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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> | |
5a0e3ad6 | 37 | #include <linux/slab.h> |
ad9a8612 JF |
38 | #include <linux/vmalloc.h> |
39 | #include <linux/uaccess.h> | |
183d03cc | 40 | #include <linux/io.h> |
ad9a8612 | 41 | |
1ccbf534 | 42 | #include <xen/xen.h> |
ad9a8612 JF |
43 | #include <xen/interface/xen.h> |
44 | #include <xen/page.h> | |
45 | #include <xen/grant_table.h> | |
183d03cc | 46 | #include <xen/interface/memory.h> |
ecbf29cd | 47 | #include <asm/xen/hypercall.h> |
ad9a8612 JF |
48 | |
49 | #include <asm/pgtable.h> | |
50 | #include <asm/sync_bitops.h> | |
51 | ||
52 | ||
53 | /* External tools reserve first few grant table entries. */ | |
54 | #define NR_RESERVED_ENTRIES 8 | |
55 | #define GNTTAB_LIST_END 0xffffffff | |
56 | #define GREFS_PER_GRANT_FRAME (PAGE_SIZE / sizeof(struct grant_entry)) | |
57 | ||
58 | static grant_ref_t **gnttab_list; | |
59 | static unsigned int nr_grant_frames; | |
60 | static unsigned int boot_max_nr_grant_frames; | |
61 | static int gnttab_free_count; | |
62 | static grant_ref_t gnttab_free_head; | |
63 | static DEFINE_SPINLOCK(gnttab_list_lock); | |
183d03cc SS |
64 | unsigned long xen_hvm_resume_frames; |
65 | EXPORT_SYMBOL_GPL(xen_hvm_resume_frames); | |
ad9a8612 JF |
66 | |
67 | static struct grant_entry *shared; | |
68 | ||
69 | static struct gnttab_free_callback *gnttab_free_callback_list; | |
70 | ||
71 | static int gnttab_expand(unsigned int req_entries); | |
72 | ||
73 | #define RPP (PAGE_SIZE / sizeof(grant_ref_t)) | |
74 | ||
75 | static inline grant_ref_t *__gnttab_entry(grant_ref_t entry) | |
76 | { | |
77 | return &gnttab_list[(entry) / RPP][(entry) % RPP]; | |
78 | } | |
79 | /* This can be used as an l-value */ | |
80 | #define gnttab_entry(entry) (*__gnttab_entry(entry)) | |
81 | ||
82 | static int get_free_entries(unsigned count) | |
83 | { | |
84 | unsigned long flags; | |
85 | int ref, rc; | |
86 | grant_ref_t head; | |
87 | ||
88 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
89 | ||
90 | if ((gnttab_free_count < count) && | |
91 | ((rc = gnttab_expand(count - gnttab_free_count)) < 0)) { | |
92 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
93 | return rc; | |
94 | } | |
95 | ||
96 | ref = head = gnttab_free_head; | |
97 | gnttab_free_count -= count; | |
98 | while (count-- > 1) | |
99 | head = gnttab_entry(head); | |
100 | gnttab_free_head = gnttab_entry(head); | |
101 | gnttab_entry(head) = GNTTAB_LIST_END; | |
102 | ||
103 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
104 | ||
105 | return ref; | |
106 | } | |
107 | ||
108 | static void do_free_callbacks(void) | |
109 | { | |
110 | struct gnttab_free_callback *callback, *next; | |
111 | ||
112 | callback = gnttab_free_callback_list; | |
113 | gnttab_free_callback_list = NULL; | |
114 | ||
115 | while (callback != NULL) { | |
116 | next = callback->next; | |
117 | if (gnttab_free_count >= callback->count) { | |
118 | callback->next = NULL; | |
119 | callback->fn(callback->arg); | |
120 | } else { | |
121 | callback->next = gnttab_free_callback_list; | |
122 | gnttab_free_callback_list = callback; | |
123 | } | |
124 | callback = next; | |
125 | } | |
126 | } | |
127 | ||
128 | static inline void check_free_callbacks(void) | |
129 | { | |
130 | if (unlikely(gnttab_free_callback_list)) | |
131 | do_free_callbacks(); | |
132 | } | |
133 | ||
134 | static void put_free_entry(grant_ref_t ref) | |
135 | { | |
136 | unsigned long flags; | |
