linux/arch/x86/mm/init_64.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *  linux/arch/x86_64/mm/init.c
   4 *
   5 *  Copyright (C) 1995  Linus Torvalds
   6 *  Copyright (C) 2000  Pavel Machek <pavel@ucw.cz>
   7 *  Copyright (C) 2002,2003 Andi Kleen <ak@suse.de>
   8 */
   9
  10#include <linux/signal.h>
  11#include <linux/sched.h>
  12#include <linux/kernel.h>
  13#include <linux/errno.h>
  14#include <linux/string.h>
  15#include <linux/types.h>
  16#include <linux/ptrace.h>
  17#include <linux/mman.h>
  18#include <linux/mm.h>
  19#include <linux/swap.h>
  20#include <linux/smp.h>
  21#include <linux/init.h>
  22#include <linux/initrd.h>
  23#include <linux/pagemap.h>
  24#include <linux/memblock.h>
  25#include <linux/proc_fs.h>
  26#include <linux/pci.h>
  27#include <linux/pfn.h>
  28#include <linux/poison.h>
  29#include <linux/dma-mapping.h>
  30#include <linux/memory.h>
  31#include <linux/memory_hotplug.h>
  32#include <linux/memremap.h>
  33#include <linux/nmi.h>
  34#include <linux/gfp.h>
  35#include <linux/kcore.h>
  36
  37#include <asm/processor.h>
  38#include <asm/bios_ebda.h>
  39#include <linux/uaccess.h>
  40#include <asm/pgtable.h>
  41#include <asm/pgalloc.h>
  42#include <asm/dma.h>
  43#include <asm/fixmap.h>
  44#include <asm/e820/api.h>
  45#include <asm/apic.h>
  46#include <asm/tlb.h>
  47#include <asm/mmu_context.h>
  48#include <asm/proto.h>
  49#include <asm/smp.h>
  50#include <asm/sections.h>
  51#include <asm/kdebug.h>
  52#include <asm/numa.h>
  53#include <asm/set_memory.h>
  54#include <asm/init.h>
  55#include <asm/uv/uv.h>
  56#include <asm/setup.h>
  57
  58#include "mm_internal.h"
  59
  60#include "ident_map.c"
  61
  62#define DEFINE_POPULATE(fname, type1, type2, init)              \
  63static inline void fname##_init(struct mm_struct *mm,           \
  64                type1##_t *arg1, type2##_t *arg2, bool init)    \
  65{                                                               \
  66        if (init)                                               \
  67                fname##_safe(mm, arg1, arg2);                   \
  68        else                                                    \
  69                fname(mm, arg1, arg2);                          \
  70}
  71
  72DEFINE_POPULATE(p4d_populate, p4d, pud, init)
  73DEFINE_POPULATE(pgd_populate, pgd, p4d, init)
  74DEFINE_POPULATE(pud_populate, pud, pmd, init)
  75DEFINE_POPULATE(pmd_populate_kernel, pmd, pte, init)
  76
  77#define DEFINE_ENTRY(type1, type2, init)                        \
  78static inline void set_##type1##_init(type1##_t *arg1,          \
  79                        type2##_t arg2, bool init)              \
  80{                                                               \
  81        if (init)                                               \
  82                set_##type1##_safe(arg1, arg2);                 \
  83        else                                                    \
  84                set_##type1(arg1, arg2);                        \
  85}
  86
  87DEFINE_ENTRY(p4d, p4d, init)
  88DEFINE_ENTRY(pud, pud, init)
  89DEFINE_ENTRY(pmd, pmd, init)
  90DEFINE_ENTRY(pte, pte, init)
  91
  92
  93/*
  94 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
  95 * physical space so we can cache the place of the first one and move
  96 * around without checking the pgd every time.
  97 */
  98
  99/* Bits supported by the hardware: */
 100pteval_t __supported_pte_mask __read_mostly = ~0;
 101/* Bits allowed in normal kernel mappings: */
 102pteval_t __default_kernel_pte_mask __read_mostly = ~0;
 103EXPORT_SYMBOL_GPL(__supported_pte_mask);
 104/* Used in PAGE_KERNEL_* macros which are reasonably used out-of-tree: */
 105EXPORT_SYMBOL(__default_kernel_pte_mask);
 106
 107int force_personality32;
 108
 109/*
 110 * noexec32=on|off
 111 * Control non executable heap for 32bit processes.
 112 * To control the stack too use noexec=off
 113 *
 114 * on   PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
 115 * off  PROT_READ implies PROT_EXEC
 116 */
 117static int __init nonx32_setup(char *str)
 118{
 119        if (!strcmp(str, "on"))
 120                force_personality32 &= ~READ_IMPLIES_EXEC;
 121        else if (!strcmp(str, "off"))
 122                force_personality32 |= READ_IMPLIES_EXEC;
 123        return 1;
 124}
 125__setup("noexec32=", nonx32_setup);
 126
 127static void sync_global_pgds_l5(unsigned long start, unsigned long end)
 128{
 129        unsigned long addr;
 130
 131        for (addr = start; addr <= end; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
 132                const pgd_t *pgd_ref = pgd_offset_k(addr);
 133                struct page *page;
 134
 135                /* Check for overflow */
 136                if (addr < start)
 137                        break;
 138
 139                if (pgd_none(*pgd_ref))
 140                        continue;
 141
 142                spin_lock(&pgd_lock);
 143                list_for_each_entry(page, &pgd_list, lru) {
 144                        pgd_t *pgd;
 145                        spinlock_t *pgt_lock;
 146
 147                        pgd = (pgd_t *)page_address(page) + pgd_index(addr);
 148                        /* the pgt_lock only for Xen */
 149                        pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
 150                        spin_lock(pgt_lock);
 151
 152                        if (!pgd_none(*pgd_ref) && !pgd_none(*pgd))
 153                                BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref));
 154
 155                        if (pgd_none(*pgd))
 156                                set_pgd(pgd, *pgd_ref);
 157
 158                        spin_unlock(pgt_lock);
 159                }
 160                spin_unlock(&pgd_lock);
 161        }
 162}
 163
 164static void sync_global_pgds_l4(unsigned long start, unsigned long end)
 165{
 166        unsigned long addr;
 167
 168        for (addr = start; addr <= end; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
 169                pgd_t *pgd_ref = pgd_offset_k(addr);
 170                const p4d_t *p4d_ref;
 171                struct page *page;
 172
 173                /*
 174                 * With folded p4d, pgd_none() is always false, we need to
 175                 * handle synchonization on p4d level.
 176                 */
 177                MAYBE_BUILD_BUG_ON(pgd_none(*pgd_ref));
 178                p4d_ref = p4d_offset(pgd_ref, addr);
 179
 180                if (p4d_none(*p4d_ref))
 181                        continue;
 182
 183                spin_lock(&pgd_lock);
 184                list_for_each_entry(page, &pgd_list, lru) {
 185                        pgd_t *pgd;
 186                        p4d_t *p4d;
 187                        spinlock_t *pgt_lock;
 188
 189                        pgd = (pgd_t *)page_address(page) + pgd_index(addr);
 190                        p4d = p4d_offset(pgd, addr);
 191                        /* the pgt_lock only for Xen */
 192                        pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
 193                        spin_lock(pgt_lock);
 194
 195                        if (!p4d_none(*p4d_ref) && !p4d_none(*p4d))
 196                                BUG_ON(p4d_page_vaddr(*p4d)
 197                                       != p4d_page_vaddr(*p4d_ref));
 198
 199                        if (p4d_none(*p4d))
 200                                set_p4d(p4d, *p4d_ref);
 201
 202                        spin_unlock(pgt_lock);
 203                }
 204                spin_unlock(&pgd_lock);
 205        }
 206}
 207
 208/*
 209 * When memory was added make sure all the processes MM have
 210 * suitable PGD entries in the local PGD level page.
