arch/x86/mm/init_64.c

   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)              \
  64 static 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
  73 DEFINE_POPULATE(p4d_populate, p4d, pud, init)
  74 DEFINE_POPULATE(pgd_populate, pgd, p4d, init)
  75 DEFINE_POPULATE(pud_populate, pud, pmd, init)
  76 DEFINE_POPULATE(pmd_populate_kernel, pmd, pte, init)
  77
  78 #define DEFINE_ENTRY(type1, type2, init)                        \
  79 static 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
  88 DEFINE_ENTRY(p4d, p4d, init)
  89 DEFINE_ENTRY(pud, pud, init)
  90 DEFINE_ENTRY(pmd, pmd, init)
  91 DEFINE_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: */
 101 pteval_t __supported_pte_mask __read_mostly = ~0;
 102 /* Bits allowed in normal kernel mappings: */
 103 pteval_t __default_kernel_pte_mask __read_mostly = ~0;
 104 EXPORT_SYMBOL_GPL(__supported_pte_mask);
 105 /* Used in PAGE_KERNEL_* macros which are reasonably used out-of-tree: */
 106 EXPORT_SYMBOL(__default_kernel_pte_mask);
 107
 108 int 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  */
 118 static 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
 128 static 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
 165 static 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  */
 213 static 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  */
 225 static __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
 244 static 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
 256 static 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
 268 static 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
 280 static 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
 291 static 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
 305 void 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
 313 void 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
 320 void 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
 338 pmd_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
 350 pte_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  */
 361 static 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
 398 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
 399 {
 400         __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_WB);
 401 }
 402
 403 void __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  */
 421 void __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  */
 448 static unsigned long __meminit
 449 phys_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  */
 502 static unsigned long __meminit
 503 phys_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  */
 587 static unsigned long __meminit
 588 phys_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
 674 static unsigned long __meminit
 675 phys_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
 725 static 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  */
 782 unsigned long __meminit
 783 kernel_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  */
 797 unsigned long __meminit
 798 kernel_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
 808 void __init initmem_init(void)
 809 {
 810         memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
 811 }
 812 #endif
 813
 814 void __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  */
 837 static unsigned long unused_pmd_start __meminitdata;
 838
 839 static 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 */
 853 static 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
 868 static 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
 880 static 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
 903 static 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  */
 938 static 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
 949 int 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
 964 int 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
 975 static 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
 995 static 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
1004 static 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
1022 static 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
1040 static 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
1058 static void __meminit
1059 remove_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
1101 static void __meminit
1102 remove_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
1150 static void __meminit
1151 remove_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
1184 static void __meminit
1185 remove_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. */
1217 static void __meminit
1218 remove_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
1240 void __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
1249 static void __meminit
1250 kernel_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
1258 void __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
1259 {
1260         unsigned long start_pfn = start >> PAGE_SHIFT;
1261         unsigned long nr_pages = size >> PAGE_SHIFT;
1262
1263         __remove_pages(start_pfn, nr_pages, altmap);
1264         kernel_physical_mapping_remove(start, start + size);
1265 }
1266 #endif /* CONFIG_MEMORY_HOTPLUG */
1267
1268 static struct kcore_list kcore_vsyscall;
1269
1270 static void __init register_page_bootmem_info(void)
1271 {
1272 #if defined(CONFIG_NUMA) || defined(CONFIG_HUGETLB_PAGE_FREE_VMEMMAP)
1273         int i;
1274
1275         for_each_online_node(i)
1276                 register_page_bootmem_info_node(NODE_DATA(i));
1277 #endif
1278 }
1279
1280 /*
1281  * Pre-allocates page-table pages for the vmalloc area in the kernel page-table.
1282  * Only the level which needs to be synchronized between all page-tables is
1283  * allocated because the synchronization can be expensive.
1284  */
1285 static void __init preallocate_vmalloc_pages(void)
1286 {
1287         unsigned long addr;
1288         const char *lvl;
1289
1290         for (addr = VMALLOC_START; addr <= VMALLOC_END; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
1291                 pgd_t *pgd = pgd_offset_k(addr);
1292                 p4d_t *p4d;
1293                 pud_t *pud;
1294
1295                 lvl = "p4d";
1296                 p4d = p4d_alloc(&init_mm, pgd, addr);
1297                 if (!p4d)
1298                         goto failed;
1299
1300                 if (pgtable_l5_enabled())
1301                         continue;
1302
1303                 /*
1304                  * The goal here is to allocate all possibly required
1305                  * hardware page tables pointed to by the top hardware
1306                  * level.
1307                  *
1308                  * On 4-level systems, the P4D layer is folded away and
1309                  * the above code does no preallocation.  Below, go down
1310                  * to the pud _software_ level to ensure the second
1311                  * hardware level is allocated on 4-level systems too.
