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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
33#include <asm/uaccess.h>
34#include <asm/tlbflush.h>
35#include <asm/shmparam.h>
36
37struct vfree_deferred {
38 struct llist_head list;
39 struct work_struct wq;
40};
41static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred);
42
43static void __vunmap(const void *, int);
44
45static void free_work(struct work_struct *w)
46{
47 struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq);
48 struct llist_node *llnode = llist_del_all(&p->list);
49 while (llnode) {
50 void *p = llnode;
51 llnode = llist_next(llnode);
52 __vunmap(p, 1);
53 }
54}
55
56/*** Page table manipulation functions ***/
57
58static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
59{
60 pte_t *pte;
61
62 pte = pte_offset_kernel(pmd, addr);
63 do {
64 pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
65 WARN_ON(!pte_none(ptent) && !pte_present(ptent));
66 } while (pte++, addr += PAGE_SIZE, addr != end);
67}
68
69static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
70{
71 pmd_t *pmd;
72 unsigned long next;
73
74 pmd = pmd_offset(pud, addr);
75 do {
76 next = pmd_addr_end(addr, end);
77 if (pmd_none_or_clear_bad(pmd))
78 continue;
79 vunmap_pte_range(pmd, addr, next);
80 } while (pmd++, addr = next, addr != end);
81}
82
83static void vunmap_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end)
84{
85 pud_t *pud;
86 unsigned long next;
87
88 pud = pud_offset(pgd, addr);
89 do {
90 next = pud_addr_end(addr, end);
91 if (pud_none_or_clear_bad(pud))
92 continue;
93 vunmap_pmd_range(pud, addr, next);
94 } while (pud++, addr = next, addr != end);
95}
96
97static void vunmap_page_range(unsigned long addr, unsigned long end)
98{
99 pgd_t *pgd;
100 unsigned long next;
101
102 BUG_ON(addr >= end);
103 pgd = pgd_offset_k(addr);
104 do {
105 next = pgd_addr_end(addr, end);
106 if (pgd_none_or_clear_bad(pgd))
107 continue;
108 vunmap_pud_range(pgd, addr, next);
109 } while (pgd++, addr = next, addr != end);
110}
111
112static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
113 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
114{
115 pte_t *pte;
116
117 /*
118 * nr is a running index into the array which helps higher level
119 * callers keep track of where we're up to.
120 */
121
122 pte = pte_alloc_kernel(pmd, addr);
123 if (!pte)
124 return -ENOMEM;
125 do {
126 struct page *page = pages[*nr];
127
128 if (WARN_ON(!pte_none(*pte)))
129 return -EBUSY;
130 if (WARN_ON(!page))
131 return -ENOMEM;
132 set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
133 (*nr)++;
134 } while (pte++, addr += PAGE_SIZE, addr != end);
135 return 0;
136}
137
138static int vmap_pmd_range(pud_t *pud, unsigned long addr,
139 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
140{
141 pmd_t *pmd;
142 unsigned long next;
143
144 pmd = pmd_alloc(&init_mm, pud, addr);
145 if (!pmd)
146 return -ENOMEM;
147 do {
148 next = pmd_addr_end(addr, end);
149 if (vmap_pte_range(pmd, addr, next, prot, pages, nr))
150 return -ENOMEM;
151 } while (pmd++, addr = next, addr != end);
152 return 0;
153}
154
155static int vmap_pud_range(pgd_t *pgd, unsigned long addr,
156 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
157{
158 pud_t *pud;
159 unsigned long next;
160
161 pud = pud_alloc(&init_mm, pgd, addr);
162 if (!pud)
163 return -ENOMEM;
164 do {
165 next = pud_addr_end(addr, end);
166 if (vmap_pmd_range(pud, addr, next, prot, pages, nr))
167 return -ENOMEM;
168 } while (pud++, addr = next, addr != end);
169 return 0;
170}
171
172/*
173 * Set up page tables in kva (addr, end). The ptes shall have prot "prot", and
174 * will have pfns corresponding to the "pages" array.
175 *
176 * Ie. pte at addr+N*PAGE_SIZE shall point to pfn corresponding to pages[N]
177 */
178static int vmap_page_range_noflush(unsigned long start, unsigned long end,
179 pgprot_t prot, struct page **pages)
180{
181 pgd_t *pgd;
182 unsigned long next;
183 unsigned long addr = start;
184 int err = 0;
185 int nr = 0;
186
187 BUG_ON(addr >= end);
188 pgd = pgd_offset_k(addr);
189 do {
190 next = pgd_addr_end(addr, end);
191 err = vmap_pud_range(pgd, addr, next, prot, pages, &nr);
192 if (err)
193 return err;
194 } while (pgd++, addr = next, addr != end);
195
196 return nr;
197}
198
199static int vmap_page_range(unsigned long start, unsigned long end,
200 pgprot_t prot, struct page **pages)
201{
202 int ret;
203
204 ret = vmap_page_range_noflush(start, end, prot, pages);
205 flush_cache_vmap(start, end);
206 return ret;
207}
208
209int is_vmalloc_or_module_addr(const void *x)
210{
211 /*
212 * ARM, x86-64 and sparc64 put modules in a special place,
213 * and fall back on vmalloc() if that fails. Others
214 * just put it in the vmalloc space.
215 */
216#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
217 unsigned long addr = (unsigned long)x;
218 if (addr >= MODULES_VADDR && addr < MODULES_END)
219 return 1;
220#endif
221 return is_vmalloc_addr(x);
222}
223
224/*
225 * Walk a vmap address to the struct page it maps.
226 */
227struct page *vmalloc_to_page(const void *vmalloc_addr)
228{
229 unsigned long addr = (unsigned long) vmalloc_addr;
230 struct page *page = NULL;
231 pgd_t *pgd = pgd_offset_k(addr);
232
233 /*
234 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
235 * architectures that do not vmalloc module space
236 */
237 VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
238
239 if (!pgd_none(*pgd)) {
240 pud_t *pud = pud_offset(pgd, addr);
241 if (!pud_none(*pud)) {
242 pmd_t *pmd = pmd_offset(pud, addr);
243 if (!pmd_none(*pmd)) {
244 pte_t *ptep, pte;
245
246 ptep = pte_offset_map(pmd, addr);
247 pte = *ptep;
248 if (pte_present(pte))
249 page = pte_page(pte);
250 pte_unmap(ptep);
251 }
252 }
253 }
254 return page;
255}
256EXPORT_SYMBOL(vmalloc_to_page);
257
258/*
259 * Map a vmalloc()-space virtual address to the physical page frame number.
260 */
261unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
262{
263 return page_to_pfn(vmalloc_to_page(vmalloc_addr));
264}
265EXPORT_SYMBOL(vmalloc_to_pfn);
266
267
268/*** Global kva allocator ***/
269
270#define VM_LAZY_FREE 0x01
271#define VM_LAZY_FREEING 0x02
272#define VM_VM_AREA 0x04
273
274static DEFINE_SPINLOCK(vmap_area_lock);
275/* Export for kexec only */
276LIST_HEAD(vmap_area_list);
277static struct rb_root vmap_area_root = RB_ROOT;
278
279/* The vmap cache globals are protected by vmap_area_lock */
280static struct rb_node *free_vmap_cache;
281static unsigned long cached_hole_size;
282static unsigned long cached_vstart;
283static unsigned long cached_align;
284
285static unsigned long vmap_area_pcpu_hole;
286
287static struct vmap_area *__find_vmap_area(unsigned long addr)
288{
289 struct rb_node *n = vmap_area_root.rb_node;
290
291 while (n) {
292 struct vmap_area *va;
293
294 va = rb_entry(n, struct vmap_area, rb_node);
295 if (addr < va->va_start)
296 n = n->rb_left;
297 else if (addr >= va->va_end)
298 n = n->rb_right;
299 else
300 return va;
301 }
302
303 return NULL;
304}
305
306static void __insert_vmap_area(struct vmap_area *va)
307{
308 struct rb_node **p = &vmap_area_root.rb_node;
309 struct rb_node *parent = NULL;
310 struct rb_node *tmp;
311
312 while (*p) {
313 struct vmap_area *tmp_va;
314
315 parent = *p;
316 tmp_va = rb_entry(parent, struct vmap_area, rb_node);
317 if (va->va_start < tmp_va->va_end)
318 p = &(*p)->rb_left;
319 else if (va->va_end > tmp_va->va_start)
320 p = &(*p)->rb_right;
321 else
322 BUG();
323 }
324
325 rb_link_node(&va->rb_node, parent, p);
326 rb_insert_color(&va->rb_node, &vmap_area_root);
327
328 /* address-sort this list */
329 tmp = rb_prev(&va->rb_node);
330 if (tmp) {
331 struct vmap_area *prev;
332 prev = rb_entry(tmp, struct vmap_area, rb_node);
333 list_add_rcu(&va->list, &prev->list);
334 } else
335 list_add_rcu(&va->list, &vmap_area_list);
336}
337
338static void purge_vmap_area_lazy(void);
339
340/*
341 * Allocate a region of KVA of the specified size and alignment, within the
342 * vstart and vend.
343 */
344static struct vmap_area *alloc_vmap_area(unsigned long size,
345 unsigned long align,
346 unsigned long vstart, unsigned long vend,
347 int node, gfp_t gfp_mask)
348{
349 struct vmap_area *va;
350 struct rb_node *n;
351 unsigned long addr;
352 int purged = 0;
353 struct vmap_area *first;
354
355 BUG_ON(!size);
356 BUG_ON(size & ~PAGE_MASK);
357 BUG_ON(!is_power_of_2(align));
358
359 va = kmalloc_node(sizeof(struct vmap_area),
360 gfp_mask & GFP_RECLAIM_MASK, node);
361 if (unlikely(!va))
362 return ERR_PTR(-ENOMEM);
363
364 /*
365 * Only scan the relevant parts containing pointers to other objects
366 * to avoid false negatives.
367 */
368 kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask & GFP_RECLAIM_MASK);
369
370retry:
371 spin_lock(&vmap_area_lock);
372 /*
373 * Invalidate cache if we have more permissive parameters.
374 * cached_hole_size notes the largest hole noticed _below_
375 * the vmap_area cached in free_vmap_cache: if size fits
376 * into that hole, we want to scan from vstart to reuse
377 * the hole instead of allocating above free_vmap_cache.
378 * Note that __free_vmap_area may update free_vmap_cache
379 * without updating cached_hole_size or cached_align.
