arch/ia64/mm/init.c

   1 /*
   2  * Initialize MMU support.
   3  *
   4  * Copyright (C) 1998-2003 Hewlett-Packard Co
   5  *      David Mosberger-Tang <davidm@hpl.hp.com>
   6  */
   7 #include <linux/kernel.h>
   8 #include <linux/init.h>
   9
  10 #include <linux/bootmem.h>
  11 #include <linux/efi.h>
  12 #include <linux/elf.h>
  13 #include <linux/mm.h>
  14 #include <linux/mmzone.h>
  15 #include <linux/module.h>
  16 #include <linux/personality.h>
  17 #include <linux/reboot.h>
  18 #include <linux/slab.h>
  19 #include <linux/swap.h>
  20 #include <linux/proc_fs.h>
  21 #include <linux/bitops.h>
  22 #include <linux/kexec.h>
  23
  24 #include <asm/a.out.h>
  25 #include <asm/dma.h>
  26 #include <asm/ia32.h>
  27 #include <asm/io.h>
  28 #include <asm/machvec.h>
  29 #include <asm/numa.h>
  30 #include <asm/patch.h>
  31 #include <asm/pgalloc.h>
  32 #include <asm/sal.h>
  33 #include <asm/sections.h>
  34 #include <asm/system.h>
  35 #include <asm/tlb.h>
  36 #include <asm/uaccess.h>
  37 #include <asm/unistd.h>
  38 #include <asm/mca.h>
  39
  40 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  41
  42 extern void ia64_tlb_init (void);
  43
  44 unsigned long MAX_DMA_ADDRESS = PAGE_OFFSET + 0x100000000UL;
  45
  46 #ifdef CONFIG_VIRTUAL_MEM_MAP
  47 unsigned long vmalloc_end = VMALLOC_END_INIT;
  48 EXPORT_SYMBOL(vmalloc_end);
  49 struct page *vmem_map;
  50 EXPORT_SYMBOL(vmem_map);
  51 #endif
  52
  53 struct page *zero_page_memmap_ptr;      /* map entry for zero page */
  54 EXPORT_SYMBOL(zero_page_memmap_ptr);
  55
  56 void
  57 __ia64_sync_icache_dcache (pte_t pte)
  58 {
  59         unsigned long addr;
  60         struct page *page;
  61         unsigned long order;
  62
  63         page = pte_page(pte);
  64         addr = (unsigned long) page_address(page);
  65
  66         if (test_bit(PG_arch_1, &page->flags))
  67                 return;                         /* i-cache is already coherent with d-cache */
  68
  69         if (PageCompound(page)) {
  70                 order = compound_order(page);
  71                 flush_icache_range(addr, addr + (1UL << order << PAGE_SHIFT));
  72         }
  73         else
  74                 flush_icache_range(addr, addr + PAGE_SIZE);
  75         set_bit(PG_arch_1, &page->flags);       /* mark page as clean */
  76 }
  77
  78 /*
  79  * Since DMA is i-cache coherent, any (complete) pages that were written via
  80  * DMA can be marked as "clean" so that lazy_mmu_prot_update() doesn't have to
  81  * flush them when they get mapped into an executable vm-area.
  82  */
  83 void
  84 dma_mark_clean(void *addr, size_t size)
  85 {
  86         unsigned long pg_addr, end;
  87
  88         pg_addr = PAGE_ALIGN((unsigned long) addr);
  89         end = (unsigned long) addr + size;
  90         while (pg_addr + PAGE_SIZE <= end) {
  91                 struct page *page = virt_to_page(pg_addr);
  92                 set_bit(PG_arch_1, &page->flags);
  93                 pg_addr += PAGE_SIZE;
  94         }
  95 }
  96
  97 inline void
  98 ia64_set_rbs_bot (void)
  99 {
 100         unsigned long stack_size = current->signal->rlim[RLIMIT_STACK].rlim_max & -16;
 101
 102         if (stack_size > MAX_USER_STACK_SIZE)
 103                 stack_size = MAX_USER_STACK_SIZE;
 104         current->thread.rbs_bot = PAGE_ALIGN(current->mm->start_stack - stack_size);
 105 }
 106
 107 /*
 108  * This performs some platform-dependent address space initialization.
