git.oblomov.eu Git - linux-2.6/blob - 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 DEFINE_PER_CPU(unsigned long *, __pgtable_quicklist);
  43 DEFINE_PER_CPU(long, __pgtable_quicklist_size);
  44
  45 extern void ia64_tlb_init (void);
  46
  47 unsigned long MAX_DMA_ADDRESS = PAGE_OFFSET + 0x100000000UL;
  48
  49 #ifdef CONFIG_VIRTUAL_MEM_MAP
  50 unsigned long vmalloc_end = VMALLOC_END_INIT;
  51 EXPORT_SYMBOL(vmalloc_end);
  52 struct page *vmem_map;
  53 EXPORT_SYMBOL(vmem_map);
  54 #endif
  55
  56 struct page *zero_page_memmap_ptr;      /* map entry for zero page */
  57 EXPORT_SYMBOL(zero_page_memmap_ptr);
  58
  59 #define MIN_PGT_PAGES                   25UL
  60 #define MAX_PGT_FREES_PER_PASS          16L
  61 #define PGT_FRACTION_OF_NODE_MEM        16
  62
  63 static inline long
  64 max_pgt_pages(void)
  65 {
  66         u64 node_free_pages, max_pgt_pages;
  67
  68 #ifndef CONFIG_NUMA
  69         node_free_pages = nr_free_pages();
  70 #else
  71         node_free_pages = nr_free_pages_pgdat(NODE_DATA(numa_node_id()));
  72 #endif
  73         max_pgt_pages = node_free_pages / PGT_FRACTION_OF_NODE_MEM;
  74         max_pgt_pages = max(max_pgt_pages, MIN_PGT_PAGES);
  75         return max_pgt_pages;
  76 }
  77
  78 static inline long
  79 min_pages_to_free(void)
  80 {
  81         long pages_to_free;
  82
  83         pages_to_free = pgtable_quicklist_size - max_pgt_pages();
  84         pages_to_free = min(pages_to_free, MAX_PGT_FREES_PER_PASS);
  85         return pages_to_free;
  86 }
  87
  88 void
  89 check_pgt_cache(void)
  90 {
  91         long pages_to_free;
  92
  93         if (unlikely(pgtable_quicklist_size <= MIN_PGT_PAGES))
  94                 return;
  95
  96         preempt_disable();
  97         while (unlikely((pages_to_free = min_pages_to_free()) > 0)) {
  98                 while (pages_to_free--) {
  99                         free_page((unsigned long)pgtable_quicklist_alloc());
 100                 }
 101                 preempt_enable();
 102                 preempt_disable();
 103         }
 104         preempt_enable();
 105 }
 106
 107 void
 108 lazy_mmu_prot_update (pte_t pte)
 109 {
 110         unsigned long addr;
 111         struct page *page;
 112         unsigned long order;
 113
 114         if (!pte_exec(pte))
 115                 return;                         /* not an executable page... */
 116
 117         page = pte_page(pte);
 118         addr = (unsigned long) page_address(page);
 119
 120         if (test_bit(PG_arch_1, &page->flags))
 121                 return;                         /* i-cache is already coherent with d-cache */
 122
 123         if (PageCompound(page)) {
 124                 order = (unsigned long) (page[1].lru.prev);
 125                 flush_icache_range(addr, addr + (1UL << order << PAGE_SHIFT));
 126         }
 127         else
 128                 flush_icache_range(addr, addr + PAGE_SIZE);
 129         set_bit(PG_arch_1, &page->flags);       /* mark page as clean */
 130 }
 131
 132 inline void
 133 ia64_set_rbs_bot (void)
 134 {
 135         unsigned long stack_size = current->signal->rlim[RLIMIT_STACK].rlim_max & -16;
 136
 137         if (stack_size > MAX_USER_STACK_SIZE)
 138                 stack_size = MAX_USER_STACK_SIZE;
 139         current->thread.rbs_bot = STACK_TOP - stack_size;
 140 }
 141
 142 /*
 143  * This performs some platform-dependent address space initialization.
 144  * On IA-64, we want to setup the VM area for the register backing
 145  * store (which grows upwards) and install the gateway page which is
 146  * used for signal trampolines, etc.
