Merge branch 'linus' into x86/memory-corruption-check
[linux-2.6.git] / arch / x86 / mm / init_64.c
1 /*
2  *  linux/arch/x86_64/mm/init.c
3  *
4  *  Copyright (C) 1995  Linus Torvalds
5  *  Copyright (C) 2000  Pavel Machek <pavel@suse.cz>
6  *  Copyright (C) 2002,2003 Andi Kleen <ak@suse.de>
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/proc_fs.h>
25 #include <linux/pci.h>
26 #include <linux/pfn.h>
27 #include <linux/poison.h>
28 #include <linux/dma-mapping.h>
29 #include <linux/module.h>
30 #include <linux/memory_hotplug.h>
31 #include <linux/nmi.h>
32
33 #include <asm/processor.h>
34 #include <asm/bios_ebda.h>
35 #include <asm/system.h>
36 #include <asm/uaccess.h>
37 #include <asm/pgtable.h>
38 #include <asm/pgalloc.h>
39 #include <asm/dma.h>
40 #include <asm/fixmap.h>
41 #include <asm/e820.h>
42 #include <asm/apic.h>
43 #include <asm/tlb.h>
44 #include <asm/mmu_context.h>
45 #include <asm/proto.h>
46 #include <asm/smp.h>
47 #include <asm/sections.h>
48 #include <asm/kdebug.h>
49 #include <asm/numa.h>
50 #include <asm/cacheflush.h>
51
52 /*
53  * end_pfn only includes RAM, while max_pfn_mapped includes all e820 entries.
54  * The direct mapping extends to max_pfn_mapped, so that we can directly access
55  * apertures, ACPI and other tables without having to play with fixmaps.
56  */
57 unsigned long max_low_pfn_mapped;
58 unsigned long max_pfn_mapped;
59
60 static unsigned long dma_reserve __initdata;
61
62 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
63
64 int direct_gbpages
65 #ifdef CONFIG_DIRECT_GBPAGES
66                                 = 1
67 #endif
68 ;
69
70 static int __init parse_direct_gbpages_off(char *arg)
71 {
72         direct_gbpages = 0;
73         return 0;
74 }
75 early_param("nogbpages", parse_direct_gbpages_off);
76
77 static int __init parse_direct_gbpages_on(char *arg)
78 {
79         direct_gbpages = 1;
80         return 0;
81 }
82 early_param("gbpages", parse_direct_gbpages_on);
83
84 /*
85  * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
86  * physical space so we can cache the place of the first one and move
87  * around without checking the pgd every time.
88  */
89
90 int after_bootmem;
91
92 pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP;
93 EXPORT_SYMBOL_GPL(__supported_pte_mask);
94
95 static int do_not_nx __cpuinitdata;
96
97 /*
98  * noexec=on|off
99  * Control non-executable mappings for 64-bit processes.
100  *
101  * on   Enable (default)
102  * off  Disable
103  */
104 static int __init nonx_setup(char *str)
105 {
106         if (!str)
107                 return -EINVAL;
108         if (!strncmp(str, "on", 2)) {
109                 __supported_pte_mask |= _PAGE_NX;
110                 do_not_nx = 0;
111         } else if (!strncmp(str, "off", 3)) {
112                 do_not_nx = 1;
113                 __supported_pte_mask &= ~_PAGE_NX;
114         }
115         return 0;
116 }
117 early_param("noexec", nonx_setup);
118
119 void __cpuinit check_efer(void)
120 {
121         unsigned long efer;
122
123         rdmsrl(MSR_EFER, efer);
124         if (!(efer & EFER_NX) || do_not_nx)
125                 __supported_pte_mask &= ~_PAGE_NX;
126 }
127
128 int force_personality32;
129
130 /*
131  * noexec32=on|off
132  * Control non executable heap for 32bit processes.
133  * To control the stack too use noexec=off
134  *
135  * on   PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
136  * off  PROT_READ implies PROT_EXEC
137  */
138 static int __init nonx32_setup(char *str)
139 {
140         if (!strcmp(str, "on"))
141                 force_personality32 &= ~READ_IMPLIES_EXEC;
142         else if (!strcmp(str, "off"))
143                 force_personality32 |= READ_IMPLIES_EXEC;
144         return 1;
145 }
146 __setup("noexec32=", nonx32_setup);
147
148 /*
149  * NOTE: This function is marked __ref because it calls __init function
150  * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
151  */
152 static __ref void *spp_getpage(void)
153 {
154         void *ptr;
155
156         if (after_bootmem)
157                 ptr = (void *) get_zeroed_page(GFP_ATOMIC);
158         else
159                 ptr = alloc_bootmem_pages(PAGE_SIZE);
160
161         if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
162                 panic("set_pte_phys: cannot allocate page data %s\n",
163                         after_bootmem ? "after bootmem" : "");
164         }
165
166         pr_debug("spp_getpage %p\n", ptr);
167
168         return ptr;
169 }
170
171 void
172 set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
173 {
174         pud_t *pud;
175         pmd_t *pmd;
176         pte_t *pte;
177
178         pud = pud_page + pud_index(vaddr);
179         if (pud_none(*pud)) {
180                 pmd = (pmd_t *) spp_getpage();
181                 pud_populate(&init_mm, pud, pmd);
182                 if (pmd != pmd_offset(pud, 0)) {
183                         printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
184                                 pmd, pmd_offset(pud, 0));
185                         return;
186                 }
187         }
188         pmd = pmd_offset(pud, vaddr);
189         if (pmd_none(*pmd)) {
190                 pte = (pte_t *) spp_getpage();
191                 pmd_populate_kernel(&init_mm, pmd, pte);
192                 if (pte != pte_offset_kernel(pmd, 0)) {
193                         printk(KERN_ERR "PAGETABLE BUG #02!\n");
194                         return;
195                 }
196         }
197
198         pte = pte_offset_kernel(pmd, vaddr);
199         set_pte(pte, new_pte);
200
201         /*
202          * It's enough to flush this one mapping.
