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x86: unify ioremap
[deliverable/linux.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 #ifndef Dprintk
50 # define Dprintk(x...)
51 #endif
52
53 const struct dma_mapping_ops *dma_ops;
54 EXPORT_SYMBOL(dma_ops);
55
56 static unsigned long dma_reserve __initdata;
57
58 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
59
60 /*
61 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
62 * physical space so we can cache the place of the first one and move
63 * around without checking the pgd every time.
64 */
65
66 void show_mem(void)
67 {
68 long i, total = 0, reserved = 0;
69 long shared = 0, cached = 0;
70 struct page *page;
71 pg_data_t *pgdat;
72
73 printk(KERN_INFO "Mem-info:\n");
74 show_free_areas();
75 printk(KERN_INFO "Free swap: %6ldkB\n",
76 nr_swap_pages << (PAGE_SHIFT-10));
77
78 for_each_online_pgdat(pgdat) {
79 for (i = 0; i < pgdat->node_spanned_pages; ++i) {
80 /*
81 * This loop can take a while with 256 GB and
82 * 4k pages so defer the NMI watchdog:
83 */
84 if (unlikely(i % MAX_ORDER_NR_PAGES == 0))
85 touch_nmi_watchdog();
86
87 if (!pfn_valid(pgdat->node_start_pfn + i))
88 continue;
89
90 page = pfn_to_page(pgdat->node_start_pfn + i);
91 total++;
92 if (PageReserved(page))
93 reserved++;
94 else if (PageSwapCache(page))
95 cached++;
96 else if (page_count(page))
97 shared += page_count(page) - 1;
98 }
99 }
100 printk(KERN_INFO "%lu pages of RAM\n", total);
101 printk(KERN_INFO "%lu reserved pages\n", reserved);
102 printk(KERN_INFO "%lu pages shared\n", shared);
103 printk(KERN_INFO "%lu pages swap cached\n", cached);
104 }
105
106 int after_bootmem;
107
108 static __init void *spp_getpage(void)
109 {
110 void *ptr;
111
112 if (after_bootmem)
113 ptr = (void *) get_zeroed_page(GFP_ATOMIC);
114 else
115 ptr = alloc_bootmem_pages(PAGE_SIZE);
116
117 if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
118 panic("set_pte_phys: cannot allocate page data %s\n",
119 after_bootmem ? "after bootmem" : "");
120 }
121
122 Dprintk("spp_getpage %p\n", ptr);
123
124 return ptr;
125 }
126
127 static __init void
128 set_pte_phys(unsigned long vaddr, unsigned long phys, pgprot_t prot)
129 {
130 pgd_t *pgd;
131 pud_t *pud;
132 pmd_t *pmd;
133 pte_t *pte, new_pte;
134
135 Dprintk("set_pte_phys %lx to %lx\n", vaddr, phys);
136
137 pgd = pgd_offset_k(vaddr);
138 if (pgd_none(*pgd)) {
139 printk("PGD FIXMAP MISSING, it should be setup in head.S!\n");
140 return;
141 }
142 pud = pud_offset(pgd, vaddr);
143 if (pud_none(*pud)) {
144 pmd = (pmd_t *) spp_getpage();
145 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | _PAGE_USER));
146 if (pmd != pmd_offset(pud, 0)) {
147 printk("PAGETABLE BUG #01! %p <-> %p\n",
148 pmd, pmd_offset(pud, 0));
149 return;
150 }
151 }
152 pmd = pmd_offset(pud, vaddr);
153 if (pmd_none(*pmd)) {
154 pte = (pte_t *) spp_getpage();
155 set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE | _PAGE_USER));
156 if (pte != pte_offset_kernel(pmd, 0)) {
157 printk("PAGETABLE BUG #02!\n");
158 return;
159 }
160 }
161 new_pte = pfn_pte(phys >> PAGE_SHIFT, prot);
162
163 pte = pte_offset_kernel(pmd, vaddr);
164 if (!pte_none(*pte) &&
165 pte_val(*pte) != (pte_val(new_pte) & __supported_pte_mask))
166 pte_ERROR(*pte);
167 set_pte(pte, new_pte);
168
169 /*
170 * It's enough to flush this one mapping.
