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 <asm/atomic.h>
30 #include <asm/uaccess.h>
31 #include <asm/tlbflush.h>
32 #include <asm/shmparam.h>
34 bool vmap_lazy_unmap __read_mostly = true;
36 /*** Page table manipulation functions ***/
38 static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
42 pte = pte_offset_kernel(pmd, addr);
44 pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
45 WARN_ON(!pte_none(ptent) && !pte_present(ptent));
46 } while (pte++, addr += PAGE_SIZE, addr != end);
49 static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
54 pmd = pmd_offset(pud, addr);
56 next = pmd_addr_end(addr, end);
57 if (pmd_none_or_clear_bad(pmd))
59 vunmap_pte_range(pmd, addr, next);
60 } while (pmd++, addr = next, addr != end);
63 static void vunmap_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end)
68 pud = pud_offset(pgd, addr);
70 next = pud_addr_end(addr, end);
71 if (pud_none_or_clear_bad(pud))
73 vunmap_pmd_range(pud, addr, next);
74 } while (pud++, addr = next, addr != end);
77 static void vunmap_page_range(unsigned long addr, unsigned long end)
83 pgd = pgd_offset_k(addr);
85 next = pgd_addr_end(addr, end);
86 if (pgd_none_or_clear_bad(pgd))
88 vunmap_pud_range(pgd, addr, next);
89 } while (pgd++, addr = next, addr != end);
92 static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
93 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
98 * nr is a running index into the array which helps higher level
99 * callers keep track of where we're up to.
102 pte = pte_alloc_kernel(pmd, addr);
106 struct page *page = pages[*nr];
108 if (WARN_ON(!pte_none(*pte)))
112 set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
114 } while (pte++, addr += PAGE_SIZE, addr != end);
118 static int vmap_pmd_range(pud_t *pud, unsigned long addr,
119 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
124 pmd = pmd_alloc(&init_mm, pud, addr);
128 next = pmd_addr_end(addr, end);
129 if (vmap_pte_range(pmd, addr, next, prot, pages, nr))
131 } while (pmd++, addr = next, addr != end);
135 static int vmap_pud_range(pgd_t *pgd, unsigned long addr,
136 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
141 pud = pud_alloc(&init_mm, pgd, addr);
145 next = pud_addr_end(addr, end);
146 if (vmap_pmd_range(pud, addr, next, prot, pages, nr))
148 } while (pud++, addr = next, addr != end);
153 * Set up page tables in kva (addr, end). The ptes shall have prot "prot", and
154 * will have pfns corresponding to the "pages" array.
156 * Ie. pte at addr+N*PAGE_SIZE shall point to pfn corresponding to pages[N]
158 static int vmap_page_range_noflush(unsigned long start, unsigned long end,
159 pgprot_t prot, struct page **pages)
163 unsigned long addr = start;
168 pgd = pgd_offset_k(addr);
170 next = pgd_addr_end(addr, end);
171 err = vmap_pud_range(pgd, addr, next, prot, pages, &nr);
174 } while (pgd++, addr = next, addr != end);
179 static int vmap_page_range(unsigned long start, unsigned long end,
180 pgprot_t prot, struct page **pages)
184 ret = vmap_page_range_noflush(start, end, prot, pages);
185 flush_cache_vmap(start, end);
189 int is_vmalloc_or_module_addr(const void *x)
192 * ARM, x86-64 and sparc64 put modules in a special place,
193 * and fall back on vmalloc() if that fails. Others
194 * just put it in the vmalloc space.
196 #if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
197 unsigned long addr = (unsigned long)x;
198 if (addr >= MODULES_VADDR && addr < MODULES_END)
201 return is_vmalloc_addr(x);
205 * Walk a vmap address to the struct page it maps.
207 struct page *vmalloc_to_page(const void *vmalloc_addr)
209 unsigned long addr = (unsigned long) vmalloc_addr;
210 struct page *page = NULL;
211 pgd_t *pgd = pgd_offset_k(addr);
214 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
215 * architectures that do not vmalloc module space
217 VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
219 if (!pgd_none(*pgd)) {
220 pud_t *pud = pud_offset(pgd, addr);
221 if (!pud_none(*pud)) {
222 pmd_t *pmd = pmd_offset(pud, addr);
223 if (!pmd_none(*pmd)) {
226 ptep = pte_offset_map(pmd, addr);
228 if (pte_present(pte))
229 page = pte_page(pte);
236 EXPORT_SYMBOL(vmalloc_to_page);
239 * Map a vmalloc()-space virtual address to the physical page frame number.
241 unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
243 return page_to_pfn(vmalloc_to_page(vmalloc_addr));
245 EXPORT_SYMBOL(vmalloc_to_pfn);
248 /*** Global kva allocator ***/
250 #define VM_LAZY_FREE 0x01
251 #define VM_LAZY_FREEING 0x02
252 #define VM_VM_AREA 0x04
255 unsigned long va_start;
256 unsigned long va_end;
258 struct rb_node rb_node; /* address sorted rbtree */
259 struct list_head list; /* address sorted list */
260 struct list_head purge_list; /* "lazy purge" list */
262 struct rcu_head rcu_head;
265 static DEFINE_SPINLOCK(vmap_area_lock);
266 static struct rb_root vmap_area_root = RB_ROOT;
267 static LIST_HEAD(vmap_area_list);
268 static unsigned long vmap_area_pcpu_hole;
270 static struct vmap_area *__find_vmap_area(unsigned long addr)
272 struct rb_node *n = vmap_area_root.rb_node;
275 struct vmap_area *va;
277 va = rb_entry(n, struct vmap_area, rb_node);
278 if (addr < va->va_start)
280 else if (addr > va->va_start)
289 static void __insert_vmap_area(struct vmap_area *va)
291 struct rb_node **p = &vmap_area_root.rb_node;
292 struct rb_node *parent = NULL;
296 struct vmap_area *tmp;
299 tmp = rb_entry(parent, struct vmap_area, rb_node);
300 if (va->va_start < tmp->va_end)
302 else if (va->va_end > tmp->va_start)
308 rb_link_node(&va->rb_node, parent, p);
309 rb_insert_color(&va->rb_node, &vmap_area_root);
311 /* address-sort this list so it is usable like the vmlist */
312 tmp = rb_prev(&va->rb_node);
314 struct vmap_area *prev;
315 prev = rb_entry(tmp, struct vmap_area, rb_node);
316 list_add_rcu(&va->list, &prev->list);
318 list_add_rcu(&va->list, &vmap_area_list);
321 static void purge_vmap_area_lazy(void);
324 * Allocate a region of KVA of the specified size and alignment, within the
327 static struct vmap_area *alloc_vmap_area(unsigned long size,
329 unsigned long vstart, unsigned long vend,
330 int node, gfp_t gfp_mask)
332 struct vmap_area *va;
338 BUG_ON(size & ~PAGE_MASK);
340 va = kmalloc_node(sizeof(struct vmap_area),
341 gfp_mask & GFP_RECLAIM_MASK, node);
343 return ERR_PTR(-ENOMEM);
346 addr = ALIGN(vstart, align);
348 spin_lock(&vmap_area_lock);
349 if (addr + size - 1 < addr)
352 /* XXX: could have a last_hole cache */
353 n = vmap_area_root.rb_node;
355 struct vmap_area *first = NULL;
358 struct vmap_area *tmp;
359 tmp = rb_entry(n, struct vmap_area, rb_node);
360 if (tmp->va_end >= addr) {
361 if (!first && tmp->va_start < addr + size)
373 if (first->va_end < addr) {
374 n = rb_next(&first->rb_node);
376 first = rb_entry(n, struct vmap_area, rb_node);
381 while (addr + size > first->va_start && addr + size <= vend) {
382 addr = ALIGN(first->va_end + PAGE_SIZE, align);
383 if (addr + size - 1 < addr)
386 n = rb_next(&first->rb_node);
388 first = rb_entry(n, struct vmap_area, rb_node);
394 if (addr + size > vend) {
396 spin_unlock(&vmap_area_lock);
398 purge_vmap_area_lazy();
402 if (printk_ratelimit())
404 "vmap allocation for size %lu failed: "
405 "use vmalloc=<size> to increase size.\n", size);
407 return ERR_PTR(-EBUSY);
410 BUG_ON(addr & (align-1));
413 va->va_end = addr + size;
415 __insert_vmap_area(va);
416 spin_unlock(&vmap_area_lock);
421 static void rcu_free_va(struct rcu_head *head)
423 struct vmap_area *va = container_of(head, struct vmap_area, rcu_head);
428 static void __free_vmap_area(struct vmap_area *va)
430 BUG_ON(RB_EMPTY_NODE(&va->rb_node));
431 rb_erase(&va->rb_node, &vmap_area_root);
432 RB_CLEAR_NODE(&va->rb_node);
433 list_del_rcu(&va->list);
436 * Track the highest possible candidate for pcpu area
437 * allocation. Areas outside of vmalloc area can be returned
438 * here too, consider only end addresses which fall inside
439 * vmalloc area proper.
