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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 | ||
283c0972 JP |
34 | #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt |
35 | ||
ad9a8612 JF |
36 | #include <linux/module.h> |
37 | #include <linux/sched.h> | |
38 | #include <linux/mm.h> | |
5a0e3ad6 | 39 | #include <linux/slab.h> |
ad9a8612 JF |
40 | #include <linux/vmalloc.h> |
41 | #include <linux/uaccess.h> | |
183d03cc | 42 | #include <linux/io.h> |
c571898f | 43 | #include <linux/delay.h> |
f62805f1 | 44 | #include <linux/hardirq.h> |
3f9f1c67 | 45 | #include <linux/workqueue.h> |
ad9a8612 | 46 | |
1ccbf534 | 47 | #include <xen/xen.h> |
ad9a8612 JF |
48 | #include <xen/interface/xen.h> |
49 | #include <xen/page.h> | |
50 | #include <xen/grant_table.h> | |
183d03cc | 51 | #include <xen/interface/memory.h> |
85ff6acb | 52 | #include <xen/hvc-console.h> |
3d24bbd7 | 53 | #include <xen/swiotlb-xen.h> |
ff4b156f | 54 | #include <xen/balloon.h> |
ecbf29cd | 55 | #include <asm/xen/hypercall.h> |
4d9310e3 | 56 | #include <asm/xen/interface.h> |
ad9a8612 JF |
57 | |
58 | #include <asm/pgtable.h> | |
59 | #include <asm/sync_bitops.h> | |
60 | ||
ad9a8612 JF |
61 | /* External tools reserve first few grant table entries. */ |
62 | #define NR_RESERVED_ENTRIES 8 | |
63 | #define GNTTAB_LIST_END 0xffffffff | |
ad9a8612 JF |
64 | |
65 | static grant_ref_t **gnttab_list; | |
66 | static unsigned int nr_grant_frames; | |
ad9a8612 JF |
67 | static int gnttab_free_count; |
68 | static grant_ref_t gnttab_free_head; | |
69 | static DEFINE_SPINLOCK(gnttab_list_lock); | |
efaf30a3 | 70 | struct grant_frames xen_auto_xlat_grant_frames; |
ad9a8612 | 71 | |
0f9f5a95 AL |
72 | static union { |
73 | struct grant_entry_v1 *v1; | |
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 | */ |
ef32f892 | 85 | int (*map_frames)(xen_pfn_t *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); |
0f9f5a95 AL |
124 | }; |
125 | ||
126 | static struct gnttab_ops *gnttab_interface; | |
127 | ||
128 | static int grant_table_version; | |
d0b4d64a | 129 | static int grefs_per_grant_frame; |
ad9a8612 JF |
130 | |
131 | static struct gnttab_free_callback *gnttab_free_callback_list; | |
132 | ||
133 | static int gnttab_expand(unsigned int req_entries); | |
134 | ||
135 | #define RPP (PAGE_SIZE / sizeof(grant_ref_t)) | |
85ff6acb | 136 | #define SPP (PAGE_SIZE / sizeof(grant_status_t)) |
ad9a8612 JF |
137 | |
138 | static inline grant_ref_t *__gnttab_entry(grant_ref_t entry) | |
139 | { | |
140 | return &gnttab_list[(entry) / RPP][(entry) % RPP]; | |
141 | } | |
142 | /* This can be used as an l-value */ | |
143 | #define gnttab_entry(entry) (*__gnttab_entry(entry)) | |
144 | ||
145 | static int get_free_entries(unsigned count) | |
146 | { | |
147 | unsigned long flags; | |
272800dc | 148 | int ref, rc = 0; |
ad9a8612 JF |
149 | grant_ref_t head; |
150 | ||
151 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
152 | ||
153 | if ((gnttab_free_count < count) && | |
154 | ((rc = gnttab_expand(count - gnttab_free_count)) < 0)) { | |
155 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
156 | return rc; | |
157 | } | |
158 | ||
159 | ref = head = gnttab_free_head; | |
160 | gnttab_free_count -= count; | |
161 | while (count-- > 1) | |
162 | head = gnttab_entry(head); | |
