1 /* 2 * linux/arch/arm/mm/init.c 3 * 4 * Copyright (C) 1995-2002 Russell King 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 #include <linux/config.h> 11 #include <linux/kernel.h> 12 #include <linux/errno.h> 13 #include <linux/ptrace.h> 14 #include <linux/swap.h> 15 #include <linux/init.h> 16 #include <linux/bootmem.h> 17 #include <linux/mman.h> 18 #include <linux/nodemask.h> 19 #include <linux/initrd.h> 20 21 #include <asm/mach-types.h> 22 #include <asm/hardware.h> 23 #include <asm/setup.h> 24 #include <asm/tlb.h> 25 26 #include <asm/mach/arch.h> 27 #include <asm/mach/map.h> 28 29 #define TABLE_SIZE (2 * PTRS_PER_PTE * sizeof(pte_t)) 30 31 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); 32 33 extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; 34 extern void _stext, _text, _etext, __data_start, _end, __init_begin, __init_end; 35 extern unsigned long phys_initrd_start; 36 extern unsigned long phys_initrd_size; 37 38 /* 39 * The sole use of this is to pass memory configuration 40 * data from paging_init to mem_init. 41 */ 42 static struct meminfo meminfo __initdata = { 0, }; 43 44 /* 45 * empty_zero_page is a special page that is used for 46 * zero-initialized data and COW. 47 */ 48 struct page *empty_zero_page; 49 50 void show_mem(void) 51 { 52 int free = 0, total = 0, reserved = 0; 53 int shared = 0, cached = 0, slab = 0, node; 54 55 printk("Mem-info:\n"); 56 show_free_areas(); 57 printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10)); 58 59 for_each_online_node(node) { 60 struct page *page, *end; 61 62 page = NODE_MEM_MAP(node); 63 end = page + NODE_DATA(node)->node_spanned_pages; 64 65 do { 66 total++; 67 if (PageReserved(page)) 68 reserved++; 69 else if (PageSwapCache(page)) 70 cached++; 71 else if (PageSlab(page)) 72 slab++; 73 else if (!page_count(page)) 74 free++; 75 else 76 shared += page_count(page) - 1; 77 page++; 78 } while (page < end); 79 } 80 81 printk("%d pages of RAM\n", total); 82 printk("%d free pages\n", free); 83 printk("%d reserved pages\n", reserved); 84 printk("%d slab pages\n", slab); 85 printk("%d pages shared\n", shared); 86 printk("%d pages swap cached\n", cached); 87 } 88 89 struct node_info { 90 unsigned int start; 91 unsigned int end; 92 int bootmap_pages; 93 }; 94 95 #define O_PFN_DOWN(x) ((x) >> PAGE_SHIFT) 96 #define V_PFN_DOWN(x) O_PFN_DOWN(__pa(x)) 97 98 #define O_PFN_UP(x) (PAGE_ALIGN(x) >> PAGE_SHIFT) 99 #define V_PFN_UP(x) O_PFN_UP(__pa(x)) 100 101 #define PFN_SIZE(x) ((x) >> PAGE_SHIFT) 102 #define PFN_RANGE(s,e) PFN_SIZE(PAGE_ALIGN((unsigned long)(e)) - \ 103 (((unsigned long)(s)) & PAGE_MASK)) 104 105 /* 106 * FIXME: We really want to avoid allocating the bootmap bitmap 107 * over the top of the initrd. Hopefully, this is located towards 108 * the start of a bank, so if we allocate the bootmap bitmap at 109 * the end, we won't clash. 