x86: get max_pfn_mapped in init_memory_mapping
[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  * PFN of last memory page.
53  */
54 unsigned long end_pfn;
55
56 /*
57  * end_pfn only includes RAM, while max_pfn_mapped includes all e820 entries.
58  * The direct mapping extends to max_pfn_mapped, so that we can directly access
59  * apertures, ACPI and other tables without having to play with fixmaps.
60  */
61 unsigned long max_pfn_mapped;
62
63 static unsigned long dma_reserve __initdata;
64
65 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
66
67 int direct_gbpages __meminitdata
68 #ifdef CONFIG_DIRECT_GBPAGES
69                                 = 1
70 #endif
71 ;
72
73 static int __init parse_direct_gbpages_off(char *arg)
74 {
75         direct_gbpages = 0;
76         return 0;
77 }
78 early_param("nogbpages", parse_direct_gbpages_off);
79
80 static int __init parse_direct_gbpages_on(char *arg)
81 {
82         direct_gbpages = 1;
83         return 0;
84 }
85 early_param("gbpages", parse_direct_gbpages_on);
86
87 /*
88  * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
89  * physical space so we can cache the place of the first one and move
90  * around without checking the pgd every time.
91  */
92
93 void show_mem(void)
94 {
95         long i, total = 0, reserved = 0;
96         long shared = 0, cached = 0;
97         struct page *page;
98         pg_data_t *pgdat;
99
100         printk(KERN_INFO "Mem-info:\n");
101         show_free_areas();
102         for_each_online_pgdat(pgdat) {
103                 for (i = 0; i < pgdat->node_spanned_pages; ++i) {
104                         /*
105                          * This loop can take a while with 256 GB and
106                          * 4k pages so defer the NMI watchdog:
107                          */
108                         if (unlikely(i % MAX_ORDER_NR_PAGES == 0))
109                                 touch_nmi_watchdog();
110
111                         if (!pfn_valid(pgdat->node_start_pfn + i))
112                                 continue;
113
114                         page = pfn_to_page(pgdat->node_start_pfn + i);
115                         total++;
116                         if (PageReserved(page))
117                                 reserved++;
118                         else if (PageSwapCache(page))
119                                 cached++;
120                         else if (page_count(page))
121                                 shared += page_count(page) - 1;
122                 }
123         }
124         printk(KERN_INFO "%lu pages of RAM\n",          total);
125         printk(KERN_INFO "%lu reserved pages\n",        reserved);
126         printk(KERN_INFO "%lu pages shared\n",          shared);
127         printk(KERN_INFO "%lu pages swap cached\n",     cached);
128 }
129
130 int after_bootmem;
131
132 static __init void *spp_getpage(void)
133 {
134         void *ptr;
135
136         if (after_bootmem)
137                 ptr = (void *) get_zeroed_page(GFP_ATOMIC);
138         else
139                 ptr = alloc_bootmem_pages(PAGE_SIZE);
140
141         if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
142                 panic("set_pte_phys: cannot allocate page data %s\n",
143                         after_bootmem ? "after bootmem" : "");
144         }
145
146         pr_debug("spp_getpage %p\n", ptr);
147
148         return ptr;
149 }
150
151 void
152 set_pte_vaddr(unsigned long vaddr, pte_t new_pte)
153 {
154         pgd_t *pgd;
155         pud_t *pud;
156         pmd_t *pmd;
157         pte_t *pte;
158
159         pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(new_pte));
160
161         pgd = pgd_offset_k(vaddr);
162         if (pgd_none(*pgd)) {
163                 printk(KERN_ERR
164                         "PGD FIXMAP MISSING, it should be setup in head.S!\n");
165                 return;
166         }
167         pud = pud_offset(pgd, vaddr);
168         if (pud_none(*pud)) {
169                 pmd = (pmd_t *) spp_getpage();
170                 pud_populate(&init_mm, pud, pmd);
171                 if (pmd != pmd_offset(pud, 0)) {
172                         printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
173                                 pmd, pmd_offset(pud, 0));
174                         return;
175                 }
176         }
177         pmd = pmd_offset(pud, vaddr);
178         if (pmd_none(*pmd)) {
179                 pte = (pte_t *) spp_getpage();
180                 pmd_populate_kernel(&init_mm, pmd, pte);
181                 if (pte != pte_offset_kernel(pmd, 0)) {
182                         printk(KERN_ERR "PAGETABLE BUG #02!\n");
183                         return;
184                 }
185         }
186
187         pte = pte_offset_kernel(pmd, vaddr);
188         if (!pte_none(*pte) && pte_val(new_pte) &&
189             pte_val(*pte) != (pte_val(new_pte) & __supported_pte_mask))
190                 pte_ERROR(*pte);
191         set_pte(pte, new_pte);
192
193         /*
194          * It's enough to flush this one mapping.