380 */
381 if (!free_vmap_cache ||
382 size < cached_hole_size ||
383 vstart < cached_vstart ||
384 align < cached_align) {
385nocache:
386 cached_hole_size = 0;
387 free_vmap_cache = NULL;
388 }
389 /* record if we encounter less permissive parameters */
390 cached_vstart = vstart;
391 cached_align = align;
392
393 /* find starting point for our search */
394 if (free_vmap_cache) {
395 first = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
396 addr = ALIGN(first->va_end, align);
397 if (addr < vstart)
398 goto nocache;
399 if (addr + size < addr)
400 goto overflow;
401
402 } else {
403 addr = ALIGN(vstart, align);
404 if (addr + size < addr)
405 goto overflow;
406
407 n = vmap_area_root.rb_node;
408 first = NULL;
409
410 while (n) {
411 struct vmap_area *tmp;
412 tmp = rb_entry(n, struct vmap_area, rb_node);
413 if (tmp->va_end >= addr) {
414 first = tmp;
415 if (tmp->va_start <= addr)
416 break;
417 n = n->rb_left;
418 } else
419 n = n->rb_right;
420 }
421
422 if (!first)
423 goto found;
424 }
425
426 /* from the starting point, walk areas until a suitable hole is found */
427 while (addr + size > first->va_start && addr + size <= vend) {
428 if (addr + cached_hole_size < first->va_start)
429 cached_hole_size = first->va_start - addr;
430 addr = ALIGN(first->va_end, align);
431 if (addr + size < addr)
432 goto overflow;
433
434 if (list_is_last(&first->list, &vmap_area_list))
435 goto found;
436
437 first = list_entry(first->list.next,
438 struct vmap_area, list);
439 }
440
441found:
442 if (addr + size > vend)
443 goto overflow;
444
445 va->va_start = addr;
446 va->va_end = addr + size;
447 va->flags = 0;
448 __insert_vmap_area(va);
449 free_vmap_cache = &va->rb_node;
450 spin_unlock(&vmap_area_lock);
451
452 BUG_ON(va->va_start & (align-1));
453 BUG_ON(va->va_start < vstart);
454 BUG_ON(va->va_end > vend);
455
456 return va;
457
458overflow:
459 spin_unlock(&vmap_area_lock);
460 if (!purged) {
461 purge_vmap_area_lazy();
462 purged = 1;
463 goto retry;
464 }
465 if (printk_ratelimit())
466 printk(KERN_WARNING
467 "vmap allocation for size %lu failed: "
468 "use vmalloc=<size> to increase size.\n", size);
469 kfree(va);
470 return ERR_PTR(-EBUSY);
471}
472
473static void __free_vmap_area(struct vmap_area *va)
474{
475 BUG_ON(RB_EMPTY_NODE(&va->rb_node));
476
477 if (free_vmap_cache) {
478 if (va->va_end < cached_vstart) {
479 free_vmap_cache = NULL;
480 } else {
481 struct vmap_area *cache;
482 cache = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
483 if (va->va_start <= cache->va_start) {
484 free_vmap_cache = rb_prev(&va->rb_node);
485 /*
486 * We don't try to update cached_hole_size or
487 * cached_align, but it won't go very wrong.
488 */
489 }
490 }
491 }
492 rb_erase(&va->rb_node, &vmap_area_root);
493 RB_CLEAR_NODE(&va->rb_node);
494 list_del_rcu(&va->list);
495
496 /*
497 * Track the highest possible candidate for pcpu area
498 * allocation. Areas outside of vmalloc area can be returned
499 * here too, consider only end addresses which fall inside
500 * vmalloc area proper.
501 */
502 if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END)
503 vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end);
504
505 kfree_rcu(va, rcu_head);
506}
507
508/*
509 * Free a region of KVA allocated by alloc_vmap_area
510 */
511static void free_vmap_area(struct vmap_area *va)
512{
513 spin_lock(&vmap_area_lock);
514 __free_vmap_area(va);
515 spin_unlock(&vmap_area_lock);
516}
517
518/*
519 * Clear the pagetable entries of a given vmap_area
520 */
521static void unmap_vmap_area(struct vmap_area *va)
522{
523 vunmap_page_range(va->va_start, va->va_end);
524}
525
526static void vmap_debug_free_range(unsigned long start, unsigned long end)
527{
528 /*
529 * Unmap page tables and force a TLB flush immediately if
530 * CONFIG_DEBUG_PAGEALLOC is set. This catches use after free
531 * bugs similarly to those in linear kernel virtual address
532 * space after a page has been freed.
533 *
534 * All the lazy freeing logic is still retained, in order to
535 * minimise intrusiveness of this debugging feature.
536 *
537 * This is going to be *slow* (linear kernel virtual address
538 * debugging doesn't do a broadcast TLB flush so it is a lot
539 * faster).
540 */
541#ifdef CONFIG_DEBUG_PAGEALLOC
542 vunmap_page_range(start, end);
543 flush_tlb_kernel_range(start, end);
544#endif
545}
546
547/*
548 * lazy_max_pages is the maximum amount of virtual address space we gather up
549 * before attempting to purge with a TLB flush.
550 *
551 * There is a tradeoff here: a larger number will cover more kernel page tables
552 * and take slightly longer to purge, but it will linearly reduce the number of
553 * global TLB flushes that must be performed. It would seem natural to scale
554 * this number up linearly with the number of CPUs (because vmapping activity
555 * could also scale linearly with the number of CPUs), however it is likely
556 * that in practice, workloads might be constrained in other ways that mean
557 * vmap activity will not scale linearly with CPUs. Also, I want to be
558 * conservative and not introduce a big latency on huge systems, so go with
559 * a less aggressive log scale. It will still be an improvement over the old
560 * code, and it will be simple to change the scale factor if we find that it
561 * becomes a problem on bigger systems.
562 */
563static unsigned long lazy_max_pages(void)
564{
565 unsigned int log;
566
567 log = fls(num_online_cpus());
568
569 return log * (32UL * 1024 * 1024 / PAGE_SIZE);
570}
571
572static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);
573
574/* for per-CPU blocks */
575static void purge_fragmented_blocks_allcpus(void);
576
577/*
578 * called before a call to iounmap() if the caller wants vm_area_struct's
579 * immediately freed.
580 */
581void set_iounmap_nonlazy(void)
582{
583 atomic_set(&vmap_lazy_nr, lazy_max_pages()+1);
584}
585
586/*
587 * Purges all lazily-freed vmap areas.
588 *
589 * If sync is 0 then don't purge if there is already a purge in progress.
590 * If force_flush is 1, then flush kernel TLBs between *start and *end even
591 * if we found no lazy vmap areas to unmap (callers can use this to optimise
592 * their own TLB flushing).
593 * Returns with *start = min(*start, lowest purged address)
594 * *end = max(*end, highest purged address)
595 */
596static void __purge_vmap_area_lazy(unsigned long *start, unsigned long *end,
597 int sync, int force_flush)
598{
599 static DEFINE_SPINLOCK(purge_lock);
600 LIST_HEAD(valist);
601 struct vmap_area *va;
602 struct vmap_area *n_va;
603 int nr = 0;
604
605 /*
606 * If sync is 0 but force_flush is 1, we'll go sync anyway but callers
607 * should not expect such behaviour. This just simplifies locking for
608 * the case that isn't actually used at the moment anyway.
609 */
610 if (!sync && !force_flush) {
611 if (!spin_trylock(&purge_lock))
612 return;
613 } else
614 spin_lock(&purge_lock);
615
616 if (sync)
617 purge_fragmented_blocks_allcpus();
618
619 rcu_read_lock();
620 list_for_each_entry_rcu(va, &vmap_area_list, list) {
621 if (va->flags & VM_LAZY_FREE) {
622 if (va->va_start < *start)
623 *start = va->va_start;
624 if (va->va_end > *end)
625 *end = va->va_end;
626 nr += (va->va_end - va->va_start) >> PAGE_SHIFT;
627 list_add_tail(&va->purge_list, &valist);
628 va->flags |= VM_LAZY_FREEING;
629 va->flags &= ~VM_LAZY_FREE;
630 }
631 }
632 rcu_read_unlock();
633
634 if (nr)
635 atomic_sub(nr, &vmap_lazy_nr);
636
637 if (nr || force_flush)
638 flush_tlb_kernel_range(*start, *end);
639
640 if (nr) {
641 spin_lock(&vmap_area_lock);
642 list_for_each_entry_safe(va, n_va, &valist, purge_list)
643 __free_vmap_area(va);
644 spin_unlock(&vmap_area_lock);
645 }
646 spin_unlock(&purge_lock);
647}
648
649/*
650 * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
651 * is already purging.
652 */
653static void try_purge_vmap_area_lazy(void)
654{
655 unsigned long start = ULONG_MAX, end = 0;
656
657 __purge_vmap_area_lazy(&start, &end, 0, 0);
658}
659
660/*
661 * Kick off a purge of the outstanding lazy areas.
662 */
663static void purge_vmap_area_lazy(void)
664{
665 unsigned long start = ULONG_MAX, end = 0;
666
667 __purge_vmap_area_lazy(&start, &end, 1, 0);
668}
669
670/*
671 * Free a vmap area, caller ensuring that the area has been unmapped
672 * and flush_cache_vunmap had been called for the correct range
673 * previously.
674 */
675static void free_vmap_area_noflush(struct vmap_area *va)
676{
677 va->flags |= VM_LAZY_FREE;
678 atomic_add((va->va_end - va->va_start) >> PAGE_SHIFT, &vmap_lazy_nr);
679 if (unlikely(atomic_read(&vmap_lazy_nr) > lazy_max_pages()))
680 try_purge_vmap_area_lazy();
681}
682
683/*
684 * Free and unmap a vmap area, caller ensuring flush_cache_vunmap had been
685 * called for the correct range previously.
686 */
687static void free_unmap_vmap_area_noflush(struct vmap_area *va)
688{
689 unmap_vmap_area(va);
690 free_vmap_area_noflush(va);
691}
692
693/*
694 * Free and unmap a vmap area
695 */
696static void free_unmap_vmap_area(struct vmap_area *va)
697{
698 flush_cache_vunmap(va->va_start, va->va_end);
699 free_unmap_vmap_area_noflush(va);
700}
701
702static struct vmap_area *find_vmap_area(unsigned long addr)
703{
704 struct vmap_area *va;
705
706 spin_lock(&vmap_area_lock);
707 va = __find_vmap_area(addr);
708 spin_unlock(&vmap_area_lock);
709
710 return va;
711}
712
713static void free_unmap_vmap_area_addr(unsigned long addr)
714{
715 struct vmap_area *va;
716
717 va = find_vmap_area(addr);
718 BUG_ON(!va);
719 free_unmap_vmap_area(va);
720}
721
722
723/*** Per cpu kva allocator ***/
724
725/*
726 * vmap space is limited especially on 32 bit architectures. Ensure there is
727 * room for at least 16 percpu vmap blocks per CPU.
