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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> |
f62805f1 | 41 | #include <linux/hardirq.h> |
ad9a8612 | 42 | |
1ccbf534 | 43 | #include <xen/xen.h> |
ad9a8612 JF |
44 | #include <xen/interface/xen.h> |
45 | #include <xen/page.h> | |
46 | #include <xen/grant_table.h> | |
183d03cc | 47 | #include <xen/interface/memory.h> |
85ff6acb | 48 | #include <xen/hvc-console.h> |
ecbf29cd | 49 | #include <asm/xen/hypercall.h> |
ad9a8612 JF |
50 | |
51 | #include <asm/pgtable.h> | |
52 | #include <asm/sync_bitops.h> | |
53 | ||
ad9a8612 JF |
54 | /* External tools reserve first few grant table entries. */ |
55 | #define NR_RESERVED_ENTRIES 8 | |
56 | #define GNTTAB_LIST_END 0xffffffff | |
85ff6acb AL |
57 | #define GREFS_PER_GRANT_FRAME \ |
58 | (grant_table_version == 1 ? \ | |
59 | (PAGE_SIZE / sizeof(struct grant_entry_v1)) : \ | |
60 | (PAGE_SIZE / sizeof(union grant_entry_v2))) | |
ad9a8612 JF |
61 | |
62 | static grant_ref_t **gnttab_list; | |
63 | static unsigned int nr_grant_frames; | |
64 | static unsigned int boot_max_nr_grant_frames; | |
65 | static int gnttab_free_count; | |
66 | static grant_ref_t gnttab_free_head; | |
67 | static DEFINE_SPINLOCK(gnttab_list_lock); | |
183d03cc SS |
68 | unsigned long xen_hvm_resume_frames; |
69 | EXPORT_SYMBOL_GPL(xen_hvm_resume_frames); | |
ad9a8612 | 70 | |
0f9f5a95 AL |
71 | static union { |
72 | struct grant_entry_v1 *v1; | |
85ff6acb | 73 | union grant_entry_v2 *v2; |
0f9f5a95 AL |
74 | void *addr; |
75 | } gnttab_shared; | |
76 | ||
77 | /*This is a structure of function pointers for grant table*/ | |
78 | struct gnttab_ops { | |
79 | /* | |
9dbc71d5 AL |
80 | * Mapping a list of frames for storing grant entries. Frames parameter |
81 | * is used to store grant table address when grant table being setup, | |
82 | * nr_gframes is the number of frames to map grant table. Returning | |
83 | * GNTST_okay means success and negative value means failure. | |
0f9f5a95 | 84 | */ |
9dbc71d5 | 85 | int (*map_frames)(unsigned long *frames, unsigned int nr_gframes); |
0f9f5a95 AL |
86 | /* |
87 | * Release a list of frames which are mapped in map_frames for grant | |
88 | * entry status. | |
89 | */ | |
90 | void (*unmap_frames)(void); | |
91 | /* | |
9dbc71d5 AL |
92 | * Introducing a valid entry into the grant table, granting the frame of |
93 | * this grant entry to domain for accessing or transfering. Ref | |
94 | * parameter is reference of this introduced grant entry, domid is id of | |
95 | * granted domain, frame is the page frame to be granted, and flags is | |
96 | * status of the grant entry to be updated. | |
0f9f5a95 | 97 | */ |
9dbc71d5 AL |
98 | void (*update_entry)(grant_ref_t ref, domid_t domid, |
99 | unsigned long frame, unsigned flags); | |
0f9f5a95 | 100 | /* |
9dbc71d5 AL |
101 | * Stop granting a grant entry to domain for accessing. Ref parameter is |
102 | * reference of a grant entry whose grant access will be stopped, | |
103 | * readonly is not in use in this function. If the grant entry is | |
0f9f5a95 AL |
104 | * currently mapped for reading or writing, just return failure(==0) |
105 | * directly and don't tear down the grant access. Otherwise, stop grant | |
106 | * access for this entry and return success(==1). | |
107 | */ | |
9dbc71d5 | 108 | int (*end_foreign_access_ref)(grant_ref_t ref, int readonly); |
0f9f5a95 | 109 | /* |
9dbc71d5 AL |
110 | * Stop granting a grant entry to domain for transfer. Ref parameter is |
111 | * reference of a grant entry whose grant transfer will be stopped. If | |
112 | * tranfer has not started, just reclaim the grant entry and return | |
113 | * failure(==0). Otherwise, wait for the transfer to complete and then | |
114 | * return the frame. | |
0f9f5a95 | 115 | */ |
9dbc71d5 | 116 | unsigned long (*end_foreign_transfer_ref)(grant_ref_t ref); |
0f9f5a95 | 117 | /* |
9dbc71d5 | 118 | * Query the status of a grant entry. Ref parameter is reference of |
0f9f5a95 AL |
119 | * queried grant entry, return value is the status of queried entry. |
120 | * Detailed status(writing/reading) can be gotten from the return value | |
121 | * by bit operations. | |
122 | */ | |
9dbc71d5 | 123 | int (*query_foreign_access)(grant_ref_t ref); |
6666754b AL |
124 | /* |
125 | * Grant a domain to access a range of bytes within the page referred by | |
126 | * an available grant entry. Ref parameter is reference of a grant entry | |
127 | * which will be sub-page accessed, domid is id of grantee domain, frame | |
128 | * is frame address of subpage grant, flags is grant type and flag | |
129 | * information, page_off is offset of the range of bytes, and length is | |
130 | * length of bytes to be accessed. | |
131 | */ | |
132 | void (*update_subpage_entry)(grant_ref_t ref, domid_t domid, | |
133 | unsigned long frame, int flags, | |
134 | unsigned page_off, unsigned length); | |
9438ce9d AL |
135 | /* |
136 | * Redirect an available grant entry on domain A to another grant | |
137 | * reference of domain B, then allow domain C to use grant reference | |
138 | * of domain B transitively. Ref parameter is an available grant entry | |
139 | * reference on domain A, domid is id of domain C which accesses grant | |
140 | * entry transitively, flags is grant type and flag information, | |