 211 */
 212void sync_global_pgds(unsigned long start, unsigned long end)
 213{
 214        if (pgtable_l5_enabled())
 215                sync_global_pgds_l5(start, end);
 216        else
 217                sync_global_pgds_l4(start, end);
 218}
 219
 220/*
 221 * NOTE: This function is marked __ref because it calls __init function
 222 * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
 223 */
 224static __ref void *spp_getpage(void)
 225{
 226        void *ptr;
 227
 228        if (after_bootmem)
 229                ptr = (void *) get_zeroed_page(GFP_ATOMIC);
 230        else
 231                ptr = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
 232
 233        if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
 234                panic("set_pte_phys: cannot allocate page data %s\n",
 235                        after_bootmem ? "after bootmem" : "");
 236        }
 237
 238        pr_debug("spp_getpage %p\n", ptr);
 239
 240        return ptr;
 241}
 242
 243static p4d_t *fill_p4d(pgd_t *pgd, unsigned long vaddr)
 244{
 245        if (pgd_none(*pgd)) {
 246                p4d_t *p4d = (p4d_t *)spp_getpage();
 247                pgd_populate(&init_mm, pgd, p4d);
 248                if (p4d != p4d_offset(pgd, 0))
 249                        printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n",
 250                               p4d, p4d_offset(pgd, 0));
 251        }
 252        return p4d_offset(pgd, vaddr);
 253}
 254
 255static pud_t *fill_pud(p4d_t *p4d, unsigned long vaddr)
 256{
 257        if (p4d_none(*p4d)) {
 258                pud_t *pud = (pud_t *)spp_getpage();
 259                p4d_populate(&init_mm, p4d, pud);
 260                if (pud != pud_offset(p4d, 0))
 261                        printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
 262                               pud, pud_offset(p4d, 0));
 263        }
 264        return pud_offset(p4d, vaddr);
 265}
 266
 267static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr)
 268{
 269        if (pud_none(*pud)) {
 270                pmd_t *pmd = (pmd_t *) spp_getpage();
 271                pud_populate(&init_mm, pud, pmd);
 272                if (pmd != pmd_offset(pud, 0))
 273                        printk(KERN_ERR "PAGETABLE BUG #02! %p <-> %p\n",
 274                               pmd, pmd_offset(pud, 0));
 275        }
 276        return pmd_offset(pud, vaddr);
 277}
 278
 279static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr)
 280{
 281        if (pmd_none(*pmd)) {
 282                pte_t *pte = (pte_t *) spp_getpage();
 283                pmd_populate_kernel(&init_mm, pmd, pte);
 284                if (pte != pte_offset_kernel(pmd, 0))
 285                        printk(KERN_ERR "PAGETABLE BUG #03!\n");
 286        }
 287        return pte_offset_kernel(pmd, vaddr);
 288}
 289
 290static void __set_pte_vaddr(pud_t *pud, unsigned long vaddr, pte_t new_pte)
 291{
 292        pmd_t *pmd = fill_pmd(pud, vaddr);
 293        pte_t *pte = fill_pte(pmd, vaddr);
 294
 295        set_pte(pte, new_pte);
 296
 297        /*
 298         * It's enough to flush this one mapping.
 299         * (PGE mappings get flushed as well)
 300         */
 301        __flush_tlb_one_kernel(vaddr);
 302}
 303
 304void set_pte_vaddr_p4d(p4d_t *p4d_page, unsigned long vaddr, pte_t new_pte)
 305{
 306        p4d_t *p4d = p4d_page + p4d_index(vaddr);
 307        pud_t *pud = fill_pud(p4d, vaddr);
 308
 309        __set_pte_vaddr(pud, vaddr, new_pte);
 310}
 311
 312void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
 313{
 314        pud_t *pud = pud_page + pud_index(vaddr);
 315
 316        __set_pte_vaddr(pud, vaddr, new_pte);
 317}
 318
 319void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
 320{
 321        pgd_t *pgd;
 322        p4d_t *p4d_page;
 323
 324        pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
 325
 326        pgd = pgd_offset_k(vaddr);
 327        if (pgd_none(*pgd)) {
 328                printk(KERN_ERR
 329                        "PGD FIXMAP MISSING, it should be setup in head.S!\n");
 330                return;
 331        }
 332
 333        p4d_page = p4d_offset(pgd, 0);
 334        set_pte_vaddr_p4d(p4d_page, vaddr, pteval);
 335}
 336
 337pmd_t * __init populate_extra_pmd(unsigned long vaddr)
 338{
 339        pgd_t *pgd;
 340        p4d_t *p4d;
 341        pud_t *pud;
 342
 343        pgd = pgd_offset_k(vaddr);
 344        p4d = fill_p4d(pgd, vaddr);
 345        pud = fill_pud(p4d, vaddr);
 346        return fill_pmd(pud, vaddr);
 347}
 348
 349pte_t * __init populate_extra_pte(unsigned long vaddr)
 350{
 351        pmd_t *pmd;
 352
 353        pmd = populate_extra_pmd(vaddr);
 354        return fill_pte(pmd, vaddr);
 355}
 356
 357/*
 358 * Create large page table mappings for a range of physical addresses.
 359 */
 360static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
 361                                        enum page_cache_mode cache)
 362{
 363        pgd_t *pgd;
 364        p4d_t *p4d;
 365        pud_t *pud;
 366        pmd_t *pmd;
 367        pgprot_t prot;
 368
 369        pgprot_val(prot) = pgprot_val(PAGE_KERNEL_LARGE) |
 370                pgprot_val(pgprot_4k_2_large(cachemode2pgprot(cache)));
 371        BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
 372        for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
 373                pgd = pgd_offset_k((unsigned long)__va(phys));
 374                if (pgd_none(*pgd)) {
 375                        p4d = (p4d_t *) spp_getpage();
 376                        set_pgd(pgd, __pgd(__pa(p4d) | _KERNPG_TABLE |
 377                                                _PAGE_USER));
 378                }
 379                p4d = p4d_offset(pgd, (unsigned long)__va(phys));
 380                if (p4d_none(*p4d)) {
 381                        pud = (pud_t *) spp_getpage();
 382                        set_p4d(p4d, __p4d(__pa(pud) | _KERNPG_TABLE |
 383                                                _PAGE_USER));
 384                }
 385                pud = pud_offset(p4d, (unsigned long)__va(phys));
 386                if (pud_none(*pud)) {
 387                        pmd = (pmd_t *) spp_getpage();
 388                        set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
 389                                                _PAGE_USER));
 390                }
 391                pmd = pmd_offset(pud, phys);
 392                BUG_ON(!pmd_none(*pmd));
 393                set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
 394        }
 395}
 396
 397void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
 398{
 399        __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_WB);
 400}
 401
 402void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
 403{
 404        __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_UC);
 405}
 406
 407/*
 408 * The head.S code sets up the kernel high mapping:
 409 *
 410 *   from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
 411 *
 412 * phys_base holds the negative offset to the kernel, which is added
 413 * to the compile time generated pmds. This results in invalid pmds up
 414 * to the point where we hit the physaddr 0 mapping.
