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
parse_direct_gbpages_off(char * arg)58 static int __init parse_direct_gbpages_off(char *arg)
59 {
60 direct_gbpages = 0;
61 return 0;
62 }
63 early_param("nogbpages", parse_direct_gbpages_off);
64
parse_direct_gbpages_on(char * arg)65 static int __init parse_direct_gbpages_on(char *arg)
66 {
67 direct_gbpages = 1;
68 return 0;
69 }
70 early_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
78 pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP;
79 EXPORT_SYMBOL_GPL(__supported_pte_mask);
80
81 int 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 */
nonx32_setup(char * str)91 static 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 */
sync_global_pgds(unsigned long start,unsigned long end)105 void 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 */
spp_getpage(void)142 static __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
fill_pud(pgd_t * pgd,unsigned long vaddr)161 static 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
fill_pmd(pud_t * pud,unsigned long vaddr)173 static 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
fill_pte(pmd_t * pmd,unsigned long vaddr)185 static 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
set_pte_vaddr_pud(pud_t * pud_page,unsigned long vaddr,pte_t new_pte)196 void 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
set_pte_vaddr(unsigned long vaddr,pte_t pteval)215 void 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
populate_extra_pmd(unsigned long vaddr)232 pmd_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
populate_extra_pte(unsigned long vaddr)242 pte_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 */
__init_extra_mapping(unsigned long phys,unsigned long size,pgprot_t prot)253 static 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
init_extra_mapping_wb(unsigned long phys,unsigned long size)280 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
281 {
282 __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE);
283 }
284
init_extra_mapping_uc(unsigned long phys,unsigned long size)285 void __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 */
cleanup_highmap(void)303 void __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
alloc_low_page(unsigned long * phys)318 static __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
map_low_page(void * virt)339 static __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
unmap_low_page(void * adr)355 static __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
363 static unsigned long __meminit
phys_pte_init(pte_t * pte_page,unsigned long addr,unsigned long end,pgprot_t prot)364 phys_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
407 static unsigned long __meminit
phys_pmd_init(pmd_t * pmd_page,unsigned long address,unsigned long end,unsigned long page_size_mask,pgprot_t prot)408 phys_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
482 static unsigned long __meminit
phys_pud_init(pud_t * pud_page,unsigned long addr,unsigned long end,unsigned long page_size_mask)483 phys_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
559 unsigned long __meminit
kernel_physical_mapping_init(unsigned long start,unsigned long end,unsigned long page_size_mask)560 kernel_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
initmem_init(void)609 void __init initmem_init(void)
610 {
611 memblock_set_node(0, (phys_addr_t)ULLONG_MAX, 0);
612 }
613 #endif
614
paging_init(void)615 void __init paging_init(void)
616 {
617 sparse_memory_present_with_active_regions(MAX_NUMNODES);
618 sparse_init();
619
620 /*
621 * clear the default setting with node 0
622 * note: don't use nodes_clear here, that is really clearing when
623 * numa support is not compiled in, and later node_set_state
624 * will not set it back.
625 */
626 node_clear_state(0, N_NORMAL_MEMORY);
627
628 zone_sizes_init();
629 }
630
631 /*
632 * Memory hotplug specific functions
633 */
634 #ifdef CONFIG_MEMORY_HOTPLUG
635 /*
636 * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
637 * updating.
638 */
update_end_of_memory_vars(u64 start,u64 size)639 static void update_end_of_memory_vars(u64 start, u64 size)
640 {
641 unsigned long end_pfn = PFN_UP(start + size);
642
643 if (end_pfn > max_pfn) {
644 max_pfn = end_pfn;
645 max_low_pfn = end_pfn;
646 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
647 }
648 }
649
650 /*
651 * Memory is added always to NORMAL zone. This means you will never get
652 * additional DMA/DMA32 memory.
