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1// SPDX-License-Identifier: GPL-2.0
2#include <linux/mm.h>
3#include <linux/gfp.h>
4#include <linux/hugetlb.h>
5#include <asm/pgalloc.h>
6#include <asm/tlb.h>
7#include <asm/fixmap.h>
8#include <asm/mtrr.h>
9
10#ifdef CONFIG_DYNAMIC_PHYSICAL_MASK
11phys_addr_t physical_mask __ro_after_init = (1ULL << __PHYSICAL_MASK_SHIFT) - 1;
12EXPORT_SYMBOL(physical_mask);
13#endif
14
15#ifdef CONFIG_HIGHPTE
16#define PGTABLE_HIGHMEM __GFP_HIGHMEM
17#else
18#define PGTABLE_HIGHMEM 0
19#endif
20
21#ifndef CONFIG_PARAVIRT
22static inline
23void paravirt_tlb_remove_table(struct mmu_gather *tlb, void *table)
24{
25 tlb_remove_page(tlb, table);
26}
27#endif
28
29gfp_t __userpte_alloc_gfp = GFP_PGTABLE_USER | PGTABLE_HIGHMEM;
30
31pgtable_t pte_alloc_one(struct mm_struct *mm)
32{
33 return __pte_alloc_one(mm, __userpte_alloc_gfp);
34}
35
36static int __init setup_userpte(char *arg)
37{
38 if (!arg)
39 return -EINVAL;
40
41 /*
42 * "userpte=nohigh" disables allocation of user pagetables in
43 * high memory.
44 */
45 if (strcmp(arg, "nohigh") == 0)
46 __userpte_alloc_gfp &= ~__GFP_HIGHMEM;
47 else
48 return -EINVAL;
49 return 0;
50}
51early_param("userpte", setup_userpte);
52
53void ___pte_free_tlb(struct mmu_gather *tlb, struct page *pte)
54{
55 pgtable_pte_page_dtor(pte);
56 paravirt_release_pte(page_to_pfn(pte));
57 paravirt_tlb_remove_table(tlb, pte);
58}
59
60#if CONFIG_PGTABLE_LEVELS > 2
61void ___pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd)
62{
63 struct page *page = virt_to_page(pmd);
64 paravirt_release_pmd(__pa(pmd) >> PAGE_SHIFT);
65 /*
66 * NOTE! For PAE, any changes to the top page-directory-pointer-table
67 * entries need a full cr3 reload to flush.
68 */
69#ifdef CONFIG_X86_PAE
70 tlb->need_flush_all = 1;
71#endif
72 pgtable_pmd_page_dtor(page);
73 paravirt_tlb_remove_table(tlb, page);
74}
75
76#if CONFIG_PGTABLE_LEVELS > 3
77void ___pud_free_tlb(struct mmu_gather *tlb, pud_t *pud)
78{
79 paravirt_release_pud(__pa(pud) >> PAGE_SHIFT);
80 paravirt_tlb_remove_table(tlb, virt_to_page(pud));
81}
82
83#if CONFIG_PGTABLE_LEVELS > 4
84void ___p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d)
85{
86 paravirt_release_p4d(__pa(p4d) >> PAGE_SHIFT);
87 paravirt_tlb_remove_table(tlb, virt_to_page(p4d));
88}
89#endif /* CONFIG_PGTABLE_LEVELS > 4 */
90#endif /* CONFIG_PGTABLE_LEVELS > 3 */
91#endif /* CONFIG_PGTABLE_LEVELS > 2 */
92
93static inline void pgd_list_add(pgd_t *pgd)
94{
95 struct page *page = virt_to_page(pgd);
96
97 list_add(&page->lru, &pgd_list);
98}
99
100static inline void pgd_list_del(pgd_t *pgd)
101{
102 struct page *page = virt_to_page(pgd);
103
104 list_del(&page->lru);
105}
106
107#define UNSHARED_PTRS_PER_PGD \
108 (SHARED_KERNEL_PMD ? KERNEL_PGD_BOUNDARY : PTRS_PER_PGD)
109#define MAX_UNSHARED_PTRS_PER_PGD \
110 max_t(size_t, KERNEL_PGD_BOUNDARY, PTRS_PER_PGD)
111
112
113static void pgd_set_mm(pgd_t *pgd, struct mm_struct *mm)
114{
115 virt_to_page(pgd)->pt_mm = mm;
116}
117
118struct mm_struct *pgd_page_get_mm(struct page *page)
119{
120 return page->pt_mm;
121}
122
123static void pgd_ctor(struct mm_struct *mm, pgd_t *pgd)
124{
125 /* If the pgd points to a shared pagetable level (either the
126 ptes in non-PAE, or shared PMD in PAE), then just copy the
127 references from swapper_pg_dir. */
128 if (CONFIG_PGTABLE_LEVELS == 2 ||
129 (CONFIG_PGTABLE_LEVELS == 3 && SHARED_KERNEL_PMD) ||
130 CONFIG_PGTABLE_LEVELS >= 4) {
131 clone_pgd_range(pgd + KERNEL_PGD_BOUNDARY,
132 swapper_pg_dir + KERNEL_PGD_BOUNDARY,
133 KERNEL_PGD_PTRS);
134 }
135
136 /* list required to sync kernel mapping updates */
137 if (!SHARED_KERNEL_PMD) {
138 pgd_set_mm(pgd, mm);
139 pgd_list_add(pgd);
140 }
141}
142
143static void pgd_dtor(pgd_t *pgd)
144{
145 if (SHARED_KERNEL_PMD)
146 return;
147
148 spin_lock(&pgd_lock);
149 pgd_list_del(pgd);
150 spin_unlock(&pgd_lock);
151}
152
153/*
154 * List of all pgd's needed for non-PAE so it can invalidate entries
155 * in both cached and uncached pgd's; not needed for PAE since the
156 * kernel pmd is shared. If PAE were not to share the pmd a similar
157 * tactic would be needed. This is essentially codepath-based locking
158 * against pageattr.c; it is the unique case in which a valid change
159 * of kernel pagetables can't be lazily synchronized by vmalloc faults.
