1 /* 2 * linux/arch/arm/mm/mmu.c 3 * 4 * Copyright (C) 1995-2005 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/module.h> 11 #include <linux/kernel.h> 12 #include <linux/errno.h> 13 #include <linux/init.h> 14 #include <linux/bootmem.h> 15 #include <linux/mman.h> 16 #include <linux/nodemask.h> 17 #include <linux/sort.h> 18 19 #include <asm/cputype.h> 20 #include <asm/mach-types.h> 21 #include <asm/sections.h> 22 #include <asm/cachetype.h> 23 #include <asm/setup.h> 24 #include <asm/sizes.h> 25 #include <asm/smp_plat.h> 26 #include <asm/tlb.h> 27 #include <asm/highmem.h> 28 29 #include <asm/mach/arch.h> 30 #include <asm/mach/map.h> 31 32 #include "mm.h" 33 34 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); 35 36 /* 37 * empty_zero_page is a special page that is used for 38 * zero-initialized data and COW. 39 */ 40 struct page *empty_zero_page; 41 EXPORT_SYMBOL(empty_zero_page); 42 43 /* 44 * The pmd table for the upper-most set of pages. 45 */ 46 pmd_t *top_pmd; 47 48 #define CPOLICY_UNCACHED 0 49 #define CPOLICY_BUFFERED 1 50 #define CPOLICY_WRITETHROUGH 2 51 #define CPOLICY_WRITEBACK 3 52 #define CPOLICY_WRITEALLOC 4 53 54 static unsigned int cachepolicy __initdata = CPOLICY_WRITEBACK; 55 static unsigned int ecc_mask __initdata = 0; 56 pgprot_t pgprot_user; 57 pgprot_t pgprot_kernel; 58 59 EXPORT_SYMBOL(pgprot_user); 60 EXPORT_SYMBOL(pgprot_kernel); 61 62 struct cachepolicy { 63 const char policy[16]; 64 unsigned int cr_mask; 65 unsigned int pmd; 66 unsigned int pte; 67 }; 68 69 static struct cachepolicy cache_policies[] __initdata = { 70 { 71 .policy = "uncached", 72 .cr_mask = CR_W|CR_C, 73 .pmd = PMD_SECT_UNCACHED, 74 .pte = L_PTE_MT_UNCACHED, 75 }, { 76 .policy = "buffered", 77 .cr_mask = CR_C, 78 .pmd = PMD_SECT_BUFFERED, 79 .pte = L_PTE_MT_BUFFERABLE, 80 }, { 81 .policy = "writethrough", 82 .cr_mask = 0, 83 .pmd = PMD_SECT_WT, 84 .pte = L_PTE_MT_WRITETHROUGH, 85 }, { 86 .policy = "writeback", 87 .cr_mask = 0, 88 .pmd = PMD_SECT_WB, 89 .pte = L_PTE_MT_WRITEBACK, 90 }, { 91 .policy = "writealloc", 92 .cr_mask = 0, 93 .pmd = PMD_SECT_WBWA, 94 .pte = L_PTE_MT_WRITEALLOC, 95 } 96 }; 97 98 /* 99 * These are useful for identifying cache coherency 100 * problems by allowing the cache or the cache and 101 * writebuffer to be turned off. (Note: the write 102 * buffer should not be on and the cache off). 103 */ 104 static int __init early_cachepolicy(char *p) 105 { 106 int i; 107 108 for (i = 0; i < ARRAY_SIZE(cache_policies); i++) { 109 int len = strlen(cache_policies[i].policy); 110 111 if (memcmp(p, cache_policies[i].policy, len) == 0) { 112 cachepolicy = i; 113 cr_alignment &= ~cache_policies[i].cr_mask; 114 cr_no_alignment &= ~cache_policies[i].cr_mask; 115 break; 116 } 117 } 118 if (i == ARRAY_SIZE(cache_policies)) 119 printk(KERN_ERR "ERROR: unknown or unsupported cache policy\n"); 120 /* 121 * This restriction is partly to do with the way we boot; it is 122 * unpredictable to have memory mapped using two different sets of 123 * memory attributes (shared, type, and cache attribs). We can not 124 * change these attributes once the initial assembly has setup the 125 * page tables. 126 */ 127 if (cpu_architecture() >= CPU_ARCH_ARMv6) { 128 printk(KERN_WARNING "Only cachepolicy=writeback supported on ARMv6 and later\n"); 129 cachepolicy = CPOLICY_WRITEBACK; 130 } 131 flush_cache_all(); 132 set_cr(cr_alignment); 133 return 0; 134 } 135 early_param("cachepolicy", early_cachepolicy); 136 137 static int __init early_nocache(char *__unused) 138 { 139 char *p = "buffered"; 140 printk(KERN_WARNING "nocache is deprecated; use cachepolicy=%s\n", p); 141 early_cachepolicy(p); 142 return 0; 143 } 144 early_param("nocache", early_nocache); 145 146 static int __init early_nowrite(char *__unused) 147 { 148 char *p = "uncached"; 149 printk(KERN_WARNING "nowb is deprecated; use cachepolicy=%s\n", p); 150 early_cachepolicy(p); 151 return 0; 152 } 153 early_param("nowb", early_nowrite); 154 155 static int __init early_ecc(char *p) 156 { 157 if (memcmp(p, "on", 2) == 0) 158 ecc_mask = PMD_PROTECTION; 159 else if (memcmp(p, "off", 3) == 