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