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ad9a8612 JF |
1 | /****************************************************************************** |
2 | * grant_table.c | |
3 | * | |
4 | * Granting foreign access to our memory reservation. | |
5 | * | |
6 | * Copyright (c) 2005-2006, Christopher Clark | |
7 | * Copyright (c) 2004-2005, K A Fraser | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License version 2 | |
11 | * as published by the Free Software Foundation; or, when distributed | |
12 | * separately from the Linux kernel or incorporated into other | |
13 | * software packages, subject to the following license: | |
14 | * | |
15 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
16 | * of this source file (the "Software"), to deal in the Software without | |
17 | * restriction, including without limitation the rights to use, copy, modify, | |
18 | * merge, publish, distribute, sublicense, and/or sell copies of the Software, | |
19 | * and to permit persons to whom the Software is furnished to do so, subject to | |
20 | * the following conditions: | |
21 | * | |
22 | * The above copyright notice and this permission notice shall be included in | |
23 | * all copies or substantial portions of the Software. | |
24 | * | |
25 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
26 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
27 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
28 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
29 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | |
30 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS | |
31 | * IN THE SOFTWARE. | |
32 | */ | |
33 | ||
34 | #include <linux/module.h> | |
35 | #include <linux/sched.h> | |
36 | #include <linux/mm.h> | |
37 | #include <linux/vmalloc.h> | |
38 | #include <linux/uaccess.h> | |
39 | ||
40 | #include <xen/interface/xen.h> | |
41 | #include <xen/page.h> | |
42 | #include <xen/grant_table.h> | |
ecbf29cd | 43 | #include <asm/xen/hypercall.h> |
ad9a8612 JF |
44 | |
45 | #include <asm/pgtable.h> | |
46 | #include <asm/sync_bitops.h> | |
47 | ||
48 | ||
49 | /* External tools reserve first few grant table entries. */ | |
50 | #define NR_RESERVED_ENTRIES 8 | |
51 | #define GNTTAB_LIST_END 0xffffffff | |
52 | #define GREFS_PER_GRANT_FRAME (PAGE_SIZE / sizeof(struct grant_entry)) | |
53 | ||
54 | static grant_ref_t **gnttab_list; | |
55 | static unsigned int nr_grant_frames; | |
56 | static unsigned int boot_max_nr_grant_frames; | |
57 | static int gnttab_free_count; | |
58 | static grant_ref_t gnttab_free_head; | |
59 | static DEFINE_SPINLOCK(gnttab_list_lock); | |
60 | ||
61 | static struct grant_entry *shared; | |
62 | ||
63 | static struct gnttab_free_callback *gnttab_free_callback_list; | |
64 | ||
65 | static int gnttab_expand(unsigned int req_entries); | |
66 | ||
67 | #define RPP (PAGE_SIZE / sizeof(grant_ref_t)) | |
68 | ||
69 | static inline grant_ref_t *__gnttab_entry(grant_ref_t entry) | |
70 | { | |
71 | return &gnttab_list[(entry) / RPP][(entry) % RPP]; | |
72 | } | |
73 | /* This can be used as an l-value */ | |
74 | #define gnttab_entry(entry) (*__gnttab_entry(entry)) | |
75 | ||
76 | static int get_free_entries(unsigned count) | |
77 | { | |
78 | unsigned long flags; | |
79 | int ref, rc; | |
80 | grant_ref_t head; | |
81 | ||
82 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
83 | ||
84 | if ((gnttab_free_count < count) && | |
85 | ((rc = gnttab_expand(count - gnttab_free_count)) < 0)) { | |
86 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
87 | return rc; | |
88 | } | |
89 | ||
90 | ref = head = gnttab_free_head; | |
91 | gnttab_free_count -= count; | |
92 | while (count-- > 1) | |
93 | head = gnttab_entry(head); | |
94 | gnttab_free_head = gnttab_entry(head); | |
95 | gnttab_entry(head) = GNTTAB_LIST_END; | |
96 | ||
97 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
