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x86: fix /proc/meminfo DirectMap
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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@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/system.h>
35 #include <asm/uaccess.h>
36 #include <asm/pgtable.h>
37 #include <asm/pgalloc.h>
38 #include <asm/dma.h>
39 #include <asm/fixmap.h>
40 #include <asm/e820.h>
41 #include <asm/apic.h>
42 #include <asm/tlb.h>
43 #include <asm/mmu_context.h>
44 #include <asm/proto.h>
45 #include <asm/smp.h>
46 #include <asm/sections.h>
47 #include <asm/kdebug.h>
48 #include <asm/numa.h>
49 #include <asm/cacheflush.h>
50
51 /*
52  * end_pfn only includes RAM, while max_pfn_mapped includes all e820 entries.
53  * The direct mapping extends to max_pfn_mapped, so that we can directly access
54  * apertures, ACPI and other tables without having to play with fixmaps.
55  */
56 unsigned long max_low_pfn_mapped;
57 unsigned long max_pfn_mapped;
58
59 static unsigned long dma_reserve __initdata;
60
61 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
62
63 int direct_gbpages
64 #ifdef CONFIG_DIRECT_GBPAGES
65                                 = 1
66 #endif
67 ;
68
69 static int __init parse_direct_gbpages_off(char *arg)
70 {
71         direct_gbpages = 0;
72         return 0;
73 }
74 early_param("nogbpages", parse_direct_gbpages_off);
75
76 static int __init parse_direct_gbpages_on(char *arg)
77 {
78         direct_gbpages = 1;
79         return 0;
80 }
81 early_param("gbpages", parse_direct_gbpages_on);
82
83 /*
84  * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
85  * physical space so we can cache the place of the first one and move
86  * around without checking the pgd every time.
87  */
88
89 int after_bootmem;
90
91 static __init void *spp_getpage(void)
92 {
93         void *ptr;
94
95         if (after_bootmem)
96                 ptr = (void *) get_zeroed_page(GFP_ATOMIC);
97         else
98                 ptr = alloc_bootmem_pages(PAGE_SIZE);
99
100         if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
101                 panic("set_pte_phys: cannot allocate page data %s\n",
102                         after_bootmem ? "after bootmem" : "");
103         }
104
105         pr_debug("spp_getpage %p\n", ptr);
106
107         return ptr;
108 }
109
110 void
111 set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
112 {
113         pud_t *pud;
114         pmd_t *pmd;
115         pte_t *pte;
116
117         pud = pud_page + pud_index(vaddr);
118         if (pud_none(*pud)) {
119                 pmd = (pmd_t *) spp_getpage();
120                 pud_populate(&init_mm, pud, pmd);
121                 if (pmd != pmd_offset(pud, 0)) {
122                         printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
123                                 pmd, pmd_offset(pud, 0));
124                         return;
125                 }
126         }
127         pmd = pmd_offset(pud, vaddr);
128         if (pmd_none(*pmd)) {
129                 pte = (pte_t *) spp_getpage();
130                 pmd_populate_kernel(&init_mm, pmd, pte);
131                 if (pte != pte_offset_kernel(pmd, 0)) {
132                         printk(KERN_ERR "PAGETABLE BUG #02!\n");
133                         return;
134                 }
135         }
136
137         pte = pte_offset_kernel(pmd, vaddr);
138         if (!pte_none(*pte) && pte_val(new_pte) &&
139             pte_val(*pte) != (pte_val(new_pte) & __supported_pte_mask))
140                 pte_ERROR(*pte);
141         set_pte(pte, new_pte);
142
143         /*
144          * It's enough to flush this one mapping.
145          * (PGE mappings get flushed as well)
146          */
147         __flush_tlb_one(vaddr);
148 }
149
150 void
151 set_pte_vaddr(unsigned long vaddr, pte_t pteval)
152 {
153         pgd_t *pgd;
154         pud_t *pud_page;
155
156         pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
157
158         pgd = pgd_offset_k(vaddr);
159         if (pgd_none(*pgd)) {
160                 printk(KERN_ERR
161                         "PGD FIXMAP MISSING, it should be setup in head.S!\n");
162                 return;
163         }
164         pud_page = (pud_t*)pgd_page_vaddr(*pgd);
165         set_pte_vaddr_pud(pud_page, vaddr, pteval);
166 }
167
168 /*
169  * Create large page table mappings for a range of physical addresses.
