arch/arm/mm/init.c

   1 /*
   2  *  linux/arch/arm/mm/init.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/kernel.h>
  11 #include <linux/errno.h>
  12 #include <linux/swap.h>
  13 #include <linux/init.h>
  14 #include <linux/bootmem.h>
  15 #include <linux/mman.h>
  16 #include <linux/export.h>
  17 #include <linux/nodemask.h>
  18 #include <linux/initrd.h>
  19 #include <linux/of_fdt.h>
  20 #include <linux/highmem.h>
  21 #include <linux/gfp.h>
  22 #include <linux/memblock.h>
  23 #include <linux/dma-contiguous.h>
  24 #include <linux/sizes.h>
  25
  26 #include <asm/cp15.h>
  27 #include <asm/mach-types.h>
  28 #include <asm/memblock.h>
  29 #include <asm/prom.h>
  30 #include <asm/sections.h>
  31 #include <asm/setup.h>
  32 #include <asm/system_info.h>
  33 #include <asm/tlb.h>
  34 #include <asm/fixmap.h>
  35
  36 #include <asm/mach/arch.h>
  37 #include <asm/mach/map.h>
  38
  39 #include "mm.h"
  40
  41 #ifdef CONFIG_CPU_CP15_MMU
  42 unsigned long __init __clear_cr(unsigned long mask)
  43 {
  44         cr_alignment = cr_alignment & ~mask;
  45         return cr_alignment;
  46 }
  47 #endif
  48
  49 static phys_addr_t phys_initrd_start __initdata = 0;
  50 static unsigned long phys_initrd_size __initdata = 0;
  51
  52 static int __init early_initrd(char *p)
  53 {
  54         phys_addr_t start;
  55         unsigned long size;
  56         char *endp;
  57
  58         start = memparse(p, &endp);
  59         if (*endp == ',') {
  60                 size = memparse(endp + 1, NULL);
  61
  62                 phys_initrd_start = start;
  63                 phys_initrd_size = size;
  64         }
  65         return 0;
  66 }
  67 early_param("initrd", early_initrd);
  68
  69 static int __init parse_tag_initrd(const struct tag *tag)
  70 {
  71         pr_warn("ATAG_INITRD is deprecated; "
  72                 "please update your bootloader.\n");
  73         phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
  74         phys_initrd_size = tag->u.initrd.size;
  75         return 0;
  76 }
  77
  78 __tagtable(ATAG_INITRD, parse_tag_initrd);
  79
  80 static int __init parse_tag_initrd2(const struct tag *tag)
  81 {
  82         phys_initrd_start = tag->u.initrd.start;
  83         phys_initrd_size = tag->u.initrd.size;
  84         return 0;
  85 }
  86
  87 __tagtable(ATAG_INITRD2, parse_tag_initrd2);
  88
  89 /*
  90  * This keeps memory configuration data used by a couple memory
  91  * initialization functions, as well as show_mem() for the skipping
  92  * of holes in the memory map.  It is populated by arm_add_memory().
