Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/mm/vmalloc.c | |
3 | * | |
4 | * Copyright (C) 1993 Linus Torvalds | |
5 | * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 | |
6 | * SMP-safe vmalloc/vfree/ioremap, Tigran Aivazian <tigran@veritas.com>, May 2000 | |
7 | * Major rework to support vmap/vunmap, Christoph Hellwig, SGI, August 2002 | |
930fc45a | 8 | * Numa awareness, Christoph Lameter, SGI, June 2005 |
1da177e4 LT |
9 | */ |
10 | ||
11 | #include <linux/mm.h> | |
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> | |
17 | ||
18 | #include <linux/vmalloc.h> | |
19 | ||
20 | #include <asm/uaccess.h> | |
21 | #include <asm/tlbflush.h> | |
22 | ||
23 | ||
24 | DEFINE_RWLOCK(vmlist_lock); | |
25 | struct vm_struct *vmlist; | |
26 | ||
b221385b AB |
27 | static void *__vmalloc_node(unsigned long size, gfp_t gfp_mask, pgprot_t prot, |
28 | int node); | |
29 | ||
1da177e4 LT |
30 | static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end) |
31 | { | |
32 | pte_t *pte; | |
33 | ||
34 | pte = pte_offset_kernel(pmd, addr); | |
35 | do { | |
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); | |
39 | } | |
40 | ||
41 | static inline void vunmap_pmd_range(pud_t *pud, unsigned long addr, | |
42 | unsigned long end) | |
43 | { | |
44 | pmd_t *pmd; | |
45 | unsigned long next; | |
46 | ||
47 | pmd = pmd_offset(pud, addr); | |
48 | do { | |
49 | next = pmd_addr_end(addr, end); | |
50 | if (pmd_none_or_clear_bad(pmd)) | |
51 | continue; | |
52 | vunmap_pte_range(pmd, addr, next); | |
53 | } while (pmd++, addr = next, addr != end); | |
54 | } | |
55 | ||
56 | static inline void vunmap_pud_range(pgd_t *pgd, unsigned long addr, | |
57 | unsigned long end) | |
58 | { | |
59 | pud_t *pud; | |
60 | unsigned long next; | |
61 | ||
62 | pud = pud_offset(pgd, addr); | |
63 | do { | |
64 | next = pud_addr_end(addr, end); | |
65 | if (pud_none_or_clear_bad(pud)) | |
66 | continue; | |
67 | vunmap_pmd_range(pud, addr, next); | |
68 | } while (pud++, addr = next, addr != end); | |
69 | } | |
70 | ||
71 | void unmap_vm_area(struct vm_struct *area) | |
72 | { | |
73 | pgd_t *pgd; | |
74 | unsigned long next; | |
75 | unsigned long addr = (unsigned long) area->addr; | |
76 | unsigned long end = addr + area->size; | |
77 | ||
78 | BUG_ON(addr >= end); | |
79 | pgd = pgd_offset_k(addr); | |
80 | flush_cache_vunmap(addr, end); | |
81 | do { | |
82 | next = pgd_addr_end(addr, end); | |
83 | if (pgd_none_or_clear_bad(pgd)) | |
84 | continue; | |
85 | vunmap_pud_range(pgd, addr, next); | |
86 | } while (pgd++, addr = next, addr != end); | |
87 | flush_tlb_kernel_range((unsigned long) area->addr, end); | |
88 | } | |
89 | ||
90 | static int vmap_pte_range(pmd_t *pmd, unsigned long addr, | |
91 | unsigned long end, pgprot_t prot, struct page ***pages) | |
92 | { | |
93 | pte_t *pte; | |
94 | ||
872fec16 | 95 | pte = pte_alloc_kernel(pmd, addr); |
1da177e4 LT |
96 | if (!pte) |
97 | return -ENOMEM; | |
98 | do { | |
99 | struct page *page = **pages; | |
100 | WARN_ON(!pte_none(*pte)); | |
101 | if (!page) | |
102 | return -ENOMEM; | |
103 | set_pte_at(&init_mm, addr, pte, mk_pte(page, prot)); | |
104 | (*pages)++; | |
105 | } while (pte++, addr += PAGE_SIZE, addr != end); | |
106 | return 0; | |
107 | } | |
108 | ||
109 | static inline int vmap_pmd_range(pud_t *pud, unsigned long addr, | |
110 | unsigned long end, pgprot_t prot, struct page ***pages) | |
111 | { | |
112 | pmd_t *pmd; | |
113 | unsigned long next; | |
114 | ||
115 | pmd = pmd_alloc(&init_mm, pud, addr); | |