98 | ||
99 | return ref; | |
100 | } | |
101 | ||
102 | static void do_free_callbacks(void) | |
103 | { | |
104 | struct gnttab_free_callback *callback, *next; | |
105 | ||
106 | callback = gnttab_free_callback_list; | |
107 | gnttab_free_callback_list = NULL; | |
108 | ||
109 | while (callback != NULL) { | |
110 | next = callback->next; | |
111 | if (gnttab_free_count >= callback->count) { | |
112 | callback->next = NULL; | |
113 | callback->fn(callback->arg); | |
114 | } else { | |
115 | callback->next = gnttab_free_callback_list; | |
116 | gnttab_free_callback_list = callback; | |
117 | } | |
118 | callback = next; | |
119 | } | |
120 | } | |
121 | ||
122 | static inline void check_free_callbacks(void) | |
123 | { | |
124 | if (unlikely(gnttab_free_callback_list)) | |
125 | do_free_callbacks(); | |
126 | } | |
127 | ||
128 | static void put_free_entry(grant_ref_t ref) | |
129 | { | |
130 | unsigned long flags; | |
131 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
132 | gnttab_entry(ref) = gnttab_free_head; | |
133 | gnttab_free_head = ref; | |
134 | gnttab_free_count++; | |
135 | check_free_callbacks(); | |
136 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
137 | } | |
138 | ||
139 | static void update_grant_entry(grant_ref_t ref, domid_t domid, | |
140 | unsigned long frame, unsigned flags) | |
141 | { | |
142 | /* | |
143 | * Introducing a valid entry into the grant table: | |
144 | * 1. Write ent->domid. | |
145 | * 2. Write ent->frame: | |
146 | * GTF_permit_access: Frame to which access is permitted. | |
147 | * GTF_accept_transfer: Pseudo-phys frame slot being filled by new | |
148 | * frame, or zero if none. | |
149 | * 3. Write memory barrier (WMB). | |
150 | * 4. Write ent->flags, inc. valid type. | |
151 | */ | |
152 | shared[ref].frame = frame; | |
153 | shared[ref].domid = domid; | |
154 | wmb(); | |
155 | shared[ref].flags = flags; | |
156 | } | |
157 | ||
158 | /* | |
159 | * Public grant-issuing interface functions | |
160 | */ | |
161 | void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid, | |
162 | unsigned long frame, int readonly) | |
163 | { | |
164 | update_grant_entry(ref, domid, frame, | |
165 | GTF_permit_access | (readonly ? GTF_readonly : 0)); | |
166 | } | |
167 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_ref); | |
168 | ||
169 | int gnttab_grant_foreign_access(domid_t domid, unsigned long frame, | |
170 | int readonly) | |
171 | { | |
172 | int ref; | |
173 | ||
174 | ref = get_free_entries(1); | |
175 | if (unlikely(ref < 0)) | |
176 | return -ENOSPC; | |
177 | ||
178 | gnttab_grant_foreign_access_ref(ref, domid, frame, readonly); | |
179 | ||
180 | return ref; | |
181 | } | |
182 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access); | |
183 | ||
184 | int gnttab_query_foreign_access(grant_ref_t ref) | |
185 | { | |
186 | u16 nflags; | |
187 | ||
188 | nflags = shared[ref].flags; | |
189 | ||
190 | return (nflags & (GTF_reading|GTF_writing)); | |
191 | } | |
192 | EXPORT_SYMBOL_GPL(gnttab_query_foreign_access); | |
193 | ||
194 | int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly) | |
195 | { | |
196 | u16 flags, nflags; | |
197 | ||
198 | nflags = shared[ref].flags; | |
199 | do { | |
200 | flags = nflags; | |
201 | if (flags & (GTF_reading|GTF_writing)) { | |
202 | printk(KERN_ALERT "WARNING: g.e. still in use!\n"); | |
203 | return 0; | |
204 | } | |
205 | } while ((nflags = sync_cmpxchg(&shared[ref].flags, flags, 0)) != flags); | |
206 | ||
207 | return 1; | |
208 | } | |
209 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_access_ref); | |
210 | ||
211 | void gnttab_end_foreign_access(grant_ref_t ref, int readonly, | |
212 | unsigned long page) | |
213 | { | |
214 | if (gnttab_end_foreign_access_ref(ref, readonly)) { | |
215 | put_free_entry(ref); | |
216 | if (page != 0) | |
217 | free_page(page); | |
