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
12 #include <linux/module.h>
13 #include <linux/highmem.h>
14 #include <linux/slab.h>
15 #include <linux/spinlock.h>
16 #include <linux/interrupt.h>
18 #include <linux/vmalloc.h>
20 #include <asm/uaccess.h>
21 #include <asm/tlbflush.h>
24 DEFINE_RWLOCK(vmlist_lock);
25 struct vm_struct *vmlist;
27 static void *__vmalloc_node(unsigned long size, gfp_t gfp_mask, pgprot_t prot,
30 static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
34 pte = pte_offset_kernel(pmd, addr);
36 pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
37 WARN_ON(!pte_none(ptent) && !pte_present(ptent));
38 } while (pte++, addr += PAGE_SIZE, addr != end);
41 static inline void vunmap_pmd_range(pud_t *pud, unsigned long addr,
47 pmd = pmd_offset(pud, addr);
49 next = pmd_addr_end(addr, end);
50 if (pmd_none_or_clear_bad(pmd))
52 vunmap_pte_range(pmd, addr, next);
53 } while (pmd++, addr = next, addr != end);
56 static inline void vunmap_pud_range(pgd_t *pgd, unsigned long addr,
62 pud = pud_offset(pgd, addr);
64 next = pud_addr_end(addr, end);
65 if (pud_none_or_clear_bad(pud))
67 vunmap_pmd_range(pud, addr, next);
68 } while (pud++, addr = next, addr != end);
71 void unmap_kernel_range(unsigned long addr, unsigned long size)
75 unsigned long start = addr;
76 unsigned long end = addr + size;
79 pgd = pgd_offset_k(addr);
80 flush_cache_vunmap(addr, end);
82 next = pgd_addr_end(addr, end);
83 if (pgd_none_or_clear_bad(pgd))
85 vunmap_pud_range(pgd, addr, next);
86 } while (pgd++, addr = next, addr != end);
87 flush_tlb_kernel_range(start, end);
90 static void unmap_vm_area(struct vm_struct *area)
92 unmap_kernel_range((unsigned long)area->addr, area->size);
95 static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
96 unsigned long end, pgprot_t prot, struct page ***pages)
100 pte = pte_alloc_kernel(pmd, addr);
104 struct page *page = **pages;
105 WARN_ON(!pte_none(*pte));
108 set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
110 } while (pte++, addr += PAGE_SIZE, addr != end);
114 static inline int vmap_pmd_range(pud_t *pud, unsigned long addr,
115 unsigned long end, pgprot_t prot, struct page ***pages)
120 pmd = pmd_alloc(&init_mm, pud, addr);
124 next = pmd_addr_end(addr, end);
125 if (vmap_pte_range(pmd, addr, next, prot, pages))
127 } while (pmd++, addr = next, addr != end);
131 static inline int vmap_pud_range(pgd_t *pgd, unsigned long addr,
132 unsigned long end, pgprot_t prot, struct page ***pages)
137 pud = pud_alloc(&init_mm, pgd, addr);
141 next = pud_addr_end(addr, end);
142 if (vmap_pmd_range(pud, addr, next, prot, pages))
144 } while (pud++, addr = next, addr != end);
148 int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages)
152 unsigned long addr = (unsigned long) area->addr;
153 unsigned long end = addr + area->size - PAGE_SIZE;
157 pgd = pgd_offset_k(addr);
159 next = pgd_addr_end(addr, end);
160 err = vmap_pud_range(pgd, addr, next, prot, pages);
163 } while (pgd++, addr = next, addr != end);
164 flush_cache_vmap((unsigned long) area->addr, end);
167 EXPORT_SYMBOL_GPL(map_vm_area);
170 * Map a vmalloc()-space virtual address to the physical page.
