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1/*
2 * linux/mm/vmalloc.c
3 *
4 * Copyright (C) 1993 Linus Torvalds
5 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
6 * SMP-safe vmalloc/vfree/ioremap, Tigran Aivazian <tigran@veritas.com>, May 2000
7 * Major rework to support vmap/vunmap, Christoph Hellwig, SGI, August 2002
8 * Numa awareness, Christoph Lameter, SGI, June 2005
9 */
10
11#include <linux/vmalloc.h>
12#include <linux/mm.h>
13#include <linux/module.h>
14#include <linux/highmem.h>
15#include <linux/sched.h>
16#include <linux/slab.h>
17#include <linux/spinlock.h>
18#include <linux/interrupt.h>
19#include <linux/proc_fs.h>
20#include <linux/seq_file.h>
21#include <linux/debugobjects.h>
22#include <linux/kallsyms.h>
23#include <linux/list.h>
24#include <linux/rbtree.h>
25#include <linux/radix-tree.h>
26#include <linux/rcupdate.h>
27#include <linux/pfn.h>
28#include <linux/kmemleak.h>
29#include <linux/atomic.h>
30#include <linux/compiler.h>
31#include <linux/llist.h>
32#include <linux/bitops.h>
33
34#include <asm/uaccess.h>
35#include <asm/tlbflush.h>
36#include <asm/shmparam.h>
37
38#include "internal.h"
39
40struct vfree_deferred {
41 struct llist_head list;
42 struct work_struct wq;
43};
44static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred);
45
46static void __vunmap(const void *, int);
47
48static void free_work(struct work_struct *w)
49{
50 struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq);
51 struct llist_node *llnode = llist_del_all(&p->list);
52 while (llnode) {
53 void *p = llnode;
54 llnode = llist_next(llnode);
55 __vunmap(p, 1);
56 }
57}
58
59/*** Page table manipulation functions ***/
60
61static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
62{
63 pte_t *pte;
64
65 pte = pte_offset_kernel(pmd, addr);
66 do {
67 pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
68 WARN_ON(!pte_none(ptent) && !pte_present(ptent));
69 } while (pte++, addr += PAGE_SIZE, addr != end);
70}
71
72static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
73{
74 pmd_t *pmd;
75 unsigned long next;
76
77 pmd = pmd_offset(pud, addr);
78 do {
79 next = pmd_addr_end(addr, end);
80 if (pmd_clear_huge(pmd))
81 continue;
82 if (pmd_none_or_clear_bad(pmd))
83 continue;
84 vunmap_pte_range(pmd, addr, next);
85 } while (pmd++, addr = next, addr != end);
86}
87
88static void vunmap_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end)
89{
90 pud_t *pud;
91 unsigned long next;
92
93 pud = pud_offset(pgd, addr);
94 do {
95 next = pud_addr_end(addr, end);
96 if (pud_clear_huge(pud))
97 continue;
98 if (pud_none_or_clear_bad(pud))
99 continue;
100 vunmap_pmd_range(pud, addr, next);
101 } while (pud++, addr = next, addr != end);
102}
103
104static void vunmap_page_range(unsigned long addr, unsigned long end)
105{
106 pgd_t *pgd;
107 unsigned long next;
108
109 BUG_ON(addr >= end);
110 pgd = pgd_offset_k(addr);
111 do {
112 next = pgd_addr_end(addr, end);
113 if (pgd_none_or_clear_bad(pgd))
114 continue;
115 vunmap_pud_range(pgd, addr, next);
116 } while (pgd++, addr = next, addr != end);
117}
118
119static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
120 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
121{
122 pte_t *pte;
123
124 /*
125 * nr is a running index into the array which helps higher level
126 * callers keep track of where we're up to.
127 */
128
129 pte = pte_alloc_kernel(pmd, addr);
130 if (!pte)
131 return -ENOMEM;
132 do {
133 struct page *page = pages[*nr];
134
135 if (WARN_ON(!pte_none(*pte)))
136 return -EBUSY;
137 if (WARN_ON(!page))
138 return -ENOMEM;
139 set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
140 (*nr)++;
141 } while (pte++, addr += PAGE_SIZE, addr != end);
142 return 0;
143}
144
145static int vmap_pmd_range(pud_t *pud, unsigned long addr,
146 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
147{
148 pmd_t *pmd;
149 unsigned long next;
150
151 pmd = pmd_alloc(&init_mm, pud, addr);
152 if (!pmd)
153 return -ENOMEM;
154 do {
155 next = pmd_addr_end(addr, end);
156 if (vmap_pte_range(pmd, addr, next, prot, pages, nr))
157 return -ENOMEM;
158 } while (pmd++, addr = next, addr != end);
159 return 0;
160}
161
162static int vmap_pud_range(pgd_t *pgd, unsigned long addr,
163 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
164{
165 pud_t *pud;
166 unsigned long next;
167
168 pud = pud_alloc(&init_mm, pgd, addr);
169 if (!pud)
170 return -ENOMEM;
171 do {
172 next = pud_addr_end(addr, end);
173 if (vmap_pmd_range(pud, addr, next, prot, pages, nr))
174 return -ENOMEM;
175 } while (pud++, addr = next, addr != end);
176 return 0;
177}
178
179/*
180 * Set up page tables in kva (addr, end). The ptes shall have prot "prot", and
181 * will have pfns corresponding to the "pages" array.
182 *
183 * Ie. pte at addr+N*PAGE_SIZE shall point to pfn corresponding to pages[N]
184 */
185static int vmap_page_range_noflush(unsigned long start, unsigned long end,
186 pgprot_t prot, struct page **pages)
187{
188 pgd_t *pgd;
189 unsigned long next;
190 unsigned long addr = start;
191 int err = 0;
192 int nr = 0;
193
194 BUG_ON(addr >= end);
195 pgd = pgd_offset_k(addr);
196 do {
197 next = pgd_addr_end(addr, end);
198 err = vmap_pud_range(pgd, addr, next, prot, pages, &nr);
199 if (err)
200 return err;
201 } while (pgd++, addr = next, addr != end);
202
203 return nr;
204}
205
206static int vmap_page_range(unsigned long start, unsigned long end,
207 pgprot_t prot, struct page **pages)
208{
209 int ret;
210
211 ret = vmap_page_range_noflush(start, end, prot, pages);
212 flush_cache_vmap(start, end);
213 return ret;
214}
215
216int is_vmalloc_or_module_addr(const void *x)
217{
218 /*
219 * ARM, x86-64 and sparc64 put modules in a special place,
220 * and fall back on vmalloc() if that fails. Others
221 * just put it in the vmalloc space.
222 */
223#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
224 unsigned long addr = (unsigned long)x;
225 if (addr >= MODULES_VADDR && addr < MODULES_END)
226 return 1;
227#endif
228 return is_vmalloc_addr(x);
229}
230
231/*
232 * Walk a vmap address to the struct page it maps.
233 */
234struct page *vmalloc_to_page(const void *vmalloc_addr)
235{
236 unsigned long addr = (unsigned long) vmalloc_addr;
237 struct page *page = NULL;
238 pgd_t *pgd = pgd_offset_k(addr);
239
240 /*
241 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
242 * architectures that do not vmalloc module space
243 */
244 VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
245
246 if (!pgd_none(*pgd)) {
247 pud_t *pud = pud_offset(pgd, addr);
248 if (!pud_none(*pud)) {
249 pmd_t *pmd = pmd_offset(pud, addr);
250 if (!pmd_none(*pmd)) {
251 pte_t *ptep, pte;
252
253 ptep = pte_offset_map(pmd, addr);
254 pte = *ptep;
255 if (pte_present(pte))
256 page = pte_page(pte);
257 pte_unmap(ptep);
258 }
259 }
260 }
261 return page;
262}
263EXPORT_SYMBOL(vmalloc_to_page);
264
265/*
266 * Map a vmalloc()-space virtual address to the physical page frame number.
267 */
268unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
269{
270 return page_to_pfn(vmalloc_to_page(vmalloc_addr));
271}
272EXPORT_SYMBOL(vmalloc_to_pfn);
273
274
275/*** Global kva allocator ***/
276
277#define VM_LAZY_FREE 0x01
278#define VM_LAZY_FREEING 0x02
279#define VM_VM_AREA 0x04
280
281static DEFINE_SPINLOCK(vmap_area_lock);
282/* Export for kexec only */
283LIST_HEAD(vmap_area_list);
284static struct rb_root vmap_area_root = RB_ROOT;
285
286/* The vmap cache globals are protected by vmap_area_lock */
287static struct rb_node *free_vmap_cache;
288static unsigned long cached_hole_size;
289static unsigned long cached_vstart;
290static unsigned long cached_align;
291
292static unsigned long vmap_area_pcpu_hole;
293
294static struct vmap_area *__find_vmap_area(unsigned long addr)
295{
296 struct rb_node *n = vmap_area_root.rb_node;
297
298 while (n) {
299 struct vmap_area *va;
300
301 va = rb_entry(n, struct vmap_area, rb_node);
302 if (addr < va->va_start)
303 n = n->rb_left;
304 else if (addr >= va->va_end)
305 n = n->rb_right;
306 else
307 return va;
308 }
309
310 return NULL;
311}
312
313static void __insert_vmap_area(struct vmap_area *va)
314{
315 struct rb_node **p = &vmap_area_root.rb_node;
316 struct rb_node *parent = NULL;
317 struct rb_node *tmp;
318
319 while (*p) {
320 struct vmap_area *tmp_va;
321
322 parent = *p;
323 tmp_va = rb_entry(parent, struct vmap_area, rb_node);
324 if (va->va_start < tmp_va->va_end)
325 p = &(*p)->rb_left;
326 else if (va->va_end > tmp_va->va_start)
327 p = &(*p)->rb_right;
328 else
329 BUG();
330 }
331
332 rb_link_node(&va->rb_node, parent, p);
333 rb_insert_color(&va->rb_node, &vmap_area_root);
334
335 /* address-sort this list */
336 tmp = rb_prev(&va->rb_node);
337 if (tmp) {
338 struct vmap_area *prev;
339 prev = rb_entry(tmp, struct vmap_area, rb_node);
340 list_add_rcu(&va->list, &prev->list);
341 } else
342 list_add_rcu(&va->list, &vmap_area_list);
343}
344
345static void purge_vmap_area_lazy(void);
346
347/*
348 * Allocate a region of KVA of the specified size and alignment, within the
349 * vstart and vend.
350 */
351static struct vmap_area *alloc_vmap_area(unsigned long size,
352 unsigned long align,
353 unsigned long vstart, unsigned long vend,
354 int node, gfp_t gfp_mask)
355{
356 struct vmap_area *va;
357 struct rb_node *n;
358 unsigned long addr;
359 int purged = 0;
360 struct vmap_area *first;
361
362 BUG_ON(!size);
363 BUG_ON(offset_in_page(size));
364 BUG_ON(!is_power_of_2(align));
365
366 va = kmalloc_node(sizeof(struct vmap_area),
367 gfp_mask & GFP_RECLAIM_MASK, node);
368 if (unlikely(!va))
369 return ERR_PTR(-ENOMEM);
370
371 /*
372 * Only scan the relevant parts containing pointers to other objects
373 * to avoid false negatives.
374 */
375 kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask & GFP_RECLAIM_MASK);
376
377retry:
378 spin_lock(&vmap_area_lock);
379 /*
380 * Invalidate cache if we have more permissive parameters.
381 * cached_hole_size notes the largest hole noticed _below_
382 * the vmap_area cached in free_vmap_cache: if size fits
383 * into that hole, we want to scan from vstart to reuse
384 * the hole instead of allocating above free_vmap_cache.
385 * Note that __free_vmap_area may update free_vmap_cache
386 * without updating cached_hole_size or cached_align.
387 */
388 if (!free_vmap_cache ||
389 size < cached_hole_size ||
390 vstart < cached_vstart ||
391 align < cached_align) {
392nocache:
393 cached_hole_size = 0;
394 free_vmap_cache = NULL;
395 }
396 /* record if we encounter less permissive parameters */
397 cached_vstart = vstart;
398 cached_align = align;
399
400 /* find starting point for our search */
401 if (free_vmap_cache) {
402 first = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
403 addr = ALIGN(first->va_end, align);
404 if (addr < vstart)
405 goto nocache;
406 if (addr + size < addr)
407 goto overflow;
408
409 } else {
410 addr = ALIGN(vstart, align);
411 if (addr + size < addr)
412 goto overflow;
413
414 n = vmap_area_root.rb_node;
415 first = NULL;
416
417 while (n) {
418 struct vmap_area *tmp;
419 tmp = rb_entry(n, struct vmap_area, rb_node);
420 if (tmp->va_end >= addr) {
421 first = tmp;
422 if (tmp->va_start <= addr)
423 break;
424 n = n->rb_left;
425 } else
426 n = n->rb_right;
427 }
428
429 if (!first)
430 goto found;
431 }
432
433 /* from the starting point, walk areas until a suitable hole is found */
434 while (addr + size > first->va_start && addr + size <= vend) {
435 if (addr + cached_hole_size < first->va_start)
436 cached_hole_size = first->va_start - addr;
437 addr = ALIGN(first->va_end, align);
438 if (addr + size < addr)
439 goto overflow;
440
441 if (list_is_last(&first->list, &vmap_area_list))
442 goto found;
443
444 first = list_next_entry(first, list);
445 }
446
447found:
448 if (addr + size > vend)
449 goto overflow;
450
451 va->va_start = addr;
452 va->va_end = addr + size;
453 va->flags = 0;
454 __insert_vmap_area(va);
455 free_vmap_cache = &va->rb_node;
456 spin_unlock(&vmap_area_lock);
457
458 BUG_ON(!IS_ALIGNED(va->va_start, align));
459 BUG_ON(va->va_start < vstart);
460 BUG_ON(va->va_end > vend);
461
462 return va;
463
464overflow:
465 spin_unlock(&vmap_area_lock);
466 if (!purged) {
467 purge_vmap_area_lazy();
468 purged = 1;
469 goto retry;
470 }
471 if (printk_ratelimit())
472 pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n",
473 size);
474 kfree(va);
475 return ERR_PTR(-EBUSY);
476}
477
478static void __free_vmap_area(struct vmap_area *va)
479{
480 BUG_ON(RB_EMPTY_NODE(&va->rb_node));
481
482 if (free_vmap_cache) {
483 if (va->va_end < cached_vstart) {
484 free_vmap_cache = NULL;
485 } else {
486 struct vmap_area *cache;
487 cache = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
488 if (va->va_start <= cache->va_start) {
489 free_vmap_cache = rb_prev(&va->rb_node);
490 /*
491 * We don't try to update cached_hole_size or
492 * cached_align, but it won't go very wrong.
493 */
494 }
495 }
496 }
497 rb_erase(&va->rb_node, &vmap_area_root);
498 RB_CLEAR_NODE(&va->rb_node);
499 list_del_rcu(&va->list);
500
501 /*
502 * Track the highest possible candidate for pcpu area
503 * allocation. Areas outside of vmalloc area can be returned
504 * here too, consider only end addresses which fall inside
505 * vmalloc area proper.
506 */
507 if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END)
508 vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end);
509
510 kfree_rcu(va, rcu_head);
511}
512
513/*
514 * Free a region of KVA allocated by alloc_vmap_area
515 */
516static void free_vmap_area(struct vmap_area *va)
517{
518 spin_lock(&vmap_area_lock);
519 __free_vmap_area(va);
520 spin_unlock(&vmap_area_lock);
521}
522
523/*
524 * Clear the pagetable entries of a given vmap_area
525 */
526static void unmap_vmap_area(struct vmap_area *va)
527{
528 vunmap_page_range(va->va_start, va->va_end);
529}
530
531static void vmap_debug_free_range(unsigned long start, unsigned long end)
532{
533 /*
534 * Unmap page tables and force a TLB flush immediately if pagealloc
535 * debugging is enabled. This catches use after free bugs similarly to
536 * those in linear kernel virtual address space after a page has been
537 * freed.
538 *
539 * All the lazy freeing logic is still retained, in order to minimise
540 * intrusiveness of this debugging feature.
541 *
542 * This is going to be *slow* (linear kernel virtual address debugging
543 * doesn't do a broadcast TLB flush so it is a lot faster).
544 */
545 if (debug_pagealloc_enabled()) {
546 vunmap_page_range(start, end);
547 flush_tlb_kernel_range(start, end);
548 }
549}
550
551/*
552 * lazy_max_pages is the maximum amount of virtual address space we gather up
553 * before attempting to purge with a TLB flush.
554 *
555 * There is a tradeoff here: a larger number will cover more kernel page tables
556 * and take slightly longer to purge, but it will linearly reduce the number of
557 * global TLB flushes that must be performed. It would seem natural to scale
558 * this number up linearly with the number of CPUs (because vmapping activity
559 * could also scale linearly with the number of CPUs), however it is likely
560 * that in practice, workloads might be constrained in other ways that mean
561 * vmap activity will not scale linearly with CPUs. Also, I want to be
562 * conservative and not introduce a big latency on huge systems, so go with
563 * a less aggressive log scale. It will still be an improvement over the old
564 * code, and it will be simple to change the scale factor if we find that it
565 * becomes a problem on bigger systems.
566 */
567static unsigned long lazy_max_pages(void)
568{
569 unsigned int log;
570
571 log = fls(num_online_cpus());
572
573 return log * (32UL * 1024 * 1024 / PAGE_SIZE);
574}
575
576static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);
577
578/* for per-CPU blocks */
579static void purge_fragmented_blocks_allcpus(void);
580
581/*
582 * called before a call to iounmap() if the caller wants vm_area_struct's
583 * immediately freed.
584 */
585void set_iounmap_nonlazy(void)
586{
587 atomic_set(&vmap_lazy_nr, lazy_max_pages()+1);
588}
589
590/*
591 * Purges all lazily-freed vmap areas.
592 *
593 * If sync is 0 then don't purge if there is already a purge in progress.
594 * If force_flush is 1, then flush kernel TLBs between *start and *end even
595 * if we found no lazy vmap areas to unmap (callers can use this to optimise
596 * their own TLB flushing).
597 * Returns with *start = min(*start, lowest purged address)
598 * *end = max(*end, highest purged address)
599 */
600static void __purge_vmap_area_lazy(unsigned long *start, unsigned long *end,
601 int sync, int force_flush)
602{
603 static DEFINE_SPINLOCK(purge_lock);
604 LIST_HEAD(valist);
605 struct vmap_area *va;
606 struct vmap_area *n_va;
607 int nr = 0;
608
609 /*
610 * If sync is 0 but force_flush is 1, we'll go sync anyway but callers
611 * should not expect such behaviour. This just simplifies locking for
612 * the case that isn't actually used at the moment anyway.
613 */
614 if (!sync && !force_flush) {
615 if (!spin_trylock(&purge_lock))
616 return;
617 } else
618 spin_lock(&purge_lock);
619
620 if (sync)
621 purge_fragmented_blocks_allcpus();
622
623 rcu_read_lock();
624 list_for_each_entry_rcu(va, &vmap_area_list, list) {
625 if (va->flags & VM_LAZY_FREE) {
626 if (va->va_start < *start)
627 *start = va->va_start;
628 if (va->va_end > *end)
629 *end = va->va_end;
630 nr += (va->va_end - va->va_start) >> PAGE_SHIFT;
631 list_add_tail(&va->purge_list, &valist);
632 va->flags |= VM_LAZY_FREEING;
633 va->flags &= ~VM_LAZY_FREE;
634 }
635 }
636 rcu_read_unlock();
637
638 if (nr)
639 atomic_sub(nr, &vmap_lazy_nr);
640
641 if (nr || force_flush)
642 flush_tlb_kernel_range(*start, *end);
643
644 if (nr) {
645 spin_lock(&vmap_area_lock);
646 list_for_each_entry_safe(va, n_va, &valist, purge_list)
647 __free_vmap_area(va);
648 spin_unlock(&vmap_area_lock);
649 }
650 spin_unlock(&purge_lock);
651}
652
653/*
654 * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
655 * is already purging.
656 */
657static void try_purge_vmap_area_lazy(void)
658{
659 unsigned long start = ULONG_MAX, end = 0;
660
661 __purge_vmap_area_lazy(&start, &end, 0, 0);
662}
663
664/*
665 * Kick off a purge of the outstanding lazy areas.
666 */
667static void purge_vmap_area_lazy(void)
668{
669 unsigned long start = ULONG_MAX, end = 0;
670
671 __purge_vmap_area_lazy(&start, &end, 1, 0);
672}
673
674/*
675 * Free a vmap area, caller ensuring that the area has been unmapped
676 * and flush_cache_vunmap had been called for the correct range
677 * previously.