 415 *
 416 * We limit the mappings to the region from _text to _brk_end.  _brk_end
 417 * is rounded up to the 2MB boundary. This catches the invalid pmds as
 418 * well, as they are located before _text:
 419 */
 420void __init cleanup_highmap(void)
 421{
 422        unsigned long vaddr = __START_KERNEL_map;
 423        unsigned long vaddr_end = __START_KERNEL_map + KERNEL_IMAGE_SIZE;
 424        unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1;
 425        pmd_t *pmd = level2_kernel_pgt;
 426
 427        /*
 428         * Native path, max_pfn_mapped is not set yet.
 429         * Xen has valid max_pfn_mapped set in
 430         *      arch/x86/xen/mmu.c:xen_setup_kernel_pagetable().
 431         */
 432        if (max_pfn_mapped)
 433                vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT);
 434
 435        for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) {
 436                if (pmd_none(*pmd))
 437                        continue;
 438                if (vaddr < (unsigned long) _text || vaddr > end)
 439                        set_pmd(pmd, __pmd(0));
 440        }
 441}
 442
 443/*
 444 * Create PTE level page table mapping for physical addresses.
 445 * It returns the last physical address mapped.
 446 */
 447static unsigned long __meminit
 448phys_pte_init(pte_t *pte_page, unsigned long paddr, unsigned long paddr_end,
 449              pgprot_t prot, bool init)
 450{
 451        unsigned long pages = 0, paddr_next;
 452        unsigned long paddr_last = paddr_end;
 453        pte_t *pte;
 454        int i;
 455
 456        pte = pte_page + pte_index(paddr);
 457        i = pte_index(paddr);
 458
 459        for (; i < PTRS_PER_PTE; i++, paddr = paddr_next, pte++) {
 460                paddr_next = (paddr & PAGE_MASK) + PAGE_SIZE;
 461                if (paddr >= paddr_end) {
 462                        if (!after_bootmem &&
 463                            !e820__mapped_any(paddr & PAGE_MASK, paddr_next,
 464                                             E820_TYPE_RAM) &&
 465                            !e820__mapped_any(paddr & PAGE_MASK, paddr_next,
 466                                             E820_TYPE_RESERVED_KERN))
 467                                set_pte_init(pte, __pte(0), init);
 468                        continue;
 469                }
 470
 471                /*
 472                 * We will re-use the existing mapping.
 473                 * Xen for example has some special requirements, like mapping
 474                 * pagetable pages as RO. So assume someone who pre-setup
 475                 * these mappings are more intelligent.
 476                 */
 477                if (!pte_none(*pte)) {
 478                        if (!after_bootmem)
 479                                pages++;
 480                        continue;
 481                }
 482
 483                if (0)
 484                        pr_info("   pte=%p addr=%lx pte=%016lx\n", pte, paddr,
 485                                pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL).pte);
 486                pages++;
 487                set_pte_init(pte, pfn_pte(paddr >> PAGE_SHIFT, prot), init);
 488                paddr_last = (paddr & PAGE_MASK) + PAGE_SIZE;
 489        }
 490
 491        update_page_count(PG_LEVEL_4K, pages);
 492
 493        return paddr_last;
 494}
 495
 496/*
 497 * Create PMD level page table mapping for physical addresses. The virtual
 498 * and physical address have to be aligned at this level.
 499 * It returns the last physical address mapped.
 500 */
 501static unsigned long __meminit
 502phys_pmd_init(pmd_t *pmd_page, unsigned long paddr, unsigned long paddr_end,
 503              unsigned long page_size_mask, pgprot_t prot, bool init)
 504{
 505        unsigned long pages = 0, paddr_next;
 506        unsigned long paddr_last = paddr_end;
 507
 508        int i = pmd_index(paddr);
 509
 510        for (; i < PTRS_PER_PMD; i++, paddr = paddr_next) {
 511                pmd_t *pmd = pmd_page + pmd_index(paddr);
 512                pte_t *pte;
 513                pgprot_t new_prot = prot;
 514
 515                paddr_next = (paddr & PMD_MASK) + PMD_SIZE;
 516                if (paddr >= paddr_end) {
 517                        if (!after_bootmem &&
 518                            !e820__mapped_any(paddr & PMD_MASK, paddr_next,
 519                                             E820_TYPE_RAM) &&
 520                            !e820__mapped_any(paddr & PMD_MASK, paddr_next,
 521                                             E820_TYPE_RESERVED_KERN))
 522                                set_pmd_init(pmd, __pmd(0), init);
 523                        continue;
 524                }
 525
 526                if (!pmd_none(*pmd)) {
 527                        if (!pmd_large(*pmd)) {
 528                                spin_lock(&init_mm.page_table_lock);
 529                                pte = (pte_t *)pmd_page_vaddr(*pmd);
 530                                paddr_last = phys_pte_init(pte, paddr,
 531                                                           paddr_end, prot,
 532                                                           init);
 533                                spin_unlock(&init_mm.page_table_lock);
 534                                continue;
 535                        }
 536                        /*
 537                         * If we are ok with PG_LEVEL_2M mapping, then we will
 538                         * use the existing mapping,
 539                         *
 540                         * Otherwise, we will split the large page mapping but
 541                         * use the same existing protection bits except for
 542                         * large page, so that we don't violate Intel's TLB
 543                         * Application note (317080) which says, while changing
 544                         * the page sizes, new and old translations should
 545                         * not differ with respect to page frame and
 546                         * attributes.
 547                         */
 548                        if (page_size_mask & (1 << PG_LEVEL_2M)) {
 549                                if (!after_bootmem)
 550                                        pages++;
 551                                paddr_last = paddr_next;
 552                                continue;
 553                        }
 554                        new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
 555                }
 556
 557                if (page_size_mask & (1<<PG_LEVEL_2M)) {
 558                        pages++;
 559                        spin_lock(&init_mm.page_table_lock);
 560                        set_pte_init((pte_t *)pmd,
 561                                     pfn_pte((paddr & PMD_MASK) >> PAGE_SHIFT,
 562                                             __pgprot(pgprot_val(prot) | _PAGE_PSE)),
 563                                     init);
 564                        spin_unlock(&init_mm.page_table_lock);
 565                        paddr_last = paddr_next;
 566                        continue;
 567                }
 568
 569                pte = alloc_low_page();
 570                paddr_last = phys_pte_init(pte, paddr, paddr_end, new_prot, init);
 571
 572                spin_lock(&init_mm.page_table_lock);
 573                pmd_populate_kernel_init(&init_mm, pmd, pte, init);
 574                spin_unlock(&init_mm.page_table_lock);
 575        }
 576        update_page_count(PG_LEVEL_2M, pages);
 577        return paddr_last;
 578}
 579
 580/*
 581 * Create PUD level page table mapping for physical addresses. The virtual
 582 * and physical address do not have to be aligned at this level. KASLR can
 583 * randomize virtual addresses up to this level.
 584 * It returns the last physical address mapped.