116 | if (!pmd) | |
117 | return -ENOMEM; | |
118 | do { | |
119 | next = pmd_addr_end(addr, end); | |
120 | if (vmap_pte_range(pmd, addr, next, prot, pages)) | |
121 | return -ENOMEM; | |
122 | } while (pmd++, addr = next, addr != end); | |
123 | return 0; | |
124 | } | |
125 | ||
126 | static inline int vmap_pud_range(pgd_t *pgd, unsigned long addr, | |
127 | unsigned long end, pgprot_t prot, struct page ***pages) | |
128 | { | |
129 | pud_t *pud; | |
130 | unsigned long next; | |
131 | ||
132 | pud = pud_alloc(&init_mm, pgd, addr); | |
133 | if (!pud) | |
134 | return -ENOMEM; | |
135 | do { | |
136 | next = pud_addr_end(addr, end); | |
137 | if (vmap_pmd_range(pud, addr, next, prot, pages)) | |
138 | return -ENOMEM; | |
139 | } while (pud++, addr = next, addr != end); | |
140 | return 0; | |
141 | } | |
142 | ||
143 | int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages) | |
144 | { | |
145 | pgd_t *pgd; | |
146 | unsigned long next; | |
147 | unsigned long addr = (unsigned long) area->addr; | |
148 | unsigned long end = addr + area->size - PAGE_SIZE; | |
149 | int err; | |
150 | ||
151 | BUG_ON(addr >= end); | |
152 | pgd = pgd_offset_k(addr); | |
1da177e4 LT |
153 | do { |
154 | next = pgd_addr_end(addr, end); | |
155 | err = vmap_pud_range(pgd, addr, next, prot, pages); | |
156 | if (err) | |
157 | break; | |
158 | } while (pgd++, addr = next, addr != end); | |
1da177e4 LT |
159 | flush_cache_vmap((unsigned long) area->addr, end); |
160 | return err; | |
161 | } | |
162 | ||
930fc45a CL |
163 | struct vm_struct *__get_vm_area_node(unsigned long size, unsigned long flags, |
164 | unsigned long start, unsigned long end, int node) | |
1da177e4 LT |
165 | { |
166 | struct vm_struct **p, *tmp, *area; | |
167 | unsigned long align = 1; | |
168 | unsigned long addr; | |
169 | ||
170 | if (flags & VM_IOREMAP) { | |
171 | int bit = fls(size); | |
172 | ||
173 | if (bit > IOREMAP_MAX_ORDER) | |
174 | bit = IOREMAP_MAX_ORDER; | |
175 | else if (bit < PAGE_SHIFT) | |
176 | bit = PAGE_SHIFT; | |
177 | ||
178 | align = 1ul << bit; | |
179 | } | |
180 | addr = ALIGN(start, align); | |
181 | size = PAGE_ALIGN(size); | |
182 | ||
930fc45a | 183 | area = kmalloc_node(sizeof(*area), GFP_KERNEL, node); |
1da177e4 LT |
184 | if (unlikely(!area)) |
185 | return NULL; | |
186 | ||
187 | if (unlikely(!size)) { | |
188 | kfree (area); | |
189 | return NULL; | |
190 | } | |
191 | ||
192 | /* | |
193 | * We always allocate a guard page. | |
194 | */ | |
195 | size += PAGE_SIZE; | |
196 | ||
197 | write_lock(&vmlist_lock); | |
198 | for (p = &vmlist; (tmp = *p) != NULL ;p = &tmp->next) { | |
199 | if ((unsigned long)tmp->addr < addr) { | |
200 | if((unsigned long)tmp->addr + tmp->size >= addr) | |
201 | addr = ALIGN(tmp->size + | |
202 | (unsigned long)tmp->addr, align); | |
203 | continue; | |
204 | } | |
205 | if ((size + addr) < addr) | |
206 | goto out; | |
207 | if (size + addr <= (unsigned long)tmp->addr) | |
208 | goto found; | |
209 | addr = ALIGN(tmp->size + (unsigned long)tmp->addr, align); | |
210 | if (addr > end - size) | |
211 | goto out; | |
212 | } | |
213 | ||
214 | found: | |
215 | area->next = *p; | |
216 | *p = area; | |
217 | ||
218 | area->flags = flags; | |
219 | area->addr = (void *)addr; | |
220 | area->size = size; | |
221 | area->pages = NULL; | |
222 | area->nr_pages = 0; | |
223 | area->phys_addr = 0; | |
224 | write_unlock(&vmlist_lock); | |
225 | ||
226 | return area; | |
227 | ||
228 | out: | |