203          * (PGE mappings get flushed as well)
204          */
205         __flush_tlb_one(vaddr);
206 }
207
208 void
209 set_pte_vaddr(unsigned long vaddr, pte_t pteval)
210 {
211         pgd_t *pgd;
212         pud_t *pud_page;
213
214         pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
215
216         pgd = pgd_offset_k(vaddr);
217         if (pgd_none(*pgd)) {
218                 printk(KERN_ERR
219                         "PGD FIXMAP MISSING, it should be setup in head.S!\n");
220                 return;
221         }
222         pud_page = (pud_t*)pgd_page_vaddr(*pgd);
223         set_pte_vaddr_pud(pud_page, vaddr, pteval);
224 }
225
226 /*
227  * Create large page table mappings for a range of physical addresses.
228  */
229 static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
230                                                 pgprot_t prot)
231 {
232         pgd_t *pgd;
233         pud_t *pud;
234         pmd_t *pmd;
235
236         BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
237         for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
238                 pgd = pgd_offset_k((unsigned long)__va(phys));
239                 if (pgd_none(*pgd)) {
240                         pud = (pud_t *) spp_getpage();
241                         set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE |
242                                                 _PAGE_USER));
243                 }
244                 pud = pud_offset(pgd, (unsigned long)__va(phys));
245                 if (pud_none(*pud)) {
246                         pmd = (pmd_t *) spp_getpage();
247                         set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
248                                                 _PAGE_USER));
249                 }
250                 pmd = pmd_offset(pud, phys);
251                 BUG_ON(!pmd_none(*pmd));
252                 set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
253         }
254 }
255
256 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
257 {
258         __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE);
259 }
260
261 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
262 {
263         __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE_NOCACHE);
264 }
265
266 /*
267  * The head.S code sets up the kernel high mapping:
268  *
269  *   from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
270  *
271  * phys_addr holds the negative offset to the kernel, which is added
272  * to the compile time generated pmds. This results in invalid pmds up
273  * to the point where we hit the physaddr 0 mapping.
274  *
275  * We limit the mappings to the region from _text to _end.  _end is
276  * rounded up to the 2MB boundary. This catches the invalid pmds as
277  * well, as they are located before _text:
278  */
279 void __init cleanup_highmap(void)
280 {
281         unsigned long vaddr = __START_KERNEL_map;
282         unsigned long end = roundup((unsigned long)_end, PMD_SIZE) - 1;
283         pmd_t *pmd = level2_kernel_pgt;
284         pmd_t *last_pmd = pmd + PTRS_PER_PMD;
285
286         for (; pmd < last_pmd; pmd++, vaddr += PMD_SIZE) {
287                 if (pmd_none(*pmd))
288                         continue;
289                 if (vaddr < (unsigned long) _text || vaddr > end)
290                         set_pmd(pmd, __pmd(0));
291         }
292 }
293
294 static unsigned long __initdata table_start;
295 static unsigned long __meminitdata table_end;
296 static unsigned long __meminitdata table_top;
297
298 static __ref void *alloc_low_page(unsigned long *phys)
299 {
300         unsigned long pfn = table_end++;
301         void *adr;
302
303         if (after_bootmem) {
304                 adr = (void *)get_zeroed_page(GFP_ATOMIC);
305                 *phys = __pa(adr);
306
307                 return adr;
308         }
309
310         if (pfn >= table_top)
311                 panic("alloc_low_page: ran out of memory");
312
313         adr = early_memremap(pfn * PAGE_SIZE, PAGE_SIZE);
314         memset(adr, 0, PAGE_SIZE);
315         *phys  = pfn * PAGE_SIZE;
316         return adr;
317 }
318
319 static __ref void unmap_low_page(void *adr)
320 {
321         if (after_bootmem)
322                 return;
323
324         early_iounmap(adr, PAGE_SIZE);
325 }
326
327 static unsigned long __meminit
328 phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end,
329               pgprot_t prot)
330 {
331         unsigned pages = 0;
332         unsigned long last_map_addr = end;
333         int i;
334
335         pte_t *pte = pte_page + pte_index(addr);
336
337         for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) {
338
339                 if (addr >= end) {
340                         if (!after_bootmem) {
341                                 for(; i < PTRS_PER_PTE; i++, pte++)
342                                         set_pte(pte, __pte(0));
343                         }
344                         break;
345                 }
346
347                 /*
348                  * We will re-use the existing mapping.