141 | * trans_domid is id of domain B whose grant entry is finally accessed | |
142 | * transitively, trans_gref is grant entry transitive reference of | |
143 | * domain B. | |
144 | */ | |
145 | void (*update_trans_entry)(grant_ref_t ref, domid_t domid, int flags, | |
146 | domid_t trans_domid, grant_ref_t trans_gref); | |
0f9f5a95 AL |
147 | }; |
148 | ||
149 | static struct gnttab_ops *gnttab_interface; | |
150 | ||
85ff6acb AL |
151 | /*This reflects status of grant entries, so act as a global value*/ |
152 | static grant_status_t *grstatus; | |
153 | ||
0f9f5a95 | 154 | static int grant_table_version; |
ad9a8612 JF |
155 | |
156 | static struct gnttab_free_callback *gnttab_free_callback_list; | |
157 | ||
158 | static int gnttab_expand(unsigned int req_entries); | |
159 | ||
160 | #define RPP (PAGE_SIZE / sizeof(grant_ref_t)) | |
85ff6acb | 161 | #define SPP (PAGE_SIZE / sizeof(grant_status_t)) |
ad9a8612 JF |
162 | |
163 | static inline grant_ref_t *__gnttab_entry(grant_ref_t entry) | |
164 | { | |
165 | return &gnttab_list[(entry) / RPP][(entry) % RPP]; | |
166 | } | |
167 | /* This can be used as an l-value */ | |
168 | #define gnttab_entry(entry) (*__gnttab_entry(entry)) | |
169 | ||
170 | static int get_free_entries(unsigned count) | |
171 | { | |
172 | unsigned long flags; | |
272800dc | 173 | int ref, rc = 0; |
ad9a8612 JF |
174 | grant_ref_t head; |
175 | ||
176 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
177 | ||
178 | if ((gnttab_free_count < count) && | |
179 | ((rc = gnttab_expand(count - gnttab_free_count)) < 0)) { | |
180 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
181 | return rc; | |
182 | } | |
183 | ||
184 | ref = head = gnttab_free_head; | |
185 | gnttab_free_count -= count; | |
186 | while (count-- > 1) | |
187 | head = gnttab_entry(head); | |
188 | gnttab_free_head = gnttab_entry(head); | |
189 | gnttab_entry(head) = GNTTAB_LIST_END; | |
190 | ||
191 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
192 | ||
193 | return ref; | |
194 | } | |
195 | ||
196 | static void do_free_callbacks(void) | |
197 | { | |
198 | struct gnttab_free_callback *callback, *next; | |
199 | ||
200 | callback = gnttab_free_callback_list; | |
201 | gnttab_free_callback_list = NULL; | |
202 | ||
203 | while (callback != NULL) { | |
204 | next = callback->next; | |
205 | if (gnttab_free_count >= callback->count) { | |
206 | callback->next = NULL; | |
207 | callback->fn(callback->arg); | |
208 | } else { | |
209 | callback->next = gnttab_free_callback_list; | |
210 | gnttab_free_callback_list = callback; | |
211 | } | |
212 | callback = next; | |
213 | } | |
214 | } | |
215 | ||
216 | static inline void check_free_callbacks(void) | |
217 | { | |
218 | if (unlikely(gnttab_free_callback_list)) | |
219 | do_free_callbacks(); | |
220 | } | |
221 | ||
222 | static void put_free_entry(grant_ref_t ref) | |
223 | { | |
224 | unsigned long flags; | |
225 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
226 | gnttab_entry(ref) = gnttab_free_head; | |
227 | gnttab_free_head = ref; | |
228 | gnttab_free_count++; | |
229 | check_free_callbacks(); | |
230 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
231 | } | |
232 | ||
0f9f5a95 | 233 | /* |
85ff6acb | 234 | * Following applies to gnttab_update_entry_v1 and gnttab_update_entry_v2. |
0f9f5a95 AL |
235 | * Introducing a valid entry into the grant table: |
236 | * 1. Write ent->domid. | |
237 | * 2. Write ent->frame: | |
238 | * GTF_permit_access: Frame to which access is permitted. | |
239 | * GTF_accept_transfer: Pseudo-phys frame slot being filled by new | |
240 | * frame, or zero if none. | |
241 | * 3. Write memory barrier (WMB). | |
242 | * 4. Write ent->flags, inc. valid type. | |
243 | */ | |
244 | static void gnttab_update_entry_v1(grant_ref_t ref, domid_t domid, | |
245 | unsigned long frame, unsigned flags) | |
ad9a8612 | 246 | { |
0f9f5a95 AL |
247 | gnttab_shared.v1[ref].domid = domid; |
248 | gnttab_shared.v1[ref].frame = frame; | |
ad9a8612 | 249 | wmb(); |
0f9f5a95 | 250 | gnttab_shared.v1[ref].flags = flags; |
ad9a8612 JF |
251 | } |
252 | ||
85ff6acb AL |
253 | static void gnttab_update_entry_v2(grant_ref_t ref, domid_t domid, |
254 | unsigned long frame, unsigned flags) | |
255 | { | |
256 | gnttab_shared.v2[ref].hdr.domid = domid; | |
257 | gnttab_shared.v2[ref].full_page.frame = frame; | |
258 | wmb(); | |
259 | gnttab_shared.v2[ref].hdr.flags = GTF_permit_access | flags; | |
260 | } | |
261 | ||
ad9a8612 JF |
262 | /* |
263 | * Public grant-issuing interface functions | |
264 | */ | |
265 | void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid, | |
266 | unsigned long frame, int readonly) | |
267 | { | |
0f9f5a95 | 268 | gnttab_interface->update_entry(ref, domid, frame, |
ad9a8612 JF |
269 | GTF_permit_access | (readonly ? GTF_readonly : 0)); |
270 | } | |
271 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_ref); | |
272 | ||
273 | int gnttab_grant_foreign_access(domid_t domid, unsigned long frame, | |
274 | int readonly) | |
275 | { | |
276 | int ref; | |
277 | ||
278 | ref = get_free_entries(1); | |
279 | if (unlikely(ref < 0)) | |
280 | return -ENOSPC; | |
281 | ||
282 | gnttab_grant_foreign_access_ref(ref, domid, frame, readonly); | |
283 | ||
284 | return ref; | |
285 | } | |
286 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access); | |
287 | ||
6666754b AL |
