mm/bootmem_info.c

   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 }