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 static inline pgprot_t prot_sethuge(pgprot_t prot)
  94 {
  95         WARN_ON_ONCE(pgprot_val(prot) & _PAGE_PAT);
  96
  97         return __pgprot(pgprot_val(prot) | _PAGE_PSE);
  98 }
  99
 100 /*
 101  * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
 102  * physical space so we can cache the place of the first one and move
 103  * around without checking the pgd every time.
 104  */
 105
 106 /* Bits supported by the hardware: */
 107 pteval_t __supported_pte_mask __read_mostly = ~0;
 108 /* Bits allowed in normal kernel mappings: */
 109 pteval_t __default_kernel_pte_mask __read_mostly = ~0;
 110 EXPORT_SYMBOL_GPL(__supported_pte_mask);
 111 /* Used in PAGE_KERNEL_* macros which are reasonably used out-of-tree: */
 112 EXPORT_SYMBOL(__default_kernel_pte_mask);
 113
 114 int force_personality32;
 115
 116 /*
 117  * noexec32=on|off
 118  * Control non executable heap for 32bit processes.
 119  *
 120  * on   PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
 121  * off  PROT_READ implies PROT_EXEC
 122  */
 123 static int __init nonx32_setup(char *str)
 124 {
 125         if (!strcmp(str, "on"))
 126                 force_personality32 &= ~READ_IMPLIES_EXEC;
 127         else if (!strcmp(str, "off"))
 128                 force_personality32 |= READ_IMPLIES_EXEC;
 129         return 1;
 130 }
 131 __setup("noexec32=", nonx32_setup);
 132
 133 static void sync_global_pgds_l5(unsigned long start, unsigned long end)
 134 {
 135         unsigned long addr;
 136
 137         for (addr = start; addr <= end; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
 138                 const pgd_t *pgd_ref = pgd_offset_k(addr);
 139                 struct page *page;
 140
 141                 /* Check for overflow */
 142                 if (addr < start)
 143                         break;
 144
 145                 if (pgd_none(*pgd_ref))
 146                         continue;
 147
 148                 spin_lock(&pgd_lock);
 149                 list_for_each_entry(page, &pgd_list, lru) {
 150                         pgd_t *pgd;
 151                         spinlock_t *pgt_lock;
 152
 153                         pgd = (pgd_t *)page_address(page) + pgd_index(addr);
 154                         /* the pgt_lock only for Xen */
 155                         pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
 156                         spin_lock(pgt_lock);
 157
 158                         if (!pgd_none(*pgd_ref) && !pgd_none(*pgd))
 159                                 BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref));
 160
 161                         if (pgd_none(*pgd))
 162                                 set_pgd(pgd, *pgd_ref);
 163
 164                         spin_unlock(pgt_lock);
 165                 }
 166                 spin_unlock(&pgd_lock);
 167         }
 168 }
 169
 170 static void sync_global_pgds_l4(unsigned long start, unsigned long end)
 171 {
 172         unsigned long addr;
 173
 174         for (addr = start; addr <= end; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
 175                 pgd_t *pgd_ref = pgd_offset_k(addr);
 176                 const p4d_t *p4d_ref;
 177                 struct page *page;
 178
 179                 /*
 180                  * With folded p4d, pgd_none() is always false, we need to
 181                  * handle synchronization on p4d level.
 182                  */
 183                 MAYBE_BUILD_BUG_ON(pgd_none(*pgd_ref));
 184                 p4d_ref = p4d_offset(pgd_ref, addr);
 185
 186                 if (p4d_none(*p4d_ref))
 187                         continue;
 188
 189                 spin_lock(&pgd_lock);
 190                 list_for_each_entry(page, &pgd_list, lru) {
 191                         pgd_t *pgd;
 192                         p4d_t *p4d;
 193                         spinlock_t *pgt_lock;
 194
 195                         pgd = (pgd_t *)page_address(page) + pgd_index(addr);
 196                         p4d = p4d_offset(pgd, addr);
 197                         /* the pgt_lock only for Xen */
 198                         pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
 199                         spin_lock(pgt_lock);
 200
 201                         if (!p4d_none(*p4d_ref) && !p4d_none(*p4d))
 202                                 BUG_ON(p4d_pgtable(*p4d)
 203                                        != p4d_pgtable(*p4d_ref));
 204
 205                         if (p4d_none(*p4d))
 206                                 set_p4d(p4d, *p4d_ref);
 207
 208                         spin_unlock(pgt_lock);
 209                 }
 210                 spin_unlock(&pgd_lock);
 211         }
 212 }
 213
 214 /*
 215  * When memory was added make sure all the processes MM have
 216  * suitable PGD entries in the local PGD level page.