229 | write_unlock(&vmlist_lock); | |
230 | kfree(area); | |
231 | if (printk_ratelimit()) | |
232 | printk(KERN_WARNING "allocation failed: out of vmalloc space - use vmalloc=<size> to increase size.\n"); | |
233 | return NULL; | |
234 | } | |
235 | ||
930fc45a CL |
236 | struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags, |
237 | unsigned long start, unsigned long end) | |
238 | { | |
239 | return __get_vm_area_node(size, flags, start, end, -1); | |
240 | } | |
241 | ||
1da177e4 LT |
242 | /** |
243 | * get_vm_area - reserve a contingous kernel virtual area | |
1da177e4 LT |
244 | * @size: size of the area |
245 | * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC | |
246 | * | |
247 | * Search an area of @size in the kernel virtual mapping area, | |
248 | * and reserved it for out purposes. Returns the area descriptor | |
249 | * on success or %NULL on failure. | |
250 | */ | |
251 | struct vm_struct *get_vm_area(unsigned long size, unsigned long flags) | |
252 | { | |
253 | return __get_vm_area(size, flags, VMALLOC_START, VMALLOC_END); | |
254 | } | |
255 | ||
930fc45a CL |
256 | struct vm_struct *get_vm_area_node(unsigned long size, unsigned long flags, int node) |
257 | { | |
258 | return __get_vm_area_node(size, flags, VMALLOC_START, VMALLOC_END, node); | |
259 | } | |
260 | ||
83342314 NP |
261 | /* Caller must hold vmlist_lock */ |
262 | static struct vm_struct *__find_vm_area(void *addr) | |
263 | { | |
264 | struct vm_struct *tmp; | |
265 | ||
266 | for (tmp = vmlist; tmp != NULL; tmp = tmp->next) { | |
267 | if (tmp->addr == addr) | |
268 | break; | |
269 | } | |
270 | ||
271 | return tmp; | |
272 | } | |
273 | ||
7856dfeb | 274 | /* Caller must hold vmlist_lock */ |
d24afc57 | 275 | static struct vm_struct *__remove_vm_area(void *addr) |
1da177e4 LT |
276 | { |
277 | struct vm_struct **p, *tmp; | |
278 | ||
1da177e4 LT |
279 | for (p = &vmlist ; (tmp = *p) != NULL ;p = &tmp->next) { |
280 | if (tmp->addr == addr) | |
281 | goto found; | |
282 | } | |
1da177e4 LT |
283 | return NULL; |
284 | ||
285 | found: | |
286 | unmap_vm_area(tmp); | |
287 | *p = tmp->next; | |
1da177e4 LT |
288 | |
289 | /* | |
290 | * Remove the guard page. | |
291 | */ | |
292 | tmp->size -= PAGE_SIZE; | |
293 | return tmp; | |
294 | } | |
295 | ||
7856dfeb AK |
296 | /** |
297 | * remove_vm_area - find and remove a contingous kernel virtual area | |
7856dfeb AK |
298 | * @addr: base address |
299 | * | |
300 | * Search for the kernel VM area starting at @addr, and remove it. | |
301 | * This function returns the found VM area, but using it is NOT safe | |
302 | * on SMP machines, except for its size or flags. | |
303 | */ | |
304 | struct vm_struct *remove_vm_area(void *addr) | |
305 | { | |
306 | struct vm_struct *v; | |
307 | write_lock(&vmlist_lock); | |
308 | v = __remove_vm_area(addr); | |
309 | write_unlock(&vmlist_lock); | |
310 | return v; | |
311 | } | |
312 | ||
1da177e4 LT |
313 | void __vunmap(void *addr, int deallocate_pages) |
314 | { | |
315 | struct vm_struct *area; | |
316 | ||
317 | if (!addr) | |
318 | return; | |
319 | ||
320 | if ((PAGE_SIZE-1) & (unsigned long)addr) { | |
321 | printk(KERN_ERR "Trying to vfree() bad address (%p)\n", addr); | |
322 | WARN_ON(1); | |
323 | return; | |
324 | } | |
325 | ||
326 | area = remove_vm_area(addr); | |
327 | if (unlikely(!area)) { | |
328 | printk(KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n", | |
329 | addr); | |
330 | WARN_ON(1); | |
331 | return; | |
332 | } | |
333 | ||
9a11b49a IM |
