Contents of /alx-src/tags/kernel26-2.6.12-alx-r9/mm/vmalloc.c
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Wed Mar 4 11:03:09 2009 UTC (15 years, 6 months ago) by niro
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Wed Mar 4 11:03:09 2009 UTC (15 years, 6 months ago) by niro
File MIME type: text/plain
File size: 13378 byte(s)
Tag kernel26-2.6.12-alx-r9
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 |
8 | */ |
9 | |
10 | #include <linux/mm.h> |
11 | #include <linux/module.h> |
12 | #include <linux/highmem.h> |
13 | #include <linux/slab.h> |
14 | #include <linux/spinlock.h> |
15 | #include <linux/interrupt.h> |
16 | |
17 | #include <linux/vmalloc.h> |
18 | |
19 | #include <asm/uaccess.h> |
20 | #include <asm/tlbflush.h> |
21 | |
22 | |
23 | DEFINE_RWLOCK(vmlist_lock); |
24 | struct vm_struct *vmlist; |
25 | |
26 | static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end) |
27 | { |
28 | pte_t *pte; |
29 | |
30 | pte = pte_offset_kernel(pmd, addr); |
31 | do { |
32 | pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte); |
33 | WARN_ON(!pte_none(ptent) && !pte_present(ptent)); |
34 | } while (pte++, addr += PAGE_SIZE, addr != end); |
35 | } |
36 | |
37 | static inline void vunmap_pmd_range(pud_t *pud, unsigned long addr, |
38 | unsigned long end) |
39 | { |
40 | pmd_t *pmd; |
41 | unsigned long next; |
42 | |
43 | pmd = pmd_offset(pud, addr); |
44 | do { |
45 | next = pmd_addr_end(addr, end); |
46 | if (pmd_none_or_clear_bad(pmd)) |
47 | continue; |
48 | vunmap_pte_range(pmd, addr, next); |
49 | } while (pmd++, addr = next, addr != end); |
50 | } |
51 | |
52 | static inline void vunmap_pud_range(pgd_t *pgd, unsigned long addr, |
53 | unsigned long end) |
54 | { |
55 | pud_t *pud; |
56 | unsigned long next; |
57 | |
58 | pud = pud_offset(pgd, addr); |
59 | do { |
60 | next = pud_addr_end(addr, end); |
61 | if (pud_none_or_clear_bad(pud)) |
62 | continue; |
63 | vunmap_pmd_range(pud, addr, next); |
64 | } while (pud++, addr = next, addr != end); |
65 | } |
66 | |
67 | void unmap_vm_area(struct vm_struct *area) |
68 | { |
69 | pgd_t *pgd; |
70 | unsigned long next; |
71 | unsigned long addr = (unsigned long) area->addr; |
72 | unsigned long end = addr + area->size; |
73 | |
74 | BUG_ON(addr >= end); |
75 | pgd = pgd_offset_k(addr); |
76 | flush_cache_vunmap(addr, end); |
77 | do { |
78 | next = pgd_addr_end(addr, end); |
79 | if (pgd_none_or_clear_bad(pgd)) |
80 | continue; |
81 | vunmap_pud_range(pgd, addr, next); |
82 | } while (pgd++, addr = next, addr != end); |
83 | flush_tlb_kernel_range((unsigned long) area->addr, end); |
84 | } |
85 | |
86 | static int vmap_pte_range(pmd_t *pmd, unsigned long addr, |
87 | unsigned long end, pgprot_t prot, struct page ***pages) |
88 | { |
89 | pte_t *pte; |
90 | |
91 | pte = pte_alloc_kernel(&init_mm, pmd, addr); |
92 | if (!pte) |
93 | return -ENOMEM; |
94 | do { |
95 | struct page *page = **pages; |
96 | WARN_ON(!pte_none(*pte)); |
97 | if (!page) |
98 | return -ENOMEM; |
99 | set_pte_at(&init_mm, addr, pte, mk_pte(page, prot)); |
100 | (*pages)++; |
101 | } while (pte++, addr += PAGE_SIZE, addr != end); |
102 | return 0; |
103 | } |
104 | |
105 | static inline int vmap_pmd_range(pud_t *pud, unsigned long addr, |
106 | unsigned long end, pgprot_t prot, struct page ***pages) |
107 | { |
108 | pmd_t *pmd; |
109 | unsigned long next; |
110 | |
111 | pmd = pmd_alloc(&init_mm, pud, addr); |
112 | if (!pmd) |
113 | return -ENOMEM; |
114 | do { |
115 | next = pmd_addr_end(addr, end); |
116 | if (vmap_pte_range(pmd, addr, next, prot, pages)) |
117 | return -ENOMEM; |
118 | } while (pmd++, addr = next, addr != end); |
119 | return 0; |
120 | } |
121 | |
122 | static inline int vmap_pud_range(pgd_t *pgd, unsigned long addr, |
123 | unsigned long end, pgprot_t prot, struct page ***pages) |
124 | { |
125 | pud_t *pud; |
126 | unsigned long next; |
127 | |
