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
11 #include <linux/vmalloc.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)
40 pte = pte_offset_kernel(pmd, addr);
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)
52 pmd = pmd_offset(pud, addr);
54 next = pmd_addr_end(addr, end);
55 if (pmd_none_or_clear_bad(pmd))
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)
66 pud = pud_offset(pgd, addr);
68 next = pud_addr_end(addr, end);
69 if (pud_none_or_clear_bad(pud))
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)
81 pgd = pgd_offset_k(addr);
83 next = pgd_addr_end(addr, end);
84 if (pgd_none_or_clear_bad(pgd))
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)
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);
104 struct page *page = pages[*nr];
106 if (WARN_ON(!pte_none(*pte)))
110 set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
112 } while (pte++, addr += PAGE_SIZE, addr != end);
116 static int vmap_pmd_range(pud_t *pud, unsigned long addr,
117 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
122 pmd = pmd_alloc(&init_mm, pud, addr);
126 next = pmd_addr_end(addr, end);
127 if (vmap_pte_range(pmd, addr, next, prot, pages, nr))
129 } while (pmd++, addr = next, addr != end);
133 static int vmap_pud_range(pgd_t *pgd, unsigned long addr,
134 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
139 pud = pud_alloc(&init_mm, pgd, addr);
143 next = pud_addr_end(addr, end);
144 if (vmap_pmd_range(pud, addr, next, prot, pages, nr))
146 } while (pud++, addr = next, addr != end);
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)
161 unsigned long addr = start;
166 pgd = pgd_offset_k(addr);
168 next = pgd_addr_end(addr, end);
169 err = vmap_pud_range(pgd, addr, next, prot, pages, &nr);
172 } while (pgd++, addr = next, addr != end);
177 static int vmap_page_range(unsigned long start, unsigned long end,
178 pgprot_t prot, struct page **pages)
182 ret = vmap_page_range_noflush(start, end, prot, pages);
183 flush_cache_vmap(start, end);
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)
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)) {
224 ptep = pte_offset_map(pmd, addr);
226 if (pte_present(pte))
227 page = pte_page(pte);
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
253 unsigned long va_start;
254 unsigned long va_end;
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;
280 struct vmap_area *va;
282 va = rb_entry(n, struct vmap_area, rb_node);
283 if (addr < va->va_start)
285 else if (addr > va->va_start)
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;
301 struct vmap_area *tmp_va;
304 tmp_va = rb_entry(parent, struct vmap_area, rb_node);
305 if (va->va_start < tmp_va->va_end)
307 else if (va->va_end > tmp_va->va_start)
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);
319 struct vmap_area *prev;
320 prev = rb_entry(tmp, struct vmap_area, rb_node);
321 list_add_rcu(&va->list, &prev->list);
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
332 static struct vmap_area *alloc_vmap_area(unsigned long size,
334 unsigned long vstart, unsigned long vend,
335 int node, gfp_t gfp_mask)
337 struct vmap_area *va;
341 struct vmap_area *first;
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);
350 return ERR_PTR(-ENOMEM);
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) {
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);
381 if (addr + size - 1 < addr)
385 addr = ALIGN(vstart, align);
386 if (addr + size - 1 < addr)
389 n = vmap_area_root.rb_node;
393 struct vmap_area *tmp;
394 tmp = rb_entry(n, struct vmap_area, rb_node);
395 if (tmp->va_end >= addr) {
397 if (tmp->va_start <= addr)
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)
416 if (list_is_last(&first->list, &vmap_area_list))
419 first = list_entry(first->list.next,
420 struct vmap_area, list);
424 if (addr + size > vend)
428 va->va_end = addr + size;
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);
441 spin_unlock(&vmap_area_lock);
443 purge_vmap_area_lazy();
447 if (printk_ratelimit())
449 "vmap allocation for size %lu failed: "
450 "use vmalloc=<size> to increase size.\n", size);
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;
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
523 #ifdef CONFIG_DEBUG_PAGEALLOC
524 vunmap_page_range(start, end);
525 flush_tlb_kernel_range(start, end);
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)
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
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);
583 struct vmap_area *va;
584 struct vmap_area *n_va;
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))
596 spin_lock(&purge_lock);
599 purge_fragmented_blocks_allcpus();
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)
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;
617 atomic_sub(nr, &vmap_lazy_nr);
619 if (nr || force_flush)
620 flush_tlb_kernel_range(*start, *end);
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
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)
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);
695 static void free_unmap_vmap_area_addr(unsigned long addr)
697 struct vmap_area *va;
699 va = find_vmap_area(addr);
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)
719 #define VMALLOC_SPACE (128UL*1024*1024*1024)
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 {
739 struct list_head free;
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
772 static unsigned long addr_to_vb_idx(unsigned long addr)
774 addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
775 addr /= VMAP_BLOCK_SIZE;
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;
787 node = numa_node_id();
789 vb = kmalloc_node(sizeof(struct vmap_block),
790 gfp_mask & GFP_RECLAIM_MASK, node);
792 return ERR_PTR(-ENOMEM);
794 va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
795 VMALLOC_START, VMALLOC_END,
802 err = radix_tree_preload(gfp_mask);
809 spin_lock_init(&vb->lock);
811 vb->free = VMAP_BBMAP_BITS;
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);
822 radix_tree_preload_end();
824 vbq = &get_cpu_var(vmap_block_queue);
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);
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);
845 free_vmap_area_noflush(vb->va);
846 kfree_rcu(vb, rcu_head);
849 static void purge_fragmented_blocks(int cpu)
852 struct vmap_block *vb;