349                  * Xen for example has some special requirements, like mapping
350                  * pagetable pages as RO. So assume someone who pre-setup
351                  * these mappings are more intelligent.
352                  */
353                 if (pte_val(*pte)) {
354                         pages++;
355                         continue;
356                 }
357
358                 if (0)
359                         printk("   pte=%p addr=%lx pte=%016lx\n",
360                                pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte);
361                 pages++;
362                 set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot));
363                 last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
364         }
365
366         update_page_count(PG_LEVEL_4K, pages);
367
368         return last_map_addr;
369 }
370
371 static unsigned long __meminit
372 phys_pte_update(pmd_t *pmd, unsigned long address, unsigned long end,
373                 pgprot_t prot)
374 {
375         pte_t *pte = (pte_t *)pmd_page_vaddr(*pmd);
376
377         return phys_pte_init(pte, address, end, prot);
378 }
379
380 static unsigned long __meminit
381 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
382               unsigned long page_size_mask, pgprot_t prot)
383 {
384         unsigned long pages = 0;
385         unsigned long last_map_addr = end;
386
387         int i = pmd_index(address);
388
389         for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
390                 unsigned long pte_phys;
391                 pmd_t *pmd = pmd_page + pmd_index(address);
392                 pte_t *pte;
393                 pgprot_t new_prot = prot;
394
395                 if (address >= end) {
396                         if (!after_bootmem) {
397                                 for (; i < PTRS_PER_PMD; i++, pmd++)
398                                         set_pmd(pmd, __pmd(0));
399                         }
400                         break;
401                 }
402
403                 if (pmd_val(*pmd)) {
404                         if (!pmd_large(*pmd)) {
405                                 spin_lock(&init_mm.page_table_lock);
406                                 last_map_addr = phys_pte_update(pmd, address,
407                                                                 end, prot);
408                                 spin_unlock(&init_mm.page_table_lock);
409                                 continue;
410                         }
411                         /*
412                          * If we are ok with PG_LEVEL_2M mapping, then we will
413                          * use the existing mapping,
414                          *
415                          * Otherwise, we will split the large page mapping but
416                          * use the same existing protection bits except for
417                          * large page, so that we don't violate Intel's TLB
418                          * Application note (317080) which says, while changing
419                          * the page sizes, new and old translations should
420                          * not differ with respect to page frame and
421                          * attributes.
422                          */
423                         if (page_size_mask & (1 << PG_LEVEL_2M)) {
424                                 pages++;
425                                 continue;
426                         }
427                         new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
428                 }
429
430                 if (page_size_mask & (1<<PG_LEVEL_2M)) {
431                         pages++;
432                         spin_lock(&init_mm.page_table_lock);
433                         set_pte((pte_t *)pmd,
434                                 pfn_pte(address >> PAGE_SHIFT,
435                                         __pgprot(pgprot_val(prot) | _PAGE_PSE)));
436                         spin_unlock(&init_mm.page_table_lock);
437                         last_map_addr = (address & PMD_MASK) + PMD_SIZE;
438                         continue;
439                 }
440
441                 pte = alloc_low_page(&pte_phys);
442                 last_map_addr = phys_pte_init(pte, address, end, new_prot);
443                 unmap_low_page(pte);
444
445                 spin_lock(&init_mm.page_table_lock);
446                 pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
447                 spin_unlock(&init_mm.page_table_lock);
448         }
449         update_page_count(PG_LEVEL_2M, pages);
450         return last_map_addr;
451 }
452
453 static unsigned long __meminit
454 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end,
455                 unsigned long page_size_mask, pgprot_t prot)
456 {
457         pmd_t *pmd = pmd_offset(pud, 0);
458         unsigned long last_map_addr;
459
460         last_map_addr = phys_pmd_init(pmd, address, end, page_size_mask, prot);
461         __flush_tlb_all();
462         return last_map_addr;
463 }
464
465 static unsigned long __meminit
466 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
467                          unsigned long page_size_mask)
468 {
469         unsigned long pages = 0;
470         unsigned long last_map_addr = end;
471         int i = pud_index(addr);
472
473         for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
474                 unsigned long pmd_phys;
475                 pud_t *pud = pud_page + pud_index(addr);
476                 pmd_t *pmd;
477                 pgprot_t prot = PAGE_KERNEL;
478
479                 if (addr >= end)
480                         break;
481
482                 if (!after_bootmem &&
483                                 !e820_any_mapped(addr, addr+PUD_SIZE, 0)) {
484                         set_pud(pud, __pud(0));
485                         continue;
486                 }
487
488                 if (pud_val(*pud)) {
489                         if (!pud_large(*pud)) {
490                                 last_map_addr = phys_pmd_update(pud, addr, end,
491                                                          page_size_mask, prot);
492                                 continue;
493                         }
494                         /*
495                          * If we are ok with PG_LEVEL_1G mapping, then we will
496                          * use the existing mapping.
