ae225c3ae9a8990e974e425fc680ddd0b592814b
[sfrench/cifs-2.6.git] / arch / x86 / mm / init_64.c
1 /*
2  *  linux/arch/x86_64/mm/init.c
3  *
4  *  Copyright (C) 1995  Linus Torvalds
5  *  Copyright (C) 2000  Pavel Machek <pavel@suse.cz>
6  *  Copyright (C) 2002,2003 Andi Kleen <ak@suse.de>
7  */
8
9 #include <linux/signal.h>
10 #include <linux/sched.h>
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
13 #include <linux/string.h>
14 #include <linux/types.h>
15 #include <linux/ptrace.h>
16 #include <linux/mman.h>
17 #include <linux/mm.h>
18 #include <linux/swap.h>
19 #include <linux/smp.h>
20 #include <linux/init.h>
21 #include <linux/pagemap.h>
22 #include <linux/bootmem.h>
23 #include <linux/proc_fs.h>
24 #include <linux/pci.h>
25 #include <linux/pfn.h>
26 #include <linux/poison.h>
27 #include <linux/dma-mapping.h>
28 #include <linux/module.h>
29 #include <linux/memory_hotplug.h>
30 #include <linux/nmi.h>
31
32 #include <asm/processor.h>
33 #include <asm/system.h>
34 #include <asm/uaccess.h>
35 #include <asm/pgtable.h>
36 #include <asm/pgalloc.h>
37 #include <asm/dma.h>
38 #include <asm/fixmap.h>
39 #include <asm/e820.h>
40 #include <asm/apic.h>
41 #include <asm/tlb.h>
42 #include <asm/mmu_context.h>
43 #include <asm/proto.h>
44 #include <asm/smp.h>
45 #include <asm/sections.h>
46 #include <asm/kdebug.h>
47 #include <asm/numa.h>
48 #include <asm/cacheflush.h>
49
50 const struct dma_mapping_ops *dma_ops;
51 EXPORT_SYMBOL(dma_ops);
52
53 static unsigned long dma_reserve __initdata;
54
55 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
56
57 int direct_gbpages __meminitdata
58 #ifdef CONFIG_DIRECT_GBPAGES
59                                 = 1
60 #endif
61 ;
62
63 static int __init parse_direct_gbpages_off(char *arg)
64 {
65         direct_gbpages = 0;
66         return 0;
67 }
68 early_param("nogbpages", parse_direct_gbpages_off);
69
70 static int __init parse_direct_gbpages_on(char *arg)
71 {
72         direct_gbpages = 1;
73         return 0;
74 }
75 early_param("gbpages", parse_direct_gbpages_on);
76
77 /*
78  * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
79  * physical space so we can cache the place of the first one and move
80  * around without checking the pgd every time.
81  */
82
83 void show_mem(void)
84 {
85         long i, total = 0, reserved = 0;
86         long shared = 0, cached = 0;
87         struct page *page;
88         pg_data_t *pgdat;
89
90         printk(KERN_INFO "Mem-info:\n");
91         show_free_areas();
92         for_each_online_pgdat(pgdat) {
93                 for (i = 0; i < pgdat->node_spanned_pages; ++i) {
94                         /*
95                          * This loop can take a while with 256 GB and
96                          * 4k pages so defer the NMI watchdog:
97                          */
98                         if (unlikely(i % MAX_ORDER_NR_PAGES == 0))
99                                 touch_nmi_watchdog();
100
101                         if (!pfn_valid(pgdat->node_start_pfn + i))
102                                 continue;
103
104                         page = pfn_to_page(pgdat->node_start_pfn + i);
105                         total++;
106                         if (PageReserved(page))
107                                 reserved++;
108                         else if (PageSwapCache(page))
109                                 cached++;
110                         else if (page_count(page))
111                                 shared += page_count(page) - 1;
112                 }
113         }
114         printk(KERN_INFO "%lu pages of RAM\n",          total);
115         printk(KERN_INFO "%lu reserved pages\n",        reserved);
116         printk(KERN_INFO "%lu pages shared\n",          shared);
117         printk(KERN_INFO "%lu pages swap cached\n",     cached);
118 }
119
120 int after_bootmem;
121
122 static __init void *spp_getpage(void)
123 {
124         void *ptr;
125
126         if (after_bootmem)
127                 ptr = (void *) get_zeroed_page(GFP_ATOMIC);
128         else
129                 ptr = alloc_bootmem_pages(PAGE_SIZE);
130
131         if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
132                 panic("set_pte_phys: cannot allocate page data %s\n",
133                         after_bootmem ? "after bootmem" : "");
134         }
135
136         pr_debug("spp_getpage %p\n", ptr);
137
138         return ptr;
139 }
140
141 static __init void
142 set_pte_phys(unsigned long vaddr, unsigned long phys, pgprot_t prot)
143 {
144         pgd_t *pgd;
145         pud_t *pud;
146         pmd_t *pmd;