110 */ 111 static unsigned int __init 112 find_bootmap_pfn(int node, struct meminfo *mi, unsigned int bootmap_pages) 113 { 114 unsigned int start_pfn, bank, bootmap_pfn; 115 116 start_pfn = V_PFN_UP(&_end); 117 bootmap_pfn = 0; 118 119 for (bank = 0; bank < mi->nr_banks; bank ++) { 120 unsigned int start, end; 121 122 if (mi->bank[bank].node != node) 123 continue; 124 125 start = O_PFN_UP(mi->bank[bank].start); 126 end = O_PFN_DOWN(mi->bank[bank].size + 127 mi->bank[bank].start); 128 129 if (end < start_pfn) 130 continue; 131 132 if (start < start_pfn) 133 start = start_pfn; 134 135 if (end <= start) 136 continue; 137 138 if (end - start >= bootmap_pages) { 139 bootmap_pfn = start; 140 break; 141 } 142 } 143 144 if (bootmap_pfn == 0) 145 BUG(); 146 147 return bootmap_pfn; 148 } 149 150 /* 151 * Scan the memory info structure and pull out: 152 * - the end of memory 153 * - the number of nodes 154 * - the pfn range of each node 155 * - the number of bootmem bitmap pages 156 */ 157 static unsigned int __init 158 find_memend_and_nodes(struct meminfo *mi, struct node_info *np) 159 { 160 unsigned int i, bootmem_pages = 0, memend_pfn = 0; 161 162 for (i = 0; i < MAX_NUMNODES; i++) { 163 np[i].start = -1U; 164 np[i].end = 0; 165 np[i].bootmap_pages = 0; 166 } 167 168 for (i = 0; i < mi->nr_banks; i++) { 169 unsigned long start, end; 170 int node; 171 172 if (mi->bank[i].size == 0) { 173 /* 174 * Mark this bank with an invalid node number 175 */ 176 mi->bank[i].node = -1; 177 continue; 178 } 179 180 node = mi->bank[i].node; 181 182 /* 183 * Make sure we haven't exceeded the maximum number of nodes 184 * that we have in this configuration. If we have, we're in 185 * trouble. (maybe we ought to limit, instead of bugging?) 186 */ 187 if (node >= MAX_NUMNODES) 188 BUG(); 189 node_set_online(node); 190 191 /* 192 * Get the start and end pfns for this bank 193 */ 194 start = O_PFN_UP(mi->bank[i].start); 195 end = O_PFN_DOWN(mi->bank[i].start + mi->bank[i].size); 196 197 if (np[node].start > start) 198 np[node].start = start; 199 200 if (np[node].end < end) 201 np[node].end = end; 202 203 if (memend_pfn < end) 204 memend_pfn = end; 205 } 206 207 /* 208 * Calculate the number of pages we require to 209 * store the bootmem bitmaps. 210 */ 211 for_each_online_node(i) { 212 if (np[i].end == 0) 213 continue; 214 215 np[i].bootmap_pages = bootmem_bootmap_pages(np[i].end - 216 np[i].start); 217 bootmem_pages += np[i].bootmap_pages; 218 } 219 220 high_memory = __va(memend_pfn << PAGE_SHIFT); 221 222 /* 223 * This doesn't seem to be used by the Linux memory 224 * manager any more. If we can get rid of it, we 225 * also get rid of some of the stuff above as well. 226 */ 227 max_low_pfn = memend_pfn - O_PFN_DOWN(PHYS_OFFSET); 228 max_pfn = memend_pfn - O_PFN_DOWN(PHYS_OFFSET); 229 230 return bootmem_pages; 231 } 232 233 static int __init check_initrd(struct meminfo *mi) 234 { 235 int initrd_node = -2; 236 #ifdef CONFIG_BLK_DEV_INITRD 237 unsigned long end = phys_initrd_start + phys_initrd_size; 238 239 /* 240 * Make sure that the initrd is within a valid area of 241 * memory. 242 */ 243 if (phys_initrd_size) { 244 unsigned int i; 245 246 initrd_node = -1; 247 248 for (i = 0; i < mi->nr_banks; i++) { 249 unsigned long bank_end; 250 251 bank_end = mi->bank[i].start + mi->bank[i].size; 252 253 if (mi->bank[i].start <= phys_initrd_start && 254 end <= bank_end) 255 initrd_node = mi->bank[i].node; 256 } 257 } 258 259 if (initrd_node == -1) { 260 printk(KERN_ERR "initrd (0x%08lx - 0x%08lx) extends beyond " 261 "physical memory - disabling initrd\n", 262 phys_initrd_start, end); 263 phys_initrd_start = phys_initrd_size = 0; 264 } 265 #endif 266 267 return initrd_node; 268 } 269 270 /* 271 * Reserve the various regions of node 0 272 */ 273 static __init void reserve_node_zero(unsigned int bootmap_pfn, unsigned int bootmap_pages) 274 { 275 pg_data_t *pgdat = NODE_DATA(0); 276 unsigned long res_size = 0; 277 278 /* 279 * Register the kernel text and data with bootmem. 