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Merge tag 'iio-for-4.8b' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio...
[deliverable/linux.git] / arch / x86 / mm / init_64.c
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/memremap.h>
34 #include <linux/nmi.h>
35 #include <linux/gfp.h>
36 #include <linux/kcore.h>
37
38 #include <asm/processor.h>
39 #include <asm/bios_ebda.h>
40 #include <asm/uaccess.h>
41 #include <asm/pgtable.h>
42 #include <asm/pgalloc.h>
43 #include <asm/dma.h>
44 #include <asm/fixmap.h>
45 #include <asm/e820.h>
46 #include <asm/apic.h>
47 #include <asm/tlb.h>
48 #include <asm/mmu_context.h>
49 #include <asm/proto.h>
50 #include <asm/smp.h>
51 #include <asm/sections.h>
52 #include <asm/kdebug.h>
53 #include <asm/numa.h>
54 #include <asm/cacheflush.h>
55 #include <asm/init.h>
56 #include <asm/uv/uv.h>
57 #include <asm/setup.h>
58
59 #include "mm_internal.h"
60
61 #include "ident_map.c"
62
63 /*
64 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
65 * physical space so we can cache the place of the first one and move
66 * around without checking the pgd every time.
67 */
68
69 pteval_t __supported_pte_mask __read_mostly = ~0;
70 EXPORT_SYMBOL_GPL(__supported_pte_mask);
71
72 int force_personality32;
73
74 /*
75 * noexec32=on|off
76 * Control non executable heap for 32bit processes.
77 * To control the stack too use noexec=off
78 *
79 * on PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
80 * off PROT_READ implies PROT_EXEC
81 */
82 static int __init nonx32_setup(char *str)
83 {
84 if (!strcmp(str, "on"))
85 force_personality32 &= ~READ_IMPLIES_EXEC;
86 else if (!strcmp(str, "off"))
87 force_personality32 |= READ_IMPLIES_EXEC;
88 return 1;
89 }
90 __setup("noexec32=", nonx32_setup);
91
92 /*
93 * When memory was added/removed make sure all the processes MM have
94 * suitable PGD entries in the local PGD level page.
95 */
96 void sync_global_pgds(unsigned long start, unsigned long end, int removed)
97 {
98 unsigned long address;
99
100 for (address = start; address <= end; address += PGDIR_SIZE) {
101 const pgd_t *pgd_ref = pgd_offset_k(address);
102 struct page *page;
103
104 /*
105 * When it is called after memory hot remove, pgd_none()
106 * returns true. In this case (removed == 1), we must clear
107 * the PGD entries in the local PGD level page.
108 */
109 if (pgd_none(*pgd_ref) && !removed)
110 continue;
111
112 spin_lock(&pgd_lock);
113 list_for_each_entry(page, &pgd_list, lru) {
114 pgd_t *pgd;
115 spinlock_t *pgt_lock;
116
117 pgd = (pgd_t *)page_address(page) + pgd_index(address);
118 /* the pgt_lock only for Xen */
119 pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
120 spin_lock(pgt_lock);
121
122 if (!pgd_none(*pgd_ref) && !pgd_none(*pgd))
123 BUG_ON(pgd_page_vaddr(*pgd)
124 != pgd_page_vaddr(*pgd_ref));
125
126 if (removed) {
127 if (pgd_none(*pgd_ref) && !pgd_none(*pgd))
128 pgd_clear(pgd);
129 } else {
130 if (pgd_none(*pgd))
131 set_pgd(pgd, *pgd_ref);
132 }
133
134 spin_unlock(pgt_lock);
135 }
136 spin_unlock(&pgd_lock);
137 }
138 }
139
140 /*
141 * NOTE: This function is marked __ref because it calls __init function
142 * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
143 */
144 static __ref void *spp_getpage(void)
145 {
146 void *ptr;
147
148 if (after_bootmem)
149 ptr = (void *) get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK);
150 else
151 ptr = alloc_bootmem_pages(PAGE_SIZE);
152
153 if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
154 panic("set_pte_phys: cannot allocate page data %s\n",
155 after_bootmem ? "after bootmem" : "");
156 }
157
158 pr_debug("spp_getpage %p\n", ptr);
159
160 return ptr;
161 }
162
163 static pud_t *fill_pud(pgd_t *pgd, unsigned long vaddr)
164 {
165 if (pgd_none(*pgd)) {
166 pud_t *pud = (pud_t *)spp_getpage();
167 pgd_populate(&init_mm, pgd, pud);
168 if (pud != pud_offset(pgd, 0))
169 printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n",
170 pud, pud_offset(pgd, 0));
171 }
172 return pud_offset(pgd, vaddr);
173 }
174
175 static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr)
176 {
177 if (pud_none(*pud)) {
178 pmd_t *pmd = (pmd_t *) spp_getpage();
179 pud_populate(&init_mm, pud, pmd);
180 if (pmd != pmd_offset(pud, 0))
181 printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
182 pmd, pmd_offset(pud, 0));
183 }
184 return pmd_offset(pud, vaddr);
185 }
186
187 static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr)
188 {
189 if (pmd_none(*pmd)) {
190 pte_t *pte = (pte_t *) spp_getpage();
191 pmd_populate_kernel(&init_mm, pmd, pte);
192 if (pte != pte_offset_kernel(pmd, 0))
193 printk(KERN_ERR "PAGETABLE BUG #02!\n");
194 }
195 return pte_offset_kernel(pmd, vaddr);
196 }
197
198 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
199 {
200 pud_t *pud;
201 pmd_t *pmd;
202 pte_t *pte;
203
204 pud = pud_page + pud_index(vaddr);
205 pmd = fill_pmd(pud, vaddr);
206 pte = fill_pte(pmd, vaddr);
207
208 set_pte(pte, new_pte);
209
210 /*
211 * It's enough to flush this one mapping.
