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 /*
 133  * Since DMA is i-cache coherent, any (complete) pages that were written via
 134  * DMA can be marked as "clean" so that lazy_mmu_prot_update() doesn't have to
 135  * flush them when they get mapped into an executable vm-area.
 136  */
 137 void
 138 dma_mark_clean(void *addr, size_t size)
 139 {
 140         unsigned long pg_addr, end;
 141
 142         pg_addr = PAGE_ALIGN((unsigned long) addr);
 143         end = (unsigned long) addr + size;
 144         while (pg_addr + PAGE_SIZE <= end) {
 145                 struct page *page = virt_to_page(pg_addr);
 146                 set_bit(PG_arch_1, &page->flags);
 147                 pg_addr += PAGE_SIZE;
 148         }
 149 }
 150
 151 inline void
 152 ia64_set_rbs_bot (void)
 153 {
 154         unsigned long stack_size = current->signal->rlim[RLIMIT_STACK].rlim_max & -16;
 155
 156         if (stack_size > MAX_USER_STACK_SIZE)
 157                 stack_size = MAX_USER_STACK_SIZE;
 158         current->thread.rbs_bot = STACK_TOP - stack_size;
 159 }
 160
 161 /*
 162  * This performs some platform-dependent address space initialization.
 163  * On IA-64, we want to setup the VM area for the register backing
 164  * store (which grows upwards) and install the gateway page which is
 165  * used for signal trampolines, etc.
 166  */
 167 void
 168 ia64_init_addr_space (void)
 169 {
 170         struct vm_area_struct *vma;
 171
 172         ia64_set_rbs_bot();
 173
 174         /*
 175          * If we're out of memory and kmem_cache_alloc() returns NULL, we simply ignore
 176          * the problem.  When the process attempts to write to the register backing store
 177          * for the first time, it will get a SEGFAULT in this case.
 178          */
 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_start = current->thread.rbs_bot & PAGE_MASK;
 184                 vma->vm_end = vma->vm_start + PAGE_SIZE;
 185                 vma->vm_page_prot = protection_map[VM_DATA_DEFAULT_FLAGS & 0x7];
 186                 vma->vm_flags = VM_DATA_DEFAULT_FLAGS|VM_GROWSUP|VM_ACCOUNT;
 187                 down_write(&current->mm->mmap_sem);
 188                 if (insert_vm_struct(current->mm, vma)) {
 189                         up_write(&current->mm->mmap_sem);
 190                         kmem_cache_free(vm_area_cachep, vma);
 191                         return;
 192                 }
 193                 up_write(&current->mm->mmap_sem);
 194         }
 195
 196         /* map NaT-page at address zero to speed up speculative dereferencing of NULL: */
 197         if (!(current->personality & MMAP_PAGE_ZERO)) {
 198                 vma = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
 199                 if (vma) {
 200                         memset(vma, 0, sizeof(*vma));
 201                         vma->vm_mm = current->mm;
 202                         vma->vm_end = PAGE_SIZE;
 203                         vma->vm_page_prot = __pgprot(pgprot_val(PAGE_READONLY) | _PAGE_MA_NAT);
 204                         vma->vm_flags = VM_READ | VM_MAYREAD | VM_IO | VM_RESERVED;
 205                         down_write(&current->mm->mmap_sem);
 206                         if (insert_vm_struct(current->mm, vma)) {
 207                                 up_write(&current->mm->mmap_sem);
 208                                 kmem_cache_free(vm_area_cachep, vma);
 209                                 return;
 210                         }
 211                         up_write(&current->mm->mmap_sem);
 212                 }
 213         }
 214 }
 215
 216 void
 217 free_initmem (void)
 218 {
 219         unsigned long addr, eaddr;
 220
 221         addr = (unsigned long) ia64_imva(__init_begin);
 222         eaddr = (unsigned long) ia64_imva(__init_end);
 223         while (addr < eaddr) {
 224                 ClearPageReserved(virt_to_page(addr));
 225                 init_page_count(virt_to_page(addr));
 226                 free_page(addr);
 227                 ++totalram_pages;
 228                 addr += PAGE_SIZE;
 229         }
 230         printk(KERN_INFO "Freeing unused kernel memory: %ldkB freed\n",
 231                (__init_end - __init_begin) >> 10);
 232 }
 233
 234 void __init
 235 free_initrd_mem (unsigned long start, unsigned long end)
 236 {
 237         struct page *page;
 238         /*
 239          * EFI uses 4KB pages while the kernel can use 4KB or bigger.