853 struct vmap_block *n_vb;
854 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
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))
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);
874 spin_unlock(&vb->lock);
878 list_for_each_entry_safe(vb, n_vb, &purge, purge) {
879 list_del(&vb->purge);
884 static void purge_fragmented_blocks_thiscpu(void)
886 purge_fragmented_blocks(smp_processor_id());
889 static void purge_fragmented_blocks_allcpus(void)
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;
905 BUG_ON(size & ~PAGE_MASK);
906 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
907 if (WARN_ON(size == 0)) {
909 * Allocating 0 bytes isn't what caller wants since
910 * get_order(0) returns funny result. Just warn and terminate
915 order = get_order(size);
919 vbq = &get_cpu_var(vmap_block_queue);
920 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
923 spin_lock(&vb->lock);
924 if (vb->free < 1UL << order)
927 i = bitmap_find_free_region(vb->alloc_map,
928 VMAP_BBMAP_BITS, order);
931 if (vb->free + vb->dirty == VMAP_BBMAP_BITS) {
932 /* fragmented and no outstanding allocations */
933 BUG_ON(vb->dirty != VMAP_BBMAP_BITS);
938 addr = vb->va->va_start + (i << PAGE_SHIFT);
939 BUG_ON(addr_to_vb_idx(addr) !=
940 addr_to_vb_idx(vb->va->va_start));
941 vb->free -= 1UL << order;
943 spin_lock(&vbq->lock);
944 list_del_rcu(&vb->free_list);
945 spin_unlock(&vbq->lock);
947 spin_unlock(&vb->lock);
950 spin_unlock(&vb->lock);
954 purge_fragmented_blocks_thiscpu();
956 put_cpu_var(vmap_block_queue);
960 vb = new_vmap_block(gfp_mask);
969 static void vb_free(const void *addr, unsigned long size)
971 unsigned long offset;
972 unsigned long vb_idx;
974 struct vmap_block *vb;
976 BUG_ON(size & ~PAGE_MASK);
977 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
979 flush_cache_vunmap((unsigned long)addr, (unsigned long)addr + size);
981 order = get_order(size);
983 offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1);
985 vb_idx = addr_to_vb_idx((unsigned long)addr);
987 vb = radix_tree_lookup(&vmap_block_tree, vb_idx);
991 vunmap_page_range((unsigned long)addr, (unsigned long)addr + size);
993 spin_lock(&vb->lock);
994 BUG_ON(bitmap_allocate_region(vb->dirty_map, offset >> PAGE_SHIFT, order));
996 vb->dirty += 1UL << order;
997 if (vb->dirty == VMAP_BBMAP_BITS) {
999 spin_unlock(&vb->lock);
1000 free_vmap_block(vb);
1002 spin_unlock(&vb->lock);
1006 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
1008 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
1009 * to amortize TLB flushing overheads. What this means is that any page you
1010 * have now, may, in a former life, have been mapped into kernel virtual
1011 * address by the vmap layer and so there might be some CPUs with TLB entries
1012 * still referencing that page (additional to the regular 1:1 kernel mapping).
1014 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
1015 * be sure that none of the pages we have control over will have any aliases
1016 * from the vmap layer.
1018 void vm_unmap_aliases(void)
1020 unsigned long start = ULONG_MAX, end = 0;
1024 if (unlikely(!vmap_initialized))
1027 for_each_possible_cpu(cpu) {
1028 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
1029 struct vmap_block *vb;
1032 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
1035 spin_lock(&vb->lock);
1036 i = find_first_bit(vb->dirty_map, VMAP_BBMAP_BITS);
1037 while (i < VMAP_BBMAP_BITS) {
1040 j = find_next_zero_bit(vb->dirty_map,
1041 VMAP_BBMAP_BITS, i);
1043 s = vb->va->va_start + (i << PAGE_SHIFT);
1044 e = vb->va->va_start + (j << PAGE_SHIFT);
1053 i = find_next_bit(vb->dirty_map,
1054 VMAP_BBMAP_BITS, i);
1056 spin_unlock(&vb->lock);
1061 __purge_vmap_area_lazy(&start, &end, 1, flush);
1063 EXPORT_SYMBOL_GPL(vm_unmap_aliases);
1066 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
1067 * @mem: the pointer returned by vm_map_ram
1068 * @count: the count passed to that vm_map_ram call (cannot unmap partial)
1070 void vm_unmap_ram(const void *mem, unsigned int count)
1072 unsigned long size = count << PAGE_SHIFT;
1073 unsigned long addr = (unsigned long)mem;
1076 BUG_ON(addr < VMALLOC_START);
1077 BUG_ON(addr > VMALLOC_END);
1078 BUG_ON(addr & (PAGE_SIZE-1));
1080 debug_check_no_locks_freed(mem, size);
1081 vmap_debug_free_range(addr, addr+size);
1083 if (likely(count <= VMAP_MAX_ALLOC))
1086 free_unmap_vmap_area_addr(addr);
1088 EXPORT_SYMBOL(vm_unmap_ram);
1091 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
1092 * @pages: an array of pointers to the pages to be mapped
1093 * @count: number of pages
1094 * @node: prefer to allocate data structures on this node
1095 * @prot: memory protection to use. PAGE_KERNEL for regular RAM
1097 * Returns: a pointer to the address that has been mapped, or %NULL on failure
1099 void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot)
1101 unsigned long size = count << PAGE_SHIFT;
1105 if (likely(count <= VMAP_MAX_ALLOC)) {
1106 mem = vb_alloc(size, GFP_KERNEL);
1109 addr = (unsigned long)mem;
1111 struct vmap_area *va;
1112 va = alloc_vmap_area(size, PAGE_SIZE,
1113 VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
1117 addr = va->va_start;
1120 if (vmap_page_range(addr, addr + size, prot, pages) < 0) {
1121 vm_unmap_ram(mem, count);
1126 EXPORT_SYMBOL(vm_map_ram);
1129 * vm_area_add_early - add vmap area early during boot
1130 * @vm: vm_struct to add
1132 * This function is used to add fixed kernel vm area to vmlist before
1133 * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags
1134 * should contain proper values and the other fields should be zero.
1136 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
1138 void __init vm_area_add_early(struct vm_struct *vm)
1140 struct vm_struct *tmp, **p;
1142 BUG_ON(vmap_initialized);
1143 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
1144 if (tmp->addr >= vm->addr) {
1145 BUG_ON(tmp->addr < vm->addr + vm->size);
1148 BUG_ON(tmp->addr + tmp->size > vm->addr);
1155 * vm_area_register_early - register vmap area early during boot
1156 * @vm: vm_struct to register
1157 * @align: requested alignment
1159 * This function is used to register kernel vm area before
1160 * vmalloc_init() is called. @vm->size and @vm->flags should contain
1161 * proper values on entry and other fields should be zero. On return,
1162 * vm->addr contains the allocated address.
