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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 <pavel@ucw.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 #include <linux/gfp.h>
33
34 #include <asm/processor.h>
35 #include <asm/bios_ebda.h>
36 #include <asm/system.h>
37 #include <asm/uaccess.h>
38 #include <asm/pgtable.h>
39 #include <asm/pgalloc.h>
40 #include <asm/dma.h>
41 #include <asm/fixmap.h>
42 #include <asm/e820.h>
43 #include <asm/apic.h>
44 #include <asm/tlb.h>
45 #include <asm/mmu_context.h>
46 #include <asm/proto.h>
47 #include <asm/smp.h>
48 #include <asm/sections.h>
49 #include <asm/kdebug.h>
50 #include <asm/numa.h>
51 #include <asm/cacheflush.h>
52 #include <asm/init.h>
53 #include <linux/bootmem.h>
54
55 static unsigned long dma_reserve __initdata;
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
77 pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP;
78 EXPORT_SYMBOL_GPL(__supported_pte_mask);
79
80 int force_personality32;
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"))
93                 force_personality32 &= ~READ_IMPLIES_EXEC;
94         else if (!strcmp(str, "off"))
95                 force_personality32 |= READ_IMPLIES_EXEC;
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                 unsigned long flags;
111                 struct page *page;
112
113                 if (pgd_none(*pgd_ref))
114                         continue;
115
116                 spin_lock_irqsave(&pgd_lock, flags);
117                 list_for_each_entry(page, &pgd_list, lru) {
118                         pgd_t *pgd;
119                         spinlock_t *pgt_lock;
120
121                         pgd = (pgd_t *)page_address(page) + pgd_index(address);
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_irqrestore(&pgd_lock, flags);
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
148                 ptr = alloc_bootmem_pages(PAGE_SIZE);
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)) {
223                 printk(KERN_ERR
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 _end.  _end is
299  * rounded up to the 2MB boundary. This catches the invalid pmds as
300  * well, as they are located before _text:
301  */
302 void __init cleanup_highmap(void)
303 {
304         unsigned long vaddr = __START_KERNEL_map;
305         unsigned long end = roundup((unsigned long)_end, PMD_SIZE) - 1;
306         pmd_t *pmd = level2_kernel_pgt;
307         pmd_t *last_pmd = pmd + PTRS_PER_PMD;
308
309         for (; pmd < last_pmd; 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 = e820_table_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 >= e820_table_top)
330                 panic("alloc_low_page: ran out of memory");
331
332         adr = early_memremap(pfn * PAGE_SIZE, PAGE_SIZE);
333         memset(adr, 0, PAGE_SIZE);
334         *phys  = pfn * PAGE_SIZE;
335         return adr;
336 }
337
338 static __ref void unmap_low_page(void *adr)
339 {
340         if (after_bootmem)
341                 return;
342
343         early_iounmap(adr, PAGE_SIZE);
344 }
345
346 static unsigned long __meminit
347 phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end,
348               pgprot_t prot)
349 {
350         unsigned pages = 0;
351         unsigned long last_map_addr = end;
352         int i;
353
354         pte_t *pte = pte_page + pte_index(addr);
355
356         for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) {
357
358                 if (addr >= end) {
359                         if (!after_bootmem) {
360                                 for(; i < PTRS_PER_PTE; i++, pte++)
361                                         set_pte(pte, __pte(0));
362                         }
363                         break;
364                 }
365
366                 /*
367                  * We will re-use the existing mapping.
368                  * Xen for example has some special requirements, like mapping
369                  * pagetable pages as RO. So assume someone who pre-setup
370                  * these mappings are more intelligent.
