sparse.c revision 98f3cfc1dc7a53b629d43b7844a9b3f786213048
1/* 2 * sparse memory mappings. 3 */ 4#include <linux/mm.h> 5#include <linux/mmzone.h> 6#include <linux/bootmem.h> 7#include <linux/highmem.h> 8#include <linux/module.h> 9#include <linux/spinlock.h> 10#include <linux/vmalloc.h> 11#include <asm/dma.h> 12#include <asm/pgalloc.h> 13#include <asm/pgtable.h> 14 15/* 16 * Permanent SPARSEMEM data: 17 * 18 * 1) mem_section - memory sections, mem_map's for valid memory 19 */ 20#ifdef CONFIG_SPARSEMEM_EXTREME 21struct mem_section *mem_section[NR_SECTION_ROOTS] 22 ____cacheline_internodealigned_in_smp; 23#else 24struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT] 25 ____cacheline_internodealigned_in_smp; 26#endif 27EXPORT_SYMBOL(mem_section); 28 29#ifdef NODE_NOT_IN_PAGE_FLAGS 30/* 31 * If we did not store the node number in the page then we have to 32 * do a lookup in the section_to_node_table in order to find which 33 * node the page belongs to. 34 */ 35#if MAX_NUMNODES <= 256 36static u8 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned; 37#else 38static u16 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned; 39#endif 40 41int page_to_nid(struct page *page) 42{ 43 return section_to_node_table[page_to_section(page)]; 44} 45EXPORT_SYMBOL(page_to_nid); 46 47static void set_section_nid(unsigned long section_nr, int nid) 48{ 49 section_to_node_table[section_nr] = nid; 50} 51#else /* !NODE_NOT_IN_PAGE_FLAGS */ 52static inline void set_section_nid(unsigned long section_nr, int nid) 53{ 54} 55#endif 56 57#ifdef CONFIG_SPARSEMEM_EXTREME 58static struct mem_section noinline __init_refok *sparse_index_alloc(int nid) 59{ 60 struct mem_section *section = NULL; 61 unsigned long array_size = SECTIONS_PER_ROOT * 62 sizeof(struct mem_section); 63 64 if (slab_is_available()) 65 section = kmalloc_node(array_size, GFP_KERNEL, nid); 66 else 67 section = alloc_bootmem_node(NODE_DATA(nid), array_size); 68 69 if (section) 70 memset(section, 0, array_size); 71 72 return section; 73} 74 75static int __meminit sparse_index_init(unsigned long section_nr, int nid) 76{ 77 static DEFINE_SPINLOCK(index_init_lock); 78 unsigned long root = SECTION_NR_TO_ROOT(section_nr); 79 struct mem_section *section; 80 int ret = 0; 81 82 if (mem_section[root]) 83 return -EEXIST; 84 85 section = sparse_index_alloc(nid); 86 /* 87 * This lock keeps two different sections from 88 * reallocating for the same index 89 */ 90 spin_lock(&index_init_lock); 91 92 if (mem_section[root]) { 93 ret = -EEXIST; 94 goto out; 95 } 96 97 mem_section[root] = section; 98out: 99 spin_unlock(&index_init_lock); 100 return ret; 101} 102#else /* !SPARSEMEM_EXTREME */ 103static inline int sparse_index_init(unsigned long section_nr, int nid) 104{ 105 return 0; 106} 107#endif 108 109/* 110 * Although written for the SPARSEMEM_EXTREME case, this happens 111 * to also work for the flat array case because 112 * NR_SECTION_ROOTS==NR_MEM_SECTIONS. 113 */ 114int __section_nr(struct mem_section* ms) 115{ 116 unsigned long root_nr; 117 struct mem_section* root; 118 119 for (root_nr = 0; root_nr < NR_SECTION_ROOTS; root_nr++) { 120 root = __nr_to_section(root_nr * SECTIONS_PER_ROOT); 121 if (!root) 122 continue; 123 124 if ((ms >= root) && (ms < (root + SECTIONS_PER_ROOT))) 125 break; 126 } 127 128 return (root_nr * SECTIONS_PER_ROOT) + (ms - root); 129} 130 131/* 132 * During early boot, before section_mem_map is used for an actual 133 * mem_map, we use section_mem_map to store the section's NUMA 134 * node. This keeps us from having to use another data structure. The 135 * node information is cleared just before we store the real mem_map. 136 */ 137static inline unsigned long sparse_encode_early_nid(int nid) 138{ 139 return (nid << SECTION_NID_SHIFT); 140} 141 142static inline int sparse_early_nid(struct mem_section *section) 