1164 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
1166 void __init vm_area_register_early(struct vm_struct *vm, size_t align)
1168 static size_t vm_init_off __initdata;
1171 addr = ALIGN(VMALLOC_START + vm_init_off, align);
1172 vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
1174 vm->addr = (void *)addr;
1176 vm_area_add_early(vm);
1179 void __init vmalloc_init(void)
1181 struct vmap_area *va;
1182 struct vm_struct *tmp;
1185 for_each_possible_cpu(i) {
1186 struct vmap_block_queue *vbq;
1188 vbq = &per_cpu(vmap_block_queue, i);
1189 spin_lock_init(&vbq->lock);
1190 INIT_LIST_HEAD(&vbq->free);
1193 /* Import existing vmlist entries. */
1194 for (tmp = vmlist; tmp; tmp = tmp->next) {
1195 va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
1196 va->flags = VM_VM_AREA;
1197 va->va_start = (unsigned long)tmp->addr;
1198 va->va_end = va->va_start + tmp->size;
1200 __insert_vmap_area(va);
1203 vmap_area_pcpu_hole = VMALLOC_END;
1205 vmap_initialized = true;
1209 * map_kernel_range_noflush - map kernel VM area with the specified pages
1210 * @addr: start of the VM area to map
1211 * @size: size of the VM area to map
1212 * @prot: page protection flags to use
1213 * @pages: pages to map
1215 * Map PFN_UP(@size) pages at @addr. The VM area @addr and @size
1216 * specify should have been allocated using get_vm_area() and its
1220 * This function does NOT do any cache flushing. The caller is
1221 * responsible for calling flush_cache_vmap() on to-be-mapped areas
1222 * before calling this function.
1225 * The number of pages mapped on success, -errno on failure.
1227 int map_kernel_range_noflush(unsigned long addr, unsigned long size,
1228 pgprot_t prot, struct page **pages)
1230 return vmap_page_range_noflush(addr, addr + size, prot, pages);
1234 * unmap_kernel_range_noflush - unmap kernel VM area
1235 * @addr: start of the VM area to unmap
1236 * @size: size of the VM area to unmap
1238 * Unmap PFN_UP(@size) pages at @addr. The VM area @addr and @size
1239 * specify should have been allocated using get_vm_area() and its
1243 * This function does NOT do any cache flushing. The caller is
1244 * responsible for calling flush_cache_vunmap() on to-be-mapped areas
1245 * before calling this function and flush_tlb_kernel_range() after.
1247 void unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
1249 vunmap_page_range(addr, addr + size);
1251 EXPORT_SYMBOL_GPL(unmap_kernel_range_noflush);
1254 * unmap_kernel_range - unmap kernel VM area and flush cache and TLB
1255 * @addr: start of the VM area to unmap
1256 * @size: size of the VM area to unmap
1258 * Similar to unmap_kernel_range_noflush() but flushes vcache before
1259 * the unmapping and tlb after.
1261 void unmap_kernel_range(unsigned long addr, unsigned long size)
1263 unsigned long end = addr + size;
1265 flush_cache_vunmap(addr, end);
1266 vunmap_page_range(addr, end);
1267 flush_tlb_kernel_range(addr, end);
1270 int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages)
1272 unsigned long addr = (unsigned long)area->addr;
1273 unsigned long end = addr + area->size - PAGE_SIZE;
1276 err = vmap_page_range(addr, end, prot, *pages);
1284 EXPORT_SYMBOL_GPL(map_vm_area);
1286 /*** Old vmalloc interfaces ***/
1287 DEFINE_RWLOCK(vmlist_lock);
1288 struct vm_struct *vmlist;
1290 static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
1291 unsigned long flags, const void *caller)
1293 spin_lock(&vmap_area_lock);
1295 vm->addr = (void *)va->va_start;
1296 vm->size = va->va_end - va->va_start;
1297 vm->caller = caller;
1299 va->flags |= VM_VM_AREA;
1300 spin_unlock(&vmap_area_lock);
1303 static void insert_vmalloc_vmlist(struct vm_struct *vm)
1305 struct vm_struct *tmp, **p;
1307 vm->flags &= ~VM_UNLIST;
1308 write_lock(&vmlist_lock);
1309 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
1310 if (tmp->addr >= vm->addr)
1315 write_unlock(&vmlist_lock);
1318 static void insert_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
1319 unsigned long flags, const void *caller)
1321 setup_vmalloc_vm(vm, va, flags, caller);
1322 insert_vmalloc_vmlist(vm);
1325 static struct vm_struct *__get_vm_area_node(unsigned long size,
1326 unsigned long align, unsigned long flags, unsigned long start,
1327 unsigned long end, int node, gfp_t gfp_mask, const void *caller)
1329 struct vmap_area *va;
1330 struct vm_struct *area;
1332 BUG_ON(in_interrupt());
1333 if (flags & VM_IOREMAP) {
1334 int bit = fls(size);
1336 if (bit > IOREMAP_MAX_ORDER)
1337 bit = IOREMAP_MAX_ORDER;
1338 else if (bit < PAGE_SHIFT)
1344 size = PAGE_ALIGN(size);
1345 if (unlikely(!size))
1348 area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
1349 if (unlikely(!area))
1353 * We always allocate a guard page.
1357 va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
1364 * When this function is called from __vmalloc_node_range,
1365 * we do not add vm_struct to vmlist here to avoid
1366 * accessing uninitialized members of vm_struct such as
1367 * pages and nr_pages fields. They will be set later.
1368 * To distinguish it from others, we use a VM_UNLIST flag.
1370 if (flags & VM_UNLIST)
1371 setup_vmalloc_vm(area, va, flags, caller);
1373 insert_vmalloc_vm(area, va, flags, caller);
1378 struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
1379 unsigned long start, unsigned long end)
1381 return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE,
1382 GFP_KERNEL, __builtin_return_address(0));
1384 EXPORT_SYMBOL_GPL(__get_vm_area);
1386 struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
1387 unsigned long start, unsigned long end,
1390 return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE,
1391 GFP_KERNEL, caller);
1395 * get_vm_area - reserve a contiguous kernel virtual area
1396 * @size: size of the area
1397 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC
1399 * Search an area of @size in the kernel virtual mapping area,
1400 * and reserved it for out purposes. Returns the area descriptor
1401 * on success or %NULL on failure.
1403 struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
1405 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1406 NUMA_NO_NODE, GFP_KERNEL,
1407 __builtin_return_address(0));
1410 struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
1413 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1414 NUMA_NO_NODE, GFP_KERNEL, caller);
1418 * find_vm_area - find a continuous kernel virtual area
1419 * @addr: base address
1421 * Search for the kernel VM area starting at @addr, and return it.
