1#include <linux/mm.h>
2#include <linux/gfp.h>
3#include <asm/pgalloc.h>
4#include <asm/pgtable.h>
5#include <asm/tlb.h>
6#include <asm/fixmap.h>
7#include <asm/mtrr.h>
8
9#define PGALLOC_GFP GFP_KERNEL | __GFP_NOTRACK | __GFP_REPEAT | __GFP_ZERO
10
11#ifdef CONFIG_HIGHPTE
12#define PGALLOC_USER_GFP __GFP_HIGHMEM
13#else
14#define PGALLOC_USER_GFP 0
15#endif
16
17gfp_t __userpte_alloc_gfp = PGALLOC_GFP | PGALLOC_USER_GFP;
18
19pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
20{
21 return (pte_t *)__get_free_page(PGALLOC_GFP);
22}
23
24pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
25{
26 struct page *pte;
27
28 pte = alloc_pages(__userpte_alloc_gfp, 0);
29 if (!pte)
30 return NULL;
31 if (!pgtable_page_ctor(pte)) {
32 __free_page(pte);
33 return NULL;
34 }
35 return pte;
36}
37
38static int __init setup_userpte(char *arg)
39{
40 if (!arg)
41 return -EINVAL;
42
43
44
45
46
47 if (strcmp(arg, "nohigh") == 0)
48 __userpte_alloc_gfp &= ~__GFP_HIGHMEM;
49 else
50 return -EINVAL;
51 return 0;
52}
53early_param("userpte", setup_userpte);
54
55void ___pte_free_tlb(struct mmu_gather *tlb, struct page *pte)
56{
57 pgtable_page_dtor(pte);
58 paravirt_release_pte(page_to_pfn(pte));
59 tlb_remove_page(tlb, pte);
60}
61
62#if CONFIG_PGTABLE_LEVELS > 2
63void ___pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd)
64{
65 struct page *page = virt_to_page(pmd);
66 paravirt_release_pmd(__pa(pmd) >> PAGE_SHIFT);
67
68
69
70
71#ifdef CONFIG_X86_PAE
72 tlb->need_flush_all = 1;
73#endif
74 pgtable_pmd_page_dtor(page);
75 tlb_remove_page(tlb, page);
76}
77
78#if CONFIG_PGTABLE_LEVELS > 3
79void ___pud_free_tlb(struct mmu_gather *tlb, pud_t *pud)
80{
81 paravirt_release_pud(__pa(pud) >> PAGE_SHIFT);
82 tlb_remove_page(tlb, virt_to_page(pud));
83}
84#endif
85#endif
86
87static inline void pgd_list_add(pgd_t *pgd)
88{
89 struct page *page = virt_to_page(pgd);
90
91 list_add(&page->lru, &pgd_list);
92}
93
94static inline void pgd_list_del(pgd_t *pgd)
95{
96 struct page *page = virt_to_page(pgd);
97
98 list_del(&page->lru);
99}
100
101#define UNSHARED_PTRS_PER_PGD \
102 (SHARED_KERNEL_PMD ? KERNEL_PGD_BOUNDARY : PTRS_PER_PGD)
103
104
105static void pgd_set_mm(pgd_t *pgd, struct mm_struct *mm)
106{
107 BUILD_BUG_ON(sizeof(virt_to_page(pgd)->index) < sizeof(mm));
108 virt_to_page(pgd)->index = (pgoff_t)mm;
109}
110
111struct mm_struct *pgd_page_get_mm(struct page *page)
112{
113 return (struct mm_struct *)page->index;
114}
115
116static void pgd_ctor(struct mm_struct *mm, pgd_t *pgd)
117{
118
119
120
121 if (CONFIG_PGTABLE_LEVELS == 2 ||
122 (CONFIG_PGTABLE_LEVELS == 3 && SHARED_KERNEL_PMD) ||
123 CONFIG_PGTABLE_LEVELS == 4) {
124 clone_pgd_range(pgd + KERNEL_PGD_BOUNDARY,
125 swapper_pg_dir + KERNEL_PGD_BOUNDARY,
126 KERNEL_PGD_PTRS);
127 }
128
129
130 if (!SHARED_KERNEL_PMD) {