334 | debug_check_no_locks_freed(addr, area->size); |
335 | ||
1da177e4 LT |
336 | if (deallocate_pages) { |
337 | int i; | |
338 | ||
339 | for (i = 0; i < area->nr_pages; i++) { | |
5aae277e | 340 | BUG_ON(!area->pages[i]); |
1da177e4 LT |
341 | __free_page(area->pages[i]); |
342 | } | |
343 | ||
8757d5fa | 344 | if (area->flags & VM_VPAGES) |
1da177e4 LT |
345 | vfree(area->pages); |
346 | else | |
347 | kfree(area->pages); | |
348 | } | |
349 | ||
350 | kfree(area); | |
351 | return; | |
352 | } | |
353 | ||
354 | /** | |
355 | * vfree - release memory allocated by vmalloc() | |
1da177e4 LT |
356 | * @addr: memory base address |
357 | * | |
358 | * Free the virtually contiguous memory area starting at @addr, as | |
80e93eff PE |
359 | * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is |
360 | * NULL, no operation is performed. | |
1da177e4 | 361 | * |
80e93eff | 362 | * Must not be called in interrupt context. |
1da177e4 LT |
363 | */ |
364 | void vfree(void *addr) | |
365 | { | |
366 | BUG_ON(in_interrupt()); | |
367 | __vunmap(addr, 1); | |
368 | } | |
1da177e4 LT |
369 | EXPORT_SYMBOL(vfree); |
370 | ||
371 | /** | |
372 | * vunmap - release virtual mapping obtained by vmap() | |
1da177e4 LT |
373 | * @addr: memory base address |
374 | * | |
375 | * Free the virtually contiguous memory area starting at @addr, | |
376 | * which was created from the page array passed to vmap(). | |
377 | * | |
80e93eff | 378 | * Must not be called in interrupt context. |
1da177e4 LT |
379 | */ |
380 | void vunmap(void *addr) | |
381 | { | |
382 | BUG_ON(in_interrupt()); | |
383 | __vunmap(addr, 0); | |
384 | } | |
1da177e4 LT |
385 | EXPORT_SYMBOL(vunmap); |
386 | ||
387 | /** | |
388 | * vmap - map an array of pages into virtually contiguous space | |
1da177e4 LT |
389 | * @pages: array of page pointers |
390 | * @count: number of pages to map | |
391 | * @flags: vm_area->flags | |
392 | * @prot: page protection for the mapping | |
393 | * | |
394 | * Maps @count pages from @pages into contiguous kernel virtual | |
395 | * space. | |
396 | */ | |
397 | void *vmap(struct page **pages, unsigned int count, | |
398 | unsigned long flags, pgprot_t prot) | |
399 | { | |
400 | struct vm_struct *area; | |
401 | ||
402 | if (count > num_physpages) | |
403 | return NULL; | |
404 | ||
405 | area = get_vm_area((count << PAGE_SHIFT), flags); | |
406 | if (!area) | |
407 | return NULL; | |
408 | if (map_vm_area(area, prot, &pages)) { | |
409 | vunmap(area->addr); | |
410 | return NULL; | |
411 | } | |
412 | ||
413 | return area->addr; | |
414 | } | |
1da177e4 LT |
415 | EXPORT_SYMBOL(vmap); |
416 | ||
930fc45a CL |
417 | void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, |
418 | pgprot_t prot, int node) | |
1da177e4 LT |
419 | { |
420 | struct page **pages; | |
421 | unsigned int nr_pages, array_size, i; | |
422 | ||
423 | nr_pages = (area->size - PAGE_SIZE) >> PAGE_SHIFT; | |
424 | array_size = (nr_pages * sizeof(struct page *)); | |
425 | ||
426 | area->nr_pages = nr_pages; | |
427 | /* Please note that the recursion is strictly bounded. */ | |
8757d5fa | 428 | if (array_size > PAGE_SIZE) { |
930fc45a | 429 | pages = __vmalloc_node(array_size, gfp_mask, PAGE_KERNEL, node); |
8757d5fa JK |
430 | area->flags |= VM_VPAGES; |
431 | } else | |
930fc45a | 432 | pages = kmalloc_node(array_size, (gfp_mask & ~__GFP_HIGHMEM), node); |
1da177e4 LT |
433 | area->pages = pages; |
434 | if (!area->pages) { | |
435 | remove_vm_area(area->addr); | |
436 | kfree(area); | |