371                  */
372                 if (pte_val(*pte)) {
373                         pages++;
374                         continue;
375                 }
376
377                 if (0)
378                         printk("   pte=%p addr=%lx pte=%016lx\n",
379                                pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte);
380                 pages++;
381                 set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot));
382                 last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
383         }
384
385         update_page_count(PG_LEVEL_4K, pages);
386
387         return last_map_addr;
388 }
389
390 static unsigned long __meminit
391 phys_pte_update(pmd_t *pmd, unsigned long address, unsigned long end,
392                 pgprot_t prot)
393 {
394         pte_t *pte = (pte_t *)pmd_page_vaddr(*pmd);
395
396         return phys_pte_init(pte, address, end, prot);
397 }
398
399 static unsigned long __meminit
400 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
401               unsigned long page_size_mask, pgprot_t prot)
402 {
403         unsigned long pages = 0;
404         unsigned long last_map_addr = end;
405
406         int i = pmd_index(address);
407
408         for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
409                 unsigned long pte_phys;
410                 pmd_t *pmd = pmd_page + pmd_index(address);
411                 pte_t *pte;
412                 pgprot_t new_prot = prot;
413
414                 if (address >= end) {
415                         if (!after_bootmem) {
416                                 for (; i < PTRS_PER_PMD; i++, pmd++)
417                                         set_pmd(pmd, __pmd(0));
418                         }
419                         break;
420                 }
421
422                 if (pmd_val(*pmd)) {
423                         if (!pmd_large(*pmd)) {
424                                 spin_lock(&init_mm.page_table_lock);
425                                 last_map_addr = phys_pte_update(pmd, address,
426                                                                 end, prot);
427                                 spin_unlock(&init_mm.page_table_lock);
428                                 continue;
429                         }
430                         /*
431                          * If we are ok with PG_LEVEL_2M mapping, then we will
432                          * use the existing mapping,
433                          *
434                          * Otherwise, we will split the large page mapping but
435                          * use the same existing protection bits except for
436                          * large page, so that we don't violate Intel's TLB
437                          * Application note (317080) which says, while changing
438                          * the page sizes, new and old translations should
439                          * not differ with respect to page frame and
440                          * attributes.
441                          */
442                         if (page_size_mask & (1 << PG_LEVEL_2M)) {
443                                 pages++;
444                                 continue;
445                         }
446                         new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
447                 }
448
449                 if (page_size_mask & (1<<PG_LEVEL_2M)) {
450                         pages++;
451                         spin_lock(&init_mm.page_table_lock);
452                         set_pte((pte_t *)pmd,
453                                 pfn_pte(address >> PAGE_SHIFT,
454                                         __pgprot(pgprot_val(prot) | _PAGE_PSE)));
455                         spin_unlock(&init_mm.page_table_lock);
456                         last_map_addr = (address & PMD_MASK) + PMD_SIZE;
457                         continue;
458                 }
459
460                 pte = alloc_low_page(&pte_phys);
461                 last_map_addr = phys_pte_init(pte, address, end, new_prot);
462                 unmap_low_page(pte);
463
464                 spin_lock(&init_mm.page_table_lock);
465                 pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
466                 spin_unlock(&init_mm.page_table_lock);
467         }
468         update_page_count(PG_LEVEL_2M, pages);
469         return last_map_addr;
470 }
471
472 static unsigned long __meminit
473 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end,
474                 unsigned long page_size_mask, pgprot_t prot)
475 {
476         pmd_t *pmd = pmd_offset(pud, 0);
477         unsigned long last_map_addr;
478
479         last_map_addr = phys_pmd_init(pmd, address, end, page_size_mask, prot);
480         __flush_tlb_all();
481         return last_map_addr;
482 }
483
484 static unsigned long __meminit
485 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
486                          unsigned long page_size_mask)
487 {
488         unsigned long pages = 0;
489         unsigned long last_map_addr = end;
490         int i = pud_index(addr);
491
492         for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
493                 unsigned long pmd_phys;
494                 pud_t *pud = pud_page + pud_index(addr);
495                 pmd_t *pmd;
496                 pgprot_t prot = PAGE_KERNEL;
497
498                 if (addr >= end)
499                         break;
500
501                 if (!after_bootmem &&
502                                 !e820_any_mapped(addr, addr+PUD_SIZE, 0)) {
503                         set_pud(pud, __pud(0));
504                         continue;
505                 }
506
507                 if (pud_val(*pud)) {
508                         if (!pud_large(*pud)) {
509                                 last_map_addr = phys_pmd_update(pud, addr, end,
510                                                          page_size_mask, prot);
511                                 continue;
512                         }
513                         /*
514                          * If we are ok with PG_LEVEL_1G mapping, then we will
515                          * use the existing mapping.
516                          *
517                          * Otherwise, we will split the gbpage mapping but use
518                          * the same existing protection  bits except for large
519                          * page, so that we don't violate Intel's TLB
520                          * Application note (317080) which says, while changing
521                          * the page sizes, new and old translations should
522                          * not differ with respect to page frame and
523                          * attributes.