 147  */
 148 void
 149 ia64_init_addr_space (void)
 150 {
 151         struct vm_area_struct *vma;
 152
 153         ia64_set_rbs_bot();
 154
 155         /*
 156          * If we're out of memory and kmem_cache_alloc() returns NULL, we simply ignore
 157          * the problem.  When the process attempts to write to the register backing store
 158          * for the first time, it will get a SEGFAULT in this case.
 159          */
 160         vma = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
 161         if (vma) {
 162                 memset(vma, 0, sizeof(*vma));
 163                 vma->vm_mm = current->mm;
 164                 vma->vm_start = current->thread.rbs_bot & PAGE_MASK;
 165                 vma->vm_end = vma->vm_start + PAGE_SIZE;
 166                 vma->vm_page_prot = protection_map[VM_DATA_DEFAULT_FLAGS & 0x7];
 167                 vma->vm_flags = VM_DATA_DEFAULT_FLAGS|VM_GROWSUP|VM_ACCOUNT;
 168                 down_write(&current->mm->mmap_sem);
 169                 if (insert_vm_struct(current->mm, vma)) {
 170                         up_write(&current->mm->mmap_sem);
 171                         kmem_cache_free(vm_area_cachep, vma);
 172                         return;
 173                 }
 174                 up_write(&current->mm->mmap_sem);
 175         }
 176
 177         /* map NaT-page at address zero to speed up speculative dereferencing of NULL: */
 178         if (!(current->personality & MMAP_PAGE_ZERO)) {
 179                 vma = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
 180                 if (vma) {
 181                         memset(vma, 0, sizeof(*vma));
 182                         vma->vm_mm = current->mm;
 183                         vma->vm_end = PAGE_SIZE;
 184                         vma->vm_page_prot = __pgprot(pgprot_val(PAGE_READONLY) | _PAGE_MA_NAT);
 185                         vma->vm_flags = VM_READ | VM_MAYREAD | VM_IO | VM_RESERVED;
 186                         down_write(&current->mm->mmap_sem);
 187                         if (insert_vm_struct(current->mm, vma)) {
 188                                 up_write(&current->mm->mmap_sem);
 189                                 kmem_cache_free(vm_area_cachep, vma);
 190                                 return;
 191                         }
 192                         up_write(&current->mm->mmap_sem);
 193                 }
 194         }
 195 }
 196
 197 void
 198 free_initmem (void)
 199 {
 200         unsigned long addr, eaddr;
 201
 202         addr = (unsigned long) ia64_imva(__init_begin);
 203         eaddr = (unsigned long) ia64_imva(__init_end);
 204         while (addr < eaddr) {
 205                 ClearPageReserved(virt_to_page(addr));
 206                 init_page_count(virt_to_page(addr));
 207                 free_page(addr);
 208                 ++totalram_pages;
 209                 addr += PAGE_SIZE;
 210         }
 211         printk(KERN_INFO "Freeing unused kernel memory: %ldkB freed\n",
 212                (__init_end - __init_begin) >> 10);
 213 }
 214
 215 void __init
 216 free_initrd_mem (unsigned long start, unsigned long end)
 217 {
 218         struct page *page;
 219         /*
 220          * EFI uses 4KB pages while the kernel can use 4KB or bigger.
 221          * Thus EFI and the kernel may have different page sizes. It is
 222          * therefore possible to have the initrd share the same page as
 223          * the end of the kernel (given current setup).
 224          *
 225          * To avoid freeing/using the wrong page (kernel sized) we:
 226          *      - align up the beginning of initrd
 227          *      - align down the end of initrd
 228          *
 229          *  |             |
 230          *  |=============| a000
 231          *  |             |
 232          *  |             |
 233          *  |             | 9000
 234          *  |/////////////|
 235          *  |/////////////|
 236          *  |=============| 8000
 237          *  |///INITRD////|
 238          *  |/////////////|
 239          *  |/////////////| 7000
 240          *  |             |
 241          *  |KKKKKKKKKKKKK|
 242          *  |=============| 6000
 243          *  |KKKKKKKKKKKKK|
 244          *  |KKKKKKKKKKKKK|
 245          *  K=kernel using 8KB pages
 246          *
 247          * In this example, we must free page 8000 ONLY. So we must align up
 248          * initrd_start and keep initrd_end as is.
