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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> |
85ff6acb | 47 | #include <xen/hvc-console.h> |
ecbf29cd | 48 | #include <asm/xen/hypercall.h> |
ad9a8612 JF |
49 | |
50 | #include <asm/pgtable.h> | |
51 | #include <asm/sync_bitops.h> | |
52 | ||
ad9a8612 JF |
53 | /* External tools reserve first few grant table entries. */ |
54 | #define NR_RESERVED_ENTRIES 8 | |
55 | #define GNTTAB_LIST_END 0xffffffff | |
85ff6acb AL |
56 | #define GREFS_PER_GRANT_FRAME \ |
57 | (grant_table_version == 1 ? \ | |
58 | (PAGE_SIZE / sizeof(struct grant_entry_v1)) : \ | |
59 | (PAGE_SIZE / sizeof(union grant_entry_v2))) | |
ad9a8612 JF |
60 | |
61 | static grant_ref_t **gnttab_list; | |
62 | static unsigned int nr_grant_frames; | |
63 | static unsigned int boot_max_nr_grant_frames; | |
64 | static int gnttab_free_count; | |
65 | static grant_ref_t gnttab_free_head; | |
66 | static DEFINE_SPINLOCK(gnttab_list_lock); | |
183d03cc SS |
67 | unsigned long xen_hvm_resume_frames; |
68 | EXPORT_SYMBOL_GPL(xen_hvm_resume_frames); | |
ad9a8612 | 69 | |
0f9f5a95 AL |
70 | static union { |
71 | struct grant_entry_v1 *v1; | |
85ff6acb | 72 | union grant_entry_v2 *v2; |
0f9f5a95 AL |
73 | void *addr; |
74 | } gnttab_shared; | |
75 | ||
76 | /*This is a structure of function pointers for grant table*/ | |
77 | struct gnttab_ops { | |
78 | /* | |
9dbc71d5 AL |
79 | * Mapping a list of frames for storing grant entries. Frames parameter |
80 | * is used to store grant table address when grant table being setup, | |
81 | * nr_gframes is the number of frames to map grant table. Returning | |
82 | * GNTST_okay means success and negative value means failure. | |
0f9f5a95 | 83 | */ |
9dbc71d5 | 84 | int (*map_frames)(unsigned long *frames, unsigned int nr_gframes); |
0f9f5a95 AL |
85 | /* |
86 | * Release a list of frames which are mapped in map_frames for grant | |
87 | * entry status. | |
88 | */ | |
89 | void (*unmap_frames)(void); | |
90 | /* | |
9dbc71d5 AL |
91 | * Introducing a valid entry into the grant table, granting the frame of |
92 | * this grant entry to domain for accessing or transfering. Ref | |
93 | * parameter is reference of this introduced grant entry, domid is id of | |
94 | * granted domain, frame is the page frame to be granted, and flags is | |
95 | * status of the grant entry to be updated. | |
0f9f5a95 | 96 | */ |
9dbc71d5 AL |
97 | void (*update_entry)(grant_ref_t ref, domid_t domid, |
98 | unsigned long frame, unsigned flags); | |
0f9f5a95 | 99 | /* |
9dbc71d5 AL |
100 | * Stop granting a grant entry to domain for accessing. Ref parameter is |
101 | * reference of a grant entry whose grant access will be stopped, | |
102 | * readonly is not in use in this function. If the grant entry is | |
0f9f5a95 AL |
103 | * currently mapped for reading or writing, just return failure(==0) |
104 | * directly and don't tear down the grant access. Otherwise, stop grant | |
105 | * access for this entry and return success(==1). | |
106 | */ | |
9dbc71d5 | 107 | int (*end_foreign_access_ref)(grant_ref_t ref, int readonly); |
0f9f5a95 | 108 | /* |
9dbc71d5 AL |
109 | * Stop granting a grant entry to domain for transfer. Ref parameter is |
110 | * reference of a grant entry whose grant transfer will be stopped. If | |
111 | * tranfer has not started, just reclaim the grant entry and return | |
112 | * failure(==0). Otherwise, wait for the transfer to complete and then | |
113 | * return the frame. | |
0f9f5a95 | 114 | */ |
9dbc71d5 | 115 | unsigned long (*end_foreign_transfer_ref)(grant_ref_t ref); |
0f9f5a95 | 116 | /* |
9dbc71d5 | 117 | * Query the status of a grant entry. Ref parameter is reference of |
0f9f5a95 AL |
118 | * queried grant entry, return value is the status of queried entry. |
119 | * Detailed status(writing/reading) can be gotten from the return value | |
120 | * by bit operations. | |
121 | */ | |
9dbc71d5 | 122 | int (*query_foreign_access)(grant_ref_t ref); |
6666754b AL |
123 | /* |
124 | * Grant a domain to access a range of bytes within the page referred by | |
125 | * an available grant entry. Ref parameter is reference of a grant entry | |
126 | * which will be sub-page accessed, domid is id of grantee domain, frame | |
127 | * is frame address of subpage grant, flags is grant type and flag | |
128 | * information, page_off is offset of the range of bytes, and length is | |
129 | * length of bytes to be accessed. | |
130 | */ | |
131 | void (*update_subpage_entry)(grant_ref_t ref, domid_t domid, | |
132 | unsigned long frame, int flags, | |
133 | unsigned page_off, unsigned length); | |
9438ce9d AL |
134 | /* |
135 | * Redirect an available grant entry on domain A to another grant | |
136 | * reference of domain B, then allow domain C to use grant reference | |
137 | * of domain B transitively. Ref parameter is an available grant entry | |
138 | * reference on domain A, domid is id of domain C which accesses grant | |
139 | * entry transitively, flags is grant type and flag information, | |
140 | * trans_domid is id of domain B whose grant entry is finally accessed | |
141 | * transitively, trans_gref is grant entry transitive reference of | |
142 | * domain B. | |