160 * vmalloc faults work because attached pagetables are never freed.
161 * -- nyc
162 */
163
164#ifdef CONFIG_X86_PAE
165/*
166 * In PAE mode, we need to do a cr3 reload (=tlb flush) when
167 * updating the top-level pagetable entries to guarantee the
168 * processor notices the update. Since this is expensive, and
169 * all 4 top-level entries are used almost immediately in a
170 * new process's life, we just pre-populate them here.
171 *
172 * Also, if we're in a paravirt environment where the kernel pmd is
173 * not shared between pagetables (!SHARED_KERNEL_PMDS), we allocate
174 * and initialize the kernel pmds here.
175 */
176#define PREALLOCATED_PMDS UNSHARED_PTRS_PER_PGD
177#define MAX_PREALLOCATED_PMDS MAX_UNSHARED_PTRS_PER_PGD
178
179/*
180 * We allocate separate PMDs for the kernel part of the user page-table
181 * when PTI is enabled. We need them to map the per-process LDT into the
182 * user-space page-table.
183 */
184#define PREALLOCATED_USER_PMDS (boot_cpu_has(X86_FEATURE_PTI) ? \
185 KERNEL_PGD_PTRS : 0)
186#define MAX_PREALLOCATED_USER_PMDS KERNEL_PGD_PTRS
187
188void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmd)
189{
190 paravirt_alloc_pmd(mm, __pa(pmd) >> PAGE_SHIFT);
191
192 /* Note: almost everything apart from _PAGE_PRESENT is
193 reserved at the pmd (PDPT) level. */
194 set_pud(pudp, __pud(__pa(pmd) | _PAGE_PRESENT));
195
196 /*
197 * According to Intel App note "TLBs, Paging-Structure Caches,
198 * and Their Invalidation", April 2007, document 317080-001,
199 * section 8.1: in PAE mode we explicitly have to flush the
200 * TLB via cr3 if the top-level pgd is changed...
201 */
202 flush_tlb_mm(mm);
203}
204#else /* !CONFIG_X86_PAE */
205
206/* No need to prepopulate any pagetable entries in non-PAE modes. */
207#define PREALLOCATED_PMDS 0
208#define MAX_PREALLOCATED_PMDS 0
209#define PREALLOCATED_USER_PMDS 0
210#define MAX_PREALLOCATED_USER_PMDS 0
211#endif /* CONFIG_X86_PAE */
212
213static void free_pmds(struct mm_struct *mm, pmd_t *pmds[], int count)
214{
215 int i;
216
217 for (i = 0; i < count; i++)
218 if (pmds[i]) {
219 pgtable_pmd_page_dtor(virt_to_page(pmds[i]));
220 free_page((unsigned long)pmds[i]);
221 mm_dec_nr_pmds(mm);
222 }
223}
224
225static int preallocate_pmds(struct mm_struct *mm, pmd_t *pmds[], int count)
226{
227 int i;
228 bool failed = false;
229 gfp_t gfp = GFP_PGTABLE_USER;
230
231 if (mm == &init_mm)
232 gfp &= ~__GFP_ACCOUNT;
233
234 for (i = 0; i < count; i++) {
235 pmd_t *pmd = (pmd_t *)__get_free_page(gfp);
236 if (!pmd)
237 failed = true;
238 if (pmd && !pgtable_pmd_page_ctor(virt_to_page(pmd))) {
239 free_page((unsigned long)pmd);
240 pmd = NULL;
241 failed = true;
242 }
243 if (pmd)
244 mm_inc_nr_pmds(mm);
245 pmds[i] = pmd;
246 }
247
248 if (failed) {
249 free_pmds(mm, pmds, count);
250 return -ENOMEM;
251 }
252
253 return 0;
254}
255
256/*
257 * Mop up any pmd pages which may still be attached to the pgd.