 240          * Thus EFI and the kernel may have different page sizes. It is
 241          * therefore possible to have the initrd share the same page as
 242          * the end of the kernel (given current setup).
 243          *
 244          * To avoid freeing/using the wrong page (kernel sized) we:
 245          *      - align up the beginning of initrd
 246          *      - align down the end of initrd
 247          *
 248          *  |             |
 249          *  |=============| a000
 250          *  |             |
 251          *  |             |
 252          *  |             | 9000
 253          *  |/////////////|
 254          *  |/////////////|
 255          *  |=============| 8000
 256          *  |///INITRD////|
 257          *  |/////////////|
 258          *  |/////////////| 7000
 259          *  |             |
 260          *  |KKKKKKKKKKKKK|
 261          *  |=============| 6000
 262          *  |KKKKKKKKKKKKK|
 263          *  |KKKKKKKKKKKKK|
 264          *  K=kernel using 8KB pages
 265          *
 266          * In this example, we must free page 8000 ONLY. So we must align up
 267          * initrd_start and keep initrd_end as is.
 268          */
 269         start = PAGE_ALIGN(start);
 270         end = end & PAGE_MASK;
 271
 272         if (start < end)
 273                 printk(KERN_INFO "Freeing initrd memory: %ldkB freed\n", (end - start) >> 10);
 274
 275         for (; start < end; start += PAGE_SIZE) {
 276                 if (!virt_addr_valid(start))
 277                         continue;
 278                 page = virt_to_page(start);
 279                 ClearPageReserved(page);
 280                 init_page_count(page);
 281                 free_page(start);
 282                 ++totalram_pages;
 283         }
 284 }
 285
 286 /*
 287  * This installs a clean page in the kernel's page table.
 288  */
 289 static struct page * __init
 290 put_kernel_page (struct page *page, unsigned long address, pgprot_t pgprot)
 291 {
 292         pgd_t *pgd;
 293         pud_t *pud;
 294         pmd_t *pmd;
 295         pte_t *pte;
 296
 297         if (!PageReserved(page))
 298                 printk(KERN_ERR "put_kernel_page: page at 0x%p not in reserved memory\n",
 299                        page_address(page));
 300
 301         pgd = pgd_offset_k(address);            /* note: this is NOT pgd_offset()! */
 302
 303         {
 304                 pud = pud_alloc(&init_mm, pgd, address);
 305                 if (!pud)
 306                         goto out;
 307                 pmd = pmd_alloc(&init_mm, pud, address);
 308                 if (!pmd)
 309                         goto out;
 310                 pte = pte_alloc_kernel(pmd, address);
 311                 if (!pte)
 312                         goto out;
 313                 if (!pte_none(*pte))
 314                         goto out;
 315                 set_pte(pte, mk_pte(page, pgprot));
 316         }
 317   out:
 318         /* no need for flush_tlb */
 319         return page;
 320 }
 321
 322 static void __init
 323 setup_gate (void)
 324 {
 325         struct page *page;
 326
 327         /*
 328          * Map the gate page twice: once read-only to export the ELF
 329          * headers etc. and once execute-only page to enable
 330          * privilege-promotion via "epc":
 331          */
 332         page = virt_to_page(ia64_imva(__start_gate_section));
 333         put_kernel_page(page, GATE_ADDR, PAGE_READONLY);
 334 #ifdef HAVE_BUGGY_SEGREL
 335         page = virt_to_page(ia64_imva(__start_gate_section + PAGE_SIZE));
 336         put_kernel_page(page, GATE_ADDR + PAGE_SIZE, PAGE_GATE);
 337 #else
 338         put_kernel_page(page, GATE_ADDR + PERCPU_PAGE_SIZE, PAGE_GATE);
 339         /* Fill in the holes (if any) with read-only zero pages: */
 340         {
 341                 unsigned long addr;
 342
 343                 for (addr = GATE_ADDR + PAGE_SIZE;
 344                      addr < GATE_ADDR + PERCPU_PAGE_SIZE;
