1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * 4 * Copyright (C) 1995 Linus Torvalds 5 * 6 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 7 */ 8 9#include <linux/signal.h> 10#include <linux/sched.h> 11#include <linux/kernel.h> 12#include <linux/errno.h> 13#include <linux/string.h> 14#include <linux/types.h> 15#include <linux/ptrace.h> 16#include <linux/mman.h> 17#include <linux/mm.h> 18#include <linux/hugetlb.h> 19#include <linux/swap.h> 20#include <linux/smp.h> 21#include <linux/init.h> 22#include <linux/highmem.h> 23#include <linux/pagemap.h> 24#include <linux/pci.h> 25#include <linux/pfn.h> 26#include <linux/poison.h> 27#include <linux/memblock.h> 28#include <linux/proc_fs.h> 29#include <linux/memory_hotplug.h> 30#include <linux/initrd.h> 31#include <linux/cpumask.h> 32#include <linux/gfp.h> 33 34#include <asm/asm.h> 35#include <asm/bios_ebda.h> 36#include <asm/processor.h> 37#include <linux/uaccess.h> 38#include <asm/dma.h> 39#include <asm/fixmap.h> 40#include <asm/e820/api.h> 41#include <asm/apic.h> 42#include <asm/bugs.h> 43#include <asm/tlb.h> 44#include <asm/tlbflush.h> 45#include <asm/olpc_ofw.h> 46#include <asm/pgalloc.h> 47#include <asm/sections.h> 48#include <asm/setup.h> 49#include <asm/set_memory.h> 50#include <asm/page_types.h> 51#include <asm/cpu_entry_area.h> 52#include <asm/init.h> 53#include <asm/pgtable_areas.h> 54#include <asm/numa.h> 55 56#include "mm_internal.h" 57 58unsigned long highstart_pfn, highend_pfn; 59 60bool __read_mostly __vmalloc_start_set = false; 61 62/* 63 * Creates a middle page table and puts a pointer to it in the 64 * given global directory entry. This only returns the gd entry 65 * in non-PAE compilation mode, since the middle layer is folded. 66 */ 67static pmd_t * __init one_md_table_init(pgd_t *pgd) 68{ 69 p4d_t *p4d; 70 pud_t *pud; 71 pmd_t *pmd_table; 72 73#ifdef CONFIG_X86_PAE 74 if (!(pgd_val(*pgd) & _PAGE_PRESENT)) { 75 pmd_table = (pmd_t *)alloc_low_page(); 76 set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT)); 77 p4d = p4d_offset(pgd, 0); 78 pud = pud_offset(p4d, 0); 79 BUG_ON(pmd_table != pmd_offset(pud, 0)); 80 81 return pmd_table; 82 } 83#endif 84 p4d = p4d_offset(pgd, 0); 85 pud = pud_offset(p4d, 0); 86 pmd_table = pmd_offset(pud, 0); 87 88 return pmd_table; 89} 90 91/* 92 * Create a page table and place a pointer to it in a middle page 93 * directory entry: 94 */ 95static pte_t * __init one_page_table_init(pmd_t *pmd) 96{ 97 if (!(pmd_val(*pmd) & _PAGE_PRESENT)) { 98 pte_t *page_table = (pte_t *)alloc_low_page(); 99 100 set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE)); 101 BUG_ON(page_table != pte_offset_kernel(pmd, 0)); 102 } 103 104 return pte_offset_kernel(pmd, 0); 105} 106 107pmd_t * __init populate_extra_pmd(unsigned long vaddr) 108{ 109 int pgd_idx = pgd_index(vaddr); 110 int pmd_idx = pmd_index(vaddr); 111 112 return one_md_table_init(swapper_pg_dir + pgd_idx) + pmd_idx; 113} 114 115pte_t * __init populate_extra_pte(unsigned long vaddr) 116{ 117 int pte_idx = pte_index(vaddr); 118 pmd_t *pmd; 119 120 pmd = populate_extra_pmd(vaddr); 121 return one_page_table_init(pmd) + pte_idx; 122} 123 124static unsigned long __init 125page_table_range_init_count(unsigned long start, unsigned long end) 126{ 127 unsigned long count = 0; 128#ifdef CONFIG_HIGHMEM 129 int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT; 