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/memblock.h>
  14 #include <linux/mm.h>
  15 #include <linux/mmzone.h>
  16 #include <linux/module.h>
  17 #include <linux/personality.h>
  18 #include <linux/reboot.h>
  19 #include <linux/slab.h>
  20 #include <linux/swap.h>
  21 #include <linux/proc_fs.h>
  22 #include <linux/bitops.h>
  23 #include <linux/kexec.h>
  24
  25 #include <asm/dma.h>
  26 #include <asm/io.h>
  27 #include <asm/machvec.h>
  28 #include <asm/numa.h>
  29 #include <asm/patch.h>
  30 #include <asm/pgalloc.h>
  31 #include <asm/sal.h>
  32 #include <asm/sections.h>
  33 #include <asm/tlb.h>
  34 #include <asm/uaccess.h>
  35 #include <asm/unistd.h>
  36 #include <asm/mca.h>
  37 #include <asm/paravirt.h>
  38
  39 extern void ia64_tlb_init (void);
  40
  41 unsigned long MAX_DMA_ADDRESS = PAGE_OFFSET + 0x100000000UL;
  42
  43 #ifdef CONFIG_VIRTUAL_MEM_MAP
  44 unsigned long VMALLOC_END = VMALLOC_END_INIT;
  45 EXPORT_SYMBOL(VMALLOC_END);
  46 struct page *vmem_map;
  47 EXPORT_SYMBOL(vmem_map);
  48 #endif
  49
  50 struct page *zero_page_memmap_ptr;      /* map entry for zero page */
  51 EXPORT_SYMBOL(zero_page_memmap_ptr);
  52
  53 void
  54 __ia64_sync_icache_dcache (pte_t pte)
  55 {
  56         unsigned long addr;
  57         struct page *page;
  58
  59         page = pte_page(pte);
  60         addr = (unsigned long) page_address(page);
  61
  62         if (test_bit(PG_arch_1, &page->flags))
  63                 return;                         /* i-cache is already coherent with d-cache */
  64
  65         flush_icache_range(addr, addr + (PAGE_SIZE << compound_order(page)));
  66         set_bit(PG_arch_1, &page->flags);       /* mark page as clean */
  67 }
  68
  69 /*
  70  * Since DMA is i-cache coherent, any (complete) pages that were written via
  71  * DMA can be marked as "clean" so that lazy_mmu_prot_update() doesn't have to
  72  * flush them when they get mapped into an executable vm-area.
  73  */
  74 void
  75 dma_mark_clean(void *addr, size_t size)
  76 {
  77         unsigned long pg_addr, end;
  78
  79         pg_addr = PAGE_ALIGN((unsigned long) addr);
  80         end = (unsigned long) addr + size;
  81         while (pg_addr + PAGE_SIZE <= end) {
  82                 struct page *page = virt_to_page(pg_addr);
  83                 set_bit(PG_arch_1, &page->flags);
  84                 pg_addr += PAGE_SIZE;
  85         }
  86 }
  87
  88 inline void
  89 ia64_set_rbs_bot (void)
  90 {
  91         unsigned long stack_size = rlimit_max(RLIMIT_STACK) & -16;
  92
  93         if (stack_size > MAX_USER_STACK_SIZE)
  94                 stack_size = MAX_USER_STACK_SIZE;
  95         current->thread.rbs_bot = PAGE_ALIGN(current->mm->start_stack - stack_size);
  96 }
  97
  98 /*
  99  * This performs some platform-dependent address space initialization.
 100  * On IA-64, we want to setup the VM area for the register backing
 101  * store (which grows upwards) and install the gateway page which is
 102  * used for signal trampolines, etc.
 103  */
 104 void
 105 ia64_init_addr_space (void)
 106 {
 107         struct vm_area_struct *vma;
 108
 109         ia64_set_rbs_bot();
 110
 111         /*
 112          * If we're out of memory and kmem_cache_alloc() returns NULL, we simply ignore
 113          * the problem.  When the process attempts to write to the register backing store
 114          * for the first time, it will get a SEGFAULT in this case.