0) 160 ecc_mask = 0; 161 return 0; 162 } 163 early_param("ecc", early_ecc); 164 165 static int __init noalign_setup(char *__unused) 166 { 167 cr_alignment &= ~CR_A; 168 cr_no_alignment &= ~CR_A; 169 set_cr(cr_alignment); 170 return 1; 171 } 172 __setup("noalign", noalign_setup); 173 174 #ifndef CONFIG_SMP 175 void adjust_cr(unsigned long mask, unsigned long set) 176 { 177 unsigned long flags; 178 179 mask &= ~CR_A; 180 181 set &= mask; 182 183 local_irq_save(flags); 184 185 cr_no_alignment = (cr_no_alignment & ~mask) | set; 186 cr_alignment = (cr_alignment & ~mask) | set; 187 188 set_cr((get_cr() & ~mask) | set); 189 190 local_irq_restore(flags); 191 } 192 #endif 193 194 #define PROT_PTE_DEVICE L_PTE_PRESENT|L_PTE_YOUNG|L_PTE_DIRTY|L_PTE_WRITE 195 #define PROT_SECT_DEVICE PMD_TYPE_SECT|PMD_SECT_AP_WRITE 196 197 static struct mem_type mem_types[] = { 198 [MT_DEVICE] = { /* Strongly ordered / ARMv6 shared device */ 199 .prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_SHARED | 200 L_PTE_SHARED, 201 .prot_l1 = PMD_TYPE_TABLE, 202 .prot_sect = PROT_SECT_DEVICE | PMD_SECT_S, 203 .domain = DOMAIN_IO, 204 }, 205 [MT_DEVICE_NONSHARED] = { /* ARMv6 non-shared device */ 206 .prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_NONSHARED, 207 .prot_l1 = PMD_TYPE_TABLE, 208 .prot_sect = PROT_SECT_DEVICE, 209 .domain = DOMAIN_IO, 210 }, 211 [MT_DEVICE_CACHED] = { /* ioremap_cached */ 212 .prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_CACHED, 213 .prot_l1 = PMD_TYPE_TABLE, 214 .prot_sect = PROT_SECT_DEVICE | PMD_SECT_WB, 215 .domain = DOMAIN_IO, 216 }, 217 [MT_DEVICE_WC] = { /* ioremap_wc */ 218 .prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_WC, 219 .prot_l1 = PMD_TYPE_TABLE, 220 .prot_sect = PROT_SECT_DEVICE, 221 .domain = DOMAIN_IO, 222 }, 223 [MT_UNCACHED] = { 224 .prot_pte = PROT_PTE_DEVICE, 225 .prot_l1 = PMD_TYPE_TABLE, 226 .prot_sect = PMD_TYPE_SECT | PMD_SECT_XN, 227 .domain = DOMAIN_IO, 228 }, 229 [MT_CACHECLEAN] = { 230 .prot_sect = PMD_TYPE_SECT | PMD_SECT_XN, 231 .domain = DOMAIN_KERNEL, 232 }, 233 [MT_MINICLEAN] = { 234 .prot_sect = PMD_TYPE_SECT | PMD_SECT_XN | PMD_SECT_MINICACHE, 235 .domain = DOMAIN_KERNEL, 236 }, 237 [MT_LOW_VECTORS] = { 238 .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | 239 L_PTE_EXEC, 240 .prot_l1 = PMD_TYPE_TABLE, 241 .domain = DOMAIN_USER, 242 }, 243 [MT_HIGH_VECTORS] = { 244 .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | 245 L_PTE_USER | L_PTE_EXEC, 246 .prot_l1 = PMD_TYPE_TABLE, 247 .domain = DOMAIN_USER, 248 }, 249 [MT_MEMORY] = { 250 .prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE, 251 .domain = DOMAIN_KERNEL, 252 }, 253 [MT_ROM] = { 254 .prot_sect = PMD_TYPE_SECT, 255 .domain = DOMAIN_KERNEL, 256 }, 257 [MT_MEMORY_NONCACHED] = { 258 .prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE, 259 .domain = DOMAIN_KERNEL, 260 }, 261 }; 262 263 const struct mem_type *get_mem_type(unsigned int type) 264 { 265 return type < ARRAY_SIZE(mem_types) ? &mem_types[type] : NULL; 266 } 267 EXPORT_SYMBOL(get_mem_type); 268 269 /* 270 * Adjust the PMD section entries according to the CPU in use. 271 */ 272 static void __init build_mem_type_table(void) 273 { 274 struct cachepolicy *cp; 275 unsigned int cr = get_cr(); 276 unsigned int user_pgprot, kern_pgprot, vecs_pgprot; 277 int cpu_arch = cpu_architecture(); 278 int i; 279 280 if (cpu_arch < CPU_ARCH_ARMv6) { 281 #if defined(CONFIG_CPU_DCACHE_DISABLE) 282 if (cachepolicy > CPOLICY_BUFFERED) 283 cachepolicy = CPOLICY_BUFFERED; 284 #elif defined(CONFIG_CPU_DCACHE_WRITETHROUGH) 285 if (cachepolicy > CPOLICY_WRITETHROUGH) 286 cachepolicy = CPOLICY_WRITETHROUGH; 287 #endif 288 } 289 if (cpu_arch < CPU_ARCH_ARMv5) { 290 if (cachepolicy >= CPOLICY_WRITEALLOC) 291 cachepolicy = CPOLICY_WRITEBACK; 292 ecc_mask = 0; 293 } 294 #ifdef CONFIG_SMP 295 cachepolicy = CPOLICY_WRITEALLOC; 296 #endif 297 298 /* 299 * Strip out features not present on earlier architectures. 300 * Pre-ARMv5 CPUs don't have TEX bits. Pre-ARMv6 CPUs or those 301 * without extended page tables don't have the 'Shared' bit. 302 */ 303 if (cpu_arch < CPU_ARCH_ARMv5) 304 for (i = 0; i < ARRAY_SIZE(mem_types); i++) 305 mem_types[i].prot_sect &= ~PMD_SECT_TEX(7); 306 if ((cpu_arch < CPU_ARCH_ARMv6 || !