212 * (PGE mappings get flushed as well)
213 */
214 __flush_tlb_one(vaddr);
215 }
216
217 void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
218 {
219 pgd_t *pgd;
220 pud_t *pud_page;
221
222 pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
223
224 pgd = pgd_offset_k(vaddr);
225 if (pgd_none(*pgd)) {
226 printk(KERN_ERR
227 "PGD FIXMAP MISSING, it should be setup in head.S!\n");
228 return;
229 }
230 pud_page = (pud_t*)pgd_page_vaddr(*pgd);
231 set_pte_vaddr_pud(pud_page, vaddr, pteval);
232 }
233
234 pmd_t * __init populate_extra_pmd(unsigned long vaddr)
235 {
236 pgd_t *pgd;
237 pud_t *pud;
238
239 pgd = pgd_offset_k(vaddr);
240 pud = fill_pud(pgd, vaddr);
241 return fill_pmd(pud, vaddr);
242 }
243
244 pte_t * __init populate_extra_pte(unsigned long vaddr)
245 {
246 pmd_t *pmd;
247
248 pmd = populate_extra_pmd(vaddr);
249 return fill_pte(pmd, vaddr);
250 }
251
252 /*
253 * Create large page table mappings for a range of physical addresses.
254 */
255 static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
256 enum page_cache_mode cache)
257 {
258 pgd_t *pgd;
259 pud_t *pud;
260 pmd_t *pmd;
261 pgprot_t prot;
262
263 pgprot_val(prot) = pgprot_val(PAGE_KERNEL_LARGE) |
264 pgprot_val(pgprot_4k_2_large(cachemode2pgprot(cache)));
265 BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
266 for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
267 pgd = pgd_offset_k((unsigned long)__va(phys));
268 if (pgd_none(*pgd)) {
269 pud = (pud_t *) spp_getpage();
270 set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE |
271 _PAGE_USER));
272 }
273 pud = pud_offset(pgd, (unsigned long)__va(phys));
274 if (pud_none(*pud)) {
275 pmd = (pmd_t *) spp_getpage();
276 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
277 _PAGE_USER));
278 }
279 pmd = pmd_offset(pud, phys);
280 BUG_ON(!pmd_none(*pmd));
281 set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
282 }
283 }
284
285 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
286 {
287 __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_WB);
288 }
289
290 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
291 {
292 __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_UC);
293 }
294
295 /*
296 * The head.S code sets up the kernel high mapping:
297 *
298 * from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
299 *
300 * phys_base holds the negative offset to the kernel, which is added
301 * to the compile time generated pmds. This results in invalid pmds up
302 * to the point where we hit the physaddr 0 mapping.
303 *
304 * We limit the mappings to the region from _text to _brk_end. _brk_end
305 * is rounded up to the 2MB boundary. This catches the invalid pmds as
306 * well, as they are located before _text:
307 */
308 void __init cleanup_highmap(void)
309 {
310 unsigned long vaddr = __START_KERNEL_map;
311 unsigned long vaddr_end = __START_KERNEL_map + KERNEL_IMAGE_SIZE;
312 unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1;
313 pmd_t *pmd = level2_kernel_pgt;
314
315 /*
316 * Native path, max_pfn_mapped is not set yet.
317 * Xen has valid max_pfn_mapped set in
318 * arch/x86/xen/mmu.c:xen_setup_kernel_pagetable().
319 */
320 if (max_pfn_mapped)
321 vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT);
322
323 for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) {
324 if (pmd_none(*pmd))
325 continue;
326 if (vaddr < (unsigned long) _text || vaddr > end)
327 set_pmd(pmd, __pmd(0));
328 }
329 }
330
331 static unsigned long __meminit
332 phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end,
333 pgprot_t prot)
334 {
335 unsigned long pages = 0, next;
336 unsigned long last_map_addr = end;
337 int i;
338
339 pte_t *pte = pte_page + pte_index(addr);
340
341 for (i = pte_index(addr); i < PTRS_PER_PTE; i++, addr = next, pte++) {
342 next = (addr & PAGE_MASK) + PAGE_SIZE;
343 if (addr >= end) {
344 if (!after_bootmem &&
345 !e820_any_mapped(addr & PAGE_MASK, next, E820_RAM) &&
346 !e820_any_mapped(addr & PAGE_MASK, next, E820_RESERVED_KERN))
347 set_pte(pte, __pte(0));
348 continue;
349 }
350
351 /*
352 * We will re-use the existing mapping.
353 * Xen for example has some special requirements, like mapping
354 * pagetable pages as RO. So assume someone who pre-setup
355 * these mappings are more intelligent.