288 | void gnttab_update_subpage_entry_v2(grant_ref_t ref, domid_t domid, |
289 | unsigned long frame, int flags, | |
290 | unsigned page_off, | |
291 | unsigned length) | |
292 | { | |
293 | gnttab_shared.v2[ref].sub_page.frame = frame; | |
294 | gnttab_shared.v2[ref].sub_page.page_off = page_off; | |
295 | gnttab_shared.v2[ref].sub_page.length = length; | |
296 | gnttab_shared.v2[ref].hdr.domid = domid; | |
297 | wmb(); | |
298 | gnttab_shared.v2[ref].hdr.flags = | |
299 | GTF_permit_access | GTF_sub_page | flags; | |
300 | } | |
301 | ||
302 | int gnttab_grant_foreign_access_subpage_ref(grant_ref_t ref, domid_t domid, | |
303 | unsigned long frame, int flags, | |
304 | unsigned page_off, | |
305 | unsigned length) | |
306 | { | |
307 | if (flags & (GTF_accept_transfer | GTF_reading | | |
308 | GTF_writing | GTF_transitive)) | |
309 | return -EPERM; | |
310 | ||
311 | if (gnttab_interface->update_subpage_entry == NULL) | |
312 | return -ENOSYS; | |
313 | ||
314 | gnttab_interface->update_subpage_entry(ref, domid, frame, flags, | |
315 | page_off, length); | |
316 | ||
317 | return 0; | |
318 | } | |
319 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_subpage_ref); | |
320 | ||
321 | int gnttab_grant_foreign_access_subpage(domid_t domid, unsigned long frame, | |
322 | int flags, unsigned page_off, | |
323 | unsigned length) | |
324 | { | |
325 | int ref, rc; | |
326 | ||
327 | ref = get_free_entries(1); | |
328 | if (unlikely(ref < 0)) | |
329 | return -ENOSPC; | |
330 | ||
331 | rc = gnttab_grant_foreign_access_subpage_ref(ref, domid, frame, flags, | |
332 | page_off, length); | |
333 | if (rc < 0) { | |
334 | put_free_entry(ref); | |
335 | return rc; | |
336 | } | |
337 | ||
338 | return ref; | |
339 | } | |
340 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_subpage); | |
341 | ||
342 | bool gnttab_subpage_grants_available(void) | |
343 | { | |
344 | return gnttab_interface->update_subpage_entry != NULL; | |
345 | } | |
346 | EXPORT_SYMBOL_GPL(gnttab_subpage_grants_available); | |
347 | ||
9438ce9d AL |
348 | void gnttab_update_trans_entry_v2(grant_ref_t ref, domid_t domid, |
349 | int flags, domid_t trans_domid, | |
350 | grant_ref_t trans_gref) | |
351 | { | |
352 | gnttab_shared.v2[ref].transitive.trans_domid = trans_domid; | |
353 | gnttab_shared.v2[ref].transitive.gref = trans_gref; | |
354 | gnttab_shared.v2[ref].hdr.domid = domid; | |
355 | wmb(); | |
356 | gnttab_shared.v2[ref].hdr.flags = | |
357 | GTF_permit_access | GTF_transitive | flags; | |
358 | } | |
359 | ||
360 | int gnttab_grant_foreign_access_trans_ref(grant_ref_t ref, domid_t domid, | |
361 | int flags, domid_t trans_domid, | |
362 | grant_ref_t trans_gref) | |
363 | { | |
364 | if (flags & (GTF_accept_transfer | GTF_reading | | |
365 | GTF_writing | GTF_sub_page)) | |
366 | return -EPERM; | |
367 | ||
368 | if (gnttab_interface->update_trans_entry == NULL) | |
369 | return -ENOSYS; | |
370 | ||
371 | gnttab_interface->update_trans_entry(ref, domid, flags, trans_domid, | |
372 | trans_gref); | |
373 | ||
374 | return 0; | |
375 | } | |
376 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_trans_ref); | |
377 | ||
378 | int gnttab_grant_foreign_access_trans(domid_t domid, int flags, | |
379 | domid_t trans_domid, | |
380 | grant_ref_t trans_gref) | |
381 | { | |
382 | int ref, rc; | |
383 | ||
384 | ref = get_free_entries(1); | |
385 | if (unlikely(ref < 0)) | |
386 | return -ENOSPC; | |
387 | ||
388 | rc = gnttab_grant_foreign_access_trans_ref(ref, domid, flags, | |
389 | trans_domid, trans_gref); | |
390 | if (rc < 0) { | |
391 | put_free_entry(ref); | |
392 | return rc; | |
393 | } | |
394 | ||
395 | return ref; | |
396 | } | |
397 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_trans); | |
398 | ||
399 | bool gnttab_trans_grants_available(void) | |
400 | { | |
401 | return gnttab_interface->update_trans_entry != NULL; | |
402 | } | |
403 | EXPORT_SYMBOL_GPL(gnttab_trans_grants_available); | |
404 | ||
0f9f5a95 | 405 | static int gnttab_query_foreign_access_v1(grant_ref_t ref) |
ad9a8612 | 406 | { |
0f9f5a95 AL |
407 | return gnttab_shared.v1[ref].flags & (GTF_reading|GTF_writing); |
408 | } | |
ad9a8612 | 409 | |
85ff6acb AL |
410 | static int gnttab_query_foreign_access_v2(grant_ref_t ref) |
411 | { | |
412 | return grstatus[ref] & (GTF_reading|GTF_writing); | |
413 | } | |
414 | ||
0f9f5a95 AL |
415 | int gnttab_query_foreign_access(grant_ref_t ref) |
416 | { | |
417 | return gnttab_interface->query_foreign_access(ref); | |
ad9a8612 JF |
418 | } |
419 | EXPORT_SYMBOL_GPL(gnttab_query_foreign_access); | |
420 | ||
0f9f5a95 | 421 | static int gnttab_end_foreign_access_ref_v1(grant_ref_t ref, int readonly) |
ad9a8612 JF |
422 | { |
423 | u16 flags, nflags; | |
b1e495b2 | 424 | u16 *pflags; |
ad9a8612 | 425 | |
b1e495b2 AL |
426 | pflags = &gnttab_shared.v1[ref].flags; |
427 | nflags = *pflags; | |
ad9a8612 JF |
428 | do { |
429 | flags = nflags; | |
569ca5b3 | 430 | if (flags & (GTF_reading|GTF_writing)) |
ad9a8612 | 431 | return 0; |
b1e495b2 | 432 | } while ((nflags = sync_cmpxchg(pflags, flags, 0)) != flags); |
ad9a8612 JF |
433 | |
434 | return 1; | |
435 | } | |
0f9f5a95 | 436 | |
85ff6acb AL |
437 | static int gnttab_end_foreign_access_ref_v2(grant_ref_t ref, int readonly) |
438 | { | |
439 | gnttab_shared.v2[ref].hdr.flags = 0; | |
440 | mb(); | |