137 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
138 | gnttab_entry(ref) = gnttab_free_head; | |
139 | gnttab_free_head = ref; | |
140 | gnttab_free_count++; | |
141 | check_free_callbacks(); | |
142 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
143 | } | |
144 | ||
145 | static void update_grant_entry(grant_ref_t ref, domid_t domid, | |
146 | unsigned long frame, unsigned flags) | |
147 | { | |
148 | /* | |
149 | * Introducing a valid entry into the grant table: | |
150 | * 1. Write ent->domid. | |
151 | * 2. Write ent->frame: | |
152 | * GTF_permit_access: Frame to which access is permitted. | |
153 | * GTF_accept_transfer: Pseudo-phys frame slot being filled by new | |
154 | * frame, or zero if none. | |
155 | * 3. Write memory barrier (WMB). | |
156 | * 4. Write ent->flags, inc. valid type. | |
157 | */ | |
158 | shared[ref].frame = frame; | |
159 | shared[ref].domid = domid; | |
160 | wmb(); | |
161 | shared[ref].flags = flags; | |
162 | } | |
163 | ||
164 | /* | |
165 | * Public grant-issuing interface functions | |
166 | */ | |
167 | void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid, | |
168 | unsigned long frame, int readonly) | |
169 | { | |
170 | update_grant_entry(ref, domid, frame, | |
171 | GTF_permit_access | (readonly ? GTF_readonly : 0)); | |
172 | } | |
173 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_ref); | |
174 | ||
175 | int gnttab_grant_foreign_access(domid_t domid, unsigned long frame, | |
176 | int readonly) | |
177 | { | |
178 | int ref; | |
179 | ||
180 | ref = get_free_entries(1); | |
181 | if (unlikely(ref < 0)) | |
182 | return -ENOSPC; | |
183 | ||
184 | gnttab_grant_foreign_access_ref(ref, domid, frame, readonly); | |
185 | ||
186 | return ref; | |
187 | } | |
188 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access); | |
189 | ||
190 | int gnttab_query_foreign_access(grant_ref_t ref) | |
191 | { | |
192 | u16 nflags; | |
193 | ||
194 | nflags = shared[ref].flags; | |
195 | ||
196 | return (nflags & (GTF_reading|GTF_writing)); | |
197 | } | |
198 | EXPORT_SYMBOL_GPL(gnttab_query_foreign_access); | |
199 | ||
200 | int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly) | |
201 | { | |
202 | u16 flags, nflags; | |
203 | ||
204 | nflags = shared[ref].flags; | |
205 | do { | |
206 | flags = nflags; | |
207 | if (flags & (GTF_reading|GTF_writing)) { | |
208 | printk(KERN_ALERT "WARNING: g.e. still in use!\n"); | |
209 | return 0; | |
210 | } | |
211 | } while ((nflags = sync_cmpxchg(&shared[ref].flags, flags, 0)) != flags); | |
212 | ||
213 | return 1; | |
214 | } | |
215 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_access_ref); | |
216 | ||
217 | void gnttab_end_foreign_access(grant_ref_t ref, int readonly, | |
218 | unsigned long page) | |
219 | { | |
220 | if (gnttab_end_foreign_access_ref(ref, readonly)) { | |
221 | put_free_entry(ref); | |
222 | if (page != 0) | |
223 | free_page(page); | |
224 | } else { | |
225 | /* XXX This needs to be fixed so that the ref and page are | |
226 | placed on a list to be freed up later. */ | |
227 | printk(KERN_WARNING | |
228 | "WARNING: leaking g.e. and page still in use!\n"); | |
229 | } | |
230 | } | |
231 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_access); | |
232 | ||
233 | int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn) | |
234 | { | |
235 | int ref; | |
236 | ||
237 | ref = get_free_entries(1); | |
238 | if (unlikely(ref < 0)) | |
239 | return -ENOSPC; | |
240 | gnttab_grant_foreign_transfer_ref(ref, domid, pfn); | |
