projects/linux·blob v3.0 · refs

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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 <[email protected]>, 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 <asm/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 rcu_free_va(struct rcu_head *head)
456{
457 struct vmap_area *va = container_of(head, struct vmap_area, rcu_head);
458
459 kfree(va);
460}
461
462static void __free_vmap_area(struct vmap_area *va)
463{
464 BUG_ON(RB_EMPTY_NODE(&va->rb_node));
465
466 if (free_vmap_cache) {
467 if (va->va_end < cached_vstart) {
468 free_vmap_cache = NULL;
469 } else {
470 struct vmap_area *cache;
471 cache = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
472 if (va->va_start <= cache->va_start) {
473 free_vmap_cache = rb_prev(&va->rb_node);
474 /*
475 * We don't try to update cached_hole_size or
476 * cached_align, but it won't go very wrong.
477 */
478 }
479 }
480 }
481 rb_erase(&va->rb_node, &vmap_area_root);
482 RB_CLEAR_NODE(&va->rb_node);
483 list_del_rcu(&va->list);
484
485 /*
486 * Track the highest possible candidate for pcpu area
487 * allocation. Areas outside of vmalloc area can be returned
488 * here too, consider only end addresses which fall inside
489 * vmalloc area proper.
490 */
491 if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END)
492 vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end);
493
494 call_rcu(&va->rcu_head, rcu_free_va);
495}
496
497/*
498 * Free a region of KVA allocated by alloc_vmap_area
499 */
500static void free_vmap_area(struct vmap_area *va)
501{
502 spin_lock(&vmap_area_lock);
503 __free_vmap_area(va);
504 spin_unlock(&vmap_area_lock);
505}
506
507/*
508 * Clear the pagetable entries of a given vmap_area
509 */
510static void unmap_vmap_area(struct vmap_area *va)
511{
512 vunmap_page_range(va->va_start, va->va_end);
513}
514
515static void vmap_debug_free_range(unsigned long start, unsigned long end)
516{
517 /*
518 * Unmap page tables and force a TLB flush immediately if
519 * CONFIG_DEBUG_PAGEALLOC is set. This catches use after free
520 * bugs similarly to those in linear kernel virtual address
521 * space after a page has been freed.
522 *
523 * All the lazy freeing logic is still retained, in order to
524 * minimise intrusiveness of this debugging feature.
525 *
526 * This is going to be *slow* (linear kernel virtual address
527 * debugging doesn't do a broadcast TLB flush so it is a lot
528 * faster).
529 */
530#ifdef CONFIG_DEBUG_PAGEALLOC
531 vunmap_page_range(start, end);
532 flush_tlb_kernel_range(start, end);
533#endif
534}
535
536/*
537 * lazy_max_pages is the maximum amount of virtual address space we gather up
538 * before attempting to purge with a TLB flush.
539 *
540 * There is a tradeoff here: a larger number will cover more kernel page tables
541 * and take slightly longer to purge, but it will linearly reduce the number of
542 * global TLB flushes that must be performed. It would seem natural to scale
543 * this number up linearly with the number of CPUs (because vmapping activity
544 * could also scale linearly with the number of CPUs), however it is likely
545 * that in practice, workloads might be constrained in other ways that mean
546 * vmap activity will not scale linearly with CPUs. Also, I want to be
547 * conservative and not introduce a big latency on huge systems, so go with
548 * a less aggressive log scale. It will still be an improvement over the old
549 * code, and it will be simple to change the scale factor if we find that it
550 * becomes a problem on bigger systems.
551 */
552static unsigned long lazy_max_pages(void)
553{
554 unsigned int log;
555
556 log = fls(num_online_cpus());
557
558 return log * (32UL * 1024 * 1024 / PAGE_SIZE);
559}
560
561static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);
562
563/* for per-CPU blocks */
564static void purge_fragmented_blocks_allcpus(void);
565
566/*
567 * called before a call to iounmap() if the caller wants vm_area_struct's
568 * immediately freed.
569 */
570void set_iounmap_nonlazy(void)
571{
572 atomic_set(&vmap_lazy_nr, lazy_max_pages()+1);
573}
574
575/*
576 * Purges all lazily-freed vmap areas.
577 *
578 * If sync is 0 then don't purge if there is already a purge in progress.
579 * If force_flush is 1, then flush kernel TLBs between *start and *end even
580 * if we found no lazy vmap areas to unmap (callers can use this to optimise
581 * their own TLB flushing).
582 * Returns with *start = min(*start, lowest purged address)
583 * *end = max(*end, highest purged address)
584 */
585static void __purge_vmap_area_lazy(unsigned long *start, unsigned long *end,
586 int sync, int force_flush)
587{
588 static DEFINE_SPINLOCK(purge_lock);
589 LIST_HEAD(valist);
590 struct vmap_area *va;
591 struct vmap_area *n_va;
592 int nr = 0;
593
594 /*
595 * If sync is 0 but force_flush is 1, we'll go sync anyway but callers
596 * should not expect such behaviour. This just simplifies locking for
597 * the case that isn't actually used at the moment anyway.
598 */
599 if (!sync && !force_flush) {
600 if (!spin_trylock(&purge_lock))
601 return;
602 } else
603 spin_lock(&purge_lock);
604
605 if (sync)
606 purge_fragmented_blocks_allcpus();
607
608 rcu_read_lock();
609 list_for_each_entry_rcu(va, &vmap_area_list, list) {
610 if (va->flags & VM_LAZY_FREE) {
611 if (va->va_start < *start)
612 *start = va->va_start;
613 if (va->va_end > *end)
614 *end = va->va_end;
615 nr += (va->va_end - va->va_start) >> PAGE_SHIFT;
616 list_add_tail(&va->purge_list, &valist);
617 va->flags |= VM_LAZY_FREEING;
618 va->flags &= ~VM_LAZY_FREE;
619 }
620 }
621 rcu_read_unlock();
622
623 if (nr)
624 atomic_sub(nr, &vmap_lazy_nr);
625
626 if (nr || force_flush)
627 flush_tlb_kernel_range(*start, *end);
628
629 if (nr) {
630 spin_lock(&vmap_area_lock);
631 list_for_each_entry_safe(va, n_va, &valist, purge_list)
632 __free_vmap_area(va);
633 spin_unlock(&vmap_area_lock);
634 }
635 spin_unlock(&purge_lock);
636}
637
638/*
639 * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
640 * is already purging.
641 */
642static void try_purge_vmap_area_lazy(void)
643{
644 unsigned long start = ULONG_MAX, end = 0;
645
646 __purge_vmap_area_lazy(&start, &end, 0, 0);
647}
648
649/*
650 * Kick off a purge of the outstanding lazy areas.
651 */
652static void purge_vmap_area_lazy(void)
653{
654 unsigned long start = ULONG_MAX, end = 0;
655
656 __purge_vmap_area_lazy(&start, &end, 1, 0);
657}
658
659/*
660 * Free a vmap area, caller ensuring that the area has been unmapped
661 * and flush_cache_vunmap had been called for the correct range
662 * previously.
663 */
664static void free_vmap_area_noflush(struct vmap_area *va)
665{
666 va->flags |= VM_LAZY_FREE;
667 atomic_add((va->va_end - va->va_start) >> PAGE_SHIFT, &vmap_lazy_nr);
668 if (unlikely(atomic_read(&vmap_lazy_nr) > lazy_max_pages()))
669 try_purge_vmap_area_lazy();
670}
671
672/*
673 * Free and unmap a vmap area, caller ensuring flush_cache_vunmap had been
674 * called for the correct range previously.
675 */
676static void free_unmap_vmap_area_noflush(struct vmap_area *va)
677{
678 unmap_vmap_area(va);
679 free_vmap_area_noflush(va);
680}
681
682/*
683 * Free and unmap a vmap area
684 */
685static void free_unmap_vmap_area(struct vmap_area *va)
686{
687 flush_cache_vunmap(va->va_start, va->va_end);
688 free_unmap_vmap_area_noflush(va);
689}
690
691static struct vmap_area *find_vmap_area(unsigned long addr)
692{
693 struct vmap_area *va;
694
695 spin_lock(&vmap_area_lock);
696 va = __find_vmap_area(addr);
697 spin_unlock(&vmap_area_lock);
698
699 return va;
700}
701
702static void free_unmap_vmap_area_addr(unsigned long addr)
703{
704 struct vmap_area *va;
705
706 va = find_vmap_area(addr);
707 BUG_ON(!va);
708 free_unmap_vmap_area(va);
709}
710
711
712/*** Per cpu kva allocator ***/
713
714/*
715 * vmap space is limited especially on 32 bit architectures. Ensure there is
716 * room for at least 16 percpu vmap blocks per CPU.