 217  */
 218 static void sync_global_pgds(unsigned long start, unsigned long end)
 219 {
 220         if (pgtable_l5_enabled())
 221                 sync_global_pgds_l5(start, end);
 222         else
 223                 sync_global_pgds_l4(start, end);
 224 }
 225
 226 /*
 227  * NOTE: This function is marked __ref because it calls __init function
 228  * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
 229  */
 230 static __ref void *spp_getpage(void)
 231 {
 232         void *ptr;
 233
 234         if (after_bootmem)
 235                 ptr = (void *) get_zeroed_page(GFP_ATOMIC);
 236         else
 237                 ptr = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
 238
 239         if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
 240                 panic("set_pte_phys: cannot allocate page data %s\n",
 241                         after_bootmem ? "after bootmem" : "");
 242         }
 243
 244         pr_debug("spp_getpage %p\n", ptr);
 245
 246         return ptr;
 247 }
 248
 249 static p4d_t *fill_p4d(pgd_t *pgd, unsigned long vaddr)
 250 {
 251         if (pgd_none(*pgd)) {
 252                 p4d_t *p4d = (p4d_t *)spp_getpage();
 253                 pgd_populate(&init_mm, pgd, p4d);
 254                 if (p4d != p4d_offset(pgd, 0))
 255                         printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n",
 256                                p4d, p4d_offset(pgd, 0));
 257         }
 258         return p4d_offset(pgd, vaddr);
 259 }
 260
 261 static pud_t *fill_pud(p4d_t *p4d, unsigned long vaddr)
 262 {
 263         if (p4d_none(*p4d)) {
 264                 pud_t *pud = (pud_t *)spp_getpage();
 265                 p4d_populate(&init_mm, p4d, pud);
 266                 if (pud != pud_offset(p4d, 0))
 267                         printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
 268                                pud, pud_offset(p4d, 0));
 269         }
 270         return pud_offset(p4d, vaddr);
 271 }
 272
 273 static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr)
 274 {
 275         if (pud_none(*pud)) {
 276                 pmd_t *pmd = (pmd_t *) spp_getpage();
 277                 pud_populate(&init_mm, pud, pmd);
 278                 if (pmd != pmd_offset(pud, 0))
 279                         printk(KERN_ERR "PAGETABLE BUG #02! %p <-> %p\n",
 280                                pmd, pmd_offset(pud, 0));
 281         }
 282         return pmd_offset(pud, vaddr);
 283 }
 284
 285 static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr)
 286 {
 287         if (pmd_none(*pmd)) {
 288                 pte_t *pte = (pte_t *) spp_getpage();
 289                 pmd_populate_kernel(&init_mm, pmd, pte);
 290                 if (pte != pte_offset_kernel(pmd, 0))
 291                         printk(KERN_ERR "PAGETABLE BUG #03!\n");
 292         }
 293         return pte_offset_kernel(pmd, vaddr);
 294 }
 295
 296 static void __set_pte_vaddr(pud_t *pud, unsigned long vaddr, pte_t new_pte)
 297 {
 298         pmd_t *pmd = fill_pmd(pud, vaddr);
 299         pte_t *pte = fill_pte(pmd, vaddr);
 300
 301         set_pte(pte, new_pte);
 302
 303         /*
 304          * It's enough to flush this one mapping.
 305          * (PGE mappings get flushed as well)
 306          */
 307         flush_tlb_one_kernel(vaddr);
 308 }
 309
 310 void set_pte_vaddr_p4d(p4d_t *p4d_page, unsigned long vaddr, pte_t new_pte)
 311 {
 312         p4d_t *p4d = p4d_page + p4d_index(vaddr);
 313         pud_t *pud = fill_pud(p4d, vaddr);
 314
 315         __set_pte_vaddr(pud, vaddr, new_pte);
 316 }
 317
 318 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
 319 {
 320         pud_t *pud = pud_page + pud_index(vaddr);
 321
 322         __set_pte_vaddr(pud, vaddr, new_pte);
 323 }
 324
 325 void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
 326 {
 327         pgd_t *pgd;
 328         p4d_t *p4d_page;
 329
 330         pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
 331
 332         pgd = pgd_offset_k(vaddr);
 333         if (pgd_none(*pgd)) {
 334                 printk(KERN_ERR
 335                         "PGD FIXMAP MISSING, it should be setup in head.S!\n");
 336                 return;
 337         }
 338
 339         p4d_page = p4d_offset(pgd, 0);
 340         set_pte_vaddr_p4d(p4d_page, vaddr, pteval);
 341 }
 342
 343 pmd_t * __init populate_extra_pmd(unsigned long vaddr)
 344 {
 345         pgd_t *pgd;
 346         p4d_t *p4d;
 347         pud_t *pud;
 348
 349         pgd = pgd_offset_k(vaddr);
 350         p4d = fill_p4d(pgd, vaddr);
 351         pud = fill_pud(p4d, vaddr);
 352         return fill_pmd(pud, vaddr);
 353 }
 354
 355 pte_t * __init populate_extra_pte(unsigned long vaddr)
 356 {
 357         pmd_t *pmd;
 358
 359         pmd = populate_extra_pmd(vaddr);
 360         return fill_pte(pmd, vaddr);
 361 }
 362
 363 /*
 364  * Create large page table mappings for a range of physical addresses.