728 */
729/*
730 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
731 * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess
732 * instead (we just need a rough idea)
733 */
734#if BITS_PER_LONG == 32
735#define VMALLOC_SPACE (128UL*1024*1024)
736#else
737#define VMALLOC_SPACE (128UL*1024*1024*1024)
738#endif
739
740#define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE)
741#define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */
742#define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */
743#define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
744#define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
745#define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
746#define VMAP_BBMAP_BITS \
747 VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
748 VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
749 VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
750
751#define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
752
753static bool vmap_initialized __read_mostly = false;
754
755struct vmap_block_queue {
756 spinlock_t lock;
757 struct list_head free;
758};
759
760struct vmap_block {
761 spinlock_t lock;
762 struct vmap_area *va;
763 unsigned long free, dirty;
764 DECLARE_BITMAP(dirty_map, VMAP_BBMAP_BITS);
765 struct list_head free_list;
766 struct rcu_head rcu_head;
767 struct list_head purge;
768};
769
770/* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
771static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
772
773/*
774 * Radix tree of vmap blocks, indexed by address, to quickly find a vmap block
775 * in the free path. Could get rid of this if we change the API to return a
776 * "cookie" from alloc, to be passed to free. But no big deal yet.
777 */
778static DEFINE_SPINLOCK(vmap_block_tree_lock);
779static RADIX_TREE(vmap_block_tree, GFP_ATOMIC);
780
781/*
782 * We should probably have a fallback mechanism to allocate virtual memory
783 * out of partially filled vmap blocks. However vmap block sizing should be
784 * fairly reasonable according to the vmalloc size, so it shouldn't be a
785 * big problem.
786 */
787
788static unsigned long addr_to_vb_idx(unsigned long addr)
789{
790 addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
791 addr /= VMAP_BLOCK_SIZE;
792 return addr;
793}
794
795static struct vmap_block *new_vmap_block(gfp_t gfp_mask)
796{
797 struct vmap_block_queue *vbq;
798 struct vmap_block *vb;
799 struct vmap_area *va;
800 unsigned long vb_idx;
801 int node, err;
802
803 node = numa_node_id();
804
805 vb = kmalloc_node(sizeof(struct vmap_block),
806 gfp_mask & GFP_RECLAIM_MASK, node);
807 if (unlikely(!vb))
808 return ERR_PTR(-ENOMEM);
809
810 va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
811 VMALLOC_START, VMALLOC_END,
812 node, gfp_mask);
813 if (IS_ERR(va)) {
814 kfree(vb);
815 return ERR_CAST(va);
816 }
817
818 err = radix_tree_preload(gfp_mask);
819 if (unlikely(err)) {
820 kfree(vb);
821 free_vmap_area(va);
822 return ERR_PTR(err);
823 }
824
825 spin_lock_init(&vb->lock);
826 vb->va = va;
827 vb->free = VMAP_BBMAP_BITS;
828 vb->dirty = 0;
829 bitmap_zero(vb->dirty_map, VMAP_BBMAP_BITS);
830 INIT_LIST_HEAD(&vb->free_list);
831
832 vb_idx = addr_to_vb_idx(va->va_start);
833 spin_lock(&vmap_block_tree_lock);
834 err = radix_tree_insert(&vmap_block_tree, vb_idx, vb);
835 spin_unlock(&vmap_block_tree_lock);
836 BUG_ON(err);
837 radix_tree_preload_end();
838
839 vbq = &get_cpu_var(vmap_block_queue);
840 spin_lock(&vbq->lock);
841 list_add_rcu(&vb->free_list, &vbq->free);
842 spin_unlock(&vbq->lock);
843 put_cpu_var(vmap_block_queue);
844
845 return vb;
846}
847
848static void free_vmap_block(struct vmap_block *vb)
849{
850 struct vmap_block *tmp;
851 unsigned long vb_idx;
852
853 vb_idx = addr_to_vb_idx(vb->va->va_start);
854 spin_lock(&vmap_block_tree_lock);
855 tmp = radix_tree_delete(&vmap_block_tree, vb_idx);
856 spin_unlock(&vmap_block_tree_lock);
857 BUG_ON(tmp != vb);
858
859 free_vmap_area_noflush(vb->va);
860 kfree_rcu(vb, rcu_head);
861}
862
863static void purge_fragmented_blocks(int cpu)
864{
865 LIST_HEAD(purge);
866 struct vmap_block *vb;
867 struct vmap_block *n_vb;
868 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
869
870 rcu_read_lock();
871 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
872
873 if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
874 continue;
875
876 spin_lock(&vb->lock);
877 if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
878 vb->free = 0; /* prevent further allocs after releasing lock */
879 vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
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_allcpus(void)
898{
899 int cpu;
900
901 for_each_possible_cpu(cpu)
902 purge_fragmented_blocks(cpu);
903}
904
905static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
906{
907 struct vmap_block_queue *vbq;
908 struct vmap_block *vb;
909 unsigned long addr = 0;
910 unsigned int order;
911
912 BUG_ON(size & ~PAGE_MASK);
913 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
914 if (WARN_ON(size == 0)) {
915 /*
916 * Allocating 0 bytes isn't what caller wants since
917 * get_order(0) returns funny result. Just warn and terminate
918 * early.
919 */
920 return NULL;
921 }
922 order = get_order(size);
923
924again:
925 rcu_read_lock();
926 vbq = &get_cpu_var(vmap_block_queue);
927 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
928 int i;
929
930 spin_lock(&vb->lock);
931 if (vb->free < 1UL << order)
932 goto next;
933
934 i = VMAP_BBMAP_BITS - vb->free;
935 addr = vb->va->va_start + (i << PAGE_SHIFT);
936 BUG_ON(addr_to_vb_idx(addr) !=
937 addr_to_vb_idx(vb->va->va_start));
938 vb->free -= 1UL << order;
939 if (vb->free == 0) {
940 spin_lock(&vbq->lock);
941 list_del_rcu(&vb->free_list);
942 spin_unlock(&vbq->lock);
943 }
944 spin_unlock(&vb->lock);
945 break;
946next:
947 spin_unlock(&vb->lock);
948 }
949
950 put_cpu_var(vmap_block_queue);
951 rcu_read_unlock();
952
953 if (!addr) {
954 vb = new_vmap_block(gfp_mask);
955 if (IS_ERR(vb))
956 return vb;
957 goto again;
958 }
959
960 return (void *)addr;
961}
962
963static void vb_free(const void *addr, unsigned long size)
964{
965 unsigned long offset;
966 unsigned long vb_idx;
967 unsigned int order;
968 struct vmap_block *vb;
969
970 BUG_ON(size & ~PAGE_MASK);
971 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
972
973 flush_cache_vunmap((unsigned long)addr, (unsigned long)addr + size);
974
975 order = get_order(size);
976
977 offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1);
978
979 vb_idx = addr_to_vb_idx((unsigned long)addr);
980 rcu_read_lock();
981 vb = radix_tree_lookup(&vmap_block_tree, vb_idx);
982 rcu_read_unlock();
983 BUG_ON(!vb);
984
985 vunmap_page_range((unsigned long)addr, (unsigned long)addr + size);
986
987 spin_lock(&vb->lock);
988 BUG_ON(bitmap_allocate_region(vb->dirty_map, offset >> PAGE_SHIFT, order));
989
990 vb->dirty += 1UL << order;
991 if (vb->dirty == VMAP_BBMAP_BITS) {
992 BUG_ON(vb->free);
993 spin_unlock(&vb->lock);
994 free_vmap_block(vb);
995 } else
996 spin_unlock(&vb->lock);
997}
998
999/**
1000 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
1001 *
1002 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
1003 * to amortize TLB flushing overheads. What this means is that any page you
1004 * have now, may, in a former life, have been mapped into kernel virtual
1005 * address by the vmap layer and so there might be some CPUs with TLB entries
1006 * still referencing that page (additional to the regular 1:1 kernel mapping).
1007 *
1008 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
1009 * be sure that none of the pages we have control over will have any aliases
1010 * from the vmap layer.
1011 */
1012void vm_unmap_aliases(void)
1013{
1014 unsigned long start = ULONG_MAX, end = 0;
1015 int cpu;
1016 int flush = 0;
1017
1018 if (unlikely(!vmap_initialized))
1019 return;
1020
1021 for_each_possible_cpu(cpu) {
1022 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
1023 struct vmap_block *vb;
1024
1025 rcu_read_lock();
1026 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
1027 int i, j;
1028
1029 spin_lock(&vb->lock);
1030 i = find_first_bit(vb->dirty_map, VMAP_BBMAP_BITS);
1031 if (i < VMAP_BBMAP_BITS) {
1032 unsigned long s, e;
1033
1034 j = find_last_bit(vb->dirty_map,
1035 VMAP_BBMAP_BITS);
1036 j = j + 1; /* need exclusive index */
1037
1038 s = vb->va->va_start + (i << PAGE_SHIFT);
1039 e = vb->va->va_start + (j << PAGE_SHIFT);
1040 flush = 1;
1041
1042 if (s < start)
1043 start = s;
1044 if (e > end)
1045 end = e;
1046 }
1047 spin_unlock(&vb->lock);
1048 }
1049 rcu_read_unlock();
1050 }
1051
1052 __purge_vmap_area_lazy(&start, &end, 1, flush);
1053}
1054EXPORT_SYMBOL_GPL(vm_unmap_aliases);
1055
1056/**
1057 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
1058 * @mem: the pointer returned by vm_map_ram
1059 * @count: the count passed to that vm_map_ram call (cannot unmap partial)
1060 */
1061void vm_unmap_ram(const void *mem, unsigned int count)
1062{
1063 unsigned long size = count << PAGE_SHIFT;
1064 unsigned long addr = (unsigned long)mem;
1065
1066 BUG_ON(!addr);
1067 BUG_ON(addr < VMALLOC_START);
1068 BUG_ON(addr > VMALLOC_END);
1069 BUG_ON(addr & (PAGE_SIZE-1));
1070
1071 debug_check_no_locks_freed(mem, size);
1072 vmap_debug_free_range(addr, addr+size);
1073
1074 if (likely(count <= VMAP_MAX_ALLOC))
1075 vb_free(mem, size);
1076 else
1077 free_unmap_vmap_area_addr(addr);
1078}
1079EXPORT_SYMBOL(vm_unmap_ram);
1080
1081/**
1082 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
1083 * @pages: an array of pointers to the pages to be mapped
1084 * @count: number of pages
1085 * @node: prefer to allocate data structures on this node
1086 * @prot: memory protection to use. PAGE_KERNEL for regular RAM
1087 *
1088 * If you use this function for less than VMAP_MAX_ALLOC pages, it could be
1089 * faster than vmap so it's good. But if you mix long-life and short-life
1090 * objects with vm_map_ram(), it could consume lots of address space through
1091 * fragmentation (especially on a 32bit machine). You could see failures in
1092 * the end. Please use this function for short-lived objects.