170  */
171 static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
172                                                 pgprot_t prot)
173 {
174         pgd_t *pgd;
175         pud_t *pud;
176         pmd_t *pmd;
177
178         BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
179         for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
180                 pgd = pgd_offset_k((unsigned long)__va(phys));
181                 if (pgd_none(*pgd)) {
182                         pud = (pud_t *) spp_getpage();
183                         set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE |
184                                                 _PAGE_USER));
185                 }
186                 pud = pud_offset(pgd, (unsigned long)__va(phys));
187                 if (pud_none(*pud)) {
188                         pmd = (pmd_t *) spp_getpage();
189                         set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
190                                                 _PAGE_USER));
191                 }
192                 pmd = pmd_offset(pud, phys);
193                 BUG_ON(!pmd_none(*pmd));
194                 set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
195         }
196 }
197
198 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
199 {
200         __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE);
201 }
202
203 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
204 {
205         __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE_NOCACHE);
206 }
207
208 /*
209  * The head.S code sets up the kernel high mapping:
210  *
211  *   from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
212  *
213  * phys_addr holds the negative offset to the kernel, which is added
214  * to the compile time generated pmds. This results in invalid pmds up
215  * to the point where we hit the physaddr 0 mapping.
216  *
217  * We limit the mappings to the region from _text to _end.  _end is
218  * rounded up to the 2MB boundary. This catches the invalid pmds as
219  * well, as they are located before _text:
220  */
221 void __init cleanup_highmap(void)
222 {
223         unsigned long vaddr = __START_KERNEL_map;
224         unsigned long end = round_up((unsigned long)_end, PMD_SIZE) - 1;
225         pmd_t *pmd = level2_kernel_pgt;
226         pmd_t *last_pmd = pmd + PTRS_PER_PMD;
227
228         for (; pmd < last_pmd; pmd++, vaddr += PMD_SIZE) {
229                 if (pmd_none(*pmd))
230                         continue;
231                 if (vaddr < (unsigned long) _text || vaddr > end)
232                         set_pmd(pmd, __pmd(0));
233         }
234 }
235
236 static unsigned long __initdata table_start;
237 static unsigned long __meminitdata table_end;
238 static unsigned long __meminitdata table_top;
239
240 static __meminit void *alloc_low_page(unsigned long *phys)
241 {
242         unsigned long pfn = table_end++;
243         void *adr;
244
245         if (after_bootmem) {
246                 adr = (void *)get_zeroed_page(GFP_ATOMIC);
247                 *phys = __pa(adr);
248
249                 return adr;
250         }
251
252         if (pfn >= table_top)
253                 panic("alloc_low_page: ran out of memory");
254
255         adr = early_ioremap(pfn * PAGE_SIZE, PAGE_SIZE);
256         memset(adr, 0, PAGE_SIZE);
257         *phys  = pfn * PAGE_SIZE;
258         return adr;
259 }
260
261 static __meminit void unmap_low_page(void *adr)
262 {
263         if (after_bootmem)
264                 return;
265
266         early_iounmap(adr, PAGE_SIZE);
267 }
268
269 static unsigned long __meminit
270 phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end)
271 {
272         unsigned pages = 0;
273         unsigned long last_map_addr = end;
274         int i;
275
276         pte_t *pte = pte_page + pte_index(addr);
277
278         for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) {
279
280                 if (addr >= end) {
281                         if (!after_bootmem) {
282                                 for(; i < PTRS_PER_PTE; i++, pte++)
283                                         set_pte(pte, __pte(0));
284                         }
285                         break;
286                 }
287
288                 if (pte_val(*pte))
289                         continue;
290
291                 if (0)
292                         printk("   pte=%p addr=%lx pte=%016lx\n",
293                                pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte);
294                 set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL));
295                 last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
296                 pages++;
297         }
298         update_page_count(PG_LEVEL_4K, pages);
299
300         return last_map_addr;
301 }
302
303 static unsigned long __meminit
304 phys_pte_update(pmd_t *pmd, unsigned long address, unsigned long end)
305 {
306         pte_t *pte = (pte_t *)pmd_page_vaddr(*pmd);
307
308         return phys_pte_init(pte, address, end);
309 }
310
311 static unsigned long __meminit
312 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
313                          unsigned long page_size_mask)
314 {
315         unsigned long pages = 0;
316         unsigned long last_map_addr = end;
317         unsigned long start = address;
318
319         int i = pmd_index(address);
320
321         for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
322                 unsigned long pte_phys;
323                 pmd_t *pmd = pmd_page + pmd_index(address);
324                 pte_t *pte;