128 | pud = pud_alloc(&init_mm, pgd, addr); |
129 | if (!pud) |
130 | return -ENOMEM; |
131 | do { |
132 | next = pud_addr_end(addr, end); |
133 | if (vmap_pmd_range(pud, addr, next, prot, pages)) |
134 | return -ENOMEM; |
135 | } while (pud++, addr = next, addr != end); |
136 | return 0; |
137 | } |
138 | |
139 | int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages) |
140 | { |
141 | pgd_t *pgd; |
142 | unsigned long next; |
143 | unsigned long addr = (unsigned long) area->addr; |
144 | unsigned long end = addr + area->size - PAGE_SIZE; |
145 | int err; |
146 | |
147 | BUG_ON(addr >= end); |
148 | pgd = pgd_offset_k(addr); |
149 | spin_lock(&init_mm.page_table_lock); |
150 | do { |
151 | next = pgd_addr_end(addr, end); |
152 | err = vmap_pud_range(pgd, addr, next, prot, pages); |
153 | if (err) |
154 | break; |
155 | } while (pgd++, addr = next, addr != end); |
156 | spin_unlock(&init_mm.page_table_lock); |
157 | flush_cache_vmap((unsigned long) area->addr, end); |
158 | return err; |
159 | } |
160 | |
161 | #define IOREMAP_MAX_ORDER (7 + PAGE_SHIFT) /* 128 pages */ |
162 | |
163 | struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags, |
164 | unsigned long start, unsigned long end) |
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 | |
183 | area = kmalloc(sizeof(*area), GFP_KERNEL); |
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 | |
236 | /** |
237 | * get_vm_area - reserve a contingous kernel virtual area |
238 | * |
239 | * @size: size of the area |
240 | * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC |
241 | * |
242 | * Search an area of @size in the kernel virtual mapping area, |
243 | * and reserved it for out purposes. Returns the area descriptor |
244 | * on success or %NULL on failure. |
245 | */ |
246 | struct vm_struct *get_vm_area(unsigned long size, unsigned long flags) |
247 | { |
248 | return __get_vm_area(size, flags, VMALLOC_START, VMALLOC_END); |
249 | } |
250 | |
251 | /* Caller must hold vmlist_lock */ |
252 | struct vm_struct *__remove_vm_area(void *addr) |
253 | { |
254 | struct vm_struct **p, *tmp; |
255 | |
256 | for (p = &vmlist ; (tmp = *p) != NULL ;p = &tmp->next) { |
257 | if (tmp->addr == addr) |
258 | goto found; |
259 | } |
260 | return NULL; |
261 | |
262 | found: |
263 | unmap_vm_area(tmp); |
264 | *p = tmp->next; |
265 | |
266 | /* |
267 | * Remove the guard page. |
268 | */ |
269 | tmp->size -= PAGE_SIZE; |
270 | return tmp; |
271 | } |
272 | |
273 | /** |
274 | * remove_vm_area - find and remove a contingous kernel virtual area |
275 | * |
276 | * @addr: base address |
277 | * |
278 | * Search for the kernel VM area starting at @addr, and remove it. |
279 | * This function returns the found VM area, but using it is NOT safe |
280 | * on SMP machines, except for its size or flags. |
281 | */ |
282 | struct vm_struct *remove_vm_area(void *addr) |
283 | { |
284 | struct vm_struct *v; |
285 | write_lock(&vmlist_lock); |
286 | v = __remove_vm_area(addr); |
287 | write_unlock(&vmlist_lock); |
288 | return v; |
289 | } |
290 | |
291 | void __vunmap(void *addr, int deallocate_pages) |
292 | { |
293 | struct vm_struct *area; |
294 | |
295 | if (!addr) |
296 | return; |
297 | |
298 | if ((PAGE_SIZE-1) & (unsigned long)addr) { |
299 | printk(KERN_ERR "Trying to vfree() bad address (%p)\n", addr); |
300 | WARN_ON(1); |
301 | return; |
302 | } |
303 | |
304 | area = remove_vm_area(addr); |
305 | if (unlikely(!area)) { |
306 | printk(KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n", |
307 | addr); |
308 | WARN_ON(1); |
309 | return; |
310 | } |
311 | |
312 | if (deallocate_pages) { |
313 | int i; |
314 | |
315 | for (i = 0; i < area->nr_pages; i++) { |
316 | if (unlikely(!area->pages[i])) |
317 | BUG(); |
318 | __free_page(area->pages[i]); |
319 | } |
320 | |
321 | if (area->nr_pages > PAGE_SIZE/sizeof(struct page *)) |
322 | vfree(area->pages); |
323 | else |
324 | kfree(area->pages); |