258 * Normally they will be freed by munmap/exit_mmap, but any pmd we
259 * preallocate which never got a corresponding vma will need to be
260 * freed manually.
261 */
262static void mop_up_one_pmd(struct mm_struct *mm, pgd_t *pgdp)
263{
264 pgd_t pgd = *pgdp;
265
266 if (pgd_val(pgd) != 0) {
267 pmd_t *pmd = (pmd_t *)pgd_page_vaddr(pgd);
268
269 pgd_clear(pgdp);
270
271 paravirt_release_pmd(pgd_val(pgd) >> PAGE_SHIFT);
272 pmd_free(mm, pmd);
273 mm_dec_nr_pmds(mm);
274 }
275}
276
277static void pgd_mop_up_pmds(struct mm_struct *mm, pgd_t *pgdp)
278{
279 int i;
280
281 for (i = 0; i < PREALLOCATED_PMDS; i++)
282 mop_up_one_pmd(mm, &pgdp[i]);
283
284#ifdef CONFIG_PAGE_TABLE_ISOLATION
285
286 if (!boot_cpu_has(X86_FEATURE_PTI))
287 return;
288
289 pgdp = kernel_to_user_pgdp(pgdp);
290
291 for (i = 0; i < PREALLOCATED_USER_PMDS; i++)
292 mop_up_one_pmd(mm, &pgdp[i + KERNEL_PGD_BOUNDARY]);
293#endif
294}
295
296static void pgd_prepopulate_pmd(struct mm_struct *mm, pgd_t *pgd, pmd_t *pmds[])
297{
298 p4d_t *p4d;
299 pud_t *pud;
300 int i;
301
302 if (PREALLOCATED_PMDS == 0) /* Work around gcc-3.4.x bug */
303 return;
304
305 p4d = p4d_offset(pgd, 0);
306 pud = pud_offset(p4d, 0);
307
308 for (i = 0; i < PREALLOCATED_PMDS; i++, pud++) {
309 pmd_t *pmd = pmds[i];
310
311 if (i >= KERNEL_PGD_BOUNDARY)
312 memcpy(pmd, (pmd_t *)pgd_page_vaddr(swapper_pg_dir[i]),
313 sizeof(pmd_t) * PTRS_PER_PMD);
314
315 pud_populate(mm, pud, pmd);
316 }
317}
318
319#ifdef CONFIG_PAGE_TABLE_ISOLATION
320static void pgd_prepopulate_user_pmd(struct mm_struct *mm,
321 pgd_t *k_pgd, pmd_t *pmds[])
322{
323 pgd_t *s_pgd = kernel_to_user_pgdp(swapper_pg_dir);
324 pgd_t *u_pgd = kernel_to_user_pgdp(k_pgd);
325 p4d_t *u_p4d;
326 pud_t *u_pud;
327 int i;
328
329 u_p4d = p4d_offset(u_pgd, 0);
330 u_pud = pud_offset(u_p4d, 0);
331
332 s_pgd += KERNEL_PGD_BOUNDARY;
333 u_pud += KERNEL_PGD_BOUNDARY;
334
335 for (i = 0; i < PREALLOCATED_USER_PMDS; i++, u_pud++, s_pgd++) {
336 pmd_t *pmd = pmds[i];
337
338 memcpy(pmd, (pmd_t *)pgd_page_vaddr(*s_pgd),
339 sizeof(pmd_t) * PTRS_PER_PMD);
340
341 pud_populate(mm, u_pud, pmd);
342 }
343
344}
345#else
346static void pgd_prepopulate_user_pmd(struct mm_struct *mm,
347 pgd_t *k_pgd, pmd_t *pmds[])
348{
349}
350#endif
351/*
352 * Xen paravirt assumes pgd table should be in one page. 64 bit kernel also
353 * assumes that pgd should be in one page.
354 *
355 * But kernel with PAE paging that is not running as a Xen domain
356 * only needs to allocate 32 bytes for pgd instead of one page.
357 */
358#ifdef CONFIG_X86_PAE
359
360#include <linux/slab.h>
361
362#define PGD_SIZE (PTRS_PER_PGD * sizeof(pgd_t))
363#define PGD_ALIGN 32
364
365static struct kmem_cache *pgd_cache;
366
367void __init pgtable_cache_init(void)
368{
369 /*
370 * When PAE kernel is running as a Xen domain, it does not use
371 * shared kernel pmd. And this requires a whole page for pgd.
