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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; | |
429 | if (flags & (GTF_reading|GTF_writing)) { | |
430 | printk(KERN_ALERT "WARNING: g.e. still in use!\n"); | |
431 | return 0; | |
432 | } | |
b1e495b2 | 433 | } while ((nflags = sync_cmpxchg(pflags, flags, 0)) != flags); |
ad9a8612 JF |
434 | |
435 | return 1; | |
436 | } | |
0f9f5a95 | 437 | |
85ff6acb AL |
438 | static int gnttab_end_foreign_access_ref_v2(grant_ref_t ref, int readonly) |
439 | { | |
440 | gnttab_shared.v2[ref].hdr.flags = 0; | |
441 | mb(); | |
442 | if (grstatus[ref] & (GTF_reading|GTF_writing)) { | |
443 | return 0; | |
444 | } else { | |
445 | /* The read of grstatus needs to have acquire | |
446 | semantics. On x86, reads already have | |
447 | that, and we just need to protect against | |
448 | compiler reorderings. On other | |
449 | architectures we may need a full | |
450 | barrier. */ | |
451 | #ifdef CONFIG_X86 | |
452 | barrier(); | |
453 | #else | |
454 | mb(); | |
455 | #endif | |
456 | } | |
457 | ||
458 | return 1; | |
459 | } | |
460 | ||
0f9f5a95 AL |
461 | int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly) |
462 | { | |
463 | return gnttab_interface->end_foreign_access_ref(ref, readonly); | |
464 | } | |
ad9a8612 JF |
465 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_access_ref); |
466 | ||
467 | void gnttab_end_foreign_access(grant_ref_t ref, int readonly, | |
468 | unsigned long page) | |
469 | { | |
470 | if (gnttab_end_foreign_access_ref(ref, readonly)) { | |
471 | put_free_entry(ref); | |
472 | if (page != 0) | |
473 | free_page(page); | |
474 | } else { | |
475 | /* XXX This needs to be fixed so that the ref and page are | |
476 | placed on a list to be freed up later. */ | |
477 | printk(KERN_WARNING | |
478 | "WARNING: leaking g.e. and page still in use!\n"); | |
479 | } | |
480 | } | |
481 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_access); | |
482 | ||
483 | int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn) | |
484 | { | |
485 | int ref; | |
486 | ||
487 | ref = get_free_entries(1); | |
488 | if (unlikely(ref < 0)) | |
489 | return -ENOSPC; | |
490 | gnttab_grant_foreign_transfer_ref(ref, domid, pfn); | |
491 | ||
492 | return ref; | |
493 | } | |
494 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer); | |
495 | ||
496 | void gnttab_grant_foreign_transfer_ref(grant_ref_t ref, domid_t domid, | |
497 | unsigned long pfn) | |
498 | { | |
0f9f5a95 | 499 | gnttab_interface->update_entry(ref, domid, pfn, GTF_accept_transfer); |
ad9a8612 JF |
500 | } |
501 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer_ref); | |
502 | ||
0f9f5a95 | 503 | static unsigned long gnttab_end_foreign_transfer_ref_v1(grant_ref_t ref) |
ad9a8612 JF |
504 | { |
505 | unsigned long frame; | |
506 | u16 flags; | |
b1e495b2 AL |
507 | u16 *pflags; |
508 | ||
509 | pflags = &gnttab_shared.v1[ref].flags; | |
ad9a8612 JF |
510 | |
511 | /* | |
512 | * If a transfer is not even yet started, try to reclaim the grant | |
513 | * reference and return failure (== 0). | |
514 | */ | |
b1e495b2 AL |
515 | while (!((flags = *pflags) & GTF_transfer_committed)) { |
516 | if (sync_cmpxchg(pflags, flags, 0) == flags) | |
ad9a8612 JF |
517 | return 0; |
518 | cpu_relax(); | |
519 | } | |
520 | ||
