init_64.c revision 8ee2debce32412118cf8c239e0026ace56ea1425
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/initrd.h>
22#include <linux/pagemap.h>
23#include <linux/bootmem.h>
24#include <linux/proc_fs.h>
25#include <linux/pci.h>
26#include <linux/pfn.h>
27#include <linux/poison.h>
28#include <linux/dma-mapping.h>
29#include <linux/module.h>
30#include <linux/memory_hotplug.h>
31#include <linux/nmi.h>
32
33#include <asm/processor.h>
34#include <asm/bios_ebda.h>
35#include <asm/system.h>
36#include <asm/uaccess.h>
37#include <asm/pgtable.h>
38#include <asm/pgalloc.h>
39#include <asm/dma.h>
40#include <asm/fixmap.h>
41#include <asm/e820.h>
42#include <asm/apic.h>
43#include <asm/tlb.h>
44#include <asm/mmu_context.h>
45#include <asm/proto.h>
46#include <asm/smp.h>
47#include <asm/sections.h>
48#include <asm/kdebug.h>
49#include <asm/numa.h>
50#include <asm/cacheflush.h>
51#include <asm/init.h>
52
53static unsigned long dma_reserve __initdata;
54
55static int __init parse_direct_gbpages_off(char *arg)
56{
57	direct_gbpages = 0;
58	return 0;
59}
60early_param("nogbpages", parse_direct_gbpages_off);
61
62static int __init parse_direct_gbpages_on(char *arg)
63{
64	direct_gbpages = 1;
65	return 0;
66}
67early_param("gbpages", parse_direct_gbpages_on);
68
69/*
70 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
71 * physical space so we can cache the place of the first one and move
72 * around without checking the pgd every time.
73 */
74
75pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP;
76EXPORT_SYMBOL_GPL(__supported_pte_mask);
77
78int force_personality32;
79
80/*
81 * noexec32=on|off
82 * Control non executable heap for 32bit processes.
83 * To control the stack too use noexec=off
84 *
85 * on	PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
86 * off	PROT_READ implies PROT_EXEC
87 */
88static int __init nonx32_setup(char *str)
89{
90	if (!strcmp(str, "on"))
91		force_personality32 &= ~READ_IMPLIES_EXEC;
92	else if (!strcmp(str, "off"))
93		force_personality32 |= READ_IMPLIES_EXEC;
94	return 1;
95}
96__setup("noexec32=", nonx32_setup);
97
98/*
99 * NOTE: This function is marked __ref because it calls __init function
100 * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
101 */
102static __ref void *spp_getpage(void)
103{
104	void *ptr;
105
106	if (after_bootmem)
107		ptr = (void *) get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK);
108	else
109		ptr = alloc_bootmem_pages(PAGE_SIZE);
110
111	if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
112		panic("set_pte_phys: cannot allocate page data %s\n",
113			after_bootmem ? "after bootmem" : "");
114	}
115
116	pr_debug("spp_getpage %p\n", ptr);
117
118	return ptr;
119}
120
121static pud_t *fill_pud(pgd_t *pgd, unsigned long vaddr)
122{
123	if (pgd_none(*pgd)) {
124		pud_t *pud = (pud_t *)spp_getpage();
125		pgd_populate(&init_mm, pgd, pud);
126		if (pud != pud_offset(pgd, 0))
127			printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n",
128			       pud, pud_offset(pgd, 0));
129	}
130	return pud_offset(pgd, vaddr);
131}
132
133static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr)
134{
135	if (pud_none(*pud)) {
136		pmd_t *pmd = (pmd_t *) spp_getpage();
137		pud_populate(&init_mm, pud, pmd);
138		if (pmd != pmd_offset(pud, 0))
139			printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
140			       pmd, pmd_offset(pud, 0));
141	}
142	return pmd_offset(pud, vaddr);
143}
144
145static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr)
146{
147	if (pmd_none(*pmd)) {
148		pte_t *pte = (pte_t *) spp_getpage();
149		pmd_populate_kernel(&init_mm, pmd, pte);
150		if (pte != pte_offset_kernel(pmd, 0))
151			printk(KERN_ERR "PAGETABLE BUG #02!\n");
152	}
153	return pte_offset_kernel(pmd, vaddr);
154}
155
156void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
157{
158	pud_t *pud;
159	pmd_t *pmd;
160	pte_t *pte;
161
162	pud = pud_page + pud_index(vaddr);
163	pmd = fill_pmd(pud, vaddr);
164	pte = fill_pte(pmd, vaddr);
165
166	set_pte(pte, new_pte);
167
168	/*
169	 * It's enough to flush this one mapping.
