[PATCH 07/11] mm/sparse-vmemmap: move HVO helpers to a public header
From: Muchun Song <hidden>
Date: 2026-08-31 07:55:01
Also in:
linux-doc, linux-mm, lkml
Subsystem:
hugetlb subsystem, memory hot(un)plug, memory management, memory management - core, the rest · Maintainers:
Muchun Song, Oscar Salvador, David Hildenbrand, Andrew Morton, Linus Torvalds
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. Signed-off-by: Muchun Song <redacted> --- MAINTAINERS | 1 + include/linux/vmemmap-optimization.h | 88 ++++++++++++++++++++++++++++ mm/hugetlb.c | 2 +- mm/hugetlb_vmemmap.c | 2 +- mm/memory_hotplug.c | 1 + mm/sparse.h | 73 +---------------------- 6 files changed, 93 insertions(+), 74 deletions(-) create mode 100644 include/linux/vmemmap-optimization.h
diff --git a/MAINTAINERS b/MAINTAINERS
index a3167bcbe589..ccc7f75bbeb0 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS@@ -12099,6 +12099,7 @@ 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
diff --git a/include/linux/vmemmap-optimization.h b/include/linux/vmemmap-optimization.h
new file mode 100644
index 000000000000..171553fabd47
--- /dev/null
+++ b/include/linux/vmemmap-optimization.h@@ -0,0 +1,88 @@ +/* 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/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 */
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 8fa1bafa03d9..5aa9c0eaf2d0 100644
--- a/mm/hugetlb.c
+++ b/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)
diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c
index 4a57e6c3352c..25c4e7d2664c 100644
--- a/mm/hugetlb_vmemmap.c
+++ b/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" /**
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index d28bafb6fd53..4f3387632883 100644
--- a/mm/memory_hotplug.c
+++ b/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,
diff --git a/mm/sparse.h b/mm/sparse.h
index 59b825df83b9..e511d99fc26b 100644
--- a/mm/sparse.h
+++ b/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(void) {} * 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);
--
2.54.0