1312                  */
1313                 lvl = "pud";
1314                 pud = pud_alloc(&init_mm, p4d, addr);
1315                 if (!pud)
1316                         goto failed;
1317         }
1318
1319         return;
1320
1321 failed:
1322
1323         /*
1324          * The pages have to be there now or they will be missing in
1325          * process page-tables later.
1326          */
1327         panic("Failed to pre-allocate %s pages for vmalloc area\n", lvl);
1328 }
1329
1330 void __init mem_init(void)
1331 {
1332         pci_iommu_alloc();
1333
1334         /* clear_bss() already clear the empty_zero_page */
1335
1336         /* this will put all memory onto the freelists */
1337         memblock_free_all();
1338         after_bootmem = 1;
1339         x86_init.hyper.init_after_bootmem();
1340
1341         /*
1342          * Must be done after boot memory is put on freelist, because here we
1343          * might set fields in deferred struct pages that have not yet been
1344          * initialized, and memblock_free_all() initializes all the reserved
1345          * deferred pages for us.
1346          */
1347         register_page_bootmem_info();
1348
1349         /* Register memory areas for /proc/kcore */
1350         if (get_gate_vma(&init_mm))
1351                 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR, PAGE_SIZE, KCORE_USER);
1352
1353         preallocate_vmalloc_pages();
1354 }
1355
1356 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1357 int __init deferred_page_init_max_threads(const struct cpumask *node_cpumask)
1358 {
1359         /*
1360          * More CPUs always led to greater speedups on tested systems, up to
1361          * all the nodes' CPUs.  Use all since the system is otherwise idle
1362          * now.
1363          */
1364         return max_t(int, cpumask_weight(node_cpumask), 1);
1365 }
1366 #endif
1367
1368 int kernel_set_to_readonly;
1369
1370 void mark_rodata_ro(void)
1371 {
1372         unsigned long start = PFN_ALIGN(_text);
1373         unsigned long rodata_start = PFN_ALIGN(__start_rodata);
1374         unsigned long end = (unsigned long)__end_rodata_hpage_align;
1375         unsigned long text_end = PFN_ALIGN(_etext);
1376         unsigned long rodata_end = PFN_ALIGN(__end_rodata);
1377         unsigned long all_end;
1378
1379         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
1380                (end - start) >> 10);
1381         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1382
1383         kernel_set_to_readonly = 1;
1384
1385         /*
1386          * The rodata/data/bss/brk section (but not the kernel text!)
1387          * should also be not-executable.
1388          *
1389          * We align all_end to PMD_SIZE because the existing mapping
1390          * is a full PMD. If we would align _brk_end to PAGE_SIZE we
1391          * split the PMD and the reminder between _brk_end and the end
1392          * of the PMD will remain mapped executable.
1393          *
1394          * Any PMD which was setup after the one which covers _brk_end
1395          * has been zapped already via cleanup_highmem().
1396          */
1397         all_end = roundup((unsigned long)_brk_end, PMD_SIZE);
1398         set_memory_nx(text_end, (all_end - text_end) >> PAGE_SHIFT);
1399
1400         set_ftrace_ops_ro();
1401
1402 #ifdef CONFIG_CPA_DEBUG
1403         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
1404         set_memory_rw(start, (end-start) >> PAGE_SHIFT);
1405
1406         printk(KERN_INFO "Testing CPA: again\n");
1407         set_memory_ro(start, (end-start) >> PAGE_SHIFT);
1408 #endif
1409
1410         free_kernel_image_pages("unused kernel image (text/rodata gap)",
1411                                 (void *)text_end, (void *)rodata_start);
1412         free_kernel_image_pages("unused kernel image (rodata/data gap)",
1413                                 (void *)rodata_end, (void *)_sdata);
1414
1415         debug_checkwx();
1416 }
1417
1418 int kern_addr_valid(unsigned long addr)
1419 {
1420         unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
1421         pgd_t *pgd;
1422         p4d_t *p4d;
1423         pud_t *pud;
1424         pmd_t *pmd;
1425         pte_t *pte;
1426
1427         if (above != 0 && above != -1UL)
1428                 return 0;
1429
1430         pgd = pgd_offset_k(addr);
1431         if (pgd_none(*pgd))
1432                 return 0;
1433
1434         p4d = p4d_offset(pgd, addr);
1435         if (p4d_none(*p4d))
1436                 return 0;
1437
1438         pud = pud_offset(p4d, addr);
1439         if (pud_none(*pud))
1440                 return 0;
1441
1442         if (pud_large(*pud))
1443                 return pfn_valid(pud_pfn(*pud));
1444
1445         pmd = pmd_offset(pud, addr);
1446         if (pmd_none(*pmd))
1447                 return 0;
1448
1449         if (pmd_large(*pmd))
1450                 return pfn_valid(pmd_pfn(*pmd));
1451
1452         pte = pte_offset_kernel(pmd, addr);
1453         if (pte_none(*pte))
1454                 return 0;
1455
1456         return pfn_valid(pte_pfn(*pte));
1457 }
1458
1459 /*
1460  * Block size is the minimum amount of memory which can be hotplugged or
1461  * hotremoved. It must be power of two and must be equal or larger than
1462  * MIN_MEMORY_BLOCK_SIZE.
