Merge branch 'x86/uv' into x86/devel
[linux-2.6] / arch / x86 / mm / pageattr.c
1 /*
2  * Copyright 2002 Andi Kleen, SuSE Labs.
3  * Thanks to Ben LaHaise for precious feedback.
4  */
5 #include <linux/highmem.h>
6 #include <linux/bootmem.h>
7 #include <linux/module.h>
8 #include <linux/sched.h>
9 #include <linux/slab.h>
10 #include <linux/mm.h>
11 #include <linux/interrupt.h>
12 #include <linux/seq_file.h>
13 #include <linux/debugfs.h>
14
15 #include <asm/e820.h>
16 #include <asm/processor.h>
17 #include <asm/tlbflush.h>
18 #include <asm/sections.h>
19 #include <asm/uaccess.h>
20 #include <asm/pgalloc.h>
21 #include <asm/proto.h>
22 #include <asm/pat.h>
23
24 /*
25  * The current flushing context - we pass it instead of 5 arguments:
26  */
27 struct cpa_data {
28         unsigned long   vaddr;
29         pgprot_t        mask_set;
30         pgprot_t        mask_clr;
31         int             numpages;
32         int             flushtlb;
33         unsigned long   pfn;
34         unsigned        force_split : 1;
35 };
36
37 #ifdef CONFIG_PROC_FS
38 static unsigned long direct_pages_count[PG_LEVEL_NUM];
39
40 void update_page_count(int level, unsigned long pages)
41 {
42         unsigned long flags;
43
44         /* Protect against CPA */
45         spin_lock_irqsave(&pgd_lock, flags);
46         direct_pages_count[level] += pages;
47         spin_unlock_irqrestore(&pgd_lock, flags);
48 }
49
50 static void split_page_count(int level)
51 {
52         direct_pages_count[level]--;
53         direct_pages_count[level - 1] += PTRS_PER_PTE;
54 }
55
56 int arch_report_meminfo(char *page)
57 {
58         int n = sprintf(page, "DirectMap4k:  %8lu\n"
59                         "DirectMap2M:  %8lu\n",
60                         direct_pages_count[PG_LEVEL_4K],
61                         direct_pages_count[PG_LEVEL_2M]);
62 #ifdef CONFIG_X86_64
63         n += sprintf(page + n, "DirectMap1G:  %8lu\n",
64                      direct_pages_count[PG_LEVEL_1G]);
65 #endif
66         return n;
67 }
68 #else
69 static inline void split_page_count(int level) { }
70 #endif
71
72 #ifdef CONFIG_X86_64
73
74 static inline unsigned long highmap_start_pfn(void)
75 {
76         return __pa(_text) >> PAGE_SHIFT;
77 }
78
79 static inline unsigned long highmap_end_pfn(void)
80 {
81         return __pa(round_up((unsigned long)_end, PMD_SIZE)) >> PAGE_SHIFT;
82 }
83
84 #endif
85
86 #ifdef CONFIG_DEBUG_PAGEALLOC
87 # define debug_pagealloc 1
88 #else
89 # define debug_pagealloc 0
90 #endif
91
92 static inline int
93 within(unsigned long addr, unsigned long start, unsigned long end)
94 {
95         return addr >= start && addr < end;
96 }
97
98 /*
99  * Flushing functions
100  */
101
102 /**
103  * clflush_cache_range - flush a cache range with clflush
104  * @addr:       virtual start address
105  * @size:       number of bytes to flush
106  *
107  * clflush is an unordered instruction which needs fencing with mfence
108  * to avoid ordering issues.
109  */
110 void clflush_cache_range(void *vaddr, unsigned int size)
111 {
112         void *vend = vaddr + size - 1;
113
114         mb();
115
116         for (; vaddr < vend; vaddr += boot_cpu_data.x86_clflush_size)
117                 clflush(vaddr);
118         /*
119          * Flush any possible final partial cacheline:
120          */
121         clflush(vend);
122
123         mb();
124 }
125
126 static void __cpa_flush_all(void *arg)
127 {
128         unsigned long cache = (unsigned long)arg;
129
130         /*
131          * Flush all to work around Errata in early athlons regarding
132          * large page flushing.
133          */
134         __flush_tlb_all();
135
136         if (cache && boot_cpu_data.x86_model >= 4)
137                 wbinvd();
138 }
139
140 static void cpa_flush_all(unsigned long cache)
141 {
142         BUG_ON(irqs_disabled());
143
144         on_each_cpu(__cpa_flush_all, (void *) cache, 1, 1);
145 }
146
147 static void __cpa_flush_range(void *arg)
148 {
149         /*
150          * We could optimize that further and do individual per page
151          * tlb invalidates for a low number of pages. Caveat: we must
152          * flush the high aliases on 64bit as well.
