1/*
  2 *  linux/arch/x86_64/mm/init.c
  3 *
  4 *  Copyright (C) 1995  Linus Torvalds
  5 *  Copyright (C) 2000  Pavel Machek <pavel@ucw.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/memblock.h>
 25#include <linux/proc_fs.h>
 26#include <linux/pci.h>
 27#include <linux/pfn.h>
 28#include <linux/poison.h>
 29#include <linux/dma-mapping.h>
 30#include <linux/module.h>
 31#include <linux/memory.h>
 32#include <linux/memory_hotplug.h>
 
 33#include <linux/nmi.h>
 34#include <linux/gfp.h>
 
 35
 36#include <asm/processor.h>
 37#include <asm/bios_ebda.h>
 38#include <asm/system.h>
 39#include <asm/uaccess.h>
 40#include <asm/pgtable.h>
 41#include <asm/pgalloc.h>
 42#include <asm/dma.h>
 43#include <asm/fixmap.h>
 44#include <asm/e820.h>
 45#include <asm/apic.h>
 46#include <asm/tlb.h>
 47#include <asm/mmu_context.h>
 48#include <asm/proto.h>
 49#include <asm/smp.h>
 50#include <asm/sections.h>
 51#include <asm/kdebug.h>
 52#include <asm/numa.h>
 53#include <asm/cacheflush.h>
 54#include <asm/init.h>
 55#include <asm/uv/uv.h>
 56#include <asm/setup.h>
 57
 58static int __init parse_direct_gbpages_off(char *arg)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 59{
 60	direct_gbpages = 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 61	return 0;
 62}
 63early_param("nogbpages", parse_direct_gbpages_off);
 64
 65static int __init parse_direct_gbpages_on(char *arg)
 
 66{
 67	direct_gbpages = 1;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 68	return 0;
 69}
 70early_param("gbpages", parse_direct_gbpages_on);
 71
 72/*
 73 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
 74 * physical space so we can cache the place of the first one and move
 75 * around without checking the pgd every time.
 76 */
 77
 78pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP;
 79EXPORT_SYMBOL_GPL(__supported_pte_mask);
 80
 81int force_personality32;
 82
 83/*
 84 * noexec32=on|off
 85 * Control non executable heap for 32bit processes.
 86 * To control the stack too use noexec=off
 87 *
 88 * on	PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
 89 * off	PROT_READ implies PROT_EXEC
 90 */
 91static int __init nonx32_setup(char *str)
 92{
 93	if (!strcmp(str, "on"))
 94		force_personality32 &= ~READ_IMPLIES_EXEC;
 95	else if (!strcmp(str, "off"))
 96		force_personality32 |= READ_IMPLIES_EXEC;
 97	return 1;
 98}
 99__setup("noexec32=", nonx32_setup);
100
101/*
102 * When memory was added/removed make sure all the processes MM have
103 * suitable PGD entries in the local PGD level page.
104 */
105void sync_global_pgds(unsigned long start, unsigned long end)
106{
107	unsigned long address;
108
109	for (address = start; address <= end; address += PGDIR_SIZE) {
110		const pgd_t *pgd_ref = pgd_offset_k(address);
111		struct page *page;
112
113		if (pgd_none(*pgd_ref))
 
 
 
 
 
114			continue;
115
116		spin_lock(&pgd_lock);
117		list_for_each_entry(page, &pgd_list, lru) {
118			pgd_t *pgd;
119			spinlock_t *pgt_lock;
120
121			pgd = (pgd_t *)page_address(page) + pgd_index(address);
122			/* the pgt_lock only for Xen */
123			pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
124			spin_lock(pgt_lock);
125
126			if (pgd_none(*pgd))
127				set_pgd(pgd, *pgd_ref);
128			else
129				BUG_ON(pgd_page_vaddr(*pgd)
130				       != pgd_page_vaddr(*pgd_ref));
131
 
 
 
 
 
 
 