143{ 144 return (section->section_mem_map >> SECTION_NID_SHIFT); 145} 146 147/* Record a memory area against a node. */ 148void __init memory_present(int nid, unsigned long start, unsigned long end) 149{ 150 unsigned long pfn; 151 152 start &= PAGE_SECTION_MASK; 153 for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) { 154 unsigned long section = pfn_to_section_nr(pfn); 155 struct mem_section *ms; 156 157 sparse_index_init(section, nid); 158 set_section_nid(section, nid); 159 160 ms = __nr_to_section(section); 161 if (!ms->section_mem_map) 162 ms->section_mem_map = sparse_encode_early_nid(nid) | 163 SECTION_MARKED_PRESENT; 164 } 165} 166 167/* 168 * Only used by the i386 NUMA architecures, but relatively 169 * generic code. 170 */ 171unsigned long __init node_memmap_size_bytes(int nid, unsigned long start_pfn, 172 unsigned long end_pfn) 173{ 174 unsigned long pfn; 175 unsigned long nr_pages = 0; 176 177 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { 178 if (nid != early_pfn_to_nid(pfn)) 179 continue; 180 181 if (pfn_present(pfn)) 182 nr_pages += PAGES_PER_SECTION; 183 } 184 185 return nr_pages * sizeof(struct page); 186} 187 188/* 189 * Subtle, we encode the real pfn into the mem_map such that 190 * the identity pfn - section_mem_map will return the actual 191 * physical page frame number. 192 */ 193static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long pnum) 194{ 195 return (unsigned long)(mem_map - (section_nr_to_pfn(pnum))); 196} 197 198/* 199 * We need this if we ever free the mem_maps. While not implemented yet, 200 * this function is included for parity with its sibling. 201 */ 202static __attribute((unused)) 203struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum) 204{ 205 return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum); 206} 207 208static int __meminit sparse_init_one_section(struct mem_section *ms, 209 unsigned long pnum, struct page *mem_map, 210 unsigned long *pageblock_bitmap) 211{ 212 if (!present_section(ms)) 213 return -EINVAL; 214 215 ms->section_mem_map &= ~SECTION_MAP_MASK; 216 ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) | 217 SECTION_HAS_MEM_MAP; 218 ms->pageblock_flags = pageblock_bitmap; 219 220 return 1; 221} 222 223__attribute__((weak)) __init 224void *alloc_bootmem_high_node(pg_data_t *pgdat, unsigned long size) 225{ 226 return NULL; 227} 228 229static unsigned long usemap_size(void) 230{ 231 unsigned long size_bytes; 232 size_bytes = roundup(SECTION_BLOCKFLAGS_BITS, 8) / 8; 233 size_bytes = roundup(size_bytes, sizeof(unsigned long)); 234 return size_bytes; 235} 236 237#ifdef CONFIG_MEMORY_HOTPLUG 238static unsigned long *__kmalloc_section_usemap(void) 239{ 240 return kmalloc(usemap_size(), GFP_KERNEL); 241} 242#endif /* CONFIG_MEMORY_HOTPLUG */ 243 244static unsigned long *sparse_early_usemap_alloc(unsigned long pnum) 245{ 246 unsigned long *usemap; 247 struct mem_section *ms = __nr_to_section(pnum); 248 int nid = sparse_early_nid(ms); 249 250 usemap = alloc_bootmem_node(NODE_DATA(nid), usemap_size()); 251 if (usemap) 252 return usemap; 253 254 /* Stupid: suppress gcc warning for SPARSEMEM && !NUMA */ 255 nid = 0; 256 257 printk(KERN_WARNING "%s: allocation failed\n", __FUNCTION__); 258 return NULL; 259} 260 261#ifndef CONFIG_SPARSEMEM_VMEMMAP 262struct page __init *sparse_mem_map_populate(unsigned long pnum, int nid) 263{ 264 struct page *map; 265 266 map = alloc_remap(nid, sizeof(struct page) * PAGES_PER_SECTION); 267 if (map) 268 return map; 269 270 map = alloc_bootmem_high_node(NODE_DATA(nid), 271 sizeof(struct page) * PAGES_PER_SECTION); 272 if (map) 273 return map; 274 275 map = alloc_bootmem_node(NODE_DATA(nid), 276 sizeof(struct page) * PAGES_PER_SECTION); 277 return map; 278} 279#endif /* !CONFIG_SPARSEMEM_VMEMMAP */ 280 281struct page __init *sparse_early_mem_map_alloc(unsigned long pnum) 282{ 283 struct page *map; 284 struct mem_section *ms = __nr_to_section(pnum); 285 int nid = sparse_early_nid(ms); 286 287 map = sparse_mem_map_populate(pnum, nid); 288 if (map) 289 return map; 290 291 printk(KERN_ERR "%s: sparsemem memory map backing failed " 292 "some memory will not be available.