1422 * It is up to the caller to do all required locking to keep the returned
1425 struct vm_struct *find_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)
1437 * remove_vm_area - find and remove a continuous kernel virtual area
1438 * @addr: base address
1440 * Search for the kernel VM area starting at @addr, and remove it.
1441 * This function returns the found VM area, but using it is NOT safe
1442 * on SMP machines, except for its size or flags.
1444 struct vm_struct *remove_vm_area(const void *addr)
1446 struct vmap_area *va;
1448 va = find_vmap_area((unsigned long)addr);
1449 if (va && va->flags & VM_VM_AREA) {
1450 struct vm_struct *vm = va->vm;
1452 spin_lock(&vmap_area_lock);
1454 va->flags &= ~VM_VM_AREA;
1455 spin_unlock(&vmap_area_lock);
1457 if (!(vm->flags & VM_UNLIST)) {
1458 struct vm_struct *tmp, **p;
1460 * remove from list and disallow access to
1461 * this vm_struct before unmap. (address range
1462 * confliction is maintained by vmap.)
1464 write_lock(&vmlist_lock);
1465 for (p = &vmlist; (tmp = *p) != vm; p = &tmp->next)
1468 write_unlock(&vmlist_lock);
1471 vmap_debug_free_range(va->va_start, va->va_end);
1472 free_unmap_vmap_area(va);
1473 vm->size -= PAGE_SIZE;
1480 static void __vunmap(const void *addr, int deallocate_pages)
1482 struct vm_struct *area;
1487 if ((PAGE_SIZE-1) & (unsigned long)addr) {
1488 WARN(1, KERN_ERR "Trying to vfree() bad address (%p)\n", addr);
1492 area = remove_vm_area(addr);
1493 if (unlikely(!area)) {
1494 WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
1499 debug_check_no_locks_freed(addr, area->size);
1500 debug_check_no_obj_freed(addr, area->size);
1502 if (deallocate_pages) {
1505 for (i = 0; i < area->nr_pages; i++) {
1506 struct page *page = area->pages[i];
1512 if (area->flags & VM_VPAGES)
1523 * vfree - release memory allocated by vmalloc()
1524 * @addr: memory base address
1526 * Free the virtually continuous memory area starting at @addr, as
1527 * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
1528 * NULL, no operation is performed.
1530 * Must not be called in interrupt context.
1532 void vfree(const void *addr)
1534 BUG_ON(in_interrupt());
1536 kmemleak_free(addr);
1540 EXPORT_SYMBOL(vfree);
1543 * vunmap - release virtual mapping obtained by vmap()
1544 * @addr: memory base address
1546 * Free the virtually contiguous memory area starting at @addr,
1547 * which was created from the page array passed to vmap().
1549 * Must not be called in interrupt context.
1551 void vunmap(const void *addr)
1553 BUG_ON(in_interrupt());
1557 EXPORT_SYMBOL(vunmap);
1560 * vmap - map an array of pages into virtually contiguous space
1561 * @pages: array of page pointers
1562 * @count: number of pages to map
1563 * @flags: vm_area->flags
1564 * @prot: page protection for the mapping
1566 * Maps @count pages from @pages into contiguous kernel virtual
1569 void *vmap(struct page **pages, unsigned int count,
1570 unsigned long flags, pgprot_t prot)
1572 struct vm_struct *area;
1576 if (count > totalram_pages)
1579 area = get_vm_area_caller((count << PAGE_SHIFT), flags,
1580 __builtin_return_address(0));
1584 if (map_vm_area(area, prot, &pages)) {
1591 EXPORT_SYMBOL(vmap);
1593 static void *__vmalloc_node(unsigned long size, unsigned long align,
1594 gfp_t gfp_mask, pgprot_t prot,
1595 int node, const void *caller);
1596 static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
1597 pgprot_t prot, int node, const void *caller)
1599 const int order = 0;
1600 struct page **pages;
1601 unsigned int nr_pages, array_size, i;
1602 gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
1604 nr_pages = (area->size - PAGE_SIZE) >> PAGE_SHIFT;
1605 array_size = (nr_pages * sizeof(struct page *));
1607 area->nr_pages = nr_pages;
1608 /* Please note that the recursion is strictly bounded. */
1609 if (array_size > PAGE_SIZE) {
1610 pages = __vmalloc_node(array_size, 1, nested_gfp|__GFP_HIGHMEM,
1611 PAGE_KERNEL, node, caller);
1612 area->flags |= VM_VPAGES;
1614 pages = kmalloc_node(array_size, nested_gfp, node);
1616 area->pages = pages;
1617 area->caller = caller;
1619 remove_vm_area(area->addr);
1624 for (i = 0; i < area->nr_pages; i++) {
1626 gfp_t tmp_mask = gfp_mask | __GFP_NOWARN;
1629 page = alloc_page(tmp_mask);
1631 page = alloc_pages_node(node, tmp_mask, order);
1633 if (unlikely(!page)) {
1634 /* Successfully allocated i pages, free them in __vunmap() */
1638 area->pages[i] = page;
1641 if (map_vm_area(area, prot, &pages))
1646 warn_alloc_failed(gfp_mask, order,
1647 "vmalloc: allocation failure, allocated %ld of %ld bytes\n",
1648 (area->nr_pages*PAGE_SIZE), area->size);
1654 * __vmalloc_node_range - allocate virtually contiguous memory
1655 * @size: allocation size
1656 * @align: desired alignment
1657 * @start: vm area range start
1658 * @end: vm area range end
1659 * @gfp_mask: flags for the page level allocator
1660 * @prot: protection mask for the allocated pages
1661 * @node: node to use for allocation or NUMA_NO_NODE
1662 * @caller: caller's return address
1664 * Allocate enough pages to cover @size from the page level
1665 * allocator with @gfp_mask flags. Map them into contiguous
1666 * kernel virtual space, using a pagetable protection of @prot.
1668 void *__vmalloc_node_range(unsigned long size, unsigned long align,
1669 unsigned long start, unsigned long end, gfp_t gfp_mask,
1670 pgprot_t prot, int node, const void *caller)
1672 struct vm_struct *area;
1674 unsigned long real_size = size;
1676 size = PAGE_ALIGN(size);
1677 if (!size || (size >> PAGE_SHIFT) > totalram_pages)
1680 area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNLIST,
1681 start, end, node, gfp_mask, caller);
1685 addr = __vmalloc_area_node(area, gfp_mask, prot, node, caller);
1690 * In this function, newly allocated vm_struct is not added
1691 * to vmlist at __get_vm_area_node(). so, it is added here.