 249          */
 250         start = PAGE_ALIGN(start);
 251         end = end & PAGE_MASK;
 252
 253         if (start < end)
 254                 printk(KERN_INFO "Freeing initrd memory: %ldkB freed\n", (end - start) >> 10);
 255
 256         for (; start < end; start += PAGE_SIZE) {
 257                 if (!virt_addr_valid(start))
 258                         continue;
 259                 page = virt_to_page(start);
 260                 ClearPageReserved(page);
 261                 init_page_count(page);
 262                 free_page(start);
 263                 ++totalram_pages;
 264         }
 265 }
 266
 267 /*
 268  * This installs a clean page in the kernel's page table.
 269  */
 270 static struct page * __init
 271 put_kernel_page (struct page *page, unsigned long address, pgprot_t pgprot)
 272 {
 273         pgd_t *pgd;
 274         pud_t *pud;
 275         pmd_t *pmd;
 276         pte_t *pte;
 277
 278         if (!PageReserved(page))
 279                 printk(KERN_ERR "put_kernel_page: page at 0x%p not in reserved memory\n",
 280                        page_address(page));
 281
 282         pgd = pgd_offset_k(address);            /* note: this is NOT pgd_offset()! */
 283
 284         {
 285                 pud = pud_alloc(&init_mm, pgd, address);
 286                 if (!pud)
 287                         goto out;
 288                 pmd = pmd_alloc(&init_mm, pud, address);
 289                 if (!pmd)
 290                         goto out;
 291                 pte = pte_alloc_kernel(pmd, address);
 292                 if (!pte)
 293                         goto out;
 294                 if (!pte_none(*pte))
 295                         goto out;
 296                 set_pte(pte, mk_pte(page, pgprot));
 297         }
 298   out:
 299         /* no need for flush_tlb */
 300         return page;
 301 }
 302
 303 static void __init
 304 setup_gate (void)
 305 {
 306         struct page *page;
 307
 308         /*
 309          * Map the gate page twice: once read-only to export the ELF
 310          * headers etc. and once execute-only page to enable
 311          * privilege-promotion via "epc":
 312          */
 313         page = virt_to_page(ia64_imva(__start_gate_section));
 314         put_kernel_page(page, GATE_ADDR, PAGE_READONLY);
 315 #ifdef HAVE_BUGGY_SEGREL
 316         page = virt_to_page(ia64_imva(__start_gate_section + PAGE_SIZE));
 317         put_kernel_page(page, GATE_ADDR + PAGE_SIZE, PAGE_GATE);
 318 #else
 319         put_kernel_page(page, GATE_ADDR + PERCPU_PAGE_SIZE, PAGE_GATE);
 320         /* Fill in the holes (if any) with read-only zero pages: */
 321         {
 322                 unsigned long addr;
 323
 324                 for (addr = GATE_ADDR + PAGE_SIZE;
 325                      addr < GATE_ADDR + PERCPU_PAGE_SIZE;
 326                      addr += PAGE_SIZE)
 327                 {
 328                         put_kernel_page(ZERO_PAGE(0), addr,
 329                                         PAGE_READONLY);
 330                         put_kernel_page(ZERO_PAGE(0), addr + PERCPU_PAGE_SIZE,
 331                                         PAGE_READONLY);
 332                 }
 333         }
 334 #endif
 335         ia64_patch_gate();
 336 }
 337
 338 void __devinit
 339 ia64_mmu_init (void *my_cpu_data)
 340 {
 341         unsigned long psr, pta, impl_va_bits;
 342         extern void __devinit tlb_init (void);
 343
 344 #ifdef CONFIG_DISABLE_VHPT
 345 #       define VHPT_ENABLE_BIT  0
 346 #else
 347 #       define VHPT_ENABLE_BIT  1
 348 #endif
 349
 350         /* Pin mapping for percpu area into TLB */
 351         psr = ia64_clear_ic();
 352         ia64_itr(0x2, IA64_TR_PERCPU_DATA, PERCPU_ADDR,
 353                  pte_val(pfn_pte(__pa(my_cpu_data) >> PAGE_SHIFT, PAGE_KERNEL)),
 354                  PERCPU_PAGE_SHIFT);
 355
 356         ia64_set_psr(psr);
 357         ia64_srlz_i();
 358
 359         /*
 360          * Check if the virtually mapped linear page table (VMLPT) overlaps with a mapped
 361          * address space.  The IA-64 architecture guarantees that at least 50 bits of
 362          * virtual address space are implemented but if we pick a large enough page size
 363          * (e.g., 64KB), the mapped address space is big enough that it will overlap with
 364          * VMLPT.  I assume that once we run on machines big enough to warrant 64KB pages,
 365          * IMPL_VA_MSB will be significantly bigger, so this is unlikely to become a
 366          * problem in practice.  Alternatively, we could truncate the top of the mapped
 367          * address space to not permit mappings that would overlap with the VMLPT.