678 */
679static void free_vmap_area_noflush(struct vmap_area *va)
680{
681 va->flags |= VM_LAZY_FREE;
682 atomic_add((va->va_end - va->va_start) >> PAGE_SHIFT, &vmap_lazy_nr);
683 if (unlikely(atomic_read(&vmap_lazy_nr) > lazy_max_pages()))
684 try_purge_vmap_area_lazy();
685}
686
687/*
688 * Free and unmap a vmap area, caller ensuring flush_cache_vunmap had been
689 * called for the correct range previously.
690 */
691static void free_unmap_vmap_area_noflush(struct vmap_area *va)
692{
693 unmap_vmap_area(va);
694 free_vmap_area_noflush(va);
695}
696
697/*
698 * Free and unmap a vmap area
699 */
700static void free_unmap_vmap_area(struct vmap_area *va)
701{
702 flush_cache_vunmap(va->va_start, va->va_end);
703 free_unmap_vmap_area_noflush(va);
704}
705
706static struct vmap_area *find_vmap_area(unsigned long addr)
707{
708 struct vmap_area *va;
709
710 spin_lock(&vmap_area_lock);
711 va = __find_vmap_area(addr);
712 spin_unlock(&vmap_area_lock);
713
714 return va;
715}
716
717static void free_unmap_vmap_area_addr(unsigned long addr)
718{
719 struct vmap_area *va;
720
721 va = find_vmap_area(addr);
722 BUG_ON(!va);
723 free_unmap_vmap_area(va);
724}
725
726
727/*** Per cpu kva allocator ***/
728
729/*
730 * vmap space is limited especially on 32 bit architectures. Ensure there is
731 * room for at least 16 percpu vmap blocks per CPU.
732 */
733/*
734 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
735 * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess
736 * instead (we just need a rough idea)
737 */
738#if BITS_PER_LONG == 32
739#define VMALLOC_SPACE (128UL*1024*1024)
740#else
741#define VMALLOC_SPACE (128UL*1024*1024*1024)
742#endif
743
744#define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE)
745#define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */
746#define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */
747#define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
748#define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
749#define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
750#define VMAP_BBMAP_BITS \
751 VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
752 VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
753 VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
754
755#define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
756
757static bool vmap_initialized __read_mostly = false;
758
759struct vmap_block_queue {
760 spinlock_t lock;
761 struct list_head free;
762};
763
764struct vmap_block {
765 spinlock_t lock;
766 struct vmap_area *va;
767 unsigned long free, dirty;
768 unsigned long dirty_min, dirty_max; /*< dirty range */
769 struct list_head free_list;
770 struct rcu_head rcu_head;
771 struct list_head purge;
772};
773
774/* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
775static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
776
777/*
778 * Radix tree of vmap blocks, indexed by address, to quickly find a vmap block
779 * in the free path. Could get rid of this if we change the API to return a
780 * "cookie" from alloc, to be passed to free. But no big deal yet.
781 */
782static DEFINE_SPINLOCK(vmap_block_tree_lock);
783static RADIX_TREE(vmap_block_tree, GFP_ATOMIC);
784
785/*
786 * We should probably have a fallback mechanism to allocate virtual memory
787 * out of partially filled vmap blocks. However vmap block sizing should be
788 * fairly reasonable according to the vmalloc size, so it shouldn't be a
789 * big problem.
790 */
791
792static unsigned long addr_to_vb_idx(unsigned long addr)
793{
794 addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
795 addr /= VMAP_BLOCK_SIZE;
796 return addr;
797}
798
799static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off)
800{
801 unsigned long addr;
802
803 addr = va_start + (pages_off << PAGE_SHIFT);
804 BUG_ON(addr_to_vb_idx(addr) != addr_to_vb_idx(va_start));
805 return (void *)addr;
806}
807
808/**
809 * new_vmap_block - allocates new vmap_block and occupies 2^order pages in this
810 * block. Of course pages number can't exceed VMAP_BBMAP_BITS
811 * @order: how many 2^order pages should be occupied in newly allocated block
812 * @gfp_mask: flags for the page level allocator
813 *
814 * Returns: virtual address in a newly allocated block or ERR_PTR(-errno)
815 */
816static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
817{
818 struct vmap_block_queue *vbq;
819 struct vmap_block *vb;
820 struct vmap_area *va;
821 unsigned long vb_idx;
822 int node, err;
823 void *vaddr;
824
825 node = numa_node_id();
826
827 vb = kmalloc_node(sizeof(struct vmap_block),
828 gfp_mask & GFP_RECLAIM_MASK, node);
829 if (unlikely(!vb))
830 return ERR_PTR(-ENOMEM);
831
832 va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
833 VMALLOC_START, VMALLOC_END,
834 node, gfp_mask);
835 if (IS_ERR(va)) {
836 kfree(vb);
837 return ERR_CAST(va);
838 }
839
840 err = radix_tree_preload(gfp_mask);
841 if (unlikely(err)) {
842 kfree(vb);
843 free_vmap_area(va);
844 return ERR_PTR(err);
845 }
846
847 vaddr = vmap_block_vaddr(va->va_start, 0);
848 spin_lock_init(&vb->lock);
849 vb->va = va;
850 /* At least something should be left free */
851 BUG_ON(VMAP_BBMAP_BITS <= (1UL << order));
852 vb->free = VMAP_BBMAP_BITS - (1UL << order);
853 vb->dirty = 0;
854 vb->dirty_min = VMAP_BBMAP_BITS;
855 vb->dirty_max = 0;
856 INIT_LIST_HEAD(&vb->free_list);
857
858 vb_idx = addr_to_vb_idx(va->va_start);
859 spin_lock(&vmap_block_tree_lock);
860 err = radix_tree_insert(&vmap_block_tree, vb_idx, vb);
861 spin_unlock(&vmap_block_tree_lock);
862 BUG_ON(err);
863 radix_tree_preload_end();
864
865 vbq = &get_cpu_var(vmap_block_queue);
866 spin_lock(&vbq->lock);
867 list_add_tail_rcu(&vb->free_list, &vbq->free);
868 spin_unlock(&vbq->lock);
869 put_cpu_var(vmap_block_queue);
870
871 return vaddr;
872}
873
874static void free_vmap_block(struct vmap_block *vb)
875{
876 struct vmap_block *tmp;
877 unsigned long vb_idx;
878
879 vb_idx = addr_to_vb_idx(vb->va->va_start);
880 spin_lock(&vmap_block_tree_lock);
881 tmp = radix_tree_delete(&vmap_block_tree, vb_idx);
882 spin_unlock(&vmap_block_tree_lock);
883 BUG_ON(tmp != vb);
884
885 free_vmap_area_noflush(vb->va);
886 kfree_rcu(vb, rcu_head);
887}
888
889static void purge_fragmented_blocks(int cpu)
890{
891 LIST_HEAD(purge);
892 struct vmap_block *vb;
893 struct vmap_block *n_vb;
894 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
895
896 rcu_read_lock();
897 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
898
899 if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
900 continue;
901
902 spin_lock(&vb->lock);
903 if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
904 vb->free = 0; /* prevent further allocs after releasing lock */
905 vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
906 vb->dirty_min = 0;
907 vb->dirty_max = VMAP_BBMAP_BITS;
908 spin_lock(&vbq->lock);
909 list_del_rcu(&vb->free_list);
910 spin_unlock(&vbq->lock);
911 spin_unlock(&vb->lock);
912 list_add_tail(&vb->purge, &purge);
913 } else
914 spin_unlock(&vb->lock);
915 }
916 rcu_read_unlock();
917
918 list_for_each_entry_safe(vb, n_vb, &purge, purge) {
919 list_del(&vb->purge);
920 free_vmap_block(vb);
921 }
922}
923
924static void purge_fragmented_blocks_allcpus(void)
925{
926 int cpu;
927
928 for_each_possible_cpu(cpu)
929 purge_fragmented_blocks(cpu);
930}
931
932static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
933{
934 struct vmap_block_queue *vbq;
935 struct vmap_block *vb;
936 void *vaddr = NULL;
937 unsigned int order;
938
939 BUG_ON(offset_in_page(size));
940 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
941 if (WARN_ON(size == 0)) {
942 /*
943 * Allocating 0 bytes isn't what caller wants since
944 * get_order(0) returns funny result. Just warn and terminate
945 * early.
946 */
947 return NULL;
948 }
949 order = get_order(size);
950
951 rcu_read_lock();
952 vbq = &get_cpu_var(vmap_block_queue);
953 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
954 unsigned long pages_off;
955
956 spin_lock(&vb->lock);
957 if (vb->free < (1UL << order)) {
958 spin_unlock(&vb->lock);
959 continue;
960 }
961
962 pages_off = VMAP_BBMAP_BITS - vb->free;
963 vaddr = vmap_block_vaddr(vb->va->va_start, pages_off);
964 vb->free -= 1UL << order;
965 if (vb->free == 0) {
966 spin_lock(&vbq->lock);
967 list_del_rcu(&vb->free_list);
968 spin_unlock(&vbq->lock);
969 }
970
971 spin_unlock(&vb->lock);
972 break;
973 }
974
975 put_cpu_var(vmap_block_queue);
976 rcu_read_unlock();
977
978 /* Allocate new block if nothing was found */
979 if (!vaddr)
980 vaddr = new_vmap_block(order, gfp_mask);
981
982 return vaddr;
983}
984
985static void vb_free(const void *addr, unsigned long size)
986{
987 unsigned long offset;
988 unsigned long vb_idx;
989 unsigned int order;
990 struct vmap_block *vb;
991
992 BUG_ON(offset_in_page(size));
993 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
994
995 flush_cache_vunmap((unsigned long)addr, (unsigned long)addr + size);
996
997 order = get_order(size);
998
999 offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1);
1000 offset >>= PAGE_SHIFT;
1001
1002 vb_idx = addr_to_vb_idx((unsigned long)addr);
1003 rcu_read_lock();
1004 vb = radix_tree_lookup(&vmap_block_tree, vb_idx);
1005 rcu_read_unlock();
1006 BUG_ON(!vb);
1007
1008 vunmap_page_range((unsigned long)addr, (unsigned long)addr + size);
1009
1010 spin_lock(&vb->lock);
1011
1012 /* Expand dirty range */
1013 vb->dirty_min = min(vb->dirty_min, offset);
1014 vb->dirty_max = max(vb->dirty_max, offset + (1UL << order));
1015
1016 vb->dirty += 1UL << order;
1017 if (vb->dirty == VMAP_BBMAP_BITS) {
1018 BUG_ON(vb->free);
1019 spin_unlock(&vb->lock);
1020 free_vmap_block(vb);
1021 } else
1022 spin_unlock(&vb->lock);
1023}
1024
1025/**
1026 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
1027 *
1028 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
1029 * to amortize TLB flushing overheads. What this means is that any page you
1030 * have now, may, in a former life, have been mapped into kernel virtual
1031 * address by the vmap layer and so there might be some CPUs with TLB entries
1032 * still referencing that page (additional to the regular 1:1 kernel mapping).
1033 *
1034 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
1035 * be sure that none of the pages we have control over will have any aliases
1036 * from the vmap layer.
1037 */
1038void vm_unmap_aliases(void)
1039{
1040 unsigned long start = ULONG_MAX, end = 0;
1041 int cpu;
1042 int flush = 0;
1043
1044 if (unlikely(!vmap_initialized))
1045 return;
1046
1047 for_each_possible_cpu(cpu) {
1048 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
1049 struct vmap_block *vb;
1050
1051 rcu_read_lock();
1052 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
1053 spin_lock(&vb->lock);
1054 if (vb->dirty) {
1055 unsigned long va_start = vb->va->va_start;
1056 unsigned long s, e;
1057
1058 s = va_start + (vb->dirty_min << PAGE_SHIFT);
1059 e = va_start + (vb->dirty_max << PAGE_SHIFT);
1060
1061 start = min(s, start);
1062 end = max(e, end);
1063
1064 flush = 1;
1065 }
1066 spin_unlock(&vb->lock);
1067 }
1068 rcu_read_unlock();
1069 }
1070
1071 __purge_vmap_area_lazy(&start, &end, 1, flush);
1072}
1073EXPORT_SYMBOL_GPL(vm_unmap_aliases);
1074
1075/**
1076 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
1077 * @mem: the pointer returned by vm_map_ram
1078 * @count: the count passed to that vm_map_ram call (cannot unmap partial)
1079 */
1080void vm_unmap_ram(const void *mem, unsigned int count)
1081{
1082 unsigned long size = count << PAGE_SHIFT;
1083 unsigned long addr = (unsigned long)mem;
1084
1085 BUG_ON(!addr);
1086 BUG_ON(addr < VMALLOC_START);
1087 BUG_ON(addr > VMALLOC_END);
1088 BUG_ON(!PAGE_ALIGNED(addr));
1089
1090 debug_check_no_locks_freed(mem, size);
1091 vmap_debug_free_range(addr, addr+size);
1092
1093 if (likely(count <= VMAP_MAX_ALLOC))
1094 vb_free(mem, size);
1095 else
1096 free_unmap_vmap_area_addr(addr);
1097}
1098EXPORT_SYMBOL(vm_unmap_ram);
1099
1100/**
1101 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
1102 * @pages: an array of pointers to the pages to be mapped
1103 * @count: number of pages
1104 * @node: prefer to allocate data structures on this node
1105 * @prot: memory protection to use. PAGE_KERNEL for regular RAM
1106 *
1107 * If you use this function for less than VMAP_MAX_ALLOC pages, it could be
1108 * faster than vmap so it's good. But if you mix long-life and short-life
1109 * objects with vm_map_ram(), it could consume lots of address space through
1110 * fragmentation (especially on a 32bit machine). You could see failures in
1111 * the end. Please use this function for short-lived objects.
1112 *
1113 * Returns: a pointer to the address that has been mapped, or %NULL on failure
1114 */
1115void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot)
1116{
1117 unsigned long size = count << PAGE_SHIFT;
1118 unsigned long addr;
1119 void *mem;
1120
1121 if (likely(count <= VMAP_MAX_ALLOC)) {
1122 mem = vb_alloc(size, GFP_KERNEL);
1123 if (IS_ERR(mem))
1124 return NULL;
1125 addr = (unsigned long)mem;
1126 } else {
1127 struct vmap_area *va;
1128 va = alloc_vmap_area(size, PAGE_SIZE,
1129 VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
1130 if (IS_ERR(va))
1131 return NULL;
1132
1133 addr = va->va_start;
1134 mem = (void *)addr;
1135 }
1136 if (vmap_page_range(addr, addr + size, prot, pages) < 0) {
1137 vm_unmap_ram(mem, count);
1138 return NULL;
1139 }
1140 return mem;
1141}
1142EXPORT_SYMBOL(vm_map_ram);
1143
1144static struct vm_struct *vmlist __initdata;
1145/**
1146 * vm_area_add_early - add vmap area early during boot
1147 * @vm: vm_struct to add
1148 *
1149 * This function is used to add fixed kernel vm area to vmlist before
1150 * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags
1151 * should contain proper values and the other fields should be zero.
1152 *
1153 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
1154 */
1155void __init vm_area_add_early(struct vm_struct *vm)
1156{
1157 struct vm_struct *tmp, **p;
1158
1159 BUG_ON(vmap_initialized);
1160 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
1161 if (tmp->addr >= vm->addr) {
1162 BUG_ON(tmp->addr < vm->addr + vm->size);
1163 break;
1164 } else
1165 BUG_ON(tmp->addr + tmp->size > vm->addr);
1166 }
1167 vm->next = *p;
1168 *p = vm;
1169}
1170
1171/**
1172 * vm_area_register_early - register vmap area early during boot
1173 * @vm: vm_struct to register
1174 * @align: requested alignment
1175 *
1176 * This function is used to register kernel vm area before
1177 * vmalloc_init() is called. @vm->size and @vm->flags should contain
1178 * proper values on entry and other fields should be zero. On return,
1179 * vm->addr contains the allocated address.
1180 *
1181 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
1182 */
1183void __init vm_area_register_early(struct vm_struct *vm, size_t align)
1184{
1185 static size_t vm_init_off __initdata;
1186 unsigned long addr;
1187
1188 addr = ALIGN(VMALLOC_START + vm_init_off, align);
1189 vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
1190
1191 vm->addr = (void *)addr;
1192
1193 vm_area_add_early(vm);
1194}
1195
1196void __init vmalloc_init(void)
1197{
1198 struct vmap_area *va;
1199 struct vm_struct *tmp;
1200 int i;
1201
1202 for_each_possible_cpu(i) {
1203 struct vmap_block_queue *vbq;
1204 struct vfree_deferred *p;
1205
1206 vbq = &per_cpu(vmap_block_queue, i);
1207 spin_lock_init(&vbq->lock);
1208 INIT_LIST_HEAD(&vbq->free);
1209 p = &per_cpu(vfree_deferred, i);
1210 init_llist_head(&p->list);
1211 INIT_WORK(&p->wq, free_work);
1212 }
1213
1214 /* Import existing vmlist entries. */
1215 for (tmp = vmlist; tmp; tmp = tmp->next) {
1216 va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
1217 va->flags = VM_VM_AREA;
1218 va->va_start = (unsigned long)tmp->addr;
1219 va->va_end = va->va_start + tmp->size;
1220 va->vm = tmp;
1221 __insert_vmap_area(va);
1222 }
1223
1224 vmap_area_pcpu_hole = VMALLOC_END;
1225
1226 vmap_initialized = true;
1227}
1228
1229/**
1230 * map_kernel_range_noflush - map kernel VM area with the specified pages
1231 * @addr: start of the VM area to map
1232 * @size: size of the VM area to map
1233 * @prot: page protection flags to use
1234 * @pages: pages to map
1235 *
1236 * Map PFN_UP(@size) pages at @addr. The VM area @addr and @size
1237 * specify should have been allocated using get_vm_area() and its
1238 * friends.
1239 *
1240 * NOTE:
1241 * This function does NOT do any cache flushing. The caller is
1242 * responsible for calling flush_cache_vmap() on to-be-mapped areas
1243 * before calling this function.
1244 *
1245 * RETURNS:
1246 * The number of pages mapped on success, -errno on failure.
1247 */
1248int map_kernel_range_noflush(unsigned long addr, unsigned long size,
1249 pgprot_t prot, struct page **pages)
1250{
1251 return vmap_page_range_noflush(addr, addr + size, prot, pages);
1252}
1253
1254/**
1255 * unmap_kernel_range_noflush - unmap kernel VM area
1256 * @addr: start of the VM area to unmap
1257 * @size: size of the VM area to unmap
1258 *
1259 * Unmap PFN_UP(@size) pages at @addr. The VM area @addr and @size
1260 * specify should have been allocated using get_vm_area() and its
1261 * friends.
1262 *
1263 * NOTE:
1264 * This function does NOT do any cache flushing. The caller is
1265 * responsible for calling flush_cache_vunmap() on to-be-mapped areas
1266 * before calling this function and flush_tlb_kernel_range() after.
1267 */
1268void unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
1269{
1270 vunmap_page_range(addr, addr + size);
1271}
1272EXPORT_SYMBOL_GPL(unmap_kernel_range_noflush);
1273
1274/**
1275 * unmap_kernel_range - unmap kernel VM area and flush cache and TLB
1276 * @addr: start of the VM area to unmap
1277 * @size: size of the VM area to unmap
1278 *
1279 * Similar to unmap_kernel_range_noflush() but flushes vcache before
1280 * the unmapping and tlb after.
1281 */
1282void unmap_kernel_range(unsigned long addr, unsigned long size)
1283{
1284 unsigned long end = addr + size;
1285
1286 flush_cache_vunmap(addr, end);
1287 vunmap_page_range(addr, end);
1288 flush_tlb_kernel_range(addr, end);
1289}
1290EXPORT_SYMBOL_GPL(unmap_kernel_range);
1291
1292int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page **pages)
1293{
1294 unsigned long addr = (unsigned long)area->addr;
1295 unsigned long end = addr + get_vm_area_size(area);
1296 int err;
1297
1298 err = vmap_page_range(addr, end, prot, pages);
1299
1300 return err > 0 ? 0 : err;
1301}
1302EXPORT_SYMBOL_GPL(map_vm_area);
1303
1304static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
1305 unsigned long flags, const void *caller)
1306{
1307 spin_lock(&vmap_area_lock);
1308 vm->flags = flags;
1309 vm->addr = (void *)va->va_start;
1310 vm->size = va->va_end - va->va_start;
1311 vm->caller = caller;
1312 va->vm = vm;
1313 va->flags |= VM_VM_AREA;
1314 spin_unlock(&vmap_area_lock);
1315}
1316
1317static void clear_vm_uninitialized_flag(struct vm_struct *vm)
1318{
1319 /*
1320 * Before removing VM_UNINITIALIZED,
1321 * we should make sure that vm has proper values.
1322 * Pair with smp_rmb() in show_numa_info().