172 struct page *vmalloc_to_page(const void *vmalloc_addr)
174 unsigned long addr = (unsigned long) vmalloc_addr;
175 struct page *page = NULL;
176 pgd_t *pgd = pgd_offset_k(addr);
181 if (!pgd_none(*pgd)) {
182 pud = pud_offset(pgd, addr);
183 if (!pud_none(*pud)) {
184 pmd = pmd_offset(pud, addr);
185 if (!pmd_none(*pmd)) {
186 ptep = pte_offset_map(pmd, addr);
188 if (pte_present(pte))
189 page = pte_page(pte);
196 EXPORT_SYMBOL(vmalloc_to_page);
199 * Map a vmalloc()-space virtual address to the physical page frame number.
201 unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
203 return page_to_pfn(vmalloc_to_page(vmalloc_addr));
205 EXPORT_SYMBOL(vmalloc_to_pfn);
207 static struct vm_struct *__get_vm_area_node(unsigned long size, unsigned long flags,
208 unsigned long start, unsigned long end,
209 int node, gfp_t gfp_mask)
211 struct vm_struct **p, *tmp, *area;
212 unsigned long align = 1;
215 BUG_ON(in_interrupt());
216 if (flags & VM_IOREMAP) {
219 if (bit > IOREMAP_MAX_ORDER)
220 bit = IOREMAP_MAX_ORDER;
221 else if (bit < PAGE_SHIFT)
226 addr = ALIGN(start, align);
227 size = PAGE_ALIGN(size);
231 area = kmalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
237 * We always allocate a guard page.
241 write_lock(&vmlist_lock);
242 for (p = &vmlist; (tmp = *p) != NULL ;p = &tmp->next) {
243 if ((unsigned long)tmp->addr < addr) {
244 if((unsigned long)tmp->addr + tmp->size >= addr)
245 addr = ALIGN(tmp->size +
246 (unsigned long)tmp->addr, align);
249 if ((size + addr) < addr)
251 if (size + addr <= (unsigned long)tmp->addr)
253 addr = ALIGN(tmp->size + (unsigned long)tmp->addr, align);
254 if (addr > end - size)
257 if ((size + addr) < addr)
259 if (addr > end - size)
267 area->addr = (void *)addr;
272 write_unlock(&vmlist_lock);
277 write_unlock(&vmlist_lock);
279 if (printk_ratelimit())
280 printk(KERN_WARNING "allocation failed: out of vmalloc space - use vmalloc=<size> to increase size.\n");
284 struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
285 unsigned long start, unsigned long end)
287 return __get_vm_area_node(size, flags, start, end, -1, GFP_KERNEL);
289 EXPORT_SYMBOL_GPL(__get_vm_area);
292 * get_vm_area - reserve a contiguous kernel virtual area
293 * @size: size of the area
294 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC
296 * Search an area of @size in the kernel virtual mapping area,
297 * and reserved it for out purposes. Returns the area descriptor
298 * on success or %NULL on failure.
300 struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
302 return __get_vm_area(size, flags, VMALLOC_START, VMALLOC_END);
305 struct vm_struct *get_vm_area_node(unsigned long size, unsigned long flags,
306 int node, gfp_t gfp_mask)
308 return __get_vm_area_node(size, flags, VMALLOC_START, VMALLOC_END, node,
312 /* Caller must hold vmlist_lock */
313 static struct vm_struct *__find_vm_area(const void *addr)
315 struct vm_struct *tmp;
317 for (tmp = vmlist; tmp != NULL; tmp = tmp->next) {
318 if (tmp->addr == addr)
325 /* Caller must hold vmlist_lock */
326 static struct vm_struct *__remove_vm_area(const void *addr)
328 struct vm_struct **p, *tmp;
330 for (p = &vmlist ; (tmp = *p) != NULL ;p = &tmp->next) {
331 if (tmp->addr == addr)
341 * Remove the guard page.
343 tmp->size -= PAGE_SIZE;
348 * remove_vm_area - find and remove a continuous kernel virtual area
349 * @addr: base address
351 * Search for the kernel VM area starting at @addr, and remove it.
