arch/x86/mm/init_64.c

   1 /*
   2  *  linux/arch/x86_64/mm/init.c
   3  *
   4  *  Copyright (C) 1995  Linus Torvalds
   5  *  Copyright (C) 2000  Pavel Machek <pavel@ucw.cz>
   6  *  Copyright (C) 2002,2003 Andi Kleen <ak@suse.de>
   7  */
   8
   9 #include <linux/signal.h>
  10 #include <linux/sched.h>
  11 #include <linux/kernel.h>
  12 #include <linux/errno.h>
  13 #include <linux/string.h>
  14 #include <linux/types.h>
  15 #include <linux/ptrace.h>
  16 #include <linux/mman.h>
  17 #include <linux/mm.h>
  18 #include <linux/swap.h>
  19 #include <linux/smp.h>
  20 #include <linux/init.h>
  21 #include <linux/initrd.h>
  22 #include <linux/pagemap.h>
  23 #include <linux/bootmem.h>
  24 #include <linux/memblock.h>
  25 #include <linux/proc_fs.h>
  26 #include <linux/pci.h>
  27 #include <linux/pfn.h>
  28 #include <linux/poison.h>
  29 #include <linux/dma-mapping.h>
  30 #include <linux/memory.h>
  31 #include <linux/memory_hotplug.h>
  32 #include <linux/memremap.h>
  33 #include <linux/nmi.h>
  34 #include <linux/gfp.h>
  35 #include <linux/kcore.h>
  36
  37 #include <asm/processor.h>
  38 #include <asm/bios_ebda.h>
  39 #include <linux/uaccess.h>
  40 #include <asm/pgtable.h>
  41 #include <asm/pgalloc.h>
  42 #include <asm/dma.h>
  43 #include <asm/fixmap.h>
  44 #include <asm/e820/api.h>
  45 #include <asm/apic.h>
  46 #include <asm/tlb.h>
  47 #include <asm/mmu_context.h>
  48 #include <asm/proto.h>
  49 #include <asm/smp.h>
  50 #include <asm/sections.h>
  51 #include <asm/kdebug.h>
  52 #include <asm/numa.h>
  53 #include <asm/set_memory.h>
  54 #include <asm/init.h>
  55 #include <asm/uv/uv.h>
  56 #include <asm/setup.h>
  57
  58 #include "mm_internal.h"
  59
  60 #include "ident_map.c"
  61
  62 /*
  63  * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
  64  * physical space so we can cache the place of the first one and move
  65  * around without checking the pgd every time.
  66  */
  67
  68 pteval_t __supported_pte_mask __read_mostly = ~0;
  69 EXPORT_SYMBOL_GPL(__supported_pte_mask);
  70
  71 int force_personality32;
  72
  73 /*
  74  * noexec32=on|off
  75  * Control non executable heap for 32bit processes.
  76  * To control the stack too use noexec=off
  77  *
  78  * on   PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
  79  * off  PROT_READ implies PROT_EXEC
  80  */
  81 static int __init nonx32_setup(char *str)
  82 {
  83         if (!strcmp(str, "on"))
  84                 force_personality32 &= ~READ_IMPLIES_EXEC;
  85         else if (!strcmp(str, "off"))
  86                 force_personality32 |= READ_IMPLIES_EXEC;
  87         return 1;
  88 }
  89 __setup("noexec32=", nonx32_setup);
  90
  91 /*
  92  * When memory was added make sure all the processes MM have
  93  * suitable PGD entries in the local PGD level page.
  94  */
  95 #ifdef CONFIG_X86_5LEVEL
  96 void sync_global_pgds(unsigned long start, unsigned long end)
  97 {
  98         unsigned long addr;
  99
 100         for (addr = start; addr <= end; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
 101                 const pgd_t *pgd_ref = pgd_offset_k(addr);
 102                 struct page *page;
 103
 104                 /* Check for overflow */
 105                 if (addr < start)
 106                         break;
 107
 108                 if (pgd_none(*pgd_ref))
 109                         continue;
 110
 111                 spin_lock(&pgd_lock);
 112                 list_for_each_entry(page, &pgd_list, lru) {
 113                         pgd_t *pgd;
 114                         spinlock_t *pgt_lock;
 115
 116                         pgd = (pgd_t *)page_address(page) + pgd_index(addr);
 117                         /* the pgt_lock only for Xen */
 118                         pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
 119                         spin_lock(pgt_lock);
 120
 121                         if (!pgd_none(*pgd_ref) && !pgd_none(*pgd))
 122                                 BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref));
 123
 124                         if (pgd_none(*pgd))
 125                                 set_pgd(pgd, *pgd_ref);
 126
 127                         spin_unlock(pgt_lock);
 128                 }
 129                 spin_unlock(&pgd_lock);
 130         }
 131 }
 132 #else
 133 void sync_global_pgds(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                 pgd_t *pgd_ref = pgd_offset_k(addr);
 139                 const p4d_t *p4d_ref;
 140                 struct page *page;
 141
 142                 /*
 143                  * With folded p4d, pgd_none() is always false, we need to
 144                  * handle synchonization on p4d level.