 115          */
 116         vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
 117         if (vma) {
 118                 INIT_LIST_HEAD(&vma->anon_vma_chain);
 119                 vma->vm_mm = current->mm;
 120                 vma->vm_start = current->thread.rbs_bot & PAGE_MASK;
 121                 vma->vm_end = vma->vm_start + PAGE_SIZE;
 122                 vma->vm_flags = VM_DATA_DEFAULT_FLAGS|VM_GROWSUP|VM_ACCOUNT;
 123                 vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
 124                 down_write(&current->mm->mmap_sem);
 125                 if (insert_vm_struct(current->mm, vma)) {
 126                         up_write(&current->mm->mmap_sem);
 127                         kmem_cache_free(vm_area_cachep, vma);
 128                         return;
 129                 }
 130                 up_write(&current->mm->mmap_sem);
 131         }
 132
 133         /* map NaT-page at address zero to speed up speculative dereferencing of NULL: */
 134         if (!(current->personality & MMAP_PAGE_ZERO)) {
 135                 vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
 136                 if (vma) {
 137                         INIT_LIST_HEAD(&vma->anon_vma_chain);
 138                         vma->vm_mm = current->mm;
 139                         vma->vm_end = PAGE_SIZE;
 140                         vma->vm_page_prot = __pgprot(pgprot_val(PAGE_READONLY) | _PAGE_MA_NAT);
 141                         vma->vm_flags = VM_READ | VM_MAYREAD | VM_IO |
 142                                         VM_DONTEXPAND | VM_DONTDUMP;
 143                         down_write(&current->mm->mmap_sem);
 144                         if (insert_vm_struct(current->mm, vma)) {
 145                                 up_write(&current->mm->mmap_sem);
 146                                 kmem_cache_free(vm_area_cachep, vma);
 147                                 return;
 148                         }
 149                         up_write(&current->mm->mmap_sem);
 150                 }
 151         }
 152 }
 153
 154 void
 155 free_initmem (void)
 156 {
 157         free_reserved_area(ia64_imva(__init_begin), ia64_imva(__init_end),
 158                            -1, "unused kernel");
 159 }
 160
 161 void __init
 162 free_initrd_mem (unsigned long start, unsigned long end)
 163 {
 164         /*
 165          * EFI uses 4KB pages while the kernel can use 4KB or bigger.
 166          * Thus EFI and the kernel may have different page sizes. It is
 167          * therefore possible to have the initrd share the same page as
 168          * the end of the kernel (given current setup).
 169          *
 170          * To avoid freeing/using the wrong page (kernel sized) we:
 171          *      - align up the beginning of initrd
 172          *      - align down the end of initrd
 173          *
 174          *  |             |
 175          *  |=============| a000
 176          *  |             |
 177          *  |             |
 178          *  |             | 9000
 179          *  |/////////////|
 180          *  |/////////////|
 181          *  |=============| 8000
 182          *  |///INITRD////|
 183          *  |/////////////|
 184          *  |/////////////| 7000
 185          *  |             |
 186          *  |KKKKKKKKKKKKK|
 187          *  |=============| 6000
 188          *  |KKKKKKKKKKKKK|
 189          *  |KKKKKKKKKKKKK|
 190          *  K=kernel using 8KB pages
 191          *
 192          * In this example, we must free page 8000 ONLY. So we must align up
 193          * initrd_start and keep initrd_end as is.
 194          */
 195         start = PAGE_ALIGN(start);
 196         end = end & PAGE_MASK;
 197
 198         if (start < end)
 199                 printk(KERN_INFO "Freeing initrd memory: %ldkB freed\n", (end - start) >> 10);
 200
 201         for (; start < end; start += PAGE_SIZE) {
 202                 if (!virt_addr_valid(start))
 203                         continue;
 204                 free_reserved_page(virt_to_page(start));
 205         }
 206 }
 207
 208 /*
 209  * This installs a clean page in the kernel's page table.
