init_64.c revision 24a5da73f49c17ca88f369b257fef620a494e79d 
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
49const struct dma_mapping_ops *dma_ops;
50EXPORT_SYMBOL(dma_ops);
51
52static unsigned long dma_reserve __initdata;
53
54DEFINE_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
62void 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
102int after_bootmem;
103
104static __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
123static __init void
124set_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 */
174void __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
186static unsigned long __initdata table_start;
187static unsigned long __meminitdata table_end;
188
189static __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
210static __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;
243continue_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
270static void __meminit
271phys_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		unsigned long entry;
277		pmd_t *pmd = pmd_page + pmd_index(address);
278
279		if (address >= end) {
280			if (!after_bootmem) {
281				for (; i < PTRS_PER_PMD; i++, pmd++)
282					set_pmd(pmd, __pmd(0));
283			}
284			break;
285		}
286
287		if (pmd_val(*pmd))
288			continue;
289
290		entry = __PAGE_KERNEL_LARGE|_PAGE_GLOBAL|address;
291		entry &= __supported_pte_mask;
292		set_pmd(pmd, __pmd(entry));
293	}
294}
295
296static void __meminit
297phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end)
298{
299	pmd_t *pmd = pmd_offset(pud, 0);
300	spin_lock(&init_mm.page_table_lock);
301	phys_pmd_init(pmd, address, end);
302	spin_unlock(&init_mm.page_table_lock);
303	__flush_tlb_all();
304}
305
306static void __meminit
307phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end)
308{
309	int i = pud_index(addr);
310
311	for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
312		unsigned long pmd_phys;
313		pud_t *pud = pud_page + pud_index(addr);
314		pmd_t *pmd;
315
316		if (addr >= end)
317			break;
318
319		if (!after_bootmem &&
320				!e820_any_mapped(addr, addr+PUD_SIZE, 0)) {
321			set_pud(pud, __pud(0));
322			continue;
323		}
324
325		if (pud_val(*pud)) {
326			phys_pmd_update(pud, addr, end);
327			continue;
328		}
329
330		pmd = alloc_low_page(&pmd_phys);
331
332		spin_lock(&init_mm.page_table_lock);
333		set_pud(pud, __pud(pmd_phys | _KERNPG_TABLE));
334		phys_pmd_init(pmd, addr, end);
335		spin_unlock(&init_mm.page_table_lock);
336
337		unmap_low_page(pmd);
338	}
339	__flush_tlb_all();
340}
341
342static void __init find_early_table_space(unsigned long end)
343{
344	unsigned long puds, pmds, tables, start;
345
346	puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
347	pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
348	tables = round_up(puds * sizeof(pud_t), PAGE_SIZE) +
349		 round_up(pmds * sizeof(pmd_t), PAGE_SIZE);
350
351	/*
352	 * RED-PEN putting page tables only on node 0 could
353	 * cause a hotspot and fill up ZONE_DMA. The page tables
354	 * need roughly 0.5KB per GB.
355	 */
356	start = 0x8000;
357	table_start = find_e820_area(start, end, tables, PAGE_SIZE);
358	if (table_start == -1UL)
359		panic("Cannot find space for the kernel page tables");
360
361	table_start >>= PAGE_SHIFT;
362	table_end = table_start;
363
364	early_printk("kernel direct mapping tables up to %lx @ %lx-%lx\n",
365		end, table_start << PAGE_SHIFT,
366		(table_start << PAGE_SHIFT) + tables);
367}
368
369/*
370 * Setup the direct mapping of the physical memory at PAGE_OFFSET.
371 * This runs before bootmem is initialized and gets pages directly from
372 * the physical memory. To access them they are temporarily mapped.
373 */
374void __init_refok init_memory_mapping(unsigned long start, unsigned long end)
375{
376	unsigned long next;
377
378	pr_debug("init_memory_mapping\n");
379
380	/*
381	 * Find space for the kernel direct mapping tables.
382	 *
383	 * Later we should allocate these tables in the local node of the
384	 * memory mapped. Unfortunately this is done currently before the
385	 * nodes are discovered.