147         pte_t *pte, new_pte;
148
149         pr_debug("set_pte_phys %lx to %lx\n", vaddr, phys);
150
151         pgd = pgd_offset_k(vaddr);
152         if (pgd_none(*pgd)) {
153                 printk(KERN_ERR
154                         "PGD FIXMAP MISSING, it should be setup in head.S!\n");
155                 return;
156         }
157         pud = pud_offset(pgd, vaddr);
158         if (pud_none(*pud)) {
159                 pmd = (pmd_t *) spp_getpage();
160                 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | _PAGE_USER));
161                 if (pmd != pmd_offset(pud, 0)) {
162                         printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
163                                 pmd, pmd_offset(pud, 0));
164                         return;
165                 }
166         }
167         pmd = pmd_offset(pud, vaddr);
168         if (pmd_none(*pmd)) {
169                 pte = (pte_t *) spp_getpage();
170                 set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE | _PAGE_USER));
171                 if (pte != pte_offset_kernel(pmd, 0)) {
172                         printk(KERN_ERR "PAGETABLE BUG #02!\n");
173                         return;
174                 }
175         }
176         new_pte = pfn_pte(phys >> PAGE_SHIFT, prot);
177
178         pte = pte_offset_kernel(pmd, vaddr);
179         if (!pte_none(*pte) &&
180             pte_val(*pte) != (pte_val(new_pte) & __supported_pte_mask))
181                 pte_ERROR(*pte);
182         set_pte(pte, new_pte);
183
184         /*
185          * It's enough to flush this one mapping.
186          * (PGE mappings get flushed as well)
187          */
188         __flush_tlb_one(vaddr);
189 }
190
191 /*
192  * The head.S code sets up the kernel high mapping:
193  *
194  *   from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
195  *
196  * phys_addr holds the negative offset to the kernel, which is added
197  * to the compile time generated pmds. This results in invalid pmds up
198  * to the point where we hit the physaddr 0 mapping.
199  *
200  * We limit the mappings to the region from _text to _end.  _end is
201  * rounded up to the 2MB boundary. This catches the invalid pmds as
202  * well, as they are located before _text:
203  */
204 void __init cleanup_highmap(void)
205 {
206         unsigned long vaddr = __START_KERNEL_map;
207         unsigned long end = round_up((unsigned long)_end, PMD_SIZE) - 1;
208         pmd_t *pmd = level2_kernel_pgt;
209         pmd_t *last_pmd = pmd + PTRS_PER_PMD;
210
211         for (; pmd < last_pmd; pmd++, vaddr += PMD_SIZE) {
212                 if (!pmd_present(*pmd))
213                         continue;
214                 if (vaddr < (unsigned long) _text || vaddr > end)
215                         set_pmd(pmd, __pmd(0));
216         }
217 }
218
219 /* NOTE: this is meant to be run only at boot */
220 void __init
221 __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
222 {
223         unsigned long address = __fix_to_virt(idx);
224
225         if (idx >= __end_of_fixed_addresses) {
226                 printk(KERN_ERR "Invalid __set_fixmap\n");
227                 return;
228         }
229         set_pte_phys(address, phys, prot);
230 }
231
232 static unsigned long __initdata table_start;
233 static unsigned long __meminitdata table_end;
234
235 static __meminit void *alloc_low_page(unsigned long *phys)
236 {
237         unsigned long pfn = table_end++;
238         void *adr;
239
240         if (after_bootmem) {
241                 adr = (void *)get_zeroed_page(GFP_ATOMIC);
242                 *phys = __pa(adr);
243
244                 return adr;
245         }
246
247         if (pfn >= end_pfn)
248                 panic("alloc_low_page: ran out of memory");
249
250         adr = early_ioremap(pfn * PAGE_SIZE, PAGE_SIZE);
251         memset(adr, 0, PAGE_SIZE);
252         *phys  = pfn * PAGE_SIZE;
253         return adr;
254 }
255
256 static __meminit void unmap_low_page(void *adr)
257 {
258         if (after_bootmem)
259                 return;
260
261         early_iounmap(adr, PAGE_SIZE);
262 }
263
264 /* Must run before zap_low_mappings */
265 __meminit void *early_ioremap(unsigned long addr, unsigned long size)
266 {
267         pmd_t *pmd, *last_pmd;
268         unsigned long vaddr;
269         int i, pmds;
270
271         pmds = ((addr & ~PMD_MASK) + size + ~PMD_MASK) / PMD_SIZE;
272         vaddr = __START_KERNEL_map;
273         pmd = level2_kernel_pgt;
274         last_pmd = level2_kernel_pgt + PTRS_PER_PMD - 1;
275
