x86: introduce page pool in cpa
[linux-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
49 const struct dma_mapping_ops *dma_ops;
50 EXPORT_SYMBOL(dma_ops);
51
52 static unsigned long dma_reserve __initdata;
53
54 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
55
56 /*
57  * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
58  * physical space so we can cache the place of the first one and move
59  * around without checking the pgd every time.
60  */
61
62 void show_mem(void)
63 {
64         long i, total = 0, reserved = 0;
65         long shared = 0, cached = 0;
66         struct page *page;
67         pg_data_t *pgdat;
68
69         printk(KERN_INFO "Mem-info:\n");
70         show_free_areas();
71         printk(KERN_INFO "Free swap:       %6ldkB\n",
72                 nr_swap_pages << (PAGE_SHIFT-10));
73
74         for_each_online_pgdat(pgdat) {
75                 for (i = 0; i < pgdat->node_spanned_pages; ++i) {
76                         /*
77                          * This loop can take a while with 256 GB and
78                          * 4k pages so defer the NMI watchdog:
79                          */
80                         if (unlikely(i % MAX_ORDER_NR_PAGES == 0))
81                                 touch_nmi_watchdog();
82
83                         if (!pfn_valid(pgdat->node_start_pfn + i))
84                                 continue;
85
86                         page = pfn_to_page(pgdat->node_start_pfn + i);
87                         total++;
88                         if (PageReserved(page))
89                                 reserved++;
90                         else if (PageSwapCache(page))
91                                 cached++;
92                         else if (page_count(page))
93                                 shared += page_count(page) - 1;
94                 }
95         }
96         printk(KERN_INFO "%lu pages of RAM\n",          total);
97         printk(KERN_INFO "%lu reserved pages\n",        reserved);
98         printk(KERN_INFO "%lu pages shared\n",          shared);
99         printk(KERN_INFO "%lu pages swap cached\n",     cached);
100 }
101
102 int after_bootmem;
103
104 static __init void *spp_getpage(void)
105 {
106         void *ptr;
107
108         if (after_bootmem)
109                 ptr = (void *) get_zeroed_page(GFP_ATOMIC);
110         else
111                 ptr = alloc_bootmem_pages(PAGE_SIZE);
112
113         if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
114                 panic("set_pte_phys: cannot allocate page data %s\n",
115                         after_bootmem ? "after bootmem" : "");
116         }
117
118         pr_debug("spp_getpage %p\n", ptr);
119
120         return ptr;
121 }
122
123 static __init void
124 set_pte_phys(unsigned long vaddr, unsigned long phys, pgprot_t prot)
125 {
126         pgd_t *pgd;
127         pud_t *pud;
128         pmd_t *pmd;
129         pte_t *pte, new_pte;
130
131         pr_debug("set_pte_phys %lx to %lx\n", vaddr, phys);
132
133         pgd = pgd_offset_k(vaddr);
134         if (pgd_none(*pgd)) {
135                 printk(KERN_ERR
136                         "PGD FIXMAP MISSING, it should be setup in head.S!\n");
137                 return;
138         }
139         pud = pud_offset(pgd, vaddr);
140         if (pud_none(*pud)) {
141                 pmd = (pmd_t *) spp_getpage();
142                 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | _PAGE_USER));
143                 if (pmd != pmd_offset(pud, 0)) {
144                         printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
145                                 pmd, pmd_offset(pud, 0));
146                         return;
147                 }
148         }
149         pmd = pmd_offset(pud, vaddr);
150         if (pmd_none(*pmd)) {
151                 pte = (pte_t *) spp_getpage();
152                 set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE | _PAGE_USER));
153                 if (pte != pte_offset_kernel(pmd, 0)) {
154                         printk(KERN_ERR "PAGETABLE BUG #02!\n");
155                         return;
156                 }
157         }
158         new_pte = pfn_pte(phys >> PAGE_SHIFT, prot);
159
160         pte = pte_offset_kernel(pmd, vaddr);
161         if (!pte_none(*pte) &&
162             pte_val(*pte) != (pte_val(new_pte) & __supported_pte_mask))
163                 pte_ERROR(*pte);
164         set_pte(pte, new_pte);
165
166         /*
167          * It's enough to flush this one mapping.