131 pgd_set_mm(pgd, mm);
132 pgd_list_add(pgd);
133 }
134}
135
136static void pgd_dtor(pgd_t *pgd)
137{
138 if (SHARED_KERNEL_PMD)
139 return;
140
141 spin_lock(&pgd_lock);
142 pgd_list_del(pgd);
143 spin_unlock(&pgd_lock);
144}
145
146
147
148
149
150
151
152
153
154
155
156
157#ifdef CONFIG_X86_PAE
158
159
160
161
162
163
164
165
166
167
168
169#define PREALLOCATED_PMDS UNSHARED_PTRS_PER_PGD
170
171void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmd)
172{
173 paravirt_alloc_pmd(mm, __pa(pmd) >> PAGE_SHIFT);
174
175
176
177 set_pud(pudp, __pud(__pa(pmd) | _PAGE_PRESENT));
178
179
180
181
182
183
184
185 flush_tlb_mm(mm);
186}
187#else
188
189
190#define PREALLOCATED_PMDS 0
191
192#endif
193
194static void free_pmds(struct mm_struct *mm, pmd_t *pmds[])
195{
196 int i;
197
198 for(i = 0; i < PREALLOCATED_PMDS; i++)
199 if (pmds[i]) {
200 pgtable_pmd_page_dtor(virt_to_page(pmds[i]));
201 free_page((unsigned long)pmds[i]);
202 mm_dec_nr_pmds(mm);
203 }
204}
205
206static int preallocate_pmds(struct mm_struct *mm, pmd_t *pmds[])
207{
208 int i;
209 bool failed = false;
210
211 for(i = 0; i < PREALLOCATED_PMDS; i++) {
212 pmd_t *pmd = (pmd_t *)__get_free_page(PGALLOC_GFP);
213 if (!pmd)
214 failed = true;
215 if (pmd && !pgtable_pmd_page_ctor(virt_to_page(pmd))) {
216 free_page((unsigned long)pmd);
217 pmd = NULL;
218 failed = true;
219 }
220 if (pmd)
221 mm_inc_nr_pmds(mm);
222 pmds[i] = pmd;
223 }
224
225 if (failed) {
226 free_pmds(mm, pmds);
227 return -ENOMEM;
228 }
229
230 return 0;
231}
232
233
234
235
236
237
238
239static void pgd_mop_up_pmds(struct mm_struct *mm, pgd_t *pgdp)
240{
241 int i;
242
243 for(i = 0; i < PREALLOCATED_PMDS; i++) {
244 pgd_t pgd = pgdp[i];
245
246 if (pgd_val(pgd) != 0) {
247 pmd_t *pmd = (pmd_t *)pgd_page_vaddr(pgd);
248
249 pgdp[i] = native_make_pgd(0);
250
251 paravirt_release_pmd(pgd_val(pgd) >> PAGE_SHIFT);
252 pmd_free(mm, pmd);
253 mm_dec_nr_pmds(mm);
254 }
255 }
256}
257
258static void pgd_prepopulate_pmd(struct mm_struct *mm, pgd_t *pgd, pmd_t *pmds[])
259{
260 pud_t *pud;
261 int i;
262
263 if (PREALLOCATED_PMDS == 0)
264 return;
265
266 pud = pud_offset(pgd, 0);
267
268 for (i = 0; i < PREALLOCATED_PMDS; i++, pud++) {
269 pmd_t *pmd = pmds[i];
270
271 if (i >= KERNEL_PGD_BOUNDARY)
272 memcpy(pmd, (pmd_t *)pgd_page_vaddr(swapper_pg_dir[i]),
273 sizeof(pmd_t) * PTRS_PER_PMD);
274
275 pud_populate(mm, pud, pmd);
276 }
277}
278
279
280
281
282
283
284
285
286#ifdef CONFIG_X86_PAE
287
288#include <linux/slab.h>
289
290#define PGD_SIZE (PTRS_PER_PGD * sizeof(pgd_t))
291#define PGD_ALIGN 32
292
293static struct kmem_cache *pgd_cache;
294
295static int __init pgd_cache_init(void)
296{
297
298
299
300
301 if (!SHARED_KERNEL_PMD)
302 return 0;
303
304
305
306
307
308
309
310 pgd_cache = kmem_cache_create("pgd_cache", PGD_SIZE, PGD_ALIGN,