441 if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END)
442 vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end);
444 call_rcu(&va->rcu_head, rcu_free_va);
448 * Free a region of KVA allocated by alloc_vmap_area
450 static void free_vmap_area(struct vmap_area *va)
452 spin_lock(&vmap_area_lock);
453 __free_vmap_area(va);
454 spin_unlock(&vmap_area_lock);
458 * Clear the pagetable entries of a given vmap_area
460 static void unmap_vmap_area(struct vmap_area *va)
462 vunmap_page_range(va->va_start, va->va_end);
465 static void vmap_debug_free_range(unsigned long start, unsigned long end)
468 * Unmap page tables and force a TLB flush immediately if
469 * CONFIG_DEBUG_PAGEALLOC is set. This catches use after free
470 * bugs similarly to those in linear kernel virtual address
471 * space after a page has been freed.
473 * All the lazy freeing logic is still retained, in order to
474 * minimise intrusiveness of this debugging feature.
476 * This is going to be *slow* (linear kernel virtual address
477 * debugging doesn't do a broadcast TLB flush so it is a lot
480 #ifdef CONFIG_DEBUG_PAGEALLOC
481 vunmap_page_range(start, end);
482 flush_tlb_kernel_range(start, end);
487 * lazy_max_pages is the maximum amount of virtual address space we gather up
488 * before attempting to purge with a TLB flush.
490 * There is a tradeoff here: a larger number will cover more kernel page tables
491 * and take slightly longer to purge, but it will linearly reduce the number of
492 * global TLB flushes that must be performed. It would seem natural to scale
493 * this number up linearly with the number of CPUs (because vmapping activity
494 * could also scale linearly with the number of CPUs), however it is likely
495 * that in practice, workloads might be constrained in other ways that mean
496 * vmap activity will not scale linearly with CPUs. Also, I want to be
497 * conservative and not introduce a big latency on huge systems, so go with
498 * a less aggressive log scale. It will still be an improvement over the old
499 * code, and it will be simple to change the scale factor if we find that it
500 * becomes a problem on bigger systems.
502 static unsigned long lazy_max_pages(void)
506 if (!vmap_lazy_unmap)
509 log = fls(num_online_cpus());
511 return log * (32UL * 1024 * 1024 / PAGE_SIZE);
514 static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);
516 /* for per-CPU blocks */
517 static void purge_fragmented_blocks_allcpus(void);
520 * Purges all lazily-freed vmap areas.
522 * If sync is 0 then don't purge if there is already a purge in progress.
523 * If force_flush is 1, then flush kernel TLBs between *start and *end even
524 * if we found no lazy vmap areas to unmap (callers can use this to optimise
525 * their own TLB flushing).
526 * Returns with *start = min(*start, lowest purged address)
527 * *end = max(*end, highest purged address)
529 static void __purge_vmap_area_lazy(unsigned long *start, unsigned long *end,
530 int sync, int force_flush)
532 static DEFINE_SPINLOCK(purge_lock);
534 struct vmap_area *va;
535 struct vmap_area *n_va;
539 * If sync is 0 but force_flush is 1, we'll go sync anyway but callers
540 * should not expect such behaviour. This just simplifies locking for
541 * the case that isn't actually used at the moment anyway.
543 if (!sync && !force_flush) {
544 if (!spin_trylock(&purge_lock))
547 spin_lock(&purge_lock);
550 purge_fragmented_blocks_allcpus();
553 list_for_each_entry_rcu(va, &vmap_area_list, list) {
554 if (va->flags & VM_LAZY_FREE) {
555 if (va->va_start < *start)
556 *start = va->va_start;
557 if (va->va_end > *end)
559 nr += (va->va_end - va->va_start) >> PAGE_SHIFT;
561 list_add_tail(&va->purge_list, &valist);
562 va->flags |= VM_LAZY_FREEING;
563 va->flags &= ~VM_LAZY_FREE;
569 atomic_sub(nr, &vmap_lazy_nr);
571 if (nr || force_flush)
572 flush_tlb_kernel_range(*start, *end);
575 spin_lock(&vmap_area_lock);
576 list_for_each_entry_safe(va, n_va, &valist, purge_list)
577 __free_vmap_area(va);
578 spin_unlock(&vmap_area_lock);
580 spin_unlock(&purge_lock);
584 * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
585 * is already purging.
587 static void try_purge_vmap_area_lazy(void)
589 unsigned long start = ULONG_MAX, end = 0;
591 __purge_vmap_area_lazy(&start, &end, 0, 0);
595 * Kick off a purge of the outstanding lazy areas.
597 static void purge_vmap_area_lazy(void)
599 unsigned long start = ULONG_MAX, end = 0;
601 __purge_vmap_area_lazy(&start, &end, 1, 0);
605 * Free and unmap a vmap area, caller ensuring flush_cache_vunmap had been
606 * called for the correct range previously.
608 static void free_unmap_vmap_area_noflush(struct vmap_area *va)
610 va->flags |= VM_LAZY_FREE;
611 atomic_add((va->va_end - va->va_start) >> PAGE_SHIFT, &vmap_lazy_nr);
612 if (unlikely(atomic_read(&vmap_lazy_nr) > lazy_max_pages()))
613 try_purge_vmap_area_lazy();
617 * Free and unmap a vmap area
619 static void free_unmap_vmap_area(struct vmap_area *va)
621 flush_cache_vunmap(va->va_start, va->va_end);
622 free_unmap_vmap_area_noflush(va);
625 static struct vmap_area *find_vmap_area(unsigned long addr)
627 struct vmap_area *va;
629 spin_lock(&vmap_area_lock);
630 va = __find_vmap_area(addr);
631 spin_unlock(&vmap_area_lock);
636 static void free_unmap_vmap_area_addr(unsigned long addr)
638 struct vmap_area *va;
640 va = find_vmap_area(addr);
642 free_unmap_vmap_area(va);
646 /*** Per cpu kva allocator ***/
649 * vmap space is limited especially on 32 bit architectures. Ensure there is
650 * room for at least 16 percpu vmap blocks per CPU.