168          * (PGE mappings get flushed as well)
169          */
170         __flush_tlb_one(vaddr);
171 }
172
173 /* NOTE: this is meant to be run only at boot */
174 void __init
175 __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
176 {
177         unsigned long address = __fix_to_virt(idx);
178
179         if (idx >= __end_of_fixed_addresses) {
180                 printk(KERN_ERR "Invalid __set_fixmap\n");
181                 return;
182         }
183         set_pte_phys(address, phys, prot);
184 }
185
186 static unsigned long __initdata table_start;
187 static unsigned long __meminitdata table_end;
188
189 static __meminit void *alloc_low_page(unsigned long *phys)
190 {
191         unsigned long pfn = table_end++;
192         void *adr;
193
194         if (after_bootmem) {
195                 adr = (void *)get_zeroed_page(GFP_ATOMIC);
196                 *phys = __pa(adr);
197
198                 return adr;
199         }
200
201         if (pfn >= end_pfn)
202                 panic("alloc_low_page: ran out of memory");
203
204         adr = early_ioremap(pfn * PAGE_SIZE, PAGE_SIZE);
205         memset(adr, 0, PAGE_SIZE);
206         *phys  = pfn * PAGE_SIZE;
207         return adr;
208 }
209
210 static __meminit void unmap_low_page(void *adr)
211 {
212         if (after_bootmem)
213                 return;
214
215         early_iounmap(adr, PAGE_SIZE);
216 }
217
218 /* Must run before zap_low_mappings */
219 __meminit void *early_ioremap(unsigned long addr, unsigned long size)
220 {
221         pmd_t *pmd, *last_pmd;
222         unsigned long vaddr;
223         int i, pmds;
224
225         pmds = ((addr & ~PMD_MASK) + size + ~PMD_MASK) / PMD_SIZE;
226         vaddr = __START_KERNEL_map;
227         pmd = level2_kernel_pgt;
228         last_pmd = level2_kernel_pgt + PTRS_PER_PMD - 1;
229
230         for (; pmd <= last_pmd; pmd++, vaddr += PMD_SIZE) {
231                 for (i = 0; i < pmds; i++) {
232                         if (pmd_present(pmd[i]))
233                                 goto continue_outer_loop;
234                 }
235                 vaddr += addr & ~PMD_MASK;
236                 addr &= PMD_MASK;
237
238                 for (i = 0; i < pmds; i++, addr += PMD_SIZE)
239                         set_pmd(pmd+i, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC));
240                 __flush_tlb_all();
241
242                 return (void *)vaddr;
243 continue_outer_loop:
244                 ;
245         }
246         printk(KERN_ERR "early_ioremap(0x%lx, %lu) failed\n", addr, size);
247
248         return NULL;
249 }
250
251 /*
252  * To avoid virtual aliases later:
253  */
254 __meminit void early_iounmap(void *addr, unsigned long size)
255 {
256         unsigned long vaddr;
257         pmd_t *pmd;
258         int i, pmds;
259
260         vaddr = (unsigned long)addr;
261         pmds = ((vaddr & ~PMD_MASK) + size + ~PMD_MASK) / PMD_SIZE;
262         pmd = level2_kernel_pgt + pmd_index(vaddr);
263
264         for (i = 0; i < pmds; i++)
265                 pmd_clear(pmd + i);
266
267         __flush_tlb_all();
268 }
269
270 static void __meminit
271 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end)
272 {
273         int i = pmd_index(address);
274
275         for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
276                 pmd_t *pmd = pmd_page + pmd_index(address);
277
278                 if (address >= end) {
279                         if (!after_bootmem) {
280                                 for (; i < PTRS_PER_PMD; i++, pmd++)
281                                         set_pmd(pmd, __pmd(0));
282                         }
283                         break;
284                 }
285
286                 if (pmd_val(*pmd))
287                         continue;
288
289                 set_pte((pte_t *)pmd,
290                         pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
291         }
292 }
293
294 static void __meminit
295 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end)
296 {
297         pmd_t *pmd = pmd_offset(pud, 0);
298         spin_lock(&init_mm.page_table_lock);
299         phys_pmd_init(pmd, address, end);
300         spin_unlock(&init_mm.page_table_lock);
301         __flush_tlb_all();
302 }
303
304 static void __meminit
305 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end)
306 {
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                         phys_pmd_update(pud, addr, end);
325                         continue;
326                 }
327
328                 pmd = alloc_low_page(&pmd_phys);
329
330                 spin_lock(&init_mm.page_table_lock);
331                 set_pud(pud, __pud(pmd_phys | _KERNPG_TABLE));
332                 phys_pmd_init(pmd, addr, end);
333                 spin_unlock(&init_mm.page_table_lock);
334
335                 unmap_low_page(pmd);
336         }
337         __flush_tlb_all();
338 }
339
340 static void __init find_early_table_space(unsigned long end)
341 {
342         unsigned long puds, pmds, tables, start;
343
344         puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
345         pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
346         tables = round_up(puds * sizeof(pud_t), PAGE_SIZE) +
347                  round_up(pmds * sizeof(pmd_t), PAGE_SIZE);
348
349         /*
350          * RED-PEN putting page tables only on node 0 could
351          * cause a hotspot and fill up ZONE_DMA. The page tables
352          * need roughly 0.5KB per GB.