 368          * --davidm 00/12/06
 369          */
 370 #       define pte_bits                 3
 371 #       define mapped_space_bits        (3*(PAGE_SHIFT - pte_bits) + PAGE_SHIFT)
 372         /*
 373          * The virtual page table has to cover the entire implemented address space within
 374          * a region even though not all of this space may be mappable.  The reason for
 375          * this is that the Access bit and Dirty bit fault handlers perform
 376          * non-speculative accesses to the virtual page table, so the address range of the
 377          * virtual page table itself needs to be covered by virtual page table.
 378          */
 379 #       define vmlpt_bits               (impl_va_bits - PAGE_SHIFT + pte_bits)
 380 #       define POW2(n)                  (1ULL << (n))
 381
 382         impl_va_bits = ffz(~(local_cpu_data->unimpl_va_mask | (7UL << 61)));
 383
 384         if (impl_va_bits < 51 || impl_va_bits > 61)
 385                 panic("CPU has bogus IMPL_VA_MSB value of %lu!\n", impl_va_bits - 1);
 386         /*
 387          * mapped_space_bits - PAGE_SHIFT is the total number of ptes we need,
 388          * which must fit into "vmlpt_bits - pte_bits" slots. Second half of
 389          * the test makes sure that our mapped space doesn't overlap the
 390          * unimplemented hole in the middle of the region.
 391          */
 392         if ((mapped_space_bits - PAGE_SHIFT > vmlpt_bits - pte_bits) ||
 393             (mapped_space_bits > impl_va_bits - 1))
 394                 panic("Cannot build a big enough virtual-linear page table"
 395                       " to cover mapped address space.\n"
 396                       " Try using a smaller page size.\n");
 397
 398
 399         /* place the VMLPT at the end of each page-table mapped region: */
 400         pta = POW2(61) - POW2(vmlpt_bits);
 401
 402         /*
 403          * Set the (virtually mapped linear) page table address.  Bit
 404          * 8 selects between the short and long format, bits 2-7 the
 405          * size of the table, and bit 0 whether the VHPT walker is
 406          * enabled.