  93  */
  94 void show_mem(unsigned int filter)
  95 {
  96         int free = 0, total = 0, reserved = 0;
  97         int shared = 0, cached = 0, slab = 0;
  98         struct memblock_region *reg;
  99
 100         printk("Mem-info:\n");
 101         show_free_areas(filter);
 102
 103         for_each_memblock (memory, reg) {
 104                 unsigned int pfn1, pfn2;
 105                 struct page *page, *end;
 106
 107                 pfn1 = memblock_region_memory_base_pfn(reg);
 108                 pfn2 = memblock_region_memory_end_pfn(reg);
 109
 110                 page = pfn_to_page(pfn1);
 111                 end  = pfn_to_page(pfn2 - 1) + 1;
 112
 113                 do {
 114                         total++;
 115                         if (PageReserved(page))
 116                                 reserved++;
 117                         else if (PageSwapCache(page))
 118                                 cached++;
 119                         else if (PageSlab(page))
 120                                 slab++;
 121                         else if (!page_count(page))
 122                                 free++;
 123                         else
 124                                 shared += page_count(page) - 1;
 125                         pfn1++;
 126                         page = pfn_to_page(pfn1);
 127                 } while (pfn1 < pfn2);
 128         }
 129
 130         printk("%d pages of RAM\n", total);
 131         printk("%d free pages\n", free);
 132         printk("%d reserved pages\n", reserved);
 133         printk("%d slab pages\n", slab);
 134         printk("%d pages shared\n", shared);
 135         printk("%d pages swap cached\n", cached);
 136 }
 137
 138 static void __init find_limits(unsigned long *min, unsigned long *max_low,
 139                                unsigned long *max_high)
 140 {
 141         *max_low = PFN_DOWN(memblock_get_current_limit());
 142         *min = PFN_UP(memblock_start_of_DRAM());
 143         *max_high = PFN_DOWN(memblock_end_of_DRAM());
 144 }
 145
 146 #ifdef CONFIG_ZONE_DMA
 147
 148 phys_addr_t arm_dma_zone_size __read_mostly;
 149 EXPORT_SYMBOL(arm_dma_zone_size);
 150
 151 /*
 152  * The DMA mask corresponding to the maximum bus address allocatable
 153  * using GFP_DMA.  The default here places no restriction on DMA
 154  * allocations.  This must be the smallest DMA mask in the system,
 155  * so a successful GFP_DMA allocation will always satisfy this.
 156  */
 157 phys_addr_t arm_dma_limit;
 158 unsigned long arm_dma_pfn_limit;
 159
 160 static void __init arm_adjust_dma_zone(unsigned long *size, unsigned long *hole,
 161         unsigned long dma_size)
 162 {
 163         if (size[0] <= dma_size)
 164                 return;
 165
 166         size[ZONE_NORMAL] = size[0] - dma_size;
 167         size[ZONE_DMA] = dma_size;
 168         hole[ZONE_NORMAL] = hole[0];
 169         hole[ZONE_DMA] = 0;
 170 }
 171 #endif
 172
 173 void __init setup_dma_zone(const struct machine_desc *mdesc)
 174 {
 175 #ifdef CONFIG_ZONE_DMA
 176         if (mdesc->dma_zone_size) {
 177                 arm_dma_zone_size = mdesc->dma_zone_size;
 178                 arm_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1;
 179         } else
 180                 arm_dma_limit = 0xffffffff;
 181         arm_dma_pfn_limit = arm_dma_limit >> PAGE_SHIFT;
 182 #endif
 183 }
 184
 185 static void __init zone_sizes_init(unsigned long min, unsigned long max_low,
 186         unsigned long max_high)
 187 {
 188         unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
 189         struct memblock_region *reg;
 190
 191         /*
 192          * initialise the zones.
 193          */
 194         memset(zone_size, 0, sizeof(zone_size));
 195
 196         /*
 197          * The memory size has already been determined.  If we need
 198          * to do anything fancy with the allocation of this memory
 199          * to the zones, now is the time to do it.
 200          */
 201         zone_size[0] = max_low - min;
 202 #ifdef CONFIG_HIGHMEM
 203         zone_size[ZONE_HIGHMEM] = max_high - max_low;
 204 #endif
 205
 206         /*
 207          * Calculate the size of the holes.
 208          *  holes = node_size - sum(bank_sizes)
 209          */
 210         memcpy(zhole_size, zone_size, sizeof(zhole_size));
 211         for_each_memblock(memory, reg) {
 212                 unsigned long start = memblock_region_memory_base_pfn(reg);
 213                 unsigned long end = memblock_region_memory_end_pfn(reg);
 214
 215                 if (start < max_low) {
 216                         unsigned long low_end = min(end, max_low);
 217                         zhole_size[0] -= low_end - start;
 218                 }
 219 #ifdef CONFIG_HIGHMEM
 220                 if (end > max_low) {
 221                         unsigned long high_start = max(start, max_low);
 222                         zhole_size[ZONE_HIGHMEM] -= end - high_start;
 223                 }
 224 #endif
 225         }
 226
 227 #ifdef CONFIG_ZONE_DMA
 228         /*
 229          * Adjust the sizes according to any special requirements for
 230          * this machine type.