130 int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT; 131 int pgd_idx, pmd_idx; 132 unsigned long vaddr; 133 134 if (pmd_idx_kmap_begin == pmd_idx_kmap_end) 135 return 0; 136 137 vaddr = start; 138 pgd_idx = pgd_index(vaddr); 139 pmd_idx = pmd_index(vaddr); 140 141 for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd_idx++) { 142 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end); 143 pmd_idx++) { 144 if ((vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin && 145 (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end) 146 count++; 147 vaddr += PMD_SIZE; 148 } 149 pmd_idx = 0; 150 } 151#endif 152 return count; 153} 154 155static pte_t *__init page_table_kmap_check(pte_t *pte, pmd_t *pmd, 156 unsigned long vaddr, pte_t *lastpte, 157 void **adr) 158{ 159#ifdef CONFIG_HIGHMEM 160 /* 161 * Something (early fixmap) may already have put a pte 162 * page here, which causes the page table allocation 163 * to become nonlinear. Attempt to fix it, and if it 164 * is still nonlinear then we have to bug. 165 */ 166 int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT; 167 int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT; 168 169 if (pmd_idx_kmap_begin != pmd_idx_kmap_end 170 && (vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin 171 && (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end) { 172 pte_t *newpte; 173 int i; 174 175 BUG_ON(after_bootmem); 176 newpte = *adr; 177 for (i = 0; i < PTRS_PER_PTE; i++) 178 set_pte(newpte + i, pte[i]); 179 *adr = (void *)(((unsigned long)(*adr)) + PAGE_SIZE); 180 181 set_pmd(pmd, __pmd(__pa(newpte)|_PAGE_TABLE)); 182 BUG_ON(newpte != pte_offset_kernel(pmd, 0)); 183 __flush_tlb_all(); 184 185 pte = newpte; 186 } 187 BUG_ON(vaddr < fix_to_virt(FIX_KMAP_BEGIN - 1) 188 && vaddr > fix_to_virt(FIX_KMAP_END) 189 && lastpte && lastpte + PTRS_PER_PTE != pte); 190#endif 191 return pte; 192} 193 194/* 195 * This function initializes a certain range of kernel virtual memory 196 * with new bootmem page tables, everywhere page tables are missing in 197 * the given range. 198 * 199 * NOTE: The pagetables are allocated contiguous on the physical space 200 * so we can cache the place of the first one and move around without 201 * checking the pgd every time. 202 */ 203static void __init 204page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base) 205{ 206 int pgd_idx, pmd_idx; 207 unsigned long vaddr; 208 pgd_t *pgd; 209 pmd_t *pmd; 210 pte_t *pte = NULL; 211 unsigned long count = page_table_range_init_count(start, end); 212 void *adr = NULL; 213 214 if (count) 215 adr = alloc_low_pages(count); 216 217 vaddr = start; 218 pgd_idx = pgd_index(vaddr); 219 pmd_idx = pmd_index(vaddr); 220 pgd = pgd_base + pgd_idx; 221 222 for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) { 223 pmd = one_md_table_init(pgd); 224 pmd = pmd + pmd_index(vaddr); 225 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end); 226 pmd++, pmd_idx++) { 227 pte = page_table_kmap_check(one_page_table_init(pmd), 228 pmd, vaddr, pte, &adr); 229 230 vaddr += PMD_SIZE; 231 } 232 pmd_idx = 0; 233 } 234} 235 236static inline int is_x86_32_kernel_text(unsigned long addr) 237{ 238 if (addr >= (unsigned long)_text && addr <= (unsigned long)__init_end) 239 return 1; 240 return 0; 241} 242 243/* 244 * This maps the physical memory to kernel virtual