 585 */
 586static unsigned long __meminit
 587phys_pud_init(pud_t *pud_page, unsigned long paddr, unsigned long paddr_end,
 588              unsigned long page_size_mask, bool init)
 589{
 590        unsigned long pages = 0, paddr_next;
 591        unsigned long paddr_last = paddr_end;
 592        unsigned long vaddr = (unsigned long)__va(paddr);
 593        int i = pud_index(vaddr);
 594
 595        for (; i < PTRS_PER_PUD; i++, paddr = paddr_next) {
 596                pud_t *pud;
 597                pmd_t *pmd;
 598                pgprot_t prot = PAGE_KERNEL;
 599
 600                vaddr = (unsigned long)__va(paddr);
 601                pud = pud_page + pud_index(vaddr);
 602                paddr_next = (paddr & PUD_MASK) + PUD_SIZE;
 603
 604                if (paddr >= paddr_end) {
 605                        if (!after_bootmem &&
 606                            !e820__mapped_any(paddr & PUD_MASK, paddr_next,
 607                                             E820_TYPE_RAM) &&
 608                            !e820__mapped_any(paddr & PUD_MASK, paddr_next,
 609                                             E820_TYPE_RESERVED_KERN))
 610                                set_pud_init(pud, __pud(0), init);
 611                        continue;
 612                }
 613
 614                if (!pud_none(*pud)) {
 615                        if (!pud_large(*pud)) {
 616                                pmd = pmd_offset(pud, 0);
 617                                paddr_last = phys_pmd_init(pmd, paddr,
 618                                                           paddr_end,
 619                                                           page_size_mask,
 620                                                           prot, init);
 621                                continue;
 622                        }
 623                        /*
 624                         * If we are ok with PG_LEVEL_1G mapping, then we will
 625                         * use the existing mapping.
 626                         *
 627                         * Otherwise, we will split the gbpage mapping but use
 628                         * the same existing protection  bits except for large
 629                         * page, so that we don't violate Intel's TLB
 630                         * Application note (317080) which says, while changing
 631                         * the page sizes, new and old translations should
 632                         * not differ with respect to page frame and
 633                         * attributes.
 634                         */
 635                        if (page_size_mask & (1 << PG_LEVEL_1G)) {
 636                                if (!after_bootmem)
 637                                        pages++;
 638                                paddr_last = paddr_next;
 639                                continue;
 640                        }
 641                        prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
 642                }
 643
 644                if (page_size_mask & (1<<PG_LEVEL_1G)) {
 645                        pages++;
 646                        spin_lock(&init_mm.page_table_lock);
 647                        set_pte_init((pte_t *)pud,
 648                                     pfn_pte((paddr & PUD_MASK) >> PAGE_SHIFT,
 649                                             PAGE_KERNEL_LARGE),
 650                                     init);
 651                        spin_unlock(&init_mm.page_table_lock);
 652                        paddr_last = paddr_next;
 653                        continue;
 654                }
 655
 656                pmd = alloc_low_page();
 657                paddr_last = phys_pmd_init(pmd, paddr, paddr_end,
 658                                           page_size_mask, prot, init);
 659
 660                spin_lock(&init_mm.page_table_lock);
 661                pud_populate_init(&init_mm, pud, pmd, init);
 662                spin_unlock(&init_mm.page_table_lock);
 663        }
 664
 665        update_page_count(PG_LEVEL_1G, pages);
 666
 667        return paddr_last;
 668}
 669
 670static unsigned long __meminit
 671phys_p4d_init(p4d_t *p4d_page, unsigned long paddr, unsigned long paddr_end,
 672              unsigned long page_size_mask, bool init)
 673{
 674        unsigned long vaddr, vaddr_end, vaddr_next, paddr_next, paddr_last;
 675
 676        paddr_last = paddr_end;
 677        vaddr = (unsigned long)__va(paddr);
 678        vaddr_end = (unsigned long)__va(paddr_end);
 679
 680        if (!pgtable_l5_enabled())
 681                return phys_pud_init((pud_t *) p4d_page, paddr, paddr_end,
 682                                     page_size_mask, init);
 683
 684        for (; vaddr < vaddr_end; vaddr = vaddr_next) {
 685                p4d_t *p4d = p4d_page + p4d_index(vaddr);
 686                pud_t *pud;
 687
 688                vaddr_next = (vaddr & P4D_MASK) + P4D_SIZE;
 689                paddr = __pa(vaddr);
 690
 691                if (paddr >= paddr_end) {
 692                        paddr_next = __pa(vaddr_next);
 693                        if (!after_bootmem &&
 694                            !e820__mapped_any(paddr & P4D_MASK, paddr_next,
 695                                             E820_TYPE_RAM) &&
 696                            !e820__mapped_any(paddr & P4D_MASK, paddr_next,
 697                                             E820_TYPE_RESERVED_KERN))
 698                                set_p4d_init(p4d, __p4d(0), init);
 699                        continue;
 700                }
 701
 702                if (!p4d_none(*p4d)) {
 703                        pud = pud_offset(p4d, 0);
 704                        paddr_last = phys_pud_init(pud, paddr, __pa(vaddr_end),
 705                                        page_size_mask, init);
 706                        continue;
 707                }
 708
 709                pud = alloc_low_page();
 710                paddr_last = phys_pud_init(pud, paddr, __pa(vaddr_end),
 711                                           page_size_mask, init);
 712
 713                spin_lock(&init_mm.page_table_lock);
 714                p4d_populate_init(&init_mm, p4d, pud, init);
 715                spin_unlock(&init_mm.page_table_lock);
 716        }
 717
 718        return paddr_last;
 719}
 720
 721static unsigned long __meminit
 722__kernel_physical_mapping_init(unsigned long paddr_start,
 723                               unsigned long paddr_end,
 724                               unsigned long page_size_mask,
 725                               bool init)
 726{
 727        bool pgd_changed = false;
 728        unsigned long vaddr, vaddr_start, vaddr_end, vaddr_next, paddr_last;
 729
 730        paddr_last = paddr_end;
 731        vaddr = (unsigned long)__va(paddr_start);
 732        vaddr_end = (unsigned long)__va(paddr_end);
 733        vaddr_start = vaddr;
 734
 735        for (; vaddr < vaddr_end; vaddr = vaddr_next) {
 736                pgd_t *pgd = pgd_offset_k(vaddr);
 737                p4d_t *p4d;
 738
 739                vaddr_next = (vaddr & PGDIR_MASK) + PGDIR_SIZE;
 740
 741                if (pgd_val(*pgd)) {
 742                        p4d = (p4d_t *)pgd_page_vaddr(*pgd);
 743                        paddr_last = phys_p4d_init(p4d, __pa(vaddr),
 744                                                   __pa(vaddr_end),
 745                                                   page_size_mask,
 746                                                   init);
 747                        continue;
 748                }
 749
 750                p4d = alloc_low_page();
 751                paddr_last = phys_p4d_init(p4d, __pa(vaddr), __pa(vaddr_end),
 752                                           page_size_mask, init);
 753
 754                spin_lock(&init_mm.page_table_lock);
 755                if (pgtable_l5_enabled())
 756                        pgd_populate_init(&init_mm, pgd, p4d, init);
 757                else
 758                        p4d_populate_init(&init_mm, p4d_offset(pgd, vaddr),
 759                                          (pud_t *) p4d, init);
 760
 761                spin_unlock(&init_mm.page_table_lock);
 762                pgd_changed = true;
 763        }
 764
 765        if (pgd_changed)
 766                sync_global_pgds(vaddr_start, vaddr_end - 1);
 767
 768        return paddr_last;
 769}
 770
 771
 772/*
 773 * Create page table mapping for the physical memory for specific physical
 774 * addresses. Note that it can only be used to populate non-present entries.