325 | } |
326 | |
327 | kfree(area); |
328 | return; |
329 | } |
330 | |
331 | /** |
332 | * vfree - release memory allocated by vmalloc() |
333 | * |
334 | * @addr: memory base address |
335 | * |
336 | * Free the virtually contiguous memory area starting at @addr, as |
337 | * obtained from vmalloc(), vmalloc_32() or __vmalloc(). |
338 | * |
339 | * May not be called in interrupt context. |
340 | */ |
341 | void vfree(void *addr) |
342 | { |
343 | BUG_ON(in_interrupt()); |
344 | __vunmap(addr, 1); |
345 | } |
346 | |
347 | EXPORT_SYMBOL(vfree); |
348 | |
349 | /** |
350 | * vunmap - release virtual mapping obtained by vmap() |
351 | * |
352 | * @addr: memory base address |
353 | * |
354 | * Free the virtually contiguous memory area starting at @addr, |
355 | * which was created from the page array passed to vmap(). |
356 | * |
357 | * May not be called in interrupt context. |
358 | */ |
359 | void vunmap(void *addr) |
360 | { |
361 | BUG_ON(in_interrupt()); |
362 | __vunmap(addr, 0); |
363 | } |
364 | |
365 | EXPORT_SYMBOL(vunmap); |
366 | |
367 | /** |
368 | * vmap - map an array of pages into virtually contiguous space |
369 | * |
370 | * @pages: array of page pointers |
371 | * @count: number of pages to map |
372 | * @flags: vm_area->flags |
373 | * @prot: page protection for the mapping |
374 | * |
375 | * Maps @count pages from @pages into contiguous kernel virtual |
376 | * space. |
377 | */ |
378 | void *vmap(struct page **pages, unsigned int count, |
379 | unsigned long flags, pgprot_t prot) |
380 | { |
381 | struct vm_struct *area; |
382 | |
383 | if (count > num_physpages) |
384 | return NULL; |
385 | |
386 | area = get_vm_area((count << PAGE_SHIFT), flags); |
387 | if (!area) |
388 | return NULL; |
389 | if (map_vm_area(area, prot, &pages)) { |
390 | vunmap(area->addr); |
391 | return NULL; |
392 | } |
393 | |
394 | return area->addr; |
395 | } |
396 | |
397 | EXPORT_SYMBOL(vmap); |
398 | |
399 | void *__vmalloc_area(struct vm_struct *area, unsigned int __nocast gfp_mask, pgprot_t prot) |
400 | { |
401 | struct page **pages; |
402 | unsigned int nr_pages, array_size, i; |
403 | |
404 | nr_pages = (area->size - PAGE_SIZE) >> PAGE_SHIFT; |
405 | array_size = (nr_pages * sizeof(struct page *)); |
406 | |
407 | area->nr_pages = nr_pages; |
408 | /* Please note that the recursion is strictly bounded. */ |
409 | if (array_size > PAGE_SIZE) |
410 | pages = __vmalloc(array_size, gfp_mask, PAGE_KERNEL); |
411 | else |
412 | pages = kmalloc(array_size, (gfp_mask & ~__GFP_HIGHMEM)); |
413 | area->pages = pages; |
414 | if (!area->pages) { |
415 | remove_vm_area(area->addr); |
416 | kfree(area); |
417 | return NULL; |
418 | } |
419 | memset(area->pages, 0, array_size); |
420 | |
421 | for (i = 0; i < area->nr_pages; i++) { |
422 | area->pages[i] = alloc_page(gfp_mask); |
423 | if (unlikely(!area->pages[i])) { |
424 | /* Successfully allocated i pages, free them in __vunmap() */ |
425 | area->nr_pages = i; |
426 | goto fail; |
427 | } |
428 | } |
429 | |
430 | if (map_vm_area(area, prot, &pages)) |
431 | goto fail; |
432 | return area->addr; |
433 | |
434 | fail: |
435 | vfree(area->addr); |
436 | return NULL; |
437 | } |
438 | |
439 | /** |
440 | * __vmalloc - allocate virtually contiguous memory |
441 | * |
442 | * @size: allocation size |
443 | * @gfp_mask: flags for the page level allocator |
444 | * @prot: protection mask for the allocated pages |
445 | * |
446 | * Allocate enough pages to cover @size from the page level |
447 | * allocator with @gfp_mask flags. Map them into contiguous |
448 | * kernel virtual space, using a pagetable protection of @prot. |
449 | */ |
450 | void *__vmalloc(unsigned long size, unsigned int __nocast gfp_mask, pgprot_t prot) |
451 | { |
452 | struct vm_struct *area; |
453 | |
454 | size = PAGE_ALIGN(size); |
455 | if (!size || (size >> PAGE_SHIFT) > num_physpages) |
456 | return NULL; |
