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x86: introduce /dev/mem restrictions with a config option
[linux-2.6/btrfs-unstable.git] / arch / x86 / mm / init_64.c
blob49c274ee2fba64ea9b48713b96f814fc0afa5d23
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 #include <asm/cacheflush.h>
49
50 static unsigned long dma_reserve __initdata;
51
52 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
53
54 int direct_gbpages __meminitdata
55 #ifdef CONFIG_DIRECT_GBPAGES
56 = 1
57 #endif
58 ;
59
60 static int __init parse_direct_gbpages_off(char *arg)
61 {
62 direct_gbpages = 0;
63 return 0;
64 }
65 early_param("nogbpages", parse_direct_gbpages_off);
66
67 static int __init parse_direct_gbpages_on(char *arg)
68 {
69 direct_gbpages = 1;
70 return 0;
71 }
72 early_param("gbpages", parse_direct_gbpages_on);
73
74 /*
75 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
76 * physical space so we can cache the place of the first one and move
77 * around without checking the pgd every time.
78 */
79
80 void show_mem(void)
81 {
82 long i, total = 0, reserved = 0;
83 long shared = 0, cached = 0;
84 struct page *page;
85 pg_data_t *pgdat;
86
87 printk(KERN_INFO "Mem-info:\n");
88 show_free_areas();
89 for_each_online_pgdat(pgdat) {
90 for (i = 0; i < pgdat->node_spanned_pages; ++i) {
91 /*
92 * This loop can take a while with 256 GB and
93 * 4k pages so defer the NMI watchdog:
94 */
95 if (unlikely(i % MAX_ORDER_NR_PAGES == 0))
96 touch_nmi_watchdog();
97
98 if (!pfn_valid(pgdat->node_start_pfn + i))
99 continue;
100
101 page = pfn_to_page(pgdat->node_start_pfn + i);
102 total++;
103 if (PageReserved(page))
104 reserved++;
105 else if (PageSwapCache(page))
106 cached++;
107 else if (page_count(page))
108 shared += page_count(page) - 1;
109 }
110 }
111 printk(KERN_INFO "%lu pages of RAM\n", total);
112 printk(KERN_INFO "%lu reserved pages\n", reserved);
113 printk(KERN_INFO "%lu pages shared\n", shared);
114 printk(KERN_INFO "%lu pages swap cached\n", cached);
115 }
116
117 int after_bootmem;
118
119 static __init void *spp_getpage(void)
120 {
121 void *ptr;
122
123 if (after_bootmem)
124 ptr = (void *) get_zeroed_page(GFP_ATOMIC);
125 else
126 ptr = alloc_bootmem_pages(PAGE_SIZE);
127
128 if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
129 panic("set_pte_phys: cannot allocate page data %s\n",
130 after_bootmem ? "after bootmem" : "");
131 }
132
133 pr_debug("spp_getpage %p\n", ptr);
134
135 return ptr;
136 }
137
138 static __init void
139 set_pte_phys(unsigned long vaddr, unsigned long phys, pgprot_t prot)
140 {
141 pgd_t *pgd;
142 pud_t *pud;
143 pmd_t *pmd;
144 pte_t *pte, new_pte;
145
146 pr_debug("set_pte_phys %lx to %lx\n", vaddr, phys);
147
148 pgd = pgd_offset_k(vaddr);
149 if (pgd_none(*pgd)) {
150 printk(KERN_ERR
151 "PGD FIXMAP MISSING, it should be setup in head.S!\n");
152 return;
153 }
154 pud = pud_offset(pgd, vaddr);
155 if (pud_none(*pud)) {
156 pmd = (pmd_t *) spp_getpage();
157 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | _PAGE_USER));
158 if (pmd != pmd_offset(pud, 0)) {
159 printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
160 pmd, pmd_offset(pud, 0));
161 return;
162 }
163 }
164 pmd = pmd_offset(pud, vaddr);
165 if (pmd_none(*pmd)) {
166 pte = (pte_t *) spp_getpage();
167 set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE | _PAGE_USER));
168 if (pte != pte_offset_kernel(pmd, 0)) {
169 printk(KERN_ERR "PAGETABLE BUG #02!\n");
170 return;
171 }
172 }
173 new_pte = pfn_pte(phys >> PAGE_SHIFT, prot);
174
175 pte = pte_offset_kernel(pmd, vaddr);
176 if (!pte_none(*pte) &&
177 pte_val(*pte) != (pte_val(new_pte) & __supported_pte_mask))
178 pte_ERROR(*pte);
179 set_pte(pte, new_pte);
180
181 /*
182 * It's enough to flush this one mapping.
