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 #include <asm/ptdump.h>
  40
  41 #include <asm/mach/arch.h>
  42 #include <asm/mach/map.h>
  43
  44 #include "mm.h"
  45
  46 #ifdef CONFIG_CPU_CP15_MMU
  47 unsigned long __init __clear_cr(unsigned long mask)
  48 {
  49         cr_alignment = cr_alignment & ~mask;
  50         return cr_alignment;
  51 }
  52 #endif
  53
  54 static phys_addr_t phys_initrd_start __initdata = 0;
  55 static unsigned long phys_initrd_size __initdata = 0;
  56
  57 static int __init early_initrd(char *p)
  58 {
  59         phys_addr_t start;
  60         unsigned long size;
  61         char *endp;
  62
  63         start = memparse(p, &endp);
  64         if (*endp == ',') {
  65                 size = memparse(endp + 1, NULL);
  66
  67                 phys_initrd_start = start;
  68                 phys_initrd_size = size;
  69         }
  70         return 0;
  71 }
  72 early_param("initrd", early_initrd);
  73
  74 static int __init parse_tag_initrd(const struct tag *tag)
  75 {
  76         pr_warn("ATAG_INITRD is deprecated; "
  77                 "please update your bootloader.\n");
  78         phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
  79         phys_initrd_size = tag->u.initrd.size;
  80         return 0;
  81 }
  82
  83 __tagtable(ATAG_INITRD, parse_tag_initrd);
  84
  85 static int __init parse_tag_initrd2(const struct tag *tag)
  86 {
  87         phys_initrd_start = tag->u.initrd.start;
  88         phys_initrd_size = tag->u.initrd.size;
  89         return 0;
  90 }
  91
  92 __tagtable(ATAG_INITRD2, parse_tag_initrd2);
  93
  94 static void __init find_limits(unsigned long *min, unsigned long *max_low,
  95                                unsigned long *max_high)
  96 {
  97         *max_low = PFN_DOWN(memblock_get_current_limit());
  98         *min = PFN_UP(memblock_start_of_DRAM());
  99         *max_high = PFN_DOWN(memblock_end_of_DRAM());
 100 }
 101
 102 #ifdef CONFIG_ZONE_DMA
 103
 104 phys_addr_t arm_dma_zone_size __read_mostly;
 105 EXPORT_SYMBOL(arm_dma_zone_size);
 106
 107 /*
 108  * The DMA mask corresponding to the maximum bus address allocatable
 109  * using GFP_DMA.  The default here places no restriction on DMA
 110  * allocations.  This must be the smallest DMA mask in the system,
 111  * so a successful GFP_DMA allocation will always satisfy this.
 112  */
 113 phys_addr_t arm_dma_limit;
 114 unsigned long arm_dma_pfn_limit;
 115
 116 static void __init arm_adjust_dma_zone(unsigned long *size, unsigned long *hole,
 117         unsigned long dma_size)
 118 {
 119         if (size[0] <= dma_size)
 120                 return;
 121
 122         size[ZONE_NORMAL] = size[0] - dma_size;
 123         size[ZONE_DMA] = dma_size;
 124         hole[ZONE_NORMAL] = hole[0];
 125         hole[ZONE_DMA] = 0;
 126 }
 127 #endif
 128
 129 void __init setup_dma_zone(const struct machine_desc *mdesc)
 130 {
 131 #ifdef CONFIG_ZONE_DMA
 132         if (mdesc->dma_zone_size) {
 133                 arm_dma_zone_size = mdesc->dma_zone_size;
 134                 arm_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1;
 135         } else
 136                 arm_dma_limit = 0xffffffff;
 137         arm_dma_pfn_limit = arm_dma_limit >> PAGE_SHIFT;
 138 #endif
 139 }
 140
 141 static void __init zone_sizes_init(unsigned long min, unsigned long max_low,
 142         unsigned long max_high)
 143 {
 144         unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
 145         struct memblock_region *reg;
 146
 147         /*
 148          * initialise the zones.