1693 insert_vmalloc_vmlist(area);
1696 * A ref_count = 3 is needed because the vm_struct and vmap_area
1697 * structures allocated in the __get_vm_area_node() function contain
1698 * references to the virtual address of the vmalloc'ed block.
1700 kmemleak_alloc(addr, real_size, 3, gfp_mask);
1705 warn_alloc_failed(gfp_mask, 0,
1706 "vmalloc: allocation failure: %lu bytes\n",
1712 * __vmalloc_node - allocate virtually contiguous memory
1713 * @size: allocation size
1714 * @align: desired alignment
1715 * @gfp_mask: flags for the page level allocator
1716 * @prot: protection mask for the allocated pages
1717 * @node: node to use for allocation or NUMA_NO_NODE
1718 * @caller: caller's return address
1720 * Allocate enough pages to cover @size from the page level
1721 * allocator with @gfp_mask flags. Map them into contiguous
1722 * kernel virtual space, using a pagetable protection of @prot.
1724 static void *__vmalloc_node(unsigned long size, unsigned long align,
1725 gfp_t gfp_mask, pgprot_t prot,
1726 int node, const void *caller)
1728 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
1729 gfp_mask, prot, node, caller);
1732 void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
1734 return __vmalloc_node(size, 1, gfp_mask, prot, NUMA_NO_NODE,
1735 __builtin_return_address(0));
1737 EXPORT_SYMBOL(__vmalloc);
1739 static inline void *__vmalloc_node_flags(unsigned long size,
1740 int node, gfp_t flags)
1742 return __vmalloc_node(size, 1, flags, PAGE_KERNEL,
1743 node, __builtin_return_address(0));
1747 * vmalloc - allocate virtually contiguous memory
1748 * @size: allocation size
1749 * Allocate enough pages to cover @size from the page level
1750 * allocator and map them into contiguous kernel virtual space.
1752 * For tight control over page level allocator and protection flags
1753 * use __vmalloc() instead.
1755 void *vmalloc(unsigned long size)
1757 return __vmalloc_node_flags(size, NUMA_NO_NODE,
1758 GFP_KERNEL | __GFP_HIGHMEM);
1760 EXPORT_SYMBOL(vmalloc);
1763 * vzalloc - allocate virtually contiguous memory with zero fill
1764 * @size: allocation size
1765 * Allocate enough pages to cover @size from the page level
1766 * allocator and map them into contiguous kernel virtual space.
1767 * The memory allocated is set to zero.
1769 * For tight control over page level allocator and protection flags
1770 * use __vmalloc() instead.
1772 void *vzalloc(unsigned long size)
1774 return __vmalloc_node_flags(size, NUMA_NO_NODE,
1775 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
1777 EXPORT_SYMBOL(vzalloc);
1780 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
1781 * @size: allocation size
1783 * The resulting memory area is zeroed so it can be mapped to userspace
1784 * without leaking data.
1786 void *vmalloc_user(unsigned long size)
1788 struct vm_struct *area;
1791 ret = __vmalloc_node(size, SHMLBA,
1792 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
1793 PAGE_KERNEL, NUMA_NO_NODE,
1794 __builtin_return_address(0));
1796 area = find_vm_area(ret);
1797 area->flags |= VM_USERMAP;
1801 EXPORT_SYMBOL(vmalloc_user);
1804 * vmalloc_node - allocate memory on a specific node
1805 * @size: allocation size
1808 * Allocate enough pages to cover @size from the page level
1809 * allocator and map them into contiguous kernel virtual space.
1811 * For tight control over page level allocator and protection flags
1812 * use __vmalloc() instead.
1814 void *vmalloc_node(unsigned long size, int node)
1816 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
1817 node, __builtin_return_address(0));
1819 EXPORT_SYMBOL(vmalloc_node);
1822 * vzalloc_node - allocate memory on a specific node with zero fill
1823 * @size: allocation size
1826 * Allocate enough pages to cover @size from the page level
1827 * allocator and map them into contiguous kernel virtual space.
1828 * The memory allocated is set to zero.
1830 * For tight control over page level allocator and protection flags
1831 * use __vmalloc_node() instead.
1833 void *vzalloc_node(unsigned long size, int node)
1835 return __vmalloc_node_flags(size, node,
1836 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
1838 EXPORT_SYMBOL(vzalloc_node);
1840 #ifndef PAGE_KERNEL_EXEC
1841 # define PAGE_KERNEL_EXEC PAGE_KERNEL
1845 * vmalloc_exec - allocate virtually contiguous, executable memory
1846 * @size: allocation size
1848 * Kernel-internal function to allocate enough pages to cover @size
1849 * the page level allocator and map them into contiguous and
1850 * executable kernel virtual space.
1852 * For tight control over page level allocator and protection flags
1853 * use __vmalloc() instead.
1856 void *vmalloc_exec(unsigned long size)
1858 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
1859 NUMA_NO_NODE, __builtin_return_address(0));
1862 #if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
1863 #define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
1864 #elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
1865 #define GFP_VMALLOC32 GFP_DMA | GFP_KERNEL
1867 #define GFP_VMALLOC32 GFP_KERNEL
1871 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
1872 * @size: allocation size
1874 * Allocate enough 32bit PA addressable pages to cover @size from the
1875 * page level allocator and map them into contiguous kernel virtual space.
1877 void *vmalloc_32(unsigned long size)
1879 return __vmalloc_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL,
1880 NUMA_NO_NODE, __builtin_return_address(0));
1882 EXPORT_SYMBOL(vmalloc_32);
1885 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
1886 * @size: allocation size
1888 * The resulting memory area is 32bit addressable and zeroed so it can be
1889 * mapped to userspace without leaking data.
1891 void *vmalloc_32_user(unsigned long size)
1893 struct vm_struct *area;
1896 ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
1897 NUMA_NO_NODE, __builtin_return_address(0));
1899 area = find_vm_area(ret);
1900 area->flags |= VM_USERMAP;
1904 EXPORT_SYMBOL(vmalloc_32_user);
1907 * small helper routine , copy contents to buf from addr.
1908 * If the page is not present, fill zero.