153          */
154         __flush_tlb_all();
155 }
156
157 static void cpa_flush_range(unsigned long start, int numpages, int cache)
158 {
159         unsigned int i, level;
160         unsigned long addr;
161
162         BUG_ON(irqs_disabled());
163         WARN_ON(PAGE_ALIGN(start) != start);
164
165         on_each_cpu(__cpa_flush_range, NULL, 1, 1);
166
167         if (!cache)
168                 return;
169
170         /*
171          * We only need to flush on one CPU,
172          * clflush is a MESI-coherent instruction that
173          * will cause all other CPUs to flush the same
174          * cachelines:
175          */
176         for (i = 0, addr = start; i < numpages; i++, addr += PAGE_SIZE) {
177                 pte_t *pte = lookup_address(addr, &level);
178
179                 /*
180                  * Only flush present addresses:
181                  */
182                 if (pte && (pte_val(*pte) & _PAGE_PRESENT))
183                         clflush_cache_range((void *) addr, PAGE_SIZE);
184         }
185 }
186
187 /*
188  * Certain areas of memory on x86 require very specific protection flags,
189  * for example the BIOS area or kernel text. Callers don't always get this
190  * right (again, ioremap() on BIOS memory is not uncommon) so this function
191  * checks and fixes these known static required protection bits.
192  */
193 static inline pgprot_t static_protections(pgprot_t prot, unsigned long address,
194                                    unsigned long pfn)
195 {
196         pgprot_t forbidden = __pgprot(0);
197
198         /*
199          * The BIOS area between 640k and 1Mb needs to be executable for
200          * PCI BIOS based config access (CONFIG_PCI_GOBIOS) support.
201          */
202         if (within(pfn, BIOS_BEGIN >> PAGE_SHIFT, BIOS_END >> PAGE_SHIFT))
203                 pgprot_val(forbidden) |= _PAGE_NX;
204
205         /*
206          * The kernel text needs to be executable for obvious reasons
207          * Does not cover __inittext since that is gone later on. On
208          * 64bit we do not enforce !NX on the low mapping
209          */
210         if (within(address, (unsigned long)_text, (unsigned long)_etext))
211                 pgprot_val(forbidden) |= _PAGE_NX;
212
213         /*
214          * The .rodata section needs to be read-only. Using the pfn
215          * catches all aliases.
216          */
217         if (within(pfn, __pa((unsigned long)__start_rodata) >> PAGE_SHIFT,
218                    __pa((unsigned long)__end_rodata) >> PAGE_SHIFT))
219                 pgprot_val(forbidden) |= _PAGE_RW;
220
221         prot = __pgprot(pgprot_val(prot) & ~pgprot_val(forbidden));
222
223         return prot;
224 }
225
226 /*
227  * Lookup the page table entry for a virtual address. Return a pointer
228  * to the entry and the level of the mapping.
229  *
230  * Note: We return pud and pmd either when the entry is marked large
231  * or when the present bit is not set. Otherwise we would return a
232  * pointer to a nonexisting mapping.
