1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/arch/arm/mm/mmu.c 4 * 5 * Copyright (C) 1995-2005 Russell King 6 */ 7 #include <linux/module.h> 8 #include <linux/kernel.h> 9 #include <linux/errno.h> 10 #include <linux/init.h> 11 #include <linux/mman.h> 12 #include <linux/nodemask.h> 13 #include <linux/memblock.h> 14 #include <linux/fs.h> 15 #include <linux/vmalloc.h> 16 #include <linux/sizes.h> 17 18 #include <asm/cp15.h> 19 #include <asm/cputype.h> 20 #include <asm/cachetype.h> 21 #include <asm/sections.h> 22 #include <asm/setup.h> 23 #include <asm/smp_plat.h> 24 #include <asm/tlb.h> 25 #include <asm/highmem.h> 26 #include <asm/system_info.h> 27 #include <asm/traps.h> 28 #include <asm/procinfo.h> 29 #include <asm/memory.h> 30 #include <asm/pgalloc.h> 31 #include <asm/kasan_def.h> 32 33 #include <asm/mach/arch.h> 34 #include <asm/mach/map.h> 35 #include <asm/mach/pci.h> 36 #include <asm/fixmap.h> 37 38 #include "fault.h" 39 #include "mm.h" 40 #include "tcm.h" 41 42 extern unsigned long __atags_pointer; 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 EXPORT_SYMBOL(empty_zero_page); 50 51 /* 52 * The pmd table for the upper-most set of pages. 53 */ 54 pmd_t *top_pmd; 55 56 pmdval_t user_pmd_table = _PAGE_USER_TABLE; 57 58 #define CPOLICY_UNCACHED 0 59 #define CPOLICY_BUFFERED 1 60 #define CPOLICY_WRITETHROUGH 2 61 #define CPOLICY_WRITEBACK 3 62 #define CPOLICY_WRITEALLOC 4 63 64 static unsigned int cachepolicy __initdata = CPOLICY_WRITEBACK; 65 static unsigned int ecc_mask __initdata = 0; 66 pgprot_t pgprot_user; 67 pgprot_t pgprot_kernel; 68 69 EXPORT_SYMBOL(pgprot_user); 70 EXPORT_SYMBOL(pgprot_kernel); 71 72 struct cachepolicy { 73 const char policy[16]; 74 unsigned int cr_mask; 75 pmdval_t pmd; 76 pteval_t pte; 77 }; 78 79 static struct cachepolicy cache_policies[] __initdata = { 80 { 81 .policy = "uncached", 82 .cr_mask = CR_W|CR_C, 83 .pmd = PMD_SECT_UNCACHED, 84 .pte = L_PTE_MT_UNCACHED, 85 }, { 86 .policy = "buffered", 87 .cr_mask = CR_C, 88 .pmd = PMD_SECT_BUFFERED, 89 .pte = L_PTE_MT_BUFFERABLE, 90 }, { 91 .policy = "writethrough", 92 .cr_mask = 0, 93 .pmd = PMD_SECT_WT, 94 .pte = L_PTE_MT_WRITETHROUGH, 95 }, { 96 .policy = "writeback", 97 .cr_mask = 0, 98 .pmd = PMD_SECT_WB, 99 .pte = L_PTE_MT_WRITEBACK, 100 }, { 101 .policy = "writealloc", 102 .cr_mask = 0, 103 .pmd = PMD_SECT_WBWA, 104 .pte = L_PTE_MT_WRITEALLOC, 105 } 106 }; 107 108 #ifdef CONFIG_CPU_CP15 109 static unsigned long initial_pmd_value __initdata = 0; 110 111 /* 112 * Initialise the cache_policy variable with the initial state specified 113 * via the "pmd" value. This is used to ensure that on ARMv6 and later, 114 * the C code sets the page tables up with the same policy as the head 115 * assembly code, which avoids an illegal state where the TLBs can get 116 * confused. See comments in early_cachepolicy() for more information. 117 */ 118 void __init init_default_cache_policy(unsigned long pmd) 119 { 120 int i; 121 122 initial_pmd_value = pmd; 123 124 pmd &= PMD_SECT_CACHE_MASK; 125 126 for (i = 0; i < ARRAY_SIZE(cache_policies); i++) 127 if (cache_policies[i].pmd == pmd) { 128 cachepolicy = i; 129 break; 130 } 131 132 if (i == ARRAY_SIZE(cache_policies)) 133 pr_err("ERROR: could not find cache policy\n"); 134 } 135 136 /* 137 * These are useful for identifying cache coherency problems by allowing 138 * the cache or the cache and writebuffer to be turned off. (Note: the 139 * write buffer should not be on and the cache off). 140 */ 141 static int __init early_cachepolicy(char *p) 142 { 143 int i, selected = -1; 144 145 for (i = 0; i < ARRAY_SIZE(cache_policies); i++) { 146 int len = strlen(cache_policies[i].policy); 147 148 if (memcmp(p, cache_policies[i].policy, len) == 0) { 149 selected = i; 150 break; 151 } 152 } 153 154 if (selected == -1) 155 pr_err("ERROR: unknown or unsupported cache policy\n"); 156 157 /* 158 * This restriction is partly to do with the way we boot; it is 159 * unpredictable to have memory mapped using two different sets of 160 * memory attributes (shared, type, and cache attribs). We can not 161 * change these attributes once the initial assembly has setup the 162 * page tables. 163 */ 164 if (cpu_architecture() >= CPU_ARCH_ARMv6 && selected != cachepolicy) { 165 pr_warn("Only cachepolicy=%s supported on ARMv6 and later\n", 166 cache_policies[cachepolicy].policy); 167 return 0; 168 } 169 170 if (selected != cachepolicy) { 171 unsigned long cr = __clear_cr(cache_policies[selected].cr_mask); 172 cachepolicy = selected; 173 flush_cache_all(); 174 set_cr(cr); 175 } 176 return 0; 177 } 178 early_param("cachepolicy", early_cachepolicy); 179 180 static int __init early_nocache(char *__unused) 181 { 182 char *p = "buffered"; 183 pr_warn("nocache is deprecated; use cachepolicy=%s\n", p); 184 early_cachepolicy(p); 185 return 0; 186 } 187 early_param("nocache", early_nocache); 188 189 static int __init early_nowrite(char *__unused) 190 { 191 char *p = "uncached"; 192 pr_warn("nowb is deprecated; use cachepolicy=%s\n", p); 193 early_cachepolicy(p); 194 return 0; 195 } 196 early_param("nowb", early_nowrite); 197 198 #ifndef CONFIG_ARM_LPAE 199 static int __init early_ecc(char *p) 200 { 201 if (memcmp(p, "on", 2) == 0) 202 ecc_mask = PMD_PROTECTION; 203 else if (memcmp(p, "off", 3) == 0) 204 ecc_mask = 0; 205 return 0; 206 } 207 early_param("ecc", early_ecc); 208 #endif 209 210 #else /* ifdef CONFIG_CPU_CP15 */ 211 212 static int __init early_cachepolicy(char *p) 213 { 214 pr_warn("cachepolicy kernel parameter not supported without cp15\n"); 215 return 0; 216 } 217 early_param("cachepolicy", early_cachepolicy); 218 219 static int __init noalign_setup(char *__unused) 220 { 221 pr_warn("noalign kernel parameter not supported without cp15\n"); 222 return 1; 223 } 224 __setup("noalign", noalign_setup); 225 226 #endif /* ifdef CONFIG_CPU_CP15 / else */ 227 228 #define PROT_PTE_DEVICE L_PTE_PRESENT|L_PTE_YOUNG|L_PTE_DIRTY|L_PTE_XN 229 #define PROT_PTE_S2_DEVICE PROT_PTE_DEVICE 230 #define PROT_SECT_DEVICE PMD_TYPE_SECT|PMD_SECT_AP_WRITE 231 232 static struct mem_type mem_types[] __ro_after_init = { 233 [MT_DEVICE] = { /* Strongly ordered / ARMv6 shared device */ 234 .prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_SHARED | 235 L_PTE_SHARED, 236 .prot_l1 = PMD_TYPE_TABLE, 237 .prot_sect = PROT_SECT_DEVICE | PMD_SECT_S, 238 .domain = DOMAIN_IO, 239 }, 240 [MT_DEVICE_NONSHARED] = { /* ARMv6 non-shared device */ 241 .prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_NONSHARED, 242 .prot_l1 = PMD_TYPE_TABLE, 243 .prot_sect = PROT_SECT_DEVICE, 244 .domain = DOMAIN_IO, 245 }, 246 [MT_DEVICE_CACHED] = { /* ioremap_cache */ 247 .prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_CACHED, 248 .prot_l1 = PMD_TYPE_TABLE, 249 .prot_sect = PROT_SECT_DEVICE | PMD_SECT_WB, 250 .domain = DOMAIN_IO, 251 }, 252 [MT_DEVICE_WC] = { /* ioremap_wc */ 253 .prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_WC, 254 .prot_l1 = PMD_TYPE_TABLE, 255 .prot_sect = PROT_SECT_DEVICE, 256 .domain = DOMAIN_IO, 257 }, 258 [MT_UNCACHED] = { 259 .prot_pte = PROT_PTE_DEVICE, 260 .prot_l1 = PMD_TYPE_TABLE, 261 .prot_sect = PMD_TYPE_SECT | PMD_SECT_XN, 262 .domain = DOMAIN_IO, 263 }, 264 [MT_CACHECLEAN] = { 265 .prot_sect = PMD_TYPE_SECT | PMD_SECT_XN, 266 .domain = DOMAIN_KERNEL, 267 }, 268 #ifndef CONFIG_ARM_LPAE 269 [MT_MINICLEAN] = { 270 .prot_sect = PMD_TYPE_SECT | PMD_SECT_XN | PMD_SECT_MINICACHE, 271 .domain = DOMAIN_KERNEL, 272 }, 273 #endif 274 [MT_LOW_VECTORS] = { 275 .