 149          */
 150         memset(zone_size, 0, sizeof(zone_size));
 151
 152         /*
 153          * The memory size has already been determined.  If we need
 154          * to do anything fancy with the allocation of this memory
 155          * to the zones, now is the time to do it.
 156          */
 157         zone_size[0] = max_low - min;
 158 #ifdef CONFIG_HIGHMEM
 159         zone_size[ZONE_HIGHMEM] = max_high - max_low;
 160 #endif
 161
 162         /*
 163          * Calculate the size of the holes.
 164          *  holes = node_size - sum(bank_sizes)
 165          */
 166         memcpy(zhole_size, zone_size, sizeof(zhole_size));
 167         for_each_memblock(memory, reg) {
 168                 unsigned long start = memblock_region_memory_base_pfn(reg);
 169                 unsigned long end = memblock_region_memory_end_pfn(reg);
 170
 171                 if (start < max_low) {
 172                         unsigned long low_end = min(end, max_low);
 173                         zhole_size[0] -= low_end - start;
 174                 }
 175 #ifdef CONFIG_HIGHMEM
 176                 if (end > max_low) {
 177                         unsigned long high_start = max(start, max_low);
 178                         zhole_size[ZONE_HIGHMEM] -= end - high_start;
 179                 }
 180 #endif
 181         }
 182
 183 #ifdef CONFIG_ZONE_DMA
 184         /*
 185          * Adjust the sizes according to any special requirements for
 186          * this machine type.
 187          */
 188         if (arm_dma_zone_size)
 189                 arm_adjust_dma_zone(zone_size, zhole_size,
 190                         arm_dma_zone_size >> PAGE_SHIFT);
 191 #endif
 192
 193         free_area_init_node(0, zone_size, min, zhole_size);
 194 }
 195
 196 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
 197 int pfn_valid(unsigned long pfn)
 198 {
 199         return memblock_is_map_memory(__pfn_to_phys(pfn));
 200 }
 201 EXPORT_SYMBOL(pfn_valid);
 202 #endif
 203
 204 #ifndef CONFIG_SPARSEMEM
 205 static void __init arm_memory_present(void)
 206 {
 207 }
 208 #else
 209 static void __init arm_memory_present(void)
 210 {
 211         struct memblock_region *reg;
 212
 213         for_each_memblock(memory, reg)
 214                 memory_present(0, memblock_region_memory_base_pfn(reg),
 215                                memblock_region_memory_end_pfn(reg));
 216 }
 217 #endif
 218
 219 static bool arm_memblock_steal_permitted = true;
 220
 221 phys_addr_t __init arm_memblock_steal(phys_addr_t size, phys_addr_t align)
 222 {
 223         phys_addr_t phys;
 224
 225         BUG_ON(!arm_memblock_steal_permitted);
 226
 227         phys = memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ANYWHERE);
 228         memblock_free(phys, size);
 229         memblock_remove(phys, size);
 230
 231         return phys;
 232 }
 233
 234 static void __init arm_initrd_init(void)
 235 {
 236 #ifdef CONFIG_BLK_DEV_INITRD
 237         phys_addr_t start;
 238         unsigned long size;
 239
 240         /* FDT scan will populate initrd_start */
 241         if (initrd_start && !phys_initrd_size) {
 242                 phys_initrd_start = __virt_to_phys(initrd_start);
 243                 phys_initrd_size = initrd_end - initrd_start;
 244         }
 245
 246         initrd_start = initrd_end = 0;
 247
 248         if (!phys_initrd_size)
 249                 return;
 250
 251         /*
 252          * Round the memory region to page boundaries as per free_initrd_mem()
 253          * This allows us to detect whether the pages overlapping the initrd
 254          * are in use, but more importantly, reserves the entire set of pages
 255          * as we don't want these pages allocated for other purposes.