653 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
654 * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess
655 * instead (we just need a rough idea)
657 #if BITS_PER_LONG == 32
658 #define VMALLOC_SPACE (128UL*1024*1024)
660 #define VMALLOC_SPACE (128UL*1024*1024*1024)
663 #define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE)
664 #define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */
665 #define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */
666 #define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
667 #define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
668 #define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
669 #define VMAP_BBMAP_BITS VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
670 VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
671 VMALLOC_PAGES / NR_CPUS / 16))
673 #define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
675 static bool vmap_initialized __read_mostly = false;
677 struct vmap_block_queue {
679 struct list_head free;
684 struct vmap_area *va;
685 struct vmap_block_queue *vbq;
686 unsigned long free, dirty;
687 DECLARE_BITMAP(alloc_map, VMAP_BBMAP_BITS);
688 DECLARE_BITMAP(dirty_map, VMAP_BBMAP_BITS);
689 struct list_head free_list;
690 struct rcu_head rcu_head;
691 struct list_head purge;
694 /* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
695 static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
698 * Radix tree of vmap blocks, indexed by address, to quickly find a vmap block
699 * in the free path. Could get rid of this if we change the API to return a
700 * "cookie" from alloc, to be passed to free. But no big deal yet.
702 static DEFINE_SPINLOCK(vmap_block_tree_lock);
703 static RADIX_TREE(vmap_block_tree, GFP_ATOMIC);
706 * We should probably have a fallback mechanism to allocate virtual memory
707 * out of partially filled vmap blocks. However vmap block sizing should be
708 * fairly reasonable according to the vmalloc size, so it shouldn't be a
712 static unsigned long addr_to_vb_idx(unsigned long addr)
714 addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
715 addr /= VMAP_BLOCK_SIZE;
719 static struct vmap_block *new_vmap_block(gfp_t gfp_mask)
721 struct vmap_block_queue *vbq;
722 struct vmap_block *vb;
723 struct vmap_area *va;
724 unsigned long vb_idx;
727 node = numa_node_id();
729 vb = kmalloc_node(sizeof(struct vmap_block),
730 gfp_mask & GFP_RECLAIM_MASK, node);
732 return ERR_PTR(-ENOMEM);
734 va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
735 VMALLOC_START, VMALLOC_END,
737 if (unlikely(IS_ERR(va))) {
742 err = radix_tree_preload(gfp_mask);
749 spin_lock_init(&vb->lock);
751 vb->free = VMAP_BBMAP_BITS;
753 bitmap_zero(vb->alloc_map, VMAP_BBMAP_BITS);
754 bitmap_zero(vb->dirty_map, VMAP_BBMAP_BITS);
755 INIT_LIST_HEAD(&vb->free_list);
757 vb_idx = addr_to_vb_idx(va->va_start);
758 spin_lock(&vmap_block_tree_lock);
759 err = radix_tree_insert(&vmap_block_tree, vb_idx, vb);
760 spin_unlock(&vmap_block_tree_lock);
762 radix_tree_preload_end();
764 vbq = &get_cpu_var(vmap_block_queue);
766 spin_lock(&vbq->lock);
767 list_add_rcu(&vb->free_list, &vbq->free);
768 spin_unlock(&vbq->lock);
769 put_cpu_var(vmap_block_queue);
774 static void rcu_free_vb(struct rcu_head *head)
776 struct vmap_block *vb = container_of(head, struct vmap_block, rcu_head);
781 static void free_vmap_block(struct vmap_block *vb)
783 struct vmap_block *tmp;
784 unsigned long vb_idx;
786 vb_idx = addr_to_vb_idx(vb->va->va_start);
787 spin_lock(&vmap_block_tree_lock);
788 tmp = radix_tree_delete(&vmap_block_tree, vb_idx);
789 spin_unlock(&vmap_block_tree_lock);
792 free_unmap_vmap_area_noflush(vb->va);
793 call_rcu(&vb->rcu_head, rcu_free_vb);
796 static void purge_fragmented_blocks(int cpu)
799 struct vmap_block *vb;
800 struct vmap_block *n_vb;
801 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
804 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
806 if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
809 spin_lock(&vb->lock);
810 if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
811 vb->free = 0; /* prevent further allocs after releasing lock */
812 vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
813 bitmap_fill(vb->alloc_map, VMAP_BBMAP_BITS);
814 bitmap_fill(vb->dirty_map, VMAP_BBMAP_BITS);
815 spin_lock(&vbq->lock);
816 list_del_rcu(&vb->free_list);
817 spin_unlock(&vbq->lock);
818 spin_unlock(&vb->lock);
819 list_add_tail(&vb->purge, &purge);
821 spin_unlock(&vb->lock);
825 list_for_each_entry_safe(vb, n_vb, &purge, purge) {
826 list_del(&vb->purge);
831 static void purge_fragmented_blocks_thiscpu(void)
833 purge_fragmented_blocks(smp_processor_id());
836 static void purge_fragmented_blocks_allcpus(void)
840 for_each_possible_cpu(cpu)
841 purge_fragmented_blocks(cpu);
844 static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
846 struct vmap_block_queue *vbq;
847 struct vmap_block *vb;
848 unsigned long addr = 0;
852 BUG_ON(size & ~PAGE_MASK);
853 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
854 order = get_order(size);
858 vbq = &get_cpu_var(vmap_block_queue);
859 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
862 spin_lock(&vb->lock);
863 if (vb->free < 1UL << order)
866 i = bitmap_find_free_region(vb->alloc_map,
867 VMAP_BBMAP_BITS, order);
870 if (vb->free + vb->dirty == VMAP_BBMAP_BITS) {
871 /* fragmented and no outstanding allocations */
872 BUG_ON(vb->dirty != VMAP_BBMAP_BITS);
877 addr = vb->va->va_start + (i << PAGE_SHIFT);
878 BUG_ON(addr_to_vb_idx(addr) !=
879 addr_to_vb_idx(vb->va->va_start));
880 vb->free -= 1UL << order;
882 spin_lock(&vbq->lock);
883 list_del_rcu(&vb->free_list);
884 spin_unlock(&vbq->lock);
886 spin_unlock(&vb->lock);
889 spin_unlock(&vb->lock);
893 purge_fragmented_blocks_thiscpu();
895 put_cpu_var(vmap_block_queue);
899 vb = new_vmap_block(gfp_mask);
908 static void vb_free(const void *addr, unsigned long size)
910 unsigned long offset;
911 unsigned long vb_idx;
913 struct vmap_block *vb;
915 BUG_ON(size & ~PAGE_MASK);
916 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
918 flush_cache_vunmap((unsigned long)addr, (unsigned long)addr + size);
920 order = get_order(size);
922 offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1);
924 vb_idx = addr_to_vb_idx((unsigned long)addr);
926 vb = radix_tree_lookup(&vmap_block_tree, vb_idx);
930 spin_lock(&vb->lock);
931 BUG_ON(bitmap_allocate_region(vb->dirty_map, offset >> PAGE_SHIFT, order));
933 vb->dirty += 1UL << order;
934 if (vb->dirty == VMAP_BBMAP_BITS) {
936 spin_unlock(&vb->lock);
939 spin_unlock(&vb->lock);
943 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
945 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
946 * to amortize TLB flushing overheads. What this means is that any page you
947 * have now, may, in a former life, have been mapped into kernel virtual
948 * address by the vmap layer and so there might be some CPUs with TLB entries
949 * still referencing that page (additional to the regular 1:1 kernel mapping).