325
326                 if (address >= end) {
327                         if (!after_bootmem) {
328                                 for (; i < PTRS_PER_PMD; i++, pmd++)
329                                         set_pmd(pmd, __pmd(0));
330                         }
331                         break;
332                 }
333
334                 if (pmd_val(*pmd)) {
335                         if (!pmd_large(*pmd))
336                                 last_map_addr = phys_pte_update(pmd, address,
337                                                                  end);
338                         /* Count entries we're using from level2_ident_pgt */
339                         if (start == 0)
340                                 pages++;
341                         continue;
342                 }
343
344                 if (page_size_mask & (1<<PG_LEVEL_2M)) {
345                         pages++;
346                         set_pte((pte_t *)pmd,
347                                 pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
348                         last_map_addr = (address & PMD_MASK) + PMD_SIZE;
349                         continue;
350                 }
351
352                 pte = alloc_low_page(&pte_phys);
353                 last_map_addr = phys_pte_init(pte, address, end);
354                 unmap_low_page(pte);
355
356                 pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
357         }
358         update_page_count(PG_LEVEL_2M, pages);
359         return last_map_addr;
360 }
361
362 static unsigned long __meminit
363 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end,
364                          unsigned long page_size_mask)
365 {
366         pmd_t *pmd = pmd_offset(pud, 0);
367         unsigned long last_map_addr;
368
369         spin_lock(&init_mm.page_table_lock);
370         last_map_addr = phys_pmd_init(pmd, address, end, page_size_mask);
371         spin_unlock(&init_mm.page_table_lock);
372         __flush_tlb_all();
373         return last_map_addr;
374 }
375
376 static unsigned long __meminit
377 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
378                          unsigned long page_size_mask)
379 {
380         unsigned long pages = 0;
381         unsigned long last_map_addr = end;
382         int i = pud_index(addr);
383
384         for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
385                 unsigned long pmd_phys;
386                 pud_t *pud = pud_page + pud_index(addr);
387                 pmd_t *pmd;
388
389                 if (addr >= end)
390                         break;
391
392                 if (!after_bootmem &&
393                                 !e820_any_mapped(addr, addr+PUD_SIZE, 0)) {
394                         set_pud(pud, __pud(0));
395                         continue;
396                 }
397
398                 if (pud_val(*pud)) {
399                         if (!pud_large(*pud))
400                                 last_map_addr = phys_pmd_update(pud, addr, end,
401                                                          page_size_mask);
402                         continue;
403                 }
404
405                 if (page_size_mask & (1<<PG_LEVEL_1G)) {
406                         pages++;
407                         set_pte((pte_t *)pud,
408                                 pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
409                         last_map_addr = (addr & PUD_MASK) + PUD_SIZE;
410                         continue;
411                 }
412
413                 pmd = alloc_low_page(&pmd_phys);
414
415                 spin_lock(&init_mm.page_table_lock);
416                 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask);
417                 unmap_low_page(pmd);
418                 pud_populate(&init_mm, pud, __va(pmd_phys));
419                 spin_unlock(&init_mm.page_table_lock);
420
421         }
422         __flush_tlb_all();
423         update_page_count(PG_LEVEL_1G, pages);
424
425         return last_map_addr;
426 }
427
428 static unsigned long __meminit
429 phys_pud_update(pgd_t *pgd, unsigned long addr, unsigned long end,
430                  unsigned long page_size_mask)
431 {
432         pud_t *pud;
433
434         pud = (pud_t *)pgd_page_vaddr(*pgd);
435
436         return phys_pud_init(pud, addr, end, page_size_mask);
437 }
438
439 static void __init find_early_table_space(unsigned long end)
440 {
441         unsigned long puds, pmds, ptes, tables, start;
442
443         puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
444         tables = round_up(puds * sizeof(pud_t), PAGE_SIZE);
445         if (direct_gbpages) {
446                 unsigned long extra;
447                 extra = end - ((end>>PUD_SHIFT) << PUD_SHIFT);
448                 pmds = (extra + PMD_SIZE - 1) >> PMD_SHIFT;
449         } else
450                 pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
451         tables += round_up(pmds * sizeof(pmd_t), PAGE_SIZE);
452
453         if (cpu_has_pse) {
454                 unsigned long extra;
455                 extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT);
456                 ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT;
457         } else
458                 ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT;
459         tables += round_up(ptes * sizeof(pte_t), PAGE_SIZE);
460
461         /*
462          * RED-PEN putting page tables only on node 0 could
463          * cause a hotspot and fill up ZONE_DMA. The page tables
464          * need roughly 0.5KB per GB.
