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init_64.c
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1 /*
2  * linux/arch/x86_64/mm/init.c
3  *
4  * Copyright (C) 1995 Linus Torvalds
5  * Copyright (C) 2000 Pavel Machek <[email protected]>
6  * Copyright (C) 2002,2003 Andi Kleen <[email protected]>
7  */
8 
9 #include <linux/signal.h>
10 #include <linux/sched.h>
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
13 #include <linux/string.h>
14 #include <linux/types.h>
15 #include <linux/ptrace.h>
16 #include <linux/mman.h>
17 #include <linux/mm.h>
18 #include <linux/swap.h>
19 #include <linux/smp.h>
20 #include <linux/init.h>
21 #include <linux/initrd.h>
22 #include <linux/pagemap.h>
23 #include <linux/bootmem.h>
24 #include <linux/memblock.h>
25 #include <linux/proc_fs.h>
26 #include <linux/pci.h>
27 #include <linux/pfn.h>
28 #include <linux/poison.h>
29 #include <linux/dma-mapping.h>
30 #include <linux/module.h>
31 #include <linux/memory.h>
32 #include <linux/memory_hotplug.h>
33 #include <linux/nmi.h>
34 #include <linux/gfp.h>
35 
36 #include <asm/processor.h>
37 #include <asm/bios_ebda.h>
38 #include <asm/uaccess.h>
39 #include <asm/pgtable.h>
40 #include <asm/pgalloc.h>
41 #include <asm/dma.h>
42 #include <asm/fixmap.h>
43 #include <asm/e820.h>
44 #include <asm/apic.h>
45 #include <asm/tlb.h>
46 #include <asm/mmu_context.h>
47 #include <asm/proto.h>
48 #include <asm/smp.h>
49 #include <asm/sections.h>
50 #include <asm/kdebug.h>
51 #include <asm/numa.h>
52 #include <asm/cacheflush.h>
53 #include <asm/init.h>
54 #include <asm/uv/uv.h>
55 #include <asm/setup.h>
56 
57 static int __init parse_direct_gbpages_off(char *arg)
58 {
59  direct_gbpages = 0;
60  return 0;
61 }
62 early_param("nogbpages", parse_direct_gbpages_off);
63 
64 static int __init parse_direct_gbpages_on(char *arg)
65 {
66  direct_gbpages = 1;
67  return 0;
68 }
69 early_param("gbpages", parse_direct_gbpages_on);
70 
71 /*
72  * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
73  * physical space so we can cache the place of the first one and move
74  * around without checking the pgd every time.
75  */
76 
78 EXPORT_SYMBOL_GPL(__supported_pte_mask);
79 
81 
82 /*
83  * noexec32=on|off
84  * Control non executable heap for 32bit processes.
85  * To control the stack too use noexec=off
86  *
87  * on PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
88  * off PROT_READ implies PROT_EXEC
89  */
90 static int __init nonx32_setup(char *str)
91 {
92  if (!strcmp(str, "on"))
94  else if (!strcmp(str, "off"))
96  return 1;
97 }
98 __setup("noexec32=", nonx32_setup);
99 
100 /*
101  * When memory was added/removed make sure all the processes MM have
102  * suitable PGD entries in the local PGD level page.