437 | return NULL; | |
438 | } | |
439 | memset(area->pages, 0, array_size); | |
440 | ||
441 | for (i = 0; i < area->nr_pages; i++) { | |
930fc45a CL |
442 | if (node < 0) |
443 | area->pages[i] = alloc_page(gfp_mask); | |
444 | else | |
445 | area->pages[i] = alloc_pages_node(node, gfp_mask, 0); | |
1da177e4 LT |
446 | if (unlikely(!area->pages[i])) { |
447 | /* Successfully allocated i pages, free them in __vunmap() */ | |
448 | area->nr_pages = i; | |
449 | goto fail; | |
450 | } | |
451 | } | |
452 | ||
453 | if (map_vm_area(area, prot, &pages)) | |
454 | goto fail; | |
455 | return area->addr; | |
456 | ||
457 | fail: | |
458 | vfree(area->addr); | |
459 | return NULL; | |
460 | } | |
461 | ||
930fc45a CL |
462 | void *__vmalloc_area(struct vm_struct *area, gfp_t gfp_mask, pgprot_t prot) |
463 | { | |
464 | return __vmalloc_area_node(area, gfp_mask, prot, -1); | |
465 | } | |
466 | ||
1da177e4 | 467 | /** |
930fc45a | 468 | * __vmalloc_node - allocate virtually contiguous memory |
1da177e4 LT |
469 | * @size: allocation size |
470 | * @gfp_mask: flags for the page level allocator | |
471 | * @prot: protection mask for the allocated pages | |
d44e0780 | 472 | * @node: node to use for allocation or -1 |
1da177e4 LT |
473 | * |
474 | * Allocate enough pages to cover @size from the page level | |
475 | * allocator with @gfp_mask flags. Map them into contiguous | |
476 | * kernel virtual space, using a pagetable protection of @prot. | |
477 | */ | |
b221385b AB |
478 | static void *__vmalloc_node(unsigned long size, gfp_t gfp_mask, pgprot_t prot, |
479 | int node) | |
1da177e4 LT |
480 | { |
481 | struct vm_struct *area; | |
482 | ||
483 | size = PAGE_ALIGN(size); | |
484 | if (!size || (size >> PAGE_SHIFT) > num_physpages) | |
485 | return NULL; | |
486 | ||
930fc45a | 487 | area = get_vm_area_node(size, VM_ALLOC, node); |
1da177e4 LT |
488 | if (!area) |
489 | return NULL; | |
490 | ||
930fc45a | 491 | return __vmalloc_area_node(area, gfp_mask, prot, node); |
1da177e4 LT |
492 | } |
493 | ||
930fc45a CL |
494 | void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot) |
495 | { | |
496 | return __vmalloc_node(size, gfp_mask, prot, -1); | |
497 | } | |
1da177e4 LT |
498 | EXPORT_SYMBOL(__vmalloc); |
499 | ||
500 | /** | |
501 | * vmalloc - allocate virtually contiguous memory | |
1da177e4 | 502 | * @size: allocation size |
1da177e4 LT |
503 | * Allocate enough pages to cover @size from the page level |
504 | * allocator and map them into contiguous kernel virtual space. | |
505 | * | |
506 | * For tight cotrol over page level allocator and protection flags | |
507 | * use __vmalloc() instead. | |
508 | */ | |
509 | void *vmalloc(unsigned long size) | |
510 | { | |
83342314 | 511 | return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL); |
1da177e4 | 512 | } |
1da177e4 LT |
513 | EXPORT_SYMBOL(vmalloc); |
514 | ||
83342314 | 515 | /** |
ead04089 REB |
516 | * vmalloc_user - allocate zeroed virtually contiguous memory for userspace |
517 | * @size: allocation size | |
83342314 | 518 | * |
ead04089 REB |
519 | * The resulting memory area is zeroed so it can be mapped to userspace |
520 | * without leaking data. | |
83342314 NP |
521 | */ |
522 | void *vmalloc_user(unsigned long size) | |
523 | { | |
524 | struct vm_struct *area; | |
525 | void *ret; | |
526 | ||
527 | ret = __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL); | |
528 | write_lock(&vmlist_lock); | |
529 | area = __find_vm_area(ret); | |
530 | area->flags |= VM_USERMAP; | |