170	 * (PGE mappings get flushed as well)
171	 */
172	__flush_tlb_one(vaddr);
173}
174
175void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
176{
177	pgd_t *pgd;
178	pud_t *pud_page;
179
180	pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
181
182	pgd = pgd_offset_k(vaddr);
183	if (pgd_none(*pgd)) {
184		printk(KERN_ERR
185			"PGD FIXMAP MISSING, it should be setup in head.S!\n");
186		return;
187	}
188	pud_page = (pud_t*)pgd_page_vaddr(*pgd);
189	set_pte_vaddr_pud(pud_page, vaddr, pteval);
190}
191
192pmd_t * __init populate_extra_pmd(unsigned long vaddr)
193{
194	pgd_t *pgd;
195	pud_t *pud;
196
197	pgd = pgd_offset_k(vaddr);
198	pud = fill_pud(pgd, vaddr);
199	return fill_pmd(pud, vaddr);
200}
201
202pte_t * __init populate_extra_pte(unsigned long vaddr)
203{
204	pmd_t *pmd;
205
206	pmd = populate_extra_pmd(vaddr);
207	return fill_pte(pmd, vaddr);
208}
209
210/*
211 * Create large page table mappings for a range of physical addresses.
212 */
213static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
214						pgprot_t prot)
215{
216	pgd_t *pgd;
217	pud_t *pud;
218	pmd_t *pmd;
219
220	BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
221	for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
222		pgd = pgd_offset_k((unsigned long)__va(phys));
223		if (pgd_none(*pgd)) {
224			pud = (pud_t *) spp_getpage();
225			set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE |
226						_PAGE_USER));
227		}
228		pud = pud_offset(pgd, (unsigned long)__va(phys));
229		if (pud_none(*pud)) {
230			pmd = (pmd_t *) spp_getpage();
231			set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
232						_PAGE_USER));
233		}
234		pmd = pmd_offset(pud, phys);
235		BUG_ON(!pmd_none(*pmd));
236		set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
237	}
238}
239
240void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
241{
242	__init_extra_mapping(phys, size, PAGE_KERNEL_LARGE);
243}
244
245void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
246{
247	__init_extra_mapping(phys, size, PAGE_KERNEL_LARGE_NOCACHE);
248}
249
250/*
251 * The head.S code sets up the kernel high mapping:
252 *
253 *   from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
254 *
255 * phys_addr holds the negative offset to the kernel, which is added
256 * to the compile time generated pmds. This results in invalid pmds up
257 * to the point where we hit the physaddr 0 mapping.
258 *
259 * We limit the mappings to the region from _text to _end.  _end is
260 * rounded up to the 2MB boundary. This catches the invalid pmds as
261 * well, as they are located before _text:
262 */
263void __init cleanup_highmap(void)
264{
265	unsigned long vaddr = __START_KERNEL_map;
266	unsigned long end = roundup((unsigned long)_end, PMD_SIZE) - 1;
267	pmd_t *pmd = level2_kernel_pgt;
268	pmd_t *last_pmd = pmd + PTRS_PER_PMD;
269
270	for (; pmd < last_pmd; pmd++, vaddr += PMD_SIZE) {
271		if (pmd_none(*pmd))
272			continue;
273		if (vaddr < (unsigned long) _text || vaddr > end)
274			set_pmd(pmd, __pmd(0));
275	}
276}
277
278static __ref void *alloc_low_page(unsigned long *phys)
279{
280	unsigned long pfn = e820_table_end++;
281	void *adr;
282
283	if (after_bootmem) {
284		adr = (void *)get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK);
285		*phys = __pa(adr);
286
287		return adr;
288	}
289
290	if (pfn >= e820_table_top)
291		panic("alloc_low_page: ran out of memory");
292
293	adr = early_memremap(pfn * PAGE_SIZE, PAGE_SIZE);
294	memset(adr, 0, PAGE_SIZE);
295	*phys  = pfn * PAGE_SIZE;
296	return adr;
297}
298
299static __ref void unmap_low_page(void *adr)
300{
301	if (after_bootmem)
302		return;
303
304	early_iounmap(adr, PAGE_SIZE);
305}
306
307static unsigned long __meminit
308phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end,
309	      pgprot_t prot)
310{
311	unsigned pages = 0;
312	unsigned long last_map_addr = end;
313	int i;
314
315	pte_t *pte = pte_page + pte_index(addr);
316
317	for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) {
318
319		if (addr >= end) {
320			if (!after_bootmem) {
321				for(; i < PTRS_PER_PTE; i++, pte++)
322					set_pte(pte, __pte(0));
323			}
324			break;
325		}
326
327		/*
328		 * We will re-use the existing mapping.