103  */
104 void sync_global_pgds(unsigned long start, unsigned long end)
105 {
106  unsigned long address;
107 
108  for (address = start; address <= end; address += PGDIR_SIZE) {
109  const pgd_t *pgd_ref = pgd_offset_k(address);
110  struct page *page;
111 
112  if (pgd_none(*pgd_ref))
113  continue;
114 
115  spin_lock(&pgd_lock);
116  list_for_each_entry(page, &pgd_list, lru) {
117  pgd_t *pgd;
118  spinlock_t *pgt_lock;
119 
120  pgd = (pgd_t *)page_address(page) + pgd_index(address);
121  /* the pgt_lock only for Xen */
122  pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
123  spin_lock(pgt_lock);
124 
125  if (pgd_none(*pgd))
126  set_pgd(pgd, *pgd_ref);
127  else
128  BUG_ON(pgd_page_vaddr(*pgd)
129  != pgd_page_vaddr(*pgd_ref));
130 
131  spin_unlock(pgt_lock);
132  }
133  spin_unlock(&pgd_lock);
134  }
135 }
136 
137 /*
138  * NOTE: This function is marked __ref because it calls __init function
139  * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
140  */
141 static __ref void *spp_getpage(void)
142 {
143  void *ptr;
144 
145  if (after_bootmem)
146  ptr = (void *) get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK);
147  else
149 
150  if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
151  panic("set_pte_phys: cannot allocate page data %s\n",
152  after_bootmem ? "after bootmem" : "");
153  }
154 
155  pr_debug("spp_getpage %p\n", ptr);
156 
157  return ptr;
158 }
159 
160 static pud_t *fill_pud(pgd_t *pgd, unsigned long vaddr)
161 {
162  if (pgd_none(*pgd)) {
163  pud_t *pud = (pud_t *)spp_getpage();
164  pgd_populate(&init_mm, pgd, pud);
165  if (pud != pud_offset(pgd, 0))
166  printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n",
167  pud, pud_offset(pgd, 0));
168  }
169  return pud_offset(pgd, vaddr);
170 }
171 
172 static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr)
173 {
174  if (pud_none(*pud)) {
175  pmd_t *pmd = (pmd_t *) spp_getpage();
176  pud_populate(&init_mm, pud, pmd);
177  if (pmd != pmd_offset(pud, 0))
178  printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
179  pmd, pmd_offset(pud, 0));
180  }
181  return pmd_offset(pud, vaddr);
182 }
183 
184 static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr)
185 {
186  if (pmd_none(*pmd)) {
187  pte_t *pte = (pte_t *) spp_getpage();
188  pmd_populate_kernel(&init_mm, pmd, pte);
189  if (pte != pte_offset_kernel(pmd, 0))
190  printk(KERN_ERR "PAGETABLE BUG #02!\n");
191  }
192  return pte_offset_kernel(pmd, vaddr);
193 }
194 
195 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
196 {
197  pud_t *pud;
198  pmd_t *pmd;
199  pte_t *pte;
200 
201  pud = pud_page + pud_index(vaddr);
202  pmd = fill_pmd(pud, vaddr);
203  pte = fill_pte(pmd, vaddr);
204 
205  set_pte(pte, new_pte);
206 
207  /*
208  * It's enough to flush this one mapping.
209  * (PGE mappings get flushed as well)
210  */
211  __flush_tlb_one(vaddr);
212 }
213 
214 void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
215 {
216  pgd_t *pgd;
217  pud_t *pud_page;
218 
219  pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
220 
221  pgd = pgd_offset_k(vaddr);
222  if (pgd_none(*pgd)) {
224  "PGD FIXMAP MISSING, it should be setup in head.S!\n");
225  return;
226  }
227  pud_page = (pud_t*)pgd_page_vaddr(*pgd);
228  set_pte_vaddr_pud(pud_page, vaddr, pteval);
229 }
230 
231 pmd_t * __init populate_extra_pmd(unsigned long vaddr)
232 {
233  pgd_t *pgd;
234  pud_t *pud;
235 
236  pgd = pgd_offset_k(vaddr);
237  pud = fill_pud(pgd, vaddr);
238  return fill_pmd(pud, vaddr);
239 }
240 
241 pte_t * __init populate_extra_pte(unsigned long vaddr)
242 {
243  pmd_t *pmd;
244 
245  pmd = populate_extra_pmd(vaddr);
246  return fill_pte(pmd, vaddr);
247 }
248 
249 /*
250  * Create large page table mappings for a range of physical addresses.
251  */
252 static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
253  pgprot_t prot)
254 {
255  pgd_t *pgd;
256  pud_t *pud;
257  pmd_t *pmd;
258 
259  BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
260  for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
261  pgd = pgd_offset_k((unsigned long)__va(phys));
262  if (pgd_none(*pgd)) {
263  pud = (pud_t *) spp_getpage();
264  set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE |
265  _PAGE_USER));
266  }
267  pud = pud_offset(pgd, (unsigned long)__va(phys));
268  if (pud_none(*pud)) {
269  pmd = (pmd_t *) spp_getpage();
270  set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
271  _PAGE_USER));
272  }
273  pmd = pmd_offset(pud, phys);
274  BUG_ON(!pmd_none(*pmd));
275  set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
276  }
277 }
278 
279 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
280 {
281  __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE);
282 }
283 
284 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
285 {
286  __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE_NOCACHE);
287 }
288 
289 /*
290  * The head.S code sets up the kernel high mapping:
291  *
292  * from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
293  *
294  * phys_addr holds the negative offset to the kernel, which is added
295  * to the compile time generated pmds. This results in invalid pmds up
296  * to the point where we hit the physaddr 0 mapping.