233  */
234 pte_t *lookup_address(unsigned long address, unsigned int *level)
235 {
236         pgd_t *pgd = pgd_offset_k(address);
237         pud_t *pud;
238         pmd_t *pmd;
239
240         *level = PG_LEVEL_NONE;
241
242         if (pgd_none(*pgd))
243                 return NULL;
244
245         pud = pud_offset(pgd, address);
246         if (pud_none(*pud))
247                 return NULL;
248
249         *level = PG_LEVEL_1G;
250         if (pud_large(*pud) || !pud_present(*pud))
251                 return (pte_t *)pud;
252
253         pmd = pmd_offset(pud, address);
254         if (pmd_none(*pmd))
255                 return NULL;
256
257         *level = PG_LEVEL_2M;
258         if (pmd_large(*pmd) || !pmd_present(*pmd))
259                 return (pte_t *)pmd;
260
261         *level = PG_LEVEL_4K;
262
263         return pte_offset_kernel(pmd, address);
264 }
265
266 /*
267  * Set the new pmd in all the pgds we know about:
268  */
269 static void __set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
270 {
271         /* change init_mm */
272         set_pte_atomic(kpte, pte);
273 #ifdef CONFIG_X86_32
274         if (!SHARED_KERNEL_PMD) {
275                 struct page *page;
276
277                 list_for_each_entry(page, &pgd_list, lru) {
278                         pgd_t *pgd;
279                         pud_t *pud;
280                         pmd_t *pmd;
281
282                         pgd = (pgd_t *)page_address(page) + pgd_index(address);
283                         pud = pud_offset(pgd, address);
284                         pmd = pmd_offset(pud, address);
285                         set_pte_atomic((pte_t *)pmd, pte);
286                 }
287         }
288 #endif
289 }
290
291 static int
292 try_preserve_large_page(pte_t *kpte, unsigned long address,
293                         struct cpa_data *cpa)
294 {
295         unsigned long nextpage_addr, numpages, pmask, psize, flags, addr, pfn;
296         pte_t new_pte, old_pte, *tmp;
297         pgprot_t old_prot, new_prot;
298         int i, do_split = 1;
299         unsigned int level;
300
301         if (cpa->force_split)
302                 return 1;
303
304         spin_lock_irqsave(&pgd_lock, flags);
305         /*
306          * Check for races, another CPU might have split this page
307          * up already:
308          */
309         tmp = lookup_address(address, &level);
310         if (tmp != kpte)
311                 goto out_unlock;
312
313         switch (level) {
314         case PG_LEVEL_2M:
315                 psize = PMD_PAGE_SIZE;
316                 pmask = PMD_PAGE_MASK;
317                 break;
318 #ifdef CONFIG_X86_64
319         case PG_LEVEL_1G:
320                 psize = PUD_PAGE_SIZE;
321                 pmask = PUD_PAGE_MASK;
322                 break;
323 #endif
324         default:
325                 do_split = -EINVAL;
326                 goto out_unlock;
327         }
328
329         /*
330          * Calculate the number of pages, which fit into this large
331          * page starting at address:
332          */
333         nextpage_addr = (address + psize) & pmask;
334         numpages = (nextpage_addr - address) >> PAGE_SHIFT;
335         if (numpages < cpa->numpages)
336                 cpa->numpages = numpages;
337
338         /*
339          * We are safe now. Check whether the new pgprot is the same:
340          */
341         old_pte = *kpte;
342         old_prot = new_prot = pte_pgprot(old_pte);
343
344         pgprot_val(new_prot) &= ~pgprot_val(cpa->mask_clr);
345         pgprot_val(new_prot) |= pgprot_val(cpa->mask_set);
346
347         /*
348          * old_pte points to the large page base address. So we need
349          * to add the offset of the virtual address:
350          */
351         pfn = pte_pfn(old_pte) + ((address & (psize - 1)) >> PAGE_SHIFT);
352         cpa->pfn = pfn;
353
354         new_prot = static_protections(new_prot, address, pfn);
355
356         /*
357          * We need to check the full range, whether
358          * static_protection() requires a different pgprot for one of
359          * the pages in the range we try to preserve:
360          */
361         addr = address + PAGE_SIZE;
362         pfn++;
363         for (i = 1; i < cpa->numpages; i++, addr += PAGE_SIZE, pfn++) {
364                 pgprot_t chk_prot = static_protections(new_prot, addr, pfn);
365
366                 if (pgprot_val(chk_prot) != pgprot_val(new_prot))
367                         goto out_unlock;
368         }
369
370         /*
371          * If there are no changes, return. maxpages has been updated
372          * above:
373          */
374         if (pgprot_val(new_prot) == pgprot_val(old_prot)) {
375                 do_split = 0;
376                 goto out_unlock;
377         }
378
379         /*
380          * We need to change the attributes. Check, whether we can
381          * change the large page in one go. We request a split, when
382          * the address is not aligned and the number of pages is
383          * smaller than the number of pages in the large page. Note
384          * that we limited the number of possible pages already to
385          * the number of pages in the large page.
386          */
387         if (address == (nextpage_addr - psize) && cpa->numpages == numpages) {
388                 /*
389                  * The address is aligned and the number of pages
390                  * covers the full page.