1093 *
1094 * Returns: a pointer to the address that has been mapped, or %NULL on failure
1095 */
1096void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot)
1097{
1098 unsigned long size = count << PAGE_SHIFT;
1099 unsigned long addr;
1100 void *mem;
1101
1102 if (likely(count <= VMAP_MAX_ALLOC)) {
1103 mem = vb_alloc(size, GFP_KERNEL);
1104 if (IS_ERR(mem))
1105 return NULL;
1106 addr = (unsigned long)mem;
1107 } else {
1108 struct vmap_area *va;
1109 va = alloc_vmap_area(size, PAGE_SIZE,
1110 VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
1111 if (IS_ERR(va))
1112 return NULL;
1113
1114 addr = va->va_start;
1115 mem = (void *)addr;
1116 }
1117 if (vmap_page_range(addr, addr + size, prot, pages) < 0) {
1118 vm_unmap_ram(mem, count);
1119 return NULL;
1120 }
1121 return mem;
1122}
1123EXPORT_SYMBOL(vm_map_ram);
1124
1125static struct vm_struct *vmlist __initdata;
1126/**
1127 * vm_area_add_early - add vmap area early during boot
1128 * @vm: vm_struct to add
1129 *
1130 * This function is used to add fixed kernel vm area to vmlist before
1131 * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags
1132 * should contain proper values and the other fields should be zero.
1133 *
1134 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
1135 */
1136void __init vm_area_add_early(struct vm_struct *vm)
1137{
1138 struct vm_struct *tmp, **p;
1139
1140 BUG_ON(vmap_initialized);
1141 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
1142 if (tmp->addr >= vm->addr) {
1143 BUG_ON(tmp->addr < vm->addr + vm->size);
1144 break;
1145 } else
1146 BUG_ON(tmp->addr + tmp->size > vm->addr);
1147 }
1148 vm->next = *p;
1149 *p = vm;
1150}
1151
1152/**
1153 * vm_area_register_early - register vmap area early during boot
1154 * @vm: vm_struct to register
1155 * @align: requested alignment
1156 *
1157 * This function is used to register kernel vm area before
1158 * vmalloc_init() is called. @vm->size and @vm->flags should contain
1159 * proper values on entry and other fields should be zero. On return,
1160 * vm->addr contains the allocated address.
1161 *
1162 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
1163 */
1164void __init vm_area_register_early(struct vm_struct *vm, size_t align)
1165{
1166 static size_t vm_init_off __initdata;
1167 unsigned long addr;
1168
1169 addr = ALIGN(VMALLOC_START + vm_init_off, align);
1170 vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
1171
1172 vm->addr = (void *)addr;
1173
1174 vm_area_add_early(vm);
1175}
1176
1177void __init vmalloc_init(void)
1178{
1179 struct vmap_area *va;
1180 struct vm_struct *tmp;
1181 int i;
1182
1183 for_each_possible_cpu(i) {
1184 struct vmap_block_queue *vbq;
1185 struct vfree_deferred *p;
1186
1187 vbq = &per_cpu(vmap_block_queue, i);
1188 spin_lock_init(&vbq->lock);
1189 INIT_LIST_HEAD(&vbq->free);
1190 p = &per_cpu(vfree_deferred, i);
1191 init_llist_head(&p->list);
1192 INIT_WORK(&p->wq, free_work);
1193 }
1194
1195 /* Import existing vmlist entries. */
1196 for (tmp = vmlist; tmp; tmp = tmp->next) {
1197 va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
1198 va->flags = VM_VM_AREA;
1199 va->va_start = (unsigned long)tmp->addr;
1200 va->va_end = va->va_start + tmp->size;
1201 va->vm = tmp;
1202 __insert_vmap_area(va);
1203 }
1204
1205 vmap_area_pcpu_hole = VMALLOC_END;
1206
1207 vmap_initialized = true;
1208}
1209
1210/**
1211 * map_kernel_range_noflush - map kernel VM area with the specified pages
1212 * @addr: start of the VM area to map
1213 * @size: size of the VM area to map
1214 * @prot: page protection flags to use
1215 * @pages: pages to map
1216 *
1217 * Map 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_vmap() on to-be-mapped areas
1224 * before calling this function.
1225 *
1226 * RETURNS:
1227 * The number of pages mapped on success, -errno on failure.
1228 */
1229int map_kernel_range_noflush(unsigned long addr, unsigned long size,
1230 pgprot_t prot, struct page **pages)
1231{
1232 return vmap_page_range_noflush(addr, addr + size, prot, pages);
1233}
1234
1235/**
1236 * unmap_kernel_range_noflush - unmap kernel VM area
1237 * @addr: start of the VM area to unmap
1238 * @size: size of the VM area to unmap
1239 *
1240 * Unmap PFN_UP(@size) pages at @addr. The VM area @addr and @size
1241 * specify should have been allocated using get_vm_area() and its
1242 * friends.
1243 *
1244 * NOTE:
1245 * This function does NOT do any cache flushing. The caller is
1246 * responsible for calling flush_cache_vunmap() on to-be-mapped areas
1247 * before calling this function and flush_tlb_kernel_range() after.
1248 */
1249void unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
1250{
1251 vunmap_page_range(addr, addr + size);
1252}
1253EXPORT_SYMBOL_GPL(unmap_kernel_range_noflush);
1254
1255/**
1256 * unmap_kernel_range - unmap kernel VM area and flush cache and TLB
1257 * @addr: start of the VM area to unmap
1258 * @size: size of the VM area to unmap
1259 *
1260 * Similar to unmap_kernel_range_noflush() but flushes vcache before
1261 * the unmapping and tlb after.
1262 */
1263void unmap_kernel_range(unsigned long addr, unsigned long size)
1264{
1265 unsigned long end = addr + size;
1266
1267 flush_cache_vunmap(addr, end);
1268 vunmap_page_range(addr, end);
1269 flush_tlb_kernel_range(addr, end);
1270}
1271
1272int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages)
1273{
1274 unsigned long addr = (unsigned long)area->addr;
1275 unsigned long end = addr + get_vm_area_size(area);
1276 int err;
1277
1278 err = vmap_page_range(addr, end, prot, *pages);
1279 if (err > 0) {
1280 *pages += err;
1281 err = 0;
1282 }
1283
1284 return err;
1285}
1286EXPORT_SYMBOL_GPL(map_vm_area);
1287
1288static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
1289 unsigned long flags, const void *caller)
1290{
1291 spin_lock(&vmap_area_lock);
1292 vm->flags = flags;
1293 vm->addr = (void *)va->va_start;
1294 vm->size = va->va_end - va->va_start;
1295 vm->caller = caller;
1296 va->vm = vm;
1297 va->flags |= VM_VM_AREA;
1298 spin_unlock(&vmap_area_lock);
1299}
1300
1301static void clear_vm_uninitialized_flag(struct vm_struct *vm)
1302{
1303 /*
1304 * Before removing VM_UNINITIALIZED,
1305 * we should make sure that vm has proper values.
1306 * Pair with smp_rmb() in show_numa_info().
1307 */
1308 smp_wmb();
1309 vm->flags &= ~VM_UNINITIALIZED;
1310}
1311
1312static struct vm_struct *__get_vm_area_node(unsigned long size,
1313 unsigned long align, unsigned long flags, unsigned long start,
1314 unsigned long end, int node, gfp_t gfp_mask, const void *caller)
1315{
1316 struct vmap_area *va;
1317 struct vm_struct *area;
1318
1319 BUG_ON(in_interrupt());
1320 if (flags & VM_IOREMAP)
1321 align = 1ul << clamp(fls(size), PAGE_SHIFT, IOREMAP_MAX_ORDER);
1322
1323 size = PAGE_ALIGN(size);
1324 if (unlikely(!size))
1325 return NULL;
1326
1327 area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
1328 if (unlikely(!area))
1329 return NULL;
1330
1331 /*
1332 * We always allocate a guard page.
1333 */
1334 size += PAGE_SIZE;
1335
1336 va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
1337 if (IS_ERR(va)) {
1338 kfree(area);
1339 return NULL;
1340 }
1341
1342 setup_vmalloc_vm(area, va, flags, caller);
1343
1344 return area;
1345}
1346
1347struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
1348 unsigned long start, unsigned long end)
1349{
1350 return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE,
1351 GFP_KERNEL, __builtin_return_address(0));
1352}
1353EXPORT_SYMBOL_GPL(__get_vm_area);
1354
1355struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
1356 unsigned long start, unsigned long end,
1357 const void *caller)
1358{
1359 return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE,
1360 GFP_KERNEL, caller);
1361}
1362
1363/**
1364 * get_vm_area - reserve a contiguous kernel virtual area
1365 * @size: size of the area
1366 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC
1367 *
1368 * Search an area of @size in the kernel virtual mapping area,
1369 * and reserved it for out purposes. Returns the area descriptor
1370 * on success or %NULL on failure.
1371 */
1372struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
1373{
1374 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1375 NUMA_NO_NODE, GFP_KERNEL,
1376 __builtin_return_address(0));
1377}
1378
1379struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
1380 const void *caller)
1381{
1382 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1383 NUMA_NO_NODE, GFP_KERNEL, caller);
1384}
1385
1386/**
1387 * find_vm_area - find a continuous kernel virtual area
1388 * @addr: base address
1389 *
1390 * Search for the kernel VM area starting at @addr, and return it.
1391 * It is up to the caller to do all required locking to keep the returned
1392 * pointer valid.
1393 */
1394struct vm_struct *find_vm_area(const void *addr)
1395{
1396 struct vmap_area *va;
1397
1398 va = find_vmap_area((unsigned long)addr);
1399 if (va && va->flags & VM_VM_AREA)
1400 return va->vm;
1401
1402 return NULL;
1403}
1404
1405/**
1406 * remove_vm_area - find and remove a continuous kernel virtual area
1407 * @addr: base address
1408 *
1409 * Search for the kernel VM area starting at @addr, and remove it.
1410 * This function returns the found VM area, but using it is NOT safe
1411 * on SMP machines, except for its size or flags.