 345                      addr += PAGE_SIZE)
 346                 {
 347                         put_kernel_page(ZERO_PAGE(0), addr,
 348                                         PAGE_READONLY);
 349                         put_kernel_page(ZERO_PAGE(0), addr + PERCPU_PAGE_SIZE,
 350                                         PAGE_READONLY);
 351                 }
 352         }
 353 #endif
 354         ia64_patch_gate();
 355 }
 356
 357 void __devinit
 358 ia64_mmu_init (void *my_cpu_data)
 359 {
 360         unsigned long psr, pta, impl_va_bits;
 361         extern void __devinit tlb_init (void);
 362
 363 #ifdef CONFIG_DISABLE_VHPT
 364 #       define VHPT_ENABLE_BIT  0
 365 #else
 366 #       define VHPT_ENABLE_BIT  1
 367 #endif
 368
 369         /* Pin mapping for percpu area into TLB */
 370         psr = ia64_clear_ic();
 371         ia64_itr(0x2, IA64_TR_PERCPU_DATA, PERCPU_ADDR,
 372                  pte_val(pfn_pte(__pa(my_cpu_data) >> PAGE_SHIFT, PAGE_KERNEL)),
 373                  PERCPU_PAGE_SHIFT);
 374
 375         ia64_set_psr(psr);
 376         ia64_srlz_i();
 377
 378         /*
 379          * Check if the virtually mapped linear page table (VMLPT) overlaps with a mapped
 380          * address space.  The IA-64 architecture guarantees that at least 50 bits of
 381          * virtual address space are implemented but if we pick a large enough page size
 382          * (e.g., 64KB), the mapped address space is big enough that it will overlap with
 383          * VMLPT.  I assume that once we run on machines big enough to warrant 64KB pages,
 384          * IMPL_VA_MSB will be significantly bigger, so this is unlikely to become a
 385          * problem in practice.  Alternatively, we could truncate the top of the mapped
 386          * address space to not permit mappings that would overlap with the VMLPT.
 387          * --davidm 00/12/06
 388          */
 389 #       define pte_bits                 3
 390 #       define mapped_space_bits        (3*(PAGE_SHIFT - pte_bits) + PAGE_SHIFT)
 391         /*
 392          * The virtual page table has to cover the entire implemented address space within
 393          * a region even though not all of this space may be mappable.  The reason for
 394          * this is that the Access bit and Dirty bit fault handlers perform
 395          * non-speculative accesses to the virtual page table, so the address range of the
 396          * virtual page table itself needs to be covered by virtual page table.
 397          */
 398 #       define vmlpt_bits               (impl_va_bits - PAGE_SHIFT + pte_bits)
 399 #       define POW2(n)                  (1ULL << (n))
 400
 401         impl_va_bits = ffz(~(local_cpu_data->unimpl_va_mask | (7UL << 61)));
 402
 403         if (impl_va_bits < 51 || impl_va_bits > 61)
 404                 panic("CPU has bogus IMPL_VA_MSB value of %lu!\n", impl_va_bits - 1);
 405         /*
 406          * mapped_space_bits - PAGE_SHIFT is the total number of ptes we need,
 407          * which must fit into "vmlpt_bits - pte_bits" slots. Second half of
 408          * the test makes sure that our mapped space doesn't overlap the
 409          * unimplemented hole in the middle of the region.
 410          */
 411         if ((mapped_space_bits - PAGE_SHIFT > vmlpt_bits - pte_bits) ||
 412             (mapped_space_bits > impl_va_bits - 1))
 413                 panic("Cannot build a big enough virtual-linear page table"
 414                       " to cover mapped address space.\n"
 415                       " Try using a smaller page size.\n");
 416
 417
 418         /* place the VMLPT at the end of each page-table mapped region: */
 419         pta = POW2(61) - POW2(vmlpt_bits);
 420
 421         /*
 422          * Set the (virtually mapped linear) page table address.  Bit
 423          * 8 selects between the short and long format, bits 2-7 the
 424          * size of the table, and bit 0 whether the VHPT walker is
 425          * enabled.