717 */
718/*
719 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
720 * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess
721 * instead (we just need a rough idea)
722 */
723#if BITS_PER_LONG == 32
724#define VMALLOC_SPACE (128UL*1024*1024)
725#else
726#define VMALLOC_SPACE (128UL*1024*1024*1024)
727#endif
728
729#define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE)
730#define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */
731#define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */
732#define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
733#define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
734#define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
735#define VMAP_BBMAP_BITS VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
736 VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
737 VMALLOC_PAGES / NR_CPUS / 16))
738
739#define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
740
741static bool vmap_initialized __read_mostly = false;
742
743struct vmap_block_queue {
744 spinlock_t lock;
745 struct list_head free;
746};
747
748struct vmap_block {
749 spinlock_t lock;
750 struct vmap_area *va;
751 struct vmap_block_queue *vbq;
752 unsigned long free, dirty;
753 DECLARE_BITMAP(alloc_map, VMAP_BBMAP_BITS);
754 DECLARE_BITMAP(dirty_map, VMAP_BBMAP_BITS);
755 struct list_head free_list;
756 struct rcu_head rcu_head;
757 struct list_head purge;
758};
759
760/* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
761static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
762
763/*
764 * Radix tree of vmap blocks, indexed by address, to quickly find a vmap block
765 * in the free path. Could get rid of this if we change the API to return a
766 * "cookie" from alloc, to be passed to free. But no big deal yet.
767 */
768static DEFINE_SPINLOCK(vmap_block_tree_lock);
769static RADIX_TREE(vmap_block_tree, GFP_ATOMIC);
770
771/*
772 * We should probably have a fallback mechanism to allocate virtual memory
773 * out of partially filled vmap blocks. However vmap block sizing should be
774 * fairly reasonable according to the vmalloc size, so it shouldn't be a
775 * big problem.
776 */
777
778static unsigned long addr_to_vb_idx(unsigned long addr)
779{
780 addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
781 addr /= VMAP_BLOCK_SIZE;
782 return addr;
783}
784
785static struct vmap_block *new_vmap_block(gfp_t gfp_mask)
786{
787 struct vmap_block_queue *vbq;
788 struct vmap_block *vb;
789 struct vmap_area *va;
790 unsigned long vb_idx;
791 int node, err;
792
793 node = numa_node_id();
794
795 vb = kmalloc_node(sizeof(struct vmap_block),
796 gfp_mask & GFP_RECLAIM_MASK, node);
797 if (unlikely(!vb))
798 return ERR_PTR(-ENOMEM);
799
800 va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
801 VMALLOC_START, VMALLOC_END,
802 node, gfp_mask);
803 if (IS_ERR(va)) {
804 kfree(vb);
805 return ERR_CAST(va);
806 }
807
808 err = radix_tree_preload(gfp_mask);
809 if (unlikely(err)) {
810 kfree(vb);
811 free_vmap_area(va);
812 return ERR_PTR(err);
813 }
814
815 spin_lock_init(&vb->lock);
816 vb->va = va;
817 vb->free = VMAP_BBMAP_BITS;
818 vb->dirty = 0;
819 bitmap_zero(vb->alloc_map, VMAP_BBMAP_BITS);
820 bitmap_zero(vb->dirty_map, VMAP_BBMAP_BITS);
821 INIT_LIST_HEAD(&vb->free_list);
822
823 vb_idx = addr_to_vb_idx(va->va_start);
824 spin_lock(&vmap_block_tree_lock);
825 err = radix_tree_insert(&vmap_block_tree, vb_idx, vb);
826 spin_unlock(&vmap_block_tree_lock);
827 BUG_ON(err);
828 radix_tree_preload_end();
829
830 vbq = &get_cpu_var(vmap_block_queue);
831 vb->vbq = vbq;
832 spin_lock(&vbq->lock);
833 list_add_rcu(&vb->free_list, &vbq->free);
834 spin_unlock(&vbq->lock);
835 put_cpu_var(vmap_block_queue);
836
837 return vb;
838}
839
840static void rcu_free_vb(struct rcu_head *head)
841{
842 struct vmap_block *vb = container_of(head, struct vmap_block, rcu_head);
843
844 kfree(vb);
845}
846
847static void free_vmap_block(struct vmap_block *vb)
848{
849 struct vmap_block *tmp;
850 unsigned long vb_idx;
851
852 vb_idx = addr_to_vb_idx(vb->va->va_start);
853 spin_lock(&vmap_block_tree_lock);
854 tmp = radix_tree_delete(&vmap_block_tree, vb_idx);
855 spin_unlock(&vmap_block_tree_lock);
856 BUG_ON(tmp != vb);
857
858 free_vmap_area_noflush(vb->va);
859 call_rcu(&vb->rcu_head, rcu_free_vb);
860}
861
862static void purge_fragmented_blocks(int cpu)
863{
864 LIST_HEAD(purge);
865 struct vmap_block *vb;
866 struct vmap_block *n_vb;
867 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
868
869 rcu_read_lock();
870 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
871
872 if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
873 continue;
874
875 spin_lock(&vb->lock);
876 if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
877 vb->free = 0; /* prevent further allocs after releasing lock */
878 vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
879 bitmap_fill(vb->alloc_map, VMAP_BBMAP_BITS);
880 bitmap_fill(vb->dirty_map, VMAP_BBMAP_BITS);
881 spin_lock(&vbq->lock);
882 list_del_rcu(&vb->free_list);
883 spin_unlock(&vbq->lock);
884 spin_unlock(&vb->lock);
885 list_add_tail(&vb->purge, &purge);
886 } else
887 spin_unlock(&vb->lock);
888 }
889 rcu_read_unlock();
890
891 list_for_each_entry_safe(vb, n_vb, &purge, purge) {
892 list_del(&vb->purge);
893 free_vmap_block(vb);
894 }
895}
896
897static void purge_fragmented_blocks_thiscpu(void)
898{
899 purge_fragmented_blocks(smp_processor_id());
900}
901
902static void purge_fragmented_blocks_allcpus(void)
903{
904 int cpu;
905
906 for_each_possible_cpu(cpu)
907 purge_fragmented_blocks(cpu);
908}
909
910static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
911{
912 struct vmap_block_queue *vbq;
913 struct vmap_block *vb;
914 unsigned long addr = 0;
915 unsigned int order;
916 int purge = 0;
917
918 BUG_ON(size & ~PAGE_MASK);
919 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
920 order = get_order(size);
921
922again:
923 rcu_read_lock();
924 vbq = &get_cpu_var(vmap_block_queue);
925 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
926 int i;
927
928 spin_lock(&vb->lock);
929 if (vb->free < 1UL << order)
930 goto next;
931
932 i = bitmap_find_free_region(vb->alloc_map,
933 VMAP_BBMAP_BITS, order);
934
935 if (i < 0) {
936 if (vb->free + vb->dirty == VMAP_BBMAP_BITS) {
937 /* fragmented and no outstanding allocations */
938 BUG_ON(vb->dirty != VMAP_BBMAP_BITS);
939 purge = 1;
940 }
941 goto next;
942 }
943 addr = vb->va->va_start + (i << PAGE_SHIFT);
944 BUG_ON(addr_to_vb_idx(addr) !=
945 addr_to_vb_idx(vb->va->va_start));
946 vb->free -= 1UL << order;
947 if (vb->free == 0) {
948 spin_lock(&vbq->lock);
949 list_del_rcu(&vb->free_list);
950 spin_unlock(&vbq->lock);
951 }
952 spin_unlock(&vb->lock);
953 break;
954next:
955 spin_unlock(&vb->lock);
956 }
957
958 if (purge)
959 purge_fragmented_blocks_thiscpu();
960
961 put_cpu_var(vmap_block_queue);
962 rcu_read_unlock();
963
964 if (!addr) {
965 vb = new_vmap_block(gfp_mask);
966 if (IS_ERR(vb))
967 return vb;
968 goto again;
969 }
970
971 return (void *)addr;
972}
973
974static void vb_free(const void *addr, unsigned long size)
975{
976 unsigned long offset;
977 unsigned long vb_idx;
978 unsigned int order;
979 struct vmap_block *vb;
980
981 BUG_ON(size & ~PAGE_MASK);
982 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
983
984 flush_cache_vunmap((unsigned long)addr, (unsigned long)addr + size);
985
986 order = get_order(size);
987
988 offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1);
989
990 vb_idx = addr_to_vb_idx((unsigned long)addr);
991 rcu_read_lock();
992 vb = radix_tree_lookup(&vmap_block_tree, vb_idx);
993 rcu_read_unlock();
994 BUG_ON(!vb);
995
996 vunmap_page_range((unsigned long)addr, (unsigned long)addr + size);
997
998 spin_lock(&vb->lock);
999 BUG_ON(bitmap_allocate_region(vb->dirty_map, offset >> PAGE_SHIFT, order));
1000
1001 vb->dirty += 1UL << order;
1002 if (vb->dirty == VMAP_BBMAP_BITS) {
1003 BUG_ON(vb->free);
1004 spin_unlock(&vb->lock);
1005 free_vmap_block(vb);
1006 } else
1007 spin_unlock(&vb->lock);
1008}
1009
1010/**
1011 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
1012 *
1013 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
1014 * to amortize TLB flushing overheads. What this means is that any page you
1015 * have now, may, in a former life, have been mapped into kernel virtual
1016 * address by the vmap layer and so there might be some CPUs with TLB entries
1017 * still referencing that page (additional to the regular 1:1 kernel mapping).
