serial: xilinx_uartps: fix bad register write in console_write
[linux-2.6-xlnx.git] / mm / vmalloc.c
blob2aad49981b5740ba496f30dad6eb5d5a0d862edf
1 /*
2 * linux/mm/vmalloc.c
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 */
11 #include <linux/vmalloc.h>
12 #include <linux/mm.h>
13 #include <linux/module.h>
14 #include <linux/highmem.h>
15 #include <linux/sched.h>
16 #include <linux/slab.h>
17 #include <linux/spinlock.h>
18 #include <linux/interrupt.h>
19 #include <linux/proc_fs.h>
20 #include <linux/seq_file.h>
21 #include <linux/debugobjects.h>
22 #include <linux/kallsyms.h>
23 #include <linux/list.h>
24 #include <linux/rbtree.h>
25 #include <linux/radix-tree.h>
26 #include <linux/rcupdate.h>
27 #include <linux/pfn.h>
28 #include <linux/kmemleak.h>
29 #include <linux/atomic.h>
30 #include <asm/uaccess.h>
31 #include <asm/tlbflush.h>
32 #include <asm/shmparam.h>
34 /*** Page table manipulation functions ***/
36 static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
38 pte_t *pte;
40 pte = pte_offset_kernel(pmd, addr);
41 do {
42 pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
43 WARN_ON(!pte_none(ptent) && !pte_present(ptent));
44 } while (pte++, addr += PAGE_SIZE, addr != end);
47 static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
49 pmd_t *pmd;
50 unsigned long next;
52 pmd = pmd_offset(pud, addr);
53 do {
54 next = pmd_addr_end(addr, end);
55 if (pmd_none_or_clear_bad(pmd))
56 continue;
57 vunmap_pte_range(pmd, addr, next);
58 } while (pmd++, addr = next, addr != end);
61 static void vunmap_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end)
63 pud_t *pud;
64 unsigned long next;
66 pud = pud_offset(pgd, addr);
67 do {
68 next = pud_addr_end(addr, end);
69 if (pud_none_or_clear_bad(pud))
70 continue;
71 vunmap_pmd_range(pud, addr, next);
72 } while (pud++, addr = next, addr != end);
75 static void vunmap_page_range(unsigned long addr, unsigned long end)
77 pgd_t *pgd;
78 unsigned long next;
80 BUG_ON(addr >= end);
81 pgd = pgd_offset_k(addr);
82 do {
83 next = pgd_addr_end(addr, end);
84 if (pgd_none_or_clear_bad(pgd))
85 continue;
86 vunmap_pud_range(pgd, addr, next);
87 } while (pgd++, addr = next, addr != end);
90 static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
91 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
93 pte_t *pte;
96 * nr is a running index into the array which helps higher level
97 * callers keep track of where we're up to.
100 pte = pte_alloc_kernel(pmd, addr);
101 if (!pte)
102 return -ENOMEM;
103 do {
104 struct page *page = pages[*nr];
106 if (WARN_ON(!pte_none(*pte)))
107 return -EBUSY;
108 if (WARN_ON(!page))
109 return -ENOMEM;
110 set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
111 (*nr)++;
112 } while (pte++, addr += PAGE_SIZE, addr != end);
113 return 0;
116 static int vmap_pmd_range(pud_t *pud, unsigned long addr,
117 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
119 pmd_t *pmd;
120 unsigned long next;
122 pmd = pmd_alloc(&init_mm, pud, addr);
123 if (!pmd)
124 return -ENOMEM;
125 do {
126 next = pmd_addr_end(addr, end);
127 if (vmap_pte_range(pmd, addr, next, prot, pages, nr))
128 return -ENOMEM;
129 } while (pmd++, addr = next, addr != end);
130 return 0;
133 static int vmap_pud_range(pgd_t *pgd, unsigned long addr,
134 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
136 pud_t *pud;
137 unsigned long next;
139 pud = pud_alloc(&init_mm, pgd, addr);
140 if (!pud)
141 return -ENOMEM;
142 do {
143 next = pud_addr_end(addr, end);
144 if (vmap_pmd_range(pud, addr, next, prot, pages, nr))
145 return -ENOMEM;
146 } while (pud++, addr = next, addr != end);
147 return 0;
151 * Set up page tables in kva (addr, end). The ptes shall have prot "prot", and
152 * will have pfns corresponding to the "pages" array.
154 * Ie. pte at addr+N*PAGE_SIZE shall point to pfn corresponding to pages[N]
156 static int vmap_page_range_noflush(unsigned long start, unsigned long end,
157 pgprot_t prot, struct page **pages)
159 pgd_t *pgd;
160 unsigned long next;
161 unsigned long addr = start;
162 int err = 0;
163 int nr = 0;
165 BUG_ON(addr >= end);
166 pgd = pgd_offset_k(addr);
167 do {
168 next = pgd_addr_end(addr, end);
169 err = vmap_pud_range(pgd, addr, next, prot, pages, &nr);
170 if (err)
171 return err;
172 } while (pgd++, addr = next, addr != end);
174 return nr;
177 static int vmap_page_range(unsigned long start, unsigned long end,
178 pgprot_t prot, struct page **pages)
180 int ret;
182 ret = vmap_page_range_noflush(start, end, prot, pages);
183 flush_cache_vmap(start, end);
184 return ret;
187 int is_vmalloc_or_module_addr(const void *x)
190 * ARM, x86-64 and sparc64 put modules in a special place,
191 * and fall back on vmalloc() if that fails. Others
192 * just put it in the vmalloc space.
194 #if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
195 unsigned long addr = (unsigned long)x;
196 if (addr >= MODULES_VADDR && addr < MODULES_END)
197 return 1;
198 #endif
199 return is_vmalloc_addr(x);
203 * Walk a vmap address to the struct page it maps.
205 struct page *vmalloc_to_page(const void *vmalloc_addr)
207 unsigned long addr = (unsigned long) vmalloc_addr;
208 struct page *page = NULL;
209 pgd_t *pgd = pgd_offset_k(addr);
212 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
213 * architectures that do not vmalloc module space
215 VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
217 if (!pgd_none(*pgd)) {
218 pud_t *pud = pud_offset(pgd, addr);
219 if (!pud_none(*pud)) {
220 pmd_t *pmd = pmd_offset(pud, addr);
221 if (!pmd_none(*pmd)) {
222 pte_t *ptep, pte;
224 ptep = pte_offset_map(pmd, addr);
225 pte = *ptep;
226 if (pte_present(pte))
227 page = pte_page(pte);
228 pte_unmap(ptep);
232 return page;
234 EXPORT_SYMBOL(vmalloc_to_page);
237 * Map a vmalloc()-space virtual address to the physical page frame number.
239 unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
241 return page_to_pfn(vmalloc_to_page(vmalloc_addr));
243 EXPORT_SYMBOL(vmalloc_to_pfn);
246 /*** Global kva allocator ***/
248 #define VM_LAZY_FREE 0x01
249 #define VM_LAZY_FREEING 0x02
250 #define VM_VM_AREA 0x04
252 struct vmap_area {
253 unsigned long va_start;
254 unsigned long va_end;
255 unsigned long flags;
256 struct rb_node rb_node; /* address sorted rbtree */
257 struct list_head list; /* address sorted list */
258 struct list_head purge_list; /* "lazy purge" list */
259 struct vm_struct *vm;
260 struct rcu_head rcu_head;
263 static DEFINE_SPINLOCK(vmap_area_lock);
264 static LIST_HEAD(vmap_area_list);
265 static struct rb_root vmap_area_root = RB_ROOT;
267 /* The vmap cache globals are protected by vmap_area_lock */
268 static struct rb_node *free_vmap_cache;
269 static unsigned long cached_hole_size;
270 static unsigned long cached_vstart;
271 static unsigned long cached_align;
273 static unsigned long vmap_area_pcpu_hole;
275 static struct vmap_area *__find_vmap_area(unsigned long addr)
277 struct rb_node *n = vmap_area_root.rb_node;
279 while (n) {
280 struct vmap_area *va;
282 va = rb_entry(n, struct vmap_area, rb_node);
283 if (addr < va->va_start)
284 n = n->rb_left;
285 else if (addr > va->va_start)
286 n = n->rb_right;
287 else
288 return va;
291 return NULL;
294 static void __insert_vmap_area(struct vmap_area *va)
296 struct rb_node **p = &vmap_area_root.rb_node;
297 struct rb_node *parent = NULL;
298 struct rb_node *tmp;
300 while (*p) {
301 struct vmap_area *tmp_va;
303 parent = *p;
304 tmp_va = rb_entry(parent, struct vmap_area, rb_node);
305 if (va->va_start < tmp_va->va_end)
306 p = &(*p)->rb_left;
307 else if (va->va_end > tmp_va->va_start)
308 p = &(*p)->rb_right;
309 else
310 BUG();
313 rb_link_node(&va->rb_node, parent, p);
314 rb_insert_color(&va->rb_node, &vmap_area_root);
316 /* address-sort this list so it is usable like the vmlist */
317 tmp = rb_prev(&va->rb_node);
318 if (tmp) {
319 struct vmap_area *prev;
320 prev = rb_entry(tmp, struct vmap_area, rb_node);
321 list_add_rcu(&va->list, &prev->list);
322 } else
323 list_add_rcu(&va->list, &vmap_area_list);
326 static void purge_vmap_area_lazy(void);
329 * Allocate a region of KVA of the specified size and alignment, within the
330 * vstart and vend.
