mm/bootmem_info: remove CONFIG_HAVE_BOOTMEM_INFO_NODE

The whole infrastructure is unused now. Let's remove the config option
along with mm/bootmem_info. + include/linux/bootmem_info.h.

Link: https://lore.kernel.org/20260716-bootmem_info_part2-v2-10-4afc76c73d61@kernel.org
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Brendan Jackman <brendan.jackman@linux.dev>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

5 files changed, 0 insertions, 170 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 0d47b358b2a4..8acd1aeec9db 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16880,7 +16880,6 @@ T:	git git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock.git fixes
 F:	Documentation/core-api/boot-time-mm.rst
 F:	include/linux/kho/abi/memblock.h
 F:	include/linux/memblock.h
-F:	mm/bootmem_info.c
 F:	mm/memblock.c
 F:	mm/memtest.c
 F:	mm/mm_init.c
diff --git a/include/linux/bootmem_info.h b/include/linux/bootmem_info.h
deleted file mode 100644
index 486acc612703..000000000000
--- a/include/linux/bootmem_info.h
+++ /dev/null
@@ -1,89 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef __LINUX_BOOTMEM_INFO_H
-#define __LINUX_BOOTMEM_INFO_H
-
-#include <linux/mm.h>
-#include <linux/kmemleak.h>
-
-/*
- * Types for free bootmem stored in the low bits of page->private.
- */
-enum bootmem_type {
-	MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE = 1,
-	SECTION_INFO = MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE,
-	MIX_SECTION_INFO,
-	NODE_INFO,
-	MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE = NODE_INFO,
-};
-
-#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
-void __init register_page_bootmem_info_node(struct pglist_data *pgdat);
-void register_page_bootmem_memmap(unsigned long section_nr, struct page *map,
-				  unsigned long nr_pages);
-
-void get_page_bootmem(unsigned long info, struct page *page,
-		enum bootmem_type type);
-void put_page_bootmem(struct page *page);
-
-static inline enum bootmem_type bootmem_type(const struct page *page)
-{
-	return (unsigned long)page->private & 0xf;
-}
-
-static inline unsigned long bootmem_info(const struct page *page)
-{
-	return (unsigned long)page->private >> 4;
-}
-
-/*
- * Any memory allocated via the memblock allocator and not via the
- * buddy will be marked reserved already in the memmap. For those
- * pages, we can call this function to free it to buddy allocator.
- */
-static inline void free_bootmem_page(struct page *page)
-{
-	enum bootmem_type type = bootmem_type(page);
-
-	if (type == SECTION_INFO || type == MIX_SECTION_INFO) {
-		VM_WARN_ON_PAGE(page_ref_count(page) != 2, page);
-		put_page_bootmem(page);
-	} else {
-		free_reserved_page(page);
-	}
-}
-#else
-static inline void register_page_bootmem_info_node(struct pglist_data *pgdat)
-{
-}
-
-static inline void register_page_bootmem_memmap(unsigned long section_nr,
-		struct page *map, unsigned long nr_pages)
-{
-}
-
-static inline void put_page_bootmem(struct page *page)
-{
-}
-
-static inline enum bootmem_type bootmem_type(const struct page *page)
-{
-	return SECTION_INFO;
-}
-
-static inline unsigned long bootmem_info(const struct page *page)
-{
-	return 0;
-}
-
-static inline void get_page_bootmem(unsigned long info, struct page *page,
-				    enum bootmem_type type)
-{
-}
-
-static inline void free_bootmem_page(struct page *page)
-{
-	free_reserved_page(page);
-}
-#endif
-
-#endif /* __LINUX_BOOTMEM_INFO_H */
diff --git a/mm/Kconfig b/mm/Kconfig
index 6b3430ff8788..0d06e96ff3c9 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -509,13 +509,6 @@ config EXCLUSIVE_SYSTEM_RAM
 	def_bool y
 	depends on !DEVMEM || STRICT_DEVMEM
 
-#
-# Only be set on architectures that have completely implemented memory hotplug
-# feature. If you are not sure, don't touch it.
-#
-config HAVE_BOOTMEM_INFO_NODE
-	def_bool n
-
 config ARCH_ENABLE_MEMORY_HOTPLUG
 	bool
 
diff --git a/mm/Makefile b/mm/Makefile
index 8e7e964b99a4..ab37ef428d98 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -141,7 +141,6 @@ obj-$(CONFIG_MEMFD_CREATE) += memfd.o
 obj-$(CONFIG_MAPPING_DIRTY_HELPERS) += mapping_dirty_helpers.o
 obj-$(CONFIG_PTDUMP) += ptdump.o
 obj-$(CONFIG_PAGE_REPORTING) += page_reporting.o
-obj-$(CONFIG_HAVE_BOOTMEM_INFO_NODE) += bootmem_info.o
 obj-$(CONFIG_GENERIC_IOREMAP) += ioremap.o
 obj-$(CONFIG_SHRINKER_DEBUG) += shrinker_debug.o
 obj-$(CONFIG_EXECMEM) += execmem.o
diff --git a/mm/bootmem_info.c b/mm/bootmem_info.c
deleted file mode 100644
index 0fa78db7fbc0..000000000000
--- a/mm/bootmem_info.c
+++ /dev/null
@@ -1,72 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Bootmem core functions.
- *
- * Copyright (c) 2020, Bytedance.
- *
- *     Author: Muchun Song <songmuchun@bytedance.com>
- *
- */
-#include <linux/mm.h>
-#include <linux/compiler.h>
-#include <linux/memblock.h>
-#include <linux/bootmem_info.h>
-#include <linux/memory_hotplug.h>
-#include <linux/kmemleak.h>
-
-void get_page_bootmem(unsigned long info, struct page *page,
-		enum bootmem_type type)
-{
-	BUG_ON(type > 0xf);
-	BUG_ON(info > (ULONG_MAX >> 4));
-	set_page_private(page, info << 4 | type);
-	page_ref_inc(page);
-}
-
-void put_page_bootmem(struct page *page)
-{
-	enum bootmem_type type = bootmem_type(page);
-
-	BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
-	       type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE);
-
-	if (page_ref_dec_return(page) == 1) {
-		set_page_private(page, 0);
-		free_reserved_page(page);
-	}
-}
-
-static void __init register_page_bootmem_info_section(unsigned long start_pfn)
-{
-	unsigned long section_nr;
-	struct mem_section *ms;
-
-	start_pfn = SECTION_ALIGN_DOWN(start_pfn);
-	section_nr = pfn_to_section_nr(start_pfn);
-	ms = __nr_to_section(section_nr);
-
-	if (!preinited_vmemmap_section(ms))
-		register_page_bootmem_memmap(section_nr, pfn_to_page(start_pfn),
-					     PAGES_PER_SECTION);
-}
-
-void __init register_page_bootmem_info_node(struct pglist_data *pgdat)
-{
-	unsigned long pfn, end_pfn;
-	int node = pgdat->node_id;
-
-	pfn = pgdat->node_start_pfn;
-	end_pfn = pgdat_end_pfn(pgdat);
-
-	/* register section info */
-	for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
-		/*
-		 * Some platforms can assign the same pfn to multiple nodes - on
-		 * node0 as well as nodeN.  To avoid registering a pfn against
-		 * multiple nodes we check that this pfn does not already
-		 * reside in some other nodes.
-		 */
-		if (pfn_valid(pfn) && (early_pfn_to_nid(pfn) == node))
-			register_page_bootmem_info_section(pfn);
-	}
-}