arch/x86/mm/numa_32.c

   1 /*
   2  * Written by: Patricia Gaughen <gone@us.ibm.com>, IBM Corporation
   3  * August 2002: added remote node KVA remap - Martin J. Bligh
   4  *
   5  * Copyright (C) 2002, IBM Corp.
   6  *
   7  * All rights reserved.
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  17  * NON INFRINGEMENT.  See the GNU General Public License for more
  18  * details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23  */
  24
  25 #include <linux/bootmem.h>
  26 #include <linux/memblock.h>
  27 #include <linux/module.h>
  28
  29 #include "numa_internal.h"
  30
  31 #ifdef CONFIG_DISCONTIGMEM
  32 /*
  33  * 4) physnode_map     - the mapping between a pfn and owning node
  34  * physnode_map keeps track of the physical memory layout of a generic
  35  * numa node on a 64Mb break (each element of the array will
  36  * represent 64Mb of memory and will be marked by the node id.  so,
  37  * if the first gig is on node 0, and the second gig is on node 1
  38  * physnode_map will contain:
  39  *
  40  *     physnode_map[0-15] = 0;
  41  *     physnode_map[16-31] = 1;
  42  *     physnode_map[32- ] = -1;
  43  */
  44 s8 physnode_map[MAX_ELEMENTS] __read_mostly = { [0 ... (MAX_ELEMENTS - 1)] = -1};
  45 EXPORT_SYMBOL(physnode_map);
  46
  47 void memory_present(int nid, unsigned long start, unsigned long end)
  48 {
  49         unsigned long pfn;
  50
  51         printk(KERN_INFO "Node: %d, start_pfn: %lx, end_pfn: %lx\n",
  52                         nid, start, end);
  53         printk(KERN_DEBUG "  Setting physnode_map array to node %d for pfns:\n", nid);
  54         printk(KERN_DEBUG "  ");
  55         for (pfn = start; pfn < end; pfn += PAGES_PER_ELEMENT) {
  56                 physnode_map[pfn / PAGES_PER_ELEMENT] = nid;
  57                 printk(KERN_CONT "%lx ", pfn);
  58         }
  59         printk(KERN_CONT "\n");
  60 }
  61
  62 unsigned long node_memmap_size_bytes(int nid, unsigned long start_pfn,
  63                                               unsigned long end_pfn)
  64 {
  65         unsigned long nr_pages = end_pfn - start_pfn;
  66
  67         if (!nr_pages)
  68                 return 0;
  69
  70         return (nr_pages + 1) * sizeof(struct page);
  71 }
  72 #endif
  73
  74 extern unsigned long highend_pfn, highstart_pfn;
  75
  76 #define LARGE_PAGE_BYTES (PTRS_PER_PTE * PAGE_SIZE)
  77
  78 static void *node_remap_start_vaddr[MAX_NUMNODES];
  79 void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags);
  80
  81 /*
  82  * Remap memory allocator
  83  */
  84 static unsigned long node_remap_start_pfn[MAX_NUMNODES];
  85 static void *node_remap_end_vaddr[MAX_NUMNODES];
  86 static void *node_remap_alloc_vaddr[MAX_NUMNODES];
  87
  88 /**
  89  * alloc_remap - Allocate remapped memory
  90  * @nid: NUMA node to allocate memory from
  91  * @size: The size of allocation
  92  *
  93  * Allocate @size bytes from the remap area of NUMA node @nid.  The
  94  * size of the remap area is predetermined by init_alloc_remap() and
  95  * only the callers considered there should call this function.  For
  96  * more info, please read the comment on top of init_alloc_remap().
  97  *
  98  * The caller must be ready to handle allocation failure from this
  99  * function and fall back to regular memory allocator in such cases.
 100  *
 101  * CONTEXT:
 102  * Single CPU early boot context.
 103  *
 104  * RETURNS:
 105  * Pointer to the allocated memory on success, %NULL on failure.
 106  */
 107 void *alloc_remap(int nid, unsigned long size)
 108 {
 109         void *allocation = node_remap_alloc_vaddr[nid];
 110
 111         size = ALIGN(size, L1_CACHE_BYTES);
 112
 113         if (!allocation || (allocation + size) > node_remap_end_vaddr[nid])
 114                 return NULL;
 115
 116         node_remap_alloc_vaddr[nid] += size;
 117         memset(allocation, 0, size);
 118
 119         return allocation;
 120 }
 121
 122 #ifdef CONFIG_HIBERNATION
 123 /**
 124  * resume_map_numa_kva - add KVA mapping to the temporary page tables created
 125  *                       during resume from hibernation
 126  * @pgd_base - temporary resume page directory
 127  */
 128 void resume_map_numa_kva(pgd_t *pgd_base)
 129 {
 130         int node;
 131
 132         for_each_online_node(node) {
 133                 unsigned long start_va, start_pfn, nr_pages, pfn;
 134
 135                 start_va = (unsigned long)node_remap_start_vaddr[node];
 136                 start_pfn = node_remap_start_pfn[node];
 137                 nr_pages = (node_remap_end_vaddr[node] -
 138                             node_remap_start_vaddr[node]) >> PAGE_SHIFT;
 139
 140                 printk(KERN_DEBUG "%s: node %d\n", __func__, node);
 141
 142                 for (pfn = 0; pfn < nr_pages; pfn += PTRS_PER_PTE) {
 143                         unsigned long vaddr = start_va + (pfn << PAGE_SHIFT);
 144                         pgd_t *pgd = pgd_base + pgd_index(vaddr);
 145                         pud_t *pud = pud_offset(pgd, vaddr);
 146                         pmd_t *pmd = pmd_offset(pud, vaddr);
 147
 148                         set_pmd(pmd, pfn_pmd(start_pfn + pfn,
 149                                                 PAGE_KERNEL_LARGE_EXEC));
 150
 151                         printk(KERN_DEBUG "%s: %08lx -> pfn %08lx\n",
 152                                 __func__, vaddr, start_pfn + pfn);
 153                 }
 154         }
 155 }
 156 #endif
 157
 158 /**
 159  * init_alloc_remap - Initialize remap allocator for a NUMA node
 160  * @nid: NUMA node to initizlie remap allocator for
 161  *
 162  * NUMA nodes may end up without any lowmem.  As allocating pgdat and
 163  * memmap on a different node with lowmem is inefficient, a special
 164  * remap allocator is implemented which can be used by alloc_remap().