352 * This function returns the found VM area, but using it is NOT safe
353 * on SMP machines, except for its size or flags.
355 struct vm_struct *remove_vm_area(const void *addr)
358 write_lock(&vmlist_lock);
359 v = __remove_vm_area(addr);
360 write_unlock(&vmlist_lock);
364 static void __vunmap(const void *addr, int deallocate_pages)
366 struct vm_struct *area;
371 if ((PAGE_SIZE-1) & (unsigned long)addr) {
372 printk(KERN_ERR "Trying to vfree() bad address (%p)\n", addr);
377 area = remove_vm_area(addr);
378 if (unlikely(!area)) {
379 printk(KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
385 debug_check_no_locks_freed(addr, area->size);
387 if (deallocate_pages) {
390 for (i = 0; i < area->nr_pages; i++) {
391 struct page *page = area->pages[i];
397 if (area->flags & VM_VPAGES)
408 * vfree - release memory allocated by vmalloc()
409 * @addr: memory base address
411 * Free the virtually continuous memory area starting at @addr, as
412 * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
413 * NULL, no operation is performed.
415 * Must not be called in interrupt context.
417 void vfree(const void *addr)
419 BUG_ON(in_interrupt());
422 EXPORT_SYMBOL(vfree);
425 * vunmap - release virtual mapping obtained by vmap()
426 * @addr: memory base address
428 * Free the virtually contiguous memory area starting at @addr,
429 * which was created from the page array passed to vmap().
431 * Must not be called in interrupt context.
433 void vunmap(const void *addr)
435 BUG_ON(in_interrupt());
438 EXPORT_SYMBOL(vunmap);
441 * vmap - map an array of pages into virtually contiguous space
442 * @pages: array of page pointers
443 * @count: number of pages to map
444 * @flags: vm_area->flags
445 * @prot: page protection for the mapping
447 * Maps @count pages from @pages into contiguous kernel virtual
450 void *vmap(struct page **pages, unsigned int count,
451 unsigned long flags, pgprot_t prot)
453 struct vm_struct *area;
455 if (count > num_physpages)
458 area = get_vm_area((count << PAGE_SHIFT), flags);
461 if (map_vm_area(area, prot, &pages)) {
470 static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
471 pgprot_t prot, int node)
474 unsigned int nr_pages, array_size, i;
476 nr_pages = (area->size - PAGE_SIZE) >> PAGE_SHIFT;
477 array_size = (nr_pages * sizeof(struct page *));
479 area->nr_pages = nr_pages;
480 /* Please note that the recursion is strictly bounded. */
481 if (array_size > PAGE_SIZE) {
482 pages = __vmalloc_node(array_size, gfp_mask | __GFP_ZERO,
484 area->flags |= VM_VPAGES;
486 pages = kmalloc_node(array_size,
487 (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO,
492 remove_vm_area(area->addr);
497 for (i = 0; i < area->nr_pages; i++) {
501 page = alloc_page(gfp_mask);
503 page = alloc_pages_node(node, gfp_mask, 0);
505 if (unlikely(!page)) {
506 /* Successfully allocated i pages, free them in __vunmap() */
510 area->pages[i] = page;
513 if (map_vm_area(area, prot, &pages))
522 void *__vmalloc_area(struct vm_struct *area, gfp_t gfp_mask, pgprot_t prot)
524 return __vmalloc_area_node(area, gfp_mask, prot, -1);
528 * __vmalloc_node - allocate virtually contiguous memory
529 * @size: allocation size
530 * @gfp_mask: flags for the page level allocator
531 * @prot: protection mask for the allocated pages
532 * @node: node to use for allocation or -1
534 * Allocate enough pages to cover @size from the page level
535 * allocator with @gfp_mask flags. Map them into contiguous
536 * kernel virtual space, using a pagetable protection of @prot.