386	 */
387	if (!after_bootmem)
388		find_early_table_space(end);
389
390	start = (unsigned long)__va(start);
391	end = (unsigned long)__va(end);
392
393	for (; start < end; start = next) {
394		pgd_t *pgd = pgd_offset_k(start);
395		unsigned long pud_phys;
396		pud_t *pud;
397
398		if (after_bootmem)
399			pud = pud_offset(pgd, start & PGDIR_MASK);
400		else
401			pud = alloc_low_page(&pud_phys);
402
403		next = start + PGDIR_SIZE;
404		if (next > end)
405			next = end;
406		phys_pud_init(pud, __pa(start), __pa(next));
407		if (!after_bootmem)
408			set_pgd(pgd_offset_k(start), mk_kernel_pgd(pud_phys));
409		unmap_low_page(pud);
410	}
411
412	if (!after_bootmem)
413		mmu_cr4_features = read_cr4();
414	__flush_tlb_all();
415
416	if (!after_bootmem)
417		reserve_early(table_start << PAGE_SHIFT,
418				 table_end << PAGE_SHIFT, "PGTABLE");
419}
420
421#ifndef CONFIG_NUMA
422void __init paging_init(void)
423{
424	unsigned long max_zone_pfns[MAX_NR_ZONES];
425
426	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
427	max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
428	max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
429	max_zone_pfns[ZONE_NORMAL] = end_pfn;
430
431	memory_present(0, 0, end_pfn);
432	sparse_init();
433	free_area_init_nodes(max_zone_pfns);
434}
435#endif
436
437/*
438 * Unmap a kernel mapping if it exists. This is useful to avoid
439 * prefetches from the CPU leading to inconsistent cache lines.
440 * address and size must be aligned to 2MB boundaries.
441 * Does nothing when the mapping doesn't exist.
442 */
443void __init clear_kernel_mapping(unsigned long address, unsigned long size)
444{
445	unsigned long end = address + size;
446
447	BUG_ON(address & ~LARGE_PAGE_MASK);
448	BUG_ON(size & ~LARGE_PAGE_MASK);
449
450	for (; address < end; address += LARGE_PAGE_SIZE) {
451		pgd_t *pgd = pgd_offset_k(address);
452		pud_t *pud;
453		pmd_t *pmd;
454
455		if (pgd_none(*pgd))
456			continue;
457
458		pud = pud_offset(pgd, address);
459		if (pud_none(*pud))
460			continue;
461
462		pmd = pmd_offset(pud, address);
463		if (!pmd || pmd_none(*pmd))
464			continue;
465
466		if (!(pmd_val(*pmd) & _PAGE_PSE)) {
467			/*
468			 * Could handle this, but it should not happen
469			 * currently:
470			 */
471			printk(KERN_ERR "clear_kernel_mapping: "
472				"mapping has been split. will leak memory\n");
473			pmd_ERROR(*pmd);
474		}
475		set_pmd(pmd, __pmd(0));
476	}
477	__flush_tlb_all();
478}
479
480/*
481 * Memory hotplug specific functions
482 */
483void online_page(struct page *page)
484{
485	ClearPageReserved(page);
486	init_page_count(page);
487	__free_page(page);
488	totalram_pages++;
489	num_physpages++;
490}
491
492#ifdef CONFIG_MEMORY_HOTPLUG
493/*
494 * Memory is added always to NORMAL zone. This means you will never get
495 * additional DMA/DMA32 memory.