353          */
354         start = 0x8000;
355         table_start = find_e820_area(start, end, tables, PAGE_SIZE);
356         if (table_start == -1UL)
357                 panic("Cannot find space for the kernel page tables");
358
359         table_start >>= PAGE_SHIFT;
360         table_end = table_start;
361
362         early_printk("kernel direct mapping tables up to %lx @ %lx-%lx\n",
363                 end, table_start << PAGE_SHIFT,
364                 (table_start << PAGE_SHIFT) + tables);
365 }
366
367 /*
368  * Setup the direct mapping of the physical memory at PAGE_OFFSET.
369  * This runs before bootmem is initialized and gets pages directly from
370  * the physical memory. To access them they are temporarily mapped.
371  */
372 void __init_refok init_memory_mapping(unsigned long start, unsigned long end)
373 {
374         unsigned long next;
375
376         pr_debug("init_memory_mapping\n");
377
378         /*
379          * Find space for the kernel direct mapping tables.
380          *
381          * Later we should allocate these tables in the local node of the
382          * memory mapped. Unfortunately this is done currently before the
383          * nodes are discovered.
384          */
385         if (!after_bootmem)
386                 find_early_table_space(end);
387
388         start = (unsigned long)__va(start);
389         end = (unsigned long)__va(end);
390
391         for (; start < end; start = next) {
392                 pgd_t *pgd = pgd_offset_k(start);
393                 unsigned long pud_phys;
394                 pud_t *pud;
395
396                 if (after_bootmem)
397                         pud = pud_offset(pgd, start & PGDIR_MASK);
398                 else
399                         pud = alloc_low_page(&pud_phys);
400
401                 next = start + PGDIR_SIZE;
402                 if (next > end)
403                         next = end;
404                 phys_pud_init(pud, __pa(start), __pa(next));
405                 if (!after_bootmem)
406                         set_pgd(pgd_offset_k(start), mk_kernel_pgd(pud_phys));
407                 unmap_low_page(pud);
408         }
409
410         if (!after_bootmem)
411                 mmu_cr4_features = read_cr4();
412         __flush_tlb_all();
413
414         if (!after_bootmem)
415                 reserve_early(table_start << PAGE_SHIFT,
416                                  table_end << PAGE_SHIFT, "PGTABLE");
417 }
418
419 #ifndef CONFIG_NUMA
420 void __init paging_init(void)
421 {
422         unsigned long max_zone_pfns[MAX_NR_ZONES];
423
424         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
425         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
426         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
427         max_zone_pfns[ZONE_NORMAL] = end_pfn;
428
429         memory_present(0, 0, end_pfn);
430         sparse_init();
431         free_area_init_nodes(max_zone_pfns);
432 }
433 #endif
434
435 /*
436  * Memory hotplug specific functions
437  */
438 void online_page(struct page *page)
439 {
440         ClearPageReserved(page);
441         init_page_count(page);
442         __free_page(page);
443         totalram_pages++;
444         num_physpages++;
445 }
446
447 #ifdef CONFIG_MEMORY_HOTPLUG
448 /*
449  * Memory is added always to NORMAL zone. This means you will never get
450  * additional DMA/DMA32 memory.
