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 #include <linux/kmemleak.h>
16 
get_page_bootmem(unsigned long info,struct page * page,unsigned long type)17 void get_page_bootmem(unsigned long info, struct page *page, unsigned long type)
18 {
19 	page->index = type;
20 	SetPagePrivate(page);
21 	set_page_private(page, info);
22 	page_ref_inc(page);
23 }
24 
put_page_bootmem(struct page * page)25 void put_page_bootmem(struct page *page)
26 {
27 	unsigned long type = page->index;
28 
29 	BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
30 	       type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE);
31 
32 	if (page_ref_dec_return(page) == 1) {
33 		page->index = 0;
34 		ClearPagePrivate(page);
35 		set_page_private(page, 0);
36 		INIT_LIST_HEAD(&page->lru);
37 		kmemleak_free_part_phys(PFN_PHYS(page_to_pfn(page)), PAGE_SIZE);
38 		free_reserved_page(page);
39 	}
40 }
41 
42 #ifndef CONFIG_SPARSEMEM_VMEMMAP
register_page_bootmem_info_section(unsigned long start_pfn)43 static void __init register_page_bootmem_info_section(unsigned long start_pfn)
44 {
45 	unsigned long mapsize, section_nr, i;
46 	struct mem_section *ms;
47 	struct page *page, *memmap;
48 	struct mem_section_usage *usage;
49 
50 	section_nr = pfn_to_section_nr(start_pfn);
51 	ms = __nr_to_section(section_nr);
52 
53 	/* Get section's memmap address */
54 	memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
55 
56 	/*
57 	 * Get page for the memmap's phys address
58 	 * XXX: need more consideration for sparse_vmemmap...
59 	 */
60 	page = virt_to_page(memmap);
61 	mapsize = sizeof(struct page) * PAGES_PER_SECTION;
62 	mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT;
63 
64 	/* remember memmap's page */
65 	for (i = 0; i < mapsize; i++, page++)
66 		get_page_bootmem(section_nr, page, SECTION_INFO);
67 
68 	usage = ms->usage;
69 	page = virt_to_page(usage);
70 
71 	mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT;
72 
73 	for (i = 0; i < mapsize; i++, page++)
74 		get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
75 
76 }
77 #else /* CONFIG_SPARSEMEM_VMEMMAP */
register_page_bootmem_info_section(unsigned long start_pfn)78 static void __init register_page_bootmem_info_section(unsigned long start_pfn)
79 {
80 	unsigned long mapsize, section_nr, i;
81 	struct mem_section *ms;
82 	struct page *page, *memmap;
83 	struct mem_section_usage *usage;
84 
85 	section_nr = pfn_to_section_nr(start_pfn);
86 	ms = __nr_to_section(section_nr);
87 
88 	memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
89 
90 	register_page_bootmem_memmap(section_nr, memmap, PAGES_PER_SECTION);
91 
92 	usage = ms->usage;
93 	page = virt_to_page(usage);
94 
95 	mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT;
96 
97 	for (i = 0; i < mapsize; i++, page++)
98 		get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
99 }
100 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
101 
register_page_bootmem_info_node(struct pglist_data * pgdat)102 void __init register_page_bootmem_info_node(struct pglist_data *pgdat)
103 {
104 	unsigned long i, pfn, end_pfn, nr_pages;
105 	int node = pgdat->node_id;
106 	struct page *page;
107 
108 	nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT;
109 	page = virt_to_page(pgdat);
110 
111 	for (i = 0; i < nr_pages; i++, page++)
112 		get_page_bootmem(node, page, NODE_INFO);
113 
114 	pfn = pgdat->node_start_pfn;
115 	end_pfn = pgdat_end_pfn(pgdat);
116 
117 	/* register section info */
118 	for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
119 		/*
120 		 * Some platforms can assign the same pfn to multiple nodes - on
121 		 * node0 as well as nodeN.  To avoid registering a pfn against
122 		 * multiple nodes we check that this pfn does not already
123 		 * reside in some other nodes.
124 		 */
125 		if (pfn_valid(pfn) && (early_pfn_to_nid(pfn) == node))
126 			register_page_bootmem_info_section(pfn);
127 	}
128 }
129