 426          */
 427         ia64_set_pta(pta | (0 << 8) | (vmlpt_bits << 2) | VHPT_ENABLE_BIT);
 428
 429         ia64_tlb_init();
 430
 431 #ifdef  CONFIG_HUGETLB_PAGE
 432         ia64_set_rr(HPAGE_REGION_BASE, HPAGE_SHIFT << 2);
 433         ia64_srlz_d();
 434 #endif
 435 }
 436
 437 #ifdef CONFIG_VIRTUAL_MEM_MAP
 438 int vmemmap_find_next_valid_pfn(int node, int i)
 439 {
 440         unsigned long end_address, hole_next_pfn;
 441         unsigned long stop_address;
 442         pg_data_t *pgdat = NODE_DATA(node);
 443
 444         end_address = (unsigned long) &vmem_map[pgdat->node_start_pfn + i];
 445         end_address = PAGE_ALIGN(end_address);
 446
 447         stop_address = (unsigned long) &vmem_map[
 448                 pgdat->node_start_pfn + pgdat->node_spanned_pages];
 449
 450         do {
 451                 pgd_t *pgd;
 452                 pud_t *pud;
 453                 pmd_t *pmd;
 454                 pte_t *pte;
 455
 456                 pgd = pgd_offset_k(end_address);
 457                 if (pgd_none(*pgd)) {
 458                         end_address += PGDIR_SIZE;
 459                         continue;
 460                 }
 461
 462                 pud = pud_offset(pgd, end_address);
 463                 if (pud_none(*pud)) {
 464                         end_address += PUD_SIZE;
 465                         continue;
 466                 }
 467
 468                 pmd = pmd_offset(pud, end_address);
 469                 if (pmd_none(*pmd)) {
 470                         end_address += PMD_SIZE;
 471                         continue;
 472                 }
 473
 474                 pte = pte_offset_kernel(pmd, end_address);
 475 retry_pte:
 476                 if (pte_none(*pte)) {
 477                         end_address += PAGE_SIZE;
 478                         pte++;
 479                         if ((end_address < stop_address) &&
 480                             (end_address != ALIGN(end_address, 1UL << PMD_SHIFT)))
 481                                 goto retry_pte;
 482                         continue;
 483                 }
 484                 /* Found next valid vmem_map page */
 485                 break;
 486         } while (end_address < stop_address);
 487
 488         end_address = min(end_address, stop_address);
 489         end_address = end_address - (unsigned long) vmem_map + sizeof(struct page) - 1;
 490         hole_next_pfn = end_address / sizeof(struct page);
 491         return hole_next_pfn - pgdat->node_start_pfn;
 492 }
 493
 494 int __init
 495 create_mem_map_page_table (u64 start, u64 end, void *arg)
 496 {
 497         unsigned long address, start_page, end_page;
 498         struct page *map_start, *map_end;
 499         int node;
 500         pgd_t *pgd;
 501         pud_t *pud;
 502         pmd_t *pmd;
 503         pte_t *pte;
 504
 505         map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
 506         map_end   = vmem_map + (__pa(end) >> PAGE_SHIFT);
 507
 508         start_page = (unsigned long) map_start & PAGE_MASK;
 509         end_page = PAGE_ALIGN((unsigned long) map_end);
 510         node = paddr_to_nid(__pa(start));
 511
 512         for (address = start_page; address < end_page; address += PAGE_SIZE) {
 513                 pgd = pgd_offset_k(address);
 514                 if (pgd_none(*pgd))
 515                         pgd_populate(&init_mm, pgd, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
 516                 pud = pud_offset(pgd, address);
 517
 518                 if (pud_none(*pud))
 519                         pud_populate(&init_mm, pud, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
 520                 pmd = pmd_offset(pud, address);
 521
 522                 if (pmd_none(*pmd))
 523                         pmd_populate_kernel(&init_mm, pmd, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
 524                 pte = pte_offset_kernel(pmd, address);
 525
 526                 if (pte_none(*pte))
 527                         set_pte(pte, pfn_pte(__pa(alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE)) >> PAGE_SHIFT,
 528                                              PAGE_KERNEL));
 529         }
 530         return 0;
 531 }
 532
 533 struct memmap_init_callback_data {
 534         struct page *start;
 535         struct page *end;
 536         int nid;
 537         unsigned long zone;
 538 };
 539
 540 static int
 541 virtual_memmap_init (u64 start, u64 end, void *arg)
 542 {
 543         struct memmap_init_callback_data *args;
 544         struct page *map_start, *map_end;
 545
 546         args = (struct memmap_init_callback_data *) arg;
 547         map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
 548         map_end   = vmem_map + (__pa(end) >> PAGE_SHIFT);
 549
 550         if (map_start < args->start)
 551                 map_start = args->start;
 552         if (map_end > args->end)
 553                 map_end = args->end;
 554
 555         /*
 556          * We have to initialize "out of bounds" struct page elements that fit completely
 557          * on the same pages that were allocated for the "in bounds" elements because they
 558          * may be referenced later (and found to be "reserved").