143 | */ | |
144 | void (*update_trans_entry)(grant_ref_t ref, domid_t domid, int flags, | |
145 | domid_t trans_domid, grant_ref_t trans_gref); | |
0f9f5a95 AL |
146 | }; |
147 | ||
148 | static struct gnttab_ops *gnttab_interface; | |
149 | ||
85ff6acb AL |
150 | /*This reflects status of grant entries, so act as a global value*/ |
151 | static grant_status_t *grstatus; | |
152 | ||
0f9f5a95 | 153 | static int grant_table_version; |
ad9a8612 JF |
154 | |
155 | static struct gnttab_free_callback *gnttab_free_callback_list; | |
156 | ||
157 | static int gnttab_expand(unsigned int req_entries); | |
158 | ||
159 | #define RPP (PAGE_SIZE / sizeof(grant_ref_t)) | |
85ff6acb | 160 | #define SPP (PAGE_SIZE / sizeof(grant_status_t)) |
ad9a8612 JF |
161 | |
162 | static inline grant_ref_t *__gnttab_entry(grant_ref_t entry) | |
163 | { | |
164 | return &gnttab_list[(entry) / RPP][(entry) % RPP]; | |
165 | } | |
166 | /* This can be used as an l-value */ | |
167 | #define gnttab_entry(entry) (*__gnttab_entry(entry)) | |
168 | ||
169 | static int get_free_entries(unsigned count) | |
170 | { | |
171 | unsigned long flags; | |
272800dc | 172 | int ref, rc = 0; |
ad9a8612 JF |
173 | grant_ref_t head; |
174 | ||
175 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
176 | ||
177 | if ((gnttab_free_count < count) && | |
178 | ((rc = gnttab_expand(count - gnttab_free_count)) < 0)) { | |
179 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
180 | return rc; | |
181 | } | |
182 | ||
183 | ref = head = gnttab_free_head; | |
184 | gnttab_free_count -= count; | |
185 | while (count-- > 1) | |
186 | head = gnttab_entry(head); | |
187 | gnttab_free_head = gnttab_entry(head); | |
188 | gnttab_entry(head) = GNTTAB_LIST_END; | |
189 | ||
190 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
191 | ||
192 | return ref; | |
193 | } | |
194 | ||
195 | static void do_free_callbacks(void) | |
196 | { | |
197 | struct gnttab_free_callback *callback, *next; | |
198 | ||
199 | callback = gnttab_free_callback_list; | |
200 | gnttab_free_callback_list = NULL; | |
201 | ||
202 | while (callback != NULL) { | |
203 | next = callback->next; | |
204 | if (gnttab_free_count >= callback->count) { | |
205 | callback->next = NULL; | |
206 | callback->fn(callback->arg); | |
207 | } else { | |
208 | callback->next = gnttab_free_callback_list; | |
209 | gnttab_free_callback_list = callback; | |
210 | } | |
211 | callback = next; | |
212 | } | |
213 | } | |
214 | ||
215 | static inline void check_free_callbacks(void) | |
216 | { | |
217 | if (unlikely(gnttab_free_callback_list)) | |
218 | do_free_callbacks(); | |
219 | } | |
220 | ||
221 | static void put_free_entry(grant_ref_t ref) | |
222 | { | |
223 | unsigned long flags; | |
224 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
225 | gnttab_entry(ref) = gnttab_free_head; | |
226 | gnttab_free_head = ref; | |
227 | gnttab_free_count++; | |
228 | check_free_callbacks(); | |
229 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
230 | } | |
231 | ||
0f9f5a95 | 232 | /* |
85ff6acb | 233 | * Following applies to gnttab_update_entry_v1 and gnttab_update_entry_v2. |
0f9f5a95 AL |
234 | * Introducing a valid entry into the grant table: |
235 | * 1. Write ent->domid. | |
236 | * 2. Write ent->frame: | |
237 | * GTF_permit_access: Frame to which access is permitted. | |
238 | * GTF_accept_transfer: Pseudo-phys frame slot being filled by new | |
239 | * frame, or zero if none. | |
240 | * 3. Write memory barrier (WMB). | |
241 | * 4. Write ent->flags, inc. valid type. | |
242 | */ | |
243 | static void gnttab_update_entry_v1(grant_ref_t ref, domid_t domid, | |
244 | unsigned long frame, unsigned flags) | |
ad9a8612 | 245 | { |
0f9f5a95 AL |
246 | gnttab_shared.v1[ref].domid = domid; |
247 | gnttab_shared.v1[ref].frame = frame; | |
ad9a8612 | 248 | wmb(); |
0f9f5a95 | 249 | gnttab_shared.v1[ref].flags = flags; |
ad9a8612 JF |
250 | } |
251 | ||
85ff6acb AL |
252 | static void gnttab_update_entry_v2(grant_ref_t ref, domid_t domid, |
253 | unsigned long frame, unsigned flags) | |
254 | { | |
255 | gnttab_shared.v2[ref].hdr.domid = domid; | |
256 | gnttab_shared.v2[ref].full_page.frame = frame; | |
257 | wmb(); | |
258 | gnttab_shared.v2[ref].hdr.flags = GTF_permit_access | flags; | |
259 | } | |
260 | ||
ad9a8612 JF |
261 | /* |
262 | * Public grant-issuing interface functions | |
263 | */ | |
264 | void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid, | |
265 | unsigned long frame, int readonly) | |
266 | { | |
0f9f5a95 | 267 | gnttab_interface->update_entry(ref, domid, frame, |
ad9a8612 JF |
268 | GTF_permit_access | (readonly ? GTF_readonly : 0)); |
269 | } | |
270 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_ref); | |
271 | ||
272 | int gnttab_grant_foreign_access(domid_t domid, unsigned long frame, | |
273 | int readonly) | |
274 | { | |
275 | int ref; | |
276 | ||
277 | ref = get_free_entries(1); | |
278 | if (unlikely(ref < 0)) | |
279 | return -ENOSPC; | |
280 | ||
281 | gnttab_grant_foreign_access_ref(ref, domid, frame, readonly); | |
282 | ||
283 | return ref; | |
284 | } | |
285 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access); | |
286 | ||
6666754b AL |