241 | ||
242 | return ref; | |
243 | } | |
244 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer); | |
245 | ||
246 | void gnttab_grant_foreign_transfer_ref(grant_ref_t ref, domid_t domid, | |
247 | unsigned long pfn) | |
248 | { | |
249 | update_grant_entry(ref, domid, pfn, GTF_accept_transfer); | |
250 | } | |
251 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer_ref); | |
252 | ||
253 | unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref) | |
254 | { | |
255 | unsigned long frame; | |
256 | u16 flags; | |
257 | ||
258 | /* | |
259 | * If a transfer is not even yet started, try to reclaim the grant | |
260 | * reference and return failure (== 0). | |
261 | */ | |
262 | while (!((flags = shared[ref].flags) & GTF_transfer_committed)) { | |
263 | if (sync_cmpxchg(&shared[ref].flags, flags, 0) == flags) | |
264 | return 0; | |
265 | cpu_relax(); | |
266 | } | |
267 | ||
268 | /* If a transfer is in progress then wait until it is completed. */ | |
269 | while (!(flags & GTF_transfer_completed)) { | |
270 | flags = shared[ref].flags; | |
271 | cpu_relax(); | |
272 | } | |
273 | ||
274 | rmb(); /* Read the frame number /after/ reading completion status. */ | |
275 | frame = shared[ref].frame; | |
276 | BUG_ON(frame == 0); | |
277 | ||
278 | return frame; | |
279 | } | |
280 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer_ref); | |
281 | ||
282 | unsigned long gnttab_end_foreign_transfer(grant_ref_t ref) | |
283 | { | |
284 | unsigned long frame = gnttab_end_foreign_transfer_ref(ref); | |
285 | put_free_entry(ref); | |
286 | return frame; | |
287 | } | |
288 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer); | |
289 | ||
290 | void gnttab_free_grant_reference(grant_ref_t ref) | |
291 | { | |
292 | put_free_entry(ref); | |
293 | } | |
294 | EXPORT_SYMBOL_GPL(gnttab_free_grant_reference); | |
295 | ||
296 | void gnttab_free_grant_references(grant_ref_t head) | |
297 | { | |
298 | grant_ref_t ref; | |
299 | unsigned long flags; | |
300 | int count = 1; | |
301 | if (head == GNTTAB_LIST_END) | |
302 | return; | |
303 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
304 | ref = head; | |
305 | while (gnttab_entry(ref) != GNTTAB_LIST_END) { | |
306 | ref = gnttab_entry(ref); | |
307 | count++; | |
308 | } | |
309 | gnttab_entry(ref) = gnttab_free_head; | |
310 | gnttab_free_head = head; | |
311 | gnttab_free_count += count; | |
312 | check_free_callbacks(); | |
313 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
314 | } | |
315 | EXPORT_SYMBOL_GPL(gnttab_free_grant_references); | |
316 | ||
317 | int gnttab_alloc_grant_references(u16 count, grant_ref_t *head) | |
318 | { | |
319 | int h = get_free_entries(count); | |
320 | ||
321 | if (h < 0) | |
322 | return -ENOSPC; | |
323 | ||
324 | *head = h; | |
325 | ||
326 | return 0; | |
327 | } | |
328 | EXPORT_SYMBOL_GPL(gnttab_alloc_grant_references); | |
329 | ||
330 | int gnttab_empty_grant_references(const grant_ref_t *private_head) | |
331 | { | |
332 | return (*private_head == GNTTAB_LIST_END); | |
333 | } | |
334 | EXPORT_SYMBOL_GPL(gnttab_empty_grant_references); | |
335 | ||
336 | int gnttab_claim_grant_reference(grant_ref_t *private_head) | |
337 | { | |
338 | grant_ref_t g = *private_head; | |
339 | if (unlikely(g == GNTTAB_LIST_END)) | |
340 | return -ENOSPC; | |
341 | *private_head = gnttab_entry(g); | |
342 | return g; | |
343 | } | |
344 | EXPORT_SYMBOL_GPL(gnttab_claim_grant_reference); | |
345 | ||
