arch/x86/mm/init_64.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  linux/arch/x86_64/mm/init.c
   4  *
   5  *  Copyright (C) 1995  Linus Torvalds
   6  *  Copyright (C) 2000  Pavel Machek <pavel@ucw.cz>
   7  *  Copyright (C) 2002,2003 Andi Kleen <ak@suse.de>
   8  */
   9
  10 #include <linux/signal.h>
  11 #include <linux/sched.h>
  12 #include <linux/kernel.h>
  13 #include <linux/errno.h>
  14 #include <linux/string.h>
  15 #include <linux/types.h>
  16 #include <linux/ptrace.h>
  17 #include <linux/mman.h>
  18 #include <linux/mm.h>
  19 #include <linux/swap.h>
  20 #include <linux/smp.h>
  21 #include <linux/init.h>
  22 #include <linux/initrd.h>
  23 #include <linux/pagemap.h>
  24 #include <linux/memblock.h>
  25 #include <linux/proc_fs.h>
  26 #include <linux/pci.h>
  27 #include <linux/pfn.h>
  28 #include <linux/poison.h>
  29 #include <linux/dma-mapping.h>
  30 #include <linux/memory.h>
  31 #include <linux/memory_hotplug.h>
  32 #include <linux/memremap.h>
  33 #include <linux/nmi.h>
  34 #include <linux/gfp.h>
  35 #include <linux/kcore.h>
  36
  37 #include <asm/processor.h>
  38 #include <asm/bios_ebda.h>
  39 #include <linux/uaccess.h>
  40 #include <asm/pgalloc.h>
  41 #include <asm/dma.h>
  42 #include <asm/fixmap.h>
  43 #include <asm/e820/api.h>
  44 #include <asm/apic.h>
  45 #include <asm/tlb.h>
  46 #include <asm/mmu_context.h>
  47 #include <asm/proto.h>
  48 #include <asm/smp.h>
  49 #include <asm/sections.h>
  50 #include <asm/kdebug.h>
  51 #include <asm/numa.h>
  52 #include <asm/set_memory.h>
  53 #include <asm/init.h>
  54 #include <asm/uv/uv.h>
  55 #include <asm/setup.h>
  56 #include <asm/ftrace.h>
  57
  58 #include "mm_internal.h"
  59
  60 #include "ident_map.c"
  61
  62 #define DEFINE_POPULATE(fname, type1, type2, init)              \
  63 static inline void fname##_init(struct mm_struct *mm,           \
  64                 type1##_t *arg1, type2##_t *arg2, bool init)    \
  65 {                                                               \
  66         if (init)                                               \
  67                 fname##_safe(mm, arg1, arg2);                   \
  68         else                                                    \
  69                 fname(mm, arg1, arg2);                          \
  70 }
  71
  72 DEFINE_POPULATE(p4d_populate, p4d, pud, init)
  73 DEFINE_POPULATE(pgd_populate, pgd, p4d, init)
  74 DEFINE_POPULATE(pud_populate, pud, pmd, init)
  75 DEFINE_POPULATE(pmd_populate_kernel, pmd, pte, init)
  76
  77 #define DEFINE_ENTRY(type1, type2, init)                        \
  78 static inline void set_##type1##_init(type1##_t *arg1,          \
  79                         type2##_t arg2, bool init)              \
  80 {                                                               \
  81         if (init)                                               \
  82                 set_##type1##_safe(arg1, arg2);                 \
  83         else                                                    \
  84                 set_##type1(arg1, arg2);                        \
  85 }
  86
  87 DEFINE_ENTRY(p4d, p4d, init)
  88 DEFINE_ENTRY(pud, pud, init)
  89 DEFINE_ENTRY(pmd, pmd, init)
  90 DEFINE_ENTRY(pte, pte, init)
  91
  92
  93 /*
  94  * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
  95  * physical space so we can cache the place of the first one and move
  96  * around without checking the pgd every time.
  97  */
  98
  99 /* Bits supported by the hardware: */
 100 pteval_t __supported_pte_mask __read_mostly = ~0;
 101 /* Bits allowed in normal kernel mappings: */
 102 pteval_t __default_kernel_pte_mask __read_mostly = ~0;
 103 EXPORT_SYMBOL_GPL(__supported_pte_mask);
 104 /* Used in PAGE_KERNEL_* macros which are reasonably used out-of-tree: */
 105 EXPORT_SYMBOL(__default_kernel_pte_mask);
 106
 107 int force_personality32;
 108
 109 /*
 110  * noexec32=on|off
 111  * Control non executable heap for 32bit processes.
 112  * To control the stack too use noexec=off
 113  *
 114  * on   PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
 115  * off  PROT_READ implies PROT_EXEC
 116  */
 117 static int __init nonx32_setup(char *str)
 118 {
 119         if (!strcmp(str, "on"))
 120                 force_personality32 &= ~READ_IMPLIES_EXEC;
 121         else if (!strcmp(str, "off"))
 122                 force_personality32 |= READ_IMPLIES_EXEC;
 123         return 1;
 124 }
 125 __setup("noexec32=", nonx32_setup);
 126
 127 static void sync_global_pgds_l5(unsigned long start, unsigned long end)
 128 {
 129         unsigned long addr;
 130
 131         for (addr = start; addr <= end; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
 132                 const pgd_t *pgd_ref = pgd_offset_k(addr);
 133                 struct page *page;
 134
 135                 /* Check for overflow */
 136                 if (addr < start)
 137                         break;
 138
 139                 if (pgd_none(*pgd_ref))
 140                         continue;
 141
 142                 spin_lock(&pgd_lock);
 143                 list_for_each_entry(page, &pgd_list, lru) {
 144                         pgd_t *pgd;
 145                         spinlock_t *pgt_lock;
 146
 147                         pgd = (pgd_t *)page_address(page) + pgd_index(addr);
 148                         /* the pgt_lock only for Xen */
 149                         pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
 150                         spin_lock(pgt_lock);
 151
 152                         if (!pgd_none(*pgd_ref) && !pgd_none(*pgd))
 153                                 BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref));
 154
 155                         if (pgd_none(*pgd))
 156                                 set_pgd(pgd, *pgd_ref);
 157
 158                         spin_unlock(pgt_lock);
 159                 }
 160                 spin_unlock(&pgd_lock);
 161         }
 162 }
 163
 164 static void sync_global_pgds_l4(unsigned long start, unsigned long end)
 165 {
 166         unsigned long addr;
 167
 168         for (addr = start; addr <= end; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
 169                 pgd_t *pgd_ref = pgd_offset_k(addr);
 170                 const p4d_t *p4d_ref;
 171                 struct page *page;
 172
 173                 /*
 174                  * With folded p4d, pgd_none() is always false, we need to
 175                  * handle synchronization on p4d level.
 176                  */
 177                 MAYBE_BUILD_BUG_ON(pgd_none(*pgd_ref));
 178                 p4d_ref = p4d_offset(pgd_ref, addr);
 179
 180                 if (p4d_none(*p4d_ref))
 181                         continue;
 182
 183                 spin_lock(&pgd_lock);
 184                 list_for_each_entry(page, &pgd_list, lru) {
 185                         pgd_t *pgd;
 186                         p4d_t *p4d;
 187                         spinlock_t *pgt_lock;
 188
 189                         pgd = (pgd_t *)page_address(page) + pgd_index(addr);
 190                         p4d = p4d_offset(pgd, addr);
 191                         /* the pgt_lock only for Xen */
 192                         pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
 193                         spin_lock(pgt_lock);
 194
 195                         if (!p4d_none(*p4d_ref) && !p4d_none(*p4d))
 196                                 BUG_ON(p4d_page_vaddr(*p4d)
 197                                        != p4d_page_vaddr(*p4d_ref));
 198
 199                         if (p4d_none(*p4d))
 200                                 set_p4d(p4d, *p4d_ref);
 201
 202                         spin_unlock(pgt_lock);
 203                 }
 204                 spin_unlock(&pgd_lock);
 205         }
 206 }
 207
 208 /*
 209  * When memory was added make sure all the processes MM have
 210  * suitable PGD entries in the local PGD level page.