287 | void gnttab_update_subpage_entry_v2(grant_ref_t ref, domid_t domid, |
288 | unsigned long frame, int flags, | |
289 | unsigned page_off, | |
290 | unsigned length) | |
291 | { | |
292 | gnttab_shared.v2[ref].sub_page.frame = frame; | |
293 | gnttab_shared.v2[ref].sub_page.page_off = page_off; | |
294 | gnttab_shared.v2[ref].sub_page.length = length; | |
295 | gnttab_shared.v2[ref].hdr.domid = domid; | |
296 | wmb(); | |
297 | gnttab_shared.v2[ref].hdr.flags = | |
298 | GTF_permit_access | GTF_sub_page | flags; | |
299 | } | |
300 | ||
301 | int gnttab_grant_foreign_access_subpage_ref(grant_ref_t ref, domid_t domid, | |
302 | unsigned long frame, int flags, | |
303 | unsigned page_off, | |
304 | unsigned length) | |
305 | { | |
306 | if (flags & (GTF_accept_transfer | GTF_reading | | |
307 | GTF_writing | GTF_transitive)) | |
308 | return -EPERM; | |
309 | ||
310 | if (gnttab_interface->update_subpage_entry == NULL) | |
311 | return -ENOSYS; | |
312 | ||
313 | gnttab_interface->update_subpage_entry(ref, domid, frame, flags, | |
314 | page_off, length); | |
315 | ||
316 | return 0; | |
317 | } | |
318 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_subpage_ref); | |
319 | ||
320 | int gnttab_grant_foreign_access_subpage(domid_t domid, unsigned long frame, | |
321 | int flags, unsigned page_off, | |
322 | unsigned length) | |
323 | { | |
324 | int ref, rc; | |
325 | ||
326 | ref = get_free_entries(1); | |
327 | if (unlikely(ref < 0)) | |
328 | return -ENOSPC; | |
329 | ||
330 | rc = gnttab_grant_foreign_access_subpage_ref(ref, domid, frame, flags, | |
331 | page_off, length); | |
332 | if (rc < 0) { | |
333 | put_free_entry(ref); | |
334 | return rc; | |
335 | } | |
336 | ||
337 | return ref; | |
338 | } | |
339 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_subpage); | |
340 | ||
341 | bool gnttab_subpage_grants_available(void) | |
342 | { | |
343 | return gnttab_interface->update_subpage_entry != NULL; | |
344 | } | |
345 | EXPORT_SYMBOL_GPL(gnttab_subpage_grants_available); | |
346 | ||
9438ce9d AL |
347 | void gnttab_update_trans_entry_v2(grant_ref_t ref, domid_t domid, |
348 | int flags, domid_t trans_domid, | |
349 | grant_ref_t trans_gref) | |
350 | { | |
351 | gnttab_shared.v2[ref].transitive.trans_domid = trans_domid; | |
352 | gnttab_shared.v2[ref].transitive.gref = trans_gref; | |
353 | gnttab_shared.v2[ref].hdr.domid = domid; | |
354 | wmb(); | |
355 | gnttab_shared.v2[ref].hdr.flags = | |
356 | GTF_permit_access | GTF_transitive | flags; | |
357 | } | |
358 | ||
359 | int gnttab_grant_foreign_access_trans_ref(grant_ref_t ref, domid_t domid, | |
360 | int flags, domid_t trans_domid, | |
361 | grant_ref_t trans_gref) | |
362 | { | |
363 | if (flags & (GTF_accept_transfer | GTF_reading | | |
364 | GTF_writing | GTF_sub_page)) | |
365 | return -EPERM; | |
366 | ||
367 | if (gnttab_interface->update_trans_entry == NULL) | |
368 | return -ENOSYS; | |
369 | ||
370 | gnttab_interface->update_trans_entry(ref, domid, flags, trans_domid, | |
371 | trans_gref); | |
372 | ||
373 | return 0; | |
374 | } | |
375 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_trans_ref); | |
376 | ||
377 | int gnttab_grant_foreign_access_trans(domid_t domid, int flags, | |
378 | domid_t trans_domid, | |
379 | grant_ref_t trans_gref) | |
380 | { | |
381 | int ref, rc; | |
382 | ||
383 | ref = get_free_entries(1); | |
384 | if (unlikely(ref < 0)) | |
385 | return -ENOSPC; | |
386 | ||
387 | rc = gnttab_grant_foreign_access_trans_ref(ref, domid, flags, | |
388 | trans_domid, trans_gref); | |
389 | if (rc < 0) { | |
390 | put_free_entry(ref); | |
391 | return rc; | |
392 | } | |
393 | ||
394 | return ref; | |
395 | } | |
396 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_trans); | |
397 | ||
398 | bool gnttab_trans_grants_available(void) | |
399 | { | |
400 | return gnttab_interface->update_trans_entry != NULL; | |
401 | } | |
402 | EXPORT_SYMBOL_GPL(gnttab_trans_grants_available); | |
403 | ||
0f9f5a95 | 404 | static int gnttab_query_foreign_access_v1(grant_ref_t ref) |
ad9a8612 | 405 | { |
0f9f5a95 AL |
406 | return gnttab_shared.v1[ref].flags & (GTF_reading|GTF_writing); |
407 | } | |
ad9a8612 | 408 | |
85ff6acb AL |
409 | static int gnttab_query_foreign_access_v2(grant_ref_t ref) |
410 | { | |
411 | return grstatus[ref] & (GTF_reading|GTF_writing); | |
412 | } | |
413 | ||
0f9f5a95 AL |
414 | int gnttab_query_foreign_access(grant_ref_t ref) |
415 | { | |
416 | return gnttab_interface->query_foreign_access(ref); | |
ad9a8612 JF |
417 | } |
418 | EXPORT_SYMBOL_GPL(gnttab_query_foreign_access); | |
419 | ||
0f9f5a95 | 420 | static int gnttab_end_foreign_access_ref_v1(grant_ref_t ref, int readonly) |
ad9a8612 JF |
421 | { |
422 | u16 flags, nflags; | |
b1e495b2 | 423 | u16 *pflags; |
ad9a8612 | 424 | |
b1e495b2 AL |
425 | pflags = &gnttab_shared.v1[ref].flags; |
426 | nflags = *pflags; | |
ad9a8612 JF |
427 | do { |
428 | flags = nflags; | |
569ca5b3 | 429 | if (flags & (GTF_reading|GTF_writing)) |
ad9a8612 | 430 | return 0; |
b1e495b2 | 431 | } while ((nflags = sync_cmpxchg(pflags, flags, 0)) != flags); |
ad9a8612 JF |
432 | |
433 | return 1; | |
434 | } | |
0f9f5a95 | 435 | |
85ff6acb AL |