457 | |
458 | area = get_vm_area(size, VM_ALLOC); |
459 | if (!area) |
460 | return NULL; |
461 | |
462 | return __vmalloc_area(area, gfp_mask, prot); |
463 | } |
464 | |
465 | EXPORT_SYMBOL(__vmalloc); |
466 | |
467 | /** |
468 | * vmalloc - allocate virtually contiguous memory |
469 | * |
470 | * @size: allocation size |
471 | * |
472 | * Allocate enough pages to cover @size from the page level |
473 | * allocator and map them into contiguous kernel virtual space. |
474 | * |
475 | * For tight cotrol over page level allocator and protection flags |
476 | * use __vmalloc() instead. |
477 | */ |
478 | void *vmalloc(unsigned long size) |
479 | { |
480 | return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL); |
481 | } |
482 | |
483 | EXPORT_SYMBOL(vmalloc); |
484 | |
485 | #ifndef PAGE_KERNEL_EXEC |
486 | # define PAGE_KERNEL_EXEC PAGE_KERNEL |
487 | #endif |
488 | |
489 | /** |
490 | * vmalloc_exec - allocate virtually contiguous, executable memory |
491 | * |
492 | * @size: allocation size |
493 | * |
494 | * Kernel-internal function to allocate enough pages to cover @size |
495 | * the page level allocator and map them into contiguous and |
496 | * executable kernel virtual space. |
497 | * |
498 | * For tight cotrol over page level allocator and protection flags |
499 | * use __vmalloc() instead. |
500 | */ |
501 | |
502 | void *vmalloc_exec(unsigned long size) |
503 | { |
504 | return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC); |
505 | } |
506 | |
507 | /** |
508 | * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) |
509 | * |
510 | * @size: allocation size |
511 | * |
512 | * Allocate enough 32bit PA addressable pages to cover @size from the |
513 | * page level allocator and map them into contiguous kernel virtual space. |
514 | */ |
515 | void *vmalloc_32(unsigned long size) |
516 | { |
517 | return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL); |
518 | } |
519 | |
520 | EXPORT_SYMBOL(vmalloc_32); |
521 | |
522 | long vread(char *buf, char *addr, unsigned long count) |
523 | { |
524 | struct vm_struct *tmp; |
525 | char *vaddr, *buf_start = buf; |
526 | unsigned long n; |
527 | |
528 | /* Don't allow overflow */ |
529 | if ((unsigned long) addr + count < count) |
530 | count = -(unsigned long) addr; |
531 | |
532 | read_lock(&vmlist_lock); |
533 | for (tmp = vmlist; tmp; tmp = tmp->next) { |
534 | vaddr = (char *) tmp->addr; |
535 | if (addr >= vaddr + tmp->size - PAGE_SIZE) |
536 | continue; |
537 | while (addr < vaddr) { |
538 | if (count == 0) |
539 | goto finished; |
540 | *buf = '\0'; |
541 | buf++; |
542 | addr++; |
543 | count--; |
544 | } |
545 | n = vaddr + tmp->size - PAGE_SIZE - addr; |
546 | do { |
547 | if (count == 0) |
548 | goto finished; |
549 | *buf = *addr; |
550 | buf++; |
551 | addr++; |
552 | count--; |
553 | } while (--n > 0); |
554 | } |
555 | finished: |
556 | read_unlock(&vmlist_lock); |
557 | return buf - buf_start; |
558 | } |
559 | |
560 | long vwrite(char *buf, char *addr, unsigned long count) |
561 | { |
562 | struct vm_struct *tmp; |
563 | char *vaddr, *buf_start = buf; |
564 | unsigned long n; |
565 | |
566 | /* Don't allow overflow */ |
567 | if ((unsigned long) addr + count < count) |
568 | count = -(unsigned long) addr; |
569 | |
570 | read_lock(&vmlist_lock); |
571 | for (tmp = vmlist; tmp; tmp = tmp->next) { |
572 | vaddr = (char *) tmp->addr; |
573 | if (addr >= vaddr + tmp->size - PAGE_SIZE) |
574 | continue; |
575 | while (addr < vaddr) { |
576 | if (count == 0) |
577 | goto finished; |
578 | buf++; |
579 | addr++; |
580 | count--; |
581 | } |
582 | n = vaddr + tmp->size - PAGE_SIZE - addr; |
583 | do { |
584 | if (count == 0) |
585 | goto finished; |
586 | *addr = *buf; |
587 | buf++; |
588 | addr++; |
589 | count--; |
590 | } while (--n > 0); |
591 | } |
592 | finished: |
593 | read_unlock(&vmlist_lock); |
594 | return buf - buf_start; |
595 | } |