497                          *
498                          * Otherwise, we will split the gbpage mapping but use
499                          * the same existing protection  bits except for large
500                          * page, so that we don't violate Intel's TLB
501                          * Application note (317080) which says, while changing
502                          * the page sizes, new and old translations should
503                          * not differ with respect to page frame and
504                          * attributes.
505                          */
506                         if (page_size_mask & (1 << PG_LEVEL_1G)) {
507                                 pages++;
508                                 continue;
509                         }
510                         prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
511                 }
512
513                 if (page_size_mask & (1<<PG_LEVEL_1G)) {
514                         pages++;
515                         spin_lock(&init_mm.page_table_lock);
516                         set_pte((pte_t *)pud,
517                                 pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
518                         spin_unlock(&init_mm.page_table_lock);
519                         last_map_addr = (addr & PUD_MASK) + PUD_SIZE;
520                         continue;
521                 }
522
523                 pmd = alloc_low_page(&pmd_phys);
524                 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask,
525                                               prot);
526                 unmap_low_page(pmd);
527
528                 spin_lock(&init_mm.page_table_lock);
529                 pud_populate(&init_mm, pud, __va(pmd_phys));
530                 spin_unlock(&init_mm.page_table_lock);
531         }
532         __flush_tlb_all();
533
534         update_page_count(PG_LEVEL_1G, pages);
535
536         return last_map_addr;
537 }
538
539 static unsigned long __meminit
540 phys_pud_update(pgd_t *pgd, unsigned long addr, unsigned long end,
541                  unsigned long page_size_mask)
542 {
543         pud_t *pud;
544
545         pud = (pud_t *)pgd_page_vaddr(*pgd);
546
547         return phys_pud_init(pud, addr, end, page_size_mask);
548 }
549
550 static void __init find_early_table_space(unsigned long end, int use_pse,
551                                           int use_gbpages)
552 {
553         unsigned long puds, pmds, ptes, tables, start;
554
555         puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
556         tables = roundup(puds * sizeof(pud_t), PAGE_SIZE);
557         if (use_gbpages) {
558                 unsigned long extra;
559                 extra = end - ((end>>PUD_SHIFT) << PUD_SHIFT);
560                 pmds = (extra + PMD_SIZE - 1) >> PMD_SHIFT;
561         } else
562                 pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
563         tables += roundup(pmds * sizeof(pmd_t), PAGE_SIZE);
564
565         if (use_pse) {
566                 unsigned long extra;
567                 extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT);
568                 ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT;
569         } else
570                 ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT;
571         tables += roundup(ptes * sizeof(pte_t), PAGE_SIZE);
572
573         /*
574          * RED-PEN putting page tables only on node 0 could
575          * cause a hotspot and fill up ZONE_DMA. The page tables
576          * need roughly 0.5KB per GB.
577          */
578         start = 0x8000;
579         table_start = find_e820_area(start, end, tables, PAGE_SIZE);
580         if (table_start == -1UL)
581                 panic("Cannot find space for the kernel page tables");
582
583         table_start >>= PAGE_SHIFT;
584         table_end = table_start;
585         table_top = table_start + (tables >> PAGE_SHIFT);
586
587         printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n",
588                 end, table_start << PAGE_SHIFT, table_top << PAGE_SHIFT);
589 }
590
591 static void __init init_gbpages(void)
592 {
593         if (direct_gbpages && cpu_has_gbpages)
594                 printk(KERN_INFO "Using GB pages for direct mapping\n");
595         else
596                 direct_gbpages = 0;
597 }
598
599 static unsigned long __init kernel_physical_mapping_init(unsigned long start,
600                                                 unsigned long end,
601                                                 unsigned long page_size_mask)
602 {
603
604         unsigned long next, last_map_addr = end;
605
606         start = (unsigned long)__va(start);
607         end = (unsigned long)__va(end);
608
609         for (; start < end; start = next) {
610                 pgd_t *pgd = pgd_offset_k(start);
611                 unsigned long pud_phys;
612                 pud_t *pud;
613
614                 next = (start + PGDIR_SIZE) & PGDIR_MASK;
615                 if (next > end)
616                         next = end;
617
618                 if (pgd_val(*pgd)) {
619                         last_map_addr = phys_pud_update(pgd, __pa(start),
620                                                  __pa(end), page_size_mask);
621                         continue;
622                 }
623
624                 pud = alloc_low_page(&pud_phys);
625                 last_map_addr = phys_pud_init(pud, __pa(start), __pa(next),
626                                                  page_size_mask);
627                 unmap_low_page(pud);
628
629                 spin_lock(&init_mm.page_table_lock);
630                 pgd_populate(&init_mm, pgd, __va(pud_phys));
631                 spin_unlock(&init_mm.page_table_lock);
632         }
633         __flush_tlb_all();
634
635         return last_map_addr;
636 }
637
638 struct map_range {
639         unsigned long start;
640         unsigned long end;
641         unsigned page_size_mask;
642 };
643
644 #define NR_RANGE_MR 5
645
646 static int save_mr(struct map_range *mr, int nr_range,
647                    unsigned long start_pfn, unsigned long end_pfn,
648                    unsigned long page_size_mask)
649 {
650
651         if (start_pfn < end_pfn) {
652                 if (nr_range >= NR_RANGE_MR)
653                         panic("run out of range for init_memory_mapping\n");
654                 mr[nr_range].start = start_pfn<<PAGE_SHIFT;
655                 mr[nr_range].end   = end_pfn<<PAGE_SHIFT;
656                 mr[nr_range].page_size_mask = page_size_mask;
657                 nr_range++;
658         }
659
660         return nr_range;
661 }
662
663 /*
664  * Setup the direct mapping of the physical memory at PAGE_OFFSET.