521 | /* If a transfer is in progress then wait until it is completed. */ | |
522 | while (!(flags & GTF_transfer_completed)) { | |
b1e495b2 | 523 | flags = *pflags; |
ad9a8612 JF |
524 | cpu_relax(); |
525 | } | |
526 | ||
527 | rmb(); /* Read the frame number /after/ reading completion status. */ | |
0f9f5a95 | 528 | frame = gnttab_shared.v1[ref].frame; |
ad9a8612 JF |
529 | BUG_ON(frame == 0); |
530 | ||
531 | return frame; | |
532 | } | |
0f9f5a95 | 533 | |
85ff6acb AL |
534 | static unsigned long gnttab_end_foreign_transfer_ref_v2(grant_ref_t ref) |
535 | { | |
536 | unsigned long frame; | |
537 | u16 flags; | |
538 | u16 *pflags; | |
539 | ||
540 | pflags = &gnttab_shared.v2[ref].hdr.flags; | |
541 | ||
542 | /* | |
543 | * If a transfer is not even yet started, try to reclaim the grant | |
544 | * reference and return failure (== 0). | |
545 | */ | |
546 | while (!((flags = *pflags) & GTF_transfer_committed)) { | |
547 | if (sync_cmpxchg(pflags, flags, 0) == flags) | |
548 | return 0; | |
549 | cpu_relax(); | |
550 | } | |
551 | ||
552 | /* If a transfer is in progress then wait until it is completed. */ | |
553 | while (!(flags & GTF_transfer_completed)) { | |
554 | flags = *pflags; | |
555 | cpu_relax(); | |
556 | } | |
557 | ||
558 | rmb(); /* Read the frame number /after/ reading completion status. */ | |
559 | frame = gnttab_shared.v2[ref].full_page.frame; | |
560 | BUG_ON(frame == 0); | |
561 | ||
562 | return frame; | |
563 | } | |
564 | ||
0f9f5a95 AL |
565 | unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref) |
566 | { | |
567 | return gnttab_interface->end_foreign_transfer_ref(ref); | |
568 | } | |
ad9a8612 JF |
569 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer_ref); |
570 | ||
571 | unsigned long gnttab_end_foreign_transfer(grant_ref_t ref) | |
572 | { | |
573 | unsigned long frame = gnttab_end_foreign_transfer_ref(ref); | |
574 | put_free_entry(ref); | |
575 | return frame; | |
576 | } | |
577 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer); | |
578 | ||
579 | void gnttab_free_grant_reference(grant_ref_t ref) | |
580 | { | |
581 | put_free_entry(ref); | |
582 | } | |
583 | EXPORT_SYMBOL_GPL(gnttab_free_grant_reference); | |
584 | ||
585 | void gnttab_free_grant_references(grant_ref_t head) | |
586 | { | |
587 | grant_ref_t ref; | |
588 | unsigned long flags; | |
589 | int count = 1; | |
590 | if (head == GNTTAB_LIST_END) | |
591 | return; | |
592 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
593 | ref = head; | |
594 | while (gnttab_entry(ref) != GNTTAB_LIST_END) { | |
595 | ref = gnttab_entry(ref); | |
596 | count++; | |
597 | } | |
598 | gnttab_entry(ref) = gnttab_free_head; | |
599 | gnttab_free_head = head; | |
600 | gnttab_free_count += count; | |
601 | check_free_callbacks(); | |
602 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
603 | } | |
604 | EXPORT_SYMBOL_GPL(gnttab_free_grant_references); | |
605 | ||
606 | int gnttab_alloc_grant_references(u16 count, grant_ref_t *head) | |
607 | { | |
608 | int h = get_free_entries(count); | |
609 | ||
610 | if (h < 0) | |
611 | return -ENOSPC; | |
612 | ||
613 | *head = h; | |
614 | ||
615 | return 0; | |
616 | } | |
617 | EXPORT_SYMBOL_GPL(gnttab_alloc_grant_references); | |
618 | ||
619 | int gnttab_empty_grant_references(const grant_ref_t *private_head) | |
620 | { | |