297  *
298  * We limit the mappings to the region from _text to _brk_end. _brk_end
299  * is rounded up to the 2MB boundary. This catches the invalid pmds as
300  * well, as they are located before _text:
301  */
303 {
304  unsigned long vaddr = __START_KERNEL_map;
305  unsigned long vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT);
306  unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1;
307  pmd_t *pmd = level2_kernel_pgt;
308 
309  for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) {
310  if (pmd_none(*pmd))
311  continue;
312  if (vaddr < (unsigned long) _text || vaddr > end)
313  set_pmd(pmd, __pmd(0));
314  }
315 }
316 
317 static __ref void *alloc_low_page(unsigned long *phys)
318 {
319  unsigned long pfn = pgt_buf_end++;
320  void *adr;
321 
322  if (after_bootmem) {
323  adr = (void *)get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK);
324  *phys = __pa(adr);
325 
326  return adr;
327  }
328 
329  if (pfn >= pgt_buf_top)
330  panic("alloc_low_page: ran out of memory");
331 
332  adr = early_memremap(pfn * PAGE_SIZE, PAGE_SIZE);
333  clear_page(adr);
334  *phys = pfn * PAGE_SIZE;
335  return adr;
336 }
337 
338 static __ref void *map_low_page(void *virt)
339 {
340  void *adr;
341  unsigned long phys, left;
342 
343  if (after_bootmem)
344  return virt;
345 
346  phys = __pa(virt);
347  left = phys & (PAGE_SIZE - 1);
348  adr = early_memremap(phys & PAGE_MASK, PAGE_SIZE);
349  adr = (void *)(((unsigned long)adr) | left);
350 
351  return adr;
352 }
353 
354 static __ref void unmap_low_page(void *adr)
355 {
356  if (after_bootmem)
357  return;
358 
359  early_iounmap((void *)((unsigned long)adr & PAGE_MASK), PAGE_SIZE);
360 }
361 
362 static unsigned long __meminit
363 phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end,
364  pgprot_t prot)
365 {
366  unsigned pages = 0;
367  unsigned long last_map_addr = end;
368  int i;
369 
370  pte_t *pte = pte_page + pte_index(addr);
371 
372  for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) {
373 
374  if (addr >= end) {
375  if (!after_bootmem) {
376  for(; i < PTRS_PER_PTE; i++, pte++)
377  set_pte(pte, __pte(0));
378  }
379  break;
380  }
381 
382  /*
383  * We will re-use the existing mapping.
384  * Xen for example has some special requirements, like mapping
385  * pagetable pages as RO. So assume someone who pre-setup
386  * these mappings are more intelligent.
387  */
388  if (pte_val(*pte)) {
389  if (!after_bootmem)
390  pages++;
391  continue;
392  }
393 
394  if (0)
395  printk(" pte=%p addr=%lx pte=%016lx\n",
396  pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte);
397  pages++;
398  set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot));
399  last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
400  }
401 
402  update_page_count(PG_LEVEL_4K, pages);
403 
404  return last_map_addr;
405 }
406 
407 static unsigned long __meminit
408 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
409  unsigned long page_size_mask, pgprot_t prot)
410 {
411  unsigned long pages = 0, next;
412  unsigned long last_map_addr = end;
413 
414  int i = pmd_index(address);
415 
416  for (; i < PTRS_PER_PMD; i++, address = next) {
417  unsigned long pte_phys;
418  pmd_t *pmd = pmd_page + pmd_index(address);
419  pte_t *pte;
420  pgprot_t new_prot = prot;
421 
422  if (address >= end) {
423  if (!after_bootmem) {
424  for (; i < PTRS_PER_PMD; i++, pmd++)
425  set_pmd(pmd, __pmd(0));
426  }
427  break;
428  }
429 
430  next = (address & PMD_MASK) + PMD_SIZE;
431 
432  if (pmd_val(*pmd)) {
433  if (!pmd_large(*pmd)) {
434  spin_lock(&init_mm.page_table_lock);
435  pte = map_low_page((pte_t *)pmd_page_vaddr(*pmd));
436  last_map_addr = phys_pte_init(pte, address,
437  end, prot);
438  unmap_low_page(pte);
439  spin_unlock(&init_mm.page_table_lock);
440  continue;
441  }
442  /*
443  * If we are ok with PG_LEVEL_2M mapping, then we will
444  * use the existing mapping,
445  *
446  * Otherwise, we will split the large page mapping but
447  * use the same existing protection bits except for
448  * large page, so that we don't violate Intel's TLB
449  * Application note (317080) which says, while changing
450  * the page sizes, new and old translations should
451  * not differ with respect to page frame and
452  * attributes.