436 | static int gnttab_end_foreign_access_ref_v2(grant_ref_t ref, int readonly) |
437 | { | |
438 | gnttab_shared.v2[ref].hdr.flags = 0; | |
439 | mb(); | |
440 | if (grstatus[ref] & (GTF_reading|GTF_writing)) { | |
441 | return 0; | |
442 | } else { | |
443 | /* The read of grstatus needs to have acquire | |
444 | semantics. On x86, reads already have | |
445 | that, and we just need to protect against | |
446 | compiler reorderings. On other | |
447 | architectures we may need a full | |
448 | barrier. */ | |
449 | #ifdef CONFIG_X86 | |
450 | barrier(); | |
451 | #else | |
452 | mb(); | |
453 | #endif | |
454 | } | |
455 | ||
456 | return 1; | |
457 | } | |
458 | ||
569ca5b3 | 459 | static inline int _gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly) |
0f9f5a95 AL |
460 | { |
461 | return gnttab_interface->end_foreign_access_ref(ref, readonly); | |
462 | } | |
569ca5b3 JB |
463 | |
464 | int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly) | |
465 | { | |
466 | if (_gnttab_end_foreign_access_ref(ref, readonly)) | |
467 | return 1; | |
468 | pr_warn("WARNING: g.e. %#x still in use!\n", ref); | |
469 | return 0; | |
470 | } | |
ad9a8612 JF |
471 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_access_ref); |
472 | ||
569ca5b3 JB |
473 | struct deferred_entry { |
474 | struct list_head list; | |
475 | grant_ref_t ref; | |
476 | bool ro; | |
477 | uint16_t warn_delay; | |
478 | struct page *page; | |
479 | }; | |
480 | static LIST_HEAD(deferred_list); | |
481 | static void gnttab_handle_deferred(unsigned long); | |
482 | static DEFINE_TIMER(deferred_timer, gnttab_handle_deferred, 0, 0); | |
483 | ||
484 | static void gnttab_handle_deferred(unsigned long unused) | |
485 | { | |
486 | unsigned int nr = 10; | |
487 | struct deferred_entry *first = NULL; | |
488 | unsigned long flags; | |
489 | ||
490 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
491 | while (nr--) { | |
492 | struct deferred_entry *entry | |
493 | = list_first_entry(&deferred_list, | |
494 | struct deferred_entry, list); | |
495 | ||
496 | if (entry == first) | |
497 | break; | |
498 | list_del(&entry->list); | |
499 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
500 | if (_gnttab_end_foreign_access_ref(entry->ref, entry->ro)) { | |
501 | put_free_entry(entry->ref); | |
502 | if (entry->page) { | |
503 | pr_debug("freeing g.e. %#x (pfn %#lx)\n", | |
504 | entry->ref, page_to_pfn(entry->page)); | |
505 | __free_page(entry->page); | |
506 | } else | |
507 | pr_info("freeing g.e. %#x\n", entry->ref); | |
508 | kfree(entry); | |
509 | entry = NULL; | |
510 | } else { | |
511 | if (!--entry->warn_delay) | |
512 | pr_info("g.e. %#x still pending\n", | |
513 | entry->ref); | |
514 | if (!first) | |
515 | first = entry; | |
516 | } | |
517 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
518 | if (entry) | |
519 | list_add_tail(&entry->list, &deferred_list); | |
520 | else if (list_empty(&deferred_list)) | |
521 | break; | |
522 | } | |
523 | if (!list_empty(&deferred_list) && !timer_pending(&deferred_timer)) { | |
524 | deferred_timer.expires = jiffies + HZ; | |
525 | add_timer(&deferred_timer); | |
526 | } | |
527 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
528 | } | |
529 | ||
530 | static void gnttab_add_deferred(grant_ref_t ref, bool readonly, | |
531 | struct page *page) | |
532 | { | |
533 | struct deferred_entry *entry = kmalloc(sizeof(*entry), GFP_ATOMIC); | |
534 | const char *what = KERN_WARNING "leaking"; | |
535 | ||
536 | if (entry) { | |
537 | unsigned long flags; | |
538 | ||
539 | entry->ref = ref; | |
540 | entry->ro = readonly; | |
541 | entry->page = page; | |
542 | entry->warn_delay = 60; | |
543 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
544 | list_add_tail(&entry->list, &deferred_list); | |
545 | if (!timer_pending(&deferred_timer)) { | |
546 | deferred_timer.expires = jiffies + HZ; | |
547 | add_timer(&deferred_timer); | |
548 | } | |
549 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
550 | what = KERN_DEBUG "deferring"; | |
551 | } | |
552 | printk("%s g.e. %#x (pfn %#lx)\n", | |
553 | what, ref, page ? page_to_pfn(page) : -1); | |
554 | } | |
555 | ||
ad9a8612 JF |
556 | void gnttab_end_foreign_access(grant_ref_t ref, int readonly, |
557 | unsigned long page) | |
558 | { | |
559 | if (gnttab_end_foreign_access_ref(ref, readonly)) { | |
560 | put_free_entry(ref); | |
561 | if (page != 0) | |
562 | free_page(page); | |
569ca5b3 JB |
563 | } else |
564 | gnttab_add_deferred(ref, readonly, | |
565 | page ? virt_to_page(page) : NULL); | |
ad9a8612 JF |
566 | } |
567 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_access); | |
568 | ||
569 | int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn) | |
570 | { | |
571 | int ref; | |
572 | ||
573 | ref = get_free_entries(1); | |
574 | if (unlikely(ref < 0)) | |
575 | return -ENOSPC; | |
576 | gnttab_grant_foreign_transfer_ref(ref, domid, pfn); | |
577 | ||
578 | return ref; | |
579 | } | |
580 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer); | |
581 | ||
582 | void gnttab_grant_foreign_transfer_ref(grant_ref_t ref, domid_t domid, | |
583 | unsigned long pfn) | |
584 | { | |
0f9f5a95 | 585 | gnttab_interface->update_entry(ref, domid, pfn, GTF_accept_transfer); |
