linux/arch/x86/mm/init_64.c
<<
>>
Prefs
   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#include <linux/bootmem_info.h>
  37
  38#include <asm/processor.h>
  39#include <asm/bios_ebda.h>
  40#include <linux/uaccess.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#include <asm/ftrace.h>
  58
  59#include "mm_internal.h"
  60
  61#include "ident_map.c"
  62
  63#define DEFINE_POPULATE(fname, type1, type2, init)              \
  64static inline void fname##_init(struct mm_struct *mm,           \
  65                type1##_t *arg1, type2##_t *arg2, bool init)    \
  66{                                                               \
  67        if (init)                                               \
  68                fname##_safe(mm, arg1, arg2);                   \
  69        else                                                    \
  70                fname(mm, arg1, arg2);                          \
  71}
  72
  73DEFINE_POPULATE(p4d_populate, p4d, pud, init)
  74DEFINE_POPULATE(pgd_populate, pgd, p4d, init)
  75DEFINE_POPULATE(pud_populate, pud, pmd, init)
  76DEFINE_POPULATE(pmd_populate_kernel, pmd, pte, init)
  77
  78#define DEFINE_ENTRY(type1, type2, init)                        \
  79static inline void set_##type1##_init(type1##_t *arg1,          \
  80                        type2##_t arg2, bool init)              \
  81{                                                               \
  82        if (init)                                               \
  83                set_##type1##_safe(arg1, arg2);                 \
  84        else                                                    \
  85                set_##type1(arg1, arg2);                        \
  86}
  87
  88DEFINE_ENTRY(p4d, p4d, init)
  89DEFINE_ENTRY(pud, pud, init)
  90DEFINE_ENTRY(pmd, pmd, init)
  91DEFINE_ENTRY(pte, pte, init)
  92
  93
  94/*
  95 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
  96 * physical space so we can cache the place of the first one and move
  97 * around without checking the pgd every time.
  98 */
  99
 100/* Bits supported by the hardware: */
 101pteval_t __supported_pte_mask __read_mostly = ~0;
 102/* Bits allowed in normal kernel mappings: */
 103pteval_t __default_kernel_pte_mask __read_mostly = ~0;
 104EXPORT_SYMBOL_GPL(__supported_pte_mask);
 105/* Used in PAGE_KERNEL_* macros which are reasonably used out-of-tree: */
 106EXPORT_SYMBOL(__default_kernel_pte_mask);
 107
 108int force_personality32;
 109
 110/*
 111 * noexec32=on|off
 112 * Control non executable heap for 32bit processes.
 113 * To control the stack too use noexec=off
 114 *
 115 * on   PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
 116 * off  PROT_READ implies PROT_EXEC
 117 */
 118static int __init nonx32_setup(char *str)
 119{
 120        if (!strcmp(str, "on"))
 121                force_personality32 &= ~READ_IMPLIES_EXEC;
 122        else if (!strcmp(str, "off"))
 123                force_personality32 |= READ_IMPLIES_EXEC;
 124        return 1;
 125}
 126__setup("noexec32=", nonx32_setup);
 127
 128static void sync_global_pgds_l5(unsigned long start, unsigned long end)
 129{
 130        unsigned long addr;
 131
 132        for (addr = start; addr <= end; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
 133                const pgd_t *pgd_ref = pgd_offset_k(addr);
 134                struct page *page;
 135
 136                /* Check for overflow */
 137                if (addr < start)
 138                        break;
 139
 140                if (pgd_none(*pgd_ref))
 141                        continue;
 142
 143                spin_lock(&pgd_lock);
 144                list_for_each_entry(page, &pgd_list, lru) {
 145                        pgd_t *pgd;
 146                        spinlock_t *pgt_lock;
 147
 148                        pgd = (pgd_t *)page_address(page) + pgd_index(addr);
 149                        /* the pgt_lock only for Xen */
 150                        pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
 151                        spin_lock(pgt_lock);
 152
 153                        if (!pgd_none(*pgd_ref) && !pgd_none(*pgd))
 154                                BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref));
 155
 156                        if (pgd_none(*pgd))
 157                                set_pgd(pgd, *pgd_ref);
 158
 159                        spin_unlock(pgt_lock);
 160                }
 161                spin_unlock(&pgd_lock);
 162        }
 163}
 164
 165static void sync_global_pgds_l4(unsigned long start, unsigned long end)
 166{
 167        unsigned long addr;
 168
 169        for (addr = start; addr <= end; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
 170                pgd_t *pgd_ref = pgd_offset_k(addr);
 171                const p4d_t *p4d_ref;
 172                struct page *page;
 173
 174                /*
 175                 * With folded p4d, pgd_none() is always false, we need to
 176                 * handle synchronization on p4d level.
 177                 */
 178                MAYBE_BUILD_BUG_ON(pgd_none(*pgd_ref));
 179                p4d_ref = p4d_offset(pgd_ref, addr);
 180
 181                if (p4d_none(*p4d_ref))
 182                        continue;
 183
 184                spin_lock(&pgd_lock);
 185                list_for_each_entry(page, &pgd_list, lru) {
 186                        pgd_t *pgd;
 187                        p4d_t *p4d;
 188                        spinlock_t *pgt_lock;
 189
 190                        pgd = (pgd_t *)page_address(page) + pgd_index(addr);
 191                        p4d = p4d_offset(pgd, addr);
 192                        /* the pgt_lock only for Xen */
 193                        pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
 194                        spin_lock(pgt_lock);
 195
 196                        if (!p4d_none(*p4d_ref) && !p4d_none(*p4d))
 197                                BUG_ON(p4d_pgtable(*p4d)
 198                                       != p4d_pgtable(*p4d_ref));
 199
 200                        if (p4d_none(*p4d))
 201                                set_p4d(p4d, *p4d_ref);
 202
 203                        spin_unlock(pgt_lock);
 204                }
 205                spin_unlock(&pgd_lock);
 206        }
 207}
 208
 209/*
 210 * When memory was added make sure all the processes MM have
 211 * suitable PGD entries in the local PGD level page.