183 * (PGE mappings get flushed as well)
184 */
185 __flush_tlb_one(vaddr);
186 }
187
188 /*
189 * The head.S code sets up the kernel high mapping:
190 *
191 * from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
192 *
193 * phys_addr holds the negative offset to the kernel, which is added
194 * to the compile time generated pmds. This results in invalid pmds up
195 * to the point where we hit the physaddr 0 mapping.
196 *
197 * We limit the mappings to the region from _text to _end. _end is
198 * rounded up to the 2MB boundary. This catches the invalid pmds as
199 * well, as they are located before _text:
200 */
201 void __init cleanup_highmap(void)
202 {
203 unsigned long vaddr = __START_KERNEL_map;
204 unsigned long end = round_up((unsigned long)_end, PMD_SIZE) - 1;
205 pmd_t *pmd = level2_kernel_pgt;
206 pmd_t *last_pmd = pmd + PTRS_PER_PMD;
207
208 for (; pmd < last_pmd; pmd++, vaddr += PMD_SIZE) {
209 if (!pmd_present(*pmd))
210 continue;
211 if (vaddr < (unsigned long) _text || vaddr > end)
212 set_pmd(pmd, __pmd(0));
213 }
214 }
215
216 /* NOTE: this is meant to be run only at boot */
217 void __init
218 __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
219 {
220 unsigned long address = __fix_to_virt(idx);
221
222 if (idx >= __end_of_fixed_addresses) {
223 printk(KERN_ERR "Invalid __set_fixmap\n");
224 return;
225 }
226 set_pte_phys(address, phys, prot);
227 }
228
229 static unsigned long __initdata table_start;
230 static unsigned long __meminitdata table_end;
231
232 static __meminit void *alloc_low_page(unsigned long *phys)
233 {
234 unsigned long pfn = table_end++;
235 void *adr;
236
237 if (after_bootmem) {
238 adr = (void *)get_zeroed_page(GFP_ATOMIC);
239 *phys = __pa(adr);
240
241 return adr;
242 }
243
244 if (pfn >= end_pfn)
245 panic("alloc_low_page: ran out of memory");
246
247 adr = early_ioremap(pfn * PAGE_SIZE, PAGE_SIZE);
248 memset(adr, 0, PAGE_SIZE);
249 *phys = pfn * PAGE_SIZE;
250 return adr;
251 }
252
253 static __meminit void unmap_low_page(void *adr)
254 {
255 if (after_bootmem)
256 return;
257
258 early_iounmap(adr, PAGE_SIZE);
259 }
260
261 /* Must run before zap_low_mappings */
262 __meminit void *early_ioremap(unsigned long addr, unsigned long size)
263 {
264 pmd_t *pmd, *last_pmd;
265 unsigned long vaddr;
266 int i, pmds;
267
268 pmds = ((addr & ~PMD_MASK) + size + ~PMD_MASK) / PMD_SIZE;
269 vaddr = __START_KERNEL_map;
270 pmd = level2_kernel_pgt;
271 last_pmd = level2_kernel_pgt + PTRS_PER_PMD - 1;
272
273 for (; pmd <= last_pmd; pmd++, vaddr += PMD_SIZE) {
274 for (i = 0; i < pmds; i++) {
275 if (pmd_present(pmd[i]))
276 goto continue_outer_loop;
277 }
278 vaddr += addr & ~PMD_MASK;
279 addr &= PMD_MASK;
280
281 for (i = 0; i < pmds; i++, addr += PMD_SIZE)
282 set_pmd(pmd+i, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC));
283 __flush_tlb_all();
284
285 return (void *)vaddr;
286 continue_outer_loop:
287 ;
288 }
289 printk(KERN_ERR "early_ioremap(0x%lx, %lu) failed\n", addr, size);
290
291 return NULL;
292 }
293
294 /*