163 | gnttab_free_head = gnttab_entry(head); | |
164 | gnttab_entry(head) = GNTTAB_LIST_END; | |
165 | ||
166 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
167 | ||
168 | return ref; | |
169 | } | |
170 | ||
171 | static void do_free_callbacks(void) | |
172 | { | |
173 | struct gnttab_free_callback *callback, *next; | |
174 | ||
175 | callback = gnttab_free_callback_list; | |
176 | gnttab_free_callback_list = NULL; | |
177 | ||
178 | while (callback != NULL) { | |
179 | next = callback->next; | |
180 | if (gnttab_free_count >= callback->count) { | |
181 | callback->next = NULL; | |
182 | callback->fn(callback->arg); | |
183 | } else { | |
184 | callback->next = gnttab_free_callback_list; | |
185 | gnttab_free_callback_list = callback; | |
186 | } | |
187 | callback = next; | |
188 | } | |
189 | } | |
190 | ||
191 | static inline void check_free_callbacks(void) | |
192 | { | |
193 | if (unlikely(gnttab_free_callback_list)) | |
194 | do_free_callbacks(); | |
195 | } | |
196 | ||
197 | static void put_free_entry(grant_ref_t ref) | |
198 | { | |
199 | unsigned long flags; | |
200 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
201 | gnttab_entry(ref) = gnttab_free_head; | |
202 | gnttab_free_head = ref; | |
203 | gnttab_free_count++; | |
204 | check_free_callbacks(); | |
205 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
206 | } | |
207 | ||
0f9f5a95 | 208 | /* |
438b33c7 | 209 | * Following applies to gnttab_update_entry_v1. |
0f9f5a95 AL |
210 | * Introducing a valid entry into the grant table: |
211 | * 1. Write ent->domid. | |
212 | * 2. Write ent->frame: | |
213 | * GTF_permit_access: Frame to which access is permitted. | |
214 | * GTF_accept_transfer: Pseudo-phys frame slot being filled by new | |
215 | * frame, or zero if none. | |
216 | * 3. Write memory barrier (WMB). | |
217 | * 4. Write ent->flags, inc. valid type. | |
218 | */ | |
219 | static void gnttab_update_entry_v1(grant_ref_t ref, domid_t domid, | |
220 | unsigned long frame, unsigned flags) | |
ad9a8612 | 221 | { |
0f9f5a95 AL |
222 | gnttab_shared.v1[ref].domid = domid; |
223 | gnttab_shared.v1[ref].frame = frame; | |
ad9a8612 | 224 | wmb(); |
0f9f5a95 | 225 | gnttab_shared.v1[ref].flags = flags; |
ad9a8612 JF |
226 | } |
227 | ||
228 | /* | |
229 | * Public grant-issuing interface functions | |
230 | */ | |
231 | void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid, | |
232 | unsigned long frame, int readonly) | |
233 | { | |
0f9f5a95 | 234 | gnttab_interface->update_entry(ref, domid, frame, |
ad9a8612 JF |
235 | GTF_permit_access | (readonly ? GTF_readonly : 0)); |
236 | } | |
237 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_ref); | |
238 | ||
239 | int gnttab_grant_foreign_access(domid_t domid, unsigned long frame, | |
240 | int readonly) | |
241 | { | |
242 | int ref; | |
243 | ||
244 | ref = get_free_entries(1); | |
245 | if (unlikely(ref < 0)) | |
246 | return -ENOSPC; | |
247 | ||
248 | gnttab_grant_foreign_access_ref(ref, domid, frame, readonly); | |
249 | ||
250 | return ref; | |
251 | } | |
252 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access); | |
253 | ||
0f9f5a95 | 254 | static int gnttab_query_foreign_access_v1(grant_ref_t ref) |
ad9a8612 | 255 | { |
0f9f5a95 AL |
256 | return gnttab_shared.v1[ref].flags & (GTF_reading|GTF_writing); |