951 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
952 * be sure that none of the pages we have control over will have any aliases
953 * from the vmap layer.
955 void vm_unmap_aliases(void)
957 unsigned long start = ULONG_MAX, end = 0;
961 if (unlikely(!vmap_initialized))
964 for_each_possible_cpu(cpu) {
965 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
966 struct vmap_block *vb;
969 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
972 spin_lock(&vb->lock);
973 i = find_first_bit(vb->dirty_map, VMAP_BBMAP_BITS);
974 while (i < VMAP_BBMAP_BITS) {
977 j = find_next_zero_bit(vb->dirty_map,
980 s = vb->va->va_start + (i << PAGE_SHIFT);
981 e = vb->va->va_start + (j << PAGE_SHIFT);
982 vunmap_page_range(s, e);
991 i = find_next_bit(vb->dirty_map,
994 spin_unlock(&vb->lock);
999 __purge_vmap_area_lazy(&start, &end, 1, flush);
1001 EXPORT_SYMBOL_GPL(vm_unmap_aliases);
1004 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
1005 * @mem: the pointer returned by vm_map_ram
1006 * @count: the count passed to that vm_map_ram call (cannot unmap partial)
1008 void vm_unmap_ram(const void *mem, unsigned int count)
1010 unsigned long size = count << PAGE_SHIFT;
1011 unsigned long addr = (unsigned long)mem;
1014 BUG_ON(addr < VMALLOC_START);
1015 BUG_ON(addr > VMALLOC_END);
1016 BUG_ON(addr & (PAGE_SIZE-1));
1018 debug_check_no_locks_freed(mem, size);
1019 vmap_debug_free_range(addr, addr+size);
1021 if (likely(count <= VMAP_MAX_ALLOC))
1024 free_unmap_vmap_area_addr(addr);
1026 EXPORT_SYMBOL(vm_unmap_ram);
1029 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
1030 * @pages: an array of pointers to the pages to be mapped
1031 * @count: number of pages
1032 * @node: prefer to allocate data structures on this node
1033 * @prot: memory protection to use. PAGE_KERNEL for regular RAM
1035 * Returns: a pointer to the address that has been mapped, or %NULL on failure
1037 void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot)
1039 unsigned long size = count << PAGE_SHIFT;
1043 if (likely(count <= VMAP_MAX_ALLOC)) {
1044 mem = vb_alloc(size, GFP_KERNEL);
1047 addr = (unsigned long)mem;
1049 struct vmap_area *va;
1050 va = alloc_vmap_area(size, PAGE_SIZE,
1051 VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
1055 addr = va->va_start;
1058 if (vmap_page_range(addr, addr + size, prot, pages) < 0) {
1059 vm_unmap_ram(mem, count);
1064 EXPORT_SYMBOL(vm_map_ram);
1067 * vm_area_register_early - register vmap area early during boot
1068 * @vm: vm_struct to register
1069 * @align: requested alignment
1071 * This function is used to register kernel vm area before
1072 * vmalloc_init() is called. @vm->size and @vm->flags should contain
1073 * proper values on entry and other fields should be zero. On return,
1074 * vm->addr contains the allocated address.
1076 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
1078 void __init vm_area_register_early(struct vm_struct *vm, size_t align)
1080 static size_t vm_init_off __initdata;
1083 addr = ALIGN(VMALLOC_START + vm_init_off, align);
1084 vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
1086 vm->addr = (void *)addr;
1092 void __init vmalloc_init(void)
1094 struct vmap_area *va;
1095 struct vm_struct *tmp;
1098 for_each_possible_cpu(i) {
1099 struct vmap_block_queue *vbq;
1101 vbq = &per_cpu(vmap_block_queue, i);
1102 spin_lock_init(&vbq->lock);
1103 INIT_LIST_HEAD(&vbq->free);
1106 /* Import existing vmlist entries. */
1107 for (tmp = vmlist; tmp; tmp = tmp->next) {
1108 va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
1109 va->flags = tmp->flags | VM_VM_AREA;
1110 va->va_start = (unsigned long)tmp->addr;
1111 va->va_end = va->va_start + tmp->size;
1112 __insert_vmap_area(va);
1115 vmap_area_pcpu_hole = VMALLOC_END;
1117 vmap_initialized = true;
1121 * map_kernel_range_noflush - map kernel VM area with the specified pages
1122 * @addr: start of the VM area to map
1123 * @size: size of the VM area to map
1124 * @prot: page protection flags to use
1125 * @pages: pages to map
1127 * Map PFN_UP(@size) pages at @addr. The VM area @addr and @size
1128 * specify should have been allocated using get_vm_area() and its
1132 * This function does NOT do any cache flushing. The caller is
1133 * responsible for calling flush_cache_vmap() on to-be-mapped areas
1134 * before calling this function.
1137 * The number of pages mapped on success, -errno on failure.
1139 int map_kernel_range_noflush(unsigned long addr, unsigned long size,
1140 pgprot_t prot, struct page **pages)
1142 return vmap_page_range_noflush(addr, addr + size, prot, pages);
1146 * unmap_kernel_range_noflush - unmap kernel VM area
1147 * @addr: start of the VM area to unmap
1148 * @size: size of the VM area to unmap
1150 * Unmap PFN_UP(@size) pages at @addr. The VM area @addr and @size
1151 * specify should have been allocated using get_vm_area() and its
1155 * This function does NOT do any cache flushing. The caller is
1156 * responsible for calling flush_cache_vunmap() on to-be-mapped areas
1157 * before calling this function and flush_tlb_kernel_range() after.
1159 void unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
1161 vunmap_page_range(addr, addr + size);
1165 * unmap_kernel_range - unmap kernel VM area and flush cache and TLB
1166 * @addr: start of the VM area to unmap
1167 * @size: size of the VM area to unmap
1169 * Similar to unmap_kernel_range_noflush() but flushes vcache before
1170 * the unmapping and tlb after.
1172 void unmap_kernel_range(unsigned long addr, unsigned long size)
1174 unsigned long end = addr + size;
1176 flush_cache_vunmap(addr, end);
1177 vunmap_page_range(addr, end);
1178 flush_tlb_kernel_range(addr, end);
1181 int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages)
1183 unsigned long addr = (unsigned long)area->addr;
1184 unsigned long end = addr + area->size - PAGE_SIZE;
1187 err = vmap_page_range(addr, end, prot, *pages);
1195 EXPORT_SYMBOL_GPL(map_vm_area);
1197 /*** Old vmalloc interfaces ***/
1198 DEFINE_RWLOCK(vmlist_lock);
1199 struct vm_struct *vmlist;
1201 static void insert_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
1202 unsigned long flags, void *caller)
1204 struct vm_struct *tmp, **p;
1207 vm->addr = (void *)va->va_start;
1208 vm->size = va->va_end - va->va_start;
1209 vm->caller = caller;
1211 va->flags |= VM_VM_AREA;
1213 write_lock(&vmlist_lock);
1214 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
1215 if (tmp->addr >= vm->addr)
1220 write_unlock(&vmlist_lock);
1223 static struct vm_struct *__get_vm_area_node(unsigned long size,
1224 unsigned long align, unsigned long flags, unsigned long start,
1225 unsigned long end, int node, gfp_t gfp_mask, void *caller)
1227 static struct vmap_area *va;
1228 struct vm_struct *area;
1230 BUG_ON(in_interrupt());
1231 if (flags & VM_IOREMAP) {
1232 int bit = fls(size);
1234 if (bit > IOREMAP_MAX_ORDER)
1235 bit = IOREMAP_MAX_ORDER;
1236 else if (bit < PAGE_SHIFT)
1242 size = PAGE_ALIGN(size);
1243 if (unlikely(!size))
1246 area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
1247 if (unlikely(!area))
1251 * We always allocate a guard page.