1463  */
1464 #define MAX_BLOCK_SIZE (2UL << 30)
1465
1466 /* Amount of ram needed to start using large blocks */
1467 #define MEM_SIZE_FOR_LARGE_BLOCK (64UL << 30)
1468
1469 /* Adjustable memory block size */
1470 static unsigned long set_memory_block_size;
1471 int __init set_memory_block_size_order(unsigned int order)
1472 {
1473         unsigned long size = 1UL << order;
1474
1475         if (size > MEM_SIZE_FOR_LARGE_BLOCK || size < MIN_MEMORY_BLOCK_SIZE)
1476                 return -EINVAL;
1477
1478         set_memory_block_size = size;
1479         return 0;
1480 }
1481
1482 static unsigned long probe_memory_block_size(void)
1483 {
1484         unsigned long boot_mem_end = max_pfn << PAGE_SHIFT;
1485         unsigned long bz;
1486
1487         /* If memory block size has been set, then use it */
1488         bz = set_memory_block_size;
1489         if (bz)
1490                 goto done;
1491
1492         /* Use regular block if RAM is smaller than MEM_SIZE_FOR_LARGE_BLOCK */
1493         if (boot_mem_end < MEM_SIZE_FOR_LARGE_BLOCK) {
1494                 bz = MIN_MEMORY_BLOCK_SIZE;
1495                 goto done;
1496         }
1497
1498         /*
1499          * Use max block size to minimize overhead on bare metal, where
1500          * alignment for memory hotplug isn't a concern.
1501          */
1502         if (!boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
1503                 bz = MAX_BLOCK_SIZE;
1504                 goto done;
1505         }
1506
1507         /* Find the largest allowed block size that aligns to memory end */
1508         for (bz = MAX_BLOCK_SIZE; bz > MIN_MEMORY_BLOCK_SIZE; bz >>= 1) {
1509                 if (IS_ALIGNED(boot_mem_end, bz))
1510                         break;
1511         }
1512 done:
1513         pr_info("x86/mm: Memory block size: %ldMB\n", bz >> 20);
1514
1515         return bz;
1516 }
1517
1518 static unsigned long memory_block_size_probed;
1519 unsigned long memory_block_size_bytes(void)
1520 {
1521         if (!memory_block_size_probed)
1522                 memory_block_size_probed = probe_memory_block_size();
1523
1524         return memory_block_size_probed;
1525 }
1526
1527 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1528 /*
1529  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1530  */
1531 static long __meminitdata addr_start, addr_end;
1532 static void __meminitdata *p_start, *p_end;
1533 static int __meminitdata node_start;
1534
1535 static int __meminit vmemmap_populate_hugepages(unsigned long start,
1536                 unsigned long end, int node, struct vmem_altmap *altmap)
1537 {
1538         unsigned long addr;
1539         unsigned long next;
1540         pgd_t *pgd;
1541         p4d_t *p4d;
1542         pud_t *pud;
1543         pmd_t *pmd;
1544
1545         for (addr = start; addr < end; addr = next) {
1546                 next = pmd_addr_end(addr, end);
1547
1548                 pgd = vmemmap_pgd_populate(addr, node);
1549                 if (!pgd)
1550                         return -ENOMEM;
1551
1552                 p4d = vmemmap_p4d_populate(pgd, addr, node);
1553                 if (!p4d)
1554                         return -ENOMEM;
1555
1556                 pud = vmemmap_pud_populate(p4d, addr, node);
1557                 if (!pud)
1558                         return -ENOMEM;
1559
1560                 pmd = pmd_offset(pud, addr);
1561                 if (pmd_none(*pmd)) {
1562                         void *p;
1563
1564                         p = vmemmap_alloc_block_buf(PMD_SIZE, node, altmap);
1565                         if (p) {
1566                                 pte_t entry;
1567
1568                                 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1569                                                 PAGE_KERNEL_LARGE);
1570                                 set_pmd(pmd, __pmd(pte_val(entry)));
1571
1572                                 /* check to see if we have contiguous blocks */
1573                                 if (p_end != p || node_start != node) {
1574                                         if (p_start)
1575                                                 pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1576                                                        addr_start, addr_end-1, p_start, p_end-1, node_start);
1577                                         addr_start = addr;
1578                                         node_start = node;
1579                                         p_start = p;
1580                                 }
1581
1582                                 addr_end = addr + PMD_SIZE;
1583                                 p_end = p + PMD_SIZE;
1584
1585                                 if (!IS_ALIGNED(addr, PMD_SIZE) ||
1586                                     !IS_ALIGNED(next, PMD_SIZE))
1587                                         vmemmap_use_new_sub_pmd(addr, next);