372 */
373 if (!SHARED_KERNEL_PMD)
374 return;
375
376 /*
377 * when PAE kernel is not running as a Xen domain, it uses
378 * shared kernel pmd. Shared kernel pmd does not require a whole
379 * page for pgd. We are able to just allocate a 32-byte for pgd.
380 * During boot time, we create a 32-byte slab for pgd table allocation.
381 */
382 pgd_cache = kmem_cache_create("pgd_cache", PGD_SIZE, PGD_ALIGN,
383 SLAB_PANIC, NULL);
384}
385
386static inline pgd_t *_pgd_alloc(void)
387{
388 /*
389 * If no SHARED_KERNEL_PMD, PAE kernel is running as a Xen domain.
390 * We allocate one page for pgd.
391 */
392 if (!SHARED_KERNEL_PMD)
393 return (pgd_t *)__get_free_pages(GFP_PGTABLE_USER,
394 PGD_ALLOCATION_ORDER);
395
396 /*
397 * Now PAE kernel is not running as a Xen domain. We can allocate
398 * a 32-byte slab for pgd to save memory space.
399 */
400 return kmem_cache_alloc(pgd_cache, GFP_PGTABLE_USER);
401}
402
403static inline void _pgd_free(pgd_t *pgd)
404{
405 if (!SHARED_KERNEL_PMD)
406 free_pages((unsigned long)pgd, PGD_ALLOCATION_ORDER);
407 else
408 kmem_cache_free(pgd_cache, pgd);
409}
410#else
411
412static inline pgd_t *_pgd_alloc(void)
413{
414 return (pgd_t *)__get_free_pages(GFP_PGTABLE_USER,
415 PGD_ALLOCATION_ORDER);
416}
417
418static inline void _pgd_free(pgd_t *pgd)
419{
420 free_pages((unsigned long)pgd, PGD_ALLOCATION_ORDER);
421}
422#endif /* CONFIG_X86_PAE */
423
424pgd_t *pgd_alloc(struct mm_struct *mm)
425{
426 pgd_t *pgd;
427 pmd_t *u_pmds[MAX_PREALLOCATED_USER_PMDS];
428 pmd_t *pmds[MAX_PREALLOCATED_PMDS];
429
430 pgd = _pgd_alloc();
431
432 if (pgd == NULL)
433 goto out;
434
435 mm->pgd = pgd;
436
437 if (preallocate_pmds(mm, pmds, PREALLOCATED_PMDS) != 0)
438 goto out_free_pgd;
439
440 if (preallocate_pmds(mm, u_pmds, PREALLOCATED_USER_PMDS) != 0)
441 goto out_free_pmds;
442
443 if (paravirt_pgd_alloc(mm) != 0)
444 goto out_free_user_pmds;
445
446 /*
447 * Make sure that pre-populating the pmds is atomic with
448 * respect to anything walking the pgd_list, so that they
449 * never see a partially populated pgd.
450 */
451 spin_lock(&pgd_lock);
452
453 pgd_ctor(mm, pgd);
454 pgd_prepopulate_pmd(mm, pgd, pmds);
455 pgd_prepopulate_user_pmd(mm, pgd, u_pmds);
456
457 spin_unlock(&pgd_lock);
458
459 return pgd;
460
461out_free_user_pmds:
462 free_pmds(mm, u_pmds, PREALLOCATED_USER_PMDS);
463out_free_pmds:
464 free_pmds(mm, pmds, PREALLOCATED_PMDS);
465out_free_pgd:
466 _pgd_free(pgd);
467out:
468 return NULL;
469}
470
471void pgd_free(struct mm_struct *mm, pgd_t *pgd)
472{
473 pgd_mop_up_pmds(mm, pgd);
474 pgd_dtor(pgd);
475 paravirt_pgd_free(mm, pgd);
476 _pgd_free(pgd);
477}
478
479/*
480 * Used to set accessed or dirty bits in the page table entries
481 * on other architectures. On x86, the accessed and dirty bits
482 * are tracked by hardware. However, do_wp_page calls this function
483 * to also make the pte writeable at the same time the dirty bit is
484 * set. In that case we do actually need to write the PTE.
485 */
486int ptep_set_access_flags(struct vm_area_struct *vma,
487 unsigned long address, pte_t *ptep,
488 pte_t entry, int dirty)
489{
490 int changed = !pte_same(*ptep, entry);
491
492 if (changed && dirty)
493 set_pte(ptep, entry);
494
495 return changed;
496}
497
498#ifdef CONFIG_TRANSPARENT_HUGEPAGE
499int pmdp_set_access_flags(struct vm_area_struct *vma,
500 unsigned long address, pmd_t *pmdp,
501 pmd_t entry, int dirty)
502{
503 int changed = !pmd_same(*pmdp, entry);
504
505 VM_BUG_ON(address & ~HPAGE_PMD_MASK);
506
507 if (changed && dirty) {
508 set_pmd(pmdp, entry);
509 /*
510 * We had a write-protection fault here and changed the pmd
511 * to to more permissive. No need to flush the TLB for that,
512 * #PF is architecturally guaranteed to do that and in the
513 * worst-case we'll generate a spurious fault.