 109  * On IA-64, we want to setup the VM area for the register backing
 110  * store (which grows upwards) and install the gateway page which is
 111  * used for signal trampolines, etc.
 112  */
 113 void
 114 ia64_init_addr_space (void)
 115 {
 116         struct vm_area_struct *vma;
 117
 118         ia64_set_rbs_bot();
 119
 120         /*
 121          * If we're out of memory and kmem_cache_alloc() returns NULL, we simply ignore
 122          * the problem.  When the process attempts to write to the register backing store
 123          * for the first time, it will get a SEGFAULT in this case.
 124          */
 125         vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
 126         if (vma) {
 127                 vma->vm_mm = current->mm;
 128                 vma->vm_start = current->thread.rbs_bot & PAGE_MASK;
 129                 vma->vm_end = vma->vm_start + PAGE_SIZE;
 130                 vma->vm_flags = VM_DATA_DEFAULT_FLAGS|VM_GROWSUP|VM_ACCOUNT;
 131                 vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
 132                 down_write(&current->mm->mmap_sem);
 133                 if (insert_vm_struct(current->mm, vma)) {
 134                         up_write(&current->mm->mmap_sem);
 135                         kmem_cache_free(vm_area_cachep, vma);
 136                         return;
 137                 }
 138                 up_write(&current->mm->mmap_sem);
 139         }
 140
 141         /* map NaT-page at address zero to speed up speculative dereferencing of NULL: */
 142         if (!(current->personality & MMAP_PAGE_ZERO)) {
 143                 vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
 144                 if (vma) {
 145                         vma->vm_mm = current->mm;
 146                         vma->vm_end = PAGE_SIZE;
 147                         vma->vm_page_prot = __pgprot(pgprot_val(PAGE_READONLY) | _PAGE_MA_NAT);
 148                         vma->vm_flags = VM_READ | VM_MAYREAD | VM_IO | VM_RESERVED;
 149                         down_write(&current->mm->mmap_sem);
 150                         if (insert_vm_struct(current->mm, vma)) {
 151                                 up_write(&current->mm->mmap_sem);
 152                                 kmem_cache_free(vm_area_cachep, vma);
 153                                 return;
 154                         }
 155                         up_write(&current->mm->mmap_sem);
 156                 }
 157         }
 158 }
 159
 160 void
 161 free_initmem (void)
 162 {
 163         unsigned long addr, eaddr;
 164
 165         addr = (unsigned long) ia64_imva(__init_begin);
 166         eaddr = (unsigned long) ia64_imva(__init_end);
 167         while (addr < eaddr) {
 168                 ClearPageReserved(virt_to_page(addr));
 169                 init_page_count(virt_to_page(addr));
 170                 free_page(addr);
 171                 ++totalram_pages;
 172                 addr += PAGE_SIZE;
 173         }
 174         printk(KERN_INFO "Freeing unused kernel memory: %ldkB freed\n",
 175                (__init_end - __init_begin) >> 10);
 176 }
 177
 178 void __init
 179 free_initrd_mem (unsigned long start, unsigned long end)
 180 {
 181         struct page *page;
 182         /*
 183          * EFI uses 4KB pages while the kernel can use 4KB or bigger.
 184          * Thus EFI and the kernel may have different page sizes. It is
 185          * therefore possible to have the initrd share the same page as
 186          * the end of the kernel (given current setup).
 187          *
 188          * To avoid freeing/using the wrong page (kernel sized) we:
 189          *      - align up the beginning of initrd
 190          *      - align down the end of initrd
 191          *
 192          *  |             |
 193          *  |=============| a000
 194          *  |             |
 195          *  |             |
 196          *  |             | 9000
 197          *  |/////////////|
 198          *  |/////////////|
 199          *  |=============| 8000
 200          *  |///INITRD////|
 201          *  |/////////////|
 202          *  |/////////////| 7000
 203          *  |             |
 204          *  |KKKKKKKKKKKKK|
 205          *  |=============| 6000
 206          *  |KKKKKKKKKKKKK|
 207          *  |KKKKKKKKKKKKK|
 208          *  K=kernel using 8KB pages
 209          *
 210          * In this example, we must free page 8000 ONLY. So we must align up
 211          * initrd_start and keep initrd_end as is.
