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[linux-2.6] / 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/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 __meminitdata
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
318         int i = pmd_index(address);
319
320         for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
321                 unsigned long pte_phys;
322                 pmd_t *pmd = pmd_page + pmd_index(address);
323                 pte_t *pte;
324
325                 if (address >= end) {
326                         if (!after_bootmem) {
327                                 for (; i < PTRS_PER_PMD; i++, pmd++)
328                                         set_pmd(pmd, __pmd(0));
329                         }
330                         break;
331                 }
332
333                 if (pmd_val(*pmd)) {
334                         if (!pmd_large(*pmd))
335                                 last_map_addr = phys_pte_update(pmd, address,
336                                                                  end);
337                         continue;
338                 }
339
340                 if (page_size_mask & (1<<PG_LEVEL_2M)) {
341                         pages++;
342                         set_pte((pte_t *)pmd,
343                                 pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
344                         last_map_addr = (address & PMD_MASK) + PMD_SIZE;
345                         continue;
346                 }
347
348                 pte = alloc_low_page(&pte_phys);
349                 last_map_addr = phys_pte_init(pte, address, end);
350                 unmap_low_page(pte);
351
352                 pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
353         }
354         update_page_count(PG_LEVEL_2M, pages);
355         return last_map_addr;
356 }
357
358 static unsigned long __meminit
359 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end,
360                          unsigned long page_size_mask)
361 {
362         pmd_t *pmd = pmd_offset(pud, 0);
363         unsigned long last_map_addr;
364
365         spin_lock(&init_mm.page_table_lock);
366         last_map_addr = phys_pmd_init(pmd, address, end, page_size_mask);
367         spin_unlock(&init_mm.page_table_lock);
368         __flush_tlb_all();
369         return last_map_addr;
370 }
371
372 static unsigned long __meminit
373 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
374                          unsigned long page_size_mask)
375 {
376         unsigned long pages = 0;
377         unsigned long last_map_addr = end;
378         int i = pud_index(addr);
379
380         for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
381                 unsigned long pmd_phys;
382                 pud_t *pud = pud_page + pud_index(addr);
383                 pmd_t *pmd;
384
385                 if (addr >= end)
386                         break;
387
388                 if (!after_bootmem &&
389                                 !e820_any_mapped(addr, addr+PUD_SIZE, 0)) {
390                         set_pud(pud, __pud(0));
391                         continue;
392                 }
393
394                 if (pud_val(*pud)) {
395                         if (!pud_large(*pud))
396                                 last_map_addr = phys_pmd_update(pud, addr, end,
397                                                          page_size_mask);
398                         continue;
399                 }
400
401                 if (page_size_mask & (1<<PG_LEVEL_1G)) {
402                         pages++;
403                         set_pte((pte_t *)pud,
404                                 pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
405                         last_map_addr = (addr & PUD_MASK) + PUD_SIZE;
406                         continue;
407                 }
408
409                 pmd = alloc_low_page(&pmd_phys);
410
411                 spin_lock(&init_mm.page_table_lock);
412                 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask);
413                 unmap_low_page(pmd);
414                 pud_populate(&init_mm, pud, __va(pmd_phys));
415                 spin_unlock(&init_mm.page_table_lock);
416
417         }
418         __flush_tlb_all();
419         update_page_count(PG_LEVEL_1G, pages);
420
421         return last_map_addr;
422 }
423
424 static unsigned long __meminit
425 phys_pud_update(pgd_t *pgd, unsigned long addr, unsigned long end,
426                  unsigned long page_size_mask)
427 {
428         pud_t *pud;
429
430         pud = (pud_t *)pgd_page_vaddr(*pgd);
431
432         return phys_pud_init(pud, addr, end, page_size_mask);
433 }
434
435 static void __init find_early_table_space(unsigned long end)
436 {
437         unsigned long puds, pmds, ptes, tables, start;
438
439         puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
440         tables = round_up(puds * sizeof(pud_t), PAGE_SIZE);
441         if (direct_gbpages) {
442                 unsigned long extra;
443                 extra = end - ((end>>PUD_SHIFT) << PUD_SHIFT);
444                 pmds = (extra + PMD_SIZE - 1) >> PMD_SHIFT;
445         } else
446                 pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
447         tables += round_up(pmds * sizeof(pmd_t), PAGE_SIZE);
448
449         if (cpu_has_pse) {
450                 unsigned long extra;
451                 extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT);
452                 ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT;
453         } else
454                 ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT;
455         tables += round_up(ptes * sizeof(pte_t), PAGE_SIZE);
456
457         /*
458          * RED-PEN putting page tables only on node 0 could
459          * cause a hotspot and fill up ZONE_DMA. The page tables
460          * need roughly 0.5KB per GB.