 775 * The virtual and physical addresses have to be aligned on PMD level
 776 * down. It returns the last physical address mapped.
 777 */
 778unsigned long __meminit
 779kernel_physical_mapping_init(unsigned long paddr_start,
 780                             unsigned long paddr_end,
 781                             unsigned long page_size_mask)
 782{
 783        return __kernel_physical_mapping_init(paddr_start, paddr_end,
 784                                              page_size_mask, true);
 785}
 786
 787/*
 788 * This function is similar to kernel_physical_mapping_init() above with the
 789 * exception that it uses set_{pud,pmd}() instead of the set_{pud,pte}_safe()
 790 * when updating the mapping. The caller is responsible to flush the TLBs after
 791 * the function returns.
 792 */
 793unsigned long __meminit
 794kernel_physical_mapping_change(unsigned long paddr_start,
 795                               unsigned long paddr_end,
 796                               unsigned long page_size_mask)
 797{
 798        return __kernel_physical_mapping_init(paddr_start, paddr_end,
 799                                              page_size_mask, false);
 800}
 801
 802#ifndef CONFIG_NUMA
 803void __init initmem_init(void)
 804{
 805        memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
 806}
 807#endif
 808
 809void __init paging_init(void)
 810{
 811        sparse_memory_present_with_active_regions(MAX_NUMNODES);
 812        sparse_init();
 813
 814        /*
 815         * clear the default setting with node 0
 816         * note: don't use nodes_clear here, that is really clearing when
 817         *       numa support is not compiled in, and later node_set_state
 818         *       will not set it back.
 819         */
 820        node_clear_state(0, N_MEMORY);
 821        if (N_MEMORY != N_NORMAL_MEMORY)
 822                node_clear_state(0, N_NORMAL_MEMORY);
 823
 824        zone_sizes_init();
 825}
 826
 827/*
 828 * Memory hotplug specific functions
 829 */
 830#ifdef CONFIG_MEMORY_HOTPLUG
 831/*
 832 * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
 833 * updating.
 834 */
 835static void update_end_of_memory_vars(u64 start, u64 size)
 836{
 837        unsigned long end_pfn = PFN_UP(start + size);
 838
 839        if (end_pfn > max_pfn) {
 840                max_pfn = end_pfn;
 841                max_low_pfn = end_pfn;
 842                high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
 843        }
 844}
 845
 846int add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
 847                                struct mhp_restrictions *restrictions)
 848{
 849        int ret;
 850
 851        ret = __add_pages(nid, start_pfn, nr_pages, restrictions);
 852        WARN_ON_ONCE(ret);
 853
 854        /* update max_pfn, max_low_pfn and high_memory */
 855        update_end_of_memory_vars(start_pfn << PAGE_SHIFT,
 856                                  nr_pages << PAGE_SHIFT);
 857
 858        return ret;
 859}
 860
 861int arch_add_memory(int nid, u64 start, u64 size,
 862                        struct mhp_restrictions *restrictions)
 863{
 864        unsigned long start_pfn = start >> PAGE_SHIFT;
 865        unsigned long nr_pages = size >> PAGE_SHIFT;
 866
 867        init_memory_mapping(start, start + size);
 868
 869        return add_pages(nid, start_pfn, nr_pages, restrictions);
 870}
 871
 872#define PAGE_INUSE 0xFD
 873
 874static void __meminit free_pagetable(struct page *page, int order)
 875{
 876        unsigned long magic;
 877        unsigned int nr_pages = 1 << order;
 878
 879        /* bootmem page has reserved flag */
 880        if (PageReserved(page)) {
 881                __ClearPageReserved(page);
 882
 883                magic = (unsigned long)page->freelist;
 884                if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
 885                        while (nr_pages--)
 886                                put_page_bootmem(page++);
 887                } else
 888                        while (nr_pages--)
 889                                free_reserved_page(page++);
 890        } else
 891                free_pages((unsigned long)page_address(page), order);
 892}
 893
 894static void __meminit free_hugepage_table(struct page *page,
 895                struct vmem_altmap *altmap)
 896{
 897        if (altmap)
 898                vmem_altmap_free(altmap, PMD_SIZE / PAGE_SIZE);
 899        else
 900                free_pagetable(page, get_order(PMD_SIZE));
 901}
 902
 903static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
 904{
 905        pte_t *pte;
 906        int i;
 907
 908        for (i = 0; i < PTRS_PER_PTE; i++) {
 909                pte = pte_start + i;
 910                if (!pte_none(*pte))
 911                        return;
 912        }
 913
 914        /* free a pte talbe */
 915        free_pagetable(pmd_page(*pmd), 0);
 916        spin_lock(&init_mm.page_table_lock);
 917        pmd_clear(pmd);
 918        spin_unlock(&init_mm.page_table_lock);
 919}
 920
 921static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud)
 922{
 923        pmd_t *pmd;
 924        int i;
 925
 926        for (i = 0; i < PTRS_PER_PMD; i++) {
 927                pmd = pmd_start + i;
 928                if (!pmd_none(*pmd))
 929                        return;
 930        }
 931
 932        /* free a pmd talbe */
 933        free_pagetable(pud_page(*pud), 0);
 934        spin_lock(&init_mm.page_table_lock);
 935        pud_clear(pud);
 936        spin_unlock(&init_mm.page_table_lock);
 937}
 938
 939static void __meminit free_pud_table(pud_t *pud_start, p4d_t *p4d)
 940{
 941        pud_t *pud;
 942        int i;
 943
 944        for (i = 0; i < PTRS_PER_PUD; i++) {
 945                pud = pud_start + i;
 946                if (!pud_none(*pud))
 947                        return;
 948        }
 949
 950        /* free a pud talbe */
 951        free_pagetable(p4d_page(*p4d), 0);
 952        spin_lock(&init_mm.page_table_lock);
 953        p4d_clear(p4d);
 954        spin_unlock(&init_mm.page_table_lock);
 955}
 956
 957static void __meminit
 958remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
 959                 bool direct)
 960{
 961        unsigned long next, pages = 0;
 962        pte_t *pte;
 963        void *page_addr;
 964        phys_addr_t phys_addr;
 965
 966        pte = pte_start + pte_index(addr);
 967        for (; addr < end; addr = next, pte++) {
 968                next = (addr + PAGE_SIZE) & PAGE_MASK;
 969                if (next > end)
 970                        next = end;
 971
 972                if (!pte_present(*pte))
 973                        continue;
 974
 975                /*
 976                 * We mapped [0,1G) memory as identity mapping when
 977                 * initializing, in arch/x86/kernel/head_64.S. These
 978                 * pagetables cannot be removed.
 979                 */
 980                phys_addr = pte_val(*pte) + (addr & PAGE_MASK);
 981                if (phys_addr < (phys_addr_t)0x40000000)
 982                        return;
 983
 984                if (PAGE_ALIGNED(addr) && PAGE_ALIGNED(next)) {
 985                        /*
 986                         * Do not free direct mapping pages since they were
 987                         * freed when offlining, or simplely not in use.
 988                         */
 989                        if (!direct)
 990                                free_pagetable(pte_page(*pte), 0);
 991
 992                        spin_lock(&init_mm.page_table_lock);
 993                        pte_clear(&init_mm, addr, pte);
 994                        spin_unlock(&init_mm.page_table_lock);
 995
 996                        /* For non-direct mapping, pages means nothing. */
 997                        pages++;
 998                } else {
 999                        /*
1000                         * If we are here, we are freeing vmemmap pages since
1001                         * direct mapped memory ranges to be freed are aligned.