524                          */
525                         if (page_size_mask & (1 << PG_LEVEL_1G)) {
526                                 pages++;
527                                 continue;
528                         }
529                         prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
530                 }
531
532                 if (page_size_mask & (1<<PG_LEVEL_1G)) {
533                         pages++;
534                         spin_lock(&init_mm.page_table_lock);
535                         set_pte((pte_t *)pud,
536                                 pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
537                         spin_unlock(&init_mm.page_table_lock);
538                         last_map_addr = (addr & PUD_MASK) + PUD_SIZE;
539                         continue;
540                 }
541
542                 pmd = alloc_low_page(&pmd_phys);
543                 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask,
544                                               prot);
545                 unmap_low_page(pmd);
546
547                 spin_lock(&init_mm.page_table_lock);
548                 pud_populate(&init_mm, pud, __va(pmd_phys));
549                 spin_unlock(&init_mm.page_table_lock);
550         }
551         __flush_tlb_all();
552
553         update_page_count(PG_LEVEL_1G, pages);
554
555         return last_map_addr;
556 }
557
558 static unsigned long __meminit
559 phys_pud_update(pgd_t *pgd, unsigned long addr, unsigned long end,
560                  unsigned long page_size_mask)
561 {
562         pud_t *pud;
563
564         pud = (pud_t *)pgd_page_vaddr(*pgd);
565
566         return phys_pud_init(pud, addr, end, page_size_mask);
567 }
568
569 unsigned long __meminit
570 kernel_physical_mapping_init(unsigned long start,
571                              unsigned long end,
572                              unsigned long page_size_mask)
573 {
574         bool pgd_changed = false;
575         unsigned long next, last_map_addr = end;
576         unsigned long addr;
577
578         start = (unsigned long)__va(start);
579         end = (unsigned long)__va(end);
580         addr = start;
581
582         for (; start < end; start = next) {
583                 pgd_t *pgd = pgd_offset_k(start);
584                 unsigned long pud_phys;
585                 pud_t *pud;
586
587                 next = (start + PGDIR_SIZE) & PGDIR_MASK;
588                 if (next > end)
589                         next = end;
590
591                 if (pgd_val(*pgd)) {
592                         last_map_addr = phys_pud_update(pgd, __pa(start),
593                                                  __pa(end), page_size_mask);
594                         continue;
595                 }
596
597                 pud = alloc_low_page(&pud_phys);
598                 last_map_addr = phys_pud_init(pud, __pa(start), __pa(next),
599                                                  page_size_mask);
600                 unmap_low_page(pud);
601
602                 spin_lock(&init_mm.page_table_lock);
603                 pgd_populate(&init_mm, pgd, __va(pud_phys));
604                 spin_unlock(&init_mm.page_table_lock);
605                 pgd_changed = true;
606         }
607
608         if (pgd_changed)
609                 sync_global_pgds(addr, end);
610
611         __flush_tlb_all();
612
613         return last_map_addr;
614 }
615
616 #ifndef CONFIG_NUMA
617 void __init initmem_init(unsigned long start_pfn, unsigned long end_pfn,
618                                 int acpi, int k8)
619 {
620 #ifndef CONFIG_NO_BOOTMEM
621         unsigned long bootmap_size, bootmap;
622
623         bootmap_size = bootmem_bootmap_pages(end_pfn)<<PAGE_SHIFT;
624         bootmap = find_e820_area(0, end_pfn<<PAGE_SHIFT, bootmap_size,
625                                  PAGE_SIZE);
626         if (bootmap == -1L)
627                 panic("Cannot find bootmem map of size %ld\n", bootmap_size);
628         reserve_early(bootmap, bootmap + bootmap_size, "BOOTMAP");
629         /* don't touch min_low_pfn */
630         bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap >> PAGE_SHIFT,
631                                          0, end_pfn);
632         e820_register_active_regions(0, start_pfn, end_pfn);
633         free_bootmem_with_active_regions(0, end_pfn);
634 #else
635         e820_register_active_regions(0, start_pfn, end_pfn);
636 #endif
637 }
638 #endif
639
640 void __init paging_init(void)
641 {
642         unsigned long max_zone_pfns[MAX_NR_ZONES];
643
644         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
645         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
646         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
647         max_zone_pfns[ZONE_NORMAL] = max_pfn;
648
649         sparse_memory_present_with_active_regions(MAX_NUMNODES);
650         sparse_init();
651
652         /*
653          * clear the default setting with node 0
654          * note: don't use nodes_clear here, that is really clearing when
655          *       numa support is not compiled in, and later node_set_state
656          *       will not set it back.