 145                  */
 146                 BUILD_BUG_ON(pgd_none(*pgd_ref));
 147                 p4d_ref = p4d_offset(pgd_ref, addr);
 148
 149                 if (p4d_none(*p4d_ref))
 150                         continue;
 151
 152                 spin_lock(&pgd_lock);
 153                 list_for_each_entry(page, &pgd_list, lru) {
 154                         pgd_t *pgd;
 155                         p4d_t *p4d;
 156                         spinlock_t *pgt_lock;
 157
 158                         pgd = (pgd_t *)page_address(page) + pgd_index(addr);
 159                         p4d = p4d_offset(pgd, addr);
 160                         /* the pgt_lock only for Xen */
 161                         pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
 162                         spin_lock(pgt_lock);
 163
 164                         if (!p4d_none(*p4d_ref) && !p4d_none(*p4d))
 165                                 BUG_ON(p4d_page_vaddr(*p4d)
 166                                        != p4d_page_vaddr(*p4d_ref));
 167
 168                         if (p4d_none(*p4d))
 169                                 set_p4d(p4d, *p4d_ref);
 170
 171                         spin_unlock(pgt_lock);
 172                 }
 173                 spin_unlock(&pgd_lock);
 174         }
 175 }
 176 #endif
 177
 178 /*
 179  * NOTE: This function is marked __ref because it calls __init function
 180  * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
 181  */
 182 static __ref void *spp_getpage(void)
 183 {
 184         void *ptr;
 185
 186         if (after_bootmem)
 187                 ptr = (void *) get_zeroed_page(GFP_ATOMIC);
 188         else
 189                 ptr = alloc_bootmem_pages(PAGE_SIZE);
 190
 191         if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
 192                 panic("set_pte_phys: cannot allocate page data %s\n",
 193                         after_bootmem ? "after bootmem" : "");
 194         }
 195
 196         pr_debug("spp_getpage %p\n", ptr);
 197
 198         return ptr;
 199 }
 200
 201 static p4d_t *fill_p4d(pgd_t *pgd, unsigned long vaddr)
 202 {
 203         if (pgd_none(*pgd)) {
 204                 p4d_t *p4d = (p4d_t *)spp_getpage();
 205                 pgd_populate(&init_mm, pgd, p4d);
 206                 if (p4d != p4d_offset(pgd, 0))
 207                         printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n",
 208                                p4d, p4d_offset(pgd, 0));
 209         }
 210         return p4d_offset(pgd, vaddr);
 211 }
 212
 213 static pud_t *fill_pud(p4d_t *p4d, unsigned long vaddr)
 214 {
 215         if (p4d_none(*p4d)) {
 216                 pud_t *pud = (pud_t *)spp_getpage();
 217                 p4d_populate(&init_mm, p4d, pud);
 218                 if (pud != pud_offset(p4d, 0))
 219                         printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
 220                                pud, pud_offset(p4d, 0));
 221         }
 222         return pud_offset(p4d, vaddr);
 223 }
 224
 225 static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr)
 226 {
 227         if (pud_none(*pud)) {
 228                 pmd_t *pmd = (pmd_t *) spp_getpage();
 229                 pud_populate(&init_mm, pud, pmd);
 230                 if (pmd != pmd_offset(pud, 0))
 231                         printk(KERN_ERR "PAGETABLE BUG #02! %p <-> %p\n",
 232                                pmd, pmd_offset(pud, 0));
 233         }
 234         return pmd_offset(pud, vaddr);
 235 }
 236
 237 static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr)
 238 {
 239         if (pmd_none(*pmd)) {
 240                 pte_t *pte = (pte_t *) spp_getpage();
 241                 pmd_populate_kernel(&init_mm, pmd, pte);
 242                 if (pte != pte_offset_kernel(pmd, 0))
 243                         printk(KERN_ERR "PAGETABLE BUG #03!\n");
 244         }
 245         return pte_offset_kernel(pmd, vaddr);
 246 }
 247
 248 static void __set_pte_vaddr(pud_t *pud, unsigned long vaddr, pte_t new_pte)
 249 {
 250         pmd_t *pmd = fill_pmd(pud, vaddr);
 251         pte_t *pte = fill_pte(pmd, vaddr);
 252
 253         set_pte(pte, new_pte);
 254
 255         /*
 256          * It's enough to flush this one mapping.
 257          * (PGE mappings get flushed as well)
 258          */
 259         __flush_tlb_one(vaddr);
 260 }
 261
 262 void set_pte_vaddr_p4d(p4d_t *p4d_page, unsigned long vaddr, pte_t new_pte)
 263 {
 264         p4d_t *p4d = p4d_page + p4d_index(vaddr);
 265         pud_t *pud = fill_pud(p4d, vaddr);
 266
 267         __set_pte_vaddr(pud, vaddr, new_pte);
 268 }
 269
 270 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
 271 {
 272         pud_t *pud = pud_page + pud_index(vaddr);
 273
 274         __set_pte_vaddr(pud, vaddr, new_pte);
 275 }
 276
 277 void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
 278 {
 279         pgd_t *pgd;
 280         p4d_t *p4d_page;
 281
 282         pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
 283
 284         pgd = pgd_offset_k(vaddr);
 285         if (pgd_none(*pgd)) {
 286                 printk(KERN_ERR
 287                         "PGD FIXMAP MISSING, it should be setup in head.S!\n");
 288                 return;
 289         }
 290
 291         p4d_page = p4d_offset(pgd, 0);
 292         set_pte_vaddr_p4d(p4d_page, vaddr, pteval);
 293 }
 294
 295 pmd_t * __init populate_extra_pmd(unsigned long vaddr)
 296 {
 297         pgd_t *pgd;
 298         p4d_t *p4d;
 299         pud_t *pud;
 300
 301         pgd = pgd_offset_k(vaddr);
 302         p4d = fill_p4d(pgd, vaddr);
 303         pud = fill_pud(p4d, vaddr);
 304         return fill_pmd(pud, vaddr);
 305 }
 306
 307 pte_t * __init populate_extra_pte(unsigned long vaddr)
 308 {
 309         pmd_t *pmd;
 310
 311         pmd = populate_extra_pmd(vaddr);
 312         return fill_pte(pmd, vaddr);
 313 }
 314
 315 /*
 316  * Create large page table mappings for a range of physical addresses.
 317  */
 318 static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
 319                                         enum page_cache_mode cache)
 320 {
 321         pgd_t *pgd;
 322         p4d_t *p4d;
 323         pud_t *pud;
 324         pmd_t *pmd;
 325         pgprot_t prot;
 326
 327         pgprot_val(prot) = pgprot_val(PAGE_KERNEL_LARGE) |
 328                 pgprot_val(pgprot_4k_2_large(cachemode2pgprot(cache)));
 329         BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
 330         for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
 331                 pgd = pgd_offset_k((unsigned long)__va(phys));
 332                 if (pgd_none(*pgd)) {
 333                         p4d = (p4d_t *) spp_getpage();
 334                         set_pgd(pgd, __pgd(__pa(p4d) | _KERNPG_TABLE |
 335                                                 _PAGE_USER));
 336                 }
 337                 p4d = p4d_offset(pgd, (unsigned long)__va(phys));
 338                 if (p4d_none(*p4d)) {
 339                         pud = (pud_t *) spp_getpage();
 340                         set_p4d(p4d, __p4d(__pa(pud) | _KERNPG_TABLE |
 341                                                 _PAGE_USER));
 342                 }
 343                 pud = pud_offset(p4d, (unsigned long)__va(phys));
 344                 if (pud_none(*pud)) {
 345                         pmd = (pmd_t *) spp_getpage();
 346                         set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
 347                                                 _PAGE_USER));
 348                 }
 349                 pmd = pmd_offset(pud, phys);
 350                 BUG_ON(!pmd_none(*pmd));
 351                 set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
 352         }
 353 }
 354
 355 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
 356 {
 357         __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_WB);
 358 }
 359
 360 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
 361 {
 362         __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_UC);
 363 }
 364
 365 /*
 366  * The head.S code sets up the kernel high mapping:
 367  *
 368  *   from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
 369  *
 370  * phys_base holds the negative offset to the kernel, which is added
 371  * to the compile time generated pmds. This results in invalid pmds up
 372  * to the point where we hit the physaddr 0 mapping.
 373  *
 374  * We limit the mappings to the region from _text to _brk_end.  _brk_end
 375  * is rounded up to the 2MB boundary. This catches the invalid pmds as
 376  * well, as they are located before _text:
 377  */
 378 void __init cleanup_highmap(void)
 379 {
 380         unsigned long vaddr = __START_KERNEL_map;
 381         unsigned long vaddr_end = __START_KERNEL_map + KERNEL_IMAGE_SIZE;
 382         unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1;
 383         pmd_t *pmd = level2_kernel_pgt;
 384
 385         /*
 386          * Native path, max_pfn_mapped is not set yet.