1255 va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
1261 insert_vmalloc_vm(area, va, flags, caller);
1265 struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
1266 unsigned long start, unsigned long end)
1268 return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
1269 __builtin_return_address(0));
1271 EXPORT_SYMBOL_GPL(__get_vm_area);
1273 struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
1274 unsigned long start, unsigned long end,
1277 return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
1282 * get_vm_area - reserve a contiguous kernel virtual area
1283 * @size: size of the area
1284 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC
1286 * Search an area of @size in the kernel virtual mapping area,
1287 * and reserved it for out purposes. Returns the area descriptor
1288 * on success or %NULL on failure.
1290 struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
1292 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1293 -1, GFP_KERNEL, __builtin_return_address(0));
1296 struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
1299 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1300 -1, GFP_KERNEL, caller);
1303 struct vm_struct *get_vm_area_node(unsigned long size, unsigned long flags,
1304 int node, gfp_t gfp_mask)
1306 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1307 node, gfp_mask, __builtin_return_address(0));
1310 static struct vm_struct *find_vm_area(const void *addr)
1312 struct vmap_area *va;
1314 va = find_vmap_area((unsigned long)addr);
1315 if (va && va->flags & VM_VM_AREA)
1322 * remove_vm_area - find and remove a continuous kernel virtual area
1323 * @addr: base address
1325 * Search for the kernel VM area starting at @addr, and remove it.
1326 * This function returns the found VM area, but using it is NOT safe
1327 * on SMP machines, except for its size or flags.
1329 struct vm_struct *remove_vm_area(const void *addr)
1331 struct vmap_area *va;
1333 va = find_vmap_area((unsigned long)addr);
1334 if (va && va->flags & VM_VM_AREA) {
1335 struct vm_struct *vm = va->private;
1336 struct vm_struct *tmp, **p;
1338 * remove from list and disallow access to this vm_struct
1339 * before unmap. (address range confliction is maintained by
1342 write_lock(&vmlist_lock);
1343 for (p = &vmlist; (tmp = *p) != vm; p = &tmp->next)
1346 write_unlock(&vmlist_lock);
1348 vmap_debug_free_range(va->va_start, va->va_end);
1349 free_unmap_vmap_area(va);
1350 vm->size -= PAGE_SIZE;
1357 static void __vunmap(const void *addr, int deallocate_pages)
1359 struct vm_struct *area;
1364 if ((PAGE_SIZE-1) & (unsigned long)addr) {
1365 WARN(1, KERN_ERR "Trying to vfree() bad address (%p)\n", addr);
1369 area = remove_vm_area(addr);
1370 if (unlikely(!area)) {
1371 WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
1376 debug_check_no_locks_freed(addr, area->size);
1377 debug_check_no_obj_freed(addr, area->size);
1379 if (deallocate_pages) {
1382 for (i = 0; i < area->nr_pages; i++) {
1383 struct page *page = area->pages[i];
1389 if (area->flags & VM_VPAGES)
1400 * vfree - release memory allocated by vmalloc()
1401 * @addr: memory base address
1403 * Free the virtually continuous memory area starting at @addr, as
1404 * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
1405 * NULL, no operation is performed.
1407 * Must not be called in interrupt context.
1409 void vfree(const void *addr)
1411 BUG_ON(in_interrupt());
1413 kmemleak_free(addr);
1417 EXPORT_SYMBOL(vfree);
1420 * vunmap - release virtual mapping obtained by vmap()
1421 * @addr: memory base address
1423 * Free the virtually contiguous memory area starting at @addr,
1424 * which was created from the page array passed to vmap().
1426 * Must not be called in interrupt context.
1428 void vunmap(const void *addr)
1430 BUG_ON(in_interrupt());
1434 EXPORT_SYMBOL(vunmap);
1437 * vmap - map an array of pages into virtually contiguous space
1438 * @pages: array of page pointers
1439 * @count: number of pages to map
1440 * @flags: vm_area->flags
1441 * @prot: page protection for the mapping
1443 * Maps @count pages from @pages into contiguous kernel virtual
1446 void *vmap(struct page **pages, unsigned int count,
1447 unsigned long flags, pgprot_t prot)
1449 struct vm_struct *area;
1453 if (count > totalram_pages)
1456 area = get_vm_area_caller((count << PAGE_SHIFT), flags,
1457 __builtin_return_address(0));
1461 if (map_vm_area(area, prot, &pages)) {
1468 EXPORT_SYMBOL(vmap);
1470 static void *__vmalloc_node(unsigned long size, unsigned long align,
1471 gfp_t gfp_mask, pgprot_t prot,
1472 int node, void *caller);
1473 static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
1474 pgprot_t prot, int node, void *caller)
1476 struct page **pages;
1477 unsigned int nr_pages, array_size, i;
1478 gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
1480 nr_pages = (area->size - PAGE_SIZE) >> PAGE_SHIFT;
1481 array_size = (nr_pages * sizeof(struct page *));
1483 area->nr_pages = nr_pages;
1484 /* Please note that the recursion is strictly bounded. */
1485 if (array_size > PAGE_SIZE) {
1486 pages = __vmalloc_node(array_size, 1, nested_gfp|__GFP_HIGHMEM,
1487 PAGE_KERNEL, node, caller);
1488 area->flags |= VM_VPAGES;
1490 pages = kmalloc_node(array_size, nested_gfp, node);
1492 area->pages = pages;
1493 area->caller = caller;
1495 remove_vm_area(area->addr);
1500 for (i = 0; i < area->nr_pages; i++) {
1504 page = alloc_page(gfp_mask);
1506 page = alloc_pages_node(node, gfp_mask, 0);
1508 if (unlikely(!page)) {
1509 /* Successfully allocated i pages, free them in __vunmap() */
1513 area->pages[i] = page;
1516 if (map_vm_area(area, prot, &pages))
1525 void *__vmalloc_area(struct vm_struct *area, gfp_t gfp_mask, pgprot_t prot)
1527 void *addr = __vmalloc_area_node(area, gfp_mask, prot, -1,
1528 __builtin_return_address(0));
1531 * A ref_count = 3 is needed because the vm_struct and vmap_area
1532 * structures allocated in the __get_vm_area_node() function contain
1533 * references to the virtual address of the vmalloc'ed block.
1535 kmemleak_alloc(addr, area->size - PAGE_SIZE, 3, gfp_mask);
1541 * __vmalloc_node - allocate virtually contiguous memory
1542 * @size: allocation size
1543 * @align: desired alignment
1544 * @gfp_mask: flags for the page level allocator
1545 * @prot: protection mask for the allocated pages
1546 * @node: node to use for allocation or -1
1547 * @caller: caller's return address
1549 * Allocate enough pages to cover @size from the page level
1550 * allocator with @gfp_mask flags. Map them into contiguous
1551 * kernel virtual space, using a pagetable protection of @prot.