 212 */
 213static void sync_global_pgds(unsigned long start, unsigned long end)
 214{
 215        if (pgtable_l5_enabled())
 216                sync_global_pgds_l5(start, end);
 217        else
 218                sync_global_pgds_l4(start, end);
 219}
 220
 221/*
 222 * NOTE: This function is marked __ref because it calls __init function
 223 * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
 224 */
 225static __ref void *spp_getpage(void)
 226{
 227        void *ptr;
 228
 229        if (after_bootmem)
 230                ptr = (void *) get_zeroed_page(GFP_ATOMIC);
 231        else
 232                ptr = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
 233
 234        if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
 235                panic("set_pte_phys: cannot allocate page data %s\n",
 236                        after_bootmem ? "after bootmem" : "");
 237        }
 238
 239        pr_debug("spp_getpage %p\n", ptr);
 240
 241        return ptr;
 242}
 243
 244static p4d_t *fill_p4d(pgd_t *pgd, unsigned long vaddr)
 245{
 246        if (pgd_none(*pgd)) {
 247                p4d_t *p4d = (p4d_t *)spp_getpage();
 248                pgd_populate(&init_mm, pgd, p4d);
 249                if (p4d != p4d_offset(pgd, 0))
 250                        printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n",
 251                               p4d, p4d_offset(pgd, 0));
 252        }
 253        return p4d_offset(pgd, vaddr);
 254}
 255
 256static pud_t *fill_pud(p4d_t *p4d, unsigned long vaddr)
 257{
 258        if (p4d_none(*p4d)) {
 259                pud_t *pud = (pud_t *)spp_getpage();
 260                p4d_populate(&init_mm, p4d, pud);
 261                if (pud != pud_offset(p4d, 0))
 262                        printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
 263                               pud, pud_offset(p4d, 0));
 264        }
 265        return pud_offset(p4d, vaddr);
 266}
 267
 268static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr)
 269{
 270        if (pud_none(*pud)) {
 271                pmd_t *pmd = (pmd_t *) spp_getpage();
 272                pud_populate(&init_mm, pud, pmd);
 273                if (pmd != pmd_offset(pud, 0))
 274                        printk(KERN_ERR "PAGETABLE BUG #02! %p <-> %p\n",
 275                               pmd, pmd_offset(pud, 0));
 276        }
 277        return pmd_offset(pud, vaddr);
 278}
 279
 280static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr)
 281{
 282        if (pmd_none(*pmd)) {
 283                pte_t *pte = (pte_t *) spp_getpage();
 284                pmd_populate_kernel(&init_mm, pmd, pte);
 285                if (pte != pte_offset_kernel(pmd, 0))
 286                        printk(KERN_ERR "PAGETABLE BUG #03!\n");
 287        }
 288        return pte_offset_kernel(pmd, vaddr);
 289}
 290
 291static void __set_pte_vaddr(pud_t *pud, unsigned long vaddr, pte_t new_pte)
 292{
 293        pmd_t *pmd = fill_pmd(pud, vaddr);
 294        pte_t *pte = fill_pte(pmd, vaddr);
 295
 296        set_pte(pte, new_pte);
 297
 298        /*
 299         * It's enough to flush this one mapping.
 300         * (PGE mappings get flushed as well)
 301         */
 302        flush_tlb_one_kernel(vaddr);
 303}
 304
 305void set_pte_vaddr_p4d(p4d_t *p4d_page, unsigned long vaddr, pte_t new_pte)
 306{
 307        p4d_t *p4d = p4d_page + p4d_index(vaddr);
 308        pud_t *pud = fill_pud(p4d, vaddr);
 309
 310        __set_pte_vaddr(pud, vaddr, new_pte);
 311}
 312
 313void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
 314{
 315        pud_t *pud = pud_page + pud_index(vaddr);
 316
 317        __set_pte_vaddr(pud, vaddr, new_pte);
 318}
 319
 320void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
 321{
 322        pgd_t *pgd;
 323        p4d_t *p4d_page;
 324
 325        pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
 326
 327        pgd = pgd_offset_k(vaddr);
 328        if (pgd_none(*pgd)) {
 329                printk(KERN_ERR
 330                        "PGD FIXMAP MISSING, it should be setup in head.S!\n");
 331                return;
 332        }
 333
 334        p4d_page = p4d_offset(pgd, 0);
 335        set_pte_vaddr_p4d(p4d_page, vaddr, pteval);
 336}
 337
 338pmd_t * __init populate_extra_pmd(unsigned long vaddr)
 339{
 340        pgd_t *pgd;
 341        p4d_t *p4d;
 342        pud_t *pud;
 343
 344        pgd = pgd_offset_k(vaddr);
 345        p4d = fill_p4d(pgd, vaddr);
 346        pud = fill_pud(p4d, vaddr);
 347        return fill_pmd(pud, vaddr);
 348}
 349
 350pte_t * __init populate_extra_pte(unsigned long vaddr)
 351{
 352        pmd_t *pmd;
 353
 354        pmd = populate_extra_pmd(vaddr);
 355        return fill_pte(pmd, vaddr);
 356}
 357
 358/*
 359 * Create large page table mappings for a range of physical addresses.
 360 */
 361static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
 362                                        enum page_cache_mode cache)
 363{
 364        pgd_t *pgd;
 365        p4d_t *p4d;
 366        pud_t *pud;
 367        pmd_t *pmd;
 368        pgprot_t prot;
 369
 370        pgprot_val(prot) = pgprot_val(PAGE_KERNEL_LARGE) |
 371                protval_4k_2_large(cachemode2protval(cache));
 372        BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
 373        for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
 374                pgd = pgd_offset_k((unsigned long)__va(phys));
 375                if (pgd_none(*pgd)) {
 376                        p4d = (p4d_t *) spp_getpage();
 377                        set_pgd(pgd, __pgd(__pa(p4d) | _KERNPG_TABLE |
 378                                                _PAGE_USER));
 379                }
 380                p4d = p4d_offset(pgd, (unsigned long)__va(phys));
 381                if (p4d_none(*p4d)) {
 382                        pud = (pud_t *) spp_getpage();
 383                        set_p4d(p4d, __p4d(__pa(pud) | _KERNPG_TABLE |
 384                                                _PAGE_USER));
 385                }
 386                pud = pud_offset(p4d, (unsigned long)__va(phys));
 387                if (pud_none(*pud)) {
 388                        pmd = (pmd_t *) spp_getpage();
 389                        set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
 390                                                _PAGE_USER));
 391                }
 392                pmd = pmd_offset(pud, phys);
 393                BUG_ON(!pmd_none(*pmd));
 394                set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
 395        }
 396}
 397
 398void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
 399{
 400        __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_WB);
 401}
 402
 403void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
 404{
 405        __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_UC);
 406}
 407
 408/*
 409 * The head.S code sets up the kernel high mapping:
 410 *
 411 *   from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
 412 *
 413 * phys_base holds the negative offset to the kernel, which is added
 414 * to the compile time generated pmds. This results in invalid pmds up
 415 * to the point where we hit the physaddr 0 mapping.
 416 *
 417 * We limit the mappings to the region from _text to _brk_end.  _brk_end
 418 * is rounded up to the 2MB boundary. This catches the invalid pmds as
 419 * well, as they are located before _text:
 420 */
 421void __init cleanup_highmap(void)
 422{
 423        unsigned long vaddr = __START_KERNEL_map;
 424        unsigned long vaddr_end = __START_KERNEL_map + KERNEL_IMAGE_SIZE;
 425        unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1;
 426        pmd_t *pmd = level2_kernel_pgt;
 427
 428        /*
 429         * Native path, max_pfn_mapped is not set yet.
 430         * Xen has valid max_pfn_mapped set in
 431         *      arch/x86/xen/mmu.c:xen_setup_kernel_pagetable().
 432         */
 433        if (max_pfn_mapped)
 434                vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT);
 435
 436        for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) {
 437                if (pmd_none(*pmd))
 438                        continue;
 439                if (vaddr < (unsigned long) _text || vaddr > end)
 440                        set_pmd(pmd, __pmd(0));
 441        }
 442}
 443
 444/*
 445 * Create PTE level page table mapping for physical addresses.
 446 * It returns the last physical address mapped.
 447 */
 448static unsigned long __meminit
 449phys_pte_init(pte_t *pte_page, unsigned long paddr, unsigned long paddr_end,
 450              pgprot_t prot, bool init)
 451{
 452        unsigned long pages = 0, paddr_next;
 453        unsigned long paddr_last = paddr_end;
 454        pte_t *pte;
 455        int i;
 456
 457        pte = pte_page + pte_index(paddr);
 458        i = pte_index(paddr);
 459
 460        for (; i < PTRS_PER_PTE; i++, paddr = paddr_next, pte++) {
 461                paddr_next = (paddr & PAGE_MASK) + PAGE_SIZE;
 462                if (paddr >= paddr_end) {
 463                        if (!after_bootmem &&
 464                            !e820__mapped_any(paddr & PAGE_MASK, paddr_next,
 465                                             E820_TYPE_RAM) &&
 466                            !e820__mapped_any(paddr & PAGE_MASK, paddr_next,
 467                                             E820_TYPE_RESERVED_KERN))
 468                                set_pte_init(pte, __pte(0), init);
 469                        continue;
 470                }
 471
 472                /*
 473                 * We will re-use the existing mapping.