 387          * Xen has valid max_pfn_mapped set in
 388          *      arch/x86/xen/mmu.c:xen_setup_kernel_pagetable().
 389          */
 390         if (max_pfn_mapped)
 391                 vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT);
 392
 393         for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) {
 394                 if (pmd_none(*pmd))
 395                         continue;
 396                 if (vaddr < (unsigned long) _text || vaddr > end)
 397                         set_pmd(pmd, __pmd(0));
 398         }
 399 }
 400
 401 /*
 402  * Create PTE level page table mapping for physical addresses.
 403  * It returns the last physical address mapped.
 404  */
 405 static unsigned long __meminit
 406 phys_pte_init(pte_t *pte_page, unsigned long paddr, unsigned long paddr_end,
 407               pgprot_t prot)
 408 {
 409         unsigned long pages = 0, paddr_next;
 410         unsigned long paddr_last = paddr_end;
 411         pte_t *pte;
 412         int i;
 413
 414         pte = pte_page + pte_index(paddr);
 415         i = pte_index(paddr);
 416
 417         for (; i < PTRS_PER_PTE; i++, paddr = paddr_next, pte++) {
 418                 paddr_next = (paddr & PAGE_MASK) + PAGE_SIZE;
 419                 if (paddr >= paddr_end) {
 420                         if (!after_bootmem &&
 421                             !e820__mapped_any(paddr & PAGE_MASK, paddr_next,
 422                                              E820_TYPE_RAM) &&
 423                             !e820__mapped_any(paddr & PAGE_MASK, paddr_next,
 424                                              E820_TYPE_RESERVED_KERN))
 425                                 set_pte(pte, __pte(0));
 426                         continue;
 427                 }
 428
 429                 /*
 430                  * We will re-use the existing mapping.
 431                  * Xen for example has some special requirements, like mapping
 432                  * pagetable pages as RO. So assume someone who pre-setup
 433                  * these mappings are more intelligent.
 434                  */
 435                 if (!pte_none(*pte)) {
 436                         if (!after_bootmem)
 437                                 pages++;
 438                         continue;
 439                 }
 440
 441                 if (0)
 442                         pr_info("   pte=%p addr=%lx pte=%016lx\n", pte, paddr,
 443                                 pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL).pte);
 444                 pages++;
 445                 set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, prot));
 446                 paddr_last = (paddr & PAGE_MASK) + PAGE_SIZE;
 447         }
 448
 449         update_page_count(PG_LEVEL_4K, pages);
 450
 451         return paddr_last;
 452 }
 453
 454 /*
 455  * Create PMD level page table mapping for physical addresses. The virtual
 456  * and physical address have to be aligned at this level.
 457  * It returns the last physical address mapped.
 458  */
 459 static unsigned long __meminit
 460 phys_pmd_init(pmd_t *pmd_page, unsigned long paddr, unsigned long paddr_end,
 461               unsigned long page_size_mask, pgprot_t prot)
 462 {
 463         unsigned long pages = 0, paddr_next;
 464         unsigned long paddr_last = paddr_end;
 465
 466         int i = pmd_index(paddr);
 467
 468         for (; i < PTRS_PER_PMD; i++, paddr = paddr_next) {
 469                 pmd_t *pmd = pmd_page + pmd_index(paddr);
 470                 pte_t *pte;
 471                 pgprot_t new_prot = prot;
 472
 473                 paddr_next = (paddr & PMD_MASK) + PMD_SIZE;
 474                 if (paddr >= paddr_end) {
 475                         if (!after_bootmem &&
 476                             !e820__mapped_any(paddr & PMD_MASK, paddr_next,
 477                                              E820_TYPE_RAM) &&
 478                             !e820__mapped_any(paddr & PMD_MASK, paddr_next,
 479                                              E820_TYPE_RESERVED_KERN))
 480                                 set_pmd(pmd, __pmd(0));
 481                         continue;
 482                 }
 483
 484                 if (!pmd_none(*pmd)) {
 485                         if (!pmd_large(*pmd)) {
 486                                 spin_lock(&init_mm.page_table_lock);
 487                                 pte = (pte_t *)pmd_page_vaddr(*pmd);
 488                                 paddr_last = phys_pte_init(pte, paddr,
 489                                                            paddr_end, prot);
 490                                 spin_unlock(&init_mm.page_table_lock);
 491                                 continue;
 492                         }
 493                         /*
 494                          * If we are ok with PG_LEVEL_2M mapping, then we will
 495                          * use the existing mapping,
 496                          *
 497                          * Otherwise, we will split the large page mapping but
 498                          * use the same existing protection bits except for
 499                          * large page, so that we don't violate Intel's TLB
 500                          * Application note (317080) which says, while changing
 501                          * the page sizes, new and old translations should
 502                          * not differ with respect to page frame and
 503                          * attributes.
 504                          */
 505                         if (page_size_mask & (1 << PG_LEVEL_2M)) {
 506                                 if (!after_bootmem)
 507                                         pages++;
 508                                 paddr_last = paddr_next;
 509                                 continue;
 510                         }
 511                         new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
 512                 }
 513
 514                 if (page_size_mask & (1<<PG_LEVEL_2M)) {
 515                         pages++;
 516                         spin_lock(&init_mm.page_table_lock);
 517                         set_pte((pte_t *)pmd,
 518                                 pfn_pte((paddr & PMD_MASK) >> PAGE_SHIFT,
 519                                         __pgprot(pgprot_val(prot) | _PAGE_PSE)));
 520                         spin_unlock(&init_mm.page_table_lock);
 521                         paddr_last = paddr_next;
 522                         continue;
 523                 }
 524
 525                 pte = alloc_low_page();
 526                 paddr_last = phys_pte_init(pte, paddr, paddr_end, new_prot);
 527
 528                 spin_lock(&init_mm.page_table_lock);
 529                 pmd_populate_kernel(&init_mm, pmd, pte);
 530                 spin_unlock(&init_mm.page_table_lock);
 531         }
 532         update_page_count(PG_LEVEL_2M, pages);
 533         return paddr_last;
 534 }
 535
 536 /*
 537  * Create PUD level page table mapping for physical addresses. The virtual
 538  * and physical address do not have to be aligned at this level. KASLR can
 539  * randomize virtual addresses up to this level.
 540  * It returns the last physical address mapped.