276         for (; pmd <= last_pmd; pmd++, vaddr += PMD_SIZE) {
277                 for (i = 0; i < pmds; i++) {
278                         if (pmd_present(pmd[i]))
279                                 goto continue_outer_loop;
280                 }
281                 vaddr += addr & ~PMD_MASK;
282                 addr &= PMD_MASK;
283
284                 for (i = 0; i < pmds; i++, addr += PMD_SIZE)
285                         set_pmd(pmd+i, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC));
286                 __flush_tlb_all();
287
288                 return (void *)vaddr;
289 continue_outer_loop:
290                 ;
291         }
292         printk(KERN_ERR "early_ioremap(0x%lx, %lu) failed\n", addr, size);
293
294         return NULL;
295 }
296
297 /*
298  * To avoid virtual aliases later:
299  */
300 __meminit void early_iounmap(void *addr, unsigned long size)
301 {
302         unsigned long vaddr;
303         pmd_t *pmd;
304         int i, pmds;
305
306         vaddr = (unsigned long)addr;
307         pmds = ((vaddr & ~PMD_MASK) + size + ~PMD_MASK) / PMD_SIZE;
308         pmd = level2_kernel_pgt + pmd_index(vaddr);
309
310         for (i = 0; i < pmds; i++)
311                 pmd_clear(pmd + i);
312
313         __flush_tlb_all();
314 }
315
316 static void __meminit
317 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end)
318 {
319         int i = pmd_index(address);
320
321         for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
322                 pmd_t *pmd = pmd_page + pmd_index(address);
323
324                 if (address >= end) {
325                         if (!after_bootmem) {
326                                 for (; i < PTRS_PER_PMD; i++, pmd++)
327                                         set_pmd(pmd, __pmd(0));
328                         }
329                         break;
330                 }
331
332                 if (pmd_val(*pmd))
333                         continue;
334
335                 set_pte((pte_t *)pmd,
336                         pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
337         }
338 }
339
340 static void __meminit
341 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end)
342 {
343         pmd_t *pmd = pmd_offset(pud, 0);
344         spin_lock(&init_mm.page_table_lock);
345         phys_pmd_init(pmd, address, end);
346         spin_unlock(&init_mm.page_table_lock);
347         __flush_tlb_all();
348 }
349
350 static void __meminit
351 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end)
352 {
353         int i = pud_index(addr);
354
355         for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
356                 unsigned long pmd_phys;
357                 pud_t *pud = pud_page + pud_index(addr);
358                 pmd_t *pmd;
359
360                 if (addr >= end)
361                         break;
362
363                 if (!after_bootmem &&
364                                 !e820_any_mapped(addr, addr+PUD_SIZE, 0)) {
365                         set_pud(pud, __pud(0));
366                         continue;
367                 }
368
369                 if (pud_val(*pud)) {
370                         if (!pud_large(*pud))
371                                 phys_pmd_update(pud, addr, end);
372                         continue;
373                 }
374
375                 if (direct_gbpages) {
376                         set_pte((pte_t *)pud,
377                                 pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
378                         continue;
379                 }
380
381                 pmd = alloc_low_page(&pmd_phys);
382
383                 spin_lock(&init_mm.page_table_lock);
384                 set_pud(pud, __pud(pmd_phys | _KERNPG_TABLE));
385                 phys_pmd_init(pmd, addr, end);
386                 spin_unlock(&init_mm.page_table_lock);
387
388                 unmap_low_page(pmd);
389         }
390         __flush_tlb_all();
391 }
392
393 static void __init find_early_table_space(unsigned long end)
394 {
395         unsigned long puds, pmds, tables, start;
396
397         puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
398         tables = round_up(puds * sizeof(pud_t), PAGE_SIZE);
399         if (!direct_gbpages) {
400                 pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
401                 tables += round_up(pmds * sizeof(pmd_t), PAGE_SIZE);
402         }
403
404         /*
405          * RED-PEN putting page tables only on node 0 could
406          * cause a hotspot and fill up ZONE_DMA. The page tables
407          * need roughly 0.5KB per GB.