 256          */
 257         start = round_down(phys_initrd_start, PAGE_SIZE);
 258         size = phys_initrd_size + (phys_initrd_start - start);
 259         size = round_up(size, PAGE_SIZE);
 260
 261         if (!memblock_is_region_memory(start, size)) {
 262                 pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region - disabling initrd\n",
 263                        (u64)start, size);
 264                 return;
 265         }
 266
 267         if (memblock_is_region_reserved(start, size)) {
 268                 pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region - disabling initrd\n",
 269                        (u64)start, size);
 270                 return;
 271         }
 272
 273         memblock_reserve(start, size);
 274
 275         /* Now convert initrd to virtual addresses */
 276         initrd_start = __phys_to_virt(phys_initrd_start);
 277         initrd_end = initrd_start + phys_initrd_size;
 278 #endif
 279 }
 280
 281 void __init arm_memblock_init(const struct machine_desc *mdesc)
 282 {
 283         /* Register the kernel text, kernel data and initrd with memblock. */
 284         memblock_reserve(__pa(KERNEL_START), KERNEL_END - KERNEL_START);
 285
 286         arm_initrd_init();
 287
 288         arm_mm_memblock_reserve();
 289
 290         /* reserve any platform specific memblock areas */
 291         if (mdesc->reserve)
 292                 mdesc->reserve();
 293
 294         early_init_fdt_reserve_self();
 295         early_init_fdt_scan_reserved_mem();
 296
 297         /* reserve memory for DMA contiguous allocations */
 298         dma_contiguous_reserve(arm_dma_limit);
 299
 300         arm_memblock_steal_permitted = false;
 301         memblock_dump_all();
 302 }
 303
 304 void __init bootmem_init(void)
 305 {
 306         unsigned long min, max_low, max_high;
 307
 308         memblock_allow_resize();
 309         max_low = max_high = 0;
 310
 311         find_limits(&min, &max_low, &max_high);
 312
 313         early_memtest((phys_addr_t)min << PAGE_SHIFT,
 314                       (phys_addr_t)max_low << PAGE_SHIFT);
 315
 316         /*
 317          * Sparsemem tries to allocate bootmem in memory_present(),
 318          * so must be done after the fixed reservations
 319          */
 320         arm_memory_present();
 321
 322         /*
 323          * sparse_init() needs the bootmem allocator up and running.
 324          */
 325         sparse_init();
 326
 327         /*
 328          * Now free the memory - free_area_init_node needs
 329          * the sparse mem_map arrays initialized by sparse_init()
 330          * for memmap_init_zone(), otherwise all PFNs are invalid.
 331          */
 332         zone_sizes_init(min, max_low, max_high);
 333
 334         /*
 335          * This doesn't seem to be used by the Linux memory manager any
 336          * more, but is used by ll_rw_block.  If we can get rid of it, we
 337          * also get rid of some of the stuff above as well.
 338          */
 339         min_low_pfn = min;
 340         max_low_pfn = max_low;
 341         max_pfn = max_high;
 342 }
 343
 344 /*
 345  * Poison init memory with an undefined instruction (ARM) or a branch to an
 346  * undefined instruction (Thumb).
 347  */
 348 static inline void poison_init_mem(void *s, size_t count)
 349 {
 350         u32 *p = (u32 *)s;
 351         for (; count != 0; count -= 4)
 352                 *p++ = 0xe7fddef0;
 353 }
 354
 355 static inline void
 356 free_memmap(unsigned long start_pfn, unsigned long end_pfn)
 357 {
 358         struct page *start_pg, *end_pg;
 359         phys_addr_t pg, pgend;
 360
 361         /*
 362          * Convert start_pfn/end_pfn to a struct page pointer.
 363          */
 364         start_pg = pfn_to_page(start_pfn - 1) + 1;
 365         end_pg = pfn_to_page(end_pfn - 1) + 1;
 366
 367         /*
 368          * Convert to physical addresses, and
 369          * round start upwards and end downwards.
 370          */
 371         pg = PAGE_ALIGN(__pa(start_pg));
 372         pgend = __pa(end_pg) & PAGE_MASK;
 373
 374         /*
 375          * If there are free pages between these,
 376          * free the section of the memmap array.