 211  */
 212 static void sync_global_pgds(unsigned long start, unsigned long end)
 213 {
 214         if (pgtable_l5_enabled())
 215                 sync_global_pgds_l5(start, end);
 216         else
 217                 sync_global_pgds_l4(start, end);
 218 }
 219
 220 /*
 221  * NOTE: This function is marked __ref because it calls __init function
 222  * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
 223  */
 224 static __ref void *spp_getpage(void)
 225 {
 226         void *ptr;
 227
 228         if (after_bootmem)
 229                 ptr = (void *) get_zeroed_page(GFP_ATOMIC);
 230         else
 231                 ptr = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
 232
 233         if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
 234                 panic("set_pte_phys: cannot allocate page data %s\n",
 235                         after_bootmem ? "after bootmem" : "");
 236         }
 237
 238         pr_debug("spp_getpage %p\n", ptr);
 239
 240         return ptr;
 241 }
 242
 243 static p4d_t *fill_p4d(pgd_t *pgd, unsigned long vaddr)
 244 {
 245         if (pgd_none(*pgd)) {
 246                 p4d_t *p4d = (p4d_t *)spp_getpage();
 247                 pgd_populate(&init_mm, pgd, p4d);
 248                 if (p4d != p4d_offset(pgd, 0))
 249                         printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n",
 250                                p4d, p4d_offset(pgd, 0));
 251         }
 252         return p4d_offset(pgd, vaddr);
 253 }
 254
 255 static pud_t *fill_pud(p4d_t *p4d, unsigned long vaddr)
 256 {
 257         if (p4d_none(*p4d)) {
 258                 pud_t *pud = (pud_t *)spp_getpage();
 259                 p4d_populate(&init_mm, p4d, pud);
 260                 if (pud != pud_offset(p4d, 0))
 261                         printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
 262                                pud, pud_offset(p4d, 0));
 263         }
 264         return pud_offset(p4d, vaddr);
 265 }
 266
 267 static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr)
 268 {
 269         if (pud_none(*pud)) {
 270                 pmd_t *pmd = (pmd_t *) spp_getpage();
 271                 pud_populate(&init_mm, pud, pmd);
 272                 if (pmd != pmd_offset(pud, 0))
 273                         printk(KERN_ERR "PAGETABLE BUG #02! %p <-> %p\n",
 274                                pmd, pmd_offset(pud, 0));
 275         }
 276         return pmd_offset(pud, vaddr);
 277 }
 278
 279 static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr)
 280 {
 281         if (pmd_none(*pmd)) {
 282                 pte_t *pte = (pte_t *) spp_getpage();
 283                 pmd_populate_kernel(&init_mm, pmd, pte);
 284                 if (pte != pte_offset_kernel(pmd, 0))
 285                         printk(KERN_ERR "PAGETABLE BUG #03!\n");
 286         }
 287         return pte_offset_kernel(pmd, vaddr);
 288 }
 289
 290 static void __set_pte_vaddr(pud_t *pud, unsigned long vaddr, pte_t new_pte)
 291 {
 292         pmd_t *pmd = fill_pmd(pud, vaddr);
 293         pte_t *pte = fill_pte(pmd, vaddr);
 294
 295         set_pte(pte, new_pte);
 296
 297         /*
 298          * It's enough to flush this one mapping.
 299          * (PGE mappings get flushed as well)
 300          */
 301         flush_tlb_one_kernel(vaddr);
 302 }
 303
 304 void set_pte_vaddr_p4d(p4d_t *p4d_page, unsigned long vaddr, pte_t new_pte)
 305 {
 306         p4d_t *p4d = p4d_page + p4d_index(vaddr);
 307         pud_t *pud = fill_pud(p4d, vaddr);
 308
 309         __set_pte_vaddr(pud, vaddr, new_pte);
 310 }
 311
 312 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
 313 {
 314         pud_t *pud = pud_page + pud_index(vaddr);
 315
 316         __set_pte_vaddr(pud, vaddr, new_pte);
 317 }
 318
 319 void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
 320 {
 321         pgd_t *pgd;
 322         p4d_t *p4d_page;
 323
 324         pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
 325
 326         pgd = pgd_offset_k(vaddr);
 327         if (pgd_none(*pgd)) {
 328                 printk(KERN_ERR
 329                         "PGD FIXMAP MISSING, it should be setup in head.S!\n");
 330                 return;
 331         }
 332
 333         p4d_page = p4d_offset(pgd, 0);
 334         set_pte_vaddr_p4d(p4d_page, vaddr, pteval);
 335 }
 336
 337 pmd_t * __init populate_extra_pmd(unsigned long vaddr)
 338 {
 339         pgd_t *pgd;
 340         p4d_t *p4d;
 341         pud_t *pud;
 342
 343         pgd = pgd_offset_k(vaddr);
 344         p4d = fill_p4d(pgd, vaddr);
 345         pud = fill_pud(p4d, vaddr);
 346         return fill_pmd(pud, vaddr);
 347 }
 348
 349 pte_t * __init populate_extra_pte(unsigned long vaddr)
 350 {
 351         pmd_t *pmd;
 352
 353         pmd = populate_extra_pmd(vaddr);
 354         return fill_pte(pmd, vaddr);
 355 }
 356
 357 /*
 358  * Create large page table mappings for a range of physical addresses.
 359  */
 360 static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
 361                                         enum page_cache_mode cache)
 362 {
 363         pgd_t *pgd;
 364         p4d_t *p4d;
 365         pud_t *pud;
 366         pmd_t *pmd;
 367         pgprot_t prot;
 368
 369         pgprot_val(prot) = pgprot_val(PAGE_KERNEL_LARGE) |
 370                 protval_4k_2_large(cachemode2protval(cache));
 371         BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
 372         for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
 373                 pgd = pgd_offset_k((unsigned long)__va(phys));
 374                 if (pgd_none(*pgd)) {
 375                         p4d = (p4d_t *) spp_getpage();
 376                         set_pgd(pgd, __pgd(__pa(p4d) | _KERNPG_TABLE |
 377                                                 _PAGE_USER));
 378                 }
 379                 p4d = p4d_offset(pgd, (unsigned long)__va(phys));
 380                 if (p4d_none(*p4d)) {
 381                         pud = (pud_t *) spp_getpage();
 382                         set_p4d(p4d, __p4d(__pa(pud) | _KERNPG_TABLE |
 383                                                 _PAGE_USER));
 384                 }
 385                 pud = pud_offset(p4d, (unsigned long)__va(phys));
 386                 if (pud_none(*pud)) {
 387                         pmd = (pmd_t *) spp_getpage();
 388                         set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
 389                                                 _PAGE_USER));
 390                 }
 391                 pmd = pmd_offset(pud, phys);
 392                 BUG_ON(!pmd_none(*pmd));
 393                 set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
 394         }
 395 }
 396
 397 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
 398 {
 399         __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_WB);
 400 }
 401
 402 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
 403 {
 404         __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_UC);
 405 }
 406
 407 /*
 408  * The head.S code sets up the kernel high mapping:
 409  *
 410  *   from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
 411  *
 412  * phys_base holds the negative offset to the kernel, which is added
 413  * to the compile time generated pmds. This results in invalid pmds up
 414  * to the point where we hit the physaddr 0 mapping.
 415  *
 416  * We limit the mappings to the region from _text to _brk_end.  _brk_end
 417  * is rounded up to the 2MB boundary. This catches the invalid pmds as
 418  * well, as they are located before _text:
 419  */
 420 void __init cleanup_highmap(void)
 421 {
 422         unsigned long vaddr = __START_KERNEL_map;
 423         unsigned long vaddr_end = __START_KERNEL_map + KERNEL_IMAGE_SIZE;
 424         unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1;
 425         pmd_t *pmd = level2_kernel_pgt;
 426
 427         /*
 428          * Native path, max_pfn_mapped is not set yet.