1911 static int aligned_vread(char *buf, char *addr, unsigned long count)
1917 unsigned long offset, length;
1919 offset = (unsigned long)addr & ~PAGE_MASK;
1920 length = PAGE_SIZE - offset;
1923 p = vmalloc_to_page(addr);
1925 * To do safe access to this _mapped_ area, we need
1926 * lock. But adding lock here means that we need to add
1927 * overhead of vmalloc()/vfree() calles for this _debug_
1928 * interface, rarely used. Instead of that, we'll use
1929 * kmap() and get small overhead in this access function.
1933 * we can expect USER0 is not used (see vread/vwrite's
1934 * function description)
1936 void *map = kmap_atomic(p);
1937 memcpy(buf, map + offset, length);
1940 memset(buf, 0, length);
1950 static int aligned_vwrite(char *buf, char *addr, unsigned long count)
1956 unsigned long offset, length;
1958 offset = (unsigned long)addr & ~PAGE_MASK;
1959 length = PAGE_SIZE - offset;
1962 p = vmalloc_to_page(addr);
1964 * To do safe access to this _mapped_ area, we need
1965 * lock. But adding lock here means that we need to add
1966 * overhead of vmalloc()/vfree() calles for this _debug_
1967 * interface, rarely used. Instead of that, we'll use
1968 * kmap() and get small overhead in this access function.
1972 * we can expect USER0 is not used (see vread/vwrite's
1973 * function description)
1975 void *map = kmap_atomic(p);
1976 memcpy(map + offset, buf, length);
1988 * vread() - read vmalloc area in a safe way.
1989 * @buf: buffer for reading data
1990 * @addr: vm address.
1991 * @count: number of bytes to be read.
1993 * Returns # of bytes which addr and buf should be increased.
1994 * (same number to @count). Returns 0 if [addr...addr+count) doesn't
1995 * includes any intersect with alive vmalloc area.
1997 * This function checks that addr is a valid vmalloc'ed area, and
1998 * copy data from that area to a given buffer. If the given memory range
1999 * of [addr...addr+count) includes some valid address, data is copied to
2000 * proper area of @buf. If there are memory holes, they'll be zero-filled.
2001 * IOREMAP area is treated as memory hole and no copy is done.
2003 * If [addr...addr+count) doesn't includes any intersects with alive
2004 * vm_struct area, returns 0. @buf should be kernel's buffer.
2006 * Note: In usual ops, vread() is never necessary because the caller
2007 * should know vmalloc() area is valid and can use memcpy().
2008 * This is for routines which have to access vmalloc area without
2009 * any informaion, as /dev/kmem.
2013 long vread(char *buf, char *addr, unsigned long count)
2015 struct vmap_area *va;
2016 struct vm_struct *vm;
2017 char *vaddr, *buf_start = buf;
2018 unsigned long buflen = count;
2021 /* Don't allow overflow */
2022 if ((unsigned long) addr + count < count)
2023 count = -(unsigned long) addr;
2025 spin_lock(&vmap_area_lock);
2026 list_for_each_entry(va, &vmap_area_list, list) {
2030 if (!(va->flags & VM_VM_AREA))
2034 vaddr = (char *) vm->addr;
2035 if (addr >= vaddr + vm->size - PAGE_SIZE)
2037 while (addr < vaddr) {
2045 n = vaddr + vm->size - PAGE_SIZE - addr;
2048 if (!(vm->flags & VM_IOREMAP))
2049 aligned_vread(buf, addr, n);
2050 else /* IOREMAP area is treated as memory hole */
2057 spin_unlock(&vmap_area_lock);
2059 if (buf == buf_start)
2061 /* zero-fill memory holes */
2062 if (buf != buf_start + buflen)
2063 memset(buf, 0, buflen - (buf - buf_start));
2069 * vwrite() - write vmalloc area in a safe way.
2070 * @buf: buffer for source data
2071 * @addr: vm address.
2072 * @count: number of bytes to be read.
2074 * Returns # of bytes which addr and buf should be incresed.
2075 * (same number to @count).
2076 * If [addr...addr+count) doesn't includes any intersect with valid
2077 * vmalloc area, returns 0.
2079 * This function checks that addr is a valid vmalloc'ed area, and
2080 * copy data from a buffer to the given addr. If specified range of
2081 * [addr...addr+count) includes some valid address, data is copied from
2082 * proper area of @buf. If there are memory holes, no copy to hole.
2083 * IOREMAP area is treated as memory hole and no copy is done.
2085 * If [addr...addr+count) doesn't includes any intersects with alive
2086 * vm_struct area, returns 0. @buf should be kernel's buffer.
2088 * Note: In usual ops, vwrite() is never necessary because the caller
2089 * should know vmalloc() area is valid and can use memcpy().
2090 * This is for routines which have to access vmalloc area without
2091 * any informaion, as /dev/kmem.
2094 long vwrite(char *buf, char *addr, unsigned long count)
2096 struct vmap_area *va;
2097 struct vm_struct *vm;
2099 unsigned long n, buflen;
2102 /* Don't allow overflow */
2103 if ((unsigned long) addr + count < count)
2104 count = -(unsigned long) addr;
2107 spin_lock(&vmap_area_lock);
2108 list_for_each_entry(va, &vmap_area_list, list) {
2112 if (!(va->flags & VM_VM_AREA))
2116 vaddr = (char *) vm->addr;
2117 if (addr >= vaddr + vm->size - PAGE_SIZE)
2119 while (addr < vaddr) {
2126 n = vaddr + vm->size - PAGE_SIZE - addr;
2129 if (!(vm->flags & VM_IOREMAP)) {
2130 aligned_vwrite(buf, addr, n);
2138 spin_unlock(&vmap_area_lock);
2145 * remap_vmalloc_range - map vmalloc pages to userspace
2146 * @vma: vma to cover (map full range of vma)
2147 * @addr: vmalloc memory
2148 * @pgoff: number of pages into addr before first page to map
2150 * Returns: 0 for success, -Exxx on failure
2152 * This function checks that addr is a valid vmalloc'ed area, and
2153 * that it is big enough to cover the vma. Will return failure if
2154 * that criteria isn't met.