195          * (PGE mappings get flushed as well)
196          */
197         __flush_tlb_one(vaddr);
198 }
199
200 /*
201  * The head.S code sets up the kernel high mapping:
202  *
203  *   from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
204  *
205  * phys_addr holds the negative offset to the kernel, which is added
206  * to the compile time generated pmds. This results in invalid pmds up
207  * to the point where we hit the physaddr 0 mapping.
208  *
209  * We limit the mappings to the region from _text to _end.  _end is
210  * rounded up to the 2MB boundary. This catches the invalid pmds as
211  * well, as they are located before _text:
212  */
213 void __init cleanup_highmap(void)
214 {
215         unsigned long vaddr = __START_KERNEL_map;
216         unsigned long end = round_up((unsigned long)_end, PMD_SIZE) - 1;
217         pmd_t *pmd = level2_kernel_pgt;
218         pmd_t *last_pmd = pmd + PTRS_PER_PMD;
219
220         for (; pmd < last_pmd; pmd++, vaddr += PMD_SIZE) {
221                 if (pmd_none(*pmd))
222                         continue;
223                 if (vaddr < (unsigned long) _text || vaddr > end)
224                         set_pmd(pmd, __pmd(0));
225         }
226 }
227
228 static unsigned long __initdata table_start;
229 static unsigned long __meminitdata table_end;
230
231 static __meminit void *alloc_low_page(unsigned long *phys)
232 {
233         unsigned long pfn = table_end++;
234         void *adr;
235
236         if (after_bootmem) {
237                 adr = (void *)get_zeroed_page(GFP_ATOMIC);
238                 *phys = __pa(adr);
239
240                 return adr;
241         }
242
243         if (pfn >= end_pfn)
244                 panic("alloc_low_page: ran out of memory");
245
246         adr = early_ioremap(pfn * PAGE_SIZE, PAGE_SIZE);
247         memset(adr, 0, PAGE_SIZE);
248         *phys  = pfn * PAGE_SIZE;
249         return adr;
250 }
251
252 static __meminit void unmap_low_page(void *adr)
253 {
254         if (after_bootmem)
255                 return;
256
257         early_iounmap(adr, PAGE_SIZE);
258 }
259
260 static unsigned long __meminit
261 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end)
262 {
263         unsigned long pages = 0;
264
265         int i = pmd_index(address);
266
267         for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
268                 pmd_t *pmd = pmd_page + pmd_index(address);
269
270                 if (address >= end) {
271                         if (!after_bootmem) {
272                                 for (; i < PTRS_PER_PMD; i++, pmd++)
273                                         set_pmd(pmd, __pmd(0));
274                         }
275                         break;
276                 }
277
278                 if (pmd_val(*pmd))
279                         continue;
280
281                 pages++;
282                 set_pte((pte_t *)pmd,
283                         pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
284         }
285         update_page_count(PG_LEVEL_2M, pages);
286         return address;
287 }
288
289 static unsigned long __meminit
290 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end)
291 {
292         pmd_t *pmd = pmd_offset(pud, 0);
293         unsigned long last_map_addr;
294
295         spin_lock(&init_mm.page_table_lock);
296         last_map_addr = phys_pmd_init(pmd, address, end);
297         spin_unlock(&init_mm.page_table_lock);
298         __flush_tlb_all();
299         return last_map_addr;
300 }
301
302 static unsigned long __meminit
303 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end)
304 {
305         unsigned long pages = 0;
306         unsigned long last_map_addr = end;
307         int i = pud_index(addr);
308
309         for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
310                 unsigned long pmd_phys;
311                 pud_t *pud = pud_page + pud_index(addr);
312                 pmd_t *pmd;
313
314                 if (addr >= end)
315                         break;
316
317                 if (!after_bootmem &&
318                                 !e820_any_mapped(addr, addr+PUD_SIZE, 0)) {
319                         set_pud(pud, __pud(0));
320                         continue;
321                 }
322
323                 if (pud_val(*pud)) {
324                         if (!pud_large(*pud))
325                                 last_map_addr = phys_pmd_update(pud, addr, end);
326                         continue;
327                 }
328
329                 if (direct_gbpages) {
330                         pages++;