332 static struct vmap_area *alloc_vmap_area(unsigned long size,
333 unsigned long align,
334 unsigned long vstart, unsigned long vend,
335 int node, gfp_t gfp_mask)
337 struct vmap_area *va;
338 struct rb_node *n;
339 unsigned long addr;
340 int purged = 0;
341 struct vmap_area *first;
343 BUG_ON(!size);
344 BUG_ON(size & ~PAGE_MASK);
345 BUG_ON(!is_power_of_2(align));
347 va = kmalloc_node(sizeof(struct vmap_area),
348 gfp_mask & GFP_RECLAIM_MASK, node);
349 if (unlikely(!va))
350 return ERR_PTR(-ENOMEM);
352 retry:
353 spin_lock(&vmap_area_lock);
355 * Invalidate cache if we have more permissive parameters.
356 * cached_hole_size notes the largest hole noticed _below_
357 * the vmap_area cached in free_vmap_cache: if size fits
358 * into that hole, we want to scan from vstart to reuse
359 * the hole instead of allocating above free_vmap_cache.
360 * Note that __free_vmap_area may update free_vmap_cache
361 * without updating cached_hole_size or cached_align.
363 if (!free_vmap_cache ||
364 size < cached_hole_size ||
365 vstart < cached_vstart ||
366 align < cached_align) {
367 nocache:
368 cached_hole_size = 0;
369 free_vmap_cache = NULL;
371 /* record if we encounter less permissive parameters */
372 cached_vstart = vstart;
373 cached_align = align;
375 /* find starting point for our search */
376 if (free_vmap_cache) {
377 first = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
378 addr = ALIGN(first->va_end, align);
379 if (addr < vstart)
380 goto nocache;
381 if (addr + size - 1 < addr)
382 goto overflow;
384 } else {
385 addr = ALIGN(vstart, align);
386 if (addr + size - 1 < addr)
387 goto overflow;
389 n = vmap_area_root.rb_node;
390 first = NULL;
392 while (n) {
393 struct vmap_area *tmp;
394 tmp = rb_entry(n, struct vmap_area, rb_node);
395 if (tmp->va_end >= addr) {
396 first = tmp;
397 if (tmp->va_start <= addr)
398 break;
399 n = n->rb_left;
400 } else
401 n = n->rb_right;
404 if (!first)
405 goto found;
408 /* from the starting point, walk areas until a suitable hole is found */
409 while (addr + size > first->va_start && addr + size <= vend) {
410 if (addr + cached_hole_size < first->va_start)
411 cached_hole_size = first->va_start - addr;
412 addr = ALIGN(first->va_end, align);
413 if (addr + size - 1 < addr)
414 goto overflow;
416 n = rb_next(&first->rb_node);
417 if (n)
418 first = rb_entry(n, struct vmap_area, rb_node);
419 else
420 goto found;
423 found:
424 if (addr + size > vend)
425 goto overflow;
427 va->va_start = addr;
428 va->va_end = addr + size;
429 va->flags = 0;
430 __insert_vmap_area(va);
431 free_vmap_cache = &va->rb_node;
432 spin_unlock(&vmap_area_lock);
434 BUG_ON(va->va_start & (align-1));
435 BUG_ON(va->va_start < vstart);
436 BUG_ON(va->va_end > vend);
438 return va;
440 overflow:
441 spin_unlock(&vmap_area_lock);
442 if (!purged) {
443 purge_vmap_area_lazy();
444 purged = 1;
445 goto retry;
447 if (printk_ratelimit())
448 printk(KERN_WARNING
449 "vmap allocation for size %lu failed: "
450 "use vmalloc=<size> to increase size.\n", size);
451 kfree(va);
452 return ERR_PTR(-EBUSY);
455 static void __free_vmap_area(struct vmap_area *va)
457 BUG_ON(RB_EMPTY_NODE(&va->rb_node));
459 if (free_vmap_cache) {
460 if (va->va_end < cached_vstart) {
461 free_vmap_cache = NULL;
462 } else {
463 struct vmap_area *cache;
464 cache = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
465 if (va->va_start <= cache->va_start) {
466 free_vmap_cache = rb_prev(&va->rb_node);
468 * We don't try to update cached_hole_size or
469 * cached_align, but it won't go very wrong.
474 rb_erase(&va->rb_node, &vmap_area_root);
475 RB_CLEAR_NODE(&va->rb_node);
476 list_del_rcu(&va->list);
479 * Track the highest possible candidate for pcpu area
480 * allocation. Areas outside of vmalloc area can be returned
481 * here too, consider only end addresses which fall inside
482 * vmalloc area proper.
484 if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END)
485 vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end);
487 kfree_rcu(va, rcu_head);
491 * Free a region of KVA allocated by alloc_vmap_area
493 static void free_vmap_area(struct vmap_area *va)
495 spin_lock(&vmap_area_lock);
496 __free_vmap_area(va);
497 spin_unlock(&vmap_area_lock);
501 * Clear the pagetable entries of a given vmap_area
503 static void unmap_vmap_area(struct vmap_area *va)
505 vunmap_page_range(va->va_start, va->va_end);
508 static void vmap_debug_free_range(unsigned long start, unsigned long end)
511 * Unmap page tables and force a TLB flush immediately if
512 * CONFIG_DEBUG_PAGEALLOC is set. This catches use after free
513 * bugs similarly to those in linear kernel virtual address
514 * space after a page has been freed.
516 * All the lazy freeing logic is still retained, in order to
517 * minimise intrusiveness of this debugging feature.
519 * This is going to be *slow* (linear kernel virtual address
520 * debugging doesn't do a broadcast TLB flush so it is a lot
521 * faster).
523 #ifdef CONFIG_DEBUG_PAGEALLOC
524 vunmap_page_range(start, end);
525 flush_tlb_kernel_range(start, end);
526 #endif
530 * lazy_max_pages is the maximum amount of virtual address space we gather up
531 * before attempting to purge with a TLB flush.
533 * There is a tradeoff here: a larger number will cover more kernel page tables
534 * and take slightly longer to purge, but it will linearly reduce the number of
535 * global TLB flushes that must be performed. It would seem natural to scale
536 * this number up linearly with the number of CPUs (because vmapping activity
537 * could also scale linearly with the number of CPUs), however it is likely
538 * that in practice, workloads might be constrained in other ways that mean
539 * vmap activity will not scale linearly with CPUs. Also, I want to be
540 * conservative and not introduce a big latency on huge systems, so go with
541 * a less aggressive log scale. It will still be an improvement over the old
542 * code, and it will be simple to change the scale factor if we find that it
543 * becomes a problem on bigger systems.
545 static unsigned long lazy_max_pages(void)
547 unsigned int log;
549 log = fls(num_online_cpus());
551 return log * (32UL * 1024 * 1024 / PAGE_SIZE);
554 static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);
556 /* for per-CPU blocks */
557 static void purge_fragmented_blocks_allcpus(void);
560 * called before a call to iounmap() if the caller wants vm_area_struct's
561 * immediately freed.
563 void set_iounmap_nonlazy(void)
565 atomic_set(&vmap_lazy_nr, lazy_max_pages()+1);
569 * Purges all lazily-freed vmap areas.
571 * If sync is 0 then don't purge if there is already a purge in progress.
572 * If force_flush is 1, then flush kernel TLBs between *start and *end even
573 * if we found no lazy vmap areas to unmap (callers can use this to optimise
574 * their own TLB flushing).
575 * Returns with *start = min(*start, lowest purged address)
576 * *end = max(*end, highest purged address)
578 static void __purge_vmap_area_lazy(unsigned long *start, unsigned long *end,
579 int sync, int force_flush)
581 static DEFINE_SPINLOCK(purge_lock);
582 LIST_HEAD(valist);
583 struct vmap_area *va;
584 struct vmap_area *n_va;
585 int nr = 0;
588 * If sync is 0 but force_flush is 1, we'll go sync anyway but callers
589 * should not expect such behaviour. This just simplifies locking for
590 * the case that isn't actually used at the moment anyway.
592 if (!sync && !force_flush) {
593 if (!spin_trylock(&purge_lock))
594 return;
595 } else
596 spin_lock(&purge_lock);
598 if (sync)
599 purge_fragmented_blocks_allcpus();
601 rcu_read_lock();
602 list_for_each_entry_rcu(va, &vmap_area_list, list) {
603 if (va->flags & VM_LAZY_FREE) {
604 if (va->va_start < *start)
605 *start = va->va_start;
606 if (va->va_end > *end)
607 *end = va->va_end;
608 nr += (va->va_end - va->va_start) >> PAGE_SHIFT;
609 list_add_tail(&va->purge_list, &valist);
610 va->flags |= VM_LAZY_FREEING;
611 va->flags &= ~VM_LAZY_FREE;
614 rcu_read_unlock();
616 if (nr)
617 atomic_sub(nr, &vmap_lazy_nr);
619 if (nr || force_flush)
620 flush_tlb_kernel_range(*start, *end);
622 if (nr) {
623 spin_lock(&vmap_area_lock);
624 list_for_each_entry_safe(va, n_va, &valist, purge_list)
625 __free_vmap_area(va);
626 spin_unlock(&vmap_area_lock);
628 spin_unlock(&purge_lock);
632 * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
633 * is already purging.
635 static void try_purge_vmap_area_lazy(void)
637 unsigned long start = ULONG_MAX, end = 0;
639 __purge_vmap_area_lazy(&start, &end, 0, 0);
643 * Kick off a purge of the outstanding lazy areas.
645 static void purge_vmap_area_lazy(void)
647 unsigned long start = ULONG_MAX, end = 0;
649 __purge_vmap_area_lazy(&start, &end, 1, 0);
653 * Free a vmap area, caller ensuring that the area has been unmapped
654 * and flush_cache_vunmap had been called for the correct range
655 * previously.