 541  */
 542 static unsigned long __meminit
 543 phys_pud_init(pud_t *pud_page, unsigned long paddr, unsigned long paddr_end,
 544               unsigned long page_size_mask)
 545 {
 546         unsigned long pages = 0, paddr_next;
 547         unsigned long paddr_last = paddr_end;
 548         unsigned long vaddr = (unsigned long)__va(paddr);
 549         int i = pud_index(vaddr);
 550
 551         for (; i < PTRS_PER_PUD; i++, paddr = paddr_next) {
 552                 pud_t *pud;
 553                 pmd_t *pmd;
 554                 pgprot_t prot = PAGE_KERNEL;
 555
 556                 vaddr = (unsigned long)__va(paddr);
 557                 pud = pud_page + pud_index(vaddr);
 558                 paddr_next = (paddr & PUD_MASK) + PUD_SIZE;
 559
 560                 if (paddr >= paddr_end) {
 561                         if (!after_bootmem &&
 562                             !e820__mapped_any(paddr & PUD_MASK, paddr_next,
 563                                              E820_TYPE_RAM) &&
 564                             !e820__mapped_any(paddr & PUD_MASK, paddr_next,
 565                                              E820_TYPE_RESERVED_KERN))
 566                                 set_pud(pud, __pud(0));
 567                         continue;
 568                 }
 569
 570                 if (!pud_none(*pud)) {
 571                         if (!pud_large(*pud)) {
 572                                 pmd = pmd_offset(pud, 0);
 573                                 paddr_last = phys_pmd_init(pmd, paddr,
 574                                                            paddr_end,
 575                                                            page_size_mask,
 576                                                            prot);
 577                                 __flush_tlb_all();
 578                                 continue;
 579                         }
 580                         /*
 581                          * If we are ok with PG_LEVEL_1G mapping, then we will
 582                          * use the existing mapping.
 583                          *
 584                          * Otherwise, we will split the gbpage mapping but use
 585                          * the same existing protection  bits except for large
 586                          * page, so that we don't violate Intel's TLB
 587                          * Application note (317080) which says, while changing
 588                          * the page sizes, new and old translations should
 589                          * not differ with respect to page frame and
 590                          * attributes.
 591                          */
 592                         if (page_size_mask & (1 << PG_LEVEL_1G)) {
 593                                 if (!after_bootmem)
 594                                         pages++;
 595                                 paddr_last = paddr_next;
 596                                 continue;
 597                         }
 598                         prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
 599                 }
 600
 601                 if (page_size_mask & (1<<PG_LEVEL_1G)) {
 602                         pages++;
 603                         spin_lock(&init_mm.page_table_lock);
 604                         set_pte((pte_t *)pud,
 605                                 pfn_pte((paddr & PUD_MASK) >> PAGE_SHIFT,
 606                                         PAGE_KERNEL_LARGE));
 607                         spin_unlock(&init_mm.page_table_lock);
 608                         paddr_last = paddr_next;
 609                         continue;
 610                 }
 611
 612                 pmd = alloc_low_page();
 613                 paddr_last = phys_pmd_init(pmd, paddr, paddr_end,
 614                                            page_size_mask, prot);
 615
 616                 spin_lock(&init_mm.page_table_lock);
 617                 pud_populate(&init_mm, pud, pmd);
 618                 spin_unlock(&init_mm.page_table_lock);
 619         }
 620         __flush_tlb_all();
 621
 622         update_page_count(PG_LEVEL_1G, pages);
 623
 624         return paddr_last;
 625 }
 626
 627 static unsigned long __meminit
 628 phys_p4d_init(p4d_t *p4d_page, unsigned long paddr, unsigned long paddr_end,
 629               unsigned long page_size_mask)
 630 {
 631         unsigned long paddr_next, paddr_last = paddr_end;
 632         unsigned long vaddr = (unsigned long)__va(paddr);
 633         int i = p4d_index(vaddr);
 634
 635         if (!IS_ENABLED(CONFIG_X86_5LEVEL))
 636                 return phys_pud_init((pud_t *) p4d_page, paddr, paddr_end, page_size_mask);
 637
 638         for (; i < PTRS_PER_P4D; i++, paddr = paddr_next) {
 639                 p4d_t *p4d;
 640                 pud_t *pud;
 641
 642                 vaddr = (unsigned long)__va(paddr);
 643                 p4d = p4d_page + p4d_index(vaddr);
 644                 paddr_next = (paddr & P4D_MASK) + P4D_SIZE;
 645
 646                 if (paddr >= paddr_end) {
 647                         if (!after_bootmem &&
 648                             !e820__mapped_any(paddr & P4D_MASK, paddr_next,
 649                                              E820_TYPE_RAM) &&
 650                             !e820__mapped_any(paddr & P4D_MASK, paddr_next,
 651                                              E820_TYPE_RESERVED_KERN))
 652                                 set_p4d(p4d, __p4d(0));
 653                         continue;
 654                 }
 655
 656                 if (!p4d_none(*p4d)) {
 657                         pud = pud_offset(p4d, 0);
 658                         paddr_last = phys_pud_init(pud, paddr,
 659                                         paddr_end,
 660                                         page_size_mask);
 661                         __flush_tlb_all();
 662                         continue;
 663                 }
 664
 665                 pud = alloc_low_page();
 666                 paddr_last = phys_pud_init(pud, paddr, paddr_end,
 667                                            page_size_mask);
 668
 669                 spin_lock(&init_mm.page_table_lock);
 670                 p4d_populate(&init_mm, p4d, pud);
 671                 spin_unlock(&init_mm.page_table_lock);
 672         }
 673         __flush_tlb_all();
 674
 675         return paddr_last;
 676 }
 677
 678 /*
 679  * Create page table mapping for the physical memory for specific physical
 680  * addresses. The virtual and physical addresses have to be aligned on PMD level
 681  * down. It returns the last physical address mapped.
 682  */
 683 unsigned long __meminit
 684 kernel_physical_mapping_init(unsigned long paddr_start,
 685                              unsigned long paddr_end,
 686                              unsigned long page_size_mask)
 687 {
 688         bool pgd_changed = false;
 689         unsigned long vaddr, vaddr_start, vaddr_end, vaddr_next, paddr_last;
 690
 691         paddr_last = paddr_end;
 692         vaddr = (unsigned long)__va(paddr_start);
 693         vaddr_end = (unsigned long)__va(paddr_end);
 694         vaddr_start = vaddr;
 695
 696         for (; vaddr < vaddr_end; vaddr = vaddr_next) {
 697                 pgd_t *pgd = pgd_offset_k(vaddr);
 698                 p4d_t *p4d;
 699
 700                 vaddr_next = (vaddr & PGDIR_MASK) + PGDIR_SIZE;
 701
 702                 if (pgd_val(*pgd)) {
 703                         p4d = (p4d_t *)pgd_page_vaddr(*pgd);
 704                         paddr_last = phys_p4d_init(p4d, __pa(vaddr),
 705                                                    __pa(vaddr_end),
 706                                                    page_size_mask);
 707                         continue;
 708                 }
 709
 710                 p4d = alloc_low_page();
 711                 paddr_last = phys_p4d_init(p4d, __pa(vaddr), __pa(vaddr_end),
 712                                            page_size_mask);
 713
 714                 spin_lock(&init_mm.page_table_lock);
 715                 if (IS_ENABLED(CONFIG_X86_5LEVEL))
 716                         pgd_populate(&init_mm, pgd, p4d);
 717                 else
 718                         p4d_populate(&init_mm, p4d_offset(pgd, vaddr), (pud_t *) p4d);
 719                 spin_unlock(&init_mm.page_table_lock);
 720                 pgd_changed = true;
 721         }
 722
 723         if (pgd_changed)
 724                 sync_global_pgds(vaddr_start, vaddr_end - 1);
 725
 726         __flush_tlb_all();
 727
 728         return paddr_last;
 729 }
 730
 731 #ifndef CONFIG_NUMA
 732 void __init initmem_init(void)
 733 {
 734         memblock_set_node(0, (phys_addr_t)ULLONG_MAX, &memblock.memory, 0);
 735 }
 736 #endif
 737
 738 void __init paging_init(void)
 739 {
 740         sparse_memory_present_with_active_regions(MAX_NUMNODES);
 741         sparse_init();
 742
 743         /*
 744          * clear the default setting with node 0
 745          * note: don't use nodes_clear here, that is really clearing when
 746          *       numa support is not compiled in, and later node_set_state
 747          *       will not set it back.