329		 * Xen for example has some special requirements, like mapping
330		 * pagetable pages as RO. So assume someone who pre-setup
331		 * these mappings are more intelligent.
332		 */
333		if (pte_val(*pte)) {
334			pages++;
335			continue;
336		}
337
338		if (0)
339			printk("   pte=%p addr=%lx pte=%016lx\n",
340			       pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte);
341		pages++;
342		set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot));
343		last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
344	}
345
346	update_page_count(PG_LEVEL_4K, pages);
347
348	return last_map_addr;
349}
350
351static unsigned long __meminit
352phys_pte_update(pmd_t *pmd, unsigned long address, unsigned long end,
353		pgprot_t prot)
354{
355	pte_t *pte = (pte_t *)pmd_page_vaddr(*pmd);
356
357	return phys_pte_init(pte, address, end, prot);
358}
359
360static unsigned long __meminit
361phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
362	      unsigned long page_size_mask, pgprot_t prot)
363{
364	unsigned long pages = 0;
365	unsigned long last_map_addr = end;
366
367	int i = pmd_index(address);
368
369	for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
370		unsigned long pte_phys;
371		pmd_t *pmd = pmd_page + pmd_index(address);
372		pte_t *pte;
373		pgprot_t new_prot = prot;
374
375		if (address >= end) {
376			if (!after_bootmem) {
377				for (; i < PTRS_PER_PMD; i++, pmd++)
378					set_pmd(pmd, __pmd(0));
379			}
380			break;
381		}
382
383		if (pmd_val(*pmd)) {
384			if (!pmd_large(*pmd)) {
385				spin_lock(&init_mm.page_table_lock);
386				last_map_addr = phys_pte_update(pmd, address,
387								end, prot);
388				spin_unlock(&init_mm.page_table_lock);
389				continue;
390			}
391			/*
392			 * If we are ok with PG_LEVEL_2M mapping, then we will
393			 * use the existing mapping,
394			 *
395			 * Otherwise, we will split the large page mapping but
396			 * use the same existing protection bits except for
397			 * large page, so that we don't violate Intel's TLB
398			 * Application note (317080) which says, while changing
399			 * the page sizes, new and old translations should
400			 * not differ with respect to page frame and
401			 * attributes.