331                         set_pte((pte_t *)pud,
332                                 pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
333                         last_map_addr = (addr & PUD_MASK) + PUD_SIZE;
334                         continue;
335                 }
336
337                 pmd = alloc_low_page(&pmd_phys);
338
339                 spin_lock(&init_mm.page_table_lock);
340                 pud_populate(&init_mm, pud, __va(pmd_phys));
341                 last_map_addr = phys_pmd_init(pmd, addr, end);
342                 spin_unlock(&init_mm.page_table_lock);
343
344                 unmap_low_page(pmd);
345         }
346         __flush_tlb_all();
347         update_page_count(PG_LEVEL_1G, pages);
348
349         return last_map_addr;
350 }
351
352 static void __init find_early_table_space(unsigned long end)
353 {
354         unsigned long puds, pmds, tables, start;
355
356         puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
357         tables = round_up(puds * sizeof(pud_t), PAGE_SIZE);
358         if (!direct_gbpages) {
359                 pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
360                 tables += round_up(pmds * sizeof(pmd_t), PAGE_SIZE);
361         }
362
363         /*
364          * RED-PEN putting page tables only on node 0 could
365          * cause a hotspot and fill up ZONE_DMA. The page tables
366          * need roughly 0.5KB per GB.
367          */
368         start = 0x8000;
369         table_start = find_e820_area(start, end, tables, PAGE_SIZE);
370         if (table_start == -1UL)
371                 panic("Cannot find space for the kernel page tables");
372
373         table_start >>= PAGE_SHIFT;
374         table_end = table_start;
375
376         early_printk("kernel direct mapping tables up to %lx @ %lx-%lx\n",
377                 end, table_start << PAGE_SHIFT,
378                 (table_start << PAGE_SHIFT) + tables);
379 }
380
381 static void __init init_gbpages(void)
382 {
383         if (direct_gbpages && cpu_has_gbpages)
384                 printk(KERN_INFO "Using GB pages for direct mapping\n");
385         else
386                 direct_gbpages = 0;
387 }
388
389 #ifdef CONFIG_MEMTEST
390
391 static void __init memtest(unsigned long start_phys, unsigned long size,
392                                  unsigned pattern)
393 {
394         unsigned long i;
395         unsigned long *start;
396         unsigned long start_bad;
397         unsigned long last_bad;
398         unsigned long val;
399         unsigned long start_phys_aligned;
400         unsigned long count;
401         unsigned long incr;
402
403         switch (pattern) {
404         case 0:
405                 val = 0UL;
406                 break;
407         case 1:
408                 val = -1UL;
409                 break;
410         case 2:
411                 val = 0x5555555555555555UL;
412                 break;
413         case 3:
414                 val = 0xaaaaaaaaaaaaaaaaUL;
415                 break;
416         default:
417                 return;
418         }
419
420         incr = sizeof(unsigned long);
421         start_phys_aligned = ALIGN(start_phys, incr);
422         count = (size - (start_phys_aligned - start_phys))/incr;
423         start = __va(start_phys_aligned);
424         start_bad = 0;
425         last_bad = 0;
426
427         for (i = 0; i < count; i++)
428                 start[i] = val;
429         for (i = 0; i < count; i++, start++, start_phys_aligned += incr) {
430                 if (*start != val) {
431                         if (start_phys_aligned == last_bad + incr) {
432                                 last_bad += incr;
433                         } else {
434                                 if (start_bad) {
435                                         printk(KERN_CONT "\n  %016lx bad mem addr %016lx - %016lx reserved",
436                                                 val, start_bad, last_bad + incr);
437                                         reserve_early(start_bad, last_bad - start_bad, "BAD RAM");
438                                 }
439                                 start_bad = last_bad = start_phys_aligned;
440                         }
441                 }
442         }
443         if (start_bad) {
444                 printk(KERN_CONT "\n  %016lx bad mem addr %016lx - %016lx reserved",
445                         val, start_bad, last_bad + incr);
446                 reserve_early(start_bad, last_bad - start_bad, "BAD RAM");
447         }
448
449 }
450
451 /* default is disabled */
452 static int memtest_pattern __initdata;