 377          */
 378         if (pg < pgend)
 379                 memblock_free_early(pg, pgend - pg);
 380 }
 381
 382 /*
 383  * The mem_map array can get very big.  Free the unused area of the memory map.
 384  */
 385 static void __init free_unused_memmap(void)
 386 {
 387         unsigned long start, prev_end = 0;
 388         struct memblock_region *reg;
 389
 390         /*
 391          * This relies on each bank being in address order.
 392          * The banks are sorted previously in bootmem_init().
 393          */
 394         for_each_memblock(memory, reg) {
 395                 start = memblock_region_memory_base_pfn(reg);
 396
 397 #ifdef CONFIG_SPARSEMEM
 398                 /*
 399                  * Take care not to free memmap entries that don't exist
 400                  * due to SPARSEMEM sections which aren't present.
 401                  */
 402                 start = min(start,
 403                                  ALIGN(prev_end, PAGES_PER_SECTION));
 404 #else
 405                 /*
 406                  * Align down here since the VM subsystem insists that the
 407                  * memmap entries are valid from the bank start aligned to
 408                  * MAX_ORDER_NR_PAGES.
 409                  */
 410                 start = round_down(start, MAX_ORDER_NR_PAGES);
 411 #endif
 412                 /*
 413                  * If we had a previous bank, and there is a space
 414                  * between the current bank and the previous, free it.
 415                  */
 416                 if (prev_end && prev_end < start)
 417                         free_memmap(prev_end, start);
 418
 419                 /*
 420                  * Align up here since the VM subsystem insists that the
 421                  * memmap entries are valid from the bank end aligned to
 422                  * MAX_ORDER_NR_PAGES.
 423                  */
 424                 prev_end = ALIGN(memblock_region_memory_end_pfn(reg),
 425                                  MAX_ORDER_NR_PAGES);
 426         }
 427
 428 #ifdef CONFIG_SPARSEMEM
 429         if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
 430                 free_memmap(prev_end,
 431                             ALIGN(prev_end, PAGES_PER_SECTION));
 432 #endif
 433 }
 434
 435 #ifdef CONFIG_HIGHMEM
 436 static inline void free_area_high(unsigned long pfn, unsigned long end)
 437 {
 438         for (; pfn < end; pfn++)
 439                 free_highmem_page(pfn_to_page(pfn));
 440 }
 441 #endif
 442
 443 static void __init free_highpages(void)
 444 {
 445 #ifdef CONFIG_HIGHMEM
 446         unsigned long max_low = max_low_pfn;
 447         struct memblock_region *mem, *res;
 448
 449         /* set highmem page free */
 450         for_each_memblock(memory, mem) {
 451                 unsigned long start = memblock_region_memory_base_pfn(mem);
 452                 unsigned long end = memblock_region_memory_end_pfn(mem);
 453
 454                 /* Ignore complete lowmem entries */
 455                 if (end <= max_low)
 456                         continue;
 457
 458                 if (memblock_is_nomap(mem))
 459                         continue;
 460
 461                 /* Truncate partial highmem entries */
 462                 if (start < max_low)
 463                         start = max_low;
 464
 465                 /* Find and exclude any reserved regions */
 466                 for_each_memblock(reserved, res) {
 467                         unsigned long res_start, res_end;
 468
 469                         res_start = memblock_region_reserved_base_pfn(res);
 470                         res_end = memblock_region_reserved_end_pfn(res);
 471
 472                         if (res_end < start)
 473                                 continue;
 474                         if (res_start < start)
 475                                 res_start = start;
 476                         if (res_start > end)
 477                                 res_start = end;
 478                         if (res_end > end)
 479                                 res_end = end;
 480                         if (res_start != start)
 481                                 free_area_high(start, res_start);
 482                         start = res_end;
 483                         if (start == end)
 484                                 break;
 485                 }
 486
 487                 /* And now free anything which remains */
 488                 if (start < end)
 489                         free_area_high(start, end);
 490         }
 491 #endif
 492 }
 493
 494 /*
 495  * mem_init() marks the free areas in the mem_map and tells us how much
 496  * memory is free.  This is done after various parts of the system have
 497  * claimed their memory after the kernel image.