402			 */
403			if (page_size_mask & (1 << PG_LEVEL_2M)) {
404				pages++;
405				continue;
406			}
407			new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
408		}
409
410		if (page_size_mask & (1<<PG_LEVEL_2M)) {
411			pages++;
412			spin_lock(&init_mm.page_table_lock);
413			set_pte((pte_t *)pmd,
414				pfn_pte(address >> PAGE_SHIFT,
415					__pgprot(pgprot_val(prot) | _PAGE_PSE)));
416			spin_unlock(&init_mm.page_table_lock);
417			last_map_addr = (address & PMD_MASK) + PMD_SIZE;
418			continue;
419		}
420
421		pte = alloc_low_page(&pte_phys);
422		last_map_addr = phys_pte_init(pte, address, end, new_prot);
423		unmap_low_page(pte);
424
425		spin_lock(&init_mm.page_table_lock);
426		pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
427		spin_unlock(&init_mm.page_table_lock);
428	}
429	update_page_count(PG_LEVEL_2M, pages);
430	return last_map_addr;
431}
432
433static unsigned long __meminit
434phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end,
435		unsigned long page_size_mask, pgprot_t prot)
436{
437	pmd_t *pmd = pmd_offset(pud, 0);
438	unsigned long last_map_addr;
439
440	last_map_addr = phys_pmd_init(pmd, address, end, page_size_mask, prot);
441	__flush_tlb_all();
442	return last_map_addr;
443}
444
445static unsigned long __meminit
446phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
447			 unsigned long page_size_mask)
448{
449	unsigned long pages = 0;
450	unsigned long last_map_addr = end;
451	int i = pud_index(addr);
452
453	for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
454		unsigned long pmd_phys;
455		pud_t *pud = pud_page + pud_index(addr);
456		pmd_t *pmd;
457		pgprot_t prot = PAGE_KERNEL;
458
459		if (addr >= end)
460			break;
461
462		if (!after_bootmem &&
463				!e820_any_mapped(addr, addr+PUD_SIZE, 0)) {
464			set_pud(pud, __pud(0));
465			continue;
466		}
467
468		if (pud_val(*pud)) {
469			if (!pud_large(*pud)) {
470				last_map_addr = phys_pmd_update(pud, addr, end,
471							 page_size_mask, prot);
472				continue;
473			}
474			/*
475			 * If we are ok with PG_LEVEL_1G mapping, then we will
476			 * use the existing mapping.
477			 *
478			 * Otherwise, we will split the gbpage mapping but use
479			 * the same existing protection  bits except for large
480			 * page, so that we don't violate Intel's TLB
481			 * Application note (317080) which says, while changing
482			 * the page sizes, new and old translations should
483			 * not differ with respect to page frame and
484			 * attributes.
485			 */
486			if (page_size_mask & (1 << PG_LEVEL_1G)) {
487				pages++;
488				continue;
489			}
490			prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
491		}
492
493		if (page_size_mask & (1<<PG_LEVEL_1G)) {
494			pages++;
495			spin_lock(&init_mm.page_table_lock);
496			set_pte((pte_t *)pud,
497				pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
498			spin_unlock(&init_mm.page_table_lock);
499			last_map_addr = (addr & PUD_MASK) + PUD_SIZE;
500			continue;
501		}
502
503		pmd = alloc_low_page(&pmd_phys);
504		last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask,
505					      prot);
506		unmap_low_page(pmd);
507
508		spin_lock(&init_mm.page_table_lock);
509		pud_populate(&init_mm, pud, __va(pmd_phys));
510		spin_unlock(&init_mm.page_table_lock);
511	}
512	__flush_tlb_all();
513
514	update_page_count(PG_LEVEL_1G, pages);
515
516	return last_map_addr;
517}
518
519static unsigned long __meminit
520phys_pud_update(pgd_t *pgd, unsigned long addr, unsigned long end,
521		 unsigned long page_size_mask)
522{
523	pud_t *pud;
524
525	pud = (pud_t *)pgd_page_vaddr(*pgd);
526
527	return phys_pud_init(pud, addr, end, page_size_mask);
528}
529
530unsigned long __meminit
531kernel_physical_mapping_init(unsigned long start,
532			     unsigned long end,
533			     unsigned long page_size_mask)
534{
535
536	unsigned long next, last_map_addr = end;
537
538	start = (unsigned long)__va(start);
