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 #include <linux/kmemleak.h>
  16
  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
  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(page_to_virt(page), PAGE_SIZE);
  38                 free_reserved_page(page);
  39         }
  40 }
  41
  42 #ifndef CONFIG_SPARSEMEM_VMEMMAP
  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 */
  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
 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 }