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | 276 L_PTE_RDONLY, 277 .prot_l1 = PMD_TYPE_TABLE, 278 .domain = DOMAIN_VECTORS, 279 }, 280 [MT_HIGH_VECTORS] = { 281 .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | 282 L_PTE_USER | L_PTE_RDONLY, 283 .prot_l1 = PMD_TYPE_TABLE, 284 .domain = DOMAIN_VECTORS, 285 }, 286 [MT_MEMORY_RWX] = { 287 .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY, 288 .prot_l1 = PMD_TYPE_TABLE, 289 .prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE, 290 .domain = DOMAIN_KERNEL, 291 }, 292 [MT_MEMORY_RW] = { 293 .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | 294 L_PTE_XN, 295 .prot_l1 = PMD_TYPE_TABLE, 296 .prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE, 297 .domain = DOMAIN_KERNEL, 298 }, 299 [MT_MEMORY_RO] = { 300 .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | 301 L_PTE_XN | L_PTE_RDONLY, 302 .prot_l1 = PMD_TYPE_TABLE, 303 #ifdef CONFIG_ARM_LPAE 304 .prot_sect = PMD_TYPE_SECT | L_PMD_SECT_RDONLY | PMD_SECT_AP2, 305 #else 306 .prot_sect = PMD_TYPE_SECT, 307 #endif 308 .domain = DOMAIN_KERNEL, 309 }, 310 [MT_ROM] = { 311 .prot_sect = PMD_TYPE_SECT, 312 .domain = DOMAIN_KERNEL, 313 }, 314 [MT_MEMORY_RWX_NONCACHED] = { 315 .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | 316 L_PTE_MT_BUFFERABLE, 317 .prot_l1 = PMD_TYPE_TABLE, 318 .prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE, 319 .domain = DOMAIN_KERNEL, 320 }, 321 [MT_MEMORY_RW_DTCM] = { 322 .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | 323 L_PTE_XN, 324 .prot_l1 = PMD_TYPE_TABLE, 325 .prot_sect = PMD_TYPE_SECT | PMD_SECT_XN, 326 .domain = DOMAIN_KERNEL, 327 }, 328 [MT_MEMORY_RWX_ITCM] = { 329 .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY, 330 .prot_l1 = PMD_TYPE_TABLE, 331 .domain = DOMAIN_KERNEL, 332 }, 333 [MT_MEMORY_RW_SO] = { 334 .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | 335 L_PTE_MT_UNCACHED | L_PTE_XN, 336 .prot_l1 = PMD_TYPE_TABLE, 337 .prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_S | 338 PMD_SECT_UNCACHED | PMD_SECT_XN, 339 .domain = DOMAIN_KERNEL, 340 }, 341 [MT_MEMORY_DMA_READY] = { 342 .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | 343 L_PTE_XN, 344 .prot_l1 = PMD_TYPE_TABLE, 345 .domain = DOMAIN_KERNEL, 346 }, 347 }; 348 349 const struct mem_type *get_mem_type(unsigned int type) 350 { 351 return type < ARRAY_SIZE(mem_types) ? &mem_types[type] : NULL; 352 } 353 EXPORT_SYMBOL(get_mem_type); 354 355 static pte_t *(*pte_offset_fixmap)(pmd_t *dir, unsigned long addr); 356 357 static pte_t bm_pte[PTRS_PER_PTE + PTE_HWTABLE_PTRS] 358 __aligned(PTE_HWTABLE_OFF + PTE_HWTABLE_SIZE) __initdata; 359 360 static pte_t * __init pte_offset_early_fixmap(pmd_t *dir, unsigned long addr) 361 { 362 return &bm_pte[pte_index(addr)]; 363 } 364 365 static pte_t *pte_offset_late_fixmap(pmd_t *dir, unsigned long addr) 366 { 367 return pte_offset_kernel(dir, addr); 368 } 369 370 static inline pmd_t * __init fixmap_pmd(unsigned long addr) 371 { 372 return pmd_off_k(addr); 373 } 374 375 void __init early_fixmap_init(void) 376 { 377 pmd_t *pmd; 378 379 /* 380 * The early fixmap range spans multiple pmds, for which 381 * we are not prepared: 382 */ 383 BUILD_BUG_ON((__fix_to_virt(__end_of_early_ioremap_region) >> PMD_SHIFT) 384 != FIXADDR_TOP >> PMD_SHIFT); 385 386 pmd = fixmap_pmd(FIXADDR_TOP); 387 pmd_populate_kernel(&init_mm, pmd, bm_pte); 388 389 pte_offset_fixmap = pte_offset_early_fixmap; 390 } 391 392 /* 393 * To avoid TLB flush broadcasts, this uses local_flush_tlb_kernel_range(). 394 * As a result, this can only be called with preemption disabled, as under 395 * stop_machine(). 396 */ 397 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot) 398 { 399 unsigned long vaddr = __fix_to_virt(idx); 400 pte_t *pte = pte_offset_fixmap(pmd_off_k(vaddr), vaddr); 401 402 /* Make sure fixmap region does not exceed available allocation. */ 403 BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) < FIXADDR_START); 404 BUG_ON(idx >= __end_of_fixed_addresses); 405 406 /* We support only device mappings before pgprot_kernel is set. */ 407 if (WARN_ON(pgprot_val(prot) != pgprot_val(FIXMAP_PAGE_IO) && 408 pgprot_val(prot) && pgprot_val(pgprot_kernel) == 0)) 409 return; 410 411 if (pgprot_val(prot)) 412 set_pte_at(NULL, vaddr, pte, 413 pfn_pte(phys >> PAGE_SHIFT, prot)); 414 else 415 pte_clear(NULL, vaddr, pte); 416 local_flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE); 417 } 418 419 static pgprot_t protection_map[16] __ro_after_init = { 420 [VM_NONE] = __PAGE_NONE, 421 [VM_READ] = __PAGE_READONLY, 422 [VM_WRITE] = __PAGE_COPY, 423 [VM_WRITE | VM_READ] = __PAGE_COPY, 424 [VM_EXEC] = __PAGE_READONLY_EXEC, 425 [VM_EXEC | VM_READ] = __PAGE_READONLY_EXEC, 426 [VM_EXEC | VM_WRITE] = __PAGE_COPY_EXEC, 427 [VM_EXEC | VM_WRITE | VM_READ] = __PAGE_COPY_EXEC, 428 [VM_SHARED] = __PAGE_NONE, 429 [VM_SHARED | VM_READ] = __PAGE_READONLY, 430 [VM_SHARED | VM_WRITE] = __PAGE_SHARED, 431 [VM_SHARED | VM_WRITE | VM_READ] = __PAGE_SHARED, 432 [VM_SHARED | VM_EXEC] = __PAGE_READONLY_EXEC, 433 [VM_SHARED | VM_EXEC | VM_READ] = __PAGE_READONLY_EXEC, 434 [VM_SHARED | VM_EXEC | VM_WRITE] = __PAGE_SHARED_EXEC, 435 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = __PAGE_SHARED_EXEC 436 }; 437 DECLARE_VM_GET_PAGE_PROT 438 439 /* 440 * Adjust the PMD section entries according to the CPU in use. 441 */ 442 static void __init build_mem_type_table(void) 443 { 444 struct cachepolicy *cp; 445 unsigned int cr = get_cr(); 446 pteval_t user_pgprot, kern_pgprot, vecs_pgprot; 447 int cpu_arch = cpu_architecture(); 448 int i; 449 450 if (cpu_arch < CPU_ARCH_ARMv6) { 451 #if defined(CONFIG_CPU_DCACHE_DISABLE) 452 if (cachepolicy > CPOLICY_BUFFERED) 453 cachepolicy = CPOLICY_BUFFERED; 454 #elif defined(CONFIG_CPU_DCACHE_WRITETHROUGH) 455 if (cachepolicy > CPOLICY_WRITETHROUGH) 456 cachepolicy = CPOLICY_WRITETHROUGH; 457 #endif 458 } 459 if (cpu_arch < CPU_ARCH_ARMv5) { 460 if (cachepolicy >= CPOLICY_WRITEALLOC) 461 cachepolicy = CPOLICY_WRITEBACK; 462 ecc_mask = 0; 463 } 464 465 if (is_smp()) { 466 if (cachepolicy != CPOLICY_WRITEALLOC) { 467 pr_warn("Forcing write-allocate cache policy for SMP\n"); 468 cachepolicy = CPOLICY_WRITEALLOC; 469 } 470 if (!(initial_pmd_value & PMD_SECT_S)) { 471 pr_warn("Forcing shared mappings for SMP\n"); 472 initial_pmd_value |= PMD_SECT_S; 473 } 474 } 475 476 /* 477 * Strip out features not present on earlier architectures. 478 * Pre-ARMv5 CPUs don't have TEX bits. Pre-ARMv6 CPUs or those 479 * without extended page tables don't have the 'Shared' bit. 480 */ 481 if (cpu_arch < CPU_ARCH_ARMv5) 482 for (i = 0; i < ARRAY_SIZE(mem_types); i++) 483 mem_types[i].prot_sect &= ~PMD_SECT_TEX(7); 484 if ((cpu_arch < CPU_ARCH_ARMv6 || !