1553 static void *__vmalloc_node(unsigned long size, unsigned long align,
1554 gfp_t gfp_mask, pgprot_t prot,
1555 int node, void *caller)
1557 struct vm_struct *area;
1559 unsigned long real_size = size;
1561 size = PAGE_ALIGN(size);
1562 if (!size || (size >> PAGE_SHIFT) > totalram_pages)
1565 area = __get_vm_area_node(size, align, VM_ALLOC, VMALLOC_START,
1566 VMALLOC_END, node, gfp_mask, caller);
1571 addr = __vmalloc_area_node(area, gfp_mask, prot, node, caller);
1574 * A ref_count = 3 is needed because the vm_struct and vmap_area
1575 * structures allocated in the __get_vm_area_node() function contain
1576 * references to the virtual address of the vmalloc'ed block.
1578 kmemleak_alloc(addr, real_size, 3, gfp_mask);
1583 void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
1585 return __vmalloc_node(size, 1, gfp_mask, prot, -1,
1586 __builtin_return_address(0));
1588 EXPORT_SYMBOL(__vmalloc);
1591 * vmalloc - allocate virtually contiguous memory
1592 * @size: allocation size
1593 * Allocate enough pages to cover @size from the page level
1594 * allocator and map them into contiguous kernel virtual space.
1596 * For tight control over page level allocator and protection flags
1597 * use __vmalloc() instead.
1599 void *vmalloc(unsigned long size)
1601 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
1602 -1, __builtin_return_address(0));
1604 EXPORT_SYMBOL(vmalloc);
1607 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
1608 * @size: allocation size
1610 * The resulting memory area is zeroed so it can be mapped to userspace
1611 * without leaking data.
1613 void *vmalloc_user(unsigned long size)
1615 struct vm_struct *area;
1618 ret = __vmalloc_node(size, SHMLBA,
1619 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
1620 PAGE_KERNEL, -1, __builtin_return_address(0));
1622 area = find_vm_area(ret);
1623 area->flags |= VM_USERMAP;
1627 EXPORT_SYMBOL(vmalloc_user);
1630 * vmalloc_node - allocate memory on a specific node
1631 * @size: allocation size
1634 * Allocate enough pages to cover @size from the page level
1635 * allocator and map them into contiguous kernel virtual space.
1637 * For tight control over page level allocator and protection flags
1638 * use __vmalloc() instead.
1640 void *vmalloc_node(unsigned long size, int node)
1642 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
1643 node, __builtin_return_address(0));
1645 EXPORT_SYMBOL(vmalloc_node);
1647 #ifndef PAGE_KERNEL_EXEC
1648 # define PAGE_KERNEL_EXEC PAGE_KERNEL
1652 * vmalloc_exec - allocate virtually contiguous, executable memory
1653 * @size: allocation size
1655 * Kernel-internal function to allocate enough pages to cover @size
1656 * the page level allocator and map them into contiguous and
1657 * executable kernel virtual space.
1659 * For tight control over page level allocator and protection flags
1660 * use __vmalloc() instead.
1663 void *vmalloc_exec(unsigned long size)
1665 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
1666 -1, __builtin_return_address(0));
1669 #if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
1670 #define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
1671 #elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
1672 #define GFP_VMALLOC32 GFP_DMA | GFP_KERNEL
1674 #define GFP_VMALLOC32 GFP_KERNEL
1678 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
1679 * @size: allocation size
1681 * Allocate enough 32bit PA addressable pages to cover @size from the
1682 * page level allocator and map them into contiguous kernel virtual space.
1684 void *vmalloc_32(unsigned long size)
1686 return __vmalloc_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL,
1687 -1, __builtin_return_address(0));
1689 EXPORT_SYMBOL(vmalloc_32);
1692 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
1693 * @size: allocation size
1695 * The resulting memory area is 32bit addressable and zeroed so it can be
1696 * mapped to userspace without leaking data.
1698 void *vmalloc_32_user(unsigned long size)
1700 struct vm_struct *area;
1703 ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
1704 -1, __builtin_return_address(0));
1706 area = find_vm_area(ret);
1707 area->flags |= VM_USERMAP;
1711 EXPORT_SYMBOL(vmalloc_32_user);
1714 * small helper routine , copy contents to buf from addr.
1715 * If the page is not present, fill zero.
1718 static int aligned_vread(char *buf, char *addr, unsigned long count)
1724 unsigned long offset, length;
1726 offset = (unsigned long)addr & ~PAGE_MASK;
1727 length = PAGE_SIZE - offset;
1730 p = vmalloc_to_page(addr);
1732 * To do safe access to this _mapped_ area, we need
1733 * lock. But adding lock here means that we need to add
1734 * overhead of vmalloc()/vfree() calles for this _debug_
1735 * interface, rarely used. Instead of that, we'll use
1736 * kmap() and get small overhead in this access function.
1740 * we can expect USER0 is not used (see vread/vwrite's
1741 * function description)
1743 void *map = kmap_atomic(p, KM_USER0);
1744 memcpy(buf, map + offset, length);
1745 kunmap_atomic(map, KM_USER0);
1747 memset(buf, 0, length);
1757 static int aligned_vwrite(char *buf, char *addr, unsigned long count)
1763 unsigned long offset, length;
1765 offset = (unsigned long)addr & ~PAGE_MASK;
1766 length = PAGE_SIZE - offset;
1769 p = vmalloc_to_page(addr);
1771 * To do safe access to this _mapped_ area, we need
1772 * lock. But adding lock here means that we need to add
1773 * overhead of vmalloc()/vfree() calles for this _debug_
1774 * interface, rarely used. Instead of that, we'll use
1775 * kmap() and get small overhead in this access function.
1779 * we can expect USER0 is not used (see vread/vwrite's
1780 * function description)
1782 void *map = kmap_atomic(p, KM_USER0);
1783 memcpy(map + offset, buf, length);
1784 kunmap_atomic(map, KM_USER0);
1795 * vread() - read vmalloc area in a safe way.
1796 * @buf: buffer for reading data
1797 * @addr: vm address.
1798 * @count: number of bytes to be read.
1800 * Returns # of bytes which addr and buf should be increased.
1801 * (same number to @count). Returns 0 if [addr...addr+count) doesn't
1802 * includes any intersect with alive vmalloc area.
1804 * This function checks that addr is a valid vmalloc'ed area, and
1805 * copy data from that area to a given buffer. If the given memory range
1806 * of [addr...addr+count) includes some valid address, data is copied to
1807 * proper area of @buf. If there are memory holes, they'll be zero-filled.
1808 * IOREMAP area is treated as memory hole and no copy is done.
1810 * If [addr...addr+count) doesn't includes any intersects with alive
1811 * vm_struct area, returns 0.
1812 * @buf should be kernel's buffer. Because this function uses KM_USER0,
1813 * the caller should guarantee KM_USER0 is not used.
1815 * Note: In usual ops, vread() is never necessary because the caller
1816 * should know vmalloc() area is valid and can use memcpy().
1817 * This is for routines which have to access vmalloc area without
1818 * any informaion, as /dev/kmem.
1822 long vread(char *buf, char *addr, unsigned long count)
1824 struct vm_struct *tmp;
1825 char *vaddr, *buf_start = buf;
1826 unsigned long buflen = count;
1829 /* Don't allow overflow */
1830 if ((unsigned long) addr + count < count)
1831 count = -(unsigned long) addr;
1833 read_lock(&vmlist_lock);
1834 for (tmp = vmlist; count && tmp; tmp = tmp->next) {
1835 vaddr = (char *) tmp->addr;
1836 if (addr >= vaddr + tmp->size - PAGE_SIZE)
1838 while (addr < vaddr) {
1846 n = vaddr + tmp->size - PAGE_SIZE - addr;
1849 if (!(tmp->flags & VM_IOREMAP))
1850 aligned_vread(buf, addr, n);
1851 else /* IOREMAP area is treated as memory hole */
1858 read_unlock(&vmlist_lock);
1860 if (buf == buf_start)
1862 /* zero-fill memory holes */
1863 if (buf != buf_start + buflen)
1864 memset(buf, 0, buflen - (buf - buf_start));
1870 * vwrite() - write vmalloc area in a safe way.