539	end = (unsigned long)__va(end);
540
541	for (; start < end; start = next) {
542		pgd_t *pgd = pgd_offset_k(start);
543		unsigned long pud_phys;
544		pud_t *pud;
545
546		next = (start + PGDIR_SIZE) & PGDIR_MASK;
547		if (next > end)
548			next = end;
549
550		if (pgd_val(*pgd)) {
551			last_map_addr = phys_pud_update(pgd, __pa(start),
552						 __pa(end), page_size_mask);
553			continue;
554		}
555
556		pud = alloc_low_page(&pud_phys);
557		last_map_addr = phys_pud_init(pud, __pa(start), __pa(next),
558						 page_size_mask);
559		unmap_low_page(pud);
560
561		spin_lock(&init_mm.page_table_lock);
562		pgd_populate(&init_mm, pgd, __va(pud_phys));
563		spin_unlock(&init_mm.page_table_lock);
564	}
565	__flush_tlb_all();
566
567	return last_map_addr;
568}
569
570#ifndef CONFIG_NUMA
571void __init initmem_init(unsigned long start_pfn, unsigned long end_pfn,
572				int acpi, int k8)
573{
574	unsigned long bootmap_size, bootmap;
575
576	bootmap_size = bootmem_bootmap_pages(end_pfn)<<PAGE_SHIFT;
577	bootmap = find_e820_area(0, end_pfn<<PAGE_SHIFT, bootmap_size,
578				 PAGE_SIZE);
579	if (bootmap == -1L)
580		panic("Cannot find bootmem map of size %ld\n", bootmap_size);
581	/* don't touch min_low_pfn */
582	bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap >> PAGE_SHIFT,
583					 0, end_pfn);
584	e820_register_active_regions(0, start_pfn, end_pfn);
585	free_bootmem_with_active_regions(0, end_pfn);
586	early_res_to_bootmem(0, end_pfn<<PAGE_SHIFT);
587	reserve_bootmem(bootmap, bootmap_size, BOOTMEM_DEFAULT);
588}
589#endif
590
591void __init paging_init(void)
592{
593	unsigned long max_zone_pfns[MAX_NR_ZONES];
594
595	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
596	max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
597	max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
598	max_zone_pfns[ZONE_NORMAL] = max_pfn;
599
600	sparse_memory_present_with_active_regions(MAX_NUMNODES);
601	sparse_init();
602
603	/*
604	 * clear the default setting with node 0
605	 * note: don't use nodes_clear here, that is really clearing when
606	 *	 numa support is not compiled in, and later node_set_state
607	 *	 will not set it back.
608	 */
609	node_clear_state(0, N_NORMAL_MEMORY);
610
611	free_area_init_nodes(max_zone_pfns);
612}
613
614/*
615 * Memory hotplug specific functions
616 */
617#ifdef CONFIG_MEMORY_HOTPLUG
618/*
619 * Memory is added always to NORMAL zone. This means you will never get
620 * additional DMA/DMA32 memory.
621 */
622int arch_add_memory(int nid, u64 start, u64 size)
623{
624	struct pglist_data *pgdat = NODE_DATA(nid);
625	struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
626	unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT;
627	unsigned long nr_pages = size >> PAGE_SHIFT;
628	int ret;
629
630	last_mapped_pfn = init_memory_mapping(start, start + size);
631	if (last_mapped_pfn > max_pfn_mapped)
632		max_pfn_mapped = last_mapped_pfn;
633
634	ret = __add_pages(nid, zone, start_pfn, nr_pages);
635	WARN_ON_ONCE(ret);
636
637	return ret;
638}
639EXPORT_SYMBOL_GPL(arch_add_memory);
640
641#if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
642int memory_add_physaddr_to_nid(u64 start)
643{
644	return 0;
645}
646EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
647#endif
648
649#endif /* CONFIG_MEMORY_HOTPLUG */
650
651static struct kcore_list kcore_vsyscall;
652
653void __init mem_init(void)
654{
655	long codesize, reservedpages, datasize, initsize;
656	unsigned long absent_pages;
657
658	pci_iommu_alloc();
659
660	/* clear_bss() already clear the empty_zero_page */
661
662	reservedpages = 0;
663
664	/* this will put all low memory onto the freelists */
665#ifdef CONFIG_NUMA
666	totalram_pages = numa_free_all_bootmem();
667#else
668	totalram_pages = free_all_bootmem();
669#endif
670
671	absent_pages = absent_pages_in_range(0, max_pfn);
672	reservedpages = max_pfn - totalram_pages - absent_pages;
673	after_bootmem = 1;
