arch/arm/mm/mmu.c

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