657 static void free_vmap_area_noflush(struct vmap_area *va)
659 va->flags |= VM_LAZY_FREE;
660 atomic_add((va->va_end - va->va_start) >> PAGE_SHIFT, &vmap_lazy_nr);
661 if (unlikely(atomic_read(&vmap_lazy_nr) > lazy_max_pages()))
662 try_purge_vmap_area_lazy();
666 * Free and unmap a vmap area, caller ensuring flush_cache_vunmap had been
667 * called for the correct range previously.
669 static void free_unmap_vmap_area_noflush(struct vmap_area *va)
671 unmap_vmap_area(va);
672 free_vmap_area_noflush(va);
676 * Free and unmap a vmap area
678 static void free_unmap_vmap_area(struct vmap_area *va)
680 flush_cache_vunmap(va->va_start, va->va_end);
681 free_unmap_vmap_area_noflush(va);
684 static struct vmap_area *find_vmap_area(unsigned long addr)
686 struct vmap_area *va;
688 spin_lock(&vmap_area_lock);
689 va = __find_vmap_area(addr);
690 spin_unlock(&vmap_area_lock);
692 return va;
695 static void free_unmap_vmap_area_addr(unsigned long addr)
697 struct vmap_area *va;
699 va = find_vmap_area(addr);
700 BUG_ON(!va);
701 free_unmap_vmap_area(va);
705 /*** Per cpu kva allocator ***/
708 * vmap space is limited especially on 32 bit architectures. Ensure there is
709 * room for at least 16 percpu vmap blocks per CPU.
712 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
713 * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess
714 * instead (we just need a rough idea)
716 #if BITS_PER_LONG == 32
717 #define VMALLOC_SPACE (128UL*1024*1024)
718 #else
719 #define VMALLOC_SPACE (128UL*1024*1024*1024)
720 #endif
722 #define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE)
723 #define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */
724 #define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */
725 #define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
726 #define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
727 #define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
728 #define VMAP_BBMAP_BITS \
729 VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
730 VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
731 VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
733 #define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
735 static bool vmap_initialized __read_mostly = false;
737 struct vmap_block_queue {
738 spinlock_t lock;
739 struct list_head free;
742 struct vmap_block {
743 spinlock_t lock;
744 struct vmap_area *va;
745 struct vmap_block_queue *vbq;
746 unsigned long free, dirty;
747 DECLARE_BITMAP(alloc_map, VMAP_BBMAP_BITS);
748 DECLARE_BITMAP(dirty_map, VMAP_BBMAP_BITS);
749 struct list_head free_list;
750 struct rcu_head rcu_head;
751 struct list_head purge;
754 /* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
755 static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
758 * Radix tree of vmap blocks, indexed by address, to quickly find a vmap block
759 * in the free path. Could get rid of this if we change the API to return a
760 * "cookie" from alloc, to be passed to free. But no big deal yet.
762 static DEFINE_SPINLOCK(vmap_block_tree_lock);
763 static RADIX_TREE(vmap_block_tree, GFP_ATOMIC);
766 * We should probably have a fallback mechanism to allocate virtual memory
767 * out of partially filled vmap blocks. However vmap block sizing should be
768 * fairly reasonable according to the vmalloc size, so it shouldn't be a
769 * big problem.
772 static unsigned long addr_to_vb_idx(unsigned long addr)
774 addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
775 addr /= VMAP_BLOCK_SIZE;
776 return addr;
779 static struct vmap_block *new_vmap_block(gfp_t gfp_mask)
781 struct vmap_block_queue *vbq;
782 struct vmap_block *vb;
783 struct vmap_area *va;
784 unsigned long vb_idx;
785 int node, err;
787 node = numa_node_id();
789 vb = kmalloc_node(sizeof(struct vmap_block),
790 gfp_mask & GFP_RECLAIM_MASK, node);
791 if (unlikely(!vb))
792 return ERR_PTR(-ENOMEM);
794 va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
795 VMALLOC_START, VMALLOC_END,
796 node, gfp_mask);
797 if (IS_ERR(va)) {
798 kfree(vb);
799 return ERR_CAST(va);
802 err = radix_tree_preload(gfp_mask);
803 if (unlikely(err)) {
804 kfree(vb);
805 free_vmap_area(va);
806 return ERR_PTR(err);
809 spin_lock_init(&vb->lock);
810 vb->va = va;
811 vb->free = VMAP_BBMAP_BITS;
812 vb->dirty = 0;
813 bitmap_zero(vb->alloc_map, VMAP_BBMAP_BITS);
814 bitmap_zero(vb->dirty_map, VMAP_BBMAP_BITS);
815 INIT_LIST_HEAD(&vb->free_list);
817 vb_idx = addr_to_vb_idx(va->va_start);
818 spin_lock(&vmap_block_tree_lock);
819 err = radix_tree_insert(&vmap_block_tree, vb_idx, vb);
820 spin_unlock(&vmap_block_tree_lock);
821 BUG_ON(err);
822 radix_tree_preload_end();
824 vbq = &get_cpu_var(vmap_block_queue);
825 vb->vbq = vbq;
826 spin_lock(&vbq->lock);
827 list_add_rcu(&vb->free_list, &vbq->free);
828 spin_unlock(&vbq->lock);
829 put_cpu_var(vmap_block_queue);
831 return vb;
834 static void free_vmap_block(struct vmap_block *vb)
836 struct vmap_block *tmp;
837 unsigned long vb_idx;
839 vb_idx = addr_to_vb_idx(vb->va->va_start);
840 spin_lock(&vmap_block_tree_lock);
841 tmp = radix_tree_delete(&vmap_block_tree, vb_idx);
842 spin_unlock(&vmap_block_tree_lock);
843 BUG_ON(tmp != vb);
845 free_vmap_area_noflush(vb->va);
846 kfree_rcu(vb, rcu_head);
849 static void purge_fragmented_blocks(int cpu)
851 LIST_HEAD(purge);
852 struct vmap_block *vb;
853 struct vmap_block *n_vb;
854 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
856 rcu_read_lock();
857 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
859 if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
860 continue;
862 spin_lock(&vb->lock);
863 if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
864 vb->free = 0; /* prevent further allocs after releasing lock */
865 vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
866 bitmap_fill(vb->alloc_map, VMAP_BBMAP_BITS);
867 bitmap_fill(vb->dirty_map, VMAP_BBMAP_BITS);
868 spin_lock(&vbq->lock);
869 list_del_rcu(&vb->free_list);
870 spin_unlock(&vbq->lock);
871 spin_unlock(&vb->lock);
872 list_add_tail(&vb->purge, &purge);
873 } else
874 spin_unlock(&vb->lock);
876 rcu_read_unlock();
878 list_for_each_entry_safe(vb, n_vb, &purge, purge) {
879 list_del(&vb->purge);
880 free_vmap_block(vb);
884 static void purge_fragmented_blocks_thiscpu(void)
886 purge_fragmented_blocks(smp_processor_id());
889 static void purge_fragmented_blocks_allcpus(void)
891 int cpu;
893 for_each_possible_cpu(cpu)
894 purge_fragmented_blocks(cpu);
897 static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
899 struct vmap_block_queue *vbq;
900 struct vmap_block *vb;
901 unsigned long addr = 0;
902 unsigned int order;
903 int purge = 0;
905 BUG_ON(size & ~PAGE_MASK);
906 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
907 order = get_order(size);
909 again:
910 rcu_read_lock();
911 vbq = &get_cpu_var(vmap_block_queue);
912 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
913 int i;
915 spin_lock(&vb->lock);
916 if (vb->free < 1UL << order)
917 goto next;
919 i = bitmap_find_free_region(vb->alloc_map,
920 VMAP_BBMAP_BITS, order);
922 if (i < 0) {
923 if (vb->free + vb->dirty == VMAP_BBMAP_BITS) {
924 /* fragmented and no outstanding allocations */
925 BUG_ON(vb->dirty != VMAP_BBMAP_BITS);
926 purge = 1;
928 goto next;
930 addr = vb->va->va_start + (i << PAGE_SHIFT);
931 BUG_ON(addr_to_vb_idx(addr) !=
932 addr_to_vb_idx(vb->va->va_start));
933 vb->free -= 1UL << order;
934 if (vb->free == 0) {
935 spin_lock(&vbq->lock);
936 list_del_rcu(&vb->free_list);
937 spin_unlock(&vbq->lock);
939 spin_unlock(&vb->lock);
940 break;
941 next:
942 spin_unlock(&vb->lock);
945 if (purge)
946 purge_fragmented_blocks_thiscpu();
948 put_cpu_var(vmap_block_queue);
949 rcu_read_unlock();
951 if (!addr) {
952 vb = new_vmap_block(gfp_mask);
953 if (IS_ERR(vb))
954 return vb;
955 goto again;
958 return (void *)addr;
961 static void vb_free(const void *addr, unsigned long size)
963 unsigned long offset;
964 unsigned long vb_idx;
965 unsigned int order;
966 struct vmap_block *vb;
968 BUG_ON(size & ~PAGE_MASK);
969 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
971 flush_cache_vunmap((unsigned long)addr, (unsigned long)addr + size);
973 order = get_order(size);
975 offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1);
977 vb_idx = addr_to_vb_idx((unsigned long)addr);
978 rcu_read_lock();
979 vb = radix_tree_lookup(&vmap_block_tree, vb_idx);
980 rcu_read_unlock();
981 BUG_ON(!vb);
983 vunmap_page_range((unsigned long)addr, (unsigned long)addr + size);
985 spin_lock(&vb->lock);
986 BUG_ON(bitmap_allocate_region(vb->dirty_map, offset >> PAGE_SHIFT, order));
988 vb->dirty += 1UL << order;
989 if (vb->dirty == VMAP_BBMAP_BITS) {
990 BUG_ON(vb->free);
991 spin_unlock(&vb->lock);
992 free_vmap_block(vb);
993 } else
994 spin_unlock(&vb->lock);
998 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
1000 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
1001 * to amortize TLB flushing overheads. What this means is that any page you
1002 * have now, may, in a former life, have been mapped into kernel virtual
1003 * address by the vmap layer and so there might be some CPUs with TLB entries
1004 * still referencing that page (additional to the regular 1:1 kernel mapping).