(cr & CR_XP)) && !cpu_is_xsc3()) 485 for (i = 0; i < ARRAY_SIZE(mem_types); i++) 486 mem_types[i].prot_sect &= ~PMD_SECT_S; 487 488 /* 489 * ARMv5 and lower, bit 4 must be set for page tables (was: cache 490 * "update-able on write" bit on ARM610). However, Xscale and 491 * Xscale3 require this bit to be cleared. 492 */ 493 if (cpu_is_xscale_family()) { 494 for (i = 0; i < ARRAY_SIZE(mem_types); i++) { 495 mem_types[i].prot_sect &= ~PMD_BIT4; 496 mem_types[i].prot_l1 &= ~PMD_BIT4; 497 } 498 } else if (cpu_arch < CPU_ARCH_ARMv6) { 499 for (i = 0; i < ARRAY_SIZE(mem_types); i++) { 500 if (mem_types[i].prot_l1) 501 mem_types[i].prot_l1 |= PMD_BIT4; 502 if (mem_types[i].prot_sect) 503 mem_types[i].prot_sect |= PMD_BIT4; 504 } 505 } 506 507 /* 508 * Mark the device areas according to the CPU/architecture. 509 */ 510 if (cpu_is_xsc3() || (cpu_arch >= CPU_ARCH_ARMv6 && (cr & CR_XP))) { 511 if (!cpu_is_xsc3()) { 512 /* 513 * Mark device regions on ARMv6+ as execute-never 514 * to prevent speculative instruction fetches. 515 */ 516 mem_types[MT_DEVICE].prot_sect |= PMD_SECT_XN; 517 mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_XN; 518 mem_types[MT_DEVICE_CACHED].prot_sect |= PMD_SECT_XN; 519 mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_XN; 520 521 /* Also setup NX memory mapping */ 522 mem_types[MT_MEMORY_RW].prot_sect |= PMD_SECT_XN; 523 mem_types[MT_MEMORY_RO].prot_sect |= PMD_SECT_XN; 524 } 525 if (cpu_arch >= CPU_ARCH_ARMv7 && (cr & CR_TRE)) { 526 /* 527 * For ARMv7 with TEX remapping, 528 * - shared device is SXCB=1100 529 * - nonshared device is SXCB=0100 530 * - write combine device mem is SXCB=0001 531 * (Uncached Normal memory) 532 */ 533 mem_types[MT_DEVICE].prot_sect |= PMD_SECT_TEX(1); 534 mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(1); 535 mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_BUFFERABLE; 536 } else if (cpu_is_xsc3()) { 537 /* 538 * For Xscale3, 539 * - shared device is TEXCB=00101 540 * - nonshared device is TEXCB=01000 541 * - write combine device mem is TEXCB=00100 542 * (Inner/Outer Uncacheable in xsc3 parlance) 543 */ 544 mem_types[MT_DEVICE].prot_sect |= PMD_SECT_TEX(1) | PMD_SECT_BUFFERED; 545 mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(2); 546 mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_TEX(1); 547 } else { 548 /* 549 * For ARMv6 and ARMv7 without TEX remapping, 550 * - shared device is TEXCB=00001 551 * - nonshared device is TEXCB=01000 552 * - write combine device mem is TEXCB=00100 553 * (Uncached Normal in ARMv6 parlance). 554 */ 555 mem_types[MT_DEVICE].prot_sect |= PMD_SECT_BUFFERED; 556 mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(2); 557 mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_TEX(1); 558 } 559 } else { 560 /* 561 * On others, write combining is "Uncached/Buffered" 562 */ 563 mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_BUFFERABLE; 564 } 565 566 /* 567 * Now deal with the memory-type mappings 568 */ 569 cp = &cache_policies[cachepolicy]; 570 vecs_pgprot = kern_pgprot = user_pgprot = cp->pte; 571 572 #ifndef CONFIG_ARM_LPAE 573 /* 574 * We don't use domains on ARMv6 (since this causes problems with 575 * v6/v7 kernels), so we must use a separate memory type for user 576 * r/o, kernel r/w to map the vectors page. 577 */ 578 if (cpu_arch == CPU_ARCH_ARMv6) 579 vecs_pgprot |= L_PTE_MT_VECTORS; 580 581 /* 582 * Check is it with support for the PXN bit 583 * in the Short-descriptor translation table format descriptors. 584 */ 585 if (cpu_arch == CPU_ARCH_ARMv7 && 586 (read_cpuid_ext(CPUID_EXT_MMFR0) & 0xF) >= 4) { 587 user_pmd_table |= PMD_PXNTABLE; 588 } 589 #endif 590 591 /* 592 * ARMv6 and above have extended page tables. 593 */ 594 if (cpu_arch >= CPU_ARCH_ARMv6 && (cr & CR_XP)) { 595 #ifndef CONFIG_ARM_LPAE 596 /* 597 * Mark cache clean areas and XIP ROM read only 598 * from SVC mode and no access from userspace. 599 */ 600 mem_types[MT_ROM].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE; 601 mem_types[MT_MINICLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE; 602 mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE; 603 mem_types[MT_MEMORY_RO].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE; 604 #endif 605 606 /* 607 * If the initial page tables were created with the S bit 608 * set, then we need to do the same here for the same 609 * reasons given in early_cachepolicy(). 610 */ 611 if (initial_pmd_value & PMD_SECT_S) { 612 user_pgprot |= L_PTE_SHARED; 613 kern_pgprot |= L_PTE_SHARED; 614 vecs_pgprot |= L_PTE_SHARED; 615 mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_S; 616 mem_types[MT_DEVICE_WC].prot_pte |= L_PTE_SHARED; 617 mem_types[MT_DEVICE_CACHED].prot_sect |= PMD_SECT_S; 618 mem_types[MT_DEVICE_CACHED].prot_pte |= L_PTE_SHARED; 619 mem_types[MT_MEMORY_RWX].prot_sect |= PMD_SECT_S; 620 mem_types[MT_MEMORY_RWX].prot_pte |= L_PTE_SHARED; 621 mem_types[MT_MEMORY_RW].prot_sect |= PMD_SECT_S; 622 mem_types[MT_MEMORY_RW].prot_pte |= L_PTE_SHARED; 623 mem_types[MT_MEMORY_RO].prot_sect |= PMD_SECT_S; 624 mem_types[MT_MEMORY_RO].prot_pte |= L_PTE_SHARED; 625 mem_types[MT_MEMORY_DMA_READY].prot_pte |= L_PTE_SHARED; 626 mem_types[MT_MEMORY_RWX_NONCACHED].prot_sect |= PMD_SECT_S; 627 mem_types[MT_MEMORY_RWX_NONCACHED].prot_pte |= L_PTE_SHARED; 628 } 629 } 630 631 /* 632 * Non-cacheable Normal - intended for memory areas that must 633 * not cause dirty cache line writebacks when used 634 */ 635 if (cpu_arch >= CPU_ARCH_ARMv6) { 636 if (cpu_arch >= CPU_ARCH_ARMv7 && (cr & CR_TRE)) { 637 /* Non-cacheable Normal is XCB = 001 */ 638 mem_types[MT_MEMORY_RWX_NONCACHED].prot_sect |= 639 PMD_SECT_BUFFERED; 640 } else { 641 /* For both ARMv6 and non-TEX-remapping ARMv7 */ 642 mem_types[MT_MEMORY_RWX_NONCACHED].prot_sect |= 643 PMD_SECT_TEX(1); 644 } 645 } else { 646 mem_types[MT_MEMORY_RWX_NONCACHED].prot_sect |= PMD_SECT_BUFFERABLE; 647 } 648 649 #ifdef CONFIG_ARM_LPAE 650 /* 651 * Do not generate access flag faults for the kernel mappings. 