1018 *
1019 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
1020 * be sure that none of the pages we have control over will have any aliases
1021 * from the vmap layer.
1022 */
1023void vm_unmap_aliases(void)
1024{
1025 unsigned long start = ULONG_MAX, end = 0;
1026 int cpu;
1027 int flush = 0;
1028
1029 if (unlikely(!vmap_initialized))
1030 return;
1031
1032 for_each_possible_cpu(cpu) {
1033 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
1034 struct vmap_block *vb;
1035
1036 rcu_read_lock();
1037 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
1038 int i;
1039
1040 spin_lock(&vb->lock);
1041 i = find_first_bit(vb->dirty_map, VMAP_BBMAP_BITS);
1042 while (i < VMAP_BBMAP_BITS) {
1043 unsigned long s, e;
1044 int j;
1045 j = find_next_zero_bit(vb->dirty_map,
1046 VMAP_BBMAP_BITS, i);
1047
1048 s = vb->va->va_start + (i << PAGE_SHIFT);
1049 e = vb->va->va_start + (j << PAGE_SHIFT);
1050 flush = 1;
1051
1052 if (s < start)
1053 start = s;
1054 if (e > end)
1055 end = e;
1056
1057 i = j;
1058 i = find_next_bit(vb->dirty_map,
1059 VMAP_BBMAP_BITS, i);
1060 }
1061 spin_unlock(&vb->lock);
1062 }
1063 rcu_read_unlock();
1064 }
1065
1066 __purge_vmap_area_lazy(&start, &end, 1, flush);
1067}
1068EXPORT_SYMBOL_GPL(vm_unmap_aliases);
1069
1070/**
1071 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
1072 * @mem: the pointer returned by vm_map_ram
1073 * @count: the count passed to that vm_map_ram call (cannot unmap partial)
1074 */
1075void vm_unmap_ram(const void *mem, unsigned int count)
1076{
1077 unsigned long size = count << PAGE_SHIFT;
1078 unsigned long addr = (unsigned long)mem;
1079
1080 BUG_ON(!addr);
1081 BUG_ON(addr < VMALLOC_START);
1082 BUG_ON(addr > VMALLOC_END);
1083 BUG_ON(addr & (PAGE_SIZE-1));
1084
1085 debug_check_no_locks_freed(mem, size);
1086 vmap_debug_free_range(addr, addr+size);
1087
1088 if (likely(count <= VMAP_MAX_ALLOC))
1089 vb_free(mem, size);
1090 else
1091 free_unmap_vmap_area_addr(addr);
1092}
1093EXPORT_SYMBOL(vm_unmap_ram);
1094
1095/**
1096 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
1097 * @pages: an array of pointers to the pages to be mapped
1098 * @count: number of pages
1099 * @node: prefer to allocate data structures on this node
1100 * @prot: memory protection to use. PAGE_KERNEL for regular RAM
1101 *
1102 * Returns: a pointer to the address that has been mapped, or %NULL on failure
1103 */
1104void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot)
1105{
1106 unsigned long size = count << PAGE_SHIFT;
1107 unsigned long addr;
1108 void *mem;
1109
1110 if (likely(count <= VMAP_MAX_ALLOC)) {
1111 mem = vb_alloc(size, GFP_KERNEL);
1112 if (IS_ERR(mem))
1113 return NULL;
1114 addr = (unsigned long)mem;
1115 } else {
1116 struct vmap_area *va;
1117 va = alloc_vmap_area(size, PAGE_SIZE,
1118 VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
1119 if (IS_ERR(va))
1120 return NULL;
1121
1122 addr = va->va_start;
1123 mem = (void *)addr;
1124 }
1125 if (vmap_page_range(addr, addr + size, prot, pages) < 0) {
1126 vm_unmap_ram(mem, count);
1127 return NULL;
1128 }
1129 return mem;
1130}
1131EXPORT_SYMBOL(vm_map_ram);
1132
1133/**
1134 * vm_area_register_early - register vmap area early during boot
1135 * @vm: vm_struct to register
1136 * @align: requested alignment
1137 *
1138 * This function is used to register kernel vm area before
1139 * vmalloc_init() is called. @vm->size and @vm->flags should contain
1140 * proper values on entry and other fields should be zero. On return,
1141 * vm->addr contains the allocated address.
1142 *
1143 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
1144 */
1145void __init vm_area_register_early(struct vm_struct *vm, size_t align)
1146{
1147 static size_t vm_init_off __initdata;
1148 unsigned long addr;
1149
1150 addr = ALIGN(VMALLOC_START + vm_init_off, align);
1151 vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
1152
1153 vm->addr = (void *)addr;
1154
1155 vm->next = vmlist;
1156 vmlist = vm;
1157}
1158
1159void __init vmalloc_init(void)
1160{
1161 struct vmap_area *va;
1162 struct vm_struct *tmp;
1163 int i;
1164
1165 for_each_possible_cpu(i) {
1166 struct vmap_block_queue *vbq;
1167
1168 vbq = &per_cpu(vmap_block_queue, i);
1169 spin_lock_init(&vbq->lock);
1170 INIT_LIST_HEAD(&vbq->free);
1171 }
1172
1173 /* Import existing vmlist entries. */
1174 for (tmp = vmlist; tmp; tmp = tmp->next) {
1175 va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
1176 va->flags = tmp->flags | VM_VM_AREA;
1177 va->va_start = (unsigned long)tmp->addr;
1178 va->va_end = va->va_start + tmp->size;
1179 __insert_vmap_area(va);
1180 }
1181
1182 vmap_area_pcpu_hole = VMALLOC_END;
1183
1184 vmap_initialized = true;
1185}
1186
1187/**
1188 * map_kernel_range_noflush - map kernel VM area with the specified pages
1189 * @addr: start of the VM area to map
1190 * @size: size of the VM area to map
1191 * @prot: page protection flags to use
1192 * @pages: pages to map
1193 *
1194 * Map PFN_UP(@size) pages at @addr. The VM area @addr and @size
1195 * specify should have been allocated using get_vm_area() and its
1196 * friends.
1197 *
1198 * NOTE:
1199 * This function does NOT do any cache flushing. The caller is
1200 * responsible for calling flush_cache_vmap() on to-be-mapped areas
1201 * before calling this function.
1202 *
1203 * RETURNS:
1204 * The number of pages mapped on success, -errno on failure.
1205 */
1206int map_kernel_range_noflush(unsigned long addr, unsigned long size,
1207 pgprot_t prot, struct page **pages)
1208{
1209 return vmap_page_range_noflush(addr, addr + size, prot, pages);
1210}
1211
1212/**
1213 * unmap_kernel_range_noflush - unmap kernel VM area
1214 * @addr: start of the VM area to unmap
1215 * @size: size of the VM area to unmap
1216 *
1217 * Unmap PFN_UP(@size) pages at @addr. The VM area @addr and @size
1218 * specify should have been allocated using get_vm_area() and its
1219 * friends.
1220 *
1221 * NOTE:
1222 * This function does NOT do any cache flushing. The caller is
1223 * responsible for calling flush_cache_vunmap() on to-be-mapped areas
1224 * before calling this function and flush_tlb_kernel_range() after.
1225 */
1226void unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
1227{
1228 vunmap_page_range(addr, addr + size);
1229}
1230EXPORT_SYMBOL_GPL(unmap_kernel_range_noflush);
1231
1232/**
1233 * unmap_kernel_range - unmap kernel VM area and flush cache and TLB
1234 * @addr: start of the VM area to unmap
1235 * @size: size of the VM area to unmap
1236 *
1237 * Similar to unmap_kernel_range_noflush() but flushes vcache before
1238 * the unmapping and tlb after.