441 | if (grstatus[ref] & (GTF_reading|GTF_writing)) { | |
442 | return 0; | |
443 | } else { | |
444 | /* The read of grstatus needs to have acquire | |
445 | semantics. On x86, reads already have | |
446 | that, and we just need to protect against | |
447 | compiler reorderings. On other | |
448 | architectures we may need a full | |
449 | barrier. */ | |
450 | #ifdef CONFIG_X86 | |
451 | barrier(); | |
452 | #else | |
453 | mb(); | |
454 | #endif | |
455 | } | |
456 | ||
457 | return 1; | |
458 | } | |
459 | ||
569ca5b3 | 460 | static inline int _gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly) |
0f9f5a95 AL |
461 | { |
462 | return gnttab_interface->end_foreign_access_ref(ref, readonly); | |
463 | } | |
569ca5b3 JB |
464 | |
465 | int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly) | |
466 | { | |
467 | if (_gnttab_end_foreign_access_ref(ref, readonly)) | |
468 | return 1; | |
469 | pr_warn("WARNING: g.e. %#x still in use!\n", ref); | |
470 | return 0; | |
471 | } | |
ad9a8612 JF |
472 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_access_ref); |
473 | ||
569ca5b3 JB |
474 | struct deferred_entry { |
475 | struct list_head list; | |
476 | grant_ref_t ref; | |
477 | bool ro; | |
478 | uint16_t warn_delay; | |
479 | struct page *page; | |
480 | }; | |
481 | static LIST_HEAD(deferred_list); | |
482 | static void gnttab_handle_deferred(unsigned long); | |
483 | static DEFINE_TIMER(deferred_timer, gnttab_handle_deferred, 0, 0); | |
484 | ||
485 | static void gnttab_handle_deferred(unsigned long unused) | |
486 | { | |
487 | unsigned int nr = 10; | |
488 | struct deferred_entry *first = NULL; | |
489 | unsigned long flags; | |
490 | ||
491 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
492 | while (nr--) { | |
493 | struct deferred_entry *entry | |
494 | = list_first_entry(&deferred_list, | |
495 | struct deferred_entry, list); | |
496 | ||
497 | if (entry == first) | |
498 | break; | |
499 | list_del(&entry->list); | |
500 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
501 | if (_gnttab_end_foreign_access_ref(entry->ref, entry->ro)) { | |
502 | put_free_entry(entry->ref); | |
503 | if (entry->page) { | |
504 | pr_debug("freeing g.e. %#x (pfn %#lx)\n", | |
505 | entry->ref, page_to_pfn(entry->page)); | |
506 | __free_page(entry->page); | |
507 | } else | |
508 | pr_info("freeing g.e. %#x\n", entry->ref); | |
509 | kfree(entry); | |
510 | entry = NULL; | |
511 | } else { | |
512 | if (!--entry->warn_delay) | |
513 | pr_info("g.e. %#x still pending\n", | |
514 | entry->ref); | |
515 | if (!first) | |
516 | first = entry; | |
517 | } | |
518 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
519 | if (entry) | |
520 | list_add_tail(&entry->list, &deferred_list); | |
521 | else if (list_empty(&deferred_list)) | |
522 | break; | |
523 | } | |
524 | if (!list_empty(&deferred_list) && !timer_pending(&deferred_timer)) { | |
525 | deferred_timer.expires = jiffies + HZ; | |
526 | add_timer(&deferred_timer); | |
527 | } | |
528 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
529 | } | |
530 | ||
531 | static void gnttab_add_deferred(grant_ref_t ref, bool readonly, | |
532 | struct page *page) | |
533 | { | |
534 | struct deferred_entry *entry = kmalloc(sizeof(*entry), GFP_ATOMIC); | |
535 | const char *what = KERN_WARNING "leaking"; | |
536 | ||
537 | if (entry) { | |
538 | unsigned long flags; | |
539 | ||
540 | entry->ref = ref; | |
541 | entry->ro = readonly; | |
542 | entry->page = page; | |
543 | entry->warn_delay = 60; | |
544 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
545 | list_add_tail(&entry->list, &deferred_list); | |
546 | if (!timer_pending(&deferred_timer)) { | |
547 | deferred_timer.expires = jiffies + HZ; | |
548 | add_timer(&deferred_timer); | |
549 | } | |
550 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
551 | what = KERN_DEBUG "deferring"; | |
552 | } | |
553 | printk("%s g.e. %#x (pfn %#lx)\n", | |
554 | what, ref, page ? page_to_pfn(page) : -1); | |
555 | } | |
556 | ||
ad9a8612 JF |
557 | void gnttab_end_foreign_access(grant_ref_t ref, int readonly, |
558 | unsigned long page) | |
559 | { | |
560 | if (gnttab_end_foreign_access_ref(ref, readonly)) { | |
561 | put_free_entry(ref); | |
562 | if (page != 0) | |
563 | free_page(page); | |
569ca5b3 JB |
564 | } else |
565 | gnttab_add_deferred(ref, readonly, | |
566 | page ? virt_to_page(page) : NULL); | |
ad9a8612 JF |
567 | } |
568 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_access); | |
569 | ||
570 | int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn) | |
571 | { | |
572 | int ref; | |
573 | ||
574 | ref = get_free_entries(1); | |
575 | if (unlikely(ref < 0)) | |
576 | return -ENOSPC; | |
577 | gnttab_grant_foreign_transfer_ref(ref, domid, pfn); | |
578 | ||
579 | return ref; | |
580 | } | |
581 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer); | |
582 | ||
583 | void gnttab_grant_foreign_transfer_ref(grant_ref_t ref, domid_t domid, | |
584 | unsigned long pfn) | |
585 | { | |
0f9f5a95 | 586 | gnttab_interface->update_entry(ref, domid, pfn, GTF_accept_transfer); |
ad9a8612 JF |
587 | } |
588 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer_ref); | |
589 | ||
0f9f5a95 | 590 | static unsigned long gnttab_end_foreign_transfer_ref_v1(grant_ref_t ref) |
ad9a8612 JF |
591 | { |
592 | unsigned long frame; | |