 407          */
 408         ia64_set_pta(pta | (0 << 8) | (vmlpt_bits << 2) | VHPT_ENABLE_BIT);
 409
 410         ia64_tlb_init();
 411
 412 #ifdef  CONFIG_HUGETLB_PAGE
 413         ia64_set_rr(HPAGE_REGION_BASE, HPAGE_SHIFT << 2);
 414         ia64_srlz_d();
 415 #endif
 416 }
 417
 418 #ifdef CONFIG_VIRTUAL_MEM_MAP
 419 int vmemmap_find_next_valid_pfn(int node, int i)
 420 {
 421         unsigned long end_address, hole_next_pfn;
 422         unsigned long stop_address;
 423         pg_data_t *pgdat = NODE_DATA(node);
 424
 425         end_address = (unsigned long) &vmem_map[pgdat->node_start_pfn + i];
 426         end_address = PAGE_ALIGN(end_address);
 427
 428         stop_address = (unsigned long) &vmem_map[
 429                 pgdat->node_start_pfn + pgdat->node_spanned_pages];
 430
 431         do {
 432                 pgd_t *pgd;
 433                 pud_t *pud;
 434                 pmd_t *pmd;
 435                 pte_t *pte;
 436
 437                 pgd = pgd_offset_k(end_address);
 438                 if (pgd_none(*pgd)) {
 439                         end_address += PGDIR_SIZE;
 440                         continue;
 441                 }
 442
 443                 pud = pud_offset(pgd, end_address);
 444                 if (pud_none(*pud)) {
 445                         end_address += PUD_SIZE;
 446                         continue;
 447                 }
 448
 449                 pmd = pmd_offset(pud, end_address);
 450                 if (pmd_none(*pmd)) {
 451                         end_address += PMD_SIZE;
 452                         continue;
 453                 }
 454
 455                 pte = pte_offset_kernel(pmd, end_address);
 456 retry_pte:
 457                 if (pte_none(*pte)) {
 458                         end_address += PAGE_SIZE;
 459                         pte++;
 460                         if ((end_address < stop_address) &&
 461                             (end_address != ALIGN(end_address, 1UL << PMD_SHIFT)))
 462                                 goto retry_pte;
 463                         continue;
 464                 }
 465                 /* Found next valid vmem_map page */
 466                 break;
 467         } while (end_address < stop_address);
 468
 469         end_address = min(end_address, stop_address);
 470         end_address = end_address - (unsigned long) vmem_map + sizeof(struct page) - 1;
 471         hole_next_pfn = end_address / sizeof(struct page);
 472         return hole_next_pfn - pgdat->node_start_pfn;
 473 }
 474
 475 int __init
 476 create_mem_map_page_table (u64 start, u64 end, void *arg)
 477 {
 478         unsigned long address, start_page, end_page;
 479         struct page *map_start, *map_end;
 480         int node;
 481         pgd_t *pgd;
 482         pud_t *pud;
 483         pmd_t *pmd;
 484         pte_t *pte;
 485
 486         map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
 487         map_end   = vmem_map + (__pa(end) >> PAGE_SHIFT);
 488
 489         start_page = (unsigned long) map_start & PAGE_MASK;
 490         end_page = PAGE_ALIGN((unsigned long) map_end);
 491         node = paddr_to_nid(__pa(start));
 492
 493         for (address = start_page; address < end_page; address += PAGE_SIZE) {
 494                 pgd = pgd_offset_k(address);
 495                 if (pgd_none(*pgd))
 496                         pgd_populate(&init_mm, pgd, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
 497                 pud = pud_offset(pgd, address);
 498
 499                 if (pud_none(*pud))
 500                         pud_populate(&init_mm, pud, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
 501                 pmd = pmd_offset(pud, address);
 502
 503                 if (pmd_none(*pmd))
 504                         pmd_populate_kernel(&init_mm, pmd, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
 505                 pte = pte_offset_kernel(pmd, address);
 506
 507                 if (pte_none(*pte))
 508                         set_pte(pte, pfn_pte(__pa(alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE)) >> PAGE_SHIFT,
 509                                              PAGE_KERNEL));
 510         }
 511         return 0;
 512 }
 513
 514 struct memmap_init_callback_data {
 515         struct page *start;
 516         struct page *end;
 517         int nid;
 518         unsigned long zone;
 519 };
 520
 521 static int
 522 virtual_memmap_init (u64 start, u64 end, void *arg)
 523 {
 524         struct memmap_init_callback_data *args;
 525         struct page *map_start, *map_end;
 526
 527         args = (struct memmap_init_callback_data *) arg;
 528         map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
 529         map_end   = vmem_map + (__pa(end) >> PAGE_SHIFT);
 530
 531         if (map_start < args->start)
 532                 map_start = args->start;
 533         if (map_end > args->end)
 534                 map_end = args->end;
 535
 536         /*
 537          * We have to initialize "out of bounds" struct page elements that fit completely
 538          * on the same pages that were allocated for the "in bounds" elements because they
 539          * may be referenced later (and found to be "reserved").