1323 */
1324 smp_wmb();
1325 vm->flags &= ~VM_UNINITIALIZED;
1326}
1327
1328static struct vm_struct *__get_vm_area_node(unsigned long size,
1329 unsigned long align, unsigned long flags, unsigned long start,
1330 unsigned long end, int node, gfp_t gfp_mask, const void *caller)
1331{
1332 struct vmap_area *va;
1333 struct vm_struct *area;
1334
1335 BUG_ON(in_interrupt());
1336 if (flags & VM_IOREMAP)
1337 align = 1ul << clamp_t(int, fls_long(size),
1338 PAGE_SHIFT, IOREMAP_MAX_ORDER);
1339
1340 size = PAGE_ALIGN(size);
1341 if (unlikely(!size))
1342 return NULL;
1343
1344 area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
1345 if (unlikely(!area))
1346 return NULL;
1347
1348 if (!(flags & VM_NO_GUARD))
1349 size += PAGE_SIZE;
1350
1351 va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
1352 if (IS_ERR(va)) {
1353 kfree(area);
1354 return NULL;
1355 }
1356
1357 setup_vmalloc_vm(area, va, flags, caller);
1358
1359 return area;
1360}
1361
1362struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
1363 unsigned long start, unsigned long end)
1364{
1365 return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE,
1366 GFP_KERNEL, __builtin_return_address(0));
1367}
1368EXPORT_SYMBOL_GPL(__get_vm_area);
1369
1370struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
1371 unsigned long start, unsigned long end,
1372 const void *caller)
1373{
1374 return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE,
1375 GFP_KERNEL, caller);
1376}
1377
1378/**
1379 * get_vm_area - reserve a contiguous kernel virtual area
1380 * @size: size of the area
1381 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC
1382 *
1383 * Search an area of @size in the kernel virtual mapping area,
1384 * and reserved it for out purposes. Returns the area descriptor
1385 * on success or %NULL on failure.
1386 */
1387struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
1388{
1389 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1390 NUMA_NO_NODE, GFP_KERNEL,
1391 __builtin_return_address(0));
1392}
1393
1394struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
1395 const void *caller)
1396{
1397 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1398 NUMA_NO_NODE, GFP_KERNEL, caller);
1399}
1400
1401/**
1402 * find_vm_area - find a continuous kernel virtual area
1403 * @addr: base address
1404 *
1405 * Search for the kernel VM area starting at @addr, and return it.
1406 * It is up to the caller to do all required locking to keep the returned
1407 * pointer valid.
1408 */
1409struct vm_struct *find_vm_area(const void *addr)
1410{
1411 struct vmap_area *va;
1412
1413 va = find_vmap_area((unsigned long)addr);
1414 if (va && va->flags & VM_VM_AREA)
1415 return va->vm;
1416
1417 return NULL;
1418}
1419
1420/**
1421 * remove_vm_area - find and remove a continuous kernel virtual area
1422 * @addr: base address
1423 *
1424 * Search for the kernel VM area starting at @addr, and remove it.
1425 * This function returns the found VM area, but using it is NOT safe
1426 * on SMP machines, except for its size or flags.
1427 */
1428struct vm_struct *remove_vm_area(const void *addr)
1429{
1430 struct vmap_area *va;
1431
1432 va = find_vmap_area((unsigned long)addr);
1433 if (va && va->flags & VM_VM_AREA) {
1434 struct vm_struct *vm = va->vm;
1435
1436 spin_lock(&vmap_area_lock);
1437 va->vm = NULL;
1438 va->flags &= ~VM_VM_AREA;
1439 spin_unlock(&vmap_area_lock);
1440
1441 vmap_debug_free_range(va->va_start, va->va_end);
1442 kasan_free_shadow(vm);
1443 free_unmap_vmap_area(va);
1444
1445 return vm;
1446 }
1447 return NULL;
1448}
1449
1450static void __vunmap(const void *addr, int deallocate_pages)
1451{
1452 struct vm_struct *area;
1453
1454 if (!addr)
1455 return;
1456
1457 if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n",
1458 addr))
1459 return;
1460
1461 area = remove_vm_area(addr);
1462 if (unlikely(!area)) {
1463 WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
1464 addr);
1465 return;
1466 }
1467
1468 debug_check_no_locks_freed(addr, get_vm_area_size(area));
1469 debug_check_no_obj_freed(addr, get_vm_area_size(area));
1470
1471 if (deallocate_pages) {
1472 int i;
1473
1474 for (i = 0; i < area->nr_pages; i++) {
1475 struct page *page = area->pages[i];
1476
1477 BUG_ON(!page);
1478 __free_kmem_pages(page, 0);
1479 }
1480
1481 kvfree(area->pages);
1482 }
1483
1484 kfree(area);
1485 return;
1486}
1487
1488/**
1489 * vfree - release memory allocated by vmalloc()
1490 * @addr: memory base address
1491 *
1492 * Free the virtually continuous memory area starting at @addr, as
1493 * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
1494 * NULL, no operation is performed.
1495 *
1496 * Must not be called in NMI context (strictly speaking, only if we don't
1497 * have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
1498 * conventions for vfree() arch-depenedent would be a really bad idea)
1499 *
1500 * NOTE: assumes that the object at *addr has a size >= sizeof(llist_node)
1501 */
1502void vfree(const void *addr)
1503{
1504 BUG_ON(in_nmi());
1505
1506 kmemleak_free(addr);
1507
1508 if (!addr)
1509 return;
1510 if (unlikely(in_interrupt())) {
1511 struct vfree_deferred *p = this_cpu_ptr(&vfree_deferred);
1512 if (llist_add((struct llist_node *)addr, &p->list))
1513 schedule_work(&p->wq);
1514 } else
1515 __vunmap(addr, 1);
1516}
1517EXPORT_SYMBOL(vfree);
1518
1519/**
1520 * vunmap - release virtual mapping obtained by vmap()
1521 * @addr: memory base address
1522 *
1523 * Free the virtually contiguous memory area starting at @addr,
1524 * which was created from the page array passed to vmap().
1525 *
1526 * Must not be called in interrupt context.
1527 */
1528void vunmap(const void *addr)
1529{
1530 BUG_ON(in_interrupt());
1531 might_sleep();
1532 if (addr)
1533 __vunmap(addr, 0);
1534}
1535EXPORT_SYMBOL(vunmap);
1536
1537/**
1538 * vmap - map an array of pages into virtually contiguous space
1539 * @pages: array of page pointers
1540 * @count: number of pages to map
1541 * @flags: vm_area->flags
1542 * @prot: page protection for the mapping
1543 *
1544 * Maps @count pages from @pages into contiguous kernel virtual
1545 * space.
1546 */
1547void *vmap(struct page **pages, unsigned int count,
1548 unsigned long flags, pgprot_t prot)
1549{
1550 struct vm_struct *area;
1551
1552 might_sleep();
1553
1554 if (count > totalram_pages)
1555 return NULL;
1556
1557 area = get_vm_area_caller((count << PAGE_SHIFT), flags,
1558 __builtin_return_address(0));
1559 if (!area)
1560 return NULL;
1561
1562 if (map_vm_area(area, prot, pages)) {
1563 vunmap(area->addr);
1564 return NULL;
1565 }
1566
1567 return area->addr;
1568}
1569EXPORT_SYMBOL(vmap);
1570
1571static void *__vmalloc_node(unsigned long size, unsigned long align,
1572 gfp_t gfp_mask, pgprot_t prot,
1573 int node, const void *caller);
1574static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
1575 pgprot_t prot, int node)
1576{
1577 const int order = 0;
1578 struct page **pages;
1579 unsigned int nr_pages, array_size, i;
1580 const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
1581 const gfp_t alloc_mask = gfp_mask | __GFP_NOWARN;
1582
1583 nr_pages = get_vm_area_size(area) >> PAGE_SHIFT;
1584 array_size = (nr_pages * sizeof(struct page *));
1585
1586 area->nr_pages = nr_pages;
1587 /* Please note that the recursion is strictly bounded. */
1588 if (array_size > PAGE_SIZE) {
1589 pages = __vmalloc_node(array_size, 1, nested_gfp|__GFP_HIGHMEM,
1590 PAGE_KERNEL, node, area->caller);
1591 } else {
1592 pages = kmalloc_node(array_size, nested_gfp, node);
1593 }
1594 area->pages = pages;
1595 if (!area->pages) {
1596 remove_vm_area(area->addr);
1597 kfree(area);
1598 return NULL;
1599 }
1600
1601 for (i = 0; i < area->nr_pages; i++) {
1602 struct page *page;
1603
1604 if (node == NUMA_NO_NODE)
1605 page = alloc_kmem_pages(alloc_mask, order);
1606 else
1607 page = alloc_kmem_pages_node(node, alloc_mask, order);
1608
1609 if (unlikely(!page)) {
1610 /* Successfully allocated i pages, free them in __vunmap() */
1611 area->nr_pages = i;
1612 goto fail;
1613 }
1614 area->pages[i] = page;
1615 if (gfpflags_allow_blocking(gfp_mask))
1616 cond_resched();
1617 }
1618
1619 if (map_vm_area(area, prot, pages))
1620 goto fail;
1621 return area->addr;
1622
1623fail:
1624 warn_alloc_failed(gfp_mask, order,
1625 "vmalloc: allocation failure, allocated %ld of %ld bytes\n",
1626 (area->nr_pages*PAGE_SIZE), area->size);
1627 vfree(area->addr);
1628 return NULL;
1629}
1630
1631/**
1632 * __vmalloc_node_range - allocate virtually contiguous memory
1633 * @size: allocation size
1634 * @align: desired alignment
1635 * @start: vm area range start
1636 * @end: vm area range end
1637 * @gfp_mask: flags for the page level allocator
1638 * @prot: protection mask for the allocated pages
1639 * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD)
1640 * @node: node to use for allocation or NUMA_NO_NODE
1641 * @caller: caller's return address
1642 *
1643 * Allocate enough pages to cover @size from the page level
1644 * allocator with @gfp_mask flags. Map them into contiguous
1645 * kernel virtual space, using a pagetable protection of @prot.
1646 */
1647void *__vmalloc_node_range(unsigned long size, unsigned long align,
1648 unsigned long start, unsigned long end, gfp_t gfp_mask,
1649 pgprot_t prot, unsigned long vm_flags, int node,
1650 const void *caller)
1651{
1652 struct vm_struct *area;
1653 void *addr;
1654 unsigned long real_size = size;
1655
1656 size = PAGE_ALIGN(size);
1657 if (!size || (size >> PAGE_SHIFT) > totalram_pages)
1658 goto fail;
1659
1660 area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNINITIALIZED |
1661 vm_flags, start, end, node, gfp_mask, caller);
1662 if (!area)
1663 goto fail;
1664
1665 addr = __vmalloc_area_node(area, gfp_mask, prot, node);
1666 if (!addr)
1667 return NULL;
1668
1669 /*
1670 * In this function, newly allocated vm_struct has VM_UNINITIALIZED
1671 * flag. It means that vm_struct is not fully initialized.
1672 * Now, it is fully initialized, so remove this flag here.
1673 */
1674 clear_vm_uninitialized_flag(area);
1675
1676 /*
1677 * A ref_count = 2 is needed because vm_struct allocated in
1678 * __get_vm_area_node() contains a reference to the virtual address of
1679 * the vmalloc'ed block.
1680 */
1681 kmemleak_alloc(addr, real_size, 2, gfp_mask);
1682
1683 return addr;
1684
1685fail:
1686 warn_alloc_failed(gfp_mask, 0,
1687 "vmalloc: allocation failure: %lu bytes\n",
1688 real_size);
1689 return NULL;
1690}
1691
1692/**
1693 * __vmalloc_node - allocate virtually contiguous memory
1694 * @size: allocation size
1695 * @align: desired alignment
1696 * @gfp_mask: flags for the page level allocator
1697 * @prot: protection mask for the allocated pages
1698 * @node: node to use for allocation or NUMA_NO_NODE
1699 * @caller: caller's return address
1700 *
1701 * Allocate enough pages to cover @size from the page level
1702 * allocator with @gfp_mask flags. Map them into contiguous
1703 * kernel virtual space, using a pagetable protection of @prot.
1704 */
1705static void *__vmalloc_node(unsigned long size, unsigned long align,
1706 gfp_t gfp_mask, pgprot_t prot,
1707 int node, const void *caller)
1708{
1709 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
1710 gfp_mask, prot, 0, node, caller);
1711}
1712
1713void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
1714{
1715 return __vmalloc_node(size, 1, gfp_mask, prot, NUMA_NO_NODE,
1716 __builtin_return_address(0));
1717}
1718EXPORT_SYMBOL(__vmalloc);
1719
1720static inline void *__vmalloc_node_flags(unsigned long size,
1721 int node, gfp_t flags)
1722{
1723 return __vmalloc_node(size, 1, flags, PAGE_KERNEL,
1724 node, __builtin_return_address(0));
1725}
1726
1727/**
1728 * vmalloc - allocate virtually contiguous memory
1729 * @size: allocation size
1730 * Allocate enough pages to cover @size from the page level
1731 * allocator and map them into contiguous kernel virtual space.
1732 *
1733 * For tight control over page level allocator and protection flags
1734 * use __vmalloc() instead.
1735 */
1736void *vmalloc(unsigned long size)
1737{
1738 return __vmalloc_node_flags(size, NUMA_NO_NODE,
1739 GFP_KERNEL | __GFP_HIGHMEM);
1740}
1741EXPORT_SYMBOL(vmalloc);
1742
1743/**
1744 * vzalloc - allocate virtually contiguous memory with zero fill
1745 * @size: allocation size
1746 * Allocate enough pages to cover @size from the page level
1747 * allocator and map them into contiguous kernel virtual space.
1748 * The memory allocated is set to zero.
1749 *
1750 * For tight control over page level allocator and protection flags
1751 * use __vmalloc() instead.
1752 */
1753void *vzalloc(unsigned long size)
1754{
1755 return __vmalloc_node_flags(size, NUMA_NO_NODE,
1756 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
1757}
1758EXPORT_SYMBOL(vzalloc);
1759
1760/**
1761 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
1762 * @size: allocation size
1763 *
1764 * The resulting memory area is zeroed so it can be mapped to userspace
1765 * without leaking data.
1766 */
1767void *vmalloc_user(unsigned long size)
1768{
1769 struct vm_struct *area;
1770 void *ret;
1771
1772 ret = __vmalloc_node(size, SHMLBA,
1773 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
1774 PAGE_KERNEL, NUMA_NO_NODE,
1775 __builtin_return_address(0));
1776 if (ret) {
1777 area = find_vm_area(ret);
1778 area->flags |= VM_USERMAP;
1779 }
1780 return ret;
1781}
1782EXPORT_SYMBOL(vmalloc_user);
1783
1784/**
1785 * vmalloc_node - allocate memory on a specific node
1786 * @size: allocation size
1787 * @node: numa node
1788 *
1789 * Allocate enough pages to cover @size from the page level
1790 * allocator and map them into contiguous kernel virtual space.
1791 *
1792 * For tight control over page level allocator and protection flags
1793 * use __vmalloc() instead.
1794 */
1795void *vmalloc_node(unsigned long size, int node)
1796{
1797 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
1798 node, __builtin_return_address(0));
1799}
1800EXPORT_SYMBOL(vmalloc_node);
1801
1802/**
1803 * vzalloc_node - allocate memory on a specific node with zero fill
1804 * @size: allocation size
1805 * @node: numa node
1806 *
1807 * Allocate enough pages to cover @size from the page level
1808 * allocator and map them into contiguous kernel virtual space.
1809 * The memory allocated is set to zero.
1810 *
1811 * For tight control over page level allocator and protection flags
1812 * use __vmalloc_node() instead.
1813 */
1814void *vzalloc_node(unsigned long size, int node)
1815{
1816 return __vmalloc_node_flags(size, node,
1817 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
1818}
1819EXPORT_SYMBOL(vzalloc_node);
1820
1821#ifndef PAGE_KERNEL_EXEC
1822# define PAGE_KERNEL_EXEC PAGE_KERNEL
1823#endif
1824
1825/**
1826 * vmalloc_exec - allocate virtually contiguous, executable memory
1827 * @size: allocation size
1828 *
1829 * Kernel-internal function to allocate enough pages to cover @size
1830 * the page level allocator and map them into contiguous and
1831 * executable kernel virtual space.
1832 *
1833 * For tight control over page level allocator and protection flags
1834 * use __vmalloc() instead.
1835 */
1836
1837void *vmalloc_exec(unsigned long size)
1838{
1839 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
1840 NUMA_NO_NODE, __builtin_return_address(0));
1841}
1842
1843#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
1844#define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
1845#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
1846#define GFP_VMALLOC32 GFP_DMA | GFP_KERNEL
1847#else
1848#define GFP_VMALLOC32 GFP_KERNEL
1849#endif
1850
1851/**
1852 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
1853 * @size: allocation size
1854 *
1855 * Allocate enough 32bit PA addressable pages to cover @size from the
1856 * page level allocator and map them into contiguous kernel virtual space.
1857 */
1858void *vmalloc_32(unsigned long size)
1859{
1860 return __vmalloc_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL,
1861 NUMA_NO_NODE, __builtin_return_address(0));
1862}
1863EXPORT_SYMBOL(vmalloc_32);
1864
1865/**
1866 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
1867 * @size: allocation size
1868 *
1869 * The resulting memory area is 32bit addressable and zeroed so it can be
1870 * mapped to userspace without leaking data.
1871 */
1872void *vmalloc_32_user(unsigned long size)
1873{
1874 struct vm_struct *area;
1875 void *ret;
1876
1877 ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
1878 NUMA_NO_NODE, __builtin_return_address(0));
1879 if (ret) {
1880 area = find_vm_area(ret);
1881 area->flags |= VM_USERMAP;
1882 }
1883 return ret;
1884}
1885EXPORT_SYMBOL(vmalloc_32_user);
1886
1887/*
1888 * small helper routine , copy contents to buf from addr.
1889 * If the page is not present, fill zero.
1890 */
1891
1892static int aligned_vread(char *buf, char *addr, unsigned long count)
1893{
1894 struct page *p;
1895 int copied = 0;
1896
1897 while (count) {
1898 unsigned long offset, length;
1899
1900 offset = offset_in_page(addr);
1901 length = PAGE_SIZE - offset;
1902 if (length > count)
1903 length = count;
1904 p = vmalloc_to_page(addr);
1905 /*
1906 * To do safe access to this _mapped_ area, we need
1907 * lock. But adding lock here means that we need to add
1908 * overhead of vmalloc()/vfree() calles for this _debug_
1909 * interface, rarely used. Instead of that, we'll use
1910 * kmap() and get small overhead in this access function.
1911 */
1912 if (p) {
1913 /*
1914 * we can expect USER0 is not used (see vread/vwrite's
1915 * function description)
1916 */
1917 void *map = kmap_atomic(p);
1918 memcpy(buf, map + offset, length);
1919 kunmap_atomic(map);
1920 } else
1921 memset(buf, 0, length);
1922
1923 addr += length;
1924 buf += length;
1925 copied += length;
1926 count -= length;
1927 }
1928 return copied;
1929}
1930
1931static int aligned_vwrite(char *buf, char *addr, unsigned long count)
1932{
1933 struct page *p;
1934 int copied = 0;
1935
1936 while (count) {
1937 unsigned long offset, length;
1938
1939 offset = offset_in_page(addr);
1940 length = PAGE_SIZE - offset;
1941 if (length > count)
1942 length = count;
1943 p = vmalloc_to_page(addr);
1944 /*
1945 * To do safe access to this _mapped_ area, we need
1946 * lock. But adding lock here means that we need to add
1947 * overhead of vmalloc()/vfree() calles for this _debug_
1948 * interface, rarely used. Instead of that, we'll use
1949 * kmap() and get small overhead in this access function.
1950 */
1951 if (p) {
1952 /*
1953 * we can expect USER0 is not used (see vread/vwrite's
1954 * function description)
1955 */
1956 void *map = kmap_atomic(p);
1957 memcpy(map + offset, buf, length);
1958 kunmap_atomic(map);
1959 }
1960 addr += length;
1961 buf += length;
1962 copied += length;
1963 count -= length;
1964 }
1965 return copied;
1966}
1967
1968/**
1969 * vread() - read vmalloc area in a safe way.
1970 * @buf: buffer for reading data
1971 * @addr: vm address.
1972 * @count: number of bytes to be read.
1973 *
1974 * Returns # of bytes which addr and buf should be increased.
1975 * (same number to @count). Returns 0 if [addr...addr+count) doesn't
1976 * includes any intersect with alive vmalloc area.
1977 *
1978 * This function checks that addr is a valid vmalloc'ed area, and
1979 * copy data from that area to a given buffer. If the given memory range
1980 * of [addr...addr+count) includes some valid address, data is copied to
1981 * proper area of @buf. If there are memory holes, they'll be zero-filled.