address space, a total 245 * of max_low_pfn pages, by creating page tables starting from address 246 * PAGE_OFFSET: 247 */ 248unsigned long __init 249kernel_physical_mapping_init(unsigned long start, 250 unsigned long end, 251 unsigned long page_size_mask, 252 pgprot_t prot) 253{ 254 int use_pse = page_size_mask == (1<<PG_LEVEL_2M); 255 unsigned long last_map_addr = end; 256 unsigned long start_pfn, end_pfn; 257 pgd_t *pgd_base = swapper_pg_dir; 258 int pgd_idx, pmd_idx, pte_ofs; 259 unsigned long pfn; 260 pgd_t *pgd; 261 pmd_t *pmd; 262 pte_t *pte; 263 unsigned pages_2m, pages_4k; 264 int mapping_iter; 265 266 start_pfn = start >> PAGE_SHIFT; 267 end_pfn = end >> PAGE_SHIFT; 268 269 /* 270 * First iteration will setup identity mapping using large/small pages 271 * based on use_pse, with other attributes same as set by 272 * the early code in head_32.S 273 * 274 * Second iteration will setup the appropriate attributes (NX, GLOBAL..) 275 * as desired for the kernel identity mapping. 276 * 277 * This two pass mechanism conforms to the TLB app note which says: 278 * 279 * "Software should not write to a paging-structure entry in a way 280 * that would change, for any linear address, both the page size 281 * and either the page frame or attributes." 282 */ 283 mapping_iter = 1; 284 285 if (!boot_cpu_has(X86_FEATURE_PSE)) 286 use_pse = 0; 287 288repeat: 289 pages_2m = pages_4k = 0; 290 pfn = start_pfn; 291 pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); 292 pgd = pgd_base + pgd_idx; 293 for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) { 294 pmd = one_md_table_init(pgd); 295 296 if (pfn >= end_pfn) 297 continue; 298#ifdef CONFIG_X86_PAE 299 pmd_idx = pmd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); 300 pmd += pmd_idx; 301#else 302 pmd_idx = 0; 303#endif 304 for (; pmd_idx < PTRS_PER_PMD && pfn < end_pfn; 305 pmd++, pmd_idx++) { 306 unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET; 307 308 /* 309 * Map with big pages if possible, otherwise 310 * create normal page tables: 311 */ 312 if (use_pse) { 313 unsigned int addr2; 314 pgprot_t prot = PAGE_KERNEL_LARGE; 315 /* 316 * first pass will use the same initial 317 * identity mapping attribute + _PAGE_PSE. 318 */ 319 pgprot_t init_prot = 320 __pgprot(PTE_IDENT_ATTR | 321 _PAGE_PSE); 322 323 pfn &= PMD_MASK >> PAGE_SHIFT; 324 addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE + 325 PAGE_OFFSET + PAGE_SIZE-1; 326 327 if (is_x86_32_kernel_text(addr) || 328 is_x86_32_kernel_text(addr2)) 329 prot = PAGE_KERNEL_LARGE_EXEC; 330 331 pages_2m++; 332 if (mapping_iter == 1) 333 set_pmd(pmd, pfn_pmd(pfn, init_prot)); 334 else 335 set_pmd(pmd, pfn_pmd(pfn, prot)); 336 337 pfn += PTRS_PER_PTE; 338 continue; 339 } 340 pte = one_page_table_init(pmd); 341 342 pte_ofs = pte_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); 343 pte += pte_ofs; 344 for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn; 345 pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) { 346 pgprot_t prot = PAGE_KERNEL; 347 /* 348 * first pass will use the same initial 349 * identity mapping attribute. 350 */ 351 pgprot_t init_prot = __pgprot(PTE_IDENT_ATTR); 352 353 if (is_x86_32_kernel_text(addr)) 354 prot = PAGE_KERNEL_EXEC; 355 356 pages_4k++; 357 if (mapping_iter == 1) { 358 set_pte(pte, pfn_pte(pfn, init_prot)); 359 last_map_addr = (pfn << PAGE_SHIFT) + PAGE_SIZE; 360 } else 361 set_pte(pte, pfn_pte(pfn, prot)); 362 } 363 } 364 } 365 if (mapping_iter == 1) { 366 /* 367 * update direct mapping page count only in the first 368 * iteration. 