 429          * Xen has valid max_pfn_mapped set in
 430          *      arch/x86/xen/mmu.c:xen_setup_kernel_pagetable().
 431          */
 432         if (max_pfn_mapped)
 433                 vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT);
 434
 435         for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) {
 436                 if (pmd_none(*pmd))
 437                         continue;
 438                 if (vaddr < (unsigned long) _text || vaddr > end)
 439                         set_pmd(pmd, __pmd(0));
 440         }
 441 }
 442
 443 /*
 444  * Create PTE level page table mapping for physical addresses.
 445  * It returns the last physical address mapped.
 446  */
 447 static unsigned long __meminit
 448 phys_pte_init(pte_t *pte_page, unsigned long paddr, unsigned long paddr_end,
 449               pgprot_t prot, bool init)
 450 {
 451         unsigned long pages = 0, paddr_next;
 452         unsigned long paddr_last = paddr_end;
 453         pte_t *pte;
 454         int i;
 455
 456         pte = pte_page + pte_index(paddr);
 457         i = pte_index(paddr);
 458
 459         for (; i < PTRS_PER_PTE; i++, paddr = paddr_next, pte++) {
 460                 paddr_next = (paddr & PAGE_MASK) + PAGE_SIZE;
 461                 if (paddr >= paddr_end) {
 462                         if (!after_bootmem &&
 463                             !e820__mapped_any(paddr & PAGE_MASK, paddr_next,
 464                                              E820_TYPE_RAM) &&
 465                             !e820__mapped_any(paddr & PAGE_MASK, paddr_next,
 466                                              E820_TYPE_RESERVED_KERN))
 467                                 set_pte_init(pte, __pte(0), init);
 468                         continue;
 469                 }
 470
 471                 /*
 472                  * We will re-use the existing mapping.
 473                  * Xen for example has some special requirements, like mapping
 474                  * pagetable pages as RO. So assume someone who pre-setup
 475                  * these mappings are more intelligent.
 476                  */
 477                 if (!pte_none(*pte)) {
 478                         if (!after_bootmem)
 479                                 pages++;
 480                         continue;
 481                 }
 482
 483                 if (0)
 484                         pr_info("   pte=%p addr=%lx pte=%016lx\n", pte, paddr,
 485                                 pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL).pte);
 486                 pages++;
 487                 set_pte_init(pte, pfn_pte(paddr >> PAGE_SHIFT, prot), init);
 488                 paddr_last = (paddr & PAGE_MASK) + PAGE_SIZE;
 489         }
 490
 491         update_page_count(PG_LEVEL_4K, pages);
 492
 493         return paddr_last;
 494 }
 495
 496 /*
 497  * Create PMD level page table mapping for physical addresses. The virtual
 498  * and physical address have to be aligned at this level.
 499  * It returns the last physical address mapped.
 500  */
 501 static unsigned long __meminit
 502 phys_pmd_init(pmd_t *pmd_page, unsigned long paddr, unsigned long paddr_end,
 503               unsigned long page_size_mask, pgprot_t prot, bool init)
 504 {
 505         unsigned long pages = 0, paddr_next;
 506         unsigned long paddr_last = paddr_end;
 507
 508         int i = pmd_index(paddr);
 509
 510         for (; i < PTRS_PER_PMD; i++, paddr = paddr_next) {
 511                 pmd_t *pmd = pmd_page + pmd_index(paddr);
 512                 pte_t *pte;
 513                 pgprot_t new_prot = prot;
 514
 515                 paddr_next = (paddr & PMD_MASK) + PMD_SIZE;
 516                 if (paddr >= paddr_end) {
 517                         if (!after_bootmem &&
 518                             !e820__mapped_any(paddr & PMD_MASK, paddr_next,
 519                                              E820_TYPE_RAM) &&
 520                             !e820__mapped_any(paddr & PMD_MASK, paddr_next,
 521                                              E820_TYPE_RESERVED_KERN))
 522                                 set_pmd_init(pmd, __pmd(0), init);
 523                         continue;
 524                 }
 525
 526                 if (!pmd_none(*pmd)) {
 527                         if (!pmd_large(*pmd)) {
 528                                 spin_lock(&init_mm.page_table_lock);
 529                                 pte = (pte_t *)pmd_page_vaddr(*pmd);
 530                                 paddr_last = phys_pte_init(pte, paddr,
 531                                                            paddr_end, prot,
 532                                                            init);
 533                                 spin_unlock(&init_mm.page_table_lock);
 534                                 continue;
 535                         }
 536                         /*
 537                          * If we are ok with PG_LEVEL_2M mapping, then we will
 538                          * use the existing mapping,
 539                          *
 540                          * Otherwise, we will split the large page mapping but
 541                          * use the same existing protection bits except for
 542                          * large page, so that we don't violate Intel's TLB
 543                          * Application note (317080) which says, while changing
 544                          * the page sizes, new and old translations should
 545                          * not differ with respect to page frame and
 546                          * attributes.
 547                          */
 548                         if (page_size_mask & (1 << PG_LEVEL_2M)) {
 549                                 if (!after_bootmem)
 550                                         pages++;
 551                                 paddr_last = paddr_next;
 552                                 continue;
 553                         }
 554                         new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
 555                 }
 556
 557                 if (page_size_mask & (1<<PG_LEVEL_2M)) {
 558                         pages++;
 559                         spin_lock(&init_mm.page_table_lock);
 560                         set_pte_init((pte_t *)pmd,
 561                                      pfn_pte((paddr & PMD_MASK) >> PAGE_SHIFT,
 562                                              __pgprot(pgprot_val(prot) | _PAGE_PSE)),
 563                                      init);
 564                         spin_unlock(&init_mm.page_table_lock);
 565                         paddr_last = paddr_next;
 566                         continue;
 567                 }
 568
 569                 pte = alloc_low_page();
 570                 paddr_last = phys_pte_init(pte, paddr, paddr_end, new_prot, init);
 571
 572                 spin_lock(&init_mm.page_table_lock);
 573                 pmd_populate_kernel_init(&init_mm, pmd, pte, init);
 574                 spin_unlock(&init_mm.page_table_lock);
 575         }
 576         update_page_count(PG_LEVEL_2M, pages);
 577         return paddr_last;
 578 }
 579
 580 /*
 581  * Create PUD level page table mapping for physical addresses. The virtual
 582  * and physical address do not have to be aligned at this level. KASLR can
 583  * randomize virtual addresses up to this level.
 584  * It returns the last physical address mapped.
 585  */
 586 static unsigned long __meminit
 587 phys_pud_init(pud_t *pud_page, unsigned long paddr, unsigned long paddr_end,
 588               unsigned long page_size_mask, pgprot_t _prot, bool init)
 589 {
 590         unsigned long pages = 0, paddr_next;
 591         unsigned long paddr_last = paddr_end;
 592         unsigned long vaddr = (unsigned long)__va(paddr);
 593         int i = pud_index(vaddr);
 594
 595         for (; i < PTRS_PER_PUD; i++, paddr = paddr_next) {
 596                 pud_t *pud;
 597                 pmd_t *pmd;
 598                 pgprot_t prot = _prot;
 599
 600                 vaddr = (unsigned long)__va(paddr);
 601                 pud = pud_page + pud_index(vaddr);
 602                 paddr_next = (paddr & PUD_MASK) + PUD_SIZE;
 603
 604                 if (paddr >= paddr_end) {
 605                         if (!after_bootmem &&
 606                             !e820__mapped_any(paddr & PUD_MASK, paddr_next,
 607                                              E820_TYPE_RAM) &&
 608                             !e820__mapped_any(paddr & PUD_MASK, paddr_next,
 609                                              E820_TYPE_RESERVED_KERN))
 610                                 set_pud_init(pud, __pud(0), init);
 611                         continue;
 612                 }
 613
 614                 if (!pud_none(*pud)) {
 615                         if (!pud_large(*pud)) {
 616                                 pmd = pmd_offset(pud, 0);
 617                                 paddr_last = phys_pmd_init(pmd, paddr,
 618                                                            paddr_end,
 619                                                            page_size_mask,
 620                                                            prot, init);
 621                                 continue;
 622                         }
 623                         /*
 624                          * If we are ok with PG_LEVEL_1G mapping, then we will
 625                          * use the existing mapping.