674
675	codesize =  (unsigned long) &_etext - (unsigned long) &_text;
676	datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
677	initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
678
679	/* Register memory areas for /proc/kcore */
680	kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
681			 VSYSCALL_END - VSYSCALL_START, KCORE_OTHER);
682
683	printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
684			 "%ldk absent, %ldk reserved, %ldk data, %ldk init)\n",
685		nr_free_pages() << (PAGE_SHIFT-10),
686		max_pfn << (PAGE_SHIFT-10),
687		codesize >> 10,
688		absent_pages << (PAGE_SHIFT-10),
689		reservedpages << (PAGE_SHIFT-10),
690		datasize >> 10,
691		initsize >> 10);
692}
693
694#ifdef CONFIG_DEBUG_RODATA
695const int rodata_test_data = 0xC3;
696EXPORT_SYMBOL_GPL(rodata_test_data);
697
698static int kernel_set_to_readonly;
699
700void set_kernel_text_rw(void)
701{
702	unsigned long start = PFN_ALIGN(_stext);
703	unsigned long end = PFN_ALIGN(__start_rodata);
704
705	if (!kernel_set_to_readonly)
706		return;
707
708	pr_debug("Set kernel text: %lx - %lx for read write\n",
709		 start, end);
710
711	set_memory_rw(start, (end - start) >> PAGE_SHIFT);
712}
713
714void set_kernel_text_ro(void)
715{
716	unsigned long start = PFN_ALIGN(_stext);
717	unsigned long end = PFN_ALIGN(__start_rodata);
718
719	if (!kernel_set_to_readonly)
720		return;
721
722	pr_debug("Set kernel text: %lx - %lx for read only\n",
723		 start, end);
724
725	set_memory_ro(start, (end - start) >> PAGE_SHIFT);
726}
727
728void mark_rodata_ro(void)
729{
730	unsigned long start = PFN_ALIGN(_stext), end = PFN_ALIGN(__end_rodata);
731	unsigned long rodata_start =
732		((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
733
734	printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
735	       (end - start) >> 10);
736	set_memory_ro(start, (end - start) >> PAGE_SHIFT);
737
738	kernel_set_to_readonly = 1;
739
740	/*
741	 * The rodata section (but not the kernel text!) should also be
742	 * not-executable.
743	 */
744	set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT);
745
746	rodata_test();
747
748#ifdef CONFIG_CPA_DEBUG
749	printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
750	set_memory_rw(start, (end-start) >> PAGE_SHIFT);
751
752	printk(KERN_INFO "Testing CPA: again\n");
753	set_memory_ro(start, (end-start) >> PAGE_SHIFT);
754#endif
755}
756
757#endif
758
759int __init reserve_bootmem_generic(unsigned long phys, unsigned long len,
760				   int flags)
761{
762#ifdef CONFIG_NUMA
763	int nid, next_nid;
764	int ret;
765#endif
766	unsigned long pfn = phys >> PAGE_SHIFT;
767
768	if (pfn >= max_pfn) {
769		/*
770		 * This can happen with kdump kernels when accessing
771		 * firmware tables:
772		 */
773		if (pfn < max_pfn_mapped)
774			return -EFAULT;
775
776		printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %lu\n",
777				phys, len);
778		return -EFAULT;
779	}
780
781	/* Should check here against the e820 map to avoid double free */
782#ifdef CONFIG_NUMA
783	nid = phys_to_nid(phys);
784	next_nid = phys_to_nid(phys + len - 1);
785	if (nid == next_nid)
786		ret = reserve_bootmem_node(NODE_DATA(nid), phys, len, flags);
787	else
788		ret = reserve_bootmem(phys, len, flags);
789
790	if (ret != 0)
791		return ret;
792
793#else
794	reserve_bootmem(phys, len, flags);
795#endif
796
797	if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
798		dma_reserve += len / PAGE_SIZE;
799		set_dma_reserve(dma_reserve);
800	}
801
802	return 0;
803}
804
805int kern_addr_valid(unsigned long addr)
806{
807	unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
808	pgd_t *pgd;
809	pud_t *pud;
810	pmd_t *pmd;
811	pte_t *pte;
812
813	if (above != 0 && above != -1UL)
814		return 0;
815
816	pgd = pgd_offset_k(addr);
817	if (pgd_none(*pgd))
818		return 0;
819
820	pud = pud_offset(pgd, addr);
821	if (pud_none(*pud))
822		return 0;
823
824	pmd = pmd_offset(pud, addr);