465          */
466         start = 0x8000;
467         table_start = find_e820_area(start, end, tables, PAGE_SIZE);
468         if (table_start == -1UL)
469                 panic("Cannot find space for the kernel page tables");
470
471         table_start >>= PAGE_SHIFT;
472         table_end = table_start;
473         table_top = table_start + (tables >> PAGE_SHIFT);
474
475         printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n",
476                 end, table_start << PAGE_SHIFT, table_top << PAGE_SHIFT);
477 }
478
479 static void __init init_gbpages(void)
480 {
481         if (direct_gbpages && cpu_has_gbpages)
482                 printk(KERN_INFO "Using GB pages for direct mapping\n");
483         else
484                 direct_gbpages = 0;
485 }
486
487 static unsigned long __init kernel_physical_mapping_init(unsigned long start,
488                                                 unsigned long end,
489                                                 unsigned long page_size_mask)
490 {
491
492         unsigned long next, last_map_addr = end;
493
494         start = (unsigned long)__va(start);
495         end = (unsigned long)__va(end);
496
497         for (; start < end; start = next) {
498                 pgd_t *pgd = pgd_offset_k(start);
499                 unsigned long pud_phys;
500                 pud_t *pud;
501
502                 next = (start + PGDIR_SIZE) & PGDIR_MASK;
503                 if (next > end)
504                         next = end;
505
506                 if (pgd_val(*pgd)) {
507                         last_map_addr = phys_pud_update(pgd, __pa(start),
508                                                  __pa(end), page_size_mask);
509                         continue;
510                 }
511
512                 if (after_bootmem)
513                         pud = pud_offset(pgd, start & PGDIR_MASK);
514                 else
515                         pud = alloc_low_page(&pud_phys);
516
517                 last_map_addr = phys_pud_init(pud, __pa(start), __pa(next),
518                                                  page_size_mask);
519                 unmap_low_page(pud);
520                 pgd_populate(&init_mm, pgd_offset_k(start),
521                              __va(pud_phys));
522         }
523
524         return last_map_addr;
525 }
526
527 struct map_range {
528         unsigned long start;
529         unsigned long end;
530         unsigned page_size_mask;
531 };
532
533 #define NR_RANGE_MR 5
534
535 static int save_mr(struct map_range *mr, int nr_range,
536                    unsigned long start_pfn, unsigned long end_pfn,
537                    unsigned long page_size_mask)
538 {
539
540         if (start_pfn < end_pfn) {
541                 if (nr_range >= NR_RANGE_MR)
542                         panic("run out of range for init_memory_mapping\n");
543                 mr[nr_range].start = start_pfn<<PAGE_SHIFT;
544                 mr[nr_range].end   = end_pfn<<PAGE_SHIFT;
545                 mr[nr_range].page_size_mask = page_size_mask;
546                 nr_range++;
547         }
548
549         return nr_range;
550 }
551
552 /*
553  * Setup the direct mapping of the physical memory at PAGE_OFFSET.
554  * This runs before bootmem is initialized and gets pages directly from
555  * the physical memory. To access them they are temporarily mapped.
556  */
557 unsigned long __init_refok init_memory_mapping(unsigned long start,
558                                                unsigned long end)
559 {
560         unsigned long last_map_addr = 0;
561         unsigned long page_size_mask = 0;
562         unsigned long start_pfn, end_pfn;
563
564         struct map_range mr[NR_RANGE_MR];
565         int nr_range, i;
566
567         printk(KERN_INFO "init_memory_mapping\n");
568
569         /*
570          * Find space for the kernel direct mapping tables.
571          *
572          * Later we should allocate these tables in the local node of the
573          * memory mapped. Unfortunately this is done currently before the
574          * nodes are discovered.