356 */
357 if (pte_val(*pte)) {
358 if (!after_bootmem)
359 pages++;
360 continue;
361 }
362
363 if (0)
364 printk(" pte=%p addr=%lx pte=%016lx\n",
365 pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte);
366 pages++;
367 set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot));
368 last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
369 }
370
371 update_page_count(PG_LEVEL_4K, pages);
372
373 return last_map_addr;
374 }
375
376 static unsigned long __meminit
377 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
378 unsigned long page_size_mask, pgprot_t prot)
379 {
380 unsigned long pages = 0, next;
381 unsigned long last_map_addr = end;
382
383 int i = pmd_index(address);
384
385 for (; i < PTRS_PER_PMD; i++, address = next) {
386 pmd_t *pmd = pmd_page + pmd_index(address);
387 pte_t *pte;
388 pgprot_t new_prot = prot;
389
390 next = (address & PMD_MASK) + PMD_SIZE;
391 if (address >= end) {
392 if (!after_bootmem &&
393 !e820_any_mapped(address & PMD_MASK, next, E820_RAM) &&
394 !e820_any_mapped(address & PMD_MASK, next, E820_RESERVED_KERN))
395 set_pmd(pmd, __pmd(0));
396 continue;
397 }
398
399 if (pmd_val(*pmd)) {
400 if (!pmd_large(*pmd)) {
401 spin_lock(&init_mm.page_table_lock);
402 pte = (pte_t *)pmd_page_vaddr(*pmd);
403 last_map_addr = phys_pte_init(pte, address,
404 end, prot);
405 spin_unlock(&init_mm.page_table_lock);
406 continue;
407 }
408 /*
409 * If we are ok with PG_LEVEL_2M mapping, then we will
410 * use the existing mapping,
411 *
412 * Otherwise, we will split the large page mapping but
413 * use the same existing protection bits except for
414 * large page, so that we don't violate Intel's TLB
415 * Application note (317080) which says, while changing
416 * the page sizes, new and old translations should
417 * not differ with respect to page frame and
418 * attributes.
419 */
420 if (page_size_mask & (1 << PG_LEVEL_2M)) {
421 if (!after_bootmem)
422 pages++;
423 last_map_addr = next;
424 continue;
425 }
426 new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
427 }
428
429 if (page_size_mask & (1<<PG_LEVEL_2M)) {
430 pages++;
431 spin_lock(&init_mm.page_table_lock);
432 set_pte((pte_t *)pmd,
433 pfn_pte((address & PMD_MASK) >> PAGE_SHIFT,
434 __pgprot(pgprot_val(prot) | _PAGE_PSE)));
435 spin_unlock(&init_mm.page_table_lock);
436 last_map_addr = next;
437 continue;
438 }
439
440 pte = alloc_low_page();
441 last_map_addr = phys_pte_init(pte, address, end, new_prot);
442
443 spin_lock(&init_mm.page_table_lock);
444 pmd_populate_kernel(&init_mm, pmd, pte);
445 spin_unlock(&init_mm.page_table_lock);
446 }
447 update_page_count(PG_LEVEL_2M, pages);
448 return last_map_addr;
449 }
450
451 static unsigned long __meminit
452 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
453 unsigned long page_size_mask)
454 {
455 unsigned long pages = 0, next;
456 unsigned long last_map_addr = end;
457 int i = pud_index(addr);
458
459 for (; i < PTRS_PER_PUD; i++, addr = next) {
460 pud_t *pud = pud_page + pud_index(addr);
461 pmd_t *pmd;
462 pgprot_t prot = PAGE_KERNEL;
463
464 next = (addr & PUD_MASK) + PUD_SIZE;
465 if (addr >= end) {
466 if (!after_bootmem &&
467 !e820_any_mapped(addr & PUD_MASK, next, E820_RAM) &&
468 !e820_any_mapped(addr & PUD_MASK, next, E820_RESERVED_KERN))
469 set_pud(pud, __pud(0));
470 continue;
471 }
472
473 if (pud_val(*pud)) {
474 if (!pud_large(*pud)) {
475 pmd = pmd_offset(pud, 0);
476 last_map_addr = phys_pmd_init(pmd, addr, end,
477 page_size_mask, prot);
478 __flush_tlb_all();
479 continue;
480 }
481 /*
482 * If we are ok with PG_LEVEL_1G mapping, then we will
483 * use the existing mapping.
484 *
485 * Otherwise, we will split the gbpage mapping but use
486 * the same existing protection bits except for large
487 * page, so that we don't violate Intel's TLB
488 * Application note (317080) which says, while changing
489 * the page sizes, new and old translations should
490 * not differ with respect to page frame and
491 * attributes.