461          */
462         start = 0x8000;
463         table_start = find_e820_area(start, end, tables, PAGE_SIZE);
464         if (table_start == -1UL)
465                 panic("Cannot find space for the kernel page tables");
466
467         table_start >>= PAGE_SHIFT;
468         table_end = table_start;
469         table_top = table_start + (tables >> PAGE_SHIFT);
470
471         printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n",
472                 end, table_start << PAGE_SHIFT, table_top << PAGE_SHIFT);
473 }
474
475 static void __init init_gbpages(void)
476 {
477         if (direct_gbpages && cpu_has_gbpages)
478                 printk(KERN_INFO "Using GB pages for direct mapping\n");
479         else
480                 direct_gbpages = 0;
481 }
482
483 static unsigned long __init kernel_physical_mapping_init(unsigned long start,
484                                                 unsigned long end,
485                                                 unsigned long page_size_mask)
486 {
487
488         unsigned long next, last_map_addr = end;
489
490         start = (unsigned long)__va(start);
491         end = (unsigned long)__va(end);
492
493         for (; start < end; start = next) {
494                 pgd_t *pgd = pgd_offset_k(start);
495                 unsigned long pud_phys;
496                 pud_t *pud;
497
498                 next = (start + PGDIR_SIZE) & PGDIR_MASK;
499                 if (next > end)
500                         next = end;
501
502                 if (pgd_val(*pgd)) {
503                         last_map_addr = phys_pud_update(pgd, __pa(start),
504                                                  __pa(end), page_size_mask);
505                         continue;
506                 }
507
508                 if (after_bootmem)
509                         pud = pud_offset(pgd, start & PGDIR_MASK);
510                 else
511                         pud = alloc_low_page(&pud_phys);
512
513                 last_map_addr = phys_pud_init(pud, __pa(start), __pa(next),
514                                                  page_size_mask);
515                 unmap_low_page(pud);
516                 pgd_populate(&init_mm, pgd_offset_k(start),
517                              __va(pud_phys));
518         }
519
520         return last_map_addr;
521 }
522
523 struct map_range {
524         unsigned long start;
525         unsigned long end;
526         unsigned page_size_mask;
527 };
528
529 #define NR_RANGE_MR 5
530
531 static int save_mr(struct map_range *mr, int nr_range,
532                    unsigned long start_pfn, unsigned long end_pfn,
533                    unsigned long page_size_mask)
534 {
535
536         if (start_pfn < end_pfn) {
537                 if (nr_range >= NR_RANGE_MR)
538                         panic("run out of range for init_memory_mapping\n");
539                 mr[nr_range].start = start_pfn<<PAGE_SHIFT;
540                 mr[nr_range].end   = end_pfn<<PAGE_SHIFT;
541                 mr[nr_range].page_size_mask = page_size_mask;
542                 nr_range++;
543         }
544
545         return nr_range;
546 }
547
548 /*
549  * Setup the direct mapping of the physical memory at PAGE_OFFSET.
550  * This runs before bootmem is initialized and gets pages directly from
551  * the physical memory. To access them they are temporarily mapped.
552  */
553 unsigned long __init_refok init_memory_mapping(unsigned long start,
554                                                unsigned long end)
555 {
556         unsigned long last_map_addr = 0;
557         unsigned long page_size_mask = 0;
558         unsigned long start_pfn, end_pfn;
559
560         struct map_range mr[NR_RANGE_MR];
561         int nr_range, i;
562
563         printk(KERN_INFO "init_memory_mapping\n");
564
565         /*
566          * Find space for the kernel direct mapping tables.
567          *
568          * Later we should allocate these tables in the local node of the
569          * memory mapped. Unfortunately this is done currently before the
570          * nodes are discovered.