 
132			spin_unlock(pgt_lock);
133		}
134		spin_unlock(&pgd_lock);
135	}
136}
137
138/*
139 * NOTE: This function is marked __ref because it calls __init function
140 * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
141 */
142static __ref void *spp_getpage(void)
143{
144	void *ptr;
145
146	if (after_bootmem)
147		ptr = (void *) get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK);
148	else
149		ptr = alloc_bootmem_pages(PAGE_SIZE);
150
151	if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
152		panic("set_pte_phys: cannot allocate page data %s\n",
153			after_bootmem ? "after bootmem" : "");
154	}
155
156	pr_debug("spp_getpage %p\n", ptr);
157
158	return ptr;
159}
160
161static pud_t *fill_pud(pgd_t *pgd, unsigned long vaddr)
162{
163	if (pgd_none(*pgd)) {
164		pud_t *pud = (pud_t *)spp_getpage();
165		pgd_populate(&init_mm, pgd, pud);
166		if (pud != pud_offset(pgd, 0))
167			printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n",
168			       pud, pud_offset(pgd, 0));
169	}
170	return pud_offset(pgd, vaddr);
171}
172
173static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr)
174{
175	if (pud_none(*pud)) {
176		pmd_t *pmd = (pmd_t *) spp_getpage();
177		pud_populate(&init_mm, pud, pmd);
178		if (pmd != pmd_offset(pud, 0))
179			printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
180			       pmd, pmd_offset(pud, 0));
181	}
182	return pmd_offset(pud, vaddr);
183}
184
185static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr)
186{
187	if (pmd_none(*pmd)) {
188		pte_t *pte = (pte_t *) spp_getpage();
189		pmd_populate_kernel(&init_mm, pmd, pte);
190		if (pte != pte_offset_kernel(pmd, 0))
191			printk(KERN_ERR "PAGETABLE BUG #02!\n");
192	}
193	return pte_offset_kernel(pmd, vaddr);
194}
195
196void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
197{
198	pud_t *pud;
199	pmd_t *pmd;
200	pte_t *pte;
201
202	pud = pud_page + pud_index(vaddr);
203	pmd = fill_pmd(pud, vaddr);
204	pte = fill_pte(pmd, vaddr);
205
206	set_pte(pte, new_pte);
207
208	/*
209	 * It's enough to flush this one mapping.
210	 * (PGE mappings get flushed as well)
211	 */
212	__flush_tlb_one(vaddr);
213}
214
215void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
216{
217	pgd_t *pgd;
218	pud_t *pud_page;
219
220	pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
221
222	pgd = pgd_offset_k(vaddr);
223	if (pgd_none(*pgd)) {
224		printk(KERN_ERR
225			"PGD FIXMAP MISSING, it should be setup in head.S!\n");
226		return;
227	}
228	pud_page = (pud_t*)pgd_page_vaddr(*pgd);
229	set_pte_vaddr_pud(pud_page, vaddr, pteval);
230}
231
232pmd_t * __init populate_extra_pmd(unsigned long vaddr)
233{
234	pgd_t *pgd;
235	pud_t *pud;
236
237	pgd = pgd_offset_k(vaddr);
238	pud = fill_pud(pgd, vaddr);
239	return fill_pmd(pud, vaddr);
240}
241
242pte_t * __init populate_extra_pte(unsigned long vaddr)
243{
244	pmd_t *pmd;
245
246	pmd = populate_extra_pmd(vaddr);
247	return fill_pte(pmd, vaddr);
248}
249
250/*
251 * Create large page table mappings for a range of physical addresses.
252 */
253static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
254						pgprot_t prot)
255{
256	pgd_t *pgd;
257	pud_t *pud;
258	pmd_t *pmd;
 
259
 
 
260	BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
261	for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
262		pgd = pgd_offset_k((unsigned long)__va(phys));
263		if (pgd_none(*pgd)) {
264			pud = (pud_t *) spp_getpage();
265			set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE |
266						_PAGE_USER));
267		}
268		pud = pud_offset(pgd, (unsigned long)__va(phys));
269		if (pud_none(*pud)) {
270			pmd = (pmd_t *) spp_getpage();
271			set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
272						_PAGE_USER));
273		}
274		pmd = pmd_offset(pud, phys);
275		BUG_ON(!pmd_none(*pmd));
276		set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
277	}
278}
279
280void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
281{
282	__init_extra_mapping(phys, size, PAGE_KERNEL_LARGE);
283}
284
285void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
286{
287	__init_extra_mapping(phys, size, PAGE_KERNEL_LARGE_NOCACHE);
288}
289
290/*
291 * The head.S code sets up the kernel high mapping:
292 *
293 *   from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
294 *
295 * phys_addr holds the negative offset to the kernel, which is added
296 * to the compile time generated pmds. This results in invalid pmds up
297 * to the point where we hit the physaddr 0 mapping.
298 *
299 * We limit the mappings to the region from _text to _brk_end.  _brk_end
300 * is rounded up to the 2MB boundary. This catches the invalid pmds as
301 * well, as they are located before _text:
302 */
303void __init cleanup_highmap(void)
304{
305	unsigned long vaddr = __START_KERNEL_map;
306	unsigned long vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT);
307	unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1;
308	pmd_t *pmd = level2_kernel_pgt;
309
 