621 | return (*private_head == GNTTAB_LIST_END); | |
622 | } | |
623 | EXPORT_SYMBOL_GPL(gnttab_empty_grant_references); | |
624 | ||
625 | int gnttab_claim_grant_reference(grant_ref_t *private_head) | |
626 | { | |
627 | grant_ref_t g = *private_head; | |
628 | if (unlikely(g == GNTTAB_LIST_END)) | |
629 | return -ENOSPC; | |
630 | *private_head = gnttab_entry(g); | |
631 | return g; | |
632 | } | |
633 | EXPORT_SYMBOL_GPL(gnttab_claim_grant_reference); | |
634 | ||
635 | void gnttab_release_grant_reference(grant_ref_t *private_head, | |
636 | grant_ref_t release) | |
637 | { | |
638 | gnttab_entry(release) = *private_head; | |
639 | *private_head = release; | |
640 | } | |
641 | EXPORT_SYMBOL_GPL(gnttab_release_grant_reference); | |
642 | ||
643 | void gnttab_request_free_callback(struct gnttab_free_callback *callback, | |
644 | void (*fn)(void *), void *arg, u16 count) | |
645 | { | |
646 | unsigned long flags; | |
647 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
648 | if (callback->next) | |
649 | goto out; | |
650 | callback->fn = fn; | |
651 | callback->arg = arg; | |
652 | callback->count = count; | |
653 | callback->next = gnttab_free_callback_list; | |
654 | gnttab_free_callback_list = callback; | |
655 | check_free_callbacks(); | |
656 | out: | |
657 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
658 | } | |
659 | EXPORT_SYMBOL_GPL(gnttab_request_free_callback); | |
660 | ||
661 | void gnttab_cancel_free_callback(struct gnttab_free_callback *callback) | |
662 | { | |
663 | struct gnttab_free_callback **pcb; | |
664 | unsigned long flags; | |
665 | ||
666 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
667 | for (pcb = &gnttab_free_callback_list; *pcb; pcb = &(*pcb)->next) { | |
668 | if (*pcb == callback) { | |
669 | *pcb = callback->next; | |
670 | break; | |
671 | } | |
672 | } | |
673 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
674 | } | |
675 | EXPORT_SYMBOL_GPL(gnttab_cancel_free_callback); | |
676 | ||
677 | static int grow_gnttab_list(unsigned int more_frames) | |
678 | { | |
679 | unsigned int new_nr_grant_frames, extra_entries, i; | |
bbc60c18 | 680 | unsigned int nr_glist_frames, new_nr_glist_frames; |
ad9a8612 JF |
681 | |
682 | new_nr_grant_frames = nr_grant_frames + more_frames; | |
683 | extra_entries = more_frames * GREFS_PER_GRANT_FRAME; | |
684 | ||
bbc60c18 MAEM |
685 | nr_glist_frames = (nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP; |
686 | new_nr_glist_frames = | |
687 | (new_nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP; | |
688 | for (i = nr_glist_frames; i < new_nr_glist_frames; i++) { | |
ad9a8612 JF |
689 | gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_ATOMIC); |
690 | if (!gnttab_list[i]) | |
691 | goto grow_nomem; | |
692 | } | |
693 | ||
694 | ||
695 | for (i = GREFS_PER_GRANT_FRAME * nr_grant_frames; | |
696 | i < GREFS_PER_GRANT_FRAME * new_nr_grant_frames - 1; i++) | |
697 | gnttab_entry(i) = i + 1; | |
698 | ||
699 | gnttab_entry(i) = gnttab_free_head; | |
700 | gnttab_free_head = GREFS_PER_GRANT_FRAME * nr_grant_frames; | |
701 | gnttab_free_count += extra_entries; | |
702 | ||
703 | nr_grant_frames = new_nr_grant_frames; | |
704 | ||
705 | check_free_callbacks(); | |
706 | ||
707 | return 0; | |
708 | ||
709 | grow_nomem: | |
bbc60c18 | 710 | for ( ; i >= nr_glist_frames; i--) |