 626                          *
 627                          * Otherwise, we will split the gbpage mapping but use
 628                          * the same existing protection  bits except for large
 629                          * page, so that we don't violate Intel's TLB
 630                          * Application note (317080) which says, while changing
 631                          * the page sizes, new and old translations should
 632                          * not differ with respect to page frame and
 633                          * attributes.
 634                          */
 635                         if (page_size_mask & (1 << PG_LEVEL_1G)) {
 636                                 if (!after_bootmem)
 637                                         pages++;
 638                                 paddr_last = paddr_next;
 639                                 continue;
 640                         }
 641                         prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
 642                 }
 643
 644                 if (page_size_mask & (1<<PG_LEVEL_1G)) {
 645                         pages++;
 646                         spin_lock(&init_mm.page_table_lock);
 647
 648                         prot = __pgprot(pgprot_val(prot) | __PAGE_KERNEL_LARGE);
 649
 650                         set_pte_init((pte_t *)pud,
 651                                      pfn_pte((paddr & PUD_MASK) >> PAGE_SHIFT,
 652                                              prot),
 653                                      init);
 654                         spin_unlock(&init_mm.page_table_lock);
 655                         paddr_last = paddr_next;
 656                         continue;
 657                 }
 658
 659                 pmd = alloc_low_page();
 660                 paddr_last = phys_pmd_init(pmd, paddr, paddr_end,
 661                                            page_size_mask, prot, init);
 662
 663                 spin_lock(&init_mm.page_table_lock);
 664                 pud_populate_init(&init_mm, pud, pmd, init);
 665                 spin_unlock(&init_mm.page_table_lock);
 666         }
 667
 668         update_page_count(PG_LEVEL_1G, pages);
 669
 670         return paddr_last;
 671 }
 672
 673 static unsigned long __meminit
 674 phys_p4d_init(p4d_t *p4d_page, unsigned long paddr, unsigned long paddr_end,
 675               unsigned long page_size_mask, pgprot_t prot, bool init)
 676 {
 677         unsigned long vaddr, vaddr_end, vaddr_next, paddr_next, paddr_last;
 678
 679         paddr_last = paddr_end;
 680         vaddr = (unsigned long)__va(paddr);
 681         vaddr_end = (unsigned long)__va(paddr_end);
 682
 683         if (!pgtable_l5_enabled())
 684                 return phys_pud_init((pud_t *) p4d_page, paddr, paddr_end,
 685                                      page_size_mask, prot, init);
 686
 687         for (; vaddr < vaddr_end; vaddr = vaddr_next) {
 688                 p4d_t *p4d = p4d_page + p4d_index(vaddr);
 689                 pud_t *pud;
 690
 691                 vaddr_next = (vaddr & P4D_MASK) + P4D_SIZE;
 692                 paddr = __pa(vaddr);
 693
 694                 if (paddr >= paddr_end) {
 695                         paddr_next = __pa(vaddr_next);
 696                         if (!after_bootmem &&
 697                             !e820__mapped_any(paddr & P4D_MASK, paddr_next,
 698                                              E820_TYPE_RAM) &&
 699                             !e820__mapped_any(paddr & P4D_MASK, paddr_next,
 700                                              E820_TYPE_RESERVED_KERN))
 701                                 set_p4d_init(p4d, __p4d(0), init);
 702                         continue;
 703                 }
 704
 705                 if (!p4d_none(*p4d)) {
 706                         pud = pud_offset(p4d, 0);
 707                         paddr_last = phys_pud_init(pud, paddr, __pa(vaddr_end),
 708                                         page_size_mask, prot, init);
 709                         continue;
 710                 }
 711
 712                 pud = alloc_low_page();
 713                 paddr_last = phys_pud_init(pud, paddr, __pa(vaddr_end),
 714                                            page_size_mask, prot, init);
 715
 716                 spin_lock(&init_mm.page_table_lock);
 717                 p4d_populate_init(&init_mm, p4d, pud, init);
 718                 spin_unlock(&init_mm.page_table_lock);
 719         }
 720
 721         return paddr_last;
 722 }
 723
 724 static unsigned long __meminit
 725 __kernel_physical_mapping_init(unsigned long paddr_start,
 726                                unsigned long paddr_end,
 727                                unsigned long page_size_mask,
 728                                pgprot_t prot, bool init)
 729 {
 730         bool pgd_changed = false;
 731         unsigned long vaddr, vaddr_start, vaddr_end, vaddr_next, paddr_last;
 732
 733         paddr_last = paddr_end;
 734         vaddr = (unsigned long)__va(paddr_start);
 735         vaddr_end = (unsigned long)__va(paddr_end);
 736         vaddr_start = vaddr;
 737
 738         for (; vaddr < vaddr_end; vaddr = vaddr_next) {
 739                 pgd_t *pgd = pgd_offset_k(vaddr);
 740                 p4d_t *p4d;
 741
 742                 vaddr_next = (vaddr & PGDIR_MASK) + PGDIR_SIZE;
 743
 744                 if (pgd_val(*pgd)) {
 745                         p4d = (p4d_t *)pgd_page_vaddr(*pgd);
 746                         paddr_last = phys_p4d_init(p4d, __pa(vaddr),
 747                                                    __pa(vaddr_end),
 748                                                    page_size_mask,
 749                                                    prot, init);
 750                         continue;
 751                 }
 752
 753                 p4d = alloc_low_page();
 754                 paddr_last = phys_p4d_init(p4d, __pa(vaddr), __pa(vaddr_end),
 755                                            page_size_mask, prot, init);
 756
 757                 spin_lock(&init_mm.page_table_lock);
 758                 if (pgtable_l5_enabled())
 759                         pgd_populate_init(&init_mm, pgd, p4d, init);
 760                 else
 761                         p4d_populate_init(&init_mm, p4d_offset(pgd, vaddr),
 762                                           (pud_t *) p4d, init);
 763
 764                 spin_unlock(&init_mm.page_table_lock);
 765                 pgd_changed = true;
 766         }
 767
 768         if (pgd_changed)
 769                 sync_global_pgds(vaddr_start, vaddr_end - 1);
 770
 771         return paddr_last;
 772 }
 773
 774
 775 /*
 776  * Create page table mapping for the physical memory for specific physical
 777  * addresses. Note that it can only be used to populate non-present entries.
 778  * The virtual and physical addresses have to be aligned on PMD level
 779  * down. It returns the last physical address mapped.
 780  */
 781 unsigned long __meminit
 782 kernel_physical_mapping_init(unsigned long paddr_start,
 783                              unsigned long paddr_end,
 784                              unsigned long page_size_mask, pgprot_t prot)
 785 {
 786         return __kernel_physical_mapping_init(paddr_start, paddr_end,
 787                                               page_size_mask, prot, true);
 788 }
 789
 790 /*
 791  * This function is similar to kernel_physical_mapping_init() above with the
 792  * exception that it uses set_{pud,pmd}() instead of the set_{pud,pte}_safe()
 793  * when updating the mapping. The caller is responsible to flush the TLBs after
 794  * the function returns.
 795  */
 796 unsigned long __meminit
 797 kernel_physical_mapping_change(unsigned long paddr_start,
 798                                unsigned long paddr_end,
 799                                unsigned long page_size_mask)
 800 {
 801         return __kernel_physical_mapping_init(paddr_start, paddr_end,
 802                                               page_size_mask, PAGE_KERNEL,
 803                                               false);
 804 }
 805
 806 #ifndef CONFIG_NUMA
 807 void __init initmem_init(void)
 808 {
 809         memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
 810 }
 811 #endif
 812
 813 void __init paging_init(void)
 814 {
 815         sparse_init();
 816
 817         /*
 818          * clear the default setting with node 0
 819          * note: don't use nodes_clear here, that is really clearing when
 820          *       numa support is not compiled in, and later node_set_state
 821          *       will not set it back.