571          */
572         if (!after_bootmem)
573                 init_gbpages();
574
575         if (direct_gbpages)
576                 page_size_mask |= 1 << PG_LEVEL_1G;
577         if (cpu_has_pse)
578                 page_size_mask |= 1 << PG_LEVEL_2M;
579
580         memset(mr, 0, sizeof(mr));
581         nr_range = 0;
582
583         /* head if not big page alignment ?*/
584         start_pfn = start >> PAGE_SHIFT;
585         end_pfn = ((start + (PMD_SIZE - 1)) >> PMD_SHIFT)
586                         << (PMD_SHIFT - PAGE_SHIFT);
587         nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
588
589         /* big page (2M) range*/
590         start_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT)
591                          << (PMD_SHIFT - PAGE_SHIFT);
592         end_pfn = ((start + (PUD_SIZE - 1))>>PUD_SHIFT)
593                          << (PUD_SHIFT - PAGE_SHIFT);
594         if (end_pfn > ((end>>PUD_SHIFT)<<(PUD_SHIFT - PAGE_SHIFT)))
595                 end_pfn = ((end>>PUD_SHIFT)<<(PUD_SHIFT - PAGE_SHIFT));
596         nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
597                         page_size_mask & (1<<PG_LEVEL_2M));
598
599         /* big page (1G) range */
600         start_pfn = end_pfn;
601         end_pfn = (end>>PUD_SHIFT) << (PUD_SHIFT - PAGE_SHIFT);
602         nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
603                                 page_size_mask &
604                                  ((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G)));
605
606         /* tail is not big page (1G) alignment */
607         start_pfn = end_pfn;
608         end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
609         nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
610                         page_size_mask & (1<<PG_LEVEL_2M));
611
612         /* tail is not big page (2M) alignment */
613         start_pfn = end_pfn;
614         end_pfn = end>>PAGE_SHIFT;
615         nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
616
617         /* try to merge same page size and continuous */
618         for (i = 0; nr_range > 1 && i < nr_range - 1; i++) {
619                 unsigned long old_start;
620                 if (mr[i].end != mr[i+1].start ||
621                     mr[i].page_size_mask != mr[i+1].page_size_mask)
622                         continue;
623                 /* move it */
624                 old_start = mr[i].start;
625                 memmove(&mr[i], &mr[i+1],
626                          (nr_range - 1 - i) * sizeof (struct map_range));
627                 mr[i].start = old_start;
628                 nr_range--;
629         }
630
631         for (i = 0; i < nr_range; i++)
632                 printk(KERN_DEBUG " %010lx - %010lx page %s\n",
633                                 mr[i].start, mr[i].end,
634                         (mr[i].page_size_mask & (1<<PG_LEVEL_1G))?"1G":(
635                          (mr[i].page_size_mask & (1<<PG_LEVEL_2M))?"2M":"4k"));
636
637         if (!after_bootmem)
638                 find_early_table_space(end);
639
640         for (i = 0; i < nr_range; i++)
641                 last_map_addr = kernel_physical_mapping_init(
642                                         mr[i].start, mr[i].end,
643                                         mr[i].page_size_mask);
644
645         if (!after_bootmem)
646                 mmu_cr4_features = read_cr4();
647         __flush_tlb_all();
648
649         if (!after_bootmem && table_end > table_start)
650                 reserve_early(table_start << PAGE_SHIFT,
651                                  table_end << PAGE_SHIFT, "PGTABLE");
652
653         printk(KERN_INFO "last_map_addr: %lx end: %lx\n",
654                          last_map_addr, end);
655
656         if (!after_bootmem)
657                 early_memtest(start, end);
658
659         return last_map_addr >> PAGE_SHIFT;
660 }
661
662 #ifndef CONFIG_NUMA
663 void __init initmem_init(unsigned long start_pfn, unsigned long end_pfn)
664 {
665         unsigned long bootmap_size, bootmap;
666
667         bootmap_size = bootmem_bootmap_pages(end_pfn)<<PAGE_SHIFT;
668         bootmap = find_e820_area(0, end_pfn<<PAGE_SHIFT, bootmap_size,
669                                  PAGE_SIZE);
670         if (bootmap == -1L)
671                 panic("Cannot find bootmem map of size %ld\n", bootmap_size);
672         /* don't touch min_low_pfn */
673         bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap >> PAGE_SHIFT,
674                                          0, end_pfn);
675         e820_register_active_regions(0, start_pfn, end_pfn);
676         free_bootmem_with_active_regions(0, end_pfn);
677         early_res_to_bootmem(0, end_pfn<<PAGE_SHIFT);
678         reserve_bootmem(bootmap, bootmap_size, BOOTMEM_DEFAULT);
679 }
680
681 void __init paging_init(void)
682 {
683         unsigned long max_zone_pfns[MAX_NR_ZONES];
684
685         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
686         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
687         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
688         max_zone_pfns[ZONE_NORMAL] = max_pfn;
689
690         memory_present(0, 0, max_pfn);
691         sparse_init();
692         free_area_init_nodes(max_zone_pfns);
693 }
694 #endif
695
696 /*
697  * Memory hotplug specific functions
698  */
699 #ifdef CONFIG_MEMORY_HOTPLUG
700 /*
701  * Memory is added always to NORMAL zone. This means you will never get
702  * additional DMA/DMA32 memory.