652 */ 653 for (i = 0; i < ARRAY_SIZE(mem_types); i++) { 654 mem_types[i].prot_pte |= PTE_EXT_AF; 655 if (mem_types[i].prot_sect) 656 mem_types[i].prot_sect |= PMD_SECT_AF; 657 } 658 kern_pgprot |= PTE_EXT_AF; 659 vecs_pgprot |= PTE_EXT_AF; 660 661 /* 662 * Set PXN for user mappings 663 */ 664 user_pgprot |= PTE_EXT_PXN; 665 #endif 666 667 for (i = 0; i < 16; i++) { 668 pteval_t v = pgprot_val(protection_map[i]); 669 protection_map[i] = __pgprot(v | user_pgprot); 670 } 671 672 mem_types[MT_LOW_VECTORS].prot_pte |= vecs_pgprot; 673 mem_types[MT_HIGH_VECTORS].prot_pte |= vecs_pgprot; 674 675 pgprot_user = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | user_pgprot); 676 pgprot_kernel = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | 677 L_PTE_DIRTY | kern_pgprot); 678 679 mem_types[MT_LOW_VECTORS].prot_l1 |= ecc_mask; 680 mem_types[MT_HIGH_VECTORS].prot_l1 |= ecc_mask; 681 mem_types[MT_MEMORY_RWX].prot_sect |= ecc_mask | cp->pmd; 682 mem_types[MT_MEMORY_RWX].prot_pte |= kern_pgprot; 683 mem_types[MT_MEMORY_RW].prot_sect |= ecc_mask | cp->pmd; 684 mem_types[MT_MEMORY_RW].prot_pte |= kern_pgprot; 685 mem_types[MT_MEMORY_RO].prot_sect |= ecc_mask | cp->pmd; 686 mem_types[MT_MEMORY_RO].prot_pte |= kern_pgprot; 687 mem_types[MT_MEMORY_DMA_READY].prot_pte |= kern_pgprot; 688 mem_types[MT_MEMORY_RWX_NONCACHED].prot_sect |= ecc_mask; 689 mem_types[MT_ROM].prot_sect |= cp->pmd; 690 691 switch (cp->pmd) { 692 case PMD_SECT_WT: 693 mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_WT; 694 break; 695 case PMD_SECT_WB: 696 case PMD_SECT_WBWA: 697 mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_WB; 698 break; 699 } 700 pr_info("Memory policy: %sData cache %s\n", 701 ecc_mask ? "ECC enabled, " : "", cp->policy); 702 703 for (i = 0; i < ARRAY_SIZE(mem_types); i++) { 704 struct mem_type *t = &mem_types[i]; 705 if (t->prot_l1) 706 t->prot_l1 |= PMD_DOMAIN(t->domain); 707 if (t->prot_sect) 708 t->prot_sect |= PMD_DOMAIN(t->domain); 709 } 710 } 711 712 #ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE 713 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, 714 unsigned long size, pgprot_t vma_prot) 715 { 716 if (!pfn_valid(pfn)) 717 return pgprot_noncached(vma_prot); 718 else if (file->f_flags & O_SYNC) 719 return pgprot_writecombine(vma_prot); 720 return vma_prot; 721 } 722 EXPORT_SYMBOL(phys_mem_access_prot); 723 #endif 724 725 #define vectors_base() (vectors_high() ? 0xffff0000 : 0) 726 727 static void __init *early_alloc(unsigned long sz) 728 { 729 void *ptr = memblock_alloc(sz, sz); 730 731 if (!ptr) 732 panic("%s: Failed to allocate %lu bytes align=0x%lx\n", 733 __func__, sz, sz); 734 735 return ptr; 736 } 737 738 static void *__init late_alloc(unsigned long sz) 739 { 740 void *ptr = (void *)__get_free_pages(GFP_PGTABLE_KERNEL, get_order(sz)); 741 742 if (!ptr || !pgtable_pte_page_ctor(virt_to_page(ptr))) 743 BUG(); 744 return ptr; 745 } 746 747 static pte_t * __init arm_pte_alloc(pmd_t *pmd, unsigned long addr, 748 unsigned long prot, 749 void *(*alloc)(unsigned long sz)) 750 { 751 if (pmd_none(*pmd)) { 752 pte_t *pte = alloc(PTE_HWTABLE_OFF + PTE_HWTABLE_SIZE); 753 __pmd_populate(pmd, __pa(pte), prot); 754 } 755 BUG_ON(pmd_bad(*pmd)); 756 return pte_offset_kernel(pmd, addr); 757 } 758 759 static pte_t * __init early_pte_alloc(pmd_t *pmd, unsigned long addr, 760 unsigned long prot) 761 { 762 return arm_pte_alloc(pmd, addr, prot, early_alloc); 763 } 764 765 static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr, 766 unsigned long end, unsigned long pfn, 767 const struct mem_type *type, 768 void *(*alloc)(unsigned long sz), 769 bool ng) 770 { 771 pte_t *pte = arm_pte_alloc(pmd, addr, type->prot_l1, alloc); 772 do { 773 set_pte_ext(pte, pfn_pte(pfn, __pgprot(type->prot_pte)), 774 ng ? PTE_EXT_NG : 0); 775 pfn++; 776 } while (pte++, addr += PAGE_SIZE, addr != end); 777 } 778 779 static void __init __map_init_section(pmd_t *pmd, unsigned long addr, 780 unsigned long end, phys_addr_t phys, 781 const struct mem_type *type, bool ng) 782 { 783 pmd_t *p = pmd; 784 785 #ifndef CONFIG_ARM_LPAE 786 /* 787 * In classic MMU format, puds and pmds are folded in to 788 * the pgds. pmd_offset gives the PGD entry. PGDs refer to a 789 * group of L1 entries making up one logical pointer to 790 * an L2 table (2MB), where as PMDs refer to the individual 791 * L1 entries (1MB). Hence increment to get the correct 792 * offset for odd 1MB sections. 793 * (See arch/arm/include/asm/pgtable-2level.h) 794 */ 795 if (addr & SECTION_SIZE) 796 pmd++; 797 #endif 798 do { 799 *pmd = __pmd(phys | type->prot_sect | (ng ? PMD_SECT_nG : 0)); 800 phys += SECTION_SIZE; 801 } while (pmd++, addr += SECTION_SIZE, addr != end); 802 803 flush_pmd_entry(p); 804 } 805 806 static void __init alloc_init_pmd(pud_t *pud, unsigned long addr, 807 unsigned long end, phys_addr_t phys, 808 const struct mem_type *type, 809 void *(*alloc)(unsigned long sz), bool ng) 810 { 811 pmd_t *pmd = pmd_offset(pud, addr); 812 unsigned long next; 813 814 do { 815 /* 816 * With LPAE, we must loop over to map 817 * all the pmds for the given range. 818 */ 819 next = pmd_addr_end(addr, end); 820 821 /* 822 * Try a section mapping - addr, next and phys must all be 823 * aligned to a section boundary. 824 */ 825 if (type->prot_sect && 826 ((addr | next | phys) & ~SECTION_MASK) == 0) { 827 __map_init_section(pmd, addr, next, phys, type, ng); 828 } else { 829 alloc_init_pte(pmd, addr, next, 830 __phys_to_pfn(phys), type, alloc, ng); 831 } 832 833 phys += next - addr; 834 835 } while (pmd++, addr = next, addr != end); 836 } 837 838 static void __init alloc_init_pud(p4d_t *p4d, unsigned long addr, 839 unsigned long end, phys_addr_t phys, 840 const struct mem_type *type, 841 void *(*alloc)(unsigned long sz), bool ng) 842 { 843 pud_t *pud = pud_offset(p4d, addr); 844 unsigned long next; 845 846 do { 847 next = pud_addr_end(addr, end); 848 alloc_init_pmd(pud, addr, next, phys, type, alloc, ng); 849 phys += next - addr; 850 } while (pud++, addr = next, addr != end); 851 } 852 853 static void __init alloc_init_p4d(pgd_t *pgd, unsigned long addr, 854 unsigned long end, phys_addr_t phys, 855 const struct mem_type *type, 856 void *(*alloc)(unsigned long sz), bool ng) 857 { 858 p4d_t *p4d = p4d_offset(pgd, addr); 859 unsigned long next; 860 861 do { 862 next = p4d_addr_end(addr, end); 863 alloc_init_pud(p4d, addr, next, phys, type, alloc, ng); 864 phys += next - addr; 865 } while (p4d++, addr = next, addr != end); 866 } 867 868 #ifndef CONFIG_ARM_LPAE 869 static void __init create_36bit_mapping(struct mm_struct *mm, 870 struct map_desc *md, 871 const struct mem_type *type, 872 bool ng) 873 { 874 unsigned long addr, length, end; 875 phys_addr_t phys; 876 pgd_t *pgd; 877 878 addr = md->virtual; 879 phys = __pfn_to_phys(md->pfn); 880 length = PAGE_ALIGN(md->length); 881 882 if (!(cpu_architecture() >= CPU_ARCH_ARMv6 || cpu_is_xsc3())) { 883 pr_err("MM: CPU does not support supersection mapping for 0x%08llx at 0x%08lx\n", 884 (long long)__pfn_to_phys((u64)md->pfn), addr); 885 return; 886 } 887 888 /* N.B. ARMv6 supersections are only defined to work with domain 0. 889 * Since domain assignments can in fact be arbitrary, the 890 * 'domain == 0' check below is required to insure that ARMv6 891 * supersections are only allocated for domain 0 regardless 892 * of the actual domain assignments in use. 893 */ 894 if (type->domain) { 895 pr_err("MM: invalid domain in supersection mapping for 0x%08llx at 0x%08lx\n", 896 (long long)__pfn_to_phys((u64)md->pfn), addr); 897 return; 898 } 899 900 if ((addr | length | __pfn_to_phys(md->pfn)) & ~SUPERSECTION_MASK) { 901 pr_err("MM: cannot create mapping for 0x%08llx at 0x%08lx invalid alignment\n", 902 (long long)__pfn_to_phys((u64)md->pfn), addr); 903 return; 904 } 905 906 /* 907 * Shift bits [35:32] of address into bits [23:20] of PMD 908 * (See ARMv6 spec). 