1002                         *
1003                         * If we are not removing the whole page, it means
1004                         * other page structs in this page are being used and
1005                         * we canot remove them. So fill the unused page_structs
1006                         * with 0xFD, and remove the page when it is wholly
1007                         * filled with 0xFD.
1008                         */
1009                        memset((void *)addr, PAGE_INUSE, next - addr);
1010
1011                        page_addr = page_address(pte_page(*pte));
1012                        if (!memchr_inv(page_addr, PAGE_INUSE, PAGE_SIZE)) {
1013                                free_pagetable(pte_page(*pte), 0);
1014
1015                                spin_lock(&init_mm.page_table_lock);
1016                                pte_clear(&init_mm, addr, pte);
1017                                spin_unlock(&init_mm.page_table_lock);
1018                        }
1019                }
1020        }
1021
1022        /* Call free_pte_table() in remove_pmd_table(). */
1023        flush_tlb_all();
1024        if (direct)
1025                update_page_count(PG_LEVEL_4K, -pages);
1026}
1027
1028static void __meminit
1029remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
1030                 bool direct, struct vmem_altmap *altmap)
1031{
1032        unsigned long next, pages = 0;
1033        pte_t *pte_base;
1034        pmd_t *pmd;
1035        void *page_addr;
1036
1037        pmd = pmd_start + pmd_index(addr);
1038        for (; addr < end; addr = next, pmd++) {
1039                next = pmd_addr_end(addr, end);
1040
1041                if (!pmd_present(*pmd))
1042                        continue;
1043
1044                if (pmd_large(*pmd)) {
1045                        if (IS_ALIGNED(addr, PMD_SIZE) &&
1046                            IS_ALIGNED(next, PMD_SIZE)) {
1047                                if (!direct)
1048                                        free_hugepage_table(pmd_page(*pmd),
1049                                                            altmap);
1050
1051                                spin_lock(&init_mm.page_table_lock);
1052                                pmd_clear(pmd);
1053                                spin_unlock(&init_mm.page_table_lock);
1054                                pages++;
1055                        } else {
1056                                /* If here, we are freeing vmemmap pages. */
1057                                memset((void *)addr, PAGE_INUSE, next - addr);
1058
1059                                page_addr = page_address(pmd_page(*pmd));
1060                                if (!memchr_inv(page_addr, PAGE_INUSE,
1061                                                PMD_SIZE)) {
1062                                        free_hugepage_table(pmd_page(*pmd),
1063                                                            altmap);
1064
1065                                        spin_lock(&init_mm.page_table_lock);
1066                                        pmd_clear(pmd);
1067                                        spin_unlock(&init_mm.page_table_lock);
1068                                }
1069                        }
1070
1071                        continue;
1072                }
1073
1074                pte_base = (pte_t *)pmd_page_vaddr(*pmd);
1075                remove_pte_table(pte_base, addr, next, direct);
1076                free_pte_table(pte_base, pmd);
1077        }
1078
1079        /* Call free_pmd_table() in remove_pud_table(). */
1080        if (direct)
1081                update_page_count(PG_LEVEL_2M, -pages);
1082}
1083
1084static void __meminit
1085remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
1086                 struct vmem_altmap *altmap, bool direct)
1087{
1088        unsigned long next, pages = 0;
1089        pmd_t *pmd_base;
1090        pud_t *pud;
1091        void *page_addr;
1092
1093        pud = pud_start + pud_index(addr);
1094        for (; addr < end; addr = next, pud++) {
1095                next = pud_addr_end(addr, end);
1096
1097                if (!pud_present(*pud))
1098                        continue;
1099
1100                if (pud_large(*pud)) {
1101                        if (IS_ALIGNED(addr, PUD_SIZE) &&
1102                            IS_ALIGNED(next, PUD_SIZE)) {
1103                                if (!direct)
1104                                        free_pagetable(pud_page(*pud),
1105                                                       get_order(PUD_SIZE));
1106
1107                                spin_lock(&init_mm.page_table_lock);
1108                                pud_clear(pud);
1109                                spin_unlock(&init_mm.page_table_lock);
1110                                pages++;
1111                        } else {
1112                                /* If here, we are freeing vmemmap pages. */
1113                                memset((void *)addr, PAGE_INUSE, next - addr);
1114
1115                                page_addr = page_address(pud_page(*pud));
1116                                if (!memchr_inv(page_addr, PAGE_INUSE,
1117                                                PUD_SIZE)) {
1118                                        free_pagetable(pud_page(*pud),
1119                                                       get_order(PUD_SIZE));
1120
1121                                        spin_lock(&init_mm.page_table_lock);
1122                                        pud_clear(pud);
1123                                        spin_unlock(&init_mm.page_table_lock);
1124                                }
1125                        }
1126
1127                        continue;
1128                }
1129
1130                pmd_base = pmd_offset(pud, 0);
1131                remove_pmd_table(pmd_base, addr, next, direct, altmap);
1132                free_pmd_table(pmd_base, pud);
1133        }
1134
1135        if (direct)
1136                update_page_count(PG_LEVEL_1G, -pages);
1137}
1138
1139static void __meminit
1140remove_p4d_table(p4d_t *p4d_start, unsigned long addr, unsigned long end,
1141                 struct vmem_altmap *altmap, bool direct)
1142{
1143        unsigned long next, pages = 0;
1144        pud_t *pud_base;
1145        p4d_t *p4d;
1146
1147        p4d = p4d_start + p4d_index(addr);
1148        for (; addr < end; addr = next, p4d++) {
1149                next = p4d_addr_end(addr, end);
1150
1151                if (!p4d_present(*p4d))
1152                        continue;
1153
1154                BUILD_BUG_ON(p4d_large(*p4d));
1155
1156                pud_base = pud_offset(p4d, 0);
1157                remove_pud_table(pud_base, addr, next, altmap, direct);
1158                /*
1159                 * For 4-level page tables we do not want to free PUDs, but in the
1160                 * 5-level case we should free them. This code will have to change
1161                 * to adapt for boot-time switching between 4 and 5 level page tables.