531 | write_unlock(&vmlist_lock); | |
532 | ||
533 | return ret; | |
534 | } | |
535 | EXPORT_SYMBOL(vmalloc_user); | |
536 | ||
930fc45a CL |
537 | /** |
538 | * vmalloc_node - allocate memory on a specific node | |
930fc45a | 539 | * @size: allocation size |
d44e0780 | 540 | * @node: numa node |
930fc45a CL |
541 | * |
542 | * Allocate enough pages to cover @size from the page level | |
543 | * allocator and map them into contiguous kernel virtual space. | |
544 | * | |
545 | * For tight cotrol over page level allocator and protection flags | |
546 | * use __vmalloc() instead. | |
547 | */ | |
548 | void *vmalloc_node(unsigned long size, int node) | |
549 | { | |
83342314 | 550 | return __vmalloc_node(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL, node); |
930fc45a CL |
551 | } |
552 | EXPORT_SYMBOL(vmalloc_node); | |
553 | ||
4dc3b16b PP |
554 | #ifndef PAGE_KERNEL_EXEC |
555 | # define PAGE_KERNEL_EXEC PAGE_KERNEL | |
556 | #endif | |
557 | ||
1da177e4 LT |
558 | /** |
559 | * vmalloc_exec - allocate virtually contiguous, executable memory | |
1da177e4 LT |
560 | * @size: allocation size |
561 | * | |
562 | * Kernel-internal function to allocate enough pages to cover @size | |
563 | * the page level allocator and map them into contiguous and | |
564 | * executable kernel virtual space. | |
565 | * | |
566 | * For tight cotrol over page level allocator and protection flags | |
567 | * use __vmalloc() instead. | |
568 | */ | |
569 | ||
1da177e4 LT |
570 | void *vmalloc_exec(unsigned long size) |
571 | { | |
572 | return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC); | |
573 | } | |
574 | ||
575 | /** | |
576 | * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) | |
1da177e4 LT |
577 | * @size: allocation size |
578 | * | |
579 | * Allocate enough 32bit PA addressable pages to cover @size from the | |
580 | * page level allocator and map them into contiguous kernel virtual space. | |
581 | */ | |
582 | void *vmalloc_32(unsigned long size) | |
583 | { | |
584 | return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL); | |
585 | } | |
1da177e4 LT |
586 | EXPORT_SYMBOL(vmalloc_32); |
587 | ||
83342314 | 588 | /** |
ead04089 | 589 | * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory |
83342314 | 590 | * @size: allocation size |
ead04089 REB |
591 | * |
592 | * The resulting memory area is 32bit addressable and zeroed so it can be | |
593 | * mapped to userspace without leaking data. | |
83342314 NP |
594 | */ |
595 | void *vmalloc_32_user(unsigned long size) | |
596 | { | |
597 | struct vm_struct *area; | |
598 | void *ret; | |
599 | ||
600 | ret = __vmalloc(size, GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL); | |
601 | write_lock(&vmlist_lock); | |
602 | area = __find_vm_area(ret); | |
603 | area->flags |= VM_USERMAP; | |
604 | write_unlock(&vmlist_lock); | |
605 | ||
606 | return ret; | |
607 | } | |
608 | EXPORT_SYMBOL(vmalloc_32_user); | |
609 | ||
1da177e4 LT |
610 | long vread(char *buf, char *addr, unsigned long count) |
611 | { | |
612 | struct vm_struct *tmp; | |
613 | char *vaddr, *buf_start = buf; | |
614 | unsigned long n; | |
615 | ||
616 | /* Don't allow overflow */ | |
617 | if ((unsigned long) addr + count < count) | |
618 | count = -(unsigned long) addr; | |
619 | ||
620 | read_lock(&vmlist_lock); | |
621 | for (tmp = vmlist; tmp; tmp = tmp->next) { | |
622 | vaddr = (char *) tmp->addr; | |
623 | if (addr >= vaddr + tmp->size - PAGE_SIZE) | |
624 | continue; | |
625 | while (addr < vaddr) { | |