1006 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
1007 * be sure that none of the pages we have control over will have any aliases
1008 * from the vmap layer.
1010 void vm_unmap_aliases(void)
1012 unsigned long start = ULONG_MAX, end = 0;
1013 int cpu;
1014 int flush = 0;
1016 if (unlikely(!vmap_initialized))
1017 return;
1019 for_each_possible_cpu(cpu) {
1020 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
1021 struct vmap_block *vb;
1023 rcu_read_lock();
1024 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
1025 int i;
1027 spin_lock(&vb->lock);
1028 i = find_first_bit(vb->dirty_map, VMAP_BBMAP_BITS);
1029 while (i < VMAP_BBMAP_BITS) {
1030 unsigned long s, e;
1031 int j;
1032 j = find_next_zero_bit(vb->dirty_map,
1033 VMAP_BBMAP_BITS, i);
1035 s = vb->va->va_start + (i << PAGE_SHIFT);
1036 e = vb->va->va_start + (j << PAGE_SHIFT);
1037 flush = 1;
1039 if (s < start)
1040 start = s;
1041 if (e > end)
1042 end = e;
1044 i = j;
1045 i = find_next_bit(vb->dirty_map,
1046 VMAP_BBMAP_BITS, i);
1048 spin_unlock(&vb->lock);
1050 rcu_read_unlock();
1053 __purge_vmap_area_lazy(&start, &end, 1, flush);
1055 EXPORT_SYMBOL_GPL(vm_unmap_aliases);
1058 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
1059 * @mem: the pointer returned by vm_map_ram
1060 * @count: the count passed to that vm_map_ram call (cannot unmap partial)
1062 void vm_unmap_ram(const void *mem, unsigned int count)
1064 unsigned long size = count << PAGE_SHIFT;
1065 unsigned long addr = (unsigned long)mem;
1067 BUG_ON(!addr);
1068 BUG_ON(addr < VMALLOC_START);
1069 BUG_ON(addr > VMALLOC_END);
1070 BUG_ON(addr & (PAGE_SIZE-1));
1072 debug_check_no_locks_freed(mem, size);
1073 vmap_debug_free_range(addr, addr+size);
1075 if (likely(count <= VMAP_MAX_ALLOC))
1076 vb_free(mem, size);
1077 else
1078 free_unmap_vmap_area_addr(addr);
1080 EXPORT_SYMBOL(vm_unmap_ram);
1083 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
1084 * @pages: an array of pointers to the pages to be mapped
1085 * @count: number of pages
1086 * @node: prefer to allocate data structures on this node
1087 * @prot: memory protection to use. PAGE_KERNEL for regular RAM
1089 * Returns: a pointer to the address that has been mapped, or %NULL on failure
1091 void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot)
1093 unsigned long size = count << PAGE_SHIFT;
1094 unsigned long addr;
1095 void *mem;
1097 if (likely(count <= VMAP_MAX_ALLOC)) {
1098 mem = vb_alloc(size, GFP_KERNEL);
1099 if (IS_ERR(mem))
1100 return NULL;
1101 addr = (unsigned long)mem;
1102 } else {
1103 struct vmap_area *va;
1104 va = alloc_vmap_area(size, PAGE_SIZE,
1105 VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
1106 if (IS_ERR(va))
1107 return NULL;
1109 addr = va->va_start;
1110 mem = (void *)addr;
1112 if (vmap_page_range(addr, addr + size, prot, pages) < 0) {
1113 vm_unmap_ram(mem, count);
1114 return NULL;
1116 return mem;
1118 EXPORT_SYMBOL(vm_map_ram);
1121 * vm_area_add_early - add vmap area early during boot
1122 * @vm: vm_struct to add
1124 * This function is used to add fixed kernel vm area to vmlist before
1125 * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags
1126 * should contain proper values and the other fields should be zero.
1128 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
1130 void __init vm_area_add_early(struct vm_struct *vm)
1132 struct vm_struct *tmp, **p;
1134 BUG_ON(vmap_initialized);
1135 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
1136 if (tmp->addr >= vm->addr) {
1137 BUG_ON(tmp->addr < vm->addr + vm->size);
1138 break;
1139 } else
1140 BUG_ON(tmp->addr + tmp->size > vm->addr);
1142 vm->next = *p;
1143 *p = vm;
1147 * vm_area_register_early - register vmap area early during boot
1148 * @vm: vm_struct to register
1149 * @align: requested alignment
1151 * This function is used to register kernel vm area before
1152 * vmalloc_init() is called. @vm->size and @vm->flags should contain
1153 * proper values on entry and other fields should be zero. On return,
1154 * vm->addr contains the allocated address.
1156 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
1158 void __init vm_area_register_early(struct vm_struct *vm, size_t align)
1160 static size_t vm_init_off __initdata;
1161 unsigned long addr;
1163 addr = ALIGN(VMALLOC_START + vm_init_off, align);
1164 vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
1166 vm->addr = (void *)addr;
1168 vm_area_add_early(vm);
1171 void __init vmalloc_init(void)
1173 struct vmap_area *va;
1174 struct vm_struct *tmp;
1175 int i;
1177 for_each_possible_cpu(i) {
1178 struct vmap_block_queue *vbq;
1180 vbq = &per_cpu(vmap_block_queue, i);
1181 spin_lock_init(&vbq->lock);
1182 INIT_LIST_HEAD(&vbq->free);
1185 /* Import existing vmlist entries. */
1186 for (tmp = vmlist; tmp; tmp = tmp->next) {
1187 va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
1188 va->flags = VM_VM_AREA;
1189 va->va_start = (unsigned long)tmp->addr;
1190 va->va_end = va->va_start + tmp->size;
1191 va->vm = tmp;
1192 __insert_vmap_area(va);
1195 vmap_area_pcpu_hole = VMALLOC_END;
1197 vmap_initialized = true;
1201 * map_kernel_range_noflush - map kernel VM area with the specified pages
1202 * @addr: start of the VM area to map
1203 * @size: size of the VM area to map
1204 * @prot: page protection flags to use
1205 * @pages: pages to map
1207 * Map PFN_UP(@size) pages at @addr. The VM area @addr and @size
1208 * specify should have been allocated using get_vm_area() and its
1209 * friends.
1211 * NOTE:
1212 * This function does NOT do any cache flushing. The caller is
1213 * responsible for calling flush_cache_vmap() on to-be-mapped areas
1214 * before calling this function.
1216 * RETURNS:
1217 * The number of pages mapped on success, -errno on failure.
1219 int map_kernel_range_noflush(unsigned long addr, unsigned long size,
1220 pgprot_t prot, struct page **pages)
1222 return vmap_page_range_noflush(addr, addr + size, prot, pages);
1226 * unmap_kernel_range_noflush - unmap kernel VM area
1227 * @addr: start of the VM area to unmap
1228 * @size: size of the VM area to unmap
1230 * Unmap PFN_UP(@size) pages at @addr. The VM area @addr and @size
1231 * specify should have been allocated using get_vm_area() and its
1232 * friends.
1234 * NOTE:
1235 * This function does NOT do any cache flushing. The caller is
1236 * responsible for calling flush_cache_vunmap() on to-be-mapped areas
1237 * before calling this function and flush_tlb_kernel_range() after.
1239 void unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
1241 vunmap_page_range(addr, addr + size);
1243 EXPORT_SYMBOL_GPL(unmap_kernel_range_noflush);
1246 * unmap_kernel_range - unmap kernel VM area and flush cache and TLB
1247 * @addr: start of the VM area to unmap
1248 * @size: size of the VM area to unmap
1250 * Similar to unmap_kernel_range_noflush() but flushes vcache before
1251 * the unmapping and tlb after.
1253 void unmap_kernel_range(unsigned long addr, unsigned long size)
1255 unsigned long end = addr + size;
1257 flush_cache_vunmap(addr, end);
1258 vunmap_page_range(addr, end);
1259 flush_tlb_kernel_range(addr, end);
1262 int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages)
1264 unsigned long addr = (unsigned long)area->addr;
1265 unsigned long end = addr + area->size - PAGE_SIZE;
1266 int err;
1268 err = vmap_page_range(addr, end, prot, *pages);
1269 if (err > 0) {
1270 *pages += err;
1271 err = 0;
1274 return err;
1276 EXPORT_SYMBOL_GPL(map_vm_area);
1278 /*** Old vmalloc interfaces ***/
1279 DEFINE_RWLOCK(vmlist_lock);
1280 struct vm_struct *vmlist;
1282 static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
1283 unsigned long flags, void *caller)
1285 vm->flags = flags;
1286 vm->addr = (void *)va->va_start;
1287 vm->size = va->va_end - va->va_start;
1288 vm->caller = caller;
1289 va->vm = vm;
1290 va->flags |= VM_VM_AREA;
1293 static void insert_vmalloc_vmlist(struct vm_struct *vm)
1295 struct vm_struct *tmp, **p;
1297 vm->flags &= ~VM_UNLIST;
1298 write_lock(&vmlist_lock);
1299 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
1300 if (tmp->addr >= vm->addr)
1301 break;
1303 vm->next = *p;
1304 *p = vm;
1305 write_unlock(&vmlist_lock);
1308 static void insert_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
1309 unsigned long flags, void *caller)
1311 setup_vmalloc_vm(vm, va, flags, caller);
1312 insert_vmalloc_vmlist(vm);
1315 static struct vm_struct *__get_vm_area_node(unsigned long size,
1316 unsigned long align, unsigned long flags, unsigned long start,
1317 unsigned long end, int node, gfp_t gfp_mask, void *caller)
1319 struct vmap_area *va;
1320 struct vm_struct *area;
1322 BUG_ON(in_interrupt());
1323 if (flags & VM_IOREMAP) {
1324 int bit = fls(size);
1326 if (bit > IOREMAP_MAX_ORDER)
1327 bit = IOREMAP_MAX_ORDER;
1328 else if (bit < PAGE_SHIFT)
1329 bit = PAGE_SHIFT;
1331 align = 1ul << bit;
1334 size = PAGE_ALIGN(size);
1335 if (unlikely(!size))
1336 return NULL;
1338 area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
1339 if (unlikely(!area))
1340 return NULL;
1343 * We always allocate a guard page.