 822          */
 823         node_clear_state(0, N_MEMORY);
 824         node_clear_state(0, N_NORMAL_MEMORY);
 825
 826         zone_sizes_init();
 827 }
 828
 829 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 830 #define PAGE_UNUSED 0xFD
 831
 832 /*
 833  * The unused vmemmap range, which was not yet memset(PAGE_UNUSED), ranges
 834  * from unused_pmd_start to next PMD_SIZE boundary.
 835  */
 836 static unsigned long unused_pmd_start __meminitdata;
 837
 838 static void __meminit vmemmap_flush_unused_pmd(void)
 839 {
 840         if (!unused_pmd_start)
 841                 return;
 842         /*
 843          * Clears (unused_pmd_start, PMD_END]
 844          */
 845         memset((void *)unused_pmd_start, PAGE_UNUSED,
 846                ALIGN(unused_pmd_start, PMD_SIZE) - unused_pmd_start);
 847         unused_pmd_start = 0;
 848 }
 849
 850 #ifdef CONFIG_MEMORY_HOTPLUG
 851 /* Returns true if the PMD is completely unused and thus it can be freed */
 852 static bool __meminit vmemmap_pmd_is_unused(unsigned long addr, unsigned long end)
 853 {
 854         unsigned long start = ALIGN_DOWN(addr, PMD_SIZE);
 855
 856         /*
 857          * Flush the unused range cache to ensure that memchr_inv() will work
 858          * for the whole range.
 859          */
 860         vmemmap_flush_unused_pmd();
 861         memset((void *)addr, PAGE_UNUSED, end - addr);
 862
 863         return !memchr_inv((void *)start, PAGE_UNUSED, PMD_SIZE);
 864 }
 865 #endif
 866
 867 static void __meminit __vmemmap_use_sub_pmd(unsigned long start)
 868 {
 869         /*
 870          * As we expect to add in the same granularity as we remove, it's
 871          * sufficient to mark only some piece used to block the memmap page from
 872          * getting removed when removing some other adjacent memmap (just in
 873          * case the first memmap never gets initialized e.g., because the memory
 874          * block never gets onlined).
 875          */
 876         memset((void *)start, 0, sizeof(struct page));
 877 }
 878
 879 static void __meminit vmemmap_use_sub_pmd(unsigned long start, unsigned long end)
 880 {
 881         /*
 882          * We only optimize if the new used range directly follows the
 883          * previously unused range (esp., when populating consecutive sections).
 884          */
 885         if (unused_pmd_start == start) {
 886                 if (likely(IS_ALIGNED(end, PMD_SIZE)))
 887                         unused_pmd_start = 0;
 888                 else
 889                         unused_pmd_start = end;
 890                 return;
 891         }
 892
 893         /*
 894          * If the range does not contiguously follows previous one, make sure
 895          * to mark the unused range of the previous one so it can be removed.
 896          */
 897         vmemmap_flush_unused_pmd();
 898         __vmemmap_use_sub_pmd(start);
 899 }
 900
 901
 902 static void __meminit vmemmap_use_new_sub_pmd(unsigned long start, unsigned long end)
 903 {
 904         vmemmap_flush_unused_pmd();
 905
 906         /*
 907          * Could be our memmap page is filled with PAGE_UNUSED already from a
 908          * previous remove. Make sure to reset it.
 909          */
 910         __vmemmap_use_sub_pmd(start);
 911
 912         /*
 913          * Mark with PAGE_UNUSED the unused parts of the new memmap range
 914          */
 915         if (!IS_ALIGNED(start, PMD_SIZE))
 916                 memset((void *)start, PAGE_UNUSED,
 917                         start - ALIGN_DOWN(start, PMD_SIZE));
 918
 919         /*
 920          * We want to avoid memset(PAGE_UNUSED) when populating the vmemmap of
 921          * consecutive sections. Remember for the last added PMD where the
 922          * unused range begins.
 923          */
 924         if (!IS_ALIGNED(end, PMD_SIZE))
 925                 unused_pmd_start = end;
 926 }
 927 #endif
 928
 929 /*
 930  * Memory hotplug specific functions
 931  */
 932 #ifdef CONFIG_MEMORY_HOTPLUG
 933 /*
 934  * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
 935  * updating.
 936  */
 937 static void update_end_of_memory_vars(u64 start, u64 size)
 938 {
 939         unsigned long end_pfn = PFN_UP(start + size);
 940
 941         if (end_pfn > max_pfn) {
 942                 max_pfn = end_pfn;
 943                 max_low_pfn = end_pfn;
 944                 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
 945         }
 946 }
 947
 948 int add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
 949               struct mhp_params *params)
 950 {
 951         int ret;
 952
 953         ret = __add_pages(nid, start_pfn, nr_pages, params);
 954         WARN_ON_ONCE(ret);
 955
 956         /* update max_pfn, max_low_pfn and high_memory */
 957         update_end_of_memory_vars(start_pfn << PAGE_SHIFT,
 958                                   nr_pages << PAGE_SHIFT);
 959
 960         return ret;
 961 }
 962
 963 int arch_add_memory(int nid, u64 start, u64 size,
 964                     struct mhp_params *params)
 965 {
 966         unsigned long start_pfn = start >> PAGE_SHIFT;
 967         unsigned long nr_pages = size >> PAGE_SHIFT;
 968
 969         init_memory_mapping(start, start + size, params->pgprot);
 970
 971         return add_pages(nid, start_pfn, nr_pages, params);
 972 }
 973
 974 static void __meminit free_pagetable(struct page *page, int order)
 975 {
 976         unsigned long magic;
 977         unsigned int nr_pages = 1 << order;
 978
 979         /* bootmem page has reserved flag */
 980         if (PageReserved(page)) {
 981                 __ClearPageReserved(page);
 982
 983                 magic = (unsigned long)page->freelist;
 984                 if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
 985                         while (nr_pages--)
 986                                 put_page_bootmem(page++);
 987                 } else
 988                         while (nr_pages--)
 989                                 free_reserved_page(page++);
 990         } else
 991                 free_pages((unsigned long)page_address(page), order);
 992 }
 993
 994 static void __meminit free_hugepage_table(struct page *page,
 995                 struct vmem_altmap *altmap)
 996 {
 997         if (altmap)
 998                 vmem_altmap_free(altmap, PMD_SIZE / PAGE_SIZE);
 999         else
1000                 free_pagetable(page, get_order(PMD_SIZE));
1001 }
1002
1003 static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
1004 {
1005         pte_t *pte;
1006         int i;
1007
1008         for (i = 0; i < PTRS_PER_PTE; i++) {
1009                 pte = pte_start + i;
1010                 if (!pte_none(*pte))
1011                         return;
1012         }
1013
1014         /* free a pte talbe */
1015         free_pagetable(pmd_page(*pmd), 0);
1016         spin_lock(&init_mm.page_table_lock);
1017         pmd_clear(pmd);
1018         spin_unlock(&init_mm.page_table_lock);
1019 }
1020
1021 static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud)
1022 {
1023         pmd_t *pmd;
1024         int i;
1025
1026         for (i = 0; i < PTRS_PER_PMD; i++) {
1027                 pmd = pmd_start + i;
1028                 if (!pmd_none(*pmd))
1029                         return;
1030         }
1031
1032         /* free a pmd talbe */
1033         free_pagetable(pud_page(*pud), 0);
1034         spin_lock(&init_mm.page_table_lock);
1035         pud_clear(pud);
1036         spin_unlock(&init_mm.page_table_lock);
1037 }
1038
1039 static void __meminit free_pud_table(pud_t *pud_start, p4d_t *p4d)
1040 {
1041         pud_t *pud;
1042         int i;
1043
1044         for (i = 0; i < PTRS_PER_PUD; i++) {
1045                 pud = pud_start + i;
1046                 if (!pud_none(*pud))
1047                         return;
1048         }
1049
1050         /* free a pud talbe */
1051         free_pagetable(p4d_page(*p4d), 0);
1052         spin_lock(&init_mm.page_table_lock);
1053         p4d_clear(p4d);
1054         spin_unlock(&init_mm.page_table_lock);
1055 }
1056
1057 static void __meminit
1058 remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
1059                  bool direct)
1060 {
1061         unsigned long next, pages = 0;
1062         pte_t *pte;
1063         phys_addr_t phys_addr;
1064
1065         pte = pte_start + pte_index(addr);
1066         for (; addr < end; addr = next, pte++) {
1067                 next = (addr + PAGE_SIZE) & PAGE_MASK;
1068                 if (next > end)
1069                         next = end;
1070
1071                 if (!pte_present(*pte))
1072                         continue;
1073
1074                 /*
1075                  * We mapped [0,1G) memory as identity mapping when
1076                  * initializing, in arch/x86/kernel/head_64.S. These
1077                  * pagetables cannot be removed.