1871 * @buf: buffer for source data
1872 * @addr: vm address.
1873 * @count: number of bytes to be read.
1875 * Returns # of bytes which addr and buf should be incresed.
1876 * (same number to @count).
1877 * If [addr...addr+count) doesn't includes any intersect with valid
1878 * vmalloc area, returns 0.
1880 * This function checks that addr is a valid vmalloc'ed area, and
1881 * copy data from a buffer to the given addr. If specified range of
1882 * [addr...addr+count) includes some valid address, data is copied from
1883 * proper area of @buf. If there are memory holes, no copy to hole.
1884 * IOREMAP area is treated as memory hole and no copy is done.
1886 * If [addr...addr+count) doesn't includes any intersects with alive
1887 * vm_struct area, returns 0.
1888 * @buf should be kernel's buffer. Because this function uses KM_USER0,
1889 * the caller should guarantee KM_USER0 is not used.
1891 * Note: In usual ops, vwrite() is never necessary because the caller
1892 * should know vmalloc() area is valid and can use memcpy().
1893 * This is for routines which have to access vmalloc area without
1894 * any informaion, as /dev/kmem.
1896 * The caller should guarantee KM_USER1 is not used.
1899 long vwrite(char *buf, char *addr, unsigned long count)
1901 struct vm_struct *tmp;
1903 unsigned long n, buflen;
1906 /* Don't allow overflow */
1907 if ((unsigned long) addr + count < count)
1908 count = -(unsigned long) addr;
1911 read_lock(&vmlist_lock);
1912 for (tmp = vmlist; count && tmp; tmp = tmp->next) {
1913 vaddr = (char *) tmp->addr;
1914 if (addr >= vaddr + tmp->size - PAGE_SIZE)
1916 while (addr < vaddr) {
1923 n = vaddr + tmp->size - PAGE_SIZE - addr;
1926 if (!(tmp->flags & VM_IOREMAP)) {
1927 aligned_vwrite(buf, addr, n);
1935 read_unlock(&vmlist_lock);
1942 * remap_vmalloc_range - map vmalloc pages to userspace
1943 * @vma: vma to cover (map full range of vma)
1944 * @addr: vmalloc memory
1945 * @pgoff: number of pages into addr before first page to map
1947 * Returns: 0 for success, -Exxx on failure
1949 * This function checks that addr is a valid vmalloc'ed area, and
1950 * that it is big enough to cover the vma. Will return failure if
1951 * that criteria isn't met.
1953 * Similar to remap_pfn_range() (see mm/memory.c)
1955 int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
1956 unsigned long pgoff)
1958 struct vm_struct *area;
1959 unsigned long uaddr = vma->vm_start;
1960 unsigned long usize = vma->vm_end - vma->vm_start;
1962 if ((PAGE_SIZE-1) & (unsigned long)addr)
1965 area = find_vm_area(addr);
1969 if (!(area->flags & VM_USERMAP))
1972 if (usize + (pgoff << PAGE_SHIFT) > area->size - PAGE_SIZE)
1975 addr += pgoff << PAGE_SHIFT;
1977 struct page *page = vmalloc_to_page(addr);
1980 ret = vm_insert_page(vma, uaddr, page);
1987 } while (usize > 0);
1989 /* Prevent "things" like memory migration? VM_flags need a cleanup... */
1990 vma->vm_flags |= VM_RESERVED;
1994 EXPORT_SYMBOL(remap_vmalloc_range);
1997 * Implement a stub for vmalloc_sync_all() if the architecture chose not to
2000 void __attribute__((weak)) vmalloc_sync_all(void)
2005 static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
2007 /* apply_to_page_range() does all the hard work. */
2012 * alloc_vm_area - allocate a range of kernel address space
2013 * @size: size of the area
2015 * Returns: NULL on failure, vm_struct on success
2017 * This function reserves a range of kernel address space, and
2018 * allocates pagetables to map that range. No actual mappings
2019 * are created. If the kernel address space is not shared
2020 * between processes, it syncs the pagetable across all
2023 struct vm_struct *alloc_vm_area(size_t size)
2025 struct vm_struct *area;
2027 area = get_vm_area_caller(size, VM_IOREMAP,
2028 __builtin_return_address(0));
2033 * This ensures that page tables are constructed for this region
2034 * of kernel virtual address space and mapped into init_mm.
2036 if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
2037 area->size, f, NULL)) {
2042 /* Make sure the pagetables are constructed in process kernel
2048 EXPORT_SYMBOL_GPL(alloc_vm_area);
2050 void free_vm_area(struct vm_struct *area)
2052 struct vm_struct *ret;
2053 ret = remove_vm_area(area->addr);
2054 BUG_ON(ret != area);
2057 EXPORT_SYMBOL_GPL(free_vm_area);
2059 static struct vmap_area *node_to_va(struct rb_node *n)
2061 return n ? rb_entry(n, struct vmap_area, rb_node) : NULL;
2065 * pvm_find_next_prev - find the next and prev vmap_area surrounding @end
2066 * @end: target address
2067 * @pnext: out arg for the next vmap_area
2068 * @pprev: out arg for the previous vmap_area
2070 * Returns: %true if either or both of next and prev are found,
2071 * %false if no vmap_area exists
2073 * Find vmap_areas end addresses of which enclose @end. ie. if not
2074 * NULL, *pnext->va_end > @end and *pprev->va_end <= @end.
2076 static bool pvm_find_next_prev(unsigned long end,
2077 struct vmap_area **pnext,
2078 struct vmap_area **pprev)
2080 struct rb_node *n = vmap_area_root.rb_node;
2081 struct vmap_area *va = NULL;
2084 va = rb_entry(n, struct vmap_area, rb_node);
2085 if (end < va->va_end)
2087 else if (end > va->va_end)
2096 if (va->va_end > end) {
2098 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2101 *pnext = node_to_va(rb_next(&(*pprev)->rb_node));
2107 * pvm_determine_end - find the highest aligned address between two vmap_areas
2108 * @pnext: in/out arg for the next vmap_area
2109 * @pprev: in/out arg for the previous vmap_area
2112 * Returns: determined end address
2114 * Find the highest aligned address between *@pnext and *@pprev below
2115 * VMALLOC_END. *@pnext and *@pprev are adjusted so that the aligned
2116 * down address is between the end addresses of the two vmap_areas.
2118 * Please note that the address returned by this function may fall
2119 * inside *@pnext vmap_area. The caller is responsible for checking
2122 static unsigned long pvm_determine_end(struct vmap_area **pnext,
2123 struct vmap_area **pprev,
2124 unsigned long align)
2126 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2130 addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end);
2134 while (*pprev && (*pprev)->va_end > addr) {
2136 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2143 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
2144 * @offsets: array containing offset of each area
2145 * @sizes: array containing size of each area
2146 * @nr_vms: the number of areas to allocate
2147 * @align: alignment, all entries in @offsets and @sizes must be aligned to this
2148 * @gfp_mask: allocation mask
2150 * Returns: kmalloc'd vm_struct pointer array pointing to allocated
2151 * vm_structs on success, %NULL on failure
2153 * Percpu allocator wants to use congruent vm areas so that it can
2154 * maintain the offsets among percpu areas. This function allocates
2155 * congruent vmalloc areas for it. These areas tend to be scattered
2156 * pretty far, distance between two areas easily going up to
2157 * gigabytes. To avoid interacting with regular vmallocs, these areas
2158 * are allocated from top.