408          */
409         start = 0x8000;
410         table_start = find_e820_area(start, end, tables, PAGE_SIZE);
411         if (table_start == -1UL)
412                 panic("Cannot find space for the kernel page tables");
413
414         table_start >>= PAGE_SHIFT;
415         table_end = table_start;
416
417         early_printk("kernel direct mapping tables up to %lx @ %lx-%lx\n",
418                 end, table_start << PAGE_SHIFT,
419                 (table_start << PAGE_SHIFT) + tables);
420 }
421
422 static void __init init_gbpages(void)
423 {
424         if (direct_gbpages && cpu_has_gbpages)
425                 printk(KERN_INFO "Using GB pages for direct mapping\n");
426         else
427                 direct_gbpages = 0;
428 }
429
430 #ifdef CONFIG_MEMTEST_BOOTPARAM
431
432 static void __init memtest(unsigned long start_phys, unsigned long size,
433                                  unsigned pattern)
434 {
435         unsigned long i;
436         unsigned long *start;
437         unsigned long start_bad;
438         unsigned long last_bad;
439         unsigned long val;
440         unsigned long start_phys_aligned;
441         unsigned long count;
442         unsigned long incr;
443
444         switch (pattern) {
445         case 0:
446                 val = 0UL;
447                 break;
448         case 1:
449                 val = -1UL;
450                 break;
451         case 2:
452                 val = 0x5555555555555555UL;
453                 break;
454         case 3:
455                 val = 0xaaaaaaaaaaaaaaaaUL;
456                 break;
457         default:
458                 return;
459         }
460
461         incr = sizeof(unsigned long);
462         start_phys_aligned = ALIGN(start_phys, incr);
463         count = (size - (start_phys_aligned - start_phys))/incr;
464         start = __va(start_phys_aligned);
465         start_bad = 0;
466         last_bad = 0;
467
468         for (i = 0; i < count; i++)
469                 start[i] = val;
470         for (i = 0; i < count; i++, start++, start_phys_aligned += incr) {
471                 if (*start != val) {
472                         if (start_phys_aligned == last_bad + incr) {
473                                 last_bad += incr;
474                         } else {
475                                 if (start_bad) {
476                                         printk(KERN_INFO "  %016lxx bad mem addr %016lx - %016lx reserved\n",
477                                                 val, start_bad, last_bad + incr);
478                                         reserve_early(start_bad, last_bad - start_bad, "BAD RAM");
479                                 }
480                                 start_bad = last_bad = start_phys_aligned;
481                         }
482                 }
483         }
484         if (start_bad) {
485                 printk(KERN_INFO "  %016lx bad mem addr %016lx - %016lx reserved\n",
486                         val, start_bad, last_bad + incr);
487                 reserve_early(start_bad, last_bad - start_bad, "BAD RAM");
488         }
489
490 }
491
492 static int memtest_pattern __initdata = CONFIG_MEMTEST_BOOTPARAM_VALUE;
493
494 static int __init parse_memtest(char *arg)
495 {
496         if (arg)
497                 memtest_pattern = simple_strtoul(arg, NULL, 0);
498         return 0;
499 }
500
501 early_param("memtest", parse_memtest);
502
503 static void __init early_memtest(unsigned long start, unsigned long end)
504 {
505         unsigned long t_start, t_size;
506         unsigned pattern;
507
508         if (!memtest_pattern)
509                 return;
510
511         printk(KERN_INFO "early_memtest: pattern num %d", memtest_pattern);
512         for (pattern = 0; pattern < memtest_pattern; pattern++) {
513                 t_start = start;
514                 t_size = 0;
515                 while (t_start < end) {
516                         t_start = find_e820_area_size(t_start, &t_size, 1);
517
518                         /* done ? */
519                         if (t_start >= end)
520                                 break;
521                         if (t_start + t_size > end)
522                                 t_size = end - t_start;
523
524                         printk(KERN_CONT "\n  %016lx - %016lx pattern %d",
525                                 t_start, t_start + t_size, pattern);
526
527                         memtest(t_start, t_size, pattern);
528
529                         t_start += t_size;
530                 }
531         }
532         printk(KERN_CONT "\n");
533 }
534 #else
535 static void __init early_memtest(unsigned long start, unsigned long end)
536 {
537 }
538 #endif
539
540 /*
541  * Setup the direct mapping of the physical memory at PAGE_OFFSET.