575          */
576         if (!after_bootmem)
577                 init_gbpages();
578
579         if (direct_gbpages)
580                 page_size_mask |= 1 << PG_LEVEL_1G;
581         if (cpu_has_pse)
582                 page_size_mask |= 1 << PG_LEVEL_2M;
583
584         memset(mr, 0, sizeof(mr));
585         nr_range = 0;
586
587         /* head if not big page alignment ?*/
588         start_pfn = start >> PAGE_SHIFT;
589         end_pfn = ((start + (PMD_SIZE - 1)) >> PMD_SHIFT)
590                         << (PMD_SHIFT - PAGE_SHIFT);
591         nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
592
593         /* big page (2M) range*/
594         start_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT)
595                          << (PMD_SHIFT - PAGE_SHIFT);
596         end_pfn = ((start + (PUD_SIZE - 1))>>PUD_SHIFT)
597                          << (PUD_SHIFT - PAGE_SHIFT);
598         if (end_pfn > ((end>>PUD_SHIFT)<<(PUD_SHIFT - PAGE_SHIFT)))
599                 end_pfn = ((end>>PUD_SHIFT)<<(PUD_SHIFT - PAGE_SHIFT));
600         nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
601                         page_size_mask & (1<<PG_LEVEL_2M));
602
603         /* big page (1G) range */
604         start_pfn = end_pfn;
605         end_pfn = (end>>PUD_SHIFT) << (PUD_SHIFT - PAGE_SHIFT);
606         nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
607                                 page_size_mask &
608                                  ((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G)));
609
610         /* tail is not big page (1G) alignment */
611         start_pfn = end_pfn;
612         end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
613         nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
614                         page_size_mask & (1<<PG_LEVEL_2M));
615
616         /* tail is not big page (2M) alignment */
617         start_pfn = end_pfn;
618         end_pfn = end>>PAGE_SHIFT;
619         nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
620
621         /* try to merge same page size and continuous */
622         for (i = 0; nr_range > 1 && i < nr_range - 1; i++) {
623                 unsigned long old_start;
624                 if (mr[i].end != mr[i+1].start ||
625                     mr[i].page_size_mask != mr[i+1].page_size_mask)
626                         continue;
627                 /* move it */
628                 old_start = mr[i].start;
629                 memmove(&mr[i], &mr[i+1],
630                          (nr_range - 1 - i) * sizeof (struct map_range));
631                 mr[i].start = old_start;
632                 nr_range--;
633         }
634
635         for (i = 0; i < nr_range; i++)
636                 printk(KERN_DEBUG " %010lx - %010lx page %s\n",
637                                 mr[i].start, mr[i].end,
638                         (mr[i].page_size_mask & (1<<PG_LEVEL_1G))?"1G":(
639                          (mr[i].page_size_mask & (1<<PG_LEVEL_2M))?"2M":"4k"));
640
641         if (!after_bootmem)
642                 find_early_table_space(end);
643
644         for (i = 0; i < nr_range; i++)
645                 last_map_addr = kernel_physical_mapping_init(
646                                         mr[i].start, mr[i].end,
647                                         mr[i].page_size_mask);
648
649         if (!after_bootmem)
650                 mmu_cr4_features = read_cr4();
651         __flush_tlb_all();
652
653         if (!after_bootmem && table_end > table_start)
654                 reserve_early(table_start << PAGE_SHIFT,
655                                  table_end << PAGE_SHIFT, "PGTABLE");
656
657         printk(KERN_INFO "last_map_addr: %lx end: %lx\n",
658                          last_map_addr, end);
659
660         if (!after_bootmem)
661                 early_memtest(start, end);
662
663         return last_map_addr >> PAGE_SHIFT;
664 }
665
666 #ifndef CONFIG_NUMA
667 void __init initmem_init(unsigned long start_pfn, unsigned long end_pfn)
668 {
669         unsigned long bootmap_size, bootmap;
670
671         bootmap_size = bootmem_bootmap_pages(end_pfn)<<PAGE_SHIFT;
672         bootmap = find_e820_area(0, end_pfn<<PAGE_SHIFT, bootmap_size,
673                                  PAGE_SIZE);
674         if (bootmap == -1L)
675                 panic("Cannot find bootmem map of size %ld\n", bootmap_size);
676         /* don't touch min_low_pfn */
677         bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap >> PAGE_SHIFT,
678                                          0, end_pfn);
679         e820_register_active_regions(0, start_pfn, end_pfn);
680         free_bootmem_with_active_regions(0, end_pfn);
681         early_res_to_bootmem(0, end_pfn<<PAGE_SHIFT);
682         reserve_bootmem(bootmap, bootmap_size, BOOTMEM_DEFAULT);
683 }
684
685 void __init paging_init(void)
686 {
687         unsigned long max_zone_pfns[MAX_NR_ZONES];
688
689         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
690         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
691         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
692         max_zone_pfns[ZONE_NORMAL] = max_pfn;
693
694         memory_present(0, 0, max_pfn);
695         sparse_init();
696         free_area_init_nodes(max_zone_pfns);
697 }
698 #endif
699
700 /*
701  * Memory hotplug specific functions
702  */
703 #ifdef CONFIG_MEMORY_HOTPLUG
704 /*
705  * Memory is added always to NORMAL zone. This means you will never get
706  * additional DMA/DMA32 memory.