369 */ 370 update_page_count(PG_LEVEL_2M, pages_2m); 371 update_page_count(PG_LEVEL_4K, pages_4k); 372 373 /* 374 * local global flush tlb, which will flush the previous 375 * mappings present in both small and large page TLB's. 376 */ 377 __flush_tlb_all(); 378 379 /* 380 * Second iteration will set the actual desired PTE attributes. 381 */ 382 mapping_iter = 2; 383 goto repeat; 384 } 385 return last_map_addr; 386} 387 388#ifdef CONFIG_HIGHMEM 389static void __init permanent_kmaps_init(pgd_t *pgd_base) 390{ 391 unsigned long vaddr = PKMAP_BASE; 392 393 page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base); 394 395 pkmap_page_table = virt_to_kpte(vaddr); 396} 397 398void __init add_highpages_with_active_regions(int nid, 399 unsigned long start_pfn, unsigned long end_pfn) 400{ 401 phys_addr_t start, end; 402 u64 i; 403 404 for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &start, &end, NULL) { 405 unsigned long pfn = clamp_t(unsigned long, PFN_UP(start), 406 start_pfn, end_pfn); 407 unsigned long e_pfn = clamp_t(unsigned long, PFN_DOWN(end), 408 start_pfn, end_pfn); 409 for ( ; pfn < e_pfn; pfn++) 410 if (pfn_valid(pfn)) 411 free_highmem_page(pfn_to_page(pfn)); 412 } 413} 414#else 415static inline void permanent_kmaps_init(pgd_t *pgd_base) 416{ 417} 418#endif /* CONFIG_HIGHMEM */ 419 420void __init sync_initial_page_table(void) 421{ 422 clone_pgd_range(initial_page_table + KERNEL_PGD_BOUNDARY, 423 swapper_pg_dir + KERNEL_PGD_BOUNDARY, 424 KERNEL_PGD_PTRS); 425 426 /* 427 * sync back low identity map too. It is used for example 428 * in the 32-bit EFI stub. 429 */ 430 clone_pgd_range(initial_page_table, 431 swapper_pg_dir + KERNEL_PGD_BOUNDARY, 432 min(KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY)); 433} 434 435void __init native_pagetable_init(void) 436{ 437 unsigned long pfn, va; 438 pgd_t *pgd, *base = swapper_pg_dir; 439 p4d_t *p4d; 440 pud_t *pud; 441 pmd_t *pmd; 442 pte_t *pte; 443 444 /* 445 * Remove any mappings which extend past the end of physical 446 * memory from the boot time page table. 447 * In virtual address space, we should have at least two pages 448 * from VMALLOC_END to pkmap or fixmap according to VMALLOC_END 449 * definition. And max_low_pfn is set to VMALLOC_END physical 450 * address. If initial memory mapping is doing right job, we 451 * should have pte used near max_low_pfn or one pmd is not present. 452 */ 453 for (pfn = max_low_pfn; pfn < 1<<(32-PAGE_SHIFT); pfn++) { 454 va = PAGE_OFFSET + (pfn<<PAGE_SHIFT); 455 pgd = base + pgd_index(va); 456 if (!pgd_present(*pgd)) 457 break; 458 459 p4d = p4d_offset(pgd, va); 460 pud = pud_offset(p4d, va); 461 pmd = pmd_offset(pud, va); 462 if (!pmd_present(*pmd)) 463 break; 464 465 /* should not be large page here */ 466 if (pmd_leaf(*pmd)) { 467 pr_warn("try to clear pte for ram above max_low_pfn: pfn: %lx pmd: %p pmd phys: %lx, but pmd is big page and is not using pte !