 210  */
 211 static struct page * __init
 212 put_kernel_page (struct page *page, unsigned long address, pgprot_t pgprot)
 213 {
 214         pgd_t *pgd;
 215         pud_t *pud;
 216         pmd_t *pmd;
 217         pte_t *pte;
 218
 219         if (!PageReserved(page))
 220                 printk(KERN_ERR "put_kernel_page: page at 0x%p not in reserved memory\n",
 221                        page_address(page));
 222
 223         pgd = pgd_offset_k(address);            /* note: this is NOT pgd_offset()! */
 224
 225         {
 226                 pud = pud_alloc(&init_mm, pgd, address);
 227                 if (!pud)
 228                         goto out;
 229                 pmd = pmd_alloc(&init_mm, pud, address);
 230                 if (!pmd)
 231                         goto out;
 232                 pte = pte_alloc_kernel(pmd, address);
 233                 if (!pte)
 234                         goto out;
 235                 if (!pte_none(*pte))
 236                         goto out;
 237                 set_pte(pte, mk_pte(page, pgprot));
 238         }
 239   out:
 240         /* no need for flush_tlb */
 241         return page;
 242 }
 243
 244 static void __init
 245 setup_gate (void)
 246 {
 247         void *gate_section;
 248         struct page *page;
 249
 250         /*
 251          * Map the gate page twice: once read-only to export the ELF
 252          * headers etc. and once execute-only page to enable
 253          * privilege-promotion via "epc":
 254          */
 255         gate_section = paravirt_get_gate_section();
 256         page = virt_to_page(ia64_imva(gate_section));
 257         put_kernel_page(page, GATE_ADDR, PAGE_READONLY);
 258 #ifdef HAVE_BUGGY_SEGREL
 259         page = virt_to_page(ia64_imva(gate_section + PAGE_SIZE));
 260         put_kernel_page(page, GATE_ADDR + PAGE_SIZE, PAGE_GATE);
 261 #else
 262         put_kernel_page(page, GATE_ADDR + PERCPU_PAGE_SIZE, PAGE_GATE);
 263         /* Fill in the holes (if any) with read-only zero pages: */
 264         {
 265                 unsigned long addr;
 266
 267                 for (addr = GATE_ADDR + PAGE_SIZE;
 268                      addr < GATE_ADDR + PERCPU_PAGE_SIZE;
 269                      addr += PAGE_SIZE)
 270                 {
 271                         put_kernel_page(ZERO_PAGE(0), addr,
 272                                         PAGE_READONLY);
 273                         put_kernel_page(ZERO_PAGE(0), addr + PERCPU_PAGE_SIZE,
 274                                         PAGE_READONLY);
 275                 }
 276         }
 277 #endif
 278         ia64_patch_gate();
 279 }
 280
 281 void ia64_mmu_init(void *my_cpu_data)
 282 {
 283         unsigned long pta, impl_va_bits;
 284         extern void tlb_init(void);
 285
 286 #ifdef CONFIG_DISABLE_VHPT
 287 #       define VHPT_ENABLE_BIT  0
 288 #else
 289 #       define VHPT_ENABLE_BIT  1
 290 #endif
 291
 292         /*
 293          * Check if the virtually mapped linear page table (VMLPT) overlaps with a mapped
 294          * address space.  The IA-64 architecture guarantees that at least 50 bits of
 295          * virtual address space are implemented but if we pick a large enough page size
 296          * (e.g., 64KB), the mapped address space is big enough that it will overlap with
 297          * VMLPT.  I assume that once we run on machines big enough to warrant 64KB pages,
 298          * IMPL_VA_MSB will be significantly bigger, so this is unlikely to become a
 299          * problem in practice.  Alternatively, we could truncate the top of the mapped
 300          * address space to not permit mappings that would overlap with the VMLPT.
 301          * --davidm 00/12/06
 302          */
 303 #       define pte_bits                 3
 304 #       define mapped_space_bits        (3*(PAGE_SHIFT - pte_bits) + PAGE_SHIFT)
 305         /*
 306          * The virtual page table has to cover the entire implemented address space within
 307          * a region even though not all of this space may be mappable.  The reason for
 308          * this is that the Access bit and Dirty bit fault handlers perform
 309          * non-speculative accesses to the virtual page table, so the address range of the
 310          * virtual page table itself needs to be covered by virtual page table.
