_dt_check_kho(void)
+{
+	unsigned long node = chosen_node_offset;
+	u64 fdt_start, fdt_size, scratch_start, scratch_size;
+	const __be32 *p;
+	int l;
+
+	if (!IS_ENABLED(CONFIG_KEXEC_HANDOVER) || (long)node < 0)
+		return;
+
+	p = of_get_flat_dt_prop(node, "linux,kho-fdt", &l);
+	if (l != (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32))
+		return;
+
+	fdt_start = dt_mem_next_cell(dt_root_addr_cells, &p);
+	fdt_size = dt_mem_next_cell(dt_root_addr_cells, &p);
+
+	p = of_get_flat_dt_prop(node, "linux,kho-scratch", &l);
+	if (l != (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32))
+		return;
+
+	scratch_start = dt_mem_next_cell(dt_root_addr_cells, &p);
+	scratch_size = dt_mem_next_cell(dt_root_addr_cells, &p);
+
+	kho_populate(fdt_start, fdt_size, scratch_start, scratch_size);
+}
+
 #ifdef CONFIG_SERIAL_EARLYCON
 
 int __init early_init_dt_scan_chosen_stdout(void)
@@ -1169,6 +1200,9 @@ void __init early_init_dt_scan_nodes(void)
 
 	/* Handle linux,usable-memory-range property */
 	early_init_dt_check_for_usable_mem_range();
+
+	/* Handle kexec handover */
+	early_init_dt_check_kho();
 }
 
 bool __init early_init_dt_scan(void *dt_virt, phys_addr_t dt_phys)
diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
index 5b924597a4de..1ee2d31816ae 100644
--- a/drivers/of/kexec.c
+++ b/drivers/of/kexec.c
@@ -264,6 +264,43 @@ static inline int setup_ima_buffer(const struct kimage *image, void *fdt,
 }
 #endif /* CONFIG_IMA_KEXEC */
 
+static int kho_add_chosen(const struct kimage *image, void *fdt, int chosen_node)
+{
+	int ret = 0;
+#ifdef CONFIG_KEXEC_HANDOVER
+	phys_addr_t fdt_mem = 0;
+	phys_addr_t fdt_len = 0;
+	phys_addr_t scratch_mem = 0;
+	phys_addr_t scratch_len = 0;
+
+	ret = fdt_delprop(fdt, chosen_node, "linux,kho-fdt");
+	if (ret && ret != -FDT_ERR_NOTFOUND)
+		return ret;
+	ret = fdt_delprop(fdt, chosen_node, "linux,kho-scratch");
+	if (ret && ret != -FDT_ERR_NOTFOUND)
+		return ret;
+
+	if (!image->kho.fdt || !image->kho.scratch)
+		return 0;
+
+	fdt_mem = image->kho.fdt;
+	fdt_len = PAGE_SIZE;
+	scratch_mem = image->kho.scratch->mem;
+	scratch_len = image->kho.scratch->bufsz;
+
+	pr_debug("Adding kho metadata to DT");
+
+	ret = fdt_appendprop_addrrange(fdt, 0, chosen_node, "linux,kho-fdt",
+				       fdt_mem, fdt_len);
+	if (ret)
+		return ret;
+	ret = fdt_appendprop_addrrange(fdt, 0, chosen_node, "linux,kho-scratch",
+				       scratch_mem, scratch_len);
+
+#endif /* CONFIG_KEXEC_HANDOVER */
+	return ret;
+}
+
 /*
  * of_kexec_alloc_and_setup_fdt - Alloc and setup a new Flattened Device Tree
  *
@@ -414,6 +451,11 @@ void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
 #endif
 	}
 
+	/* Add kho metadata if this is a KHO image */
+	ret = kho_add_chosen(image, fdt, chosen_node);
+	if (ret)
+		goto out;
+
 	/* add bootargs */
 	if (cmdline) {
 		ret = fdt_setprop_string(fdt, chosen_node, "bootargs", cmdline);