280 * Note that this can only be in node 0. 281 */ 282 #ifdef CONFIG_XIP_KERNEL 283 reserve_bootmem_node(pgdat, __pa(&__data_start), &_end - &__data_start); 284 #else 285 reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext); 286 #endif 287 288 /* 289 * Reserve the page tables. These are already in use, 290 * and can only be in node 0. 291 */ 292 reserve_bootmem_node(pgdat, __pa(swapper_pg_dir), 293 PTRS_PER_PGD * sizeof(pgd_t)); 294 295 /* 296 * And don't forget to reserve the allocator bitmap, 297 * which will be freed later. 298 */ 299 reserve_bootmem_node(pgdat, bootmap_pfn << PAGE_SHIFT, 300 bootmap_pages << PAGE_SHIFT); 301 302 /* 303 * Hmm... This should go elsewhere, but we really really need to 304 * stop things allocating the low memory; ideally we need a better 305 * implementation of GFP_DMA which does not assume that DMA-able 306 * memory starts at zero. 307 */ 308 if (machine_is_integrator() || machine_is_cintegrator()) 309 res_size = __pa(swapper_pg_dir) - PHYS_OFFSET; 310 311 /* 312 * These should likewise go elsewhere. They pre-reserve the 313 * screen memory region at the start of main system memory. 314 */ 315 if (machine_is_edb7211()) 316 res_size = 0x00020000; 317 if (machine_is_p720t()) 318 res_size = 0x00014000; 319 320 #ifdef CONFIG_SA1111 321 /* 322 * Because of the SA1111 DMA bug, we want to preserve our 323 * precious DMA-able memory... 324 */ 325 res_size = __pa(swapper_pg_dir) - PHYS_OFFSET; 326 #endif 327 if (res_size) 328 reserve_bootmem_node(pgdat, PHYS_OFFSET, res_size); 329 } 330 331 /* 332 * Register all available RAM in this node with the bootmem allocator. 333 */ 334 static inline void free_bootmem_node_bank(int node, struct meminfo *mi) 335 { 336 pg_data_t *pgdat = NODE_DATA(node); 337 int bank; 338 339 for (bank = 0; bank < mi->nr_banks; bank++) 340 if (mi->bank[bank].node == node) 341 free_bootmem_node(pgdat, mi->bank[bank].start, 342 mi->bank[bank].size); 343 } 344 345 /* 346 * Initialise the bootmem allocator for all nodes. This is called 347 * early during the architecture specific initialisation. 348 */ 349 static void __init bootmem_init(struct meminfo *mi) 350 { 351 struct node_info node_info[MAX_NUMNODES], *np = node_info; 352 unsigned int bootmap_pages, bootmap_pfn, map_pg; 353 int node, initrd_node; 354 355 bootmap_pages = find_memend_and_nodes(mi, np); 356 bootmap_pfn = find_bootmap_pfn(0, mi, bootmap_pages); 357 initrd_node = check_initrd(mi); 358 359 map_pg = bootmap_pfn; 360 361 /* 362 * Initialise the bootmem nodes. 363 * 364 * What we really want to do is: 365 * 366 * unmap_all_regions_except_kernel(); 367 * for_each_node_in_reverse_order(node) { 368 * map_node(node); 369 * allocate_bootmem_map(node); 370 * init_bootmem_node(node); 371 * free_bootmem_node(node); 372 * } 373 * 374 * but this is a 2.5-type change. For now, we just set 375 * the nodes up in reverse order. 