 231          */
 232         if (arm_dma_zone_size)
 233                 arm_adjust_dma_zone(zone_size, zhole_size,
 234                         arm_dma_zone_size >> PAGE_SHIFT);
 235 #endif
 236
 237         free_area_init_node(0, zone_size, min, zhole_size);
 238 }
 239
 240 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
 241 int pfn_valid(unsigned long pfn)
 242 {
 243         return memblock_is_memory(__pfn_to_phys(pfn));
 244 }
 245 EXPORT_SYMBOL(pfn_valid);
 246 #endif
 247
 248 #ifndef CONFIG_SPARSEMEM
 249 static void __init arm_memory_present(void)
 250 {
 251 }
 252 #else
 253 static void __init arm_memory_present(void)
 254 {
 255         struct memblock_region *reg;
 256
 257         for_each_memblock(memory, reg)
 258                 memory_present(0, memblock_region_memory_base_pfn(reg),
 259                                memblock_region_memory_end_pfn(reg));
 260 }
 261 #endif
 262
 263 static bool arm_memblock_steal_permitted = true;
 264
 265 phys_addr_t __init arm_memblock_steal(phys_addr_t size, phys_addr_t align)
 266 {
 267         phys_addr_t phys;
 268
 269         BUG_ON(!arm_memblock_steal_permitted);
 270
 271         phys = memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ANYWHERE);
 272         memblock_free(phys, size);
 273         memblock_remove(phys, size);
 274
 275         return phys;
 276 }
 277
 278 void __init arm_memblock_init(const struct machine_desc *mdesc)
 279 {
 280         /* Register the kernel text, kernel data and initrd with memblock. */
 281 #ifdef CONFIG_XIP_KERNEL
 282         memblock_reserve(__pa(_sdata), _end - _sdata);
 283 #else
 284         memblock_reserve(__pa(_stext), _end - _stext);
 285 #endif
 286 #ifdef CONFIG_BLK_DEV_INITRD
 287         /* FDT scan will populate initrd_start */
 288         if (initrd_start && !phys_initrd_size) {
 289                 phys_initrd_start = __virt_to_phys(initrd_start);
 290                 phys_initrd_size = initrd_end - initrd_start;
 291         }
 292         initrd_start = initrd_end = 0;
 293         if (phys_initrd_size &&
 294             !memblock_is_region_memory(phys_initrd_start, phys_initrd_size)) {
 295                 pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region - disabling initrd\n",
 296                        (u64)phys_initrd_start, phys_initrd_size);
 297                 phys_initrd_start = phys_initrd_size = 0;
 298         }
 299         if (phys_initrd_size &&
 300             memblock_is_region_reserved(phys_initrd_start, phys_initrd_size)) {
 301                 pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region - disabling initrd\n",
 302                        (u64)phys_initrd_start, phys_initrd_size);
 303                 phys_initrd_start = phys_initrd_size = 0;
 304         }
 305         if (phys_initrd_size) {
 306                 memblock_reserve(phys_initrd_start, phys_initrd_size);
 307
 308                 /* Now convert initrd to virtual addresses */
 309                 initrd_start = __phys_to_virt(phys_initrd_start);
 310                 initrd_end = initrd_start + phys_initrd_size;
 311         }
 312 #endif
 313
 314         arm_mm_memblock_reserve();
 315
 316         /* reserve any platform specific memblock areas */
 317         if (mdesc->reserve)
 318                 mdesc->reserve();
 319
 320         early_init_fdt_scan_reserved_mem();
 321
 322         /*
 323          * reserve memory for DMA contigouos allocations,
 324          * must come from DMA area inside low memory
 325          */
 326         dma_contiguous_reserve(arm_dma_limit);
 327
 328         arm_memblock_steal_permitted = false;
 329         memblock_dump_all();
 330 }
 331
 332 void __init bootmem_init(void)
 333 {
 334         unsigned long min, max_low, max_high;
 335
 336         memblock_allow_resize();
 337         max_low = max_high = 0;
 338
 339         find_limits(&min, &max_low, &max_high);
 340
 341         /*
 342          * Sparsemem tries to allocate bootmem in memory_present(),
 343          * so must be done after the fixed reservations
 344          */
 345         arm_memory_present();
 346
 347         /*
 348          * sparse_init() needs the bootmem allocator up and running.