 540          */
 541         map_start -= ((unsigned long) map_start & (PAGE_SIZE - 1)) / sizeof(struct page);
 542         map_end += ((PAGE_ALIGN((unsigned long) map_end) - (unsigned long) map_end)
 543                     / sizeof(struct page));
 544
 545         if (map_start < map_end)
 546                 memmap_init_zone((unsigned long)(map_end - map_start),
 547                                  args->nid, args->zone, page_to_pfn(map_start),
 548                                  MEMMAP_EARLY);
 549         return 0;
 550 }
 551
 552 void
 553 memmap_init (unsigned long size, int nid, unsigned long zone,
 554              unsigned long start_pfn)
 555 {
 556         if (!vmem_map)
 557                 memmap_init_zone(size, nid, zone, start_pfn, MEMMAP_EARLY);
 558         else {
 559                 struct page *start;
 560                 struct memmap_init_callback_data args;
 561
 562                 start = pfn_to_page(start_pfn);
 563                 args.start = start;
 564                 args.end = start + size;
 565                 args.nid = nid;
 566                 args.zone = zone;
 567
 568                 efi_memmap_walk(virtual_memmap_init, &args);
 569         }
 570 }
 571
 572 int
 573 ia64_pfn_valid (unsigned long pfn)
 574 {
 575         char byte;
 576         struct page *pg = pfn_to_page(pfn);
 577
 578         return     (__get_user(byte, (char __user *) pg) == 0)
 579                 && ((((u64)pg & PAGE_MASK) == (((u64)(pg + 1) - 1) & PAGE_MASK))
 580                         || (__get_user(byte, (char __user *) (pg + 1) - 1) == 0));
 581 }
 582 EXPORT_SYMBOL(ia64_pfn_valid);
 583
 584 int __init
 585 find_largest_hole (u64 start, u64 end, void *arg)
 586 {
 587         u64 *max_gap = arg;
 588
 589         static u64 last_end = PAGE_OFFSET;
 590
 591         /* NOTE: this algorithm assumes efi memmap table is ordered */
 592
 593         if (*max_gap < (start - last_end))
 594                 *max_gap = start - last_end;
 595         last_end = end;
 596         return 0;
 597 }
 598
 599 #endif /* CONFIG_VIRTUAL_MEM_MAP */
 600
 601 int __init
 602 register_active_ranges(u64 start, u64 end, void *arg)
 603 {
 604         int nid = paddr_to_nid(__pa(start));
 605
 606         if (nid < 0)
 607                 nid = 0;
 608 #ifdef CONFIG_KEXEC
 609         if (start > crashk_res.start && start < crashk_res.end)
 610                 start = crashk_res.end;
 611         if (end > crashk_res.start && end < crashk_res.end)
 612                 end = crashk_res.start;
 613 #endif
 614
 615         if (start < end)
 616                 add_active_range(nid, __pa(start) >> PAGE_SHIFT,
 617                         __pa(end) >> PAGE_SHIFT);
 618         return 0;
 619 }
 620
 621 static int __init
 622 count_reserved_pages (u64 start, u64 end, void *arg)
 623 {
 624         unsigned long num_reserved = 0;
 625         unsigned long *count = arg;
 626
 627         for (; start < end; start += PAGE_SIZE)
 628                 if (PageReserved(virt_to_page(start)))
 629                         ++num_reserved;
 630         *count += num_reserved;
 631         return 0;
 632 }
 633
 634 /*
 635  * Boot command-line option "nolwsys" can be used to disable the use of any light-weight
 636  * system call handler.  When this option is in effect, all fsyscalls will end up bubbling
 637  * down into the kernel and calling the normal (heavy-weight) syscall handler.  This is
 638  * useful for performance testing, but conceivably could also come in handy for debugging
 639  * purposes.
 640  */
 641
 642 static int nolwsys __initdata;
 643
 644 static int __init
 645 nolwsys_setup (char *s)
 646 {
 647         nolwsys = 1;
 648         return 1;
 649 }
 650
 651 __setup("nolwsys", nolwsys_setup);
 652
 653 void __init
 654 mem_init (void)
 655 {
 656         long reserved_pages, codesize, datasize, initsize;
 657         pg_data_t *pgdat;
 658         int i;
 659         static struct kcore_list kcore_mem, kcore_vmem, kcore_kernel;
 660
 661         BUG_ON(PTRS_PER_PGD * sizeof(pgd_t) != PAGE_SIZE);
 662         BUG_ON(PTRS_PER_PMD * sizeof(pmd_t) != PAGE_SIZE);
 663         BUG_ON(PTRS_PER_PTE * sizeof(pte_t) != PAGE_SIZE);
 664
 665 #ifdef CONFIG_PCI
 666         /*
 667          * This needs to be called _after_ the command line has been parsed but _before_
 668          * any drivers that may need the PCI DMA interface are initialized or bootmem has
 669          * been freed.
