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