538 static void *__vmalloc_node(unsigned long size, gfp_t gfp_mask, pgprot_t prot,
541 struct vm_struct *area;
543 size = PAGE_ALIGN(size);
544 if (!size || (size >> PAGE_SHIFT) > num_physpages)
547 area = get_vm_area_node(size, VM_ALLOC, node, gfp_mask);
551 return __vmalloc_area_node(area, gfp_mask, prot, node);
554 void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
556 return __vmalloc_node(size, gfp_mask, prot, -1);
558 EXPORT_SYMBOL(__vmalloc);
561 * vmalloc - allocate virtually contiguous memory
562 * @size: allocation size
563 * Allocate enough pages to cover @size from the page level
564 * allocator and map them into contiguous kernel virtual space.
566 * For tight control over page level allocator and protection flags
567 * use __vmalloc() instead.
569 void *vmalloc(unsigned long size)
571 return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL);
573 EXPORT_SYMBOL(vmalloc);
576 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
577 * @size: allocation size
579 * The resulting memory area is zeroed so it can be mapped to userspace
580 * without leaking data.
582 void *vmalloc_user(unsigned long size)
584 struct vm_struct *area;
587 ret = __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL);
589 write_lock(&vmlist_lock);
590 area = __find_vm_area(ret);
591 area->flags |= VM_USERMAP;
592 write_unlock(&vmlist_lock);
596 EXPORT_SYMBOL(vmalloc_user);
599 * vmalloc_node - allocate memory on a specific node
600 * @size: allocation size
603 * Allocate enough pages to cover @size from the page level
604 * allocator and map them into contiguous kernel virtual space.
606 * For tight control over page level allocator and protection flags
607 * use __vmalloc() instead.
609 void *vmalloc_node(unsigned long size, int node)
611 return __vmalloc_node(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL, node);
613 EXPORT_SYMBOL(vmalloc_node);
615 #ifndef PAGE_KERNEL_EXEC
616 # define PAGE_KERNEL_EXEC PAGE_KERNEL
620 * vmalloc_exec - allocate virtually contiguous, executable memory
621 * @size: allocation size
623 * Kernel-internal function to allocate enough pages to cover @size
624 * the page level allocator and map them into contiguous and
625 * executable kernel virtual space.
627 * For tight control over page level allocator and protection flags
628 * use __vmalloc() instead.
631 void *vmalloc_exec(unsigned long size)
633 return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC);
636 #if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
637 #define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
638 #elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
639 #define GFP_VMALLOC32 GFP_DMA | GFP_KERNEL
641 #define GFP_VMALLOC32 GFP_KERNEL
645 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
646 * @size: allocation size
648 * Allocate enough 32bit PA addressable pages to cover @size from the
649 * page level allocator and map them into contiguous kernel virtual space.
651 void *vmalloc_32(unsigned long size)
653 return __vmalloc(size, GFP_VMALLOC32, PAGE_KERNEL);
655 EXPORT_SYMBOL(vmalloc_32);
658 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
659 * @size: allocation size
661 * The resulting memory area is 32bit addressable and zeroed so it can be
662 * mapped to userspace without leaking data.