 
 
 
 
 
 
 
310	for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) {
311		if (pmd_none(*pmd))
312			continue;
313		if (vaddr < (unsigned long) _text || vaddr > end)
314			set_pmd(pmd, __pmd(0));
315	}
316}
317
318static __ref void *alloc_low_page(unsigned long *phys)
319{
320	unsigned long pfn = pgt_buf_end++;
321	void *adr;
322
323	if (after_bootmem) {
324		adr = (void *)get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK);
325		*phys = __pa(adr);
326
327		return adr;
328	}
329
330	if (pfn >= pgt_buf_top)
331		panic("alloc_low_page: ran out of memory");
332
333	adr = early_memremap(pfn * PAGE_SIZE, PAGE_SIZE);
334	clear_page(adr);
335	*phys  = pfn * PAGE_SIZE;
336	return adr;
337}
338
339static __ref void *map_low_page(void *virt)
340{
341	void *adr;
342	unsigned long phys, left;
343
344	if (after_bootmem)
345		return virt;
346
347	phys = __pa(virt);
348	left = phys & (PAGE_SIZE - 1);
349	adr = early_memremap(phys & PAGE_MASK, PAGE_SIZE);
350	adr = (void *)(((unsigned long)adr) | left);
351
352	return adr;
353}
354
355static __ref void unmap_low_page(void *adr)
356{
357	if (after_bootmem)
358		return;
359
360	early_iounmap((void *)((unsigned long)adr & PAGE_MASK), PAGE_SIZE);
361}
362
363static unsigned long __meminit
364phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end,
365	      pgprot_t prot)
366{
367	unsigned pages = 0;
368	unsigned long last_map_addr = end;
369	int i;
370
371	pte_t *pte = pte_page + pte_index(addr);
372
373	for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) {
374
375		if (addr >= end) {
376			if (!after_bootmem) {
377				for(; i < PTRS_PER_PTE; i++, pte++)
378					set_pte(pte, __pte(0));
379			}
380			break;
381		}
382
383		/*
384		 * We will re-use the existing mapping.
385		 * Xen for example has some special requirements, like mapping
386		 * pagetable pages as RO. So assume someone who pre-setup
387		 * these mappings are more intelligent.
388		 */
389		if (pte_val(*pte)) {
390			pages++;
 
391			continue;
392		}
393
394		if (0)
395			printk("   pte=%p addr=%lx pte=%016lx\n",
396			       pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte);
397		pages++;
398		set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot));
399		last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
400	}
401
402	update_page_count(PG_LEVEL_4K, pages);
403
404	return last_map_addr;
405}
406
407static unsigned long __meminit
408phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
409	      unsigned long page_size_mask, pgprot_t prot)
410{
411	unsigned long pages = 0;
412	unsigned long last_map_addr = end;
413
414	int i = pmd_index(address);
415
416	for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
417		unsigned long pte_phys;
418		pmd_t *pmd = pmd_page + pmd_index(address);
419		pte_t *pte;
420		pgprot_t new_prot = prot;
421
 
422		if (address >= end) {
423			if (!after_bootmem) {
424				for (; i < PTRS_PER_PMD; i++, pmd++)
425					set_pmd(pmd, __pmd(0));
426			}
427			break;
428		}
429
430		if (pmd_val(*pmd)) {
431			if (!pmd_large(*pmd)) {
432				spin_lock(&init_mm.page_table_lock);
433				pte = map_low_page((pte_t *)pmd_page_vaddr(*pmd));
434				last_map_addr = phys_pte_init(pte, address,
435								end, prot);
436				unmap_low_page(pte);
437				spin_unlock(&init_mm.page_table_lock);
438				continue;
439			}
440			/*
441			 * If we are ok with PG_LEVEL_2M mapping, then we will
442			 * use the existing mapping,
443			 *
444			 * Otherwise, we will split the large page mapping but
445			 * use the same existing protection bits except for
446			 * large page, so that we don't violate Intel's TLB
447			 * Application note (317080) which says, while changing
448			 * the page sizes, new and old translations should
449			 * not differ with respect to page frame and
450			 * attributes.
451			 */
452			if (page_size_mask & (1 << PG_LEVEL_2M)) {
453				pages++;
 
