[to-be-updated] mm-sparse-vmemmap-move-hvo-helpers-to-a-public-header.patch removed from -mm tree

[Andrew Morton <akpm@linux-foundation.org>]

The quilt patch titled
     Subject: mm/sparse-vmemmap: move HVO helpers to a public header
has been removed from the -mm tree.  Its filename was
     mm-sparse-vmemmap-move-hvo-helpers-to-a-public-header.patch

This patch was dropped because an updated version will be issued

------------------------------------------------------
From: Muchun Song <songmuchun@bytedance.com>
Subject: mm/sparse-vmemmap: move HVO helpers to a public header
Date: Tue, 8 Sep 2026 11:03:31 +0800

The vmemmap optimization helpers currently live in mm/sparse.h, which is
an internal MM header.  That works for MM code, but prevents powerpc from
using the same interfaces without including a private header.

Move the declarations and inline helpers to
include/linux/vmemmap-optimization.h.  This is a preparatory change for
powerpc, which has its own vmemmap optimization implementation and needs
to use the HVO interfaces from architecture code.

Link:
https://lore.kernel.org/20260908030335.96549-8-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Qi Zheng <qi.zheng@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 MAINTAINERS                          |    1 
 include/linux/vmemmap-optimization.h |   91 +++++++++++++++++++++++++
 mm/hugetlb.c                         |    2 
 mm/hugetlb_vmemmap.c                 |    2 
 mm/memory_hotplug.c                  |    1 
 mm/sparse.h                          |   73 --------------------
 6 files changed, 96 insertions(+), 74 deletions(-)

diff --git a/include/linux/vmemmap-optimization.h a/include/linux/vmemmap-optimization.h
new file mode 100644
--- /dev/null
+++ a/include/linux/vmemmap-optimization.h
@@ -0,0 +1,91 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * vmemmap-optimization.h
+ *
+ * Generic vmemmap optimization declarations.
+ *
+ * Author: Muchun Song <songmuchun@bytedance.com>
+ */
+#ifndef _LINUX_VMEMMAP_OPTIMIZATION_H
+#define _LINUX_VMEMMAP_OPTIMIZATION_H
+
+#include <linux/align.h>
+#include <linux/log2.h>
+#include <linux/mmdebug.h>
+#include <linux/mmzone.h>
+
+#ifdef CONFIG_SPARSEMEM_VMEMMAP_OPTIMIZATION
+static inline unsigned int section_order(const struct mem_section *section)
+{
+	return section->order;
+}
+
+static inline void section_set_order(struct mem_section *section, unsigned int order)
+{
+	VM_WARN_ON(section_order(section) && order && section_order(section) != order);
+	section->order = order;
+}
+
+static inline void section_set_order_range(unsigned long pfn, unsigned long nr_pages,
+					   unsigned int order)
+{
+	unsigned long section_nr = pfn_to_section_nr(pfn);
+
+	if (!IS_ALIGNED(pfn | nr_pages, PAGES_PER_SECTION))
+		return;
+
+	for (unsigned long i = 0; i < nr_pages / PAGES_PER_SECTION; i++)
+		section_set_order(__nr_to_section(section_nr + i), order);
+}
+
+static inline unsigned int pfn_to_section_order(unsigned long pfn)
+{
+	return section_order(__pfn_to_section(pfn));
+}
+#else
+static inline unsigned int section_order(const struct mem_section *section)
+{
+	return 0;
+}
+
+static inline void section_set_order(struct mem_section *section, unsigned int order)
+{
+}
+
+static inline void section_set_order_range(unsigned long pfn, unsigned long nr_pages,
+					   unsigned int order)
+{
+}
+
+static inline unsigned int pfn_to_section_order(unsigned long pfn)
+{
+	return 0;
+}
+#endif /* CONFIG_SPARSEMEM_VMEMMAP_OPTIMIZATION */
+
+static inline bool vmemmap_optimizable_pfn(unsigned long pfn)
+{
+	const unsigned int order = pfn_to_section_order(pfn);
+	const unsigned long nr_pages = 1UL << order;
+
+	if (!is_power_of_2(sizeof(struct page)))
+		return false;
+
+	return (pfn & (nr_pages - 1)) >= VMEMMAP_OPTIMIZATION_NR_STRUCT_PAGES;
+}
+
+static inline bool vmemmap_optimizable_order(unsigned int order)
+{
+	if (!IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP_OPTIMIZATION))
+		return false;
+
+	if (!is_power_of_2(sizeof(struct page)))
+		return false;
+
+	return order >= VMEMMAP_OPTIMIZATION_MIN_ORDER;
+}
+
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+struct page *vmemmap_shared_tail_page(unsigned int order, struct zone *zone);
+#endif /* CONFIG_SPARSEMEM_VMEMMAP */
+#endif /* _LINUX_VMEMMAP_OPTIMIZATION_H */
--- a/MAINTAINERS~mm-sparse-vmemmap-move-hvo-helpers-to-a-public-header
+++ a/MAINTAINERS
@@ -12096,6 +12096,7 @@ F:	Documentation/mm/hugetlbfs_reserv.rst
 F:	Documentation/mm/vmemmap_dedup.rst
 F:	fs/hugetlbfs/
 F:	include/linux/hugetlb.h
+F:	include/linux/vmemmap-optimization.h
 F:	include/trace/events/hugetlbfs.h
 F:	mm/hugetlb.c
 F:	mm/hugetlb_cgroup.c
--- a/mm/hugetlb.c~mm-sparse-vmemmap-move-hvo-helpers-to-a-public-header
+++ a/mm/hugetlb.c
@@ -38,6 +38,7 @@
 #include <linux/mm_inline.h>
 #include <linux/padata.h>
 #include <linux/pgalloc.h>
+#include <linux/vmemmap-optimization.h>
 