453
454 static int __init parse_memtest(char *arg)
455 {
456         if (arg)
457                 memtest_pattern = simple_strtoul(arg, NULL, 0);
458         return 0;
459 }
460
461 early_param("memtest", parse_memtest);
462
463 static void __init early_memtest(unsigned long start, unsigned long end)
464 {
465         u64 t_start, t_size;
466         unsigned pattern;
467
468         if (!memtest_pattern)
469                 return;
470
471         printk(KERN_INFO "early_memtest: pattern num %d", memtest_pattern);
472         for (pattern = 0; pattern < memtest_pattern; pattern++) {
473                 t_start = start;
474                 t_size = 0;
475                 while (t_start < end) {
476                         t_start = find_e820_area_size(t_start, &t_size, 1);
477
478                         /* done ? */
479                         if (t_start >= end)
480                                 break;
481                         if (t_start + t_size > end)
482                                 t_size = end - t_start;
483
484                         printk(KERN_CONT "\n  %016llx - %016llx pattern %d",
485                                 (unsigned long long)t_start,
486                                 (unsigned long long)t_start + t_size, pattern);
487
488                         memtest(t_start, t_size, pattern);
489
490                         t_start += t_size;
491                 }
492         }
493         printk(KERN_CONT "\n");
494 }
495 #else
496 static void __init early_memtest(unsigned long start, unsigned long end)
497 {
498 }
499 #endif
500
501 /*
502  * Setup the direct mapping of the physical memory at PAGE_OFFSET.
503  * This runs before bootmem is initialized and gets pages directly from
504  * the physical memory. To access them they are temporarily mapped.
505  */
506 unsigned long __init_refok init_memory_mapping(unsigned long start, unsigned long end)
507 {
508         unsigned long next, last_map_addr = end;
509         unsigned long start_phys = start, end_phys = end;
510
511         printk(KERN_INFO "init_memory_mapping\n");
512
513         /*
514          * Find space for the kernel direct mapping tables.
515          *
516          * Later we should allocate these tables in the local node of the
517          * memory mapped. Unfortunately this is done currently before the
518          * nodes are discovered.
519          */
520         if (!after_bootmem) {
521                 init_gbpages();
522                 find_early_table_space(end);
523         }
524
525         start = (unsigned long)__va(start);
526         end = (unsigned long)__va(end);
527
528         for (; start < end; start = next) {
529                 pgd_t *pgd = pgd_offset_k(start);
530                 unsigned long pud_phys;
531                 pud_t *pud;
532
533                 if (after_bootmem)
534                         pud = pud_offset(pgd, start & PGDIR_MASK);
535                 else
536                         pud = alloc_low_page(&pud_phys);
537
538                 next = start + PGDIR_SIZE;
539                 if (next > end)
540                         next = end;
541                 last_map_addr = phys_pud_init(pud, __pa(start), __pa(next));
542                 if (!after_bootmem)
543                         pgd_populate(&init_mm, pgd_offset_k(start),
544                                      __va(pud_phys));
545                 unmap_low_page(pud);
546         }
547
548         if (!after_bootmem)
549                 mmu_cr4_features = read_cr4();
550         __flush_tlb_all();
551
552         if (!after_bootmem)
553                 reserve_early(table_start << PAGE_SHIFT,
554                                  table_end << PAGE_SHIFT, "PGTABLE");
555
556         if (!after_bootmem)
557                 early_memtest(start_phys, end_phys);
558
559         return last_map_addr >> PAGE_SHIFT;
560 }
561
562 #ifndef CONFIG_NUMA
563 void __init initmem_init(unsigned long start_pfn, unsigned long end_pfn)
564 {
565         unsigned long bootmap_size, bootmap;
566
567         bootmap_size = bootmem_bootmap_pages(end_pfn)<<PAGE_SHIFT;
568         bootmap = find_e820_area(0, end_pfn<<PAGE_SHIFT, bootmap_size,
569                                  PAGE_SIZE);
570         if (bootmap == -1L)
571                 panic("Cannot find bootmem map of size %ld\n", bootmap_size);
572         /* don't touch min_low_pfn */
573         bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap >> PAGE_SHIFT,
574                                          0, end_pfn);
575         e820_register_active_regions(0, start_pfn, end_pfn);