ad9a8612 JF |
711 | free_page((unsigned long) gnttab_list[i]); |
712 | return -ENOMEM; | |
713 | } | |
714 | ||
715 | static unsigned int __max_nr_grant_frames(void) | |
716 | { | |
717 | struct gnttab_query_size query; | |
718 | int rc; | |
719 | ||
720 | query.dom = DOMID_SELF; | |
721 | ||
722 | rc = HYPERVISOR_grant_table_op(GNTTABOP_query_size, &query, 1); | |
723 | if ((rc < 0) || (query.status != GNTST_okay)) | |
724 | return 4; /* Legacy max supported number of frames */ | |
725 | ||
726 | return query.max_nr_frames; | |
727 | } | |
728 | ||
183d03cc | 729 | unsigned int gnttab_max_grant_frames(void) |
ad9a8612 JF |
730 | { |
731 | unsigned int xen_max = __max_nr_grant_frames(); | |
732 | ||
733 | if (xen_max > boot_max_nr_grant_frames) | |
734 | return boot_max_nr_grant_frames; | |
735 | return xen_max; | |
736 | } | |
183d03cc | 737 | EXPORT_SYMBOL_GPL(gnttab_max_grant_frames); |
ad9a8612 | 738 | |
289b777e | 739 | int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, |
c123799a AL |
740 | struct gnttab_map_grant_ref *kmap_ops, |
741 | struct page **pages, unsigned int count) | |
289b777e SS |
742 | { |
743 | int i, ret; | |
744 | pte_t *pte; | |
745 | unsigned long mfn; | |
746 | ||
747 | ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map_ops, count); | |
87f1d40a JF |
748 | if (ret) |
749 | return ret; | |
289b777e | 750 | |
aab8f11a DDG |
751 | if (xen_feature(XENFEAT_auto_translated_physmap)) |
752 | return ret; | |
753 | ||
289b777e | 754 | for (i = 0; i < count; i++) { |
dc4972a4 IC |
755 | /* Do not add to override if the map failed. */ |
756 | if (map_ops[i].status) | |
757 | continue; | |
758 | ||
cf8d9163 KRW |
759 | if (map_ops[i].flags & GNTMAP_contains_pte) { |
760 | pte = (pte_t *) (mfn_to_virt(PFN_DOWN(map_ops[i].host_addr)) + | |
289b777e | 761 | (map_ops[i].host_addr & ~PAGE_MASK)); |
cf8d9163 KRW |
762 | mfn = pte_mfn(*pte); |
763 | } else { | |
7d17e84b | 764 | mfn = PFN_DOWN(map_ops[i].dev_bus_addr); |
cf8d9163 | 765 | } |
7d17e84b DDG |
766 | ret = m2p_add_override(mfn, pages[i], kmap_ops ? |
767 | &kmap_ops[i] : NULL); | |
87f1d40a JF |
768 | if (ret) |
769 | return ret; | |
289b777e SS |
770 | } |
771 | ||
772 | return ret; | |
773 | } | |
774 | EXPORT_SYMBOL_GPL(gnttab_map_refs); | |
775 | ||
776 | int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, | |
7d17e84b | 777 | struct page **pages, unsigned int count, bool clear_pte) |
289b777e SS |
778 | { |
779 | int i, ret; | |
780 | ||
781 | ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops, count); | |
87f1d40a JF |
782 | if (ret) |
783 | return ret; | |
784 | ||
aab8f11a DDG |
785 | if (xen_feature(XENFEAT_auto_translated_physmap)) |
786 | return ret; | |
787 | ||
87f1d40a | 788 | for (i = 0; i < count; i++) { |
7d17e84b | 789 | ret = m2p_remove_override(pages[i], clear_pte); |
87f1d40a JF |
790 | if (ret) |
791 | return ret; | |
792 | } | |
289b777e SS |
793 | |
794 | return ret; | |
795 | } | |
796 | EXPORT_SYMBOL_GPL(gnttab_unmap_refs); | |
797 | ||
85ff6acb AL |
798 | static unsigned nr_status_frames(unsigned nr_grant_frames) |
799 | { | |
800 | return (nr_grant_frames * GREFS_PER_GRANT_FRAME + SPP - 1) / SPP; | |
801 | } | |
802 | ||
0f9f5a95 AL |
803 | static int gnttab_map_frames_v1(unsigned long *frames, unsigned int nr_gframes) |
804 | { | |