1078                  */
1079                 phys_addr = pte_val(*pte) + (addr & PAGE_MASK);
1080                 if (phys_addr < (phys_addr_t)0x40000000)
1081                         return;
1082
1083                 if (!direct)
1084                         free_pagetable(pte_page(*pte), 0);
1085
1086                 spin_lock(&init_mm.page_table_lock);
1087                 pte_clear(&init_mm, addr, pte);
1088                 spin_unlock(&init_mm.page_table_lock);
1089
1090                 /* For non-direct mapping, pages means nothing. */
1091                 pages++;
1092         }
1093
1094         /* Call free_pte_table() in remove_pmd_table(). */
1095         flush_tlb_all();
1096         if (direct)
1097                 update_page_count(PG_LEVEL_4K, -pages);
1098 }
1099
1100 static void __meminit
1101 remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
1102                  bool direct, struct vmem_altmap *altmap)
1103 {
1104         unsigned long next, pages = 0;
1105         pte_t *pte_base;
1106         pmd_t *pmd;
1107
1108         pmd = pmd_start + pmd_index(addr);
1109         for (; addr < end; addr = next, pmd++) {
1110                 next = pmd_addr_end(addr, end);
1111
1112                 if (!pmd_present(*pmd))
1113                         continue;
1114
1115                 if (pmd_large(*pmd)) {
1116                         if (IS_ALIGNED(addr, PMD_SIZE) &&
1117                             IS_ALIGNED(next, PMD_SIZE)) {
1118                                 if (!direct)
1119                                         free_hugepage_table(pmd_page(*pmd),
1120                                                             altmap);
1121
1122                                 spin_lock(&init_mm.page_table_lock);
1123                                 pmd_clear(pmd);
1124                                 spin_unlock(&init_mm.page_table_lock);
1125                                 pages++;
1126                         }
1127 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1128                         else if (vmemmap_pmd_is_unused(addr, next)) {
1129                                         free_hugepage_table(pmd_page(*pmd),
1130                                                             altmap);
1131                                         spin_lock(&init_mm.page_table_lock);
1132                                         pmd_clear(pmd);
1133                                         spin_unlock(&init_mm.page_table_lock);
1134                         }
1135 #endif
1136                         continue;
1137                 }
1138
1139                 pte_base = (pte_t *)pmd_page_vaddr(*pmd);
1140                 remove_pte_table(pte_base, addr, next, direct);
1141                 free_pte_table(pte_base, pmd);
1142         }
1143
1144         /* Call free_pmd_table() in remove_pud_table(). */
1145         if (direct)
1146                 update_page_count(PG_LEVEL_2M, -pages);
1147 }
1148
1149 static void __meminit
1150 remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
1151                  struct vmem_altmap *altmap, bool direct)
1152 {
1153         unsigned long next, pages = 0;
1154         pmd_t *pmd_base;
1155         pud_t *pud;
1156
1157         pud = pud_start + pud_index(addr);
1158         for (; addr < end; addr = next, pud++) {
1159                 next = pud_addr_end(addr, end);
1160
1161                 if (!pud_present(*pud))
1162                         continue;
1163
1164                 if (pud_large(*pud) &&
1165                     IS_ALIGNED(addr, PUD_SIZE) &&
1166                     IS_ALIGNED(next, PUD_SIZE)) {
1167                         spin_lock(&init_mm.page_table_lock);
1168                         pud_clear(pud);
1169                         spin_unlock(&init_mm.page_table_lock);
1170                         pages++;
1171                         continue;
1172                 }
1173
1174                 pmd_base = pmd_offset(pud, 0);
1175                 remove_pmd_table(pmd_base, addr, next, direct, altmap);
1176                 free_pmd_table(pmd_base, pud);
1177         }
1178
1179         if (direct)
1180                 update_page_count(PG_LEVEL_1G, -pages);
1181 }
1182
1183 static void __meminit
1184 remove_p4d_table(p4d_t *p4d_start, unsigned long addr, unsigned long end,
1185                  struct vmem_altmap *altmap, bool direct)
1186 {
1187         unsigned long next, pages = 0;
1188         pud_t *pud_base;
1189         p4d_t *p4d;
1190
1191         p4d = p4d_start + p4d_index(addr);
1192         for (; addr < end; addr = next, p4d++) {
1193                 next = p4d_addr_end(addr, end);
1194
1195                 if (!p4d_present(*p4d))
1196                         continue;
1197
1198                 BUILD_BUG_ON(p4d_large(*p4d));
1199
1200                 pud_base = pud_offset(p4d, 0);
1201                 remove_pud_table(pud_base, addr, next, altmap, direct);
1202                 /*
1203                  * For 4-level page tables we do not want to free PUDs, but in the
1204                  * 5-level case we should free them. This code will have to change
1205                  * to adapt for boot-time switching between 4 and 5 level page tables.
1206                  */
1207                 if (pgtable_l5_enabled())
1208                         free_pud_table(pud_base, p4d);
1209         }
1210
1211         if (direct)
1212                 update_page_count(PG_LEVEL_512G, -pages);
1213 }
1214
1215 /* start and end are both virtual address. */
1216 static void __meminit
1217 remove_pagetable(unsigned long start, unsigned long end, bool direct,
1218                 struct vmem_altmap *altmap)
1219 {
1220         unsigned long next;
1221         unsigned long addr;
1222         pgd_t *pgd;
1223         p4d_t *p4d;
1224
1225         for (addr = start; addr < end; addr = next) {
1226                 next = pgd_addr_end(addr, end);
1227
1228                 pgd = pgd_offset_k(addr);
1229                 if (!pgd_present(*pgd))
1230                         continue;
1231
1232                 p4d = p4d_offset(pgd, 0);
1233                 remove_p4d_table(p4d, addr, next, altmap, direct);
1234         }
1235
1236         flush_tlb_all();
1237 }
1238
1239 void __ref vmemmap_free(unsigned long start, unsigned long end,
1240                 struct vmem_altmap *altmap)
1241 {
1242         VM_BUG_ON(!IS_ALIGNED(start, PAGE_SIZE));
1243         VM_BUG_ON(!IS_ALIGNED(end, PAGE_SIZE));
1244
1245         remove_pagetable(start, end, false, altmap);
1246 }
1247
1248 static void __meminit
1249 kernel_physical_mapping_remove(unsigned long start, unsigned long end)
1250 {
1251         start = (unsigned long)__va(start);
1252         end = (unsigned long)__va(end);
1253
1254         remove_pagetable(start, end, true, NULL);
1255 }
1256
1257 void __ref arch_remove_memory(int nid, u64 start, u64 size,
1258                               struct vmem_altmap *altmap)
1259 {
1260         unsigned long start_pfn = start >> PAGE_SHIFT;
1261         unsigned long nr_pages = size >> PAGE_SHIFT;
1262
1263         __remove_pages(start_pfn, nr_pages, altmap);
1264         kernel_physical_mapping_remove(start, start + size);
1265 }
1266 #endif /* CONFIG_MEMORY_HOTPLUG */
1267
1268 static struct kcore_list kcore_vsyscall;
1269
1270 static void __init register_page_bootmem_info(void)
1271 {
1272 #ifdef CONFIG_NUMA
1273         int i;
1274
1275         for_each_online_node(i)
1276                 register_page_bootmem_info_node(NODE_DATA(i));
1277 #endif
1278 }
1279
1280 /*
1281  * Pre-allocates page-table pages for the vmalloc area in the kernel page-table.