707  */
708 int arch_add_memory(int nid, u64 start, u64 size)
709 {
710         struct pglist_data *pgdat = NODE_DATA(nid);
711         struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
712         unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT;
713         unsigned long nr_pages = size >> PAGE_SHIFT;
714         int ret;
715
716         last_mapped_pfn = init_memory_mapping(start, start + size-1);
717         if (last_mapped_pfn > max_pfn_mapped)
718                 max_pfn_mapped = last_mapped_pfn;
719
720         ret = __add_pages(zone, start_pfn, nr_pages);
721         WARN_ON(1);
722
723         return ret;
724 }
725 EXPORT_SYMBOL_GPL(arch_add_memory);
726
727 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
728 int memory_add_physaddr_to_nid(u64 start)
729 {
730         return 0;
731 }
732 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
733 #endif
734
735 #endif /* CONFIG_MEMORY_HOTPLUG */
736
737 /*
738  * devmem_is_allowed() checks to see if /dev/mem access to a certain address
739  * is valid. The argument is a physical page number.
740  *
741  *
742  * On x86, access has to be given to the first megabyte of ram because that area
743  * contains bios code and data regions used by X and dosemu and similar apps.
744  * Access has to be given to non-kernel-ram areas as well, these contain the PCI
745  * mmio resources as well as potential bios/acpi data regions.
746  */
747 int devmem_is_allowed(unsigned long pagenr)
748 {
749         if (pagenr <= 256)
750                 return 1;
751         if (!page_is_ram(pagenr))
752                 return 1;
753         return 0;
754 }
755
756
757 static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel,
758                          kcore_modules, kcore_vsyscall;
759
760 void __init mem_init(void)
761 {
762         long codesize, reservedpages, datasize, initsize;
763
764         pci_iommu_alloc();
765
766         /* clear_bss() already clear the empty_zero_page */
767
768         reservedpages = 0;
769
770         /* this will put all low memory onto the freelists */
771 #ifdef CONFIG_NUMA
772         totalram_pages = numa_free_all_bootmem();
773 #else
774         totalram_pages = free_all_bootmem();
775 #endif
776         reservedpages = max_pfn - totalram_pages -
777                                         absent_pages_in_range(0, max_pfn);
778         after_bootmem = 1;
779
780         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
781         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
782         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
783
784         /* Register memory areas for /proc/kcore */
785         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
786         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
787                    VMALLOC_END-VMALLOC_START);
788         kclist_add(&kcore_kernel, &_stext, _end - _stext);
789         kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN);
790         kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
791                                  VSYSCALL_END - VSYSCALL_START);
792
793         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
794                                 "%ldk reserved, %ldk data, %ldk init)\n",
795                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
796                 max_pfn << (PAGE_SHIFT-10),
797                 codesize >> 10,
798                 reservedpages << (PAGE_SHIFT-10),
799                 datasize >> 10,
800                 initsize >> 10);
801
802         cpa_init();
803 }
804
805 void free_init_pages(char *what, unsigned long begin, unsigned long end)
806 {
807         unsigned long addr = begin;
808
809         if (addr >= end)
810                 return;
811
812         /*
813          * If debugging page accesses then do not free this memory but
814          * mark them not present - any buggy init-section access will
815          * create a kernel page fault:
816          */
817 #ifdef CONFIG_DEBUG_PAGEALLOC
818         printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
819                 begin, PAGE_ALIGN(end));
820         set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
821 #else
822         printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
823
824         for (; addr < end; addr += PAGE_SIZE) {
825                 ClearPageReserved(virt_to_page(addr));
826                 init_page_count(virt_to_page(addr));
827                 memset((void *)(addr & ~(PAGE_SIZE-1)),
828                         POISON_FREE_INITMEM, PAGE_SIZE);
829                 free_page(addr);
830                 totalram_pages++;