496 */
497int arch_add_memory(int nid, u64 start, u64 size)
498{
499	struct pglist_data *pgdat = NODE_DATA(nid);
500	struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
501	unsigned long start_pfn = start >> PAGE_SHIFT;
502	unsigned long nr_pages = size >> PAGE_SHIFT;
503	int ret;
504
505	init_memory_mapping(start, start + size-1);
506
507	ret = __add_pages(zone, start_pfn, nr_pages);
508	WARN_ON(1);
509
510	return ret;
511}
512EXPORT_SYMBOL_GPL(arch_add_memory);
513
514#if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
515int memory_add_physaddr_to_nid(u64 start)
516{
517	return 0;
518}
519EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
520#endif
521
522#endif /* CONFIG_MEMORY_HOTPLUG */
523
524static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel,
525			 kcore_modules, kcore_vsyscall;
526
527void __init mem_init(void)
528{
529	long codesize, reservedpages, datasize, initsize;
530
531	pci_iommu_alloc();
532
533	/* clear_bss() already clear the empty_zero_page */
534
535	/* temporary debugging - double check it's true: */
536	{
537		int i;
538
539		for (i = 0; i < 1024; i++)
540			WARN_ON_ONCE(empty_zero_page[i]);
541	}
542
543	reservedpages = 0;
544
545	/* this will put all low memory onto the freelists */
546#ifdef CONFIG_NUMA
547	totalram_pages = numa_free_all_bootmem();
548#else
549	totalram_pages = free_all_bootmem();
550#endif
551	reservedpages = end_pfn - totalram_pages -
552					absent_pages_in_range(0, end_pfn);
553	after_bootmem = 1;
554
555	codesize =  (unsigned long) &_etext - (unsigned long) &_text;
556	datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
557	initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
558
559	/* Register memory areas for /proc/kcore */
560	kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
561	kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
562		   VMALLOC_END-VMALLOC_START);
563	kclist_add(&kcore_kernel, &_stext, _end - _stext);
564	kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN);
565	kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
566				 VSYSCALL_END - VSYSCALL_START);
567
568	printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
569				"%ldk reserved, %ldk data, %ldk init)\n",
570		(unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
571		end_pfn << (PAGE_SHIFT-10),
572		codesize >> 10,
573		reservedpages << (PAGE_SHIFT-10),
574		datasize >> 10,
575		initsize >> 10);
576}
577
578void free_init_pages(char *what, unsigned long begin, unsigned long end)
579{
580	unsigned long addr;
581
582	if (begin >= end)
583		return;
584
585	/*
586	 * If debugging page accesses then do not free this memory but
587	 * mark them not present - any buggy init-section access will
588	 * create a kernel page fault:
589	 */
590#ifdef CONFIG_DEBUG_PAGEALLOC
591	printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
592		begin, PAGE_ALIGN(end));
593	set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
594#else
595	printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
596
597	for (addr = begin; addr < end; addr += PAGE_SIZE) {
598		ClearPageReserved(virt_to_page(addr));
599		init_page_count(virt_to_page(addr));
600		memset((void *)(addr & ~(PAGE_SIZE-1)),
601			POISON_FREE_INITMEM, PAGE_SIZE);
602		free_page(addr);
603		totalram_pages++;
604	}
605#endif
606}
607
608void free_initmem(void)
609{
610	free_init_pages("unused kernel memory",
611			(unsigned long)(&__init_begin),
612			(unsigned long)(&__init_end));
613}
614
615#ifdef CONFIG_DEBUG_RODATA
616const int rodata_test_data = 0xC3;
617EXPORT_SYMBOL_GPL(rodata_test_data);
618
619void mark_rodata_ro(void)
620{
621	unsigned long start = (unsigned long)_stext, end;
622
623#ifdef CONFIG_HOTPLUG_CPU
624	/* It must still be possible to apply SMP alternatives. */
625	if (num_possible_cpus() > 1)
626		start = (unsigned long)_etext;
627#endif
628
629#ifdef CONFIG_KPROBES
630	start = (unsigned long)__start_rodata;
631#endif
632
633	end = (unsigned long)__end_rodata;
634	start = (start + PAGE_SIZE - 1) & PAGE_MASK;
635	end &= PAGE_MASK;
636	if (end <= start)
637		return;
638
639	set_memory_ro(start, (end - start) >> PAGE_SHIFT);
640
641	printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
642	       (end - start) >> 10);
643
644	rodata_test();
645
646#ifdef CONFIG_CPA_DEBUG
647	printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