(cr & CR_XP)) && !cpu_is_xsc3()) 307 for (i = 0; i < ARRAY_SIZE(mem_types); i++) 308 mem_types[i].prot_sect &= ~PMD_SECT_S; 309 310 /* 311 * ARMv5 and lower, bit 4 must be set for page tables (was: cache 312 * "update-able on write" bit on ARM610). However, Xscale and 313 * Xscale3 require this bit to be cleared. 314 */ 315 if (cpu_is_xscale() || cpu_is_xsc3()) { 316 for (i = 0; i < ARRAY_SIZE(mem_types); i++) { 317 mem_types[i].prot_sect &= ~PMD_BIT4; 318 mem_types[i].prot_l1 &= ~PMD_BIT4; 319 } 320 } else if (cpu_arch < CPU_ARCH_ARMv6) { 321 for (i = 0; i < ARRAY_SIZE(mem_types); i++) { 322 if (mem_types[i].prot_l1) 323 mem_types[i].prot_l1 |= PMD_BIT4; 324 if (mem_types[i].prot_sect) 325 mem_types[i].prot_sect |= PMD_BIT4; 326 } 327 } 328 329 /* 330 * Mark the device areas according to the CPU/architecture. 331 */ 332 if (cpu_is_xsc3() || (cpu_arch >= CPU_ARCH_ARMv6 && (cr & CR_XP))) { 333 if (!cpu_is_xsc3()) { 334 /* 335 * Mark device regions on ARMv6+ as execute-never 336 * to prevent speculative instruction fetches. 337 */ 338 mem_types[MT_DEVICE].prot_sect |= PMD_SECT_XN; 339 mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_XN; 340 mem_types[MT_DEVICE_CACHED].prot_sect |= PMD_SECT_XN; 341 mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_XN; 342 } 343 if (cpu_arch >= CPU_ARCH_ARMv7 && (cr & CR_TRE)) { 344 /* 345 * For ARMv7 with TEX remapping, 346 * - shared device is SXCB=1100 347 * - nonshared device is SXCB=0100 348 * - write combine device mem is SXCB=0001 349 * (Uncached Normal memory) 350 */ 351 mem_types[MT_DEVICE].prot_sect |= PMD_SECT_TEX(1); 352 mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(1); 353 mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_BUFFERABLE; 354 } else if (cpu_is_xsc3()) { 355 /* 356 * For Xscale3, 357 * - shared device is TEXCB=00101 358 * - nonshared device is TEXCB=01000 359 * - write combine device mem is TEXCB=00100 360 * (Inner/Outer Uncacheable in xsc3 parlance) 361 */ 362 mem_types[MT_DEVICE].prot_sect |= PMD_SECT_TEX(1) | PMD_SECT_BUFFERED; 363 mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(2); 364 mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_TEX(1); 365 } else { 366 /* 367 * For ARMv6 and ARMv7 without TEX remapping, 368 * - shared device is TEXCB=00001 369 * - nonshared device is TEXCB=01000 370 * - write combine device mem is TEXCB=00100 371 * (Uncached Normal in ARMv6 parlance). 372 */ 373 mem_types[MT_DEVICE].prot_sect |= PMD_SECT_BUFFERED; 374 mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(2); 375 mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_TEX(1); 376 } 377 } else { 378 /* 379 * On others, write combining is "Uncached/Buffered" 380 */ 381 mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_BUFFERABLE; 382 } 383 384 /* 385 * Now deal with the memory-type mappings 386 */ 387 cp = &cache_policies[cachepolicy]; 388 vecs_pgprot = kern_pgprot = user_pgprot = cp->pte; 389 390 #ifndef CONFIG_SMP 391 /* 392 * Only use write-through for non-SMP systems 393 */ 394 if (cpu_arch >= CPU_ARCH_ARMv5 && cachepolicy > CPOLICY_WRITETHROUGH) 395 vecs_pgprot = cache_policies[CPOLICY_WRITETHROUGH].pte; 396 #endif 397 398 /* 399 * Enable CPU-specific coherency if supported. 400 * (Only available on XSC3 at the moment.) 401 */ 402 if (arch_is_coherent() && cpu_is_xsc3()) 403 mem_types[MT_MEMORY].prot_sect |= PMD_SECT_S; 404 405 /* 406 * ARMv6 and above have extended page tables. 407 */ 408 if (cpu_arch >= CPU_ARCH_ARMv6 && (cr & CR_XP)) { 409 /* 410 * Mark cache clean areas and XIP ROM read only 411 * from SVC mode and no access from userspace. 412 */ 413 mem_types[MT_ROM].