 311          */
 312 #       define vmlpt_bits               (impl_va_bits - PAGE_SHIFT + pte_bits)
 313 #       define POW2(n)                  (1ULL << (n))
 314
 315         impl_va_bits = ffz(~(local_cpu_data->unimpl_va_mask | (7UL << 61)));
 316
 317         if (impl_va_bits < 51 || impl_va_bits > 61)
 318                 panic("CPU has bogus IMPL_VA_MSB value of %lu!\n", impl_va_bits - 1);
 319         /*
 320          * mapped_space_bits - PAGE_SHIFT is the total number of ptes we need,
 321          * which must fit into "vmlpt_bits - pte_bits" slots. Second half of
 322          * the test makes sure that our mapped space doesn't overlap the
 323          * unimplemented hole in the middle of the region.
 324          */
 325         if ((mapped_space_bits - PAGE_SHIFT > vmlpt_bits - pte_bits) ||
 326             (mapped_space_bits > impl_va_bits - 1))
 327                 panic("Cannot build a big enough virtual-linear page table"
 328                       " to cover mapped address space.\n"
 329                       " Try using a smaller page size.\n");
 330
 331
 332         /* place the VMLPT at the end of each page-table mapped region: */
 333         pta = POW2(61) - POW2(vmlpt_bits);
 334
 335         /*
 336          * Set the (virtually mapped linear) page table address.  Bit
 337          * 8 selects between the short and long format, bits 2-7 the
 338          * size of the table, and bit 0 whether the VHPT walker is
 339          * enabled.
 340          */
 341         ia64_set_pta(pta | (0 << 8) | (vmlpt_bits << 2) | VHPT_ENABLE_BIT);
 342
 343         ia64_tlb_init();
 344
 345 #ifdef  CONFIG_HUGETLB_PAGE
 346         ia64_set_rr(HPAGE_REGION_BASE, HPAGE_SHIFT << 2);
 347         ia64_srlz_d();
 348 #endif
 349 }
 350
 351 #ifdef CONFIG_VIRTUAL_MEM_MAP
 352 int vmemmap_find_next_valid_pfn(int node, int i)
 353 {
 354         unsigned long end_address, hole_next_pfn;
 355         unsigned long stop_address;
 356         pg_data_t *pgdat = NODE_DATA(node);
 357
 358         end_address = (unsigned long) &vmem_map[pgdat->node_start_pfn + i];
 359         end_address = PAGE_ALIGN(end_address);
 360         stop_address = (unsigned long) &vmem_map[pgdat_end_pfn(pgdat)];
 361
 362         do {
 363                 pgd_t *pgd;
 364                 pud_t *pud;
 365                 pmd_t *pmd;
 366                 pte_t *pte;
 367
 368                 pgd = pgd_offset_k(end_address);
 369                 if (pgd_none(*pgd)) {
 370                         end_address += PGDIR_SIZE;
 371                         continue;
 372                 }
 373
 374                 pud = pud_offset(pgd, end_address);
 375                 if (pud_none(*pud)) {
 376                         end_address += PUD_SIZE;
 377                         continue;
 378                 }
 379
 380                 pmd = pmd_offset(pud, end_address);
 381                 if (pmd_none(*pmd)) {
 382                         end_address += PMD_SIZE;
 383                         continue;
 384                 }
 385
 386                 pte = pte_offset_kernel(pmd, end_address);
 387 retry_pte:
 388                 if (pte_none(*pte)) {
 389                         end_address += PAGE_SIZE;
 390                         pte++;
 391                         if ((end_address < stop_address) &&
 392                             (end_address != ALIGN(end_address, 1UL << PMD_SHIFT)))
 393                                 goto retry_pte;
 394                         continue;
 395                 }
 396                 /* Found next valid vmem_map page */
 397                 break;
 398         } while (end_address < stop_address);
 399
 400         end_address = min(end_address, stop_address);
 401         end_address = end_address - (unsigned long) vmem_map + sizeof(struct page) - 1;
