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