703  */
704 int arch_add_memory(int nid, u64 start, u64 size)
705 {
706         struct pglist_data *pgdat = NODE_DATA(nid);
707         struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
708         unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT;
709         unsigned long nr_pages = size >> PAGE_SHIFT;
710         int ret;
711
712         last_mapped_pfn = init_memory_mapping(start, start + size-1);
713         if (last_mapped_pfn > max_pfn_mapped)
714                 max_pfn_mapped = last_mapped_pfn;
715
716         ret = __add_pages(zone, start_pfn, nr_pages);
717         WARN_ON(1);
718
719         return ret;
720 }
721 EXPORT_SYMBOL_GPL(arch_add_memory);
722
723 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
724 int memory_add_physaddr_to_nid(u64 start)
725 {
726         return 0;
727 }
728 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
729 #endif
730
731 #endif /* CONFIG_MEMORY_HOTPLUG */
732
733 /*
734  * devmem_is_allowed() checks to see if /dev/mem access to a certain address
735  * is valid. The argument is a physical page number.
736  *
737  *
738  * On x86, access has to be given to the first megabyte of ram because that area
739  * contains bios code and data regions used by X and dosemu and similar apps.
740  * Access has to be given to non-kernel-ram areas as well, these contain the PCI
741  * mmio resources as well as potential bios/acpi data regions.
742  */
743 int devmem_is_allowed(unsigned long pagenr)
744 {
745         if (pagenr <= 256)
746                 return 1;
747         if (!page_is_ram(pagenr))
748                 return 1;
749         return 0;
750 }
751
752
753 static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel,
754                          kcore_modules, kcore_vsyscall;
755
756 void __init mem_init(void)
757 {
758         long codesize, reservedpages, datasize, initsize;
759
760         pci_iommu_alloc();
761
762         /* clear_bss() already clear the empty_zero_page */
763
764         reservedpages = 0;
765
766         /* this will put all low memory onto the freelists */
767 #ifdef CONFIG_NUMA
768         totalram_pages = numa_free_all_bootmem();
769 #else
770         totalram_pages = free_all_bootmem();
771 #endif
772         reservedpages = max_pfn - totalram_pages -
773                                         absent_pages_in_range(0, max_pfn);
774         after_bootmem = 1;
775
776         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
777         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
778         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
779
780         /* Register memory areas for /proc/kcore */
781         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
782         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
783                    VMALLOC_END-VMALLOC_START);
784         kclist_add(&kcore_kernel, &_stext, _end - _stext);
785         kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN);
786         kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
787                                  VSYSCALL_END - VSYSCALL_START);
788
789         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
790                                 "%ldk reserved, %ldk data, %ldk init)\n",
791                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
792                 max_pfn << (PAGE_SHIFT-10),
793                 codesize >> 10,
794                 reservedpages << (PAGE_SHIFT-10),
795                 datasize >> 10,
796                 initsize >> 10);
797
798         cpa_init();
799 }
800
801 void free_init_pages(char *what, unsigned long begin, unsigned long end)
802 {
803         unsigned long addr = begin;
804
805         if (addr >= end)
806                 return;
807
808         /*
809          * If debugging page accesses then do not free this memory but
810          * mark them not present - any buggy init-section access will
811          * create a kernel page fault:
812          */
813 #ifdef CONFIG_DEBUG_PAGEALLOC
814         printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
815                 begin, PAGE_ALIGN(end));
816         set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
817 #else
818         printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
819
820         for (; addr < end; addr += PAGE_SIZE) {
821                 ClearPageReserved(virt_to_page(addr));
822                 init_page_count(virt_to_page(addr));
823                 memset((void *)(addr & ~(PAGE_SIZE-1)),
824                         POISON_FREE_INITMEM, PAGE_SIZE);
825                 free_page(addr);
826                 totalram_pages++;