665  * This runs before bootmem is initialized and gets pages directly from
666  * the physical memory. To access them they are temporarily mapped.
667  */
668 unsigned long __init_refok init_memory_mapping(unsigned long start,
669                                                unsigned long end)
670 {
671         unsigned long last_map_addr = 0;
672         unsigned long page_size_mask = 0;
673         unsigned long start_pfn, end_pfn;
674         unsigned long pos;
675
676         struct map_range mr[NR_RANGE_MR];
677         int nr_range, i;
678         int use_pse, use_gbpages;
679
680         printk(KERN_INFO "init_memory_mapping: %016lx-%016lx\n", start, end);
681
682         /*
683          * Find space for the kernel direct mapping tables.
684          *
685          * Later we should allocate these tables in the local node of the
686          * memory mapped. Unfortunately this is done currently before the
687          * nodes are discovered.
688          */
689         if (!after_bootmem)
690                 init_gbpages();
691
692 #ifdef CONFIG_DEBUG_PAGEALLOC
693         /*
694          * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
695          * This will simplify cpa(), which otherwise needs to support splitting
696          * large pages into small in interrupt context, etc.
697          */
698         use_pse = use_gbpages = 0;
699 #else
700         use_pse = cpu_has_pse;
701         use_gbpages = direct_gbpages;
702 #endif
703
704         if (use_gbpages)
705                 page_size_mask |= 1 << PG_LEVEL_1G;
706         if (use_pse)
707                 page_size_mask |= 1 << PG_LEVEL_2M;
708
709         memset(mr, 0, sizeof(mr));
710         nr_range = 0;
711
712         /* head if not big page alignment ?*/
713         start_pfn = start >> PAGE_SHIFT;
714         pos = start_pfn << PAGE_SHIFT;
715         end_pfn = ((pos + (PMD_SIZE - 1)) >> PMD_SHIFT)
716                         << (PMD_SHIFT - PAGE_SHIFT);
717         if (start_pfn < end_pfn) {
718                 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
719                 pos = end_pfn << PAGE_SHIFT;
720         }
721
722         /* big page (2M) range*/
723         start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
724                          << (PMD_SHIFT - PAGE_SHIFT);
725         end_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT)
726                          << (PUD_SHIFT - PAGE_SHIFT);
727         if (end_pfn > ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT)))
728                 end_pfn = ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT));
729         if (start_pfn < end_pfn) {
730                 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
731                                 page_size_mask & (1<<PG_LEVEL_2M));
732                 pos = end_pfn << PAGE_SHIFT;
733         }
734
735         /* big page (1G) range */
736         start_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT)
737                          << (PUD_SHIFT - PAGE_SHIFT);
738         end_pfn = (end >> PUD_SHIFT) << (PUD_SHIFT - PAGE_SHIFT);
739         if (start_pfn < end_pfn) {
740                 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
741                                 page_size_mask &
742                                  ((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G)));
743                 pos = end_pfn << PAGE_SHIFT;
744         }
745
746         /* tail is not big page (1G) alignment */
747         start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
748                          << (PMD_SHIFT - PAGE_SHIFT);
749         end_pfn = (end >> PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
750         if (start_pfn < end_pfn) {
751                 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
752                                 page_size_mask & (1<<PG_LEVEL_2M));
753                 pos = end_pfn << PAGE_SHIFT;
754         }
755
756         /* tail is not big page (2M) alignment */
757         start_pfn = pos>>PAGE_SHIFT;
758         end_pfn = end>>PAGE_SHIFT;
759         nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
760
761         /* try to merge same page size and continuous */
762         for (i = 0; nr_range > 1 && i < nr_range - 1; i++) {
763                 unsigned long old_start;
764                 if (mr[i].end != mr[i+1].start ||
765                     mr[i].page_size_mask != mr[i+1].page_size_mask)
766                         continue;
767                 /* move it */