 
454				continue;
455			}
456			new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
457		}
458
459		if (page_size_mask & (1<<PG_LEVEL_2M)) {
460			pages++;
461			spin_lock(&init_mm.page_table_lock);
462			set_pte((pte_t *)pmd,
463				pfn_pte(address >> PAGE_SHIFT,
464					__pgprot(pgprot_val(prot) | _PAGE_PSE)));
465			spin_unlock(&init_mm.page_table_lock);
466			last_map_addr = (address & PMD_MASK) + PMD_SIZE;
467			continue;
468		}
469
470		pte = alloc_low_page(&pte_phys);
471		last_map_addr = phys_pte_init(pte, address, end, new_prot);
472		unmap_low_page(pte);
473
474		spin_lock(&init_mm.page_table_lock);
475		pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
476		spin_unlock(&init_mm.page_table_lock);
477	}
478	update_page_count(PG_LEVEL_2M, pages);
479	return last_map_addr;
480}
481
482static unsigned long __meminit
483phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
484			 unsigned long page_size_mask)
485{
486	unsigned long pages = 0;
487	unsigned long last_map_addr = end;
488	int i = pud_index(addr);
489
490	for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
491		unsigned long pmd_phys;
492		pud_t *pud = pud_page + pud_index(addr);
493		pmd_t *pmd;
494		pgprot_t prot = PAGE_KERNEL;
495
496		if (addr >= end)
497			break;
498
499		if (!after_bootmem &&
500				!e820_any_mapped(addr, addr+PUD_SIZE, 0)) {
501			set_pud(pud, __pud(0));
502			continue;
503		}
504
505		if (pud_val(*pud)) {
506			if (!pud_large(*pud)) {
507				pmd = map_low_page(pmd_offset(pud, 0));
508				last_map_addr = phys_pmd_init(pmd, addr, end,
509							 page_size_mask, prot);
510				unmap_low_page(pmd);
511				__flush_tlb_all();
512				continue;
513			}
514			/*
515			 * If we are ok with PG_LEVEL_1G mapping, then we will
516			 * use the existing mapping.
517			 *
518			 * Otherwise, we will split the gbpage mapping but use
519			 * the same existing protection  bits except for large
520			 * page, so that we don't violate Intel's TLB
521			 * Application note (317080) which says, while changing
522			 * the page sizes, new and old translations should
523			 * not differ with respect to page frame and
524			 * attributes.
525			 */
526			if (page_size_mask & (1 << PG_LEVEL_1G)) {
527				pages++;
 
 
528				continue;
529			}
530			prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
531		}
532
533		if (page_size_mask & (1<<PG_LEVEL_1G)) {
534			pages++;
535			spin_lock(&init_mm.page_table_lock);
536			set_pte((pte_t *)pud,
537				pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
 