 #include <asm/page.h>
 #include <asm/tlb.h>
@@ -52,7 +53,6 @@
 #include "hugetlb_cma.h"
 #include "hugetlb_internal.h"
 #include "mm_init.h"
-#include "sparse.h"
 #include <linux/page-isolation.h>
 
 #define HUGE_BOOTMEM_ZONES_VALID	BIT(0)
--- a/mm/hugetlb_vmemmap.c~mm-sparse-vmemmap-move-hvo-helpers-to-a-public-header
+++ a/mm/hugetlb_vmemmap.c
@@ -15,10 +15,10 @@
 #include <linux/mmdebug.h>
 #include <linux/pagewalk.h>
 #include <linux/pgalloc.h>
+#include <linux/vmemmap-optimization.h>
 
 #include <asm/tlbflush.h>
 #include "hugetlb_vmemmap.h"
-#include "sparse.h"
 #include "internal.h"
 
 /**
--- a/mm/memory_hotplug.c~mm-sparse-vmemmap-move-hvo-helpers-to-a-public-header
+++ a/mm/memory_hotplug.c
@@ -43,6 +43,7 @@
 #include "mm_init.h"
 #include "page_alloc.h"
 #include "shuffle.h"
+#include "sparse.h"
 
 enum {
 	MEMMAP_ON_MEMORY_DISABLE = 0,
--- a/mm/sparse.h~mm-sparse-vmemmap-move-hvo-helpers-to-a-public-header
+++ a/mm/sparse.h
@@ -9,77 +9,7 @@
 #define __MM_SPARSE_H
 
