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/sched/signal.h>
  17 #include <linux/sched/task.h>
  18 #include <linux/export.h>
  19 #include <linux/nodemask.h>
  20 #include <linux/initrd.h>
  21 #include <linux/of_fdt.h>
  22 #include <linux/highmem.h>
  23 #include <linux/gfp.h>
  24 #include <linux/memblock.h>
  25 #include <linux/dma-contiguous.h>
  26 #include <linux/sizes.h>
  27 #include <linux/stop_machine.h>
  28
  29 #include <asm/cp15.h>
  30 #include <asm/mach-types.h>
  31 #include <asm/memblock.h>
  32 #include <asm/memory.h>
  33 #include <asm/prom.h>
  34 #include <asm/sections.h>
  35 #include <asm/setup.h>
  36 #include <asm/system_info.h>
  37 #include <asm/tlb.h>
  38 #include <asm/fixmap.h>
  39
  40 #include <asm/mach/arch.h>
  41 #include <asm/mach/map.h>
  42
  43 #include "mm.h"
  44
  45 #ifdef CONFIG_CPU_CP15_MMU
  46 unsigned long __init __clear_cr(unsigned long mask)
  47 {
  48         cr_alignment = cr_alignment & ~mask;
  49         return cr_alignment;
  50 }
  51 #endif
  52
  53 static phys_addr_t phys_initrd_start __initdata = 0;
  54 static unsigned long phys_initrd_size __initdata = 0;
  55
  56 static int __init early_initrd(char *p)
  57 {
  58         phys_addr_t start;
  59         unsigned long size;
  60         char *endp;
  61
  62         start = memparse(p, &endp);
  63         if (*endp == ',') {
  64                 size = memparse(endp + 1, NULL);
  65
  66                 phys_initrd_start = start;
  67                 phys_initrd_size = size;
  68         }
  69         return 0;
  70 }
  71 early_param("initrd", early_initrd);
  72
  73 static int __init parse_tag_initrd(const struct tag *tag)
  74 {
  75         pr_warn("ATAG_INITRD is deprecated; "
  76                 "please update your bootloader.\n");
  77         phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
  78         phys_initrd_size = tag->u.initrd.size;
  79         return 0;
  80 }
  81
  82 __tagtable(ATAG_INITRD, parse_tag_initrd);
  83
  84 static int __init parse_tag_initrd2(const struct tag *tag)
  85 {
  86         phys_initrd_start = tag->u.initrd.start;
  87         phys_initrd_size = tag->u.initrd.size;
  88         return 0;
  89 }
  90
  91 __tagtable(ATAG_INITRD2, parse_tag_initrd2);
  92
  93 static void __init find_limits(unsigned long *min, unsigned long *max_low,
  94                                unsigned long *max_high)
  95 {
  96         *max_low = PFN_DOWN(memblock_get_current_limit());
  97         *min = PFN_UP(memblock_start_of_DRAM());
  98         *max_high = PFN_DOWN(memblock_end_of_DRAM());
  99 }
 100
 101 #ifdef CONFIG_ZONE_DMA
 102
 103 phys_addr_t arm_dma_zone_size __read_mostly;
 104 EXPORT_SYMBOL(arm_dma_zone_size);
 105
 106 /*
 107  * The DMA mask corresponding to the maximum bus address allocatable
 108  * using GFP_DMA.  The default here places no restriction on DMA
 109  * allocations.  This must be the smallest DMA mask in the system,
 110  * so a successful GFP_DMA allocation will always satisfy this.