657          */
658         node_clear_state(0, N_NORMAL_MEMORY);
659
660         free_area_init_nodes(max_zone_pfns);
661 }
662
663 /*
664  * Memory hotplug specific functions
665  */
666 #ifdef CONFIG_MEMORY_HOTPLUG
667 /*
668  * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
669  * updating.
670  */
671 static void  update_end_of_memory_vars(u64 start, u64 size)
672 {
673         unsigned long end_pfn = PFN_UP(start + size);
674
675         if (end_pfn > max_pfn) {
676                 max_pfn = end_pfn;
677                 max_low_pfn = end_pfn;
678                 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
679         }
680 }
681
682 /*
683  * Memory is added always to NORMAL zone. This means you will never get
684  * additional DMA/DMA32 memory.
685  */
686 int arch_add_memory(int nid, u64 start, u64 size)
687 {
688         struct pglist_data *pgdat = NODE_DATA(nid);
689         struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
690         unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT;
691         unsigned long nr_pages = size >> PAGE_SHIFT;
692         int ret;
693
694         last_mapped_pfn = init_memory_mapping(start, start + size);
695         if (last_mapped_pfn > max_pfn_mapped)
696                 max_pfn_mapped = last_mapped_pfn;
697
698         ret = __add_pages(nid, zone, start_pfn, nr_pages);
699         WARN_ON_ONCE(ret);
700
701         /* update max_pfn, max_low_pfn and high_memory */
702         update_end_of_memory_vars(start, size);
703
704         return ret;
705 }
706 EXPORT_SYMBOL_GPL(arch_add_memory);
707
708 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
709 int memory_add_physaddr_to_nid(u64 start)
710 {
711         return 0;
712 }
713 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
714 #endif
715
716 #endif /* CONFIG_MEMORY_HOTPLUG */
717
718 static struct kcore_list kcore_vsyscall;
719
720 void __init mem_init(void)
721 {
722         long codesize, reservedpages, datasize, initsize;
723         unsigned long absent_pages;
724
725         pci_iommu_alloc();
726
727         /* clear_bss() already clear the empty_zero_page */
728
729         reservedpages = 0;
730
731         /* this will put all low memory onto the freelists */
732 #ifdef CONFIG_NUMA
733         totalram_pages = numa_free_all_bootmem();
734 #else
735         totalram_pages = free_all_bootmem();
736 #endif
737
738         absent_pages = absent_pages_in_range(0, max_pfn);
739         reservedpages = max_pfn - totalram_pages - absent_pages;
740         after_bootmem = 1;
741
742         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
743         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
744         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
745
746         /* Register memory areas for /proc/kcore */
747         kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
748                          VSYSCALL_END - VSYSCALL_START, KCORE_OTHER);
749
750         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
751                          "%ldk absent, %ldk reserved, %ldk data, %ldk init)\n",
752                 nr_free_pages() << (PAGE_SHIFT-10),
753                 max_pfn << (PAGE_SHIFT-10),
754                 codesize >> 10,
755                 absent_pages << (PAGE_SHIFT-10),
756                 reservedpages << (PAGE_SHIFT-10),
757                 datasize >> 10,
758                 initsize >> 10);
759 }
760
761 #ifdef CONFIG_DEBUG_RODATA
762 const int rodata_test_data = 0xC3;
763 EXPORT_SYMBOL_GPL(rodata_test_data);
764
765 int kernel_set_to_readonly;
766
767 void set_kernel_text_rw(void)
768 {
769         unsigned long start = PFN_ALIGN(_text);
770         unsigned long end = PFN_ALIGN(__stop___ex_table);
771
772         if (!kernel_set_to_readonly)
773                 return;
774
775         pr_debug("Set kernel text: %lx - %lx for read write\n",
776                  start, end);
777
778         /*
779          * Make the kernel identity mapping for text RW. Kernel text
780          * mapping will always be RO. Refer to the comment in
781          * static_protections() in pageattr.c
782          */
783         set_memory_rw(start, (end - start) >> PAGE_SHIFT);
784 }
785
786 void set_kernel_text_ro(void)
787 {
788         unsigned long start = PFN_ALIGN(_text);
789         unsigned long end = PFN_ALIGN(__stop___ex_table);
790
791         if (!kernel_set_to_readonly)
792                 return;
793
794         pr_debug("Set kernel text: %lx - %lx for read only\n",
795                  start, end);
796
797         /*
798          * Set the kernel identity mapping for text RO.