 748          */
 749         node_clear_state(0, N_MEMORY);
 750         if (N_MEMORY != N_NORMAL_MEMORY)
 751                 node_clear_state(0, N_NORMAL_MEMORY);
 752
 753         zone_sizes_init();
 754 }
 755
 756 /*
 757  * Memory hotplug specific functions
 758  */
 759 #ifdef CONFIG_MEMORY_HOTPLUG
 760 /*
 761  * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
 762  * updating.
 763  */
 764 static void update_end_of_memory_vars(u64 start, u64 size)
 765 {
 766         unsigned long end_pfn = PFN_UP(start + size);
 767
 768         if (end_pfn > max_pfn) {
 769                 max_pfn = end_pfn;
 770                 max_low_pfn = end_pfn;
 771                 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
 772         }
 773 }
 774
 775 int add_pages(int nid, unsigned long start_pfn,
 776               unsigned long nr_pages, bool want_memblock)
 777 {
 778         int ret;
 779
 780         ret = __add_pages(nid, start_pfn, nr_pages, want_memblock);
 781         WARN_ON_ONCE(ret);
 782
 783         /* update max_pfn, max_low_pfn and high_memory */
 784         update_end_of_memory_vars(start_pfn << PAGE_SHIFT,
 785                                   nr_pages << PAGE_SHIFT);
 786
 787         return ret;
 788 }
 789
 790 int arch_add_memory(int nid, u64 start, u64 size, bool want_memblock)
 791 {
 792         unsigned long start_pfn = start >> PAGE_SHIFT;
 793         unsigned long nr_pages = size >> PAGE_SHIFT;
 794
 795         init_memory_mapping(start, start + size);
 796
 797         return add_pages(nid, start_pfn, nr_pages, want_memblock);
 798 }
 799 EXPORT_SYMBOL_GPL(arch_add_memory);
 800
 801 #define PAGE_INUSE 0xFD
 802
 803 static void __meminit free_pagetable(struct page *page, int order)
 804 {
 805         unsigned long magic;
 806         unsigned int nr_pages = 1 << order;
 807         struct vmem_altmap *altmap = to_vmem_altmap((unsigned long) page);
 808
 809         if (altmap) {
 810                 vmem_altmap_free(altmap, nr_pages);
 811                 return;
 812         }
 813
 814         /* bootmem page has reserved flag */
 815         if (PageReserved(page)) {
 816                 __ClearPageReserved(page);
 817
 818                 magic = (unsigned long)page->freelist;
 819                 if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
 820                         while (nr_pages--)
 821                                 put_page_bootmem(page++);
 822                 } else
 823                         while (nr_pages--)
 824                                 free_reserved_page(page++);
 825         } else
 826                 free_pages((unsigned long)page_address(page), order);
 827 }
 828
 829 static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
 830 {
 831         pte_t *pte;
 832         int i;
 833
 834         for (i = 0; i < PTRS_PER_PTE; i++) {
 835                 pte = pte_start + i;
 836                 if (!pte_none(*pte))
 837                         return;
 838         }
 839
 840         /* free a pte talbe */
 841         free_pagetable(pmd_page(*pmd), 0);
 842         spin_lock(&init_mm.page_table_lock);
 843         pmd_clear(pmd);
 844         spin_unlock(&init_mm.page_table_lock);
 845 }
 846
 847 static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud)
 848 {
 849         pmd_t *pmd;
 850         int i;
 851
 852         for (i = 0; i < PTRS_PER_PMD; i++) {
 853                 pmd = pmd_start + i;
 854                 if (!pmd_none(*pmd))
 855                         return;
 856         }
 857
 858         /* free a pmd talbe */
 859         free_pagetable(pud_page(*pud), 0);
 860         spin_lock(&init_mm.page_table_lock);
 861         pud_clear(pud);
 862         spin_unlock(&init_mm.page_table_lock);
 863 }
 864
 865 static void __meminit free_pud_table(pud_t *pud_start, p4d_t *p4d)
 866 {
 867         pud_t *pud;
 868         int i;
 869
 870         for (i = 0; i < PTRS_PER_PUD; i++) {
 871                 pud = pud_start + i;
 872                 if (!pud_none(*pud))
 873                         return;
 874         }
 875
 876         /* free a pud talbe */
 877         free_pagetable(p4d_page(*p4d), 0);
 878         spin_lock(&init_mm.page_table_lock);
 879         p4d_clear(p4d);
 880         spin_unlock(&init_mm.page_table_lock);
 881 }
 882
 883 static void __meminit
 884 remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
 885                  bool direct)
 886 {
 887         unsigned long next, pages = 0;
 888         pte_t *pte;
 889         void *page_addr;
 890         phys_addr_t phys_addr;
 891
 892         pte = pte_start + pte_index(addr);
 893         for (; addr < end; addr = next, pte++) {
 894                 next = (addr + PAGE_SIZE) & PAGE_MASK;
 895                 if (next > end)
 896                         next = end;
 897
 898                 if (!pte_present(*pte))
 899                         continue;
 900
 901                 /*
 902                  * We mapped [0,1G) memory as identity mapping when
 903                  * initializing, in arch/x86/kernel/head_64.S. These
 904                  * pagetables cannot be removed.
 905                  */
 906                 phys_addr = pte_val(*pte) + (addr & PAGE_MASK);
 907                 if (phys_addr < (phys_addr_t)0x40000000)
 908                         return;
 909
 910                 if (PAGE_ALIGNED(addr) && PAGE_ALIGNED(next)) {
 911                         /*
 912                          * Do not free direct mapping pages since they were
 913                          * freed when offlining, or simplely not in use.
 914                          */
 915                         if (!direct)
 916                                 free_pagetable(pte_page(*pte), 0);
 917
 918                         spin_lock(&init_mm.page_table_lock);
 919                         pte_clear(&init_mm, addr, pte);
 920                         spin_unlock(&init_mm.page_table_lock);
 921
 922                         /* For non-direct mapping, pages means nothing. */
 923                         pages++;
 924                 } else {
 925                         /*
 926                          * If we are here, we are freeing vmemmap pages since
 927                          * direct mapped memory ranges to be freed are aligned.