1345 size += PAGE_SIZE;
1347 va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
1348 if (IS_ERR(va)) {
1349 kfree(area);
1350 return NULL;
1354 * When this function is called from __vmalloc_node_range,
1355 * we do not add vm_struct to vmlist here to avoid
1356 * accessing uninitialized members of vm_struct such as
1357 * pages and nr_pages fields. They will be set later.
1358 * To distinguish it from others, we use a VM_UNLIST flag.
1360 if (flags & VM_UNLIST)
1361 setup_vmalloc_vm(area, va, flags, caller);
1362 else
1363 insert_vmalloc_vm(area, va, flags, caller);
1365 return area;
1368 struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
1369 unsigned long start, unsigned long end)
1371 return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
1372 __builtin_return_address(0));
1374 EXPORT_SYMBOL_GPL(__get_vm_area);
1376 struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
1377 unsigned long start, unsigned long end,
1378 void *caller)
1380 return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
1381 caller);
1385 * get_vm_area - reserve a contiguous kernel virtual area
1386 * @size: size of the area
1387 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC
1389 * Search an area of @size in the kernel virtual mapping area,
1390 * and reserved it for out purposes. Returns the area descriptor
1391 * on success or %NULL on failure.
1393 struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
1395 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1396 -1, GFP_KERNEL, __builtin_return_address(0));
1399 struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
1400 void *caller)
1402 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1403 -1, GFP_KERNEL, caller);
1406 static struct vm_struct *find_vm_area(const void *addr)
1408 struct vmap_area *va;
1410 va = find_vmap_area((unsigned long)addr);
1411 if (va && va->flags & VM_VM_AREA)
1412 return va->vm;
1414 return NULL;
1418 * remove_vm_area - find and remove a continuous kernel virtual area
1419 * @addr: base address
1421 * Search for the kernel VM area starting at @addr, and remove it.
1422 * This function returns the found VM area, but using it is NOT safe
1423 * on SMP machines, except for its size or flags.
1425 struct vm_struct *remove_vm_area(const void *addr)
1427 struct vmap_area *va;
1429 va = find_vmap_area((unsigned long)addr);
1430 if (va && va->flags & VM_VM_AREA) {
1431 struct vm_struct *vm = va->vm;
1433 if (!(vm->flags & VM_UNLIST)) {
1434 struct vm_struct *tmp, **p;
1436 * remove from list and disallow access to
1437 * this vm_struct before unmap. (address range
1438 * confliction is maintained by vmap.)
1440 write_lock(&vmlist_lock);
1441 for (p = &vmlist; (tmp = *p) != vm; p = &tmp->next)
1443 *p = tmp->next;
1444 write_unlock(&vmlist_lock);
1447 vmap_debug_free_range(va->va_start, va->va_end);
1448 free_unmap_vmap_area(va);
1449 vm->size -= PAGE_SIZE;
1451 return vm;
1453 return NULL;
1456 static void __vunmap(const void *addr, int deallocate_pages)
1458 struct vm_struct *area;
1460 if (!addr)
1461 return;
1463 if ((PAGE_SIZE-1) & (unsigned long)addr) {
1464 WARN(1, KERN_ERR "Trying to vfree() bad address (%p)\n", addr);
1465 return;
1468 area = remove_vm_area(addr);
1469 if (unlikely(!area)) {
1470 WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
1471 addr);
1472 return;
1475 debug_check_no_locks_freed(addr, area->size);
1476 debug_check_no_obj_freed(addr, area->size);
1478 if (deallocate_pages) {
1479 int i;
1481 for (i = 0; i < area->nr_pages; i++) {
1482 struct page *page = area->pages[i];
1484 BUG_ON(!page);
1485 __free_page(page);
1488 if (area->flags & VM_VPAGES)
1489 vfree(area->pages);
1490 else
1491 kfree(area->pages);
1494 kfree(area);
1495 return;
1499 * vfree - release memory allocated by vmalloc()
1500 * @addr: memory base address
1502 * Free the virtually continuous memory area starting at @addr, as
1503 * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
1504 * NULL, no operation is performed.
1506 * Must not be called in interrupt context.
1508 void vfree(const void *addr)
1510 BUG_ON(in_interrupt());
1512 kmemleak_free(addr);
1514 __vunmap(addr, 1);
1516 EXPORT_SYMBOL(vfree);
1519 * vunmap - release virtual mapping obtained by vmap()
1520 * @addr: memory base address
1522 * Free the virtually contiguous memory area starting at @addr,
1523 * which was created from the page array passed to vmap().
1525 * Must not be called in interrupt context.
1527 void vunmap(const void *addr)
1529 BUG_ON(in_interrupt());
1530 might_sleep();
1531 __vunmap(addr, 0);
1533 EXPORT_SYMBOL(vunmap);
1536 * vmap - map an array of pages into virtually contiguous space
1537 * @pages: array of page pointers
1538 * @count: number of pages to map
1539 * @flags: vm_area->flags
1540 * @prot: page protection for the mapping
1542 * Maps @count pages from @pages into contiguous kernel virtual
1543 * space.
1545 void *vmap(struct page **pages, unsigned int count,
1546 unsigned long flags, pgprot_t prot)
1548 struct vm_struct *area;
1550 might_sleep();
1552 if (count > totalram_pages)
1553 return NULL;
1555 area = get_vm_area_caller((count << PAGE_SHIFT), flags,
1556 __builtin_return_address(0));
1557 if (!area)
1558 return NULL;
1560 if (map_vm_area(area, prot, &pages)) {
1561 vunmap(area->addr);
1562 return NULL;
1565 return area->addr;
1567 EXPORT_SYMBOL(vmap);
1569 static void *__vmalloc_node(unsigned long size, unsigned long align,
1570 gfp_t gfp_mask, pgprot_t prot,
1571 int node, void *caller);
1572 static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
1573 pgprot_t prot, int node, void *caller)
1575 const int order = 0;
1576 struct page **pages;
1577 unsigned int nr_pages, array_size, i;
1578 gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
1580 nr_pages = (area->size - PAGE_SIZE) >> PAGE_SHIFT;
1581 array_size = (nr_pages * sizeof(struct page *));
1583 area->nr_pages = nr_pages;
1584 /* Please note that the recursion is strictly bounded. */
1585 if (array_size > PAGE_SIZE) {
1586 pages = __vmalloc_node(array_size, 1, nested_gfp|__GFP_HIGHMEM,
1587 PAGE_KERNEL, node, caller);
1588 area->flags |= VM_VPAGES;
1589 } else {
1590 pages = kmalloc_node(array_size, nested_gfp, node);
1592 area->pages = pages;
1593 area->caller = caller;
1594 if (!area->pages) {
1595 remove_vm_area(area->addr);
1596 kfree(area);
1597 return NULL;
1600 for (i = 0; i < area->nr_pages; i++) {
1601 struct page *page;
1602 gfp_t tmp_mask = gfp_mask | __GFP_NOWARN;
1604 if (node < 0)
1605 page = alloc_page(tmp_mask);
1606 else
1607 page = alloc_pages_node(node, tmp_mask, order);
1609 if (unlikely(!page)) {
1610 /* Successfully allocated i pages, free them in __vunmap() */
1611 area->nr_pages = i;
1612 goto fail;
1614 area->pages[i] = page;
1617 if (map_vm_area(area, prot, &pages))
1618 goto fail;
1619 return area->addr;
1621 fail:
1622 warn_alloc_failed(gfp_mask, order,
1623 "vmalloc: allocation failure, allocated %ld of %ld bytes\n",
1624 (area->nr_pages*PAGE_SIZE), area->size);
1625 vfree(area->addr);
1626 return NULL;
1630 * __vmalloc_node_range - allocate virtually contiguous memory
1631 * @size: allocation size
1632 * @align: desired alignment
1633 * @start: vm area range start
1634 * @end: vm area range end
1635 * @gfp_mask: flags for the page level allocator
1636 * @prot: protection mask for the allocated pages
1637 * @node: node to use for allocation or -1
1638 * @caller: caller's return address
1640 * Allocate enough pages to cover @size from the page level
1641 * allocator with @gfp_mask flags. Map them into contiguous
1642 * kernel virtual space, using a pagetable protection of @prot.