391                  */
392                 new_pte = pfn_pte(pte_pfn(old_pte), canon_pgprot(new_prot));
393                 __set_pmd_pte(kpte, address, new_pte);
394                 cpa->flushtlb = 1;
395                 do_split = 0;
396         }
397
398 out_unlock:
399         spin_unlock_irqrestore(&pgd_lock, flags);
400
401         return do_split;
402 }
403
404 static LIST_HEAD(page_pool);
405 static unsigned long pool_size, pool_pages, pool_low;
406 static unsigned long pool_used, pool_failed;
407
408 static void cpa_fill_pool(struct page **ret)
409 {
410         gfp_t gfp = GFP_KERNEL;
411         unsigned long flags;
412         struct page *p;
413
414         /*
415          * Avoid recursion (on debug-pagealloc) and also signal
416          * our priority to get to these pagetables:
417          */
418         if (current->flags & PF_MEMALLOC)
419                 return;
420         current->flags |= PF_MEMALLOC;
421
422         /*
423          * Allocate atomically from atomic contexts:
424          */
425         if (in_atomic() || irqs_disabled() || debug_pagealloc)
426                 gfp =  GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN;
427
428         while (pool_pages < pool_size || (ret && !*ret)) {
429                 p = alloc_pages(gfp, 0);
430                 if (!p) {
431                         pool_failed++;
432                         break;
433                 }
434                 /*
435                  * If the call site needs a page right now, provide it:
436                  */
437                 if (ret && !*ret) {
438                         *ret = p;
439                         continue;
440                 }
441                 spin_lock_irqsave(&pgd_lock, flags);
442                 list_add(&p->lru, &page_pool);
443                 pool_pages++;
444                 spin_unlock_irqrestore(&pgd_lock, flags);
445         }
446
447         current->flags &= ~PF_MEMALLOC;
448 }
449
450 #define SHIFT_MB                (20 - PAGE_SHIFT)
451 #define ROUND_MB_GB             ((1 << 10) - 1)
452 #define SHIFT_MB_GB             10
453 #define POOL_PAGES_PER_GB       16
454
455 void __init cpa_init(void)
456 {
457         struct sysinfo si;
458         unsigned long gb;
459
460         si_meminfo(&si);
461         /*
462          * Calculate the number of pool pages:
463          *
464          * Convert totalram (nr of pages) to MiB and round to the next
465          * GiB. Shift MiB to Gib and multiply the result by
466          * POOL_PAGES_PER_GB:
467          */
468         if (debug_pagealloc) {
469                 gb = ((si.totalram >> SHIFT_MB) + ROUND_MB_GB) >> SHIFT_MB_GB;
470                 pool_size = POOL_PAGES_PER_GB * gb;
471         } else {
472                 pool_size = 1;
473         }
474         pool_low = pool_size;
475
476         cpa_fill_pool(NULL);
477         printk(KERN_DEBUG
478                "CPA: page pool initialized %lu of %lu pages preallocated\n",
479                pool_pages, pool_size);
480 }
481
482 static int split_large_page(pte_t *kpte, unsigned long address)
483 {
484         unsigned long flags, pfn, pfninc = 1;
485         unsigned int i, level;
486         pte_t *pbase, *tmp;
487         pgprot_t ref_prot;
488         struct page *base;
489
490         /*
491          * Get a page from the pool. The pool list is protected by the
492          * pgd_lock, which we have to take anyway for the split
493          * operation:
494          */
495         spin_lock_irqsave(&pgd_lock, flags);
496         if (list_empty(&page_pool)) {
497                 spin_unlock_irqrestore(&pgd_lock, flags);
498                 base = NULL;
499                 cpa_fill_pool(&base);
500                 if (!base)
501                         return -ENOMEM;
502                 spin_lock_irqsave(&pgd_lock, flags);
503         } else {
504                 base = list_first_entry(&page_pool, struct page, lru);
505                 list_del(&base->lru);
506                 pool_pages--;
507
508                 if (pool_pages < pool_low)
509                         pool_low = pool_pages;
510         }
511
512         /*
513          * Check for races, another CPU might have split this page
514          * up for us already:
515          */
516         tmp = lookup_address(address, &level);
517         if (tmp != kpte)
518                 goto out_unlock;
519
520         pbase = (pte_t *)page_address(base);
521         paravirt_alloc_pte(&init_mm, page_to_pfn(base));
522         ref_prot = pte_pgprot(pte_clrhuge(*kpte));
523
524 #ifdef CONFIG_X86_64
525         if (level == PG_LEVEL_1G) {
526                 pfninc = PMD_PAGE_SIZE >> PAGE_SHIFT;
527                 pgprot_val(ref_prot) |= _PAGE_PSE;
528         }
529 #endif
530
531         /*
532          * Get the target pfn from the original entry:
533          */
534         pfn = pte_pfn(*kpte);
535         for (i = 0; i < PTRS_PER_PTE; i++, pfn += pfninc)
536                 set_pte(&pbase[i], pfn_pte(pfn, ref_prot));
537
538         if (address >= (unsigned long)__va(0) &&
539                 address < (unsigned long)__va(max_pfn_mapped << PAGE_SHIFT))
540                 split_page_count(level);
541
542         /*
543          * Install the new, split up pagetable. Important details here:
544          *
545          * On Intel the NX bit of all levels must be cleared to make a
546          * page executable. See section 4.13.2 of Intel 64 and IA-32
547          * Architectures Software Developer's Manual).