2160 * Despite its complicated look, this allocator is rather simple. It
2161 * does everything top-down and scans areas from the end looking for
2162 * matching slot. While scanning, if any of the areas overlaps with
2163 * existing vmap_area, the base address is pulled down to fit the
2164 * area. Scanning is repeated till all the areas fit and then all
2165 * necessary data structres are inserted and the result is returned.
2167 struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
2168 const size_t *sizes, int nr_vms,
2169 size_t align, gfp_t gfp_mask)
2171 const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
2172 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2173 struct vmap_area **vas, *prev, *next;
2174 struct vm_struct **vms;
2175 int area, area2, last_area, term_area;
2176 unsigned long base, start, end, last_end;
2177 bool purged = false;
2179 gfp_mask &= GFP_RECLAIM_MASK;
2181 /* verify parameters and allocate data structures */
2182 BUG_ON(align & ~PAGE_MASK || !is_power_of_2(align));
2183 for (last_area = 0, area = 0; area < nr_vms; area++) {
2184 start = offsets[area];
2185 end = start + sizes[area];
2187 /* is everything aligned properly? */
2188 BUG_ON(!IS_ALIGNED(offsets[area], align));
2189 BUG_ON(!IS_ALIGNED(sizes[area], align));
2191 /* detect the area with the highest address */
2192 if (start > offsets[last_area])
2195 for (area2 = 0; area2 < nr_vms; area2++) {
2196 unsigned long start2 = offsets[area2];
2197 unsigned long end2 = start2 + sizes[area2];
2202 BUG_ON(start2 >= start && start2 < end);
2203 BUG_ON(end2 <= end && end2 > start);
2206 last_end = offsets[last_area] + sizes[last_area];
2208 if (vmalloc_end - vmalloc_start < last_end) {
2213 vms = kzalloc(sizeof(vms[0]) * nr_vms, gfp_mask);
2214 vas = kzalloc(sizeof(vas[0]) * nr_vms, gfp_mask);
2218 for (area = 0; area < nr_vms; area++) {
2219 vas[area] = kzalloc(sizeof(struct vmap_area), gfp_mask);
2220 vms[area] = kzalloc(sizeof(struct vm_struct), gfp_mask);
2221 if (!vas[area] || !vms[area])
2225 spin_lock(&vmap_area_lock);
2227 /* start scanning - we scan from the top, begin with the last area */
2228 area = term_area = last_area;
2229 start = offsets[area];
2230 end = start + sizes[area];
2232 if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) {
2233 base = vmalloc_end - last_end;
2236 base = pvm_determine_end(&next, &prev, align) - end;
2239 BUG_ON(next && next->va_end <= base + end);
2240 BUG_ON(prev && prev->va_end > base + end);
2243 * base might have underflowed, add last_end before
2246 if (base + last_end < vmalloc_start + last_end) {
2247 spin_unlock(&vmap_area_lock);
2249 purge_vmap_area_lazy();
2257 * If next overlaps, move base downwards so that it's
2258 * right below next and then recheck.
2260 if (next && next->va_start < base + end) {
2261 base = pvm_determine_end(&next, &prev, align) - end;
2267 * If prev overlaps, shift down next and prev and move
2268 * base so that it's right below new next and then
2271 if (prev && prev->va_end > base + start) {
2273 prev = node_to_va(rb_prev(&next->rb_node));
2274 base = pvm_determine_end(&next, &prev, align) - end;
2280 * This area fits, move on to the previous one. If
2281 * the previous one is the terminal one, we're done.
2283 area = (area + nr_vms - 1) % nr_vms;
2284 if (area == term_area)
2286 start = offsets[area];
2287 end = start + sizes[area];
2288 pvm_find_next_prev(base + end, &next, &prev);
2291 /* we've found a fitting base, insert all va's */
2292 for (area = 0; area < nr_vms; area++) {
2293 struct vmap_area *va = vas[area];
2295 va->va_start = base + offsets[area];
2296 va->va_end = va->va_start + sizes[area];
2297 __insert_vmap_area(va);
2300 vmap_area_pcpu_hole = base + offsets[last_area];
2302 spin_unlock(&vmap_area_lock);
2304 /* insert all vm's */
2305 for (area = 0; area < nr_vms; area++)
2306 insert_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
2313 for (area = 0; area < nr_vms; area++) {
2325 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
2326 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
2327 * @nr_vms: the number of allocated areas
2329 * Free vm_structs and the array allocated by pcpu_get_vm_areas().
2331 void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
2335 for (i = 0; i < nr_vms; i++)
2336 free_vm_area(vms[i]);
2340 #ifdef CONFIG_PROC_FS
2341 static void *s_start(struct seq_file *m, loff_t *pos)
2344 struct vm_struct *v;
2346 read_lock(&vmlist_lock);
2348 while (n > 0 && v) {
2359 static void *s_next(struct seq_file *m, void *p, loff_t *pos)
2361 struct vm_struct *v = p;
2367 static void s_stop(struct seq_file *m, void *p)
2369 read_unlock(&vmlist_lock);
2372 static void show_numa_info(struct seq_file *m, struct vm_struct *v)
2375 unsigned int nr, *counters = m->private;
2380 memset(counters, 0, nr_node_ids * sizeof(unsigned int));
2382 for (nr = 0; nr < v->nr_pages; nr++)
2383 counters[page_to_nid(v->pages[nr])]++;
2385 for_each_node_state(nr, N_HIGH_MEMORY)
2387 seq_printf(m, " N%u=%u", nr, counters[nr]);
2391 static int s_show(struct seq_file *m, void *p)
2393 struct vm_struct *v = p;
2395 seq_printf(m, "0x%p-0x%p %7ld",
2396 v->addr, v->addr + v->size, v->size);
2399 char buff[KSYM_SYMBOL_LEN];
2402 sprint_symbol(buff, (unsigned long)v->caller);
2407 seq_printf(m, " pages=%d", v->nr_pages);
2410 seq_printf(m, " phys=%llx", (unsigned long long)v->phys_addr);
2412 if (v->flags & VM_IOREMAP)
2413 seq_printf(m, " ioremap");
2415 if (v->flags & VM_ALLOC)
2416 seq_printf(m, " vmalloc");
2418 if (v->flags & VM_MAP)
2419 seq_printf(m, " vmap");
2421 if (v->flags & VM_USERMAP)
2422 seq_printf(m, " user");
2424 if (v->flags & VM_VPAGES)
2425 seq_printf(m, " vpages");
2427 show_numa_info(m, v);
2432 static const struct seq_operations vmalloc_op = {
2439 static int vmalloc_open(struct inode *inode, struct file *file)
2441 unsigned int *ptr = NULL;
2445 ptr = kmalloc(nr_node_ids * sizeof(unsigned int), GFP_KERNEL);
2449 ret = seq_open(file, &vmalloc_op);
2451 struct seq_file *m = file->private_data;
2458 static const struct file_operations proc_vmalloc_operations = {
2459 .open = vmalloc_open,
2461 .llseek = seq_lseek,
2462 .release = seq_release_private,
2465 static int __init proc_vmalloc_init(void)
2467 proc_create("vmallocinfo", S_IRUSR, NULL, &proc_vmalloc_operations);
2470 module_init(proc_vmalloc_init);