805 | int rc; | |
806 | ||
807 | rc = arch_gnttab_map_shared(frames, nr_gframes, | |
808 | gnttab_max_grant_frames(), | |
809 | &gnttab_shared.addr); | |
810 | BUG_ON(rc); | |
811 | ||
812 | return 0; | |
813 | } | |
814 | ||
815 | static void gnttab_unmap_frames_v1(void) | |
816 | { | |
85ff6acb AL |
817 | arch_gnttab_unmap(gnttab_shared.addr, nr_grant_frames); |
818 | } | |
819 | ||
820 | static int gnttab_map_frames_v2(unsigned long *frames, unsigned int nr_gframes) | |
821 | { | |
822 | uint64_t *sframes; | |
823 | unsigned int nr_sframes; | |
824 | struct gnttab_get_status_frames getframes; | |
825 | int rc; | |
826 | ||
827 | nr_sframes = nr_status_frames(nr_gframes); | |
828 | ||
829 | /* No need for kzalloc as it is initialized in following hypercall | |
830 | * GNTTABOP_get_status_frames. | |
831 | */ | |
832 | sframes = kmalloc(nr_sframes * sizeof(uint64_t), GFP_ATOMIC); | |
833 | if (!sframes) | |
834 | return -ENOMEM; | |
835 | ||
836 | getframes.dom = DOMID_SELF; | |
837 | getframes.nr_frames = nr_sframes; | |
838 | set_xen_guest_handle(getframes.frame_list, sframes); | |
839 | ||
840 | rc = HYPERVISOR_grant_table_op(GNTTABOP_get_status_frames, | |
841 | &getframes, 1); | |
842 | if (rc == -ENOSYS) { | |
843 | kfree(sframes); | |
844 | return -ENOSYS; | |
845 | } | |
846 | ||
847 | BUG_ON(rc || getframes.status); | |
848 | ||
849 | rc = arch_gnttab_map_status(sframes, nr_sframes, | |
850 | nr_status_frames(gnttab_max_grant_frames()), | |
851 | &grstatus); | |
852 | BUG_ON(rc); | |
853 | kfree(sframes); | |
854 | ||
855 | rc = arch_gnttab_map_shared(frames, nr_gframes, | |
856 | gnttab_max_grant_frames(), | |
857 | &gnttab_shared.addr); | |
858 | BUG_ON(rc); | |
859 | ||
860 | return 0; | |
861 | } | |
862 | ||
863 | static void gnttab_unmap_frames_v2(void) | |
864 | { | |
865 | arch_gnttab_unmap(gnttab_shared.addr, nr_grant_frames); | |
866 | arch_gnttab_unmap(grstatus, nr_status_frames(nr_grant_frames)); | |
0f9f5a95 AL |
867 | } |
868 | ||
ad9a8612 JF |
869 | static int gnttab_map(unsigned int start_idx, unsigned int end_idx) |
870 | { | |
871 | struct gnttab_setup_table setup; | |
872 | unsigned long *frames; | |
873 | unsigned int nr_gframes = end_idx + 1; | |
874 | int rc; | |
875 | ||
183d03cc SS |
876 | if (xen_hvm_domain()) { |
877 | struct xen_add_to_physmap xatp; | |
878 | unsigned int i = end_idx; | |
879 | rc = 0; | |
880 | /* | |
881 | * Loop backwards, so that the first hypercall has the largest | |
882 | * index, ensuring that the table will grow only once. | |
883 | */ | |
884 | do { | |
885 | xatp.domid = DOMID_SELF; | |
886 | xatp.idx = i; | |
887 | xatp.space = XENMAPSPACE_grant_table; | |
888 | xatp.gpfn = (xen_hvm_resume_frames >> PAGE_SHIFT) + i; | |
889 | rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp); | |
890 | if (rc != 0) { | |
891 | printk(KERN_WARNING | |
892 | "grant table add_to_physmap failed, err=%d\n", rc); | |
893 | break; | |
894 | } | |
895 | } while (i-- > start_idx); | |
896 | ||
897 | return rc; | |
898 | } | |
899 | ||
85ff6acb AL |
900 | /* No need for kzalloc as it is initialized in following hypercall |
901 | * GNTTABOP_setup_table. | |
902 | */ | |
ad9a8612 JF |
903 | frames = kmalloc(nr_gframes * sizeof(unsigned long), GFP_ATOMIC); |
904 | if (!frames) | |
905 | return -ENOMEM; | |
906 | ||