548          *
549          * Mark the entry present. The current mapping might be
550          * set to not present, which we preserved above.
551          */
552         ref_prot = pte_pgprot(pte_mkexec(pte_clrhuge(*kpte)));
553         pgprot_val(ref_prot) |= _PAGE_PRESENT;
554         __set_pmd_pte(kpte, address, mk_pte(base, ref_prot));
555         base = NULL;
556
557 out_unlock:
558         /*
559          * If we dropped out via the lookup_address check under
560          * pgd_lock then stick the page back into the pool:
561          */
562         if (base) {
563                 list_add(&base->lru, &page_pool);
564                 pool_pages++;
565         } else
566                 pool_used++;
567         spin_unlock_irqrestore(&pgd_lock, flags);
568
569         return 0;
570 }
571
572 static int __change_page_attr(struct cpa_data *cpa, int primary)
573 {
574         unsigned long address = cpa->vaddr;
575         int do_split, err;
576         unsigned int level;
577         pte_t *kpte, old_pte;
578
579 repeat:
580         kpte = lookup_address(address, &level);
581         if (!kpte)
582                 return 0;
583
584         old_pte = *kpte;
585         if (!pte_val(old_pte)) {
586                 if (!primary)
587                         return 0;
588                 printk(KERN_WARNING "CPA: called for zero pte. "
589                        "vaddr = %lx cpa->vaddr = %lx\n", address,
590                        cpa->vaddr);
591                 WARN_ON(1);
592                 return -EINVAL;
593         }
594
595         if (level == PG_LEVEL_4K) {
596                 pte_t new_pte;
597                 pgprot_t new_prot = pte_pgprot(old_pte);
598                 unsigned long pfn = pte_pfn(old_pte);
599
600                 pgprot_val(new_prot) &= ~pgprot_val(cpa->mask_clr);
601                 pgprot_val(new_prot) |= pgprot_val(cpa->mask_set);
602
603                 new_prot = static_protections(new_prot, address, pfn);
604
605                 /*
606                  * We need to keep the pfn from the existing PTE,
607                  * after all we're only going to change it's attributes
608                  * not the memory it points to
609                  */
610                 new_pte = pfn_pte(pfn, canon_pgprot(new_prot));
611                 cpa->pfn = pfn;
612                 /*
613                  * Do we really change anything ?
614                  */
615                 if (pte_val(old_pte) != pte_val(new_pte)) {
616                         set_pte_atomic(kpte, new_pte);
617                         cpa->flushtlb = 1;
618                 }
619                 cpa->numpages = 1;
620                 return 0;
621         }
622
623         /*
624          * Check, whether we can keep the large page intact
625          * and just change the pte:
626          */
627         do_split = try_preserve_large_page(kpte, address, cpa);
628         /*
629          * When the range fits into the existing large page,
630          * return. cp->numpages and cpa->tlbflush have been updated in
631          * try_large_page:
632          */
633         if (do_split <= 0)
634                 return do_split;
635
636         /*
637          * We have to split the large page:
638          */
639         err = split_large_page(kpte, address);
640         if (!err) {
641                 cpa->flushtlb = 1;
642                 goto repeat;
643         }
644
645         return err;
646 }
647
648 static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias);
649
650 static int cpa_process_alias(struct cpa_data *cpa)
651 {
652         struct cpa_data alias_cpa;
653         int ret = 0;
654
655         if (cpa->pfn > max_pfn_mapped)
656                 return 0;
657
658         /*
659          * No need to redo, when the primary call touched the direct
660          * mapping already:
661          */
662         if (!within(cpa->vaddr, PAGE_OFFSET,
663                     PAGE_OFFSET + (max_pfn_mapped << PAGE_SHIFT))) {
664
665                 alias_cpa = *cpa;
666                 alias_cpa.vaddr = (unsigned long) __va(cpa->pfn << PAGE_SHIFT);
667
668                 ret = __change_page_attr_set_clr(&alias_cpa, 0);
669         }
670
671 #ifdef CONFIG_X86_64
672         if (ret)
673                 return ret;
674         /*
675          * No need to redo, when the primary call touched the high
676          * mapping already:
677          */
678         if (within(cpa->vaddr, (unsigned long) _text, (unsigned long) _end))
679                 return 0;
680
681         /*
682          * If the physical address is inside the kernel map, we need
683          * to touch the high mapped kernel as well:
684          */
685         if (!within(cpa->pfn, highmap_start_pfn(), highmap_end_pfn()))
686                 return 0;
687
688         alias_cpa = *cpa;
689         alias_cpa.vaddr =
690                 (cpa->pfn << PAGE_SHIFT) + __START_KERNEL_map - phys_base;
691
692         /*
693          * The high mapping range is imprecise, so ignore the return value.