257 | } | |
ad9a8612 | 258 | |
0f9f5a95 AL |
259 | int gnttab_query_foreign_access(grant_ref_t ref) |
260 | { | |
261 | return gnttab_interface->query_foreign_access(ref); | |
ad9a8612 JF |
262 | } |
263 | EXPORT_SYMBOL_GPL(gnttab_query_foreign_access); | |
264 | ||
0f9f5a95 | 265 | static int gnttab_end_foreign_access_ref_v1(grant_ref_t ref, int readonly) |
ad9a8612 JF |
266 | { |
267 | u16 flags, nflags; | |
b1e495b2 | 268 | u16 *pflags; |
ad9a8612 | 269 | |
b1e495b2 AL |
270 | pflags = &gnttab_shared.v1[ref].flags; |
271 | nflags = *pflags; | |
ad9a8612 JF |
272 | do { |
273 | flags = nflags; | |
569ca5b3 | 274 | if (flags & (GTF_reading|GTF_writing)) |
ad9a8612 | 275 | return 0; |
b1e495b2 | 276 | } while ((nflags = sync_cmpxchg(pflags, flags, 0)) != flags); |
ad9a8612 JF |
277 | |
278 | return 1; | |
279 | } | |
0f9f5a95 | 280 | |
569ca5b3 | 281 | static inline int _gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly) |
0f9f5a95 AL |
282 | { |
283 | return gnttab_interface->end_foreign_access_ref(ref, readonly); | |
284 | } | |
569ca5b3 JB |
285 | |
286 | int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly) | |
287 | { | |
288 | if (_gnttab_end_foreign_access_ref(ref, readonly)) | |
289 | return 1; | |
290 | pr_warn("WARNING: g.e. %#x still in use!\n", ref); | |
291 | return 0; | |
292 | } | |
ad9a8612 JF |
293 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_access_ref); |
294 | ||
569ca5b3 JB |
295 | struct deferred_entry { |
296 | struct list_head list; | |
297 | grant_ref_t ref; | |
298 | bool ro; | |
299 | uint16_t warn_delay; | |
300 | struct page *page; | |
301 | }; | |
302 | static LIST_HEAD(deferred_list); | |
303 | static void gnttab_handle_deferred(unsigned long); | |
304 | static DEFINE_TIMER(deferred_timer, gnttab_handle_deferred, 0, 0); | |
305 | ||
306 | static void gnttab_handle_deferred(unsigned long unused) | |
307 | { | |
308 | unsigned int nr = 10; | |
309 | struct deferred_entry *first = NULL; | |
310 | unsigned long flags; | |
311 | ||
312 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
313 | while (nr--) { | |
314 | struct deferred_entry *entry | |
315 | = list_first_entry(&deferred_list, | |
316 | struct deferred_entry, list); | |
317 | ||
318 | if (entry == first) | |
319 | break; | |
320 | list_del(&entry->list); | |
321 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
322 | if (_gnttab_end_foreign_access_ref(entry->ref, entry->ro)) { | |
323 | put_free_entry(entry->ref); | |
324 | if (entry->page) { | |
325 | pr_debug("freeing g.e. %#x (pfn %#lx)\n", | |
326 | entry->ref, page_to_pfn(entry->page)); | |
327 | __free_page(entry->page); | |
328 | } else | |
329 | pr_info("freeing g.e. %#x\n", entry->ref); | |
330 | kfree(entry); | |
331 | entry = NULL; | |
332 | } else { | |
333 | if (!--entry->warn_delay) | |
283c0972 | 334 | pr_info("g.e. %#x still pending\n", entry->ref); |
569ca5b3 JB |
335 | if (!first) |
336 | first = entry; | |
337 | } | |
338 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
339 | if (entry) | |
340 | list_add_tail(&entry->list, &deferred_list); | |
341 | else if (list_empty(&deferred_list)) | |
342 | break; | |
343 | } | |
344 | if (!list_empty(&deferred_list) && !timer_pending(&deferred_timer)) { | |