576         free_bootmem_with_active_regions(0, end_pfn);
577         early_res_to_bootmem(0, end_pfn<<PAGE_SHIFT);
578         reserve_bootmem(bootmap, bootmap_size, BOOTMEM_DEFAULT);
579 }
580
581 void __init paging_init(void)
582 {
583         unsigned long max_zone_pfns[MAX_NR_ZONES];
584
585         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
586         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
587         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
588         max_zone_pfns[ZONE_NORMAL] = end_pfn;
589
590         memory_present(0, 0, end_pfn);
591         sparse_init();
592         free_area_init_nodes(max_zone_pfns);
593 }
594 #endif
595
596 /*
597  * Memory hotplug specific functions
598  */
599 #ifdef CONFIG_MEMORY_HOTPLUG
600 /*
601  * Memory is added always to NORMAL zone. This means you will never get
602  * additional DMA/DMA32 memory.
603  */
604 int arch_add_memory(int nid, u64 start, u64 size)
605 {
606         struct pglist_data *pgdat = NODE_DATA(nid);
607         struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
608         unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT;
609         unsigned long nr_pages = size >> PAGE_SHIFT;
610         int ret;
611
612         last_mapped_pfn = init_memory_mapping(start, start + size-1);
613         if (last_mapped_pfn > max_pfn_mapped)
614                 max_pfn_mapped = last_mapped_pfn;
615
616         ret = __add_pages(zone, start_pfn, nr_pages);
617         WARN_ON(1);
618
619         return ret;
620 }
621 EXPORT_SYMBOL_GPL(arch_add_memory);
622
623 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
624 int memory_add_physaddr_to_nid(u64 start)
625 {
626         return 0;
627 }
628 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
629 #endif
630
631 #endif /* CONFIG_MEMORY_HOTPLUG */
632
633 /*
634  * devmem_is_allowed() checks to see if /dev/mem access to a certain address
635  * is valid. The argument is a physical page number.
636  *
637  *
638  * On x86, access has to be given to the first megabyte of ram because that area
639  * contains bios code and data regions used by X and dosemu and similar apps.
640  * Access has to be given to non-kernel-ram areas as well, these contain the PCI
641  * mmio resources as well as potential bios/acpi data regions.
642  */
643 int devmem_is_allowed(unsigned long pagenr)
644 {
645         if (pagenr <= 256)
646                 return 1;
647         if (!page_is_ram(pagenr))
648                 return 1;
649         return 0;
650 }
651
652
653 static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel,
654                          kcore_modules, kcore_vsyscall;
655
656 void __init mem_init(void)
657 {
658         long codesize, reservedpages, datasize, initsize;
659
660         pci_iommu_alloc();
661
662         /* clear_bss() already clear the empty_zero_page */
663
664         reservedpages = 0;
665
666         /* this will put all low memory onto the freelists */
667 #ifdef CONFIG_NUMA
668         totalram_pages = numa_free_all_bootmem();
669 #else
670         totalram_pages = free_all_bootmem();
671 #endif
672         reservedpages = end_pfn - totalram_pages -
673                                         absent_pages_in_range(0, end_pfn);
674         after_bootmem = 1;
675
676         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
677         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
678         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
679
680         /* Register memory areas for /proc/kcore */
681         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
682         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
683                    VMALLOC_END-VMALLOC_START);
684         kclist_add(&kcore_kernel, &_stext, _end - _stext);
685         kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN);
686         kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
687                                  VSYSCALL_END - VSYSCALL_START);
688
689         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
690                                 "%ldk reserved, %ldk data, %ldk init)\n",
691                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
692                 end_pfn << (PAGE_SHIFT-10),
693                 codesize >> 10,
694                 reservedpages << (PAGE_SHIFT-10),
695                 datasize >> 10,
696                 initsize >> 10);
697
698         cpa_init();
699 }
700
701 void free_init_pages(char *what, unsigned long begin, unsigned long end)
702 {
703         unsigned long addr = begin;