909 */ 910 phys |= (((md->pfn >> (32 - PAGE_SHIFT)) & 0xF) << 20); 911 912 pgd = pgd_offset(mm, addr); 913 end = addr + length; 914 do { 915 p4d_t *p4d = p4d_offset(pgd, addr); 916 pud_t *pud = pud_offset(p4d, addr); 917 pmd_t *pmd = pmd_offset(pud, addr); 918 int i; 919 920 for (i = 0; i < 16; i++) 921 *pmd++ = __pmd(phys | type->prot_sect | PMD_SECT_SUPER | 922 (ng ? PMD_SECT_nG : 0)); 923 924 addr += SUPERSECTION_SIZE; 925 phys += SUPERSECTION_SIZE; 926 pgd += SUPERSECTION_SIZE >> PGDIR_SHIFT; 927 } while (addr != end); 928 } 929 #endif /* !CONFIG_ARM_LPAE */ 930 931 static void __init __create_mapping(struct mm_struct *mm, struct map_desc *md, 932 void *(*alloc)(unsigned long sz), 933 bool ng) 934 { 935 unsigned long addr, length, end; 936 phys_addr_t phys; 937 const struct mem_type *type; 938 pgd_t *pgd; 939 940 type = &mem_types[md->type]; 941 942 #ifndef CONFIG_ARM_LPAE 943 /* 944 * Catch 36-bit addresses 945 */ 946 if (md->pfn >= 0x100000) { 947 create_36bit_mapping(mm, md, type, ng); 948 return; 949 } 950 #endif 951 952 addr = md->virtual & PAGE_MASK; 953 phys = __pfn_to_phys(md->pfn); 954 length = PAGE_ALIGN(md->length + (md->virtual & ~PAGE_MASK)); 955 956 if (type->prot_l1 == 0 && ((addr | phys | length) & ~SECTION_MASK)) { 957 pr_warn("BUG: map for 0x%08llx at 0x%08lx can not be mapped using pages, ignoring.\n", 958 (long long)__pfn_to_phys(md->pfn), addr); 959 return; 960 } 961 962 pgd = pgd_offset(mm, addr); 963 end = addr + length; 964 do { 965 unsigned long next = pgd_addr_end(addr, end); 966 967 alloc_init_p4d(pgd, addr, next, phys, type, alloc, ng); 968 969 phys += next - addr; 970 addr = next; 971 } while (pgd++, addr != end); 972 } 973 974 /* 975 * Create the page directory entries and any necessary 976 * page tables for the mapping specified by `md'. We 977 * are able to cope here with varying sizes and address 978 * offsets, and we take full advantage of sections and 979 * supersections. 980 */ 981 static void __init create_mapping(struct map_desc *md) 982 { 983 if (md->virtual != vectors_base() && md->virtual < TASK_SIZE) { 984 pr_warn("BUG: not creating mapping for 0x%08llx at 0x%08lx in user region\n", 985 (long long)__pfn_to_phys((u64)md->pfn), md->virtual); 986 return; 987 } 988 989 if (md->type == MT_DEVICE && 990 md->virtual >= PAGE_OFFSET && md->virtual < FIXADDR_START && 991 (md->virtual < VMALLOC_START || md->virtual >= VMALLOC_END)) { 992 pr_warn("BUG: mapping for 0x%08llx at 0x%08lx out of vmalloc space\n", 993 (long long)__pfn_to_phys((u64)md->pfn), md->virtual); 994 } 995 996 __create_mapping(&init_mm, md, early_alloc, false); 997 } 998 999 void __init create_mapping_late(struct mm_struct *mm, struct map_desc *md, 1000 bool ng) 1001 { 1002 #ifdef CONFIG_ARM_LPAE 1003 p4d_t *p4d; 1004 pud_t *pud; 1005 1006 p4d = p4d_alloc(mm, pgd_offset(mm, md->virtual), md->virtual); 1007 if (WARN_ON(!p4d)) 1008 return; 1009 pud = pud_alloc(mm, p4d, md->virtual); 1010 if (WARN_ON(!pud)) 1011 return; 1012 pmd_alloc(mm, pud, 0); 1013 #endif 1014 __create_mapping(mm, md, late_alloc, ng); 1015 } 1016 1017 /* 1018 * Create the architecture specific mappings 1019 */ 1020 void __init iotable_init(struct map_desc *io_desc, int nr) 1021 { 1022 struct map_desc *md; 1023 struct vm_struct *vm; 1024 struct static_vm *svm; 1025 1026 if (!nr) 1027 return; 1028 1029 svm = memblock_alloc(sizeof(*svm) * nr, __alignof__(*svm)); 1030 if (!svm) 1031 panic("%s: Failed to allocate %zu bytes align=0x%zx\n", 1032 __func__, sizeof(*svm) * nr, __alignof__(*svm)); 1033 1034 for (md = io_desc; nr; md++, nr--) { 1035 create_mapping(md); 1036 1037 vm = &svm->vm; 1038 vm->addr = (void *)(md->virtual & PAGE_MASK); 1039 vm->size = PAGE_ALIGN(md->length + (md->virtual & ~PAGE_MASK)); 1040 vm->phys_addr = __pfn_to_phys(md->pfn); 1041 vm->flags = VM_IOREMAP | VM_ARM_STATIC_MAPPING; 1042 vm->flags |= VM_ARM_MTYPE(md->type); 1043 vm->caller = iotable_init; 1044 add_static_vm_early(svm++); 1045 } 1046 } 1047 1048 void __init vm_reserve_area_early(unsigned long addr, unsigned long size, 1049 void *caller) 1050 { 1051 struct vm_struct *vm; 1052 struct static_vm *svm; 1053 1054 svm = memblock_alloc(sizeof(*svm), __alignof__(*svm)); 1055 if (!svm) 1056 panic("%s: Failed to allocate %zu bytes align=0x%zx\n", 1057 __func__, sizeof(*svm), __alignof__(*svm)); 1058 1059 vm = &svm->vm; 1060 vm->addr = (void *)addr; 1061 vm->size = size; 1062 vm->flags = VM_IOREMAP | VM_ARM_EMPTY_MAPPING; 1063 vm->caller = caller; 1064 add_static_vm_early(svm); 1065 } 1066 1067 #ifndef CONFIG_ARM_LPAE 1068 1069 /* 1070 * The Linux PMD is made of two consecutive section entries covering 2MB 1071 * (see definition in include/asm/pgtable-2level.h). However a call to 1072 * create_mapping() may optimize static mappings by using individual 1073 * 1MB section mappings. This leaves the actual PMD potentially half 1074 * initialized if the top or bottom section entry isn't used, leaving it 1075 * open to problems if a subsequent ioremap() or vmalloc() tries to use 1076 * the virtual space left free by that unused section entry. 1077 * 1078 * Let's avoid the issue by inserting dummy vm entries covering the unused 1079 * PMD halves once the static mappings are in place. 1080 */ 1081 1082 static void __init pmd_empty_section_gap(unsigned long addr) 1083 { 1084 vm_reserve_area_early(addr, SECTION_SIZE, pmd_empty_section_gap); 1085 } 1086 1087 static void __init fill_pmd_gaps(void) 1088 { 1089 struct static_vm *svm; 1090 struct vm_struct *vm; 1091 unsigned long addr, next = 0; 1092 pmd_t *pmd; 1093 1094 list_for_each_entry(svm, &static_vmlist, list) { 1095 vm = &svm->vm; 1096 addr = (unsigned long)vm->addr; 1097 if (addr < next) 1098 continue; 1099 1100 /* 1101 * Check if this vm starts on an odd section boundary. 1102 * If so and the first section entry for this PMD is free 1103 * then we block the corresponding virtual address. 1104 */ 1105 if ((addr & ~PMD_MASK) == SECTION_SIZE) { 1106 pmd = pmd_off_k(addr); 1107 if (pmd_none(*pmd)) 1108 pmd_empty_section_gap(addr & PMD_MASK); 1109 } 1110 1111 /* 1112 * Then check if this vm ends on an odd section boundary. 1113 * If so and the second section entry for this PMD is empty 1114 * then we block the corresponding virtual address. 