 474                 * Xen for example has some special requirements, like mapping
 475                 * pagetable pages as RO. So assume someone who pre-setup
 476                 * these mappings are more intelligent.
 477                 */
 478                if (!pte_none(*pte)) {
 479                        if (!after_bootmem)
 480                                pages++;
 481                        continue;
 482                }
 483
 484                if (0)
 485                        pr_info("   pte=%p addr=%lx pte=%016lx\n", pte, paddr,
 486                                pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL).pte);
 487                pages++;
 488                set_pte_init(pte, pfn_pte(paddr >> PAGE_SHIFT, prot), init);
 489                paddr_last = (paddr & PAGE_MASK) + PAGE_SIZE;
 490        }
 491
 492        update_page_count(PG_LEVEL_4K, pages);
 493
 494        return paddr_last;
 495}
 496
 497/*
 498 * Create PMD level page table mapping for physical addresses. The virtual
 499 * and physical address have to be aligned at this level.
 500 * It returns the last physical address mapped.
 501 */
 502static unsigned long __meminit
 503phys_pmd_init(pmd_t *pmd_page, unsigned long paddr, unsigned long paddr_end,
 504              unsigned long page_size_mask, pgprot_t prot, bool init)
 505{
 506        unsigned long pages = 0, paddr_next;
 507        unsigned long paddr_last = paddr_end;
 508
 509        int i = pmd_index(paddr);
 510
 511        for (; i < PTRS_PER_PMD; i++, paddr = paddr_next) {
 512                pmd_t *pmd = pmd_page + pmd_index(paddr);
 513                pte_t *pte;
 514                pgprot_t new_prot = prot;
 515
 516                paddr_next = (paddr & PMD_MASK) + PMD_SIZE;
 517                if (paddr >= paddr_end) {
 518                        if (!after_bootmem &&
 519                            !e820__mapped_any(paddr & PMD_MASK, paddr_next,
 520                                             E820_TYPE_RAM) &&
 521                            !e820__mapped_any(paddr & PMD_MASK, paddr_next,
 522                                             E820_TYPE_RESERVED_KERN))
 523                                set_pmd_init(pmd, __pmd(0), init);
 524                        continue;
 525                }
 526
 527                if (!pmd_none(*pmd)) {
 528                        if (!pmd_large(*pmd)) {
 529                                spin_lock(&init_mm.page_table_lock);
 530                                pte = (pte_t *)pmd_page_vaddr(*pmd);
 531                                paddr_last = phys_pte_init(pte, paddr,
 532                                                           paddr_end, prot,
 533                                                           init);
 534                                spin_unlock(&init_mm.page_table_lock);
 535                                continue;
 536                        }
 537                        /*
 538                         * If we are ok with PG_LEVEL_2M mapping, then we will
 539                         * use the existing mapping,
 540                         *
 541                         * Otherwise, we will split the large page mapping but
 542                         * use the same existing protection bits except for
 543                         * large page, so that we don't violate Intel's TLB
 544                         * Application note (317080) which says, while changing
 545                         * the page sizes, new and old translations should
 546                         * not differ with respect to page frame and
 547                         * attributes.
 548                         */
 549                        if (page_size_mask & (1 << PG_LEVEL_2M)) {
 550                                if (!after_bootmem)
 551                                        pages++;
 552                                paddr_last = paddr_next;
 553                                continue;
 554                        }
 555                        new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
 556                }
 557
 558                if (page_size_mask & (1<<PG_LEVEL_2M)) {
 559                        pages++;
 560                        spin_lock(&init_mm.page_table_lock);
 561                        set_pte_init((pte_t *)pmd,
 562                                     pfn_pte((paddr & PMD_MASK) >> PAGE_SHIFT,
 563                                             __pgprot(pgprot_val(prot) | _PAGE_PSE)),
 564                                     init);
 565                        spin_unlock(&init_mm.page_table_lock);
 566                        paddr_last = paddr_next;
 567                        continue;
 568                }
 569
 570                pte = alloc_low_page();
 571                paddr_last = phys_pte_init(pte, paddr, paddr_end, new_prot, init);
 572
 573                spin_lock(&init_mm.page_table_lock);
 574                pmd_populate_kernel_init(&init_mm, pmd, pte, init);
 575                spin_unlock(&init_mm.page_table_lock);
 576        }
 577        update_page_count(PG_LEVEL_2M, pages);
 578        return paddr_last;
 579}
 580
 581/*
 582 * Create PUD level page table mapping for physical addresses. The virtual
 583 * and physical address do not have to be aligned at this level. KASLR can
 584 * randomize virtual addresses up to this level.
 585 * It returns the last physical address mapped.
 586 */
 587static unsigned long __meminit
 588phys_pud_init(pud_t *pud_page, unsigned long paddr, unsigned long paddr_end,
 589              unsigned long page_size_mask, pgprot_t _prot, bool init)
 590{
 591        unsigned long pages = 0, paddr_next;
 592        unsigned long paddr_last = paddr_end;
 593        unsigned long vaddr = (unsigned long)__va(paddr);
 594        int i = pud_index(vaddr);
 595
 596        for (; i < PTRS_PER_PUD; i++, paddr = paddr_next) {
 597                pud_t *pud;
 598                pmd_t *pmd;
 599                pgprot_t prot = _prot;
 600
 601                vaddr = (unsigned long)__va(paddr);
 602                pud = pud_page + pud_index(vaddr);
 603                paddr_next = (paddr & PUD_MASK) + PUD_SIZE;
 604
 605                if (paddr >= paddr_end) {
 606                        if (!after_bootmem &&
 607                            !e820__mapped_any(paddr & PUD_MASK, paddr_next,
 608                                             E820_TYPE_RAM) &&
 609                            !e820__mapped_any(paddr & PUD_MASK, paddr_next,
 610                                             E820_TYPE_RESERVED_KERN))
 611                                set_pud_init(pud, __pud(0), init);
 612                        continue;
 613                }
 614
 615                if (!pud_none(*pud)) {
 616                        if (!pud_large(*pud)) {
 617                                pmd = pmd_offset(pud, 0);
 618                                paddr_last = phys_pmd_init(pmd, paddr,
 619                                                           paddr_end,
 620                                                           page_size_mask,
 621                                                           prot, init);
 622                                continue;
 623                        }
 624                        /*
 625                         * If we are ok with PG_LEVEL_1G mapping, then we will
 626                         * use the existing mapping.
 627                         *
 628                         * Otherwise, we will split the gbpage mapping but use
 629                         * the same existing protection  bits except for large
 630                         * page, so that we don't violate Intel's TLB
 631                         * Application note (317080) which says, while changing
 632                         * the page sizes, new and old translations should
 633                         * not differ with respect to page frame and
 634                         * attributes.