514 */
515 }
516
517 return changed;
518}
519
520int pudp_set_access_flags(struct vm_area_struct *vma, unsigned long address,
521 pud_t *pudp, pud_t entry, int dirty)
522{
523 int changed = !pud_same(*pudp, entry);
524
525 VM_BUG_ON(address & ~HPAGE_PUD_MASK);
526
527 if (changed && dirty) {
528 set_pud(pudp, entry);
529 /*
530 * We had a write-protection fault here and changed the pud
531 * to to more permissive. No need to flush the TLB for that,
532 * #PF is architecturally guaranteed to do that and in the
533 * worst-case we'll generate a spurious fault.
534 */
535 }
536
537 return changed;
538}
539#endif
540
541int ptep_test_and_clear_young(struct vm_area_struct *vma,
542 unsigned long addr, pte_t *ptep)
543{
544 int ret = 0;
545
546 if (pte_young(*ptep))
547 ret = test_and_clear_bit(_PAGE_BIT_ACCESSED,
548 (unsigned long *) &ptep->pte);
549
550 return ret;
551}
552
553#ifdef CONFIG_TRANSPARENT_HUGEPAGE
554int pmdp_test_and_clear_young(struct vm_area_struct *vma,
555 unsigned long addr, pmd_t *pmdp)
556{
557 int ret = 0;
558
559 if (pmd_young(*pmdp))
560 ret = test_and_clear_bit(_PAGE_BIT_ACCESSED,
561 (unsigned long *)pmdp);
562
563 return ret;
564}
565int pudp_test_and_clear_young(struct vm_area_struct *vma,
566 unsigned long addr, pud_t *pudp)
567{
568 int ret = 0;
569
570 if (pud_young(*pudp))
571 ret = test_and_clear_bit(_PAGE_BIT_ACCESSED,
572 (unsigned long *)pudp);
573
574 return ret;
575}
576#endif
577
578int ptep_clear_flush_young(struct vm_area_struct *vma,
579 unsigned long address, pte_t *ptep)
580{
581 /*
582 * On x86 CPUs, clearing the accessed bit without a TLB flush
583 * doesn't cause data corruption. [ It could cause incorrect
584 * page aging and the (mistaken) reclaim of hot pages, but the
585 * chance of that should be relatively low. ]
586 *
587 * So as a performance optimization don't flush the TLB when
588 * clearing the accessed bit, it will eventually be flushed by
589 * a context switch or a VM operation anyway. [ In the rare
590 * event of it not getting flushed for a long time the delay
591 * shouldn't really matter because there's no real memory
592 * pressure for swapout to react to. ]
593 */
594 return ptep_test_and_clear_young(vma, address, ptep);
595}
596
597#ifdef CONFIG_TRANSPARENT_HUGEPAGE
598int pmdp_clear_flush_young(struct vm_area_struct *vma,
599 unsigned long address, pmd_t *pmdp)
600{
601 int young;
602
603 VM_BUG_ON(address & ~HPAGE_PMD_MASK);
604
605 young = pmdp_test_and_clear_young(vma, address, pmdp);
606 if (young)
607 flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
608
609 return young;
610}
611#endif
612
613/**
614 * reserve_top_address - reserves a hole in the top of kernel address space
615 * @reserve - size of hole to reserve
616 *
617 * Can be used to relocate the fixmap area and poke a hole in the top
618 * of kernel address space to make room for a hypervisor.
619 */
620void __init reserve_top_address(unsigned long reserve)
621{
622#ifdef CONFIG_X86_32
623 BUG_ON(fixmaps_set > 0);
624 __FIXADDR_TOP = round_down(-reserve, 1 << PMD_SHIFT) - PAGE_SIZE;
625 printk(KERN_INFO "Reserving virtual address space above 0x%08lx (rounded to 0x%08lx)\n",
626 -reserve, __FIXADDR_TOP + PAGE_SIZE);
627#endif
628}
629
630int fixmaps_set;
631
632void __native_set_fixmap(enum fixed_addresses idx, pte_t pte)
633{
634 unsigned long address = __fix_to_virt(idx);
635
636#ifdef CONFIG_X86_64
637 /*
638 * Ensure that the static initial page tables are covering the
639 * fixmap completely.