1282  * Only the level which needs to be synchronized between all page-tables is
1283  * allocated because the synchronization can be expensive.
1284  */
1285 static void __init preallocate_vmalloc_pages(void)
1286 {
1287         unsigned long addr;
1288         const char *lvl;
1289
1290         for (addr = VMALLOC_START; addr <= VMALLOC_END; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
1291                 pgd_t *pgd = pgd_offset_k(addr);
1292                 p4d_t *p4d;
1293                 pud_t *pud;
1294
1295                 lvl = "p4d";
1296                 p4d = p4d_alloc(&init_mm, pgd, addr);
1297                 if (!p4d)
1298                         goto failed;
1299
1300                 if (pgtable_l5_enabled())
1301                         continue;
1302
1303                 /*
1304                  * The goal here is to allocate all possibly required
1305                  * hardware page tables pointed to by the top hardware
1306                  * level.
1307                  *
1308                  * On 4-level systems, the P4D layer is folded away and
1309                  * the above code does no preallocation.  Below, go down
1310                  * to the pud _software_ level to ensure the second
1311                  * hardware level is allocated on 4-level systems too.
1312                  */
1313                 lvl = "pud";
1314                 pud = pud_alloc(&init_mm, p4d, addr);
1315                 if (!pud)
1316                         goto failed;
1317         }
1318
1319         return;
1320
1321 failed:
1322
1323         /*
1324          * The pages have to be there now or they will be missing in
1325          * process page-tables later.
1326          */
1327         panic("Failed to pre-allocate %s pages for vmalloc area\n", lvl);
1328 }
1329
1330 void __init mem_init(void)
1331 {
1332         pci_iommu_alloc();
1333
1334         /* clear_bss() already clear the empty_zero_page */
1335
1336         /* this will put all memory onto the freelists */
1337         memblock_free_all();
1338         after_bootmem = 1;
1339         x86_init.hyper.init_after_bootmem();
1340
1341         /*
1342          * Must be done after boot memory is put on freelist, because here we
1343          * might set fields in deferred struct pages that have not yet been
1344          * initialized, and memblock_free_all() initializes all the reserved
1345          * deferred pages for us.
1346          */
1347         register_page_bootmem_info();
1348
1349         /* Register memory areas for /proc/kcore */
1350         if (get_gate_vma(&init_mm))
1351                 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR, PAGE_SIZE, KCORE_USER);
1352
1353         preallocate_vmalloc_pages();
1354 }
1355
1356 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1357 int __init deferred_page_init_max_threads(const struct cpumask *node_cpumask)
1358 {
1359         /*
1360          * More CPUs always led to greater speedups on tested systems, up to
1361          * all the nodes' CPUs.  Use all since the system is otherwise idle
1362          * now.
1363          */
1364         return max_t(int, cpumask_weight(node_cpumask), 1);
1365 }
1366 #endif
1367
1368 int kernel_set_to_readonly;
1369
1370 void mark_rodata_ro(void)
1371 {
1372         unsigned long start = PFN_ALIGN(_text);
1373         unsigned long rodata_start = PFN_ALIGN(__start_rodata);
1374         unsigned long end = (unsigned long)__end_rodata_hpage_align;
1375         unsigned long text_end = PFN_ALIGN(_etext);
1376         unsigned long rodata_end = PFN_ALIGN(__end_rodata);
1377         unsigned long all_end;
1378
1379         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
1380                (end - start) >> 10);
1381         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1382
1383         kernel_set_to_readonly = 1;
1384
1385         /*
1386          * The rodata/data/bss/brk section (but not the kernel text!)
1387          * should also be not-executable.
1388          *
1389          * We align all_end to PMD_SIZE because the existing mapping
1390          * is a full PMD. If we would align _brk_end to PAGE_SIZE we
1391          * split the PMD and the reminder between _brk_end and the end
1392          * of the PMD will remain mapped executable.
1393          *
1394          * Any PMD which was setup after the one which covers _brk_end
1395          * has been zapped already via cleanup_highmem().
1396          */
1397         all_end = roundup((unsigned long)_brk_end, PMD_SIZE);
1398         set_memory_nx(text_end, (all_end - text_end) >> PAGE_SHIFT);
1399
1400         set_ftrace_ops_ro();
1401
1402 #ifdef CONFIG_CPA_DEBUG
1403         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
1404         set_memory_rw(start, (end-start) >> PAGE_SHIFT);
1405
1406         printk(KERN_INFO "Testing CPA: again\n");
1407         set_memory_ro(start, (end-start) >> PAGE_SHIFT);
1408 #endif
1409
1410         free_kernel_image_pages("unused kernel image (text/rodata gap)",
1411                                 (void *)text_end, (void *)rodata_start);
1412         free_kernel_image_pages("unused kernel image (rodata/data gap)",
1413                                 (void *)rodata_end, (void *)_sdata);
1414
1415         debug_checkwx();
1416 }
1417
1418 int kern_addr_valid(unsigned long addr)
1419 {
1420         unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
1421         pgd_t *pgd;
1422         p4d_t *p4d;
1423         pud_t *pud;
1424         pmd_t *pmd;
1425         pte_t *pte;
1426
1427         if (above != 0 && above != -1UL)
1428                 return 0;
1429
1430         pgd = pgd_offset_k(addr);
1431         if (pgd_none(*pgd))
1432                 return 0;
1433
1434         p4d = p4d_offset(pgd, addr);
1435         if (p4d_none(*p4d))
1436                 return 0;
1437
1438         pud = pud_offset(p4d, addr);
1439         if (pud_none(*pud))
1440                 return 0;
1441
1442         if (pud_large(*pud))
1443                 return pfn_valid(pud_pfn(*pud));
1444
1445         pmd = pmd_offset(pud, addr);
1446         if (pmd_none(*pmd))
1447                 return 0;
1448
1449         if (pmd_large(*pmd))
1450                 return pfn_valid(pmd_pfn(*pmd));
1451
1452         pte = pte_offset_kernel(pmd, addr);
1453         if (pte_none(*pte))
1454                 return 0;
1455
1456         return pfn_valid(pte_pfn(*pte));
1457 }
1458
1459 /*
1460  * Block size is the minimum amount of memory which can be hotplugged or
1461  * hotremoved. It must be power of two and must be equal or larger than
1462  * MIN_MEMORY_BLOCK_SIZE.
1463  */
1464 #define MAX_BLOCK_SIZE (2UL << 30)
1465
1466 /* Amount of ram needed to start using large blocks */
1467 #define MEM_SIZE_FOR_LARGE_BLOCK (64UL << 30)
1468
1469 /* Adjustable memory block size */
1470 static unsigned long set_memory_block_size;
1471 int __init set_memory_block_size_order(unsigned int order)
1472 {
1473         unsigned long size = 1UL << order;
1474
1475         if (size > MEM_SIZE_FOR_LARGE_BLOCK || size < MIN_MEMORY_BLOCK_SIZE)
1476                 return -EINVAL;
1477
1478         set_memory_block_size = size;
1479         return 0;
1480 }
1481
1482 static unsigned long probe_memory_block_size(void)
1483 {
1484         unsigned long boot_mem_end = max_pfn << PAGE_SHIFT;
1485         unsigned long bz;
1486
1487         /* If memory block size has been set, then use it */
1488         bz = set_memory_block_size;
1489         if (bz)
1490                 goto done;
1491
1492         /* Use regular block if RAM is smaller than MEM_SIZE_FOR_LARGE_BLOCK */
1493         if (boot_mem_end < MEM_SIZE_FOR_LARGE_BLOCK) {
1494                 bz = MIN_MEMORY_BLOCK_SIZE;
1495                 goto done;
1496         }
1497
1498         /*
1499          * Use max block size to minimize overhead on bare metal, where
1500          * alignment for memory hotplug isn't a concern.