1412 */
1413struct vm_struct *remove_vm_area(const void *addr)
1414{
1415 struct vmap_area *va;
1416
1417 va = find_vmap_area((unsigned long)addr);
1418 if (va && va->flags & VM_VM_AREA) {
1419 struct vm_struct *vm = va->vm;
1420
1421 spin_lock(&vmap_area_lock);
1422 va->vm = NULL;
1423 va->flags &= ~VM_VM_AREA;
1424 spin_unlock(&vmap_area_lock);
1425
1426 vmap_debug_free_range(va->va_start, va->va_end);
1427 free_unmap_vmap_area(va);
1428 vm->size -= PAGE_SIZE;
1429
1430 return vm;
1431 }
1432 return NULL;
1433}
1434
1435static void __vunmap(const void *addr, int deallocate_pages)
1436{
1437 struct vm_struct *area;
1438
1439 if (!addr)
1440 return;
1441
1442 if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n",
1443 addr))
1444 return;
1445
1446 area = remove_vm_area(addr);
1447 if (unlikely(!area)) {
1448 WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
1449 addr);
1450 return;
1451 }
1452
1453 debug_check_no_locks_freed(addr, area->size);
1454 debug_check_no_obj_freed(addr, area->size);
1455
1456 if (deallocate_pages) {
1457 int i;
1458
1459 for (i = 0; i < area->nr_pages; i++) {
1460 struct page *page = area->pages[i];
1461
1462 BUG_ON(!page);
1463 __free_page(page);
1464 }
1465
1466 if (area->flags & VM_VPAGES)
1467 vfree(area->pages);
1468 else
1469 kfree(area->pages);
1470 }
1471
1472 kfree(area);
1473 return;
1474}
1475
1476/**
1477 * vfree - release memory allocated by vmalloc()
1478 * @addr: memory base address
1479 *
1480 * Free the virtually continuous memory area starting at @addr, as
1481 * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
1482 * NULL, no operation is performed.
1483 *
1484 * Must not be called in NMI context (strictly speaking, only if we don't
1485 * have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
1486 * conventions for vfree() arch-depenedent would be a really bad idea)
1487 *
1488 * NOTE: assumes that the object at *addr has a size >= sizeof(llist_node)
1489 */
1490void vfree(const void *addr)
1491{
1492 BUG_ON(in_nmi());
1493
1494 kmemleak_free(addr);
1495
1496 if (!addr)
1497 return;
1498 if (unlikely(in_interrupt())) {
1499 struct vfree_deferred *p = &__get_cpu_var(vfree_deferred);
1500 if (llist_add((struct llist_node *)addr, &p->list))
1501 schedule_work(&p->wq);
1502 } else
1503 __vunmap(addr, 1);
1504}
1505EXPORT_SYMBOL(vfree);
1506
1507/**
1508 * vunmap - release virtual mapping obtained by vmap()
1509 * @addr: memory base address
1510 *
1511 * Free the virtually contiguous memory area starting at @addr,
1512 * which was created from the page array passed to vmap().
1513 *
1514 * Must not be called in interrupt context.
1515 */
1516void vunmap(const void *addr)
1517{
1518 BUG_ON(in_interrupt());
1519 might_sleep();
1520 if (addr)
1521 __vunmap(addr, 0);
1522}
1523EXPORT_SYMBOL(vunmap);
1524
1525/**
1526 * vmap - map an array of pages into virtually contiguous space
1527 * @pages: array of page pointers
1528 * @count: number of pages to map
1529 * @flags: vm_area->flags
1530 * @prot: page protection for the mapping
1531 *
1532 * Maps @count pages from @pages into contiguous kernel virtual
1533 * space.
1534 */
1535void *vmap(struct page **pages, unsigned int count,
1536 unsigned long flags, pgprot_t prot)
1537{
1538 struct vm_struct *area;
1539
1540 might_sleep();
1541
1542 if (count > totalram_pages)
1543 return NULL;
1544
1545 area = get_vm_area_caller((count << PAGE_SHIFT), flags,
1546 __builtin_return_address(0));
1547 if (!area)
1548 return NULL;
1549
1550 if (map_vm_area(area, prot, &pages)) {
1551 vunmap(area->addr);
1552 return NULL;
1553 }
1554
1555 return area->addr;
1556}
1557EXPORT_SYMBOL(vmap);
1558
1559static void *__vmalloc_node(unsigned long size, unsigned long align,
1560 gfp_t gfp_mask, pgprot_t prot,
1561 int node, const void *caller);
1562static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
1563 pgprot_t prot, int node)
1564{
1565 const int order = 0;
1566 struct page **pages;
1567 unsigned int nr_pages, array_size, i;
1568 gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
1569
1570 nr_pages = get_vm_area_size(area) >> PAGE_SHIFT;
1571 array_size = (nr_pages * sizeof(struct page *));
1572
1573 area->nr_pages = nr_pages;
1574 /* Please note that the recursion is strictly bounded. */
1575 if (array_size > PAGE_SIZE) {
1576 pages = __vmalloc_node(array_size, 1, nested_gfp|__GFP_HIGHMEM,
1577 PAGE_KERNEL, node, area->caller);
1578 area->flags |= VM_VPAGES;
1579 } else {
1580 pages = kmalloc_node(array_size, nested_gfp, node);
1581 }
1582 area->pages = pages;
1583 if (!area->pages) {
1584 remove_vm_area(area->addr);
1585 kfree(area);
1586 return NULL;
1587 }
1588
1589 for (i = 0; i < area->nr_pages; i++) {
1590 struct page *page;
1591 gfp_t tmp_mask = gfp_mask | __GFP_NOWARN;
1592
1593 if (node == NUMA_NO_NODE)
1594 page = alloc_page(tmp_mask);
1595 else
1596 page = alloc_pages_node(node, tmp_mask, order);
1597
1598 if (unlikely(!page)) {
1599 /* Successfully allocated i pages, free them in __vunmap() */
1600 area->nr_pages = i;
1601 goto fail;
1602 }
1603 area->pages[i] = page;
1604 }
1605
1606 if (map_vm_area(area, prot, &pages))
1607 goto fail;
1608 return area->addr;
1609
1610fail:
1611 warn_alloc_failed(gfp_mask, order,
1612 "vmalloc: allocation failure, allocated %ld of %ld bytes\n",
1613 (area->nr_pages*PAGE_SIZE), area->size);
1614 vfree(area->addr);
1615 return NULL;
1616}
1617
1618/**
1619 * __vmalloc_node_range - allocate virtually contiguous memory
1620 * @size: allocation size
1621 * @align: desired alignment
1622 * @start: vm area range start
1623 * @end: vm area range end
1624 * @gfp_mask: flags for the page level allocator
1625 * @prot: protection mask for the allocated pages
1626 * @node: node to use for allocation or NUMA_NO_NODE
1627 * @caller: caller's return address
1628 *
1629 * Allocate enough pages to cover @size from the page level
1630 * allocator with @gfp_mask flags. Map them into contiguous
1631 * kernel virtual space, using a pagetable protection of @prot.
1632 */
1633void *__vmalloc_node_range(unsigned long size, unsigned long align,
1634 unsigned long start, unsigned long end, gfp_t gfp_mask,
1635 pgprot_t prot, int node, const void *caller)
1636{
1637 struct vm_struct *area;
1638 void *addr;
1639 unsigned long real_size = size;
1640
1641 size = PAGE_ALIGN(size);
1642 if (!size || (size >> PAGE_SHIFT) > totalram_pages)
1643 goto fail;
1644
1645 area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNINITIALIZED,
1646 start, end, node, gfp_mask, caller);
1647 if (!area)
1648 goto fail;
1649
1650 addr = __vmalloc_area_node(area, gfp_mask, prot, node);
1651 if (!addr)
1652 return NULL;
1653
1654 /*
1655 * In this function, newly allocated vm_struct has VM_UNINITIALIZED
1656 * flag. It means that vm_struct is not fully initialized.
1657 * Now, it is fully initialized, so remove this flag here.
1658 */
1659 clear_vm_uninitialized_flag(area);
1660
1661 /*
1662 * A ref_count = 2 is needed because vm_struct allocated in
1663 * __get_vm_area_node() contains a reference to the virtual address of
1664 * the vmalloc'ed block.
1665 */
1666 kmemleak_alloc(addr, real_size, 2, gfp_mask);
1667
1668 return addr;
1669
1670fail:
1671 warn_alloc_failed(gfp_mask, 0,
1672 "vmalloc: allocation failure: %lu bytes\n",
1673 real_size);
1674 return NULL;
1675}
1676
1677/**
1678 * __vmalloc_node - allocate virtually contiguous memory
1679 * @size: allocation size
1680 * @align: desired alignment
1681 * @gfp_mask: flags for the page level allocator
1682 * @prot: protection mask for the allocated pages
1683 * @node: node to use for allocation or NUMA_NO_NODE
1684 * @caller: caller's return address
1685 *
1686 * Allocate enough pages to cover @size from the page level
1687 * allocator with @gfp_mask flags. Map them into contiguous
1688 * kernel virtual space, using a pagetable protection of @prot.
1689 */
1690static void *__vmalloc_node(unsigned long size, unsigned long align,
1691 gfp_t gfp_mask, pgprot_t prot,
1692 int node, const void *caller)
1693{
1694 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
1695 gfp_mask, prot, node, caller);
1696}
1697
1698void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
1699{
1700 return __vmalloc_node(size, 1, gfp_mask, prot, NUMA_NO_NODE,
1701 __builtin_return_address(0));
1702}
1703EXPORT_SYMBOL(__vmalloc);
1704
1705static inline void *__vmalloc_node_flags(unsigned long size,
1706 int node, gfp_t flags)
1707{
1708 return __vmalloc_node(size, 1, flags, PAGE_KERNEL,
1709 node, __builtin_return_address(0));
1710}
1711
1712/**
1713 * vmalloc - allocate virtually contiguous memory
1714 * @size: allocation size
1715 * Allocate enough pages to cover @size from the page level
1716 * allocator and map them into contiguous kernel virtual space.
1717 *
1718 * For tight control over page level allocator and protection flags
1719 * use __vmalloc() instead.
1720 */
1721void *vmalloc(unsigned long size)
1722{
1723 return __vmalloc_node_flags(size, NUMA_NO_NODE,
1724 GFP_KERNEL | __GFP_HIGHMEM);
1725}
1726EXPORT_SYMBOL(vmalloc);
1727
1728/**
1729 * vzalloc - allocate virtually contiguous memory with zero fill
1730 * @size: allocation size
1731 * Allocate enough pages to cover @size from the page level
1732 * allocator and map them into contiguous kernel virtual space.