640 */
641 BUILD_BUG_ON(__end_of_permanent_fixed_addresses >
642 (FIXMAP_PMD_NUM * PTRS_PER_PTE));
643#endif
644
645 if (idx >= __end_of_fixed_addresses) {
646 BUG();
647 return;
648 }
649 set_pte_vaddr(address, pte);
650 fixmaps_set++;
651}
652
653void native_set_fixmap(unsigned /* enum fixed_addresses */ idx,
654 phys_addr_t phys, pgprot_t flags)
655{
656 /* Sanitize 'prot' against any unsupported bits: */
657 pgprot_val(flags) &= __default_kernel_pte_mask;
658
659 __native_set_fixmap(idx, pfn_pte(phys >> PAGE_SHIFT, flags));
660}
661
662#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
663#ifdef CONFIG_X86_5LEVEL
664/**
665 * p4d_set_huge - setup kernel P4D mapping
666 *
667 * No 512GB pages yet -- always return 0
668 */
669int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot)
670{
671 return 0;
672}
673
674/**
675 * p4d_clear_huge - clear kernel P4D mapping when it is set
676 *
677 * No 512GB pages yet -- always return 0
678 */
679int p4d_clear_huge(p4d_t *p4d)
680{
681 return 0;
682}
683#endif
684
685/**
686 * pud_set_huge - setup kernel PUD mapping
687 *
688 * MTRRs can override PAT memory types with 4KiB granularity. Therefore, this
689 * function sets up a huge page only if any of the following conditions are met:
690 *
691 * - MTRRs are disabled, or
692 *
693 * - MTRRs are enabled and the range is completely covered by a single MTRR, or
694 *
695 * - MTRRs are enabled and the corresponding MTRR memory type is WB, which
696 * has no effect on the requested PAT memory type.
697 *
698 * Callers should try to decrease page size (1GB -> 2MB -> 4K) if the bigger
699 * page mapping attempt fails.
700 *
701 * Returns 1 on success and 0 on failure.
702 */
703int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot)
704{
705 u8 mtrr, uniform;
706
707 mtrr = mtrr_type_lookup(addr, addr + PUD_SIZE, &uniform);
708 if ((mtrr != MTRR_TYPE_INVALID) && (!uniform) &&
709 (mtrr != MTRR_TYPE_WRBACK))
710 return 0;
711
712 /* Bail out if we are we on a populated non-leaf entry: */
713 if (pud_present(*pud) && !pud_huge(*pud))
714 return 0;
715
716 set_pte((pte_t *)pud, pfn_pte(
717 (u64)addr >> PAGE_SHIFT,
718 __pgprot(protval_4k_2_large(pgprot_val(prot)) | _PAGE_PSE)));
719
720 return 1;
721}
722
723/**
724 * pmd_set_huge - setup kernel PMD mapping
725 *
726 * See text over pud_set_huge() above.
727 *
728 * Returns 1 on success and 0 on failure.
729 */
730int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot)
731{
732 u8 mtrr, uniform;
733
734 mtrr = mtrr_type_lookup(addr, addr + PMD_SIZE, &uniform);
735 if ((mtrr != MTRR_TYPE_INVALID) && (!uniform) &&
736 (mtrr != MTRR_TYPE_WRBACK)) {
737 pr_warn_once("%s: Cannot satisfy [mem %#010llx-%#010llx] with a huge-page mapping due to MTRR override.\n",
738 __func__, addr, addr + PMD_SIZE);
739 return 0;
740 }
741
742 /* Bail out if we are we on a populated non-leaf entry: */
743 if (pmd_present(*pmd) && !pmd_huge(*pmd))
744 return 0;
745
746 set_pte((pte_t *)pmd, pfn_pte(
747 (u64)addr >> PAGE_SHIFT,
748 __pgprot(protval_4k_2_large(pgprot_val(prot)) | _PAGE_PSE)));
749
750 return 1;
751}
752
753/**
754 * pud_clear_huge - clear kernel PUD mapping when it is set
755 *
756 * Returns 1 on success and 0 on failure (no PUD map is found).
757 */
758int pud_clear_huge(pud_t *pud)
759{
760 if (pud_large(*pud)) {
761 pud_clear(pud);
762 return 1;
763 }
764
765 return 0;
766}
767
768/**
769 * pmd_clear_huge - clear kernel PMD mapping when it is set
770 *
771 * Returns 1 on success and 0 on failure (no PMD map is found).
772 */
773int pmd_clear_huge(pmd_t *pmd)
774{
775 if (pmd_large(*pmd)) {
776 pmd_clear(pmd);
777 return 1;
778 }
779
780 return 0;
781}
782
783/*
784 * Until we support 512GB pages, skip them in the vmap area.