345 | deferred_timer.expires = jiffies + HZ; | |
346 | add_timer(&deferred_timer); | |
347 | } | |
348 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
349 | } | |
350 | ||
351 | static void gnttab_add_deferred(grant_ref_t ref, bool readonly, | |
352 | struct page *page) | |
353 | { | |
354 | struct deferred_entry *entry = kmalloc(sizeof(*entry), GFP_ATOMIC); | |
355 | const char *what = KERN_WARNING "leaking"; | |
356 | ||
357 | if (entry) { | |
358 | unsigned long flags; | |
359 | ||
360 | entry->ref = ref; | |
361 | entry->ro = readonly; | |
362 | entry->page = page; | |
363 | entry->warn_delay = 60; | |
364 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
365 | list_add_tail(&entry->list, &deferred_list); | |
366 | if (!timer_pending(&deferred_timer)) { | |
367 | deferred_timer.expires = jiffies + HZ; | |
368 | add_timer(&deferred_timer); | |
369 | } | |
370 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
371 | what = KERN_DEBUG "deferring"; | |
372 | } | |
373 | printk("%s g.e. %#x (pfn %#lx)\n", | |
374 | what, ref, page ? page_to_pfn(page) : -1); | |
375 | } | |
376 | ||
ad9a8612 JF |
377 | void gnttab_end_foreign_access(grant_ref_t ref, int readonly, |
378 | unsigned long page) | |
379 | { | |
380 | if (gnttab_end_foreign_access_ref(ref, readonly)) { | |
381 | put_free_entry(ref); | |
382 | if (page != 0) | |
383 | free_page(page); | |
569ca5b3 JB |
384 | } else |
385 | gnttab_add_deferred(ref, readonly, | |
386 | page ? virt_to_page(page) : NULL); | |
ad9a8612 JF |
387 | } |
388 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_access); | |
389 | ||
390 | int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn) | |
391 | { | |
392 | int ref; | |
393 | ||
394 | ref = get_free_entries(1); | |
395 | if (unlikely(ref < 0)) | |
396 | return -ENOSPC; | |
397 | gnttab_grant_foreign_transfer_ref(ref, domid, pfn); | |
398 | ||
399 | return ref; | |
400 | } | |
401 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer); | |
402 | ||
403 | void gnttab_grant_foreign_transfer_ref(grant_ref_t ref, domid_t domid, | |
404 | unsigned long pfn) | |
405 | { | |
0f9f5a95 | 406 | gnttab_interface->update_entry(ref, domid, pfn, GTF_accept_transfer); |
ad9a8612 JF |
407 | } |
408 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer_ref); | |
409 | ||
0f9f5a95 | 410 | static unsigned long gnttab_end_foreign_transfer_ref_v1(grant_ref_t ref) |
ad9a8612 JF |
411 | { |
412 | unsigned long frame; | |
413 | u16 flags; | |
b1e495b2 AL |
414 | u16 *pflags; |
415 | ||
416 | pflags = &gnttab_shared.v1[ref].flags; | |
ad9a8612 JF |
417 | |
418 | /* | |
419 | * If a transfer is not even yet started, try to reclaim the grant | |
420 | * reference and return failure (== 0). | |
421 | */ | |
b1e495b2 AL |
422 | while (!((flags = *pflags) & GTF_transfer_committed)) { |
423 | if (sync_cmpxchg(pflags, flags, 0) == flags) | |
ad9a8612 JF |
424 | return 0; |
425 | cpu_relax(); | |
426 | } | |
427 | ||
428 | /* If a transfer is in progress then wait until it is completed. */ | |
429 | while (!(flags & GTF_transfer_completed)) { | |
b1e495b2 | 430 | flags = *pflags; |
ad9a8612 JF |
431 | cpu_relax(); |
432 | } | |
433 | ||
434 | rmb(); /* Read the frame number /after/ reading completion status. */ | |
0f9f5a95 | 435 | frame = gnttab_shared.v1[ref].frame; |
ad9a8612 JF |