653 */
arch_add_memory(int nid,u64 start,u64 size)654 int arch_add_memory(int nid, u64 start, u64 size)
655 {
656 struct pglist_data *pgdat = NODE_DATA(nid);
657 struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
658 unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT;
659 unsigned long nr_pages = size >> PAGE_SHIFT;
660 int ret;
661
662 last_mapped_pfn = init_memory_mapping(start, start + size);
663 if (last_mapped_pfn > max_pfn_mapped)
664 max_pfn_mapped = last_mapped_pfn;
665
666 ret = __add_pages(nid, zone, start_pfn, nr_pages);
667 WARN_ON_ONCE(ret);
668
669 /* update max_pfn, max_low_pfn and high_memory */
670 update_end_of_memory_vars(start, size);
671
672 return ret;
673 }
674 EXPORT_SYMBOL_GPL(arch_add_memory);
675
676 #endif /* CONFIG_MEMORY_HOTPLUG */
677
678 static struct kcore_list kcore_vsyscall;
679
mem_init(void)680 void __init mem_init(void)
681 {
682 long codesize, reservedpages, datasize, initsize;
683 unsigned long absent_pages;
684
685 pci_iommu_alloc();
686
687 /* clear_bss() already clear the empty_zero_page */
688
689 reservedpages = 0;
690
691 /* this will put all low memory onto the freelists */
692 #ifdef CONFIG_NUMA
693 totalram_pages = numa_free_all_bootmem();
694 #else
695 totalram_pages = free_all_bootmem();
696 #endif
697
698 absent_pages = absent_pages_in_range(0, max_pfn);
699 reservedpages = max_pfn - totalram_pages - absent_pages;
700 after_bootmem = 1;
701
702 codesize = (unsigned long) &_etext - (unsigned long) &_text;
703 datasize = (unsigned long) &_edata - (unsigned long) &_etext;
704 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
705
706 /* Register memory areas for /proc/kcore */
707 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
708 VSYSCALL_END - VSYSCALL_START, KCORE_OTHER);
709
710 printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
711 "%ldk absent, %ldk reserved, %ldk data, %ldk init)\n",
712 nr_free_pages() << (PAGE_SHIFT-10),
713 max_pfn << (PAGE_SHIFT-10),
714 codesize >> 10,
715 absent_pages << (PAGE_SHIFT-10),
716 reservedpages << (PAGE_SHIFT-10),
717 datasize >> 10,
718 initsize >> 10);
719 }
720
721 #ifdef CONFIG_DEBUG_RODATA
722 const int rodata_test_data = 0xC3;
723 EXPORT_SYMBOL_GPL(rodata_test_data);
724
725 int kernel_set_to_readonly;
726
set_kernel_text_rw(void)727 void set_kernel_text_rw(void)
728 {
729 unsigned long start = PFN_ALIGN(_text);
730 unsigned long end = PFN_ALIGN(__stop___ex_table);
731
732 if (!kernel_set_to_readonly)
733 return;
734
735 pr_debug("Set kernel text: %lx - %lx for read write\n",
736 start, end);
737
738 /*
739 * Make the kernel identity mapping for text RW. Kernel text
740 * mapping will always be RO. Refer to the comment in
741 * static_protections() in pageattr.c
742 */
743 set_memory_rw(start, (end - start) >> PAGE_SHIFT);
744 }
745
set_kernel_text_ro(void)746 void set_kernel_text_ro(void)
747 {
748 unsigned long start = PFN_ALIGN(_text);
749 unsigned long end = PFN_ALIGN(__stop___ex_table);
750
751 if (!kernel_set_to_readonly)
752 return;
753
754 pr_debug("Set kernel text: %lx - %lx for read only\n",
755 start, end);
756
757 /*
758 * Set the kernel identity mapping for text RO.
759 */
760 set_memory_ro(start, (end - start) >> PAGE_SHIFT);
761 }
762
mark_rodata_ro(void)763 void mark_rodata_ro(void)
764 {
765 unsigned long start = PFN_ALIGN(_text);
766 unsigned long rodata_start =
767 ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
768 unsigned long end = (unsigned long) &__end_rodata_hpage_align;
769 unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table);
770 unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata);
771 unsigned long data_start = (unsigned long) &_sdata;
772
773 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
774 (end - start) >> 10);
775 set_memory_ro(start, (end - start) >> PAGE_SHIFT);
776
777 kernel_set_to_readonly = 1;
778
779 /*
780 * The rodata section (but not the kernel text!) should also be
781 * not-executable.
782 */
783 set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT);
784
785 rodata_test();
786
787 #ifdef CONFIG_CPA_DEBUG
788 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
789 set_memory_rw(start, (end-start) >> PAGE_SHIFT);
790
791 printk(KERN_INFO "Testing CPA: again\n");
792 set_memory_ro(start, (end-start) >> PAGE_SHIFT);
793 #endif
794
795 free_init_pages("unused kernel memory",
796 (unsigned long) page_address(virt_to_page(text_end)),
797 (unsigned long)
798 page_address(virt_to_page(rodata_start)));
799 free_init_pages("unused kernel memory",
800 (unsigned long) page_address(virt_to_page(rodata_end)),
801 (unsigned long) page_address(virt_to_page(data_start)));
802 }
803
804 #endif
805
kern_addr_valid(unsigned long addr)806 int kern_addr_valid(unsigned long addr)
807 {
808 unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
809 pgd_t *pgd;
810 pud_t *pud;
811 pmd_t *pmd;
812 pte_t *pte;
813
814 if (above != 0 && above != -1UL)
815 return 0;
816
817 pgd = pgd_offset_k(addr);
818 if (pgd_none(*pgd))
819 return 0;
820
821 pud = pud_offset(pgd, addr);
822 if (pud_none(*pud))
823 return 0;
824
825 pmd = pmd_offset(pud, addr);
826 if (pmd_none(*pmd))
827 return 0;
828
829 if (pmd_large(*pmd))
830 return pfn_valid(pmd_pfn(*pmd));
831
832 pte = pte_offset_kernel(pmd, addr);
833 if (pte_none(*pte))
834 return 0;
835
836 return pfn_valid(pte_pfn(*pte));
837 }
838
839 /*
840 * A pseudo VMA to allow ptrace access for the vsyscall page. This only
841 * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
842 * not need special handling anymore:
843 */
844 static struct vm_area_struct gate_vma = {
845 .vm_start = VSYSCALL_START,
846 .vm_end = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
847 .vm_page_prot = PAGE_READONLY_EXEC,
848 .vm_flags = VM_READ | VM_EXEC
849 };
850
get_gate_vma(struct mm_struct * mm)851 struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
852 {
853 #ifdef CONFIG_IA32_EMULATION
854 if (!mm || mm->context.ia32_compat)
855 return NULL;
856 #endif
857 return &gate_vma;
858 }
859
in_gate_area(struct mm_struct * mm,unsigned long addr)860 int in_gate_area(struct mm_struct *mm, unsigned long addr)
861 {
862 struct vm_area_struct *vma = get_gate_vma(mm);
863
864 if (!vma)
865 return 0;
866
867 return (addr >= vma->vm_start) && (addr < vma->vm_end);
868 }
869
870 /*
871 * Use this when you have no reliable mm, typically from interrupt
872 * context. It is less reliable than using a task's mm and may give
873 * false positives.