171 * (PGE mappings get flushed as well)
172 */
173 __flush_tlb_one(vaddr);
174 }
175
176 /* NOTE: this is meant to be run only at boot */
177 void __init
178 __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
179 {
180 unsigned long address = __fix_to_virt(idx);
181
182 if (idx >= __end_of_fixed_addresses) {
183 printk("Invalid __set_fixmap\n");
184 return;
185 }
186 set_pte_phys(address, phys, prot);
187 }
188
189 static unsigned long __initdata table_start;
190 static unsigned long __meminitdata table_end;
191
192 static __meminit void *alloc_low_page(unsigned long *phys)
193 {
194 unsigned long pfn = table_end++;
195 void *adr;
196
197 if (after_bootmem) {
198 adr = (void *)get_zeroed_page(GFP_ATOMIC);
199 *phys = __pa(adr);
200
201 return adr;
202 }
203
204 if (pfn >= end_pfn)
205 panic("alloc_low_page: ran out of memory");
206
207 adr = early_ioremap(pfn * PAGE_SIZE, PAGE_SIZE);
208 memset(adr, 0, PAGE_SIZE);
209 *phys = pfn * PAGE_SIZE;
210 return adr;
211 }
212
213 static __meminit void unmap_low_page(void *adr)
214 {
215 if (after_bootmem)
216 return;
217
218 early_iounmap(adr, PAGE_SIZE);
219 }
220
221 /* Must run before zap_low_mappings */
222 __meminit void *early_ioremap(unsigned long addr, unsigned long size)
223 {
224 pmd_t *pmd, *last_pmd;
225 unsigned long vaddr;
226 int i, pmds;
227
228 pmds = ((addr & ~PMD_MASK) + size + ~PMD_MASK) / PMD_SIZE;
229 vaddr = __START_KERNEL_map;
230 pmd = level2_kernel_pgt;
231 last_pmd = level2_kernel_pgt + PTRS_PER_PMD - 1;
232
233 for (; pmd <= last_pmd; pmd++, vaddr += PMD_SIZE) {
234 for (i = 0; i < pmds; i++) {
235 if (pmd_present(pmd[i]))
236 goto continue_outer_loop;
237 }
238 vaddr += addr & ~PMD_MASK;
239 addr &= PMD_MASK;
240
241 for (i = 0; i < pmds; i++, addr += PMD_SIZE)
242 set_pmd(pmd+i, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC));
243 __flush_tlb_all();
244
245 return (void *)vaddr;
246 continue_outer_loop:
247 ;
248 }
249 printk("early_ioremap(0x%lx, %lu) failed\n", addr, size);
250
251 return NULL;
252 }
253
254 /*
255 * To avoid virtual aliases later:
256 */
257 __meminit void early_iounmap(void *addr, unsigned long size)
258 {
259 unsigned long vaddr;
260 pmd_t *pmd;
261 int i, pmds;
262
263 vaddr = (unsigned long)addr;
264 pmds = ((vaddr & ~PMD_MASK) + size + ~PMD_MASK) / PMD_SIZE;
265 pmd = level2_kernel_pgt + pmd_index(vaddr);
266
267 for (i = 0; i < pmds; i++)
268 pmd_clear(pmd + i);
269
270 __flush_tlb_all();
271 }
272
273 static void __meminit
274 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end)
275 {
276 int i = pmd_index(address);
277
278 for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
279 unsigned long entry;
280 pmd_t *pmd = pmd_page + pmd_index(address);
281
282 if (address >= end) {
283 if (!after_bootmem) {
284 for (; i < PTRS_PER_PMD; i++, pmd++)
285 set_pmd(pmd, __pmd(0));
286 }
287 break;
288 }
289
290 if (pmd_val(*pmd))
291 continue;
292
293 entry = __PAGE_KERNEL_LARGE|_PAGE_GLOBAL|address;
294 entry &= __supported_pte_mask;
295 set_pmd(pmd, __pmd(entry));
296 }
297 }
298
299 static void __meminit
300 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end)
301 {
302 pmd_t *pmd = pmd_offset(pud, 0);
303 spin_lock(&init_mm.page_table_lock);
304 phys_pmd_init(pmd, address, end);
305 spin_unlock(&init_mm.page_table_lock);
306 __flush_tlb_all();
307 }
308
309 static void __meminit
310 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end)
311 {
312 int i = pud_index(addr);
313
314 for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