ad9a8612 JF |
586 | } |
587 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer_ref); | |
588 | ||
0f9f5a95 | 589 | static unsigned long gnttab_end_foreign_transfer_ref_v1(grant_ref_t ref) |
ad9a8612 JF |
590 | { |
591 | unsigned long frame; | |
592 | u16 flags; | |
b1e495b2 AL |
593 | u16 *pflags; |
594 | ||
595 | pflags = &gnttab_shared.v1[ref].flags; | |
ad9a8612 JF |
596 | |
597 | /* | |
598 | * If a transfer is not even yet started, try to reclaim the grant | |
599 | * reference and return failure (== 0). | |
600 | */ | |
b1e495b2 AL |
601 | while (!((flags = *pflags) & GTF_transfer_committed)) { |
602 | if (sync_cmpxchg(pflags, flags, 0) == flags) | |
ad9a8612 JF |
603 | return 0; |
604 | cpu_relax(); | |
605 | } | |
606 | ||
607 | /* If a transfer is in progress then wait until it is completed. */ | |
608 | while (!(flags & GTF_transfer_completed)) { | |
b1e495b2 | 609 | flags = *pflags; |
ad9a8612 JF |
610 | cpu_relax(); |
611 | } | |
612 | ||
613 | rmb(); /* Read the frame number /after/ reading completion status. */ | |
0f9f5a95 | 614 | frame = gnttab_shared.v1[ref].frame; |
ad9a8612 JF |
615 | BUG_ON(frame == 0); |
616 | ||
617 | return frame; | |
618 | } | |
0f9f5a95 | 619 | |
85ff6acb AL |
620 | static unsigned long gnttab_end_foreign_transfer_ref_v2(grant_ref_t ref) |
621 | { | |
622 | unsigned long frame; | |
623 | u16 flags; | |
624 | u16 *pflags; | |
625 | ||
626 | pflags = &gnttab_shared.v2[ref].hdr.flags; | |
627 | ||
628 | /* | |
629 | * If a transfer is not even yet started, try to reclaim the grant | |
630 | * reference and return failure (== 0). | |
631 | */ | |
632 | while (!((flags = *pflags) & GTF_transfer_committed)) { | |
633 | if (sync_cmpxchg(pflags, flags, 0) == flags) | |
634 | return 0; | |
635 | cpu_relax(); | |
636 | } | |
637 | ||
638 | /* If a transfer is in progress then wait until it is completed. */ | |
639 | while (!(flags & GTF_transfer_completed)) { | |
640 | flags = *pflags; | |
641 | cpu_relax(); | |
642 | } | |
643 | ||
644 | rmb(); /* Read the frame number /after/ reading completion status. */ | |
645 | frame = gnttab_shared.v2[ref].full_page.frame; | |
646 | BUG_ON(frame == 0); | |
647 | ||
648 | return frame; | |
649 | } | |
650 | ||
0f9f5a95 AL |
651 | unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref) |
652 | { | |
653 | return gnttab_interface->end_foreign_transfer_ref(ref); | |
654 | } | |
ad9a8612 JF |
655 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer_ref); |
656 | ||
657 | unsigned long gnttab_end_foreign_transfer(grant_ref_t ref) | |
658 | { | |
659 | unsigned long frame = gnttab_end_foreign_transfer_ref(ref); | |
660 | put_free_entry(ref); | |
661 | return frame; | |
662 | } | |
663 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer); | |
664 | ||
665 | void gnttab_free_grant_reference(grant_ref_t ref) | |
666 | { | |
667 | put_free_entry(ref); | |
668 | } | |
669 | EXPORT_SYMBOL_GPL(gnttab_free_grant_reference); | |
670 | ||
671 | void gnttab_free_grant_references(grant_ref_t head) | |
672 | { | |
673 | grant_ref_t ref; | |
674 | unsigned long flags; | |
675 | int count = 1; | |
676 | if (head == GNTTAB_LIST_END) | |
677 | return; | |
678 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
679 | ref = head; | |
680 | while (gnttab_entry(ref) != GNTTAB_LIST_END) { | |
681 | ref = gnttab_entry(ref); | |
682 | count++; | |
683 | } | |
684 | gnttab_entry(ref) = gnttab_free_head; | |
685 | gnttab_free_head = head; | |
686 | gnttab_free_count += count; | |
687 | check_free_callbacks(); | |
688 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
689 | } | |
690 | EXPORT_SYMBOL_GPL(gnttab_free_grant_references); | |
691 | ||
692 | int gnttab_alloc_grant_references(u16 count, grant_ref_t *head) | |
693 | { | |
694 | int h = get_free_entries(count); | |
695 | ||
696 | if (h < 0) | |
697 | return -ENOSPC; | |
698 | ||
699 | *head = h; | |
700 | ||
701 | return 0; | |
702 | } | |
703 | EXPORT_SYMBOL_GPL(gnttab_alloc_grant_references); | |
704 | ||
705 | int gnttab_empty_grant_references(const grant_ref_t *private_head) | |
706 | { | |
707 | return (*private_head == GNTTAB_LIST_END); | |
708 | } | |
709 | EXPORT_SYMBOL_GPL(gnttab_empty_grant_references); | |
710 | ||
711 | int gnttab_claim_grant_reference(grant_ref_t *private_head) | |
712 | { | |
713 | grant_ref_t g = *private_head; | |
714 | if (unlikely(g == GNTTAB_LIST_END)) | |
715 | return -ENOSPC; | |
716 | *private_head = gnttab_entry(g); | |
717 | return g; | |
718 | } | |
719 | EXPORT_SYMBOL_GPL(gnttab_claim_grant_reference); | |
720 | ||
721 | void gnttab_release_grant_reference(grant_ref_t *private_head, | |
722 | grant_ref_t release) | |
723 | { | |
724 | gnttab_entry(release) = *private_head; | |
725 | *private_head = release; | |
726 | } | |
727 | EXPORT_SYMBOL_GPL(gnttab_release_grant_reference); | |
728 | ||
729 | void gnttab_request_free_callback(struct gnttab_free_callback *callback, | |
730 | void (*fn)(void *), void *arg, u16 count) | |
731 | { | |
732 | unsigned long flags; | |
733 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
734 | if (callback->next) | |
735 | goto out; | |
736 | callback->fn = fn; | |
737 | callback->arg = arg; | |