2156 * Similar to remap_pfn_range() (see mm/memory.c)
2158 int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
2159 unsigned long pgoff)
2161 struct vm_struct *area;
2162 unsigned long uaddr = vma->vm_start;
2163 unsigned long usize = vma->vm_end - vma->vm_start;
2165 if ((PAGE_SIZE-1) & (unsigned long)addr)
2168 area = find_vm_area(addr);
2172 if (!(area->flags & VM_USERMAP))
2175 if (usize + (pgoff << PAGE_SHIFT) > area->size - PAGE_SIZE)
2178 addr += pgoff << PAGE_SHIFT;
2180 struct page *page = vmalloc_to_page(addr);
2183 ret = vm_insert_page(vma, uaddr, page);
2190 } while (usize > 0);
2192 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
2196 EXPORT_SYMBOL(remap_vmalloc_range);
2199 * Implement a stub for vmalloc_sync_all() if the architecture chose not to
2202 void __attribute__((weak)) vmalloc_sync_all(void)
2207 static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
2219 * alloc_vm_area - allocate a range of kernel address space
2220 * @size: size of the area
2221 * @ptes: returns the PTEs for the address space
2223 * Returns: NULL on failure, vm_struct on success
2225 * This function reserves a range of kernel address space, and
2226 * allocates pagetables to map that range. No actual mappings
2229 * If @ptes is non-NULL, pointers to the PTEs (in init_mm)
2230 * allocated for the VM area are returned.
2232 struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes)
2234 struct vm_struct *area;
2236 area = get_vm_area_caller(size, VM_IOREMAP,
2237 __builtin_return_address(0));
2242 * This ensures that page tables are constructed for this region
2243 * of kernel virtual address space and mapped into init_mm.
2245 if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
2246 size, f, ptes ? &ptes : NULL)) {
2253 EXPORT_SYMBOL_GPL(alloc_vm_area);
2255 void free_vm_area(struct vm_struct *area)
2257 struct vm_struct *ret;
2258 ret = remove_vm_area(area->addr);
2259 BUG_ON(ret != area);
2262 EXPORT_SYMBOL_GPL(free_vm_area);
2265 static struct vmap_area *node_to_va(struct rb_node *n)
2267 return n ? rb_entry(n, struct vmap_area, rb_node) : NULL;
2271 * pvm_find_next_prev - find the next and prev vmap_area surrounding @end
2272 * @end: target address
2273 * @pnext: out arg for the next vmap_area
2274 * @pprev: out arg for the previous vmap_area
2276 * Returns: %true if either or both of next and prev are found,
2277 * %false if no vmap_area exists
2279 * Find vmap_areas end addresses of which enclose @end. ie. if not
2280 * NULL, *pnext->va_end > @end and *pprev->va_end <= @end.
2282 static bool pvm_find_next_prev(unsigned long end,
2283 struct vmap_area **pnext,
2284 struct vmap_area **pprev)
2286 struct rb_node *n = vmap_area_root.rb_node;
2287 struct vmap_area *va = NULL;
2290 va = rb_entry(n, struct vmap_area, rb_node);
2291 if (end < va->va_end)
2293 else if (end > va->va_end)
2302 if (va->va_end > end) {
2304 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2307 *pnext = node_to_va(rb_next(&(*pprev)->rb_node));
2313 * pvm_determine_end - find the highest aligned address between two vmap_areas
2314 * @pnext: in/out arg for the next vmap_area
2315 * @pprev: in/out arg for the previous vmap_area
2318 * Returns: determined end address
2320 * Find the highest aligned address between *@pnext and *@pprev below
2321 * VMALLOC_END. *@pnext and *@pprev are adjusted so that the aligned
2322 * down address is between the end addresses of the two vmap_areas.
2324 * Please note that the address returned by this function may fall
2325 * inside *@pnext vmap_area. The caller is responsible for checking
2328 static unsigned long pvm_determine_end(struct vmap_area **pnext,
2329 struct vmap_area **pprev,
2330 unsigned long align)
2332 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2336 addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end);
2340 while (*pprev && (*pprev)->va_end > addr) {
2342 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2349 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
2350 * @offsets: array containing offset of each area
2351 * @sizes: array containing size of each area
2352 * @nr_vms: the number of areas to allocate
2353 * @align: alignment, all entries in @offsets and @sizes must be aligned to this
2355 * Returns: kmalloc'd vm_struct pointer array pointing to allocated
2356 * vm_structs on success, %NULL on failure
2358 * Percpu allocator wants to use congruent vm areas so that it can
2359 * maintain the offsets among percpu areas. This function allocates
2360 * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to
2361 * be scattered pretty far, distance between two areas easily going up
2362 * to gigabytes. To avoid interacting with regular vmallocs, these
2363 * areas are allocated from top.
2365 * Despite its complicated look, this allocator is rather simple. It
2366 * does everything top-down and scans areas from the end looking for
2367 * matching slot. While scanning, if any of the areas overlaps with
2368 * existing vmap_area, the base address is pulled down to fit the
2369 * area. Scanning is repeated till all the areas fit and then all
2370 * necessary data structres are inserted and the result is returned.
2372 struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
2373 const size_t *sizes, int nr_vms,
2376 const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
2377 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2378 struct vmap_area **vas, *prev, *next;
2379 struct vm_struct **vms;
2380 int area, area2, last_area, term_area;
2381 unsigned long base, start, end, last_end;
2382 bool purged = false;
2384 /* verify parameters and allocate data structures */
2385 BUG_ON(align & ~PAGE_MASK || !is_power_of_2(align));
2386 for (last_area = 0, area = 0; area < nr_vms; area++) {
2387 start = offsets[area];
2388 end = start + sizes[area];
2390 /* is everything aligned properly? */
2391 BUG_ON(!IS_ALIGNED(offsets[area], align));
2392 BUG_ON(!IS_ALIGNED(sizes[area], align));
2394 /* detect the area with the highest address */
2395 if (start > offsets[last_area])
2398 for (area2 = 0; area2 < nr_vms; area2++) {
2399 unsigned long start2 = offsets[area2];
2400 unsigned long end2 = start2 + sizes[area2];
2405 BUG_ON(start2 >= start && start2 < end);
2406 BUG_ON(end2 <= end && end2 > start);
2409 last_end = offsets[last_area] + sizes[last_area];
2411 if (vmalloc_end - vmalloc_start < last_end) {
2416 vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL);
2417 vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL);
2421 for (area = 0; area < nr_vms; area++) {
2422 vas[area] = kzalloc(sizeof(struct vmap_area), GFP_KERNEL);
2423 vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
2424 if (!vas[area] || !vms[area])
2428 spin_lock(&vmap_area_lock);
2430 /* start scanning - we scan from the top, begin with the last area */
2431 area = term_area = last_area;
2432 start = offsets[area];
2433 end = start + sizes[area];
2435 if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) {
2436 base = vmalloc_end - last_end;
2439 base = pvm_determine_end(&next, &prev, align) - end;
2442 BUG_ON(next && next->va_end <= base + end);
2443 BUG_ON(prev && prev->va_end > base + end);
2446 * base might have underflowed, add last_end before
2449 if (base + last_end < vmalloc_start + last_end) {
2450 spin_unlock(&vmap_area_lock);
2452 purge_vmap_area_lazy();
2460 * If next overlaps, move base downwards so that it's
2461 * right below next and then recheck.