218 | } else { | |
219 | /* XXX This needs to be fixed so that the ref and page are | |
220 | placed on a list to be freed up later. */ | |
221 | printk(KERN_WARNING | |
222 | "WARNING: leaking g.e. and page still in use!\n"); | |
223 | } | |
224 | } | |
225 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_access); | |
226 | ||
227 | int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn) | |
228 | { | |
229 | int ref; | |
230 | ||
231 | ref = get_free_entries(1); | |
232 | if (unlikely(ref < 0)) | |
233 | return -ENOSPC; | |
234 | gnttab_grant_foreign_transfer_ref(ref, domid, pfn); | |
235 | ||
236 | return ref; | |
237 | } | |
238 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer); | |
239 | ||
240 | void gnttab_grant_foreign_transfer_ref(grant_ref_t ref, domid_t domid, | |
241 | unsigned long pfn) | |
242 | { | |
243 | update_grant_entry(ref, domid, pfn, GTF_accept_transfer); | |
244 | } | |
245 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer_ref); | |
246 | ||
247 | unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref) | |
248 | { | |
249 | unsigned long frame; | |
250 | u16 flags; | |
251 | ||
252 | /* | |
253 | * If a transfer is not even yet started, try to reclaim the grant | |
254 | * reference and return failure (== 0). | |
255 | */ | |
256 | while (!((flags = shared[ref].flags) & GTF_transfer_committed)) { | |
257 | if (sync_cmpxchg(&shared[ref].flags, flags, 0) == flags) | |
258 | return 0; | |
259 | cpu_relax(); | |
260 | } | |
261 | ||
262 | /* If a transfer is in progress then wait until it is completed. */ | |
263 | while (!(flags & GTF_transfer_completed)) { | |
264 | flags = shared[ref].flags; | |
265 | cpu_relax(); | |
266 | } | |
267 | ||
268 | rmb(); /* Read the frame number /after/ reading completion status. */ | |
269 | frame = shared[ref].frame; | |
270 | BUG_ON(frame == 0); | |
271 | ||
272 | return frame; | |
273 | } | |
274 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer_ref); | |
275 | ||
276 | unsigned long gnttab_end_foreign_transfer(grant_ref_t ref) | |
277 | { | |
278 | unsigned long frame = gnttab_end_foreign_transfer_ref(ref); | |
279 | put_free_entry(ref); | |
280 | return frame; | |
281 | } | |
282 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer); | |
283 | ||
284 | void gnttab_free_grant_reference(grant_ref_t ref) | |
285 | { | |
286 | put_free_entry(ref); | |
287 | } | |
288 | EXPORT_SYMBOL_GPL(gnttab_free_grant_reference); | |
289 | ||
290 | void gnttab_free_grant_references(grant_ref_t head) | |
291 | { | |
292 | grant_ref_t ref; | |
293 | unsigned long flags; | |
294 | int count = 1; | |
295 | if (head == GNTTAB_LIST_END) | |
296 | return; | |
297 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
298 | ref = head; | |
299 | while (gnttab_entry(ref) != GNTTAB_LIST_END) { | |
300 | ref = gnttab_entry(ref); | |
301 | count++; | |
302 | } | |
303 | gnttab_entry(ref) = gnttab_free_head; | |
304 | gnttab_free_head = head; | |
305 | gnttab_free_count += count; | |
306 | check_free_callbacks(); | |
307 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
308 | } | |
309 | EXPORT_SYMBOL_GPL(gnttab_free_grant_references); | |
310 | ||
311 | int gnttab_alloc_grant_references(u16 count, grant_ref_t *head) | |
312 | { | |
313 | int h = get_free_entries(count); | |
314 | ||
315 | if (h < 0) | |
316 | return -ENOSPC; | |
317 | ||
318 | *head = h; | |
319 | ||
320 | return 0; | |
321 | } | |
322 | EXPORT_SYMBOL_GPL(gnttab_alloc_grant_references); | |
323 | ||
324 | int gnttab_empty_grant_references(const grant_ref_t *private_head) | |
325 | { | |
326 | return (*private_head == GNTTAB_LIST_END); | |
327 | } | |
328 | EXPORT_SYMBOL_GPL(gnttab_empty_grant_references); | |
329 | ||
330 | int gnttab_claim_grant_reference(grant_ref_t *private_head) | |
331 | { | |
332 | grant_ref_t g = *private_head; | |
333 | if (unlikely(g == GNTTAB_LIST_END)) | |