436 | BUG_ON(frame == 0); |
437 | ||
438 | return frame; | |
439 | } | |
0f9f5a95 AL |
440 | |
441 | unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref) | |
442 | { | |
443 | return gnttab_interface->end_foreign_transfer_ref(ref); | |
444 | } | |
ad9a8612 JF |
445 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer_ref); |
446 | ||
447 | unsigned long gnttab_end_foreign_transfer(grant_ref_t ref) | |
448 | { | |
449 | unsigned long frame = gnttab_end_foreign_transfer_ref(ref); | |
450 | put_free_entry(ref); | |
451 | return frame; | |
452 | } | |
453 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer); | |
454 | ||
455 | void gnttab_free_grant_reference(grant_ref_t ref) | |
456 | { | |
457 | put_free_entry(ref); | |
458 | } | |
459 | EXPORT_SYMBOL_GPL(gnttab_free_grant_reference); | |
460 | ||
461 | void gnttab_free_grant_references(grant_ref_t head) | |
462 | { | |
463 | grant_ref_t ref; | |
464 | unsigned long flags; | |
465 | int count = 1; | |
466 | if (head == GNTTAB_LIST_END) | |
467 | return; | |
468 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
469 | ref = head; | |
470 | while (gnttab_entry(ref) != GNTTAB_LIST_END) { | |
471 | ref = gnttab_entry(ref); | |
472 | count++; | |
473 | } | |
474 | gnttab_entry(ref) = gnttab_free_head; | |
475 | gnttab_free_head = head; | |
476 | gnttab_free_count += count; | |
477 | check_free_callbacks(); | |
478 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
479 | } | |
480 | EXPORT_SYMBOL_GPL(gnttab_free_grant_references); | |
481 | ||
482 | int gnttab_alloc_grant_references(u16 count, grant_ref_t *head) | |
483 | { | |
484 | int h = get_free_entries(count); | |
485 | ||
486 | if (h < 0) | |
487 | return -ENOSPC; | |
488 | ||
489 | *head = h; | |
490 | ||
491 | return 0; | |
492 | } | |
493 | EXPORT_SYMBOL_GPL(gnttab_alloc_grant_references); | |
494 | ||
495 | int gnttab_empty_grant_references(const grant_ref_t *private_head) | |
496 | { | |
497 | return (*private_head == GNTTAB_LIST_END); | |
498 | } | |
499 | EXPORT_SYMBOL_GPL(gnttab_empty_grant_references); | |
500 | ||
501 | int gnttab_claim_grant_reference(grant_ref_t *private_head) | |
502 | { | |
503 | grant_ref_t g = *private_head; | |
504 | if (unlikely(g == GNTTAB_LIST_END)) | |
505 | return -ENOSPC; | |
506 | *private_head = gnttab_entry(g); | |
507 | return g; | |
508 | } | |
509 | EXPORT_SYMBOL_GPL(gnttab_claim_grant_reference); | |
510 | ||
511 | void gnttab_release_grant_reference(grant_ref_t *private_head, | |
512 | grant_ref_t release) | |
513 | { | |
514 | gnttab_entry(release) = *private_head; | |
515 | *private_head = release; | |
516 | } | |
517 | EXPORT_SYMBOL_GPL(gnttab_release_grant_reference); | |
518 | ||
519 | void gnttab_request_free_callback(struct gnttab_free_callback *callback, | |
520 | void (*fn)(void *), void *arg, u16 count) | |
521 | { | |
522 | unsigned long flags; | |
5f338d90 RPM |
523 | struct gnttab_free_callback *cb; |
524 | ||
ad9a8612 | 525 | spin_lock_irqsave(&gnttab_list_lock, flags); |
5f338d90 RPM |
526 | |
527 | /* Check if the callback is already on the list */ | |
528 | cb = gnttab_free_callback_list; | |
529 | while (cb) { | |
530 | if (cb == callback) | |
531 | goto out; | |
532 | cb = cb->next; | |
533 | } | |
534 | ||
ad9a8612 JF |
535 | callback->fn = fn; |