1982 * IOREMAP area is treated as memory hole and no copy is done.
1983 *
1984 * If [addr...addr+count) doesn't includes any intersects with alive
1985 * vm_struct area, returns 0. @buf should be kernel's buffer.
1986 *
1987 * Note: In usual ops, vread() is never necessary because the caller
1988 * should know vmalloc() area is valid and can use memcpy().
1989 * This is for routines which have to access vmalloc area without
1990 * any informaion, as /dev/kmem.
1991 *
1992 */
1993
1994long vread(char *buf, char *addr, unsigned long count)
1995{
1996 struct vmap_area *va;
1997 struct vm_struct *vm;
1998 char *vaddr, *buf_start = buf;
1999 unsigned long buflen = count;
2000 unsigned long n;
2001
2002 /* Don't allow overflow */
2003 if ((unsigned long) addr + count < count)
2004 count = -(unsigned long) addr;
2005
2006 spin_lock(&vmap_area_lock);
2007 list_for_each_entry(va, &vmap_area_list, list) {
2008 if (!count)
2009 break;
2010
2011 if (!(va->flags & VM_VM_AREA))
2012 continue;
2013
2014 vm = va->vm;
2015 vaddr = (char *) vm->addr;
2016 if (addr >= vaddr + get_vm_area_size(vm))
2017 continue;
2018 while (addr < vaddr) {
2019 if (count == 0)
2020 goto finished;
2021 *buf = '\0';
2022 buf++;
2023 addr++;
2024 count--;
2025 }
2026 n = vaddr + get_vm_area_size(vm) - addr;
2027 if (n > count)
2028 n = count;
2029 if (!(vm->flags & VM_IOREMAP))
2030 aligned_vread(buf, addr, n);
2031 else /* IOREMAP area is treated as memory hole */
2032 memset(buf, 0, n);
2033 buf += n;
2034 addr += n;
2035 count -= n;
2036 }
2037finished:
2038 spin_unlock(&vmap_area_lock);
2039
2040 if (buf == buf_start)
2041 return 0;
2042 /* zero-fill memory holes */
2043 if (buf != buf_start + buflen)
2044 memset(buf, 0, buflen - (buf - buf_start));
2045
2046 return buflen;
2047}
2048
2049/**
2050 * vwrite() - write vmalloc area in a safe way.
2051 * @buf: buffer for source data
2052 * @addr: vm address.
2053 * @count: number of bytes to be read.
2054 *
2055 * Returns # of bytes which addr and buf should be incresed.
2056 * (same number to @count).
2057 * If [addr...addr+count) doesn't includes any intersect with valid
2058 * vmalloc area, returns 0.
2059 *
2060 * This function checks that addr is a valid vmalloc'ed area, and
2061 * copy data from a buffer to the given addr. If specified range of
2062 * [addr...addr+count) includes some valid address, data is copied from
2063 * proper area of @buf. If there are memory holes, no copy to hole.
2064 * IOREMAP area is treated as memory hole and no copy is done.
2065 *
2066 * If [addr...addr+count) doesn't includes any intersects with alive
2067 * vm_struct area, returns 0. @buf should be kernel's buffer.
2068 *
2069 * Note: In usual ops, vwrite() is never necessary because the caller
2070 * should know vmalloc() area is valid and can use memcpy().
2071 * This is for routines which have to access vmalloc area without
2072 * any informaion, as /dev/kmem.
2073 */
2074
2075long vwrite(char *buf, char *addr, unsigned long count)
2076{
2077 struct vmap_area *va;
2078 struct vm_struct *vm;
2079 char *vaddr;
2080 unsigned long n, buflen;
2081 int copied = 0;
2082
2083 /* Don't allow overflow */
2084 if ((unsigned long) addr + count < count)
2085 count = -(unsigned long) addr;
2086 buflen = count;
2087
2088 spin_lock(&vmap_area_lock);
2089 list_for_each_entry(va, &vmap_area_list, list) {
2090 if (!count)
2091 break;
2092
2093 if (!(va->flags & VM_VM_AREA))
2094 continue;
2095
2096 vm = va->vm;
2097 vaddr = (char *) vm->addr;
2098 if (addr >= vaddr + get_vm_area_size(vm))
2099 continue;
2100 while (addr < vaddr) {
2101 if (count == 0)
2102 goto finished;
2103 buf++;
2104 addr++;
2105 count--;
2106 }
2107 n = vaddr + get_vm_area_size(vm) - addr;
2108 if (n > count)
2109 n = count;
2110 if (!(vm->flags & VM_IOREMAP)) {
2111 aligned_vwrite(buf, addr, n);
2112 copied++;
2113 }
2114 buf += n;
2115 addr += n;
2116 count -= n;
2117 }
2118finished:
2119 spin_unlock(&vmap_area_lock);
2120 if (!copied)
2121 return 0;
2122 return buflen;
2123}
2124
2125/**
2126 * remap_vmalloc_range_partial - map vmalloc pages to userspace
2127 * @vma: vma to cover
2128 * @uaddr: target user address to start at
2129 * @kaddr: virtual address of vmalloc kernel memory
2130 * @size: size of map area
2131 *
2132 * Returns: 0 for success, -Exxx on failure
2133 *
2134 * This function checks that @kaddr is a valid vmalloc'ed area,
2135 * and that it is big enough to cover the range starting at
2136 * @uaddr in @vma. Will return failure if that criteria isn't
2137 * met.
2138 *
2139 * Similar to remap_pfn_range() (see mm/memory.c)
2140 */
2141int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr,
2142 void *kaddr, unsigned long size)
2143{
2144 struct vm_struct *area;
2145
2146 size = PAGE_ALIGN(size);
2147
2148 if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr))
2149 return -EINVAL;
2150
2151 area = find_vm_area(kaddr);
2152 if (!area)
2153 return -EINVAL;
2154
2155 if (!(area->flags & VM_USERMAP))
2156 return -EINVAL;
2157
2158 if (kaddr + size > area->addr + area->size)
2159 return -EINVAL;
2160
2161 do {
2162 struct page *page = vmalloc_to_page(kaddr);
2163 int ret;
2164
2165 ret = vm_insert_page(vma, uaddr, page);
2166 if (ret)
2167 return ret;
2168
2169 uaddr += PAGE_SIZE;
2170 kaddr += PAGE_SIZE;
2171 size -= PAGE_SIZE;
2172 } while (size > 0);
2173
2174 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
2175
2176 return 0;
2177}
2178EXPORT_SYMBOL(remap_vmalloc_range_partial);
2179
2180/**
2181 * remap_vmalloc_range - map vmalloc pages to userspace
2182 * @vma: vma to cover (map full range of vma)
2183 * @addr: vmalloc memory
2184 * @pgoff: number of pages into addr before first page to map
2185 *
2186 * Returns: 0 for success, -Exxx on failure
2187 *
2188 * This function checks that addr is a valid vmalloc'ed area, and
2189 * that it is big enough to cover the vma. Will return failure if
2190 * that criteria isn't met.
2191 *
2192 * Similar to remap_pfn_range() (see mm/memory.c)
2193 */
2194int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
2195 unsigned long pgoff)
2196{
2197 return remap_vmalloc_range_partial(vma, vma->vm_start,
2198 addr + (pgoff << PAGE_SHIFT),
2199 vma->vm_end - vma->vm_start);
2200}
2201EXPORT_SYMBOL(remap_vmalloc_range);
2202
2203/*
2204 * Implement a stub for vmalloc_sync_all() if the architecture chose not to
2205 * have one.
2206 */
2207void __weak vmalloc_sync_all(void)
2208{
2209}
2210
2211
2212static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
2213{
2214 pte_t ***p = data;
2215
2216 if (p) {
2217 *(*p) = pte;
2218 (*p)++;
2219 }
2220 return 0;
2221}
2222
2223/**
2224 * alloc_vm_area - allocate a range of kernel address space
2225 * @size: size of the area
2226 * @ptes: returns the PTEs for the address space
2227 *
2228 * Returns: NULL on failure, vm_struct on success
2229 *
2230 * This function reserves a range of kernel address space, and
2231 * allocates pagetables to map that range. No actual mappings
2232 * are created.
2233 *
2234 * If @ptes is non-NULL, pointers to the PTEs (in init_mm)
2235 * allocated for the VM area are returned.
2236 */
2237struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes)
2238{
2239 struct vm_struct *area;
2240
2241 area = get_vm_area_caller(size, VM_IOREMAP,
2242 __builtin_return_address(0));
2243 if (area == NULL)
2244 return NULL;
2245
2246 /*
2247 * This ensures that page tables are constructed for this region
2248 * of kernel virtual address space and mapped into init_mm.
2249 */
2250 if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
2251 size, f, ptes ? &ptes : NULL)) {
2252 free_vm_area(area);
2253 return NULL;
2254 }
2255
2256 return area;
2257}
2258EXPORT_SYMBOL_GPL(alloc_vm_area);
2259
2260void free_vm_area(struct vm_struct *area)
2261{
2262 struct vm_struct *ret;
2263 ret = remove_vm_area(area->addr);
2264 BUG_ON(ret != area);
2265 kfree(area);
2266}
2267EXPORT_SYMBOL_GPL(free_vm_area);
2268
2269#ifdef CONFIG_SMP
2270static struct vmap_area *node_to_va(struct rb_node *n)
2271{
2272 return n ? rb_entry(n, struct vmap_area, rb_node) : NULL;
2273}
2274
2275/**
2276 * pvm_find_next_prev - find the next and prev vmap_area surrounding @end
2277 * @end: target address
2278 * @pnext: out arg for the next vmap_area
2279 * @pprev: out arg for the previous vmap_area
2280 *
2281 * Returns: %true if either or both of next and prev are found,
2282 * %false if no vmap_area exists
2283 *
2284 * Find vmap_areas end addresses of which enclose @end. ie. if not
2285 * NULL, *pnext->va_end > @end and *pprev->va_end <= @end.
2286 */
2287static bool pvm_find_next_prev(unsigned long end,
2288 struct vmap_area **pnext,
2289 struct vmap_area **pprev)
2290{
2291 struct rb_node *n = vmap_area_root.rb_node;
2292 struct vmap_area *va = NULL;
2293
2294 while (n) {
2295 va = rb_entry(n, struct vmap_area, rb_node);
2296 if (end < va->va_end)
2297 n = n->rb_left;
2298 else if (end > va->va_end)
2299 n = n->rb_right;
2300 else
2301 break;
2302 }
2303
2304 if (!va)
2305 return false;
2306
2307 if (va->va_end > end) {
2308 *pnext = va;
2309 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2310 } else {
2311 *pprev = va;
2312 *pnext = node_to_va(rb_next(&(*pprev)->rb_node));
2313 }
2314 return true;
2315}
2316
2317/**
2318 * pvm_determine_end - find the highest aligned address between two vmap_areas
2319 * @pnext: in/out arg for the next vmap_area
2320 * @pprev: in/out arg for the previous vmap_area
2321 * @align: alignment
2322 *
2323 * Returns: determined end address
2324 *
2325 * Find the highest aligned address between *@pnext and *@pprev below
2326 * VMALLOC_END. *@pnext and *@pprev are adjusted so that the aligned
2327 * down address is between the end addresses of the two vmap_areas.
2328 *
2329 * Please note that the address returned by this function may fall
2330 * inside *@pnext vmap_area. The caller is responsible for checking
2331 * that.
2332 */
2333static unsigned long pvm_determine_end(struct vmap_area **pnext,
2334 struct vmap_area **pprev,
2335 unsigned long align)
2336{
2337 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2338 unsigned long addr;
2339
2340 if (*pnext)
2341 addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end);
2342 else
2343 addr = vmalloc_end;
2344
2345 while (*pprev && (*pprev)->va_end > addr) {
2346 *pnext = *pprev;
2347 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2348 }
2349
2350 return addr;
2351}
2352
2353/**
2354 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
2355 * @offsets: array containing offset of each area
2356 * @sizes: array containing size of each area
2357 * @nr_vms: the number of areas to allocate
2358 * @align: alignment, all entries in @offsets and @sizes must be aligned to this
2359 *
2360 * Returns: kmalloc'd vm_struct pointer array pointing to allocated
2361 * vm_structs on success, %NULL on failure
2362 *
2363 * Percpu allocator wants to use congruent vm areas so that it can
2364 * maintain the offsets among percpu areas. This function allocates
2365 * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to
2366 * be scattered pretty far, distance between two areas easily going up
2367 * to gigabytes. To avoid interacting with regular vmallocs, these
2368 * areas are allocated from top.
2369 *
2370 * Despite its complicated look, this allocator is rather simple. It
2371 * does everything top-down and scans areas from the end looking for
2372 * matching slot. While scanning, if any of the areas overlaps with
2373 * existing vmap_area, the base address is pulled down to fit the
2374 * area. Scanning is repeated till all the areas fit and then all
2375 * necessary data structres are inserted and the result is returned.
2376 */
2377struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
2378 const size_t *sizes, int nr_vms,
2379 size_t align)
2380{
2381 const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
2382 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2383 struct vmap_area **vas, *prev, *next;
2384 struct vm_struct **vms;
2385 int area, area2, last_area, term_area;
2386 unsigned long base, start, end, last_end;
2387 bool purged = false;
2388
2389 /* verify parameters and allocate data structures */
2390 BUG_ON(offset_in_page(align) || !is_power_of_2(align));
2391 for (last_area = 0, area = 0; area < nr_vms; area++) {
2392 start = offsets[area];
2393 end = start + sizes[area];
2394
2395 /* is everything aligned properly? */
2396 BUG_ON(!IS_ALIGNED(offsets[area], align));
2397 BUG_ON(!IS_ALIGNED(sizes[area], align));
2398
2399 /* detect the area with the highest address */
2400 if (start > offsets[last_area])
2401 last_area = area;
2402
2403 for (area2 = 0; area2 < nr_vms; area2++) {
2404 unsigned long start2 = offsets[area2];
2405 unsigned long end2 = start2 + sizes[area2];
2406
2407 if (area2 == area)
2408 continue;
2409
2410 BUG_ON(start2 >= start && start2 < end);
2411 BUG_ON(end2 <= end && end2 > start);
2412 }
2413 }
2414 last_end = offsets[last_area] + sizes[last_area];
2415
2416 if (vmalloc_end - vmalloc_start < last_end) {
2417 WARN_ON(true);
2418 return NULL;
2419 }
2420
2421 vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL);
2422 vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL);
2423 if (!vas || !vms)
2424 goto err_free2;
2425
2426 for (area = 0; area < nr_vms; area++) {
2427 vas[area] = kzalloc(sizeof(struct vmap_area), GFP_KERNEL);
2428 vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
2429 if (!vas[area] || !vms[area])
2430 goto err_free;
2431 }
2432retry:
2433 spin_lock(&vmap_area_lock);
2434
2435 /* start scanning - we scan from the top, begin with the last area */
2436 area = term_area = last_area;
2437 start = offsets[area];
2438 end = start + sizes[area];
2439
2440 if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) {
2441 base = vmalloc_end - last_end;
2442 goto found;
2443 }
2444 base = pvm_determine_end(&next, &prev, align) - end;
2445
2446 while (true) {
2447 BUG_ON(next && next->va_end <= base + end);
2448 BUG_ON(prev && prev->va_end > base + end);
2449
2450 /*
2451 * base might have underflowed, add last_end before
2452 * comparing.
2453 */
2454 if (base + last_end < vmalloc_start + last_end) {
2455 spin_unlock(&vmap_area_lock);
2456 if (!purged) {
2457 purge_vmap_area_lazy();
2458 purged = true;
2459 goto retry;
2460 }
2461 goto err_free;
2462 }
2463
2464 /*
2465 * If next overlaps, move base downwards so that it's
2466 * right below next and then recheck.
2467 */
2468 if (next && next->va_start < base + end) {
2469 base = pvm_determine_end(&next, &prev, align) - end;
2470 term_area = area;
2471 continue;
2472 }
2473
2474 /*
2475 * If prev overlaps, shift down next and prev and move
2476 * base so that it's right below new next and then
2477 * recheck.
2478 */
2479 if (prev && prev->va_end > base + start) {
2480 next = prev;
2481 prev = node_to_va(rb_prev(&next->rb_node));
2482 base = pvm_determine_end(&next, &prev, align) - end;
2483 term_area = area;
2484 continue;
2485 }
2486
2487 /*
2488 * This area fits, move on to the previous one. If
2489 * the previous one is the terminal one, we're done.
2490 */
2491 area = (area + nr_vms - 1) % nr_vms;
2492 if (area == term_area)
2493 break;
2494 start = offsets[area];
2495 end = start + sizes[area];
2496 pvm_find_next_prev(base + end, &next, &prev);
2497 }
2498found:
2499 /* we've found a fitting base, insert all va's */
2500 for (area = 0; area < nr_vms; area++) {
2501 struct vmap_area *va = vas[area];
2502
2503 va->va_start = base + offsets[area];
2504 va->va_end = va->va_start + sizes[area];
2505 __insert_vmap_area(va);
2506 }
2507
2508 vmap_area_pcpu_hole = base + offsets[last_area];
2509
2510 spin_unlock(&vmap_area_lock);
2511
2512 /* insert all vm's */
2513 for (area = 0; area < nr_vms; area++)
2514 setup_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
2515 pcpu_get_vm_areas);
2516
2517 kfree(vas);
2518 return vms;
2519
2520err_free:
2521 for (area = 0; area < nr_vms; area++) {
2522 kfree(vas[area]);
2523 kfree(vms[area]);
2524 }
2525err_free2:
2526 kfree(vas);
2527 kfree(vms);
2528 return NULL;
2529}
2530
2531/**
2532 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
2533 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
2534 * @nr_vms: the number of allocated areas
2535 *
2536 * Free vm_structs and the array allocated by pcpu_get_vm_areas().
2537 */
2538void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
2539{
2540 int i;
2541
2542 for (i = 0; i < nr_vms; i++)
2543 free_vm_area(vms[i]);
2544 kfree(vms);
2545}
2546#endif /* CONFIG_SMP */
2547
2548#ifdef CONFIG_PROC_FS
2549static void *s_start(struct seq_file *m, loff_t *pos)
2550 __acquires(&vmap_area_lock)
2551{
2552 loff_t n = *pos;
2553 struct vmap_area *va;
2554
2555 spin_lock(&vmap_area_lock);
2556 va = list_first_entry(&vmap_area_list, typeof(*va), list);
2557 while (n > 0 && &va->list != &vmap_area_list) {
2558 n--;
2559 va = list_next_entry(va, list);
2560 }
2561 if (!n && &va->list != &vmap_area_list)
2562 return va;
2563
2564 return NULL;
2565
2566}
2567
2568static void *s_next(struct seq_file *m, void *p, loff_t *pos)
2569{
2570 struct vmap_area *va = p, *next;
2571
2572 ++*pos;
2573 next = list_next_entry(va, list);
2574 if (&next->list != &vmap_area_list)
2575 return next;
2576
2577 return NULL;
2578}
2579
2580static void s_stop(struct seq_file *m, void *p)
2581 __releases(&vmap_area_lock)
2582{
2583 spin_unlock(&vmap_area_lock);
2584}
2585
2586static void show_numa_info(struct seq_file *m, struct vm_struct *v)
2587{
2588 if (IS_ENABLED(CONFIG_NUMA)) {
2589 unsigned int nr, *counters = m->private;
2590
2591 if (!counters)
2592 return;
2593
2594 if (v->flags & VM_UNINITIALIZED)
2595 return;
2596 /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
2597 smp_rmb();
2598
2599 memset(counters, 0, nr_node_ids * sizeof(unsigned int));
2600
2601 for (nr = 0; nr < v->nr_pages; nr++)
2602 counters[page_to_nid(v->pages[nr])]++;
2603
2604 for_each_node_state(nr, N_HIGH_MEMORY)
2605 if (counters[nr])
2606 seq_printf(m, " N%u=%u", nr, counters[nr]);
2607 }
2608}
2609
2610static int s_show(struct seq_file *m, void *p)
2611{
2612 struct vmap_area *va = p;
2613 struct vm_struct *v;
2614
2615 /*
2616 * s_show can encounter race with remove_vm_area, !VM_VM_AREA on
2617 * behalf of vmap area is being tear down or vm_map_ram allocation.