694          */
695         __change_page_attr_set_clr(&alias_cpa, 0);
696 #endif
697         return ret;
698 }
699
700 static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias)
701 {
702         int ret, numpages = cpa->numpages;
703
704         while (numpages) {
705                 /*
706                  * Store the remaining nr of pages for the large page
707                  * preservation check.
708                  */
709                 cpa->numpages = numpages;
710
711                 ret = __change_page_attr(cpa, checkalias);
712                 if (ret)
713                         return ret;
714
715                 if (checkalias) {
716                         ret = cpa_process_alias(cpa);
717                         if (ret)
718                                 return ret;
719                 }
720
721                 /*
722                  * Adjust the number of pages with the result of the
723                  * CPA operation. Either a large page has been
724                  * preserved or a single page update happened.
725                  */
726                 BUG_ON(cpa->numpages > numpages);
727                 numpages -= cpa->numpages;
728                 cpa->vaddr += cpa->numpages * PAGE_SIZE;
729         }
730         return 0;
731 }
732
733 static inline int cache_attr(pgprot_t attr)
734 {
735         return pgprot_val(attr) &
736                 (_PAGE_PAT | _PAGE_PAT_LARGE | _PAGE_PWT | _PAGE_PCD);
737 }
738
739 static int change_page_attr_set_clr(unsigned long addr, int numpages,
740                                     pgprot_t mask_set, pgprot_t mask_clr,
741                                     int force_split)
742 {
743         struct cpa_data cpa;
744         int ret, cache, checkalias;
745
746         /*
747          * Check, if we are requested to change a not supported
748          * feature:
749          */
750         mask_set = canon_pgprot(mask_set);
751         mask_clr = canon_pgprot(mask_clr);
752         if (!pgprot_val(mask_set) && !pgprot_val(mask_clr) && !force_split)
753                 return 0;
754
755         /* Ensure we are PAGE_SIZE aligned */
756         if (addr & ~PAGE_MASK) {
757                 addr &= PAGE_MASK;
758                 /*
759                  * People should not be passing in unaligned addresses:
760                  */
761                 WARN_ON_ONCE(1);
762         }
763
764         cpa.vaddr = addr;
765         cpa.numpages = numpages;
766         cpa.mask_set = mask_set;
767         cpa.mask_clr = mask_clr;
768         cpa.flushtlb = 0;
769         cpa.force_split = force_split;
770
771         /* No alias checking for _NX bit modifications */
772         checkalias = (pgprot_val(mask_set) | pgprot_val(mask_clr)) != _PAGE_NX;
773
774         ret = __change_page_attr_set_clr(&cpa, checkalias);
775
776         /*
777          * Check whether we really changed something:
778          */
779         if (!cpa.flushtlb)
780                 goto out;
781
782         /*
783          * No need to flush, when we did not set any of the caching
784          * attributes:
785          */
786         cache = cache_attr(mask_set);
787
788         /*
789          * On success we use clflush, when the CPU supports it to
790          * avoid the wbindv. If the CPU does not support it and in the
791          * error case we fall back to cpa_flush_all (which uses
792          * wbindv):
793          */
794         if (!ret && cpu_has_clflush)
795                 cpa_flush_range(addr, numpages, cache);
796         else
797                 cpa_flush_all(cache);
798
799 out:
800         cpa_fill_pool(NULL);
801
802         return ret;
803 }
804
805 static inline int change_page_attr_set(unsigned long addr, int numpages,
806                                        pgprot_t mask)
807 {
808         return change_page_attr_set_clr(addr, numpages, mask, __pgprot(0), 0);
809 }
810
811 static inline int change_page_attr_clear(unsigned long addr, int numpages,
812                                          pgprot_t mask)
813 {
814         return change_page_attr_set_clr(addr, numpages, __pgprot(0), mask, 0);
815 }
816