907 | setup.dom = DOMID_SELF; | |
908 | setup.nr_frames = nr_gframes; | |
87e27cf6 | 909 | set_xen_guest_handle(setup.frame_list, frames); |
ad9a8612 JF |
910 | |
911 | rc = HYPERVISOR_grant_table_op(GNTTABOP_setup_table, &setup, 1); | |
912 | if (rc == -ENOSYS) { | |
913 | kfree(frames); | |
914 | return -ENOSYS; | |
915 | } | |
916 | ||
917 | BUG_ON(rc || setup.status); | |
918 | ||
0f9f5a95 | 919 | rc = gnttab_interface->map_frames(frames, nr_gframes); |
ad9a8612 JF |
920 | |
921 | kfree(frames); | |
922 | ||
0f9f5a95 AL |
923 | return rc; |
924 | } | |
925 | ||
926 | static struct gnttab_ops gnttab_v1_ops = { | |
927 | .map_frames = gnttab_map_frames_v1, | |
928 | .unmap_frames = gnttab_unmap_frames_v1, | |
929 | .update_entry = gnttab_update_entry_v1, | |
930 | .end_foreign_access_ref = gnttab_end_foreign_access_ref_v1, | |
931 | .end_foreign_transfer_ref = gnttab_end_foreign_transfer_ref_v1, | |
932 | .query_foreign_access = gnttab_query_foreign_access_v1, | |
933 | }; | |
934 | ||
85ff6acb AL |
935 | static struct gnttab_ops gnttab_v2_ops = { |
936 | .map_frames = gnttab_map_frames_v2, | |
937 | .unmap_frames = gnttab_unmap_frames_v2, | |
938 | .update_entry = gnttab_update_entry_v2, | |
939 | .end_foreign_access_ref = gnttab_end_foreign_access_ref_v2, | |
940 | .end_foreign_transfer_ref = gnttab_end_foreign_transfer_ref_v2, | |
941 | .query_foreign_access = gnttab_query_foreign_access_v2, | |
6666754b | 942 | .update_subpage_entry = gnttab_update_subpage_entry_v2, |
9438ce9d | 943 | .update_trans_entry = gnttab_update_trans_entry_v2, |
85ff6acb AL |
944 | }; |
945 | ||
0f9f5a95 AL |
946 | static void gnttab_request_version(void) |
947 | { | |
85ff6acb AL |
948 | int rc; |
949 | struct gnttab_set_version gsv; | |
950 | ||
69e8f430 KRW |
951 | if (xen_hvm_domain()) |
952 | gsv.version = 1; | |
953 | else | |
954 | gsv.version = 2; | |
85ff6acb | 955 | rc = HYPERVISOR_grant_table_op(GNTTABOP_set_version, &gsv, 1); |
69e8f430 | 956 | if (rc == 0 && gsv.version == 2) { |
85ff6acb AL |
957 | grant_table_version = 2; |
958 | gnttab_interface = &gnttab_v2_ops; | |
959 | } else if (grant_table_version == 2) { | |
960 | /* | |
961 | * If we've already used version 2 features, | |
962 | * but then suddenly discover that they're not | |
963 | * available (e.g. migrating to an older | |
964 | * version of Xen), almost unbounded badness | |
965 | * can happen. | |
966 | */ | |
967 | panic("we need grant tables version 2, but only version 1 is available"); | |
968 | } else { | |
969 | grant_table_version = 1; | |
970 | gnttab_interface = &gnttab_v1_ops; | |
971 | } | |
0f9f5a95 AL |
972 | printk(KERN_INFO "Grant tables using version %d layout.\n", |
973 | grant_table_version); | |
ad9a8612 JF |
974 | } |
975 | ||
0e91398f | 976 | int gnttab_resume(void) |
ad9a8612 | 977 | { |
183d03cc SS |
978 | unsigned int max_nr_gframes; |
979 | ||
0f9f5a95 | 980 | gnttab_request_version(); |
183d03cc SS |
981 | max_nr_gframes = gnttab_max_grant_frames(); |
982 | if (max_nr_gframes < nr_grant_frames) | |
ad9a8612 | 983 | return -ENOSYS; |
183d03cc SS |
984 | |
985 | if (xen_pv_domain()) | |
986 | return gnttab_map(0, nr_grant_frames - 1); | |
987 | ||
0f9f5a95 AL |
988 | if (gnttab_shared.addr == NULL) { |
989 | gnttab_shared.addr = ioremap(xen_hvm_resume_frames, | |
990 | PAGE_SIZE * max_nr_gframes); | |