593 | u16 flags; | |
b1e495b2 AL |
594 | u16 *pflags; |
595 | ||
596 | pflags = &gnttab_shared.v1[ref].flags; | |
ad9a8612 JF |
597 | |
598 | /* | |
599 | * If a transfer is not even yet started, try to reclaim the grant | |
600 | * reference and return failure (== 0). | |
601 | */ | |
b1e495b2 AL |
602 | while (!((flags = *pflags) & GTF_transfer_committed)) { |
603 | if (sync_cmpxchg(pflags, flags, 0) == flags) | |
ad9a8612 JF |
604 | return 0; |
605 | cpu_relax(); | |
606 | } | |
607 | ||
608 | /* If a transfer is in progress then wait until it is completed. */ | |
609 | while (!(flags & GTF_transfer_completed)) { | |
b1e495b2 | 610 | flags = *pflags; |
ad9a8612 JF |
611 | cpu_relax(); |
612 | } | |
613 | ||
614 | rmb(); /* Read the frame number /after/ reading completion status. */ | |
0f9f5a95 | 615 | frame = gnttab_shared.v1[ref].frame; |
ad9a8612 JF |
616 | BUG_ON(frame == 0); |
617 | ||
618 | return frame; | |
619 | } | |
0f9f5a95 | 620 | |
85ff6acb AL |
621 | static unsigned long gnttab_end_foreign_transfer_ref_v2(grant_ref_t ref) |
622 | { | |
623 | unsigned long frame; | |
624 | u16 flags; | |
625 | u16 *pflags; | |
626 | ||
627 | pflags = &gnttab_shared.v2[ref].hdr.flags; | |
628 | ||
629 | /* | |
630 | * If a transfer is not even yet started, try to reclaim the grant | |
631 | * reference and return failure (== 0). | |
632 | */ | |
633 | while (!((flags = *pflags) & GTF_transfer_committed)) { | |
634 | if (sync_cmpxchg(pflags, flags, 0) == flags) | |
635 | return 0; | |
636 | cpu_relax(); | |
637 | } | |
638 | ||
639 | /* If a transfer is in progress then wait until it is completed. */ | |
640 | while (!(flags & GTF_transfer_completed)) { | |
641 | flags = *pflags; | |
642 | cpu_relax(); | |
643 | } | |
644 | ||
645 | rmb(); /* Read the frame number /after/ reading completion status. */ | |
646 | frame = gnttab_shared.v2[ref].full_page.frame; | |
647 | BUG_ON(frame == 0); | |
648 | ||
649 | return frame; | |
650 | } | |
651 | ||
0f9f5a95 AL |
652 | unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref) |
653 | { | |
654 | return gnttab_interface->end_foreign_transfer_ref(ref); | |
655 | } | |
ad9a8612 JF |
656 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer_ref); |
657 | ||
658 | unsigned long gnttab_end_foreign_transfer(grant_ref_t ref) | |
659 | { | |
660 | unsigned long frame = gnttab_end_foreign_transfer_ref(ref); | |
661 | put_free_entry(ref); | |
662 | return frame; | |
663 | } | |
664 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer); | |
665 | ||
666 | void gnttab_free_grant_reference(grant_ref_t ref) | |
667 | { | |
668 | put_free_entry(ref); | |
669 | } | |
670 | EXPORT_SYMBOL_GPL(gnttab_free_grant_reference); | |
671 | ||
672 | void gnttab_free_grant_references(grant_ref_t head) | |
673 | { | |
674 | grant_ref_t ref; | |
675 | unsigned long flags; | |
676 | int count = 1; | |
677 | if (head == GNTTAB_LIST_END) | |
678 | return; | |
679 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
680 | ref = head; | |
681 | while (gnttab_entry(ref) != GNTTAB_LIST_END) { | |
682 | ref = gnttab_entry(ref); | |
683 | count++; | |
684 | } | |
685 | gnttab_entry(ref) = gnttab_free_head; | |
686 | gnttab_free_head = head; | |
687 | gnttab_free_count += count; | |
688 | check_free_callbacks(); | |
689 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
690 | } | |
691 | EXPORT_SYMBOL_GPL(gnttab_free_grant_references); | |
692 | ||
693 | int gnttab_alloc_grant_references(u16 count, grant_ref_t *head) | |
694 | { | |
695 | int h = get_free_entries(count); | |
696 | ||
697 | if (h < 0) | |
698 | return -ENOSPC; | |
699 | ||
700 | *head = h; | |
701 | ||
702 | return 0; | |
703 | } | |
704 | EXPORT_SYMBOL_GPL(gnttab_alloc_grant_references); | |
705 | ||
706 | int gnttab_empty_grant_references(const grant_ref_t *private_head) | |
707 | { | |
708 | return (*private_head == GNTTAB_LIST_END); | |
709 | } | |
710 | EXPORT_SYMBOL_GPL(gnttab_empty_grant_references); | |
711 | ||
712 | int gnttab_claim_grant_reference(grant_ref_t *private_head) | |
713 | { | |
714 | grant_ref_t g = *private_head; | |
715 | if (unlikely(g == GNTTAB_LIST_END)) | |
716 | return -ENOSPC; | |
717 | *private_head = gnttab_entry(g); | |
718 | return g; | |
719 | } | |
720 | EXPORT_SYMBOL_GPL(gnttab_claim_grant_reference); | |
721 | ||
722 | void gnttab_release_grant_reference(grant_ref_t *private_head, | |
723 | grant_ref_t release) | |
724 | { | |
725 | gnttab_entry(release) = *private_head; | |
726 | *private_head = release; | |
727 | } | |
728 | EXPORT_SYMBOL_GPL(gnttab_release_grant_reference); | |
729 | ||
730 | void gnttab_request_free_callback(struct gnttab_free_callback *callback, | |
731 | void (*fn)(void *), void *arg, u16 count) | |
732 | { | |
733 | unsigned long flags; | |
734 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
735 | if (callback->next) | |
736 | goto out; | |
737 | callback->fn = fn; | |
738 | callback->arg = arg; | |
739 | callback->count = count; | |
740 | callback->next = gnttab_free_callback_list; | |
741 | gnttab_free_callback_list = callback; | |
742 | check_free_callbacks(); | |
743 | out: | |
744 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
745 | } | |
746 | EXPORT_SYMBOL_GPL(gnttab_request_free_callback); | |
747 | ||
748 | void gnttab_cancel_free_callback(struct gnttab_free_callback *callback) | |