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE; 414 mem_types[MT_MINICLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE; 415 mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE; 416 417 #ifdef CONFIG_SMP 418 /* 419 * Mark memory with the "shared" attribute for SMP systems 420 */ 421 user_pgprot |= L_PTE_SHARED; 422 kern_pgprot |= L_PTE_SHARED; 423 vecs_pgprot |= L_PTE_SHARED; 424 mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_S; 425 mem_types[MT_DEVICE_WC].prot_pte |= L_PTE_SHARED; 426 mem_types[MT_DEVICE_CACHED].prot_sect |= PMD_SECT_S; 427 mem_types[MT_DEVICE_CACHED].prot_pte |= L_PTE_SHARED; 428 mem_types[MT_MEMORY].prot_sect |= PMD_SECT_S; 429 mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_S; 430 #endif 431 } 432 433 /* 434 * Non-cacheable Normal - intended for memory areas that must 435 * not cause dirty cache line writebacks when used 436 */ 437 if (cpu_arch >= CPU_ARCH_ARMv6) { 438 if (cpu_arch >= CPU_ARCH_ARMv7 && (cr & CR_TRE)) { 439 /* Non-cacheable Normal is XCB = 001 */ 440 mem_types[MT_MEMORY_NONCACHED].prot_sect |= 441 PMD_SECT_BUFFERED; 442 } else { 443 /* For both ARMv6 and non-TEX-remapping ARMv7 */ 444 mem_types[MT_MEMORY_NONCACHED].prot_sect |= 445 PMD_SECT_TEX(1); 446 } 447 } else { 448 mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_BUFFERABLE; 449 } 450 451 for (i = 0; i < 16; i++) { 452 unsigned long v = pgprot_val(protection_map[i]); 453 protection_map[i] = __pgprot(v | user_pgprot); 454 } 455 456 mem_types[MT_LOW_VECTORS].prot_pte |= vecs_pgprot; 457 mem_types[MT_HIGH_VECTORS].prot_pte |= vecs_pgprot; 458 459 pgprot_user = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | user_pgprot); 460 pgprot_kernel = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | 461 L_PTE_DIRTY | L_PTE_WRITE | kern_pgprot); 462 463 mem_types[MT_LOW_VECTORS].prot_l1 |= ecc_mask; 464 mem_types[MT_HIGH_VECTORS].prot_l1 |= ecc_mask; 465 mem_types[MT_MEMORY].prot_sect |= ecc_mask | cp->pmd; 466 mem_types[MT_ROM].prot_sect |= cp->pmd; 467 468 switch (cp->pmd) { 469 case PMD_SECT_WT: 470 mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_WT; 471 break; 472 case PMD_SECT_WB: 473 case PMD_SECT_WBWA: 474 mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_WB; 475 break; 476 } 477 printk("Memory policy: ECC %sabled, Data cache %s\n", 478 ecc_mask ? "en" : "dis", cp->policy); 479 480 for (i = 0; i < ARRAY_SIZE(mem_types); i++) { 481 struct mem_type *t = &mem_types[i]; 482 if (t->prot_l1) 483 t->prot_l1 |= PMD_DOMAIN(t->domain); 484 if (t->prot_sect) 485 t->prot_sect |= PMD_DOMAIN(t->domain); 486 } 487 } 488 489 #define vectors_base() (vectors_high() ? 0xffff0000 : 0) 490 491 static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr, 492 unsigned long end, unsigned long pfn, 493 const struct mem_type *type) 494 { 495 pte_t *pte; 496 497 if (pmd_none(*pmd)) { 498 pte = alloc_bootmem_low_pages(2 * PTRS_PER_PTE * sizeof(pte_t)); 499 __pmd_populate(pmd, __pa(pte) | type->prot_l1); 500 } 501 502 pte = pte_offset_kernel(pmd, addr); 503 do { 504 set_pte_ext(pte, pfn_pte(pfn, __pgprot(type->prot_pte)), 0); 505 pfn++; 506 } while (pte++, addr += PAGE_SIZE, addr != end); 507 } 508 509 static void __init alloc_init_section(pgd_t *pgd, unsigned long addr, 510 unsigned long end, unsigned long phys, 511 const struct mem_type *type) 512 { 513 pmd_t *pmd = pmd_offset(pgd, addr); 514 515 /* 516 * Try a section mapping - end, addr and phys must all be aligned 517 * to a section boundary. Note that PMDs refer to the individual 518 * L1 entries, whereas PGDs refer to a group of L1 entries making 519 * up one logical pointer to an L2 table. 520 */ 521 if (((addr | end | phys) & ~SECTION_MASK) == 0) { 522 pmd_t *p = pmd; 523 524 if (addr & SECTION_SIZE) 525 pmd++; 526 527 do { 528 *pmd = __pmd(phys | type->prot_sect); 529 phys += SECTION_SIZE; 530 } while (pmd++, addr += SECTION_SIZE, addr != end); 531 532 flush_pmd_entry(p); 533 } else { 534 /* 535 * No need to loop; pte's aren't interested in the 536 * individual L1 entries. 537 */ 538 alloc_init_pte(pmd, addr, end, __phys_to_pfn(phys), type); 539 } 540 } 541 542 static void __init create_36bit_mapping(struct map_desc *md, 543 const struct mem_type *type) 544 { 545 unsigned long phys, addr, length, end; 546 pgd_t *pgd; 547 548 addr = md->virtual; 549 phys = (unsigned long)__pfn_to_phys(md->pfn); 550 length = PAGE_ALIGN(md->length); 551 552 if (!