init_64.c revision 984bb80d94d891592ab16d4d129b988792752c7b 
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		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
294static void __meminit
295phys_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
304static void __meminit
305phys_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
340static 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 */
372void __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
420void __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 */
438void 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 */
452int 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}
467EXPORT_SYMBOL_GPL(arch_add_memory);
468
469#if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
470int memory_add_physaddr_to_nid(u64 start)
471{
472	return 0;
473}
474EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
475#endif
476
477#endif /* CONFIG_MEMORY_HOTPLUG */
478
479static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel,
480			 kcore_modules, kcore_vsyscall;
481
482void __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
533void free_init_pages(char *what, unsigned long begin, unsigned long end)
534{
535	unsigned long addr;
536
537	if (begin >= end)
538		return;
539
540	/*
541	 * If debugging page accesses then do not free this memory but
542	 * mark them not present - any buggy init-section access will
543	 * create a kernel page fault:
544	 */
545#ifdef CONFIG_DEBUG_PAGEALLOC
546	printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
547		begin, PAGE_ALIGN(end));
548	set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
549#else
550	printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
551
552	for (addr = begin; addr < end; addr += PAGE_SIZE) {
553		ClearPageReserved(virt_to_page(addr));
554		init_page_count(virt_to_page(addr));
555		memset((void *)(addr & ~(PAGE_SIZE-1)),
556			POISON_FREE_INITMEM, PAGE_SIZE);
557		free_page(addr);
558		totalram_pages++;
559	}
560#endif
561}
562
563void free_initmem(void)
564{
565	free_init_pages("unused kernel memory",
566			(unsigned long)(&__init_begin),
567			(unsigned long)(&__init_end));
568}
569
570#ifdef CONFIG_DEBUG_RODATA
571const int rodata_test_data = 0xC3;
572EXPORT_SYMBOL_GPL(rodata_test_data);
573
574void mark_rodata_ro(void)
575{
576	unsigned long start = (unsigned long)_stext, end;
577
578#ifdef CONFIG_HOTPLUG_CPU
579	/* It must still be possible to apply SMP alternatives. */
580	if (num_possible_cpus() > 1)
581		start = (unsigned long)_etext;
582#endif
583
584#ifdef CONFIG_KPROBES
585	start = (unsigned long)__start_rodata;
586#endif
587
588	end = (unsigned long)__end_rodata;
589	start = (start + PAGE_SIZE - 1) & PAGE_MASK;
590	end &= PAGE_MASK;
591	if (end <= start)
592		return;
593
594
595	printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
596	       (end - start) >> 10);
597	set_memory_ro(start, (end - start) >> PAGE_SHIFT);
598
599	/*
600	 * The rodata section (but not the kernel text!) should also be
601	 * not-executable.
602	 */
603	start = ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
604	set_memory_nx(start, (end - start) >> PAGE_SHIFT);
605
606	rodata_test();
607
608#ifdef CONFIG_CPA_DEBUG
609	printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
610	set_memory_rw(start, (end-start) >> PAGE_SHIFT);
611
612	printk(KERN_INFO "Testing CPA: again\n");
613	set_memory_ro(start, (end-start) >> PAGE_SHIFT);
614#endif
615}
616#endif
617
618#ifdef CONFIG_BLK_DEV_INITRD
619void free_initrd_mem(unsigned long start, unsigned long end)
620{
621	free_init_pages("initrd memory", start, end);
622}
623#endif
624
625void __init reserve_bootmem_generic(unsigned long phys, unsigned len)
626{
627#ifdef CONFIG_NUMA
628	int nid = phys_to_nid(phys);
629#endif
630	unsigned long pfn = phys >> PAGE_SHIFT;
631