 365  */
 366 static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
 367                                         enum page_cache_mode cache)
 368 {
 369         pgd_t *pgd;
 370         p4d_t *p4d;
 371         pud_t *pud;
 372         pmd_t *pmd;
 373         pgprot_t prot;
 374
 375         pgprot_val(prot) = pgprot_val(PAGE_KERNEL_LARGE) |
 376                 protval_4k_2_large(cachemode2protval(cache));
 377         BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
 378         for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
 379                 pgd = pgd_offset_k((unsigned long)__va(phys));
 380                 if (pgd_none(*pgd)) {
 381                         p4d = (p4d_t *) spp_getpage();
 382                         set_pgd(pgd, __pgd(__pa(p4d) | _KERNPG_TABLE |
 383                                                 _PAGE_USER));
 384                 }
 385                 p4d = p4d_offset(pgd, (unsigned long)__va(phys));
 386                 if (p4d_none(*p4d)) {
 387                         pud = (pud_t *) spp_getpage();
 388                         set_p4d(p4d, __p4d(__pa(pud) | _KERNPG_TABLE |
 389                                                 _PAGE_USER));
 390                 }
 391                 pud = pud_offset(p4d, (unsigned long)__va(phys));
 392                 if (pud_none(*pud)) {
 393                         pmd = (pmd_t *) spp_getpage();
 394                         set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
 395                                                 _PAGE_USER));
 396                 }
 397                 pmd = pmd_offset(pud, phys);
 398                 BUG_ON(!pmd_none(*pmd));
 399                 set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
 400         }
 401 }
 402
 403 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
 404 {
 405         __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_WB);
 406 }
 407
 408 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
 409 {
 410         __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_UC);
 411 }
 412
 413 /*
 414  * The head.S code sets up the kernel high mapping:
 415  *
 416  *   from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
 417  *
 418  * phys_base holds the negative offset to the kernel, which is added
 419  * to the compile time generated pmds. This results in invalid pmds up
 420  * to the point where we hit the physaddr 0 mapping.
 421  *
 422  * We limit the mappings to the region from _text to _brk_end.  _brk_end
 423  * is rounded up to the 2MB boundary. This catches the invalid pmds as
 424  * well, as they are located before _text:
 425  */
 426 void __init cleanup_highmap(void)
 427 {
 428         unsigned long vaddr = __START_KERNEL_map;
 429         unsigned long vaddr_end = __START_KERNEL_map + KERNEL_IMAGE_SIZE;
 430         unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1;
 431         pmd_t *pmd = level2_kernel_pgt;
 432
 433         /*
 434          * Native path, max_pfn_mapped is not set yet.
 435          * Xen has valid max_pfn_mapped set in
 436          *      arch/x86/xen/mmu.c:xen_setup_kernel_pagetable().
 437          */
 438         if (max_pfn_mapped)
 439                 vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT);
 440
 441         for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) {
 442                 if (pmd_none(*pmd))
 443                         continue;
 444                 if (vaddr < (unsigned long) _text || vaddr > end)
 445                         set_pmd(pmd, __pmd(0));
 446         }
 447 }
 448
 449 /*
 450  * Create PTE level page table mapping for physical addresses.
 451  * It returns the last physical address mapped.
 452  */
 453 static unsigned long __meminit
 454 phys_pte_init(pte_t *pte_page, unsigned long paddr, unsigned long paddr_end,
 455               pgprot_t prot, bool init)
 456 {
 457         unsigned long pages = 0, paddr_next;
 458         unsigned long paddr_last = paddr_end;
 459         pte_t *pte;
 460         int i;
 461
 462         pte = pte_page + pte_index(paddr);
 463         i = pte_index(paddr);
 464
 465         for (; i < PTRS_PER_PTE; i++, paddr = paddr_next, pte++) {
 466                 paddr_next = (paddr & PAGE_MASK) + PAGE_SIZE;
 467                 if (paddr >= paddr_end) {
 468                         if (!after_bootmem &&
 469                             !e820__mapped_any(paddr & PAGE_MASK, paddr_next,
 470                                              E820_TYPE_RAM) &&
 471                             !e820__mapped_any(paddr & PAGE_MASK, paddr_next,
 472                                              E820_TYPE_RESERVED_KERN))
 473                                 set_pte_init(pte, __pte(0), init);
 474                         continue;
 475                 }
 476
 477                 /*
 478                  * We will re-use the existing mapping.
 479                  * Xen for example has some special requirements, like mapping
 480                  * pagetable pages as RO. So assume someone who pre-setup
 481                  * these mappings are more intelligent.
 482                  */
 483                 if (!pte_none(*pte)) {
 484                         if (!after_bootmem)
 485                                 pages++;
 486                         continue;
 487                 }
 488
 489                 if (0)
 490                         pr_info("   pte=%p addr=%lx pte=%016lx\n", pte, paddr,
 491                                 pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL).pte);
 492                 pages++;
 493                 set_pte_init(pte, pfn_pte(paddr >> PAGE_SHIFT, prot), init);
 494                 paddr_last = (paddr & PAGE_MASK) + PAGE_SIZE;
 495         }
 496
 497         update_page_count(PG_LEVEL_4K, pages);
 498
 499         return paddr_last;
 500 }
 501
 502 /*
 503  * Create PMD level page table mapping for physical addresses. The virtual
 504  * and physical address have to be aligned at this level.
 505  * It returns the last physical address mapped.