311 SLAB_PANIC, NULL);
312 if (!pgd_cache)
313 return -ENOMEM;
314
315 return 0;
316}
317core_initcall(pgd_cache_init);
318
319static inline pgd_t *_pgd_alloc(void)
320{
321
322
323
324
325 if (!SHARED_KERNEL_PMD)
326 return (pgd_t *)__get_free_page(PGALLOC_GFP);
327
328
329
330
331
332 return kmem_cache_alloc(pgd_cache, PGALLOC_GFP);
333}
334
335static inline void _pgd_free(pgd_t *pgd)
336{
337 if (!SHARED_KERNEL_PMD)
338 free_page((unsigned long)pgd);
339 else
340 kmem_cache_free(pgd_cache, pgd);
341}
342#else
343static inline pgd_t *_pgd_alloc(void)
344{
345 return (pgd_t *)__get_free_page(PGALLOC_GFP);
346}
347
348static inline void _pgd_free(pgd_t *pgd)
349{
350 free_page((unsigned long)pgd);
351}
352#endif
353
354pgd_t *pgd_alloc(struct mm_struct *mm)
355{
356 pgd_t *pgd;
357 pmd_t *pmds[PREALLOCATED_PMDS];
358
359 pgd = _pgd_alloc();
360
361 if (pgd == NULL)
362 goto out;
363
364 mm->pgd = pgd;
365
366 if (preallocate_pmds(mm, pmds) != 0)
367 goto out_free_pgd;
368
369 if (paravirt_pgd_alloc(mm) != 0)
370 goto out_free_pmds;
371
372
373
374
375
376
377 spin_lock(&pgd_lock);
378
379 pgd_ctor(mm, pgd);
380 pgd_prepopulate_pmd(mm, pgd, pmds);
381
382 spin_unlock(&pgd_lock);
383
384 return pgd;
385
386out_free_pmds:
387 free_pmds(mm, pmds);
388out_free_pgd:
389 _pgd_free(pgd);
390out:
391 return NULL;
392}
393
394void pgd_free(struct mm_struct *mm, pgd_t *pgd)
395{
396 pgd_mop_up_pmds(mm, pgd);
397 pgd_dtor(pgd);
398 paravirt_pgd_free(mm, pgd);
399 _pgd_free(pgd);
400}
401
402
403
404
405
406
407
408
409int ptep_set_access_flags(struct vm_area_struct *vma,
410 unsigned long address, pte_t *ptep,
411 pte_t entry, int dirty)
412{
413 int changed = !pte_same(*ptep, entry);
414
415 if (changed && dirty) {
416 *ptep = entry;
417 pte_update(vma->vm_mm, address, ptep);
418 }
419
420 return changed;
421}
422
423#ifdef CONFIG_TRANSPARENT_HUGEPAGE
424int pmdp_set_access_flags(struct vm_area_struct *vma,
425 unsigned long address, pmd_t *pmdp,
426 pmd_t entry, int dirty)
427{
428 int changed = !pmd_same(*pmdp, entry);
429
430 VM_BUG_ON(address & ~HPAGE_PMD_MASK);
431
432 if (changed && dirty) {
433 *pmdp = entry;
434
435
436
437
438
439
440 }
441
442 return changed;
443}
444#endif
445
446int ptep_test_and_clear_young(struct vm_area_struct *vma,
447 unsigned long addr, pte_t *ptep)
448{
449 int ret = 0;
450
451 if (pte_young(*ptep))
452 ret = test_and_clear_bit(_PAGE_BIT_ACCESSED,
453 (unsigned long *) &ptep->pte);
454
455 if (ret)
456 pte_update(vma->vm_mm, addr, ptep);
457
458 return ret;
459}
460
461#ifdef CONFIG_TRANSPARENT_HUGEPAGE
462int pmdp_test_and_clear_young(struct vm_area_struct *vma,
463 unsigned long addr, pmd_t *pmdp)
464{
465 int ret = 0;
466
467 if (pmd_young(*pmdp))
468 ret = test_and_clear_bit(_PAGE_BIT_ACCESSED,
469 (unsigned long *)pmdp);
470