1239 */
1240void unmap_kernel_range(unsigned long addr, unsigned long size)
1241{
1242 unsigned long end = addr + size;
1243
1244 flush_cache_vunmap(addr, end);
1245 vunmap_page_range(addr, end);
1246 flush_tlb_kernel_range(addr, end);
1247}
1248
1249int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages)
1250{
1251 unsigned long addr = (unsigned long)area->addr;
1252 unsigned long end = addr + area->size - PAGE_SIZE;
1253 int err;
1254
1255 err = vmap_page_range(addr, end, prot, *pages);
1256 if (err > 0) {
1257 *pages += err;
1258 err = 0;
1259 }
1260
1261 return err;
1262}
1263EXPORT_SYMBOL_GPL(map_vm_area);
1264
1265/*** Old vmalloc interfaces ***/
1266DEFINE_RWLOCK(vmlist_lock);
1267struct vm_struct *vmlist;
1268
1269static void insert_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
1270 unsigned long flags, void *caller)
1271{
1272 struct vm_struct *tmp, **p;
1273
1274 vm->flags = flags;
1275 vm->addr = (void *)va->va_start;
1276 vm->size = va->va_end - va->va_start;
1277 vm->caller = caller;
1278 va->private = vm;
1279 va->flags |= VM_VM_AREA;
1280
1281 write_lock(&vmlist_lock);
1282 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
1283 if (tmp->addr >= vm->addr)
1284 break;
1285 }
1286 vm->next = *p;
1287 *p = vm;
1288 write_unlock(&vmlist_lock);
1289}
1290
1291static struct vm_struct *__get_vm_area_node(unsigned long size,
1292 unsigned long align, unsigned long flags, unsigned long start,
1293 unsigned long end, int node, gfp_t gfp_mask, void *caller)
1294{
1295 static struct vmap_area *va;
1296 struct vm_struct *area;
1297
1298 BUG_ON(in_interrupt());
1299 if (flags & VM_IOREMAP) {
1300 int bit = fls(size);
1301
1302 if (bit > IOREMAP_MAX_ORDER)
1303 bit = IOREMAP_MAX_ORDER;
1304 else if (bit < PAGE_SHIFT)
1305 bit = PAGE_SHIFT;
1306
1307 align = 1ul << bit;
1308 }
1309
1310 size = PAGE_ALIGN(size);
1311 if (unlikely(!size))
1312 return NULL;
1313
1314 area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
1315 if (unlikely(!area))
1316 return NULL;
1317
1318 /*
1319 * We always allocate a guard page.
1320 */
1321 size += PAGE_SIZE;
1322
1323 va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
1324 if (IS_ERR(va)) {
1325 kfree(area);
1326 return NULL;
1327 }
1328
1329 insert_vmalloc_vm(area, va, flags, caller);
1330 return area;
1331}
1332
1333struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
1334 unsigned long start, unsigned long end)
1335{
1336 return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
1337 __builtin_return_address(0));
1338}
1339EXPORT_SYMBOL_GPL(__get_vm_area);
1340
1341struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
1342 unsigned long start, unsigned long end,
1343 void *caller)
1344{
1345 return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
1346 caller);
1347}
1348
1349/**
1350 * get_vm_area - reserve a contiguous kernel virtual area
1351 * @size: size of the area
1352 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC
1353 *
1354 * Search an area of @size in the kernel virtual mapping area,
1355 * and reserved it for out purposes. Returns the area descriptor
1356 * on success or %NULL on failure.
1357 */
1358struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
1359{
1360 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1361 -1, GFP_KERNEL, __builtin_return_address(0));
1362}
1363
1364struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
1365 void *caller)
1366{
1367 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1368 -1, GFP_KERNEL, caller);
1369}
1370
1371static struct vm_struct *find_vm_area(const void *addr)
1372{
1373 struct vmap_area *va;
1374
1375 va = find_vmap_area((unsigned long)addr);
1376 if (va && va->flags & VM_VM_AREA)
1377 return va->private;
1378
1379 return NULL;
1380}
1381
1382/**
1383 * remove_vm_area - find and remove a continuous kernel virtual area
1384 * @addr: base address
1385 *
1386 * Search for the kernel VM area starting at @addr, and remove it.
1387 * This function returns the found VM area, but using it is NOT safe
1388 * on SMP machines, except for its size or flags.
1389 */
1390struct vm_struct *remove_vm_area(const void *addr)
1391{
1392 struct vmap_area *va;
1393
1394 va = find_vmap_area((unsigned long)addr);
1395 if (va && va->flags & VM_VM_AREA) {
1396 struct vm_struct *vm = va->private;
1397 struct vm_struct *tmp, **p;
1398 /*
1399 * remove from list and disallow access to this vm_struct
1400 * before unmap. (address range confliction is maintained by
1401 * vmap.)
1402 */
1403 write_lock(&vmlist_lock);
1404 for (p = &vmlist; (tmp = *p) != vm; p = &tmp->next)
1405 ;
1406 *p = tmp->next;
1407 write_unlock(&vmlist_lock);
1408
1409 vmap_debug_free_range(va->va_start, va->va_end);
1410 free_unmap_vmap_area(va);
1411 vm->size -= PAGE_SIZE;
1412
1413 return vm;
1414 }
1415 return NULL;
1416}
1417
1418static void __vunmap(const void *addr, int deallocate_pages)
1419{
1420 struct vm_struct *area;
1421
1422 if (!addr)
1423 return;
1424
1425 if ((PAGE_SIZE-1) & (unsigned long)addr) {
1426 WARN(1, KERN_ERR "Trying to vfree() bad address (%p)\n", addr);
1427 return;
1428 }
1429
1430 area = remove_vm_area(addr);
1431 if (unlikely(!area)) {
1432 WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
1433 addr);
1434 return;
1435 }
1436
1437 debug_check_no_locks_freed(addr, area->size);
1438 debug_check_no_obj_freed(addr, area->size);
1439
1440 if (deallocate_pages) {
1441 int i;
1442
1443 for (i = 0; i < area->nr_pages; i++) {
1444 struct page *page = area->pages[i];
1445
1446 BUG_ON(!page);
1447 __free_page(page);
1448 }
1449
1450 if (area->flags & VM_VPAGES)
1451 vfree(area->pages);
1452 else
1453 kfree(area->pages);
1454 }
1455
1456 kfree(area);
1457 return;
1458}
1459
1460/**
1461 * vfree - release memory allocated by vmalloc()
1462 * @addr: memory base address
1463 *
1464 * Free the virtually continuous memory area starting at @addr, as
1465 * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
1466 * NULL, no operation is performed.
1467 *
1468 * Must not be called in interrupt context.
1469 */
1470void vfree(const void *addr)
1471{
1472 BUG_ON(in_interrupt());
1473
1474 kmemleak_free(addr);
1475
1476 __vunmap(addr, 1);
1477}
1478EXPORT_SYMBOL(vfree);
1479
1480/**
1481 * vunmap - release virtual mapping obtained by vmap()
1482 * @addr: memory base address
1483 *
1484 * Free the virtually contiguous memory area starting at @addr,
1485 * which was created from the page array passed to vmap().
1486 *
1487 * Must not be called in interrupt context.
1488 */
1489void vunmap(const void *addr)
1490{
1491 BUG_ON(in_interrupt());
1492 might_sleep();
1493 __vunmap(addr, 0);
1494}
1495EXPORT_SYMBOL(vunmap);
1496
1497/**
1498 * vmap - map an array of pages into virtually contiguous space
1499 * @pages: array of page pointers
1500 * @count: number of pages to map
1501 * @flags: vm_area->flags
1502 * @prot: page protection for the mapping
1503 *
1504 * Maps @count pages from @pages into contiguous kernel virtual
1505 * space.