451  */
452 int arch_add_memory(int nid, u64 start, u64 size)
453 {
454         struct pglist_data *pgdat = NODE_DATA(nid);
455         struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
456         unsigned long start_pfn = start >> PAGE_SHIFT;
457         unsigned long nr_pages = size >> PAGE_SHIFT;
458         int ret;
459
460         init_memory_mapping(start, start + size-1);
461
462         ret = __add_pages(zone, start_pfn, nr_pages);
463         WARN_ON(1);
464
465         return ret;
466 }
467 EXPORT_SYMBOL_GPL(arch_add_memory);
468
469 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
470 int memory_add_physaddr_to_nid(u64 start)
471 {
472         return 0;
473 }
474 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
475 #endif
476
477 #endif /* CONFIG_MEMORY_HOTPLUG */
478
479 static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel,
480                          kcore_modules, kcore_vsyscall;
481
482 void __init mem_init(void)
483 {
484         long codesize, reservedpages, datasize, initsize;
485
486         pci_iommu_alloc();
487
488         /* clear_bss() already clear the empty_zero_page */
489
490         /* temporary debugging - double check it's true: */
491         {
492                 int i;
493
494                 for (i = 0; i < 1024; i++)
495                         WARN_ON_ONCE(empty_zero_page[i]);
496         }
497
498         reservedpages = 0;
499
500         /* this will put all low memory onto the freelists */
501 #ifdef CONFIG_NUMA
502         totalram_pages = numa_free_all_bootmem();
503 #else
504         totalram_pages = free_all_bootmem();
505 #endif
506         reservedpages = end_pfn - totalram_pages -
507                                         absent_pages_in_range(0, end_pfn);
508         after_bootmem = 1;
509
510         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
511         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
512         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
513
514         /* Register memory areas for /proc/kcore */
515         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
516         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
517                    VMALLOC_END-VMALLOC_START);
518         kclist_add(&kcore_kernel, &_stext, _end - _stext);
519         kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN);
520         kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
521                                  VSYSCALL_END - VSYSCALL_START);
522
523         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
524                                 "%ldk reserved, %ldk data, %ldk init)\n",
525                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
526                 end_pfn << (PAGE_SHIFT-10),
527                 codesize >> 10,
528                 reservedpages << (PAGE_SHIFT-10),
529                 datasize >> 10,
530                 initsize >> 10);
531
532         cpa_init();
533 }
534
535 void free_init_pages(char *what, unsigned long begin, unsigned long end)
536 {
537         unsigned long addr = begin;
538
539         if (addr >= end)
540                 return;
541
542         /*
543          * If debugging page accesses then do not free this memory but
544          * mark them not present - any buggy init-section access will
545          * create a kernel page fault:
546          */
547 #ifdef CONFIG_DEBUG_PAGEALLOC
548         printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
549                 begin, PAGE_ALIGN(end));
550         set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
551 #else
552         printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
553
554         for (; addr < end; addr += PAGE_SIZE) {
555                 ClearPageReserved(virt_to_page(addr));
556                 init_page_count(virt_to_page(addr));
557                 memset((void *)(addr & ~(PAGE_SIZE-1)),
558                         POISON_FREE_INITMEM, PAGE_SIZE);
559                 free_page(addr);
560                 totalram_pages++;
561         }
562 #endif
563 }
564
565 void free_initmem(void)
566 {
567         free_init_pages("unused kernel memory",
568                         (unsigned long)(&__init_begin),
569                         (unsigned long)(&__init_end));
570 }
571
572 #ifdef CONFIG_DEBUG_RODATA
573 const int rodata_test_data = 0xC3;
574 EXPORT_SYMBOL_GPL(rodata_test_data);
575
576 void mark_rodata_ro(void)
577 {
578         unsigned long start = (unsigned long)_stext, end;
579
580 #ifdef CONFIG_HOTPLUG_CPU
581         /* It must still be possible to apply SMP alternatives. */
582         if (num_possible_cpus() > 1)
583                 start = (unsigned long)_etext;
584 #endif
585
586 #ifdef CONFIG_KPROBES
587         start = (unsigned long)__start_rodata;
588 #endif
589
590         end = (unsigned long)__end_rodata;
591         start = (start + PAGE_SIZE - 1) & PAGE_MASK;
592         end &= PAGE_MASK;
593         if (end <= start)
594                 return;
595
596
597         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
598                (end - start) >> 10);
599         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
600
601         /*
602          * The rodata section (but not the kernel text!) should also be
603          * not-executable.