749 | { | |
750 | struct gnttab_free_callback **pcb; | |
751 | unsigned long flags; | |
752 | ||
753 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
754 | for (pcb = &gnttab_free_callback_list; *pcb; pcb = &(*pcb)->next) { | |
755 | if (*pcb == callback) { | |
756 | *pcb = callback->next; | |
757 | break; | |
758 | } | |
759 | } | |
760 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
761 | } | |
762 | EXPORT_SYMBOL_GPL(gnttab_cancel_free_callback); | |
763 | ||
764 | static int grow_gnttab_list(unsigned int more_frames) | |
765 | { | |
766 | unsigned int new_nr_grant_frames, extra_entries, i; | |
bbc60c18 | 767 | unsigned int nr_glist_frames, new_nr_glist_frames; |
ad9a8612 JF |
768 | |
769 | new_nr_grant_frames = nr_grant_frames + more_frames; | |
770 | extra_entries = more_frames * GREFS_PER_GRANT_FRAME; | |
771 | ||
bbc60c18 MAEM |
772 | nr_glist_frames = (nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP; |
773 | new_nr_glist_frames = | |
774 | (new_nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP; | |
775 | for (i = nr_glist_frames; i < new_nr_glist_frames; i++) { | |
ad9a8612 JF |
776 | gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_ATOMIC); |
777 | if (!gnttab_list[i]) | |
778 | goto grow_nomem; | |
779 | } | |
780 | ||
781 | ||
782 | for (i = GREFS_PER_GRANT_FRAME * nr_grant_frames; | |
783 | i < GREFS_PER_GRANT_FRAME * new_nr_grant_frames - 1; i++) | |
784 | gnttab_entry(i) = i + 1; | |
785 | ||
786 | gnttab_entry(i) = gnttab_free_head; | |
787 | gnttab_free_head = GREFS_PER_GRANT_FRAME * nr_grant_frames; | |
788 | gnttab_free_count += extra_entries; | |
789 | ||
790 | nr_grant_frames = new_nr_grant_frames; | |
791 | ||
792 | check_free_callbacks(); | |
793 | ||
794 | return 0; | |
795 | ||
796 | grow_nomem: | |
bbc60c18 | 797 | for ( ; i >= nr_glist_frames; i--) |
ad9a8612 JF |
798 | free_page((unsigned long) gnttab_list[i]); |
799 | return -ENOMEM; | |
800 | } | |
801 | ||
802 | static unsigned int __max_nr_grant_frames(void) | |
803 | { | |
804 | struct gnttab_query_size query; | |
805 | int rc; | |
806 | ||
807 | query.dom = DOMID_SELF; | |
808 | ||
809 | rc = HYPERVISOR_grant_table_op(GNTTABOP_query_size, &query, 1); | |
810 | if ((rc < 0) || (query.status != GNTST_okay)) | |
811 | return 4; /* Legacy max supported number of frames */ | |
812 | ||
813 | return query.max_nr_frames; | |
814 | } | |
815 | ||
183d03cc | 816 | unsigned int gnttab_max_grant_frames(void) |
ad9a8612 JF |
817 | { |
818 | unsigned int xen_max = __max_nr_grant_frames(); | |
819 | ||
820 | if (xen_max > boot_max_nr_grant_frames) | |
821 | return boot_max_nr_grant_frames; | |
822 | return xen_max; | |
823 | } | |
183d03cc | 824 | EXPORT_SYMBOL_GPL(gnttab_max_grant_frames); |
ad9a8612 | 825 | |
289b777e | 826 | int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, |
c123799a AL |
827 | struct gnttab_map_grant_ref *kmap_ops, |
828 | struct page **pages, unsigned int count) | |
289b777e SS |
829 | { |
830 | int i, ret; | |
f62805f1 | 831 | bool lazy = false; |
289b777e SS |
832 | pte_t *pte; |
833 | unsigned long mfn; | |
834 | ||
835 | ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map_ops, count); | |
87f1d40a JF |
836 | if (ret) |
837 | return ret; | |
289b777e | 838 | |
aab8f11a DDG |
839 | if (xen_feature(XENFEAT_auto_translated_physmap)) |
840 | return ret; | |
841 | ||
f62805f1 SS |
842 | if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { |
843 | arch_enter_lazy_mmu_mode(); | |
844 | lazy = true; | |
845 | } | |
846 | ||
289b777e | 847 | for (i = 0; i < count; i++) { |
dc4972a4 IC |
848 | /* Do not add to override if the map failed. */ |
849 | if (map_ops[i].status) | |
850 | continue; | |
851 | ||
cf8d9163 KRW |
852 | if (map_ops[i].flags & GNTMAP_contains_pte) { |
853 | pte = (pte_t *) (mfn_to_virt(PFN_DOWN(map_ops[i].host_addr)) + | |
289b777e | 854 | (map_ops[i].host_addr & ~PAGE_MASK)); |
cf8d9163 KRW |
855 | mfn = pte_mfn(*pte); |
856 | } else { | |
7d17e84b | 857 | mfn = PFN_DOWN(map_ops[i].dev_bus_addr); |
cf8d9163 | 858 | } |
7d17e84b DDG |
859 | ret = m2p_add_override(mfn, pages[i], kmap_ops ? |
860 | &kmap_ops[i] : NULL); | |
87f1d40a JF |
861 | if (ret) |
862 | return ret; | |
289b777e SS |
863 | } |
864 | ||
f62805f1 SS |
865 | if (lazy) |
866 | arch_leave_lazy_mmu_mode(); | |
867 | ||
289b777e SS |
868 | return ret; |
869 | } | |
870 | EXPORT_SYMBOL_GPL(gnttab_map_refs); | |
871 | ||
872 | int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, | |
7d17e84b | 873 | struct page **pages, unsigned int count, bool clear_pte) |
289b777e SS |
874 | { |
875 | int i, ret; | |
f62805f1 | 876 | bool lazy = false; |
289b777e SS |
877 | |
878 | ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops, count); | |
87f1d40a JF |
879 | if (ret) |
880 | return ret; | |
881 | ||
aab8f11a DDG |
882 | if (xen_feature(XENFEAT_auto_translated_physmap)) |
883 | return ret; | |
884 | ||
f62805f1 SS |
885 | if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { |
886 | arch_enter_lazy_mmu_mode(); | |
887 | lazy = true; | |
888 | } | |
889 | ||
87f1d40a | 890 | for (i = 0; i < count; i++) { |
7d17e84b | 891 | ret = m2p_remove_override(pages[i], clear_pte); |
87f1d40a JF |
892 | if (ret) |
893 | return ret; | |
894 | } | |
289b777e | 895 | |
f62805f1 SS |
896 | if (lazy) |
897 | arch_leave_lazy_mmu_mode(); | |
898 | ||