 165  *
 166  * For each node, the amount of memory which will be necessary for
 167  * pgdat and memmap is calculated and two memory areas of the size are
 168  * allocated - one in the node and the other in lowmem; then, the area
 169  * in the node is remapped to the lowmem area.
 170  *
 171  * As pgdat and memmap must be allocated in lowmem anyway, this
 172  * doesn't waste lowmem address space; however, the actual lowmem
 173  * which gets remapped over is wasted.  The amount shouldn't be
 174  * problematic on machines this feature will be used.
 175  *
 176  * Initialization failure isn't fatal.  alloc_remap() is used
 177  * opportunistically and the callers will fall back to other memory
 178  * allocation mechanisms on failure.
 179  */
 180 void __init init_alloc_remap(int nid, u64 start, u64 end)
 181 {
 182         unsigned long start_pfn = start >> PAGE_SHIFT;
 183         unsigned long end_pfn = end >> PAGE_SHIFT;
 184         unsigned long size, pfn;
 185         u64 node_pa, remap_pa;
 186         void *remap_va;
 187
 188         /*
 189          * The acpi/srat node info can show hot-add memroy zones where
 190          * memory could be added but not currently present.
 191          */
 192         printk(KERN_DEBUG "node %d pfn: [%lx - %lx]\n",
 193                nid, start_pfn, end_pfn);
 194
 195         /* calculate the necessary space aligned to large page size */
 196         size = node_memmap_size_bytes(nid, start_pfn, end_pfn);
 197         size += ALIGN(sizeof(pg_data_t), PAGE_SIZE);
 198         size = ALIGN(size, LARGE_PAGE_BYTES);
 199
 200         /* allocate node memory and the lowmem remap area */
 201         node_pa = memblock_find_in_range(start, end, size, LARGE_PAGE_BYTES);
 202         if (node_pa == MEMBLOCK_ERROR) {
 203                 pr_warning("remap_alloc: failed to allocate %lu bytes for node %d\n",
 204                            size, nid);
 205                 return;
 206         }
 207         memblock_x86_reserve_range(node_pa, node_pa + size, "KVA RAM");
 208
 209         remap_pa = memblock_find_in_range(min_low_pfn << PAGE_SHIFT,
 210                                           max_low_pfn << PAGE_SHIFT,
 211                                           size, LARGE_PAGE_BYTES);
 212         if (remap_pa == MEMBLOCK_ERROR) {
 213                 pr_warning("remap_alloc: failed to allocate %lu bytes remap area for node %d\n",
 214                            size, nid);
 215                 memblock_x86_free_range(node_pa, node_pa + size);
 216                 return;
 217         }
 218         memblock_x86_reserve_range(remap_pa, remap_pa + size, "KVA PG");
 219         remap_va = phys_to_virt(remap_pa);
 220
 221         /* perform actual remap */
 222         for (pfn = 0; pfn < size >> PAGE_SHIFT; pfn += PTRS_PER_PTE)
 223                 set_pmd_pfn((unsigned long)remap_va + (pfn << PAGE_SHIFT),
 224                             (node_pa >> PAGE_SHIFT) + pfn,
 225                             PAGE_KERNEL_LARGE);
 226
 227         /* initialize remap allocator parameters */
 228         node_remap_start_pfn[nid] = node_pa >> PAGE_SHIFT;
 229         node_remap_start_vaddr[nid] = remap_va;
 230         node_remap_end_vaddr[nid] = remap_va + size;
 231         node_remap_alloc_vaddr[nid] = remap_va;
 232
 233         printk(KERN_DEBUG "remap_alloc: node %d [%08llx-%08llx) -> [%p-%p)\n",
 234                nid, node_pa, node_pa + size, remap_va, remap_va + size);
 235 }
 236
 237 void __init initmem_init(void)
 238 {
 239         x86_numa_init();
 240
 241 #ifdef CONFIG_HIGHMEM
 242         highstart_pfn = highend_pfn = max_pfn;
 243         if (max_pfn > max_low_pfn)
 244                 highstart_pfn = max_low_pfn;
 245         printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
 246                pages_to_mb(highend_pfn - highstart_pfn));
 247         num_physpages = highend_pfn;
 248         high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1;
 249 #else
 250         num_physpages = max_low_pfn;
 251         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1;
 252 #endif
 253         printk(KERN_NOTICE "%ldMB LOWMEM available.\n",
 254                         pages_to_mb(max_low_pfn));
 255         printk(KERN_DEBUG "max_low_pfn = %lx, highstart_pfn = %lx\n",
 256                         max_low_pfn, highstart_pfn);
 257
 258         printk(KERN_DEBUG "Low memory ends at vaddr %08lx\n",
 259                         (ulong) pfn_to_kaddr(max_low_pfn));
 260
 261         printk(KERN_DEBUG "High memory starts at vaddr %08lx\n",
 262                         (ulong) pfn_to_kaddr(highstart_pfn));
 263
 264         setup_bootmem_allocator();
 265 }