 349          */
 350         sparse_init();
 351
 352         /*
 353          * Now free the memory - free_area_init_node needs
 354          * the sparse mem_map arrays initialized by sparse_init()
 355          * for memmap_init_zone(), otherwise all PFNs are invalid.
 356          */
 357         zone_sizes_init(min, max_low, max_high);
 358
 359         /*
 360          * This doesn't seem to be used by the Linux memory manager any
 361          * more, but is used by ll_rw_block.  If we can get rid of it, we
 362          * also get rid of some of the stuff above as well.
 363          */
 364         min_low_pfn = min;
 365         max_low_pfn = max_low;
 366         max_pfn = max_high;
 367 }
 368
 369 /*
 370  * Poison init memory with an undefined instruction (ARM) or a branch to an
 371  * undefined instruction (Thumb).
 372  */
 373 static inline void poison_init_mem(void *s, size_t count)
 374 {
 375         u32 *p = (u32 *)s;
 376         for (; count != 0; count -= 4)
 377                 *p++ = 0xe7fddef0;
 378 }
 379
 380 static inline void
 381 free_memmap(unsigned long start_pfn, unsigned long end_pfn)
 382 {
 383         struct page *start_pg, *end_pg;
 384         phys_addr_t pg, pgend;
 385
 386         /*
 387          * Convert start_pfn/end_pfn to a struct page pointer.
 388          */
 389         start_pg = pfn_to_page(start_pfn - 1) + 1;
 390         end_pg = pfn_to_page(end_pfn - 1) + 1;
 391
 392         /*
 393          * Convert to physical addresses, and
 394          * round start upwards and end downwards.
 395          */
 396         pg = PAGE_ALIGN(__pa(start_pg));
 397         pgend = __pa(end_pg) & PAGE_MASK;
 398
 399         /*
 400          * If there are free pages between these,
 401          * free the section of the memmap array.
 402          */
 403         if (pg < pgend)
 404                 memblock_free_early(pg, pgend - pg);
 405 }
 406
 407 /*
 408  * The mem_map array can get very big.  Free the unused area of the memory map.
 409  */
 410 static void __init free_unused_memmap(void)
 411 {
 412         unsigned long start, prev_end = 0;
 413         struct memblock_region *reg;
 414
 415         /*
 416          * This relies on each bank being in address order.
 417          * The banks are sorted previously in bootmem_init().
 418          */
 419         for_each_memblock(memory, reg) {
 420                 start = memblock_region_memory_base_pfn(reg);
 421
 422 #ifdef CONFIG_SPARSEMEM
 423                 /*
 424                  * Take care not to free memmap entries that don't exist
 425                  * due to SPARSEMEM sections which aren't present.
 426                  */
 427                 start = min(start,
 428                                  ALIGN(prev_end, PAGES_PER_SECTION));
 429 #else
 430                 /*
 431                  * Align down here since the VM subsystem insists that the
 432                  * memmap entries are valid from the bank start aligned to
 433                  * MAX_ORDER_NR_PAGES.
 434                  */
 435                 start = round_down(start, MAX_ORDER_NR_PAGES);
 436 #endif
 437                 /*
 438                  * If we had a previous bank, and there is a space
 439                  * between the current bank and the previous, free it.
 440                  */
 441                 if (prev_end && prev_end < start)
 442                         free_memmap(prev_end, start);
 443
 444                 /*
 445                  * Align up here since the VM subsystem insists that the
 446                  * memmap entries are valid from the bank end aligned to
 447                  * MAX_ORDER_NR_PAGES.