 212          */
 213         start = PAGE_ALIGN(start);
 214         end = end & PAGE_MASK;
 215
 216         if (start < end)
 217                 printk(KERN_INFO "Freeing initrd memory: %ldkB freed\n", (end - start) >> 10);
 218
 219         for (; start < end; start += PAGE_SIZE) {
 220                 if (!virt_addr_valid(start))
 221                         continue;
 222                 page = virt_to_page(start);
 223                 ClearPageReserved(page);
 224                 init_page_count(page);
 225                 free_page(start);
 226                 ++totalram_pages;
 227         }
 228 }
 229
 230 /*
 231  * This installs a clean page in the kernel's page table.
 232  */
 233 static struct page * __init
 234 put_kernel_page (struct page *page, unsigned long address, pgprot_t pgprot)
 235 {
 236         pgd_t *pgd;
 237         pud_t *pud;
 238         pmd_t *pmd;
 239         pte_t *pte;
 240
 241         if (!PageReserved(page))
 242                 printk(KERN_ERR "put_kernel_page: page at 0x%p not in reserved memory\n",
 243                        page_address(page));
 244
 245         pgd = pgd_offset_k(address);            /* note: this is NOT pgd_offset()! */
 246
 247         {
 248                 pud = pud_alloc(&init_mm, pgd, address);
 249                 if (!pud)
 250                         goto out;
 251                 pmd = pmd_alloc(&init_mm, pud, address);
 252                 if (!pmd)
 253                         goto out;
 254                 pte = pte_alloc_kernel(pmd, address);
 255                 if (!pte)
 256                         goto out;
 257                 if (!pte_none(*pte))
 258                         goto out;
 259                 set_pte(pte, mk_pte(page, pgprot));
 260         }
 261   out:
 262         /* no need for flush_tlb */
 263         return page;
 264 }
 265
 266 static void __init
 267 setup_gate (void)
 268 {
 269         struct page *page;
 270
 271         /*
 272          * Map the gate page twice: once read-only to export the ELF
 273          * headers etc. and once execute-only page to enable
 274          * privilege-promotion via "epc":
 275          */
 276         page = virt_to_page(ia64_imva(__start_gate_section));
 277         put_kernel_page(page, GATE_ADDR, PAGE_READONLY);
 278 #ifdef HAVE_BUGGY_SEGREL
 279         page = virt_to_page(ia64_imva(__start_gate_section + PAGE_SIZE));
 280         put_kernel_page(page, GATE_ADDR + PAGE_SIZE, PAGE_GATE);
 281 #else
 282         put_kernel_page(page, GATE_ADDR + PERCPU_PAGE_SIZE, PAGE_GATE);
 283         /* Fill in the holes (if any) with read-only zero pages: */
 284         {
 285                 unsigned long addr;
 286
 287                 for (addr = GATE_ADDR + PAGE_SIZE;
 288                      addr < GATE_ADDR + PERCPU_PAGE_SIZE;
 289                      addr += PAGE_SIZE)
 290                 {
 291                         put_kernel_page(ZERO_PAGE(0), addr,
 292                                         PAGE_READONLY);
 293                         put_kernel_page(ZERO_PAGE(0), addr + PERCPU_PAGE_SIZE,
 294                                         PAGE_READONLY);
 295                 }
 296         }
 297 #endif
 298         ia64_patch_gate();
 299 }
 300
 301 void __devinit
 302 ia64_mmu_init (void *my_cpu_data)
 303 {
 304         unsigned long pta, impl_va_bits;
 305         extern void __devinit tlb_init (void);
 306
 307 #ifdef CONFIG_DISABLE_VHPT
 308 #       define VHPT_ENABLE_BIT  0
 309 #else
 310 #       define VHPT_ENABLE_BIT  1
 311 #endif
 312
 313         /*
 314          * Check if the virtually mapped linear page table (VMLPT) overlaps with a mapped
 315          * address space.  The IA-64 architecture guarantees that at least 50 bits of
 316          * virtual address space are implemented but if we pick a large enough page size
 317          * (e.g., 64KB), the mapped address space is big enough that it will overlap with
 318          * VMLPT.  I assume that once we run on machines big enough to warrant 64KB pages,
 319          * IMPL_VA_MSB will be significantly bigger, so this is unlikely to become a
 320          * problem in practice.  Alternatively, we could truncate the top of the mapped
 321          * address space to not permit mappings that would overlap with the VMLPT.