831         }
832 #endif
833 }
834
835 void free_initmem(void)
836 {
837         free_init_pages("unused kernel memory",
838                         (unsigned long)(&__init_begin),
839                         (unsigned long)(&__init_end));
840 }
841
842 #ifdef CONFIG_DEBUG_RODATA
843 const int rodata_test_data = 0xC3;
844 EXPORT_SYMBOL_GPL(rodata_test_data);
845
846 void mark_rodata_ro(void)
847 {
848         unsigned long start = PFN_ALIGN(_stext), end = PFN_ALIGN(__end_rodata);
849         unsigned long rodata_start =
850                 ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
851
852 #ifdef CONFIG_DYNAMIC_FTRACE
853         /* Dynamic tracing modifies the kernel text section */
854         start = rodata_start;
855 #endif
856
857         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
858                (end - start) >> 10);
859         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
860
861         /*
862          * The rodata section (but not the kernel text!) should also be
863          * not-executable.
864          */
865         set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT);
866
867         rodata_test();
868
869 #ifdef CONFIG_CPA_DEBUG
870         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
871         set_memory_rw(start, (end-start) >> PAGE_SHIFT);
872
873         printk(KERN_INFO "Testing CPA: again\n");
874         set_memory_ro(start, (end-start) >> PAGE_SHIFT);
875 #endif
876 }
877
878 #endif
879
880 #ifdef CONFIG_BLK_DEV_INITRD
881 void free_initrd_mem(unsigned long start, unsigned long end)
882 {
883         free_init_pages("initrd memory", start, end);
884 }
885 #endif
886
887 int __init reserve_bootmem_generic(unsigned long phys, unsigned long len,
888                                    int flags)
889 {
890 #ifdef CONFIG_NUMA
891         int nid, next_nid;
892         int ret;
893 #endif
894         unsigned long pfn = phys >> PAGE_SHIFT;
895
896         if (pfn >= max_pfn) {
897                 /*
898                  * This can happen with kdump kernels when accessing
899                  * firmware tables:
900                  */
901                 if (pfn < max_pfn_mapped)
902                         return -EFAULT;
903
904                 printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %lu\n",
905                                 phys, len);
906                 return -EFAULT;
907         }
908
909         /* Should check here against the e820 map to avoid double free */
910 #ifdef CONFIG_NUMA
911         nid = phys_to_nid(phys);
912         next_nid = phys_to_nid(phys + len - 1);
913         if (nid == next_nid)
914                 ret = reserve_bootmem_node(NODE_DATA(nid), phys, len, flags);
915         else
916                 ret = reserve_bootmem(phys, len, flags);
917
918         if (ret != 0)
919                 return ret;
920
921 #else
922         reserve_bootmem(phys, len, BOOTMEM_DEFAULT);
923 #endif
924
925         if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
926                 dma_reserve += len / PAGE_SIZE;
927                 set_dma_reserve(dma_reserve);
928         }
929
930         return 0;
931 }
932
933 int kern_addr_valid(unsigned long addr)
934 {
935         unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
936         pgd_t *pgd;
937         pud_t *pud;
938         pmd_t *pmd;
939         pte_t *pte;
940
941         if (above != 0 && above != -1UL)
942                 return 0;
943
944         pgd = pgd_offset_k(addr);
945         if (pgd_none(*pgd))
946                 return 0;
947
948         pud = pud_offset(pgd, addr);
949         if (pud_none(*pud))
950                 return 0;
951
952         pmd = pmd_offset(pud, addr);
953         if (pmd_none(*pmd))
954                 return 0;
955
956         if (pmd_large(*pmd))
957                 return pfn_valid(pmd_pfn(*pmd));
958
959         pte = pte_offset_kernel(pmd, addr);
960         if (pte_none(*pte))
961                 return 0;
962
963         return pfn_valid(pte_pfn(*pte));
964 }
965
966 /*
967  * A pseudo VMA to allow ptrace access for the vsyscall page.  This only
968  * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
969  * not need special handling anymore:
970  */
971 static struct vm_area_struct gate_vma = {
972         .vm_start       = VSYSCALL_START,
973         .vm_end         = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
974         .vm_page_prot   = PAGE_READONLY_EXEC,
975         .vm_flags       = VM_READ | VM_EXEC
976 };
977
978 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
979 {
980 #ifdef CONFIG_IA32_EMULATION
981         if (test_tsk_thread_flag(tsk, TIF_IA32))