 448                  */
 449                 prev_end = ALIGN(memblock_region_memory_end_pfn(reg),
 450                                  MAX_ORDER_NR_PAGES);
 451         }
 452
 453 #ifdef CONFIG_SPARSEMEM
 454         if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
 455                 free_memmap(prev_end,
 456                             ALIGN(prev_end, PAGES_PER_SECTION));
 457 #endif
 458 }
 459
 460 #ifdef CONFIG_HIGHMEM
 461 static inline void free_area_high(unsigned long pfn, unsigned long end)
 462 {
 463         for (; pfn < end; pfn++)
 464                 free_highmem_page(pfn_to_page(pfn));
 465 }
 466 #endif
 467
 468 static void __init free_highpages(void)
 469 {
 470 #ifdef CONFIG_HIGHMEM
 471         unsigned long max_low = max_low_pfn;
 472         struct memblock_region *mem, *res;
 473
 474         /* set highmem page free */
 475         for_each_memblock(memory, mem) {
 476                 unsigned long start = memblock_region_memory_base_pfn(mem);
 477                 unsigned long end = memblock_region_memory_end_pfn(mem);
 478
 479                 /* Ignore complete lowmem entries */
 480                 if (end <= max_low)
 481                         continue;
 482
 483                 /* Truncate partial highmem entries */
 484                 if (start < max_low)
 485                         start = max_low;
 486
 487                 /* Find and exclude any reserved regions */
 488                 for_each_memblock(reserved, res) {
 489                         unsigned long res_start, res_end;
 490
 491                         res_start = memblock_region_reserved_base_pfn(res);
 492                         res_end = memblock_region_reserved_end_pfn(res);
 493
 494                         if (res_end < start)
 495                                 continue;
 496                         if (res_start < start)
 497                                 res_start = start;
 498                         if (res_start > end)
 499                                 res_start = end;
 500                         if (res_end > end)
 501                                 res_end = end;
 502                         if (res_start != start)
 503                                 free_area_high(start, res_start);
 504                         start = res_end;
 505                         if (start == end)
 506                                 break;
 507                 }
 508
 509                 /* And now free anything which remains */
 510                 if (start < end)
 511                         free_area_high(start, end);
 512         }
 513 #endif
 514 }
 515
 516 /*
 517  * mem_init() marks the free areas in the mem_map and tells us how much
 518  * memory is free.  This is done after various parts of the system have
 519  * claimed their memory after the kernel image.
 520  */
 521 void __init mem_init(void)
 522 {
 523 #ifdef CONFIG_HAVE_TCM
 524         /* These pointers are filled in on TCM detection */
 525         extern u32 dtcm_end;
 526         extern u32 itcm_end;
 527 #endif
 528
 529         set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
 530
 531         /* this will put all unused low memory onto the freelists */
 532         free_unused_memmap();
 533         free_all_bootmem();
 534
 535 #ifdef CONFIG_SA1111
 536         /* now that our DMA memory is actually so designated, we can free it */
 537         free_reserved_area(__va(PHYS_OFFSET), swapper_pg_dir, -1, NULL);
 538 #endif
 539
 540         free_highpages();
 541
 542         mem_init_print_info(NULL);
 543
 544 #define MLK(b, t) b, t, ((t) - (b)) >> 10
 545 #define MLM(b, t) b, t, ((t) - (b)) >> 20
 546 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
 547
 548         pr_notice("Virtual kernel memory layout:\n"
 549                         "    vector  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 550 #ifdef CONFIG_HAVE_TCM
 551                         "    DTCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 552                         "    ITCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 553 #endif
 554                         "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 555                         "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 556                         "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 557 #ifdef CONFIG_HIGHMEM
 558                         "    pkmap   : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 559 #endif
 560 #ifdef CONFIG_MODULES
 561                         "    modules : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 562 #endif
 563                         "      .text : 0x%p" " - 0x%p" "   (%4td kB)\n"
 564                         "      .init : 0x%p" " - 0x%p" "   (%4td kB)\n"
 565                         "      .data : 0x%p" " - 0x%p" "   (%4td kB)\n"
 566                         "       .bss : 0x%p" " - 0x%p" "   (%4td kB)\n",
 567
 568                         MLK(UL(CONFIG_VECTORS_BASE), UL(CONFIG_VECTORS_BASE) +
 569                                 (PAGE_SIZE)),
 570 #ifdef CONFIG_HAVE_TCM
 571                         MLK(DTCM_OFFSET, (unsigned long) dtcm_end),
 572                         MLK(ITCM_OFFSET, (unsigned long) itcm_end),
 573 #endif
 574                         MLK(FIXADDR_START, FIXADDR_END),
 575                         MLM(VMALLOC_START, VMALLOC_END),
 576                         MLM(PAGE_OFFSET, (unsigned long)high_memory),
 577 #ifdef CONFIG_HIGHMEM
 578                         MLM(PKMAP_BASE, (PKMAP_BASE) + (LAST_PKMAP) *
 579                                 (PAGE_SIZE)),
 580 #endif
 581 #ifdef CONFIG_MODULES
 582                         MLM(MODULES_VADDR, MODULES_END),
 583 #endif
 584
 585                         MLK_ROUNDUP(_text, _etext),
 586                         MLK_ROUNDUP(__init_begin, __init_end),
 587                         MLK_ROUNDUP(_sdata, _edata),
 588                         MLK_ROUNDUP(__bss_start, __bss_stop));
 589
 590 #undef MLK
 591 #undef MLM
 592 #undef MLK_ROUNDUP
 593
 594         /*
 595          * Check boundaries twice: Some fundamental inconsistencies can
 596          * be detected at build time already.