 111  */
 112 phys_addr_t arm_dma_limit;
 113 unsigned long arm_dma_pfn_limit;
 114
 115 static void __init arm_adjust_dma_zone(unsigned long *size, unsigned long *hole,
 116         unsigned long dma_size)
 117 {
 118         if (size[0] <= dma_size)
 119                 return;
 120
 121         size[ZONE_NORMAL] = size[0] - dma_size;
 122         size[ZONE_DMA] = dma_size;
 123         hole[ZONE_NORMAL] = hole[0];
 124         hole[ZONE_DMA] = 0;
 125 }
 126 #endif
 127
 128 void __init setup_dma_zone(const struct machine_desc *mdesc)
 129 {
 130 #ifdef CONFIG_ZONE_DMA
 131         if (mdesc->dma_zone_size) {
 132                 arm_dma_zone_size = mdesc->dma_zone_size;
 133                 arm_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1;
 134         } else
 135                 arm_dma_limit = 0xffffffff;
 136         arm_dma_pfn_limit = arm_dma_limit >> PAGE_SHIFT;
 137 #endif
 138 }
 139
 140 static void __init zone_sizes_init(unsigned long min, unsigned long max_low,
 141         unsigned long max_high)
 142 {
 143         unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
 144         struct memblock_region *reg;
 145
 146         /*
 147          * initialise the zones.
 148          */
 149         memset(zone_size, 0, sizeof(zone_size));
 150
 151         /*
 152          * The memory size has already been determined.  If we need
 153          * to do anything fancy with the allocation of this memory
 154          * to the zones, now is the time to do it.
 155          */
 156         zone_size[0] = max_low - min;
 157 #ifdef CONFIG_HIGHMEM
 158         zone_size[ZONE_HIGHMEM] = max_high - max_low;
 159 #endif
 160
 161         /*
 162          * Calculate the size of the holes.
 163          *  holes = node_size - sum(bank_sizes)
 164          */
 165         memcpy(zhole_size, zone_size, sizeof(zhole_size));
 166         for_each_memblock(memory, reg) {
 167                 unsigned long start = memblock_region_memory_base_pfn(reg);
 168                 unsigned long end = memblock_region_memory_end_pfn(reg);
 169
 170                 if (start < max_low) {
 171                         unsigned long low_end = min(end, max_low);
 172                         zhole_size[0] -= low_end - start;
 173                 }
 174 #ifdef CONFIG_HIGHMEM
 175                 if (end > max_low) {
 176                         unsigned long high_start = max(start, max_low);
 177                         zhole_size[ZONE_HIGHMEM] -= end - high_start;
 178                 }
 179 #endif
 180         }
 181
 182 #ifdef CONFIG_ZONE_DMA
 183         /*
 184          * Adjust the sizes according to any special requirements for
 185          * this machine type.
 186          */
 187         if (arm_dma_zone_size)
 188                 arm_adjust_dma_zone(zone_size, zhole_size,
 189                         arm_dma_zone_size >> PAGE_SHIFT);
 190 #endif
 191
 192         free_area_init_node(0, zone_size, min, zhole_size);
 193 }
 194
 195 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
 196 int pfn_valid(unsigned long pfn)
 197 {
 198         return memblock_is_map_memory(__pfn_to_phys(pfn));
 199 }
 200 EXPORT_SYMBOL(pfn_valid);
 201 #endif
 202
 203 #ifndef CONFIG_SPARSEMEM
 204 static void __init arm_memory_present(void)
 205 {
 206 }
 207 #else
 208 static void __init arm_memory_present(void)
 209 {
 210         struct memblock_region *reg;
 211
 212         for_each_memblock(memory, reg)
 213                 memory_present(0, memblock_region_memory_base_pfn(reg),
 214                                memblock_region_memory_end_pfn(reg));
 215 }
 216 #endif
 217
 218 static bool arm_memblock_steal_permitted = true;
 219
 220 phys_addr_t __init arm_memblock_steal(phys_addr_t size, phys_addr_t align)
 221 {
 222         phys_addr_t phys;
 223
 224         BUG_ON(!arm_memblock_steal_permitted);
 225
 226         phys = memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ANYWHERE);
 227         memblock_free(phys, size);
 228         memblock_remove(phys, size);
 229
 230         return phys;
 231 }
 232
 233 static void __init arm_initrd_init(void)
 234 {
 235 #ifdef CONFIG_BLK_DEV_INITRD
 236         phys_addr_t start;
 237         unsigned long size;
 238
 239         /* FDT scan will populate initrd_start */
 240         if (initrd_start && !phys_initrd_size) {
 241                 phys_initrd_start = __virt_to_phys(initrd_start);
 242                 phys_initrd_size = initrd_end - initrd_start;
 243         }
 244
 245         initrd_start = initrd_end = 0;
 246
 247         if (!phys_initrd_size)
 248                 return;
 249
 250         /*
 251          * Round the memory region to page boundaries as per free_initrd_mem()
 252          * This allows us to detect whether the pages overlapping the initrd
 253          * are in use, but more importantly, reserves the entire set of pages
 254          * as we don't want these pages allocated for other purposes.