 322          * --davidm 00/12/06
 323          */
 324 #       define pte_bits                 3
 325 #       define mapped_space_bits        (3*(PAGE_SHIFT - pte_bits) + PAGE_SHIFT)
 326         /*
 327          * The virtual page table has to cover the entire implemented address space within
 328          * a region even though not all of this space may be mappable.  The reason for
 329          * this is that the Access bit and Dirty bit fault handlers perform
 330          * non-speculative accesses to the virtual page table, so the address range of the
 331          * virtual page table itself needs to be covered by virtual page table.
 332          */
 333 #       define vmlpt_bits               (impl_va_bits - PAGE_SHIFT + pte_bits)
 334 #       define POW2(n)                  (1ULL << (n))
 335
 336         impl_va_bits = ffz(~(local_cpu_data->unimpl_va_mask | (7UL << 61)));
 337
 338         if (impl_va_bits < 51 || impl_va_bits > 61)
 339                 panic("CPU has bogus IMPL_VA_MSB value of %lu!\n", impl_va_bits - 1);
 340         /*
 341          * mapped_space_bits - PAGE_SHIFT is the total number of ptes we need,
 342          * which must fit into "vmlpt_bits - pte_bits" slots. Second half of
 343          * the test makes sure that our mapped space doesn't overlap the
 344          * unimplemented hole in the middle of the region.
 345          */
 346         if ((mapped_space_bits - PAGE_SHIFT > vmlpt_bits - pte_bits) ||
 347             (mapped_space_bits > impl_va_bits - 1))
 348                 panic("Cannot build a big enough virtual-linear page table"
 349                       " to cover mapped address space.\n"
 350                       " Try using a smaller page size.\n");
 351
 352
 353         /* place the VMLPT at the end of each page-table mapped region: */
 354         pta = POW2(61) - POW2(vmlpt_bits);
 355
 356         /*
 357          * Set the (virtually mapped linear) page table address.  Bit
 358          * 8 selects between the short and long format, bits 2-7 the
 359          * size of the table, and bit 0 whether the VHPT walker is
 360          * enabled.
 361          */
 362         ia64_set_pta(pta | (0 << 8) | (vmlpt_bits << 2) | VHPT_ENABLE_BIT);
 363
 364         ia64_tlb_init();
 365
 366 #ifdef  CONFIG_HUGETLB_PAGE
 367         ia64_set_rr(HPAGE_REGION_BASE, HPAGE_SHIFT << 2);
 368         ia64_srlz_d();
 369 #endif
 370 }
 371
 372 #ifdef CONFIG_VIRTUAL_MEM_MAP
 373 int vmemmap_find_next_valid_pfn(int node, int i)
 374 {
 375         unsigned long end_address, hole_next_pfn;
 376         unsigned long stop_address;
 377         pg_data_t *pgdat = NODE_DATA(node);
 378
 379         end_address = (unsigned long) &vmem_map[pgdat->node_start_pfn + i];
 380         end_address = PAGE_ALIGN(end_address);
 381
 382         stop_address = (unsigned long) &vmem_map[
 383                 pgdat->node_start_pfn + pgdat->node_spanned_pages];
 384
 385         do {
 386                 pgd_t *pgd;
 387                 pud_t *pud;
 388                 pmd_t *pmd;
 389                 pte_t *pte;
 390
 391                 pgd = pgd_offset_k(end_address);
 392                 if (pgd_none(*pgd)) {
 393                         end_address += PGDIR_SIZE;
 394                         continue;
 395                 }
 396
 397                 pud = pud_offset(pgd, end_address);
 398                 if (pud_none(*pud)) {
 399                         end_address += PUD_SIZE;
 400                         continue;
 401                 }
 402
 403                 pmd = pmd_offset(pud, end_address);
 404                 if (pmd_none(*pmd)) {
 405                         end_address += PMD_SIZE;
 406                         continue;
 407                 }
 408
 409                 pte = pte_offset_kernel(pmd, end_address);
 410 retry_pte:
 411                 if (pte_none(*pte)) {
 412                         end_address += PAGE_SIZE;
 413                         pte++;
 414                         if ((end_address < stop_address) &&
 415                             (end_address != ALIGN(end_address, 1UL << PMD_SHIFT)))
 416                                 goto retry_pte;