\n", 468 pfn, pmd, __pa(pmd)); 469 BUG_ON(1); 470 } 471 472 pte = pte_offset_kernel(pmd, va); 473 if (!pte_present(*pte)) 474 break; 475 476 printk(KERN_DEBUG "clearing pte for ram above max_low_pfn: pfn: %lx pmd: %p pmd phys: %lx pte: %p pte phys: %lx\n", 477 pfn, pmd, __pa(pmd), pte, __pa(pte)); 478 pte_clear(NULL, va, pte); 479 } 480 paging_init(); 481} 482 483/* 484 * Build a proper pagetable for the kernel mappings. Up until this 485 * point, we've been running on some set of pagetables constructed by 486 * the boot process. 487 * 488 * This will be a pagetable constructed in arch/x86/kernel/head_32.S. 489 * The root of the pagetable will be swapper_pg_dir. 490 * 491 * In general, pagetable_init() assumes that the pagetable may already 492 * be partially populated, and so it avoids stomping on any existing 493 * mappings. 494 */ 495void __init early_ioremap_page_table_range_init(void) 496{ 497 pgd_t *pgd_base = swapper_pg_dir; 498 unsigned long vaddr, end; 499 500 /* 501 * Fixed mappings, only the page table structure has to be 502 * created - mappings will be set by set_fixmap(): 503 */ 504 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; 505 end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK; 506 page_table_range_init(vaddr, end, pgd_base); 507 early_ioremap_reset(); 508} 509 510static void __init pagetable_init(void) 511{ 512 pgd_t *pgd_base = swapper_pg_dir; 513 514 permanent_kmaps_init(pgd_base); 515} 516 517#define DEFAULT_PTE_MASK ~(_PAGE_NX | _PAGE_GLOBAL) 518/* Bits supported by the hardware: */ 519pteval_t __supported_pte_mask __read_mostly = DEFAULT_PTE_MASK; 520/* Bits allowed in normal kernel mappings: */ 521pteval_t __default_kernel_pte_mask __read_mostly = DEFAULT_PTE_MASK; 522EXPORT_SYMBOL_GPL(__supported_pte_mask); 523/* Used in PAGE_KERNEL_* macros which are reasonably used out-of-tree: */ 524EXPORT_SYMBOL(__default_kernel_pte_mask); 525 526/* user-defined highmem size */ 527static unsigned int highmem_pages = -1; 528 529/* 530 * highmem=size forces highmem to be exactly 'size' bytes. 531 * This works even on boxes that have no highmem otherwise. 532 * This also works to reduce highmem size on bigger boxes. 533 */ 534static int __init parse_highmem(char *arg) 535{ 536 if (!arg) 537 return -EINVAL; 538 539 highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT; 540 return 0; 541} 542early_param("highmem", parse_highmem); 543 544#define MSG_HIGHMEM_TOO_BIG \ 545 "highmem size (%luMB) is bigger than pages available (%luMB)!\n" 546 547#define MSG_LOWMEM_TOO_SMALL \ 548 "highmem size (%luMB) results in <64MB lowmem, ignoring it!\n" 549/* 550 * All of RAM fits into lowmem - but if user wants highmem 551 * artificially via the highmem=x boot parameter then create 552 * it: 553 */ 554static void __init lowmem_pfn_init(void) 555{ 556 /* max_low_pfn is 0, we already have early_res support */ 557 max_low_pfn = max_pfn; 558 559 if (highmem_pages == -1) 560 highmem_pages = 0; 561#ifdef CONFIG_HIGHMEM 562 if (highmem_pages >= max_pfn) { 563 printk(KERN_ERR MSG_HIGHMEM_TOO_BIG, 564 pages_to_mb(highmem_pages), pages_to_mb(max_pfn)); 565 highmem_pages = 0; 566 } 567 if (highmem_pages) { 568 if (max_low_pfn - highmem_pages < 64*1024*1024/PAGE_SIZE) { 569 printk(KERN_ERR MSG_LOWMEM_TOO_SMALL, 570 pages_to_mb(highmem_pages)); 571 highmem_pages = 0; 572 } 573 max_low_pfn -= highmem_pages; 574 } 575#else 576 if (highmem_pages) 577 printk(KERN_ERR "ignoring highmem size on non-highmem kernel!\n"); 578#endif 579} 580 581#define MSG_HIGHMEM_TOO_SMALL \ 582 "only %luMB highmem pages available, ignoring highmem size of %luMB!