542  * This runs before bootmem is initialized and gets pages directly from
543  * the physical memory. To access them they are temporarily mapped.
544  */
545 void __init_refok init_memory_mapping(unsigned long start, unsigned long end)
546 {
547         unsigned long next;
548         unsigned long start_phys = start, end_phys = end;
549
550         printk(KERN_INFO "init_memory_mapping\n");
551
552         /*
553          * Find space for the kernel direct mapping tables.
554          *
555          * Later we should allocate these tables in the local node of the
556          * memory mapped. Unfortunately this is done currently before the
557          * nodes are discovered.
558          */
559         if (!after_bootmem) {
560                 init_gbpages();
561                 find_early_table_space(end);
562         }
563
564         start = (unsigned long)__va(start);
565         end = (unsigned long)__va(end);
566
567         for (; start < end; start = next) {
568                 pgd_t *pgd = pgd_offset_k(start);
569                 unsigned long pud_phys;
570                 pud_t *pud;
571
572                 if (after_bootmem)
573                         pud = pud_offset(pgd, start & PGDIR_MASK);
574                 else
575                         pud = alloc_low_page(&pud_phys);
576
577                 next = start + PGDIR_SIZE;
578                 if (next > end)
579                         next = end;
580                 phys_pud_init(pud, __pa(start), __pa(next));
581                 if (!after_bootmem)
582                         set_pgd(pgd_offset_k(start), mk_kernel_pgd(pud_phys));
583                 unmap_low_page(pud);
584         }
585
586         if (!after_bootmem)
587                 mmu_cr4_features = read_cr4();
588         __flush_tlb_all();
589
590         if (!after_bootmem)
591                 reserve_early(table_start << PAGE_SHIFT,
592                                  table_end << PAGE_SHIFT, "PGTABLE");
593
594         if (!after_bootmem)
595                 early_memtest(start_phys, end_phys);
596 }
597
598 #ifndef CONFIG_NUMA
599 void __init paging_init(void)
600 {
601         unsigned long max_zone_pfns[MAX_NR_ZONES];
602
603         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
604         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
605         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
606         max_zone_pfns[ZONE_NORMAL] = end_pfn;
607
608         memory_present(0, 0, end_pfn);
609         sparse_init();
610         free_area_init_nodes(max_zone_pfns);
611 }
612 #endif
613
614 /*
615  * Memory hotplug specific functions
616  */
617 void online_page(struct page *page)
618 {
619         ClearPageReserved(page);
620         init_page_count(page);
621         __free_page(page);
622         totalram_pages++;
623         num_physpages++;
624 }
625
626 #ifdef CONFIG_MEMORY_HOTPLUG
627 /*
628  * Memory is added always to NORMAL zone. This means you will never get
629  * additional DMA/DMA32 memory.