334 | return -ENOSPC; | |
335 | *private_head = gnttab_entry(g); | |
336 | return g; | |
337 | } | |
338 | EXPORT_SYMBOL_GPL(gnttab_claim_grant_reference); | |
339 | ||
340 | void gnttab_release_grant_reference(grant_ref_t *private_head, | |
341 | grant_ref_t release) | |
342 | { | |
343 | gnttab_entry(release) = *private_head; | |
344 | *private_head = release; | |
345 | } | |
346 | EXPORT_SYMBOL_GPL(gnttab_release_grant_reference); | |
347 | ||
348 | void gnttab_request_free_callback(struct gnttab_free_callback *callback, | |
349 | void (*fn)(void *), void *arg, u16 count) | |
350 | { | |
351 | unsigned long flags; | |
352 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
353 | if (callback->next) | |
354 | goto out; | |
355 | callback->fn = fn; | |
356 | callback->arg = arg; | |
357 | callback->count = count; | |
358 | callback->next = gnttab_free_callback_list; | |
359 | gnttab_free_callback_list = callback; | |
360 | check_free_callbacks(); | |
361 | out: | |
362 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
363 | } | |
364 | EXPORT_SYMBOL_GPL(gnttab_request_free_callback); | |
365 | ||
366 | void gnttab_cancel_free_callback(struct gnttab_free_callback *callback) | |
367 | { | |
368 | struct gnttab_free_callback **pcb; | |
369 | unsigned long flags; | |
370 | ||
371 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
372 | for (pcb = &gnttab_free_callback_list; *pcb; pcb = &(*pcb)->next) { | |
373 | if (*pcb == callback) { | |
374 | *pcb = callback->next; | |
375 | break; | |
376 | } | |
377 | } | |
378 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
379 | } | |
380 | EXPORT_SYMBOL_GPL(gnttab_cancel_free_callback); | |
381 | ||
382 | static int grow_gnttab_list(unsigned int more_frames) | |
383 | { | |
384 | unsigned int new_nr_grant_frames, extra_entries, i; | |
bbc60c18 | 385 | unsigned int nr_glist_frames, new_nr_glist_frames; |
ad9a8612 JF |
386 | |
387 | new_nr_grant_frames = nr_grant_frames + more_frames; | |
388 | extra_entries = more_frames * GREFS_PER_GRANT_FRAME; | |
389 | ||
bbc60c18 MAEM |
390 | nr_glist_frames = (nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP; |
391 | new_nr_glist_frames = | |
392 | (new_nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP; | |
393 | for (i = nr_glist_frames; i < new_nr_glist_frames; i++) { | |
ad9a8612 JF |
394 | gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_ATOMIC); |
395 | if (!gnttab_list[i]) | |
396 | goto grow_nomem; | |
397 | } | |
398 | ||
399 | ||
400 | for (i = GREFS_PER_GRANT_FRAME * nr_grant_frames; | |
401 | i < GREFS_PER_GRANT_FRAME * new_nr_grant_frames - 1; i++) | |
402 | gnttab_entry(i) = i + 1; | |
403 | ||
404 | gnttab_entry(i) = gnttab_free_head; | |
405 | gnttab_free_head = GREFS_PER_GRANT_FRAME * nr_grant_frames; | |
406 | gnttab_free_count += extra_entries; | |
407 | ||
408 | nr_grant_frames = new_nr_grant_frames; | |
409 | ||
410 | check_free_callbacks(); | |
411 | ||
412 | return 0; | |
413 | ||
414 | grow_nomem: | |
bbc60c18 | 415 | for ( ; i >= nr_glist_frames; i--) |
ad9a8612 JF |
416 | free_page((unsigned long) gnttab_list[i]); |
417 | return -ENOMEM; | |
418 | } | |
419 | ||
420 | static unsigned int __max_nr_grant_frames(void) | |
421 | { | |
422 | struct gnttab_query_size query; | |
423 | int rc; | |
424 | ||
425 | query.dom = DOMID_SELF; | |
426 | ||
427 | rc = HYPERVISOR_grant_table_op(GNTTABOP_query_size, &query, 1); | |
428 | if ((rc < 0) || (query.status != GNTST_okay)) | |
429 | return 4; /* Legacy max supported number of frames */ | |
430 | ||
431 | return query.max_nr_frames; | |
432 | } | |
433 | ||
434 | static inline unsigned int max_nr_grant_frames(void) | |
435 | { | |
436 | unsigned int xen_max = __max_nr_grant_frames(); | |
437 | ||
438 | if (xen_max > boot_max_nr_grant_frames) | |
439 | return boot_max_nr_grant_frames; | |
440 | return xen_max; | |