536 | callback->arg = arg; | |
537 | callback->count = count; | |
538 | callback->next = gnttab_free_callback_list; | |
539 | gnttab_free_callback_list = callback; | |
540 | check_free_callbacks(); | |
541 | out: | |
542 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
543 | } | |
544 | EXPORT_SYMBOL_GPL(gnttab_request_free_callback); | |
545 | ||
546 | void gnttab_cancel_free_callback(struct gnttab_free_callback *callback) | |
547 | { | |
548 | struct gnttab_free_callback **pcb; | |
549 | unsigned long flags; | |
550 | ||
551 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
552 | for (pcb = &gnttab_free_callback_list; *pcb; pcb = &(*pcb)->next) { | |
553 | if (*pcb == callback) { | |
554 | *pcb = callback->next; | |
555 | break; | |
556 | } | |
557 | } | |
558 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
559 | } | |
560 | EXPORT_SYMBOL_GPL(gnttab_cancel_free_callback); | |
561 | ||
562 | static int grow_gnttab_list(unsigned int more_frames) | |
563 | { | |
564 | unsigned int new_nr_grant_frames, extra_entries, i; | |
bbc60c18 | 565 | unsigned int nr_glist_frames, new_nr_glist_frames; |
ad9a8612 | 566 | |
d0b4d64a MW |
567 | BUG_ON(grefs_per_grant_frame == 0); |
568 | ||
ad9a8612 | 569 | new_nr_grant_frames = nr_grant_frames + more_frames; |
d0b4d64a | 570 | extra_entries = more_frames * grefs_per_grant_frame; |
ad9a8612 | 571 | |
d0b4d64a | 572 | nr_glist_frames = (nr_grant_frames * grefs_per_grant_frame + RPP - 1) / RPP; |
bbc60c18 | 573 | new_nr_glist_frames = |
d0b4d64a | 574 | (new_nr_grant_frames * grefs_per_grant_frame + RPP - 1) / RPP; |
bbc60c18 | 575 | for (i = nr_glist_frames; i < new_nr_glist_frames; i++) { |
ad9a8612 JF |
576 | gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_ATOMIC); |
577 | if (!gnttab_list[i]) | |
578 | goto grow_nomem; | |
579 | } | |
580 | ||
581 | ||
d0b4d64a MW |
582 | for (i = grefs_per_grant_frame * nr_grant_frames; |
583 | i < grefs_per_grant_frame * new_nr_grant_frames - 1; i++) | |
ad9a8612 JF |
584 | gnttab_entry(i) = i + 1; |
585 | ||
586 | gnttab_entry(i) = gnttab_free_head; | |
d0b4d64a | 587 | gnttab_free_head = grefs_per_grant_frame * nr_grant_frames; |
ad9a8612 JF |
588 | gnttab_free_count += extra_entries; |
589 | ||
590 | nr_grant_frames = new_nr_grant_frames; | |
591 | ||
592 | check_free_callbacks(); | |
593 | ||
594 | return 0; | |
595 | ||
596 | grow_nomem: | |
46e3626a | 597 | while (i-- > nr_glist_frames) |
ad9a8612 JF |
598 | free_page((unsigned long) gnttab_list[i]); |
599 | return -ENOMEM; | |
600 | } | |
601 | ||
602 | static unsigned int __max_nr_grant_frames(void) | |
603 | { | |
604 | struct gnttab_query_size query; | |
605 | int rc; | |
606 | ||
607 | query.dom = DOMID_SELF; | |
608 | ||
609 | rc = HYPERVISOR_grant_table_op(GNTTABOP_query_size, &query, 1); | |
610 | if ((rc < 0) || (query.status != GNTST_okay)) | |
611 | return 4; /* Legacy max supported number of frames */ | |
612 | ||
613 | return query.max_nr_frames; | |
614 | } | |
615 | ||
183d03cc | 616 | unsigned int gnttab_max_grant_frames(void) |
ad9a8612 JF |
617 | { |
618 | unsigned int xen_max = __max_nr_grant_frames(); | |
7f256020 KRW |
619 | static unsigned int boot_max_nr_grant_frames; |
620 | ||
621 | /* First time, initialize it properly. */ | |
622 | if (!boot_max_nr_grant_frames) | |