991 | if (gnttab_shared.addr == NULL) { | |
183d03cc SS |
992 | printk(KERN_WARNING |
993 | "Failed to ioremap gnttab share frames!"); | |
994 | return -ENOMEM; | |
995 | } | |
996 | } | |
997 | ||
998 | gnttab_map(0, nr_grant_frames - 1); | |
999 | ||
1000 | return 0; | |
ad9a8612 JF |
1001 | } |
1002 | ||
0e91398f | 1003 | int gnttab_suspend(void) |
ad9a8612 | 1004 | { |
0f9f5a95 | 1005 | gnttab_interface->unmap_frames(); |
ad9a8612 JF |
1006 | return 0; |
1007 | } | |
1008 | ||
1009 | static int gnttab_expand(unsigned int req_entries) | |
1010 | { | |
1011 | int rc; | |
1012 | unsigned int cur, extra; | |
1013 | ||
1014 | cur = nr_grant_frames; | |
1015 | extra = ((req_entries + (GREFS_PER_GRANT_FRAME-1)) / | |
1016 | GREFS_PER_GRANT_FRAME); | |
183d03cc | 1017 | if (cur + extra > gnttab_max_grant_frames()) |
ad9a8612 JF |
1018 | return -ENOSPC; |
1019 | ||
1020 | rc = gnttab_map(cur, cur + extra - 1); | |
1021 | if (rc == 0) | |
1022 | rc = grow_gnttab_list(extra); | |
1023 | ||
1024 | return rc; | |
1025 | } | |
1026 | ||
183d03cc | 1027 | int gnttab_init(void) |
ad9a8612 JF |
1028 | { |
1029 | int i; | |
bbc60c18 | 1030 | unsigned int max_nr_glist_frames, nr_glist_frames; |
ad9a8612 JF |
1031 | unsigned int nr_init_grefs; |
1032 | ||
ad9a8612 JF |
1033 | nr_grant_frames = 1; |
1034 | boot_max_nr_grant_frames = __max_nr_grant_frames(); | |
1035 | ||
1036 | /* Determine the maximum number of frames required for the | |
1037 | * grant reference free list on the current hypervisor. | |
1038 | */ | |
1039 | max_nr_glist_frames = (boot_max_nr_grant_frames * | |
bbc60c18 | 1040 | GREFS_PER_GRANT_FRAME / RPP); |
ad9a8612 JF |
1041 | |
1042 | gnttab_list = kmalloc(max_nr_glist_frames * sizeof(grant_ref_t *), | |
1043 | GFP_KERNEL); | |
1044 | if (gnttab_list == NULL) | |
1045 | return -ENOMEM; | |
1046 | ||
bbc60c18 MAEM |
1047 | nr_glist_frames = (nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP; |
1048 | for (i = 0; i < nr_glist_frames; i++) { | |
ad9a8612 JF |
1049 | gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_KERNEL); |
1050 | if (gnttab_list[i] == NULL) | |
1051 | goto ini_nomem; | |
1052 | } | |
1053 | ||
1054 | if (gnttab_resume() < 0) | |
1055 | return -ENODEV; | |
1056 | ||
1057 | nr_init_grefs = nr_grant_frames * GREFS_PER_GRANT_FRAME; | |
1058 | ||
1059 | for (i = NR_RESERVED_ENTRIES; i < nr_init_grefs - 1; i++) | |
1060 | gnttab_entry(i) = i + 1; | |
1061 | ||
1062 | gnttab_entry(nr_init_grefs - 1) = GNTTAB_LIST_END; | |
1063 | gnttab_free_count = nr_init_grefs - NR_RESERVED_ENTRIES; | |
1064 | gnttab_free_head = NR_RESERVED_ENTRIES; | |
1065 | ||
1066 | printk("Grant table initialized\n"); | |
1067 | return 0; | |
1068 | ||
1069 | ini_nomem: | |
1070 | for (i--; i >= 0; i--) | |
1071 | free_page((unsigned long)gnttab_list[i]); | |
1072 | kfree(gnttab_list); | |
1073 | return -ENOMEM; | |
1074 | } | |
183d03cc SS |
1075 | EXPORT_SYMBOL_GPL(gnttab_init); |
1076 | ||
1077 | static int __devinit __gnttab_init(void) | |
1078 | { | |
1079 | /* Delay grant-table initialization in the PV on HVM case */ | |
1080 | if (xen_hvm_domain()) | |
1081 | return 0; | |
1082 | ||
1083 | if (!xen_pv_domain()) | |
1084 | return -ENODEV; | |
1085 | ||
1086 | return gnttab_init(); | |
1087 | } | |
ad9a8612 | 1088 | |
183d03cc | 1089 | core_initcall(__gnttab_init); |