492 */
493 if (page_size_mask & (1 << PG_LEVEL_1G)) {
494 if (!after_bootmem)
495 pages++;
496 last_map_addr = next;
497 continue;
498 }
499 prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
500 }
501
502 if (page_size_mask & (1<<PG_LEVEL_1G)) {
503 pages++;
504 spin_lock(&init_mm.page_table_lock);
505 set_pte((pte_t *)pud,
506 pfn_pte((addr & PUD_MASK) >> PAGE_SHIFT,
507 PAGE_KERNEL_LARGE));
508 spin_unlock(&init_mm.page_table_lock);
509 last_map_addr = next;
510 continue;
511 }
512
513 pmd = alloc_low_page();
514 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask,
515 prot);
516
517 spin_lock(&init_mm.page_table_lock);
518 pud_populate(&init_mm, pud, pmd);
519 spin_unlock(&init_mm.page_table_lock);
520 }
521 __flush_tlb_all();
522
523 update_page_count(PG_LEVEL_1G, pages);
524
525 return last_map_addr;
526 }
527
528 unsigned long __meminit
529 kernel_physical_mapping_init(unsigned long start,
530 unsigned long end,
531 unsigned long page_size_mask)
532 {
533 bool pgd_changed = false;
534 unsigned long next, last_map_addr = end;
535 unsigned long addr;
536
537 start = (unsigned long)__va(start);
538 end = (unsigned long)__va(end);
539 addr = start;
540
541 for (; start < end; start = next) {
542 pgd_t *pgd = pgd_offset_k(start);
543 pud_t *pud;
544
545 next = (start & PGDIR_MASK) + PGDIR_SIZE;
546
547 if (pgd_val(*pgd)) {
548 pud = (pud_t *)pgd_page_vaddr(*pgd);
549 last_map_addr = phys_pud_init(pud, __pa(start),
550 __pa(end), page_size_mask);
551 continue;
552 }
553
554 pud = alloc_low_page();
555 last_map_addr = phys_pud_init(pud, __pa(start), __pa(end),
556 page_size_mask);
557
558 spin_lock(&init_mm.page_table_lock);
559 pgd_populate(&init_mm, pgd, pud);
560 spin_unlock(&init_mm.page_table_lock);
561 pgd_changed = true;
562 }
563
564 if (pgd_changed)
565 sync_global_pgds(addr, end - 1, 0);
566
567 __flush_tlb_all();
568
569 return last_map_addr;
570 }
571
572 #ifndef CONFIG_NUMA
573 void __init initmem_init(void)
574 {
575 memblock_set_node(0, (phys_addr_t)ULLONG_MAX, &memblock.memory, 0);
576 }
577 #endif
578
579 void __init paging_init(void)
580 {
581 sparse_memory_present_with_active_regions(MAX_NUMNODES);
582 sparse_init();
583
584 /*
585 * clear the default setting with node 0
586 * note: don't use nodes_clear here, that is really clearing when
587 * numa support is not compiled in, and later node_set_state
588 * will not set it back.
589 */
590 node_clear_state(0, N_MEMORY);
591 if (N_MEMORY != N_NORMAL_MEMORY)
592 node_clear_state(0, N_NORMAL_MEMORY);
593
594 zone_sizes_init();
595 }
596
597 /*
598 * Memory hotplug specific functions
599 */
600 #ifdef CONFIG_MEMORY_HOTPLUG
601 /*
602 * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
603 * updating.
604 */
605 static void update_end_of_memory_vars(u64 start, u64 size)
606 {
607 unsigned long end_pfn = PFN_UP(start + size);
608
609 if (end_pfn > max_pfn) {
610 max_pfn = end_pfn;
611 max_low_pfn = end_pfn;
612 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
613 }
614 }
615
616 /*
617 * Memory is added always to NORMAL zone. This means you will never get
618 * additional DMA/DMA32 memory.
619 */
620 int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
621 {
622 struct pglist_data *pgdat = NODE_DATA(nid);
623 struct zone *zone = pgdat->node_zones +
624 zone_for_memory(nid, start, size, ZONE_NORMAL, for_device);
625 unsigned long start_pfn = start >> PAGE_SHIFT;
626 unsigned long nr_pages = size >> PAGE_SHIFT;
627 int ret;
628
629 init_memory_mapping(start, start + size);
630
631 ret = __add_pages(nid, zone, start_pfn, nr_pages);
632 WARN_ON_ONCE(ret);
633
634 /* update max_pfn, max_low_pfn and high_memory */
635 update_end_of_memory_vars(start, size);
636
637 return ret;
638 }
639 EXPORT_SYMBOL_GPL(arch_add_memory);
640
641 #define PAGE_INUSE 0xFD
642
643 static void __meminit free_pagetable(struct page *page, int order)
644 {
645 unsigned long magic;
646 unsigned int nr_pages = 1 << order;
647 struct vmem_altmap *altmap = to_vmem_altmap((unsigned long) page);
648
649 if (altmap) {
650 vmem_altmap_free(altmap, nr_pages);
651 return;
652 }
653
654 /* bootmem page has reserved flag */
655 if (PageReserved(page)) {
656 __ClearPageReserved(page);
657
658 magic = (unsigned long)page->lru.next;
659 if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
660 while (nr_pages--)
661 put_page_bootmem(page++);
662 } else
663 while (nr_pages--)
664 free_reserved_page(page++);
665 } else
666 free_pages((unsigned long)page_address(page), order);
667 }
668
669 static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
670 {
671 pte_t *pte;
672 int i;
673
674 for (i = 0; i < PTRS_PER_PTE; i++) {