315 unsigned long pmd_phys;
316 pud_t *pud = pud_page + pud_index(addr);
317 pmd_t *pmd;
318
319 if (addr >= end)
320 break;
321
322 if (!after_bootmem &&
323 !e820_any_mapped(addr, addr+PUD_SIZE, 0)) {
324 set_pud(pud, __pud(0));
325 continue;
326 }
327
328 if (pud_val(*pud)) {
329 phys_pmd_update(pud, addr, end);
330 continue;
331 }
332
333 pmd = alloc_low_page(&pmd_phys);
334
335 spin_lock(&init_mm.page_table_lock);
336 set_pud(pud, __pud(pmd_phys | _KERNPG_TABLE));
337 phys_pmd_init(pmd, addr, end);
338 spin_unlock(&init_mm.page_table_lock);
339
340 unmap_low_page(pmd);
341 }
342 __flush_tlb_all();
343 }
344
345 static void __init find_early_table_space(unsigned long end)
346 {
347 unsigned long puds, pmds, tables, start;
348
349 puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
350 pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
351 tables = round_up(puds * sizeof(pud_t), PAGE_SIZE) +
352 round_up(pmds * sizeof(pmd_t), PAGE_SIZE);
353
354 /*
355 * RED-PEN putting page tables only on node 0 could
356 * cause a hotspot and fill up ZONE_DMA. The page tables
357 * need roughly 0.5KB per GB.
358 */
359 start = 0x8000;
360 table_start = find_e820_area(start, end, tables);
361 if (table_start == -1UL)
362 panic("Cannot find space for the kernel page tables");
363
364 table_start >>= PAGE_SHIFT;
365 table_end = table_start;
366
367 early_printk("kernel direct mapping tables up to %lx @ %lx-%lx\n",
368 end, table_start << PAGE_SHIFT,
369 (table_start << PAGE_SHIFT) + tables);
370 }
371
372 /*
373 * Setup the direct mapping of the physical memory at PAGE_OFFSET.
374 * This runs before bootmem is initialized and gets pages directly from
375 * the physical memory. To access them they are temporarily mapped.
376 */
377 void __init_refok init_memory_mapping(unsigned long start, unsigned long end)
378 {
379 unsigned long next;
380
381 Dprintk("init_memory_mapping\n");
382
383 /*
384 * Find space for the kernel direct mapping tables.
385 *
386 * Later we should allocate these tables in the local node of the
387 * memory mapped. Unfortunately this is done currently before the
388 * nodes are discovered.
389 */
390 if (!after_bootmem)
391 find_early_table_space(end);
392
393 start = (unsigned long)__va(start);
394 end = (unsigned long)__va(end);
395
396 for (; start < end; start = next) {
397 pgd_t *pgd = pgd_offset_k(start);
398 unsigned long pud_phys;
399 pud_t *pud;
400
401 if (after_bootmem)
402 pud = pud_offset(pgd, start & PGDIR_MASK);
403 else
404 pud = alloc_low_page(&pud_phys);
405
406 next = start + PGDIR_SIZE;
407 if (next > end)
408 next = end;
409 phys_pud_init(pud, __pa(start), __pa(next));
410 if (!after_bootmem)
411 set_pgd(pgd_offset_k(start), mk_kernel_pgd(pud_phys));
412 unmap_low_page(pud);
413 }
414
415 if (!after_bootmem)
416 mmu_cr4_features = read_cr4();
417 __flush_tlb_all();
418
419 reserve_early(table_start << PAGE_SHIFT, table_end << PAGE_SHIFT);
420 }
421
422 #ifndef CONFIG_NUMA
423 void __init paging_init(void)
424 {
425 unsigned long max_zone_pfns[MAX_NR_ZONES];
426
427 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
428 max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
429 max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
430 max_zone_pfns[ZONE_NORMAL] = end_pfn;
431
432 memory_present(0, 0, end_pfn);
433 sparse_init();
434 free_area_init_nodes(max_zone_pfns);
435 }
436 #endif
437
438 /*
439 * Unmap a kernel mapping if it exists. This is useful to avoid
440 * prefetches from the CPU leading to inconsistent cache lines.