738 | callback->count = count; | |
739 | callback->next = gnttab_free_callback_list; | |
740 | gnttab_free_callback_list = callback; | |
741 | check_free_callbacks(); | |
742 | out: | |
743 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
744 | } | |
745 | EXPORT_SYMBOL_GPL(gnttab_request_free_callback); | |
746 | ||
747 | void gnttab_cancel_free_callback(struct gnttab_free_callback *callback) | |
748 | { | |
749 | struct gnttab_free_callback **pcb; | |
750 | unsigned long flags; | |
751 | ||
752 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
753 | for (pcb = &gnttab_free_callback_list; *pcb; pcb = &(*pcb)->next) { | |
754 | if (*pcb == callback) { | |
755 | *pcb = callback->next; | |
756 | break; | |
757 | } | |
758 | } | |
759 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
760 | } | |
761 | EXPORT_SYMBOL_GPL(gnttab_cancel_free_callback); | |
762 | ||
763 | static int grow_gnttab_list(unsigned int more_frames) | |
764 | { | |
765 | unsigned int new_nr_grant_frames, extra_entries, i; | |
bbc60c18 | 766 | unsigned int nr_glist_frames, new_nr_glist_frames; |
ad9a8612 JF |
767 | |
768 | new_nr_grant_frames = nr_grant_frames + more_frames; | |
769 | extra_entries = more_frames * GREFS_PER_GRANT_FRAME; | |
770 | ||
bbc60c18 MAEM |
771 | nr_glist_frames = (nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP; |
772 | new_nr_glist_frames = | |
773 | (new_nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP; | |
774 | for (i = nr_glist_frames; i < new_nr_glist_frames; i++) { | |
ad9a8612 JF |
775 | gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_ATOMIC); |
776 | if (!gnttab_list[i]) | |
777 | goto grow_nomem; | |
778 | } | |
779 | ||
780 | ||
781 | for (i = GREFS_PER_GRANT_FRAME * nr_grant_frames; | |
782 | i < GREFS_PER_GRANT_FRAME * new_nr_grant_frames - 1; i++) | |
783 | gnttab_entry(i) = i + 1; | |
784 | ||
785 | gnttab_entry(i) = gnttab_free_head; | |
786 | gnttab_free_head = GREFS_PER_GRANT_FRAME * nr_grant_frames; | |
787 | gnttab_free_count += extra_entries; | |
788 | ||
789 | nr_grant_frames = new_nr_grant_frames; | |
790 | ||
791 | check_free_callbacks(); | |
792 | ||
793 | return 0; | |
794 | ||
795 | grow_nomem: | |
bbc60c18 | 796 | for ( ; i >= nr_glist_frames; i--) |
ad9a8612 JF |
797 | free_page((unsigned long) gnttab_list[i]); |
798 | return -ENOMEM; | |
799 | } | |
800 | ||
801 | static unsigned int __max_nr_grant_frames(void) | |
802 | { | |
803 | struct gnttab_query_size query; | |
804 | int rc; | |
805 | ||
806 | query.dom = DOMID_SELF; | |
807 | ||
808 | rc = HYPERVISOR_grant_table_op(GNTTABOP_query_size, &query, 1); | |
809 | if ((rc < 0) || (query.status != GNTST_okay)) | |
810 | return 4; /* Legacy max supported number of frames */ | |
811 | ||
812 | return query.max_nr_frames; | |
813 | } | |
814 | ||
183d03cc | 815 | unsigned int gnttab_max_grant_frames(void) |
ad9a8612 JF |
816 | { |
817 | unsigned int xen_max = __max_nr_grant_frames(); | |
818 | ||
819 | if (xen_max > boot_max_nr_grant_frames) | |
820 | return boot_max_nr_grant_frames; | |
821 | return xen_max; | |
822 | } | |
183d03cc | 823 | EXPORT_SYMBOL_GPL(gnttab_max_grant_frames); |
ad9a8612 | 824 | |
289b777e | 825 | int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, |
c123799a AL |
826 | struct gnttab_map_grant_ref *kmap_ops, |
827 | struct page **pages, unsigned int count) | |
289b777e SS |
828 | { |
829 | int i, ret; | |
830 | pte_t *pte; | |
831 | unsigned long mfn; | |
832 | ||
833 | ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map_ops, count); | |
87f1d40a JF |
834 | if (ret) |
835 | return ret; | |
289b777e | 836 | |
aab8f11a DDG |
837 | if (xen_feature(XENFEAT_auto_translated_physmap)) |
838 | return ret; | |
839 | ||
289b777e | 840 | for (i = 0; i < count; i++) { |
dc4972a4 IC |
841 | /* Do not add to override if the map failed. */ |
842 | if (map_ops[i].status) | |
843 | continue; | |
844 | ||
cf8d9163 KRW |
845 | if (map_ops[i].flags & GNTMAP_contains_pte) { |
846 | pte = (pte_t *) (mfn_to_virt(PFN_DOWN(map_ops[i].host_addr)) + | |
289b777e | 847 | (map_ops[i].host_addr & ~PAGE_MASK)); |
cf8d9163 KRW |
848 | mfn = pte_mfn(*pte); |
849 | } else { | |
7d17e84b | 850 | mfn = PFN_DOWN(map_ops[i].dev_bus_addr); |
cf8d9163 | 851 | } |
7d17e84b DDG |
852 | ret = m2p_add_override(mfn, pages[i], kmap_ops ? |
853 | &kmap_ops[i] : NULL); | |
87f1d40a JF |
854 | if (ret) |
855 | return ret; | |
289b777e SS |
856 | } |
857 | ||
858 | return ret; | |
859 | } | |
860 | EXPORT_SYMBOL_GPL(gnttab_map_refs); | |
861 | ||
862 | int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, | |
7d17e84b | 863 | struct page **pages, unsigned int count, bool clear_pte) |
289b777e SS |
864 | { |
865 | int i, ret; | |
866 | ||
867 | ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops, count); | |
87f1d40a JF |
868 | if (ret) |
869 | return ret; | |
870 | ||
aab8f11a DDG |
871 | if (xen_feature(XENFEAT_auto_translated_physmap)) |
872 | return ret; | |
873 | ||
87f1d40a | 874 | for (i = 0; i < count; i++) { |
7d17e84b | 875 | ret = m2p_remove_override(pages[i], clear_pte); |
87f1d40a JF |
876 | if (ret) |
877 | return ret; | |
878 | } | |
289b777e SS |
879 | |
880 | return ret; | |
881 | } | |