295 * To avoid virtual aliases later:
296 */
297 __meminit void early_iounmap(void *addr, unsigned long size)
298 {
299 unsigned long vaddr;
300 pmd_t *pmd;
301 int i, pmds;
302
303 vaddr = (unsigned long)addr;
304 pmds = ((vaddr & ~PMD_MASK) + size + ~PMD_MASK) / PMD_SIZE;
305 pmd = level2_kernel_pgt + pmd_index(vaddr);
306
307 for (i = 0; i < pmds; i++)
308 pmd_clear(pmd + i);
309
310 __flush_tlb_all();
311 }
312
313 static unsigned long __meminit
314 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end)
315 {
316 int i = pmd_index(address);
317
318 for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
319 pmd_t *pmd = pmd_page + pmd_index(address);
320
321 if (address >= end) {
322 if (!after_bootmem) {
323 for (; i < PTRS_PER_PMD; i++, pmd++)
324 set_pmd(pmd, __pmd(0));
325 }
326 break;
327 }
328
329 if (pmd_val(*pmd))
330 continue;
331
332 set_pte((pte_t *)pmd,
333 pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
334 }
335 return address;
336 }
337
338 static unsigned long __meminit
339 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end)
340 {
341 pmd_t *pmd = pmd_offset(pud, 0);
342 unsigned long last_map_addr;
343
344 spin_lock(&init_mm.page_table_lock);
345 last_map_addr = phys_pmd_init(pmd, address, end);
346 spin_unlock(&init_mm.page_table_lock);
347 __flush_tlb_all();
348 return last_map_addr;
349 }
350
351 static unsigned long __meminit
352 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end)
353 {
354 unsigned long last_map_addr = end;
355 int i = pud_index(addr);
356
357 for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
358 unsigned long pmd_phys;
359 pud_t *pud = pud_page + pud_index(addr);
360 pmd_t *pmd;
361
362 if (addr >= end)
363 break;
364
365 if (!after_bootmem &&
366 !e820_any_mapped(addr, addr+PUD_SIZE, 0)) {
367 set_pud(pud, __pud(0));
368 continue;
369 }
370
371 if (pud_val(*pud)) {
372 if (!pud_large(*pud))
373 last_map_addr = phys_pmd_update(pud, addr, end);
374 continue;
375 }
376
377 if (direct_gbpages) {
378 set_pte((pte_t *)pud,
379 pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
380 last_map_addr = (addr & PUD_MASK) + PUD_SIZE;
381 continue;
382 }
383
384 pmd = alloc_low_page(&pmd_phys);
385
386 spin_lock(&init_mm.page_table_lock);
387 set_pud(pud, __pud(pmd_phys | _KERNPG_TABLE));
388 last_map_addr = phys_pmd_init(pmd, addr, end);
389 spin_unlock(&init_mm.page_table_lock);
390
391 unmap_low_page(pmd);
392 }
393 __flush_tlb_all();
394
395 return last_map_addr >> PAGE_SHIFT;
396 }
397
398 static void __init find_early_table_space(unsigned long end)
399 {
400 unsigned long puds, pmds, tables, start;
401
402 puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
403 tables = round_up(puds * sizeof(pud_t), PAGE_SIZE);
404 if (!direct_gbpages) {
405 pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
406 tables += round_up(pmds * sizeof(pmd_t), PAGE_SIZE);
407 }
408
409 /*
410 * RED-PEN putting page tables only on node 0 could
411 * cause a hotspot and fill up ZONE_DMA. The page tables
412 * need roughly 0.5KB per GB.
