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 21 struct mem_section *mem_section[NR_SECTION_ROOTS] 22 ____cacheline_internodealigned_in_smp; 23 #else 24 struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT] 25 ____cacheline_internodealigned_in_smp; 26 #endif 27 EXPORT_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 36 static u8 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned; 37 #else 38 static u16 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned; 39 #endif 40 41 int page_to_nid(struct page *page) 42 { 43 return section_to_node_table[page_to_section(page)]; 44 } 45 EXPORT_SYMBOL(page_to_nid); 46 47 static 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 */ 52 static inline void set_section_nid(unsigned long section_nr, int nid) 53 { 54 } 55 #endif 56 57 #ifdef CONFIG_SPARSEMEM_EXTREME 58 static 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 75 static 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; 98 out: 99 spin_unlock(&index_init_lock); 100 return ret; 101 } 102 #else /* !SPARSEMEM_EXTREME */ 103 static 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 */ 114 int __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 */ 137 static inline unsigned long sparse_encode_early_nid(int nid) 138 { 139 return (nid << SECTION_NID_SHIFT); 140 } 141 142 static 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. */ 148 void __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 */ 171 unsigned 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 */ 193 static 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 */ 202 static __attribute((unused)) 203 struct 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 } 207 208 static 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 static unsigned long usemap_size(void) 224 { 225 unsigned long size_bytes; 226 size_bytes = roundup(SECTION_BLOCKFLAGS_BITS, 8) / 8; 227 size_bytes = roundup(size_bytes, sizeof(unsigned long)); 228 return size_bytes; 229 } 230 231 #ifdef CONFIG_MEMORY_HOTPLUG 232 static unsigned long *__kmalloc_section_usemap(void) 233 { 234 return kmalloc(usemap_size(), GFP_KERNEL); 235 } 236 #endif /* CONFIG_MEMORY_HOTPLUG */ 237 238 static unsigned long *sparse_early_usemap_alloc(unsigned long pnum) 239 { 240 unsigned long *usemap; 241 struct mem_section *ms = __nr_to_section(pnum); 242 int nid = sparse_early_nid(ms); 243 244 usemap = alloc_bootmem_node(NODE_DATA(nid), usemap_size()); 245 if (usemap) 246 return usemap; 247 248 /* Stupid: suppress gcc warning for SPARSEMEM && !NUMA */ 249 nid = 0; 250 251 printk(KERN_WARNING "%s: allocation failed\n", __FUNCTION__); 252 return NULL; 253 } 254 255 #ifndef CONFIG_SPARSEMEM_VMEMMAP 256 struct page __init *sparse_mem_map_populate(unsigned long pnum, int nid) 257 { 258 struct page *map; 259 260 map = alloc_remap(nid, sizeof(struct page) * PAGES_PER_SECTION); 261 if (map) 262 return map; 263 264 map = alloc_bootmem_node(NODE_DATA(nid), 265 sizeof(struct page) * PAGES_PER_SECTION); 266 return map; 267 } 268 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */ 269 270 struct page __init *sparse_early_mem_map_alloc(unsigned long pnum) 271 { 272 struct page *map; 273 struct mem_section *ms = __nr_to_section(pnum); 274 int nid = sparse_early_nid(ms); 275 276 map = sparse_mem_map_populate(pnum, nid); 277 if (map) 278 return map; 279 280 printk(KERN_ERR "%s: sparsemem memory map backing failed " 281 "some memory will not be available.\n", __FUNCTION__); 282 ms->section_mem_map = 0; 283 return NULL; 284 } 285 286 /* 287 * Allocate the accumulated non-linear sections, allocate a mem_map 288 * for each and record the physical to section mapping. 289 */ 290 void __init sparse_init(void) 291 { 292 unsigned long pnum; 293 struct page *map; 294 unsigned long *usemap; 295 296 for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) { 297 if (!present_section_nr(pnum)) 298 continue; 299 300 map = sparse_early_mem_map_alloc(pnum); 301 if (!map) 302 continue; 303 304 usemap = sparse_early_usemap_alloc(pnum); 305 if (!usemap) 306 continue; 307 308 sparse_init_one_section(__nr_to_section(pnum), pnum, map, 309 usemap); 310 } 311 } 312 313 #ifdef CONFIG_MEMORY_HOTPLUG 314 #ifdef CONFIG_SPARSEMEM_VMEMMAP 315 static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid, 316 unsigned long nr_pages) 317 { 318 /* This will make the necessary allocations eventually. */ 319 return sparse_mem_map_populate(pnum, nid); 320 } 321 static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages) 322 { 323 return; /* XXX: Not implemented yet */ 324 } 325 #else 326 static struct page *__kmalloc_section_memmap(unsigned long nr_pages) 327 { 328 struct page *page, *ret; 329 unsigned long memmap_size = sizeof(struct page) * nr_pages; 330 331 page = alloc_pages(GFP_KERNEL|__GFP_NOWARN, get_order(memmap_size)); 332 if (page) 333 goto got_map_page; 334 335 ret = vmalloc(memmap_size); 336 if (ret) 337 goto got_map_ptr; 338 339 return NULL; 340 got_map_page: 341 ret = (struct page *)pfn_to_kaddr(page_to_pfn(page)); 342 got_map_ptr: 343 memset(ret, 0, memmap_size); 344 345 return ret; 346 } 347 348 static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid, 349 unsigned long nr_pages) 350 { 351 return __kmalloc_section_memmap(nr_pages); 352 } 353 354 static int vaddr_in_vmalloc_area(void *addr) 355 { 356 if (addr >= (void *)VMALLOC_START && 357 addr < (void *)VMALLOC_END) 358 return 1; 359 return 0; 360 } 361 362 static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages) 363 { 364 if (vaddr_in_vmalloc_area(memmap)) 365 vfree(memmap); 366 else 367 free_pages((unsigned long)memmap, 368 get_order(sizeof(struct page) * nr_pages)); 369 } 370 #endif /* CONFIG_SPARSEMEM_VMEMMAP */ 371 372 /* 373 * returns the number of sections whose mem_maps were properly 374 * set. If this is <=0, then that means that the passed-in 375 * map was not consumed and must be freed. 376 */ 377 int sparse_add_one_section(struct zone *zone, unsigned long start_pfn, 378 int nr_pages) 379 { 380 unsigned long section_nr = pfn_to_section_nr(start_pfn); 381 struct pglist_data *pgdat = zone->zone_pgdat; 382 struct mem_section *ms; 383 struct page *memmap; 384 unsigned long *usemap; 385 unsigned long flags; 386 int ret; 387 388 /* 389 * no locking for this, because it does its own 390 * plus, it does a kmalloc 391 */ 392 sparse_index_init(section_nr, pgdat->node_id); 393 memmap = kmalloc_section_memmap(section_nr, pgdat->node_id, nr_pages); 394 usemap = __kmalloc_section_usemap(); 395 396 pgdat_resize_lock(pgdat, &flags); 397 398 ms = __pfn_to_section(start_pfn); 399 if (ms->section_mem_map & SECTION_MARKED_PRESENT) { 400 ret = -EEXIST; 401 goto out; 402 } 403 404 if (!usemap) { 405 ret = -ENOMEM; 406 goto out; 407 } 408 ms->section_mem_map |= SECTION_MARKED_PRESENT; 409 410 ret = sparse_init_one_section(ms, section_nr, memmap, usemap); 411 412 out: 413 pgdat_resize_unlock(pgdat, &flags); 414 if (ret <= 0) 415 __kfree_section_memmap(memmap, nr_pages); 416 return ret; 417 } 418 #endif 419