 506  */
 507 static unsigned long __meminit
 508 phys_pmd_init(pmd_t *pmd_page, unsigned long paddr, unsigned long paddr_end,
 509               unsigned long page_size_mask, pgprot_t prot, bool init)
 510 {
 511         unsigned long pages = 0, paddr_next;
 512         unsigned long paddr_last = paddr_end;
 513
 514         int i = pmd_index(paddr);
 515
 516         for (; i < PTRS_PER_PMD; i++, paddr = paddr_next) {
 517                 pmd_t *pmd = pmd_page + pmd_index(paddr);
 518                 pte_t *pte;
 519                 pgprot_t new_prot = prot;
 520
 521                 paddr_next = (paddr & PMD_MASK) + PMD_SIZE;
 522                 if (paddr >= paddr_end) {
 523                         if (!after_bootmem &&
 524                             !e820__mapped_any(paddr & PMD_MASK, paddr_next,
 525                                              E820_TYPE_RAM) &&
 526                             !e820__mapped_any(paddr & PMD_MASK, paddr_next,
 527                                              E820_TYPE_RESERVED_KERN))
 528                                 set_pmd_init(pmd, __pmd(0), init);
 529                         continue;
 530                 }
 531
 532                 if (!pmd_none(*pmd)) {
 533                         if (!pmd_large(*pmd)) {
 534                                 spin_lock(&init_mm.page_table_lock);
 535                                 pte = (pte_t *)pmd_page_vaddr(*pmd);
 536                                 paddr_last = phys_pte_init(pte, paddr,
 537                                                            paddr_end, prot,
 538                                                            init);
 539                                 spin_unlock(&init_mm.page_table_lock);
 540                                 continue;
 541                         }
 542                         /*
 543                          * If we are ok with PG_LEVEL_2M mapping, then we will
 544                          * use the existing mapping,
 545                          *
 546                          * Otherwise, we will split the large page mapping but
 547                          * use the same existing protection bits except for
 548                          * large page, so that we don't violate Intel's TLB
 549                          * Application note (317080) which says, while changing
 550                          * the page sizes, new and old translations should
 551                          * not differ with respect to page frame and
 552                          * attributes.
 553                          */
 554                         if (page_size_mask & (1 << PG_LEVEL_2M)) {
 555                                 if (!after_bootmem)
 556                                         pages++;
 557                                 paddr_last = paddr_next;
 558                                 continue;
 559                         }
 560                         new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
 561                 }
 562
 563                 if (page_size_mask & (1<<PG_LEVEL_2M)) {
 564                         pages++;
 565                         spin_lock(&init_mm.page_table_lock);
 566                         set_pmd_init(pmd,
 567                                      pfn_pmd(paddr >> PAGE_SHIFT, prot_sethuge(prot)),
 568                                      init);
 569                         spin_unlock(&init_mm.page_table_lock);
 570                         paddr_last = paddr_next;
 571                         continue;
 572                 }
 573
 574                 pte = alloc_low_page();
 575                 paddr_last = phys_pte_init(pte, paddr, paddr_end, new_prot, init);
 576
 577                 spin_lock(&init_mm.page_table_lock);
 578                 pmd_populate_kernel_init(&init_mm, pmd, pte, init);
 579                 spin_unlock(&init_mm.page_table_lock);
 580         }
 581         update_page_count(PG_LEVEL_2M, pages);
 582         return paddr_last;
 583 }
 584
 585 /*
 586  * Create PUD level page table mapping for physical addresses. The virtual
 587  * and physical address do not have to be aligned at this level. KASLR can
 588  * randomize virtual addresses up to this level.
 589  * It returns the last physical address mapped.
 590  */
 591 static unsigned long __meminit
 592 phys_pud_init(pud_t *pud_page, unsigned long paddr, unsigned long paddr_end,
 593               unsigned long page_size_mask, pgprot_t _prot, bool init)
 594 {
 595         unsigned long pages = 0, paddr_next;
 596         unsigned long paddr_last = paddr_end;
 597         unsigned long vaddr = (unsigned long)__va(paddr);
 598         int i = pud_index(vaddr);
 599
 600         for (; i < PTRS_PER_PUD; i++, paddr = paddr_next) {
 601                 pud_t *pud;
 602                 pmd_t *pmd;
 603                 pgprot_t prot = _prot;
 604
 605                 vaddr = (unsigned long)__va(paddr);
 606                 pud = pud_page + pud_index(vaddr);
 607                 paddr_next = (paddr & PUD_MASK) + PUD_SIZE;
 608
 609                 if (paddr >= paddr_end) {
 610                         if (!after_bootmem &&
 611                             !e820__mapped_any(paddr & PUD_MASK, paddr_next,
 612                                              E820_TYPE_RAM) &&
 613                             !e820__mapped_any(paddr & PUD_MASK, paddr_next,
 614                                              E820_TYPE_RESERVED_KERN))
 615                                 set_pud_init(pud, __pud(0), init);
 616                         continue;
 617                 }
 618
 619                 if (!pud_none(*pud)) {
 620                         if (!pud_large(*pud)) {
 621                                 pmd = pmd_offset(pud, 0);
 622                                 paddr_last = phys_pmd_init(pmd, paddr,
 623                                                            paddr_end,
 624                                                            page_size_mask,
 625                                                            prot, init);
 626                                 continue;
 627                         }
 628                         /*
 629                          * If we are ok with PG_LEVEL_1G mapping, then we will
 630                          * use the existing mapping.
 631                          *
 632                          * Otherwise, we will split the gbpage mapping but use
 633                          * the same existing protection  bits except for large
 634                          * page, so that we don't violate Intel's TLB
 635                          * Application note (317080) which says, while changing
 636                          * the page sizes, new and old translations should
 637                          * not differ with respect to page frame and
 638                          * attributes.