664 void *vmalloc_32_user(unsigned long size)
666 struct vm_struct *area;
669 ret = __vmalloc(size, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL);
671 write_lock(&vmlist_lock);
672 area = __find_vm_area(ret);
673 area->flags |= VM_USERMAP;
674 write_unlock(&vmlist_lock);
678 EXPORT_SYMBOL(vmalloc_32_user);
680 long vread(char *buf, char *addr, unsigned long count)
682 struct vm_struct *tmp;
683 char *vaddr, *buf_start = buf;
686 /* Don't allow overflow */
687 if ((unsigned long) addr + count < count)
688 count = -(unsigned long) addr;
690 read_lock(&vmlist_lock);
691 for (tmp = vmlist; tmp; tmp = tmp->next) {
692 vaddr = (char *) tmp->addr;
693 if (addr >= vaddr + tmp->size - PAGE_SIZE)
695 while (addr < vaddr) {
703 n = vaddr + tmp->size - PAGE_SIZE - addr;
714 read_unlock(&vmlist_lock);
715 return buf - buf_start;
718 long vwrite(char *buf, char *addr, unsigned long count)
720 struct vm_struct *tmp;
721 char *vaddr, *buf_start = buf;
724 /* Don't allow overflow */
725 if ((unsigned long) addr + count < count)
726 count = -(unsigned long) addr;
728 read_lock(&vmlist_lock);
729 for (tmp = vmlist; tmp; tmp = tmp->next) {
730 vaddr = (char *) tmp->addr;
731 if (addr >= vaddr + tmp->size - PAGE_SIZE)
733 while (addr < vaddr) {
740 n = vaddr + tmp->size - PAGE_SIZE - addr;
751 read_unlock(&vmlist_lock);
752 return buf - buf_start;
756 * remap_vmalloc_range - map vmalloc pages to userspace
757 * @vma: vma to cover (map full range of vma)
758 * @addr: vmalloc memory
759 * @pgoff: number of pages into addr before first page to map
760 * @returns: 0 for success, -Exxx on failure
762 * This function checks that addr is a valid vmalloc'ed area, and
763 * that it is big enough to cover the vma. Will return failure if
764 * that criteria isn't met.
766 * Similar to remap_pfn_range() (see mm/memory.c)
768 int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
771 struct vm_struct *area;
772 unsigned long uaddr = vma->vm_start;
773 unsigned long usize = vma->vm_end - vma->vm_start;
776 if ((PAGE_SIZE-1) & (unsigned long)addr)
779 read_lock(&vmlist_lock);
780 area = __find_vm_area(addr);
782 goto out_einval_locked;
784 if (!(area->flags & VM_USERMAP))
785 goto out_einval_locked;
787 if (usize + (pgoff << PAGE_SHIFT) > area->size - PAGE_SIZE)
788 goto out_einval_locked;
789 read_unlock(&vmlist_lock);
791 addr += pgoff << PAGE_SHIFT;
793 struct page *page = vmalloc_to_page(addr);
794 ret = vm_insert_page(vma, uaddr, page);
803 /* Prevent "things" like memory migration? VM_flags need a cleanup... */
804 vma->vm_flags |= VM_RESERVED;
809 read_unlock(&vmlist_lock);
812 EXPORT_SYMBOL(remap_vmalloc_range);
815 * Implement a stub for vmalloc_sync_all() if the architecture chose not to
818 void __attribute__((weak)) vmalloc_sync_all(void)
823 static int f(pte_t *pte, struct page *pmd_page, unsigned long addr, void *data)
825 /* apply_to_page_range() does all the hard work. */
830 * alloc_vm_area - allocate a range of kernel address space
831 * @size: size of the area
832 * @returns: NULL on failure, vm_struct on success
834 * This function reserves a range of kernel address space, and
835 * allocates pagetables to map that range. No actual mappings
836 * are created. If the kernel address space is not shared
837 * between processes, it syncs the pagetable across all
840 struct vm_struct *alloc_vm_area(size_t size)
842 struct vm_struct *area;
844 area = get_vm_area(size, VM_IOREMAP);
849 * This ensures that page tables are constructed for this region
850 * of kernel virtual address space and mapped into init_mm.
852 if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
853 area->size, f, NULL)) {
858 /* Make sure the pagetables are constructed in process kernel
864 EXPORT_SYMBOL_GPL(alloc_vm_area);
866 void free_vm_area(struct vm_struct *area)
868 struct vm_struct *ret;
869 ret = remove_vm_area(area->addr);
873 EXPORT_SYMBOL_GPL(free_vm_area);