 597          */
 598 #ifdef CONFIG_MMU
 599         BUILD_BUG_ON(TASK_SIZE                          > MODULES_VADDR);
 600         BUG_ON(TASK_SIZE                                > MODULES_VADDR);
 601 #endif
 602
 603 #ifdef CONFIG_HIGHMEM
 604         BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
 605         BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE      > PAGE_OFFSET);
 606 #endif
 607
 608         if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
 609                 extern int sysctl_overcommit_memory;
 610                 /*
 611                  * On a machine this small we won't get
 612                  * anywhere without overcommit, so turn
 613                  * it on by default.
 614                  */
 615                 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
 616         }
 617 }
 618
 619 #ifdef CONFIG_ARM_KERNMEM_PERMS
 620 struct section_perm {
 621         unsigned long start;
 622         unsigned long end;
 623         pmdval_t mask;
 624         pmdval_t prot;
 625         pmdval_t clear;
 626 };
 627
 628 static struct section_perm nx_perms[] = {
 629         /* Make pages tables, etc before _stext RW (set NX). */
 630         {
 631                 .start  = PAGE_OFFSET,
 632                 .end    = (unsigned long)_stext,
 633                 .mask   = ~PMD_SECT_XN,
 634                 .prot   = PMD_SECT_XN,
 635         },
 636         /* Make init RW (set NX). */
 637         {
 638                 .start  = (unsigned long)__init_begin,
 639                 .end    = (unsigned long)_sdata,
 640                 .mask   = ~PMD_SECT_XN,
 641                 .prot   = PMD_SECT_XN,
 642         },
 643 #ifdef CONFIG_DEBUG_RODATA
 644         /* Make rodata NX (set RO in ro_perms below). */
 645         {
 646                 .start  = (unsigned long)__start_rodata,
 647                 .end    = (unsigned long)__init_begin,
 648                 .mask   = ~PMD_SECT_XN,
 649                 .prot   = PMD_SECT_XN,
 650         },
 651 #endif
 652 };
 653
 654 #ifdef CONFIG_DEBUG_RODATA
 655 static struct section_perm ro_perms[] = {
 656         /* Make kernel code and rodata RX (set RO). */
 657         {
 658                 .start  = (unsigned long)_stext,
 659                 .end    = (unsigned long)__init_begin,
 660 #ifdef CONFIG_ARM_LPAE
 661                 .mask   = ~PMD_SECT_RDONLY,
 662                 .prot   = PMD_SECT_RDONLY,
 663 #else
 664                 .mask   = ~(PMD_SECT_APX | PMD_SECT_AP_WRITE),
 665                 .prot   = PMD_SECT_APX | PMD_SECT_AP_WRITE,
 666                 .clear  = PMD_SECT_AP_WRITE,
 667 #endif
 668         },
 669 };
 670 #endif
 671
 672 /*
 673  * Updates section permissions only for the current mm (sections are
 674  * copied into each mm). During startup, this is the init_mm. Is only
 675  * safe to be called with preemption disabled, as under stop_machine().