827         }
828 #endif
829 }
830
831 void free_initmem(void)
832 {
833         free_init_pages("unused kernel memory",
834                         (unsigned long)(&__init_begin),
835                         (unsigned long)(&__init_end));
836 }
837
838 #ifdef CONFIG_DEBUG_RODATA
839 const int rodata_test_data = 0xC3;
840 EXPORT_SYMBOL_GPL(rodata_test_data);
841
842 void mark_rodata_ro(void)
843 {
844         unsigned long start = PFN_ALIGN(_stext), end = PFN_ALIGN(__end_rodata);
845         unsigned long rodata_start =
846                 ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
847
848 #ifdef CONFIG_DYNAMIC_FTRACE
849         /* Dynamic tracing modifies the kernel text section */
850         start = rodata_start;
851 #endif
852
853         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
854                (end - start) >> 10);
855         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
856
857         /*
858          * The rodata section (but not the kernel text!) should also be
859          * not-executable.
860          */
861         set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT);
862
863         rodata_test();
864
865 #ifdef CONFIG_CPA_DEBUG
866         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
867         set_memory_rw(start, (end-start) >> PAGE_SHIFT);
868
869         printk(KERN_INFO "Testing CPA: again\n");
870         set_memory_ro(start, (end-start) >> PAGE_SHIFT);
871 #endif
872 }
873
874 #endif
875
876 #ifdef CONFIG_BLK_DEV_INITRD
877 void free_initrd_mem(unsigned long start, unsigned long end)
878 {
879         free_init_pages("initrd memory", start, end);
880 }
881 #endif
882
883 int __init reserve_bootmem_generic(unsigned long phys, unsigned long len,
884                                    int flags)
885 {
886 #ifdef CONFIG_NUMA
887         int nid, next_nid;
888         int ret;
889 #endif
890         unsigned long pfn = phys >> PAGE_SHIFT;
891
892         if (pfn >= max_pfn) {
893                 /*
894                  * This can happen with kdump kernels when accessing
895                  * firmware tables:
896                  */
897                 if (pfn < max_pfn_mapped)
898                         return -EFAULT;
899
900                 printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %lu\n",
901                                 phys, len);
902                 return -EFAULT;
903         }
904
905         /* Should check here against the e820 map to avoid double free */
906 #ifdef CONFIG_NUMA
907         nid = phys_to_nid(phys);
908         next_nid = phys_to_nid(phys + len - 1);
909         if (nid == next_nid)
910                 ret = reserve_bootmem_node(NODE_DATA(nid), phys, len, flags);
911         else
912                 ret = reserve_bootmem(phys, len, flags);
913
914         if (ret != 0)
915                 return ret;
916
917 #else
918         reserve_bootmem(phys, len, BOOTMEM_DEFAULT);
919 #endif
920
921         if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
922                 dma_reserve += len / PAGE_SIZE;
923                 set_dma_reserve(dma_reserve);
924         }
925
926         return 0;
927 }
928
929 int kern_addr_valid(unsigned long addr)
930 {
931         unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
932         pgd_t *pgd;
933         pud_t *pud;
934         pmd_t *pmd;
935         pte_t *pte;
936
937         if (above != 0 && above != -1UL)
938                 return 0;
939
940         pgd = pgd_offset_k(addr);
941         if (pgd_none(*pgd))
942                 return 0;
943
944         pud = pud_offset(pgd, addr);
945         if (pud_none(*pud))
946                 return 0;
947
948         pmd = pmd_offset(pud, addr);
949         if (pmd_none(*pmd))
950                 return 0;
951
952         if (pmd_large(*pmd))
953                 return pfn_valid(pmd_pfn(*pmd));
954
955         pte = pte_offset_kernel(pmd, addr);
956         if (pte_none(*pte))
957                 return 0;
958
959         return pfn_valid(pte_pfn(*pte));
960 }
961
962 /*
963  * A pseudo VMA to allow ptrace access for the vsyscall page.  This only
964  * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
965  * not need special handling anymore:
966  */
967 static struct vm_area_struct gate_vma = {
968         .vm_start       = VSYSCALL_START,
969         .vm_end         = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
970         .vm_page_prot   = PAGE_READONLY_EXEC,
971         .vm_flags       = VM_READ | VM_EXEC
972 };
973
974 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
975 {
976 #ifdef CONFIG_IA32_EMULATION
977         if (test_tsk_thread_flag(tsk, TIF_IA32))