 635                         */
 636                        if (page_size_mask & (1 << PG_LEVEL_1G)) {
 637                                if (!after_bootmem)
 638                                        pages++;
 639                                paddr_last = paddr_next;
 640                                continue;
 641                        }
 642                        prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
 643                }
 644
 645                if (page_size_mask & (1<<PG_LEVEL_1G)) {
 646                        pages++;
 647                        spin_lock(&init_mm.page_table_lock);
 648
 649                        prot = __pgprot(pgprot_val(prot) | __PAGE_KERNEL_LARGE);
 650
 651                        set_pte_init((pte_t *)pud,
 652                                     pfn_pte((paddr & PUD_MASK) >> PAGE_SHIFT,
 653                                             prot),
 654                                     init);
 655                        spin_unlock(&init_mm.page_table_lock);
 656                        paddr_last = paddr_next;
 657                        continue;
 658                }
 659
 660                pmd = alloc_low_page();
 661                paddr_last = phys_pmd_init(pmd, paddr, paddr_end,
 662                                           page_size_mask, prot, init);
 663
 664                spin_lock(&init_mm.page_table_lock);
 665                pud_populate_init(&init_mm, pud, pmd, init);
 666                spin_unlock(&init_mm.page_table_lock);
 667        }
 668
 669        update_page_count(PG_LEVEL_1G, pages);
 670
 671        return paddr_last;
 672}
 673
 674static unsigned long __meminit
 675phys_p4d_init(p4d_t *p4d_page, unsigned long paddr, unsigned long paddr_end,
 676              unsigned long page_size_mask, pgprot_t prot, bool init)
 677{
 678        unsigned long vaddr, vaddr_end, vaddr_next, paddr_next, paddr_last;
 679
 680        paddr_last = paddr_end;
 681        vaddr = (unsigned long)__va(paddr);
 682        vaddr_end = (unsigned long)__va(paddr_end);
 683
 684        if (!pgtable_l5_enabled())
 685                return phys_pud_init((pud_t *) p4d_page, paddr, paddr_end,
 686                                     page_size_mask, prot, init);
 687
 688        for (; vaddr < vaddr_end; vaddr = vaddr_next) {
 689                p4d_t *p4d = p4d_page + p4d_index(vaddr);
 690                pud_t *pud;
 691
 692                vaddr_next = (vaddr & P4D_MASK) + P4D_SIZE;
 693                paddr = __pa(vaddr);
 694
 695                if (paddr >= paddr_end) {
 696                        paddr_next = __pa(vaddr_next);
 697                        if (!after_bootmem &&
 698                            !e820__mapped_any(paddr & P4D_MASK, paddr_next,
 699                                             E820_TYPE_RAM) &&
 700                            !e820__mapped_any(paddr & P4D_MASK, paddr_next,
 701                                             E820_TYPE_RESERVED_KERN))
 702                                set_p4d_init(p4d, __p4d(0), init);
 703                        continue;
 704                }
 705
 706                if (!p4d_none(*p4d)) {
 707                        pud = pud_offset(p4d, 0);
 708                        paddr_last = phys_pud_init(pud, paddr, __pa(vaddr_end),
 709                                        page_size_mask, prot, init);
 710                        continue;
 711                }
 712
 713                pud = alloc_low_page();
 714                paddr_last = phys_pud_init(pud, paddr, __pa(vaddr_end),
 715                                           page_size_mask, prot, init);
 716
 717                spin_lock(&init_mm.page_table_lock);
 718                p4d_populate_init(&init_mm, p4d, pud, init);
 719                spin_unlock(&init_mm.page_table_lock);
 720        }
 721
 722        return paddr_last;
 723}
 724
 725static unsigned long __meminit
 726__kernel_physical_mapping_init(unsigned long paddr_start,
 727                               unsigned long paddr_end,
 728                               unsigned long page_size_mask,
 729                               pgprot_t prot, bool init)
 730{
 731        bool pgd_changed = false;
 732        unsigned long vaddr, vaddr_start, vaddr_end, vaddr_next, paddr_last;
 733
 734        paddr_last = paddr_end;
 735        vaddr = (unsigned long)__va(paddr_start);
 736        vaddr_end = (unsigned long)__va(paddr_end);
 737        vaddr_start = vaddr;
 738
 739        for (; vaddr < vaddr_end; vaddr = vaddr_next) {
 740                pgd_t *pgd = pgd_offset_k(vaddr);
 741                p4d_t *p4d;
 742
 743                vaddr_next = (vaddr & PGDIR_MASK) + PGDIR_SIZE;
 744
 745                if (pgd_val(*pgd)) {
 746                        p4d = (p4d_t *)pgd_page_vaddr(*pgd);
 747                        paddr_last = phys_p4d_init(p4d, __pa(vaddr),
 748                                                   __pa(vaddr_end),
 749                                                   page_size_mask,
 750                                                   prot, init);
 751                        continue;
 752                }
 753
 754                p4d = alloc_low_page();
 755                paddr_last = phys_p4d_init(p4d, __pa(vaddr), __pa(vaddr_end),
 756                                           page_size_mask, prot, init);
 757
 758                spin_lock(&init_mm.page_table_lock);
 759                if (pgtable_l5_enabled())
 760                        pgd_populate_init(&init_mm, pgd, p4d, init);
 761                else
 762                        p4d_populate_init(&init_mm, p4d_offset(pgd, vaddr),
 763                                          (pud_t *) p4d, init);
 764
 765                spin_unlock(&init_mm.page_table_lock);
 766                pgd_changed = true;
 767        }
 768
 769        if (pgd_changed)
 770                sync_global_pgds(vaddr_start, vaddr_end - 1);
 771
 772        return paddr_last;
 773}
 774
 775
 776/*
 777 * Create page table mapping for the physical memory for specific physical
 778 * addresses. Note that it can only be used to populate non-present entries.
 779 * The virtual and physical addresses have to be aligned on PMD level
 780 * down. It returns the last physical address mapped.
 781 */
 782unsigned long __meminit
 783kernel_physical_mapping_init(unsigned long paddr_start,
 784                             unsigned long paddr_end,
 785                             unsigned long page_size_mask, pgprot_t prot)
 786{
 787        return __kernel_physical_mapping_init(paddr_start, paddr_end,
 788                                              page_size_mask, prot, true);
 789}
 790
 791/*
 792 * This function is similar to kernel_physical_mapping_init() above with the
 793 * exception that it uses set_{pud,pmd}() instead of the set_{pud,pte}_safe()
 794 * when updating the mapping. The caller is responsible to flush the TLBs after
 795 * the function returns.
 796 */
 797unsigned long __meminit
 798kernel_physical_mapping_change(unsigned long paddr_start,
 799                               unsigned long paddr_end,
 800                               unsigned long page_size_mask)
 801{
 802        return __kernel_physical_mapping_init(paddr_start, paddr_end,
 803                                              page_size_mask, PAGE_KERNEL,
 804                                              false);
 805}
 806
 807#ifndef CONFIG_NUMA
 808void __init initmem_init(void)
 809{
 810        memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
 811}
 812#endif
 813
 814void __init paging_init(void)
 815{
 816        sparse_init();
 817
 818        /*
 819         * clear the default setting with node 0
 820         * note: don't use nodes_clear here, that is really clearing when
 821         *       numa support is not compiled in, and later node_set_state
 822         *       will not set it back.
 823         */
 824        node_clear_state(0, N_MEMORY);
 825        node_clear_state(0, N_NORMAL_MEMORY);
 826
 827        zone_sizes_init();
 828}
 829
 830#ifdef CONFIG_SPARSEMEM_VMEMMAP
 831#define PAGE_UNUSED 0xFD
 832
 833/*
 834 * The unused vmemmap range, which was not yet memset(PAGE_UNUSED), ranges
 835 * from unused_pmd_start to next PMD_SIZE boundary.