 670          */
 671         platform_dma_init();
 672 #endif
 673
 674 #ifdef CONFIG_FLATMEM
 675         if (!mem_map)
 676                 BUG();
 677         max_mapnr = max_low_pfn;
 678 #endif
 679
 680         high_memory = __va(max_low_pfn * PAGE_SIZE);
 681
 682         kclist_add(&kcore_mem, __va(0), max_low_pfn * PAGE_SIZE);
 683         kclist_add(&kcore_vmem, (void *)VMALLOC_START, VMALLOC_END-VMALLOC_START);
 684         kclist_add(&kcore_kernel, _stext, _end - _stext);
 685
 686         for_each_online_pgdat(pgdat)
 687                 if (pgdat->bdata->node_bootmem_map)
 688                         totalram_pages += free_all_bootmem_node(pgdat);
 689
 690         reserved_pages = 0;
 691         efi_memmap_walk(count_reserved_pages, &reserved_pages);
 692
 693         codesize =  (unsigned long) _etext - (unsigned long) _stext;
 694         datasize =  (unsigned long) _edata - (unsigned long) _etext;
 695         initsize =  (unsigned long) __init_end - (unsigned long) __init_begin;
 696
 697         printk(KERN_INFO "Memory: %luk/%luk available (%luk code, %luk reserved, "
 698                "%luk data, %luk init)\n", (unsigned long) nr_free_pages() << (PAGE_SHIFT - 10),
 699                num_physpages << (PAGE_SHIFT - 10), codesize >> 10,
 700                reserved_pages << (PAGE_SHIFT - 10), datasize >> 10, initsize >> 10);
 701
 702
 703         /*
 704          * For fsyscall entrpoints with no light-weight handler, use the ordinary
 705          * (heavy-weight) handler, but mark it by setting bit 0, so the fsyscall entry
 706          * code can tell them apart.
 707          */
 708         for (i = 0; i < NR_syscalls; ++i) {
 709                 extern unsigned long fsyscall_table[NR_syscalls];
 710                 extern unsigned long sys_call_table[NR_syscalls];
 711
 712                 if (!fsyscall_table[i] || nolwsys)
 713                         fsyscall_table[i] = sys_call_table[i] | 1;
 714         }
 715         setup_gate();
 716
 717 #ifdef CONFIG_IA32_SUPPORT
 718         ia32_mem_init();
 719 #endif
 720 }
 721
 722 #ifdef CONFIG_MEMORY_HOTPLUG
 723 void online_page(struct page *page)
 724 {
 725         ClearPageReserved(page);
 726         init_page_count(page);
 727         __free_page(page);
 728         totalram_pages++;
 729         num_physpages++;
 730 }
 731
 732 int arch_add_memory(int nid, u64 start, u64 size)
 733 {
 734         pg_data_t *pgdat;
 735         struct zone *zone;
 736         unsigned long start_pfn = start >> PAGE_SHIFT;
 737         unsigned long nr_pages = size >> PAGE_SHIFT;
 738         int ret;
 739
 740         pgdat = NODE_DATA(nid);
 741
 742         zone = pgdat->node_zones + ZONE_NORMAL;
 743         ret = __add_pages(zone, start_pfn, nr_pages);
 744
 745         if (ret)
 746                 printk("%s: Problem encountered in __add_pages() as ret=%d\n",
 747                        __FUNCTION__,  ret);
 748
 749         return ret;
 750 }
 751
 752 int remove_memory(u64 start, u64 size)
 753 {
 754         return -EINVAL;
 755 }
 756 EXPORT_SYMBOL_GPL(remove_memory);
 757 #endif