675 pte = pte_start + i;
676 if (pte_val(*pte))
677 return;
678 }
679
680 /* free a pte talbe */
681 free_pagetable(pmd_page(*pmd), 0);
682 spin_lock(&init_mm.page_table_lock);
683 pmd_clear(pmd);
684 spin_unlock(&init_mm.page_table_lock);
685 }
686
687 static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud)
688 {
689 pmd_t *pmd;
690 int i;
691
692 for (i = 0; i < PTRS_PER_PMD; i++) {
693 pmd = pmd_start + i;
694 if (pmd_val(*pmd))
695 return;
696 }
697
698 /* free a pmd talbe */
699 free_pagetable(pud_page(*pud), 0);
700 spin_lock(&init_mm.page_table_lock);
701 pud_clear(pud);
702 spin_unlock(&init_mm.page_table_lock);
703 }
704
705 /* Return true if pgd is changed, otherwise return false. */
706 static bool __meminit free_pud_table(pud_t *pud_start, pgd_t *pgd)
707 {
708 pud_t *pud;
709 int i;
710
711 for (i = 0; i < PTRS_PER_PUD; i++) {
712 pud = pud_start + i;
713 if (pud_val(*pud))
714 return false;
715 }
716
717 /* free a pud table */
718 free_pagetable(pgd_page(*pgd), 0);
719 spin_lock(&init_mm.page_table_lock);
720 pgd_clear(pgd);
721 spin_unlock(&init_mm.page_table_lock);
722
723 return true;
724 }
725
726 static void __meminit
727 remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
728 bool direct)
729 {
730 unsigned long next, pages = 0;
731 pte_t *pte;
732 void *page_addr;
733 phys_addr_t phys_addr;
734
735 pte = pte_start + pte_index(addr);
736 for (; addr < end; addr = next, pte++) {
737 next = (addr + PAGE_SIZE) & PAGE_MASK;
738 if (next > end)
739 next = end;
740
741 if (!pte_present(*pte))
742 continue;
743
744 /*
745 * We mapped [0,1G) memory as identity mapping when
746 * initializing, in arch/x86/kernel/head_64.S. These
747 * pagetables cannot be removed.
748 */
749 phys_addr = pte_val(*pte) + (addr & PAGE_MASK);
750 if (phys_addr < (phys_addr_t)0x40000000)
751 return;
752
753 if (PAGE_ALIGNED(addr) && PAGE_ALIGNED(next)) {
754 /*
755 * Do not free direct mapping pages since they were
756 * freed when offlining, or simplely not in use.
757 */
758 if (!direct)
759 free_pagetable(pte_page(*pte), 0);
760
761 spin_lock(&init_mm.page_table_lock);
762 pte_clear(&init_mm, addr, pte);
763 spin_unlock(&init_mm.page_table_lock);
764
765 /* For non-direct mapping, pages means nothing. */
766 pages++;
767 } else {
768 /*
769 * If we are here, we are freeing vmemmap pages since
770 * direct mapped memory ranges to be freed are aligned.
771 *
772 * If we are not removing the whole page, it means
773 * other page structs in this page are being used and
774 * we canot remove them. So fill the unused page_structs
775 * with 0xFD, and remove the page when it is wholly
776 * filled with 0xFD.
777 */
778 memset((void *)addr, PAGE_INUSE, next - addr);
779
780 page_addr = page_address(pte_page(*pte));
781 if (!memchr_inv(page_addr, PAGE_INUSE, PAGE_SIZE)) {
782 free_pagetable(pte_page(*pte), 0);
783
784 spin_lock(&init_mm.page_table_lock);
785 pte_clear(&init_mm, addr, pte);
786 spin_unlock(&init_mm.page_table_lock);
787 }
788 }
789 }
790
791 /* Call free_pte_table() in remove_pmd_table(). */
792 flush_tlb_all();
793 if (direct)
794 update_page_count(PG_LEVEL_4K, -pages);
795 }
796
797 static void __meminit
798 remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
799 bool direct)
800 {
801 unsigned long next, pages = 0;
802 pte_t *pte_base;
803 pmd_t *pmd;
804 void *page_addr;
805
806 pmd = pmd_start + pmd_index(addr);
807 for (; addr < end; addr = next, pmd++) {
808 next = pmd_addr_end(addr, end);
809
810 if (!pmd_present(*pmd))
811 continue;
812
813 if (pmd_large(*pmd)) {
814 if (IS_ALIGNED(addr, PMD_SIZE) &&
815 IS_ALIGNED(next, PMD_SIZE)) {
816 if (!direct)
817 free_pagetable(pmd_page(*pmd),
818 get_order(PMD_SIZE));
819
820 spin_lock(&init_mm.page_table_lock);
821 pmd_clear(pmd);
822 spin_unlock(&init_mm.page_table_lock);
823 pages++;
824 } else {
825 /* If here, we are freeing vmemmap pages. */
826 memset((void *)addr, PAGE_INUSE, next - addr);
827
828 page_addr = page_address(pmd_page(*pmd));
829 if (!memchr_inv(page_addr, PAGE_INUSE,
830 PMD_SIZE)) {
831 free_pagetable(pmd_page(*pmd),
832 get_order(PMD_SIZE));
833
834 spin_lock(&init_mm.page_table_lock);
835 pmd_clear(pmd);
836 spin_unlock(&init_mm.page_table_lock);
837 }
838 }
839
840 continue;
841 }
842
843 pte_base = (pte_t *)pmd_page_vaddr(*pmd);
844 remove_pte_table(pte_base, addr, next, direct);
845 free_pte_table(pte_base, pmd);
846 }
847
848 /* Call free_pmd_table() in remove_pud_table(). */
849 if (direct)
850 update_page_count(PG_LEVEL_2M, -pages);
851 }
852
853 static void __meminit
854 remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
855 bool direct)
856 {
857 unsigned long next, pages = 0;