632	if (pfn >= end_pfn) {
633		/*
634		 * This can happen with kdump kernels when accessing
635		 * firmware tables:
636		 */
637		if (pfn < end_pfn_map)
638			return;
639
640		printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %u\n",
641				phys, len);
642		return;
643	}
644
645	/* Should check here against the e820 map to avoid double free */
646#ifdef CONFIG_NUMA
647	reserve_bootmem_node(NODE_DATA(nid), phys, len);
648#else
649	reserve_bootmem(phys, len);
650#endif
651	if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
652		dma_reserve += len / PAGE_SIZE;
653		set_dma_reserve(dma_reserve);
654	}
655}
656
657int kern_addr_valid(unsigned long addr)
658{
659	unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
660	pgd_t *pgd;
661	pud_t *pud;
662	pmd_t *pmd;
663	pte_t *pte;
664
665	if (above != 0 && above != -1UL)
666		return 0;
667
668	pgd = pgd_offset_k(addr);
669	if (pgd_none(*pgd))
670		return 0;
671
672	pud = pud_offset(pgd, addr);
673	if (pud_none(*pud))
674		return 0;
675
676	pmd = pmd_offset(pud, addr);
677	if (pmd_none(*pmd))
678		return 0;
679
680	if (pmd_large(*pmd))
681		return pfn_valid(pmd_pfn(*pmd));
682
683	pte = pte_offset_kernel(pmd, addr);
684	if (pte_none(*pte))
685		return 0;
686
687	return pfn_valid(pte_pfn(*pte));
688}
689
690/*
691 * A pseudo VMA to allow ptrace access for the vsyscall page.  This only
692 * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
693 * not need special handling anymore:
694 */
695static struct vm_area_struct gate_vma = {
696	.vm_start	= VSYSCALL_START,
697	.vm_end		= VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
698	.vm_page_prot	= PAGE_READONLY_EXEC,
699	.vm_flags	= VM_READ | VM_EXEC
700};
701
702struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
703{
704#ifdef CONFIG_IA32_EMULATION
705	if (test_tsk_thread_flag(tsk, TIF_IA32))
706		return NULL;
707#endif
708	return &gate_vma;
709}
710
711int in_gate_area(struct task_struct *task, unsigned long addr)
712{
713	struct vm_area_struct *vma = get_gate_vma(task);
714
715	if (!vma)
716		return 0;
717
718	return (addr >= vma->vm_start) && (addr < vma->vm_end);
719}
720
721/*
722 * Use this when you have no reliable task/vma, typically from interrupt
723 * context. It is less reliable than using the task's vma and may give
724 * false positives:
725 */
726int in_gate_area_no_task(unsigned long addr)
727{
728	return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
729}
730
731const char *arch_vma_name(struct vm_area_struct *vma)
732{
733	if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
734		return "[vdso]";
735	if (vma == &gate_vma)
736		return "[vsyscall]";
737	return NULL;
738}
739
740#ifdef CONFIG_SPARSEMEM_VMEMMAP
741/*
742 * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
743 */
744int __meminit
745vmemmap_populate(struct page *start_page, unsigned long size, int node)
746{
747	unsigned long addr = (unsigned long)start_page;
748	unsigned long end = (unsigned long)(start_page + size);
749	unsigned long next;
750	pgd_t *pgd;
751	pud_t *pud;
752	pmd_t *pmd;
753
754	for (; addr < end; addr = next) {
755		next = pmd_addr_end(addr, end);
756
757		pgd = vmemmap_pgd_populate(addr, node);
758		if (!pgd)
759			return -ENOMEM;
760
761		pud = vmemmap_pud_populate(pgd, addr, node);
762		if (!pud)
763			return -ENOMEM;
764
765		pmd = pmd_offset(pud, addr);
766		if (pmd_none(*pmd)) {
767			pte_t entry;
768			void *p;
769
770			p = vmemmap_alloc_block(PMD_SIZE, node);
771			if (!p)
772				return -ENOMEM;
773
774			entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
775							PAGE_KERNEL_LARGE);
776			set_pmd(pmd, __pmd(pte_val(entry)));
777
778			printk(KERN_DEBUG " [%lx-%lx] PMD ->%p on node %d\n",
779				addr, addr + PMD_SIZE - 1, p, node);
780		} else {
781			vmemmap_verify((pte_t *)pmd, node, addr, next);
782		}
783	}
784	return 0;
785}
786#endif
787