(cpu_architecture() >= CPU_ARCH_ARMv6 || cpu_is_xsc3())) { 553 printk(KERN_ERR "MM: CPU does not support supersection " 554 "mapping for 0x%08llx at 0x%08lx\n", 555 __pfn_to_phys((u64)md->pfn), addr); 556 return; 557 } 558 559 /* N.B. ARMv6 supersections are only defined to work with domain 0. 560 * Since domain assignments can in fact be arbitrary, the 561 * 'domain == 0' check below is required to insure that ARMv6 562 * supersections are only allocated for domain 0 regardless 563 * of the actual domain assignments in use. 564 */ 565 if (type->domain) { 566 printk(KERN_ERR "MM: invalid domain in supersection " 567 "mapping for 0x%08llx at 0x%08lx\n", 568 __pfn_to_phys((u64)md->pfn), addr); 569 return; 570 } 571 572 if ((addr | length | __pfn_to_phys(md->pfn)) & ~SUPERSECTION_MASK) { 573 printk(KERN_ERR "MM: cannot create mapping for " 574 "0x%08llx at 0x%08lx invalid alignment\n", 575 __pfn_to_phys((u64)md->pfn), addr); 576 return; 577 } 578 579 /* 580 * Shift bits [35:32] of address into bits [23:20] of PMD 581 * (See ARMv6 spec). 582 */ 583 phys |= (((md->pfn >> (32 - PAGE_SHIFT)) & 0xF) << 20); 584 585 pgd = pgd_offset_k(addr); 586 end = addr + length; 587 do { 588 pmd_t *pmd = pmd_offset(pgd, addr); 589 int i; 590 591 for (i = 0; i < 16; i++) 592 *pmd++ = __pmd(phys | type->prot_sect | PMD_SECT_SUPER); 593 594 addr += SUPERSECTION_SIZE; 595 phys += SUPERSECTION_SIZE; 596 pgd += SUPERSECTION_SIZE >> PGDIR_SHIFT; 597 } while (addr != end); 598 } 599 600 /* 601 * Create the page directory entries and any necessary 602 * page tables for the mapping specified by `md'. We 603 * are able to cope here with varying sizes and address 604 * offsets, and we take full advantage of sections and 605 * supersections. 606 */ 607 static void __init create_mapping(struct map_desc *md) 608 { 609 unsigned long phys, addr, length, end; 610 const struct mem_type *type; 611 pgd_t *pgd; 612 613 if (md->virtual != vectors_base() && md->virtual < TASK_SIZE) { 614 printk(KERN_WARNING "BUG: not creating mapping for " 615 "0x%08llx at 0x%08lx in user region\n", 616 __pfn_to_phys((u64)md->pfn), md->virtual); 617 return; 618 } 619 620 if ((md->type == MT_DEVICE || md->type == MT_ROM) && 621 md->virtual >= PAGE_OFFSET && md->virtual < VMALLOC_END) { 622 printk(KERN_WARNING "BUG: mapping for 0x%08llx at 0x%08lx " 623 "overlaps vmalloc space\n", 624 __pfn_to_phys((u64)md->pfn), md->virtual); 625 } 626 627 type = &mem_types[md->type]; 628 629 /* 630 * Catch 36-bit addresses 631 */ 632 if (md->pfn >= 0x100000) { 633 create_36bit_mapping(md, type); 634 return; 635 } 636 637 addr = md->virtual & PAGE_MASK; 638 phys = (unsigned long)__pfn_to_phys(md->pfn); 639 length = PAGE_ALIGN(md->length + (md->virtual & ~PAGE_MASK)); 640 641 if (type->prot_l1 == 0 && ((addr | phys | length) & ~SECTION_MASK)) { 642 printk(KERN_WARNING "BUG: map for 0x%08lx at 0x%08lx can not " 643 "be mapped using pages, ignoring.\n", 644 __pfn_to_phys(md->pfn), addr); 645 return; 646 } 647 648 pgd = pgd_offset_k(addr); 649 end = addr + length; 650 do { 651 unsigned long next = pgd_addr_end(addr, end); 652 653 alloc_init_section(pgd, addr, next, phys, type); 654 655 phys += next - addr; 656 addr = next; 657 } while (pgd++, addr != end); 658 } 659 660 /* 661 * Create the architecture specific mappings 662 */ 663 void __init iotable_init(struct map_desc *io_desc, int nr) 664 { 665 int i; 666 667 for (i = 0; i < nr; i++) 668 create_mapping(io_desc + i); 669 } 670 671 static void * __initdata vmalloc_min = (void *)(VMALLOC_END - SZ_128M); 672 673 /* 674 * vmalloc=size forces the vmalloc area to be exactly 'size' 675 * bytes. This can be used to increase (or decrease) the vmalloc 676 * area - the default is 128m. 677 */ 678 static int __init early_vmalloc(char *arg) 679 { 680 unsigned long vmalloc_reserve = memparse(arg, NULL); 681 682 if (vmalloc_reserve < SZ_16M) { 683 vmalloc_reserve = SZ_16M; 684 printk(KERN_WARNING 685 "vmalloc area too small, limiting to %luMB\n", 686 vmalloc_reserve >> 20); 687 } 688 689 if (vmalloc_reserve > VMALLOC_END - (PAGE_OFFSET + SZ_32M)) { 690 vmalloc_reserve = VMALLOC_END - (PAGE_OFFSET + SZ_32M); 