346 | void gnttab_release_grant_reference(grant_ref_t *private_head, | |
347 | grant_ref_t release) | |
348 | { | |
349 | gnttab_entry(release) = *private_head; | |
350 | *private_head = release; | |
351 | } | |
352 | EXPORT_SYMBOL_GPL(gnttab_release_grant_reference); | |
353 | ||
354 | void gnttab_request_free_callback(struct gnttab_free_callback *callback, | |
355 | void (*fn)(void *), void *arg, u16 count) | |
356 | { | |
357 | unsigned long flags; | |
358 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
359 | if (callback->next) | |
360 | goto out; | |
361 | callback->fn = fn; | |
362 | callback->arg = arg; | |
363 | callback->count = count; | |
364 | callback->next = gnttab_free_callback_list; | |
365 | gnttab_free_callback_list = callback; | |
366 | check_free_callbacks(); | |
367 | out: | |
368 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
369 | } | |
370 | EXPORT_SYMBOL_GPL(gnttab_request_free_callback); | |
371 | ||
372 | void gnttab_cancel_free_callback(struct gnttab_free_callback *callback) | |
373 | { | |
374 | struct gnttab_free_callback **pcb; | |
375 | unsigned long flags; | |
376 | ||
377 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
378 | for (pcb = &gnttab_free_callback_list; *pcb; pcb = &(*pcb)->next) { | |
379 | if (*pcb == callback) { | |
380 | *pcb = callback->next; | |
381 | break; | |
382 | } | |
383 | } | |
384 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
385 | } | |
386 | EXPORT_SYMBOL_GPL(gnttab_cancel_free_callback); | |
387 | ||
388 | static int grow_gnttab_list(unsigned int more_frames) | |
389 | { | |
390 | unsigned int new_nr_grant_frames, extra_entries, i; | |
bbc60c18 | 391 | unsigned int nr_glist_frames, new_nr_glist_frames; |
ad9a8612 JF |
392 | |
393 | new_nr_grant_frames = nr_grant_frames + more_frames; | |
394 | extra_entries = more_frames * GREFS_PER_GRANT_FRAME; | |
395 | ||
bbc60c18 MAEM |
396 | nr_glist_frames = (nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP; |
397 | new_nr_glist_frames = | |
398 | (new_nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP; | |
399 | for (i = nr_glist_frames; i < new_nr_glist_frames; i++) { | |
ad9a8612 JF |
400 | gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_ATOMIC); |
401 | if (!gnttab_list[i]) | |
402 | goto grow_nomem; | |
403 | } | |
404 | ||
405 | ||
406 | for (i = GREFS_PER_GRANT_FRAME * nr_grant_frames; | |
407 | i < GREFS_PER_GRANT_FRAME * new_nr_grant_frames - 1; i++) | |
408 | gnttab_entry(i) = i + 1; | |
409 | ||
410 | gnttab_entry(i) = gnttab_free_head; | |
411 | gnttab_free_head = GREFS_PER_GRANT_FRAME * nr_grant_frames; | |
412 | gnttab_free_count += extra_entries; | |
413 | ||
414 | nr_grant_frames = new_nr_grant_frames; | |
415 | ||
416 | check_free_callbacks(); | |
417 | ||
418 | return 0; | |
419 | ||
420 | grow_nomem: | |
bbc60c18 | 421 | for ( ; i >= nr_glist_frames; i--) |
ad9a8612 JF |
422 | free_page((unsigned long) gnttab_list[i]); |
423 | return -ENOMEM; | |
424 | } | |
425 | ||
426 | static unsigned int __max_nr_grant_frames(void) | |
427 | { | |
428 | struct gnttab_query_size query; | |
429 | int rc; | |
430 | ||
431 | query.dom = DOMID_SELF; | |
432 | ||
433 | rc = HYPERVISOR_grant_table_op(GNTTABOP_query_size, &query, 1); | |
434 | if ((rc < 0) || (query.status != GNTST_okay)) | |
435 | return 4; /* Legacy max supported number of frames */ | |
436 | ||
437 | return query.max_nr_frames; | |
438 | } | |
439 | ||
183d03cc | 440 | unsigned int gnttab_max_grant_frames(void) |
ad9a8612 JF |
441 | { |
442 | unsigned int xen_max = __max_nr_grant_frames(); | |