 928                          *
 929                          * If we are not removing the whole page, it means
 930                          * other page structs in this page are being used and
 931                          * we canot remove them. So fill the unused page_structs
 932                          * with 0xFD, and remove the page when it is wholly
 933                          * filled with 0xFD.
 934                          */
 935                         memset((void *)addr, PAGE_INUSE, next - addr);
 936
 937                         page_addr = page_address(pte_page(*pte));
 938                         if (!memchr_inv(page_addr, PAGE_INUSE, PAGE_SIZE)) {
 939                                 free_pagetable(pte_page(*pte), 0);
 940
 941                                 spin_lock(&init_mm.page_table_lock);
 942                                 pte_clear(&init_mm, addr, pte);
 943                                 spin_unlock(&init_mm.page_table_lock);
 944                         }
 945                 }
 946         }
 947
 948         /* Call free_pte_table() in remove_pmd_table(). */
 949         flush_tlb_all();
 950         if (direct)
 951                 update_page_count(PG_LEVEL_4K, -pages);
 952 }
 953
 954 static void __meminit
 955 remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
 956                  bool direct)
 957 {
 958         unsigned long next, pages = 0;
 959         pte_t *pte_base;
 960         pmd_t *pmd;
 961         void *page_addr;
 962
 963         pmd = pmd_start + pmd_index(addr);
 964         for (; addr < end; addr = next, pmd++) {
 965                 next = pmd_addr_end(addr, end);
 966
 967                 if (!pmd_present(*pmd))
 968                         continue;
 969
 970                 if (pmd_large(*pmd)) {
 971                         if (IS_ALIGNED(addr, PMD_SIZE) &&
 972                             IS_ALIGNED(next, PMD_SIZE)) {
 973                                 if (!direct)
 974                                         free_pagetable(pmd_page(*pmd),
 975                                                        get_order(PMD_SIZE));
 976
 977                                 spin_lock(&init_mm.page_table_lock);
 978                                 pmd_clear(pmd);
 979                                 spin_unlock(&init_mm.page_table_lock);
 980                                 pages++;
 981                         } else {
 982                                 /* If here, we are freeing vmemmap pages. */
 983                                 memset((void *)addr, PAGE_INUSE, next - addr);
 984
 985                                 page_addr = page_address(pmd_page(*pmd));
 986                                 if (!memchr_inv(page_addr, PAGE_INUSE,
 987                                                 PMD_SIZE)) {
 988                                         free_pagetable(pmd_page(*pmd),
 989                                                        get_order(PMD_SIZE));
 990
 991                                         spin_lock(&init_mm.page_table_lock);
 992                                         pmd_clear(pmd);
 993                                         spin_unlock(&init_mm.page_table_lock);
 994                                 }
 995                         }
 996
 997                         continue;
 998                 }
 999
1000                 pte_base = (pte_t *)pmd_page_vaddr(*pmd);
1001                 remove_pte_table(pte_base, addr, next, direct);
1002                 free_pte_table(pte_base, pmd);
1003         }
1004
1005         /* Call free_pmd_table() in remove_pud_table(). */
1006         if (direct)
1007                 update_page_count(PG_LEVEL_2M, -pages);
1008 }
1009
1010 static void __meminit
1011 remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
1012                  bool direct)
1013 {
1014         unsigned long next, pages = 0;
1015         pmd_t *pmd_base;
1016         pud_t *pud;
1017         void *page_addr;
1018
1019         pud = pud_start + pud_index(addr);
1020         for (; addr < end; addr = next, pud++) {
1021                 next = pud_addr_end(addr, end);
1022
1023                 if (!pud_present(*pud))
1024                         continue;
1025
1026                 if (pud_large(*pud)) {
1027                         if (IS_ALIGNED(addr, PUD_SIZE) &&
1028                             IS_ALIGNED(next, PUD_SIZE)) {
1029                                 if (!direct)
1030                                         free_pagetable(pud_page(*pud),
1031                                                        get_order(PUD_SIZE));
1032
1033                                 spin_lock(&init_mm.page_table_lock);
1034                                 pud_clear(pud);
1035                                 spin_unlock(&init_mm.page_table_lock);
1036                                 pages++;
1037                         } else {
1038                                 /* If here, we are freeing vmemmap pages. */
1039                                 memset((void *)addr, PAGE_INUSE, next - addr);
1040
1041                                 page_addr = page_address(pud_page(*pud));
1042                                 if (!memchr_inv(page_addr, PAGE_INUSE,
1043                                                 PUD_SIZE)) {
1044                                         free_pagetable(pud_page(*pud),
1045                                                        get_order(PUD_SIZE));
1046
1047                                         spin_lock(&init_mm.page_table_lock);
1048                                         pud_clear(pud);
1049                                         spin_unlock(&init_mm.page_table_lock);
1050                                 }
1051                         }
1052
1053                         continue;
1054                 }
1055
1056                 pmd_base = pmd_offset(pud, 0);
1057                 remove_pmd_table(pmd_base, addr, next, direct);
1058                 free_pmd_table(pmd_base, pud);
1059         }
1060
1061         if (direct)
1062                 update_page_count(PG_LEVEL_1G, -pages);
1063 }
1064
1065 static void __meminit
1066 remove_p4d_table(p4d_t *p4d_start, unsigned long addr, unsigned long end,
1067                  bool direct)
1068 {
1069         unsigned long next, pages = 0;
1070         pud_t *pud_base;
1071         p4d_t *p4d;
1072
1073         p4d = p4d_start + p4d_index(addr);
1074         for (; addr < end; addr = next, p4d++) {
1075                 next = p4d_addr_end(addr, end);
1076
1077                 if (!p4d_present(*p4d))
1078                         continue;
1079
1080                 BUILD_BUG_ON(p4d_large(*p4d));
1081
1082                 pud_base = pud_offset(p4d, 0);
1083                 remove_pud_table(pud_base, addr, next, direct);
1084                 /*
1085                  * For 4-level page tables we do not want to free PUDs, but in the
1086                  * 5-level case we should free them. This code will have to change
1087                  * to adapt for boot-time switching between 4 and 5 level page tables.