 498  */
 499 void __init mem_init(void)
 500 {
 501 #ifdef CONFIG_HAVE_TCM
 502         /* These pointers are filled in on TCM detection */
 503         extern u32 dtcm_end;
 504         extern u32 itcm_end;
 505 #endif
 506
 507         set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
 508
 509         /* this will put all unused low memory onto the freelists */
 510         free_unused_memmap();
 511         free_all_bootmem();
 512
 513 #ifdef CONFIG_SA1111
 514         /* now that our DMA memory is actually so designated, we can free it */
 515         free_reserved_area(__va(PHYS_OFFSET), swapper_pg_dir, -1, NULL);
 516 #endif
 517
 518         free_highpages();
 519
 520         mem_init_print_info(NULL);
 521
 522 #define MLK(b, t) b, t, ((t) - (b)) >> 10
 523 #define MLM(b, t) b, t, ((t) - (b)) >> 20
 524 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
 525
 526         pr_notice("Virtual kernel memory layout:\n"
 527                         "    vector  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 528 #ifdef CONFIG_HAVE_TCM
 529                         "    DTCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 530                         "    ITCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 531 #endif
 532                         "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 533                         "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 534                         "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 535 #ifdef CONFIG_HIGHMEM
 536                         "    pkmap   : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 537 #endif
 538 #ifdef CONFIG_MODULES
 539                         "    modules : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 540 #endif
 541                         "      .text : 0x%p" " - 0x%p" "   (%4td kB)\n"
 542                         "      .init : 0x%p" " - 0x%p" "   (%4td kB)\n"
 543                         "      .data : 0x%p" " - 0x%p" "   (%4td kB)\n"
 544                         "       .bss : 0x%p" " - 0x%p" "   (%4td kB)\n",
 545
 546                         MLK(VECTORS_BASE, VECTORS_BASE + PAGE_SIZE),
 547 #ifdef CONFIG_HAVE_TCM
 548                         MLK(DTCM_OFFSET, (unsigned long) dtcm_end),
 549                         MLK(ITCM_OFFSET, (unsigned long) itcm_end),
 550 #endif
 551                         MLK(FIXADDR_START, FIXADDR_END),
 552                         MLM(VMALLOC_START, VMALLOC_END),
 553                         MLM(PAGE_OFFSET, (unsigned long)high_memory),
 554 #ifdef CONFIG_HIGHMEM
 555                         MLM(PKMAP_BASE, (PKMAP_BASE) + (LAST_PKMAP) *
 556                                 (PAGE_SIZE)),
 557 #endif
 558 #ifdef CONFIG_MODULES
 559                         MLM(MODULES_VADDR, MODULES_END),
 560 #endif
 561
 562                         MLK_ROUNDUP(_text, _etext),
 563                         MLK_ROUNDUP(__init_begin, __init_end),
 564                         MLK_ROUNDUP(_sdata, _edata),
 565                         MLK_ROUNDUP(__bss_start, __bss_stop));
 566
 567 #undef MLK
 568 #undef MLM
 569 #undef MLK_ROUNDUP
 570
 571         /*
 572          * Check boundaries twice: Some fundamental inconsistencies can
 573          * be detected at build time already.