1115 */ 1116 addr += vm->size; 1117 if ((addr & ~PMD_MASK) == SECTION_SIZE) { 1118 pmd = pmd_off_k(addr) + 1; 1119 if (pmd_none(*pmd)) 1120 pmd_empty_section_gap(addr); 1121 } 1122 1123 /* no need to look at any vm entry until we hit the next PMD */ 1124 next = (addr + PMD_SIZE - 1) & PMD_MASK; 1125 } 1126 } 1127 1128 #else 1129 #define fill_pmd_gaps() do { } while (0) 1130 #endif 1131 1132 #if defined(CONFIG_PCI) && !defined(CONFIG_NEED_MACH_IO_H) 1133 static void __init pci_reserve_io(void) 1134 { 1135 struct static_vm *svm; 1136 1137 svm = find_static_vm_vaddr((void *)PCI_IO_VIRT_BASE); 1138 if (svm) 1139 return; 1140 1141 vm_reserve_area_early(PCI_IO_VIRT_BASE, SZ_2M, pci_reserve_io); 1142 } 1143 #else 1144 #define pci_reserve_io() do { } while (0) 1145 #endif 1146 1147 #ifdef CONFIG_DEBUG_LL 1148 void __init debug_ll_io_init(void) 1149 { 1150 struct map_desc map; 1151 1152 debug_ll_addr(&map.pfn, &map.virtual); 1153 if (!map.pfn || !map.virtual) 1154 return; 1155 map.pfn = __phys_to_pfn(map.pfn); 1156 map.virtual &= PAGE_MASK; 1157 map.length = PAGE_SIZE; 1158 map.type = MT_DEVICE; 1159 iotable_init(&map, 1); 1160 } 1161 #endif 1162 1163 static unsigned long __initdata vmalloc_size = 240 * SZ_1M; 1164 1165 /* 1166 * vmalloc=size forces the vmalloc area to be exactly 'size' 1167 * bytes. This can be used to increase (or decrease) the vmalloc 1168 * area - the default is 240MiB. 1169 */ 1170 static int __init early_vmalloc(char *arg) 1171 { 1172 unsigned long vmalloc_reserve = memparse(arg, NULL); 1173 unsigned long vmalloc_max; 1174 1175 if (vmalloc_reserve < SZ_16M) { 1176 vmalloc_reserve = SZ_16M; 1177 pr_warn("vmalloc area is too small, limiting to %luMiB\n", 1178 vmalloc_reserve >> 20); 1179 } 1180 1181 vmalloc_max = VMALLOC_END - (PAGE_OFFSET + SZ_32M + VMALLOC_OFFSET); 1182 if (vmalloc_reserve > vmalloc_max) { 1183 vmalloc_reserve = vmalloc_max; 1184 pr_warn("vmalloc area is too big, limiting to %luMiB\n", 1185 vmalloc_reserve >> 20); 1186 } 1187 1188 vmalloc_size = vmalloc_reserve; 1189 return 0; 1190 } 1191 early_param("vmalloc", early_vmalloc); 1192 1193 phys_addr_t arm_lowmem_limit __initdata = 0; 1194 1195 void __init adjust_lowmem_bounds(void) 1196 { 1197 phys_addr_t block_start, block_end, memblock_limit = 0; 1198 u64 vmalloc_limit, i; 1199 phys_addr_t lowmem_limit = 0; 1200 1201 /* 1202 * Let's use our own (unoptimized) equivalent of __pa() that is 1203 * not affected by wrap-arounds when sizeof(phys_addr_t) == 4. 1204 * The result is used as the upper bound on physical memory address 1205 * and may itself be outside the valid range for which phys_addr_t 1206 * and therefore __pa() is defined. 1207 */ 1208 vmalloc_limit = (u64)VMALLOC_END - vmalloc_size - VMALLOC_OFFSET - 1209 PAGE_OFFSET + PHYS_OFFSET; 1210 1211 /* 1212 * The first usable region must be PMD aligned. Mark its start 1213 * as MEMBLOCK_NOMAP if it isn't 1214 */ 1215 for_each_mem_range(i, &block_start, &block_end) { 1216 if (!IS_ALIGNED(block_start, PMD_SIZE)) { 1217 phys_addr_t len; 1218 1219 len = round_up(block_start, PMD_SIZE) - block_start; 1220 memblock_mark_nomap(block_start, len); 1221 } 1222 break; 1223 } 1224 1225 for_each_mem_range(i, &block_start, &block_end) { 1226 if (block_start < vmalloc_limit) { 1227 if (block_end > lowmem_limit) 1228 /* 1229 * Compare as u64 to ensure vmalloc_limit does 1230 * not get truncated. block_end should always 1231 * fit in phys_addr_t so there should be no 1232 * issue with assignment. 1233 */ 1234 lowmem_limit = min_t(u64, 1235 vmalloc_limit, 1236 block_end); 1237 1238 /* 1239 * Find the first non-pmd-aligned page, and point 1240 * memblock_limit at it. This relies on rounding the 1241 * limit down to be pmd-aligned, which happens at the 1242 * end of this function. 1243 * 1244 * With this algorithm, the start or end of almost any 1245 * bank can be non-pmd-aligned. The only exception is 1246 * that the start of the bank 0 must be section- 1247 * aligned, since otherwise memory would need to be 1248 * allocated when mapping the start of bank 0, which 1249 * occurs before any free memory is mapped. 1250 */ 1251 if (!memblock_limit) { 1252 if (!IS_ALIGNED(block_start, PMD_SIZE)) 1253 memblock_limit = block_start; 1254 else if (!IS_ALIGNED(block_end, PMD_SIZE)) 1255 memblock_limit = lowmem_limit; 1256 } 1257 1258 } 1259 } 1260 1261 arm_lowmem_limit = lowmem_limit; 1262 1263 high_memory = __va(arm_lowmem_limit - 1) + 1; 1264 1265 if (!memblock_limit) 1266 memblock_limit = arm_lowmem_limit; 1267 1268 /* 1269 * Round the memblock limit down to a pmd size. This 1270 * helps to ensure that we will allocate memory from the 1271 * last full pmd, which should be mapped. 1272 */ 1273 memblock_limit = round_down(memblock_limit, PMD_SIZE); 1274 1275 if (!IS_ENABLED(CONFIG_HIGHMEM) || cache_is_vipt_aliasing()) { 1276 if (memblock_end_of_DRAM() > arm_lowmem_limit) { 1277 phys_addr_t end = memblock_end_of_DRAM(); 1278 1279 pr_notice("Ignoring RAM at %pa-%pa\n", 1280 &memblock_limit, &end); 1281 pr_notice("Consider using a HIGHMEM enabled kernel.\n"); 1282 1283 memblock_remove(memblock_limit, end - memblock_limit); 1284 } 1285 } 1286 1287 memblock_set_current_limit(memblock_limit); 1288 } 1289 1290 static __init void prepare_page_table(void) 1291 { 1292 unsigned long addr; 1293 phys_addr_t end; 1294 1295 /* 1296 * Clear out all the mappings below the kernel image. 1297 */ 1298 #ifdef CONFIG_KASAN 1299 /* 1300 * KASan's shadow memory inserts itself between the TASK_SIZE 1301 * and MODULES_VADDR. Do not clear the KASan shadow memory mappings. 1302 */ 1303 for (addr = 0; addr < KASAN_SHADOW_START; addr += PMD_SIZE) 1304 pmd_clear(pmd_off_k(addr)); 1305 /* 1306 * Skip over the KASan shadow area. KASAN_SHADOW_END is sometimes 1307 * equal to MODULES_VADDR and then we exit the pmd clearing. If we 1308 * are using a thumb-compiled kernel, there there will be 8MB more 1309 * to clear as KASan always offset to 16 MB below MODULES_VADDR. 1310 */ 1311 for (addr = KASAN_SHADOW_END; addr < MODULES_VADDR; addr += PMD_SIZE) 1312 pmd_clear(pmd_off_k(addr)); 1313 #else 1314 for (addr = 0; addr < MODULES_VADDR; addr += PMD_SIZE) 1315 pmd_clear(pmd_off_k(addr)); 1316 #endif 1317 1318 #ifdef CONFIG_XIP_KERNEL 1319 /* The XIP kernel is mapped in the module area -- skip over it */ 1320 addr = ((unsigned long)_exiprom + PMD_SIZE - 1) & PMD_MASK; 1321 #endif 1322 for ( ; addr < PAGE_OFFSET; addr += PMD_SIZE) 1323 pmd_clear(pmd_off_k(addr)); 1324 1325 /* 1326 * Find the end of the first block of lowmem. 1327 */ 1328 end = memblock.memory.regions[0].base + memblock.memory.regions[0].size; 1329 if (end >= arm_lowmem_limit) 1330 end = arm_lowmem_limit; 1331 1332 /* 1333 * Clear out all the kernel space mappings, except for the first 1334 * memory bank, up to the vmalloc region. 1335 */ 1336 for (addr = __phys_to_virt(end); 1337 addr < VMALLOC_START; addr += PMD_SIZE) 1338 pmd_clear(pmd_off_k(addr)); 1339 } 1340 1341 #ifdef CONFIG_ARM_LPAE 1342 /* the first page is reserved for pgd */ 1343 #define SWAPPER_PG_DIR_SIZE (PAGE_SIZE + \ 1344 PTRS_PER_PGD * PTRS_PER_PMD * sizeof(pmd_t)) 1345 #else 1346 #define SWAPPER_PG_DIR_SIZE (PTRS_PER_PGD * sizeof(pgd_t)) 1347 #endif 1348 1349 /* 1350 * Reserve the special regions of memory 1351 */ 1352 void __init arm_mm_memblock_reserve(void) 1353 { 1354 /* 1355 * Reserve the page tables. These are already in use, 1356 * and can only be in node 0. 1357 */ 1358 memblock_reserve(__pa(swapper_pg_dir), SWAPPER_PG_DIR_SIZE); 1359 1360 #ifdef CONFIG_SA1111 1361 /* 1362 * Because of the SA1111 DMA bug, we want to preserve our 1363 * precious DMA-able memory... 1364 */ 1365 memblock_reserve(PHYS_OFFSET, __pa(swapper_pg_dir) - PHYS_OFFSET); 1366 #endif 1367 } 1368 1369 /* 1370 * Set up the device mappings. Since we clear out the page tables for all 1371 * mappings above VMALLOC_START, except early fixmap, we might remove debug 1372 * device mappings. This means earlycon can be used to debug this function 1373 * Any other function or debugging method which may touch any device _will_ 1374 * crash the kernel. 