858 pmd_t *pmd_base;
859 pud_t *pud;
860 void *page_addr;
861
862 pud = pud_start + pud_index(addr);
863 for (; addr < end; addr = next, pud++) {
864 next = pud_addr_end(addr, end);
865
866 if (!pud_present(*pud))
867 continue;
868
869 if (pud_large(*pud)) {
870 if (IS_ALIGNED(addr, PUD_SIZE) &&
871 IS_ALIGNED(next, PUD_SIZE)) {
872 if (!direct)
873 free_pagetable(pud_page(*pud),
874 get_order(PUD_SIZE));
875
876 spin_lock(&init_mm.page_table_lock);
877 pud_clear(pud);
878 spin_unlock(&init_mm.page_table_lock);
879 pages++;
880 } else {
881 /* If here, we are freeing vmemmap pages. */
882 memset((void *)addr, PAGE_INUSE, next - addr);
883
884 page_addr = page_address(pud_page(*pud));
885 if (!memchr_inv(page_addr, PAGE_INUSE,
886 PUD_SIZE)) {
887 free_pagetable(pud_page(*pud),
888 get_order(PUD_SIZE));
889
890 spin_lock(&init_mm.page_table_lock);
891 pud_clear(pud);
892 spin_unlock(&init_mm.page_table_lock);
893 }
894 }
895
896 continue;
897 }
898
899 pmd_base = (pmd_t *)pud_page_vaddr(*pud);
900 remove_pmd_table(pmd_base, addr, next, direct);
901 free_pmd_table(pmd_base, pud);
902 }
903
904 if (direct)
905 update_page_count(PG_LEVEL_1G, -pages);
906 }
907
908 /* start and end are both virtual address. */
909 static void __meminit
910 remove_pagetable(unsigned long start, unsigned long end, bool direct)
911 {
912 unsigned long next;
913 unsigned long addr;
914 pgd_t *pgd;
915 pud_t *pud;
916 bool pgd_changed = false;
917
918 for (addr = start; addr < end; addr = next) {
919 next = pgd_addr_end(addr, end);
920
921 pgd = pgd_offset_k(addr);
922 if (!pgd_present(*pgd))
923 continue;
924
925 pud = (pud_t *)pgd_page_vaddr(*pgd);
926 remove_pud_table(pud, addr, next, direct);
927 if (free_pud_table(pud, pgd))
928 pgd_changed = true;
929 }
930
931 if (pgd_changed)
932 sync_global_pgds(start, end - 1, 1);
933
934 flush_tlb_all();
935 }
936
937 void __ref vmemmap_free(unsigned long start, unsigned long end)
938 {
939 remove_pagetable(start, end, false);
940 }
941
942 #ifdef CONFIG_MEMORY_HOTREMOVE
943 static void __meminit
944 kernel_physical_mapping_remove(unsigned long start, unsigned long end)
945 {
946 start = (unsigned long)__va(start);
947 end = (unsigned long)__va(end);
948
949 remove_pagetable(start, end, true);
950 }
951
952 int __ref arch_remove_memory(u64 start, u64 size)
953 {
954 unsigned long start_pfn = start >> PAGE_SHIFT;
955 unsigned long nr_pages = size >> PAGE_SHIFT;
956 struct page *page = pfn_to_page(start_pfn);
957 struct vmem_altmap *altmap;
958 struct zone *zone;
959 int ret;
960
961 /* With altmap the first mapped page is offset from @start */
962 altmap = to_vmem_altmap((unsigned long) page);
963 if (altmap)
964 page += vmem_altmap_offset(altmap);
965 zone = page_zone(page);
966 ret = __remove_pages(zone, start_pfn, nr_pages);
967 WARN_ON_ONCE(ret);
968 kernel_physical_mapping_remove(start, start + size);
969
970 return ret;
971 }
972 #endif
973 #endif /* CONFIG_MEMORY_HOTPLUG */
974
975 static struct kcore_list kcore_vsyscall;
976
977 static void __init register_page_bootmem_info(void)
978 {
979 #ifdef CONFIG_NUMA
980 int i;
981
982 for_each_online_node(i)
983 register_page_bootmem_info_node(NODE_DATA(i));
984 #endif
985 }
986
987 void __init mem_init(void)
988 {
989 pci_iommu_alloc();
990
991 /* clear_bss() already clear the empty_zero_page */
992
993 register_page_bootmem_info();
994
995 /* this will put all memory onto the freelists */
996 free_all_bootmem();
997 after_bootmem = 1;
998
999 /* Register memory areas for /proc/kcore */
1000 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR,
1001 PAGE_SIZE, KCORE_OTHER);
1002
1003 mem_init_print_info(NULL);
1004 }
1005
1006 const int rodata_test_data = 0xC3;
1007 EXPORT_SYMBOL_GPL(rodata_test_data);
1008
1009 int kernel_set_to_readonly;
1010
1011 void set_kernel_text_rw(void)
1012 {
1013 unsigned long start = PFN_ALIGN(_text);
1014 unsigned long end = PFN_ALIGN(__stop___ex_table);
1015
1016 if (!kernel_set_to_readonly)
1017 return;
1018
1019 pr_debug("Set kernel text: %lx - %lx for read write\n",
1020 start, end);
1021
1022 /*
1023 * Make the kernel identity mapping for text RW. Kernel text
1024 * mapping will always be RO. Refer to the comment in
1025 * static_protections() in pageattr.c
1026 */
1027 set_memory_rw(start, (end - start) >> PAGE_SHIFT);
1028 }
1029
1030 void set_kernel_text_ro(void)
1031 {
1032 unsigned long start = PFN_ALIGN(_text);
1033 unsigned long end = PFN_ALIGN(__stop___ex_table);
1034
1035 if (!kernel_set_to_readonly)
1036 return;
1037
1038 pr_debug("Set kernel text: %lx - %lx for read only\n",
1039 start, end);
1040
1041 /*
1042 * Set the kernel identity mapping for text RO.