443 | ||
444 | if (xen_max > boot_max_nr_grant_frames) | |
445 | return boot_max_nr_grant_frames; | |
446 | return xen_max; | |
447 | } | |
183d03cc | 448 | EXPORT_SYMBOL_GPL(gnttab_max_grant_frames); |
ad9a8612 | 449 | |
289b777e SS |
450 | int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, |
451 | struct page **pages, unsigned int count) | |
452 | { | |
453 | int i, ret; | |
454 | pte_t *pte; | |
455 | unsigned long mfn; | |
456 | ||
457 | ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map_ops, count); | |
458 | ||
459 | for (i = 0; i < count; i++) { | |
460 | /* m2p override only supported for GNTMAP_contains_pte mappings */ | |
461 | if (!(map_ops[i].flags & GNTMAP_contains_pte)) | |
462 | continue; | |
463 | pte = (pte_t *) (mfn_to_virt(PFN_DOWN(map_ops[i].host_addr)) + | |
464 | (map_ops[i].host_addr & ~PAGE_MASK)); | |
465 | mfn = pte_mfn(*pte); | |
466 | m2p_add_override(mfn, pages[i]); | |
467 | } | |
468 | ||
469 | return ret; | |
470 | } | |
471 | EXPORT_SYMBOL_GPL(gnttab_map_refs); | |
472 | ||
473 | int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, | |
474 | struct page **pages, unsigned int count) | |
475 | { | |
476 | int i, ret; | |
477 | ||
478 | ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops, count); | |
479 | for (i = 0; i < count; i++) | |
480 | m2p_remove_override(pages[i]); | |
481 | ||
482 | return ret; | |
483 | } | |
484 | EXPORT_SYMBOL_GPL(gnttab_unmap_refs); | |
485 | ||
ad9a8612 JF |
486 | static int gnttab_map(unsigned int start_idx, unsigned int end_idx) |
487 | { | |
488 | struct gnttab_setup_table setup; | |
489 | unsigned long *frames; | |
490 | unsigned int nr_gframes = end_idx + 1; | |
491 | int rc; | |
492 | ||
183d03cc SS |
493 | if (xen_hvm_domain()) { |
494 | struct xen_add_to_physmap xatp; | |
495 | unsigned int i = end_idx; | |
496 | rc = 0; | |
497 | /* | |
498 | * Loop backwards, so that the first hypercall has the largest | |
499 | * index, ensuring that the table will grow only once. | |
500 | */ | |
501 | do { | |
502 | xatp.domid = DOMID_SELF; | |
503 | xatp.idx = i; | |
504 | xatp.space = XENMAPSPACE_grant_table; | |
505 | xatp.gpfn = (xen_hvm_resume_frames >> PAGE_SHIFT) + i; | |
506 | rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp); | |
507 | if (rc != 0) { | |
508 | printk(KERN_WARNING | |
509 | "grant table add_to_physmap failed, err=%d\n", rc); | |
510 | break; | |
511 | } | |
512 | } while (i-- > start_idx); | |
513 | ||
514 | return rc; | |
515 | } | |
516 | ||
ad9a8612 JF |
517 | frames = kmalloc(nr_gframes * sizeof(unsigned long), GFP_ATOMIC); |
518 | if (!frames) | |
519 | return -ENOMEM; | |
520 | ||
521 | setup.dom = DOMID_SELF; | |
522 | setup.nr_frames = nr_gframes; | |
87e27cf6 | 523 | set_xen_guest_handle(setup.frame_list, frames); |
ad9a8612 JF |
524 | |
525 | rc = HYPERVISOR_grant_table_op(GNTTABOP_setup_table, &setup, 1); | |
526 | if (rc == -ENOSYS) { | |
527 | kfree(frames); | |
528 | return -ENOSYS; | |
529 | } | |
530 | ||
531 | BUG_ON(rc || setup.status); | |
532 | ||
183d03cc | 533 | rc = arch_gnttab_map_shared(frames, nr_gframes, gnttab_max_grant_frames(), |
8d3d2106 | 534 | &shared); |
ad9a8612 | 535 | BUG_ON(rc); |
ad9a8612 JF |
536 | |
537 | kfree(frames); | |
538 | ||
539 | return 0; | |
540 | } | |
541 | ||
0e91398f | 542 | int gnttab_resume(void) |
ad9a8612 | 543 | { |
183d03cc SS |
544 | unsigned int max_nr_gframes; |
545 | ||
546 | max_nr_gframes = gnttab_max_grant_frames(); | |
547 | if (max_nr_gframes < nr_grant_frames) | |