1501          */
1502         if (!boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
1503                 bz = MAX_BLOCK_SIZE;
1504                 goto done;
1505         }
1506
1507         /* Find the largest allowed block size that aligns to memory end */
1508         for (bz = MAX_BLOCK_SIZE; bz > MIN_MEMORY_BLOCK_SIZE; bz >>= 1) {
1509                 if (IS_ALIGNED(boot_mem_end, bz))
1510                         break;
1511         }
1512 done:
1513         pr_info("x86/mm: Memory block size: %ldMB\n", bz >> 20);
1514
1515         return bz;
1516 }
1517
1518 static unsigned long memory_block_size_probed;
1519 unsigned long memory_block_size_bytes(void)
1520 {
1521         if (!memory_block_size_probed)
1522                 memory_block_size_probed = probe_memory_block_size();
1523
1524         return memory_block_size_probed;
1525 }
1526
1527 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1528 /*
1529  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1530  */
1531 static long __meminitdata addr_start, addr_end;
1532 static void __meminitdata *p_start, *p_end;
1533 static int __meminitdata node_start;
1534
1535 static int __meminit vmemmap_populate_hugepages(unsigned long start,
1536                 unsigned long end, int node, struct vmem_altmap *altmap)
1537 {
1538         unsigned long addr;
1539         unsigned long next;
1540         pgd_t *pgd;
1541         p4d_t *p4d;
1542         pud_t *pud;
1543         pmd_t *pmd;
1544
1545         for (addr = start; addr < end; addr = next) {
1546                 next = pmd_addr_end(addr, end);
1547
1548                 pgd = vmemmap_pgd_populate(addr, node);
1549                 if (!pgd)
1550                         return -ENOMEM;
1551
1552                 p4d = vmemmap_p4d_populate(pgd, addr, node);
1553                 if (!p4d)
1554                         return -ENOMEM;
1555
1556                 pud = vmemmap_pud_populate(p4d, addr, node);
1557                 if (!pud)
1558                         return -ENOMEM;
1559
1560                 pmd = pmd_offset(pud, addr);
1561                 if (pmd_none(*pmd)) {
1562                         void *p;
1563
1564                         p = vmemmap_alloc_block_buf(PMD_SIZE, node, altmap);
1565                         if (p) {
1566                                 pte_t entry;
1567
1568                                 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1569                                                 PAGE_KERNEL_LARGE);
1570                                 set_pmd(pmd, __pmd(pte_val(entry)));
1571
1572                                 /* check to see if we have contiguous blocks */
1573                                 if (p_end != p || node_start != node) {
1574                                         if (p_start)
1575                                                 pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1576                                                        addr_start, addr_end-1, p_start, p_end-1, node_start);
1577                                         addr_start = addr;
1578                                         node_start = node;
1579                                         p_start = p;
1580                                 }
1581
1582                                 addr_end = addr + PMD_SIZE;
1583                                 p_end = p + PMD_SIZE;
1584
1585                                 if (!IS_ALIGNED(addr, PMD_SIZE) ||
1586                                     !IS_ALIGNED(next, PMD_SIZE))
1587                                         vmemmap_use_new_sub_pmd(addr, next);
1588
1589                                 continue;
1590                         } else if (altmap)
1591                                 return -ENOMEM; /* no fallback */
1592                 } else if (pmd_large(*pmd)) {
1593                         vmemmap_verify((pte_t *)pmd, node, addr, next);
1594                         vmemmap_use_sub_pmd(addr, next);
1595                         continue;
1596                 }
1597                 if (vmemmap_populate_basepages(addr, next, node, NULL))
1598                         return -ENOMEM;
1599         }
1600         return 0;
1601 }
1602
1603 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
1604                 struct vmem_altmap *altmap)
1605 {
1606         int err;
1607
1608         VM_BUG_ON(!IS_ALIGNED(start, PAGE_SIZE));
1609         VM_BUG_ON(!IS_ALIGNED(end, PAGE_SIZE));
1610
1611         if (end - start < PAGES_PER_SECTION * sizeof(struct page))
1612                 err = vmemmap_populate_basepages(start, end, node, NULL);
1613         else if (boot_cpu_has(X86_FEATURE_PSE))
1614                 err = vmemmap_populate_hugepages(start, end, node, altmap);
1615         else if (altmap) {
1616                 pr_err_once("%s: no cpu support for altmap allocations\n",
1617                                 __func__);
1618                 err = -ENOMEM;
1619         } else
1620                 err = vmemmap_populate_basepages(start, end, node, NULL);
1621         if (!err)
1622                 sync_global_pgds(start, end - 1);
1623         return err;
1624 }
1625
1626 #if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HAVE_BOOTMEM_INFO_NODE)
1627 void register_page_bootmem_memmap(unsigned long section_nr,
1628                                   struct page *start_page, unsigned long nr_pages)
1629 {
1630         unsigned long addr = (unsigned long)start_page;
1631         unsigned long end = (unsigned long)(start_page + nr_pages);
1632         unsigned long next;
1633         pgd_t *pgd;
1634         p4d_t *p4d;
1635         pud_t *pud;
1636         pmd_t *pmd;
1637         unsigned int nr_pmd_pages;
1638         struct page *page;
1639
1640         for (; addr < end; addr = next) {
1641                 pte_t *pte = NULL;
1642
1643                 pgd = pgd_offset_k(addr);
1644                 if (pgd_none(*pgd)) {
1645                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1646                         continue;
1647                 }
1648                 get_page_bootmem(section_nr, pgd_page(*pgd), MIX_SECTION_INFO);
1649
1650                 p4d = p4d_offset(pgd, addr);
1651                 if (p4d_none(*p4d)) {
1652                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1653                         continue;
1654                 }
1655                 get_page_bootmem(section_nr, p4d_page(*p4d), MIX_SECTION_INFO);
1656
1657                 pud = pud_offset(p4d, addr);
1658                 if (pud_none(*pud)) {
1659                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1660                         continue;
1661                 }
1662                 get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO);
1663
1664                 if (!boot_cpu_has(X86_FEATURE_PSE)) {
1665                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1666                         pmd = pmd_offset(pud, addr);
1667                         if (pmd_none(*pmd))
1668                                 continue;
1669                         get_page_bootmem(section_nr, pmd_page(*pmd),
1670                                          MIX_SECTION_INFO);
1671
1672                         pte = pte_offset_kernel(pmd, addr);
1673                         if (pte_none(*pte))
1674                                 continue;
1675                         get_page_bootmem(section_nr, pte_page(*pte),
1676                                          SECTION_INFO);
1677                 } else {
1678                         next = pmd_addr_end(addr, end);
1679
1680                         pmd = pmd_offset(pud, addr);
1681                         if (pmd_none(*pmd))
1682                                 continue;
1683
1684                         nr_pmd_pages = 1 << get_order(PMD_SIZE);
1685                         page = pmd_page(*pmd);
1686                         while (nr_pmd_pages--)
1687                                 get_page_bootmem(section_nr, page++,
1688                                                  SECTION_INFO);
1689                 }
1690         }
1691 }
1692 #endif
1693
1694 void __meminit vmemmap_populate_print_last(void)
1695 {
1696         if (p_start) {
1697                 pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1698                         addr_start, addr_end-1, p_start, p_end-1, node_start);
1699                 p_start = NULL;
1700                 p_end = NULL;
1701                 node_start = 0;
1702         }
1703 }
1704 #endif