 255          */
 256         start = round_down(phys_initrd_start, PAGE_SIZE);
 257         size = phys_initrd_size + (phys_initrd_start - start);
 258         size = round_up(size, PAGE_SIZE);
 259
 260         if (!memblock_is_region_memory(start, size)) {
 261                 pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region - disabling initrd\n",
 262                        (u64)start, size);
 263                 return;
 264         }
 265
 266         if (memblock_is_region_reserved(start, size)) {
 267                 pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region - disabling initrd\n",
 268                        (u64)start, size);
 269                 return;
 270         }
 271
 272         memblock_reserve(start, size);
 273
 274         /* Now convert initrd to virtual addresses */
 275         initrd_start = __phys_to_virt(phys_initrd_start);
 276         initrd_end = initrd_start + phys_initrd_size;
 277 #endif
 278 }
 279
 280 void __init arm_memblock_init(const struct machine_desc *mdesc)
 281 {
 282         /* Register the kernel text, kernel data and initrd with memblock. */
 283         memblock_reserve(__pa(KERNEL_START), KERNEL_END - KERNEL_START);
 284
 285         arm_initrd_init();
 286
 287         arm_mm_memblock_reserve();
 288
 289         /* reserve any platform specific memblock areas */
 290         if (mdesc->reserve)
 291                 mdesc->reserve();
 292
 293         early_init_fdt_reserve_self();
 294         early_init_fdt_scan_reserved_mem();
 295
 296         /* reserve memory for DMA contiguous allocations */
 297         dma_contiguous_reserve(arm_dma_limit);
 298
 299         arm_memblock_steal_permitted = false;
 300         memblock_dump_all();
 301 }
 302
 303 void __init bootmem_init(void)
 304 {
 305         unsigned long min, max_low, max_high;
 306
 307         memblock_allow_resize();
 308         max_low = max_high = 0;
 309
 310         find_limits(&min, &max_low, &max_high);
 311
 312         early_memtest((phys_addr_t)min << PAGE_SHIFT,
 313                       (phys_addr_t)max_low << PAGE_SHIFT);
 314
 315         /*
 316          * Sparsemem tries to allocate bootmem in memory_present(),
 317          * so must be done after the fixed reservations
 318          */
 319         arm_memory_present();
 320
 321         /*
 322          * sparse_init() needs the bootmem allocator up and running.
 323          */
 324         sparse_init();
 325
 326         /*
 327          * Now free the memory - free_area_init_node needs
 328          * the sparse mem_map arrays initialized by sparse_init()
 329          * for memmap_init_zone(), otherwise all PFNs are invalid.
 330          */
 331         zone_sizes_init(min, max_low, max_high);
 332
 333         /*
 334          * This doesn't seem to be used by the Linux memory manager any
 335          * more, but is used by ll_rw_block.  If we can get rid of it, we
 336          * also get rid of some of the stuff above as well.
 337          */
 338         min_low_pfn = min;
 339         max_low_pfn = max_low;
 340         max_pfn = max_high;
 341 }
 342
 343 /*
 344  * Poison init memory with an undefined instruction (ARM) or a branch to an
 345  * undefined instruction (Thumb).
 346  */
 347 static inline void poison_init_mem(void *s, size_t count)
 348 {
 349         u32 *p = (u32 *)s;
 350         for (; count != 0; count -= 4)
 351                 *p++ = 0xe7fddef0;
 352 }
 353
 354 static inline void
 355 free_memmap(unsigned long start_pfn, unsigned long end_pfn)
 356 {
 357         struct page *start_pg, *end_pg;
 358         phys_addr_t pg, pgend;
 359
 360         /*
 361          * Convert start_pfn/end_pfn to a struct page pointer.