413 */
414 start = 0x8000;
415 table_start = find_e820_area(start, end, tables, PAGE_SIZE);
416 if (table_start == -1UL)
417 panic("Cannot find space for the kernel page tables");
418
419 table_start >>= PAGE_SHIFT;
420 table_end = table_start;
421
422 early_printk("kernel direct mapping tables up to %lx @ %lx-%lx\n",
423 end, table_start << PAGE_SHIFT,
424 (table_start << PAGE_SHIFT) + tables);
425 }
426
427 static void __init init_gbpages(void)
428 {
429 if (direct_gbpages && cpu_has_gbpages)
430 printk(KERN_INFO "Using GB pages for direct mapping\n");
431 else
432 direct_gbpages = 0;
433 }
434
435 #ifdef CONFIG_MEMTEST_BOOTPARAM
436
437 static void __init memtest(unsigned long start_phys, unsigned long size,
438 unsigned pattern)
439 {
440 unsigned long i;
441 unsigned long *start;
442 unsigned long start_bad;
443 unsigned long last_bad;
444 unsigned long val;
445 unsigned long start_phys_aligned;
446 unsigned long count;
447 unsigned long incr;
448
449 switch (pattern) {
450 case 0:
451 val = 0UL;
452 break;
453 case 1:
454 val = -1UL;
455 break;
456 case 2:
457 val = 0x5555555555555555UL;
458 break;
459 case 3:
460 val = 0xaaaaaaaaaaaaaaaaUL;
461 break;
462 default:
463 return;
464 }
465
466 incr = sizeof(unsigned long);
467 start_phys_aligned = ALIGN(start_phys, incr);
468 count = (size - (start_phys_aligned - start_phys))/incr;
469 start = __va(start_phys_aligned);
470 start_bad = 0;
471 last_bad = 0;
472
473 for (i = 0; i < count; i++)
474 start[i] = val;
475 for (i = 0; i < count; i++, start++, start_phys_aligned += incr) {
476 if (*start != val) {
477 if (start_phys_aligned == last_bad + incr) {
478 last_bad += incr;
479 } else {
480 if (start_bad) {
481 printk(KERN_CONT "\n %016lx bad mem addr %016lx - %016lx reserved",
482 val, start_bad, last_bad + incr);
483 reserve_early(start_bad, last_bad - start_bad, "BAD RAM");
484 }
485 start_bad = last_bad = start_phys_aligned;
486 }
487 }
488 }
489 if (start_bad) {
490 printk(KERN_CONT "\n %016lx bad mem addr %016lx - %016lx reserved",
491 val, start_bad, last_bad + incr);
492 reserve_early(start_bad, last_bad - start_bad, "BAD RAM");
493 }
494
495 }
496
497 static int memtest_pattern __initdata = CONFIG_MEMTEST_BOOTPARAM_VALUE;
498
499 static int __init parse_memtest(char *arg)
500 {
501 if (arg)
502 memtest_pattern = simple_strtoul(arg, NULL, 0);
503 return 0;
504 }
505
506 early_param("memtest", parse_memtest);
507
508 static void __init early_memtest(unsigned long start, unsigned long end)
509 {
510 unsigned long t_start, t_size;
511 unsigned pattern;
512
513 if (!memtest_pattern)
514 return;
515
516 printk(KERN_INFO "early_memtest: pattern num %d", memtest_pattern);
517 for (pattern = 0; pattern < memtest_pattern; pattern++) {
518 t_start = start;
519 t_size = 0;
520 while (t_start < end) {
521 t_start = find_e820_area_size(t_start, &t_size, 1);
522
523 /* done ? */
524 if (t_start >= end)
525 break;
526 if (t_start + t_size > end)
527 t_size = end - t_start;
528
529 printk(KERN_CONT "\n %016lx - %016lx pattern %d",
530 t_start, t_start + t_size, pattern);
531
532 memtest(t_start, t_size, pattern);
533
534 t_start += t_size;
535 }
536 }
537 printk(KERN_CONT "\n");
538 }
539 #else
540 static void __init early_memtest(unsigned long start, unsigned long end)
541 {
542 }
543 #endif
544
545 /*
546 * Setup the direct mapping of the physical memory at PAGE_OFFSET.
547 * This runs before bootmem is initialized and gets pages directly from
548 * the physical memory. To access them they are temporarily mapped.