1162                 */
1163                if (pgtable_l5_enabled())
1164                        free_pud_table(pud_base, p4d);
1165        }
1166
1167        if (direct)
1168                update_page_count(PG_LEVEL_512G, -pages);
1169}
1170
1171/* start and end are both virtual address. */
1172static void __meminit
1173remove_pagetable(unsigned long start, unsigned long end, bool direct,
1174                struct vmem_altmap *altmap)
1175{
1176        unsigned long next;
1177        unsigned long addr;
1178        pgd_t *pgd;
1179        p4d_t *p4d;
1180
1181        for (addr = start; addr < end; addr = next) {
1182                next = pgd_addr_end(addr, end);
1183
1184                pgd = pgd_offset_k(addr);
1185                if (!pgd_present(*pgd))
1186                        continue;
1187
1188                p4d = p4d_offset(pgd, 0);
1189                remove_p4d_table(p4d, addr, next, altmap, direct);
1190        }
1191
1192        flush_tlb_all();
1193}
1194
1195void __ref vmemmap_free(unsigned long start, unsigned long end,
1196                struct vmem_altmap *altmap)
1197{
1198        remove_pagetable(start, end, false, altmap);
1199}
1200
1201static void __meminit
1202kernel_physical_mapping_remove(unsigned long start, unsigned long end)
1203{
1204        start = (unsigned long)__va(start);
1205        end = (unsigned long)__va(end);
1206
1207        remove_pagetable(start, end, true, NULL);
1208}
1209
1210void __ref arch_remove_memory(int nid, u64 start, u64 size,
1211                              struct vmem_altmap *altmap)
1212{
1213        unsigned long start_pfn = start >> PAGE_SHIFT;
1214        unsigned long nr_pages = size >> PAGE_SHIFT;
1215        struct page *page = pfn_to_page(start_pfn) + vmem_altmap_offset(altmap);
1216        struct zone *zone = page_zone(page);
1217
1218        __remove_pages(zone, start_pfn, nr_pages, altmap);
1219        kernel_physical_mapping_remove(start, start + size);
1220}
1221#endif /* CONFIG_MEMORY_HOTPLUG */
1222
1223static struct kcore_list kcore_vsyscall;
1224
1225static void __init register_page_bootmem_info(void)
1226{
1227#ifdef CONFIG_NUMA
1228        int i;
1229
1230        for_each_online_node(i)
1231                register_page_bootmem_info_node(NODE_DATA(i));
1232#endif
1233}
1234
1235void __init mem_init(void)
1236{
1237        pci_iommu_alloc();
1238
1239        /* clear_bss() already clear the empty_zero_page */
1240
1241        /* this will put all memory onto the freelists */
1242        memblock_free_all();
1243        after_bootmem = 1;
1244        x86_init.hyper.init_after_bootmem();
1245
1246        /*
1247         * Must be done after boot memory is put on freelist, because here we
1248         * might set fields in deferred struct pages that have not yet been
1249         * initialized, and memblock_free_all() initializes all the reserved
1250         * deferred pages for us.
1251         */
1252        register_page_bootmem_info();
1253
1254        /* Register memory areas for /proc/kcore */
1255        if (get_gate_vma(&init_mm))
1256                kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR, PAGE_SIZE, KCORE_USER);
1257
1258        mem_init_print_info(NULL);
1259}
1260
1261int kernel_set_to_readonly;
1262
1263void set_kernel_text_rw(void)
1264{
1265        unsigned long start = PFN_ALIGN(_text);
1266        unsigned long end = PFN_ALIGN(__stop___ex_table);
1267
1268        if (!kernel_set_to_readonly)
1269                return;
1270
1271        pr_debug("Set kernel text: %lx - %lx for read write\n",
1272                 start, end);
1273
1274        /*
1275         * Make the kernel identity mapping for text RW. Kernel text
1276         * mapping will always be RO. Refer to the comment in
1277         * static_protections() in pageattr.c
1278         */
1279        set_memory_rw(start, (end - start) >> PAGE_SHIFT);
1280}
1281
1282void set_kernel_text_ro(void)
1283{
1284        unsigned long start = PFN_ALIGN(_text);
1285        unsigned long end = PFN_ALIGN(__stop___ex_table);
1286
1287        if (!kernel_set_to_readonly)
1288                return;
1289
1290        pr_debug("Set kernel text: %lx - %lx for read only\n",
1291                 start, end);
1292
1293        /*
1294         * Set the kernel identity mapping for text RO.
1295         */
1296        set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1297}
1298
1299void mark_rodata_ro(void)
1300{
1301        unsigned long start = PFN_ALIGN(_text);
1302        unsigned long rodata_start = PFN_ALIGN(__start_rodata);
1303        unsigned long end = (unsigned long) &__end_rodata_hpage_align;
1304        unsigned long text_end = PFN_ALIGN(&__stop___ex_table);
1305        unsigned long rodata_end = PFN_ALIGN(&__end_rodata);
1306        unsigned long all_end;
1307
1308        printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
1309               (end - start) >> 10);
1310        set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1311
1312        kernel_set_to_readonly = 1;
1313
1314        /*
1315         * The rodata/data/bss/brk section (but not the kernel text!)
1316         * should also be not-executable.
1317         *
1318         * We align all_end to PMD_SIZE because the existing mapping
1319         * is a full PMD. If we would align _brk_end to PAGE_SIZE we
1320         * split the PMD and the reminder between _brk_end and the end
1321         * of the PMD will remain mapped executable.
1322         *
1323         * Any PMD which was setup after the one which covers _brk_end
1324         * has been zapped already via cleanup_highmem().
1325         */
1326        all_end = roundup((unsigned long)_brk_end, PMD_SIZE);
1327        set_memory_nx(text_end, (all_end - text_end) >> PAGE_SHIFT);
1328
1329#ifdef CONFIG_CPA_DEBUG
1330        printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
1331        set_memory_rw(start, (end-start) >> PAGE_SHIFT);
1332
1333        printk(KERN_INFO "Testing CPA: again\n");
1334        set_memory_ro(start, (end-start) >> PAGE_SHIFT);
1335#endif
1336
1337        free_kernel_image_pages((void *)text_end, (void *)rodata_start);
1338        free_kernel_image_pages((void *)rodata_end, (void *)_sdata);
1339
1340        debug_checkwx();
1341}
1342
1343int kern_addr_valid(unsigned long addr)
1344{
1345        unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
1346        pgd_t *pgd;
1347        p4d_t *p4d;
1348        pud_t *pud;
1349        pmd_t *pmd;
1350        pte_t *pte;
1351
1352        if (above != 0 && above != -1UL)
1353                return 0;
1354
1355        pgd = pgd_offset_k(addr);
1356        if (pgd_none(*pgd))
1357                return 0;
1358
1359        p4d = p4d_offset(pgd, addr);
1360        if (p4d_none(*p4d))
1361                return 0;
1362
1363        pud = pud_offset(p4d, addr);
1364        if (pud_none(*pud))
1365                return 0;
1366
1367        if (pud_large(*pud))
1368                return pfn_valid(pud_pfn(*pud));
1369
1370        pmd = pmd_offset(pud, addr);
1371        if (pmd_none(*pmd))
1372                return 0;
1373
1374        if (pmd_large(*pmd))
1375                return pfn_valid(pmd_pfn(*pmd));
1376
1377        pte = pte_offset_kernel(pmd, addr);
1378        if (pte_none(*pte))
1379                return 0;
1380
1381        return pfn_valid(pte_pfn(*pte));
1382}
1383
1384/*
1385 * Block size is the minimum amount of memory which can be hotplugged or
1386 * hotremoved. It must be power of two and must be equal or larger than
1387 * MIN_MEMORY_BLOCK_SIZE.