704
705         if (addr >= end)
706                 return;
707
708         /*
709          * If debugging page accesses then do not free this memory but
710          * mark them not present - any buggy init-section access will
711          * create a kernel page fault:
712          */
713 #ifdef CONFIG_DEBUG_PAGEALLOC
714         printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
715                 begin, PAGE_ALIGN(end));
716         set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
717 #else
718         printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
719
720         for (; addr < end; addr += PAGE_SIZE) {
721                 ClearPageReserved(virt_to_page(addr));
722                 init_page_count(virt_to_page(addr));
723                 memset((void *)(addr & ~(PAGE_SIZE-1)),
724                         POISON_FREE_INITMEM, PAGE_SIZE);
725                 free_page(addr);
726                 totalram_pages++;
727         }
728 #endif
729 }
730
731 void free_initmem(void)
732 {
733         free_init_pages("unused kernel memory",
734                         (unsigned long)(&__init_begin),
735                         (unsigned long)(&__init_end));
736 }
737
738 #ifdef CONFIG_DEBUG_RODATA
739 const int rodata_test_data = 0xC3;
740 EXPORT_SYMBOL_GPL(rodata_test_data);
741
742 void mark_rodata_ro(void)
743 {
744         unsigned long start = PFN_ALIGN(_stext), end = PFN_ALIGN(__end_rodata);
745
746         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
747                (end - start) >> 10);
748         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
749
750         /*
751          * The rodata section (but not the kernel text!) should also be
752          * not-executable.
753          */
754         start = ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
755         set_memory_nx(start, (end - start) >> PAGE_SHIFT);
756
757         rodata_test();
758
759 #ifdef CONFIG_CPA_DEBUG
760         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
761         set_memory_rw(start, (end-start) >> PAGE_SHIFT);
762
763         printk(KERN_INFO "Testing CPA: again\n");
764         set_memory_ro(start, (end-start) >> PAGE_SHIFT);
765 #endif
766 }
767
768 #endif
769
770 #ifdef CONFIG_BLK_DEV_INITRD
771 void free_initrd_mem(unsigned long start, unsigned long end)
772 {
773         free_init_pages("initrd memory", start, end);
774 }
775 #endif
776
777 int __init reserve_bootmem_generic(unsigned long phys, unsigned long len,
778                                    int flags)
779 {
780 #ifdef CONFIG_NUMA
781         int nid, next_nid;
782         int ret;
783 #endif
784         unsigned long pfn = phys >> PAGE_SHIFT;
785
786         if (pfn >= end_pfn) {
787                 /*
788                  * This can happen with kdump kernels when accessing
789                  * firmware tables:
790                  */
791                 if (pfn < max_pfn_mapped)
792                         return -EFAULT;
793
794                 printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %lu\n",
795                                 phys, len);
796                 return -EFAULT;
797         }
798
799         /* Should check here against the e820 map to avoid double free */
800 #ifdef CONFIG_NUMA
801         nid = phys_to_nid(phys);
802         next_nid = phys_to_nid(phys + len - 1);
803         if (nid == next_nid)
804                 ret = reserve_bootmem_node(NODE_DATA(nid), phys, len, flags);
805         else
806                 ret = reserve_bootmem(phys, len, flags);
807
808         if (ret != 0)
809                 return ret;
810
811 #else
812         reserve_bootmem(phys, len, BOOTMEM_DEFAULT);
813 #endif
814
815         if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
816                 dma_reserve += len / PAGE_SIZE;
817                 set_dma_reserve(dma_reserve);
818         }
819
820         return 0;
821 }
822
823 int kern_addr_valid(unsigned long addr)
824 {
825         unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
826         pgd_t *pgd;
827         pud_t *pud;
828         pmd_t *pmd;
829         pte_t *pte;
830
831         if (above != 0 && above != -1UL)
832                 return 0;
833
834         pgd = pgd_offset_k(addr);
835         if (pgd_none(*pgd))
836                 return 0;
837
838         pud = pud_offset(pgd, addr);
839         if (pud_none(*pud))
840                 return 0;
841
842         pmd = pmd_offset(pud, addr);
843         if (pmd_none(*pmd))
844                 return 0;
845
846         if (pmd_large(*pmd))