691 printk(KERN_WARNING 692 "vmalloc area is too big, limiting to %luMB\n", 693 vmalloc_reserve >> 20); 694 } 695 696 vmalloc_min = (void *)(VMALLOC_END - vmalloc_reserve); 697 return 0; 698 } 699 early_param("vmalloc", early_vmalloc); 700 701 static void __init sanity_check_meminfo(void) 702 { 703 int i, j, highmem = 0; 704 705 for (i = 0, j = 0; i < meminfo.nr_banks; i++) { 706 struct membank *bank = &meminfo.bank[j]; 707 *bank = meminfo.bank[i]; 708 709 #ifdef CONFIG_HIGHMEM 710 if (__va(bank->start) > vmalloc_min || 711 __va(bank->start) < (void *)PAGE_OFFSET) 712 highmem = 1; 713 714 bank->highmem = highmem; 715 716 /* 717 * Split those memory banks which are partially overlapping 718 * the vmalloc area greatly simplifying things later. 719 */ 720 if (__va(bank->start) < vmalloc_min && 721 bank->size > vmalloc_min - __va(bank->start)) { 722 if (meminfo.nr_banks >= NR_BANKS) { 723 printk(KERN_CRIT "NR_BANKS too low, " 724 "ignoring high memory\n"); 725 } else { 726 memmove(bank + 1, bank, 727 (meminfo.nr_banks - i) * sizeof(*bank)); 728 meminfo.nr_banks++; 729 i++; 730 bank[1].size -= vmalloc_min - __va(bank->start); 731 bank[1].start = __pa(vmalloc_min - 1) + 1; 732 bank[1].highmem = highmem = 1; 733 j++; 734 } 735 bank->size = vmalloc_min - __va(bank->start); 736 } 737 #else 738 bank->highmem = highmem; 739 740 /* 741 * Check whether this memory bank would entirely overlap 742 * the vmalloc area. 743 */ 744 if (__va(bank->start) >= vmalloc_min || 745 __va(bank->start) < (void *)PAGE_OFFSET) { 746 printk(KERN_NOTICE "Ignoring RAM at %.8lx-%.8lx " 747 "(vmalloc region overlap).\n", 748 bank->start, bank->start + bank->size - 1); 749 continue; 750 } 751 752 /* 753 * Check whether this memory bank would partially overlap 754 * the vmalloc area. 755 */ 756 if (__va(bank->start + bank->size) > vmalloc_min || 757 __va(bank->start + bank->size) < __va(bank->start)) { 758 unsigned long newsize = vmalloc_min - __va(bank->start); 759 printk(KERN_NOTICE "Truncating RAM at %.8lx-%.8lx " 760 "to -%.8lx (vmalloc region overlap).\n", 761 bank->start, bank->start + bank->size - 1, 762 bank->start + newsize - 1); 763 bank->size = newsize; 764 } 765 #endif 766 j++; 767 } 768 #ifdef CONFIG_HIGHMEM 769 if (highmem) { 770 const char *reason = NULL; 771 772 if (cache_is_vipt_aliasing()) { 773 /* 774 * Interactions between kmap and other mappings 775 * make highmem support with aliasing VIPT caches 776 * rather difficult. 777 */ 778 reason = "with VIPT aliasing cache"; 779 #ifdef CONFIG_SMP 780 } else if (tlb_ops_need_broadcast()) { 781 /* 782 * kmap_high needs to occasionally flush TLB entries, 783 * however, if the TLB entries need to be broadcast 784 * we may deadlock: 785 * kmap_high(irqs off)->flush_all_zero_pkmaps-> 786 * flush_tlb_kernel_range->smp_call_function_many 787 * (must not be called with irqs off) 788 */ 789 reason = "without hardware TLB ops broadcasting"; 790 #endif 791 } 792 if (reason) { 793 printk(KERN_CRIT "HIGHMEM is not supported %s, ignoring high memory\n", 794 reason); 795 while (j > 0 && meminfo.bank[j - 1].highmem) 796 j--; 797 } 798 } 799 #endif 800 meminfo.nr_banks = j; 801 } 802 803 static inline void prepare_page_table(void) 804 { 805 unsigned long addr; 806 807 /* 808 * Clear out all the mappings below the kernel image. 809 */ 810 for (addr = 0; addr < MODULES_VADDR; addr += PGDIR_SIZE) 811 pmd_clear(pmd_off_k(addr)); 812 813 #ifdef CONFIG_XIP_KERNEL 814 /* The XIP kernel is mapped in the module area -- skip over it */ 815 addr = ((unsigned long)_etext + PGDIR_SIZE - 1) & PGDIR_MASK; 816 #endif 817 for ( ; addr < PAGE_OFFSET; addr += PGDIR_SIZE) 818 pmd_clear(pmd_off_k(addr)); 819 820 /* 821 * Clear out all the kernel space mappings, except for the first 822 * memory bank, up to the end of the vmalloc region. 823 */ 824 for (addr = __phys_to_virt(bank_phys_end(&meminfo.bank[0])); 825 addr < VMALLOC_END; addr += PGDIR_SIZE) 826 pmd_clear(pmd_off_k(addr)); 827 } 828 829 /* 830 * Reserve the various regions 831 */ 832 void __init reserve_special_regions(void) 833 { 834 unsigned long res_size = 0; 835 836 /* 837 * Register the kernel text and data with bootmem. 