2618 */
2619 if (!(va->flags & VM_VM_AREA))
2620 return 0;
2621
2622 v = va->vm;
2623
2624 seq_printf(m, "0x%pK-0x%pK %7ld",
2625 v->addr, v->addr + v->size, v->size);
2626
2627 if (v->caller)
2628 seq_printf(m, " %pS", v->caller);
2629
2630 if (v->nr_pages)
2631 seq_printf(m, " pages=%d", v->nr_pages);
2632
2633 if (v->phys_addr)
2634 seq_printf(m, " phys=%llx", (unsigned long long)v->phys_addr);
2635
2636 if (v->flags & VM_IOREMAP)
2637 seq_puts(m, " ioremap");
2638
2639 if (v->flags & VM_ALLOC)
2640 seq_puts(m, " vmalloc");
2641
2642 if (v->flags & VM_MAP)
2643 seq_puts(m, " vmap");
2644
2645 if (v->flags & VM_USERMAP)
2646 seq_puts(m, " user");
2647
2648 if (is_vmalloc_addr(v->pages))
2649 seq_puts(m, " vpages");
2650
2651 show_numa_info(m, v);
2652 seq_putc(m, '\n');
2653 return 0;
2654}
2655
2656static const struct seq_operations vmalloc_op = {
2657 .start = s_start,
2658 .next = s_next,
2659 .stop = s_stop,
2660 .show = s_show,
2661};
2662
2663static int vmalloc_open(struct inode *inode, struct file *file)
2664{
2665 if (IS_ENABLED(CONFIG_NUMA))
2666 return seq_open_private(file, &vmalloc_op,
2667 nr_node_ids * sizeof(unsigned int));
2668 else
2669 return seq_open(file, &vmalloc_op);
2670}
2671
2672static const struct file_operations proc_vmalloc_operations = {
2673 .open = vmalloc_open,
2674 .read = seq_read,
2675 .llseek = seq_lseek,
2676 .release = seq_release_private,
2677};
2678
2679static int __init proc_vmalloc_init(void)
2680{
2681 proc_create("vmallocinfo", S_IRUSR, NULL, &proc_vmalloc_operations);
2682 return 0;
2683}
2684module_init(proc_vmalloc_init);
2685
2686#endif
2687
1/*
2 * linux/mm/vmalloc.c
3 *
4 * Copyright (C) 1993 Linus Torvalds
5 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
6 * SMP-safe vmalloc/vfree/ioremap, Tigran Aivazian <tigran@veritas.com>, May 2000
7 * Major rework to support vmap/vunmap, Christoph Hellwig, SGI, August 2002
8 * Numa awareness, Christoph Lameter, SGI, June 2005
9 */
10
11#include <linux/vmalloc.h>
12#include <linux/mm.h>
13#include <linux/module.h>
14#include <linux/highmem.h>
15#include <linux/sched.h>
16#include <linux/slab.h>
17#include <linux/spinlock.h>
18#include <linux/interrupt.h>
19#include <linux/proc_fs.h>
20#include <linux/seq_file.h>
21#include <linux/debugobjects.h>
22#include <linux/kallsyms.h>
23#include <linux/list.h>
24#include <linux/rbtree.h>
25#include <linux/radix-tree.h>
26#include <linux/rcupdate.h>
27#include <linux/pfn.h>
28#include <linux/kmemleak.h>
29#include <linux/atomic.h>
30#include <asm/uaccess.h>
31#include <asm/tlbflush.h>
32#include <asm/shmparam.h>
33
34/*** Page table manipulation functions ***/
35
36static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
37{
38 pte_t *pte;
39
40 pte = pte_offset_kernel(pmd, addr);
41 do {
42 pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
43 WARN_ON(!pte_none(ptent) && !pte_present(ptent));
44 } while (pte++, addr += PAGE_SIZE, addr != end);
45}
46
47static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
48{
49 pmd_t *pmd;
50 unsigned long next;
51
52 pmd = pmd_offset(pud, addr);
53 do {
54 next = pmd_addr_end(addr, end);
55 if (pmd_none_or_clear_bad(pmd))
56 continue;
57 vunmap_pte_range(pmd, addr, next);
58 } while (pmd++, addr = next, addr != end);
59}
60
61static void vunmap_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end)
62{
63 pud_t *pud;
64 unsigned long next;
65
66 pud = pud_offset(pgd, addr);
67 do {
68 next = pud_addr_end(addr, end);
69 if (pud_none_or_clear_bad(pud))
70 continue;
71 vunmap_pmd_range(pud, addr, next);
72 } while (pud++, addr = next, addr != end);
73}
74
75static void vunmap_page_range(unsigned long addr, unsigned long end)
76{
77 pgd_t *pgd;
78 unsigned long next;
79
80 BUG_ON(addr >= end);
81 pgd = pgd_offset_k(addr);
82 do {
83 next = pgd_addr_end(addr, end);
84 if (pgd_none_or_clear_bad(pgd))
85 continue;
86 vunmap_pud_range(pgd, addr, next);
87 } while (pgd++, addr = next, addr != end);
88}
89
90static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
91 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
92{
93 pte_t *pte;
94
95 /*
96 * nr is a running index into the array which helps higher level
97 * callers keep track of where we're up to.
98 */
99
100 pte = pte_alloc_kernel(pmd, addr);
101 if (!pte)
102 return -ENOMEM;
103 do {
104 struct page *page = pages[*nr];
105
106 if (WARN_ON(!pte_none(*pte)))
107 return -EBUSY;
108 if (WARN_ON(!page))
109 return -ENOMEM;
110 set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
111 (*nr)++;
112 } while (pte++, addr += PAGE_SIZE, addr != end);
113 return 0;
114}
115
116static int vmap_pmd_range(pud_t *pud, unsigned long addr,
117 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
118{
119 pmd_t *pmd;
120 unsigned long next;
121
122 pmd = pmd_alloc(&init_mm, pud, addr);
123 if (!pmd)
124 return -ENOMEM;
125 do {
126 next = pmd_addr_end(addr, end);
127 if (vmap_pte_range(pmd, addr, next, prot, pages, nr))
128 return -ENOMEM;
129 } while (pmd++, addr = next, addr != end);
130 return 0;
131}
132
133static int vmap_pud_range(pgd_t *pgd, unsigned long addr,
134 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
135{
136 pud_t *pud;
137 unsigned long next;
138
139 pud = pud_alloc(&init_mm, pgd, addr);
140 if (!pud)
141 return -ENOMEM;
142 do {
143 next = pud_addr_end(addr, end);
144 if (vmap_pmd_range(pud, addr, next, prot, pages, nr))
145 return -ENOMEM;
146 } while (pud++, addr = next, addr != end);
147 return 0;
148}
149
150/*
151 * Set up page tables in kva (addr, end). The ptes shall have prot "prot", and
152 * will have pfns corresponding to the "pages" array.
153 *
154 * Ie. pte at addr+N*PAGE_SIZE shall point to pfn corresponding to pages[N]
155 */
156static int vmap_page_range_noflush(unsigned long start, unsigned long end,
157 pgprot_t prot, struct page **pages)
158{
159 pgd_t *pgd;
160 unsigned long next;
161 unsigned long addr = start;
162 int err = 0;
163 int nr = 0;
164
165 BUG_ON(addr >= end);
166 pgd = pgd_offset_k(addr);
167 do {
168 next = pgd_addr_end(addr, end);
169 err = vmap_pud_range(pgd, addr, next, prot, pages, &nr);
170 if (err)
171 return err;
172 } while (pgd++, addr = next, addr != end);
173
174 return nr;
175}
176
177static int vmap_page_range(unsigned long start, unsigned long end,
178 pgprot_t prot, struct page **pages)
179{
180 int ret;
181
182 ret = vmap_page_range_noflush(start, end, prot, pages);
183 flush_cache_vmap(start, end);
184 return ret;
185}
186
187int is_vmalloc_or_module_addr(const void *x)
188{
189 /*
190 * ARM, x86-64 and sparc64 put modules in a special place,
191 * and fall back on vmalloc() if that fails. Others
192 * just put it in the vmalloc space.
193 */
194#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
195 unsigned long addr = (unsigned long)x;
196 if (addr >= MODULES_VADDR && addr < MODULES_END)
197 return 1;
198#endif
199 return is_vmalloc_addr(x);
200}
201
202/*
203 * Walk a vmap address to the struct page it maps.
204 */
205struct page *vmalloc_to_page(const void *vmalloc_addr)
206{
207 unsigned long addr = (unsigned long) vmalloc_addr;
208 struct page *page = NULL;
209 pgd_t *pgd = pgd_offset_k(addr);
210
211 /*
212 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
213 * architectures that do not vmalloc module space
214 */
215 VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
216
217 if (!pgd_none(*pgd)) {
218 pud_t *pud = pud_offset(pgd, addr);
219 if (!pud_none(*pud)) {
220 pmd_t *pmd = pmd_offset(pud, addr);
221 if (!pmd_none(*pmd)) {
222 pte_t *ptep, pte;
223
224 ptep = pte_offset_map(pmd, addr);
225 pte = *ptep;
226 if (pte_present(pte))
227 page = pte_page(pte);
228 pte_unmap(ptep);
229 }
230 }
231 }
232 return page;
233}
234EXPORT_SYMBOL(vmalloc_to_page);
235
236/*
237 * Map a vmalloc()-space virtual address to the physical page frame number.
238 */
239unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
240{
241 return page_to_pfn(vmalloc_to_page(vmalloc_addr));
242}
243EXPORT_SYMBOL(vmalloc_to_pfn);
244
245
246/*** Global kva allocator ***/
247
248#define VM_LAZY_FREE 0x01
249#define VM_LAZY_FREEING 0x02
250#define VM_VM_AREA 0x04
251
252struct vmap_area {
253 unsigned long va_start;
254 unsigned long va_end;
255 unsigned long flags;
256 struct rb_node rb_node; /* address sorted rbtree */
257 struct list_head list; /* address sorted list */
258 struct list_head purge_list; /* "lazy purge" list */
259 void *private;
260 struct rcu_head rcu_head;
261};
262
263static DEFINE_SPINLOCK(vmap_area_lock);
264static LIST_HEAD(vmap_area_list);
265static struct rb_root vmap_area_root = RB_ROOT;
266
267/* The vmap cache globals are protected by vmap_area_lock */
268static struct rb_node *free_vmap_cache;
269static unsigned long cached_hole_size;
270static unsigned long cached_vstart;
271static unsigned long cached_align;
272
273static unsigned long vmap_area_pcpu_hole;
274
275static struct vmap_area *__find_vmap_area(unsigned long addr)
276{
277 struct rb_node *n = vmap_area_root.rb_node;
278
279 while (n) {
280 struct vmap_area *va;
281
282 va = rb_entry(n, struct vmap_area, rb_node);
283 if (addr < va->va_start)
284 n = n->rb_left;
285 else if (addr > va->va_start)
286 n = n->rb_right;
287 else
288 return va;
289 }
290
291 return NULL;
292}
293
294static void __insert_vmap_area(struct vmap_area *va)
295{
296 struct rb_node **p = &vmap_area_root.rb_node;
297 struct rb_node *parent = NULL;
298 struct rb_node *tmp;
299
300 while (*p) {
301 struct vmap_area *tmp_va;
302
303 parent = *p;
304 tmp_va = rb_entry(parent, struct vmap_area, rb_node);
305 if (va->va_start < tmp_va->va_end)
306 p = &(*p)->rb_left;
307 else if (va->va_end > tmp_va->va_start)
308 p = &(*p)->rb_right;
309 else
310 BUG();
311 }
312
313 rb_link_node(&va->rb_node, parent, p);
314 rb_insert_color(&va->rb_node, &vmap_area_root);
315
316 /* address-sort this list so it is usable like the vmlist */
317 tmp = rb_prev(&va->rb_node);
318 if (tmp) {
319 struct vmap_area *prev;
320 prev = rb_entry(tmp, struct vmap_area, rb_node);
321 list_add_rcu(&va->list, &prev->list);
322 } else
323 list_add_rcu(&va->list, &vmap_area_list);
324}
325
326static void purge_vmap_area_lazy(void);
327
328/*
329 * Allocate a region of KVA of the specified size and alignment, within the
330 * vstart and vend.
331 */
332static struct vmap_area *alloc_vmap_area(unsigned long size,
333 unsigned long align,
334 unsigned long vstart, unsigned long vend,
335 int node, gfp_t gfp_mask)
336{
337 struct vmap_area *va;
338 struct rb_node *n;
339 unsigned long addr;
340 int purged = 0;
341 struct vmap_area *first;
342
343 BUG_ON(!size);
344 BUG_ON(size & ~PAGE_MASK);
345 BUG_ON(!is_power_of_2(align));
346
347 va = kmalloc_node(sizeof(struct vmap_area),
348 gfp_mask & GFP_RECLAIM_MASK, node);
349 if (unlikely(!va))
350 return ERR_PTR(-ENOMEM);
351
352retry:
353 spin_lock(&vmap_area_lock);
354 /*
355 * Invalidate cache if we have more permissive parameters.
356 * cached_hole_size notes the largest hole noticed _below_
357 * the vmap_area cached in free_vmap_cache: if size fits
358 * into that hole, we want to scan from vstart to reuse
359 * the hole instead of allocating above free_vmap_cache.
360 * Note that __free_vmap_area may update free_vmap_cache
361 * without updating cached_hole_size or cached_align.
362 */
363 if (!free_vmap_cache ||
364 size < cached_hole_size ||
365 vstart < cached_vstart ||
366 align < cached_align) {
367nocache:
368 cached_hole_size = 0;
369 free_vmap_cache = NULL;
370 }
371 /* record if we encounter less permissive parameters */
372 cached_vstart = vstart;
373 cached_align = align;
374
375 /* find starting point for our search */
376 if (free_vmap_cache) {
377 first = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
378 addr = ALIGN(first->va_end, align);
379 if (addr < vstart)
380 goto nocache;
381 if (addr + size - 1 < addr)
382 goto overflow;
383
384 } else {
385 addr = ALIGN(vstart, align);
386 if (addr + size - 1 < addr)
387 goto overflow;
388
389 n = vmap_area_root.rb_node;
390 first = NULL;
391
392 while (n) {
393 struct vmap_area *tmp;
394 tmp = rb_entry(n, struct vmap_area, rb_node);
395 if (tmp->va_end >= addr) {
396 first = tmp;
397 if (tmp->va_start <= addr)
398 break;
399 n = n->rb_left;
400 } else
401 n = n->rb_right;
402 }
403
404 if (!first)
405 goto found;
406 }
407
408 /* from the starting point, walk areas until a suitable hole is found */
409 while (addr + size > first->va_start && addr + size <= vend) {
410 if (addr + cached_hole_size < first->va_start)
411 cached_hole_size = first->va_start - addr;
412 addr = ALIGN(first->va_end, align);
413 if (addr + size - 1 < addr)
414 goto overflow;
415
416 n = rb_next(&first->rb_node);
417 if (n)
418 first = rb_entry(n, struct vmap_area, rb_node);
419 else
420 goto found;
421 }
422
423found:
424 if (addr + size > vend)
425 goto overflow;
426
427 va->va_start = addr;
428 va->va_end = addr + size;
429 va->flags = 0;
430 __insert_vmap_area(va);
431 free_vmap_cache = &va->rb_node;
432 spin_unlock(&vmap_area_lock);
433
434 BUG_ON(va->va_start & (align-1));
435 BUG_ON(va->va_start < vstart);
436 BUG_ON(va->va_end > vend);
437
438 return va;
439
440overflow:
441 spin_unlock(&vmap_area_lock);
442 if (!purged) {
443 purge_vmap_area_lazy();
444 purged = 1;
445 goto retry;
446 }
447 if (printk_ratelimit())
448 printk(KERN_WARNING
449 "vmap allocation for size %lu failed: "
450 "use vmalloc=<size> to increase size.\n", size);
451 kfree(va);
452 return ERR_PTR(-EBUSY);
453}
454
455static void __free_vmap_area(struct vmap_area *va)
456{
457 BUG_ON(RB_EMPTY_NODE(&va->rb_node));
458
459 if (free_vmap_cache) {
460 if (va->va_end < cached_vstart) {
461 free_vmap_cache = NULL;
462 } else {
463 struct vmap_area *cache;
464 cache = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
465 if (va->va_start <= cache->va_start) {
466 free_vmap_cache = rb_prev(&va->rb_node);
467 /*
468 * We don't try to update cached_hole_size or
469 * cached_align, but it won't go very wrong.
470 */
471 }
472 }
473 }
474 rb_erase(&va->rb_node, &vmap_area_root);
475 RB_CLEAR_NODE(&va->rb_node);
476 list_del_rcu(&va->list);
477
478 /*
479 * Track the highest possible candidate for pcpu area
480 * allocation. Areas outside of vmalloc area can be returned
481 * here too, consider only end addresses which fall inside
482 * vmalloc area proper.
483 */
484 if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END)
485 vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end);
486
487 kfree_rcu(va, rcu_head);
488}
489
490/*
491 * Free a region of KVA allocated by alloc_vmap_area
492 */
493static void free_vmap_area(struct vmap_area *va)
494{
495 spin_lock(&vmap_area_lock);
496 __free_vmap_area(va);
497 spin_unlock(&vmap_area_lock);
498}
499
500/*
501 * Clear the pagetable entries of a given vmap_area
502 */
503static void unmap_vmap_area(struct vmap_area *va)
504{
505 vunmap_page_range(va->va_start, va->va_end);
506}
507
508static void vmap_debug_free_range(unsigned long start, unsigned long end)
509{
510 /*
511 * Unmap page tables and force a TLB flush immediately if
512 * CONFIG_DEBUG_PAGEALLOC is set. This catches use after free
513 * bugs similarly to those in linear kernel virtual address
514 * space after a page has been freed.
515 *
516 * All the lazy freeing logic is still retained, in order to
517 * minimise intrusiveness of this debugging feature.
518 *
519 * This is going to be *slow* (linear kernel virtual address
520 * debugging doesn't do a broadcast TLB flush so it is a lot
521 * faster).
522 */
523#ifdef CONFIG_DEBUG_PAGEALLOC
524 vunmap_page_range(start, end);
525 flush_tlb_kernel_range(start, end);
526#endif
527}
528
529/*
530 * lazy_max_pages is the maximum amount of virtual address space we gather up
531 * before attempting to purge with a TLB flush.
532 *
533 * There is a tradeoff here: a larger number will cover more kernel page tables
534 * and take slightly longer to purge, but it will linearly reduce the number of
535 * global TLB flushes that must be performed. It would seem natural to scale
536 * this number up linearly with the number of CPUs (because vmapping activity
537 * could also scale linearly with the number of CPUs), however it is likely
538 * that in practice, workloads might be constrained in other ways that mean
539 * vmap activity will not scale linearly with CPUs. Also, I want to be
540 * conservative and not introduce a big latency on huge systems, so go with
541 * a less aggressive log scale. It will still be an improvement over the old
542 * code, and it will be simple to change the scale factor if we find that it
543 * becomes a problem on bigger systems.
544 */
545static unsigned long lazy_max_pages(void)
546{
547 unsigned int log;
548
549 log = fls(num_online_cpus());
550
551 return log * (32UL * 1024 * 1024 / PAGE_SIZE);
552}
553
554static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);
555
556/* for per-CPU blocks */
557static void purge_fragmented_blocks_allcpus(void);
558
559/*
560 * called before a call to iounmap() if the caller wants vm_area_struct's
561 * immediately freed.
562 */
563void set_iounmap_nonlazy(void)
564{
565 atomic_set(&vmap_lazy_nr, lazy_max_pages()+1);
566}
567
568/*
569 * Purges all lazily-freed vmap areas.
570 *
571 * If sync is 0 then don't purge if there is already a purge in progress.
572 * If force_flush is 1, then flush kernel TLBs between *start and *end even
573 * if we found no lazy vmap areas to unmap (callers can use this to optimise
574 * their own TLB flushing).
575 * Returns with *start = min(*start, lowest purged address)
576 * *end = max(*end, highest purged address)
577 */
578static void __purge_vmap_area_lazy(unsigned long *start, unsigned long *end,
579 int sync, int force_flush)
580{
581 static DEFINE_SPINLOCK(purge_lock);
582 LIST_HEAD(valist);
583 struct vmap_area *va;
584 struct vmap_area *n_va;
585 int nr = 0;
586
587 /*
588 * If sync is 0 but force_flush is 1, we'll go sync anyway but callers
589 * should not expect such behaviour. This just simplifies locking for
590 * the case that isn't actually used at the moment anyway.
591 */
592 if (!sync && !force_flush) {
593 if (!spin_trylock(&purge_lock))
594 return;
595 } else
596 spin_lock(&purge_lock);
597
598 if (sync)
599 purge_fragmented_blocks_allcpus();
600
601 rcu_read_lock();
602 list_for_each_entry_rcu(va, &vmap_area_list, list) {
603 if (va->flags & VM_LAZY_FREE) {
604 if (va->va_start < *start)
605 *start = va->va_start;
606 if (va->va_end > *end)
607 *end = va->va_end;
608 nr += (va->va_end - va->va_start) >> PAGE_SHIFT;
609 list_add_tail(&va->purge_list, &valist);
610 va->flags |= VM_LAZY_FREEING;
611 va->flags &= ~VM_LAZY_FREE;
612 }
613 }
614 rcu_read_unlock();
615
616 if (nr)
617 atomic_sub(nr, &vmap_lazy_nr);
618
619 if (nr || force_flush)
620 flush_tlb_kernel_range(*start, *end);
621
622 if (nr) {
623 spin_lock(&vmap_area_lock);
624 list_for_each_entry_safe(va, n_va, &valist, purge_list)
625 __free_vmap_area(va);
626 spin_unlock(&vmap_area_lock);
627 }
628 spin_unlock(&purge_lock);
629}
630
631/*
632 * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
633 * is already purging.