648	set_memory_rw(start, (end-start) >> PAGE_SHIFT);
649
650	printk(KERN_INFO "Testing CPA: again\n");
651	set_memory_ro(start, (end-start) >> PAGE_SHIFT);
652#endif
653}
654#endif
655
656#ifdef CONFIG_BLK_DEV_INITRD
657void free_initrd_mem(unsigned long start, unsigned long end)
658{
659	free_init_pages("initrd memory", start, end);
660}
661#endif
662
663void __init reserve_bootmem_generic(unsigned long phys, unsigned len)
664{
665#ifdef CONFIG_NUMA
666	int nid = phys_to_nid(phys);
667#endif
668	unsigned long pfn = phys >> PAGE_SHIFT;
669
670	if (pfn >= end_pfn) {
671		/*
672		 * This can happen with kdump kernels when accessing
673		 * firmware tables:
674		 */
675		if (pfn < end_pfn_map)
676			return;
677
678		printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %u\n",
679				phys, len);
680		return;
681	}
682
683	/* Should check here against the e820 map to avoid double free */
684#ifdef CONFIG_NUMA
685	reserve_bootmem_node(NODE_DATA(nid), phys, len);
686#else
687	reserve_bootmem(phys, len);
688#endif
689	if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
690		dma_reserve += len / PAGE_SIZE;
691		set_dma_reserve(dma_reserve);
692	}
693}
694
695int kern_addr_valid(unsigned long addr)
696{
697	unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
698	pgd_t *pgd;
699	pud_t *pud;
700	pmd_t *pmd;
701	pte_t *pte;
702
703	if (above != 0 && above != -1UL)
704		return 0;
705
706	pgd = pgd_offset_k(addr);
707	if (pgd_none(*pgd))
708		return 0;
709
710	pud = pud_offset(pgd, addr);
711	if (pud_none(*pud))
712		return 0;
713
714	pmd = pmd_offset(pud, addr);
715	if (pmd_none(*pmd))
716		return 0;
717
718	if (pmd_large(*pmd))
719		return pfn_valid(pmd_pfn(*pmd));
720
721	pte = pte_offset_kernel(pmd, addr);
722	if (pte_none(*pte))
723		return 0;
724
725	return pfn_valid(pte_pfn(*pte));
726}
727
728/*
729 * A pseudo VMA to allow ptrace access for the vsyscall page.  This only
730 * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
731 * not need special handling anymore:
732 */
733static struct vm_area_struct gate_vma = {
734	.vm_start	= VSYSCALL_START,
735	.vm_end		= VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
736	.vm_page_prot	= PAGE_READONLY_EXEC,
737	.vm_flags	= VM_READ | VM_EXEC
738};
739
740struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
741{
742#ifdef CONFIG_IA32_EMULATION
743	if (test_tsk_thread_flag(tsk, TIF_IA32))
744		return NULL;
745#endif
746	return &gate_vma;
747}
748
749int in_gate_area(struct task_struct *task, unsigned long addr)
750{
751	struct vm_area_struct *vma = get_gate_vma(task);
752
753	if (!vma)
754		return 0;
755
756	return (addr >= vma->vm_start) && (addr < vma->vm_end);
757}
758
759/*
760 * Use this when you have no reliable task/vma, typically from interrupt
761 * context. It is less reliable than using the task's vma and may give
762 * false positives:
763 */
764int in_gate_area_no_task(unsigned long addr)
765{
766	return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
767}
768
769const char *arch_vma_name(struct vm_area_struct *vma)
770{
771	if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
772		return "[vdso]";
773	if (vma == &gate_vma)
774		return "[vsyscall]";
775	return NULL;
776}
777
778#ifdef CONFIG_SPARSEMEM_VMEMMAP
779/*
780 * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
781 */
782int __meminit
783vmemmap_populate(struct page *start_page, unsigned long size, int node)
784{
785	unsigned long addr = (unsigned long)start_page;
786	unsigned long end = (unsigned long)(start_page + size);
787	unsigned long next;
788	pgd_t *pgd;
789	pud_t *pud;
790	pmd_t *pmd;
791
792	for (; addr < end; addr = next) {
793		next = pmd_addr_end(addr, end);
794
795		pgd = vmemmap_pgd_populate(addr, node);
796		if (!pgd)
797			return -ENOMEM;
798
799		pud = vmemmap_pud_populate(pgd, addr, node);
800		if (!pud)
801			return -ENOMEM;
802
803		pmd = pmd_offset(pud, addr);
804		if (pmd_none(*pmd)) {
805			pte_t entry;
806			void *p;
807
808			p = vmemmap_alloc_block(PMD_SIZE, node);
809			if (!p)
810				return -ENOMEM;
811
812			entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
813							PAGE_KERNEL_LARGE);
814			set_pmd(pmd, __pmd(pte_val(entry)));
815
816			printk(KERN_DEBUG " [%lx-%lx] PMD ->%p on node %d\n",
817				addr, addr + PMD_SIZE - 1, p, node);
818		} else {
819			vmemmap_verify((pte_t *)pmd, node, addr, next);
820		}
821	}
822	return 0;
823}
824#endif
825