538			spin_unlock(&init_mm.page_table_lock);
539			last_map_addr = (addr & PUD_MASK) + PUD_SIZE;
540			continue;
541		}
542
543		pmd = alloc_low_page(&pmd_phys);
544		last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask,
545					      prot);
546		unmap_low_page(pmd);
547
548		spin_lock(&init_mm.page_table_lock);
549		pud_populate(&init_mm, pud, __va(pmd_phys));
550		spin_unlock(&init_mm.page_table_lock);
551	}
552	__flush_tlb_all();
553
554	update_page_count(PG_LEVEL_1G, pages);
555
556	return last_map_addr;
557}
558
559unsigned long __meminit
560kernel_physical_mapping_init(unsigned long start,
561			     unsigned long end,
562			     unsigned long page_size_mask)
563{
564	bool pgd_changed = false;
565	unsigned long next, last_map_addr = end;
566	unsigned long addr;
567
568	start = (unsigned long)__va(start);
569	end = (unsigned long)__va(end);
570	addr = start;
571
572	for (; start < end; start = next) {
573		pgd_t *pgd = pgd_offset_k(start);
574		unsigned long pud_phys;
575		pud_t *pud;
576
577		next = (start + PGDIR_SIZE) & PGDIR_MASK;
578		if (next > end)
579			next = end;
580
581		if (pgd_val(*pgd)) {
582			pud = map_low_page((pud_t *)pgd_page_vaddr(*pgd));
583			last_map_addr = phys_pud_init(pud, __pa(start),
584						 __pa(end), page_size_mask);
585			unmap_low_page(pud);
586			continue;
587		}
588
589		pud = alloc_low_page(&pud_phys);
590		last_map_addr = phys_pud_init(pud, __pa(start), __pa(next),
591						 page_size_mask);
592		unmap_low_page(pud);
593
594		spin_lock(&init_mm.page_table_lock);
595		pgd_populate(&init_mm, pgd, __va(pud_phys));
596		spin_unlock(&init_mm.page_table_lock);
597		pgd_changed = true;
598	}
599
600	if (pgd_changed)
601		sync_global_pgds(addr, end);
602
603	__flush_tlb_all();
604
605	return last_map_addr;
606}
607
608#ifndef CONFIG_NUMA
609void __init initmem_init(void)
610{
611	memblock_x86_register_active_regions(0, 0, max_pfn);
612}
613#endif
614
615void __init paging_init(void)
616{
617	unsigned long max_zone_pfns[MAX_NR_ZONES];
618
619	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
620#ifdef CONFIG_ZONE_DMA
621	max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
622#endif
623	max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
624	max_zone_pfns[ZONE_NORMAL] = max_pfn;
625
626	sparse_memory_present_with_active_regions(MAX_NUMNODES);
627	sparse_init();
628
629	/*
630	 * clear the default setting with node 0
631	 * note: don't use nodes_clear here, that is really clearing when
632	 *	 numa support is not compiled in, and later node_set_state
633	 *	 will not set it back.
634	 */
635	node_clear_state(0, N_NORMAL_MEMORY);
 
 
636
637	free_area_init_nodes(max_zone_pfns);
638}
639
640/*
641 * Memory hotplug specific functions
642 */
643#ifdef CONFIG_MEMORY_HOTPLUG
644/*
645 * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
646 * updating.
647 */
648static void  update_end_of_memory_vars(u64 start, u64 size)
649{
650	unsigned long end_pfn = PFN_UP(start + size);
651
652	if (end_pfn > max_pfn) {
653		max_pfn = end_pfn;
654		max_low_pfn = end_pfn;
655		high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
656	}
657}
658
659/*
660 * Memory is added always to NORMAL zone. This means you will never get
661 * additional DMA/DMA32 memory.
662 */
663int arch_add_memory(int nid, u64 start, u64 size)
664{
665	struct pglist_data *pgdat = NODE_DATA(nid);
666	struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
667	unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT;
 
668	unsigned long nr_pages = size >> PAGE_SHIFT;
669	int ret;
670
671	last_mapped_pfn = init_memory_mapping(start, start + size);
672	if (last_mapped_pfn > max_pfn_mapped)
673		max_pfn_mapped = last_mapped_pfn;
674
675	ret = __add_pages(nid, zone, start_pfn, nr_pages);
676	WARN_ON_ONCE(ret);
677
678	/* update max_pfn, max_low_pfn and high_memory */
679	update_end_of_memory_vars(start, size);
680
681	return ret;
682}
683EXPORT_SYMBOL_GPL(arch_add_memory);
684
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
685#endif /* CONFIG_MEMORY_HOTPLUG */
686
687static struct kcore_list kcore_vsyscall;
688
689void __init mem_init(void)
690{
691	long codesize, reservedpages, datasize, initsize;
692	unsigned long absent_pages;
693
 
 
 
 
 
 
 