 639                          */
 640                         if (page_size_mask & (1 << PG_LEVEL_1G)) {
 641                                 if (!after_bootmem)
 642                                         pages++;
 643                                 paddr_last = paddr_next;
 644                                 continue;
 645                         }
 646                         prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
 647                 }
 648
 649                 if (page_size_mask & (1<<PG_LEVEL_1G)) {
 650                         pages++;
 651                         spin_lock(&init_mm.page_table_lock);
 652                         set_pud_init(pud,
 653                                      pfn_pud(paddr >> PAGE_SHIFT, prot_sethuge(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         const unsigned long page = ALIGN_DOWN(start, PMD_SIZE);
 906
 907         vmemmap_flush_unused_pmd();
 908
 909         /*
 910          * Could be our memmap page is filled with PAGE_UNUSED already from a
 911          * previous remove. Make sure to reset it.
 912          */
 913         __vmemmap_use_sub_pmd(start);
 914
 915         /*
 916          * Mark with PAGE_UNUSED the unused parts of the new memmap range
 917          */
 918         if (!IS_ALIGNED(start, PMD_SIZE))
 919                 memset((void *)page, PAGE_UNUSED, start - page);
 920
 921         /*
 922          * We want to avoid memset(PAGE_UNUSED) when populating the vmemmap of
 923          * consecutive sections. Remember for the last added PMD where the
 924          * unused range begins.
 925          */
 926         if (!IS_ALIGNED(end, PMD_SIZE))
 927                 unused_pmd_start = end;
 928 }
 929 #endif
 930
 931 /*
 932  * Memory hotplug specific functions
 933  */
 934 #ifdef CONFIG_MEMORY_HOTPLUG
 935 /*
 936  * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
 937  * updating.
 938  */
 939 static void update_end_of_memory_vars(u64 start, u64 size)
 940 {
 941         unsigned long end_pfn = PFN_UP(start + size);
 942
 943         if (end_pfn > max_pfn) {
 944                 max_pfn = end_pfn;
 945                 max_low_pfn = end_pfn;
 946                 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
 947         }
 948 }
 949
 950 int add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
 951               struct mhp_params *params)
 952 {
 953         int ret;
 954
 955         ret = __add_pages(nid, start_pfn, nr_pages, params);
 956         WARN_ON_ONCE(ret);
 957
 958         /* update max_pfn, max_low_pfn and high_memory */
 959         update_end_of_memory_vars(start_pfn << PAGE_SHIFT,
 960                                   nr_pages << PAGE_SHIFT);
 961
 962         return ret;
 963 }
 964
 965 int arch_add_memory(int nid, u64 start, u64 size,
 966                     struct mhp_params *params)
 967 {
 968         unsigned long start_pfn = start >> PAGE_SHIFT;
 969         unsigned long nr_pages = size >> PAGE_SHIFT;
 970
 971         init_memory_mapping(start, start + size, params->pgprot);
 972
 973         return add_pages(nid, start_pfn, nr_pages, params);
 974 }
 975
 976 static void __meminit free_pagetable(struct page *page, int order)
 977 {
 978         unsigned long magic;
 979         unsigned int nr_pages = 1 << order;
 980
 981         /* bootmem page has reserved flag */
 982         if (PageReserved(page)) {
 983                 __ClearPageReserved(page);
 984
 985                 magic = page->index;
 986                 if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
 987                         while (nr_pages--)
 988                                 put_page_bootmem(page++);
 989                 } else
 990                         while (nr_pages--)
 991                                 free_reserved_page(page++);
 992         } else
 993                 free_pages((unsigned long)page_address(page), order);
 994 }
 995
 996 static void __meminit free_hugepage_table(struct page *page,
 997                 struct vmem_altmap *altmap)
 998 {
 999         if (altmap)
1000                 vmem_altmap_free(altmap, PMD_SIZE / PAGE_SIZE);
1001         else
1002                 free_pagetable(page, get_order(PMD_SIZE));
1003 }
1004
1005 static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
1006 {
1007         pte_t *pte;
1008         int i;
1009
1010         for (i = 0; i < PTRS_PER_PTE; i++) {
1011                 pte = pte_start + i;
1012                 if (!pte_none(*pte))
1013                         return;
1014         }
1015
1016         /* free a pte talbe */
1017         free_pagetable(pmd_page(*pmd), 0);
1018         spin_lock(&init_mm.page_table_lock);
1019         pmd_clear(pmd);
1020         spin_unlock(&init_mm.page_table_lock);
1021 }
1022
1023 static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud)
1024 {
1025         pmd_t *pmd;
1026         int i;
1027
1028         for (i = 0; i < PTRS_PER_PMD; i++) {
1029                 pmd = pmd_start + i;
1030                 if (!pmd_none(*pmd))
1031                         return;
1032         }
1033
1034         /* free a pmd talbe */
1035         free_pagetable(pud_page(*pud), 0);
1036         spin_lock(&init_mm.page_table_lock);
1037         pud_clear(pud);
1038         spin_unlock(&init_mm.page_table_lock);
1039 }
1040
1041 static void __meminit free_pud_table(pud_t *pud_start, p4d_t *p4d)
1042 {
1043         pud_t *pud;
1044         int i;
1045
1046         for (i = 0; i < PTRS_PER_PUD; i++) {
1047                 pud = pud_start + i;
1048                 if (!pud_none(*pud))
1049                         return;
1050         }
1051
1052         /* free a pud talbe */
1053         free_pagetable(p4d_page(*p4d), 0);
1054         spin_lock(&init_mm.page_table_lock);
1055         p4d_clear(p4d);
1056         spin_unlock(&init_mm.page_table_lock);
1057 }
1058
1059 static void __meminit
1060 remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
1061                  bool direct)
1062 {
1063         unsigned long next, pages = 0;
1064         pte_t *pte;
1065         phys_addr_t phys_addr;
1066
1067         pte = pte_start + pte_index(addr);
1068         for (; addr < end; addr = next, pte++) {
1069                 next = (addr + PAGE_SIZE) & PAGE_MASK;
1070                 if (next > end)
1071                         next = end;
1072
1073                 if (!pte_present(*pte))
1074                         continue;
1075
1076                 /*
1077                  * We mapped [0,1G) memory as identity mapping when
1078                  * initializing, in arch/x86/kernel/head_64.S. These
1079                  * pagetables cannot be removed.