 836 */
 837static unsigned long unused_pmd_start __meminitdata;
 838
 839static void __meminit vmemmap_flush_unused_pmd(void)
 840{
 841        if (!unused_pmd_start)
 842                return;
 843        /*
 844         * Clears (unused_pmd_start, PMD_END]
 845         */
 846        memset((void *)unused_pmd_start, PAGE_UNUSED,
 847               ALIGN(unused_pmd_start, PMD_SIZE) - unused_pmd_start);
 848        unused_pmd_start = 0;
 849}
 850
 851#ifdef CONFIG_MEMORY_HOTPLUG
 852/* Returns true if the PMD is completely unused and thus it can be freed */
 853static bool __meminit vmemmap_pmd_is_unused(unsigned long addr, unsigned long end)
 854{
 855        unsigned long start = ALIGN_DOWN(addr, PMD_SIZE);
 856
 857        /*
 858         * Flush the unused range cache to ensure that memchr_inv() will work
 859         * for the whole range.
 860         */
 861        vmemmap_flush_unused_pmd();
 862        memset((void *)addr, PAGE_UNUSED, end - addr);
 863
 864        return !memchr_inv((void *)start, PAGE_UNUSED, PMD_SIZE);
 865}
 866#endif
 867
 868static void __meminit __vmemmap_use_sub_pmd(unsigned long start)
 869{
 870        /*
 871         * As we expect to add in the same granularity as we remove, it's
 872         * sufficient to mark only some piece used to block the memmap page from
 873         * getting removed when removing some other adjacent memmap (just in
 874         * case the first memmap never gets initialized e.g., because the memory
 875         * block never gets onlined).
 876         */
 877        memset((void *)start, 0, sizeof(struct page));
 878}
 879
 880static void __meminit vmemmap_use_sub_pmd(unsigned long start, unsigned long end)
 881{
 882        /*
 883         * We only optimize if the new used range directly follows the
 884         * previously unused range (esp., when populating consecutive sections).
 885         */
 886        if (unused_pmd_start == start) {
 887                if (likely(IS_ALIGNED(end, PMD_SIZE)))
 888                        unused_pmd_start = 0;
 889                else
 890                        unused_pmd_start = end;
 891                return;
 892        }
 893
 894        /*
 895         * If the range does not contiguously follows previous one, make sure
 896         * to mark the unused range of the previous one so it can be removed.
 897         */
 898        vmemmap_flush_unused_pmd();
 899        __vmemmap_use_sub_pmd(start);
 900}
 901
 902
 903static void __meminit vmemmap_use_new_sub_pmd(unsigned long start, unsigned long end)
 904{
 905        vmemmap_flush_unused_pmd();
 906
 907        /*
 908         * Could be our memmap page is filled with PAGE_UNUSED already from a
 909         * previous remove. Make sure to reset it.
 910         */
 911        __vmemmap_use_sub_pmd(start);
 912
 913        /*
 914         * Mark with PAGE_UNUSED the unused parts of the new memmap range
 915         */
 916        if (!IS_ALIGNED(start, PMD_SIZE))
 917                memset((void *)start, PAGE_UNUSED,
 918                        start - ALIGN_DOWN(start, PMD_SIZE));
 919
 920        /*
 921         * We want to avoid memset(PAGE_UNUSED) when populating the vmemmap of
 922         * consecutive sections. Remember for the last added PMD where the
 923         * unused range begins.
 924         */
 925        if (!IS_ALIGNED(end, PMD_SIZE))
 926                unused_pmd_start = end;
 927}
 928#endif
 929
 930/*
 931 * Memory hotplug specific functions
 932 */
 933#ifdef CONFIG_MEMORY_HOTPLUG
 934/*
 935 * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
 936 * updating.
 937 */
 938static void update_end_of_memory_vars(u64 start, u64 size)
 939{
 940        unsigned long end_pfn = PFN_UP(start + size);
 941
 942        if (end_pfn > max_pfn) {
 943                max_pfn = end_pfn;
 944                max_low_pfn = end_pfn;
 945                high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
 946        }
 947}
 948
 949int add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
 950              struct mhp_params *params)
 951{
 952        int ret;
 953
 954        ret = __add_pages(nid, start_pfn, nr_pages, params);
 955        WARN_ON_ONCE(ret);
 956
 957        /* update max_pfn, max_low_pfn and high_memory */
 958        update_end_of_memory_vars(start_pfn << PAGE_SHIFT,
 959                                  nr_pages << PAGE_SHIFT);
 960
 961        return ret;
 962}
 963
 964int arch_add_memory(int nid, u64 start, u64 size,
 965                    struct mhp_params *params)
 966{
 967        unsigned long start_pfn = start >> PAGE_SHIFT;
 968        unsigned long nr_pages = size >> PAGE_SHIFT;
 969
 970        init_memory_mapping(start, start + size, params->pgprot);
 971
 972        return add_pages(nid, start_pfn, nr_pages, params);
 973}
 974
 975static void __meminit free_pagetable(struct page *page, int order)
 976{
 977        unsigned long magic;
 978        unsigned int nr_pages = 1 << order;
 979
 980        /* bootmem page has reserved flag */
 981        if (PageReserved(page)) {
 982                __ClearPageReserved(page);
 983
 984                magic = (unsigned long)page->freelist;
 985                if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
 986                        while (nr_pages--)
 987                                put_page_bootmem(page++);
 988                } else
 989                        while (nr_pages--)
 990                                free_reserved_page(page++);
 991        } else
 992                free_pages((unsigned long)page_address(page), order);
 993}
 994
 995static void __meminit free_hugepage_table(struct page *page,
 996                struct vmem_altmap *altmap)
 997{
 998        if (altmap)
 999                vmem_altmap_free(altmap, PMD_SIZE / PAGE_SIZE);
1000        else
1001                free_pagetable(page, get_order(PMD_SIZE));
1002}
1003
1004static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
1005{
1006        pte_t *pte;
1007        int i;
1008
1009        for (i = 0; i < PTRS_PER_PTE; i++) {
1010                pte = pte_start + i;
1011                if (!pte_none(*pte))
1012                        return;
1013        }
1014
1015        /* free a pte talbe */
1016        free_pagetable(pmd_page(*pmd), 0);
1017        spin_lock(&init_mm.page_table_lock);
1018        pmd_clear(pmd);
1019        spin_unlock(&init_mm.page_table_lock);
1020}
1021
1022static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud)
1023{
1024        pmd_t *pmd;
1025        int i;
1026
1027        for (i = 0; i < PTRS_PER_PMD; i++) {
1028                pmd = pmd_start + i;
1029                if (!pmd_none(*pmd))
1030                        return;
1031        }
1032
1033        /* free a pmd talbe */
1034        free_pagetable(pud_page(*pud), 0);
1035        spin_lock(&init_mm.page_table_lock);
1036        pud_clear(pud);
1037        spin_unlock(&init_mm.page_table_lock);
1038}
1039
1040static void __meminit free_pud_table(pud_t *pud_start, p4d_t *p4d)
1041{
1042        pud_t *pud;
1043        int i;
1044
1045        for (i = 0; i < PTRS_PER_PUD; i++) {
1046                pud = pud_start + i;
1047                if (!pud_none(*pud))
1048                        return;
1049        }
1050
1051        /* free a pud talbe */
1052        free_pagetable(p4d_page(*p4d), 0);
1053        spin_lock(&init_mm.page_table_lock);
1054        p4d_clear(p4d);
1055        spin_unlock(&init_mm.page_table_lock);
1056}
1057
1058static void __meminit
1059remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
1060                 bool direct)
1061{
1062        unsigned long next, pages = 0;
1063        pte_t *pte;
1064        phys_addr_t phys_addr;
1065
1066        pte = pte_start + pte_index(addr);
1067        for (; addr < end; addr = next, pte++) {
1068                next = (addr + PAGE_SIZE) & PAGE_MASK;
1069                if (next > end)
1070                        next = end;
1071
1072                if (!pte_present(*pte))
1073                        continue;
1074
1075                /*
1076                 * We mapped [0,1G) memory as identity mapping when
1077                 * initializing, in arch/x86/kernel/head_64.S. These
1078                 * pagetables cannot be removed.