 362          */
 363         start_pg = pfn_to_page(start_pfn - 1) + 1;
 364         end_pg = pfn_to_page(end_pfn - 1) + 1;
 365
 366         /*
 367          * Convert to physical addresses, and
 368          * round start upwards and end downwards.
 369          */
 370         pg = PAGE_ALIGN(__pa(start_pg));
 371         pgend = __pa(end_pg) & PAGE_MASK;
 372
 373         /*
 374          * If there are free pages between these,
 375          * free the section of the memmap array.
 376          */
 377         if (pg < pgend)
 378                 memblock_free_early(pg, pgend - pg);
 379 }
 380
 381 /*
 382  * The mem_map array can get very big.  Free the unused area of the memory map.
 383  */
 384 static void __init free_unused_memmap(void)
 385 {
 386         unsigned long start, prev_end = 0;
 387         struct memblock_region *reg;
 388
 389         /*
 390          * This relies on each bank being in address order.
 391          * The banks are sorted previously in bootmem_init().
 392          */
 393         for_each_memblock(memory, reg) {
 394                 start = memblock_region_memory_base_pfn(reg);
 395
 396 #ifdef CONFIG_SPARSEMEM
 397                 /*
 398                  * Take care not to free memmap entries that don't exist
 399                  * due to SPARSEMEM sections which aren't present.
 400                  */
 401                 start = min(start,
 402                                  ALIGN(prev_end, PAGES_PER_SECTION));
 403 #else
 404                 /*
 405                  * Align down here since the VM subsystem insists that the
 406                  * memmap entries are valid from the bank start aligned to
 407                  * MAX_ORDER_NR_PAGES.
 408                  */
 409                 start = round_down(start, MAX_ORDER_NR_PAGES);
 410 #endif
 411                 /*
 412                  * If we had a previous bank, and there is a space
 413                  * between the current bank and the previous, free it.
 414                  */
 415                 if (prev_end && prev_end < start)
 416                         free_memmap(prev_end, start);
 417
 418                 /*
 419                  * Align up here since the VM subsystem insists that the
 420                  * memmap entries are valid from the bank end aligned to
 421                  * MAX_ORDER_NR_PAGES.
 422                  */
 423                 prev_end = ALIGN(memblock_region_memory_end_pfn(reg),
 424                                  MAX_ORDER_NR_PAGES);
 425         }
 426
 427 #ifdef CONFIG_SPARSEMEM
 428         if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
 429                 free_memmap(prev_end,
 430                             ALIGN(prev_end, PAGES_PER_SECTION));
 431 #endif
 432 }
 433
 434 #ifdef CONFIG_HIGHMEM
 435 static inline void free_area_high(unsigned long pfn, unsigned long end)
 436 {
 437         for (; pfn < end; pfn++)
 438                 free_highmem_page(pfn_to_page(pfn));
 439 }
 440 #endif
 441
 442 static void __init free_highpages(void)
 443 {
 444 #ifdef CONFIG_HIGHMEM
 445         unsigned long max_low = max_low_pfn;
 446         struct memblock_region *mem, *res;
 447
 448         /* set highmem page free */
 449         for_each_memblock(memory, mem) {
 450                 unsigned long start = memblock_region_memory_base_pfn(mem);
 451                 unsigned long end = memblock_region_memory_end_pfn(mem);
 452
 453                 /* Ignore complete lowmem entries */
 454                 if (end <= max_low)
 455                         continue;
 456
 457                 if (memblock_is_nomap(mem))
 458                         continue;
 459
 460                 /* Truncate partial highmem entries */
 461                 if (start < max_low)
 462                         start = max_low;
 463
 464                 /* Find and exclude any reserved regions */
 465                 for_each_memblock(reserved, res) {
 466                         unsigned long res_start, res_end;
 467
 468                         res_start = memblock_region_reserved_base_pfn(res);
 469                         res_end = memblock_region_reserved_end_pfn(res);
 470
 471                         if (res_end < start)
 472                                 continue;
 473                         if (res_start < start)
 474                                 res_start = start;
 475                         if (res_start > end)
 476                                 res_start = end;
 477                         if (res_end > end)
 478                                 res_end = end;
 479                         if (res_start != start)
 480                                 free_area_high(start, res_start);
 481                         start = res_end;
 482                         if (start == end)
 483                                 break;
 484                 }
 485
 486                 /* And now free anything which remains */
 487                 if (start < end)
 488                         free_area_high(start, end);
 489         }
 490 #endif
 491 }
 492
 493 /*
 494  * mem_init() marks the free areas in the mem_map and tells us how much
 495  * memory is free.  This is done after various parts of the system have
 496  * claimed their memory after the kernel image.