1733 * The memory allocated is set to zero.
1734 *
1735 * For tight control over page level allocator and protection flags
1736 * use __vmalloc() instead.
1737 */
1738void *vzalloc(unsigned long size)
1739{
1740 return __vmalloc_node_flags(size, NUMA_NO_NODE,
1741 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
1742}
1743EXPORT_SYMBOL(vzalloc);
1744
1745/**
1746 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
1747 * @size: allocation size
1748 *
1749 * The resulting memory area is zeroed so it can be mapped to userspace
1750 * without leaking data.
1751 */
1752void *vmalloc_user(unsigned long size)
1753{
1754 struct vm_struct *area;
1755 void *ret;
1756
1757 ret = __vmalloc_node(size, SHMLBA,
1758 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
1759 PAGE_KERNEL, NUMA_NO_NODE,
1760 __builtin_return_address(0));
1761 if (ret) {
1762 area = find_vm_area(ret);
1763 area->flags |= VM_USERMAP;
1764 }
1765 return ret;
1766}
1767EXPORT_SYMBOL(vmalloc_user);
1768
1769/**
1770 * vmalloc_node - allocate memory on a specific node
1771 * @size: allocation size
1772 * @node: numa node
1773 *
1774 * Allocate enough pages to cover @size from the page level
1775 * allocator and map them into contiguous kernel virtual space.
1776 *
1777 * For tight control over page level allocator and protection flags
1778 * use __vmalloc() instead.
1779 */
1780void *vmalloc_node(unsigned long size, int node)
1781{
1782 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
1783 node, __builtin_return_address(0));
1784}
1785EXPORT_SYMBOL(vmalloc_node);
1786
1787/**
1788 * vzalloc_node - allocate memory on a specific node with zero fill
1789 * @size: allocation size
1790 * @node: numa node
1791 *
1792 * Allocate enough pages to cover @size from the page level
1793 * allocator and map them into contiguous kernel virtual space.
1794 * The memory allocated is set to zero.
1795 *
1796 * For tight control over page level allocator and protection flags
1797 * use __vmalloc_node() instead.
1798 */
1799void *vzalloc_node(unsigned long size, int node)
1800{
1801 return __vmalloc_node_flags(size, node,
1802 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
1803}
1804EXPORT_SYMBOL(vzalloc_node);
1805
1806#ifndef PAGE_KERNEL_EXEC
1807# define PAGE_KERNEL_EXEC PAGE_KERNEL
1808#endif
1809
1810/**
1811 * vmalloc_exec - allocate virtually contiguous, executable memory
1812 * @size: allocation size
1813 *
1814 * Kernel-internal function to allocate enough pages to cover @size
1815 * the page level allocator and map them into contiguous and
1816 * executable kernel virtual space.
1817 *
1818 * For tight control over page level allocator and protection flags
1819 * use __vmalloc() instead.
1820 */
1821
1822void *vmalloc_exec(unsigned long size)
1823{
1824 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
1825 NUMA_NO_NODE, __builtin_return_address(0));
1826}
1827
1828#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
1829#define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
1830#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
1831#define GFP_VMALLOC32 GFP_DMA | GFP_KERNEL
1832#else
1833#define GFP_VMALLOC32 GFP_KERNEL
1834#endif
1835
1836/**
1837 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
1838 * @size: allocation size
1839 *
1840 * Allocate enough 32bit PA addressable pages to cover @size from the
1841 * page level allocator and map them into contiguous kernel virtual space.
1842 */
1843void *vmalloc_32(unsigned long size)
1844{
1845 return __vmalloc_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL,
1846 NUMA_NO_NODE, __builtin_return_address(0));
1847}
1848EXPORT_SYMBOL(vmalloc_32);
1849
1850/**
1851 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
1852 * @size: allocation size
1853 *
1854 * The resulting memory area is 32bit addressable and zeroed so it can be
1855 * mapped to userspace without leaking data.
1856 */
1857void *vmalloc_32_user(unsigned long size)
1858{
1859 struct vm_struct *area;
1860 void *ret;
1861
1862 ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
1863 NUMA_NO_NODE, __builtin_return_address(0));
1864 if (ret) {
1865 area = find_vm_area(ret);
1866 area->flags |= VM_USERMAP;
1867 }
1868 return ret;
1869}
1870EXPORT_SYMBOL(vmalloc_32_user);
1871
1872/*
1873 * small helper routine , copy contents to buf from addr.
1874 * If the page is not present, fill zero.
1875 */
1876
1877static int aligned_vread(char *buf, char *addr, unsigned long count)
1878{
1879 struct page *p;
1880 int copied = 0;
1881
1882 while (count) {
1883 unsigned long offset, length;
1884
1885 offset = (unsigned long)addr & ~PAGE_MASK;
1886 length = PAGE_SIZE - offset;
1887 if (length > count)
1888 length = count;
1889 p = vmalloc_to_page(addr);
1890 /*
1891 * To do safe access to this _mapped_ area, we need
1892 * lock. But adding lock here means that we need to add
1893 * overhead of vmalloc()/vfree() calles for this _debug_
1894 * interface, rarely used. Instead of that, we'll use
1895 * kmap() and get small overhead in this access function.
1896 */
1897 if (p) {
1898 /*
1899 * we can expect USER0 is not used (see vread/vwrite's
1900 * function description)
1901 */
1902 void *map = kmap_atomic(p);
1903 memcpy(buf, map + offset, length);
1904 kunmap_atomic(map);
1905 } else
1906 memset(buf, 0, length);
1907
1908 addr += length;
1909 buf += length;
1910 copied += length;
1911 count -= length;
1912 }
1913 return copied;
1914}
1915
1916static int aligned_vwrite(char *buf, char *addr, unsigned long count)
1917{
1918 struct page *p;
1919 int copied = 0;
1920
1921 while (count) {
1922 unsigned long offset, length;
1923
1924 offset = (unsigned long)addr & ~PAGE_MASK;
1925 length = PAGE_SIZE - offset;
1926 if (length > count)
1927 length = count;
1928 p = vmalloc_to_page(addr);
1929 /*
1930 * To do safe access to this _mapped_ area, we need
1931 * lock. But adding lock here means that we need to add
1932 * overhead of vmalloc()/vfree() calles for this _debug_
1933 * interface, rarely used. Instead of that, we'll use
1934 * kmap() and get small overhead in this access function.
1935 */
1936 if (p) {
1937 /*
1938 * we can expect USER0 is not used (see vread/vwrite's
1939 * function description)
1940 */
1941 void *map = kmap_atomic(p);
1942 memcpy(map + offset, buf, length);
1943 kunmap_atomic(map);
1944 }
1945 addr += length;
1946 buf += length;
1947 copied += length;
1948 count -= length;
1949 }
1950 return copied;
1951}
1952
1953/**
1954 * vread() - read vmalloc area in a safe way.
1955 * @buf: buffer for reading data
1956 * @addr: vm address.
1957 * @count: number of bytes to be read.
1958 *
1959 * Returns # of bytes which addr and buf should be increased.
1960 * (same number to @count). Returns 0 if [addr...addr+count) doesn't
1961 * includes any intersect with alive vmalloc area.
1962 *
1963 * This function checks that addr is a valid vmalloc'ed area, and
1964 * copy data from that area to a given buffer. If the given memory range
1965 * of [addr...addr+count) includes some valid address, data is copied to
1966 * proper area of @buf. If there are memory holes, they'll be zero-filled.
1967 * IOREMAP area is treated as memory hole and no copy is done.
1968 *
1969 * If [addr...addr+count) doesn't includes any intersects with alive
1970 * vm_struct area, returns 0. @buf should be kernel's buffer.
1971 *
1972 * Note: In usual ops, vread() is never necessary because the caller
1973 * should know vmalloc() area is valid and can use memcpy().
1974 * This is for routines which have to access vmalloc area without
1975 * any informaion, as /dev/kmem.
1976 *
1977 */
1978
1979long vread(char *buf, char *addr, unsigned long count)
1980{
1981 struct vmap_area *va;
1982 struct vm_struct *vm;
1983 char *vaddr, *buf_start = buf;
1984 unsigned long buflen = count;
1985 unsigned long n;
1986
1987 /* Don't allow overflow */
1988 if ((unsigned long) addr + count < count)
1989 count = -(unsigned long) addr;
1990
1991 spin_lock(&vmap_area_lock);
1992 list_for_each_entry(va, &vmap_area_list, list) {
1993 if (!count)
1994 break;
1995
1996 if (!(va->flags & VM_VM_AREA))
1997 continue;
1998
1999 vm = va->vm;
2000 vaddr = (char *) vm->addr;
2001 if (addr >= vaddr + get_vm_area_size(vm))
2002 continue;
2003 while (addr < vaddr) {
2004 if (count == 0)
2005 goto finished;
2006 *buf = '\0';
2007 buf++;
2008 addr++;
2009 count--;
2010 }
2011 n = vaddr + get_vm_area_size(vm) - addr;
2012 if (n > count)
2013 n = count;
2014 if (!(vm->flags & VM_IOREMAP))
2015 aligned_vread(buf, addr, n);
2016 else /* IOREMAP area is treated as memory hole */
2017 memset(buf, 0, n);
2018 buf += n;
2019 addr += n;
2020 count -= n;
2021 }
2022finished:
2023 spin_unlock(&vmap_area_lock);
2024
2025 if (buf == buf_start)
2026 return 0;
2027 /* zero-fill memory holes */
2028 if (buf != buf_start + buflen)
2029 memset(buf, 0, buflen - (buf - buf_start));
2030
2031 return buflen;
2032}
2033
2034/**
2035 * vwrite() - write vmalloc area in a safe way.
2036 * @buf: buffer for source data
2037 * @addr: vm address.
2038 * @count: number of bytes to be read.
2039 *
2040 * Returns # of bytes which addr and buf should be incresed.
2041 * (same number to @count).
2042 * If [addr...addr+count) doesn't includes any intersect with valid
2043 * vmalloc area, returns 0.
2044 *
2045 * This function checks that addr is a valid vmalloc'ed area, and
2046 * copy data from a buffer to the given addr. If specified range of
2047 * [addr...addr+count) includes some valid address, data is copied from
2048 * proper area of @buf. If there are memory holes, no copy to hole.
2049 * IOREMAP area is treated as memory hole and no copy is done.
2050 *
2051 * If [addr...addr+count) doesn't includes any intersects with alive
2052 * vm_struct area, returns 0. @buf should be kernel's buffer.
2053 *
2054 * Note: In usual ops, vwrite() is never necessary because the caller
2055 * should know vmalloc() area is valid and can use memcpy().