453  */
454  if (page_size_mask & (1 << PG_LEVEL_2M)) {
455  if (!after_bootmem)
456  pages++;
457  last_map_addr = next;
458  continue;
459  }
460  new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
461  }
462 
463  if (page_size_mask & (1<<PG_LEVEL_2M)) {
464  pages++;
465  spin_lock(&init_mm.page_table_lock);
466  set_pte((pte_t *)pmd,
467  pfn_pte(address >> PAGE_SHIFT,
468  __pgprot(pgprot_val(prot) | _PAGE_PSE)));
469  spin_unlock(&init_mm.page_table_lock);
470  last_map_addr = next;
471  continue;
472  }
473 
474  pte = alloc_low_page(&pte_phys);
475  last_map_addr = phys_pte_init(pte, address, end, new_prot);
476  unmap_low_page(pte);
477 
478  spin_lock(&init_mm.page_table_lock);
479  pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
480  spin_unlock(&init_mm.page_table_lock);
481  }
482  update_page_count(PG_LEVEL_2M, pages);
483  return last_map_addr;
484 }
485 
486 static unsigned long __meminit
487 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
488  unsigned long page_size_mask)
489 {
490  unsigned long pages = 0, next;
491  unsigned long last_map_addr = end;
492  int i = pud_index(addr);
493 
494  for (; i < PTRS_PER_PUD; i++, addr = next) {
495  unsigned long pmd_phys;
496  pud_t *pud = pud_page + pud_index(addr);
497  pmd_t *pmd;
498  pgprot_t prot = PAGE_KERNEL;
499 
500  if (addr >= end)
501  break;
502 
503  next = (addr & PUD_MASK) + PUD_SIZE;
504 
505  if (!after_bootmem && !e820_any_mapped(addr, next, 0)) {
506  set_pud(pud, __pud(0));
507  continue;
508  }
509 
510  if (pud_val(*pud)) {
511  if (!pud_large(*pud)) {
512  pmd = map_low_page(pmd_offset(pud, 0));
513  last_map_addr = phys_pmd_init(pmd, addr, end,
514  page_size_mask, prot);
515  unmap_low_page(pmd);
516  __flush_tlb_all();
517  continue;
518  }
519  /*
520  * If we are ok with PG_LEVEL_1G mapping, then we will
521  * use the existing mapping.
522  *
523  * Otherwise, we will split the gbpage mapping but use
524  * the same existing protection bits except for large
525  * page, so that we don't violate Intel's TLB
526  * Application note (317080) which says, while changing
527  * the page sizes, new and old translations should
528  * not differ with respect to page frame and
529  * attributes.