1506 */
1507void *vmap(struct page **pages, unsigned int count,
1508 unsigned long flags, pgprot_t prot)
1509{
1510 struct vm_struct *area;
1511
1512 might_sleep();
1513
1514 if (count > totalram_pages)
1515 return NULL;
1516
1517 area = get_vm_area_caller((count << PAGE_SHIFT), flags,
1518 __builtin_return_address(0));
1519 if (!area)
1520 return NULL;
1521
1522 if (map_vm_area(area, prot, &pages)) {
1523 vunmap(area->addr);
1524 return NULL;
1525 }
1526
1527 return area->addr;
1528}
1529EXPORT_SYMBOL(vmap);
1530
1531static void *__vmalloc_node(unsigned long size, unsigned long align,
1532 gfp_t gfp_mask, pgprot_t prot,
1533 int node, void *caller);
1534static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
1535 pgprot_t prot, int node, void *caller)
1536{
1537 const int order = 0;
1538 struct page **pages;
1539 unsigned int nr_pages, array_size, i;
1540 gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
1541
1542 nr_pages = (area->size - PAGE_SIZE) >> PAGE_SHIFT;
1543 array_size = (nr_pages * sizeof(struct page *));
1544
1545 area->nr_pages = nr_pages;
1546 /* Please note that the recursion is strictly bounded. */
1547 if (array_size > PAGE_SIZE) {
1548 pages = __vmalloc_node(array_size, 1, nested_gfp|__GFP_HIGHMEM,
1549 PAGE_KERNEL, node, caller);
1550 area->flags |= VM_VPAGES;
1551 } else {
1552 pages = kmalloc_node(array_size, nested_gfp, node);
1553 }
1554 area->pages = pages;
1555 area->caller = caller;
1556 if (!area->pages) {
1557 remove_vm_area(area->addr);
1558 kfree(area);
1559 return NULL;
1560 }
1561
1562 for (i = 0; i < area->nr_pages; i++) {
1563 struct page *page;
1564 gfp_t tmp_mask = gfp_mask | __GFP_NOWARN;
1565
1566 if (node < 0)
1567 page = alloc_page(tmp_mask);
1568 else
1569 page = alloc_pages_node(node, tmp_mask, order);
1570
1571 if (unlikely(!page)) {
1572 /* Successfully allocated i pages, free them in __vunmap() */
1573 area->nr_pages = i;
1574 goto fail;
1575 }
1576 area->pages[i] = page;
1577 }
1578
1579 if (map_vm_area(area, prot, &pages))
1580 goto fail;
1581 return area->addr;
1582
1583fail:
1584 warn_alloc_failed(gfp_mask, order, "vmalloc: allocation failure, "
1585 "allocated %ld of %ld bytes\n",
1586 (area->nr_pages*PAGE_SIZE), area->size);
1587 vfree(area->addr);
1588 return NULL;
1589}
1590
1591/**
1592 * __vmalloc_node_range - allocate virtually contiguous memory
1593 * @size: allocation size
1594 * @align: desired alignment
1595 * @start: vm area range start
1596 * @end: vm area range end
1597 * @gfp_mask: flags for the page level allocator
1598 * @prot: protection mask for the allocated pages
1599 * @node: node to use for allocation or -1
1600 * @caller: caller's return address
1601 *
1602 * Allocate enough pages to cover @size from the page level
1603 * allocator with @gfp_mask flags. Map them into contiguous
1604 * kernel virtual space, using a pagetable protection of @prot.
1605 */
1606void *__vmalloc_node_range(unsigned long size, unsigned long align,
1607 unsigned long start, unsigned long end, gfp_t gfp_mask,
1608 pgprot_t prot, int node, void *caller)
1609{
1610 struct vm_struct *area;
1611 void *addr;
1612 unsigned long real_size = size;
1613
1614 size = PAGE_ALIGN(size);
1615 if (!size || (size >> PAGE_SHIFT) > totalram_pages)
1616 return NULL;
1617
1618 area = __get_vm_area_node(size, align, VM_ALLOC, start, end, node,
1619 gfp_mask, caller);
1620
1621 if (!area)
1622 return NULL;
1623
1624 addr = __vmalloc_area_node(area, gfp_mask, prot, node, caller);
1625
1626 /*
1627 * A ref_count = 3 is needed because the vm_struct and vmap_area
1628 * structures allocated in the __get_vm_area_node() function contain
1629 * references to the virtual address of the vmalloc'ed block.
1630 */
1631 kmemleak_alloc(addr, real_size, 3, gfp_mask);
1632
1633 return addr;
1634}
1635
1636/**
1637 * __vmalloc_node - allocate virtually contiguous memory
1638 * @size: allocation size
1639 * @align: desired alignment
1640 * @gfp_mask: flags for the page level allocator
1641 * @prot: protection mask for the allocated pages
1642 * @node: node to use for allocation or -1
1643 * @caller: caller's return address
1644 *
1645 * Allocate enough pages to cover @size from the page level
1646 * allocator with @gfp_mask flags. Map them into contiguous
1647 * kernel virtual space, using a pagetable protection of @prot.
1648 */
1649static void *__vmalloc_node(unsigned long size, unsigned long align,
1650 gfp_t gfp_mask, pgprot_t prot,
1651 int node, void *caller)
1652{
1653 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
1654 gfp_mask, prot, node, caller);
1655}
1656
1657void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
1658{
1659 return __vmalloc_node(size, 1, gfp_mask, prot, -1,
1660 __builtin_return_address(0));
1661}
1662EXPORT_SYMBOL(__vmalloc);
1663
1664static inline void *__vmalloc_node_flags(unsigned long size,
1665 int node, gfp_t flags)
1666{
1667 return __vmalloc_node(size, 1, flags, PAGE_KERNEL,
1668 node, __builtin_return_address(0));
1669}
1670
1671/**
1672 * vmalloc - allocate virtually contiguous memory
1673 * @size: allocation size
1674 * Allocate enough pages to cover @size from the page level
1675 * allocator and map them into contiguous kernel virtual space.
1676 *
1677 * For tight control over page level allocator and protection flags
1678 * use __vmalloc() instead.
1679 */
1680void *vmalloc(unsigned long size)
1681{
1682 return __vmalloc_node_flags(size, -1, GFP_KERNEL | __GFP_HIGHMEM);
1683}
1684EXPORT_SYMBOL(vmalloc);
1685
1686/**
1687 * vzalloc - allocate virtually contiguous memory with zero fill
1688 * @size: allocation size
1689 * Allocate enough pages to cover @size from the page level
1690 * allocator and map them into contiguous kernel virtual space.
1691 * The memory allocated is set to zero.
1692 *
1693 * For tight control over page level allocator and protection flags
1694 * use __vmalloc() instead.
1695 */
1696void *vzalloc(unsigned long size)
1697{
1698 return __vmalloc_node_flags(size, -1,
1699 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
1700}
1701EXPORT_SYMBOL(vzalloc);
1702
1703/**
1704 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
1705 * @size: allocation size
1706 *
1707 * The resulting memory area is zeroed so it can be mapped to userspace
1708 * without leaking data.
1709 */
1710void *vmalloc_user(unsigned long size)
1711{
1712 struct vm_struct *area;
1713 void *ret;
1714
1715 ret = __vmalloc_node(size, SHMLBA,
1716 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
1717 PAGE_KERNEL, -1, __builtin_return_address(0));
1718 if (ret) {
1719 area = find_vm_area(ret);
1720 area->flags |= VM_USERMAP;
1721 }
1722 return ret;
1723}
1724EXPORT_SYMBOL(vmalloc_user);
1725
1726/**
1727 * vmalloc_node - allocate memory on a specific node
1728 * @size: allocation size
1729 * @node: numa node
1730 *
1731 * Allocate enough pages to cover @size from the page level
1732 * allocator and map them into contiguous kernel virtual space.
1733 *
1734 * For tight control over page level allocator and protection flags
1735 * use __vmalloc() instead.
1736 */
1737void *vmalloc_node(unsigned long size, int node)
1738{
1739 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
1740 node, __builtin_return_address(0));
1741}
1742EXPORT_SYMBOL(vmalloc_node);
1743
1744/**
1745 * vzalloc_node - allocate memory on a specific node with zero fill
1746 * @size: allocation size
1747 * @node: numa node
1748 *
1749 * Allocate enough pages to cover @size from the page level
1750 * allocator and map them into contiguous kernel virtual space.
1751 * The memory allocated is set to zero.
1752 *
1753 * For tight control over page level allocator and protection flags
1754 * use __vmalloc_node() instead.
1755 */
1756void *vzalloc_node(unsigned long size, int node)
1757{
1758 return __vmalloc_node_flags(size, node,
1759 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
1760}
1761EXPORT_SYMBOL(vzalloc_node);
1762
1763#ifndef PAGE_KERNEL_EXEC
1764# define PAGE_KERNEL_EXEC PAGE_KERNEL
1765#endif
1766
1767/**
1768 * vmalloc_exec - allocate virtually contiguous, executable memory
1769 * @size: allocation size
1770 *
1771 * Kernel-internal function to allocate enough pages to cover @size
1772 * the page level allocator and map them into contiguous and
1773 * executable kernel virtual space.
1774 *
1775 * For tight control over page level allocator and protection flags
1776 * use __vmalloc() instead.