471 return ret;
472}
473#endif
474
475int ptep_clear_flush_young(struct vm_area_struct *vma,
476 unsigned long address, pte_t *ptep)
477{
478
479
480
481
482
483
484
485
486
487
488
489
490
491 return ptep_test_and_clear_young(vma, address, ptep);
492}
493
494#ifdef CONFIG_TRANSPARENT_HUGEPAGE
495int pmdp_clear_flush_young(struct vm_area_struct *vma,
496 unsigned long address, pmd_t *pmdp)
497{
498 int young;
499
500 VM_BUG_ON(address & ~HPAGE_PMD_MASK);
501
502 young = pmdp_test_and_clear_young(vma, address, pmdp);
503 if (young)
504 flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
505
506 return young;
507}
508#endif
509
510
511
512
513
514
515
516
517void __init reserve_top_address(unsigned long reserve)
518{
519#ifdef CONFIG_X86_32
520 BUG_ON(fixmaps_set > 0);
521 __FIXADDR_TOP = round_down(-reserve, 1 << PMD_SHIFT) - PAGE_SIZE;
522 printk(KERN_INFO "Reserving virtual address space above 0x%08lx (rounded to 0x%08lx)\n",
523 -reserve, __FIXADDR_TOP + PAGE_SIZE);
524#endif
525}
526
527int fixmaps_set;
528
529void __native_set_fixmap(enum fixed_addresses idx, pte_t pte)
530{
531 unsigned long address = __fix_to_virt(idx);
532
533 if (idx >= __end_of_fixed_addresses) {
534 BUG();
535 return;
536 }
537 set_pte_vaddr(address, pte);
538 fixmaps_set++;
539}
540
541void native_set_fixmap(enum fixed_addresses idx, phys_addr_t phys,
542 pgprot_t flags)
543{
544 __native_set_fixmap(idx, pfn_pte(phys >> PAGE_SHIFT, flags));
545}
546
547#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot)
567{
568 u8 mtrr, uniform;
569
570 mtrr = mtrr_type_lookup(addr, addr + PUD_SIZE, &uniform);
571 if ((mtrr != MTRR_TYPE_INVALID) && (!uniform) &&
572 (mtrr != MTRR_TYPE_WRBACK))
573 return 0;
574
575 prot = pgprot_4k_2_large(prot);
576
577 set_pte((pte_t *)pud, pfn_pte(
578 (u64)addr >> PAGE_SHIFT,
579 __pgprot(pgprot_val(prot) | _PAGE_PSE)));
580
581 return 1;
582}
583
584
585
586
587
588
589
590
591int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot)
592{
593 u8 mtrr, uniform;
594
595 mtrr = mtrr_type_lookup(addr, addr + PMD_SIZE, &uniform);
596 if ((mtrr != MTRR_TYPE_INVALID) && (!uniform) &&
597 (mtrr != MTRR_TYPE_WRBACK)) {
598 pr_warn_once("%s: Cannot satisfy [mem %#010llx-%#010llx] with a huge-page mapping due to MTRR override.\n",
599 __func__, addr, addr + PMD_SIZE);
600 return 0;
601 }
602
603 prot = pgprot_4k_2_large(prot);
604
605 set_pte((pte_t *)pmd, pfn_pte(
606 (u64)addr >> PAGE_SHIFT,
607 __pgprot(pgprot_val(prot) | _PAGE_PSE)));
608
609 return 1;
610}
611
612
613
614
615
616
617int pud_clear_huge(pud_t *pud)
618{
619 if (pud_large(*pud)) {
620 pud_clear(pud);
621 return 1;
622 }
623
624 return 0;
625}
626
627
628
629
630
631
632int pmd_clear_huge(pmd_t *pmd)
633{
634 if (pmd_large(*pmd)) {
635 pmd_clear(pmd);
636 return 1;
637 }
638
639 return 0;
640}
641#endif
642