530  */
531  if (page_size_mask & (1 << PG_LEVEL_1G)) {
532  if (!after_bootmem)
533  pages++;
534  last_map_addr = next;
535  continue;
536  }
537  prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
538  }
539 
540  if (page_size_mask & (1<<PG_LEVEL_1G)) {
541  pages++;
542  spin_lock(&init_mm.page_table_lock);
543  set_pte((pte_t *)pud,
545  spin_unlock(&init_mm.page_table_lock);
546  last_map_addr = next;
547  continue;
548  }
549 
550  pmd = alloc_low_page(&pmd_phys);
551  last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask,
552  prot);
553  unmap_low_page(pmd);
554 
555  spin_lock(&init_mm.page_table_lock);
556  pud_populate(&init_mm, pud, __va(pmd_phys));
557  spin_unlock(&init_mm.page_table_lock);
558  }
559  __flush_tlb_all();
560 
561  update_page_count(PG_LEVEL_1G, pages);
562 
563  return last_map_addr;
564 }
565 
566 unsigned long __meminit
568  unsigned long end,
569  unsigned long page_size_mask)
570 {
571  bool pgd_changed = false;
572  unsigned long next, last_map_addr = end;
573  unsigned long addr;
574 
575  start = (unsigned long)__va(start);
576  end = (unsigned long)__va(end);
577  addr = start;
578 
579  for (; start < end; start = next) {
580  pgd_t *pgd = pgd_offset_k(start);
581  unsigned long pud_phys;
582  pud_t *pud;
583 
584  next = (start + PGDIR_SIZE) & PGDIR_MASK;
585  if (next > end)
586  next = end;
587 
588  if (pgd_val(*pgd)) {
589  pud = map_low_page((pud_t *)pgd_page_vaddr(*pgd));
590  last_map_addr = phys_pud_init(pud, __pa(start),
591  __pa(end), page_size_mask);
592  unmap_low_page(pud);
593  continue;
594  }
595 
596  pud = alloc_low_page(&pud_phys);
597  last_map_addr = phys_pud_init(pud, __pa(start), __pa(next),
598  page_size_mask);
599  unmap_low_page(pud);
600 
601  spin_lock(&init_mm.page_table_lock);
602  pgd_populate(&init_mm, pgd, __va(pud_phys));
603  spin_unlock(&init_mm.page_table_lock);
604  pgd_changed = true;
605  }
606 
607  if (pgd_changed)
608  sync_global_pgds(addr, end);
609 
610  __flush_tlb_all();
611 
612  return last_map_addr;
613 }
614 
615 #ifndef CONFIG_NUMA
617 {
618  memblock_set_node(0, (phys_addr_t)ULLONG_MAX, 0);
619 }
620 #endif
621 
622 void __init paging_init(void)
623 {
624  sparse_memory_present_with_active_regions(MAX_NUMNODES);
625  sparse_init();
626 
627  /*
628  * clear the default setting with node 0
629  * note: don't use nodes_clear here, that is really clearing when
630  * numa support is not compiled in, and later node_set_state
631  * will not set it back.
632  */
633  node_clear_state(0, N_NORMAL_MEMORY);
634 
635  zone_sizes_init();
636 }
637 
638 /*
639  * Memory hotplug specific functions
640  */
641 #ifdef CONFIG_MEMORY_HOTPLUG
642 /*
643  * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
644  * updating.
645  */
646 static void update_end_of_memory_vars(u64 start, u64 size)
647 {
648  unsigned long end_pfn = PFN_UP(start + size);
649 
650  if (end_pfn > max_pfn) {
651  max_pfn = end_pfn;
652  max_low_pfn = end_pfn;
653  high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
654  }
655 }
656 
657 /*
658  * Memory is added always to NORMAL zone. This means you will never get
659  * additional DMA/DMA32 memory.
660  */
661 int arch_add_memory(int nid, u64 start, u64 size)
662 {
663  struct pglist_data *pgdat = NODE_DATA(nid);
664  struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
665  unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT;
666  unsigned long nr_pages = size >> PAGE_SHIFT;
667  int ret;
668 
669  last_mapped_pfn = init_memory_mapping(start, start + size);
670  if (last_mapped_pfn > max_pfn_mapped)
671  max_pfn_mapped = last_mapped_pfn;
672 
673  ret = __add_pages(nid, zone, start_pfn, nr_pages);
674  WARN_ON_ONCE(ret);
675 
676  /* update max_pfn, max_low_pfn and high_memory */
677  update_end_of_memory_vars(start, size);
678 
679  return ret;
680 }
682 
683 #endif /* CONFIG_MEMORY_HOTPLUG */
684 
685 static struct kcore_list kcore_vsyscall;
686 
687 void __init mem_init(void)
688 {
689  long codesize, reservedpages, datasize, initsize;
690  unsigned long absent_pages;
691 
692  pci_iommu_alloc();
693 
694  /* clear_bss() already clear the empty_zero_page */
695 
696  reservedpages = 0;
697 
698  /* this will put all low memory onto the freelists */
699 #ifdef CONFIG_NUMA
700  totalram_pages = numa_free_all_bootmem();
701 #else
702  totalram_pages = free_all_bootmem();
703 #endif
704 
705  absent_pages = absent_pages_in_range(0, max_pfn);
706  reservedpages = max_pfn - totalram_pages - absent_pages;
707  after_bootmem = 1;
708 
709  codesize = (unsigned long) &_etext - (unsigned long) &_text;
710  datasize = (unsigned long) &_edata - (unsigned long) &_etext;