 417                         continue;
 418                 }
 419                 /* Found next valid vmem_map page */
 420                 break;
 421         } while (end_address < stop_address);
 422
 423         end_address = min(end_address, stop_address);
 424         end_address = end_address - (unsigned long) vmem_map + sizeof(struct page) - 1;
 425         hole_next_pfn = end_address / sizeof(struct page);
 426         return hole_next_pfn - pgdat->node_start_pfn;
 427 }
 428
 429 int __init
 430 create_mem_map_page_table (u64 start, u64 end, void *arg)
 431 {
 432         unsigned long address, start_page, end_page;
 433         struct page *map_start, *map_end;
 434         int node;
 435         pgd_t *pgd;
 436         pud_t *pud;
 437         pmd_t *pmd;
 438         pte_t *pte;
 439
 440         map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
 441         map_end   = vmem_map + (__pa(end) >> PAGE_SHIFT);
 442
 443         start_page = (unsigned long) map_start & PAGE_MASK;
 444         end_page = PAGE_ALIGN((unsigned long) map_end);
 445         node = paddr_to_nid(__pa(start));
 446
 447         for (address = start_page; address < end_page; address += PAGE_SIZE) {
 448                 pgd = pgd_offset_k(address);
 449                 if (pgd_none(*pgd))
 450                         pgd_populate(&init_mm, pgd, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
 451                 pud = pud_offset(pgd, address);
 452
 453                 if (pud_none(*pud))
 454                         pud_populate(&init_mm, pud, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
 455                 pmd = pmd_offset(pud, address);
 456
 457                 if (pmd_none(*pmd))
 458                         pmd_populate_kernel(&init_mm, pmd, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
 459                 pte = pte_offset_kernel(pmd, address);
 460
 461                 if (pte_none(*pte))
 462                         set_pte(pte, pfn_pte(__pa(alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE)) >> PAGE_SHIFT,
 463                                              PAGE_KERNEL));
 464         }
 465         return 0;
 466 }
 467
 468 struct memmap_init_callback_data {
 469         struct page *start;
 470         struct page *end;
 471         int nid;
 472         unsigned long zone;
 473 };
 474
 475 static int __meminit
 476 virtual_memmap_init (u64 start, u64 end, void *arg)
 477 {
 478         struct memmap_init_callback_data *args;
 479         struct page *map_start, *map_end;
 480
 481         args = (struct memmap_init_callback_data *) arg;
 482         map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
 483         map_end   = vmem_map + (__pa(end) >> PAGE_SHIFT);
 484
 485         if (map_start < args->start)
 486                 map_start = args->start;
 487         if (map_end > args->end)
 488                 map_end = args->end;
 489
 490         /*
 491          * We have to initialize "out of bounds" struct page elements that fit completely
 492          * on the same pages that were allocated for the "in bounds" elements because they
 493          * may be referenced later (and found to be "reserved").
 494          */
 495         map_start -= ((unsigned long) map_start & (PAGE_SIZE - 1)) / sizeof(struct page);
 496         map_end += ((PAGE_ALIGN((unsigned long) map_end) - (unsigned long) map_end)
 497                     / sizeof(struct page));
 498
 499         if (map_start < map_end)
 500                 memmap_init_zone((unsigned long)(map_end - map_start),
 501                                  args->nid, args->zone, page_to_pfn(map_start),
 502                                  MEMMAP_EARLY);
 503         return 0;
 504 }
 505
 506 void __meminit
 507 memmap_init (unsigned long size, int nid, unsigned long zone,
 508              unsigned long start_pfn)
 509 {
 510         if (!vmem_map)
 511                 memmap_init_zone(size, nid, zone, start_pfn, MEMMAP_EARLY);
 512         else {
 513                 struct page *start;
 514                 struct memmap_init_callback_data args;
 515