441 * address and size must be aligned to 2MB boundaries.
442 * Does nothing when the mapping doesn't exist.
443 */
444 void __init clear_kernel_mapping(unsigned long address, unsigned long size)
445 {
446 unsigned long end = address + size;
447
448 BUG_ON(address & ~LARGE_PAGE_MASK);
449 BUG_ON(size & ~LARGE_PAGE_MASK);
450
451 for (; address < end; address += LARGE_PAGE_SIZE) {
452 pgd_t *pgd = pgd_offset_k(address);
453 pud_t *pud;
454 pmd_t *pmd;
455
456 if (pgd_none(*pgd))
457 continue;
458
459 pud = pud_offset(pgd, address);
460 if (pud_none(*pud))
461 continue;
462
463 pmd = pmd_offset(pud, address);
464 if (!pmd || pmd_none(*pmd))
465 continue;
466
467 if (!(pmd_val(*pmd) & _PAGE_PSE)) {
468 /*
469 * Could handle this, but it should not happen
470 * currently:
471 */
472 printk(KERN_ERR "clear_kernel_mapping: "
473 "mapping has been split. will leak memory\n");
474 pmd_ERROR(*pmd);
475 }
476 set_pmd(pmd, __pmd(0));
477 }
478 __flush_tlb_all();
479 }
480
481 /*
482 * Memory hotplug specific functions
483 */
484 void online_page(struct page *page)
485 {
486 ClearPageReserved(page);
487 init_page_count(page);
488 __free_page(page);
489 totalram_pages++;
490 num_physpages++;
491 }
492
493 #ifdef CONFIG_MEMORY_HOTPLUG
494 /*
495 * Memory is added always to NORMAL zone. This means you will never get
496 * additional DMA/DMA32 memory.
497 */
498 int arch_add_memory(int nid, u64 start, u64 size)
499 {
500 struct pglist_data *pgdat = NODE_DATA(nid);
501 struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
502 unsigned long start_pfn = start >> PAGE_SHIFT;
503 unsigned long nr_pages = size >> PAGE_SHIFT;
504 int ret;
505
506 init_memory_mapping(start, start + size-1);
507
508 ret = __add_pages(zone, start_pfn, nr_pages);
509 if (ret)
510 printk("%s: Problem encountered in __add_pages!\n", __func__);
511
512 return ret;
513 }
514 EXPORT_SYMBOL_GPL(arch_add_memory);
515
516 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
517 int memory_add_physaddr_to_nid(u64 start)
518 {
519 return 0;
520 }
521 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
522 #endif
523
524 #endif /* CONFIG_MEMORY_HOTPLUG */
525
526 static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel,
527 kcore_modules, kcore_vsyscall;
528
529 void __init mem_init(void)
530 {
531 long codesize, reservedpages, datasize, initsize;
532
533 pci_iommu_alloc();
534
535 /* clear_bss() already clear the empty_zero_page */
536
537 /* temporary debugging - double check it's true: */
538 {
539 int i;
540
541 for (i = 0; i < 1024; i++)
542 WARN_ON_ONCE(empty_zero_page[i]);
543 }
544
545 reservedpages = 0;
546
547 /* this will put all low memory onto the freelists */
548 #ifdef CONFIG_NUMA
549 totalram_pages = numa_free_all_bootmem();
550 #else
551 totalram_pages = free_all_bootmem();
552 #endif
553 reservedpages = end_pfn - totalram_pages -
554 absent_pages_in_range(0, end_pfn);
555 after_bootmem = 1;
556
557 codesize = (unsigned long) &_etext - (unsigned long) &_text;
558 datasize = (unsigned long) &_edata - (unsigned long) &_etext;
559 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
560
561 /* Register memory areas for /proc/kcore */
562 kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
563 kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
564 VMALLOC_END-VMALLOC_START);
565 kclist_add(&kcore_kernel, &_stext, _end - _stext);
