xref: /linux/mm/bootmem_info.c (revision 288440de9e5fdb4a3ff73864850f080c1250fc81)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Bootmem core functions.
4  *
5  * Copyright (c) 2020, Bytedance.
6  *
7  *     Author: Muchun Song <songmuchun@bytedance.com>
8  *
9  */
10 #include <linux/mm.h>
11 #include <linux/compiler.h>
12 #include <linux/memblock.h>
13 #include <linux/bootmem_info.h>
14 #include <linux/memory_hotplug.h>
15 
16 void get_page_bootmem(unsigned long info, struct page *page, unsigned long type)
17 {
18 	page->index = type;
19 	SetPagePrivate(page);
20 	set_page_private(page, info);
21 	page_ref_inc(page);
22 }
23 
24 void put_page_bootmem(struct page *page)
25 {
26 	unsigned long type = page->index;
27 
28 	BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
29 	       type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE);
30 
31 	if (page_ref_dec_return(page) == 1) {
32 		page->index = 0;
33 		ClearPagePrivate(page);
34 		set_page_private(page, 0);
35 		INIT_LIST_HEAD(&page->lru);
36 		free_reserved_page(page);
37 	}
38 }
39 
40 #ifndef CONFIG_SPARSEMEM_VMEMMAP
41 static void __init register_page_bootmem_info_section(unsigned long start_pfn)
42 {
43 	unsigned long mapsize, section_nr, i;
44 	struct mem_section *ms;
45 	struct page *page, *memmap;
46 	struct mem_section_usage *usage;
47 
48 	section_nr = pfn_to_section_nr(start_pfn);
49 	ms = __nr_to_section(section_nr);
50 
51 	/* Get section's memmap address */
52 	memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
53 
54 	/*
55 	 * Get page for the memmap's phys address
56 	 * XXX: need more consideration for sparse_vmemmap...
57 	 */
58 	page = virt_to_page(memmap);
59 	mapsize = sizeof(struct page) * PAGES_PER_SECTION;
60 	mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT;
61 
62 	/* remember memmap's page */
63 	for (i = 0; i < mapsize; i++, page++)
64 		get_page_bootmem(section_nr, page, SECTION_INFO);
65 
66 	usage = ms->usage;
67 	page = virt_to_page(usage);
68 
69 	mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT;
70 
71 	for (i = 0; i < mapsize; i++, page++)
72 		get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
73 
74 }
75 #else /* CONFIG_SPARSEMEM_VMEMMAP */
76 static void __init register_page_bootmem_info_section(unsigned long start_pfn)
77 {
78 	unsigned long mapsize, section_nr, i;
79 	struct mem_section *ms;
80 	struct page *page, *memmap;
81 	struct mem_section_usage *usage;
82 
83 	section_nr = pfn_to_section_nr(start_pfn);
84 	ms = __nr_to_section(section_nr);
85 
86 	memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
87 
88 	register_page_bootmem_memmap(section_nr, memmap, PAGES_PER_SECTION);
89 
90 	usage = ms->usage;
91 	page = virt_to_page(usage);
92 
93 	mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT;
94 
95 	for (i = 0; i < mapsize; i++, page++)
96 		get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
97 }
98 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
99 
100 void __init register_page_bootmem_info_node(struct pglist_data *pgdat)
101 {
102 	unsigned long i, pfn, end_pfn, nr_pages;
103 	int node = pgdat->node_id;
104 	struct page *page;
105 
106 	nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT;
107 	page = virt_to_page(pgdat);
108 
109 	for (i = 0; i < nr_pages; i++, page++)
110 		get_page_bootmem(node, page, NODE_INFO);
111 
112 	pfn = pgdat->node_start_pfn;
113 	end_pfn = pgdat_end_pfn(pgdat);
114 
115 	/* register section info */
116 	for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
117 		/*
118 		 * Some platforms can assign the same pfn to multiple nodes - on
119 		 * node0 as well as nodeN.  To avoid registering a pfn against
120 		 * multiple nodes we check that this pfn does not already
121 		 * reside in some other nodes.
122 		 */
123 		if (pfn_valid(pfn) && (early_pfn_to_nid(pfn) == node))
124 			register_page_bootmem_info_section(pfn);
125 	}
126 }
127