978                 return NULL;
979 #endif
980         return &gate_vma;
981 }
982
983 int in_gate_area(struct task_struct *task, unsigned long addr)
984 {
985         struct vm_area_struct *vma = get_gate_vma(task);
986
987         if (!vma)
988                 return 0;
989
990         return (addr >= vma->vm_start) && (addr < vma->vm_end);
991 }
992
993 /*
994  * Use this when you have no reliable task/vma, typically from interrupt
995  * context. It is less reliable than using the task's vma and may give
996  * false positives:
997  */
998 int in_gate_area_no_task(unsigned long addr)
999 {
1000         return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
1001 }
1002
1003 const char *arch_vma_name(struct vm_area_struct *vma)
1004 {
1005         if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
1006                 return "[vdso]";
1007         if (vma == &gate_vma)
1008                 return "[vsyscall]";
1009         return NULL;
1010 }
1011
1012 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1013 /*
1014  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1015  */
1016 static long __meminitdata addr_start, addr_end;
1017 static void __meminitdata *p_start, *p_end;
1018 static int __meminitdata node_start;
1019
1020 int __meminit
1021 vmemmap_populate(struct page *start_page, unsigned long size, int node)
1022 {
1023         unsigned long addr = (unsigned long)start_page;
1024         unsigned long end = (unsigned long)(start_page + size);
1025         unsigned long next;
1026         pgd_t *pgd;
1027         pud_t *pud;
1028         pmd_t *pmd;
1029
1030         for (; addr < end; addr = next) {
1031                 void *p = NULL;
1032
1033                 pgd = vmemmap_pgd_populate(addr, node);
1034                 if (!pgd)
1035                         return -ENOMEM;
1036
1037                 pud = vmemmap_pud_populate(pgd, addr, node);
1038                 if (!pud)
1039                         return -ENOMEM;
1040
1041                 if (!cpu_has_pse) {
1042                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1043                         pmd = vmemmap_pmd_populate(pud, addr, node);
1044
1045                         if (!pmd)
1046                                 return -ENOMEM;
1047
1048                         p = vmemmap_pte_populate(pmd, addr, node);
1049
1050                         if (!p)
1051                                 return -ENOMEM;
1052
1053                         addr_end = addr + PAGE_SIZE;
1054                         p_end = p + PAGE_SIZE;
1055                 } else {
1056                         next = pmd_addr_end(addr, end);
1057
1058                         pmd = pmd_offset(pud, addr);
1059                         if (pmd_none(*pmd)) {
1060                                 pte_t entry;
1061
1062                                 p = vmemmap_alloc_block(PMD_SIZE, node);
1063                                 if (!p)
1064                                         return -ENOMEM;
1065
1066                                 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1067                                                 PAGE_KERNEL_LARGE);
1068                                 set_pmd(pmd, __pmd(pte_val(entry)));
1069
1070                                 /* check to see if we have contiguous blocks */
1071                                 if (p_end != p || node_start != node) {
1072                                         if (p_start)
1073                                                 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1074                                                        addr_start, addr_end-1, p_start, p_end-1, node_start);
1075                                         addr_start = addr;
1076                                         node_start = node;
1077                                         p_start = p;
1078                                 }
1079
1080                                 addr_end = addr + PMD_SIZE;
1081                                 p_end = p + PMD_SIZE;
1082                         } else
1083                                 vmemmap_verify((pte_t *)pmd, node, addr, next);
1084                 }
1085
1086         }
1087         return 0;
1088 }
1089
1090 void __meminit vmemmap_populate_print_last(void)
1091 {
1092         if (p_start) {
1093                 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1094                         addr_start, addr_end-1, p_start, p_end-1, node_start);
1095                 p_start = NULL;
1096                 p_end = NULL;
1097                 node_start = 0;
1098         }
1099 }
1100 #endif