630  */
631 int arch_add_memory(int nid, u64 start, u64 size)
632 {
633         struct pglist_data *pgdat = NODE_DATA(nid);
634         struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
635         unsigned long start_pfn = start >> PAGE_SHIFT;
636         unsigned long nr_pages = size >> PAGE_SHIFT;
637         int ret;
638
639         init_memory_mapping(start, start + size-1);
640
641         ret = __add_pages(zone, start_pfn, nr_pages);
642         WARN_ON(1);
643
644         return ret;
645 }
646 EXPORT_SYMBOL_GPL(arch_add_memory);
647
648 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
649 int memory_add_physaddr_to_nid(u64 start)
650 {
651         return 0;
652 }
653 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
654 #endif
655
656 #endif /* CONFIG_MEMORY_HOTPLUG */
657
658 static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel,
659                          kcore_modules, kcore_vsyscall;
660
661 void __init mem_init(void)
662 {
663         long codesize, reservedpages, datasize, initsize;
664
665         pci_iommu_alloc();
666
667         /* clear_bss() already clear the empty_zero_page */
668
669         reservedpages = 0;
670
671         /* this will put all low memory onto the freelists */
672 #ifdef CONFIG_NUMA
673         totalram_pages = numa_free_all_bootmem();
674 #else
675         totalram_pages = free_all_bootmem();
676 #endif
677         reservedpages = end_pfn - totalram_pages -
678                                         absent_pages_in_range(0, end_pfn);
679         after_bootmem = 1;
680
681         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
682         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
683         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
684
685         /* Register memory areas for /proc/kcore */
686         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
687         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
688                    VMALLOC_END-VMALLOC_START);
689         kclist_add(&kcore_kernel, &_stext, _end - _stext);
690         kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN);
691         kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
692                                  VSYSCALL_END - VSYSCALL_START);
693
694         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
695                                 "%ldk reserved, %ldk data, %ldk init)\n",
696                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
697                 end_pfn << (PAGE_SHIFT-10),
698                 codesize >> 10,
699                 reservedpages << (PAGE_SHIFT-10),
700                 datasize >> 10,
701                 initsize >> 10);
702
703         cpa_init();
704 }
705
706 void free_init_pages(char *what, unsigned long begin, unsigned long end)
707 {
708         unsigned long addr = begin;
709
710         if (addr >= end)
711                 return;
712
713         /*
714          * If debugging page accesses then do not free this memory but
715          * mark them not present - any buggy init-section access will
716          * create a kernel page fault:
717          */
718 #ifdef CONFIG_DEBUG_PAGEALLOC
719         printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
720                 begin, PAGE_ALIGN(end));
721         set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
722 #else
723         printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
724
725         for (; addr < end; addr += PAGE_SIZE) {
726                 ClearPageReserved(virt_to_page(addr));
727                 init_page_count(virt_to_page(addr));
728                 memset((void *)(addr & ~(PAGE_SIZE-1)),
729                         POISON_FREE_INITMEM, PAGE_SIZE);
730                 free_page(addr);
731                 totalram_pages++;
732         }
733 #endif
734 }
735
736 void free_initmem(void)
737 {
738         free_init_pages("unused kernel memory",
739                         (unsigned long)(&__init_begin),
740                         (unsigned long)(&__init_end));
741 }
742
743 #ifdef CONFIG_DEBUG_RODATA
744 const int rodata_test_data = 0xC3;
745 EXPORT_SYMBOL_GPL(rodata_test_data);
746
747 void mark_rodata_ro(void)
748 {
749         unsigned long start = PFN_ALIGN(_stext), end = PFN_ALIGN(__end_rodata);
750
751         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
752                (end - start) >> 10);
753         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
754
755         /*
756          * The rodata section (but not the kernel text!) should also be
757          * not-executable.
758          */
759         start = ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
760         set_memory_nx(start, (end - start) >> PAGE_SHIFT);
761
762         rodata_test();
763
764 #ifdef CONFIG_CPA_DEBUG
765         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
766         set_memory_rw(start, (end-start) >> PAGE_SHIFT);
767
768         printk(KERN_INFO "Testing CPA: again\n");
769         set_memory_ro(start, (end-start) >> PAGE_SHIFT);
770 #endif
771 }
772
773 #endif
774
775 #ifdef CONFIG_BLK_DEV_INITRD
776 void free_initrd_mem(unsigned long start, unsigned long end)
777 {
778         free_init_pages("initrd memory", start, end);
779 }
780 #endif
781