289b777e SS |
899 | return ret; |
900 | } | |
901 | EXPORT_SYMBOL_GPL(gnttab_unmap_refs); | |
902 | ||
85ff6acb AL |
903 | static unsigned nr_status_frames(unsigned nr_grant_frames) |
904 | { | |
905 | return (nr_grant_frames * GREFS_PER_GRANT_FRAME + SPP - 1) / SPP; | |
906 | } | |
907 | ||
0f9f5a95 AL |
908 | static int gnttab_map_frames_v1(unsigned long *frames, unsigned int nr_gframes) |
909 | { | |
910 | int rc; | |
911 | ||
912 | rc = arch_gnttab_map_shared(frames, nr_gframes, | |
913 | gnttab_max_grant_frames(), | |
914 | &gnttab_shared.addr); | |
915 | BUG_ON(rc); | |
916 | ||
917 | return 0; | |
918 | } | |
919 | ||
920 | static void gnttab_unmap_frames_v1(void) | |
921 | { | |
85ff6acb AL |
922 | arch_gnttab_unmap(gnttab_shared.addr, nr_grant_frames); |
923 | } | |
924 | ||
925 | static int gnttab_map_frames_v2(unsigned long *frames, unsigned int nr_gframes) | |
926 | { | |
927 | uint64_t *sframes; | |
928 | unsigned int nr_sframes; | |
929 | struct gnttab_get_status_frames getframes; | |
930 | int rc; | |
931 | ||
932 | nr_sframes = nr_status_frames(nr_gframes); | |
933 | ||
934 | /* No need for kzalloc as it is initialized in following hypercall | |
935 | * GNTTABOP_get_status_frames. | |
936 | */ | |
937 | sframes = kmalloc(nr_sframes * sizeof(uint64_t), GFP_ATOMIC); | |
938 | if (!sframes) | |
939 | return -ENOMEM; | |
940 | ||
941 | getframes.dom = DOMID_SELF; | |
942 | getframes.nr_frames = nr_sframes; | |
943 | set_xen_guest_handle(getframes.frame_list, sframes); | |
944 | ||
945 | rc = HYPERVISOR_grant_table_op(GNTTABOP_get_status_frames, | |
946 | &getframes, 1); | |
947 | if (rc == -ENOSYS) { | |
948 | kfree(sframes); | |
949 | return -ENOSYS; | |
950 | } | |
951 | ||
952 | BUG_ON(rc || getframes.status); | |
953 | ||
954 | rc = arch_gnttab_map_status(sframes, nr_sframes, | |
955 | nr_status_frames(gnttab_max_grant_frames()), | |
956 | &grstatus); | |
957 | BUG_ON(rc); | |
958 | kfree(sframes); | |
959 | ||
960 | rc = arch_gnttab_map_shared(frames, nr_gframes, | |
961 | gnttab_max_grant_frames(), | |
962 | &gnttab_shared.addr); | |
963 | BUG_ON(rc); | |
964 | ||
965 | return 0; | |
966 | } | |
967 | ||
968 | static void gnttab_unmap_frames_v2(void) | |
969 | { | |
970 | arch_gnttab_unmap(gnttab_shared.addr, nr_grant_frames); | |
971 | arch_gnttab_unmap(grstatus, nr_status_frames(nr_grant_frames)); | |
0f9f5a95 AL |
972 | } |
973 | ||
ad9a8612 JF |
974 | static int gnttab_map(unsigned int start_idx, unsigned int end_idx) |
975 | { | |
976 | struct gnttab_setup_table setup; | |
977 | unsigned long *frames; | |
978 | unsigned int nr_gframes = end_idx + 1; | |
979 | int rc; | |
980 | ||
183d03cc SS |
981 | if (xen_hvm_domain()) { |
982 | struct xen_add_to_physmap xatp; | |
983 | unsigned int i = end_idx; | |
984 | rc = 0; | |
985 | /* | |
986 | * Loop backwards, so that the first hypercall has the largest | |
987 | * index, ensuring that the table will grow only once. | |
988 | */ | |
989 | do { | |
990 | xatp.domid = DOMID_SELF; | |
991 | xatp.idx = i; | |
992 | xatp.space = XENMAPSPACE_grant_table; | |
993 | xatp.gpfn = (xen_hvm_resume_frames >> PAGE_SHIFT) + i; | |
994 | rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp); | |
995 | if (rc != 0) { | |
996 | printk(KERN_WARNING | |
997 | "grant table add_to_physmap failed, err=%d\n", rc); | |
998 | break; | |
999 | } | |
1000 | } while (i-- > start_idx); | |
1001 | ||
1002 | return rc; | |
1003 | } | |
1004 | ||
85ff6acb AL |
1005 | /* No need for kzalloc as it is initialized in following hypercall |
1006 | * GNTTABOP_setup_table. | |
1007 | */ | |
ad9a8612 JF |
1008 | frames = kmalloc(nr_gframes * sizeof(unsigned long), GFP_ATOMIC); |
1009 | if (!frames) | |
1010 | return -ENOMEM; | |
1011 | ||
1012 | setup.dom = DOMID_SELF; | |
1013 | setup.nr_frames = nr_gframes; | |
87e27cf6 | 1014 | set_xen_guest_handle(setup.frame_list, frames); |
ad9a8612 JF |
1015 | |
1016 | rc = HYPERVISOR_grant_table_op(GNTTABOP_setup_table, &setup, 1); | |
1017 | if (rc == -ENOSYS) { | |
1018 | kfree(frames); | |
1019 | return -ENOSYS; | |
1020 | } | |
1021 | ||
1022 | BUG_ON(rc || setup.status); | |
1023 | ||
0f9f5a95 | 1024 | rc = gnttab_interface->map_frames(frames, nr_gframes); |
ad9a8612 JF |
1025 | |
1026 | kfree(frames); | |
1027 | ||
0f9f5a95 AL |
1028 | return rc; |
1029 | } | |
1030 | ||
1031 | static struct gnttab_ops gnttab_v1_ops = { | |
1032 | .map_frames = gnttab_map_frames_v1, | |
1033 | .unmap_frames = gnttab_unmap_frames_v1, | |
1034 | .update_entry = gnttab_update_entry_v1, | |
1035 | .end_foreign_access_ref = gnttab_end_foreign_access_ref_v1, | |
1036 | .end_foreign_transfer_ref = gnttab_end_foreign_transfer_ref_v1, | |
1037 | .query_foreign_access = gnttab_query_foreign_access_v1, | |
1038 | }; | |
1039 | ||
85ff6acb AL |
1040 | static struct gnttab_ops gnttab_v2_ops = { |
1041 | .map_frames = gnttab_map_frames_v2, | |
1042 | .unmap_frames = gnttab_unmap_frames_v2, | |
1043 | .update_entry = gnttab_update_entry_v2, | |
1044 | .end_foreign_access_ref = gnttab_end_foreign_access_ref_v2, | |
1045 | .end_foreign_transfer_ref = gnttab_end_foreign_transfer_ref_v2, | |
1046 | .query_foreign_access = gnttab_query_foreign_access_v2, | |
6666754b | 1047 | .update_subpage_entry = gnttab_update_subpage_entry_v2, |
9438ce9d | 1048 | .update_trans_entry = gnttab_update_trans_entry_v2, |
85ff6acb AL |