1375 */ 1376 static void __init devicemaps_init(const struct machine_desc *mdesc) 1377 { 1378 struct map_desc map; 1379 unsigned long addr; 1380 void *vectors; 1381 1382 /* 1383 * Allocate the vector page early. 1384 */ 1385 vectors = early_alloc(PAGE_SIZE * 2); 1386 1387 early_trap_init(vectors); 1388 1389 /* 1390 * Clear page table except top pmd used by early fixmaps 1391 */ 1392 for (addr = VMALLOC_START; addr < (FIXADDR_TOP & PMD_MASK); addr += PMD_SIZE) 1393 pmd_clear(pmd_off_k(addr)); 1394 1395 if (__atags_pointer) { 1396 /* create a read-only mapping of the device tree */ 1397 map.pfn = __phys_to_pfn(__atags_pointer & SECTION_MASK); 1398 map.virtual = FDT_FIXED_BASE; 1399 map.length = FDT_FIXED_SIZE; 1400 map.type = MT_MEMORY_RO; 1401 create_mapping(&map); 1402 } 1403 1404 /* 1405 * Map the kernel if it is XIP. 1406 * It is always first in the modulearea. 1407 */ 1408 #ifdef CONFIG_XIP_KERNEL 1409 map.pfn = __phys_to_pfn(CONFIG_XIP_PHYS_ADDR & SECTION_MASK); 1410 map.virtual = MODULES_VADDR; 1411 map.length = ((unsigned long)_exiprom - map.virtual + ~SECTION_MASK) & SECTION_MASK; 1412 map.type = MT_ROM; 1413 create_mapping(&map); 1414 #endif 1415 1416 /* 1417 * Map the cache flushing regions. 1418 */ 1419 #ifdef FLUSH_BASE 1420 map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS); 1421 map.virtual = FLUSH_BASE; 1422 map.length = SZ_1M; 1423 map.type = MT_CACHECLEAN; 1424 create_mapping(&map); 1425 #endif 1426 #ifdef FLUSH_BASE_MINICACHE 1427 map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS + SZ_1M); 1428 map.virtual = FLUSH_BASE_MINICACHE; 1429 map.length = SZ_1M; 1430 map.type = MT_MINICLEAN; 1431 create_mapping(&map); 1432 #endif 1433 1434 /* 1435 * Create a mapping for the machine vectors at the high-vectors 1436 * location (0xffff0000). If we aren't using high-vectors, also 1437 * create a mapping at the low-vectors virtual address. 1438 */ 1439 map.pfn = __phys_to_pfn(virt_to_phys(vectors)); 1440 map.virtual = 0xffff0000; 1441 map.length = PAGE_SIZE; 1442 #ifdef CONFIG_KUSER_HELPERS 1443 map.type = MT_HIGH_VECTORS; 1444 #else 1445 map.type = MT_LOW_VECTORS; 1446 #endif 1447 create_mapping(&map); 1448 1449 if (!vectors_high()) { 1450 map.virtual = 0; 1451 map.length = PAGE_SIZE * 2; 1452 map.type = MT_LOW_VECTORS; 1453 create_mapping(&map); 1454 } 1455 1456 /* Now create a kernel read-only mapping */ 1457 map.pfn += 1; 1458 map.virtual = 0xffff0000 + PAGE_SIZE; 1459 map.length = PAGE_SIZE; 1460 map.type = MT_LOW_VECTORS; 1461 create_mapping(&map); 1462 1463 /* 1464 * Ask the machine support to map in the statically mapped devices. 1465 */ 1466 if (mdesc->map_io) 1467 mdesc->map_io(); 1468 else 1469 debug_ll_io_init(); 1470 fill_pmd_gaps(); 1471 1472 /* Reserve fixed i/o space in VMALLOC region */ 1473 pci_reserve_io(); 1474 1475 /* 1476 * Finally flush the caches and tlb to ensure that we're in a 1477 * consistent state wrt the writebuffer. This also ensures that 1478 * any write-allocated cache lines in the vector page are written 1479 * back. After this point, we can start to touch devices again. 1480 */ 1481 local_flush_tlb_all(); 1482 flush_cache_all(); 1483 1484 /* Enable asynchronous aborts */ 1485 early_abt_enable(); 1486 } 1487 1488 static void __init kmap_init(void) 1489 { 1490 #ifdef CONFIG_HIGHMEM 1491 pkmap_page_table = early_pte_alloc(pmd_off_k(PKMAP_BASE), 1492 PKMAP_BASE, _PAGE_KERNEL_TABLE); 1493 #endif 1494 1495 early_pte_alloc(pmd_off_k(FIXADDR_START), FIXADDR_START, 1496 _PAGE_KERNEL_TABLE); 1497 } 1498 1499 static void __init map_lowmem(void) 1500 { 1501 phys_addr_t start, end; 1502 u64 i; 1503 1504 /* Map all the lowmem memory banks. */ 1505 for_each_mem_range(i, &start, &end) { 1506 struct map_desc map; 1507 1508 pr_debug("map lowmem start: 0x%08llx, end: 0x%08llx\n", 1509 (long long)start, (long long)end); 1510 if (end > arm_lowmem_limit) 1511 end = arm_lowmem_limit; 1512 if (start >= end) 1513 break; 1514 1515 /* 1516 * If our kernel image is in the VMALLOC area we need to remove 1517 * the kernel physical memory from lowmem since the kernel will 1518 * be mapped separately. 1519 * 1520 * The kernel will typically be at the very start of lowmem, 1521 * but any placement relative to memory ranges is possible. 1522 * 1523 * If the memblock contains the kernel, we have to chisel out 1524 * the kernel memory from it and map each part separately. We 1525 * get 6 different theoretical cases: 1526 * 1527 * +--------+ +--------+ 1528 * +-- start --+ +--------+ | Kernel | | Kernel | 1529 * | | | Kernel | | case 2 | | case 5 | 1530 * | | | case 1 | +--------+ | | +--------+ 1531 * | Memory | +--------+ | | | Kernel | 1532 * | range | +--------+ | | | case 6 | 1533 * | | | Kernel | +--------+ | | +--------+ 1534 * | | | case 3 | | Kernel | | | 1535 * +-- end ----+ +--------+ | case 4 | | | 1536 * +--------+ +--------+ 1537 */ 1538 1539 /* Case 5: kernel covers range, don't map anything, should be rare */ 1540 if ((start > kernel_sec_start) && (end < kernel_sec_end)) 1541 break; 1542 1543 /* Cases where the kernel is starting inside the range */ 1544 if ((kernel_sec_start >= start) && (kernel_sec_start <= end)) { 1545 /* Case 6: kernel is embedded in the range, we need two mappings */ 1546 if ((start < kernel_sec_start) && (end > kernel_sec_end)) { 1547 /* Map memory below the kernel */ 1548 map.pfn = __phys_to_pfn(start); 1549 map.virtual = __phys_to_virt(start); 1550 map.length = kernel_sec_start - start; 1551 map.type = MT_MEMORY_RW; 1552 create_mapping(&map); 1553 /* Map memory above the kernel */ 1554 map.pfn = __phys_to_pfn(kernel_sec_end); 1555 map.virtual = __phys_to_virt(kernel_sec_end); 1556 map.length = end - kernel_sec_end; 1557 map.type = MT_MEMORY_RW; 1558 create_mapping(&map); 1559 break; 1560 } 1561 /* Case 1: kernel and range start at the same address, should be common */ 1562 if (kernel_sec_start == start) 1563 start = kernel_sec_end; 1564 /* Case 3: kernel and range end at the same address, should be rare */ 1565 if (kernel_sec_end == end) 1566 end = kernel_sec_start; 1567 } else if ((kernel_sec_start < start) && (kernel_sec_end > start) && (kernel_sec_end < end)) { 1568 /* Case 2: kernel ends inside range, starts below it */ 1569 start = kernel_sec_end; 1570 } else if ((kernel_sec_start > start) && (kernel_sec_start < end) && (kernel_sec_end > end)) { 1571 /* Case 4: kernel starts inside range, ends above it */ 1572 end = kernel_sec_start; 1573 } 1574 map.pfn = __phys_to_pfn(start); 1575 map.virtual = __phys_to_virt(start); 1576 map.length = end - start; 1577 map.type = MT_MEMORY_RW; 1578 create_mapping(&map); 1579 } 1580 } 1581 1582 static void __init map_kernel(void) 1583 { 1584 /* 1585 * We use the well known kernel section start and end and split the area in the 1586 * middle like this: 1587 * . . 1588 * | RW memory | 1589 * +----------------+ kernel_x_start 1590 * | Executable | 1591 * | kernel memory | 1592 * +----------------+ kernel_x_end / kernel_nx_start 1593 * | Non-executable | 1594 * | kernel memory | 1595 * +----------------+ kernel_nx_end 1596 * | RW memory | 1597 * . . 