982                 return NULL;
983 #endif
984         return &gate_vma;
985 }
986
987 int in_gate_area(struct task_struct *task, unsigned long addr)
988 {
989         struct vm_area_struct *vma = get_gate_vma(task);
990
991         if (!vma)
992                 return 0;
993
994         return (addr >= vma->vm_start) && (addr < vma->vm_end);
995 }
996
997 /*
998  * Use this when you have no reliable task/vma, typically from interrupt
999  * context. It is less reliable than using the task's vma and may give
1000  * false positives:
1001  */
1002 int in_gate_area_no_task(unsigned long addr)
1003 {
1004         return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
1005 }
1006
1007 const char *arch_vma_name(struct vm_area_struct *vma)
1008 {
1009         if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
1010                 return "[vdso]";
1011         if (vma == &gate_vma)
1012                 return "[vsyscall]";
1013         return NULL;
1014 }
1015
1016 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1017 /*
1018  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1019  */
1020 static long __meminitdata addr_start, addr_end;
1021 static void __meminitdata *p_start, *p_end;
1022 static int __meminitdata node_start;
1023
1024 int __meminit
1025 vmemmap_populate(struct page *start_page, unsigned long size, int node)
1026 {
1027         unsigned long addr = (unsigned long)start_page;
1028         unsigned long end = (unsigned long)(start_page + size);
1029         unsigned long next;
1030         pgd_t *pgd;
1031         pud_t *pud;
1032         pmd_t *pmd;
1033
1034         for (; addr < end; addr = next) {
1035                 void *p = NULL;
1036
1037                 pgd = vmemmap_pgd_populate(addr, node);
1038                 if (!pgd)
1039                         return -ENOMEM;
1040
1041                 pud = vmemmap_pud_populate(pgd, addr, node);
1042                 if (!pud)
1043                         return -ENOMEM;
1044
1045                 if (!cpu_has_pse) {
1046                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1047                         pmd = vmemmap_pmd_populate(pud, addr, node);
1048
1049                         if (!pmd)
1050                                 return -ENOMEM;
1051
1052                         p = vmemmap_pte_populate(pmd, addr, node);
1053
1054                         if (!p)
1055                                 return -ENOMEM;
1056
1057                         addr_end = addr + PAGE_SIZE;
1058                         p_end = p + PAGE_SIZE;
1059                 } else {
1060                         next = pmd_addr_end(addr, end);
1061
1062                         pmd = pmd_offset(pud, addr);
1063                         if (pmd_none(*pmd)) {
1064                                 pte_t entry;
1065
1066                                 p = vmemmap_alloc_block(PMD_SIZE, node);
1067                                 if (!p)
1068                                         return -ENOMEM;
1069
1070                                 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1071                                                 PAGE_KERNEL_LARGE);
1072                                 set_pmd(pmd, __pmd(pte_val(entry)));
1073
1074                                 /* check to see if we have contiguous blocks */
1075                                 if (p_end != p || node_start != node) {
1076                                         if (p_start)
1077                                                 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1078                                                        addr_start, addr_end-1, p_start, p_end-1, node_start);
1079                                         addr_start = addr;
1080                                         node_start = node;
1081                                         p_start = p;
1082                                 }
1083
1084                                 addr_end = addr + PMD_SIZE;
1085                                 p_end = p + PMD_SIZE;
1086                         } else
1087                                 vmemmap_verify((pte_t *)pmd, node, addr, next);
1088                 }
1089
1090         }
1091         return 0;
1092 }
1093
1094 void __meminit vmemmap_populate_print_last(void)
1095 {
1096         if (p_start) {
1097                 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1098                         addr_start, addr_end-1, p_start, p_end-1, node_start);
1099                 p_start = NULL;
1100                 p_end = NULL;
1101                 node_start = 0;
1102         }
1103 }
1104 #endif