 574          */
 575 #ifdef CONFIG_MMU
 576         BUILD_BUG_ON(TASK_SIZE                          > MODULES_VADDR);
 577         BUG_ON(TASK_SIZE                                > MODULES_VADDR);
 578 #endif
 579
 580 #ifdef CONFIG_HIGHMEM
 581         BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
 582         BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE      > PAGE_OFFSET);
 583 #endif
 584 }
 585
 586 #ifdef CONFIG_STRICT_KERNEL_RWX
 587 struct section_perm {
 588         const char *name;
 589         unsigned long start;
 590         unsigned long end;
 591         pmdval_t mask;
 592         pmdval_t prot;
 593         pmdval_t clear;
 594 };
 595
 596 /* First section-aligned location at or after __start_rodata. */
 597 extern char __start_rodata_section_aligned[];
 598
 599 static struct section_perm nx_perms[] = {
 600         /* Make pages tables, etc before _stext RW (set NX). */
 601         {
 602                 .name   = "pre-text NX",
 603                 .start  = PAGE_OFFSET,
 604                 .end    = (unsigned long)_stext,
 605                 .mask   = ~PMD_SECT_XN,
 606                 .prot   = PMD_SECT_XN,
 607         },
 608         /* Make init RW (set NX). */
 609         {
 610                 .name   = "init NX",
 611                 .start  = (unsigned long)__init_begin,
 612                 .end    = (unsigned long)_sdata,
 613                 .mask   = ~PMD_SECT_XN,
 614                 .prot   = PMD_SECT_XN,
 615         },
 616         /* Make rodata NX (set RO in ro_perms below). */
 617         {
 618                 .name   = "rodata NX",
 619                 .start  = (unsigned long)__start_rodata_section_aligned,
 620                 .end    = (unsigned long)__init_begin,
 621                 .mask   = ~PMD_SECT_XN,
 622                 .prot   = PMD_SECT_XN,
 623         },
 624 };
 625
 626 static struct section_perm ro_perms[] = {
 627         /* Make kernel code and rodata RX (set RO). */
 628         {
 629                 .name   = "text/rodata RO",
 630                 .start  = (unsigned long)_stext,
 631                 .end    = (unsigned long)__init_begin,
 632 #ifdef CONFIG_ARM_LPAE
 633                 .mask   = ~(L_PMD_SECT_RDONLY | PMD_SECT_AP2),
 634                 .prot   = L_PMD_SECT_RDONLY | PMD_SECT_AP2,
 635 #else
 636                 .mask   = ~(PMD_SECT_APX | PMD_SECT_AP_WRITE),
 637                 .prot   = PMD_SECT_APX | PMD_SECT_AP_WRITE,
 638                 .clear  = PMD_SECT_AP_WRITE,
 639 #endif
 640         },
 641 };
 642
 643 /*
 644  * Updates section permissions only for the current mm (sections are
 645  * copied into each mm). During startup, this is the init_mm. Is only
 646  * safe to be called with preemption disabled, as under stop_machine().
 647  */
 648 static inline void section_update(unsigned long addr, pmdval_t mask,
 649                                   pmdval_t prot, struct mm_struct *mm)
 650 {
 651         pmd_t *pmd;
 652
 653         pmd = pmd_offset(pud_offset(pgd_offset(mm, addr), addr), addr);
 654
 655 #ifdef CONFIG_ARM_LPAE
 656         pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot);
 657 #else
 658         if (addr & SECTION_SIZE)
 659                 pmd[1] = __pmd((pmd_val(pmd[1]) & mask) | prot);
 660         else
 661                 pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot);
 662 #endif
 663         flush_pmd_entry(pmd);
 664         local_flush_tlb_kernel_range(addr, addr + SECTION_SIZE);
 665 }
 666
 667 /* Make sure extended page tables are in use. */
 668 static inline bool arch_has_strict_perms(void)
 669 {
 670         if (cpu_architecture() < CPU_ARCH_ARMv6)
 671                 return false;
 672
 673         return !!(get_cr() & CR_XP);
 674 }
 675
 676 void set_section_perms(struct section_perm *perms, int n, bool set,
 677                         struct mm_struct *mm)
 678 {
 679         size_t i;
 680         unsigned long addr;
 681
 682         if (!arch_has_strict_perms())
 683                 return;
 684
 685         for (i = 0; i < n; i++) {
 686                 if (!IS_ALIGNED(perms[i].start, SECTION_SIZE) ||
 687                     !IS_ALIGNED(perms[i].end, SECTION_SIZE)) {
 688                         pr_err("BUG: %s section %lx-%lx not aligned to %lx\n",
 689                                 perms[i].name, perms[i].start, perms[i].end,
 690                                 SECTION_SIZE);
 691                         continue;
 692                 }
 693
 694                 for (addr = perms[i].start;
 695                      addr < perms[i].end;
 696                      addr += SECTION_SIZE)
 697                         section_update(addr, perms[i].mask,
 698                                 set ? perms[i].prot : perms[i].clear, mm);
 699         }
 700
 701 }
 702
 703 /**
 704  * update_sections_early intended to be called only through stop_machine
 705  * framework and executed by only one CPU while all other CPUs will spin and
 706  * wait, so no locking is required in this function.