882 | EXPORT_SYMBOL_GPL(gnttab_unmap_refs); | |
883 | ||
85ff6acb AL |
884 | static unsigned nr_status_frames(unsigned nr_grant_frames) |
885 | { | |
886 | return (nr_grant_frames * GREFS_PER_GRANT_FRAME + SPP - 1) / SPP; | |
887 | } | |
888 | ||
0f9f5a95 AL |
889 | static int gnttab_map_frames_v1(unsigned long *frames, unsigned int nr_gframes) |
890 | { | |
891 | int rc; | |
892 | ||
893 | rc = arch_gnttab_map_shared(frames, nr_gframes, | |
894 | gnttab_max_grant_frames(), | |
895 | &gnttab_shared.addr); | |
896 | BUG_ON(rc); | |
897 | ||
898 | return 0; | |
899 | } | |
900 | ||
901 | static void gnttab_unmap_frames_v1(void) | |
902 | { | |
85ff6acb AL |
903 | arch_gnttab_unmap(gnttab_shared.addr, nr_grant_frames); |
904 | } | |
905 | ||
906 | static int gnttab_map_frames_v2(unsigned long *frames, unsigned int nr_gframes) | |
907 | { | |
908 | uint64_t *sframes; | |
909 | unsigned int nr_sframes; | |
910 | struct gnttab_get_status_frames getframes; | |
911 | int rc; | |
912 | ||
913 | nr_sframes = nr_status_frames(nr_gframes); | |
914 | ||
915 | /* No need for kzalloc as it is initialized in following hypercall | |
916 | * GNTTABOP_get_status_frames. | |
917 | */ | |
918 | sframes = kmalloc(nr_sframes * sizeof(uint64_t), GFP_ATOMIC); | |
919 | if (!sframes) | |
920 | return -ENOMEM; | |
921 | ||
922 | getframes.dom = DOMID_SELF; | |
923 | getframes.nr_frames = nr_sframes; | |
924 | set_xen_guest_handle(getframes.frame_list, sframes); | |
925 | ||
926 | rc = HYPERVISOR_grant_table_op(GNTTABOP_get_status_frames, | |
927 | &getframes, 1); | |
928 | if (rc == -ENOSYS) { | |
929 | kfree(sframes); | |
930 | return -ENOSYS; | |
931 | } | |
932 | ||
933 | BUG_ON(rc || getframes.status); | |
934 | ||
935 | rc = arch_gnttab_map_status(sframes, nr_sframes, | |
936 | nr_status_frames(gnttab_max_grant_frames()), | |
937 | &grstatus); | |
938 | BUG_ON(rc); | |
939 | kfree(sframes); | |
940 | ||
941 | rc = arch_gnttab_map_shared(frames, nr_gframes, | |
942 | gnttab_max_grant_frames(), | |
943 | &gnttab_shared.addr); | |
944 | BUG_ON(rc); | |
945 | ||
946 | return 0; | |
947 | } | |
948 | ||
949 | static void gnttab_unmap_frames_v2(void) | |
950 | { | |
951 | arch_gnttab_unmap(gnttab_shared.addr, nr_grant_frames); | |
952 | arch_gnttab_unmap(grstatus, nr_status_frames(nr_grant_frames)); | |
0f9f5a95 AL |
953 | } |
954 | ||
ad9a8612 JF |
955 | static int gnttab_map(unsigned int start_idx, unsigned int end_idx) |
956 | { | |
957 | struct gnttab_setup_table setup; | |
958 | unsigned long *frames; | |
959 | unsigned int nr_gframes = end_idx + 1; | |
960 | int rc; | |
961 | ||
183d03cc SS |
962 | if (xen_hvm_domain()) { |
963 | struct xen_add_to_physmap xatp; | |
964 | unsigned int i = end_idx; | |
965 | rc = 0; | |
966 | /* | |
967 | * Loop backwards, so that the first hypercall has the largest | |
968 | * index, ensuring that the table will grow only once. | |
969 | */ | |
970 | do { | |
971 | xatp.domid = DOMID_SELF; | |
972 | xatp.idx = i; | |
973 | xatp.space = XENMAPSPACE_grant_table; | |
974 | xatp.gpfn = (xen_hvm_resume_frames >> PAGE_SHIFT) + i; | |
975 | rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp); | |
976 | if (rc != 0) { | |
977 | printk(KERN_WARNING | |
978 | "grant table add_to_physmap failed, err=%d\n", rc); | |
979 | break; | |
980 | } | |
981 | } while (i-- > start_idx); | |
982 | ||
983 | return rc; | |
984 | } | |
985 | ||
85ff6acb AL |
986 | /* No need for kzalloc as it is initialized in following hypercall |
987 | * GNTTABOP_setup_table. | |
988 | */ | |
ad9a8612 JF |
989 | frames = kmalloc(nr_gframes * sizeof(unsigned long), GFP_ATOMIC); |
990 | if (!frames) | |
991 | return -ENOMEM; | |
992 | ||
993 | setup.dom = DOMID_SELF; | |
994 | setup.nr_frames = nr_gframes; | |
87e27cf6 | 995 | set_xen_guest_handle(setup.frame_list, frames); |
ad9a8612 JF |
996 | |
997 | rc = HYPERVISOR_grant_table_op(GNTTABOP_setup_table, &setup, 1); | |
998 | if (rc == -ENOSYS) { | |
999 | kfree(frames); | |
1000 | return -ENOSYS; | |
1001 | } | |
1002 | ||
1003 | BUG_ON(rc || setup.status); | |
1004 | ||
0f9f5a95 | 1005 | rc = gnttab_interface->map_frames(frames, nr_gframes); |
ad9a8612 JF |
1006 | |
1007 | kfree(frames); | |
1008 | ||
0f9f5a95 AL |
1009 | return rc; |
1010 | } | |
1011 | ||
1012 | static struct gnttab_ops gnttab_v1_ops = { | |
1013 | .map_frames = gnttab_map_frames_v1, | |
1014 | .unmap_frames = gnttab_unmap_frames_v1, | |
1015 | .update_entry = gnttab_update_entry_v1, | |
1016 | .end_foreign_access_ref = gnttab_end_foreign_access_ref_v1, | |
1017 | .end_foreign_transfer_ref = gnttab_end_foreign_transfer_ref_v1, | |
1018 | .query_foreign_access = gnttab_query_foreign_access_v1, | |
1019 | }; | |
1020 | ||
85ff6acb AL |
1021 | static struct gnttab_ops gnttab_v2_ops = { |
1022 | .map_frames = gnttab_map_frames_v2, | |
1023 | .unmap_frames = gnttab_unmap_frames_v2, | |
1024 | .update_entry = gnttab_update_entry_v2, | |
1025 | .end_foreign_access_ref = gnttab_end_foreign_access_ref_v2, | |
1026 | .end_foreign_transfer_ref = gnttab_end_foreign_transfer_ref_v2, | |
1027 | .query_foreign_access = gnttab_query_foreign_access_v2, | |
6666754b | 1028 | .update_subpage_entry = gnttab_update_subpage_entry_v2, |