1644 void *__vmalloc_node_range(unsigned long size, unsigned long align,
1645 unsigned long start, unsigned long end, gfp_t gfp_mask,
1646 pgprot_t prot, int node, void *caller)
1648 struct vm_struct *area;
1649 void *addr;
1650 unsigned long real_size = size;
1652 size = PAGE_ALIGN(size);
1653 if (!size || (size >> PAGE_SHIFT) > totalram_pages)
1654 goto fail;
1656 area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNLIST,
1657 start, end, node, gfp_mask, caller);
1658 if (!area)
1659 goto fail;
1661 addr = __vmalloc_area_node(area, gfp_mask, prot, node, caller);
1662 if (!addr)
1663 return NULL;
1666 * In this function, newly allocated vm_struct is not added
1667 * to vmlist at __get_vm_area_node(). so, it is added here.
1669 insert_vmalloc_vmlist(area);
1672 * A ref_count = 3 is needed because the vm_struct and vmap_area
1673 * structures allocated in the __get_vm_area_node() function contain
1674 * references to the virtual address of the vmalloc'ed block.
1676 kmemleak_alloc(addr, real_size, 3, gfp_mask);
1678 return addr;
1680 fail:
1681 warn_alloc_failed(gfp_mask, 0,
1682 "vmalloc: allocation failure: %lu bytes\n",
1683 real_size);
1684 return NULL;
1688 * __vmalloc_node - allocate virtually contiguous memory
1689 * @size: allocation size
1690 * @align: desired alignment
1691 * @gfp_mask: flags for the page level allocator
1692 * @prot: protection mask for the allocated pages
1693 * @node: node to use for allocation or -1
1694 * @caller: caller's return address
1696 * Allocate enough pages to cover @size from the page level
1697 * allocator with @gfp_mask flags. Map them into contiguous
1698 * kernel virtual space, using a pagetable protection of @prot.
1700 static void *__vmalloc_node(unsigned long size, unsigned long align,
1701 gfp_t gfp_mask, pgprot_t prot,
1702 int node, void *caller)
1704 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
1705 gfp_mask, prot, node, caller);
1708 void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
1710 return __vmalloc_node(size, 1, gfp_mask, prot, -1,
1711 __builtin_return_address(0));
1713 EXPORT_SYMBOL(__vmalloc);
1715 static inline void *__vmalloc_node_flags(unsigned long size,
1716 int node, gfp_t flags)
1718 return __vmalloc_node(size, 1, flags, PAGE_KERNEL,
1719 node, __builtin_return_address(0));
1723 * vmalloc - allocate virtually contiguous memory
1724 * @size: allocation size
1725 * Allocate enough pages to cover @size from the page level
1726 * allocator and map them into contiguous kernel virtual space.
1728 * For tight control over page level allocator and protection flags
1729 * use __vmalloc() instead.
1731 void *vmalloc(unsigned long size)
1733 return __vmalloc_node_flags(size, -1, GFP_KERNEL | __GFP_HIGHMEM);
1735 EXPORT_SYMBOL(vmalloc);
1738 * vzalloc - allocate virtually contiguous memory with zero fill
1739 * @size: allocation size
1740 * Allocate enough pages to cover @size from the page level
1741 * allocator and map them into contiguous kernel virtual space.
1742 * The memory allocated is set to zero.
1744 * For tight control over page level allocator and protection flags
1745 * use __vmalloc() instead.
1747 void *vzalloc(unsigned long size)
1749 return __vmalloc_node_flags(size, -1,
1750 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
1752 EXPORT_SYMBOL(vzalloc);
1755 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
1756 * @size: allocation size
1758 * The resulting memory area is zeroed so it can be mapped to userspace
1759 * without leaking data.
1761 void *vmalloc_user(unsigned long size)
1763 struct vm_struct *area;
1764 void *ret;
1766 ret = __vmalloc_node(size, SHMLBA,
1767 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
1768 PAGE_KERNEL, -1, __builtin_return_address(0));
1769 if (ret) {
1770 area = find_vm_area(ret);
1771 area->flags |= VM_USERMAP;
1773 return ret;
1775 EXPORT_SYMBOL(vmalloc_user);
1778 * vmalloc_node - allocate memory on a specific node
1779 * @size: allocation size
1780 * @node: numa node
1782 * Allocate enough pages to cover @size from the page level
1783 * allocator and map them into contiguous kernel virtual space.
1785 * For tight control over page level allocator and protection flags
1786 * use __vmalloc() instead.
1788 void *vmalloc_node(unsigned long size, int node)
1790 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
1791 node, __builtin_return_address(0));
1793 EXPORT_SYMBOL(vmalloc_node);
1796 * vzalloc_node - allocate memory on a specific node with zero fill
1797 * @size: allocation size
1798 * @node: numa node
1800 * Allocate enough pages to cover @size from the page level
1801 * allocator and map them into contiguous kernel virtual space.
1802 * The memory allocated is set to zero.
1804 * For tight control over page level allocator and protection flags
1805 * use __vmalloc_node() instead.
1807 void *vzalloc_node(unsigned long size, int node)
1809 return __vmalloc_node_flags(size, node,
1810 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
1812 EXPORT_SYMBOL(vzalloc_node);
1814 #ifndef PAGE_KERNEL_EXEC
1815 # define PAGE_KERNEL_EXEC PAGE_KERNEL
1816 #endif
1819 * vmalloc_exec - allocate virtually contiguous, executable memory
1820 * @size: allocation size
1822 * Kernel-internal function to allocate enough pages to cover @size
1823 * the page level allocator and map them into contiguous and
1824 * executable kernel virtual space.
1826 * For tight control over page level allocator and protection flags
1827 * use __vmalloc() instead.
1830 void *vmalloc_exec(unsigned long size)
1832 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
1833 -1, __builtin_return_address(0));
1836 #if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
1837 #define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
1838 #elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
1839 #define GFP_VMALLOC32 GFP_DMA | GFP_KERNEL
1840 #else
1841 #define GFP_VMALLOC32 GFP_KERNEL
1842 #endif
1845 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
1846 * @size: allocation size
1848 * Allocate enough 32bit PA addressable pages to cover @size from the
1849 * page level allocator and map them into contiguous kernel virtual space.
1851 void *vmalloc_32(unsigned long size)
1853 return __vmalloc_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL,
1854 -1, __builtin_return_address(0));
1856 EXPORT_SYMBOL(vmalloc_32);
1859 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
1860 * @size: allocation size
1862 * The resulting memory area is 32bit addressable and zeroed so it can be
1863 * mapped to userspace without leaking data.
1865 void *vmalloc_32_user(unsigned long size)
1867 struct vm_struct *area;
1868 void *ret;
1870 ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
1871 -1, __builtin_return_address(0));
1872 if (ret) {
1873 area = find_vm_area(ret);
1874 area->flags |= VM_USERMAP;
1876 return ret;
1878 EXPORT_SYMBOL(vmalloc_32_user);
1881 * small helper routine , copy contents to buf from addr.
1882 * If the page is not present, fill zero.
1885 static int aligned_vread(char *buf, char *addr, unsigned long count)
1887 struct page *p;
1888 int copied = 0;
1890 while (count) {
1891 unsigned long offset, length;
1893 offset = (unsigned long)addr & ~PAGE_MASK;
1894 length = PAGE_SIZE - offset;
1895 if (length > count)
1896 length = count;
1897 p = vmalloc_to_page(addr);
1899 * To do safe access to this _mapped_ area, we need
1900 * lock. But adding lock here means that we need to add
1901 * overhead of vmalloc()/vfree() calles for this _debug_
1902 * interface, rarely used. Instead of that, we'll use
1903 * kmap() and get small overhead in this access function.
1905 if (p) {
1907 * we can expect USER0 is not used (see vread/vwrite's
1908 * function description)
1910 void *map = kmap_atomic(p);
1911 memcpy(buf, map + offset, length);
1912 kunmap_atomic(map);
1913 } else
1914 memset(buf, 0, length);
1916 addr += length;
1917 buf += length;
1918 copied += length;
1919 count -= length;
1921 return copied;
1924 static int aligned_vwrite(char *buf, char *addr, unsigned long count)
1926 struct page *p;
1927 int copied = 0;
1929 while (count) {
1930 unsigned long offset, length;
1932 offset = (unsigned long)addr & ~PAGE_MASK;
1933 length = PAGE_SIZE - offset;
1934 if (length > count)
1935 length = count;
1936 p = vmalloc_to_page(addr);
1938 * To do safe access to this _mapped_ area, we need
1939 * lock. But adding lock here means that we need to add
1940 * overhead of vmalloc()/vfree() calles for this _debug_
1941 * interface, rarely used. Instead of that, we'll use
1942 * kmap() and get small overhead in this access function.
1944 if (p) {
1946 * we can expect USER0 is not used (see vread/vwrite's
1947 * function description)
1949 void *map = kmap_atomic(p);
1950 memcpy(map + offset, buf, length);
1951 kunmap_atomic(map);
1953 addr += length;
1954 buf += length;
1955 copied += length;
1956 count -= length;
1958 return copied;
1962 * vread() - read vmalloc area in a safe way.
1963 * @buf: buffer for reading data
1964 * @addr: vm address.
1965 * @count: number of bytes to be read.
1967 * Returns # of bytes which addr and buf should be increased.
1968 * (same number to @count). Returns 0 if [addr...addr+count) doesn't
1969 * includes any intersect with alive vmalloc area.
1971 * This function checks that addr is a valid vmalloc'ed area, and
1972 * copy data from that area to a given buffer. If the given memory range
1973 * of [addr...addr+count) includes some valid address, data is copied to
1974 * proper area of @buf. If there are memory holes, they'll be zero-filled.
1975 * IOREMAP area is treated as memory hole and no copy is done.
1977 * If [addr...addr+count) doesn't includes any intersects with alive
1978 * vm_struct area, returns 0.
1979 * @buf should be kernel's buffer. Because this function uses KM_USER0,
1980 * the caller should guarantee KM_USER0 is not used.