 559          */
 560         map_start -= ((unsigned long) map_start & (PAGE_SIZE - 1)) / sizeof(struct page);
 561         map_end += ((PAGE_ALIGN((unsigned long) map_end) - (unsigned long) map_end)
 562                     / sizeof(struct page));
 563
 564         if (map_start < map_end)
 565                 memmap_init_zone((unsigned long)(map_end - map_start),
 566                                  args->nid, args->zone, page_to_pfn(map_start),
 567                                  MEMMAP_EARLY);
 568         return 0;
 569 }
 570
 571 void
 572 memmap_init (unsigned long size, int nid, unsigned long zone,
 573              unsigned long start_pfn)
 574 {
 575         if (!vmem_map)
 576                 memmap_init_zone(size, nid, zone, start_pfn, MEMMAP_EARLY);
 577         else {
 578                 struct page *start;
 579                 struct memmap_init_callback_data args;
 580
 581                 start = pfn_to_page(start_pfn);
 582                 args.start = start;
 583                 args.end = start + size;
 584                 args.nid = nid;
 585                 args.zone = zone;
 586
 587                 efi_memmap_walk(virtual_memmap_init, &args);
 588         }
 589 }
 590
 591 int
 592 ia64_pfn_valid (unsigned long pfn)
 593 {
 594         char byte;
 595         struct page *pg = pfn_to_page(pfn);
 596
 597         return     (__get_user(byte, (char __user *) pg) == 0)
 598                 && ((((u64)pg & PAGE_MASK) == (((u64)(pg + 1) - 1) & PAGE_MASK))
 599                         || (__get_user(byte, (char __user *) (pg + 1) - 1) == 0));
 600 }
 601 EXPORT_SYMBOL(ia64_pfn_valid);
 602
 603 int __init
 604 find_largest_hole (u64 start, u64 end, void *arg)
 605 {
 606         u64 *max_gap = arg;
 607
 608         static u64 last_end = PAGE_OFFSET;
 609
 610         /* NOTE: this algorithm assumes efi memmap table is ordered */
 611
 612         if (*max_gap < (start - last_end))
 613                 *max_gap = start - last_end;
 614         last_end = end;
 615         return 0;
 616 }
 617
 618 #endif /* CONFIG_VIRTUAL_MEM_MAP */
 619
 620 int __init
 621 register_active_ranges(u64 start, u64 end, void *arg)
 622 {
 623         int nid = paddr_to_nid(__pa(start));
 624
 625         if (nid < 0)
 626                 nid = 0;
 627 #ifdef CONFIG_KEXEC
 628         if (start > crashk_res.start && start < crashk_res.end)
 629                 start = crashk_res.end;
 630         if (end > crashk_res.start && end < crashk_res.end)
 631                 end = crashk_res.start;
 632 #endif
 633
 634         if (start < end)
 635                 add_active_range(nid, __pa(start) >> PAGE_SHIFT,
 636                         __pa(end) >> PAGE_SHIFT);
 637         return 0;
 638 }
 639
 640 static int __init
 641 count_reserved_pages (u64 start, u64 end, void *arg)
 642 {
 643         unsigned long num_reserved = 0;
 644         unsigned long *count = arg;
 645
 646         for (; start < end; start += PAGE_SIZE)
 647                 if (PageReserved(virt_to_page(start)))
 648                         ++num_reserved;
 649         *count += num_reserved;
 650         return 0;
 651 }
 652
 653 /*
 654  * Boot command-line option "nolwsys" can be used to disable the use of any light-weight
 655  * system call handler.  When this option is in effect, all fsyscalls will end up bubbling
 656  * down into the kernel and calling the normal (heavy-weight) syscall handler.  This is
 657  * useful for performance testing, but conceivably could also come in handy for debugging
 658  * purposes.