785 */
786int p4d_free_pud_page(p4d_t *p4d, unsigned long addr)
787{
788 return 0;
789}
790
791#ifdef CONFIG_X86_64
792/**
793 * pud_free_pmd_page - Clear pud entry and free pmd page.
794 * @pud: Pointer to a PUD.
795 * @addr: Virtual address associated with pud.
796 *
797 * Context: The pud range has been unmapped and TLB purged.
798 * Return: 1 if clearing the entry succeeded. 0 otherwise.
799 *
800 * NOTE: Callers must allow a single page allocation.
801 */
802int pud_free_pmd_page(pud_t *pud, unsigned long addr)
803{
804 pmd_t *pmd, *pmd_sv;
805 pte_t *pte;
806 int i;
807
808 pmd = (pmd_t *)pud_page_vaddr(*pud);
809 pmd_sv = (pmd_t *)__get_free_page(GFP_KERNEL);
810 if (!pmd_sv)
811 return 0;
812
813 for (i = 0; i < PTRS_PER_PMD; i++) {
814 pmd_sv[i] = pmd[i];
815 if (!pmd_none(pmd[i]))
816 pmd_clear(&pmd[i]);
817 }
818
819 pud_clear(pud);
820
821 /* INVLPG to clear all paging-structure caches */
822 flush_tlb_kernel_range(addr, addr + PAGE_SIZE-1);
823
824 for (i = 0; i < PTRS_PER_PMD; i++) {
825 if (!pmd_none(pmd_sv[i])) {
826 pte = (pte_t *)pmd_page_vaddr(pmd_sv[i]);
827 free_page((unsigned long)pte);
828 }
829 }
830
831 free_page((unsigned long)pmd_sv);
832 free_page((unsigned long)pmd);
833
834 return 1;
835}
836
837/**
838 * pmd_free_pte_page - Clear pmd entry and free pte page.
839 * @pmd: Pointer to a PMD.
840 * @addr: Virtual address associated with pmd.
841 *
842 * Context: The pmd range has been unmapped and TLB purged.
843 * Return: 1 if clearing the entry succeeded. 0 otherwise.
844 */
845int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
846{
847 pte_t *pte;
848
849 pte = (pte_t *)pmd_page_vaddr(*pmd);
850 pmd_clear(pmd);
851
852 /* INVLPG to clear all paging-structure caches */
853 flush_tlb_kernel_range(addr, addr + PAGE_SIZE-1);
854
855 free_page((unsigned long)pte);
856
857 return 1;
858}
859
860#else /* !CONFIG_X86_64 */
861
862int pud_free_pmd_page(pud_t *pud, unsigned long addr)
863{
864 return pud_none(*pud);
865}
866
867/*
868 * Disable free page handling on x86-PAE. This assures that ioremap()
869 * does not update sync'd pmd entries. See vmalloc_sync_one().
870 */
871int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
872{
873 return pmd_none(*pmd);
874}
875
876#endif /* CONFIG_X86_64 */
877#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
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 * "userpte=nohigh" disables allocation of user pagetables in
45 * high memory.
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 * NOTE! For PAE, any changes to the top page-directory-pointer-table
69 * entries need a full cr3 reload to flush.
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 /* CONFIG_PGTABLE_LEVELS > 3 */
85#endif /* CONFIG_PGTABLE_LEVELS > 2 */
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 /* If the pgd points to a shared pagetable level (either the
119 ptes in non-PAE, or shared PMD in PAE), then just copy the
120 references from swapper_pg_dir. */
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 /* list required to sync kernel mapping updates */
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 * List of all pgd's needed for non-PAE so it can invalidate entries
148 * in both cached and uncached pgd's; not needed for PAE since the
149 * kernel pmd is shared. If PAE were not to share the pmd a similar
150 * tactic would be needed. This is essentially codepath-based locking
151 * against pageattr.c; it is the unique case in which a valid change
152 * of kernel pagetables can't be lazily synchronized by vmalloc faults.
153 * vmalloc faults work because attached pagetables are never freed.
154 * -- nyc
155 */
156
157#ifdef CONFIG_X86_PAE
158/*
159 * In PAE mode, we need to do a cr3 reload (=tlb flush) when
160 * updating the top-level pagetable entries to guarantee the
161 * processor notices the update. Since this is expensive, and
162 * all 4 top-level entries are used almost immediately in a
163 * new process's life, we just pre-populate them here.
164 *
165 * Also, if we're in a paravirt environment where the kernel pmd is
166 * not shared between pagetables (!SHARED_KERNEL_PMDS), we allocate
167 * and initialize the kernel pmds here.