 402         hole_next_pfn = end_address / sizeof(struct page);
 403         return hole_next_pfn - pgdat->node_start_pfn;
 404 }
 405
 406 int __init create_mem_map_page_table(u64 start, u64 end, void *arg)
 407 {
 408         unsigned long address, start_page, end_page;
 409         struct page *map_start, *map_end;
 410         int node;
 411         pgd_t *pgd;
 412         pud_t *pud;
 413         pmd_t *pmd;
 414         pte_t *pte;
 415
 416         map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
 417         map_end   = vmem_map + (__pa(end) >> PAGE_SHIFT);
 418
 419         start_page = (unsigned long) map_start & PAGE_MASK;
 420         end_page = PAGE_ALIGN((unsigned long) map_end);
 421         node = paddr_to_nid(__pa(start));
 422
 423         for (address = start_page; address < end_page; address += PAGE_SIZE) {
 424                 pgd = pgd_offset_k(address);
 425                 if (pgd_none(*pgd))
 426                         pgd_populate(&init_mm, pgd, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
 427                 pud = pud_offset(pgd, address);
 428
 429                 if (pud_none(*pud))
 430                         pud_populate(&init_mm, pud, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
 431                 pmd = pmd_offset(pud, address);
 432
 433                 if (pmd_none(*pmd))
 434                         pmd_populate_kernel(&init_mm, pmd, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
 435                 pte = pte_offset_kernel(pmd, address);
 436
 437                 if (pte_none(*pte))
 438                         set_pte(pte, pfn_pte(__pa(alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE)) >> PAGE_SHIFT,
 439                                              PAGE_KERNEL));
 440         }
 441         return 0;
 442 }
 443
 444 struct memmap_init_callback_data {
 445         struct page *start;
 446         struct page *end;
 447         int nid;
 448         unsigned long zone;
 449 };
 450
 451 static int __meminit
 452 virtual_memmap_init(u64 start, u64 end, void *arg)
 453 {
 454         struct memmap_init_callback_data *args;
 455         struct page *map_start, *map_end;
 456
 457         args = (struct memmap_init_callback_data *) arg;
 458         map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
 459         map_end   = vmem_map + (__pa(end) >> PAGE_SHIFT);
 460
 461         if (map_start < args->start)
 462                 map_start = args->start;
 463         if (map_end > args->end)
 464                 map_end = args->end;
 465
 466         /*
 467          * We have to initialize "out of bounds" struct page elements that fit completely
 468          * on the same pages that were allocated for the "in bounds" elements because they
 469          * may be referenced later (and found to be "reserved").
 470          */
 471         map_start -= ((unsigned long) map_start & (PAGE_SIZE - 1)) / sizeof(struct page);
 472         map_end += ((PAGE_ALIGN((unsigned long) map_end) - (unsigned long) map_end)
 473                     / sizeof(struct page));
 474
 475         if (map_start < map_end)
 476                 memmap_init_zone((unsigned long)(map_end - map_start),
 477                                  args->nid, args->zone, page_to_pfn(map_start),
 478                                  MEMMAP_EARLY);
 479         return 0;
 480 }
 481
 482 void __meminit
 483 memmap_init (unsigned long size, int nid, unsigned long zone,
 484              unsigned long start_pfn)
 485 {
 486         if (!vmem_map)
 487                 memmap_init_zone(size, nid, zone, start_pfn, MEMMAP_EARLY);
 488         else {
 489                 struct page *start;
 490                 struct memmap_init_callback_data args;
 491
 492                 start = pfn_to_page(start_pfn);
 493                 args.start = start;
 494                 args.end = start + size;