1388 */
1389#define MAX_BLOCK_SIZE (2UL << 30)
1390
1391/* Amount of ram needed to start using large blocks */
1392#define MEM_SIZE_FOR_LARGE_BLOCK (64UL << 30)
1393
1394/* Adjustable memory block size */
1395static unsigned long set_memory_block_size;
1396int __init set_memory_block_size_order(unsigned int order)
1397{
1398        unsigned long size = 1UL << order;
1399
1400        if (size > MEM_SIZE_FOR_LARGE_BLOCK || size < MIN_MEMORY_BLOCK_SIZE)
1401                return -EINVAL;
1402
1403        set_memory_block_size = size;
1404        return 0;
1405}
1406
1407static unsigned long probe_memory_block_size(void)
1408{
1409        unsigned long boot_mem_end = max_pfn << PAGE_SHIFT;
1410        unsigned long bz;
1411
1412        /* If memory block size has been set, then use it */
1413        bz = set_memory_block_size;
1414        if (bz)
1415                goto done;
1416
1417        /* Use regular block if RAM is smaller than MEM_SIZE_FOR_LARGE_BLOCK */
1418        if (boot_mem_end < MEM_SIZE_FOR_LARGE_BLOCK) {
1419                bz = MIN_MEMORY_BLOCK_SIZE;
1420                goto done;
1421        }
1422
1423        /* Find the largest allowed block size that aligns to memory end */
1424        for (bz = MAX_BLOCK_SIZE; bz > MIN_MEMORY_BLOCK_SIZE; bz >>= 1) {
1425                if (IS_ALIGNED(boot_mem_end, bz))
1426                        break;
1427        }
1428done:
1429        pr_info("x86/mm: Memory block size: %ldMB\n", bz >> 20);
1430
1431        return bz;
1432}
1433
1434static unsigned long memory_block_size_probed;
1435unsigned long memory_block_size_bytes(void)
1436{
1437        if (!memory_block_size_probed)
1438                memory_block_size_probed = probe_memory_block_size();
1439
1440        return memory_block_size_probed;
1441}
1442
1443#ifdef CONFIG_SPARSEMEM_VMEMMAP
1444/*
1445 * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1446 */
1447static long __meminitdata addr_start, addr_end;
1448static void __meminitdata *p_start, *p_end;
1449static int __meminitdata node_start;
1450
1451static int __meminit vmemmap_populate_hugepages(unsigned long start,
1452                unsigned long end, int node, struct vmem_altmap *altmap)
1453{
1454        unsigned long addr;
1455        unsigned long next;
1456        pgd_t *pgd;
1457        p4d_t *p4d;
1458        pud_t *pud;
1459        pmd_t *pmd;
1460
1461        for (addr = start; addr < end; addr = next) {
1462                next = pmd_addr_end(addr, end);
1463
1464                pgd = vmemmap_pgd_populate(addr, node);
1465                if (!pgd)
1466                        return -ENOMEM;
1467
1468                p4d = vmemmap_p4d_populate(pgd, addr, node);
1469                if (!p4d)
1470                        return -ENOMEM;
1471
1472                pud = vmemmap_pud_populate(p4d, addr, node);
1473                if (!pud)
1474                        return -ENOMEM;
1475
1476                pmd = pmd_offset(pud, addr);
1477                if (pmd_none(*pmd)) {
1478                        void *p;
1479
1480                        if (altmap)
1481                                p = altmap_alloc_block_buf(PMD_SIZE, altmap);
1482                        else
1483                                p = vmemmap_alloc_block_buf(PMD_SIZE, node);
1484                        if (p) {
1485                                pte_t entry;
1486
1487                                entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1488                                                PAGE_KERNEL_LARGE);
1489                                set_pmd(pmd, __pmd(pte_val(entry)));
1490
1491                                /* check to see if we have contiguous blocks */
1492                                if (p_end != p || node_start != node) {
1493                                        if (p_start)
1494                                                pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1495                                                       addr_start, addr_end-1, p_start, p_end-1, node_start);
1496                                        addr_start = addr;
1497                                        node_start = node;
1498                                        p_start = p;
1499                                }
1500
1501                                addr_end = addr + PMD_SIZE;
1502                                p_end = p + PMD_SIZE;
1503                                continue;
1504                        } else if (altmap)
1505                                return -ENOMEM; /* no fallback */
1506                } else if (pmd_large(*pmd)) {
1507                        vmemmap_verify((pte_t *)pmd, node, addr, next);
1508                        continue;
1509                }
1510                if (vmemmap_populate_basepages(addr, next, node))
1511                        return -ENOMEM;
1512        }
1513        return 0;
1514}
1515
1516int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
1517                struct vmem_altmap *altmap)
1518{
1519        int err;
1520
1521        if (end - start < PAGES_PER_SECTION * sizeof(struct page))
1522                err = vmemmap_populate_basepages(start, end, node);
1523        else if (boot_cpu_has(X86_FEATURE_PSE))
1524                err = vmemmap_populate_hugepages(start, end, node, altmap);
1525        else if (altmap) {
1526                pr_err_once("%s: no cpu support for altmap allocations\n",
1527                                __func__);
1528                err = -ENOMEM;
1529        } else
1530                err = vmemmap_populate_basepages(start, end, node);
1531        if (!err)
1532                sync_global_pgds(start, end - 1);
1533        return err;
1534}
1535
1536#if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HAVE_BOOTMEM_INFO_NODE)
1537void register_page_bootmem_memmap(unsigned long section_nr,
1538                                  struct page *start_page, unsigned long nr_pages)
1539{
1540        unsigned long addr = (unsigned long)start_page;
1541        unsigned long end = (unsigned long)(start_page + nr_pages);
1542        unsigned long next;
1543        pgd_t *pgd;
1544        p4d_t *p4d;
1545        pud_t *pud;
1546        pmd_t *pmd;
1547        unsigned int nr_pmd_pages;
1548        struct page *page;
1549
1550        for (; addr < end; addr = next) {
1551                pte_t *pte = NULL;
1552
1553                pgd = pgd_offset_k(addr);
1554                if (pgd_none(*pgd)) {
1555                        next = (addr + PAGE_SIZE) & PAGE_MASK;
1556                        continue;
1557                }
1558                get_page_bootmem(section_nr, pgd_page(*pgd), MIX_SECTION_INFO);
1559
1560                p4d = p4d_offset(pgd, addr);
1561                if (p4d_none(*p4d)) {
1562                        next = (addr + PAGE_SIZE) & PAGE_MASK;
1563                        continue;
1564                }
1565                get_page_bootmem(section_nr, p4d_page(*p4d), MIX_SECTION_INFO);
1566
1567                pud = pud_offset(p4d, addr);
1568                if (pud_none(*pud)) {
1569                        next = (addr + PAGE_SIZE) & PAGE_MASK;
1570                        continue;
1571                }
1572                get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO);
1573
1574                if (!boot_cpu_has(X86_FEATURE_PSE)) {
1575                        next = (addr + PAGE_SIZE) & PAGE_MASK;
1576                        pmd = pmd_offset(pud, addr);
1577                        if (pmd_none(*pmd))
1578                                continue;
1579                        get_page_bootmem(section_nr, pmd_page(*pmd),
1580                                         MIX_SECTION_INFO);
1581
1582                        pte = pte_offset_kernel(pmd, addr);
1583                        if (pte_none(*pte))
1584                                continue;
1585                        get_page_bootmem(section_nr, pte_page(*pte),
1586                                         SECTION_INFO);
1587                } else {
1588                        next = pmd_addr_end(addr, end);
1589
1590                        pmd = pmd_offset(pud, addr);
1591                        if (pmd_none(*pmd))
1592                                continue;
1593
1594                        nr_pmd_pages = 1 << get_order(PMD_SIZE);
1595                        page = pmd_page(*pmd);
1596                        while (nr_pmd_pages--)
1597                                get_page_bootmem(section_nr, page++,
1598                                                 SECTION_INFO);
1599                }
1600        }
1601}
1602#endif
1603
1604void __meminit vmemmap_populate_print_last(void)
1605{
1606        if (p_start) {
1607                pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1608                        addr_start, addr_end-1, p_start, p_end-1, node_start);
1609                p_start = NULL;
1610                p_end = NULL;
1611                node_start = 0;
1612        }
1613}
1614#endif
1615