376 * 377 * (we could also do with rolling bootmem_init and paging_init 378 * into one generic "memory_init" type function). 379 */ 380 np += num_online_nodes() - 1; 381 for (node = num_online_nodes() - 1; node >= 0; node--, np--) { 382 /* 383 * If there are no pages in this node, ignore it. 384 * Note that node 0 must always have some pages. 385 */ 386 if (np->end == 0 || !node_online(node)) { 387 if (node == 0) 388 BUG(); 389 continue; 390 } 391 392 /* 393 * Initialise the bootmem allocator. 394 */ 395 init_bootmem_node(NODE_DATA(node), map_pg, np->start, np->end); 396 free_bootmem_node_bank(node, mi); 397 map_pg += np->bootmap_pages; 398 399 /* 400 * If this is node 0, we need to reserve some areas ASAP - 401 * we may use bootmem on node 0 to setup the other nodes. 402 */ 403 if (node == 0) 404 reserve_node_zero(bootmap_pfn, bootmap_pages); 405 } 406 407 408 #ifdef CONFIG_BLK_DEV_INITRD 409 if (phys_initrd_size && initrd_node >= 0) { 410 reserve_bootmem_node(NODE_DATA(initrd_node), phys_initrd_start, 411 phys_initrd_size); 412 initrd_start = __phys_to_virt(phys_initrd_start); 413 initrd_end = initrd_start + phys_initrd_size; 414 } 415 #endif 416 417 BUG_ON(map_pg != bootmap_pfn + bootmap_pages); 418 } 419 420 /* 421 * paging_init() sets up the page tables, initialises the zone memory 422 * maps, and sets up the zero page, bad page and bad page tables. 423 */ 424 void __init paging_init(struct meminfo *mi, struct machine_desc *mdesc) 425 { 426 void *zero_page; 427 int node; 428 429 bootmem_init(mi); 430 431 memcpy(&meminfo, mi, sizeof(meminfo)); 432 433 /* 434 * allocate the zero page. Note that we count on this going ok. 435 */ 436 zero_page = alloc_bootmem_low_pages(PAGE_SIZE); 437 438 /* 439 * initialise the page tables. 440 */ 441 memtable_init(mi); 442 if (mdesc->map_io) 443 mdesc->map_io(); 444 flush_tlb_all(); 445 446 /* 447 * initialise the zones within each node 448 */ 449 for_each_online_node(node) { 450 unsigned long zone_size[MAX_NR_ZONES]; 451 unsigned long zhole_size[MAX_NR_ZONES]; 452 struct bootmem_data *bdata; 453 pg_data_t *pgdat; 454 int i; 455 456 /* 457 * Initialise the zone size information. 458 */ 459 for (i = 0; i < MAX_NR_ZONES; i++) { 460 zone_size[i] = 0; 461 zhole_size[i] = 0; 462 } 463 464 pgdat = NODE_DATA(node); 465 bdata = pgdat->bdata; 466 467 /* 468 * The size of this node has already been determined. 469 * If we need to do anything fancy with the allocation 470 * of this memory to the zones, now is the time to do 471 * it. 472 */ 473 zone_size[0] = bdata->node_low_pfn - 474 (bdata->node_boot_start >> PAGE_SHIFT); 475 476 /* 477 * If this zone has zero size, skip it. 478 */ 479 if (!zone_size[0]) 480 continue; 481 482 /* 483 * For each bank in this node, calculate the size of the 484 * holes. holes = node_size - sum(bank_sizes_in_node) 485 */ 486 zhole_size[0] = zone_size[0]; 487 for (i = 0; i < mi->nr_banks; i++) { 488 if (mi->bank[i].node != node) 489 continue; 490 491 zhole_size[0] -= mi->bank[i].size >> PAGE_SHIFT; 492 } 493 494 /* 495 * Adjust the sizes according to any special 496 * requirements for this machine type. 497 */ 498 arch_adjust_zones(node, zone_size, zhole_size); 499 500 free_area_init_node(node, pgdat, zone_size, 501 bdata->node_boot_start >> PAGE_SHIFT, zhole_size); 