768                 old_start = mr[i].start;
769                 memmove(&mr[i], &mr[i+1],
770                          (nr_range - 1 - i) * sizeof (struct map_range));
771                 mr[i--].start = old_start;
772                 nr_range--;
773         }
774
775         for (i = 0; i < nr_range; i++)
776                 printk(KERN_DEBUG " %010lx - %010lx page %s\n",
777                                 mr[i].start, mr[i].end,
778                         (mr[i].page_size_mask & (1<<PG_LEVEL_1G))?"1G":(
779                          (mr[i].page_size_mask & (1<<PG_LEVEL_2M))?"2M":"4k"));
780
781         if (!after_bootmem)
782                 find_early_table_space(end, use_pse, use_gbpages);
783
784         for (i = 0; i < nr_range; i++)
785                 last_map_addr = kernel_physical_mapping_init(
786                                         mr[i].start, mr[i].end,
787                                         mr[i].page_size_mask);
788
789         if (!after_bootmem)
790                 mmu_cr4_features = read_cr4();
791         __flush_tlb_all();
792
793         if (!after_bootmem && table_end > table_start)
794                 reserve_early(table_start << PAGE_SHIFT,
795                                  table_end << PAGE_SHIFT, "PGTABLE");
796
797         printk(KERN_INFO "last_map_addr: %lx end: %lx\n",
798                          last_map_addr, end);
799
800         if (!after_bootmem)
801                 early_memtest(start, end);
802
803         return last_map_addr >> PAGE_SHIFT;
804 }
805
806 #ifndef CONFIG_NUMA
807 void __init initmem_init(unsigned long start_pfn, unsigned long end_pfn)
808 {
809         unsigned long bootmap_size, bootmap;
810
811         bootmap_size = bootmem_bootmap_pages(end_pfn)<<PAGE_SHIFT;
812         bootmap = find_e820_area(0, end_pfn<<PAGE_SHIFT, bootmap_size,
813                                  PAGE_SIZE);
814         if (bootmap == -1L)
815                 panic("Cannot find bootmem map of size %ld\n", bootmap_size);
816         /* don't touch min_low_pfn */
817         bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap >> PAGE_SHIFT,
818                                          0, end_pfn);
819         e820_register_active_regions(0, start_pfn, end_pfn);
820         free_bootmem_with_active_regions(0, end_pfn);
821         early_res_to_bootmem(0, end_pfn<<PAGE_SHIFT);
822         reserve_bootmem(bootmap, bootmap_size, BOOTMEM_DEFAULT);
823 }
824
825 void __init paging_init(void)
826 {
827         unsigned long max_zone_pfns[MAX_NR_ZONES];
828
829         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
830         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
831         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
832         max_zone_pfns[ZONE_NORMAL] = max_pfn;
833
834         memory_present(0, 0, max_pfn);
835         sparse_init();
836         free_area_init_nodes(max_zone_pfns);
837 }
838 #endif
839
840 /*
841  * Memory hotplug specific functions
842  */
843 #ifdef CONFIG_MEMORY_HOTPLUG
844 /*
845  * Memory is added always to NORMAL zone. This means you will never get
846  * additional DMA/DMA32 memory.
847  */
848 int arch_add_memory(int nid, u64 start, u64 size)
849 {
850         struct pglist_data *pgdat = NODE_DATA(nid);
851         struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
852         unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT;
853         unsigned long nr_pages = size >> PAGE_SHIFT;
854         int ret;
855
856         last_mapped_pfn = init_memory_mapping(start, start + size);
857         if (last_mapped_pfn > max_pfn_mapped)
858                 max_pfn_mapped = last_mapped_pfn;
859
860         ret = __add_pages(zone, start_pfn, nr_pages);
861         WARN_ON_ONCE(ret);
862
863         return ret;
864 }
865 EXPORT_SYMBOL_GPL(arch_add_memory);
866
867 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
868 int memory_add_physaddr_to_nid(u64 start)
869 {
870         return 0;
871 }
872 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
873 #endif
874
875 #endif /* CONFIG_MEMORY_HOTPLUG */
876
877 /*
878  * devmem_is_allowed() checks to see if /dev/mem access to a certain address
879  * is valid. The argument is a physical page number.
880  *
881  *
882  * On x86, access has to be given to the first megabyte of ram because that area
883  * contains bios code and data regions used by X and dosemu and similar apps.
884  * Access has to be given to non-kernel-ram areas as well, these contain the PCI
885  * mmio resources as well as potential bios/acpi data regions.