623 | boot_max_nr_grant_frames = __max_nr_grant_frames(); | |
ad9a8612 JF |
624 | |
625 | if (xen_max > boot_max_nr_grant_frames) | |
626 | return boot_max_nr_grant_frames; | |
627 | return xen_max; | |
628 | } | |
183d03cc | 629 | EXPORT_SYMBOL_GPL(gnttab_max_grant_frames); |
ad9a8612 | 630 | |
47c54205 | 631 | int gnttab_setup_auto_xlat_frames(phys_addr_t addr) |
efaf30a3 KRW |
632 | { |
633 | xen_pfn_t *pfn; | |
634 | unsigned int max_nr_gframes = __max_nr_grant_frames(); | |
635 | unsigned int i; | |
636 | void *vaddr; | |
637 | ||
638 | if (xen_auto_xlat_grant_frames.count) | |
639 | return -EINVAL; | |
640 | ||
641 | vaddr = xen_remap(addr, PAGE_SIZE * max_nr_gframes); | |
642 | if (vaddr == NULL) { | |
47c54205 JG |
643 | pr_warn("Failed to ioremap gnttab share frames (addr=%pa)!\n", |
644 | &addr); | |
efaf30a3 KRW |
645 | return -ENOMEM; |
646 | } | |
647 | pfn = kcalloc(max_nr_gframes, sizeof(pfn[0]), GFP_KERNEL); | |
648 | if (!pfn) { | |
649 | xen_unmap(vaddr); | |
650 | return -ENOMEM; | |
651 | } | |
652 | for (i = 0; i < max_nr_gframes; i++) | |
653 | pfn[i] = PFN_DOWN(addr) + i; | |
654 | ||
655 | xen_auto_xlat_grant_frames.vaddr = vaddr; | |
656 | xen_auto_xlat_grant_frames.pfn = pfn; | |
657 | xen_auto_xlat_grant_frames.count = max_nr_gframes; | |
658 | ||
659 | return 0; | |
660 | } | |
661 | EXPORT_SYMBOL_GPL(gnttab_setup_auto_xlat_frames); | |
662 | ||
663 | void gnttab_free_auto_xlat_frames(void) | |
664 | { | |
665 | if (!xen_auto_xlat_grant_frames.count) | |
666 | return; | |
667 | kfree(xen_auto_xlat_grant_frames.pfn); | |
668 | xen_unmap(xen_auto_xlat_grant_frames.vaddr); | |
669 | ||
670 | xen_auto_xlat_grant_frames.pfn = NULL; | |
671 | xen_auto_xlat_grant_frames.count = 0; | |
672 | xen_auto_xlat_grant_frames.vaddr = NULL; | |
673 | } | |
674 | EXPORT_SYMBOL_GPL(gnttab_free_auto_xlat_frames); | |
675 | ||
ff4b156f DV |
676 | /** |
677 | * gnttab_alloc_pages - alloc pages suitable for grant mapping into | |
678 | * @nr_pages: number of pages to alloc | |
679 | * @pages: returns the pages | |
680 | */ | |
681 | int gnttab_alloc_pages(int nr_pages, struct page **pages) | |
682 | { | |
8da7633f | 683 | int i; |
ff4b156f DV |
684 | int ret; |
685 | ||
686 | ret = alloc_xenballooned_pages(nr_pages, pages, false); | |
687 | if (ret < 0) | |
688 | return ret; | |
689 | ||
8da7633f JH |
690 | for (i = 0; i < nr_pages; i++) { |
691 | #if BITS_PER_LONG < 64 | |
692 | struct xen_page_foreign *foreign; | |
693 | ||
694 | foreign = kzalloc(sizeof(*foreign), GFP_KERNEL); | |
695 | if (!foreign) { | |
696 | gnttab_free_pages(nr_pages, pages); | |
697 | return -ENOMEM; | |
698 | } | |
699 | set_page_private(pages[i], (unsigned long)foreign); | |
700 | #endif | |
701 | SetPagePrivate(pages[i]); | |
702 | } | |
703 | ||
ff4b156f DV |
704 | return 0; |
705 | } | |
706 | EXPORT_SYMBOL(gnttab_alloc_pages); | |
707 | ||
708 | /** | |
709 | * gnttab_free_pages - free pages allocated by gnttab_alloc_pages() | |
710 | * @nr_pages; number of pages to free | |
711 | * @pages: the pages | |
712 | */ | |
713 | void gnttab_free_pages(int nr_pages, struct page **pages) | |
714 | { | |
8da7633f JH |
715 | int i; |
716 | ||
717 | for (i = 0; i < nr_pages; i++) { | |
718 | if (PagePrivate(pages[i])) { | |
719 | #if BITS_PER_LONG < 64 | |