 676  */
 677 static inline void section_update(unsigned long addr, pmdval_t mask,
 678                                   pmdval_t prot)
 679 {
 680         struct mm_struct *mm;
 681         pmd_t *pmd;
 682
 683         mm = current->active_mm;
 684         pmd = pmd_offset(pud_offset(pgd_offset(mm, addr), addr), addr);
 685
 686 #ifdef CONFIG_ARM_LPAE
 687         pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot);
 688 #else
 689         if (addr & SECTION_SIZE)
 690                 pmd[1] = __pmd((pmd_val(pmd[1]) & mask) | prot);
 691         else
 692                 pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot);
 693 #endif
 694         flush_pmd_entry(pmd);
 695         local_flush_tlb_kernel_range(addr, addr + SECTION_SIZE);
 696 }
 697
 698 /* Make sure extended page tables are in use. */
 699 static inline bool arch_has_strict_perms(void)
 700 {
 701         if (cpu_architecture() < CPU_ARCH_ARMv6)
 702                 return false;
 703
 704         return !!(get_cr() & CR_XP);
 705 }
 706
 707 #define set_section_perms(perms, field) {                               \
 708         size_t i;                                                       \
 709         unsigned long addr;                                             \
 710                                                                         \
 711         if (!arch_has_strict_perms())                                   \
 712                 return;                                                 \
 713                                                                         \
 714         for (i = 0; i < ARRAY_SIZE(perms); i++) {                       \
 715                 if (!IS_ALIGNED(perms[i].start, SECTION_SIZE) ||        \
 716                     !IS_ALIGNED(perms[i].end, SECTION_SIZE)) {          \
 717                         pr_err("BUG: section %lx-%lx not aligned to %lx\n", \
 718                                 perms[i].start, perms[i].end,           \
 719                                 SECTION_SIZE);                          \
 720                         continue;                                       \
 721                 }                                                       \
 722                                                                         \
 723                 for (addr = perms[i].start;                             \
 724                      addr < perms[i].end;                               \
 725                      addr += SECTION_SIZE)                              \
 726                         section_update(addr, perms[i].mask,             \
 727                                        perms[i].field);                 \
 728         }                                                               \
 729 }
 730
 731 static inline void fix_kernmem_perms(void)
 732 {
 733         set_section_perms(nx_perms, prot);
 734 }
 735
 736 #ifdef CONFIG_DEBUG_RODATA
 737 void mark_rodata_ro(void)
 738 {
 739         set_section_perms(ro_perms, prot);
 740 }
 741
 742 void set_kernel_text_rw(void)
 743 {
 744         set_section_perms(ro_perms, clear);
 745 }
 746
 747 void set_kernel_text_ro(void)
 748 {
 749         set_section_perms(ro_perms, prot);
 750 }
 751 #endif /* CONFIG_DEBUG_RODATA */
 752
 753 #else
 754 static inline void fix_kernmem_perms(void) { }
 755 #endif /* CONFIG_ARM_KERNMEM_PERMS */
 756
 757 void free_tcmmem(void)
 758 {
 759 #ifdef CONFIG_HAVE_TCM
 760         extern char __tcm_start, __tcm_end;
 761
 762         poison_init_mem(&__tcm_start, &__tcm_end - &__tcm_start);
 763         free_reserved_area(&__tcm_start, &__tcm_end, -1, "TCM link");
 764 #endif
 765 }
 766
 767 void free_initmem(void)
 768 {
 769         fix_kernmem_perms();
 770         free_tcmmem();
 771
 772         poison_init_mem(__init_begin, __init_end - __init_begin);
 773         if (!machine_is_integrator() && !machine_is_cintegrator())
 774                 free_initmem_default(-1);
 775 }
 776
 777 #ifdef CONFIG_BLK_DEV_INITRD
 778
 779 static int keep_initrd;
 780
 781 void free_initrd_mem(unsigned long start, unsigned long end)
 782 {
 783         if (!keep_initrd) {
 784                 if (start == initrd_start)
 785                         start = round_down(start, PAGE_SIZE);
 786                 if (end == initrd_end)
 787                         end = round_up(end, PAGE_SIZE);
 788
 789                 poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
 790                 free_reserved_area((void *)start, (void *)end, -1, "initrd");
 791         }
 792 }
 793
 794 static int __init keepinitrd_setup(char *__unused)
 795 {
 796         keep_initrd = 1;
 797         return 1;
 798 }
 799
 800 __setup("keepinitrd", keepinitrd_setup);
 801 #endif