634 */
635static void try_purge_vmap_area_lazy(void)
636{
637 unsigned long start = ULONG_MAX, end = 0;
638
639 __purge_vmap_area_lazy(&start, &end, 0, 0);
640}
641
642/*
643 * Kick off a purge of the outstanding lazy areas.
644 */
645static void purge_vmap_area_lazy(void)
646{
647 unsigned long start = ULONG_MAX, end = 0;
648
649 __purge_vmap_area_lazy(&start, &end, 1, 0);
650}
651
652/*
653 * Free a vmap area, caller ensuring that the area has been unmapped
654 * and flush_cache_vunmap had been called for the correct range
655 * previously.
656 */
657static void free_vmap_area_noflush(struct vmap_area *va)
658{
659 va->flags |= VM_LAZY_FREE;
660 atomic_add((va->va_end - va->va_start) >> PAGE_SHIFT, &vmap_lazy_nr);
661 if (unlikely(atomic_read(&vmap_lazy_nr) > lazy_max_pages()))
662 try_purge_vmap_area_lazy();
663}
664
665/*
666 * Free and unmap a vmap area, caller ensuring flush_cache_vunmap had been
667 * called for the correct range previously.
668 */
669static void free_unmap_vmap_area_noflush(struct vmap_area *va)
670{
671 unmap_vmap_area(va);
672 free_vmap_area_noflush(va);
673}
674
675/*
676 * Free and unmap a vmap area
677 */
678static void free_unmap_vmap_area(struct vmap_area *va)
679{
680 flush_cache_vunmap(va->va_start, va->va_end);
681 free_unmap_vmap_area_noflush(va);
682}
683
684static struct vmap_area *find_vmap_area(unsigned long addr)
685{
686 struct vmap_area *va;
687
688 spin_lock(&vmap_area_lock);
689 va = __find_vmap_area(addr);
690 spin_unlock(&vmap_area_lock);
691
692 return va;
693}
694
695static void free_unmap_vmap_area_addr(unsigned long addr)
696{
697 struct vmap_area *va;
698
699 va = find_vmap_area(addr);
700 BUG_ON(!va);
701 free_unmap_vmap_area(va);
702}
703
704
705/*** Per cpu kva allocator ***/
706
707/*
708 * vmap space is limited especially on 32 bit architectures. Ensure there is
709 * room for at least 16 percpu vmap blocks per CPU.
710 */
711/*
712 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
713 * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess
714 * instead (we just need a rough idea)
715 */
716#if BITS_PER_LONG == 32
717#define VMALLOC_SPACE (128UL*1024*1024)
718#else
719#define VMALLOC_SPACE (128UL*1024*1024*1024)
720#endif
721
722#define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE)
723#define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */
724#define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */
725#define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
726#define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
727#define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
728#define VMAP_BBMAP_BITS \
729 VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
730 VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
731 VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
732
733#define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
734
735static bool vmap_initialized __read_mostly = false;
736
737struct vmap_block_queue {
738 spinlock_t lock;
739 struct list_head free;
740};
741
742struct vmap_block {
743 spinlock_t lock;
744 struct vmap_area *va;
745 struct vmap_block_queue *vbq;
746 unsigned long free, dirty;
747 DECLARE_BITMAP(alloc_map, VMAP_BBMAP_BITS);
748 DECLARE_BITMAP(dirty_map, VMAP_BBMAP_BITS);
749 struct list_head free_list;
750 struct rcu_head rcu_head;
751 struct list_head purge;
752};
753
754/* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
755static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
756
757/*
758 * Radix tree of vmap blocks, indexed by address, to quickly find a vmap block
759 * in the free path. Could get rid of this if we change the API to return a
760 * "cookie" from alloc, to be passed to free. But no big deal yet.
761 */
762static DEFINE_SPINLOCK(vmap_block_tree_lock);
763static RADIX_TREE(vmap_block_tree, GFP_ATOMIC);
764
765/*
766 * We should probably have a fallback mechanism to allocate virtual memory
767 * out of partially filled vmap blocks. However vmap block sizing should be
768 * fairly reasonable according to the vmalloc size, so it shouldn't be a
769 * big problem.
770 */
771
772static unsigned long addr_to_vb_idx(unsigned long addr)
773{
774 addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
775 addr /= VMAP_BLOCK_SIZE;
776 return addr;
777}
778
779static struct vmap_block *new_vmap_block(gfp_t gfp_mask)
780{
781 struct vmap_block_queue *vbq;
782 struct vmap_block *vb;
783 struct vmap_area *va;
784 unsigned long vb_idx;
785 int node, err;
786
787 node = numa_node_id();
788
789 vb = kmalloc_node(sizeof(struct vmap_block),
790 gfp_mask & GFP_RECLAIM_MASK, node);
791 if (unlikely(!vb))
792 return ERR_PTR(-ENOMEM);
793
794 va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
795 VMALLOC_START, VMALLOC_END,
796 node, gfp_mask);
797 if (IS_ERR(va)) {
798 kfree(vb);
799 return ERR_CAST(va);
800 }
801
802 err = radix_tree_preload(gfp_mask);
803 if (unlikely(err)) {
804 kfree(vb);
805 free_vmap_area(va);
806 return ERR_PTR(err);
807 }
808
809 spin_lock_init(&vb->lock);
810 vb->va = va;
811 vb->free = VMAP_BBMAP_BITS;
812 vb->dirty = 0;
813 bitmap_zero(vb->alloc_map, VMAP_BBMAP_BITS);
814 bitmap_zero(vb->dirty_map, VMAP_BBMAP_BITS);
815 INIT_LIST_HEAD(&vb->free_list);
816
817 vb_idx = addr_to_vb_idx(va->va_start);
818 spin_lock(&vmap_block_tree_lock);
819 err = radix_tree_insert(&vmap_block_tree, vb_idx, vb);
820 spin_unlock(&vmap_block_tree_lock);
821 BUG_ON(err);
822 radix_tree_preload_end();
823
824 vbq = &get_cpu_var(vmap_block_queue);
825 vb->vbq = vbq;
826 spin_lock(&vbq->lock);
827 list_add_rcu(&vb->free_list, &vbq->free);
828 spin_unlock(&vbq->lock);
829 put_cpu_var(vmap_block_queue);
830
831 return vb;
832}
833
834static void free_vmap_block(struct vmap_block *vb)
835{
836 struct vmap_block *tmp;
837 unsigned long vb_idx;
838
839 vb_idx = addr_to_vb_idx(vb->va->va_start);
840 spin_lock(&vmap_block_tree_lock);
841 tmp = radix_tree_delete(&vmap_block_tree, vb_idx);
842 spin_unlock(&vmap_block_tree_lock);
843 BUG_ON(tmp != vb);
844
845 free_vmap_area_noflush(vb->va);
846 kfree_rcu(vb, rcu_head);
847}
848
849static void purge_fragmented_blocks(int cpu)
850{
851 LIST_HEAD(purge);
852 struct vmap_block *vb;
853 struct vmap_block *n_vb;
854 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
855
856 rcu_read_lock();
857 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
858
859 if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
860 continue;
861
862 spin_lock(&vb->lock);
863 if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
864 vb->free = 0; /* prevent further allocs after releasing lock */
865 vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
866 bitmap_fill(vb->alloc_map, VMAP_BBMAP_BITS);
867 bitmap_fill(vb->dirty_map, VMAP_BBMAP_BITS);
868 spin_lock(&vbq->lock);
869 list_del_rcu(&vb->free_list);
870 spin_unlock(&vbq->lock);
871 spin_unlock(&vb->lock);
872 list_add_tail(&vb->purge, &purge);
873 } else
874 spin_unlock(&vb->lock);
875 }
876 rcu_read_unlock();
877
878 list_for_each_entry_safe(vb, n_vb, &purge, purge) {
879 list_del(&vb->purge);
880 free_vmap_block(vb);
881 }
882}
883
884static void purge_fragmented_blocks_thiscpu(void)
885{
886 purge_fragmented_blocks(smp_processor_id());
887}
888
889static void purge_fragmented_blocks_allcpus(void)
890{
891 int cpu;
892
893 for_each_possible_cpu(cpu)
894 purge_fragmented_blocks(cpu);
895}
896
897static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
898{
899 struct vmap_block_queue *vbq;
900 struct vmap_block *vb;
901 unsigned long addr = 0;
902 unsigned int order;
903 int purge = 0;
904
905 BUG_ON(size & ~PAGE_MASK);
906 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
907 order = get_order(size);
908
909again:
910 rcu_read_lock();
911 vbq = &get_cpu_var(vmap_block_queue);
912 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
913 int i;
914
915 spin_lock(&vb->lock);
916 if (vb->free < 1UL << order)
917 goto next;
918
919 i = bitmap_find_free_region(vb->alloc_map,
920 VMAP_BBMAP_BITS, order);
921
922 if (i < 0) {
923 if (vb->free + vb->dirty == VMAP_BBMAP_BITS) {
924 /* fragmented and no outstanding allocations */
925 BUG_ON(vb->dirty != VMAP_BBMAP_BITS);
926 purge = 1;
927 }
928 goto next;
929 }
930 addr = vb->va->va_start + (i << PAGE_SHIFT);
931 BUG_ON(addr_to_vb_idx(addr) !=
932 addr_to_vb_idx(vb->va->va_start));
933 vb->free -= 1UL << order;
934 if (vb->free == 0) {
935 spin_lock(&vbq->lock);
936 list_del_rcu(&vb->free_list);
937 spin_unlock(&vbq->lock);
938 }
939 spin_unlock(&vb->lock);
940 break;
941next:
942 spin_unlock(&vb->lock);
943 }
944
945 if (purge)
946 purge_fragmented_blocks_thiscpu();
947
948 put_cpu_var(vmap_block_queue);
949 rcu_read_unlock();
950
951 if (!addr) {
952 vb = new_vmap_block(gfp_mask);
953 if (IS_ERR(vb))
954 return vb;
955 goto again;
956 }
957
958 return (void *)addr;
959}
960
961static void vb_free(const void *addr, unsigned long size)
962{
963 unsigned long offset;
964 unsigned long vb_idx;
965 unsigned int order;
966 struct vmap_block *vb;
967
968 BUG_ON(size & ~PAGE_MASK);
969 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
970
971 flush_cache_vunmap((unsigned long)addr, (unsigned long)addr + size);
972
973 order = get_order(size);
974
975 offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1);
976
977 vb_idx = addr_to_vb_idx((unsigned long)addr);
978 rcu_read_lock();
979 vb = radix_tree_lookup(&vmap_block_tree, vb_idx);
980 rcu_read_unlock();
981 BUG_ON(!vb);
982
983 vunmap_page_range((unsigned long)addr, (unsigned long)addr + size);
984
985 spin_lock(&vb->lock);
986 BUG_ON(bitmap_allocate_region(vb->dirty_map, offset >> PAGE_SHIFT, order));
987
988 vb->dirty += 1UL << order;
989 if (vb->dirty == VMAP_BBMAP_BITS) {
990 BUG_ON(vb->free);
991 spin_unlock(&vb->lock);
992 free_vmap_block(vb);
993 } else
994 spin_unlock(&vb->lock);
995}
996
997/**
998 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
999 *
1000 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
1001 * to amortize TLB flushing overheads. What this means is that any page you
1002 * have now, may, in a former life, have been mapped into kernel virtual
1003 * address by the vmap layer and so there might be some CPUs with TLB entries
1004 * still referencing that page (additional to the regular 1:1 kernel mapping).
1005 *
1006 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
1007 * be sure that none of the pages we have control over will have any aliases
1008 * from the vmap layer.
1009 */
1010void vm_unmap_aliases(void)
1011{
1012 unsigned long start = ULONG_MAX, end = 0;
1013 int cpu;
1014 int flush = 0;
1015
1016 if (unlikely(!vmap_initialized))
1017 return;
1018
1019 for_each_possible_cpu(cpu) {
1020 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
1021 struct vmap_block *vb;
1022
1023 rcu_read_lock();
1024 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
1025 int i;
1026
1027 spin_lock(&vb->lock);
1028 i = find_first_bit(vb->dirty_map, VMAP_BBMAP_BITS);
1029 while (i < VMAP_BBMAP_BITS) {
1030 unsigned long s, e;
1031 int j;
1032 j = find_next_zero_bit(vb->dirty_map,
1033 VMAP_BBMAP_BITS, i);
1034
1035 s = vb->va->va_start + (i << PAGE_SHIFT);
1036 e = vb->va->va_start + (j << PAGE_SHIFT);
1037 flush = 1;
1038
1039 if (s < start)
1040 start = s;
1041 if (e > end)
1042 end = e;
1043
1044 i = j;
1045 i = find_next_bit(vb->dirty_map,
1046 VMAP_BBMAP_BITS, i);
1047 }
1048 spin_unlock(&vb->lock);
1049 }
1050 rcu_read_unlock();
1051 }
1052
1053 __purge_vmap_area_lazy(&start, &end, 1, flush);
1054}
1055EXPORT_SYMBOL_GPL(vm_unmap_aliases);
1056
1057/**
1058 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
1059 * @mem: the pointer returned by vm_map_ram
1060 * @count: the count passed to that vm_map_ram call (cannot unmap partial)
1061 */
1062void vm_unmap_ram(const void *mem, unsigned int count)
1063{
1064 unsigned long size = count << PAGE_SHIFT;
1065 unsigned long addr = (unsigned long)mem;
1066
1067 BUG_ON(!addr);
1068 BUG_ON(addr < VMALLOC_START);
1069 BUG_ON(addr > VMALLOC_END);
1070 BUG_ON(addr & (PAGE_SIZE-1));
1071
1072 debug_check_no_locks_freed(mem, size);
1073 vmap_debug_free_range(addr, addr+size);
1074
1075 if (likely(count <= VMAP_MAX_ALLOC))
1076 vb_free(mem, size);
1077 else
1078 free_unmap_vmap_area_addr(addr);
1079}
1080EXPORT_SYMBOL(vm_unmap_ram);
1081
1082/**
1083 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
1084 * @pages: an array of pointers to the pages to be mapped
1085 * @count: number of pages
1086 * @node: prefer to allocate data structures on this node
1087 * @prot: memory protection to use. PAGE_KERNEL for regular RAM
1088 *
1089 * Returns: a pointer to the address that has been mapped, or %NULL on failure
1090 */
1091void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot)
1092{
1093 unsigned long size = count << PAGE_SHIFT;
1094 unsigned long addr;
1095 void *mem;
1096
1097 if (likely(count <= VMAP_MAX_ALLOC)) {
1098 mem = vb_alloc(size, GFP_KERNEL);
1099 if (IS_ERR(mem))
1100 return NULL;
1101 addr = (unsigned long)mem;
1102 } else {
1103 struct vmap_area *va;
1104 va = alloc_vmap_area(size, PAGE_SIZE,
1105 VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
1106 if (IS_ERR(va))
1107 return NULL;
1108
1109 addr = va->va_start;
1110 mem = (void *)addr;
1111 }
1112 if (vmap_page_range(addr, addr + size, prot, pages) < 0) {
1113 vm_unmap_ram(mem, count);
1114 return NULL;
1115 }
1116 return mem;
1117}
1118EXPORT_SYMBOL(vm_map_ram);
1119
1120/**
1121 * vm_area_register_early - register vmap area early during boot
1122 * @vm: vm_struct to register
1123 * @align: requested alignment
1124 *
1125 * This function is used to register kernel vm area before
1126 * vmalloc_init() is called. @vm->size and @vm->flags should contain
1127 * proper values on entry and other fields should be zero. On return,
1128 * vm->addr contains the allocated address.
1129 *
1130 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
1131 */
1132void __init vm_area_register_early(struct vm_struct *vm, size_t align)
1133{
1134 static size_t vm_init_off __initdata;
1135 unsigned long addr;
1136
1137 addr = ALIGN(VMALLOC_START + vm_init_off, align);
1138 vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
1139
1140 vm->addr = (void *)addr;
1141
1142 vm->next = vmlist;
1143 vmlist = vm;
1144}
1145
1146void __init vmalloc_init(void)
1147{
1148 struct vmap_area *va;
1149 struct vm_struct *tmp;
1150 int i;
1151
1152 for_each_possible_cpu(i) {
1153 struct vmap_block_queue *vbq;
1154
1155 vbq = &per_cpu(vmap_block_queue, i);
1156 spin_lock_init(&vbq->lock);
1157 INIT_LIST_HEAD(&vbq->free);
1158 }
1159
1160 /* Import existing vmlist entries. */
1161 for (tmp = vmlist; tmp; tmp = tmp->next) {
1162 va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
1163 va->flags = tmp->flags | VM_VM_AREA;
1164 va->va_start = (unsigned long)tmp->addr;
1165 va->va_end = va->va_start + tmp->size;
1166 __insert_vmap_area(va);
1167 }
1168
1169 vmap_area_pcpu_hole = VMALLOC_END;
1170
1171 vmap_initialized = true;
1172}
1173
1174/**
1175 * map_kernel_range_noflush - map kernel VM area with the specified pages
1176 * @addr: start of the VM area to map
1177 * @size: size of the VM area to map
1178 * @prot: page protection flags to use
1179 * @pages: pages to map
1180 *
1181 * Map PFN_UP(@size) pages at @addr. The VM area @addr and @size
1182 * specify should have been allocated using get_vm_area() and its
1183 * friends.
1184 *
1185 * NOTE:
1186 * This function does NOT do any cache flushing. The caller is
1187 * responsible for calling flush_cache_vmap() on to-be-mapped areas
1188 * before calling this function.
1189 *
1190 * RETURNS:
1191 * The number of pages mapped on success, -errno on failure.
1192 */
1193int map_kernel_range_noflush(unsigned long addr, unsigned long size,
1194 pgprot_t prot, struct page **pages)
1195{
1196 return vmap_page_range_noflush(addr, addr + size, prot, pages);
1197}
1198
1199/**
1200 * unmap_kernel_range_noflush - unmap kernel VM area
1201 * @addr: start of the VM area to unmap
1202 * @size: size of the VM area to unmap
1203 *
1204 * Unmap PFN_UP(@size) pages at @addr. The VM area @addr and @size
1205 * specify should have been allocated using get_vm_area() and its
1206 * friends.
1207 *
1208 * NOTE:
1209 * This function does NOT do any cache flushing. The caller is
1210 * responsible for calling flush_cache_vunmap() on to-be-mapped areas
1211 * before calling this function and flush_tlb_kernel_range() after.
1212 */
1213void unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
1214{
1215 vunmap_page_range(addr, addr + size);
1216}
1217EXPORT_SYMBOL_GPL(unmap_kernel_range_noflush);
1218
1219/**
1220 * unmap_kernel_range - unmap kernel VM area and flush cache and TLB
1221 * @addr: start of the VM area to unmap
1222 * @size: size of the VM area to unmap
1223 *
1224 * Similar to unmap_kernel_range_noflush() but flushes vcache before
1225 * the unmapping and tlb after.
1226 */
1227void unmap_kernel_range(unsigned long addr, unsigned long size)
1228{
1229 unsigned long end = addr + size;
1230
1231 flush_cache_vunmap(addr, end);
1232 vunmap_page_range(addr, end);
1233 flush_tlb_kernel_range(addr, end);
1234}
1235
1236int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages)
1237{
1238 unsigned long addr = (unsigned long)area->addr;
1239 unsigned long end = addr + area->size - PAGE_SIZE;
1240 int err;
1241
1242 err = vmap_page_range(addr, end, prot, *pages);
1243 if (err > 0) {
1244 *pages += err;
1245 err = 0;
1246 }
1247
1248 return err;
1249}
1250EXPORT_SYMBOL_GPL(map_vm_area);
1251
1252/*** Old vmalloc interfaces ***/
1253DEFINE_RWLOCK(vmlist_lock);
1254struct vm_struct *vmlist;
1255
1256static void insert_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
1257 unsigned long flags, void *caller)
1258{
1259 struct vm_struct *tmp, **p;
1260
1261 vm->flags = flags;
1262 vm->addr = (void *)va->va_start;
1263 vm->size = va->va_end - va->va_start;
1264 vm->caller = caller;
1265 va->private = vm;
1266 va->flags |= VM_VM_AREA;
1267
1268 write_lock(&vmlist_lock);
1269 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
1270 if (tmp->addr >= vm->addr)
1271 break;
1272 }
1273 vm->next = *p;
1274 *p = vm;
1275 write_unlock(&vmlist_lock);
1276}
1277
1278static struct vm_struct *__get_vm_area_node(unsigned long size,
1279 unsigned long align, unsigned long flags, unsigned long start,
1280 unsigned long end, int node, gfp_t gfp_mask, void *caller)
1281{
1282 static struct vmap_area *va;
1283 struct vm_struct *area;
1284
1285 BUG_ON(in_interrupt());
1286 if (flags & VM_IOREMAP) {
1287 int bit = fls(size);
1288
1289 if (bit > IOREMAP_MAX_ORDER)
1290 bit = IOREMAP_MAX_ORDER;
1291 else if (bit < PAGE_SHIFT)
1292 bit = PAGE_SHIFT;
1293
1294 align = 1ul << bit;
1295 }
1296
1297 size = PAGE_ALIGN(size);
1298 if (unlikely(!size))
1299 return NULL;
1300
1301 area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
1302 if (unlikely(!area))
1303 return NULL;
1304
1305 /*
1306 * We always allocate a guard page.