549 */
550 unsigned long __init_refok init_memory_mapping(unsigned long start, unsigned long end)
551 {
552 unsigned long next, last_map_addr = end;
553 unsigned long start_phys = start, end_phys = end;
554
555 printk(KERN_INFO "init_memory_mapping\n");
556
557 /*
558 * Find space for the kernel direct mapping tables.
559 *
560 * Later we should allocate these tables in the local node of the
561 * memory mapped. Unfortunately this is done currently before the
562 * nodes are discovered.
563 */
564 if (!after_bootmem) {
565 init_gbpages();
566 find_early_table_space(end);
567 }
568
569 start = (unsigned long)__va(start);
570 end = (unsigned long)__va(end);
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 if (after_bootmem)
578 pud = pud_offset(pgd, start & PGDIR_MASK);
579 else
580 pud = alloc_low_page(&pud_phys);
581
582 next = start + PGDIR_SIZE;
583 if (next > end)
584 next = end;
585 last_map_addr = phys_pud_init(pud, __pa(start), __pa(next));
586 if (!after_bootmem)
587 set_pgd(pgd_offset_k(start), mk_kernel_pgd(pud_phys));
588 unmap_low_page(pud);
589 }
590
591 if (!after_bootmem)
592 mmu_cr4_features = read_cr4();
593 __flush_tlb_all();
594
595 if (!after_bootmem)
596 reserve_early(table_start << PAGE_SHIFT,
597 table_end << PAGE_SHIFT, "PGTABLE");
598
599 if (!after_bootmem)
600 early_memtest(start_phys, end_phys);
601
602 return last_map_addr;
603 }
604
605 #ifndef CONFIG_NUMA
606 void __init paging_init(void)
607 {
608 unsigned long max_zone_pfns[MAX_NR_ZONES];
609
610 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
611 max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
612 max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
613 max_zone_pfns[ZONE_NORMAL] = end_pfn;
614
615 memory_present(0, 0, end_pfn);
616 sparse_init();
617 free_area_init_nodes(max_zone_pfns);
618 }
619 #endif
620
621 /*
622 * Memory hotplug specific functions
623 */
624 void online_page(struct page *page)
625 {
626 ClearPageReserved(page);
627 init_page_count(page);
628 __free_page(page);
629 totalram_pages++;
630 num_physpages++;
631 }
632
633 #ifdef CONFIG_MEMORY_HOTPLUG
634 /*
635 * Memory is added always to NORMAL zone. This means you will never get
636 * additional DMA/DMA32 memory.
637 */
638 int arch_add_memory(int nid, u64 start, u64 size)
639 {
640 struct pglist_data *pgdat = NODE_DATA(nid);
641 struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
642 unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT;
643 unsigned long nr_pages = size >> PAGE_SHIFT;
644 int ret;
645
646 last_mapped_pfn = init_memory_mapping(start, start + size-1);
647 if (last_mapped_pfn > max_pfn_mapped)
648 max_pfn_mapped = last_mapped_pfn;
649
650 ret = __add_pages(zone, start_pfn, nr_pages);
651 WARN_ON(1);
652
653 return ret;
654 }
655 EXPORT_SYMBOL_GPL(arch_add_memory);
656
657 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
658 int memory_add_physaddr_to_nid(u64 start)
659 {
660 return 0;
661 }
662 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
663 #endif
664
665 #endif /* CONFIG_MEMORY_HOTPLUG */
666
667 /*
668 * devmem_is_allowed() checks to see if /dev/mem access to a certain address
669 * is valid. The argument is a physical page number.
670 *
671 *
672 * On x86, access has to be given to the first megabyte of ram because that area
673 * contains bios code and data regions used by X and dosemu and similar apps.
674 * Access has to be given to non-kernel-ram areas as well, these contain the PCI
675 * mmio resources as well as potential bios/acpi data regions.