1079                 */
1080                phys_addr = pte_val(*pte) + (addr & PAGE_MASK);
1081                if (phys_addr < (phys_addr_t)0x40000000)
1082                        return;
1083
1084                if (!direct)
1085                        free_pagetable(pte_page(*pte), 0);
1086
1087                spin_lock(&init_mm.page_table_lock);
1088                pte_clear(&init_mm, addr, pte);
1089                spin_unlock(&init_mm.page_table_lock);
1090
1091                /* For non-direct mapping, pages means nothing. */
1092                pages++;
1093        }
1094
1095        /* Call free_pte_table() in remove_pmd_table(). */
1096        flush_tlb_all();
1097        if (direct)
1098                update_page_count(PG_LEVEL_4K, -pages);
1099}
1100
1101static void __meminit
1102remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
1103                 bool direct, struct vmem_altmap *altmap)
1104{
1105        unsigned long next, pages = 0;
1106        pte_t *pte_base;
1107        pmd_t *pmd;
1108
1109        pmd = pmd_start + pmd_index(addr);
1110        for (; addr < end; addr = next, pmd++) {
1111                next = pmd_addr_end(addr, end);
1112
1113                if (!pmd_present(*pmd))
1114                        continue;
1115
1116                if (pmd_large(*pmd)) {
1117                        if (IS_ALIGNED(addr, PMD_SIZE) &&
1118                            IS_ALIGNED(next, PMD_SIZE)) {
1119                                if (!direct)
1120                                        free_hugepage_table(pmd_page(*pmd),
1121                                                            altmap);
1122
1123                                spin_lock(&init_mm.page_table_lock);
1124                                pmd_clear(pmd);
1125                                spin_unlock(&init_mm.page_table_lock);
1126                                pages++;
1127                        }
1128#ifdef CONFIG_SPARSEMEM_VMEMMAP
1129                        else if (vmemmap_pmd_is_unused(addr, next)) {
1130                                        free_hugepage_table(pmd_page(*pmd),
1131                                                            altmap);
1132                                        spin_lock(&init_mm.page_table_lock);
1133                                        pmd_clear(pmd);
1134                                        spin_unlock(&init_mm.page_table_lock);
1135                        }
1136#endif
1137                        continue;
1138                }
1139
1140                pte_base = (pte_t *)pmd_page_vaddr(*pmd);
1141                remove_pte_table(pte_base, addr, next, direct);
1142                free_pte_table(pte_base, pmd);
1143        }
1144
1145        /* Call free_pmd_table() in remove_pud_table(). */
1146        if (direct)
1147                update_page_count(PG_LEVEL_2M, -pages);
1148}
1149
1150static void __meminit
1151remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
1152                 struct vmem_altmap *altmap, bool direct)
1153{
1154        unsigned long next, pages = 0;
1155        pmd_t *pmd_base;
1156        pud_t *pud;
1157
1158        pud = pud_start + pud_index(addr);
1159        for (; addr < end; addr = next, pud++) {
1160                next = pud_addr_end(addr, end);
1161
1162                if (!pud_present(*pud))
1163                        continue;
1164
1165                if (pud_large(*pud) &&
1166                    IS_ALIGNED(addr, PUD_SIZE) &&
1167                    IS_ALIGNED(next, PUD_SIZE)) {
1168                        spin_lock(&init_mm.page_table_lock);
1169                        pud_clear(pud);
1170                        spin_unlock(&init_mm.page_table_lock);
1171                        pages++;
1172                        continue;
1173                }
1174
1175                pmd_base = pmd_offset(pud, 0);
1176                remove_pmd_table(pmd_base, addr, next, direct, altmap);
1177                free_pmd_table(pmd_base, pud);
1178        }
1179
1180        if (direct)
1181                update_page_count(PG_LEVEL_1G, -pages);
1182}
1183
1184static void __meminit
1185remove_p4d_table(p4d_t *p4d_start, unsigned long addr, unsigned long end,
1186                 struct vmem_altmap *altmap, bool direct)
1187{
1188        unsigned long next, pages = 0;
1189        pud_t *pud_base;
1190        p4d_t *p4d;
1191
1192        p4d = p4d_start + p4d_index(addr);
1193        for (; addr < end; addr = next, p4d++) {
1194                next = p4d_addr_end(addr, end);
1195
1196                if (!p4d_present(*p4d))
1197                        continue;
1198
1199                BUILD_BUG_ON(p4d_large(*p4d));
1200
1201                pud_base = pud_offset(p4d, 0);
1202                remove_pud_table(pud_base, addr, next, altmap, direct);
1203                /*
1204                 * For 4-level page tables we do not want to free PUDs, but in the
1205                 * 5-level case we should free them. This code will have to change
1206                 * to adapt for boot-time switching between 4 and 5 level page tables.
1207                 */
1208                if (pgtable_l5_enabled())
1209                        free_pud_table(pud_base, p4d);
1210        }
1211
1212        if (direct)
1213                update_page_count(PG_LEVEL_512G, -pages);
1214}
1215
1216/* start and end are both virtual address. */
1217static void __meminit
1218remove_pagetable(unsigned long start, unsigned long end, bool direct,
1219                struct vmem_altmap *altmap)
1220{
1221        unsigned long next;
1222        unsigned long addr;
1223        pgd_t *pgd;
1224        p4d_t *p4d;
1225
1226        for (addr = start; addr < end; addr = next) {
1227                next = pgd_addr_end(addr, end);
1228
1229                pgd = pgd_offset_k(addr);
1230                if (!pgd_present(*pgd))
1231                        continue;
1232
1233                p4d = p4d_offset(pgd, 0);
1234                remove_p4d_table(p4d, addr, next, altmap, direct);
1235        }
1236
1237        flush_tlb_all();
1238}
1239
1240void __ref vmemmap_free(unsigned long start, unsigned long end,
1241                struct vmem_altmap *altmap)
1242{
1243        VM_BUG_ON(!IS_ALIGNED(start, PAGE_SIZE));
1244        VM_BUG_ON(!IS_ALIGNED(end, PAGE_SIZE));
1245
1246        remove_pagetable(start, end, false, altmap);
1247}
1248
1249static void __meminit
1250kernel_physical_mapping_remove(unsigned long start, unsigned long end)
1251{
1252        start = (unsigned long)__va(start);
1253        end = (unsigned long)__va(end);
1254
1255        remove_pagetable(start, end, true, NULL);
1256}
1257
1258void __ref arch_remove_memory(int nid, u64 start, u64 size,
1259                              struct vmem_altmap *altmap)
1260{
1261        unsigned long start_pfn = start >> PAGE_SHIFT;
1262        unsigned long nr_pages = size >> PAGE_SHIFT;
1263
1264        __remove_pages(start_pfn, nr_pages, altmap);
1265        kernel_physical_mapping_remove(start, start + size);
1266}
1267#endif /* CONFIG_MEMORY_HOTPLUG */
1268
1269static struct kcore_list kcore_vsyscall;
1270
1271static void __init register_page_bootmem_info(void)
1272{
1273#if defined(CONFIG_NUMA) || defined(CONFIG_HUGETLB_PAGE_FREE_VMEMMAP)
1274        int i;
1275
1276        for_each_online_node(i)
1277                register_page_bootmem_info_node(NODE_DATA(i));
1278#endif
1279}
1280
1281/*
1282 * Pre-allocates page-table pages for the vmalloc area in the kernel page-table.