825	if (pmd_none(*pmd))
826		return 0;
827
828	if (pmd_large(*pmd))
829		return pfn_valid(pmd_pfn(*pmd));
830
831	pte = pte_offset_kernel(pmd, addr);
832	if (pte_none(*pte))
833		return 0;
834
835	return pfn_valid(pte_pfn(*pte));
836}
837
838/*
839 * A pseudo VMA to allow ptrace access for the vsyscall page.  This only
840 * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
841 * not need special handling anymore:
842 */
843static struct vm_area_struct gate_vma = {
844	.vm_start	= VSYSCALL_START,
845	.vm_end		= VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
846	.vm_page_prot	= PAGE_READONLY_EXEC,
847	.vm_flags	= VM_READ | VM_EXEC
848};
849
850struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
851{
852#ifdef CONFIG_IA32_EMULATION
853	if (test_tsk_thread_flag(tsk, TIF_IA32))
854		return NULL;
855#endif
856	return &gate_vma;
857}
858
859int in_gate_area(struct task_struct *task, unsigned long addr)
860{
861	struct vm_area_struct *vma = get_gate_vma(task);
862
863	if (!vma)
864		return 0;
865
866	return (addr >= vma->vm_start) && (addr < vma->vm_end);
867}
868
869/*
870 * Use this when you have no reliable task/vma, typically from interrupt
871 * context. It is less reliable than using the task's vma and may give
872 * false positives:
873 */
874int in_gate_area_no_task(unsigned long addr)
875{
876	return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
877}
878
879const char *arch_vma_name(struct vm_area_struct *vma)
880{
881	if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
882		return "[vdso]";
883	if (vma == &gate_vma)
884		return "[vsyscall]";
885	return NULL;
886}
887
888#ifdef CONFIG_SPARSEMEM_VMEMMAP
889/*
890 * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
891 */
892static long __meminitdata addr_start, addr_end;
893static void __meminitdata *p_start, *p_end;
894static int __meminitdata node_start;
895
896int __meminit
897vmemmap_populate(struct page *start_page, unsigned long size, int node)
898{
899	unsigned long addr = (unsigned long)start_page;
900	unsigned long end = (unsigned long)(start_page + size);
901	unsigned long next;
902	pgd_t *pgd;
903	pud_t *pud;
904	pmd_t *pmd;
905
906	for (; addr < end; addr = next) {
907		void *p = NULL;
908
909		pgd = vmemmap_pgd_populate(addr, node);
910		if (!pgd)
911			return -ENOMEM;
912
913		pud = vmemmap_pud_populate(pgd, addr, node);
914		if (!pud)
915			return -ENOMEM;
916
917		if (!cpu_has_pse) {
918			next = (addr + PAGE_SIZE) & PAGE_MASK;
919			pmd = vmemmap_pmd_populate(pud, addr, node);
920
921			if (!pmd)
922				return -ENOMEM;
923
924			p = vmemmap_pte_populate(pmd, addr, node);
925
926			if (!p)
927				return -ENOMEM;
928
929			addr_end = addr + PAGE_SIZE;
930			p_end = p + PAGE_SIZE;
931		} else {
932			next = pmd_addr_end(addr, end);
933
934			pmd = pmd_offset(pud, addr);
935			if (pmd_none(*pmd)) {
936				pte_t entry;
937
938				p = vmemmap_alloc_block(PMD_SIZE, node);
939				if (!p)
940					return -ENOMEM;
941
942				entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
943						PAGE_KERNEL_LARGE);
944				set_pmd(pmd, __pmd(pte_val(entry)));
945
946				/* check to see if we have contiguous blocks */
947				if (p_end != p || node_start != node) {
948					if (p_start)
949						printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
950						       addr_start, addr_end-1, p_start, p_end-1, node_start);
951					addr_start = addr;
952					node_start = node;
953					p_start = p;
954				}
955
956				addr_end = addr + PMD_SIZE;
957				p_end = p + PMD_SIZE;
958			} else
959				vmemmap_verify((pte_t *)pmd, node, addr, next);
960		}
961
962	}
963	return 0;
964}
965
966void __meminit vmemmap_populate_print_last(void)
967{
968	if (p_start) {
969		printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
970			addr_start, addr_end-1, p_start, p_end-1, node_start);
971		p_start = NULL;
972		p_end = NULL;
973		node_start = 0;
974	}
975}
976#endif
977