 497  */
 498 void __init mem_init(void)
 499 {
 500 #ifdef CONFIG_HAVE_TCM
 501         /* These pointers are filled in on TCM detection */
 502         extern u32 dtcm_end;
 503         extern u32 itcm_end;
 504 #endif
 505
 506         set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
 507
 508         /* this will put all unused low memory onto the freelists */
 509         free_unused_memmap();
 510         free_all_bootmem();
 511
 512 #ifdef CONFIG_SA1111
 513         /* now that our DMA memory is actually so designated, we can free it */
 514         free_reserved_area(__va(PHYS_OFFSET), swapper_pg_dir, -1, NULL);
 515 #endif
 516
 517         free_highpages();
 518
 519         mem_init_print_info(NULL);
 520
 521 #define MLK(b, t) b, t, ((t) - (b)) >> 10
 522 #define MLM(b, t) b, t, ((t) - (b)) >> 20
 523 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
 524
 525         pr_notice("Virtual kernel memory layout:\n"
 526                         "    vector  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 527 #ifdef CONFIG_HAVE_TCM
 528                         "    DTCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 529                         "    ITCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 530 #endif
 531                         "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 532                         "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 533                         "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 534 #ifdef CONFIG_HIGHMEM
 535                         "    pkmap   : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 536 #endif
 537 #ifdef CONFIG_MODULES
 538                         "    modules : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 539 #endif
 540                         "      .text : 0x%p" " - 0x%p" "   (%4td kB)\n"
 541                         "      .init : 0x%p" " - 0x%p" "   (%4td kB)\n"
 542                         "      .data : 0x%p" " - 0x%p" "   (%4td kB)\n"
 543                         "       .bss : 0x%p" " - 0x%p" "   (%4td kB)\n",
 544
 545                         MLK(VECTORS_BASE, VECTORS_BASE + PAGE_SIZE),
 546 #ifdef CONFIG_HAVE_TCM
 547                         MLK(DTCM_OFFSET, (unsigned long) dtcm_end),
 548                         MLK(ITCM_OFFSET, (unsigned long) itcm_end),
 549 #endif
 550                         MLK(FIXADDR_START, FIXADDR_END),
 551                         MLM(VMALLOC_START, VMALLOC_END),
 552                         MLM(PAGE_OFFSET, (unsigned long)high_memory),
 553 #ifdef CONFIG_HIGHMEM
 554                         MLM(PKMAP_BASE, (PKMAP_BASE) + (LAST_PKMAP) *
 555                                 (PAGE_SIZE)),
 556 #endif
 557 #ifdef CONFIG_MODULES
 558                         MLM(MODULES_VADDR, MODULES_END),
 559 #endif
 560
 561                         MLK_ROUNDUP(_text, _etext),
 562                         MLK_ROUNDUP(__init_begin, __init_end),
 563                         MLK_ROUNDUP(_sdata, _edata),
 564                         MLK_ROUNDUP(__bss_start, __bss_stop));
 565
 566 #undef MLK
 567 #undef MLM
 568 #undef MLK_ROUNDUP
 569
 570         /*
 571          * Check boundaries twice: Some fundamental inconsistencies can
 572          * be detected at build time already.