1043 */
1044 set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1045 }
1046
1047 void mark_rodata_ro(void)
1048 {
1049 unsigned long start = PFN_ALIGN(_text);
1050 unsigned long rodata_start = PFN_ALIGN(__start_rodata);
1051 unsigned long end = (unsigned long) &__end_rodata_hpage_align;
1052 unsigned long text_end = PFN_ALIGN(&__stop___ex_table);
1053 unsigned long rodata_end = PFN_ALIGN(&__end_rodata);
1054 unsigned long all_end;
1055
1056 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
1057 (end - start) >> 10);
1058 set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1059
1060 kernel_set_to_readonly = 1;
1061
1062 /*
1063 * The rodata/data/bss/brk section (but not the kernel text!)
1064 * should also be not-executable.
1065 *
1066 * We align all_end to PMD_SIZE because the existing mapping
1067 * is a full PMD. If we would align _brk_end to PAGE_SIZE we
1068 * split the PMD and the reminder between _brk_end and the end
1069 * of the PMD will remain mapped executable.
1070 *
1071 * Any PMD which was setup after the one which covers _brk_end
1072 * has been zapped already via cleanup_highmem().
1073 */
1074 all_end = roundup((unsigned long)_brk_end, PMD_SIZE);
1075 set_memory_nx(text_end, (all_end - text_end) >> PAGE_SHIFT);
1076
1077 rodata_test();
1078
1079 #ifdef CONFIG_CPA_DEBUG
1080 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
1081 set_memory_rw(start, (end-start) >> PAGE_SHIFT);
1082
1083 printk(KERN_INFO "Testing CPA: again\n");
1084 set_memory_ro(start, (end-start) >> PAGE_SHIFT);
1085 #endif
1086
1087 free_init_pages("unused kernel",
1088 (unsigned long) __va(__pa_symbol(text_end)),
1089 (unsigned long) __va(__pa_symbol(rodata_start)));
1090 free_init_pages("unused kernel",
1091 (unsigned long) __va(__pa_symbol(rodata_end)),
1092 (unsigned long) __va(__pa_symbol(_sdata)));
1093
1094 debug_checkwx();
1095 }
1096
1097 int kern_addr_valid(unsigned long addr)
1098 {
1099 unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
1100 pgd_t *pgd;
1101 pud_t *pud;
1102 pmd_t *pmd;
1103 pte_t *pte;
1104
1105 if (above != 0 && above != -1UL)
1106 return 0;
1107
1108 pgd = pgd_offset_k(addr);
1109 if (pgd_none(*pgd))
1110 return 0;
1111
1112 pud = pud_offset(pgd, addr);
1113 if (pud_none(*pud))
1114 return 0;
1115
1116 if (pud_large(*pud))
1117 return pfn_valid(pud_pfn(*pud));
1118
1119 pmd = pmd_offset(pud, addr);
1120 if (pmd_none(*pmd))
1121 return 0;
1122
1123 if (pmd_large(*pmd))
1124 return pfn_valid(pmd_pfn(*pmd));
1125
1126 pte = pte_offset_kernel(pmd, addr);
1127 if (pte_none(*pte))
1128 return 0;
1129
1130 return pfn_valid(pte_pfn(*pte));
1131 }
1132
1133 static unsigned long probe_memory_block_size(void)
1134 {
1135 unsigned long bz = MIN_MEMORY_BLOCK_SIZE;
1136
1137 /* if system is UV or has 64GB of RAM or more, use large blocks */
1138 if (is_uv_system() || ((max_pfn << PAGE_SHIFT) >= (64UL << 30)))
1139 bz = 2UL << 30; /* 2GB */
1140
1141 pr_info("x86/mm: Memory block size: %ldMB\n", bz >> 20);
1142
1143 return bz;
1144 }
1145
1146 static unsigned long memory_block_size_probed;
1147 unsigned long memory_block_size_bytes(void)
1148 {
1149 if (!memory_block_size_probed)
1150 memory_block_size_probed = probe_memory_block_size();
1151
1152 return memory_block_size_probed;
1153 }
1154
1155 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1156 /*
1157 * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1158 */
1159 static long __meminitdata addr_start, addr_end;
1160 static void __meminitdata *p_start, *p_end;
1161 static int __meminitdata node_start;
1162
1163 static int __meminit vmemmap_populate_hugepages(unsigned long start,
1164 unsigned long end, int node, struct vmem_altmap *altmap)
1165 {
1166 unsigned long addr;
1167 unsigned long next;
1168 pgd_t *pgd;
1169 pud_t *pud;
1170 pmd_t *pmd;
1171