1982 * Note: In usual ops, vread() is never necessary because the caller
1983 * should know vmalloc() area is valid and can use memcpy().
1984 * This is for routines which have to access vmalloc area without
1985 * any informaion, as /dev/kmem.
1989 long vread(char *buf, char *addr, unsigned long count)
1991 struct vm_struct *tmp;
1992 char *vaddr, *buf_start = buf;
1993 unsigned long buflen = count;
1994 unsigned long n;
1996 /* Don't allow overflow */
1997 if ((unsigned long) addr + count < count)
1998 count = -(unsigned long) addr;
2000 read_lock(&vmlist_lock);
2001 for (tmp = vmlist; count && tmp; tmp = tmp->next) {
2002 vaddr = (char *) tmp->addr;
2003 if (addr >= vaddr + tmp->size - PAGE_SIZE)
2004 continue;
2005 while (addr < vaddr) {
2006 if (count == 0)
2007 goto finished;
2008 *buf = '\0';
2009 buf++;
2010 addr++;
2011 count--;
2013 n = vaddr + tmp->size - PAGE_SIZE - addr;
2014 if (n > count)
2015 n = count;
2016 if (!(tmp->flags & VM_IOREMAP))
2017 aligned_vread(buf, addr, n);
2018 else /* IOREMAP area is treated as memory hole */
2019 memset(buf, 0, n);
2020 buf += n;
2021 addr += n;
2022 count -= n;
2024 finished:
2025 read_unlock(&vmlist_lock);
2027 if (buf == buf_start)
2028 return 0;
2029 /* zero-fill memory holes */
2030 if (buf != buf_start + buflen)
2031 memset(buf, 0, buflen - (buf - buf_start));
2033 return buflen;
2037 * vwrite() - write vmalloc area in a safe way.
2038 * @buf: buffer for source data
2039 * @addr: vm address.
2040 * @count: number of bytes to be read.
2042 * Returns # of bytes which addr and buf should be incresed.
2043 * (same number to @count).
2044 * If [addr...addr+count) doesn't includes any intersect with valid
2045 * vmalloc area, returns 0.
2047 * This function checks that addr is a valid vmalloc'ed area, and
2048 * copy data from a buffer to the given addr. If specified range of
2049 * [addr...addr+count) includes some valid address, data is copied from
2050 * proper area of @buf. If there are memory holes, no copy to hole.
2051 * IOREMAP area is treated as memory hole and no copy is done.
2053 * If [addr...addr+count) doesn't includes any intersects with alive
2054 * vm_struct area, returns 0.
2055 * @buf should be kernel's buffer. Because this function uses KM_USER0,
2056 * the caller should guarantee KM_USER0 is not used.
2058 * Note: In usual ops, vwrite() is never necessary because the caller
2059 * should know vmalloc() area is valid and can use memcpy().
2060 * This is for routines which have to access vmalloc area without
2061 * any informaion, as /dev/kmem.
2064 long vwrite(char *buf, char *addr, unsigned long count)
2066 struct vm_struct *tmp;
2067 char *vaddr;
2068 unsigned long n, buflen;
2069 int copied = 0;
2071 /* Don't allow overflow */
2072 if ((unsigned long) addr + count < count)
2073 count = -(unsigned long) addr;
2074 buflen = count;
2076 read_lock(&vmlist_lock);
2077 for (tmp = vmlist; count && tmp; tmp = tmp->next) {
2078 vaddr = (char *) tmp->addr;
2079 if (addr >= vaddr + tmp->size - PAGE_SIZE)
2080 continue;
2081 while (addr < vaddr) {
2082 if (count == 0)
2083 goto finished;
2084 buf++;
2085 addr++;
2086 count--;
2088 n = vaddr + tmp->size - PAGE_SIZE - addr;
2089 if (n > count)
2090 n = count;
2091 if (!(tmp->flags & VM_IOREMAP)) {
2092 aligned_vwrite(buf, addr, n);
2093 copied++;
2095 buf += n;
2096 addr += n;
2097 count -= n;
2099 finished:
2100 read_unlock(&vmlist_lock);
2101 if (!copied)
2102 return 0;
2103 return buflen;
2107 * remap_vmalloc_range - map vmalloc pages to userspace
2108 * @vma: vma to cover (map full range of vma)
2109 * @addr: vmalloc memory
2110 * @pgoff: number of pages into addr before first page to map
2112 * Returns: 0 for success, -Exxx on failure
2114 * This function checks that addr is a valid vmalloc'ed area, and
2115 * that it is big enough to cover the vma. Will return failure if
2116 * that criteria isn't met.
2118 * Similar to remap_pfn_range() (see mm/memory.c)
2120 int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
2121 unsigned long pgoff)
2123 struct vm_struct *area;
2124 unsigned long uaddr = vma->vm_start;
2125 unsigned long usize = vma->vm_end - vma->vm_start;
2127 if ((PAGE_SIZE-1) & (unsigned long)addr)
2128 return -EINVAL;
2130 area = find_vm_area(addr);
2131 if (!area)
2132 return -EINVAL;
2134 if (!(area->flags & VM_USERMAP))
2135 return -EINVAL;
2137 if (usize + (pgoff << PAGE_SHIFT) > area->size - PAGE_SIZE)
2138 return -EINVAL;
2140 addr += pgoff << PAGE_SHIFT;
2141 do {
2142 struct page *page = vmalloc_to_page(addr);
2143 int ret;
2145 ret = vm_insert_page(vma, uaddr, page);
2146 if (ret)
2147 return ret;
2149 uaddr += PAGE_SIZE;
2150 addr += PAGE_SIZE;
2151 usize -= PAGE_SIZE;
2152 } while (usize > 0);
2154 /* Prevent "things" like memory migration? VM_flags need a cleanup... */
2155 vma->vm_flags |= VM_RESERVED;
2157 return 0;
2159 EXPORT_SYMBOL(remap_vmalloc_range);
2162 * Implement a stub for vmalloc_sync_all() if the architecture chose not to
2163 * have one.
2165 void __attribute__((weak)) vmalloc_sync_all(void)
2170 static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
2172 pte_t ***p = data;
2174 if (p) {
2175 *(*p) = pte;
2176 (*p)++;
2178 return 0;
2182 * alloc_vm_area - allocate a range of kernel address space
2183 * @size: size of the area
2184 * @ptes: returns the PTEs for the address space
2186 * Returns: NULL on failure, vm_struct on success
2188 * This function reserves a range of kernel address space, and
2189 * allocates pagetables to map that range. No actual mappings
2190 * are created.
2192 * If @ptes is non-NULL, pointers to the PTEs (in init_mm)
2193 * allocated for the VM area are returned.
2195 struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes)
2197 struct vm_struct *area;
2199 area = get_vm_area_caller(size, VM_IOREMAP,
2200 __builtin_return_address(0));
2201 if (area == NULL)
2202 return NULL;
2205 * This ensures that page tables are constructed for this region
2206 * of kernel virtual address space and mapped into init_mm.
2208 if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
2209 size, f, ptes ? &ptes : NULL)) {
2210 free_vm_area(area);
2211 return NULL;
2214 return area;
2216 EXPORT_SYMBOL_GPL(alloc_vm_area);
2218 void free_vm_area(struct vm_struct *area)
2220 struct vm_struct *ret;
2221 ret = remove_vm_area(area->addr);
2222 BUG_ON(ret != area);
2223 kfree(area);
2225 EXPORT_SYMBOL_GPL(free_vm_area);
2227 #ifdef CONFIG_SMP
2228 static struct vmap_area *node_to_va(struct rb_node *n)
2230 return n ? rb_entry(n, struct vmap_area, rb_node) : NULL;
2234 * pvm_find_next_prev - find the next and prev vmap_area surrounding @end
2235 * @end: target address
2236 * @pnext: out arg for the next vmap_area
2237 * @pprev: out arg for the previous vmap_area
2239 * Returns: %true if either or both of next and prev are found,
2240 * %false if no vmap_area exists
2242 * Find vmap_areas end addresses of which enclose @end. ie. if not
2243 * NULL, *pnext->va_end > @end and *pprev->va_end <= @end.
2245 static bool pvm_find_next_prev(unsigned long end,
2246 struct vmap_area **pnext,
2247 struct vmap_area **pprev)
2249 struct rb_node *n = vmap_area_root.rb_node;
2250 struct vmap_area *va = NULL;
2252 while (n) {
2253 va = rb_entry(n, struct vmap_area, rb_node);
2254 if (end < va->va_end)
2255 n = n->rb_left;
2256 else if (end > va->va_end)
2257 n = n->rb_right;
2258 else
2259 break;
2262 if (!va)
2263 return false;
2265 if (va->va_end > end) {
2266 *pnext = va;
2267 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2268 } else {
2269 *pprev = va;
2270 *pnext = node_to_va(rb_next(&(*pprev)->rb_node));
2272 return true;
2276 * pvm_determine_end - find the highest aligned address between two vmap_areas
2277 * @pnext: in/out arg for the next vmap_area
2278 * @pprev: in/out arg for the previous vmap_area
2279 * @align: alignment
2281 * Returns: determined end address
2283 * Find the highest aligned address between *@pnext and *@pprev below
2284 * VMALLOC_END. *@pnext and *@pprev are adjusted so that the aligned
2285 * down address is between the end addresses of the two vmap_areas.
2287 * Please note that the address returned by this function may fall
2288 * inside *@pnext vmap_area. The caller is responsible for checking
2289 * that.