1307 */
1308 size += PAGE_SIZE;
1309
1310 va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
1311 if (IS_ERR(va)) {
1312 kfree(area);
1313 return NULL;
1314 }
1315
1316 insert_vmalloc_vm(area, va, flags, caller);
1317 return area;
1318}
1319
1320struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
1321 unsigned long start, unsigned long end)
1322{
1323 return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
1324 __builtin_return_address(0));
1325}
1326EXPORT_SYMBOL_GPL(__get_vm_area);
1327
1328struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
1329 unsigned long start, unsigned long end,
1330 void *caller)
1331{
1332 return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
1333 caller);
1334}
1335
1336/**
1337 * get_vm_area - reserve a contiguous kernel virtual area
1338 * @size: size of the area
1339 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC
1340 *
1341 * Search an area of @size in the kernel virtual mapping area,
1342 * and reserved it for out purposes. Returns the area descriptor
1343 * on success or %NULL on failure.
1344 */
1345struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
1346{
1347 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1348 -1, GFP_KERNEL, __builtin_return_address(0));
1349}
1350
1351struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
1352 void *caller)
1353{
1354 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1355 -1, GFP_KERNEL, caller);
1356}
1357
1358static struct vm_struct *find_vm_area(const void *addr)
1359{
1360 struct vmap_area *va;
1361
1362 va = find_vmap_area((unsigned long)addr);
1363 if (va && va->flags & VM_VM_AREA)
1364 return va->private;
1365
1366 return NULL;
1367}
1368
1369/**
1370 * remove_vm_area - find and remove a continuous kernel virtual area
1371 * @addr: base address
1372 *
1373 * Search for the kernel VM area starting at @addr, and remove it.
1374 * This function returns the found VM area, but using it is NOT safe
1375 * on SMP machines, except for its size or flags.
1376 */
1377struct vm_struct *remove_vm_area(const void *addr)
1378{
1379 struct vmap_area *va;
1380
1381 va = find_vmap_area((unsigned long)addr);
1382 if (va && va->flags & VM_VM_AREA) {
1383 struct vm_struct *vm = va->private;
1384 struct vm_struct *tmp, **p;
1385 /*
1386 * remove from list and disallow access to this vm_struct
1387 * before unmap. (address range confliction is maintained by
1388 * vmap.)
1389 */
1390 write_lock(&vmlist_lock);
1391 for (p = &vmlist; (tmp = *p) != vm; p = &tmp->next)
1392 ;
1393 *p = tmp->next;
1394 write_unlock(&vmlist_lock);
1395
1396 vmap_debug_free_range(va->va_start, va->va_end);
1397 free_unmap_vmap_area(va);
1398 vm->size -= PAGE_SIZE;
1399
1400 return vm;
1401 }
1402 return NULL;
1403}
1404
1405static void __vunmap(const void *addr, int deallocate_pages)
1406{
1407 struct vm_struct *area;
1408
1409 if (!addr)
1410 return;
1411
1412 if ((PAGE_SIZE-1) & (unsigned long)addr) {
1413 WARN(1, KERN_ERR "Trying to vfree() bad address (%p)\n", addr);
1414 return;
1415 }
1416
1417 area = remove_vm_area(addr);
1418 if (unlikely(!area)) {
1419 WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
1420 addr);
1421 return;
1422 }
1423
1424 debug_check_no_locks_freed(addr, area->size);
1425 debug_check_no_obj_freed(addr, area->size);
1426
1427 if (deallocate_pages) {
1428 int i;
1429
1430 for (i = 0; i < area->nr_pages; i++) {
1431 struct page *page = area->pages[i];
1432
1433 BUG_ON(!page);
1434 __free_page(page);
1435 }
1436
1437 if (area->flags & VM_VPAGES)
1438 vfree(area->pages);
1439 else
1440 kfree(area->pages);
1441 }
1442
1443 kfree(area);
1444 return;
1445}
1446
1447/**
1448 * vfree - release memory allocated by vmalloc()
1449 * @addr: memory base address
1450 *
1451 * Free the virtually continuous memory area starting at @addr, as
1452 * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
1453 * NULL, no operation is performed.
1454 *
1455 * Must not be called in interrupt context.
1456 */
1457void vfree(const void *addr)
1458{
1459 BUG_ON(in_interrupt());
1460
1461 kmemleak_free(addr);
1462
1463 __vunmap(addr, 1);
1464}
1465EXPORT_SYMBOL(vfree);
1466
1467/**
1468 * vunmap - release virtual mapping obtained by vmap()
1469 * @addr: memory base address
1470 *
1471 * Free the virtually contiguous memory area starting at @addr,
1472 * which was created from the page array passed to vmap().
1473 *
1474 * Must not be called in interrupt context.
1475 */
1476void vunmap(const void *addr)
1477{
1478 BUG_ON(in_interrupt());
1479 might_sleep();
1480 __vunmap(addr, 0);
1481}
1482EXPORT_SYMBOL(vunmap);
1483
1484/**
1485 * vmap - map an array of pages into virtually contiguous space
1486 * @pages: array of page pointers
1487 * @count: number of pages to map
1488 * @flags: vm_area->flags
1489 * @prot: page protection for the mapping
1490 *
1491 * Maps @count pages from @pages into contiguous kernel virtual
1492 * space.
1493 */
1494void *vmap(struct page **pages, unsigned int count,
1495 unsigned long flags, pgprot_t prot)
1496{
1497 struct vm_struct *area;
1498
1499 might_sleep();
1500
1501 if (count > totalram_pages)
1502 return NULL;
1503
1504 area = get_vm_area_caller((count << PAGE_SHIFT), flags,
1505 __builtin_return_address(0));
1506 if (!area)
1507 return NULL;
1508
1509 if (map_vm_area(area, prot, &pages)) {
1510 vunmap(area->addr);
1511 return NULL;
1512 }
1513
1514 return area->addr;
1515}
1516EXPORT_SYMBOL(vmap);
1517
1518static void *__vmalloc_node(unsigned long size, unsigned long align,
1519 gfp_t gfp_mask, pgprot_t prot,
1520 int node, void *caller);
1521static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
1522 pgprot_t prot, int node, void *caller)
1523{
1524 const int order = 0;
1525 struct page **pages;
1526 unsigned int nr_pages, array_size, i;
1527 gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
1528
1529 nr_pages = (area->size - PAGE_SIZE) >> PAGE_SHIFT;
1530 array_size = (nr_pages * sizeof(struct page *));
1531
1532 area->nr_pages = nr_pages;
1533 /* Please note that the recursion is strictly bounded. */
1534 if (array_size > PAGE_SIZE) {
1535 pages = __vmalloc_node(array_size, 1, nested_gfp|__GFP_HIGHMEM,
1536 PAGE_KERNEL, node, caller);
1537 area->flags |= VM_VPAGES;
1538 } else {
1539 pages = kmalloc_node(array_size, nested_gfp, node);
1540 }
1541 area->pages = pages;
1542 area->caller = caller;
1543 if (!area->pages) {
1544 remove_vm_area(area->addr);
1545 kfree(area);
1546 return NULL;
1547 }
1548
1549 for (i = 0; i < area->nr_pages; i++) {
1550 struct page *page;
1551 gfp_t tmp_mask = gfp_mask | __GFP_NOWARN;
1552
1553 if (node < 0)
1554 page = alloc_page(tmp_mask);
1555 else
1556 page = alloc_pages_node(node, tmp_mask, order);
1557
1558 if (unlikely(!page)) {
1559 /* Successfully allocated i pages, free them in __vunmap() */
1560 area->nr_pages = i;
1561 goto fail;
1562 }
1563 area->pages[i] = page;
1564 }
1565
1566 if (map_vm_area(area, prot, &pages))
1567 goto fail;
1568 return area->addr;
1569
1570fail:
1571 warn_alloc_failed(gfp_mask, order, "vmalloc: allocation failure, "
1572 "allocated %ld of %ld bytes\n",
1573 (area->nr_pages*PAGE_SIZE), area->size);
1574 vfree(area->addr);
1575 return NULL;
1576}
1577
1578/**
1579 * __vmalloc_node_range - allocate virtually contiguous memory
1580 * @size: allocation size
1581 * @align: desired alignment
1582 * @start: vm area range start
1583 * @end: vm area range end
1584 * @gfp_mask: flags for the page level allocator
1585 * @prot: protection mask for the allocated pages
1586 * @node: node to use for allocation or -1
1587 * @caller: caller's return address
1588 *
1589 * Allocate enough pages to cover @size from the page level
1590 * allocator with @gfp_mask flags. Map them into contiguous
1591 * kernel virtual space, using a pagetable protection of @prot.
1592 */
1593void *__vmalloc_node_range(unsigned long size, unsigned long align,
1594 unsigned long start, unsigned long end, gfp_t gfp_mask,
1595 pgprot_t prot, int node, void *caller)
1596{
1597 struct vm_struct *area;
1598 void *addr;
1599 unsigned long real_size = size;
1600
1601 size = PAGE_ALIGN(size);
1602 if (!size || (size >> PAGE_SHIFT) > totalram_pages)
1603 return NULL;
1604
1605 area = __get_vm_area_node(size, align, VM_ALLOC, start, end, node,
1606 gfp_mask, caller);
1607
1608 if (!area)
1609 return NULL;
1610
1611 addr = __vmalloc_area_node(area, gfp_mask, prot, node, caller);
1612
1613 /*
1614 * A ref_count = 3 is needed because the vm_struct and vmap_area
1615 * structures allocated in the __get_vm_area_node() function contain
1616 * references to the virtual address of the vmalloc'ed block.
1617 */
1618 kmemleak_alloc(addr, real_size, 3, gfp_mask);
1619
1620 return addr;
1621}
1622
1623/**
1624 * __vmalloc_node - allocate virtually contiguous memory
1625 * @size: allocation size
1626 * @align: desired alignment
1627 * @gfp_mask: flags for the page level allocator
1628 * @prot: protection mask for the allocated pages
1629 * @node: node to use for allocation or -1
1630 * @caller: caller's return address
1631 *
1632 * Allocate enough pages to cover @size from the page level
1633 * allocator with @gfp_mask flags. Map them into contiguous
1634 * kernel virtual space, using a pagetable protection of @prot.
1635 */
1636static void *__vmalloc_node(unsigned long size, unsigned long align,
1637 gfp_t gfp_mask, pgprot_t prot,
1638 int node, void *caller)
1639{
1640 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
1641 gfp_mask, prot, node, caller);
1642}
1643
1644void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
1645{
1646 return __vmalloc_node(size, 1, gfp_mask, prot, -1,
1647 __builtin_return_address(0));
1648}
1649EXPORT_SYMBOL(__vmalloc);
1650
1651static inline void *__vmalloc_node_flags(unsigned long size,
1652 int node, gfp_t flags)
1653{
1654 return __vmalloc_node(size, 1, flags, PAGE_KERNEL,
1655 node, __builtin_return_address(0));
1656}
1657
1658/**
1659 * vmalloc - allocate virtually contiguous memory
1660 * @size: allocation size
1661 * Allocate enough pages to cover @size from the page level
1662 * allocator and map them into contiguous kernel virtual space.
1663 *
1664 * For tight control over page level allocator and protection flags
1665 * use __vmalloc() instead.
1666 */
1667void *vmalloc(unsigned long size)
1668{
1669 return __vmalloc_node_flags(size, -1, GFP_KERNEL | __GFP_HIGHMEM);
1670}
1671EXPORT_SYMBOL(vmalloc);
1672
1673/**
1674 * vzalloc - allocate virtually contiguous memory with zero fill
1675 * @size: allocation size
1676 * Allocate enough pages to cover @size from the page level
1677 * allocator and map them into contiguous kernel virtual space.
1678 * The memory allocated is set to zero.
1679 *
1680 * For tight control over page level allocator and protection flags
1681 * use __vmalloc() instead.
1682 */
1683void *vzalloc(unsigned long size)
1684{
1685 return __vmalloc_node_flags(size, -1,
1686 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
1687}
1688EXPORT_SYMBOL(vzalloc);
1689
1690/**
1691 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
1692 * @size: allocation size
1693 *
1694 * The resulting memory area is zeroed so it can be mapped to userspace
1695 * without leaking data.
1696 */
1697void *vmalloc_user(unsigned long size)
1698{
1699 struct vm_struct *area;
1700 void *ret;
1701
1702 ret = __vmalloc_node(size, SHMLBA,
1703 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
1704 PAGE_KERNEL, -1, __builtin_return_address(0));
1705 if (ret) {
1706 area = find_vm_area(ret);
1707 area->flags |= VM_USERMAP;
1708 }
1709 return ret;
1710}
1711EXPORT_SYMBOL(vmalloc_user);
1712
1713/**
1714 * vmalloc_node - allocate memory on a specific node
1715 * @size: allocation size
1716 * @node: numa node
1717 *
1718 * Allocate enough pages to cover @size from the page level
1719 * allocator and map them into contiguous kernel virtual space.
1720 *
1721 * For tight control over page level allocator and protection flags
1722 * use __vmalloc() instead.
1723 */
1724void *vmalloc_node(unsigned long size, int node)
1725{
1726 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
1727 node, __builtin_return_address(0));
1728}
1729EXPORT_SYMBOL(vmalloc_node);
1730
1731/**
1732 * vzalloc_node - allocate memory on a specific node with zero fill
1733 * @size: allocation size
1734 * @node: numa node
1735 *
1736 * Allocate enough pages to cover @size from the page level
1737 * allocator and map them into contiguous kernel virtual space.
1738 * The memory allocated is set to zero.
1739 *
1740 * For tight control over page level allocator and protection flags
1741 * use __vmalloc_node() instead.
1742 */
1743void *vzalloc_node(unsigned long size, int node)
1744{
1745 return __vmalloc_node_flags(size, node,
1746 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
1747}
1748EXPORT_SYMBOL(vzalloc_node);
1749
1750#ifndef PAGE_KERNEL_EXEC
1751# define PAGE_KERNEL_EXEC PAGE_KERNEL
1752#endif
1753
1754/**
1755 * vmalloc_exec - allocate virtually contiguous, executable memory
1756 * @size: allocation size
1757 *
1758 * Kernel-internal function to allocate enough pages to cover @size
1759 * the page level allocator and map them into contiguous and
1760 * executable kernel virtual space.
1761 *
1762 * For tight control over page level allocator and protection flags
1763 * use __vmalloc() instead.
1764 */
1765
1766void *vmalloc_exec(unsigned long size)
1767{
1768 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
1769 -1, __builtin_return_address(0));
1770}
1771
1772#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
1773#define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
1774#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
1775#define GFP_VMALLOC32 GFP_DMA | GFP_KERNEL
1776#else
1777#define GFP_VMALLOC32 GFP_KERNEL
1778#endif
1779
1780/**
1781 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
1782 * @size: allocation size
1783 *
1784 * Allocate enough 32bit PA addressable pages to cover @size from the
1785 * page level allocator and map them into contiguous kernel virtual space.
1786 */
1787void *vmalloc_32(unsigned long size)
1788{
1789 return __vmalloc_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL,
1790 -1, __builtin_return_address(0));
1791}
1792EXPORT_SYMBOL(vmalloc_32);
1793
1794/**
1795 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
1796 * @size: allocation size
1797 *
1798 * The resulting memory area is 32bit addressable and zeroed so it can be
1799 * mapped to userspace without leaking data.
1800 */
1801void *vmalloc_32_user(unsigned long size)
1802{
1803 struct vm_struct *area;
1804 void *ret;
1805
1806 ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
1807 -1, __builtin_return_address(0));
1808 if (ret) {
1809 area = find_vm_area(ret);
1810 area->flags |= VM_USERMAP;
1811 }
1812 return ret;
1813}
1814EXPORT_SYMBOL(vmalloc_32_user);
1815
1816/*
1817 * small helper routine , copy contents to buf from addr.
1818 * If the page is not present, fill zero.
1819 */
1820
1821static int aligned_vread(char *buf, char *addr, unsigned long count)
1822{
1823 struct page *p;
1824 int copied = 0;
1825
1826 while (count) {
1827 unsigned long offset, length;
1828
1829 offset = (unsigned long)addr & ~PAGE_MASK;
1830 length = PAGE_SIZE - offset;
1831 if (length > count)
1832 length = count;
1833 p = vmalloc_to_page(addr);
1834 /*
1835 * To do safe access to this _mapped_ area, we need
1836 * lock. But adding lock here means that we need to add
1837 * overhead of vmalloc()/vfree() calles for this _debug_
1838 * interface, rarely used. Instead of that, we'll use
1839 * kmap() and get small overhead in this access function.
1840 */
1841 if (p) {
1842 /*
1843 * we can expect USER0 is not used (see vread/vwrite's
1844 * function description)
1845 */
1846 void *map = kmap_atomic(p, KM_USER0);
1847 memcpy(buf, map + offset, length);
1848 kunmap_atomic(map, KM_USER0);
1849 } else
1850 memset(buf, 0, length);
1851
1852 addr += length;
1853 buf += length;
1854 copied += length;
1855 count -= length;
1856 }
1857 return copied;
1858}
1859
1860static int aligned_vwrite(char *buf, char *addr, unsigned long count)
1861{
1862 struct page *p;
1863 int copied = 0;
1864
1865 while (count) {
1866 unsigned long offset, length;
1867
1868 offset = (unsigned long)addr & ~PAGE_MASK;
1869 length = PAGE_SIZE - offset;
1870 if (length > count)
1871 length = count;
1872 p = vmalloc_to_page(addr);
1873 /*
1874 * To do safe access to this _mapped_ area, we need
1875 * lock. But adding lock here means that we need to add
1876 * overhead of vmalloc()/vfree() calles for this _debug_
1877 * interface, rarely used. Instead of that, we'll use
1878 * kmap() and get small overhead in this access function.
1879 */
1880 if (p) {
1881 /*
1882 * we can expect USER0 is not used (see vread/vwrite's
1883 * function description)
1884 */
1885 void *map = kmap_atomic(p, KM_USER0);
1886 memcpy(map + offset, buf, length);
1887 kunmap_atomic(map, KM_USER0);
1888 }
1889 addr += length;
1890 buf += length;
1891 copied += length;
1892 count -= length;
1893 }
1894 return copied;
1895}
1896
1897/**
1898 * vread() - read vmalloc area in a safe way.
1899 * @buf: buffer for reading data
1900 * @addr: vm address.
1901 * @count: number of bytes to be read.
1902 *
1903 * Returns # of bytes which addr and buf should be increased.
1904 * (same number to @count). Returns 0 if [addr...addr+count) doesn't
1905 * includes any intersect with alive vmalloc area.
1906 *
1907 * This function checks that addr is a valid vmalloc'ed area, and
1908 * copy data from that area to a given buffer. If the given memory range
1909 * of [addr...addr+count) includes some valid address, data is copied to
1910 * proper area of @buf. If there are memory holes, they'll be zero-filled.
1911 * IOREMAP area is treated as memory hole and no copy is done.
1912 *
1913 * If [addr...addr+count) doesn't includes any intersects with alive
1914 * vm_struct area, returns 0.
1915 * @buf should be kernel's buffer. Because this function uses KM_USER0,
1916 * the caller should guarantee KM_USER0 is not used.
1917 *
1918 * Note: In usual ops, vread() is never necessary because the caller
1919 * should know vmalloc() area is valid and can use memcpy().
1920 * This is for routines which have to access vmalloc area without
1921 * any informaion, as /dev/kmem.