886  */
887 int devmem_is_allowed(unsigned long pagenr)
888 {
889         if (pagenr <= 256)
890                 return 1;
891         if (!page_is_ram(pagenr))
892                 return 1;
893         return 0;
894 }
895
896
897 static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel,
898                          kcore_modules, kcore_vsyscall;
899
900 void __init mem_init(void)
901 {
902         long codesize, reservedpages, datasize, initsize;
903         unsigned long absent_pages;
904
905         pci_iommu_alloc();
906
907         /* clear_bss() already clear the empty_zero_page */
908
909         reservedpages = 0;
910
911         /* this will put all low memory onto the freelists */
912 #ifdef CONFIG_NUMA
913         totalram_pages = numa_free_all_bootmem();
914 #else
915         totalram_pages = free_all_bootmem();
916 #endif
917
918         absent_pages = absent_pages_in_range(0, max_pfn);
919         reservedpages = max_pfn - totalram_pages - absent_pages;
920         after_bootmem = 1;
921
922         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
923         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
924         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
925
926         /* Register memory areas for /proc/kcore */
927         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
928         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
929                    VMALLOC_END-VMALLOC_START);
930         kclist_add(&kcore_kernel, &_stext, _end - _stext);
931         kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN);
932         kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
933                                  VSYSCALL_END - VSYSCALL_START);
934
935         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
936                          "%ldk absent, %ldk reserved, %ldk data, %ldk init)\n",
937                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
938                 max_pfn << (PAGE_SHIFT-10),
939                 codesize >> 10,
940                 absent_pages << (PAGE_SHIFT-10),
941                 reservedpages << (PAGE_SHIFT-10),
942                 datasize >> 10,
943                 initsize >> 10);
944 }
945
946 void free_init_pages(char *what, unsigned long begin, unsigned long end)
947 {
948         unsigned long addr = begin;
949
950         if (addr >= end)
951                 return;
952
953         /*
954          * If debugging page accesses then do not free this memory but
955          * mark them not present - any buggy init-section access will
956          * create a kernel page fault:
957          */
958 #ifdef CONFIG_DEBUG_PAGEALLOC
959         printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
960                 begin, PAGE_ALIGN(end));
961         set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
962 #else
963         printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
964
965         for (; addr < end; addr += PAGE_SIZE) {
966                 ClearPageReserved(virt_to_page(addr));
967                 init_page_count(virt_to_page(addr));
968                 memset((void *)(addr & ~(PAGE_SIZE-1)),
969                         POISON_FREE_INITMEM, PAGE_SIZE);
970                 free_page(addr);
971                 totalram_pages++;
972         }
973 #endif
974 }
975
976 void free_initmem(void)
977 {
978         free_init_pages("unused kernel memory",
979                         (unsigned long)(&__init_begin),
980                         (unsigned long)(&__init_end));
981 }
982
983 #ifdef CONFIG_DEBUG_RODATA
984 const int rodata_test_data = 0xC3;
985 EXPORT_SYMBOL_GPL(rodata_test_data);
986
987 void mark_rodata_ro(void)
988 {
989         unsigned long start = PFN_ALIGN(_stext), end = PFN_ALIGN(__end_rodata);
990         unsigned long rodata_start =
991                 ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
992
993 #ifdef CONFIG_DYNAMIC_FTRACE
994         /* Dynamic tracing modifies the kernel text section */
995         start = rodata_start;
996 #endif
997
998         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
999                (end - start) >> 10);
1000         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1001
1002         /*
1003          * The rodata section (but not the kernel text!) should also be
1004          * not-executable.
1005          */
1006         set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT);
1007
1008         rodata_test();
1009
1010 #ifdef CONFIG_CPA_DEBUG
1011         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
1012         set_memory_rw(start, (end-start) >> PAGE_SHIFT);
1013
1014         printk(KERN_INFO "Testing CPA: again\n");
1015         set_memory_ro(start, (end-start) >> PAGE_SHIFT);
1016 #endif
1017 }
1018
1019 #endif
1020
1021 #ifdef CONFIG_BLK_DEV_INITRD
1022 void free_initrd_mem(unsigned long start, unsigned long end)
1023 {
1024         free_init_pages("initrd memory", start, end);
1025 }
1026 #endif
1027
1028 int __init reserve_bootmem_generic(unsigned long phys, unsigned long len,
1029                                    int flags)
1030 {
1031 #ifdef CONFIG_NUMA
1032         int nid, next_nid;
1033         int ret;
1034 #endif
1035         unsigned long pfn = phys >> PAGE_SHIFT;
1036
1037         if (pfn >= max_pfn) {
1038                 /*
1039                  * This can happen with kdump kernels when accessing
1040                  * firmware tables:
1041                  */
1042                 if (pfn < max_pfn_mapped)
1043                         return -EFAULT;
1044
1045                 printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %lu\n",
1046                                 phys, len);
1047                 return -EFAULT;
1048         }
1049
1050         /* Should check here against the e820 map to avoid double free */
1051 #ifdef CONFIG_NUMA
1052         nid = phys_to_nid(phys);
1053         next_nid = phys_to_nid(phys + len - 1);
1054         if (nid == next_nid)
1055                 ret = reserve_bootmem_node(NODE_DATA(nid), phys, len, flags);
1056         else
1057                 ret = reserve_bootmem(phys, len, flags);
1058
1059         if (ret != 0)
1060                 return ret;
1061
1062 #else
1063         reserve_bootmem(phys, len, BOOTMEM_DEFAULT);
1064 #endif
1065
1066         if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