799          */
800         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
801 }
802
803 void mark_rodata_ro(void)
804 {
805         unsigned long start = PFN_ALIGN(_text);
806         unsigned long rodata_start =
807                 ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
808         unsigned long end = (unsigned long) &__end_rodata_hpage_align;
809         unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table);
810         unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata);
811         unsigned long data_start = (unsigned long) &_sdata;
812
813         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
814                (end - start) >> 10);
815         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
816
817         kernel_set_to_readonly = 1;
818
819         /*
820          * The rodata section (but not the kernel text!) should also be
821          * not-executable.
822          */
823         set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT);
824
825         rodata_test();
826
827 #ifdef CONFIG_CPA_DEBUG
828         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
829         set_memory_rw(start, (end-start) >> PAGE_SHIFT);
830
831         printk(KERN_INFO "Testing CPA: again\n");
832         set_memory_ro(start, (end-start) >> PAGE_SHIFT);
833 #endif
834
835         free_init_pages("unused kernel memory",
836                         (unsigned long) page_address(virt_to_page(text_end)),
837                         (unsigned long)
838                                  page_address(virt_to_page(rodata_start)));
839         free_init_pages("unused kernel memory",
840                         (unsigned long) page_address(virt_to_page(rodata_end)),
841                         (unsigned long) page_address(virt_to_page(data_start)));
842 }
843
844 #endif
845
846 int __init reserve_bootmem_generic(unsigned long phys, unsigned long len,
847                                    int flags)
848 {
849 #ifdef CONFIG_NUMA
850         int nid, next_nid;
851         int ret;
852 #endif
853         unsigned long pfn = phys >> PAGE_SHIFT;
854
855         if (pfn >= max_pfn) {
856                 /*
857                  * This can happen with kdump kernels when accessing
858                  * firmware tables:
859                  */
860                 if (pfn < max_pfn_mapped)
861                         return -EFAULT;
862
863                 printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %lu\n",
864                                 phys, len);
865                 return -EFAULT;
866         }
867
868         /* Should check here against the e820 map to avoid double free */
869 #ifdef CONFIG_NUMA
870         nid = phys_to_nid(phys);
871         next_nid = phys_to_nid(phys + len - 1);
872         if (nid == next_nid)
873                 ret = reserve_bootmem_node(NODE_DATA(nid), phys, len, flags);
874         else
875                 ret = reserve_bootmem(phys, len, flags);
876
877         if (ret != 0)
878                 return ret;
879
880 #else
881         reserve_bootmem(phys, len, flags);
882 #endif
883
884         if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
885                 dma_reserve += len / PAGE_SIZE;
886                 set_dma_reserve(dma_reserve);
887         }
888
889         return 0;
890 }
891
892 int kern_addr_valid(unsigned long addr)
893 {
894         unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
895         pgd_t *pgd;
896         pud_t *pud;
897         pmd_t *pmd;
898         pte_t *pte;
899
900         if (above != 0 && above != -1UL)
901                 return 0;
902
903         pgd = pgd_offset_k(addr);
904         if (pgd_none(*pgd))
905                 return 0;
906
907         pud = pud_offset(pgd, addr);
908         if (pud_none(*pud))
909                 return 0;
910
911         pmd = pmd_offset(pud, addr);
912         if (pmd_none(*pmd))
913                 return 0;
914
915         if (pmd_large(*pmd))
916                 return pfn_valid(pmd_pfn(*pmd));
917
918         pte = pte_offset_kernel(pmd, addr);
919         if (pte_none(*pte))
920                 return 0;
921
922         return pfn_valid(pte_pfn(*pte));
923 }
924
925 /*
926  * A pseudo VMA to allow ptrace access for the vsyscall page.  This only
927  * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
928  * not need special handling anymore:
929  */
930 static struct vm_area_struct gate_vma = {
931         .vm_start       = VSYSCALL_START,
932         .vm_end         = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
933         .vm_page_prot   = PAGE_READONLY_EXEC,
934         .vm_flags       = VM_READ | VM_EXEC
935 };
936
937 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