838 * Note that this can only be in node 0. 839 */ 840 #ifdef CONFIG_XIP_KERNEL 841 reserve_bootmem(__pa(_data), _end - _data, BOOTMEM_DEFAULT); 842 #else 843 reserve_bootmem(__pa(_stext), _end - _stext, BOOTMEM_DEFAULT); 844 #endif 845 846 /* 847 * Reserve the page tables. These are already in use, 848 * and can only be in node 0. 849 */ 850 reserve_bootmem(__pa(swapper_pg_dir), 851 PTRS_PER_PGD * sizeof(pgd_t), BOOTMEM_DEFAULT); 852 853 /* 854 * Hmm... This should go elsewhere, but we really really need to 855 * stop things allocating the low memory; ideally we need a better 856 * implementation of GFP_DMA which does not assume that DMA-able 857 * memory starts at zero. 858 */ 859 if (machine_is_integrator() || machine_is_cintegrator()) 860 res_size = __pa(swapper_pg_dir) - PHYS_OFFSET; 861 862 /* 863 * These should likewise go elsewhere. They pre-reserve the 864 * screen memory region at the start of main system memory. 865 */ 866 if (machine_is_edb7211()) 867 res_size = 0x00020000; 868 if (machine_is_p720t()) 869 res_size = 0x00014000; 870 871 /* H1940, RX3715 and RX1950 need to reserve this for suspend */ 872 873 if (machine_is_h1940() || machine_is_rx3715() 874 || machine_is_rx1950()) { 875 reserve_bootmem(0x30003000, 0x1000, BOOTMEM_DEFAULT); 876 reserve_bootmem(0x30081000, 0x1000, BOOTMEM_DEFAULT); 877 } 878 879 if (machine_is_palmld() || machine_is_palmtx()) { 880 reserve_bootmem(0xa0000000, 0x1000, BOOTMEM_EXCLUSIVE); 881 reserve_bootmem(0xa0200000, 0x1000, BOOTMEM_EXCLUSIVE); 882 } 883 884 if (machine_is_treo680() || machine_is_centro()) { 885 reserve_bootmem(0xa0000000, 0x1000, BOOTMEM_EXCLUSIVE); 886 reserve_bootmem(0xa2000000, 0x1000, BOOTMEM_EXCLUSIVE); 887 } 888 889 if (machine_is_palmt5()) 890 reserve_bootmem(0xa0200000, 0x1000, BOOTMEM_EXCLUSIVE); 891 892 /* 893 * U300 - This platform family can share physical memory 894 * between two ARM cpus, one running Linux and the other 895 * running another OS. 896 */ 897 if (machine_is_u300()) { 898 #ifdef CONFIG_MACH_U300_SINGLE_RAM 899 #if ((CONFIG_MACH_U300_ACCESS_MEM_SIZE & 1) == 1) && \ 900 CONFIG_MACH_U300_2MB_ALIGNMENT_FIX 901 res_size = 0x00100000; 902 #endif 903 #endif 904 } 905 906 #ifdef CONFIG_SA1111 907 /* 908 * Because of the SA1111 DMA bug, we want to preserve our 909 * precious DMA-able memory... 910 */ 911 res_size = __pa(swapper_pg_dir) - PHYS_OFFSET; 912 #endif 913 if (res_size) 914 reserve_bootmem(PHYS_OFFSET, res_size, BOOTMEM_DEFAULT); 915 } 916 917 /* 918 * Set up device the mappings. Since we clear out the page tables for all 919 * mappings above VMALLOC_END, we will remove any debug device mappings. 920 * This means you have to be careful how you debug this function, or any 921 * called function. This means you can't use any function or debugging 922 * method which may touch any device, otherwise the kernel _will_ crash. 923 */ 924 static void __init devicemaps_init(struct machine_desc *mdesc) 925 { 926 struct map_desc map; 927 unsigned long addr; 928 void *vectors; 929 930 /* 931 * Allocate the vector page early. 932 */ 933 vectors = alloc_bootmem_low_pages(PAGE_SIZE); 934 935 for (addr = VMALLOC_END; addr; addr += PGDIR_SIZE) 936 pmd_clear(pmd_off_k(addr)); 937 938 /* 939 * Map the kernel if it is XIP. 940 * It is always first in the modulearea. 941 */ 942 #ifdef CONFIG_XIP_KERNEL 943 map.pfn = __phys_to_pfn(CONFIG_XIP_PHYS_ADDR & SECTION_MASK); 944 map.virtual = MODULES_VADDR; 945 map.length = ((unsigned long)_etext - map.virtual + ~SECTION_MASK) & SECTION_MASK; 946 map.type = MT_ROM; 947 create_mapping(&map); 948 #endif 949 950 /* 951 * Map the cache flushing regions. 952 */ 953 #ifdef FLUSH_BASE 954 map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS); 955 map.virtual = FLUSH_BASE; 956 map.length = SZ_1M; 957 map.type = MT_CACHECLEAN; 958 create_mapping(&map); 959 #endif 960 #ifdef FLUSH_BASE_MINICACHE 961 map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS + SZ_1M); 962 map.virtual = FLUSH_BASE_MINICACHE; 963 map.length = SZ_1M; 964 map.type = MT_MINICLEAN; 965 create_mapping(&map); 966 #endif 967 968 /* 969 * Create a mapping for the machine vectors at the high-vectors 970 * location (0xffff0000). If we aren't using high-vectors, also 971 * create a mapping at the low-vectors virtual address. 