 659  */
 660
 661 static int nolwsys __initdata;
 662
 663 static int __init
 664 nolwsys_setup (char *s)
 665 {
 666         nolwsys = 1;
 667         return 1;
 668 }
 669
 670 __setup("nolwsys", nolwsys_setup);
 671
 672 void __init
 673 mem_init (void)
 674 {
 675         long reserved_pages, codesize, datasize, initsize;
 676         pg_data_t *pgdat;
 677         int i;
 678         static struct kcore_list kcore_mem, kcore_vmem, kcore_kernel;
 679
 680         BUG_ON(PTRS_PER_PGD * sizeof(pgd_t) != PAGE_SIZE);
 681         BUG_ON(PTRS_PER_PMD * sizeof(pmd_t) != PAGE_SIZE);
 682         BUG_ON(PTRS_PER_PTE * sizeof(pte_t) != PAGE_SIZE);
 683
 684 #ifdef CONFIG_PCI
 685         /*
 686          * This needs to be called _after_ the command line has been parsed but _before_
 687          * any drivers that may need the PCI DMA interface are initialized or bootmem has
 688          * been freed.
 689          */
 690         platform_dma_init();
 691 #endif
 692
 693 #ifdef CONFIG_FLATMEM
 694         if (!mem_map)
 695                 BUG();
 696         max_mapnr = max_low_pfn;
 697 #endif
 698
 699         high_memory = __va(max_low_pfn * PAGE_SIZE);
 700
 701         kclist_add(&kcore_mem, __va(0), max_low_pfn * PAGE_SIZE);
 702         kclist_add(&kcore_vmem, (void *)VMALLOC_START, VMALLOC_END-VMALLOC_START);
 703         kclist_add(&kcore_kernel, _stext, _end - _stext);
 704
 705         for_each_online_pgdat(pgdat)
 706                 if (pgdat->bdata->node_bootmem_map)
 707                         totalram_pages += free_all_bootmem_node(pgdat);
 708
 709         reserved_pages = 0;
 710         efi_memmap_walk(count_reserved_pages, &reserved_pages);
 711
 712         codesize =  (unsigned long) _etext - (unsigned long) _stext;
 713         datasize =  (unsigned long) _edata - (unsigned long) _etext;
 714         initsize =  (unsigned long) __init_end - (unsigned long) __init_begin;
 715
 716         printk(KERN_INFO "Memory: %luk/%luk available (%luk code, %luk reserved, "
 717                "%luk data, %luk init)\n", (unsigned long) nr_free_pages() << (PAGE_SHIFT - 10),
 718                num_physpages << (PAGE_SHIFT - 10), codesize >> 10,
 719                reserved_pages << (PAGE_SHIFT - 10), datasize >> 10, initsize >> 10);
 720
 721
 722         /*
 723          * For fsyscall entrpoints with no light-weight handler, use the ordinary
 724          * (heavy-weight) handler, but mark it by setting bit 0, so the fsyscall entry
 725          * code can tell them apart.
 726          */
 727         for (i = 0; i < NR_syscalls; ++i) {
 728                 extern unsigned long fsyscall_table[NR_syscalls];
 729                 extern unsigned long sys_call_table[NR_syscalls];
 730
 731                 if (!fsyscall_table[i] || nolwsys)
 732                         fsyscall_table[i] = sys_call_table[i] | 1;
 733         }
 734         setup_gate();
 735
 736 #ifdef CONFIG_IA32_SUPPORT
 737         ia32_mem_init();
 738 #endif
 739 }
 740
 741 #ifdef CONFIG_MEMORY_HOTPLUG
 742 void online_page(struct page *page)
 743 {
 744         ClearPageReserved(page);
 745         init_page_count(page);
 746         __free_page(page);
 747         totalram_pages++;
 748         num_physpages++;
 749 }
 750
 751 int arch_add_memory(int nid, u64 start, u64 size)
 752 {
 753         pg_data_t *pgdat;
 754         struct zone *zone;
 755         unsigned long start_pfn = start >> PAGE_SHIFT;
 756         unsigned long nr_pages = size >> PAGE_SHIFT;
 757         int ret;
 758
 759         pgdat = NODE_DATA(nid);
 760
 761         zone = pgdat->node_zones + ZONE_NORMAL;
 762         ret = __add_pages(zone, start_pfn, nr_pages);
 763
 764         if (ret)
 765                 printk("%s: Problem encountered in __add_pages() as ret=%d\n",
 766                        __FUNCTION__,  ret);
 767
 768         return ret;
 769 }
 770
 771 int remove_memory(u64 start, u64 size)
 772 {
 773         return -EINVAL;
 774 }
 775 EXPORT_SYMBOL_GPL(remove_memory);
 776 #endif