2463 if (next && next->va_start < base + end) {
2464 base = pvm_determine_end(&next, &prev, align) - end;
2470 * If prev overlaps, shift down next and prev and move
2471 * base so that it's right below new next and then
2474 if (prev && prev->va_end > base + start) {
2476 prev = node_to_va(rb_prev(&next->rb_node));
2477 base = pvm_determine_end(&next, &prev, align) - end;
2483 * This area fits, move on to the previous one. If
2484 * the previous one is the terminal one, we're done.
2486 area = (area + nr_vms - 1) % nr_vms;
2487 if (area == term_area)
2489 start = offsets[area];
2490 end = start + sizes[area];
2491 pvm_find_next_prev(base + end, &next, &prev);
2494 /* we've found a fitting base, insert all va's */
2495 for (area = 0; area < nr_vms; area++) {
2496 struct vmap_area *va = vas[area];
2498 va->va_start = base + offsets[area];
2499 va->va_end = va->va_start + sizes[area];
2500 __insert_vmap_area(va);
2503 vmap_area_pcpu_hole = base + offsets[last_area];
2505 spin_unlock(&vmap_area_lock);
2507 /* insert all vm's */
2508 for (area = 0; area < nr_vms; area++)
2509 insert_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
2516 for (area = 0; area < nr_vms; area++) {
2527 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
2528 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
2529 * @nr_vms: the number of allocated areas
2531 * Free vm_structs and the array allocated by pcpu_get_vm_areas().
2533 void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
2537 for (i = 0; i < nr_vms; i++)
2538 free_vm_area(vms[i]);
2541 #endif /* CONFIG_SMP */
2543 #ifdef CONFIG_PROC_FS
2544 static void *s_start(struct seq_file *m, loff_t *pos)
2545 __acquires(&vmlist_lock)
2548 struct vm_struct *v;
2550 read_lock(&vmlist_lock);
2552 while (n > 0 && v) {
2563 static void *s_next(struct seq_file *m, void *p, loff_t *pos)
2565 struct vm_struct *v = p;
2571 static void s_stop(struct seq_file *m, void *p)
2572 __releases(&vmlist_lock)
2574 read_unlock(&vmlist_lock);
2577 static void show_numa_info(struct seq_file *m, struct vm_struct *v)
2579 if (IS_ENABLED(CONFIG_NUMA)) {
2580 unsigned int nr, *counters = m->private;
2585 memset(counters, 0, nr_node_ids * sizeof(unsigned int));
2587 for (nr = 0; nr < v->nr_pages; nr++)
2588 counters[page_to_nid(v->pages[nr])]++;
2590 for_each_node_state(nr, N_HIGH_MEMORY)
2592 seq_printf(m, " N%u=%u", nr, counters[nr]);
2596 static int s_show(struct seq_file *m, void *p)
2598 struct vm_struct *v = p;
2600 seq_printf(m, "0x%pK-0x%pK %7ld",
2601 v->addr, v->addr + v->size, v->size);
2604 seq_printf(m, " %pS", v->caller);
2607 seq_printf(m, " pages=%d", v->nr_pages);
2610 seq_printf(m, " phys=%llx", (unsigned long long)v->phys_addr);
2612 if (v->flags & VM_IOREMAP)
2613 seq_printf(m, " ioremap");
2615 if (v->flags & VM_ALLOC)
2616 seq_printf(m, " vmalloc");
2618 if (v->flags & VM_MAP)
2619 seq_printf(m, " vmap");
2621 if (v->flags & VM_USERMAP)
2622 seq_printf(m, " user");
2624 if (v->flags & VM_VPAGES)
2625 seq_printf(m, " vpages");
2627 show_numa_info(m, v);
2632 static const struct seq_operations vmalloc_op = {
2639 static int vmalloc_open(struct inode *inode, struct file *file)
2641 unsigned int *ptr = NULL;
2644 if (IS_ENABLED(CONFIG_NUMA)) {
2645 ptr = kmalloc(nr_node_ids * sizeof(unsigned int), GFP_KERNEL);
2649 ret = seq_open(file, &vmalloc_op);
2651 struct seq_file *m = file->private_data;
2658 static const struct file_operations proc_vmalloc_operations = {
2659 .open = vmalloc_open,
2661 .llseek = seq_lseek,
2662 .release = seq_release_private,
2665 static int __init proc_vmalloc_init(void)
2667 proc_create("vmallocinfo", S_IRUSR, NULL, &proc_vmalloc_operations);
2670 module_init(proc_vmalloc_init);
2672 void get_vmalloc_info(struct vmalloc_info *vmi)
2674 struct vmap_area *va;
2675 unsigned long free_area_size;
2676 unsigned long prev_end;
2679 vmi->largest_chunk = 0;
2681 prev_end = VMALLOC_START;
2683 spin_lock(&vmap_area_lock);
2685 if (list_empty(&vmap_area_list)) {
2686 vmi->largest_chunk = VMALLOC_TOTAL;
2690 list_for_each_entry(va, &vmap_area_list, list) {
2691 unsigned long addr = va->va_start;
2694 * Some archs keep another range for modules in vmalloc space
2696 if (addr < VMALLOC_START)
2698 if (addr >= VMALLOC_END)
2701 if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEING))
2704 vmi->used += (va->va_end - va->va_start);
2706 free_area_size = addr - prev_end;
2707 if (vmi->largest_chunk < free_area_size)
2708 vmi->largest_chunk = free_area_size;
2710 prev_end = va->va_end;
2713 if (VMALLOC_END - prev_end > vmi->largest_chunk)
2714 vmi->largest_chunk = VMALLOC_END - prev_end;
2717 spin_unlock(&vmap_area_lock);