972 */ 973 map.pfn = __phys_to_pfn(virt_to_phys(vectors)); 974 map.virtual = 0xffff0000; 975 map.length = PAGE_SIZE; 976 map.type = MT_HIGH_VECTORS; 977 create_mapping(&map); 978 979 if (!vectors_high()) { 980 map.virtual = 0; 981 map.type = MT_LOW_VECTORS; 982 create_mapping(&map); 983 } 984 985 /* 986 * Ask the machine support to map in the statically mapped devices. 987 */ 988 if (mdesc->map_io) 989 mdesc->map_io(); 990 991 /* 992 * Finally flush the caches and tlb to ensure that we're in a 993 * consistent state wrt the writebuffer. This also ensures that 994 * any write-allocated cache lines in the vector page are written 995 * back. After this point, we can start to touch devices again. 996 */ 997 local_flush_tlb_all(); 998 flush_cache_all(); 999 } 1000 1001 static void __init kmap_init(void) 1002 { 1003 #ifdef CONFIG_HIGHMEM 1004 pmd_t *pmd = pmd_off_k(PKMAP_BASE); 1005 pte_t *pte = alloc_bootmem_low_pages(2 * PTRS_PER_PTE * sizeof(pte_t)); 1006 BUG_ON(!pmd_none(*pmd) || !pte); 1007 __pmd_populate(pmd, __pa(pte) | _PAGE_KERNEL_TABLE); 1008 pkmap_page_table = pte + PTRS_PER_PTE; 1009 #endif 1010 } 1011 1012 static inline void map_memory_bank(struct membank *bank) 1013 { 1014 struct map_desc map; 1015 1016 map.pfn = bank_pfn_start(bank); 1017 map.virtual = __phys_to_virt(bank_phys_start(bank)); 1018 map.length = bank_phys_size(bank); 1019 map.type = MT_MEMORY; 1020 1021 create_mapping(&map); 1022 } 1023 1024 static void __init map_lowmem(void) 1025 { 1026 struct meminfo *mi = &meminfo; 1027 int i; 1028 1029 /* Map all the lowmem memory banks. */ 1030 for (i = 0; i < mi->nr_banks; i++) { 1031 struct membank *bank = &mi->bank[i]; 1032 1033 if (!bank->highmem) 1034 map_memory_bank(bank); 1035 } 1036 } 1037 1038 static int __init meminfo_cmp(const void *_a, const void *_b) 1039 { 1040 const struct membank *a = _a, *b = _b; 1041 long cmp = bank_pfn_start(a) - bank_pfn_start(b); 1042 return cmp < 0 ? -1 : cmp > 0 ? 1 : 0; 1043 } 1044 1045 /* 1046 * paging_init() sets up the page tables, initialises the zone memory 1047 * maps, and sets up the zero page, bad page and bad page tables. 1048 */ 1049 void __init paging_init(struct machine_desc *mdesc) 1050 { 1051 void *zero_page; 1052 1053 sort(&meminfo.bank, meminfo.nr_banks, sizeof(meminfo.bank[0]), meminfo_cmp, NULL); 1054 1055 build_mem_type_table(); 1056 sanity_check_meminfo(); 1057 prepare_page_table(); 1058 map_lowmem(); 1059 bootmem_init(); 1060 devicemaps_init(mdesc); 1061 kmap_init(); 1062 1063 top_pmd = pmd_off_k(0xffff0000); 1064 1065 /* 1066 * allocate the zero page. Note that this always succeeds and 1067 * returns a zeroed result. 1068 */ 1069 zero_page = alloc_bootmem_low_pages(PAGE_SIZE); 1070 empty_zero_page = virt_to_page(zero_page); 1071 __flush_dcache_page(NULL, empty_zero_page); 1072 } 1073 1074 /* 1075 * In order to soft-boot, we need to insert a 1:1 mapping in place of 1076 * the user-mode pages. This will then ensure that we have predictable 1077 * results when turning the mmu off 1078 */ 1079 void setup_mm_for_reboot(char mode) 1080 { 1081 unsigned long base_pmdval; 1082 pgd_t *pgd; 1083 int i; 1084 1085 /* 1086 * We need to access to user-mode page tables here. For kernel threads 1087 * we don't have any user-mode mappings so we use the context that we 1088 * "borrowed". 1089 */ 1090 pgd = current->active_mm->pgd; 1091 1092 base_pmdval = PMD_SECT_AP_WRITE | PMD_SECT_AP_READ | PMD_TYPE_SECT; 1093 if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale()) 1094 base_pmdval |= PMD_BIT4; 1095 1096 for (i = 0; i < FIRST_USER_PGD_NR + USER_PTRS_PER_PGD; i++, pgd++) { 1097 unsigned long pmdval = (i << PGDIR_SHIFT) | base_pmdval; 1098 pmd_t *pmd; 1099 1100 pmd = pmd_off(pgd, i << PGDIR_SHIFT); 1101 pmd[0] = __pmd(pmdval); 1102 pmd[1] = __pmd(pmdval + (1 << (PGDIR_SHIFT - 1))); 1103 flush_pmd_entry(pmd); 1104 } 1105 1106 local_flush_tlb_all(); 1107 } 1108