604          */
605         start = ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
606         set_memory_nx(start, (end - start) >> PAGE_SHIFT);
607
608         rodata_test();
609
610 #ifdef CONFIG_CPA_DEBUG
611         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
612         set_memory_rw(start, (end-start) >> PAGE_SHIFT);
613
614         printk(KERN_INFO "Testing CPA: again\n");
615         set_memory_ro(start, (end-start) >> PAGE_SHIFT);
616 #endif
617 }
618 #endif
619
620 #ifdef CONFIG_BLK_DEV_INITRD
621 void free_initrd_mem(unsigned long start, unsigned long end)
622 {
623         free_init_pages("initrd memory", start, end);
624 }
625 #endif
626
627 void __init reserve_bootmem_generic(unsigned long phys, unsigned len)
628 {
629 #ifdef CONFIG_NUMA
630         int nid = phys_to_nid(phys);
631 #endif
632         unsigned long pfn = phys >> PAGE_SHIFT;
633
634         if (pfn >= end_pfn) {
635                 /*
636                  * This can happen with kdump kernels when accessing
637                  * firmware tables:
638                  */
639                 if (pfn < end_pfn_map)
640                         return;
641
642                 printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %u\n",
643                                 phys, len);
644                 return;
645         }
646
647         /* Should check here against the e820 map to avoid double free */
648 #ifdef CONFIG_NUMA
649         reserve_bootmem_node(NODE_DATA(nid), phys, len, BOOTMEM_DEFAULT);
650 #else
651         reserve_bootmem(phys, len, BOOTMEM_DEFAULT);
652 #endif
653         if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
654                 dma_reserve += len / PAGE_SIZE;
655                 set_dma_reserve(dma_reserve);
656         }
657 }
658
659 int kern_addr_valid(unsigned long addr)
660 {
661         unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
662         pgd_t *pgd;
663         pud_t *pud;
664         pmd_t *pmd;
665         pte_t *pte;
666
667         if (above != 0 && above != -1UL)
668                 return 0;
669
670         pgd = pgd_offset_k(addr);
671         if (pgd_none(*pgd))
672                 return 0;
673
674         pud = pud_offset(pgd, addr);
675         if (pud_none(*pud))
676                 return 0;
677
678         pmd = pmd_offset(pud, addr);
679         if (pmd_none(*pmd))
680                 return 0;
681
682         if (pmd_large(*pmd))
683                 return pfn_valid(pmd_pfn(*pmd));
684
685         pte = pte_offset_kernel(pmd, addr);
686         if (pte_none(*pte))
687                 return 0;
688
689         return pfn_valid(pte_pfn(*pte));
690 }
691
692 /*
693  * A pseudo VMA to allow ptrace access for the vsyscall page.  This only
694  * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
695  * not need special handling anymore:
696  */
697 static struct vm_area_struct gate_vma = {
698         .vm_start       = VSYSCALL_START,
699         .vm_end         = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
700         .vm_page_prot   = PAGE_READONLY_EXEC,
701         .vm_flags       = VM_READ | VM_EXEC
702 };
703
704 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
705 {
706 #ifdef CONFIG_IA32_EMULATION
707         if (test_tsk_thread_flag(tsk, TIF_IA32))
708                 return NULL;
709 #endif
710         return &gate_vma;
711 }
712
713 int in_gate_area(struct task_struct *task, unsigned long addr)
714 {
715         struct vm_area_struct *vma = get_gate_vma(task);
716
717         if (!vma)
718                 return 0;
719
720         return (addr >= vma->vm_start) && (addr < vma->vm_end);
721 }
722
723 /*
724  * Use this when you have no reliable task/vma, typically from interrupt
725  * context. It is less reliable than using the task's vma and may give
726  * false positives:
727  */
728 int in_gate_area_no_task(unsigned long addr)
729 {
730         return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
731 }
732
733 const char *arch_vma_name(struct vm_area_struct *vma)
734 {
735         if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
736                 return "[vdso]";
737         if (vma == &gate_vma)
738                 return "[vsyscall]";
739         return NULL;
740 }
741
742 #ifdef CONFIG_SPARSEMEM_VMEMMAP
743 /*
744  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
745  */
746 int __meminit
747 vmemmap_populate(struct page *start_page, unsigned long size, int node)
748 {
749         unsigned long addr = (unsigned long)start_page;
750         unsigned long end = (unsigned long)(start_page + size);
751         unsigned long next;
752         pgd_t *pgd;
753         pud_t *pud;
754         pmd_t *pmd;
755
756         for (; addr < end; addr = next) {
757                 next = pmd_addr_end(addr, end);
758
759                 pgd = vmemmap_pgd_populate(addr, node);
760                 if (!pgd)
761                         return -ENOMEM;
762
763                 pud = vmemmap_pud_populate(pgd, addr, node);
764                 if (!pud)
765                         return -ENOMEM;
766
767                 pmd = pmd_offset(pud, addr);
768                 if (pmd_none(*pmd)) {
769                         pte_t entry;
770                         void *p;
771
772                         p = vmemmap_alloc_block(PMD_SIZE, node);
773                         if (!p)
774                                 return -ENOMEM;
775
776                         entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
777                                                         PAGE_KERNEL_LARGE);
778                         set_pmd(pmd, __pmd(pte_val(entry)));
779
780                         printk(KERN_DEBUG " [%lx-%lx] PMD ->%p on node %d\n",
781                                 addr, addr + PMD_SIZE - 1, p, node);
782                 } else {
783                         vmemmap_verify((pte_t *)pmd, node, addr, next);
784                 }
785         }
786         return 0;
787 }
788 #endif