 #include <linux/mmzone.h>
-
-#ifdef CONFIG_SPARSEMEM_VMEMMAP_OPTIMIZATION
-static inline unsigned int section_order(const struct mem_section *section)
-{
-	return section->order;
-}
-
-static inline void section_set_order(struct mem_section *section, unsigned int order)
-{
-	VM_WARN_ON(section_order(section) && order && section_order(section) != order);
-	section->order = order;
-}
-
-static inline void section_set_order_range(unsigned long pfn, unsigned long nr_pages,
-					   unsigned int order)
-{
-	unsigned long section_nr = pfn_to_section_nr(pfn);
-
-	if (!IS_ALIGNED(pfn | nr_pages, PAGES_PER_SECTION))
-		return;
-
-	for (unsigned long i = 0; i < nr_pages / PAGES_PER_SECTION; i++)
-		section_set_order(__nr_to_section(section_nr + i), order);
-}
-
-static inline unsigned int pfn_to_section_order(unsigned long pfn)
-{
-	return section_order(__pfn_to_section(pfn));
-}
-#else
-static inline unsigned int section_order(const struct mem_section *section)
-{
-	return 0;
-}
-
-static inline void section_set_order(struct mem_section *section, unsigned int order)
-{
-}
-
-static inline void section_set_order_range(unsigned long pfn, unsigned long nr_pages,
-					   unsigned int order)
-{
-}
-
-static inline unsigned int pfn_to_section_order(unsigned long pfn)
-{
-	return 0;
-}
-#endif
-
-static inline bool vmemmap_optimizable_pfn(unsigned long pfn)
-{
-	const unsigned int order = pfn_to_section_order(pfn);
-	const unsigned long nr_pages = 1UL << order;
-
-	if (!is_power_of_2(sizeof(struct page)))
-		return false;
-
-	return (pfn & (nr_pages - 1)) >= VMEMMAP_OPTIMIZATION_NR_STRUCT_PAGES;
-}
-
-static inline bool vmemmap_optimizable_order(unsigned int order)
-{
-	if (!IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP_OPTIMIZATION))
-		return false;
-
-	if (!is_power_of_2(sizeof(struct page)))
-		return false;
-
-	return order >= VMEMMAP_OPTIMIZATION_MIN_ORDER;
-}
+#include <linux/vmemmap-optimization.h>
 
 /*
  * mm/sparse.c
@@ -139,7 +69,6 @@ static inline void sparse_sections_init(
  * mm/sparse-vmemmap.c
  */
 #ifdef CONFIG_SPARSEMEM_VMEMMAP
-struct page *vmemmap_shared_tail_page(unsigned int order, struct zone *zone);
 void sparse_init_subsection_map(void);
 int section_nr_vmemmap_pages(unsigned long pfn, unsigned long nr_pages,
 		struct vmem_altmap *altmap, struct dev_pagemap *pgmap);
_

Patches currently in -mm which might be from songmuchun@bytedance.com are

mm-sparse-relax-struct-mem_section-size-constraints.patch
mm-sparse-vmemmap-rename-hvo-order-macros.patch
mm-mm_init-skip-initializing-shared-vmemmap-tail-pages.patch
mm-sparse-vmemmap-initialize-shared-tail-vmemmap-pages-on-allocation.patch
mm-sparse-vmemmap-support-section-based-vmemmap-accounting.patch
mm-mm_init-factor-out-pfn_to_zone.patch
mm-sparse-vmemmap-move-helpers-ahead-of-future-callers.patch
mm-sparse-vmemmap-support-section-based-vmemmap-optimization.patch
mm-sparse-initialize-memory-sections-earlier.patch
mm-hugetlb-switch-hugetlb-to-section-based-vmemmap-optimization.patch
mm-sparse-vmemmap-remove-sparsemem_vmemmap_preinit-support.patch
mm-sparse-inline-usemap-allocation-into-sparse_init_nid.patch
mm-sparse-remove-section_map_size.patch
mm-hugetlb-remove-huge_bootmem_hvo.patch
mm-hugetlb-remove-huge_bootmem_cma.patch
mm-hugetlb-localize-struct-huge_bootmem_page.patch
mm-hugetlb-localize-huge_bootmem_zones_valid.patch
powerpc-mm-switch-device-dax-to-shared-tail-vmemmap-pages.patch
mm-sparse-vmemmap-drop-the-extra-tail-page-from-device-dax-reservation.patch
mm-sparse-vmemmap-drop-unused-section_nr_vmemmap_pages-arguments.patch
documentation-mm-update-dax-vmemmap-deduplication-docs.patch