441 | } | |
442 | ||
ad9a8612 JF |
443 | static int gnttab_map(unsigned int start_idx, unsigned int end_idx) |
444 | { | |
445 | struct gnttab_setup_table setup; | |
446 | unsigned long *frames; | |
447 | unsigned int nr_gframes = end_idx + 1; | |
448 | int rc; | |
449 | ||
450 | frames = kmalloc(nr_gframes * sizeof(unsigned long), GFP_ATOMIC); | |
451 | if (!frames) | |
452 | return -ENOMEM; | |
453 | ||
454 | setup.dom = DOMID_SELF; | |
455 | setup.nr_frames = nr_gframes; | |
87e27cf6 | 456 | set_xen_guest_handle(setup.frame_list, frames); |
ad9a8612 JF |
457 | |
458 | rc = HYPERVISOR_grant_table_op(GNTTABOP_setup_table, &setup, 1); | |
459 | if (rc == -ENOSYS) { | |
460 | kfree(frames); | |
461 | return -ENOSYS; | |
462 | } | |
463 | ||
464 | BUG_ON(rc || setup.status); | |
465 | ||
8d3d2106 IY |
466 | rc = arch_gnttab_map_shared(frames, nr_gframes, max_nr_grant_frames(), |
467 | &shared); | |
ad9a8612 | 468 | BUG_ON(rc); |
ad9a8612 JF |
469 | |
470 | kfree(frames); | |
471 | ||
472 | return 0; | |
473 | } | |
474 | ||
0e91398f | 475 | int gnttab_resume(void) |
ad9a8612 JF |
476 | { |
477 | if (max_nr_grant_frames() < nr_grant_frames) | |
478 | return -ENOSYS; | |
479 | return gnttab_map(0, nr_grant_frames - 1); | |
480 | } | |
481 | ||
0e91398f | 482 | int gnttab_suspend(void) |
ad9a8612 | 483 | { |
8d3d2106 | 484 | arch_gnttab_unmap_shared(shared, nr_grant_frames); |
ad9a8612 JF |
485 | return 0; |
486 | } | |
487 | ||
488 | static int gnttab_expand(unsigned int req_entries) | |
489 | { | |
490 | int rc; | |
491 | unsigned int cur, extra; | |
492 | ||
493 | cur = nr_grant_frames; | |
494 | extra = ((req_entries + (GREFS_PER_GRANT_FRAME-1)) / | |
495 | GREFS_PER_GRANT_FRAME); | |
496 | if (cur + extra > max_nr_grant_frames()) | |
497 | return -ENOSPC; | |
498 | ||
499 | rc = gnttab_map(cur, cur + extra - 1); | |
500 | if (rc == 0) | |
501 | rc = grow_gnttab_list(extra); | |
502 | ||
503 | return rc; | |
504 | } | |
505 | ||
506 | static int __devinit gnttab_init(void) | |
507 | { | |
508 | int i; | |
bbc60c18 | 509 | unsigned int max_nr_glist_frames, nr_glist_frames; |
ad9a8612 JF |
510 | unsigned int nr_init_grefs; |
511 | ||
6e833587 | 512 | if (!xen_domain()) |
ad9a8612 JF |
513 | return -ENODEV; |
514 | ||
515 | nr_grant_frames = 1; | |
516 | boot_max_nr_grant_frames = __max_nr_grant_frames(); | |
517 | ||
518 | /* Determine the maximum number of frames required for the | |
519 | * grant reference free list on the current hypervisor. | |
520 | */ | |
521 | max_nr_glist_frames = (boot_max_nr_grant_frames * | |
bbc60c18 | 522 | GREFS_PER_GRANT_FRAME / RPP); |
ad9a8612 JF |
523 | |
524 | gnttab_list = kmalloc(max_nr_glist_frames * sizeof(grant_ref_t *), | |
525 | GFP_KERNEL); | |
526 | if (gnttab_list == NULL) | |
527 | return -ENOMEM; | |
528 | ||
bbc60c18 MAEM |
529 | nr_glist_frames = (nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP; |
530 | for (i = 0; i < nr_glist_frames; i++) { | |
ad9a8612 JF |
531 | gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_KERNEL); |
532 | if (gnttab_list[i] == NULL) | |
533 | goto ini_nomem; | |
534 | } | |
535 | ||
536 | if (gnttab_resume() < 0) | |
537 | return -ENODEV; | |
538 | ||
539 | nr_init_grefs = nr_grant_frames * GREFS_PER_GRANT_FRAME; | |
540 | ||
541 | for (i = NR_RESERVED_ENTRIES; i < nr_init_grefs - 1; i++) | |
542 | gnttab_entry(i) = i + 1; | |
543 | ||
544 | gnttab_entry(nr_init_grefs - 1) = GNTTAB_LIST_END; | |
545 | gnttab_free_count = nr_init_grefs - NR_RESERVED_ENTRIES; | |
546 | gnttab_free_head = NR_RESERVED_ENTRIES; | |
547 | ||
548 | printk("Grant table initialized\n"); | |
549 | return 0; | |
550 | ||
551 | ini_nomem: | |
552 | for (i--; i >= 0; i--) | |
553 | free_page((unsigned long)gnttab_list[i]); | |
554 | kfree(gnttab_list); | |
555 | return -ENOMEM; | |
556 | } | |
557 | ||
558 | core_initcall(gnttab_init); |