502 } 503 504 /* 505 * finish off the bad pages once 506 * the mem_map is initialised 507 */ 508 memzero(zero_page, PAGE_SIZE); 509 empty_zero_page = virt_to_page(zero_page); 510 flush_dcache_page(empty_zero_page); 511 } 512 513 static inline void free_area(unsigned long addr, unsigned long end, char *s) 514 { 515 unsigned int size = (end - addr) >> 10; 516 517 for (; addr < end; addr += PAGE_SIZE) { 518 struct page *page = virt_to_page(addr); 519 ClearPageReserved(page); 520 set_page_count(page, 1); 521 free_page(addr); 522 totalram_pages++; 523 } 524 525 if (size && s) 526 printk(KERN_INFO "Freeing %s memory: %dK\n", s, size); 527 } 528 529 /* 530 * mem_init() marks the free areas in the mem_map and tells us how much 531 * memory is free. This is done after various parts of the system have 532 * claimed their memory after the kernel image. 533 */ 534 void __init mem_init(void) 535 { 536 unsigned int codepages, datapages, initpages; 537 int i, node; 538 539 codepages = &_etext - &_text; 540 datapages = &_end - &__data_start; 541 initpages = &__init_end - &__init_begin; 542 543 #ifndef CONFIG_DISCONTIGMEM 544 max_mapnr = virt_to_page(high_memory) - mem_map; 545 #endif 546 547 /* 548 * We may have non-contiguous memory. 549 */ 550 if (meminfo.nr_banks != 1) 551 create_memmap_holes(&meminfo); 552 553 /* this will put all unused low memory onto the freelists */ 554 for_each_online_node(node) { 555 pg_data_t *pgdat = NODE_DATA(node); 556 557 if (pgdat->node_spanned_pages != 0) 558 totalram_pages += free_all_bootmem_node(pgdat); 559 } 560 561 #ifdef CONFIG_SA1111 562 /* now that our DMA memory is actually so designated, we can free it */ 563 free_area(PAGE_OFFSET, (unsigned long)swapper_pg_dir, NULL); 564 #endif 565 566 /* 567 * Since our memory may not be contiguous, calculate the 568 * real number of pages we have in this system 569 */ 570 printk(KERN_INFO "Memory:"); 571 572 num_physpages = 0; 573 for (i = 0; i < meminfo.nr_banks; i++) { 574 num_physpages += meminfo.bank[i].size >> PAGE_SHIFT; 575 printk(" %ldMB", meminfo.bank[i].size >> 20); 576 } 577 578 printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT)); 579 printk(KERN_NOTICE "Memory: %luKB available (%dK code, " 580 "%dK data, %dK init)\n", 581 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), 582 codepages >> 10, datapages >> 10, initpages >> 10); 583 584 if (PAGE_SIZE >= 16384 && num_physpages <= 128) { 585 extern int sysctl_overcommit_memory; 586 /* 587 * On a machine this small we won't get 588 * anywhere without overcommit, so turn 589 * it on by default. 590 */ 591 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS; 592 } 593 } 594 595 void free_initmem(void) 596 { 597 if (!machine_is_integrator() && !machine_is_cintegrator()) { 598 free_area((unsigned long)(&__init_begin), 599 (unsigned long)(&__init_end), 600 "init"); 601 } 602 } 603 604 #ifdef CONFIG_BLK_DEV_INITRD 605 606 static int keep_initrd; 607 608 void free_initrd_mem(unsigned long start, unsigned long end) 609 { 610 if (!keep_initrd) 611 free_area(start, end, "initrd"); 612 } 613 614 static int __init keepinitrd_setup(char *__unused) 615 { 616 keep_initrd = 1; 617 return 1; 618 } 619 620 __setup("keepinitrd", keepinitrd_setup); 621 #endif 622