2056 * This is for routines which have to access vmalloc area without
2057 * any informaion, as /dev/kmem.
2058 */
2059
2060long vwrite(char *buf, char *addr, unsigned long count)
2061{
2062 struct vmap_area *va;
2063 struct vm_struct *vm;
2064 char *vaddr;
2065 unsigned long n, buflen;
2066 int copied = 0;
2067
2068 /* Don't allow overflow */
2069 if ((unsigned long) addr + count < count)
2070 count = -(unsigned long) addr;
2071 buflen = count;
2072
2073 spin_lock(&vmap_area_lock);
2074 list_for_each_entry(va, &vmap_area_list, list) {
2075 if (!count)
2076 break;
2077
2078 if (!(va->flags & VM_VM_AREA))
2079 continue;
2080
2081 vm = va->vm;
2082 vaddr = (char *) vm->addr;
2083 if (addr >= vaddr + get_vm_area_size(vm))
2084 continue;
2085 while (addr < vaddr) {
2086 if (count == 0)
2087 goto finished;
2088 buf++;
2089 addr++;
2090 count--;
2091 }
2092 n = vaddr + get_vm_area_size(vm) - addr;
2093 if (n > count)
2094 n = count;
2095 if (!(vm->flags & VM_IOREMAP)) {
2096 aligned_vwrite(buf, addr, n);
2097 copied++;
2098 }
2099 buf += n;
2100 addr += n;
2101 count -= n;
2102 }
2103finished:
2104 spin_unlock(&vmap_area_lock);
2105 if (!copied)
2106 return 0;
2107 return buflen;
2108}
2109
2110/**
2111 * remap_vmalloc_range_partial - map vmalloc pages to userspace
2112 * @vma: vma to cover
2113 * @uaddr: target user address to start at
2114 * @kaddr: virtual address of vmalloc kernel memory
2115 * @size: size of map area
2116 *
2117 * Returns: 0 for success, -Exxx on failure
2118 *
2119 * This function checks that @kaddr is a valid vmalloc'ed area,
2120 * and that it is big enough to cover the range starting at
2121 * @uaddr in @vma. Will return failure if that criteria isn't
2122 * met.
2123 *
2124 * Similar to remap_pfn_range() (see mm/memory.c)
2125 */
2126int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr,
2127 void *kaddr, unsigned long size)
2128{
2129 struct vm_struct *area;
2130
2131 size = PAGE_ALIGN(size);
2132
2133 if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr))
2134 return -EINVAL;
2135
2136 area = find_vm_area(kaddr);
2137 if (!area)
2138 return -EINVAL;
2139
2140 if (!(area->flags & VM_USERMAP))
2141 return -EINVAL;
2142
2143 if (kaddr + size > area->addr + area->size)
2144 return -EINVAL;
2145
2146 do {
2147 struct page *page = vmalloc_to_page(kaddr);
2148 int ret;
2149
2150 ret = vm_insert_page(vma, uaddr, page);
2151 if (ret)
2152 return ret;
2153
2154 uaddr += PAGE_SIZE;
2155 kaddr += PAGE_SIZE;
2156 size -= PAGE_SIZE;
2157 } while (size > 0);
2158
2159 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
2160
2161 return 0;
2162}
2163EXPORT_SYMBOL(remap_vmalloc_range_partial);
2164
2165/**
2166 * remap_vmalloc_range - map vmalloc pages to userspace
2167 * @vma: vma to cover (map full range of vma)
2168 * @addr: vmalloc memory
2169 * @pgoff: number of pages into addr before first page to map
2170 *
2171 * Returns: 0 for success, -Exxx on failure
2172 *
2173 * This function checks that addr is a valid vmalloc'ed area, and
2174 * that it is big enough to cover the vma. Will return failure if
2175 * that criteria isn't met.
2176 *
2177 * Similar to remap_pfn_range() (see mm/memory.c)
2178 */
2179int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
2180 unsigned long pgoff)
2181{
2182 return remap_vmalloc_range_partial(vma, vma->vm_start,
2183 addr + (pgoff << PAGE_SHIFT),
2184 vma->vm_end - vma->vm_start);
2185}
2186EXPORT_SYMBOL(remap_vmalloc_range);
2187
2188/*
2189 * Implement a stub for vmalloc_sync_all() if the architecture chose not to
2190 * have one.
2191 */
2192void __weak vmalloc_sync_all(void)
2193{
2194}
2195
2196
2197static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
2198{
2199 pte_t ***p = data;
2200
2201 if (p) {
2202 *(*p) = pte;
2203 (*p)++;
2204 }
2205 return 0;
2206}
2207
2208/**
2209 * alloc_vm_area - allocate a range of kernel address space
2210 * @size: size of the area
2211 * @ptes: returns the PTEs for the address space
2212 *
2213 * Returns: NULL on failure, vm_struct on success
2214 *
2215 * This function reserves a range of kernel address space, and
2216 * allocates pagetables to map that range. No actual mappings
2217 * are created.
2218 *
2219 * If @ptes is non-NULL, pointers to the PTEs (in init_mm)
2220 * allocated for the VM area are returned.
2221 */
2222struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes)
2223{
2224 struct vm_struct *area;
2225
2226 area = get_vm_area_caller(size, VM_IOREMAP,
2227 __builtin_return_address(0));
2228 if (area == NULL)
2229 return NULL;
2230
2231 /*
2232 * This ensures that page tables are constructed for this region
2233 * of kernel virtual address space and mapped into init_mm.
2234 */
2235 if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
2236 size, f, ptes ? &ptes : NULL)) {
2237 free_vm_area(area);
2238 return NULL;
2239 }
2240
2241 return area;
2242}
2243EXPORT_SYMBOL_GPL(alloc_vm_area);
2244
2245void free_vm_area(struct vm_struct *area)
2246{
2247 struct vm_struct *ret;
2248 ret = remove_vm_area(area->addr);
2249 BUG_ON(ret != area);
2250 kfree(area);
2251}
2252EXPORT_SYMBOL_GPL(free_vm_area);
2253
2254#ifdef CONFIG_SMP
2255static struct vmap_area *node_to_va(struct rb_node *n)
2256{
2257 return n ? rb_entry(n, struct vmap_area, rb_node) : NULL;
2258}
2259
2260/**
2261 * pvm_find_next_prev - find the next and prev vmap_area surrounding @end
2262 * @end: target address
2263 * @pnext: out arg for the next vmap_area
2264 * @pprev: out arg for the previous vmap_area
2265 *
2266 * Returns: %true if either or both of next and prev are found,
2267 * %false if no vmap_area exists
2268 *
2269 * Find vmap_areas end addresses of which enclose @end. ie. if not
2270 * NULL, *pnext->va_end > @end and *pprev->va_end <= @end.
2271 */
2272static bool pvm_find_next_prev(unsigned long end,
2273 struct vmap_area **pnext,
2274 struct vmap_area **pprev)
2275{
2276 struct rb_node *n = vmap_area_root.rb_node;
2277 struct vmap_area *va = NULL;
2278
2279 while (n) {
2280 va = rb_entry(n, struct vmap_area, rb_node);
2281 if (end < va->va_end)
2282 n = n->rb_left;
2283 else if (end > va->va_end)
2284 n = n->rb_right;
2285 else
2286 break;
2287 }
2288
2289 if (!va)
2290 return false;
2291
2292 if (va->va_end > end) {
2293 *pnext = va;
2294 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2295 } else {
2296 *pprev = va;
2297 *pnext = node_to_va(rb_next(&(*pprev)->rb_node));
2298 }
2299 return true;
2300}
2301
2302/**
2303 * pvm_determine_end - find the highest aligned address between two vmap_areas
2304 * @pnext: in/out arg for the next vmap_area
2305 * @pprev: in/out arg for the previous vmap_area
2306 * @align: alignment
2307 *
2308 * Returns: determined end address
2309 *
2310 * Find the highest aligned address between *@pnext and *@pprev below
2311 * VMALLOC_END. *@pnext and *@pprev are adjusted so that the aligned
2312 * down address is between the end addresses of the two vmap_areas.
2313 *
2314 * Please note that the address returned by this function may fall
2315 * inside *@pnext vmap_area. The caller is responsible for checking
2316 * that.
2317 */
2318static unsigned long pvm_determine_end(struct vmap_area **pnext,
2319 struct vmap_area **pprev,
2320 unsigned long align)
2321{
2322 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2323 unsigned long addr;
2324
2325 if (*pnext)
2326 addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end);
2327 else
2328 addr = vmalloc_end;
2329
2330 while (*pprev && (*pprev)->va_end > addr) {
2331 *pnext = *pprev;
2332 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2333 }
2334
2335 return addr;
2336}
2337
2338/**
2339 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
2340 * @offsets: array containing offset of each area
2341 * @sizes: array containing size of each area
2342 * @nr_vms: the number of areas to allocate
2343 * @align: alignment, all entries in @offsets and @sizes must be aligned to this
2344 *
2345 * Returns: kmalloc'd vm_struct pointer array pointing to allocated
2346 * vm_structs on success, %NULL on failure
2347 *
2348 * Percpu allocator wants to use congruent vm areas so that it can
2349 * maintain the offsets among percpu areas. This function allocates
2350 * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to
2351 * be scattered pretty far, distance between two areas easily going up
2352 * to gigabytes. To avoid interacting with regular vmallocs, these
2353 * areas are allocated from top.
2354 *
2355 * Despite its complicated look, this allocator is rather simple. It
2356 * does everything top-down and scans areas from the end looking for
2357 * matching slot. While scanning, if any of the areas overlaps with
2358 * existing vmap_area, the base address is pulled down to fit the
2359 * area. Scanning is repeated till all the areas fit and then all
2360 * necessary data structres are inserted and the result is returned.