1172 for (addr = start; addr < end; addr = next) {
1173 next = pmd_addr_end(addr, end);
1174
1175 pgd = vmemmap_pgd_populate(addr, node);
1176 if (!pgd)
1177 return -ENOMEM;
1178
1179 pud = vmemmap_pud_populate(pgd, addr, node);
1180 if (!pud)
1181 return -ENOMEM;
1182
1183 pmd = pmd_offset(pud, addr);
1184 if (pmd_none(*pmd)) {
1185 void *p;
1186
1187 p = __vmemmap_alloc_block_buf(PMD_SIZE, node, altmap);
1188 if (p) {
1189 pte_t entry;
1190
1191 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1192 PAGE_KERNEL_LARGE);
1193 set_pmd(pmd, __pmd(pte_val(entry)));
1194
1195 /* check to see if we have contiguous blocks */
1196 if (p_end != p || node_start != node) {
1197 if (p_start)
1198 pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1199 addr_start, addr_end-1, p_start, p_end-1, node_start);
1200 addr_start = addr;
1201 node_start = node;
1202 p_start = p;
1203 }
1204
1205 addr_end = addr + PMD_SIZE;
1206 p_end = p + PMD_SIZE;
1207 continue;
1208 } else if (altmap)
1209 return -ENOMEM; /* no fallback */
1210 } else if (pmd_large(*pmd)) {
1211 vmemmap_verify((pte_t *)pmd, node, addr, next);
1212 continue;
1213 }
1214 pr_warn_once("vmemmap: falling back to regular page backing\n");
1215 if (vmemmap_populate_basepages(addr, next, node))
1216 return -ENOMEM;
1217 }
1218 return 0;
1219 }
1220
1221 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
1222 {
1223 struct vmem_altmap *altmap = to_vmem_altmap(start);
1224 int err;
1225
1226 if (boot_cpu_has(X86_FEATURE_PSE))
1227 err = vmemmap_populate_hugepages(start, end, node, altmap);
1228 else if (altmap) {
1229 pr_err_once("%s: no cpu support for altmap allocations\n",
1230 __func__);
1231 err = -ENOMEM;
1232 } else
1233 err = vmemmap_populate_basepages(start, end, node);
1234 if (!err)
1235 sync_global_pgds(start, end - 1, 0);
1236 return err;
1237 }
1238
1239 #if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HAVE_BOOTMEM_INFO_NODE)
1240 void register_page_bootmem_memmap(unsigned long section_nr,
1241 struct page *start_page, unsigned long size)
1242 {
1243 unsigned long addr = (unsigned long)start_page;
1244 unsigned long end = (unsigned long)(start_page + size);
1245 unsigned long next;
1246 pgd_t *pgd;
1247 pud_t *pud;
1248 pmd_t *pmd;
1249 unsigned int nr_pages;
1250 struct page *page;
1251
1252 for (; addr < end; addr = next) {
1253 pte_t *pte = NULL;
1254
1255 pgd = pgd_offset_k(addr);
1256 if (pgd_none(*pgd)) {
1257 next = (addr + PAGE_SIZE) & PAGE_MASK;
1258 continue;
1259 }
1260 get_page_bootmem(section_nr, pgd_page(*pgd), MIX_SECTION_INFO);
1261
1262 pud = pud_offset(pgd, addr);
1263 if (pud_none(*pud)) {
1264 next = (addr + PAGE_SIZE) & PAGE_MASK;
1265 continue;
1266 }
1267 get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO);
1268
1269 if (!boot_cpu_has(X86_FEATURE_PSE)) {
1270 next = (addr + PAGE_SIZE) & PAGE_MASK;
1271 pmd = pmd_offset(pud, addr);
1272 if (pmd_none(*pmd))
1273 continue;
1274 get_page_bootmem(section_nr, pmd_page(*pmd),
1275 MIX_SECTION_INFO);
1276
1277 pte = pte_offset_kernel(pmd, addr);
1278 if (pte_none(*pte))
1279 continue;
1280 get_page_bootmem(section_nr, pte_page(*pte),
1281 SECTION_INFO);
1282 } else {
1283 next = pmd_addr_end(addr, end);
1284
1285 pmd = pmd_offset(pud, addr);
1286 if (pmd_none(*pmd))
1287 continue;
1288
1289 nr_pages = 1 << (get_order(PMD_SIZE));
1290 page = pmd_page(*pmd);
1291 while (nr_pages--)
1292 get_page_bootmem(section_nr, page++,
1293 SECTION_INFO);
1294 }
1295 }
1296 }
1297 #endif
1298
1299 void __meminit vmemmap_populate_print_last(void)
1300 {
1301 if (p_start) {
1302 pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1303 addr_start, addr_end-1, p_start, p_end-1, node_start);
1304 p_start = NULL;
1305 p_end = NULL;
1306 node_start = 0;
1307 }
1308 }
1309 #endif
Linux kernel - Deliverables
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