\n" 583 584#define MSG_HIGHMEM_TRIMMED \ 585 "Warning: only 4GB will be used. Use a HIGHMEM64G enabled kernel!\n" 586/* 587 * We have more RAM than fits into lowmem - we try to put it into 588 * highmem, also taking the highmem=x boot parameter into account: 589 */ 590static void __init highmem_pfn_init(void) 591{ 592 max_low_pfn = MAXMEM_PFN; 593 594 if (highmem_pages == -1) 595 highmem_pages = max_pfn - MAXMEM_PFN; 596 597 if (highmem_pages + MAXMEM_PFN < max_pfn) 598 max_pfn = MAXMEM_PFN + highmem_pages; 599 600 if (highmem_pages + MAXMEM_PFN > max_pfn) { 601 printk(KERN_WARNING MSG_HIGHMEM_TOO_SMALL, 602 pages_to_mb(max_pfn - MAXMEM_PFN), 603 pages_to_mb(highmem_pages)); 604 highmem_pages = 0; 605 } 606#ifndef CONFIG_HIGHMEM 607 /* Maximum memory usable is what is directly addressable */ 608 printk(KERN_WARNING "Warning only %ldMB will be used.\n", MAXMEM>>20); 609 if (max_pfn > MAX_NONPAE_PFN) 610 printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n"); 611 else 612 printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n"); 613 max_pfn = MAXMEM_PFN; 614#else /* !CONFIG_HIGHMEM */ 615#ifndef CONFIG_HIGHMEM64G 616 if (max_pfn > MAX_NONPAE_PFN) { 617 max_pfn = MAX_NONPAE_PFN; 618 printk(KERN_WARNING MSG_HIGHMEM_TRIMMED); 619 } 620#endif /* !CONFIG_HIGHMEM64G */ 621#endif /* !CONFIG_HIGHMEM */ 622} 623 624/* 625 * Determine low and high memory ranges: 626 */ 627void __init find_low_pfn_range(void) 628{ 629 /* it could update max_pfn */ 630 631 if (max_pfn <= MAXMEM_PFN) 632 lowmem_pfn_init(); 633 else 634 highmem_pfn_init(); 635} 636 637#ifndef CONFIG_NUMA 638void __init initmem_init(void) 639{ 640#ifdef CONFIG_HIGHMEM 641 highstart_pfn = highend_pfn = max_pfn; 642 if (max_pfn > max_low_pfn) 643 highstart_pfn = max_low_pfn; 644 printk(KERN_NOTICE "%ldMB HIGHMEM available.\n", 645 pages_to_mb(highend_pfn - highstart_pfn)); 646 high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1; 647#else 648 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1; 649#endif 650 651 memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0); 652 653#ifdef CONFIG_FLATMEM 654 max_mapnr = IS_ENABLED(CONFIG_HIGHMEM) ? highend_pfn : max_low_pfn; 655#endif 656 __vmalloc_start_set = true; 657 658 printk(KERN_NOTICE "%ldMB LOWMEM available.\n", 659 pages_to_mb(max_low_pfn)); 660 661 setup_bootmem_allocator(); 662} 663#endif /* !CONFIG_NUMA */ 664 665void __init setup_bootmem_allocator(void) 666{ 667 printk(KERN_INFO " mapped low ram: 0 - %08lx\n", 668 max_pfn_mapped<<PAGE_SHIFT); 669 printk(KERN_INFO " low ram: 0 - %08lx\n", max_low_pfn<<PAGE_SHIFT); 670} 671 672/* 673 * paging_init() sets up the page tables - note that the first 8MB are 674 * already mapped by head.S. 675 * 676 * This routines also unmaps the page at virtual kernel address 0, so 677 * that we can trap those pesky NULL-reference errors in the kernel. 678 */ 679void __init paging_init(void) 680{ 681 pagetable_init(); 682 683 __flush_tlb_all(); 684 685 /* 686 * NOTE: at this point the bootmem allocator is fully available. 