1283 * Only the level which needs to be synchronized between all page-tables is
1284 * allocated because the synchronization can be expensive.
1285 */
1286static void __init preallocate_vmalloc_pages(void)
1287{
1288        unsigned long addr;
1289        const char *lvl;
1290
1291        for (addr = VMALLOC_START; addr <= VMALLOC_END; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
1292                pgd_t *pgd = pgd_offset_k(addr);
1293                p4d_t *p4d;
1294                pud_t *pud;
1295
1296                lvl = "p4d";
1297                p4d = p4d_alloc(&init_mm, pgd, addr);
1298                if (!p4d)
1299                        goto failed;
1300
1301                if (pgtable_l5_enabled())
1302                        continue;
1303
1304                /*
1305                 * The goal here is to allocate all possibly required
1306                 * hardware page tables pointed to by the top hardware
1307                 * level.
1308                 *
1309                 * On 4-level systems, the P4D layer is folded away and
1310                 * the above code does no preallocation.  Below, go down
1311                 * to the pud _software_ level to ensure the second
1312                 * hardware level is allocated on 4-level systems too.
1313                 */
1314                lvl = "pud";
1315                pud = pud_alloc(&init_mm, p4d, addr);
1316                if (!pud)
1317                        goto failed;
1318        }
1319
1320        return;
1321
1322failed:
1323
1324        /*
1325         * The pages have to be there now or they will be missing in
1326         * process page-tables later.
1327         */
1328        panic("Failed to pre-allocate %s pages for vmalloc area\n", lvl);
1329}
1330
1331void __init mem_init(void)
1332{
1333        pci_iommu_alloc();
1334
1335        /* clear_bss() already clear the empty_zero_page */
1336
1337        /* this will put all memory onto the freelists */
1338        memblock_free_all();
1339        after_bootmem = 1;
1340        x86_init.hyper.init_after_bootmem();
1341
1342        /*
1343         * Must be done after boot memory is put on freelist, because here we
1344         * might set fields in deferred struct pages that have not yet been
1345         * initialized, and memblock_free_all() initializes all the reserved
1346         * deferred pages for us.
1347         */
1348        register_page_bootmem_info();
1349
1350        /* Register memory areas for /proc/kcore */
1351        if (get_gate_vma(&init_mm))
1352                kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR, PAGE_SIZE, KCORE_USER);
1353
1354        preallocate_vmalloc_pages();
1355}
1356
1357#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1358int __init deferred_page_init_max_threads(const struct cpumask *node_cpumask)
1359{
1360        /*
1361         * More CPUs always led to greater speedups on tested systems, up to
1362         * all the nodes' CPUs.  Use all since the system is otherwise idle
1363         * now.
1364         */
1365        return max_t(int, cpumask_weight(node_cpumask), 1);
1366}
1367#endif
1368
1369int kernel_set_to_readonly;
1370
1371void mark_rodata_ro(void)
1372{
1373        unsigned long start = PFN_ALIGN(_text);
1374        unsigned long rodata_start = PFN_ALIGN(__start_rodata);
1375        unsigned long end = (unsigned long)__end_rodata_hpage_align;
1376        unsigned long text_end = PFN_ALIGN(_etext);
1377        unsigned long rodata_end = PFN_ALIGN(__end_rodata);
1378        unsigned long all_end;
1379
1380        printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
1381               (end - start) >> 10);
1382        set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1383
1384        kernel_set_to_readonly = 1;
1385
1386        /*
1387         * The rodata/data/bss/brk section (but not the kernel text!)
1388         * should also be not-executable.
1389         *
1390         * We align all_end to PMD_SIZE because the existing mapping
1391         * is a full PMD. If we would align _brk_end to PAGE_SIZE we
1392         * split the PMD and the reminder between _brk_end and the end
1393         * of the PMD will remain mapped executable.
1394         *
1395         * Any PMD which was setup after the one which covers _brk_end
1396         * has been zapped already via cleanup_highmem().
1397         */
1398        all_end = roundup((unsigned long)_brk_end, PMD_SIZE);
1399        set_memory_nx(text_end, (all_end - text_end) >> PAGE_SHIFT);
1400
1401        set_ftrace_ops_ro();
1402
1403#ifdef CONFIG_CPA_DEBUG
1404        printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
1405        set_memory_rw(start, (end-start) >> PAGE_SHIFT);
1406
1407        printk(KERN_INFO "Testing CPA: again\n");
1408        set_memory_ro(start, (end-start) >> PAGE_SHIFT);
1409#endif
1410
1411        free_kernel_image_pages("unused kernel image (text/rodata gap)",
1412                                (void *)text_end, (void *)rodata_start);
1413        free_kernel_image_pages("unused kernel image (rodata/data gap)",
1414                                (void *)rodata_end, (void *)_sdata);
1415
1416        debug_checkwx();
1417}
1418
1419int kern_addr_valid(unsigned long addr)
1420{
1421        unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
1422        pgd_t *pgd;
1423        p4d_t *p4d;
1424        pud_t *pud;
1425        pmd_t *pmd;
1426        pte_t *pte;
1427
1428        if (above != 0 && above != -1UL)
1429                return 0;
1430
1431        pgd = pgd_offset_k(addr);
1432        if (pgd_none(*pgd))
1433                return 0;
1434
1435        p4d = p4d_offset(pgd, addr);
1436        if (p4d_none(*p4d))
1437                return 0;
1438
1439        pud = pud_offset(p4d, addr);
1440        if (pud_none(*pud))
1441                return 0;
1442
1443        if (pud_large(*pud))
1444                return pfn_valid(pud_pfn(*pud));
1445
1446        pmd = pmd_offset(pud, addr);
1447        if (pmd_none(*pmd))
1448                return 0;
1449
1450        if (pmd_large(*pmd))
1451                return pfn_valid(pmd_pfn(*pmd));
1452
1453        pte = pte_offset_kernel(pmd, addr);
1454        if (pte_none(*pte))
1455                return 0;
1456
1457        return pfn_valid(pte_pfn(*pte));
1458}
1459
1460/*
1461 * Block size is the minimum amount of memory which can be hotplugged or
1462 * hotremoved. It must be power of two and must be equal or larger than
1463 * MIN_MEMORY_BLOCK_SIZE.
1464 */
1465#define MAX_BLOCK_SIZE (2UL << 30)
1466
1467/* Amount of ram needed to start using large blocks */
1468#define MEM_SIZE_FOR_LARGE_BLOCK (64UL << 30)
1469
1470/* Adjustable memory block size */
1471static unsigned long set_memory_block_size;
1472int __init set_memory_block_size_order(unsigned int order)
1473{
1474        unsigned long size = 1UL << order;
1475
1476        if (size > MEM_SIZE_FOR_LARGE_BLOCK || size < MIN_MEMORY_BLOCK_SIZE)
1477                return -EINVAL;
1478
1479        set_memory_block_size = size;
1480        return 0;
1481}
1482
1483static unsigned long probe_memory_block_size(void)
1484{
1485        unsigned long boot_mem_end = max_pfn << PAGE_SHIFT;
1486        unsigned long bz;
1487
1488        /* If memory block size has been set, then use it */
1489        bz = set_memory_block_size;
1490        if (bz)
1491                goto done;
1492
1493        /* Use regular block if RAM is smaller than MEM_SIZE_FOR_LARGE_BLOCK */
1494        if (boot_mem_end < MEM_SIZE_FOR_LARGE_BLOCK) {
1495                bz = MIN_MEMORY_BLOCK_SIZE;
1496                goto done;
1497        }
1498
1499        /*
1500         * Use max block size to minimize overhead on bare metal, where
1501         * alignment for memory hotplug isn't a concern.