694	pci_iommu_alloc();
695
696	/* clear_bss() already clear the empty_zero_page */
697
698	reservedpages = 0;
699
700	/* this will put all low memory onto the freelists */
701#ifdef CONFIG_NUMA
702	totalram_pages = numa_free_all_bootmem();
703#else
704	totalram_pages = free_all_bootmem();
705#endif
706
707	absent_pages = absent_pages_in_range(0, max_pfn);
708	reservedpages = max_pfn - totalram_pages - absent_pages;
709	after_bootmem = 1;
710
711	codesize =  (unsigned long) &_etext - (unsigned long) &_text;
712	datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
713	initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
714
715	/* Register memory areas for /proc/kcore */
716	kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
717			 VSYSCALL_END - VSYSCALL_START, KCORE_OTHER);
718
719	printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
720			 "%ldk absent, %ldk reserved, %ldk data, %ldk init)\n",
721		nr_free_pages() << (PAGE_SHIFT-10),
722		max_pfn << (PAGE_SHIFT-10),
723		codesize >> 10,
724		absent_pages << (PAGE_SHIFT-10),
725		reservedpages << (PAGE_SHIFT-10),
726		datasize >> 10,
727		initsize >> 10);
728}
729
730#ifdef CONFIG_DEBUG_RODATA
731const int rodata_test_data = 0xC3;
732EXPORT_SYMBOL_GPL(rodata_test_data);
733
734int kernel_set_to_readonly;
735
736void set_kernel_text_rw(void)
737{
738	unsigned long start = PFN_ALIGN(_text);
739	unsigned long end = PFN_ALIGN(__stop___ex_table);
740
741	if (!kernel_set_to_readonly)
742		return;
743
744	pr_debug("Set kernel text: %lx - %lx for read write\n",
745		 start, end);
746
747	/*
748	 * Make the kernel identity mapping for text RW. Kernel text
749	 * mapping will always be RO. Refer to the comment in
750	 * static_protections() in pageattr.c
751	 */
752	set_memory_rw(start, (end - start) >> PAGE_SHIFT);
753}
754
755void set_kernel_text_ro(void)
756{
757	unsigned long start = PFN_ALIGN(_text);
758	unsigned long end = PFN_ALIGN(__stop___ex_table);
759
760	if (!kernel_set_to_readonly)
761		return;
762
763	pr_debug("Set kernel text: %lx - %lx for read only\n",
764		 start, end);
765
766	/*
767	 * Set the kernel identity mapping for text RO.
768	 */
769	set_memory_ro(start, (end - start) >> PAGE_SHIFT);
770}
771
772void mark_rodata_ro(void)
773{
774	unsigned long start = PFN_ALIGN(_text);
775	unsigned long rodata_start =
776		((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
777	unsigned long end = (unsigned long) &__end_rodata_hpage_align;
778	unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table);
779	unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata);
780	unsigned long data_start = (unsigned long) &_sdata;
781
782	printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
783	       (end - start) >> 10);
784	set_memory_ro(start, (end - start) >> PAGE_SHIFT);
785
786	kernel_set_to_readonly = 1;
787
788	/*
789	 * The rodata section (but not the kernel text!) should also be
790	 * not-executable.
 
 
 
 
 
 
 
 
791	 */
792	set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT);
 
793
794	rodata_test();
795
796#ifdef CONFIG_CPA_DEBUG
797	printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
798	set_memory_rw(start, (end-start) >> PAGE_SHIFT);
799
800	printk(KERN_INFO "Testing CPA: again\n");
801	set_memory_ro(start, (end-start) >> PAGE_SHIFT);
802#endif
803
804	free_init_pages("unused kernel memory",
805			(unsigned long) page_address(virt_to_page(text_end)),
806			(unsigned long)
807				 page_address(virt_to_page(rodata_start)));
808	free_init_pages("unused kernel memory",
809			(unsigned long) page_address(virt_to_page(rodata_end)),
810			(unsigned long) page_address(virt_to_page(data_start)));
811}
812
813#endif
 
814
815int kern_addr_valid(unsigned long addr)
816{
817	unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
818	pgd_t *pgd;
819	pud_t *pud;
820	pmd_t *pmd;
821	pte_t *pte;
822
823	if (above != 0 && above != -1UL)
824		return 0;
825
826	pgd = pgd_offset_k(addr);
827	if (pgd_none(*pgd))
828		return 0;
829
830	pud = pud_offset(pgd, addr);
831	if (pud_none(*pud))
832		return 0;
833
 
 
 