782 void __init reserve_bootmem_generic(unsigned long phys, unsigned len)
783 {
784 #ifdef CONFIG_NUMA
785         int nid = phys_to_nid(phys);
786 #endif
787         unsigned long pfn = phys >> PAGE_SHIFT;
788
789         if (pfn >= end_pfn) {
790                 /*
791                  * This can happen with kdump kernels when accessing
792                  * firmware tables:
793                  */
794                 if (pfn < end_pfn_map)
795                         return;
796
797                 printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %u\n",
798                                 phys, len);
799                 return;
800         }
801
802         /* Should check here against the e820 map to avoid double free */
803 #ifdef CONFIG_NUMA
804         reserve_bootmem_node(NODE_DATA(nid), phys, len, BOOTMEM_DEFAULT);
805 #else
806         reserve_bootmem(phys, len, BOOTMEM_DEFAULT);
807 #endif
808         if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
809                 dma_reserve += len / PAGE_SIZE;
810                 set_dma_reserve(dma_reserve);
811         }
812 }
813
814 int kern_addr_valid(unsigned long addr)
815 {
816         unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
817         pgd_t *pgd;
818         pud_t *pud;
819         pmd_t *pmd;
820         pte_t *pte;
821
822         if (above != 0 && above != -1UL)
823                 return 0;
824
825         pgd = pgd_offset_k(addr);
826         if (pgd_none(*pgd))
827                 return 0;
828
829         pud = pud_offset(pgd, addr);
830         if (pud_none(*pud))
831                 return 0;
832
833         pmd = pmd_offset(pud, addr);
834         if (pmd_none(*pmd))
835                 return 0;
836
837         if (pmd_large(*pmd))
838                 return pfn_valid(pmd_pfn(*pmd));
839
840         pte = pte_offset_kernel(pmd, addr);
841         if (pte_none(*pte))
842                 return 0;
843
844         return pfn_valid(pte_pfn(*pte));
845 }
846
847 /*
848  * A pseudo VMA to allow ptrace access for the vsyscall page.  This only
849  * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
850  * not need special handling anymore:
851  */
852 static struct vm_area_struct gate_vma = {
853         .vm_start       = VSYSCALL_START,
854         .vm_end         = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
855         .vm_page_prot   = PAGE_READONLY_EXEC,
856         .vm_flags       = VM_READ | VM_EXEC
857 };
858
859 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
860 {
861 #ifdef CONFIG_IA32_EMULATION
862         if (test_tsk_thread_flag(tsk, TIF_IA32))
863                 return NULL;
864 #endif
865         return &gate_vma;
866 }
867
868 int in_gate_area(struct task_struct *task, unsigned long addr)
869 {
870         struct vm_area_struct *vma = get_gate_vma(task);
871
872         if (!vma)
873                 return 0;
874
875         return (addr >= vma->vm_start) && (addr < vma->vm_end);
876 }
877
878 /*
879  * Use this when you have no reliable task/vma, typically from interrupt
880  * context. It is less reliable than using the task's vma and may give
881  * false positives:
882  */
883 int in_gate_area_no_task(unsigned long addr)
884 {
885         return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
886 }
887
888 const char *arch_vma_name(struct vm_area_struct *vma)
889 {
890         if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
891                 return "[vdso]";
892         if (vma == &gate_vma)
893                 return "[vsyscall]";
894         return NULL;
895 }
896
897 #ifdef CONFIG_SPARSEMEM_VMEMMAP
898 /*
899  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
900  */
901 int __meminit
902 vmemmap_populate(struct page *start_page, unsigned long size, int node)
903 {
904         unsigned long addr = (unsigned long)start_page;
905         unsigned long end = (unsigned long)(start_page + size);
906         unsigned long next;
907         pgd_t *pgd;
908         pud_t *pud;
909         pmd_t *pmd;
910
911         for (; addr < end; addr = next) {
912                 next = pmd_addr_end(addr, end);
913
914                 pgd = vmemmap_pgd_populate(addr, node);
915                 if (!pgd)
916                         return -ENOMEM;
917
918                 pud = vmemmap_pud_populate(pgd, addr, node);
919                 if (!pud)
920                         return -ENOMEM;
921
922                 pmd = pmd_offset(pud, addr);
923                 if (pmd_none(*pmd)) {
924                         pte_t entry;
925                         void *p;
926
927                         p = vmemmap_alloc_block(PMD_SIZE, node);
928                         if (!p)
929                                 return -ENOMEM;
930
931                         entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
932                                                         PAGE_KERNEL_LARGE);
933                         set_pmd(pmd, __pmd(pte_val(entry)));
934
935                         printk(KERN_DEBUG " [%lx-%lx] PMD ->%p on node %d\n",
936                                 addr, addr + PMD_SIZE - 1, p, node);
937                 } else {
938                         vmemmap_verify((pte_t *)pmd, node, addr, next);
939                 }
940         }
941         return 0;
942 }
943 #endif