626 | if (count == 0) | |
627 | goto finished; | |
628 | *buf = '\0'; | |
629 | buf++; | |
630 | addr++; | |
631 | count--; | |
632 | } | |
633 | n = vaddr + tmp->size - PAGE_SIZE - addr; | |
634 | do { | |
635 | if (count == 0) | |
636 | goto finished; | |
637 | *buf = *addr; | |
638 | buf++; | |
639 | addr++; | |
640 | count--; | |
641 | } while (--n > 0); | |
642 | } | |
643 | finished: | |
644 | read_unlock(&vmlist_lock); | |
645 | return buf - buf_start; | |
646 | } | |
647 | ||
648 | long vwrite(char *buf, char *addr, unsigned long count) | |
649 | { | |
650 | struct vm_struct *tmp; | |
651 | char *vaddr, *buf_start = buf; | |
652 | unsigned long n; | |
653 | ||
654 | /* Don't allow overflow */ | |
655 | if ((unsigned long) addr + count < count) | |
656 | count = -(unsigned long) addr; | |
657 | ||
658 | read_lock(&vmlist_lock); | |
659 | for (tmp = vmlist; tmp; tmp = tmp->next) { | |
660 | vaddr = (char *) tmp->addr; | |
661 | if (addr >= vaddr + tmp->size - PAGE_SIZE) | |
662 | continue; | |
663 | while (addr < vaddr) { | |
664 | if (count == 0) | |
665 | goto finished; | |
666 | buf++; | |
667 | addr++; | |
668 | count--; | |
669 | } | |
670 | n = vaddr + tmp->size - PAGE_SIZE - addr; | |
671 | do { | |
672 | if (count == 0) | |
673 | goto finished; | |
674 | *addr = *buf; | |
675 | buf++; | |
676 | addr++; | |
677 | count--; | |
678 | } while (--n > 0); | |
679 | } | |
680 | finished: | |
681 | read_unlock(&vmlist_lock); | |
682 | return buf - buf_start; | |
683 | } | |
83342314 NP |
684 | |
685 | /** | |
686 | * remap_vmalloc_range - map vmalloc pages to userspace | |
83342314 NP |
687 | * @vma: vma to cover (map full range of vma) |
688 | * @addr: vmalloc memory | |
689 | * @pgoff: number of pages into addr before first page to map | |
690 | * @returns: 0 for success, -Exxx on failure | |
691 | * | |
692 | * This function checks that addr is a valid vmalloc'ed area, and | |
693 | * that it is big enough to cover the vma. Will return failure if | |
694 | * that criteria isn't met. | |
695 | * | |
696 | * Similar to remap_pfn_range (see mm/memory.c) | |
697 | */ | |
698 | int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, | |
699 | unsigned long pgoff) | |
700 | { | |
701 | struct vm_struct *area; | |
702 | unsigned long uaddr = vma->vm_start; | |
703 | unsigned long usize = vma->vm_end - vma->vm_start; | |
704 | int ret; | |
705 | ||
706 | if ((PAGE_SIZE-1) & (unsigned long)addr) | |
707 | return -EINVAL; | |
708 | ||
709 | read_lock(&vmlist_lock); | |
710 | area = __find_vm_area(addr); | |
711 | if (!area) | |
712 | goto out_einval_locked; | |
713 | ||
714 | if (!(area->flags & VM_USERMAP)) | |
715 | goto out_einval_locked; | |
716 | ||
717 | if (usize + (pgoff << PAGE_SHIFT) > area->size - PAGE_SIZE) | |
718 | goto out_einval_locked; | |
719 | read_unlock(&vmlist_lock); | |
720 | ||
721 | addr += pgoff << PAGE_SHIFT; | |
722 | do { | |
723 | struct page *page = vmalloc_to_page(addr); | |
724 | ret = vm_insert_page(vma, uaddr, page); | |
725 | if (ret) | |
726 | return ret; | |
727 | ||
728 | uaddr += PAGE_SIZE; | |
729 | addr += PAGE_SIZE; | |
730 | usize -= PAGE_SIZE; | |
731 | } while (usize > 0); | |
732 | ||
733 | /* Prevent "things" like memory migration? VM_flags need a cleanup... */ | |
734 | vma->vm_flags |= VM_RESERVED; | |
735 | ||
736 | return ret; | |
737 | ||
738 | out_einval_locked: | |
739 | read_unlock(&vmlist_lock); | |
740 | return -EINVAL; | |
741 | } | |
742 | EXPORT_SYMBOL(remap_vmalloc_range); | |
743 |