1080                  */
1081                 phys_addr = pte_val(*pte) + (addr & PAGE_MASK);
1082                 if (phys_addr < (phys_addr_t)0x40000000)
1083                         return;
1084
1085                 if (!direct)
1086                         free_pagetable(pte_page(*pte), 0);
1087
1088                 spin_lock(&init_mm.page_table_lock);
1089                 pte_clear(&init_mm, addr, pte);
1090                 spin_unlock(&init_mm.page_table_lock);
1091
1092                 /* For non-direct mapping, pages means nothing. */
1093                 pages++;
1094         }
1095
1096         /* Call free_pte_table() in remove_pmd_table(). */
1097         flush_tlb_all();
1098         if (direct)
1099                 update_page_count(PG_LEVEL_4K, -pages);
1100 }
1101
1102 static void __meminit
1103 remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
1104                  bool direct, struct vmem_altmap *altmap)
1105 {
1106         unsigned long next, pages = 0;
1107         pte_t *pte_base;
1108         pmd_t *pmd;
1109
1110         pmd = pmd_start + pmd_index(addr);
1111         for (; addr < end; addr = next, pmd++) {
1112                 next = pmd_addr_end(addr, end);
1113
1114                 if (!pmd_present(*pmd))
1115                         continue;
1116
1117                 if (pmd_large(*pmd)) {
1118                         if (IS_ALIGNED(addr, PMD_SIZE) &&
1119                             IS_ALIGNED(next, PMD_SIZE)) {
1120                                 if (!direct)
1121                                         free_hugepage_table(pmd_page(*pmd),
1122                                                             altmap);
1123
1124                                 spin_lock(&init_mm.page_table_lock);
1125                                 pmd_clear(pmd);
1126                                 spin_unlock(&init_mm.page_table_lock);
1127                                 pages++;
1128                         }
1129 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1130                         else if (vmemmap_pmd_is_unused(addr, next)) {
1131                                         free_hugepage_table(pmd_page(*pmd),
1132                                                             altmap);
1133                                         spin_lock(&init_mm.page_table_lock);
1134                                         pmd_clear(pmd);
1135                                         spin_unlock(&init_mm.page_table_lock);
1136                         }
1137 #endif
1138                         continue;
1139                 }
1140
1141                 pte_base = (pte_t *)pmd_page_vaddr(*pmd);
1142                 remove_pte_table(pte_base, addr, next, direct);
1143                 free_pte_table(pte_base, pmd);
1144         }
1145
1146         /* Call free_pmd_table() in remove_pud_table(). */
1147         if (direct)
1148                 update_page_count(PG_LEVEL_2M, -pages);
1149 }
1150
1151 static void __meminit
1152 remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
1153                  struct vmem_altmap *altmap, bool direct)
1154 {
1155         unsigned long next, pages = 0;
1156         pmd_t *pmd_base;
1157         pud_t *pud;
1158
1159         pud = pud_start + pud_index(addr);
1160         for (; addr < end; addr = next, pud++) {
1161                 next = pud_addr_end(addr, end);
1162
1163                 if (!pud_present(*pud))
1164                         continue;
1165
1166                 if (pud_large(*pud) &&
1167                     IS_ALIGNED(addr, PUD_SIZE) &&
1168                     IS_ALIGNED(next, PUD_SIZE)) {
1169                         spin_lock(&init_mm.page_table_lock);
1170                         pud_clear(pud);
1171                         spin_unlock(&init_mm.page_table_lock);
1172                         pages++;
1173                         continue;
1174                 }
1175
1176                 pmd_base = pmd_offset(pud, 0);
1177                 remove_pmd_table(pmd_base, addr, next, direct, altmap);
1178                 free_pmd_table(pmd_base, pud);
1179         }
1180
1181         if (direct)
1182                 update_page_count(PG_LEVEL_1G, -pages);
1183 }
1184
1185 static void __meminit
1186 remove_p4d_table(p4d_t *p4d_start, unsigned long addr, unsigned long end,
1187                  struct vmem_altmap *altmap, bool direct)
1188 {
1189         unsigned long next, pages = 0;
1190         pud_t *pud_base;
1191         p4d_t *p4d;
1192
1193         p4d = p4d_start + p4d_index(addr);
1194         for (; addr < end; addr = next, p4d++) {
1195                 next = p4d_addr_end(addr, end);
1196
1197                 if (!p4d_present(*p4d))
1198                         continue;
1199
1200                 BUILD_BUG_ON(p4d_large(*p4d));
1201
1202                 pud_base = pud_offset(p4d, 0);
1203                 remove_pud_table(pud_base, addr, next, altmap, direct);
1204                 /*
1205                  * For 4-level page tables we do not want to free PUDs, but in the
1206                  * 5-level case we should free them. This code will have to change
1207                  * to adapt for boot-time switching between 4 and 5 level page tables.