 495                 args.nid = nid;
 496                 args.zone = zone;
 497
 498                 efi_memmap_walk(virtual_memmap_init, &args);
 499         }
 500 }
 501
 502 int
 503 ia64_pfn_valid (unsigned long pfn)
 504 {
 505         char byte;
 506         struct page *pg = pfn_to_page(pfn);
 507
 508         return     (__get_user(byte, (char __user *) pg) == 0)
 509                 && ((((u64)pg & PAGE_MASK) == (((u64)(pg + 1) - 1) & PAGE_MASK))
 510                         || (__get_user(byte, (char __user *) (pg + 1) - 1) == 0));
 511 }
 512 EXPORT_SYMBOL(ia64_pfn_valid);
 513
 514 int __init find_largest_hole(u64 start, u64 end, void *arg)
 515 {
 516         u64 *max_gap = arg;
 517
 518         static u64 last_end = PAGE_OFFSET;
 519
 520         /* NOTE: this algorithm assumes efi memmap table is ordered */
 521
 522         if (*max_gap < (start - last_end))
 523                 *max_gap = start - last_end;
 524         last_end = end;
 525         return 0;
 526 }
 527
 528 #endif /* CONFIG_VIRTUAL_MEM_MAP */
 529
 530 int __init register_active_ranges(u64 start, u64 len, int nid)
 531 {
 532         u64 end = start + len;
 533
 534 #ifdef CONFIG_KEXEC
 535         if (start > crashk_res.start && start < crashk_res.end)
 536                 start = crashk_res.end;
 537         if (end > crashk_res.start && end < crashk_res.end)
 538                 end = crashk_res.start;
 539 #endif
 540
 541         if (start < end)
 542                 memblock_add_node(__pa(start), end - start, nid);
 543         return 0;
 544 }
 545
 546 int
 547 find_max_min_low_pfn (u64 start, u64 end, void *arg)
 548 {
 549         unsigned long pfn_start, pfn_end;
 550 #ifdef CONFIG_FLATMEM
 551         pfn_start = (PAGE_ALIGN(__pa(start))) >> PAGE_SHIFT;
 552         pfn_end = (PAGE_ALIGN(__pa(end - 1))) >> PAGE_SHIFT;
 553 #else
 554         pfn_start = GRANULEROUNDDOWN(__pa(start)) >> PAGE_SHIFT;
 555         pfn_end = GRANULEROUNDUP(__pa(end - 1)) >> PAGE_SHIFT;
 556 #endif
 557         min_low_pfn = min(min_low_pfn, pfn_start);
 558         max_low_pfn = max(max_low_pfn, pfn_end);
 559         return 0;
 560 }
 561
 562 /*
 563  * Boot command-line option "nolwsys" can be used to disable the use of any light-weight
 564  * system call handler.  When this option is in effect, all fsyscalls will end up bubbling
 565  * down into the kernel and calling the normal (heavy-weight) syscall handler.  This is
 566  * useful for performance testing, but conceivably could also come in handy for debugging
 567  * purposes.
 568  */
 569
 570 static int nolwsys __initdata;
 571
 572 static int __init
 573 nolwsys_setup (char *s)
 574 {
 575         nolwsys = 1;
 576         return 1;
 577 }
 578
 579 __setup("nolwsys", nolwsys_setup);
 580
 581 void __init
 582 mem_init (void)
 583 {
 584         int i;
 585
 586         BUG_ON(PTRS_PER_PGD * sizeof(pgd_t) != PAGE_SIZE);
 587         BUG_ON(PTRS_PER_PMD * sizeof(pmd_t) != PAGE_SIZE);
 588         BUG_ON(PTRS_PER_PTE * sizeof(pte_t) != PAGE_SIZE);
 589
 590 #ifdef CONFIG_PCI
 591         /*
 592          * This needs to be called _after_ the command line has been parsed but _before_
 593          * any drivers that may need the PCI DMA interface are initialized or bootmem has
 594          * been freed.
 595          */
 596         platform_dma_init();
 597 #endif
 598
 599 #ifdef CONFIG_FLATMEM
 600         BUG_ON(!mem_map);
 601 #endif
 602
 603         set_max_mapnr(max_low_pfn);
 604         high_memory = __va(max_low_pfn * PAGE_SIZE);
 605         free_all_bootmem();
 606         mem_init_print_info(NULL);
 607
 608         /*
 609          * For fsyscall entrpoints with no light-weight handler, use the ordinary
 610          * (heavy-weight) handler, but mark it by setting bit 0, so the fsyscall entry
 611          * code can tell them apart.