834	pmd = pmd_offset(pud, addr);
835	if (pmd_none(*pmd))
836		return 0;
837
838	if (pmd_large(*pmd))
839		return pfn_valid(pmd_pfn(*pmd));
840
841	pte = pte_offset_kernel(pmd, addr);
842	if (pte_none(*pte))
843		return 0;
844
845	return pfn_valid(pte_pfn(*pte));
846}
847
848/*
849 * A pseudo VMA to allow ptrace access for the vsyscall page.  This only
850 * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
851 * not need special handling anymore:
852 */
853static struct vm_area_struct gate_vma = {
854	.vm_start	= VSYSCALL_START,
855	.vm_end		= VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
856	.vm_page_prot	= PAGE_READONLY_EXEC,
857	.vm_flags	= VM_READ | VM_EXEC
858};
859
860struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
861{
862#ifdef CONFIG_IA32_EMULATION
863	if (!mm || mm->context.ia32_compat)
864		return NULL;
865#endif
866	return &gate_vma;
867}
868
869int in_gate_area(struct mm_struct *mm, unsigned long addr)
870{
871	struct vm_area_struct *vma = get_gate_vma(mm);
872
873	if (!vma)
874		return 0;
875
876	return (addr >= vma->vm_start) && (addr < vma->vm_end);
877}
 
878
879/*
880 * Use this when you have no reliable mm, typically from interrupt
881 * context. It is less reliable than using a task's mm and may give
882 * false positives.
883 */
884int in_gate_area_no_mm(unsigned long addr)
885{
886	return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
887}
888
889const char *arch_vma_name(struct vm_area_struct *vma)
890{
891	if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
892		return "[vdso]";
893	if (vma == &gate_vma)
894		return "[vsyscall]";
895	return NULL;
896}
897
898#ifdef CONFIG_X86_UV
899unsigned long memory_block_size_bytes(void)
900{
901	if (is_uv_system()) {
902		printk(KERN_INFO "UV: memory block size 2GB\n");
903		return 2UL * 1024 * 1024 * 1024;
904	}
905	return MIN_MEMORY_BLOCK_SIZE;
906}
907#endif
908
909#ifdef CONFIG_SPARSEMEM_VMEMMAP
910/*
911 * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
912 */
913static long __meminitdata addr_start, addr_end;
914static void __meminitdata *p_start, *p_end;
915static int __meminitdata node_start;
916
917int __meminit
918vmemmap_populate(struct page *start_page, unsigned long size, int node)
919{
920	unsigned long addr = (unsigned long)start_page;
921	unsigned long end = (unsigned long)(start_page + size);
922	unsigned long next;
923	pgd_t *pgd;
924	pud_t *pud;
925	pmd_t *pmd;
926
927	for (; addr < end; addr = next) {
928		void *p = NULL;
929
930		pgd = vmemmap_pgd_populate(addr, node);
931		if (!pgd)
932			return -ENOMEM;
933
934		pud = vmemmap_pud_populate(pgd, addr, node);
935		if (!pud)
936			return -ENOMEM;
937
938		if (!cpu_has_pse) {
939			next = (addr + PAGE_SIZE) & PAGE_MASK;
940			pmd = vmemmap_pmd_populate(pud, addr, node);
941
942			if (!pmd)
943				return -ENOMEM;
944
945			p = vmemmap_pte_populate(pmd, addr, node);
946
947			if (!p)
948				return -ENOMEM;
949
950			addr_end = addr + PAGE_SIZE;
951			p_end = p + PAGE_SIZE;
952		} else {
953			next = pmd_addr_end(addr, end);
954
955			pmd = pmd_offset(pud, addr);
956			if (pmd_none(*pmd)) {
957				pte_t entry;
958
959				p = vmemmap_alloc_block_buf(PMD_SIZE, node);
960				if (!p)
961					return -ENOMEM;
962
963				entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
964						PAGE_KERNEL_LARGE);
965				set_pmd(pmd, __pmd(pte_val(entry)));
966
967				/* check to see if we have contiguous blocks */
968				if (p_end != p || node_start != node) {
969					if (p_start)
970						printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
971						       addr_start, addr_end-1, p_start, p_end-1, node_start);
972					addr_start = addr;
973					node_start = node;
974					p_start = p;
975				}
976
977				addr_end = addr + PMD_SIZE;
978				p_end = p + PMD_SIZE;
979			} else
980				vmemmap_verify((pte_t *)pmd, node, addr, next);
 
 
 
 
981		}
982
 
 
983	}
984	sync_global_pgds((unsigned long)start_page, end);
985	return 0;
986}
987
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
988void __meminit vmemmap_populate_print_last(void)
989{
990	if (p_start) {
991		printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
992			addr_start, addr_end-1, p_start, p_end-1, node_start);
993		p_start = NULL;
994		p_end = NULL;
995		node_start = 0;
996	}
997}
998#endif