676 */
677 int devmem_is_allowed(unsigned long pagenr)
678 {
679 if (pagenr <= 256)
680 return 1;
681 if (!page_is_ram(pagenr))
682 return 1;
683 return 0;
684 }
685
686
687 static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel,
688 kcore_modules, kcore_vsyscall;
689
690 void __init mem_init(void)
691 {
692 long codesize, reservedpages, datasize, initsize;
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 reservedpages = end_pfn - totalram_pages -
707 absent_pages_in_range(0, end_pfn);
708 after_bootmem = 1;
709
710 codesize = (unsigned long) &_etext - (unsigned long) &_text;
711 datasize = (unsigned long) &_edata - (unsigned long) &_etext;
712 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
713
714 /* Register memory areas for /proc/kcore */
715 kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
716 kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
717 VMALLOC_END-VMALLOC_START);
718 kclist_add(&kcore_kernel, &_stext, _end - _stext);
719 kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN);
720 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
721 VSYSCALL_END - VSYSCALL_START);
722
723 printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
724 "%ldk reserved, %ldk data, %ldk init)\n",
725 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
726 end_pfn << (PAGE_SHIFT-10),
727 codesize >> 10,
728 reservedpages << (PAGE_SHIFT-10),
729 datasize >> 10,
730 initsize >> 10);
731
732 cpa_init();
733 }
734
735 void free_init_pages(char *what, unsigned long begin, unsigned long end)
736 {
737 unsigned long addr = begin;
738
739 if (addr >= end)
740 return;
741
742 /*
743 * If debugging page accesses then do not free this memory but
744 * mark them not present - any buggy init-section access will
745 * create a kernel page fault:
746 */
747 #ifdef CONFIG_DEBUG_PAGEALLOC
748 printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
749 begin, PAGE_ALIGN(end));
750 set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
751 #else
752 printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
753
754 for (; addr < end; addr += PAGE_SIZE) {
755 ClearPageReserved(virt_to_page(addr));
756 init_page_count(virt_to_page(addr));
757 memset((void *)(addr & ~(PAGE_SIZE-1)),
758 POISON_FREE_INITMEM, PAGE_SIZE);
759 free_page(addr);
760 totalram_pages++;
761 }
762 #endif
763 }
764
765 void free_initmem(void)
766 {
767 free_init_pages("unused kernel memory",
768 (unsigned long)(&__init_begin),
769 (unsigned long)(&__init_end));
770 }
771
772 #ifdef CONFIG_DEBUG_RODATA
773 const int rodata_test_data = 0xC3;
774 EXPORT_SYMBOL_GPL(rodata_test_data);
775
776 void mark_rodata_ro(void)
777 {
778 unsigned long start = PFN_ALIGN(_stext), end = PFN_ALIGN(__end_rodata);
779
780 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
781 (end - start) >> 10);
782 set_memory_ro(start, (end - start) >> PAGE_SHIFT);
783
784 /*
785 * The rodata section (but not the kernel text!) should also be
786 * not-executable.
787 */
788 start = ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
789 set_memory_nx(start, (end - start) >> PAGE_SHIFT);
790
791 rodata_test();
792
793 #ifdef CONFIG_CPA_DEBUG
794 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
795 set_memory_rw(start, (end-start) >> PAGE_SHIFT);
796
797 printk(KERN_INFO "Testing CPA: again\n");
798 set_memory_ro(start, (end-start) >> PAGE_SHIFT);
799 #endif
800 }
801
802 #endif
803
804 #ifdef CONFIG_BLK_DEV_INITRD
805 void free_initrd_mem(unsigned long start, unsigned long end)
806 {
807 free_init_pages("initrd memory", start, end);
808 }
809 #endif
810
811 void __init reserve_bootmem_generic(unsigned long phys, unsigned len)
812 {
813 #ifdef CONFIG_NUMA
814 int nid = phys_to_nid(phys);
815 #endif
816 unsigned long pfn = phys >> PAGE_SHIFT;
817
818 if (pfn >= end_pfn) {
819 /*
820 * This can happen with kdump kernels when accessing