 707  */
 708 static void update_sections_early(struct section_perm perms[], int n)
 709 {
 710         struct task_struct *t, *s;
 711
 712         for_each_process(t) {
 713                 if (t->flags & PF_KTHREAD)
 714                         continue;
 715                 for_each_thread(t, s)
 716                         set_section_perms(perms, n, true, s->mm);
 717         }
 718         set_section_perms(perms, n, true, current->active_mm);
 719         set_section_perms(perms, n, true, &init_mm);
 720 }
 721
 722 static int __fix_kernmem_perms(void *unused)
 723 {
 724         update_sections_early(nx_perms, ARRAY_SIZE(nx_perms));
 725         return 0;
 726 }
 727
 728 static void fix_kernmem_perms(void)
 729 {
 730         stop_machine(__fix_kernmem_perms, NULL, NULL);
 731 }
 732
 733 static int __mark_rodata_ro(void *unused)
 734 {
 735         update_sections_early(ro_perms, ARRAY_SIZE(ro_perms));
 736         return 0;
 737 }
 738
 739 void mark_rodata_ro(void)
 740 {
 741         stop_machine(__mark_rodata_ro, NULL, NULL);
 742         debug_checkwx();
 743 }
 744
 745 void set_kernel_text_rw(void)
 746 {
 747         set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), false,
 748                                 current->active_mm);
 749 }
 750
 751 void set_kernel_text_ro(void)
 752 {
 753         set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), true,
 754                                 current->active_mm);
 755 }
 756
 757 #else
 758 static inline void fix_kernmem_perms(void) { }
 759 #endif /* CONFIG_STRICT_KERNEL_RWX */
 760
 761 void free_tcmmem(void)
 762 {
 763 #ifdef CONFIG_HAVE_TCM
 764         extern char __tcm_start, __tcm_end;
 765
 766         poison_init_mem(&__tcm_start, &__tcm_end - &__tcm_start);
 767         free_reserved_area(&__tcm_start, &__tcm_end, -1, "TCM link");
 768 #endif
 769 }
 770
 771 void free_initmem(void)
 772 {
 773         fix_kernmem_perms();
 774         free_tcmmem();
 775
 776         poison_init_mem(__init_begin, __init_end - __init_begin);
 777         if (!machine_is_integrator() && !machine_is_cintegrator())
 778                 free_initmem_default(-1);
 779 }
 780
 781 #ifdef CONFIG_BLK_DEV_INITRD
 782
 783 static int keep_initrd;
 784
 785 void free_initrd_mem(unsigned long start, unsigned long end)
 786 {
 787         if (!keep_initrd) {
 788                 if (start == initrd_start)
 789                         start = round_down(start, PAGE_SIZE);
 790                 if (end == initrd_end)
 791                         end = round_up(end, PAGE_SIZE);
 792
 793                 poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
 794                 free_reserved_area((void *)start, (void *)end, -1, "initrd");
 795         }
 796 }
 797
 798 static int __init keepinitrd_setup(char *__unused)
 799 {
 800         keep_initrd = 1;
 801         return 1;
 802 }
 803
 804 __setup("keepinitrd", keepinitrd_setup);
 805 #endif