2291 static unsigned long pvm_determine_end(struct vmap_area **pnext,
2292 struct vmap_area **pprev,
2293 unsigned long align)
2295 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2296 unsigned long addr;
2298 if (*pnext)
2299 addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end);
2300 else
2301 addr = vmalloc_end;
2303 while (*pprev && (*pprev)->va_end > addr) {
2304 *pnext = *pprev;
2305 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2308 return addr;
2312 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
2313 * @offsets: array containing offset of each area
2314 * @sizes: array containing size of each area
2315 * @nr_vms: the number of areas to allocate
2316 * @align: alignment, all entries in @offsets and @sizes must be aligned to this
2318 * Returns: kmalloc'd vm_struct pointer array pointing to allocated
2319 * vm_structs on success, %NULL on failure
2321 * Percpu allocator wants to use congruent vm areas so that it can
2322 * maintain the offsets among percpu areas. This function allocates
2323 * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to
2324 * be scattered pretty far, distance between two areas easily going up
2325 * to gigabytes. To avoid interacting with regular vmallocs, these
2326 * areas are allocated from top.
2328 * Despite its complicated look, this allocator is rather simple. It
2329 * does everything top-down and scans areas from the end looking for
2330 * matching slot. While scanning, if any of the areas overlaps with
2331 * existing vmap_area, the base address is pulled down to fit the
2332 * area. Scanning is repeated till all the areas fit and then all
2333 * necessary data structres are inserted and the result is returned.
2335 struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
2336 const size_t *sizes, int nr_vms,
2337 size_t align)
2339 const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
2340 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2341 struct vmap_area **vas, *prev, *next;
2342 struct vm_struct **vms;
2343 int area, area2, last_area, term_area;
2344 unsigned long base, start, end, last_end;
2345 bool purged = false;
2347 /* verify parameters and allocate data structures */
2348 BUG_ON(align & ~PAGE_MASK || !is_power_of_2(align));
2349 for (last_area = 0, area = 0; area < nr_vms; area++) {
2350 start = offsets[area];
2351 end = start + sizes[area];
2353 /* is everything aligned properly? */
2354 BUG_ON(!IS_ALIGNED(offsets[area], align));
2355 BUG_ON(!IS_ALIGNED(sizes[area], align));
2357 /* detect the area with the highest address */
2358 if (start > offsets[last_area])
2359 last_area = area;
2361 for (area2 = 0; area2 < nr_vms; area2++) {
2362 unsigned long start2 = offsets[area2];
2363 unsigned long end2 = start2 + sizes[area2];
2365 if (area2 == area)
2366 continue;
2368 BUG_ON(start2 >= start && start2 < end);
2369 BUG_ON(end2 <= end && end2 > start);
2372 last_end = offsets[last_area] + sizes[last_area];
2374 if (vmalloc_end - vmalloc_start < last_end) {
2375 WARN_ON(true);
2376 return NULL;
2379 vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL);
2380 vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL);
2381 if (!vas || !vms)
2382 goto err_free2;
2384 for (area = 0; area < nr_vms; area++) {
2385 vas[area] = kzalloc(sizeof(struct vmap_area), GFP_KERNEL);
2386 vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
2387 if (!vas[area] || !vms[area])
2388 goto err_free;
2390 retry:
2391 spin_lock(&vmap_area_lock);
2393 /* start scanning - we scan from the top, begin with the last area */
2394 area = term_area = last_area;
2395 start = offsets[area];
2396 end = start + sizes[area];
2398 if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) {
2399 base = vmalloc_end - last_end;
2400 goto found;
2402 base = pvm_determine_end(&next, &prev, align) - end;
2404 while (true) {
2405 BUG_ON(next && next->va_end <= base + end);
2406 BUG_ON(prev && prev->va_end > base + end);
2409 * base might have underflowed, add last_end before
2410 * comparing.
2412 if (base + last_end < vmalloc_start + last_end) {
2413 spin_unlock(&vmap_area_lock);
2414 if (!purged) {
2415 purge_vmap_area_lazy();
2416 purged = true;
2417 goto retry;
2419 goto err_free;
2423 * If next overlaps, move base downwards so that it's
2424 * right below next and then recheck.
2426 if (next && next->va_start < base + end) {
2427 base = pvm_determine_end(&next, &prev, align) - end;
2428 term_area = area;
2429 continue;
2433 * If prev overlaps, shift down next and prev and move
2434 * base so that it's right below new next and then
2435 * recheck.
2437 if (prev && prev->va_end > base + start) {
2438 next = prev;
2439 prev = node_to_va(rb_prev(&next->rb_node));
2440 base = pvm_determine_end(&next, &prev, align) - end;
2441 term_area = area;
2442 continue;
2446 * This area fits, move on to the previous one. If
2447 * the previous one is the terminal one, we're done.
2449 area = (area + nr_vms - 1) % nr_vms;
2450 if (area == term_area)
2451 break;
2452 start = offsets[area];
2453 end = start + sizes[area];
2454 pvm_find_next_prev(base + end, &next, &prev);
2456 found:
2457 /* we've found a fitting base, insert all va's */
2458 for (area = 0; area < nr_vms; area++) {
2459 struct vmap_area *va = vas[area];
2461 va->va_start = base + offsets[area];
2462 va->va_end = va->va_start + sizes[area];
2463 __insert_vmap_area(va);
2466 vmap_area_pcpu_hole = base + offsets[last_area];
2468 spin_unlock(&vmap_area_lock);
2470 /* insert all vm's */
2471 for (area = 0; area < nr_vms; area++)
2472 insert_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
2473 pcpu_get_vm_areas);
2475 kfree(vas);
2476 return vms;
2478 err_free:
2479 for (area = 0; area < nr_vms; area++) {
2480 kfree(vas[area]);
2481 kfree(vms[area]);
2483 err_free2:
2484 kfree(vas);
2485 kfree(vms);
2486 return NULL;
2490 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
2491 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
2492 * @nr_vms: the number of allocated areas
2494 * Free vm_structs and the array allocated by pcpu_get_vm_areas().
2496 void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
2498 int i;
2500 for (i = 0; i < nr_vms; i++)
2501 free_vm_area(vms[i]);
2502 kfree(vms);
2504 #endif /* CONFIG_SMP */
2506 #ifdef CONFIG_PROC_FS
2507 static void *s_start(struct seq_file *m, loff_t *pos)
2508 __acquires(&vmlist_lock)
2510 loff_t n = *pos;
2511 struct vm_struct *v;
2513 read_lock(&vmlist_lock);
2514 v = vmlist;
2515 while (n > 0 && v) {
2516 n--;
2517 v = v->next;
2519 if (!n)
2520 return v;
2522 return NULL;
2526 static void *s_next(struct seq_file *m, void *p, loff_t *pos)
2528 struct vm_struct *v = p;
2530 ++*pos;
2531 return v->next;
2534 static void s_stop(struct seq_file *m, void *p)
2535 __releases(&vmlist_lock)
2537 read_unlock(&vmlist_lock);
2540 static void show_numa_info(struct seq_file *m, struct vm_struct *v)
2542 if (NUMA_BUILD) {
2543 unsigned int nr, *counters = m->private;
2545 if (!counters)
2546 return;
2548 memset(counters, 0, nr_node_ids * sizeof(unsigned int));
2550 for (nr = 0; nr < v->nr_pages; nr++)
2551 counters[page_to_nid(v->pages[nr])]++;
2553 for_each_node_state(nr, N_HIGH_MEMORY)
2554 if (counters[nr])
2555 seq_printf(m, " N%u=%u", nr, counters[nr]);
2559 static int s_show(struct seq_file *m, void *p)
2561 struct vm_struct *v = p;
2563 seq_printf(m, "0x%p-0x%p %7ld",
2564 v->addr, v->addr + v->size, v->size);
2566 if (v->caller)
2567 seq_printf(m, " %pS", v->caller);
2569 if (v->nr_pages)
2570 seq_printf(m, " pages=%d", v->nr_pages);
2572 if (v->phys_addr)
2573 seq_printf(m, " phys=%llx", (unsigned long long)v->phys_addr);
2575 if (v->flags & VM_IOREMAP)
2576 seq_printf(m, " ioremap");
2578 if (v->flags & VM_ALLOC)
2579 seq_printf(m, " vmalloc");
2581 if (v->flags & VM_MAP)
2582 seq_printf(m, " vmap");
2584 if (v->flags & VM_USERMAP)
2585 seq_printf(m, " user");
2587 if (v->flags & VM_VPAGES)
2588 seq_printf(m, " vpages");
2590 show_numa_info(m, v);
2591 seq_putc(m, '\n');
2592 return 0;
2595 static const struct seq_operations vmalloc_op = {
2596 .start = s_start,
2597 .next = s_next,
2598 .stop = s_stop,
2599 .show = s_show,
2602 static int vmalloc_open(struct inode *inode, struct file *file)
2604 unsigned int *ptr = NULL;
2605 int ret;
2607 if (NUMA_BUILD) {
2608 ptr = kmalloc(nr_node_ids * sizeof(unsigned int), GFP_KERNEL);
2609 if (ptr == NULL)
2610 return -ENOMEM;
2612 ret = seq_open(file, &vmalloc_op);
2613 if (!ret) {
2614 struct seq_file *m = file->private_data;
2615 m->private = ptr;
2616 } else
2617 kfree(ptr);
2618 return ret;
2621 static const struct file_operations proc_vmalloc_operations = {
2622 .open = vmalloc_open,
2623 .read = seq_read,
2624 .llseek = seq_lseek,
2625 .release = seq_release_private,
2628 static int __init proc_vmalloc_init(void)
2630 proc_create("vmallocinfo", S_IRUSR, NULL, &proc_vmalloc_operations);
2631 return 0;
2633 module_init(proc_vmalloc_init);
2634 #endif