1598 * 1599 * Notice that we are dealing with section sized mappings here so all of this 1600 * will be bumped to the closest section boundary. This means that some of the 1601 * non-executable part of the kernel memory is actually mapped as executable. 1602 * This will only persist until we turn on proper memory management later on 1603 * and we remap the whole kernel with page granularity. 1604 */ 1605 phys_addr_t kernel_x_start = kernel_sec_start; 1606 phys_addr_t kernel_x_end = round_up(__pa(__init_end), SECTION_SIZE); 1607 phys_addr_t kernel_nx_start = kernel_x_end; 1608 phys_addr_t kernel_nx_end = kernel_sec_end; 1609 struct map_desc map; 1610 1611 map.pfn = __phys_to_pfn(kernel_x_start); 1612 map.virtual = __phys_to_virt(kernel_x_start); 1613 map.length = kernel_x_end - kernel_x_start; 1614 map.type = MT_MEMORY_RWX; 1615 create_mapping(&map); 1616 1617 /* If the nx part is small it may end up covered by the tail of the RWX section */ 1618 if (kernel_x_end == kernel_nx_end) 1619 return; 1620 1621 map.pfn = __phys_to_pfn(kernel_nx_start); 1622 map.virtual = __phys_to_virt(kernel_nx_start); 1623 map.length = kernel_nx_end - kernel_nx_start; 1624 map.type = MT_MEMORY_RW; 1625 create_mapping(&map); 1626 } 1627 1628 #ifdef CONFIG_ARM_PV_FIXUP 1629 typedef void pgtables_remap(long long offset, unsigned long pgd); 1630 pgtables_remap lpae_pgtables_remap_asm; 1631 1632 /* 1633 * early_paging_init() recreates boot time page table setup, allowing machines 1634 * to switch over to a high (>4G) address space on LPAE systems 1635 */ 1636 static void __init early_paging_init(const struct machine_desc *mdesc) 1637 { 1638 pgtables_remap *lpae_pgtables_remap; 1639 unsigned long pa_pgd; 1640 unsigned int cr, ttbcr; 1641 long long offset; 1642 1643 if (!mdesc->pv_fixup) 1644 return; 1645 1646 offset = mdesc->pv_fixup(); 1647 if (offset == 0) 1648 return; 1649 1650 /* 1651 * Offset the kernel section physical offsets so that the kernel 1652 * mapping will work out later on. 1653 */ 1654 kernel_sec_start += offset; 1655 kernel_sec_end += offset; 1656 1657 /* 1658 * Get the address of the remap function in the 1:1 identity 1659 * mapping setup by the early page table assembly code. We 1660 * must get this prior to the pv update. The following barrier 1661 * ensures that this is complete before we fixup any P:V offsets. 1662 */ 1663 lpae_pgtables_remap = (pgtables_remap *)(unsigned long)__pa(lpae_pgtables_remap_asm); 1664 pa_pgd = __pa(swapper_pg_dir); 1665 barrier(); 1666 1667 pr_info("Switching physical address space to 0x%08llx\n", 1668 (u64)PHYS_OFFSET + offset); 1669 1670 /* Re-set the phys pfn offset, and the pv offset */ 1671 __pv_offset += offset; 1672 __pv_phys_pfn_offset += PFN_DOWN(offset); 1673 1674 /* Run the patch stub to update the constants */ 1675 fixup_pv_table(&__pv_table_begin, 1676 (&__pv_table_end - &__pv_table_begin) << 2); 1677 1678 /* 1679 * We changing not only the virtual to physical mapping, but also 1680 * the physical addresses used to access memory. We need to flush 1681 * all levels of cache in the system with caching disabled to 1682 * ensure that all data is written back, and nothing is prefetched 1683 * into the caches. We also need to prevent the TLB walkers 1684 * allocating into the caches too. Note that this is ARMv7 LPAE 1685 * specific. 1686 */ 1687 cr = get_cr(); 1688 set_cr(cr & ~(CR_I | CR_C)); 1689 asm("mrc p15, 0, %0, c2, c0, 2" : "=r" (ttbcr)); 1690 asm volatile("mcr p15, 0, %0, c2, c0, 2" 1691 : : "r" (ttbcr & ~(3 << 8 | 3 << 10))); 1692 flush_cache_all(); 1693 1694 /* 1695 * Fixup the page tables - this must be in the idmap region as 1696 * we need to disable the MMU to do this safely, and hence it 1697 * needs to be assembly. It's fairly simple, as we're using the 1698 * temporary tables setup by the initial assembly code. 1699 */ 1700 lpae_pgtables_remap(offset, pa_pgd); 1701 1702 /* Re-enable the caches and cacheable TLB walks */ 1703 asm volatile("mcr p15, 0, %0, c2, c0, 2" : : "r" (ttbcr)); 1704 set_cr(cr); 1705 } 1706 1707 #else 1708 1709 static void __init early_paging_init(const struct machine_desc *mdesc) 1710 { 1711 long long offset; 1712 1713 if (!mdesc->pv_fixup) 1714 return; 1715 1716 offset = mdesc->pv_fixup(); 1717 if (offset == 0) 1718 return; 1719 1720 pr_crit("Physical address space modification is only to support Keystone2.\n"); 1721 pr_crit("Please enable ARM_LPAE and ARM_PATCH_PHYS_VIRT support to use this\n"); 1722 pr_crit("feature. Your kernel may crash now, have a good day.\n"); 1723 add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK); 1724 } 1725 1726 #endif 1727 1728 static void __init early_fixmap_shutdown(void) 1729 { 1730 int i; 1731 unsigned long va = fix_to_virt(__end_of_permanent_fixed_addresses - 1); 1732 1733 pte_offset_fixmap = pte_offset_late_fixmap; 1734 pmd_clear(fixmap_pmd(va)); 1735 local_flush_tlb_kernel_page(va); 1736 1737 for (i = 0; i < __end_of_permanent_fixed_addresses; i++) { 1738 pte_t *pte; 1739 struct map_desc map; 1740 1741 map.virtual = fix_to_virt(i); 1742 pte = pte_offset_early_fixmap(pmd_off_k(map.virtual), map.virtual); 1743 1744 /* Only i/o device mappings are supported ATM */ 1745 if (pte_none(*pte) || 1746 (pte_val(*pte) & L_PTE_MT_MASK) != L_PTE_MT_DEV_SHARED) 1747 continue; 1748 1749 map.pfn = pte_pfn(*pte); 1750 map.type = MT_DEVICE; 1751 map.length = PAGE_SIZE; 1752 1753 create_mapping(&map); 1754 } 1755 } 1756 1757 /* 1758 * paging_init() sets up the page tables, initialises the zone memory 1759 * maps, and sets up the zero page, bad page and bad page tables. 1760 */ 1761 void __init paging_init(const struct machine_desc *mdesc) 1762 { 1763 void *zero_page; 1764 1765 pr_debug("physical kernel sections: 0x%08llx-0x%08llx\n", 1766 kernel_sec_start, kernel_sec_end); 1767 1768 prepare_page_table(); 1769 map_lowmem(); 1770 memblock_set_current_limit(arm_lowmem_limit); 1771 pr_debug("lowmem limit is %08llx\n", (long long)arm_lowmem_limit); 1772 /* 1773 * After this point early_alloc(), i.e. the memblock allocator, can 1774 * be used 1775 */ 1776 map_kernel(); 1777 dma_contiguous_remap(); 1778 early_fixmap_shutdown(); 1779 devicemaps_init(mdesc); 1780 kmap_init(); 1781 tcm_init(); 1782 1783 top_pmd = pmd_off_k(0xffff0000); 1784 1785 /* allocate the zero page. */ 1786 zero_page = early_alloc(PAGE_SIZE); 1787 1788 bootmem_init(); 1789 1790 empty_zero_page = virt_to_page(zero_page); 1791 __flush_dcache_page(NULL, empty_zero_page); 1792 } 1793 1794 void __init early_mm_init(const struct machine_desc *mdesc) 1795 { 1796 build_mem_type_table(); 1797 early_paging_init(mdesc); 1798 } 1799 1800 void set_pte_at(struct mm_struct *mm, unsigned long addr, 1801 pte_t *ptep, pte_t pteval) 1802 { 1803 unsigned long ext = 0; 1804 1805 if (addr < TASK_SIZE && pte_valid_user(pteval)) { 1806 if (!pte_special(pteval)) 1807 __sync_icache_dcache(pteval); 1808 ext |= PTE_EXT_NG; 1809 } 1810 1811 set_pte_ext(ptep, pteval, ext); 1812 } 1813