1088                  */
1089                 if (CONFIG_PGTABLE_LEVELS == 5)
1090                         free_pud_table(pud_base, p4d);
1091         }
1092
1093         if (direct)
1094                 update_page_count(PG_LEVEL_512G, -pages);
1095 }
1096
1097 /* start and end are both virtual address. */
1098 static void __meminit
1099 remove_pagetable(unsigned long start, unsigned long end, bool direct)
1100 {
1101         unsigned long next;
1102         unsigned long addr;
1103         pgd_t *pgd;
1104         p4d_t *p4d;
1105
1106         for (addr = start; addr < end; addr = next) {
1107                 next = pgd_addr_end(addr, end);
1108
1109                 pgd = pgd_offset_k(addr);
1110                 if (!pgd_present(*pgd))
1111                         continue;
1112
1113                 p4d = p4d_offset(pgd, 0);
1114                 remove_p4d_table(p4d, addr, next, direct);
1115         }
1116
1117         flush_tlb_all();
1118 }
1119
1120 void __ref vmemmap_free(unsigned long start, unsigned long end)
1121 {
1122         remove_pagetable(start, end, false);
1123 }
1124
1125 #ifdef CONFIG_MEMORY_HOTREMOVE
1126 static void __meminit
1127 kernel_physical_mapping_remove(unsigned long start, unsigned long end)
1128 {
1129         start = (unsigned long)__va(start);
1130         end = (unsigned long)__va(end);
1131
1132         remove_pagetable(start, end, true);
1133 }
1134
1135 int __ref arch_remove_memory(u64 start, u64 size)
1136 {
1137         unsigned long start_pfn = start >> PAGE_SHIFT;
1138         unsigned long nr_pages = size >> PAGE_SHIFT;
1139         struct page *page = pfn_to_page(start_pfn);
1140         struct vmem_altmap *altmap;
1141         struct zone *zone;
1142         int ret;
1143
1144         /* With altmap the first mapped page is offset from @start */
1145         altmap = to_vmem_altmap((unsigned long) page);
1146         if (altmap)
1147                 page += vmem_altmap_offset(altmap);
1148         zone = page_zone(page);
1149         ret = __remove_pages(zone, start_pfn, nr_pages);
1150         WARN_ON_ONCE(ret);
1151         kernel_physical_mapping_remove(start, start + size);
1152
1153         return ret;
1154 }
1155 #endif
1156 #endif /* CONFIG_MEMORY_HOTPLUG */
1157
1158 static struct kcore_list kcore_vsyscall;
1159
1160 static void __init register_page_bootmem_info(void)
1161 {
1162 #ifdef CONFIG_NUMA
1163         int i;
1164
1165         for_each_online_node(i)
1166                 register_page_bootmem_info_node(NODE_DATA(i));
1167 #endif
1168 }
1169
1170 void __init mem_init(void)
1171 {
1172         pci_iommu_alloc();
1173
1174         /* clear_bss() already clear the empty_zero_page */
1175
1176         /* this will put all memory onto the freelists */
1177         free_all_bootmem();
1178         after_bootmem = 1;
1179
1180         /*
1181          * Must be done after boot memory is put on freelist, because here we
1182          * might set fields in deferred struct pages that have not yet been
1183          * initialized, and free_all_bootmem() initializes all the reserved
1184          * deferred pages for us.
1185          */
1186         register_page_bootmem_info();
1187
1188         /* Register memory areas for /proc/kcore */
1189         kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR,
1190                          PAGE_SIZE, KCORE_OTHER);
1191
1192         mem_init_print_info(NULL);
1193 }
1194
1195 int kernel_set_to_readonly;
1196
1197 void set_kernel_text_rw(void)
1198 {
1199         unsigned long start = PFN_ALIGN(_text);
1200         unsigned long end = PFN_ALIGN(__stop___ex_table);
1201
1202         if (!kernel_set_to_readonly)
1203                 return;
1204
1205         pr_debug("Set kernel text: %lx - %lx for read write\n",
1206                  start, end);
1207
1208         /*
1209          * Make the kernel identity mapping for text RW. Kernel text
1210          * mapping will always be RO. Refer to the comment in
1211          * static_protections() in pageattr.c
1212          */
1213         set_memory_rw(start, (end - start) >> PAGE_SHIFT);
1214 }
1215
1216 void set_kernel_text_ro(void)
1217 {
1218         unsigned long start = PFN_ALIGN(_text);
1219         unsigned long end = PFN_ALIGN(__stop___ex_table);
1220
1221         if (!kernel_set_to_readonly)
1222                 return;
1223
1224         pr_debug("Set kernel text: %lx - %lx for read only\n",
1225                  start, end);
1226
1227         /*
1228          * Set the kernel identity mapping for text RO.
1229          */
1230         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1231 }
1232
1233 void mark_rodata_ro(void)
1234 {
1235         unsigned long start = PFN_ALIGN(_text);
1236         unsigned long rodata_start = PFN_ALIGN(__start_rodata);
1237         unsigned long end = (unsigned long) &__end_rodata_hpage_align;
1238         unsigned long text_end = PFN_ALIGN(&__stop___ex_table);
1239         unsigned long rodata_end = PFN_ALIGN(&__end_rodata);
1240         unsigned long all_end;
1241
1242         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
1243                (end - start) >> 10);
1244         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1245
1246         kernel_set_to_readonly = 1;
1247
1248         /*
1249          * The rodata/data/bss/brk section (but not the kernel text!)
1250          * should also be not-executable.
1251          *
1252          * We align all_end to PMD_SIZE because the existing mapping
1253          * is a full PMD. If we would align _brk_end to PAGE_SIZE we
1254          * split the PMD and the reminder between _brk_end and the end
1255          * of the PMD will remain mapped executable.
1256          *
1257          * Any PMD which was setup after the one which covers _brk_end
1258          * has been zapped already via cleanup_highmem().