2361 */
2362struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
2363 const size_t *sizes, int nr_vms,
2364 size_t align)
2365{
2366 const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
2367 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2368 struct vmap_area **vas, *prev, *next;
2369 struct vm_struct **vms;
2370 int area, area2, last_area, term_area;
2371 unsigned long base, start, end, last_end;
2372 bool purged = false;
2373
2374 /* verify parameters and allocate data structures */
2375 BUG_ON(align & ~PAGE_MASK || !is_power_of_2(align));
2376 for (last_area = 0, area = 0; area < nr_vms; area++) {
2377 start = offsets[area];
2378 end = start + sizes[area];
2379
2380 /* is everything aligned properly? */
2381 BUG_ON(!IS_ALIGNED(offsets[area], align));
2382 BUG_ON(!IS_ALIGNED(sizes[area], align));
2383
2384 /* detect the area with the highest address */
2385 if (start > offsets[last_area])
2386 last_area = area;
2387
2388 for (area2 = 0; area2 < nr_vms; area2++) {
2389 unsigned long start2 = offsets[area2];
2390 unsigned long end2 = start2 + sizes[area2];
2391
2392 if (area2 == area)
2393 continue;
2394
2395 BUG_ON(start2 >= start && start2 < end);
2396 BUG_ON(end2 <= end && end2 > start);
2397 }
2398 }
2399 last_end = offsets[last_area] + sizes[last_area];
2400
2401 if (vmalloc_end - vmalloc_start < last_end) {
2402 WARN_ON(true);
2403 return NULL;
2404 }
2405
2406 vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL);
2407 vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL);
2408 if (!vas || !vms)
2409 goto err_free2;
2410
2411 for (area = 0; area < nr_vms; area++) {
2412 vas[area] = kzalloc(sizeof(struct vmap_area), GFP_KERNEL);
2413 vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
2414 if (!vas[area] || !vms[area])
2415 goto err_free;
2416 }
2417retry:
2418 spin_lock(&vmap_area_lock);
2419
2420 /* start scanning - we scan from the top, begin with the last area */
2421 area = term_area = last_area;
2422 start = offsets[area];
2423 end = start + sizes[area];
2424
2425 if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) {
2426 base = vmalloc_end - last_end;
2427 goto found;
2428 }
2429 base = pvm_determine_end(&next, &prev, align) - end;
2430
2431 while (true) {
2432 BUG_ON(next && next->va_end <= base + end);
2433 BUG_ON(prev && prev->va_end > base + end);
2434
2435 /*
2436 * base might have underflowed, add last_end before
2437 * comparing.
2438 */
2439 if (base + last_end < vmalloc_start + last_end) {
2440 spin_unlock(&vmap_area_lock);
2441 if (!purged) {
2442 purge_vmap_area_lazy();
2443 purged = true;
2444 goto retry;
2445 }
2446 goto err_free;
2447 }
2448
2449 /*
2450 * If next overlaps, move base downwards so that it's
2451 * right below next and then recheck.
2452 */
2453 if (next && next->va_start < base + end) {
2454 base = pvm_determine_end(&next, &prev, align) - end;
2455 term_area = area;
2456 continue;
2457 }
2458
2459 /*
2460 * If prev overlaps, shift down next and prev and move
2461 * base so that it's right below new next and then
2462 * recheck.
2463 */
2464 if (prev && prev->va_end > base + start) {
2465 next = prev;
2466 prev = node_to_va(rb_prev(&next->rb_node));
2467 base = pvm_determine_end(&next, &prev, align) - end;
2468 term_area = area;
2469 continue;
2470 }
2471
2472 /*
2473 * This area fits, move on to the previous one. If
2474 * the previous one is the terminal one, we're done.
2475 */
2476 area = (area + nr_vms - 1) % nr_vms;
2477 if (area == term_area)
2478 break;
2479 start = offsets[area];
2480 end = start + sizes[area];
2481 pvm_find_next_prev(base + end, &next, &prev);
2482 }
2483found:
2484 /* we've found a fitting base, insert all va's */
2485 for (area = 0; area < nr_vms; area++) {
2486 struct vmap_area *va = vas[area];
2487
2488 va->va_start = base + offsets[area];
2489 va->va_end = va->va_start + sizes[area];
2490 __insert_vmap_area(va);
2491 }
2492
2493 vmap_area_pcpu_hole = base + offsets[last_area];
2494
2495 spin_unlock(&vmap_area_lock);
2496
2497 /* insert all vm's */
2498 for (area = 0; area < nr_vms; area++)
2499 setup_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
2500 pcpu_get_vm_areas);
2501
2502 kfree(vas);
2503 return vms;
2504
2505err_free:
2506 for (area = 0; area < nr_vms; area++) {
2507 kfree(vas[area]);
2508 kfree(vms[area]);
2509 }
2510err_free2:
2511 kfree(vas);
2512 kfree(vms);
2513 return NULL;
2514}
2515
2516/**
2517 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
2518 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
2519 * @nr_vms: the number of allocated areas
2520 *
2521 * Free vm_structs and the array allocated by pcpu_get_vm_areas().
2522 */
2523void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
2524{
2525 int i;
2526
2527 for (i = 0; i < nr_vms; i++)
2528 free_vm_area(vms[i]);
2529 kfree(vms);
2530}
2531#endif /* CONFIG_SMP */
2532
2533#ifdef CONFIG_PROC_FS
2534static void *s_start(struct seq_file *m, loff_t *pos)
2535 __acquires(&vmap_area_lock)
2536{
2537 loff_t n = *pos;
2538 struct vmap_area *va;
2539
2540 spin_lock(&vmap_area_lock);
2541 va = list_entry((&vmap_area_list)->next, typeof(*va), list);
2542 while (n > 0 && &va->list != &vmap_area_list) {
2543 n--;
2544 va = list_entry(va->list.next, typeof(*va), list);
2545 }
2546 if (!n && &va->list != &vmap_area_list)
2547 return va;
2548
2549 return NULL;
2550
2551}
2552
2553static void *s_next(struct seq_file *m, void *p, loff_t *pos)
2554{
2555 struct vmap_area *va = p, *next;
2556
2557 ++*pos;
2558 next = list_entry(va->list.next, typeof(*va), list);
2559 if (&next->list != &vmap_area_list)
2560 return next;
2561
2562 return NULL;
2563}
2564
2565static void s_stop(struct seq_file *m, void *p)
2566 __releases(&vmap_area_lock)
2567{
2568 spin_unlock(&vmap_area_lock);
2569}
2570
2571static void show_numa_info(struct seq_file *m, struct vm_struct *v)
2572{
2573 if (IS_ENABLED(CONFIG_NUMA)) {
2574 unsigned int nr, *counters = m->private;
2575
2576 if (!counters)
2577 return;
2578
2579 /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
2580 smp_rmb();
2581 if (v->flags & VM_UNINITIALIZED)
2582 return;
2583
2584 memset(counters, 0, nr_node_ids * sizeof(unsigned int));
2585
2586 for (nr = 0; nr < v->nr_pages; nr++)
2587 counters[page_to_nid(v->pages[nr])]++;
2588
2589 for_each_node_state(nr, N_HIGH_MEMORY)
2590 if (counters[nr])
2591 seq_printf(m, " N%u=%u", nr, counters[nr]);
2592 }
2593}
2594
2595static int s_show(struct seq_file *m, void *p)
2596{
2597 struct vmap_area *va = p;
2598 struct vm_struct *v;
2599
2600 /*
2601 * s_show can encounter race with remove_vm_area, !VM_VM_AREA on
2602 * behalf of vmap area is being tear down or vm_map_ram allocation.
2603 */
2604 if (!(va->flags & VM_VM_AREA))
2605 return 0;
2606
2607 v = va->vm;
2608
2609 seq_printf(m, "0x%pK-0x%pK %7ld",
2610 v->addr, v->addr + v->size, v->size);
2611
2612 if (v->caller)
2613 seq_printf(m, " %pS", v->caller);
2614
2615 if (v->nr_pages)
2616 seq_printf(m, " pages=%d", v->nr_pages);
2617
2618 if (v->phys_addr)
2619 seq_printf(m, " phys=%llx", (unsigned long long)v->phys_addr);
2620
2621 if (v->flags & VM_IOREMAP)
2622 seq_printf(m, " ioremap");
2623
2624 if (v->flags & VM_ALLOC)
2625 seq_printf(m, " vmalloc");
2626
2627 if (v->flags & VM_MAP)
2628 seq_printf(m, " vmap");
2629
2630 if (v->flags & VM_USERMAP)
2631 seq_printf(m, " user");
2632
2633 if (v->flags & VM_VPAGES)
2634 seq_printf(m, " vpages");
2635
2636 show_numa_info(m, v);
2637 seq_putc(m, '\n');
2638 return 0;
2639}
2640
2641static const struct seq_operations vmalloc_op = {
2642 .start = s_start,
2643 .next = s_next,
2644 .stop = s_stop,
2645 .show = s_show,
2646};
2647
2648static int vmalloc_open(struct inode *inode, struct file *file)
2649{
2650 unsigned int *ptr = NULL;
2651 int ret;
2652
2653 if (IS_ENABLED(CONFIG_NUMA)) {
2654 ptr = kmalloc(nr_node_ids * sizeof(unsigned int), GFP_KERNEL);
2655 if (ptr == NULL)
2656 return -ENOMEM;
2657 }
2658 ret = seq_open(file, &vmalloc_op);
2659 if (!ret) {
2660 struct seq_file *m = file->private_data;
2661 m->private = ptr;
2662 } else
2663 kfree(ptr);
2664 return ret;
2665}
2666
2667static const struct file_operations proc_vmalloc_operations = {
2668 .open = vmalloc_open,
2669 .read = seq_read,
2670 .llseek = seq_lseek,
2671 .release = seq_release_private,
2672};
2673
2674static int __init proc_vmalloc_init(void)
2675{
2676 proc_create("vmallocinfo", S_IRUSR, NULL, &proc_vmalloc_operations);
2677 return 0;
2678}
2679module_init(proc_vmalloc_init);
2680
2681void get_vmalloc_info(struct vmalloc_info *vmi)
2682{
2683 struct vmap_area *va;
2684 unsigned long free_area_size;
2685 unsigned long prev_end;
2686
2687 vmi->used = 0;
2688 vmi->largest_chunk = 0;
2689
2690 prev_end = VMALLOC_START;
2691
2692 spin_lock(&vmap_area_lock);
2693
2694 if (list_empty(&vmap_area_list)) {
2695 vmi->largest_chunk = VMALLOC_TOTAL;
2696 goto out;
2697 }
2698
2699 list_for_each_entry(va, &vmap_area_list, list) {
2700 unsigned long addr = va->va_start;
2701
2702 /*
2703 * Some archs keep another range for modules in vmalloc space
2704 */
2705 if (addr < VMALLOC_START)
2706 continue;
2707 if (addr >= VMALLOC_END)
2708 break;
2709
2710 if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEING))
2711 continue;
2712
2713 vmi->used += (va->va_end - va->va_start);
2714
2715 free_area_size = addr - prev_end;
2716 if (vmi->largest_chunk < free_area_size)
2717 vmi->largest_chunk = free_area_size;
2718
2719 prev_end = va->va_end;
2720 }
2721
2722 if (VMALLOC_END - prev_end > vmi->largest_chunk)
2723 vmi->largest_chunk = VMALLOC_END - prev_end;
2724
2725out:
2726 spin_unlock(&vmap_area_lock);
2727}
2728#endif
2729
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