 516                 start = pfn_to_page(start_pfn);
 517                 args.start = start;
 518                 args.end = start + size;
 519                 args.nid = nid;
 520                 args.zone = zone;
 521
 522                 efi_memmap_walk(virtual_memmap_init, &args);
 523         }
 524 }
 525
 526 int
 527 ia64_pfn_valid (unsigned long pfn)
 528 {
 529         char byte;
 530         struct page *pg = pfn_to_page(pfn);
 531
 532         return     (__get_user(byte, (char __user *) pg) == 0)
 533                 && ((((u64)pg & PAGE_MASK) == (((u64)(pg + 1) - 1) & PAGE_MASK))
 534                         || (__get_user(byte, (char __user *) (pg + 1) - 1) == 0));
 535 }
 536 EXPORT_SYMBOL(ia64_pfn_valid);
 537
 538 int __init
 539 find_largest_hole (u64 start, u64 end, void *arg)
 540 {
 541         u64 *max_gap = arg;
 542
 543         static u64 last_end = PAGE_OFFSET;
 544
 545         /* NOTE: this algorithm assumes efi memmap table is ordered */
 546
 547         if (*max_gap < (start - last_end))
 548                 *max_gap = start - last_end;
 549         last_end = end;
 550         return 0;
 551 }
 552
 553 #endif /* CONFIG_VIRTUAL_MEM_MAP */
 554
 555 int __init
 556 register_active_ranges(u64 start, u64 end, void *arg)
 557 {
 558         int nid = paddr_to_nid(__pa(start));
 559
 560         if (nid < 0)
 561                 nid = 0;
 562 #ifdef CONFIG_KEXEC
 563         if (start > crashk_res.start && start < crashk_res.end)
 564                 start = crashk_res.end;
 565         if (end > crashk_res.start && end < crashk_res.end)
 566                 end = crashk_res.start;
 567 #endif
 568
 569         if (start < end)
 570                 add_active_range(nid, __pa(start) >> PAGE_SHIFT,
 571                         __pa(end) >> PAGE_SHIFT);
 572         return 0;
 573 }
 574
 575 static int __init
 576 count_reserved_pages (u64 start, u64 end, void *arg)
 577 {
 578         unsigned long num_reserved = 0;
 579         unsigned long *count = arg;
 580
 581         for (; start < end; start += PAGE_SIZE)
 582                 if (PageReserved(virt_to_page(start)))
 583                         ++num_reserved;
 584         *count += num_reserved;
 585         return 0;
 586 }
 587
 588 int
 589 find_max_min_low_pfn (unsigned long start, unsigned long end, void *arg)
 590 {
 591         unsigned long pfn_start, pfn_end;
 592 #ifdef CONFIG_FLATMEM
 593         pfn_start = (PAGE_ALIGN(__pa(start))) >> PAGE_SHIFT;
 594         pfn_end = (PAGE_ALIGN(__pa(end - 1))) >> PAGE_SHIFT;
 595 #else
 596         pfn_start = GRANULEROUNDDOWN(__pa(start)) >> PAGE_SHIFT;
 597         pfn_end = GRANULEROUNDUP(__pa(end - 1)) >> PAGE_SHIFT;
 598 #endif
 599         min_low_pfn = min(min_low_pfn, pfn_start);
 600         max_low_pfn = max(max_low_pfn, pfn_end);
 601         return 0;
 602 }
 603
 604 /*
 605  * Boot command-line option "nolwsys" can be used to disable the use of any light-weight
 606  * system call handler.  When this option is in effect, all fsyscalls will end up bubbling
 607  * down into the kernel and calling the normal (heavy-weight) syscall handler.  This is
 608  * useful for performance testing, but conceivably could also come in handy for debugging
 609  * purposes.
 610  */
 611
 612 static int nolwsys __initdata;
 613
 614 static int __init
 615 nolwsys_setup (char *s)
 616 {
 617         nolwsys = 1;
 618         return 1;
 619 }
 620
 621 __setup("nolwsys", nolwsys_setup);
 622
 623 void __init
 624 mem_init (void)
 625 {
 626         long reserved_pages, codesize, datasize, initsize;
 627         pg_data_t *pgdat;
 628         int i;
 629         static struct kcore_list kcore_mem, kcore_vmem, kcore_kernel;
 630
 631         BUG_ON(PTRS_PER_PGD * sizeof(pgd_t) != PAGE_SIZE);
 632         BUG_ON(PTRS_PER_PMD * sizeof(pmd_t) != PAGE_SIZE);
 633         BUG_ON(PTRS_PER_PTE * sizeof(pte_t) != PAGE_SIZE);
 634
 635 #ifdef CONFIG_PCI
 636         /*
 637          * This needs to be called _after_ the command line has been parsed but _before_
 638          * any drivers that may need the PCI DMA interface are initialized or bootmem has
 639          * been freed.