687 */ 688 olpc_dt_build_devicetree(); 689 sparse_init(); 690 zone_sizes_init(); 691} 692 693/* 694 * Test if the WP bit works in supervisor mode. It isn't supported on 386's 695 * and also on some strange 486's. All 586+'s are OK. This used to involve 696 * black magic jumps to work around some nasty CPU bugs, but fortunately the 697 * switch to using exceptions got rid of all that. 698 */ 699static void __init test_wp_bit(void) 700{ 701 char z = 0; 702 703 printk(KERN_INFO "Checking if this processor honours the WP bit even in supervisor mode..."); 704 705 __set_fixmap(FIX_WP_TEST, __pa_symbol(empty_zero_page), PAGE_KERNEL_RO); 706 707 if (copy_to_kernel_nofault((char *)fix_to_virt(FIX_WP_TEST), &z, 1)) { 708 clear_fixmap(FIX_WP_TEST); 709 printk(KERN_CONT "Ok.\n"); 710 return; 711 } 712 713 printk(KERN_CONT "No.\n"); 714 panic("Linux doesn't support CPUs with broken WP."); 715} 716 717void __init mem_init(void) 718{ 719 pci_iommu_alloc(); 720 721#ifdef CONFIG_FLATMEM 722 BUG_ON(!mem_map); 723#endif 724 /* 725 * With CONFIG_DEBUG_PAGEALLOC initialization of highmem pages has to 726 * be done before memblock_free_all(). Memblock use free low memory for 727 * temporary data (see find_range_array()) and for this purpose can use 728 * pages that was already passed to the buddy allocator, hence marked as 729 * not accessible in the page tables when compiled with 730 * CONFIG_DEBUG_PAGEALLOC. Otherwise order of initialization is not 731 * important here. 732 */ 733 set_highmem_pages_init(); 734 735 /* this will put all low memory onto the freelists */ 736 memblock_free_all(); 737 738 after_bootmem = 1; 739 x86_init.hyper.init_after_bootmem(); 740 741 /* 742 * Check boundaries twice: Some fundamental inconsistencies can 743 * be detected at build time already. 744 */ 745#define __FIXADDR_TOP (-PAGE_SIZE) 746#ifdef CONFIG_HIGHMEM 747 BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START); 748 BUILD_BUG_ON(VMALLOC_END > PKMAP_BASE); 749#endif 750#define high_memory (-128UL << 20) 751 BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END); 752#undef high_memory 753#undef __FIXADDR_TOP 754 755#ifdef CONFIG_HIGHMEM 756 BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START); 757 BUG_ON(VMALLOC_END > PKMAP_BASE); 758#endif 759 BUG_ON(VMALLOC_START >= VMALLOC_END); 760 BUG_ON((unsigned long)high_memory > VMALLOC_START); 761 762 test_wp_bit(); 763} 764 765int kernel_set_to_readonly __read_mostly; 766 767static void mark_nxdata_nx(void) 768{ 769 /* 770 * When this called, init has already been executed and released, 771 * so everything past _etext should be NX. 772 */ 773 unsigned long start = PFN_ALIGN(_etext); 774 /* 775 * This comes from is_x86_32_kernel_text upper limit. Also HPAGE where used: 776 */ 777 unsigned long size = (((unsigned long)__init_end + HPAGE_SIZE) & HPAGE_MASK) - start; 778 779 if (__supported_pte_mask & _PAGE_NX) 780 printk(KERN_INFO "NX-protecting the kernel data: %luk\n", size >> 10); 781 set_memory_nx(start, size >> PAGE_SHIFT); 782} 783 784void mark_rodata_ro(void) 785{ 786 unsigned long start = PFN_ALIGN(_text); 787 unsigned long size = (unsigned long)__end_rodata - start; 788 789 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 790 pr_info("Write protecting kernel text and read-only data: %luk\n", 791 size >> 10); 792 793 kernel_set_to_readonly = 1; 794 795#ifdef CONFIG_CPA_DEBUG 796 pr_info("Testing CPA: Reverting %lx-%lx\n", start, start + size); 797 set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT); 798 799 pr_info("Testing CPA: write protecting again\n"); 800 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 801#endif 802 mark_nxdata_nx(); 803} 804