817 int _set_memory_uc(unsigned long addr, int numpages)
818 {
819         /*
820          * for now UC MINUS. see comments in ioremap_nocache()
821          */
822         return change_page_attr_set(addr, numpages,
823                                     __pgprot(_PAGE_CACHE_UC_MINUS));
824 }
825
826 int set_memory_uc(unsigned long addr, int numpages)
827 {
828         /*
829          * for now UC MINUS. see comments in ioremap_nocache()
830          */
831         if (reserve_memtype(addr, addr + numpages * PAGE_SIZE,
832                             _PAGE_CACHE_UC_MINUS, NULL))
833                 return -EINVAL;
834
835         return _set_memory_uc(addr, numpages);
836 }
837 EXPORT_SYMBOL(set_memory_uc);
838
839 int _set_memory_wc(unsigned long addr, int numpages)
840 {
841         return change_page_attr_set(addr, numpages,
842                                     __pgprot(_PAGE_CACHE_WC));
843 }
844
845 int set_memory_wc(unsigned long addr, int numpages)
846 {
847         if (!pat_enabled)
848                 return set_memory_uc(addr, numpages);
849
850         if (reserve_memtype(addr, addr + numpages * PAGE_SIZE,
851                 _PAGE_CACHE_WC, NULL))
852                 return -EINVAL;
853
854         return _set_memory_wc(addr, numpages);
855 }
856 EXPORT_SYMBOL(set_memory_wc);
857
858 int _set_memory_wb(unsigned long addr, int numpages)
859 {
860         return change_page_attr_clear(addr, numpages,
861                                       __pgprot(_PAGE_CACHE_MASK));
862 }
863
864 int set_memory_wb(unsigned long addr, int numpages)
865 {
866         free_memtype(addr, addr + numpages * PAGE_SIZE);
867
868         return _set_memory_wb(addr, numpages);
869 }
870 EXPORT_SYMBOL(set_memory_wb);
871
872 int set_memory_x(unsigned long addr, int numpages)
873 {
874         return change_page_attr_clear(addr, numpages, __pgprot(_PAGE_NX));
875 }
876 EXPORT_SYMBOL(set_memory_x);
877
878 int set_memory_nx(unsigned long addr, int numpages)
879 {
880         return change_page_attr_set(addr, numpages, __pgprot(_PAGE_NX));
881 }
882 EXPORT_SYMBOL(set_memory_nx);
883
884 int set_memory_ro(unsigned long addr, int numpages)
885 {
886         return change_page_attr_clear(addr, numpages, __pgprot(_PAGE_RW));
887 }
888
889 int set_memory_rw(unsigned long addr, int numpages)
890 {
891         return change_page_attr_set(addr, numpages, __pgprot(_PAGE_RW));
892 }
893
894 int set_memory_np(unsigned long addr, int numpages)
895 {
896         return change_page_attr_clear(addr, numpages, __pgprot(_PAGE_PRESENT));
897 }
898
899 int set_memory_4k(unsigned long addr, int numpages)
900 {
901         return change_page_attr_set_clr(addr, numpages, __pgprot(0),
902                                         __pgprot(0), 1);
903 }
904
905 int set_pages_uc(struct page *page, int numpages)
906 {
907         unsigned long addr = (unsigned long)page_address(page);
908
909         return set_memory_uc(addr, numpages);
910 }
911 EXPORT_SYMBOL(set_pages_uc);
912
913 int set_pages_wb(struct page *page, int numpages)
914 {
915         unsigned long addr = (unsigned long)page_address(page);
916
917         return set_memory_wb(addr, numpages);
918 }
919 EXPORT_SYMBOL(set_pages_wb);
920
921 int set_pages_x(struct page *page, int numpages)
922 {
923         unsigned long addr = (unsigned long)page_address(page);
924
925         return set_memory_x(addr, numpages);
926 }
927 EXPORT_SYMBOL(set_pages_x);
928
929 int set_pages_nx(struct page *page, int numpages)
930 {
931         unsigned long addr = (unsigned long)page_address(page);
932
933         return set_memory_nx(addr, numpages);
934 }
935 EXPORT_SYMBOL(set_pages_nx);
936
937 int set_pages_ro(struct page *page, int numpages)
938 {
939         unsigned long addr = (unsigned long)page_address(page);
940
941         return set_memory_ro(addr, numpages);
942 }
943
944 int set_pages_rw(struct page *page, int numpages)
945 {
946         unsigned long addr = (unsigned long)page_address(page);
947
948         return set_memory_rw(addr, numpages);
949 }
950
951 #ifdef CONFIG_DEBUG_PAGEALLOC
952
953 static int __set_pages_p(struct page *page, int numpages)
954 {