\n", __FUNCTION__); 293 ms->section_mem_map = 0; 294 return NULL; 295} 296 297/* 298 * Allocate the accumulated non-linear sections, allocate a mem_map 299 * for each and record the physical to section mapping. 300 */ 301void __init sparse_init(void) 302{ 303 unsigned long pnum; 304 struct page *map; 305 unsigned long *usemap; 306 307 for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) { 308 if (!present_section_nr(pnum)) 309 continue; 310 311 map = sparse_early_mem_map_alloc(pnum); 312 if (!map) 313 continue; 314 315 usemap = sparse_early_usemap_alloc(pnum); 316 if (!usemap) 317 continue; 318 319 sparse_init_one_section(__nr_to_section(pnum), pnum, map, 320 usemap); 321 } 322} 323 324#ifdef CONFIG_MEMORY_HOTPLUG 325#ifdef CONFIG_SPARSEMEM_VMEMMAP 326static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid, 327 unsigned long nr_pages) 328{ 329 /* This will make the necessary allocations eventually. */ 330 return sparse_mem_map_populate(pnum, nid); 331} 332static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages) 333{ 334 return; /* XXX: Not implemented yet */ 335} 336#else 337static struct page *__kmalloc_section_memmap(unsigned long nr_pages) 338{ 339 struct page *page, *ret; 340 unsigned long memmap_size = sizeof(struct page) * nr_pages; 341 342 page = alloc_pages(GFP_KERNEL|__GFP_NOWARN, get_order(memmap_size)); 343 if (page) 344 goto got_map_page; 345 346 ret = vmalloc(memmap_size); 347 if (ret) 348 goto got_map_ptr; 349 350 return NULL; 351got_map_page: 352 ret = (struct page *)pfn_to_kaddr(page_to_pfn(page)); 353got_map_ptr: 354 memset(ret, 0, memmap_size); 355 356 return ret; 357} 358 359static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid, 360 unsigned long nr_pages) 361{ 362 return __kmalloc_section_memmap(nr_pages); 363} 364 365static int vaddr_in_vmalloc_area(void *addr) 366{ 367 if (addr >= (void *)VMALLOC_START && 368 addr < (void *)VMALLOC_END) 369 return 1; 370 return 0; 371} 372 373static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages) 374{ 375 if (vaddr_in_vmalloc_area(memmap)) 376 vfree(memmap); 377 else 378 free_pages((unsigned long)memmap, 379 get_order(sizeof(struct page) * nr_pages)); 380} 381#endif /* CONFIG_SPARSEMEM_VMEMMAP */ 382 383/* 384 * returns the number of sections whose mem_maps were properly 385 * set. If this is <=0, then that means that the passed-in 386 * map was not consumed and must be freed. 387 */ 388int sparse_add_one_section(struct zone *zone, unsigned long start_pfn, 389 int nr_pages) 390{ 391 unsigned long section_nr = pfn_to_section_nr(start_pfn); 392 struct pglist_data *pgdat = zone->zone_pgdat; 393 struct mem_section *ms; 394 struct page *memmap; 395 unsigned long *usemap; 396 unsigned long flags; 397 int ret; 398 399 /* 400 * no locking for this, because it does its own 401 * plus, it does a kmalloc 402 */ 403 sparse_index_init(section_nr, pgdat->node_id); 404 memmap = kmalloc_section_memmap(section_nr, pgdat->node_id, nr_pages); 405 usemap = __kmalloc_section_usemap(); 406 407 pgdat_resize_lock(pgdat, &flags); 408 409 ms = __pfn_to_section(start_pfn); 410 if (ms->section_mem_map & SECTION_MARKED_PRESENT) { 411 ret = -EEXIST; 412 goto out; 413 } 414 415 if (!usemap) { 416 ret = -ENOMEM; 417 goto out; 418 } 419 ms->section_mem_map |= SECTION_MARKED_PRESENT; 420 421 ret = sparse_init_one_section(ms, section_nr, memmap, usemap); 422 423out: 424 pgdat_resize_unlock(pgdat, &flags); 425 if (ret <= 0) 426 __kfree_section_memmap(memmap, nr_pages); 427 return ret; 428} 429#endif 430