 573          */
 574 #ifdef CONFIG_MMU
 575         BUILD_BUG_ON(TASK_SIZE                          > MODULES_VADDR);
 576         BUG_ON(TASK_SIZE                                > MODULES_VADDR);
 577 #endif
 578
 579 #ifdef CONFIG_HIGHMEM
 580         BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
 581         BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE      > PAGE_OFFSET);
 582 #endif
 583
 584         if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
 585                 extern int sysctl_overcommit_memory;
 586                 /*
 587                  * On a machine this small we won't get
 588                  * anywhere without overcommit, so turn
 589                  * it on by default.
 590                  */
 591                 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
 592         }
 593 }
 594
 595 #ifdef CONFIG_STRICT_KERNEL_RWX
 596 struct section_perm {
 597         const char *name;
 598         unsigned long start;
 599         unsigned long end;
 600         pmdval_t mask;
 601         pmdval_t prot;
 602         pmdval_t clear;
 603 };
 604
 605 /* First section-aligned location at or after __start_rodata. */
 606 extern char __start_rodata_section_aligned[];
 607
 608 static struct section_perm nx_perms[] = {
 609         /* Make pages tables, etc before _stext RW (set NX). */
 610         {
 611                 .name   = "pre-text NX",
 612                 .start  = PAGE_OFFSET,
 613                 .end    = (unsigned long)_stext,
 614                 .mask   = ~PMD_SECT_XN,
 615                 .prot   = PMD_SECT_XN,
 616         },
 617         /* Make init RW (set NX). */
 618         {
 619                 .name   = "init NX",
 620                 .start  = (unsigned long)__init_begin,
 621                 .end    = (unsigned long)_sdata,
 622                 .mask   = ~PMD_SECT_XN,
 623                 .prot   = PMD_SECT_XN,
 624         },
 625         /* Make rodata NX (set RO in ro_perms below). */
 626         {
 627                 .name   = "rodata NX",
 628                 .start  = (unsigned long)__start_rodata_section_aligned,
 629                 .end    = (unsigned long)__init_begin,
 630                 .mask   = ~PMD_SECT_XN,
 631                 .prot   = PMD_SECT_XN,
 632         },
 633 };
 634
 635 static struct section_perm ro_perms[] = {
 636         /* Make kernel code and rodata RX (set RO). */
 637         {
 638                 .name   = "text/rodata RO",
 639                 .start  = (unsigned long)_stext,
 640                 .end    = (unsigned long)__init_begin,
 641 #ifdef CONFIG_ARM_LPAE
 642                 .mask   = ~L_PMD_SECT_RDONLY,
 643                 .prot   = L_PMD_SECT_RDONLY,
 644 #else
 645                 .mask   = ~(PMD_SECT_APX | PMD_SECT_AP_WRITE),
 646                 .prot   = PMD_SECT_APX | PMD_SECT_AP_WRITE,
 647                 .clear  = PMD_SECT_AP_WRITE,
 648 #endif
 649         },
 650 };
 651
 652 /*
 653  * Updates section permissions only for the current mm (sections are
 654  * copied into each mm). During startup, this is the init_mm. Is only
 655  * safe to be called with preemption disabled, as under stop_machine().