938 {
939 #ifdef CONFIG_IA32_EMULATION
940         if (test_tsk_thread_flag(tsk, TIF_IA32))
941                 return NULL;
942 #endif
943         return &gate_vma;
944 }
945
946 int in_gate_area(struct task_struct *task, unsigned long addr)
947 {
948         struct vm_area_struct *vma = get_gate_vma(task);
949
950         if (!vma)
951                 return 0;
952
953         return (addr >= vma->vm_start) && (addr < vma->vm_end);
954 }
955
956 /*
957  * Use this when you have no reliable task/vma, typically from interrupt
958  * context. It is less reliable than using the task's vma and may give
959  * false positives:
960  */
961 int in_gate_area_no_task(unsigned long addr)
962 {
963         return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
964 }
965
966 const char *arch_vma_name(struct vm_area_struct *vma)
967 {
968         if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
969                 return "[vdso]";
970         if (vma == &gate_vma)
971                 return "[vsyscall]";
972         return NULL;
973 }
974
975 #ifdef CONFIG_SPARSEMEM_VMEMMAP
976 /*
977  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
978  */
979 static long __meminitdata addr_start, addr_end;
980 static void __meminitdata *p_start, *p_end;
981 static int __meminitdata node_start;
982
983 int __meminit
984 vmemmap_populate(struct page *start_page, unsigned long size, int node)
985 {
986         unsigned long addr = (unsigned long)start_page;
987         unsigned long end = (unsigned long)(start_page + size);
988         unsigned long next;
989         pgd_t *pgd;
990         pud_t *pud;
991         pmd_t *pmd;
992
993         for (; addr < end; addr = next) {
994                 void *p = NULL;
995
996                 pgd = vmemmap_pgd_populate(addr, node);
997                 if (!pgd)
998                         return -ENOMEM;
999
1000                 pud = vmemmap_pud_populate(pgd, addr, node);
1001                 if (!pud)
1002                         return -ENOMEM;
1003
1004                 if (!cpu_has_pse) {
1005                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1006                         pmd = vmemmap_pmd_populate(pud, addr, node);
1007
1008                         if (!pmd)
1009                                 return -ENOMEM;
1010
1011                         p = vmemmap_pte_populate(pmd, addr, node);
1012
1013                         if (!p)
1014                                 return -ENOMEM;
1015
1016                         addr_end = addr + PAGE_SIZE;
1017                         p_end = p + PAGE_SIZE;
1018                 } else {
1019                         next = pmd_addr_end(addr, end);
1020
1021                         pmd = pmd_offset(pud, addr);
1022                         if (pmd_none(*pmd)) {
1023                                 pte_t entry;
1024
1025                                 p = vmemmap_alloc_block_buf(PMD_SIZE, node);
1026                                 if (!p)
1027                                         return -ENOMEM;
1028
1029                                 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1030                                                 PAGE_KERNEL_LARGE);
1031                                 set_pmd(pmd, __pmd(pte_val(entry)));
1032
1033                                 /* check to see if we have contiguous blocks */
1034                                 if (p_end != p || node_start != node) {
1035                                         if (p_start)
1036                                                 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1037                                                        addr_start, addr_end-1, p_start, p_end-1, node_start);
1038                                         addr_start = addr;
1039                                         node_start = node;
1040                                         p_start = p;
1041                                 }
1042
1043                                 addr_end = addr + PMD_SIZE;
1044                                 p_end = p + PMD_SIZE;
1045                         } else
1046                                 vmemmap_verify((pte_t *)pmd, node, addr, next);
1047                 }
1048
1049         }
1050         sync_global_pgds((unsigned long)start_page, end);
1051         return 0;
1052 }
1053
1054 void __meminit vmemmap_populate_print_last(void)
1055 {
1056         if (p_start) {
1057                 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1058                         addr_start, addr_end-1, p_start, p_end-1, node_start);
1059                 p_start = NULL;
1060                 p_end = NULL;
1061                 node_start = 0;
1062         }
1063 }
1064 #endif