847                 return pfn_valid(pmd_pfn(*pmd));
848
849         pte = pte_offset_kernel(pmd, addr);
850         if (pte_none(*pte))
851                 return 0;
852
853         return pfn_valid(pte_pfn(*pte));
854 }
855
856 /*
857  * A pseudo VMA to allow ptrace access for the vsyscall page.  This only
858  * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
859  * not need special handling anymore:
860  */
861 static struct vm_area_struct gate_vma = {
862         .vm_start       = VSYSCALL_START,
863         .vm_end         = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
864         .vm_page_prot   = PAGE_READONLY_EXEC,
865         .vm_flags       = VM_READ | VM_EXEC
866 };
867
868 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
869 {
870 #ifdef CONFIG_IA32_EMULATION
871         if (test_tsk_thread_flag(tsk, TIF_IA32))
872                 return NULL;
873 #endif
874         return &gate_vma;
875 }
876
877 int in_gate_area(struct task_struct *task, unsigned long addr)
878 {
879         struct vm_area_struct *vma = get_gate_vma(task);
880
881         if (!vma)
882                 return 0;
883
884         return (addr >= vma->vm_start) && (addr < vma->vm_end);
885 }
886
887 /*
888  * Use this when you have no reliable task/vma, typically from interrupt
889  * context. It is less reliable than using the task's vma and may give
890  * false positives:
891  */
892 int in_gate_area_no_task(unsigned long addr)
893 {
894         return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
895 }
896
897 const char *arch_vma_name(struct vm_area_struct *vma)
898 {
899         if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
900                 return "[vdso]";
901         if (vma == &gate_vma)
902                 return "[vsyscall]";
903         return NULL;
904 }
905
906 #ifdef CONFIG_SPARSEMEM_VMEMMAP
907 /*
908  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
909  */
910 static long __meminitdata addr_start, addr_end;
911 static void __meminitdata *p_start, *p_end;
912 static int __meminitdata node_start;
913
914 int __meminit
915 vmemmap_populate(struct page *start_page, unsigned long size, int node)
916 {
917         unsigned long addr = (unsigned long)start_page;
918         unsigned long end = (unsigned long)(start_page + size);
919         unsigned long next;
920         pgd_t *pgd;
921         pud_t *pud;
922         pmd_t *pmd;
923
924         for (; addr < end; addr = next) {
925                 next = pmd_addr_end(addr, end);
926
927                 pgd = vmemmap_pgd_populate(addr, node);
928                 if (!pgd)
929                         return -ENOMEM;
930
931                 pud = vmemmap_pud_populate(pgd, addr, node);
932                 if (!pud)
933                         return -ENOMEM;
934
935                 pmd = pmd_offset(pud, addr);
936                 if (pmd_none(*pmd)) {
937                         pte_t entry;
938                         void *p;
939
940                         p = vmemmap_alloc_block(PMD_SIZE, node);
941                         if (!p)
942                                 return -ENOMEM;
943
944                         entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
945                                                         PAGE_KERNEL_LARGE);
946                         set_pmd(pmd, __pmd(pte_val(entry)));
947
948                         /* check to see if we have contiguous blocks */
949                         if (p_end != p || node_start != node) {
950                                 if (p_start)
951                                         printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
952                                                 addr_start, addr_end-1, p_start, p_end-1, node_start);
953                                 addr_start = addr;
954                                 node_start = node;
955                                 p_start = p;
956                         }
957                         addr_end = addr + PMD_SIZE;
958                         p_end = p + PMD_SIZE;
959                 } else {
960                         vmemmap_verify((pte_t *)pmd, node, addr, next);
961                 }
962         }
963         return 0;
964 }
965
966 void __meminit vmemmap_populate_print_last(void)
967 {
968         if (p_start) {
969                 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
970                         addr_start, addr_end-1, p_start, p_end-1, node_start);
971                 p_start = NULL;
972                 p_end = NULL;
973                 node_start = 0;
974         }
975 }
976 #endif