 612          */
 613         for (i = 0; i < NR_syscalls; ++i) {
 614                 extern unsigned long sys_call_table[NR_syscalls];
 615                 unsigned long *fsyscall_table = paravirt_get_fsyscall_table();
 616
 617                 if (!fsyscall_table[i] || nolwsys)
 618                         fsyscall_table[i] = sys_call_table[i] | 1;
 619         }
 620         setup_gate();
 621 }
 622
 623 #ifdef CONFIG_MEMORY_HOTPLUG
 624 int arch_add_memory(int nid, u64 start, u64 size)
 625 {
 626         pg_data_t *pgdat;
 627         struct zone *zone;
 628         unsigned long start_pfn = start >> PAGE_SHIFT;
 629         unsigned long nr_pages = size >> PAGE_SHIFT;
 630         int ret;
 631
 632         pgdat = NODE_DATA(nid);
 633
 634         zone = pgdat->node_zones + ZONE_NORMAL;
 635         ret = __add_pages(nid, zone, start_pfn, nr_pages);
 636
 637         if (ret)
 638                 printk("%s: Problem encountered in __add_pages() as ret=%d\n",
 639                        __func__,  ret);
 640
 641         return ret;
 642 }
 643
 644 #ifdef CONFIG_MEMORY_HOTREMOVE
 645 int arch_remove_memory(u64 start, u64 size)
 646 {
 647         unsigned long start_pfn = start >> PAGE_SHIFT;
 648         unsigned long nr_pages = size >> PAGE_SHIFT;
 649         struct zone *zone;
 650         int ret;
 651
 652         zone = page_zone(pfn_to_page(start_pfn));
 653         ret = __remove_pages(zone, start_pfn, nr_pages);
 654         if (ret)
 655                 pr_warn("%s: Problem encountered in __remove_pages() as"
 656                         " ret=%d\n", __func__,  ret);
 657
 658         return ret;
 659 }
 660 #endif
 661 #endif
 662
 663 /*
 664  * Even when CONFIG_IA32_SUPPORT is not enabled it is
 665  * useful to have the Linux/x86 domain registered to
 666  * avoid an attempted module load when emulators call
 667  * personality(PER_LINUX32). This saves several milliseconds
 668  * on each such call.
 669  */
 670 static struct exec_domain ia32_exec_domain;
 671
 672 static int __init
 673 per_linux32_init(void)
 674 {
 675         ia32_exec_domain.name = "Linux/x86";
 676         ia32_exec_domain.handler = NULL;
 677         ia32_exec_domain.pers_low = PER_LINUX32;
 678         ia32_exec_domain.pers_high = PER_LINUX32;
 679         ia32_exec_domain.signal_map = default_exec_domain.signal_map;
 680         ia32_exec_domain.signal_invmap = default_exec_domain.signal_invmap;
 681         register_exec_domain(&ia32_exec_domain);
 682
 683         return 0;
 684 }
 685
 686 __initcall(per_linux32_init);
 687
 688 /**
 689  * show_mem - give short summary of memory stats
 690  *
 691  * Shows a simple page count of reserved and used pages in the system.
 692  * For discontig machines, it does this on a per-pgdat basis.
 693  */
 694 void show_mem(unsigned int filter)
 695 {
 696         int total_reserved = 0;
 697         unsigned long total_present = 0;
 698         pg_data_t *pgdat;
 699
 700         printk(KERN_INFO "Mem-info:\n");
 701         show_free_areas(filter);
 702         printk(KERN_INFO "Node memory in pages:\n");
 703         for_each_online_pgdat(pgdat) {
 704                 unsigned long present;
 705                 unsigned long flags;
 706                 int reserved = 0;
 707                 int nid = pgdat->node_id;
 708                 int zoneid;
 709
 710                 if (skip_free_areas_node(filter, nid))
 711                         continue;
 712                 pgdat_resize_lock(pgdat, &flags);
 713
 714                 for (zoneid = 0; zoneid < MAX_NR_ZONES; zoneid++) {
 715                         struct zone *zone = &pgdat->node_zones[zoneid];
 716                         if (!populated_zone(zone))
 717                                 continue;
 718
 719                         reserved += zone->present_pages - zone->managed_pages;
 720                 }
 721                 present = pgdat->node_present_pages;
 722
 723                 pgdat_resize_unlock(pgdat, &flags);
 724                 total_present += present;
 725                 total_reserved += reserved;
 726                 printk(KERN_INFO "Node %4d:  RAM: %11ld, rsvd: %8d, ",
 727                        nid, present, reserved);
 728         }
 729         printk(KERN_INFO "%ld pages of RAM\n", total_present);
 730         printk(KERN_INFO "%d reserved pages\n", total_reserved);
 731         printk(KERN_INFO "Total of %ld pages in page table cache\n",
 732                quicklist_total_size());
 733         printk(KERN_INFO "%ld free buffer pages\n", nr_free_buffer_pages());
 734 }