1502         */
1503        if (!boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
1504                bz = MAX_BLOCK_SIZE;
1505                goto done;
1506        }
1507
1508        /* Find the largest allowed block size that aligns to memory end */
1509        for (bz = MAX_BLOCK_SIZE; bz > MIN_MEMORY_BLOCK_SIZE; bz >>= 1) {
1510                if (IS_ALIGNED(boot_mem_end, bz))
1511                        break;
1512        }
1513done:
1514        pr_info("x86/mm: Memory block size: %ldMB\n", bz >> 20);
1515
1516        return bz;
1517}
1518
1519static unsigned long memory_block_size_probed;
1520unsigned long memory_block_size_bytes(void)
1521{
1522        if (!memory_block_size_probed)
1523                memory_block_size_probed = probe_memory_block_size();
1524
1525        return memory_block_size_probed;
1526}
1527
1528#ifdef CONFIG_SPARSEMEM_VMEMMAP
1529/*
1530 * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1531 */
1532static long __meminitdata addr_start, addr_end;
1533static void __meminitdata *p_start, *p_end;
1534static int __meminitdata node_start;
1535
1536static int __meminit vmemmap_populate_hugepages(unsigned long start,
1537                unsigned long end, int node, struct vmem_altmap *altmap)
1538{
1539        unsigned long addr;
1540        unsigned long next;
1541        pgd_t *pgd;
1542        p4d_t *p4d;
1543        pud_t *pud;
1544        pmd_t *pmd;
1545
1546        for (addr = start; addr < end; addr = next) {
1547                next = pmd_addr_end(addr, end);
1548
1549                pgd = vmemmap_pgd_populate(addr, node);
1550                if (!pgd)
1551                        return -ENOMEM;
1552
1553                p4d = vmemmap_p4d_populate(pgd, addr, node);
1554                if (!p4d)
1555                        return -ENOMEM;
1556
1557                pud = vmemmap_pud_populate(p4d, addr, node);
1558                if (!pud)
1559                        return -ENOMEM;
1560
1561                pmd = pmd_offset(pud, addr);
1562                if (pmd_none(*pmd)) {
1563                        void *p;
1564
1565                        p = vmemmap_alloc_block_buf(PMD_SIZE, node, altmap);
1566                        if (p) {
1567                                pte_t entry;
1568
1569                                entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1570                                                PAGE_KERNEL_LARGE);
1571                                set_pmd(pmd, __pmd(pte_val(entry)));
1572
1573                                /* check to see if we have contiguous blocks */
1574                                if (p_end != p || node_start != node) {
1575                                        if (p_start)
1576                                                pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1577                                                       addr_start, addr_end-1, p_start, p_end-1, node_start);
1578                                        addr_start = addr;
1579                                        node_start = node;
1580                                        p_start = p;
1581                                }
1582
1583                                addr_end = addr + PMD_SIZE;
1584                                p_end = p + PMD_SIZE;
1585
1586                                if (!IS_ALIGNED(addr, PMD_SIZE) ||
1587                                    !IS_ALIGNED(next, PMD_SIZE))
1588                                        vmemmap_use_new_sub_pmd(addr, next);
1589
1590                                continue;
1591                        } else if (altmap)
1592                                return -ENOMEM; /* no fallback */
1593                } else if (pmd_large(*pmd)) {
1594                        vmemmap_verify((pte_t *)pmd, node, addr, next);
1595                        vmemmap_use_sub_pmd(addr, next);
1596                        continue;
1597                }
1598                if (vmemmap_populate_basepages(addr, next, node, NULL))
1599                        return -ENOMEM;
1600        }
1601        return 0;
1602}
1603
1604int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
1605                struct vmem_altmap *altmap)
1606{
1607        int err;
1608
1609        VM_BUG_ON(!IS_ALIGNED(start, PAGE_SIZE));
1610        VM_BUG_ON(!IS_ALIGNED(end, PAGE_SIZE));
1611
1612        if (end - start < PAGES_PER_SECTION * sizeof(struct page))
1613                err = vmemmap_populate_basepages(start, end, node, NULL);
1614        else if (boot_cpu_has(X86_FEATURE_PSE))
1615                err = vmemmap_populate_hugepages(start, end, node, altmap);
1616        else if (altmap) {
1617                pr_err_once("%s: no cpu support for altmap allocations\n",
1618                                __func__);
1619                err = -ENOMEM;
1620        } else
1621                err = vmemmap_populate_basepages(start, end, node, NULL);
1622        if (!err)
1623                sync_global_pgds(start, end - 1);
1624        return err;
1625}
1626
1627#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
1628void register_page_bootmem_memmap(unsigned long section_nr,
1629                                  struct page *start_page, unsigned long nr_pages)
1630{
1631        unsigned long addr = (unsigned long)start_page;
1632        unsigned long end = (unsigned long)(start_page + nr_pages);
1633        unsigned long next;
1634        pgd_t *pgd;
1635        p4d_t *p4d;
1636        pud_t *pud;
1637        pmd_t *pmd;
1638        unsigned int nr_pmd_pages;
1639        struct page *page;
1640
1641        for (; addr < end; addr = next) {
1642                pte_t *pte = NULL;
1643
1644                pgd = pgd_offset_k(addr);
1645                if (pgd_none(*pgd)) {
1646                        next = (addr + PAGE_SIZE) & PAGE_MASK;
1647                        continue;
1648                }
1649                get_page_bootmem(section_nr, pgd_page(*pgd), MIX_SECTION_INFO);
1650
1651                p4d = p4d_offset(pgd, addr);
1652                if (p4d_none(*p4d)) {
1653                        next = (addr + PAGE_SIZE) & PAGE_MASK;
1654                        continue;
1655                }
1656                get_page_bootmem(section_nr, p4d_page(*p4d), MIX_SECTION_INFO);
1657
1658                pud = pud_offset(p4d, addr);
1659                if (pud_none(*pud)) {
1660                        next = (addr + PAGE_SIZE) & PAGE_MASK;
1661                        continue;
1662                }
1663                get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO);
1664
1665                if (!boot_cpu_has(X86_FEATURE_PSE)) {
1666                        next = (addr + PAGE_SIZE) & PAGE_MASK;
1667                        pmd = pmd_offset(pud, addr);
1668                        if (pmd_none(*pmd))
1669                                continue;
1670                        get_page_bootmem(section_nr, pmd_page(*pmd),
1671                                         MIX_SECTION_INFO);
1672
1673                        pte = pte_offset_kernel(pmd, addr);
1674                        if (pte_none(*pte))
1675                                continue;
1676                        get_page_bootmem(section_nr, pte_page(*pte),
1677                                         SECTION_INFO);
1678                } else {
1679                        next = pmd_addr_end(addr, end);
1680
1681                        pmd = pmd_offset(pud, addr);
1682                        if (pmd_none(*pmd))
1683                                continue;
1684
1685                        nr_pmd_pages = 1 << get_order(PMD_SIZE);
1686                        page = pmd_page(*pmd);
1687                        while (nr_pmd_pages--)
1688                                get_page_bootmem(section_nr, page++,
1689                                                 SECTION_INFO);
1690                }
1691        }
1692}
1693#endif
1694
1695void __meminit vmemmap_populate_print_last(void)
1696{
1697        if (p_start) {
1698                pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1699                        addr_start, addr_end-1, p_start, p_end-1, node_start);
1700                p_start = NULL;
1701                p_end = NULL;
1702                node_start = 0;
1703        }
1704}
1705#endif
1706