1067                 dma_reserve += len / PAGE_SIZE;
1068                 set_dma_reserve(dma_reserve);
1069         }
1070
1071         return 0;
1072 }
1073
1074 int kern_addr_valid(unsigned long addr)
1075 {
1076         unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
1077         pgd_t *pgd;
1078         pud_t *pud;
1079         pmd_t *pmd;
1080         pte_t *pte;
1081
1082         if (above != 0 && above != -1UL)
1083                 return 0;
1084
1085         pgd = pgd_offset_k(addr);
1086         if (pgd_none(*pgd))
1087                 return 0;
1088
1089         pud = pud_offset(pgd, addr);
1090         if (pud_none(*pud))
1091                 return 0;
1092
1093         pmd = pmd_offset(pud, addr);
1094         if (pmd_none(*pmd))
1095                 return 0;
1096
1097         if (pmd_large(*pmd))
1098                 return pfn_valid(pmd_pfn(*pmd));
1099
1100         pte = pte_offset_kernel(pmd, addr);
1101         if (pte_none(*pte))
1102                 return 0;
1103
1104         return pfn_valid(pte_pfn(*pte));
1105 }
1106
1107 /*
1108  * A pseudo VMA to allow ptrace access for the vsyscall page.  This only
1109  * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
1110  * not need special handling anymore:
1111  */
1112 static struct vm_area_struct gate_vma = {
1113         .vm_start       = VSYSCALL_START,
1114         .vm_end         = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
1115         .vm_page_prot   = PAGE_READONLY_EXEC,
1116         .vm_flags       = VM_READ | VM_EXEC
1117 };
1118
1119 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
1120 {
1121 #ifdef CONFIG_IA32_EMULATION
1122         if (test_tsk_thread_flag(tsk, TIF_IA32))
1123                 return NULL;
1124 #endif
1125         return &gate_vma;
1126 }
1127
1128 int in_gate_area(struct task_struct *task, unsigned long addr)
1129 {
1130         struct vm_area_struct *vma = get_gate_vma(task);
1131
1132         if (!vma)
1133                 return 0;
1134
1135         return (addr >= vma->vm_start) && (addr < vma->vm_end);
1136 }
1137
1138 /*
1139  * Use this when you have no reliable task/vma, typically from interrupt
1140  * context. It is less reliable than using the task's vma and may give
1141  * false positives:
1142  */
1143 int in_gate_area_no_task(unsigned long addr)
1144 {
1145         return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
1146 }
1147
1148 const char *arch_vma_name(struct vm_area_struct *vma)
1149 {
1150         if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
1151                 return "[vdso]";
1152         if (vma == &gate_vma)
1153                 return "[vsyscall]";
1154         return NULL;
1155 }
1156
1157 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1158 /*
1159  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1160  */
1161 static long __meminitdata addr_start, addr_end;
1162 static void __meminitdata *p_start, *p_end;
1163 static int __meminitdata node_start;
1164
1165 int __meminit
1166 vmemmap_populate(struct page *start_page, unsigned long size, int node)
1167 {
1168         unsigned long addr = (unsigned long)start_page;
1169         unsigned long end = (unsigned long)(start_page + size);
1170         unsigned long next;
1171         pgd_t *pgd;
1172         pud_t *pud;
1173         pmd_t *pmd;
1174
1175         for (; addr < end; addr = next) {
1176                 void *p = NULL;
1177
1178                 pgd = vmemmap_pgd_populate(addr, node);
1179                 if (!pgd)
1180                         return -ENOMEM;
1181
1182                 pud = vmemmap_pud_populate(pgd, addr, node);
1183                 if (!pud)
1184                         return -ENOMEM;
1185
1186                 if (!cpu_has_pse) {
1187                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1188                         pmd = vmemmap_pmd_populate(pud, addr, node);
1189
1190                         if (!pmd)
1191                                 return -ENOMEM;
1192
1193                         p = vmemmap_pte_populate(pmd, addr, node);
1194
1195                         if (!p)
1196                                 return -ENOMEM;
1197
1198                         addr_end = addr + PAGE_SIZE;
1199                         p_end = p + PAGE_SIZE;
1200                 } else {
1201                         next = pmd_addr_end(addr, end);
1202
1203                         pmd = pmd_offset(pud, addr);
1204                         if (pmd_none(*pmd)) {
1205                                 pte_t entry;
1206
1207                                 p = vmemmap_alloc_block(PMD_SIZE, node);
1208                                 if (!p)
1209                                         return -ENOMEM;
1210
1211                                 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1212                                                 PAGE_KERNEL_LARGE);
1213                                 set_pmd(pmd, __pmd(pte_val(entry)));
1214
1215                                 /* check to see if we have contiguous blocks */
1216                                 if (p_end != p || node_start != node) {
1217                                         if (p_start)
1218                                                 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1219                                                        addr_start, addr_end-1, p_start, p_end-1, node_start);
1220                                         addr_start = addr;
1221                                         node_start = node;
1222                                         p_start = p;
1223                                 }
1224
1225                                 addr_end = addr + PMD_SIZE;
1226                                 p_end = p + PMD_SIZE;
1227                         } else
1228                                 vmemmap_verify((pte_t *)pmd, node, addr, next);
1229                 }
1230
1231         }
1232         return 0;
1233 }
1234
1235 void __meminit vmemmap_populate_print_last(void)
1236 {
1237         if (p_start) {
1238                 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1239                         addr_start, addr_end-1, p_start, p_end-1, node_start);
1240                 p_start = NULL;
1241                 p_end = NULL;
1242                 node_start = 0;
1243         }
1244 }
1245 #endif