711  initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
712 
713  /* Register memory areas for /proc/kcore */
714  kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
716 
717  printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
718  "%ldk absent, %ldk reserved, %ldk data, %ldk init)\n",
719  nr_free_pages() << (PAGE_SHIFT-10),
720  max_pfn << (PAGE_SHIFT-10),
721  codesize >> 10,
722  absent_pages << (PAGE_SHIFT-10),
723  reservedpages << (PAGE_SHIFT-10),
724  datasize >> 10,
725  initsize >> 10);
726 }
727 
728 #ifdef CONFIG_DEBUG_RODATA
729 const int rodata_test_data = 0xC3;
730 EXPORT_SYMBOL_GPL(rodata_test_data);
731 
732 int kernel_set_to_readonly;
733 
734 void set_kernel_text_rw(void)
735 {
736  unsigned long start = PFN_ALIGN(_text);
737  unsigned long end = PFN_ALIGN(__stop___ex_table);
738 
739  if (!kernel_set_to_readonly)
740  return;
741 
742  pr_debug("Set kernel text: %lx - %lx for read write\n",
743  start, end);
744 
745  /*
746  * Make the kernel identity mapping for text RW. Kernel text
747  * mapping will always be RO. Refer to the comment in
748  * static_protections() in pageattr.c
749  */
750  set_memory_rw(start, (end - start) >> PAGE_SHIFT);
751 }
752 
753 void set_kernel_text_ro(void)
754 {
755  unsigned long start = PFN_ALIGN(_text);
756  unsigned long end = PFN_ALIGN(__stop___ex_table);
757 
758  if (!kernel_set_to_readonly)
759  return;
760 
761  pr_debug("Set kernel text: %lx - %lx for read only\n",
762  start, end);
763 
764  /*
765  * Set the kernel identity mapping for text RO.
766  */
767  set_memory_ro(start, (end - start) >> PAGE_SHIFT);
768 }
769 
770 void mark_rodata_ro(void)
771 {
772  unsigned long start = PFN_ALIGN(_text);
773  unsigned long rodata_start =
774  ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
775  unsigned long end = (unsigned long) &__end_rodata_hpage_align;
776  unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table);
777  unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata);
778  unsigned long data_start = (unsigned long) &_sdata;
779 
780  printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
781  (end - start) >> 10);
782  set_memory_ro(start, (end - start) >> PAGE_SHIFT);
783 
784  kernel_set_to_readonly = 1;
785 
786  /*
787  * The rodata section (but not the kernel text!) should also be
788  * not-executable.
789  */
790  set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT);
791 
792  rodata_test();
793 
794 #ifdef CONFIG_CPA_DEBUG
795  printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
796  set_memory_rw(start, (end-start) >> PAGE_SHIFT);
797 
798  printk(KERN_INFO "Testing CPA: again\n");
799  set_memory_ro(start, (end-start) >> PAGE_SHIFT);
800 #endif
801 
802  free_init_pages("unused kernel memory",
803  (unsigned long) page_address(virt_to_page(text_end)),
804  (unsigned long)
805  page_address(virt_to_page(rodata_start)));
806  free_init_pages("unused kernel memory",
807  (unsigned long) page_address(virt_to_page(rodata_end)),
808  (unsigned long) page_address(virt_to_page(data_start)));
809 }
810 
811 #endif
812 
813 int kern_addr_valid(unsigned long addr)
814 {
815  unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
816  pgd_t *pgd;
817  pud_t *pud;
818  pmd_t *pmd;
819  pte_t *pte;
820 
821  if (above != 0 && above != -1UL)
822  return 0;
823 
824  pgd = pgd_offset_k(addr);
825  if (pgd_none(*pgd))
826  return 0;
827 
828  pud = pud_offset(pgd, addr);
829  if (pud_none(*pud))
830  return 0;
831 
832  pmd = pmd_offset(pud, addr);
833  if (pmd_none(*pmd))
834  return 0;
835 
836  if (pmd_large(*pmd))
837  return pfn_valid(pmd_pfn(*pmd));
838 
839  pte = pte_offset_kernel(pmd, addr);
840  if (pte_none(*pte))
841  return 0;
842 
843  return pfn_valid(pte_pfn(*pte));
844 }
845 
846 /*
847  * A pseudo VMA to allow ptrace access for the vsyscall page. This only
848  * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
849  * not need special handling anymore:
850  */
851 static struct vm_area_struct gate_vma = {
852  .vm_start = VSYSCALL_START,
855  .vm_flags = VM_READ | VM_EXEC
856 };
857 
859 {
860 #ifdef CONFIG_IA32_EMULATION
861  if (!mm || mm->context.ia32_compat)
862  return NULL;
863 #endif
864  return &gate_vma;
865 }
866 
867 int in_gate_area(struct mm_struct *mm, unsigned long addr)
868 {
869  struct vm_area_struct *vma = get_gate_vma(mm);
870 
871  if (!vma)
872  return 0;
873 
874  return (addr >= vma->vm_start) && (addr < vma->vm_end);
875 }
876 
877 /*
878  * Use this when you have no reliable mm, typically from interrupt
879  * context. It is less reliable than using a task's mm and may give
880  * false positives.