 656  */
 657 static inline void section_update(unsigned long addr, pmdval_t mask,
 658                                   pmdval_t prot, struct mm_struct *mm)
 659 {
 660         pmd_t *pmd;
 661
 662         pmd = pmd_offset(pud_offset(pgd_offset(mm, addr), addr), addr);
 663
 664 #ifdef CONFIG_ARM_LPAE
 665         pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot);
 666 #else
 667         if (addr & SECTION_SIZE)
 668                 pmd[1] = __pmd((pmd_val(pmd[1]) & mask) | prot);
 669         else
 670                 pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot);
 671 #endif
 672         flush_pmd_entry(pmd);
 673         local_flush_tlb_kernel_range(addr, addr + SECTION_SIZE);
 674 }
 675
 676 /* Make sure extended page tables are in use. */
 677 static inline bool arch_has_strict_perms(void)
 678 {
 679         if (cpu_architecture() < CPU_ARCH_ARMv6)
 680                 return false;
 681
 682         return !!(get_cr() & CR_XP);
 683 }
 684
 685 void set_section_perms(struct section_perm *perms, int n, bool set,
 686                         struct mm_struct *mm)
 687 {
 688         size_t i;
 689         unsigned long addr;
 690
 691         if (!arch_has_strict_perms())
 692                 return;
 693
 694         for (i = 0; i < n; i++) {
 695                 if (!IS_ALIGNED(perms[i].start, SECTION_SIZE) ||
 696                     !IS_ALIGNED(perms[i].end, SECTION_SIZE)) {
 697                         pr_err("BUG: %s section %lx-%lx not aligned to %lx\n",
 698                                 perms[i].name, perms[i].start, perms[i].end,
 699                                 SECTION_SIZE);
 700                         continue;
 701                 }
 702
 703                 for (addr = perms[i].start;
 704                      addr < perms[i].end;
 705                      addr += SECTION_SIZE)
 706                         section_update(addr, perms[i].mask,
 707                                 set ? perms[i].prot : perms[i].clear, mm);
 708         }
 709
 710 }
 711
 712 static void update_sections_early(struct section_perm perms[], int n)
 713 {
 714         struct task_struct *t, *s;
 715
 716         read_lock(&tasklist_lock);
 717         for_each_process(t) {
 718                 if (t->flags & PF_KTHREAD)
 719                         continue;
 720                 for_each_thread(t, s)
 721                         set_section_perms(perms, n, true, s->mm);
 722         }
 723         read_unlock(&tasklist_lock);
 724         set_section_perms(perms, n, true, current->active_mm);
 725         set_section_perms(perms, n, true, &init_mm);
 726 }
 727
 728 int __fix_kernmem_perms(void *unused)
 729 {
 730         update_sections_early(nx_perms, ARRAY_SIZE(nx_perms));
 731         return 0;
 732 }
 733
 734 void fix_kernmem_perms(void)
 735 {
 736         stop_machine(__fix_kernmem_perms, NULL, NULL);
 737 }
 738
 739 int __mark_rodata_ro(void *unused)
 740 {
 741         update_sections_early(ro_perms, ARRAY_SIZE(ro_perms));
 742         return 0;
 743 }
 744
 745 void mark_rodata_ro(void)
 746 {
 747         stop_machine(__mark_rodata_ro, NULL, NULL);
 748 }
 749
 750 void set_kernel_text_rw(void)
 751 {
 752         set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), false,
 753                                 current->active_mm);
 754 }
 755
 756 void set_kernel_text_ro(void)
 757 {
 758         set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), true,
 759                                 current->active_mm);
 760 }
 761
 762 #else
 763 static inline void fix_kernmem_perms(void) { }
 764 #endif /* CONFIG_STRICT_KERNEL_RWX */
 765
 766 void free_tcmmem(void)
 767 {
 768 #ifdef CONFIG_HAVE_TCM
 769         extern char __tcm_start, __tcm_end;
 770
 771         poison_init_mem(&__tcm_start, &__tcm_end - &__tcm_start);
 772         free_reserved_area(&__tcm_start, &__tcm_end, -1, "TCM link");
 773 #endif
 774 }
 775
 776 void free_initmem(void)
 777 {
 778         fix_kernmem_perms();
 779         free_tcmmem();
 780
 781         poison_init_mem(__init_begin, __init_end - __init_begin);
 782         if (!machine_is_integrator() && !machine_is_cintegrator())
 783                 free_initmem_default(-1);
 784 }
 785
 786 #ifdef CONFIG_BLK_DEV_INITRD
 787
 788 static int keep_initrd;
 789
 790 void free_initrd_mem(unsigned long start, unsigned long end)
 791 {
 792         if (!keep_initrd) {
 793                 if (start == initrd_start)
 794                         start = round_down(start, PAGE_SIZE);
 795                 if (end == initrd_end)
 796                         end = round_up(end, PAGE_SIZE);
 797
 798                 poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
 799                 free_reserved_area((void *)start, (void *)end, -1, "initrd");
 800         }
 801 }
 802
 803 static int __init keepinitrd_setup(char *__unused)
 804 {
 805         keep_initrd = 1;
 806         return 1;
 807 }
 808
 809 __setup("keepinitrd", keepinitrd_setup);
 810 #endif