955         struct cpa_data cpa = { .vaddr = (unsigned long) page_address(page),
956                                 .numpages = numpages,
957                                 .mask_set = __pgprot(_PAGE_PRESENT | _PAGE_RW),
958                                 .mask_clr = __pgprot(0)};
959
960         return __change_page_attr_set_clr(&cpa, 1);
961 }
962
963 static int __set_pages_np(struct page *page, int numpages)
964 {
965         struct cpa_data cpa = { .vaddr = (unsigned long) page_address(page),
966                                 .numpages = numpages,
967                                 .mask_set = __pgprot(0),
968                                 .mask_clr = __pgprot(_PAGE_PRESENT | _PAGE_RW)};
969
970         return __change_page_attr_set_clr(&cpa, 1);
971 }
972
973 void kernel_map_pages(struct page *page, int numpages, int enable)
974 {
975         if (PageHighMem(page))
976                 return;
977         if (!enable) {
978                 debug_check_no_locks_freed(page_address(page),
979                                            numpages * PAGE_SIZE);
980         }
981
982         /*
983          * If page allocator is not up yet then do not call c_p_a():
984          */
985         if (!debug_pagealloc_enabled)
986                 return;
987
988         /*
989          * The return value is ignored as the calls cannot fail.
990          * Large pages are kept enabled at boot time, and are
991          * split up quickly with DEBUG_PAGEALLOC. If a splitup
992          * fails here (due to temporary memory shortage) no damage
993          * is done because we just keep the largepage intact up
994          * to the next attempt when it will likely be split up:
995          */
996         if (enable)
997                 __set_pages_p(page, numpages);
998         else
999                 __set_pages_np(page, numpages);
1000
1001         /*
1002          * We should perform an IPI and flush all tlbs,
1003          * but that can deadlock->flush only current cpu:
1004          */
1005         __flush_tlb_all();
1006
1007         /*
1008          * Try to refill the page pool here. We can do this only after
1009          * the tlb flush.
1010          */
1011         cpa_fill_pool(NULL);
1012 }
1013
1014 #ifdef CONFIG_DEBUG_FS
1015 static int dpa_show(struct seq_file *m, void *v)
1016 {
1017         seq_puts(m, "DEBUG_PAGEALLOC\n");
1018         seq_printf(m, "pool_size     : %lu\n", pool_size);
1019         seq_printf(m, "pool_pages    : %lu\n", pool_pages);
1020         seq_printf(m, "pool_low      : %lu\n", pool_low);
1021         seq_printf(m, "pool_used     : %lu\n", pool_used);
1022         seq_printf(m, "pool_failed   : %lu\n", pool_failed);
1023
1024         return 0;
1025 }
1026
1027 static int dpa_open(struct inode *inode, struct file *filp)
1028 {
1029         return single_open(filp, dpa_show, NULL);
1030 }
1031
1032 static const struct file_operations dpa_fops = {
1033         .open           = dpa_open,
1034         .read           = seq_read,
1035         .llseek         = seq_lseek,
1036         .release        = single_release,
1037 };
1038
1039 static int __init debug_pagealloc_proc_init(void)
1040 {
1041         struct dentry *de;
1042
1043         de = debugfs_create_file("debug_pagealloc", 0600, NULL, NULL,
1044                                  &dpa_fops);
1045         if (!de)
1046                 return -ENOMEM;
1047
1048         return 0;
1049 }
1050 __initcall(debug_pagealloc_proc_init);
1051 #endif
1052
1053 #ifdef CONFIG_HIBERNATION
1054
1055 bool kernel_page_present(struct page *page)
1056 {
1057         unsigned int level;
1058         pte_t *pte;
1059
1060         if (PageHighMem(page))
1061                 return false;
1062
1063         pte = lookup_address((unsigned long)page_address(page), &level);
1064         return (pte_val(*pte) & _PAGE_PRESENT);
1065 }
1066
1067 #endif /* CONFIG_HIBERNATION */
1068
1069 #endif /* CONFIG_DEBUG_PAGEALLOC */
1070
1071 /*
1072  * The testcases use internal knowledge of the implementation that shouldn't
1073  * be exposed to the rest of the kernel. Include these directly here.
1074  */
1075 #ifdef CONFIG_CPA_DEBUG
1076 #include "pageattr-test.c"
1077 #endif