1777 */
1778
1779void *vmalloc_exec(unsigned long size)
1780{
1781 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
1782 -1, __builtin_return_address(0));
1783}
1784
1785#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
1786#define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
1787#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
1788#define GFP_VMALLOC32 GFP_DMA | GFP_KERNEL
1789#else
1790#define GFP_VMALLOC32 GFP_KERNEL
1791#endif
1792
1793/**
1794 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
1795 * @size: allocation size
1796 *
1797 * Allocate enough 32bit PA addressable pages to cover @size from the
1798 * page level allocator and map them into contiguous kernel virtual space.
1799 */
1800void *vmalloc_32(unsigned long size)
1801{
1802 return __vmalloc_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL,
1803 -1, __builtin_return_address(0));
1804}
1805EXPORT_SYMBOL(vmalloc_32);
1806
1807/**
1808 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
1809 * @size: allocation size
1810 *
1811 * The resulting memory area is 32bit addressable and zeroed so it can be
1812 * mapped to userspace without leaking data.
1813 */
1814void *vmalloc_32_user(unsigned long size)
1815{
1816 struct vm_struct *area;
1817 void *ret;
1818
1819 ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
1820 -1, __builtin_return_address(0));
1821 if (ret) {
1822 area = find_vm_area(ret);
1823 area->flags |= VM_USERMAP;
1824 }
1825 return ret;
1826}
1827EXPORT_SYMBOL(vmalloc_32_user);
1828
1829/*
1830 * small helper routine , copy contents to buf from addr.
1831 * If the page is not present, fill zero.
1832 */
1833
1834static int aligned_vread(char *buf, char *addr, unsigned long count)
1835{
1836 struct page *p;
1837 int copied = 0;
1838
1839 while (count) {
1840 unsigned long offset, length;
1841
1842 offset = (unsigned long)addr & ~PAGE_MASK;
1843 length = PAGE_SIZE - offset;
1844 if (length > count)
1845 length = count;
1846 p = vmalloc_to_page(addr);
1847 /*
1848 * To do safe access to this _mapped_ area, we need
1849 * lock. But adding lock here means that we need to add
1850 * overhead of vmalloc()/vfree() calles for this _debug_
1851 * interface, rarely used. Instead of that, we'll use
1852 * kmap() and get small overhead in this access function.
1853 */
1854 if (p) {
1855 /*
1856 * we can expect USER0 is not used (see vread/vwrite's
1857 * function description)
1858 */
1859 void *map = kmap_atomic(p, KM_USER0);
1860 memcpy(buf, map + offset, length);
1861 kunmap_atomic(map, KM_USER0);
1862 } else
1863 memset(buf, 0, length);
1864
1865 addr += length;
1866 buf += length;
1867 copied += length;
1868 count -= length;
1869 }
1870 return copied;
1871}
1872
1873static int aligned_vwrite(char *buf, char *addr, unsigned long count)
1874{
1875 struct page *p;
1876 int copied = 0;
1877
1878 while (count) {
1879 unsigned long offset, length;
1880
1881 offset = (unsigned long)addr & ~PAGE_MASK;
1882 length = PAGE_SIZE - offset;
1883 if (length > count)
1884 length = count;
1885 p = vmalloc_to_page(addr);
1886 /*
1887 * To do safe access to this _mapped_ area, we need
1888 * lock. But adding lock here means that we need to add
1889 * overhead of vmalloc()/vfree() calles for this _debug_
1890 * interface, rarely used. Instead of that, we'll use
1891 * kmap() and get small overhead in this access function.
1892 */
1893 if (p) {
1894 /*
1895 * we can expect USER0 is not used (see vread/vwrite's
1896 * function description)
1897 */
1898 void *map = kmap_atomic(p, KM_USER0);
1899 memcpy(map + offset, buf, length);
1900 kunmap_atomic(map, KM_USER0);
1901 }
1902 addr += length;
1903 buf += length;
1904 copied += length;
1905 count -= length;
1906 }
1907 return copied;
1908}
1909
1910/**
1911 * vread() - read vmalloc area in a safe way.
1912 * @buf: buffer for reading data
1913 * @addr: vm address.
1914 * @count: number of bytes to be read.
1915 *
1916 * Returns # of bytes which addr and buf should be increased.
1917 * (same number to @count). Returns 0 if [addr...addr+count) doesn't
1918 * includes any intersect with alive vmalloc area.
1919 *
1920 * This function checks that addr is a valid vmalloc'ed area, and
1921 * copy data from that area to a given buffer. If the given memory range
1922 * of [addr...addr+count) includes some valid address, data is copied to
1923 * proper area of @buf. If there are memory holes, they'll be zero-filled.
1924 * IOREMAP area is treated as memory hole and no copy is done.
1925 *
1926 * If [addr...addr+count) doesn't includes any intersects with alive
1927 * vm_struct area, returns 0.
1928 * @buf should be kernel's buffer. Because this function uses KM_USER0,
1929 * the caller should guarantee KM_USER0 is not used.
1930 *
1931 * Note: In usual ops, vread() is never necessary because the caller
1932 * should know vmalloc() area is valid and can use memcpy().
1933 * This is for routines which have to access vmalloc area without
1934 * any informaion, as /dev/kmem.
1935 *
1936 */
1937
1938long vread(char *buf, char *addr, unsigned long count)
1939{
1940 struct vm_struct *tmp;
1941 char *vaddr, *buf_start = buf;
1942 unsigned long buflen = count;
1943 unsigned long n;
1944
1945 /* Don't allow overflow */
1946 if ((unsigned long) addr + count < count)
1947 count = -(unsigned long) addr;
1948
1949 read_lock(&vmlist_lock);
1950 for (tmp = vmlist; count && tmp; tmp = tmp->next) {
1951 vaddr = (char *) tmp->addr;
1952 if (addr >= vaddr + tmp->size - PAGE_SIZE)
1953 continue;
1954 while (addr < vaddr) {
1955 if (count == 0)
1956 goto finished;
1957 *buf = '\0';
1958 buf++;
1959 addr++;
1960 count--;
1961 }
1962 n = vaddr + tmp->size - PAGE_SIZE - addr;
1963 if (n > count)
1964 n = count;
1965 if (!(tmp->flags & VM_IOREMAP))
1966 aligned_vread(buf, addr, n);
1967 else /* IOREMAP area is treated as memory hole */
1968 memset(buf, 0, n);
1969 buf += n;
1970 addr += n;
1971 count -= n;
1972 }
1973finished:
1974 read_unlock(&vmlist_lock);
1975
1976 if (buf == buf_start)
1977 return 0;
1978 /* zero-fill memory holes */
1979 if (buf != buf_start + buflen)
1980 memset(buf, 0, buflen - (buf - buf_start));
1981
1982 return buflen;
1983}
1984
1985/**
1986 * vwrite() - write vmalloc area in a safe way.
1987 * @buf: buffer for source data
1988 * @addr: vm address.
1989 * @count: number of bytes to be read.
1990 *
1991 * Returns # of bytes which addr and buf should be incresed.
1992 * (same number to @count).
1993 * If [addr...addr+count) doesn't includes any intersect with valid
1994 * vmalloc area, returns 0.
1995 *
1996 * This function checks that addr is a valid vmalloc'ed area, and
1997 * copy data from a buffer to the given addr. If specified range of
1998 * [addr...addr+count) includes some valid address, data is copied from
1999 * proper area of @buf. If there are memory holes, no copy to hole.
2000 * IOREMAP area is treated as memory hole and no copy is done.
2001 *
2002 * If [addr...addr+count) doesn't includes any intersects with alive
2003 * vm_struct area, returns 0.
2004 * @buf should be kernel's buffer. Because this function uses KM_USER0,
2005 * the caller should guarantee KM_USER0 is not used.
2006 *
2007 * Note: In usual ops, vwrite() is never necessary because the caller
2008 * should know vmalloc() area is valid and can use memcpy().
2009 * This is for routines which have to access vmalloc area without
2010 * any informaion, as /dev/kmem.
2011 */
2012
2013long vwrite(char *buf, char *addr, unsigned long count)
2014{
2015 struct vm_struct *tmp;
2016 char *vaddr;
2017 unsigned long n, buflen;
2018 int copied = 0;
2019
2020 /* Don't allow overflow */
2021 if ((unsigned long) addr + count < count)
2022 count = -(unsigned long) addr;
2023 buflen = count;
2024
2025 read_lock(&vmlist_lock);
2026 for (tmp = vmlist; count && tmp; tmp = tmp->next) {
2027 vaddr = (char *) tmp->addr;
2028 if (addr >= vaddr + tmp->size - PAGE_SIZE)
2029 continue;
2030 while (addr < vaddr) {
2031 if (count == 0)
2032 goto finished;
2033 buf++;
2034 addr++;
2035 count--;
2036 }
2037 n = vaddr + tmp->size - PAGE_SIZE - addr;
2038 if (n > count)
2039 n = count;
2040 if (!(tmp->flags & VM_IOREMAP)) {
2041 aligned_vwrite(buf, addr, n);
2042 copied++;
2043 }
2044 buf += n;
2045 addr += n;
2046 count -= n;
2047 }
2048finished:
2049 read_unlock(&vmlist_lock);
2050 if (!copied)
2051 return 0;
2052 return buflen;
2053}
2054
2055/**
2056 * remap_vmalloc_range - map vmalloc pages to userspace
2057 * @vma: vma to cover (map full range of vma)
2058 * @addr: vmalloc memory
2059 * @pgoff: number of pages into addr before first page to map
2060 *
2061 * Returns: 0 for success, -Exxx on failure
2062 *
2063 * This function checks that addr is a valid vmalloc'ed area, and
2064 * that it is big enough to cover the vma. Will return failure if
2065 * that criteria isn't met.