566 kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN);
567 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
568 VSYSCALL_END - VSYSCALL_START);
569
570 printk("Memory: %luk/%luk available (%ldk kernel code, "
571 "%ldk reserved, %ldk data, %ldk init)\n",
572 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
573 end_pfn << (PAGE_SHIFT-10),
574 codesize >> 10,
575 reservedpages << (PAGE_SHIFT-10),
576 datasize >> 10,
577 initsize >> 10);
578 }
579
580 void free_init_pages(char *what, unsigned long begin, unsigned long end)
581 {
582 unsigned long addr;
583
584 if (begin >= end)
585 return;
586
587 /*
588 * If debugging page accesses then do not free this memory but
589 * mark them not present - any buggy init-section access will
590 * create a kernel page fault:
591 */
592 #ifdef CONFIG_DEBUG_PAGEALLOC
593 printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
594 begin, PAGE_ALIGN(end));
595 set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
596 #else
597 printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
598
599 for (addr = begin; addr < end; addr += PAGE_SIZE) {
600 ClearPageReserved(virt_to_page(addr));
601 init_page_count(virt_to_page(addr));
602 memset((void *)(addr & ~(PAGE_SIZE-1)),
603 POISON_FREE_INITMEM, PAGE_SIZE);
604 free_page(addr);
605 totalram_pages++;
606 }
607 #endif
608 }
609
610 void free_initmem(void)
611 {
612 free_init_pages("unused kernel memory",
613 (unsigned long)(&__init_begin),
614 (unsigned long)(&__init_end));
615 }
616
617 #ifdef CONFIG_DEBUG_RODATA
618 const int rodata_test_data = 0xC3;
619 EXPORT_SYMBOL_GPL(rodata_test_data);
620
621 void mark_rodata_ro(void)
622 {
623 unsigned long start = (unsigned long)_stext, end;
624
625 #ifdef CONFIG_HOTPLUG_CPU
626 /* It must still be possible to apply SMP alternatives. */
627 if (num_possible_cpus() > 1)
628 start = (unsigned long)_etext;
629 #endif
630
631 #ifdef CONFIG_KPROBES
632 start = (unsigned long)__start_rodata;
633 #endif
634
635 end = (unsigned long)__end_rodata;
636 start = (start + PAGE_SIZE - 1) & PAGE_MASK;
637 end &= PAGE_MASK;
638 if (end <= start)
639 return;
640
641 set_memory_ro(start, (end - start) >> PAGE_SHIFT);
642
643 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
644 (end - start) >> 10);
645
646 rodata_test();
647
648 #ifdef CONFIG_CPA_DEBUG
649 printk("Testing CPA: undo %lx-%lx\n", start, end);
650 set_memory_rw(start, (end-start) >> PAGE_SHIFT);
651
652 printk("Testing CPA: again\n");
653 set_memory_ro(start, (end-start) >> PAGE_SHIFT);
654 #endif
655 }
656 #endif
657
658 #ifdef CONFIG_BLK_DEV_INITRD
659 void free_initrd_mem(unsigned long start, unsigned long end)
660 {
661 free_init_pages("initrd memory", start, end);
662 }
663 #endif
664
665 void __init reserve_bootmem_generic(unsigned long phys, unsigned len)
666 {
667 #ifdef CONFIG_NUMA
668 int nid = phys_to_nid(phys);
669 #endif
670 unsigned long pfn = phys >> PAGE_SHIFT;
671
672 if (pfn >= end_pfn) {
673 /*
674 * This can happen with kdump kernels when accessing
675 * firmware tables:
676 */
677 if (pfn < end_pfn_map)
678 return;
679
680 printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %u\n",
681 phys, len);
682 return;
683 }
684
685 /* Should check here against the e820 map to avoid double free */
686 #ifdef CONFIG_NUMA
687 reserve_bootmem_node(NODE_DATA(nid), phys, len);
688 #else
689 reserve_bootmem(phys, len);
690 #endif