881  */
882 int in_gate_area_no_mm(unsigned long addr)
883 {
884  return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
885 }
886 
887 const char *arch_vma_name(struct vm_area_struct *vma)
888 {
889  if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
890  return "[vdso]";
891  if (vma == &gate_vma)
892  return "[vsyscall]";
893  return NULL;
894 }
895 
896 #ifdef CONFIG_X86_UV
897 unsigned long memory_block_size_bytes(void)
898 {
899  if (is_uv_system()) {
900  printk(KERN_INFO "UV: memory block size 2GB\n");
901  return 2UL * 1024 * 1024 * 1024;
902  }
903  return MIN_MEMORY_BLOCK_SIZE;
904 }
905 #endif
906 
907 #ifdef CONFIG_SPARSEMEM_VMEMMAP
908 /*
909  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
910  */
911 static long __meminitdata addr_start, addr_end;
912 static void __meminitdata *p_start, *p_end;
913 static int __meminitdata node_start;
914 
915 int __meminit
916 vmemmap_populate(struct page *start_page, unsigned long size, int node)
917 {
918  unsigned long addr = (unsigned long)start_page;
919  unsigned long end = (unsigned long)(start_page + size);
920  unsigned long next;
921  pgd_t *pgd;
922  pud_t *pud;
923  pmd_t *pmd;
924 
925  for (; addr < end; addr = next) {
926  void *p = NULL;
927 
928  pgd = vmemmap_pgd_populate(addr, node);
929  if (!pgd)
930  return -ENOMEM;
931 
932  pud = vmemmap_pud_populate(pgd, addr, node);
933  if (!pud)
934  return -ENOMEM;
935 
936  if (!cpu_has_pse) {
937  next = (addr + PAGE_SIZE) & PAGE_MASK;
938  pmd = vmemmap_pmd_populate(pud, addr, node);
939 
940  if (!pmd)
941  return -ENOMEM;
942 
943  p = vmemmap_pte_populate(pmd, addr, node);
944 
945  if (!p)
946  return -ENOMEM;
947 
948  addr_end = addr + PAGE_SIZE;
949  p_end = p + PAGE_SIZE;
950  } else {
951  next = pmd_addr_end(addr, end);
952 
953  pmd = pmd_offset(pud, addr);
954  if (pmd_none(*pmd)) {
955  pte_t entry;
956 
958  if (!p)
959  return -ENOMEM;
960 
961  entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
963  set_pmd(pmd, __pmd(pte_val(entry)));
964 
965  /* check to see if we have contiguous blocks */
966  if (p_end != p || node_start != node) {
967  if (p_start)
968  printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
969  addr_start, addr_end-1, p_start, p_end-1, node_start);
970  addr_start = addr;
971  node_start = node;
972  p_start = p;
973  }
974 
975  addr_end = addr + PMD_SIZE;
976  p_end = p + PMD_SIZE;
977  } else
978  vmemmap_verify((pte_t *)pmd, node, addr, next);
979  }
980 
981  }
982  sync_global_pgds((unsigned long)start_page, end);
983  return 0;
984 }
985 
986 void __meminit vmemmap_populate_print_last(void)
987 {
988  if (p_start) {
989  printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
990  addr_start, addr_end-1, p_start, p_end-1, node_start);
991  p_start = NULL;
992  p_end = NULL;
993  node_start = 0;
994  }
995 }
996 #endif