 640          */
 641         platform_dma_init();
 642 #endif
 643
 644 #ifdef CONFIG_FLATMEM
 645         if (!mem_map)
 646                 BUG();
 647         max_mapnr = max_low_pfn;
 648 #endif
 649
 650         high_memory = __va(max_low_pfn * PAGE_SIZE);
 651
 652         kclist_add(&kcore_mem, __va(0), max_low_pfn * PAGE_SIZE);
 653         kclist_add(&kcore_vmem, (void *)VMALLOC_START, VMALLOC_END-VMALLOC_START);
 654         kclist_add(&kcore_kernel, _stext, _end - _stext);
 655
 656         for_each_online_pgdat(pgdat)
 657                 if (pgdat->bdata->node_bootmem_map)
 658                         totalram_pages += free_all_bootmem_node(pgdat);
 659
 660         reserved_pages = 0;
 661         efi_memmap_walk(count_reserved_pages, &reserved_pages);
 662
 663         codesize =  (unsigned long) _etext - (unsigned long) _stext;
 664         datasize =  (unsigned long) _edata - (unsigned long) _etext;
 665         initsize =  (unsigned long) __init_end - (unsigned long) __init_begin;
 666
 667         printk(KERN_INFO "Memory: %luk/%luk available (%luk code, %luk reserved, "
 668                "%luk data, %luk init)\n", (unsigned long) nr_free_pages() << (PAGE_SHIFT - 10),
 669                num_physpages << (PAGE_SHIFT - 10), codesize >> 10,
 670                reserved_pages << (PAGE_SHIFT - 10), datasize >> 10, initsize >> 10);
 671
 672
 673         /*
 674          * For fsyscall entrpoints with no light-weight handler, use the ordinary
 675          * (heavy-weight) handler, but mark it by setting bit 0, so the fsyscall entry
 676          * code can tell them apart.
 677          */
 678         for (i = 0; i < NR_syscalls; ++i) {
 679                 extern unsigned long fsyscall_table[NR_syscalls];
 680                 extern unsigned long sys_call_table[NR_syscalls];
 681
 682                 if (!fsyscall_table[i] || nolwsys)
 683                         fsyscall_table[i] = sys_call_table[i] | 1;
 684         }
 685         setup_gate();
 686
 687 #ifdef CONFIG_IA32_SUPPORT
 688         ia32_mem_init();
 689 #endif
 690 }
 691
 692 #ifdef CONFIG_MEMORY_HOTPLUG
 693 void online_page(struct page *page)
 694 {
 695         ClearPageReserved(page);
 696         init_page_count(page);
 697         __free_page(page);
 698         totalram_pages++;
 699         num_physpages++;
 700 }
 701
 702 int arch_add_memory(int nid, u64 start, u64 size)
 703 {
 704         pg_data_t *pgdat;
 705         struct zone *zone;
 706         unsigned long start_pfn = start >> PAGE_SHIFT;
 707         unsigned long nr_pages = size >> PAGE_SHIFT;
 708         int ret;
 709
 710         pgdat = NODE_DATA(nid);
 711
 712         zone = pgdat->node_zones + ZONE_NORMAL;
 713         ret = __add_pages(zone, start_pfn, nr_pages);
 714
 715         if (ret)
 716                 printk("%s: Problem encountered in __add_pages() as ret=%d\n",
 717                        __FUNCTION__,  ret);
 718
 719         return ret;
 720 }
 721 #ifdef CONFIG_MEMORY_HOTREMOVE
 722 int remove_memory(u64 start, u64 size)
 723 {
 724         unsigned long start_pfn, end_pfn;
 725         unsigned long timeout = 120 * HZ;
 726         int ret;
 727         start_pfn = start >> PAGE_SHIFT;
 728         end_pfn = start_pfn + (size >> PAGE_SHIFT);
 729         ret = offline_pages(start_pfn, end_pfn, timeout);
 730         if (ret)
 731                 goto out;
 732         /* we can free mem_map at this point */
 733 out:
 734         return ret;
 735 }
 736 EXPORT_SYMBOL_GPL(remove_memory);
 737 #endif /* CONFIG_MEMORY_HOTREMOVE */
 738 #endif