1049 | }; |
1050 | ||
0f9f5a95 AL |
1051 | static void gnttab_request_version(void) |
1052 | { | |
85ff6acb AL |
1053 | int rc; |
1054 | struct gnttab_set_version gsv; | |
1055 | ||
69e8f430 KRW |
1056 | if (xen_hvm_domain()) |
1057 | gsv.version = 1; | |
1058 | else | |
1059 | gsv.version = 2; | |
85ff6acb | 1060 | rc = HYPERVISOR_grant_table_op(GNTTABOP_set_version, &gsv, 1); |
69e8f430 | 1061 | if (rc == 0 && gsv.version == 2) { |
85ff6acb AL |
1062 | grant_table_version = 2; |
1063 | gnttab_interface = &gnttab_v2_ops; | |
1064 | } else if (grant_table_version == 2) { | |
1065 | /* | |
1066 | * If we've already used version 2 features, | |
1067 | * but then suddenly discover that they're not | |
1068 | * available (e.g. migrating to an older | |
1069 | * version of Xen), almost unbounded badness | |
1070 | * can happen. | |
1071 | */ | |
1072 | panic("we need grant tables version 2, but only version 1 is available"); | |
1073 | } else { | |
1074 | grant_table_version = 1; | |
1075 | gnttab_interface = &gnttab_v1_ops; | |
1076 | } | |
0f9f5a95 AL |
1077 | printk(KERN_INFO "Grant tables using version %d layout.\n", |
1078 | grant_table_version); | |
ad9a8612 JF |
1079 | } |
1080 | ||
0e91398f | 1081 | int gnttab_resume(void) |
ad9a8612 | 1082 | { |
183d03cc SS |
1083 | unsigned int max_nr_gframes; |
1084 | ||
0f9f5a95 | 1085 | gnttab_request_version(); |
183d03cc SS |
1086 | max_nr_gframes = gnttab_max_grant_frames(); |
1087 | if (max_nr_gframes < nr_grant_frames) | |
ad9a8612 | 1088 | return -ENOSYS; |
183d03cc SS |
1089 | |
1090 | if (xen_pv_domain()) | |
1091 | return gnttab_map(0, nr_grant_frames - 1); | |
1092 | ||
0f9f5a95 AL |
1093 | if (gnttab_shared.addr == NULL) { |
1094 | gnttab_shared.addr = ioremap(xen_hvm_resume_frames, | |
1095 | PAGE_SIZE * max_nr_gframes); | |
1096 | if (gnttab_shared.addr == NULL) { | |
183d03cc SS |
1097 | printk(KERN_WARNING |
1098 | "Failed to ioremap gnttab share frames!"); | |
1099 | return -ENOMEM; | |
1100 | } | |
1101 | } | |
1102 | ||
1103 | gnttab_map(0, nr_grant_frames - 1); | |
1104 | ||
1105 | return 0; | |
ad9a8612 JF |
1106 | } |
1107 | ||
0e91398f | 1108 | int gnttab_suspend(void) |
ad9a8612 | 1109 | { |
0f9f5a95 | 1110 | gnttab_interface->unmap_frames(); |
ad9a8612 JF |
1111 | return 0; |
1112 | } | |
1113 | ||
1114 | static int gnttab_expand(unsigned int req_entries) | |
1115 | { | |
1116 | int rc; | |
1117 | unsigned int cur, extra; | |
1118 | ||
1119 | cur = nr_grant_frames; | |
1120 | extra = ((req_entries + (GREFS_PER_GRANT_FRAME-1)) / | |
1121 | GREFS_PER_GRANT_FRAME); | |
183d03cc | 1122 | if (cur + extra > gnttab_max_grant_frames()) |
ad9a8612 JF |
1123 | return -ENOSPC; |
1124 | ||
1125 | rc = gnttab_map(cur, cur + extra - 1); | |
1126 | if (rc == 0) | |
1127 | rc = grow_gnttab_list(extra); | |
1128 | ||
1129 | return rc; | |
1130 | } | |
1131 | ||
183d03cc | 1132 | int gnttab_init(void) |
ad9a8612 JF |
1133 | { |
1134 | int i; | |
bbc60c18 | 1135 | unsigned int max_nr_glist_frames, nr_glist_frames; |
ad9a8612 | 1136 | unsigned int nr_init_grefs; |
6b5e7d9e | 1137 | int ret; |
ad9a8612 | 1138 | |
ad9a8612 JF |
1139 | nr_grant_frames = 1; |
1140 | boot_max_nr_grant_frames = __max_nr_grant_frames(); | |
1141 | ||
1142 | /* Determine the maximum number of frames required for the | |
1143 | * grant reference free list on the current hypervisor. | |
1144 | */ | |
1145 | max_nr_glist_frames = (boot_max_nr_grant_frames * | |
bbc60c18 | 1146 | GREFS_PER_GRANT_FRAME / RPP); |
ad9a8612 JF |
1147 | |
1148 | gnttab_list = kmalloc(max_nr_glist_frames * sizeof(grant_ref_t *), | |
1149 | GFP_KERNEL); | |
1150 | if (gnttab_list == NULL) | |
1151 | return -ENOMEM; | |
1152 | ||
bbc60c18 MAEM |
1153 | nr_glist_frames = (nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP; |
1154 | for (i = 0; i < nr_glist_frames; i++) { | |
ad9a8612 | 1155 | gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_KERNEL); |
6b5e7d9e JL |
1156 | if (gnttab_list[i] == NULL) { |
1157 | ret = -ENOMEM; | |
ad9a8612 | 1158 | goto ini_nomem; |
6b5e7d9e | 1159 | } |
ad9a8612 JF |
1160 | } |
1161 | ||
6b5e7d9e JL |
1162 | if (gnttab_resume() < 0) { |
1163 | ret = -ENODEV; | |
1164 | goto ini_nomem; | |
1165 | } | |
ad9a8612 JF |
1166 | |
1167 | nr_init_grefs = nr_grant_frames * GREFS_PER_GRANT_FRAME; | |
1168 | ||
1169 | for (i = NR_RESERVED_ENTRIES; i < nr_init_grefs - 1; i++) | |
1170 | gnttab_entry(i) = i + 1; | |
1171 | ||
1172 | gnttab_entry(nr_init_grefs - 1) = GNTTAB_LIST_END; | |
1173 | gnttab_free_count = nr_init_grefs - NR_RESERVED_ENTRIES; | |
1174 | gnttab_free_head = NR_RESERVED_ENTRIES; | |
1175 | ||
1176 | printk("Grant table initialized\n"); | |
1177 | return 0; | |
1178 | ||
1179 | ini_nomem: | |
1180 | for (i--; i >= 0; i--) | |
1181 | free_page((unsigned long)gnttab_list[i]); | |
1182 | kfree(gnttab_list); | |
6b5e7d9e | 1183 | return ret; |
ad9a8612 | 1184 | } |
183d03cc SS |
1185 | EXPORT_SYMBOL_GPL(gnttab_init); |
1186 | ||
1187 | static int __devinit __gnttab_init(void) | |
1188 | { | |
1189 | /* Delay grant-table initialization in the PV on HVM case */ | |
1190 | if (xen_hvm_domain()) | |
1191 | return 0; | |
1192 | ||
1193 | if (!xen_pv_domain()) | |
1194 | return -ENODEV; | |
1195 | ||
1196 | return gnttab_init(); | |
1197 | } | |
ad9a8612 | 1198 | |
183d03cc | 1199 | core_initcall(__gnttab_init); |