1208                  */
1209                 if (pgtable_l5_enabled())
1210                         free_pud_table(pud_base, p4d);
1211         }
1212
1213         if (direct)
1214                 update_page_count(PG_LEVEL_512G, -pages);
1215 }
1216
1217 /* start and end are both virtual address. */
1218 static void __meminit
1219 remove_pagetable(unsigned long start, unsigned long end, bool direct,
1220                 struct vmem_altmap *altmap)
1221 {
1222         unsigned long next;
1223         unsigned long addr;
1224         pgd_t *pgd;
1225         p4d_t *p4d;
1226
1227         for (addr = start; addr < end; addr = next) {
1228                 next = pgd_addr_end(addr, end);
1229
1230                 pgd = pgd_offset_k(addr);
1231                 if (!pgd_present(*pgd))
1232                         continue;
1233
1234                 p4d = p4d_offset(pgd, 0);
1235                 remove_p4d_table(p4d, addr, next, altmap, direct);
1236         }
1237
1238         flush_tlb_all();
1239 }
1240
1241 void __ref vmemmap_free(unsigned long start, unsigned long end,
1242                 struct vmem_altmap *altmap)
1243 {
1244         VM_BUG_ON(!PAGE_ALIGNED(start));
1245         VM_BUG_ON(!PAGE_ALIGNED(end));
1246
1247         remove_pagetable(start, end, false, altmap);
1248 }
1249
1250 static void __meminit
1251 kernel_physical_mapping_remove(unsigned long start, unsigned long end)
1252 {
1253         start = (unsigned long)__va(start);
1254         end = (unsigned long)__va(end);
1255
1256         remove_pagetable(start, end, true, NULL);
1257 }
1258
1259 void __ref arch_remove_memory(u64 start, u64 size, 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
1269 static struct kcore_list kcore_vsyscall;
1270
1271 static void __init register_page_bootmem_info(void)
1272 {
1273 #if defined(CONFIG_NUMA) || defined(CONFIG_HUGETLB_PAGE_OPTIMIZE_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  */
1286 static void __init preallocate_vmalloc_pages(void)
1287 {
1288         unsigned long addr;
1289         const char *lvl;
1290
1291         for (addr = VMALLOC_START; addr <= VMEMORY_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
1322 failed:
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
1331 void __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
1358 int __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
1369 int kernel_set_to_readonly;
1370
1371 void 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
1419 /*
1420  * Block size is the minimum amount of memory which can be hotplugged or
1421  * hotremoved. It must be power of two and must be equal or larger than
1422  * MIN_MEMORY_BLOCK_SIZE.
1423  */
1424 #define MAX_BLOCK_SIZE (2UL << 30)
1425
1426 /* Amount of ram needed to start using large blocks */
1427 #define MEM_SIZE_FOR_LARGE_BLOCK (64UL << 30)
1428
1429 /* Adjustable memory block size */
1430 static unsigned long set_memory_block_size;
1431 int __init set_memory_block_size_order(unsigned int order)
1432 {
1433         unsigned long size = 1UL << order;
1434
1435         if (size > MEM_SIZE_FOR_LARGE_BLOCK || size < MIN_MEMORY_BLOCK_SIZE)
1436                 return -EINVAL;
1437
1438         set_memory_block_size = size;
1439         return 0;
1440 }
1441
1442 static unsigned long probe_memory_block_size(void)
1443 {
1444         unsigned long boot_mem_end = max_pfn << PAGE_SHIFT;
1445         unsigned long bz;
1446
1447         /* If memory block size has been set, then use it */
1448         bz = set_memory_block_size;
1449         if (bz)
1450                 goto done;
1451
1452         /* Use regular block if RAM is smaller than MEM_SIZE_FOR_LARGE_BLOCK */
1453         if (boot_mem_end < MEM_SIZE_FOR_LARGE_BLOCK) {
1454                 bz = MIN_MEMORY_BLOCK_SIZE;
1455                 goto done;
1456         }
1457
1458         /*
1459          * Use max block size to minimize overhead on bare metal, where
1460          * alignment for memory hotplug isn't a concern.