1259          */
1260         all_end = roundup((unsigned long)_brk_end, PMD_SIZE);
1261         set_memory_nx(text_end, (all_end - text_end) >> PAGE_SHIFT);
1262
1263 #ifdef CONFIG_CPA_DEBUG
1264         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
1265         set_memory_rw(start, (end-start) >> PAGE_SHIFT);
1266
1267         printk(KERN_INFO "Testing CPA: again\n");
1268         set_memory_ro(start, (end-start) >> PAGE_SHIFT);
1269 #endif
1270
1271         free_init_pages("unused kernel",
1272                         (unsigned long) __va(__pa_symbol(text_end)),
1273                         (unsigned long) __va(__pa_symbol(rodata_start)));
1274         free_init_pages("unused kernel",
1275                         (unsigned long) __va(__pa_symbol(rodata_end)),
1276                         (unsigned long) __va(__pa_symbol(_sdata)));
1277
1278         debug_checkwx();
1279 }
1280
1281 int kern_addr_valid(unsigned long addr)
1282 {
1283         unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
1284         pgd_t *pgd;
1285         p4d_t *p4d;
1286         pud_t *pud;
1287         pmd_t *pmd;
1288         pte_t *pte;
1289
1290         if (above != 0 && above != -1UL)
1291                 return 0;
1292
1293         pgd = pgd_offset_k(addr);
1294         if (pgd_none(*pgd))
1295                 return 0;
1296
1297         p4d = p4d_offset(pgd, addr);
1298         if (p4d_none(*p4d))
1299                 return 0;
1300
1301         pud = pud_offset(p4d, addr);
1302         if (pud_none(*pud))
1303                 return 0;
1304
1305         if (pud_large(*pud))
1306                 return pfn_valid(pud_pfn(*pud));
1307
1308         pmd = pmd_offset(pud, addr);
1309         if (pmd_none(*pmd))
1310                 return 0;
1311
1312         if (pmd_large(*pmd))
1313                 return pfn_valid(pmd_pfn(*pmd));
1314
1315         pte = pte_offset_kernel(pmd, addr);
1316         if (pte_none(*pte))
1317                 return 0;
1318
1319         return pfn_valid(pte_pfn(*pte));
1320 }
1321
1322 static unsigned long probe_memory_block_size(void)
1323 {
1324         unsigned long bz = MIN_MEMORY_BLOCK_SIZE;
1325
1326         /* if system is UV or has 64GB of RAM or more, use large blocks */
1327         if (is_uv_system() || ((max_pfn << PAGE_SHIFT) >= (64UL << 30)))
1328                 bz = 2UL << 30; /* 2GB */
1329
1330         pr_info("x86/mm: Memory block size: %ldMB\n", bz >> 20);
1331
1332         return bz;
1333 }
1334
1335 static unsigned long memory_block_size_probed;
1336 unsigned long memory_block_size_bytes(void)
1337 {
1338         if (!memory_block_size_probed)
1339                 memory_block_size_probed = probe_memory_block_size();
1340
1341         return memory_block_size_probed;
1342 }
1343
1344 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1345 /*
1346  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1347  */
1348 static long __meminitdata addr_start, addr_end;
1349 static void __meminitdata *p_start, *p_end;
1350 static int __meminitdata node_start;
1351
1352 static int __meminit vmemmap_populate_hugepages(unsigned long start,
1353                 unsigned long end, int node, struct vmem_altmap *altmap)
1354 {
1355         unsigned long addr;
1356         unsigned long next;
1357         pgd_t *pgd;
1358         p4d_t *p4d;
1359         pud_t *pud;
1360         pmd_t *pmd;
1361
1362         for (addr = start; addr < end; addr = next) {
1363                 next = pmd_addr_end(addr, end);
1364
1365                 pgd = vmemmap_pgd_populate(addr, node);
1366                 if (!pgd)
1367                         return -ENOMEM;
1368
1369                 p4d = vmemmap_p4d_populate(pgd, addr, node);
1370                 if (!p4d)
1371                         return -ENOMEM;
1372
1373                 pud = vmemmap_pud_populate(p4d, addr, node);
1374                 if (!pud)
1375                         return -ENOMEM;
1376
1377                 pmd = pmd_offset(pud, addr);
1378                 if (pmd_none(*pmd)) {
1379                         void *p;
1380
1381                         p = __vmemmap_alloc_block_buf(PMD_SIZE, node, altmap);
1382                         if (p) {
1383                                 pte_t entry;
1384
1385                                 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1386                                                 PAGE_KERNEL_LARGE);
1387                                 set_pmd(pmd, __pmd(pte_val(entry)));
1388
1389                                 /* check to see if we have contiguous blocks */
1390                                 if (p_end != p || node_start != node) {
1391                                         if (p_start)
1392                                                 pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1393                                                        addr_start, addr_end-1, p_start, p_end-1, node_start);
1394                                         addr_start = addr;
1395                                         node_start = node;
1396                                         p_start = p;
1397                                 }
1398
1399                                 addr_end = addr + PMD_SIZE;
1400                                 p_end = p + PMD_SIZE;
1401                                 continue;
1402                         } else if (altmap)
1403                                 return -ENOMEM; /* no fallback */
1404                 } else if (pmd_large(*pmd)) {
1405                         vmemmap_verify((pte_t *)pmd, node, addr, next);
1406                         continue;
1407                 }
1408                 if (vmemmap_populate_basepages(addr, next, node))
1409                         return -ENOMEM;
1410         }
1411         return 0;
1412 }
1413
1414 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
1415 {
1416         struct vmem_altmap *altmap = to_vmem_altmap(start);
1417         int err;
1418
1419         if (boot_cpu_has(X86_FEATURE_PSE))
1420                 err = vmemmap_populate_hugepages(start, end, node, altmap);
1421         else if (altmap) {
1422                 pr_err_once("%s: no cpu support for altmap allocations\n",
1423                                 __func__);
1424                 err = -ENOMEM;
1425         } else
1426                 err = vmemmap_populate_basepages(start, end, node);
1427         if (!err)
1428                 sync_global_pgds(start, end - 1);
1429         return err;
1430 }
1431
1432 #if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HAVE_BOOTMEM_INFO_NODE)
1433 void register_page_bootmem_memmap(unsigned long section_nr,
1434                                   struct page *start_page, unsigned long nr_pages)
1435 {
1436         unsigned long addr = (unsigned long)start_page;
1437         unsigned long end = (unsigned long)(start_page + nr_pages);
1438         unsigned long next;
1439         pgd_t *pgd;
1440         p4d_t *p4d;
1441         pud_t *pud;
1442         pmd_t *pmd;
1443         unsigned int nr_pmd_pages;
1444         struct page *page;
1445
1446         for (; addr < end; addr = next) {
1447                 pte_t *pte = NULL;
1448
1449                 pgd = pgd_offset_k(addr);
1450                 if (pgd_none(*pgd)) {
1451                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1452                         continue;
1453                 }
1454                 get_page_bootmem(section_nr, pgd_page(*pgd), MIX_SECTION_INFO);
1455
1456                 p4d = p4d_offset(pgd, addr);
1457                 if (p4d_none(*p4d)) {
1458                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1459                         continue;
1460                 }
1461                 get_page_bootmem(section_nr, p4d_page(*p4d), MIX_SECTION_INFO);
1462
1463                 pud = pud_offset(p4d, addr);
1464                 if (pud_none(*pud)) {
1465                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1466                         continue;
1467                 }
1468                 get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO);
1469
1470                 if (!boot_cpu_has(X86_FEATURE_PSE)) {
1471                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1472                         pmd = pmd_offset(pud, addr);
1473                         if (pmd_none(*pmd))
1474                                 continue;
1475                         get_page_bootmem(section_nr, pmd_page(*pmd),
1476                                          MIX_SECTION_INFO);
1477
1478                         pte = pte_offset_kernel(pmd, addr);
1479                         if (pte_none(*pte))
1480                                 continue;
1481                         get_page_bootmem(section_nr, pte_page(*pte),
1482                                          SECTION_INFO);
1483                 } else {
1484                         next = pmd_addr_end(addr, end);
1485
1486                         pmd = pmd_offset(pud, addr);
1487                         if (pmd_none(*pmd))
1488                                 continue;
1489
1490                         nr_pmd_pages = 1 << get_order(PMD_SIZE);
1491                         page = pmd_page(*pmd);
1492                         while (nr_pmd_pages--)
1493                                 get_page_bootmem(section_nr, page++,
1494                                                  SECTION_INFO);
1495                 }
1496         }
1497 }
1498 #endif
1499
1500 void __meminit vmemmap_populate_print_last(void)
1501 {
1502         if (p_start) {
1503                 pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1504                         addr_start, addr_end-1, p_start, p_end-1, node_start);
1505                 p_start = NULL;
1506                 p_end = NULL;
1507                 node_start = 0;
1508         }
1509 }
1510 #endif