1588
1589                                 continue;
1590                         } else if (altmap)
1591                                 return -ENOMEM; /* no fallback */
1592                 } else if (pmd_large(*pmd)) {
1593                         vmemmap_verify((pte_t *)pmd, node, addr, next);
1594                         vmemmap_use_sub_pmd(addr, next);
1595                         continue;
1596                 }
1597                 if (vmemmap_populate_basepages(addr, next, node, NULL))
1598                         return -ENOMEM;
1599         }
1600         return 0;
1601 }
1602
1603 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
1604                 struct vmem_altmap *altmap)
1605 {
1606         int err;
1607
1608         VM_BUG_ON(!IS_ALIGNED(start, PAGE_SIZE));
1609         VM_BUG_ON(!IS_ALIGNED(end, PAGE_SIZE));
1610
1611         if (end - start < PAGES_PER_SECTION * sizeof(struct page))
1612                 err = vmemmap_populate_basepages(start, end, node, NULL);
1613         else if (boot_cpu_has(X86_FEATURE_PSE))
1614                 err = vmemmap_populate_hugepages(start, end, node, altmap);
1615         else if (altmap) {
1616                 pr_err_once("%s: no cpu support for altmap allocations\n",
1617                                 __func__);
1618                 err = -ENOMEM;
1619         } else
1620                 err = vmemmap_populate_basepages(start, end, node, NULL);
1621         if (!err)
1622                 sync_global_pgds(start, end - 1);
1623         return err;
1624 }
1625
1626 #ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
1627 void register_page_bootmem_memmap(unsigned long section_nr,
1628                                   struct page *start_page, unsigned long nr_pages)
1629 {
1630         unsigned long addr = (unsigned long)start_page;
1631         unsigned long end = (unsigned long)(start_page + nr_pages);
1632         unsigned long next;
1633         pgd_t *pgd;
1634         p4d_t *p4d;
1635         pud_t *pud;
1636         pmd_t *pmd;
1637         unsigned int nr_pmd_pages;
1638         struct page *page;
1639
1640         for (; addr < end; addr = next) {
1641                 pte_t *pte = NULL;
1642
1643                 pgd = pgd_offset_k(addr);
1644                 if (pgd_none(*pgd)) {
1645                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1646                         continue;
1647                 }
1648                 get_page_bootmem(section_nr, pgd_page(*pgd), MIX_SECTION_INFO);
1649
1650                 p4d = p4d_offset(pgd, addr);
1651                 if (p4d_none(*p4d)) {
1652                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1653                         continue;
1654                 }
1655                 get_page_bootmem(section_nr, p4d_page(*p4d), MIX_SECTION_INFO);
1656
1657                 pud = pud_offset(p4d, addr);
1658                 if (pud_none(*pud)) {
1659                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1660                         continue;
1661                 }
1662                 get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO);
1663
1664                 if (!boot_cpu_has(X86_FEATURE_PSE)) {
1665                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1666                         pmd = pmd_offset(pud, addr);
1667                         if (pmd_none(*pmd))
1668                                 continue;
1669                         get_page_bootmem(section_nr, pmd_page(*pmd),
1670                                          MIX_SECTION_INFO);
1671
1672                         pte = pte_offset_kernel(pmd, addr);
1673                         if (pte_none(*pte))
1674                                 continue;
1675                         get_page_bootmem(section_nr, pte_page(*pte),
1676                                          SECTION_INFO);
1677                 } else {
1678                         next = pmd_addr_end(addr, end);
1679
1680                         pmd = pmd_offset(pud, addr);
1681                         if (pmd_none(*pmd))
1682                                 continue;
1683
1684                         nr_pmd_pages = 1 << get_order(PMD_SIZE);
1685                         page = pmd_page(*pmd);
1686                         while (nr_pmd_pages--)
1687                                 get_page_bootmem(section_nr, page++,
1688                                                  SECTION_INFO);
1689                 }
1690         }
1691 }
1692 #endif
1693
1694 void __meminit vmemmap_populate_print_last(void)
1695 {
1696         if (p_start) {
1697                 pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1698                         addr_start, addr_end-1, p_start, p_end-1, node_start);
1699                 p_start = NULL;
1700                 p_end = NULL;
1701                 node_start = 0;
1702         }
1703 }
1704 #endif