1461          */
1462         if (!boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
1463                 bz = MAX_BLOCK_SIZE;
1464                 goto done;
1465         }
1466
1467         /* Find the largest allowed block size that aligns to memory end */
1468         for (bz = MAX_BLOCK_SIZE; bz > MIN_MEMORY_BLOCK_SIZE; bz >>= 1) {
1469                 if (IS_ALIGNED(boot_mem_end, bz))
1470                         break;
1471         }
1472 done:
1473         pr_info("x86/mm: Memory block size: %ldMB\n", bz >> 20);
1474
1475         return bz;
1476 }
1477
1478 static unsigned long memory_block_size_probed;
1479 unsigned long memory_block_size_bytes(void)
1480 {
1481         if (!memory_block_size_probed)
1482                 memory_block_size_probed = probe_memory_block_size();
1483
1484         return memory_block_size_probed;
1485 }
1486
1487 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1488 /*
1489  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1490  */
1491 static long __meminitdata addr_start, addr_end;
1492 static void __meminitdata *p_start, *p_end;
1493 static int __meminitdata node_start;
1494
1495 void __meminit vmemmap_set_pmd(pmd_t *pmd, void *p, int node,
1496                                unsigned long addr, unsigned long next)
1497 {
1498         pte_t entry;
1499
1500         entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1501                         PAGE_KERNEL_LARGE);
1502         set_pmd(pmd, __pmd(pte_val(entry)));
1503
1504         /* check to see if we have contiguous blocks */
1505         if (p_end != p || node_start != node) {
1506                 if (p_start)
1507                         pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1508                                 addr_start, addr_end-1, p_start, p_end-1, node_start);
1509                 addr_start = addr;
1510                 node_start = node;
1511                 p_start = p;
1512         }
1513
1514         addr_end = addr + PMD_SIZE;
1515         p_end = p + PMD_SIZE;
1516
1517         if (!IS_ALIGNED(addr, PMD_SIZE) ||
1518                 !IS_ALIGNED(next, PMD_SIZE))
1519                 vmemmap_use_new_sub_pmd(addr, next);
1520 }
1521
1522 int __meminit vmemmap_check_pmd(pmd_t *pmd, int node,
1523                                 unsigned long addr, unsigned long next)
1524 {
1525         int large = pmd_large(*pmd);
1526
1527         if (pmd_large(*pmd)) {
1528                 vmemmap_verify((pte_t *)pmd, node, addr, next);
1529                 vmemmap_use_sub_pmd(addr, next);
1530         }
1531
1532         return large;
1533 }
1534
1535 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
1536                 struct vmem_altmap *altmap)
1537 {
1538         int err;
1539
1540         VM_BUG_ON(!PAGE_ALIGNED(start));
1541         VM_BUG_ON(!PAGE_ALIGNED(end));
1542
1543         if (end - start < PAGES_PER_SECTION * sizeof(struct page))
1544                 err = vmemmap_populate_basepages(start, end, node, NULL);
1545         else if (boot_cpu_has(X86_FEATURE_PSE))
1546                 err = vmemmap_populate_hugepages(start, end, node, altmap);
1547         else if (altmap) {
1548                 pr_err_once("%s: no cpu support for altmap allocations\n",
1549                                 __func__);
1550                 err = -ENOMEM;
1551         } else
1552                 err = vmemmap_populate_basepages(start, end, node, NULL);
1553         if (!err)
1554                 sync_global_pgds(start, end - 1);
1555         return err;
1556 }
1557
1558 #ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
1559 void register_page_bootmem_memmap(unsigned long section_nr,
1560                                   struct page *start_page, unsigned long nr_pages)
1561 {
1562         unsigned long addr = (unsigned long)start_page;
1563         unsigned long end = (unsigned long)(start_page + nr_pages);
1564         unsigned long next;
1565         pgd_t *pgd;
1566         p4d_t *p4d;
1567         pud_t *pud;
1568         pmd_t *pmd;
1569         unsigned int nr_pmd_pages;
1570         struct page *page;
1571
1572         for (; addr < end; addr = next) {
1573                 pte_t *pte = NULL;
1574
1575                 pgd = pgd_offset_k(addr);
1576                 if (pgd_none(*pgd)) {
1577                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1578                         continue;
1579                 }
1580                 get_page_bootmem(section_nr, pgd_page(*pgd), MIX_SECTION_INFO);
1581
1582                 p4d = p4d_offset(pgd, addr);
1583                 if (p4d_none(*p4d)) {
1584                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1585                         continue;
1586                 }
1587                 get_page_bootmem(section_nr, p4d_page(*p4d), MIX_SECTION_INFO);
1588
1589                 pud = pud_offset(p4d, addr);
1590                 if (pud_none(*pud)) {
1591                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1592                         continue;
1593                 }
1594                 get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO);
1595
1596                 if (!boot_cpu_has(X86_FEATURE_PSE)) {
1597                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1598                         pmd = pmd_offset(pud, addr);
1599                         if (pmd_none(*pmd))
1600                                 continue;
1601                         get_page_bootmem(section_nr, pmd_page(*pmd),
1602                                          MIX_SECTION_INFO);
1603
1604                         pte = pte_offset_kernel(pmd, addr);
1605                         if (pte_none(*pte))
1606                                 continue;
1607                         get_page_bootmem(section_nr, pte_page(*pte),
1608                                          SECTION_INFO);
1609                 } else {
1610                         next = pmd_addr_end(addr, end);
1611
1612                         pmd = pmd_offset(pud, addr);
1613                         if (pmd_none(*pmd))
1614                                 continue;
1615
1616                         nr_pmd_pages = 1 << get_order(PMD_SIZE);
1617                         page = pmd_page(*pmd);
1618                         while (nr_pmd_pages--)
1619                                 get_page_bootmem(section_nr, page++,
1620                                                  SECTION_INFO);
1621                 }
1622         }
1623 }
1624 #endif
1625
1626 void __meminit vmemmap_populate_print_last(void)
1627 {
1628         if (p_start) {
1629                 pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1630                         addr_start, addr_end-1, p_start, p_end-1, node_start);
1631                 p_start = NULL;
1632                 p_end = NULL;
1633                 node_start = 0;
1634         }
1635 }
1636 #endif