821 * firmware tables:
822 */
823 if (pfn < max_pfn_mapped)
824 return;
825
826 printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %u\n",
827 phys, len);
828 return;
829 }
830
831 /* Should check here against the e820 map to avoid double free */
832 #ifdef CONFIG_NUMA
833 reserve_bootmem_node(NODE_DATA(nid), phys, len, BOOTMEM_DEFAULT);
834 #else
835 reserve_bootmem(phys, len, BOOTMEM_DEFAULT);
836 #endif
837 if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
838 dma_reserve += len / PAGE_SIZE;
839 set_dma_reserve(dma_reserve);
840 }
841 }
842
843 int kern_addr_valid(unsigned long addr)
844 {
845 unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
846 pgd_t *pgd;
847 pud_t *pud;
848 pmd_t *pmd;
849 pte_t *pte;
850
851 if (above != 0 && above != -1UL)
852 return 0;
853
854 pgd = pgd_offset_k(addr);
855 if (pgd_none(*pgd))
856 return 0;
857
858 pud = pud_offset(pgd, addr);
859 if (pud_none(*pud))
860 return 0;
861
862 pmd = pmd_offset(pud, addr);
863 if (pmd_none(*pmd))
864 return 0;
865
866 if (pmd_large(*pmd))
867 return pfn_valid(pmd_pfn(*pmd));
868
869 pte = pte_offset_kernel(pmd, addr);
870 if (pte_none(*pte))
871 return 0;
872
873 return pfn_valid(pte_pfn(*pte));
874 }
875
876 /*
877 * A pseudo VMA to allow ptrace access for the vsyscall page. This only
878 * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
879 * not need special handling anymore:
880 */
881 static struct vm_area_struct gate_vma = {
882 .vm_start = VSYSCALL_START,
883 .vm_end = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
884 .vm_page_prot = PAGE_READONLY_EXEC,
885 .vm_flags = VM_READ | VM_EXEC
886 };
887
888 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
889 {
890 #ifdef CONFIG_IA32_EMULATION
891 if (test_tsk_thread_flag(tsk, TIF_IA32))
892 return NULL;
893 #endif
894 return &gate_vma;
895 }
896
897 int in_gate_area(struct task_struct *task, unsigned long addr)
898 {
899 struct vm_area_struct *vma = get_gate_vma(task);
900
901 if (!vma)
902 return 0;
903
904 return (addr >= vma->vm_start) && (addr < vma->vm_end);
905 }
906
907 /*
908 * Use this when you have no reliable task/vma, typically from interrupt
909 * context. It is less reliable than using the task's vma and may give
910 * false positives:
911 */
912 int in_gate_area_no_task(unsigned long addr)
913 {
914 return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
915 }
916
917 const char *arch_vma_name(struct vm_area_struct *vma)
918 {
919 if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
920 return "[vdso]";
921 if (vma == &gate_vma)
922 return "[vsyscall]";
923 return NULL;
924 }
925
926 #ifdef CONFIG_SPARSEMEM_VMEMMAP
927 /*
928 * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
929 */
930 int __meminit
931 vmemmap_populate(struct page *start_page, unsigned long size, int node)
932 {
933 unsigned long addr = (unsigned long)start_page;
934 unsigned long end = (unsigned long)(start_page + size);
935 unsigned long next;
936 pgd_t *pgd;
937 pud_t *pud;
938 pmd_t *pmd;
939
940 for (; addr < end; addr = next) {
941 next = pmd_addr_end(addr, end);
942
943 pgd = vmemmap_pgd_populate(addr, node);
944 if (!pgd)
945 return -ENOMEM;
946
947 pud = vmemmap_pud_populate(pgd, addr, node);
948 if (!pud)
949 return -ENOMEM;
950
951 pmd = pmd_offset(pud, addr);
952 if (pmd_none(*pmd)) {
953 pte_t entry;
954 void *p;
955
956 p = vmemmap_alloc_block(PMD_SIZE, node);
957 if (!p)
958 return -ENOMEM;
959
960 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
961 PAGE_KERNEL_LARGE);
962 set_pmd(pmd, __pmd(pte_val(entry)));
963
964 printk(KERN_DEBUG " [%lx-%lx] PMD ->%p on node %d\n",
965 addr, addr + PMD_SIZE - 1, p, node);
966 } else {
967 vmemmap_verify((pte_t *)pmd, node, addr, next);
968 }
969 }
970 return 0;
971 }
972 #endif
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