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 /* Note: almost everything apart from _PAGE_PRESENT is
176 reserved at the pmd (PDPT) level. */
177 set_pud(pudp, __pud(__pa(pmd) | _PAGE_PRESENT));
178
179 /*
180 * According to Intel App note "TLBs, Paging-Structure Caches,
181 * and Their Invalidation", April 2007, document 317080-001,
182 * section 8.1: in PAE mode we explicitly have to flush the
183 * TLB via cr3 if the top-level pgd is changed...
184 */
185 flush_tlb_mm(mm);
186}
187#else /* !CONFIG_X86_PAE */
188
189/* No need to prepopulate any pagetable entries in non-PAE modes. */
190#define PREALLOCATED_PMDS 0
191
192#endif /* CONFIG_X86_PAE */
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 * Mop up any pmd pages which may still be attached to the pgd.
235 * Normally they will be freed by munmap/exit_mmap, but any pmd we
236 * preallocate which never got a corresponding vma will need to be
237 * freed manually.
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) /* Work around gcc-3.4.x bug */
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 * Xen paravirt assumes pgd table should be in one page. 64 bit kernel also
281 * assumes that pgd should be in one page.
282 *
283 * But kernel with PAE paging that is not running as a Xen domain
284 * only needs to allocate 32 bytes for pgd instead of one page.
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 * When PAE kernel is running as a Xen domain, it does not use
299 * shared kernel pmd. And this requires a whole page for pgd.
300 */
301 if (!SHARED_KERNEL_PMD)
302 return 0;
303
304 /*
305 * when PAE kernel is not running as a Xen domain, it uses
306 * shared kernel pmd. Shared kernel pmd does not require a whole
307 * page for pgd. We are able to just allocate a 32-byte for pgd.
308 * During boot time, we create a 32-byte slab for pgd table allocation.
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 * If no SHARED_KERNEL_PMD, PAE kernel is running as a Xen domain.
323 * We allocate one page for pgd.
324 */
325 if (!SHARED_KERNEL_PMD)
326 return (pgd_t *)__get_free_page(PGALLOC_GFP);
327
328 /*
329 * Now PAE kernel is not running as a Xen domain. We can allocate
330 * a 32-byte slab for pgd to save memory space.
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 /* CONFIG_X86_PAE */
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 * Make sure that pre-populating the pmds is atomic with
374 * respect to anything walking the pgd_list, so that they
375 * never see a partially populated pgd.
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 * Used to set accessed or dirty bits in the page table entries
404 * on other architectures. On x86, the accessed and dirty bits
405 * are tracked by hardware. However, do_wp_page calls this function
406 * to also make the pte writeable at the same time the dirty bit is
407 * set. In that case we do actually need to write the PTE.
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 * We had a write-protection fault here and changed the pmd
436 * to to more permissive. No need to flush the TLB for that,
437 * #PF is architecturally guaranteed to do that and in the
438 * worst-case we'll generate a spurious fault.
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 * On x86 CPUs, clearing the accessed bit without a TLB flush
480 * doesn't cause data corruption. [ It could cause incorrect
481 * page aging and the (mistaken) reclaim of hot pages, but the
482 * chance of that should be relatively low. ]
483 *
484 * So as a performance optimization don't flush the TLB when
485 * clearing the accessed bit, it will eventually be flushed by
486 * a context switch or a VM operation anyway. [ In the rare
487 * event of it not getting flushed for a long time the delay
488 * shouldn't really matter because there's no real memory
489 * pressure for swapout to react to. ]
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 * reserve_top_address - reserves a hole in the top of kernel address space
512 * @reserve - size of hole to reserve
513 *
514 * Can be used to relocate the fixmap area and poke a hole in the top
515 * of kernel address space to make room for a hypervisor.
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 * pud_set_huge - setup kernel PUD mapping
550 *
551 * MTRRs can override PAT memory types with 4KiB granularity. Therefore, this
552 * function sets up a huge page only if any of the following conditions are met:
553 *
554 * - MTRRs are disabled, or
555 *
556 * - MTRRs are enabled and the range is completely covered by a single MTRR, or
557 *
558 * - MTRRs are enabled and the corresponding MTRR memory type is WB, which
559 * has no effect on the requested PAT memory type.
560 *
561 * Callers should try to decrease page size (1GB -> 2MB -> 4K) if the bigger
562 * page mapping attempt fails.
563 *
564 * Returns 1 on success and 0 on failure.
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 * pmd_set_huge - setup kernel PMD mapping
586 *
587 * See text over pud_set_huge() above.
588 *
589 * Returns 1 on success and 0 on failure.
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 * pud_clear_huge - clear kernel PUD mapping when it is set
614 *
615 * Returns 1 on success and 0 on failure (no PUD map is found).
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 * pmd_clear_huge - clear kernel PMD mapping when it is set
629 *
630 * Returns 1 on success and 0 on failure (no PMD map is found).
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 /* CONFIG_HAVE_ARCH_HUGE_VMAP */