691 if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
692 dma_reserve += len / PAGE_SIZE;
693 set_dma_reserve(dma_reserve);
694 }
695 }
696
697 int kern_addr_valid(unsigned long addr)
698 {
699 unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
700 pgd_t *pgd;
701 pud_t *pud;
702 pmd_t *pmd;
703 pte_t *pte;
704
705 if (above != 0 && above != -1UL)
706 return 0;
707
708 pgd = pgd_offset_k(addr);
709 if (pgd_none(*pgd))
710 return 0;
711
712 pud = pud_offset(pgd, addr);
713 if (pud_none(*pud))
714 return 0;
715
716 pmd = pmd_offset(pud, addr);
717 if (pmd_none(*pmd))
718 return 0;
719
720 if (pmd_large(*pmd))
721 return pfn_valid(pmd_pfn(*pmd));
722
723 pte = pte_offset_kernel(pmd, addr);
724 if (pte_none(*pte))
725 return 0;
726
727 return pfn_valid(pte_pfn(*pte));
728 }
729
730 /*
731 * A pseudo VMA to allow ptrace access for the vsyscall page. This only
732 * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
733 * not need special handling anymore:
734 */
735 static struct vm_area_struct gate_vma = {
736 .vm_start = VSYSCALL_START,
737 .vm_end = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
738 .vm_page_prot = PAGE_READONLY_EXEC,
739 .vm_flags = VM_READ | VM_EXEC
740 };
741
742 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
743 {
744 #ifdef CONFIG_IA32_EMULATION
745 if (test_tsk_thread_flag(tsk, TIF_IA32))
746 return NULL;
747 #endif
748 return &gate_vma;
749 }
750
751 int in_gate_area(struct task_struct *task, unsigned long addr)
752 {
753 struct vm_area_struct *vma = get_gate_vma(task);
754
755 if (!vma)
756 return 0;
757
758 return (addr >= vma->vm_start) && (addr < vma->vm_end);
759 }
760
761 /*
762 * Use this when you have no reliable task/vma, typically from interrupt
763 * context. It is less reliable than using the task's vma and may give
764 * false positives:
765 */
766 int in_gate_area_no_task(unsigned long addr)
767 {
768 return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
769 }
770
771 const char *arch_vma_name(struct vm_area_struct *vma)
772 {
773 if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
774 return "[vdso]";
775 if (vma == &gate_vma)
776 return "[vsyscall]";
777 return NULL;
778 }
779
780 #ifdef CONFIG_SPARSEMEM_VMEMMAP
781 /*
782 * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
783 */
784 int __meminit
785 vmemmap_populate(struct page *start_page, unsigned long size, int node)
786 {
787 unsigned long addr = (unsigned long)start_page;
788 unsigned long end = (unsigned long)(start_page + size);
789 unsigned long next;
790 pgd_t *pgd;
791 pud_t *pud;
792 pmd_t *pmd;
793
794 for (; addr < end; addr = next) {
795 next = pmd_addr_end(addr, end);
796
797 pgd = vmemmap_pgd_populate(addr, node);
798 if (!pgd)
799 return -ENOMEM;
800
801 pud = vmemmap_pud_populate(pgd, addr, node);
802 if (!pud)
803 return -ENOMEM;
804
805 pmd = pmd_offset(pud, addr);
806 if (pmd_none(*pmd)) {
807 pte_t entry;
808 void *p;
809
810 p = vmemmap_alloc_block(PMD_SIZE, node);
811 if (!p)
812 return -ENOMEM;
813
814 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
815 PAGE_KERNEL_LARGE);
816 set_pmd(pmd, __pmd(pte_val(entry)));
817
818 printk(KERN_DEBUG " [%lx-%lx] PMD ->%p on node %d\n",
819 addr, addr + PMD_SIZE - 1, p, node);
820 } else {
821 vmemmap_verify((pte_t *)pmd, node, addr, next);
822 }
823 }
824 return 0;
825 }
826 #endif
Linux kernel - Deliverables
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