2066 *
2067 * Similar to remap_pfn_range() (see mm/memory.c)
2068 */
2069int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
2070 unsigned long pgoff)
2071{
2072 struct vm_struct *area;
2073 unsigned long uaddr = vma->vm_start;
2074 unsigned long usize = vma->vm_end - vma->vm_start;
2075
2076 if ((PAGE_SIZE-1) & (unsigned long)addr)
2077 return -EINVAL;
2078
2079 area = find_vm_area(addr);
2080 if (!area)
2081 return -EINVAL;
2082
2083 if (!(area->flags & VM_USERMAP))
2084 return -EINVAL;
2085
2086 if (usize + (pgoff << PAGE_SHIFT) > area->size - PAGE_SIZE)
2087 return -EINVAL;
2088
2089 addr += pgoff << PAGE_SHIFT;
2090 do {
2091 struct page *page = vmalloc_to_page(addr);
2092 int ret;
2093
2094 ret = vm_insert_page(vma, uaddr, page);
2095 if (ret)
2096 return ret;
2097
2098 uaddr += PAGE_SIZE;
2099 addr += PAGE_SIZE;
2100 usize -= PAGE_SIZE;
2101 } while (usize > 0);
2102
2103 /* Prevent "things" like memory migration? VM_flags need a cleanup... */
2104 vma->vm_flags |= VM_RESERVED;
2105
2106 return 0;
2107}
2108EXPORT_SYMBOL(remap_vmalloc_range);
2109
2110/*
2111 * Implement a stub for vmalloc_sync_all() if the architecture chose not to
2112 * have one.
2113 */
2114void __attribute__((weak)) vmalloc_sync_all(void)
2115{
2116}
2117
2118
2119static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
2120{
2121 /* apply_to_page_range() does all the hard work. */
2122 return 0;
2123}
2124
2125/**
2126 * alloc_vm_area - allocate a range of kernel address space
2127 * @size: size of the area
2128 *
2129 * Returns: NULL on failure, vm_struct on success
2130 *
2131 * This function reserves a range of kernel address space, and
2132 * allocates pagetables to map that range. No actual mappings
2133 * are created. If the kernel address space is not shared
2134 * between processes, it syncs the pagetable across all
2135 * processes.
2136 */
2137struct vm_struct *alloc_vm_area(size_t size)
2138{
2139 struct vm_struct *area;
2140
2141 area = get_vm_area_caller(size, VM_IOREMAP,
2142 __builtin_return_address(0));
2143 if (area == NULL)
2144 return NULL;
2145
2146 /*
2147 * This ensures that page tables are constructed for this region
2148 * of kernel virtual address space and mapped into init_mm.
2149 */
2150 if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
2151 area->size, f, NULL)) {
2152 free_vm_area(area);
2153 return NULL;
2154 }
2155
2156 return area;
2157}
2158EXPORT_SYMBOL_GPL(alloc_vm_area);
2159
2160void free_vm_area(struct vm_struct *area)
2161{
2162 struct vm_struct *ret;
2163 ret = remove_vm_area(area->addr);
2164 BUG_ON(ret != area);
2165 kfree(area);
2166}
2167EXPORT_SYMBOL_GPL(free_vm_area);
2168
2169#ifdef CONFIG_SMP
2170static struct vmap_area *node_to_va(struct rb_node *n)
2171{
2172 return n ? rb_entry(n, struct vmap_area, rb_node) : NULL;
2173}
2174
2175/**
2176 * pvm_find_next_prev - find the next and prev vmap_area surrounding @end
2177 * @end: target address
2178 * @pnext: out arg for the next vmap_area
2179 * @pprev: out arg for the previous vmap_area
2180 *
2181 * Returns: %true if either or both of next and prev are found,
2182 * %false if no vmap_area exists
2183 *
2184 * Find vmap_areas end addresses of which enclose @end. ie. if not
2185 * NULL, *pnext->va_end > @end and *pprev->va_end <= @end.
2186 */
2187static bool pvm_find_next_prev(unsigned long end,
2188 struct vmap_area **pnext,
2189 struct vmap_area **pprev)
2190{
2191 struct rb_node *n = vmap_area_root.rb_node;
2192 struct vmap_area *va = NULL;
2193
2194 while (n) {
2195 va = rb_entry(n, struct vmap_area, rb_node);
2196 if (end < va->va_end)
2197 n = n->rb_left;
2198 else if (end > va->va_end)
2199 n = n->rb_right;
2200 else
2201 break;
2202 }
2203
2204 if (!va)
2205 return false;
2206
2207 if (va->va_end > end) {
2208 *pnext = va;
2209 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2210 } else {
2211 *pprev = va;
2212 *pnext = node_to_va(rb_next(&(*pprev)->rb_node));
2213 }
2214 return true;
2215}
2216
2217/**
2218 * pvm_determine_end - find the highest aligned address between two vmap_areas
2219 * @pnext: in/out arg for the next vmap_area
2220 * @pprev: in/out arg for the previous vmap_area
2221 * @align: alignment
2222 *
2223 * Returns: determined end address
2224 *
2225 * Find the highest aligned address between *@pnext and *@pprev below
2226 * VMALLOC_END. *@pnext and *@pprev are adjusted so that the aligned
2227 * down address is between the end addresses of the two vmap_areas.
2228 *
2229 * Please note that the address returned by this function may fall
2230 * inside *@pnext vmap_area. The caller is responsible for checking
2231 * that.
2232 */
2233static unsigned long pvm_determine_end(struct vmap_area **pnext,
2234 struct vmap_area **pprev,
2235 unsigned long align)
2236{
2237 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2238 unsigned long addr;
2239
2240 if (*pnext)
2241 addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end);
2242 else
2243 addr = vmalloc_end;
2244
2245 while (*pprev && (*pprev)->va_end > addr) {
2246 *pnext = *pprev;
2247 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2248 }
2249
2250 return addr;
2251}
2252
2253/**
2254 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
2255 * @offsets: array containing offset of each area
2256 * @sizes: array containing size of each area
2257 * @nr_vms: the number of areas to allocate
2258 * @align: alignment, all entries in @offsets and @sizes must be aligned to this
2259 *
2260 * Returns: kmalloc'd vm_struct pointer array pointing to allocated
2261 * vm_structs on success, %NULL on failure
2262 *
2263 * Percpu allocator wants to use congruent vm areas so that it can
2264 * maintain the offsets among percpu areas. This function allocates
2265 * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to
2266 * be scattered pretty far, distance between two areas easily going up
2267 * to gigabytes. To avoid interacting with regular vmallocs, these
2268 * areas are allocated from top.
2269 *
2270 * Despite its complicated look, this allocator is rather simple. It
2271 * does everything top-down and scans areas from the end looking for
2272 * matching slot. While scanning, if any of the areas overlaps with
2273 * existing vmap_area, the base address is pulled down to fit the
2274 * area. Scanning is repeated till all the areas fit and then all
2275 * necessary data structres are inserted and the result is returned.