ad9a8612 | 548 | return -ENOSYS; |
183d03cc SS |
549 | |
550 | if (xen_pv_domain()) | |
551 | return gnttab_map(0, nr_grant_frames - 1); | |
552 | ||
553 | if (!shared) { | |
554 | shared = ioremap(xen_hvm_resume_frames, PAGE_SIZE * max_nr_gframes); | |
555 | if (shared == NULL) { | |
556 | printk(KERN_WARNING | |
557 | "Failed to ioremap gnttab share frames!"); | |
558 | return -ENOMEM; | |
559 | } | |
560 | } | |
561 | ||
562 | gnttab_map(0, nr_grant_frames - 1); | |
563 | ||
564 | return 0; | |
ad9a8612 JF |
565 | } |
566 | ||
0e91398f | 567 | int gnttab_suspend(void) |
ad9a8612 | 568 | { |
8d3d2106 | 569 | arch_gnttab_unmap_shared(shared, nr_grant_frames); |
ad9a8612 JF |
570 | return 0; |
571 | } | |
572 | ||
573 | static int gnttab_expand(unsigned int req_entries) | |
574 | { | |
575 | int rc; | |
576 | unsigned int cur, extra; | |
577 | ||
578 | cur = nr_grant_frames; | |
579 | extra = ((req_entries + (GREFS_PER_GRANT_FRAME-1)) / | |
580 | GREFS_PER_GRANT_FRAME); | |
183d03cc | 581 | if (cur + extra > gnttab_max_grant_frames()) |
ad9a8612 JF |
582 | return -ENOSPC; |
583 | ||
584 | rc = gnttab_map(cur, cur + extra - 1); | |
585 | if (rc == 0) | |
586 | rc = grow_gnttab_list(extra); | |
587 | ||
588 | return rc; | |
589 | } | |
590 | ||
183d03cc | 591 | int gnttab_init(void) |
ad9a8612 JF |
592 | { |
593 | int i; | |
bbc60c18 | 594 | unsigned int max_nr_glist_frames, nr_glist_frames; |
ad9a8612 JF |
595 | unsigned int nr_init_grefs; |
596 | ||
ad9a8612 JF |
597 | nr_grant_frames = 1; |
598 | boot_max_nr_grant_frames = __max_nr_grant_frames(); | |
599 | ||
600 | /* Determine the maximum number of frames required for the | |
601 | * grant reference free list on the current hypervisor. | |
602 | */ | |
603 | max_nr_glist_frames = (boot_max_nr_grant_frames * | |
bbc60c18 | 604 | GREFS_PER_GRANT_FRAME / RPP); |
ad9a8612 JF |
605 | |
606 | gnttab_list = kmalloc(max_nr_glist_frames * sizeof(grant_ref_t *), | |
607 | GFP_KERNEL); | |
608 | if (gnttab_list == NULL) | |
609 | return -ENOMEM; | |
610 | ||
bbc60c18 MAEM |
611 | nr_glist_frames = (nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP; |
612 | for (i = 0; i < nr_glist_frames; i++) { | |
ad9a8612 JF |
613 | gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_KERNEL); |
614 | if (gnttab_list[i] == NULL) | |
615 | goto ini_nomem; | |
616 | } | |
617 | ||
618 | if (gnttab_resume() < 0) | |
619 | return -ENODEV; | |
620 | ||
621 | nr_init_grefs = nr_grant_frames * GREFS_PER_GRANT_FRAME; | |
622 | ||
623 | for (i = NR_RESERVED_ENTRIES; i < nr_init_grefs - 1; i++) | |
624 | gnttab_entry(i) = i + 1; | |
625 | ||
626 | gnttab_entry(nr_init_grefs - 1) = GNTTAB_LIST_END; | |
627 | gnttab_free_count = nr_init_grefs - NR_RESERVED_ENTRIES; | |
628 | gnttab_free_head = NR_RESERVED_ENTRIES; | |
629 | ||
630 | printk("Grant table initialized\n"); | |
631 | return 0; | |
632 | ||
633 | ini_nomem: | |
634 | for (i--; i >= 0; i--) | |
635 | free_page((unsigned long)gnttab_list[i]); | |
636 | kfree(gnttab_list); | |
637 | return -ENOMEM; | |
638 | } | |
183d03cc SS |
639 | EXPORT_SYMBOL_GPL(gnttab_init); |
640 | ||
641 | static int __devinit __gnttab_init(void) | |
642 | { | |
643 | /* Delay grant-table initialization in the PV on HVM case */ | |
644 | if (xen_hvm_domain()) | |
645 | return 0; | |
646 | ||
647 | if (!xen_pv_domain()) | |
648 | return -ENODEV; | |
649 | ||
650 | return gnttab_init(); | |
651 | } | |
ad9a8612 | 652 | |
183d03cc | 653 | core_initcall(__gnttab_init); |