1922 *
1923 */
1924
1925long vread(char *buf, char *addr, unsigned long count)
1926{
1927 struct vm_struct *tmp;
1928 char *vaddr, *buf_start = buf;
1929 unsigned long buflen = count;
1930 unsigned long n;
1931
1932 /* Don't allow overflow */
1933 if ((unsigned long) addr + count < count)
1934 count = -(unsigned long) addr;
1935
1936 read_lock(&vmlist_lock);
1937 for (tmp = vmlist; count && tmp; tmp = tmp->next) {
1938 vaddr = (char *) tmp->addr;
1939 if (addr >= vaddr + tmp->size - PAGE_SIZE)
1940 continue;
1941 while (addr < vaddr) {
1942 if (count == 0)
1943 goto finished;
1944 *buf = '\0';
1945 buf++;
1946 addr++;
1947 count--;
1948 }
1949 n = vaddr + tmp->size - PAGE_SIZE - addr;
1950 if (n > count)
1951 n = count;
1952 if (!(tmp->flags & VM_IOREMAP))
1953 aligned_vread(buf, addr, n);
1954 else /* IOREMAP area is treated as memory hole */
1955 memset(buf, 0, n);
1956 buf += n;
1957 addr += n;
1958 count -= n;
1959 }
1960finished:
1961 read_unlock(&vmlist_lock);
1962
1963 if (buf == buf_start)
1964 return 0;
1965 /* zero-fill memory holes */
1966 if (buf != buf_start + buflen)
1967 memset(buf, 0, buflen - (buf - buf_start));
1968
1969 return buflen;
1970}
1971
1972/**
1973 * vwrite() - write vmalloc area in a safe way.
1974 * @buf: buffer for source data
1975 * @addr: vm address.
1976 * @count: number of bytes to be read.
1977 *
1978 * Returns # of bytes which addr and buf should be incresed.
1979 * (same number to @count).
1980 * If [addr...addr+count) doesn't includes any intersect with valid
1981 * vmalloc area, returns 0.
1982 *
1983 * This function checks that addr is a valid vmalloc'ed area, and
1984 * copy data from a buffer to the given addr. If specified range of
1985 * [addr...addr+count) includes some valid address, data is copied from
1986 * proper area of @buf. If there are memory holes, no copy to hole.
1987 * IOREMAP area is treated as memory hole and no copy is done.
1988 *
1989 * If [addr...addr+count) doesn't includes any intersects with alive
1990 * vm_struct area, returns 0.
1991 * @buf should be kernel's buffer. Because this function uses KM_USER0,
1992 * the caller should guarantee KM_USER0 is not used.
1993 *
1994 * Note: In usual ops, vwrite() is never necessary because the caller
1995 * should know vmalloc() area is valid and can use memcpy().
1996 * This is for routines which have to access vmalloc area without
1997 * any informaion, as /dev/kmem.
1998 */
1999
2000long vwrite(char *buf, char *addr, unsigned long count)
2001{
2002 struct vm_struct *tmp;
2003 char *vaddr;
2004 unsigned long n, buflen;
2005 int copied = 0;
2006
2007 /* Don't allow overflow */
2008 if ((unsigned long) addr + count < count)
2009 count = -(unsigned long) addr;
2010 buflen = count;
2011
2012 read_lock(&vmlist_lock);
2013 for (tmp = vmlist; count && tmp; tmp = tmp->next) {
2014 vaddr = (char *) tmp->addr;
2015 if (addr >= vaddr + tmp->size - PAGE_SIZE)
2016 continue;
2017 while (addr < vaddr) {
2018 if (count == 0)
2019 goto finished;
2020 buf++;
2021 addr++;
2022 count--;
2023 }
2024 n = vaddr + tmp->size - PAGE_SIZE - addr;
2025 if (n > count)
2026 n = count;
2027 if (!(tmp->flags & VM_IOREMAP)) {
2028 aligned_vwrite(buf, addr, n);
2029 copied++;
2030 }
2031 buf += n;
2032 addr += n;
2033 count -= n;
2034 }
2035finished:
2036 read_unlock(&vmlist_lock);
2037 if (!copied)
2038 return 0;
2039 return buflen;
2040}
2041
2042/**
2043 * remap_vmalloc_range - map vmalloc pages to userspace
2044 * @vma: vma to cover (map full range of vma)
2045 * @addr: vmalloc memory
2046 * @pgoff: number of pages into addr before first page to map
2047 *
2048 * Returns: 0 for success, -Exxx on failure
2049 *
2050 * This function checks that addr is a valid vmalloc'ed area, and
2051 * that it is big enough to cover the vma. Will return failure if
2052 * that criteria isn't met.
2053 *
2054 * Similar to remap_pfn_range() (see mm/memory.c)
2055 */
2056int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
2057 unsigned long pgoff)
2058{
2059 struct vm_struct *area;
2060 unsigned long uaddr = vma->vm_start;
2061 unsigned long usize = vma->vm_end - vma->vm_start;
2062
2063 if ((PAGE_SIZE-1) & (unsigned long)addr)
2064 return -EINVAL;
2065
2066 area = find_vm_area(addr);
2067 if (!area)
2068 return -EINVAL;
2069
2070 if (!(area->flags & VM_USERMAP))
2071 return -EINVAL;
2072
2073 if (usize + (pgoff << PAGE_SHIFT) > area->size - PAGE_SIZE)
2074 return -EINVAL;
2075
2076 addr += pgoff << PAGE_SHIFT;
2077 do {
2078 struct page *page = vmalloc_to_page(addr);
2079 int ret;
2080
2081 ret = vm_insert_page(vma, uaddr, page);
2082 if (ret)
2083 return ret;
2084
2085 uaddr += PAGE_SIZE;
2086 addr += PAGE_SIZE;
2087 usize -= PAGE_SIZE;
2088 } while (usize > 0);
2089
2090 /* Prevent "things" like memory migration? VM_flags need a cleanup... */
2091 vma->vm_flags |= VM_RESERVED;
2092
2093 return 0;
2094}
2095EXPORT_SYMBOL(remap_vmalloc_range);
2096
2097/*
2098 * Implement a stub for vmalloc_sync_all() if the architecture chose not to
2099 * have one.
2100 */
2101void __attribute__((weak)) vmalloc_sync_all(void)
2102{
2103}
2104
2105
2106static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
2107{
2108 /* apply_to_page_range() does all the hard work. */
2109 return 0;
2110}
2111
2112/**
2113 * alloc_vm_area - allocate a range of kernel address space
2114 * @size: size of the area
2115 *
2116 * Returns: NULL on failure, vm_struct on success
2117 *
2118 * This function reserves a range of kernel address space, and
2119 * allocates pagetables to map that range. No actual mappings
2120 * are created. If the kernel address space is not shared
2121 * between processes, it syncs the pagetable across all
2122 * processes.
2123 */
2124struct vm_struct *alloc_vm_area(size_t size)
2125{
2126 struct vm_struct *area;
2127
2128 area = get_vm_area_caller(size, VM_IOREMAP,
2129 __builtin_return_address(0));
2130 if (area == NULL)
2131 return NULL;
2132
2133 /*
2134 * This ensures that page tables are constructed for this region
2135 * of kernel virtual address space and mapped into init_mm.
2136 */
2137 if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
2138 area->size, f, NULL)) {
2139 free_vm_area(area);
2140 return NULL;
2141 }
2142
2143 /*
2144 * If the allocated address space is passed to a hypercall
2145 * before being used then we cannot rely on a page fault to
2146 * trigger an update of the page tables. So sync all the page
2147 * tables here.
2148 */
2149 vmalloc_sync_all();
2150
2151 return area;
2152}
2153EXPORT_SYMBOL_GPL(alloc_vm_area);
2154
2155void free_vm_area(struct vm_struct *area)
2156{
2157 struct vm_struct *ret;
2158 ret = remove_vm_area(area->addr);
2159 BUG_ON(ret != area);
2160 kfree(area);
2161}
2162EXPORT_SYMBOL_GPL(free_vm_area);
2163
2164#ifdef CONFIG_SMP
2165static struct vmap_area *node_to_va(struct rb_node *n)
2166{
2167 return n ? rb_entry(n, struct vmap_area, rb_node) : NULL;
2168}
2169
2170/**
2171 * pvm_find_next_prev - find the next and prev vmap_area surrounding @end
2172 * @end: target address
2173 * @pnext: out arg for the next vmap_area
2174 * @pprev: out arg for the previous vmap_area
2175 *
2176 * Returns: %true if either or both of next and prev are found,
2177 * %false if no vmap_area exists
2178 *
2179 * Find vmap_areas end addresses of which enclose @end. ie. if not
2180 * NULL, *pnext->va_end > @end and *pprev->va_end <= @end.
2181 */
2182static bool pvm_find_next_prev(unsigned long end,
2183 struct vmap_area **pnext,
2184 struct vmap_area **pprev)
2185{
2186 struct rb_node *n = vmap_area_root.rb_node;
2187 struct vmap_area *va = NULL;
2188
2189 while (n) {
2190 va = rb_entry(n, struct vmap_area, rb_node);
2191 if (end < va->va_end)
2192 n = n->rb_left;
2193 else if (end > va->va_end)
2194 n = n->rb_right;
2195 else
2196 break;
2197 }
2198
2199 if (!va)
2200 return false;
2201
2202 if (va->va_end > end) {
2203 *pnext = va;
2204 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2205 } else {
2206 *pprev = va;
2207 *pnext = node_to_va(rb_next(&(*pprev)->rb_node));
2208 }
2209 return true;
2210}
2211
2212/**
2213 * pvm_determine_end - find the highest aligned address between two vmap_areas
2214 * @pnext: in/out arg for the next vmap_area
2215 * @pprev: in/out arg for the previous vmap_area
2216 * @align: alignment
2217 *
2218 * Returns: determined end address
2219 *
2220 * Find the highest aligned address between *@pnext and *@pprev below
2221 * VMALLOC_END. *@pnext and *@pprev are adjusted so that the aligned
2222 * down address is between the end addresses of the two vmap_areas.
2223 *
2224 * Please note that the address returned by this function may fall
2225 * inside *@pnext vmap_area. The caller is responsible for checking
2226 * that.
2227 */
2228static unsigned long pvm_determine_end(struct vmap_area **pnext,
2229 struct vmap_area **pprev,
2230 unsigned long align)
2231{
2232 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2233 unsigned long addr;
2234
2235 if (*pnext)
2236 addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end);
2237 else
2238 addr = vmalloc_end;
2239
2240 while (*pprev && (*pprev)->va_end > addr) {
2241 *pnext = *pprev;
2242 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2243 }
2244
2245 return addr;
2246}
2247
2248/**
2249 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
2250 * @offsets: array containing offset of each area
2251 * @sizes: array containing size of each area
2252 * @nr_vms: the number of areas to allocate
2253 * @align: alignment, all entries in @offsets and @sizes must be aligned to this
2254 *
2255 * Returns: kmalloc'd vm_struct pointer array pointing to allocated
2256 * vm_structs on success, %NULL on failure
2257 *
2258 * Percpu allocator wants to use congruent vm areas so that it can
2259 * maintain the offsets among percpu areas. This function allocates
2260 * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to
2261 * be scattered pretty far, distance between two areas easily going up
2262 * to gigabytes. To avoid interacting with regular vmallocs, these
2263 * areas are allocated from top.
2264 *
2265 * Despite its complicated look, this allocator is rather simple. It
2266 * does everything top-down and scans areas from the end looking for
2267 * matching slot. While scanning, if any of the areas overlaps with
2268 * existing vmap_area, the base address is pulled down to fit the
2269 * area. Scanning is repeated till all the areas fit and then all
2270 * necessary data structres are inserted and the result is returned.
2271 */
2272struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
2273 const size_t *sizes, int nr_vms,
2274 size_t align)
2275{
2276 const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
2277 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2278 struct vmap_area **vas, *prev, *next;
2279 struct vm_struct **vms;
2280 int area, area2, last_area, term_area;
2281 unsigned long base, start, end, last_end;
2282 bool purged = false;
2283
2284 /* verify parameters and allocate data structures */
2285 BUG_ON(align & ~PAGE_MASK || !is_power_of_2(align));
2286 for (last_area = 0, area = 0; area < nr_vms; area++) {
2287 start = offsets[area];
2288 end = start + sizes[area];
2289
2290 /* is everything aligned properly? */
2291 BUG_ON(!IS_ALIGNED(offsets[area], align));
2292 BUG_ON(!IS_ALIGNED(sizes[area], align));
2293
2294 /* detect the area with the highest address */
2295 if (start > offsets[last_area])
2296 last_area = area;
2297
2298 for (area2 = 0; area2 < nr_vms; area2++) {
2299 unsigned long start2 = offsets[area2];
2300 unsigned long end2 = start2 + sizes[area2];
2301
2302 if (area2 == area)
2303 continue;
2304
2305 BUG_ON(start2 >= start && start2 < end);
2306 BUG_ON(end2 <= end && end2 > start);
2307 }
2308 }
2309 last_end = offsets[last_area] + sizes[last_area];
2310
2311 if (vmalloc_end - vmalloc_start < last_end) {
2312 WARN_ON(true);
2313 return NULL;
2314 }
2315
2316 vms = kzalloc(sizeof(vms[0]) * nr_vms, GFP_KERNEL);
2317 vas = kzalloc(sizeof(vas[0]) * nr_vms, GFP_KERNEL);
2318 if (!vas || !vms)
2319 goto err_free;
2320
2321 for (area = 0; area < nr_vms; area++) {
2322 vas[area] = kzalloc(sizeof(struct vmap_area), GFP_KERNEL);
2323 vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
2324 if (!vas[area] || !vms[area])
2325 goto err_free;
2326 }
2327retry:
2328 spin_lock(&vmap_area_lock);
2329
2330 /* start scanning - we scan from the top, begin with the last area */
2331 area = term_area = last_area;
2332 start = offsets[area];
2333 end = start + sizes[area];
2334
2335 if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) {
2336 base = vmalloc_end - last_end;
2337 goto found;
2338 }
2339 base = pvm_determine_end(&next, &prev, align) - end;
2340
2341 while (true) {
2342 BUG_ON(next && next->va_end <= base + end);
2343 BUG_ON(prev && prev->va_end > base + end);
2344
2345 /*
2346 * base might have underflowed, add last_end before
2347 * comparing.
2348 */
2349 if (base + last_end < vmalloc_start + last_end) {
2350 spin_unlock(&vmap_area_lock);
2351 if (!purged) {
2352 purge_vmap_area_lazy();
2353 purged = true;
2354 goto retry;
2355 }
2356 goto err_free;
2357 }
2358
2359 /*
2360 * If next overlaps, move base downwards so that it's
2361 * right below next and then recheck.
2362 */
2363 if (next && next->va_start < base + end) {
2364 base = pvm_determine_end(&next, &prev, align) - end;
2365 term_area = area;
2366 continue;
2367 }
2368
2369 /*
2370 * If prev overlaps, shift down next and prev and move
2371 * base so that it's right below new next and then
2372 * recheck.
2373 */
2374 if (prev && prev->va_end > base + start) {
2375 next = prev;
2376 prev = node_to_va(rb_prev(&next->rb_node));
2377 base = pvm_determine_end(&next, &prev, align) - end;
2378 term_area = area;
2379 continue;
2380 }
2381
2382 /*
2383 * This area fits, move on to the previous one. If
2384 * the previous one is the terminal one, we're done.
2385 */
2386 area = (area + nr_vms - 1) % nr_vms;
2387 if (area == term_area)
2388 break;
2389 start = offsets[area];
2390 end = start + sizes[area];
2391 pvm_find_next_prev(base + end, &next, &prev);
2392 }
2393found:
2394 /* we've found a fitting base, insert all va's */
2395 for (area = 0; area < nr_vms; area++) {
2396 struct vmap_area *va = vas[area];
2397
2398 va->va_start = base + offsets[area];
2399 va->va_end = va->va_start + sizes[area];
2400 __insert_vmap_area(va);
2401 }
2402
2403 vmap_area_pcpu_hole = base + offsets[last_area];
2404
2405 spin_unlock(&vmap_area_lock);
2406
2407 /* insert all vm's */
2408 for (area = 0; area < nr_vms; area++)
2409 insert_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
2410 pcpu_get_vm_areas);
2411
2412 kfree(vas);
2413 return vms;
2414
2415err_free:
2416 for (area = 0; area < nr_vms; area++) {
2417 if (vas)
2418 kfree(vas[area]);
2419 if (vms)
2420 kfree(vms[area]);
2421 }
2422 kfree(vas);
2423 kfree(vms);
2424 return NULL;
2425}
2426
2427/**
2428 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
2429 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
2430 * @nr_vms: the number of allocated areas
2431 *
2432 * Free vm_structs and the array allocated by pcpu_get_vm_areas().
2433 */
2434void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
2435{
2436 int i;
2437
2438 for (i = 0; i < nr_vms; i++)
2439 free_vm_area(vms[i]);
2440 kfree(vms);
2441}
2442#endif /* CONFIG_SMP */
2443
2444#ifdef CONFIG_PROC_FS
2445static void *s_start(struct seq_file *m, loff_t *pos)
2446 __acquires(&vmlist_lock)
2447{
2448 loff_t n = *pos;
2449 struct vm_struct *v;
2450
2451 read_lock(&vmlist_lock);
2452 v = vmlist;
2453 while (n > 0 && v) {
2454 n--;
2455 v = v->next;
2456 }
2457 if (!n)
2458 return v;
2459
2460 return NULL;
2461
2462}
2463
2464static void *s_next(struct seq_file *m, void *p, loff_t *pos)
2465{
2466 struct vm_struct *v = p;
2467
2468 ++*pos;
2469 return v->next;
2470}
2471
2472static void s_stop(struct seq_file *m, void *p)
2473 __releases(&vmlist_lock)
2474{
2475 read_unlock(&vmlist_lock);
2476}
2477
2478static void show_numa_info(struct seq_file *m, struct vm_struct *v)
2479{
2480 if (NUMA_BUILD) {
2481 unsigned int nr, *counters = m->private;
2482
2483 if (!counters)
2484 return;
2485
2486 memset(counters, 0, nr_node_ids * sizeof(unsigned int));
2487
2488 for (nr = 0; nr < v->nr_pages; nr++)
2489 counters[page_to_nid(v->pages[nr])]++;
2490
2491 for_each_node_state(nr, N_HIGH_MEMORY)
2492 if (counters[nr])
2493 seq_printf(m, " N%u=%u", nr, counters[nr]);
2494 }
2495}
2496
2497static int s_show(struct seq_file *m, void *p)
2498{
2499 struct vm_struct *v = p;
2500
2501 seq_printf(m, "0x%p-0x%p %7ld",
2502 v->addr, v->addr + v->size, v->size);
2503
2504 if (v->caller)
2505 seq_printf(m, " %pS", v->caller);
2506
2507 if (v->nr_pages)
2508 seq_printf(m, " pages=%d", v->nr_pages);
2509
2510 if (v->phys_addr)
2511 seq_printf(m, " phys=%llx", (unsigned long long)v->phys_addr);
2512
2513 if (v->flags & VM_IOREMAP)
2514 seq_printf(m, " ioremap");
2515
2516 if (v->flags & VM_ALLOC)
2517 seq_printf(m, " vmalloc");
2518
2519 if (v->flags & VM_MAP)
2520 seq_printf(m, " vmap");
2521
2522 if (v->flags & VM_USERMAP)
2523 seq_printf(m, " user");
2524
2525 if (v->flags & VM_VPAGES)
2526 seq_printf(m, " vpages");
2527
2528 show_numa_info(m, v);
2529 seq_putc(m, '\n');
2530 return 0;
2531}
2532
2533static const struct seq_operations vmalloc_op = {
2534 .start = s_start,
2535 .next = s_next,
2536 .stop = s_stop,
2537 .show = s_show,
2538};
2539
2540static int vmalloc_open(struct inode *inode, struct file *file)
2541{
2542 unsigned int *ptr = NULL;
2543 int ret;
2544
2545 if (NUMA_BUILD) {
2546 ptr = kmalloc(nr_node_ids * sizeof(unsigned int), GFP_KERNEL);
2547 if (ptr == NULL)
2548 return -ENOMEM;
2549 }
2550 ret = seq_open(file, &vmalloc_op);
2551 if (!ret) {
2552 struct seq_file *m = file->private_data;
2553 m->private = ptr;
2554 } else
2555 kfree(ptr);
2556 return ret;
2557}
2558
2559static const struct file_operations proc_vmalloc_operations = {
2560 .open = vmalloc_open,
2561 .read = seq_read,
2562 .llseek = seq_lseek,
2563 .release = seq_release_private,
2564};
2565
2566static int __init proc_vmalloc_init(void)
2567{
2568 proc_create("vmallocinfo", S_IRUSR, NULL, &proc_vmalloc_operations);
2569 return 0;
2570}
2571module_init(proc_vmalloc_init);
2572#endif
2573