874 */
in_gate_area_no_mm(unsigned long addr)875 int in_gate_area_no_mm(unsigned long addr)
876 {
877 return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
878 }
879
arch_vma_name(struct vm_area_struct * vma)880 const char *arch_vma_name(struct vm_area_struct *vma)
881 {
882 if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
883 return "[vdso]";
884 if (vma == &gate_vma)
885 return "[vsyscall]";
886 return NULL;
887 }
888
889 #ifdef CONFIG_X86_UV
memory_block_size_bytes(void)890 unsigned long memory_block_size_bytes(void)
891 {
892 if (is_uv_system()) {
893 printk(KERN_INFO "UV: memory block size 2GB\n");
894 return 2UL * 1024 * 1024 * 1024;
895 }
896 return MIN_MEMORY_BLOCK_SIZE;
897 }
898 #endif
899
900 #ifdef CONFIG_SPARSEMEM_VMEMMAP
901 /*
902 * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
903 */
904 static long __meminitdata addr_start, addr_end;
905 static void __meminitdata *p_start, *p_end;
906 static int __meminitdata node_start;
907
908 int __meminit
vmemmap_populate(struct page * start_page,unsigned long size,int node)909 vmemmap_populate(struct page *start_page, unsigned long size, int node)
910 {
911 unsigned long addr = (unsigned long)start_page;
912 unsigned long end = (unsigned long)(start_page + size);
913 unsigned long next;
914 pgd_t *pgd;
915 pud_t *pud;
916 pmd_t *pmd;
917
918 for (; addr < end; addr = next) {
919 void *p = NULL;
920
921 pgd = vmemmap_pgd_populate(addr, node);
922 if (!pgd)
923 return -ENOMEM;
924
925 pud = vmemmap_pud_populate(pgd, addr, node);
926 if (!pud)
927 return -ENOMEM;
928
929 if (!cpu_has_pse) {
930 next = (addr + PAGE_SIZE) & PAGE_MASK;
931 pmd = vmemmap_pmd_populate(pud, addr, node);
932
933 if (!pmd)
934 return -ENOMEM;
935
936 p = vmemmap_pte_populate(pmd, addr, node);
937
938 if (!p)
939 return -ENOMEM;
940
941 addr_end = addr + PAGE_SIZE;
942 p_end = p + PAGE_SIZE;
943 } else {
944 next = pmd_addr_end(addr, end);
945
946 pmd = pmd_offset(pud, addr);
947 if (pmd_none(*pmd)) {
948 pte_t entry;
949
950 p = vmemmap_alloc_block_buf(PMD_SIZE, node);
951 if (!p)
952 return -ENOMEM;
953
954 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
955 PAGE_KERNEL_LARGE);
956 set_pmd(pmd, __pmd(pte_val(entry)));
957
958 /* check to see if we have contiguous blocks */
959 if (p_end != p || node_start != node) {
960 if (p_start)
961 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
962 addr_start, addr_end-1, p_start, p_end-1, node_start);
963 addr_start = addr;
964 node_start = node;
965 p_start = p;
966 }
967
968 addr_end = addr + PMD_SIZE;
969 p_end = p + PMD_SIZE;
970 } else
971 vmemmap_verify((pte_t *)pmd, node, addr, next);
972 }
973
974 }
975 sync_global_pgds((unsigned long)start_page, end);
976 return 0;
977 }
978
vmemmap_populate_print_last(void)979 void __meminit vmemmap_populate_print_last(void)
980 {
981 if (p_start) {
982 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
983 addr_start, addr_end-1, p_start, p_end-1, node_start);
984 p_start = NULL;
985 p_end = NULL;
986 node_start = 0;
987 }
988 }
989 #endif
990