9438ce9d | 1029 | .update_trans_entry = gnttab_update_trans_entry_v2, |
85ff6acb AL |
1030 | }; |
1031 | ||
0f9f5a95 AL |
1032 | static void gnttab_request_version(void) |
1033 | { | |
85ff6acb AL |
1034 | int rc; |
1035 | struct gnttab_set_version gsv; | |
1036 | ||
69e8f430 KRW |
1037 | if (xen_hvm_domain()) |
1038 | gsv.version = 1; | |
1039 | else | |
1040 | gsv.version = 2; | |
85ff6acb | 1041 | rc = HYPERVISOR_grant_table_op(GNTTABOP_set_version, &gsv, 1); |
69e8f430 | 1042 | if (rc == 0 && gsv.version == 2) { |
85ff6acb AL |
1043 | grant_table_version = 2; |
1044 | gnttab_interface = &gnttab_v2_ops; | |
1045 | } else if (grant_table_version == 2) { | |
1046 | /* | |
1047 | * If we've already used version 2 features, | |
1048 | * but then suddenly discover that they're not | |
1049 | * available (e.g. migrating to an older | |
1050 | * version of Xen), almost unbounded badness | |
1051 | * can happen. | |
1052 | */ | |
1053 | panic("we need grant tables version 2, but only version 1 is available"); | |
1054 | } else { | |
1055 | grant_table_version = 1; | |
1056 | gnttab_interface = &gnttab_v1_ops; | |
1057 | } | |
0f9f5a95 AL |
1058 | printk(KERN_INFO "Grant tables using version %d layout.\n", |
1059 | grant_table_version); | |
ad9a8612 JF |
1060 | } |
1061 | ||
0e91398f | 1062 | int gnttab_resume(void) |
ad9a8612 | 1063 | { |
183d03cc SS |
1064 | unsigned int max_nr_gframes; |
1065 | ||
0f9f5a95 | 1066 | gnttab_request_version(); |
183d03cc SS |
1067 | max_nr_gframes = gnttab_max_grant_frames(); |
1068 | if (max_nr_gframes < nr_grant_frames) | |
ad9a8612 | 1069 | return -ENOSYS; |
183d03cc SS |
1070 | |
1071 | if (xen_pv_domain()) | |
1072 | return gnttab_map(0, nr_grant_frames - 1); | |
1073 | ||
0f9f5a95 AL |
1074 | if (gnttab_shared.addr == NULL) { |
1075 | gnttab_shared.addr = ioremap(xen_hvm_resume_frames, | |
1076 | PAGE_SIZE * max_nr_gframes); | |
1077 | if (gnttab_shared.addr == NULL) { | |
183d03cc SS |
1078 | printk(KERN_WARNING |
1079 | "Failed to ioremap gnttab share frames!"); | |
1080 | return -ENOMEM; | |
1081 | } | |
1082 | } | |
1083 | ||
1084 | gnttab_map(0, nr_grant_frames - 1); | |
1085 | ||
1086 | return 0; | |
ad9a8612 JF |
1087 | } |
1088 | ||
0e91398f | 1089 | int gnttab_suspend(void) |
ad9a8612 | 1090 | { |
0f9f5a95 | 1091 | gnttab_interface->unmap_frames(); |
ad9a8612 JF |
1092 | return 0; |
1093 | } | |
1094 | ||
1095 | static int gnttab_expand(unsigned int req_entries) | |
1096 | { | |
1097 | int rc; | |
1098 | unsigned int cur, extra; | |
1099 | ||
1100 | cur = nr_grant_frames; | |
1101 | extra = ((req_entries + (GREFS_PER_GRANT_FRAME-1)) / | |
1102 | GREFS_PER_GRANT_FRAME); | |
183d03cc | 1103 | if (cur + extra > gnttab_max_grant_frames()) |
ad9a8612 JF |
1104 | return -ENOSPC; |
1105 | ||
1106 | rc = gnttab_map(cur, cur + extra - 1); | |
1107 | if (rc == 0) | |
1108 | rc = grow_gnttab_list(extra); | |
1109 | ||
1110 | return rc; | |
1111 | } | |
1112 | ||
183d03cc | 1113 | int gnttab_init(void) |
ad9a8612 JF |
1114 | { |
1115 | int i; | |
bbc60c18 | 1116 | unsigned int max_nr_glist_frames, nr_glist_frames; |
ad9a8612 JF |
1117 | unsigned int nr_init_grefs; |
1118 | ||
ad9a8612 JF |
1119 | nr_grant_frames = 1; |
1120 | boot_max_nr_grant_frames = __max_nr_grant_frames(); | |
1121 | ||
1122 | /* Determine the maximum number of frames required for the | |
1123 | * grant reference free list on the current hypervisor. | |
1124 | */ | |
1125 | max_nr_glist_frames = (boot_max_nr_grant_frames * | |
bbc60c18 | 1126 | GREFS_PER_GRANT_FRAME / RPP); |
ad9a8612 JF |
1127 | |
1128 | gnttab_list = kmalloc(max_nr_glist_frames * sizeof(grant_ref_t *), | |
1129 | GFP_KERNEL); | |
1130 | if (gnttab_list == NULL) | |
1131 | return -ENOMEM; | |
1132 | ||
bbc60c18 MAEM |
1133 | nr_glist_frames = (nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP; |
1134 | for (i = 0; i < nr_glist_frames; i++) { | |
ad9a8612 JF |
1135 | gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_KERNEL); |
1136 | if (gnttab_list[i] == NULL) | |
1137 | goto ini_nomem; | |
1138 | } | |
1139 | ||
1140 | if (gnttab_resume() < 0) | |
1141 | return -ENODEV; | |
1142 | ||
1143 | nr_init_grefs = nr_grant_frames * GREFS_PER_GRANT_FRAME; | |
1144 | ||
1145 | for (i = NR_RESERVED_ENTRIES; i < nr_init_grefs - 1; i++) | |
1146 | gnttab_entry(i) = i + 1; | |
1147 | ||
1148 | gnttab_entry(nr_init_grefs - 1) = GNTTAB_LIST_END; | |
1149 | gnttab_free_count = nr_init_grefs - NR_RESERVED_ENTRIES; | |
1150 | gnttab_free_head = NR_RESERVED_ENTRIES; | |
1151 | ||
1152 | printk("Grant table initialized\n"); | |
1153 | return 0; | |
1154 | ||
1155 | ini_nomem: | |
1156 | for (i--; i >= 0; i--) | |
1157 | free_page((unsigned long)gnttab_list[i]); | |
1158 | kfree(gnttab_list); | |
1159 | return -ENOMEM; | |
1160 | } | |
183d03cc SS |
1161 | EXPORT_SYMBOL_GPL(gnttab_init); |
1162 | ||
1163 | static int __devinit __gnttab_init(void) | |
1164 | { | |
1165 | /* Delay grant-table initialization in the PV on HVM case */ | |
1166 | if (xen_hvm_domain()) | |
1167 | return 0; | |
1168 | ||
1169 | if (!xen_pv_domain()) | |
1170 | return -ENODEV; | |
1171 | ||
1172 | return gnttab_init(); | |
1173 | } | |
ad9a8612 | 1174 | |
183d03cc | 1175 | core_initcall(__gnttab_init); |