2276 */
2277struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
2278 const size_t *sizes, int nr_vms,
2279 size_t align)
2280{
2281 const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
2282 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2283 struct vmap_area **vas, *prev, *next;
2284 struct vm_struct **vms;
2285 int area, area2, last_area, term_area;
2286 unsigned long base, start, end, last_end;
2287 bool purged = false;
2288
2289 /* verify parameters and allocate data structures */
2290 BUG_ON(align & ~PAGE_MASK || !is_power_of_2(align));
2291 for (last_area = 0, area = 0; area < nr_vms; area++) {
2292 start = offsets[area];
2293 end = start + sizes[area];
2294
2295 /* is everything aligned properly? */
2296 BUG_ON(!IS_ALIGNED(offsets[area], align));
2297 BUG_ON(!IS_ALIGNED(sizes[area], align));
2298
2299 /* detect the area with the highest address */
2300 if (start > offsets[last_area])
2301 last_area = area;
2302
2303 for (area2 = 0; area2 < nr_vms; area2++) {
2304 unsigned long start2 = offsets[area2];
2305 unsigned long end2 = start2 + sizes[area2];
2306
2307 if (area2 == area)
2308 continue;
2309
2310 BUG_ON(start2 >= start && start2 < end);
2311 BUG_ON(end2 <= end && end2 > start);
2312 }
2313 }
2314 last_end = offsets[last_area] + sizes[last_area];
2315
2316 if (vmalloc_end - vmalloc_start < last_end) {
2317 WARN_ON(true);
2318 return NULL;
2319 }
2320
2321 vms = kzalloc(sizeof(vms[0]) * nr_vms, GFP_KERNEL);
2322 vas = kzalloc(sizeof(vas[0]) * nr_vms, GFP_KERNEL);
2323 if (!vas || !vms)
2324 goto err_free;
2325
2326 for (area = 0; area < nr_vms; area++) {
2327 vas[area] = kzalloc(sizeof(struct vmap_area), GFP_KERNEL);
2328 vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
2329 if (!vas[area] || !vms[area])
2330 goto err_free;
2331 }
2332retry:
2333 spin_lock(&vmap_area_lock);
2334
2335 /* start scanning - we scan from the top, begin with the last area */
2336 area = term_area = last_area;
2337 start = offsets[area];
2338 end = start + sizes[area];
2339
2340 if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) {
2341 base = vmalloc_end - last_end;
2342 goto found;
2343 }
2344 base = pvm_determine_end(&next, &prev, align) - end;
2345
2346 while (true) {
2347 BUG_ON(next && next->va_end <= base + end);
2348 BUG_ON(prev && prev->va_end > base + end);
2349
2350 /*
2351 * base might have underflowed, add last_end before
2352 * comparing.
2353 */
2354 if (base + last_end < vmalloc_start + last_end) {
2355 spin_unlock(&vmap_area_lock);
2356 if (!purged) {
2357 purge_vmap_area_lazy();
2358 purged = true;
2359 goto retry;
2360 }
2361 goto err_free;
2362 }
2363
2364 /*
2365 * If next overlaps, move base downwards so that it's
2366 * right below next and then recheck.
2367 */
2368 if (next && next->va_start < base + end) {
2369 base = pvm_determine_end(&next, &prev, align) - end;
2370 term_area = area;
2371 continue;
2372 }
2373
2374 /*
2375 * If prev overlaps, shift down next and prev and move
2376 * base so that it's right below new next and then
2377 * recheck.
2378 */
2379 if (prev && prev->va_end > base + start) {
2380 next = prev;
2381 prev = node_to_va(rb_prev(&next->rb_node));
2382 base = pvm_determine_end(&next, &prev, align) - end;
2383 term_area = area;
2384 continue;
2385 }
2386
2387 /*
2388 * This area fits, move on to the previous one. If
2389 * the previous one is the terminal one, we're done.
2390 */
2391 area = (area + nr_vms - 1) % nr_vms;
2392 if (area == term_area)
2393 break;
2394 start = offsets[area];
2395 end = start + sizes[area];
2396 pvm_find_next_prev(base + end, &next, &prev);
2397 }
2398found:
2399 /* we've found a fitting base, insert all va's */
2400 for (area = 0; area < nr_vms; area++) {
2401 struct vmap_area *va = vas[area];
2402
2403 va->va_start = base + offsets[area];
2404 va->va_end = va->va_start + sizes[area];
2405 __insert_vmap_area(va);
2406 }
2407
2408 vmap_area_pcpu_hole = base + offsets[last_area];
2409
2410 spin_unlock(&vmap_area_lock);
2411
2412 /* insert all vm's */
2413 for (area = 0; area < nr_vms; area++)
2414 insert_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
2415 pcpu_get_vm_areas);
2416
2417 kfree(vas);
2418 return vms;
2419
2420err_free:
2421 for (area = 0; area < nr_vms; area++) {
2422 if (vas)
2423 kfree(vas[area]);
2424 if (vms)
2425 kfree(vms[area]);
2426 }
2427 kfree(vas);
2428 kfree(vms);
2429 return NULL;
2430}
2431
2432/**
2433 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
2434 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
2435 * @nr_vms: the number of allocated areas
2436 *
2437 * Free vm_structs and the array allocated by pcpu_get_vm_areas().
2438 */
2439void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
2440{
2441 int i;
2442
2443 for (i = 0; i < nr_vms; i++)
2444 free_vm_area(vms[i]);
2445 kfree(vms);
2446}
2447#endif /* CONFIG_SMP */
2448
2449#ifdef CONFIG_PROC_FS
2450static void *s_start(struct seq_file *m, loff_t *pos)
2451 __acquires(&vmlist_lock)
2452{
2453 loff_t n = *pos;
2454 struct vm_struct *v;
2455
2456 read_lock(&vmlist_lock);
2457 v = vmlist;
2458 while (n > 0 && v) {
2459 n--;
2460 v = v->next;
2461 }
2462 if (!n)
2463 return v;
2464
2465 return NULL;
2466
2467}
2468
2469static void *s_next(struct seq_file *m, void *p, loff_t *pos)
2470{
2471 struct vm_struct *v = p;
2472
2473 ++*pos;
2474 return v->next;
2475}
2476
2477static void s_stop(struct seq_file *m, void *p)
2478 __releases(&vmlist_lock)
2479{
2480 read_unlock(&vmlist_lock);
2481}
2482
2483static void show_numa_info(struct seq_file *m, struct vm_struct *v)
2484{
2485 if (NUMA_BUILD) {
2486 unsigned int nr, *counters = m->private;
2487
2488 if (!counters)
2489 return;
2490
2491 memset(counters, 0, nr_node_ids * sizeof(unsigned int));
2492
2493 for (nr = 0; nr < v->nr_pages; nr++)
2494 counters[page_to_nid(v->pages[nr])]++;
2495
2496 for_each_node_state(nr, N_HIGH_MEMORY)
2497 if (counters[nr])
2498 seq_printf(m, " N%u=%u", nr, counters[nr]);
2499 }
2500}
2501
2502static int s_show(struct seq_file *m, void *p)
2503{
2504 struct vm_struct *v = p;
2505
2506 seq_printf(m, "0x%p-0x%p %7ld",
2507 v->addr, v->addr + v->size, v->size);
2508
2509 if (v->caller)
2510 seq_printf(m, " %pS", v->caller);
2511
2512 if (v->nr_pages)
2513 seq_printf(m, " pages=%d", v->nr_pages);
2514
2515 if (v->phys_addr)
2516 seq_printf(m, " phys=%llx", (unsigned long long)v->phys_addr);
2517
2518 if (v->flags & VM_IOREMAP)
2519 seq_printf(m, " ioremap");
2520
2521 if (v->flags & VM_ALLOC)
2522 seq_printf(m, " vmalloc");
2523
2524 if (v->flags & VM_MAP)
2525 seq_printf(m, " vmap");
2526
2527 if (v->flags & VM_USERMAP)
2528 seq_printf(m, " user");
2529
2530 if (v->flags & VM_VPAGES)
2531 seq_printf(m, " vpages");
2532
2533 show_numa_info(m, v);
2534 seq_putc(m, '\n');
2535 return 0;
2536}
2537
2538static const struct seq_operations vmalloc_op = {
2539 .start = s_start,
2540 .next = s_next,
2541 .stop = s_stop,
2542 .show = s_show,
2543};
2544
2545static int vmalloc_open(struct inode *inode, struct file *file)
2546{
2547 unsigned int *ptr = NULL;
2548 int ret;
2549
2550 if (NUMA_BUILD) {
2551 ptr = kmalloc(nr_node_ids * sizeof(unsigned int), GFP_KERNEL);
2552 if (ptr == NULL)
2553 return -ENOMEM;
2554 }
2555 ret = seq_open(file, &vmalloc_op);
2556 if (!ret) {
2557 struct seq_file *m = file->private_data;
2558 m->private = ptr;
2559 } else
2560 kfree(ptr);
2561 return ret;
2562}
2563
2564static const struct file_operations proc_vmalloc_operations = {
2565 .open = vmalloc_open,
2566 .read = seq_read,
2567 .llseek = seq_lseek,
2568 .release = seq_release_private,
2569};
2570
2571static int __init proc_vmalloc_init(void)
2572{
2573 proc_create("vmallocinfo", S_IRUSR, NULL, &proc_vmalloc_operations);
2574 return 0;
2575}
2576module_init(proc_vmalloc_init);
2577#endif
2578