720 | kfree((void *)page_private(pages[i])); | |
721 | #endif | |
722 | ClearPagePrivate(pages[i]); | |
723 | } | |
724 | } | |
ff4b156f DV |
725 | free_xenballooned_pages(nr_pages, pages); |
726 | } | |
727 | EXPORT_SYMBOL(gnttab_free_pages); | |
728 | ||
c571898f ALC |
729 | /* Handling of paged out grant targets (GNTST_eagain) */ |
730 | #define MAX_DELAY 256 | |
731 | static inline void | |
732 | gnttab_retry_eagain_gop(unsigned int cmd, void *gop, int16_t *status, | |
733 | const char *func) | |
734 | { | |
735 | unsigned delay = 1; | |
736 | ||
737 | do { | |
738 | BUG_ON(HYPERVISOR_grant_table_op(cmd, gop, 1)); | |
739 | if (*status == GNTST_eagain) | |
740 | msleep(delay++); | |
741 | } while ((*status == GNTST_eagain) && (delay < MAX_DELAY)); | |
742 | ||
743 | if (delay >= MAX_DELAY) { | |
283c0972 | 744 | pr_err("%s: %s eagain grant\n", func, current->comm); |
c571898f ALC |
745 | *status = GNTST_bad_page; |
746 | } | |
747 | } | |
748 | ||
749 | void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count) | |
750 | { | |
751 | struct gnttab_map_grant_ref *op; | |
752 | ||
753 | if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, batch, count)) | |
754 | BUG(); | |
755 | for (op = batch; op < batch + count; op++) | |
756 | if (op->status == GNTST_eagain) | |
757 | gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, op, | |
758 | &op->status, __func__); | |
759 | } | |
760 | EXPORT_SYMBOL_GPL(gnttab_batch_map); | |
761 | ||
762 | void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count) | |
763 | { | |
764 | struct gnttab_copy *op; | |
765 | ||
766 | if (HYPERVISOR_grant_table_op(GNTTABOP_copy, batch, count)) | |
767 | BUG(); | |
768 | for (op = batch; op < batch + count; op++) | |
769 | if (op->status == GNTST_eagain) | |
770 | gnttab_retry_eagain_gop(GNTTABOP_copy, op, | |
771 | &op->status, __func__); | |
772 | } | |
773 | EXPORT_SYMBOL_GPL(gnttab_batch_copy); | |
774 | ||
e85fc980 | 775 | int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, |
c123799a | 776 | struct gnttab_map_grant_ref *kmap_ops, |
e85fc980 | 777 | struct page **pages, unsigned int count) |
289b777e SS |
778 | { |
779 | int i, ret; | |
289b777e SS |
780 | |
781 | ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map_ops, count); | |
87f1d40a JF |
782 | if (ret) |
783 | return ret; | |
289b777e | 784 | |
8da7633f JH |
785 | for (i = 0; i < count; i++) { |
786 | /* Retry eagain maps */ | |
c571898f ALC |
787 | if (map_ops[i].status == GNTST_eagain) |
788 | gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, map_ops + i, | |
789 | &map_ops[i].status, __func__); | |
790 | ||
8da7633f JH |
791 | if (map_ops[i].status == GNTST_okay) { |
792 | struct xen_page_foreign *foreign; | |
793 | ||
794 | SetPageForeign(pages[i]); | |
795 | foreign = xen_page_foreign(pages[i]); | |
796 | foreign->domid = map_ops[i].dom; | |
797 | foreign->gref = map_ops[i].ref; | |
798 | } | |
799 | } | |
800 | ||
1429d46d | 801 | return set_foreign_p2m_mapping(map_ops, kmap_ops, pages, count); |
289b777e SS |
802 | } |
803 | EXPORT_SYMBOL_GPL(gnttab_map_refs); | |
804 | ||
e85fc980 | 805 | int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, |
853d0289 | 806 | struct gnttab_unmap_grant_ref *kunmap_ops, |
e85fc980 | 807 | struct page **pages, unsigned int count) |
289b777e | 808 | { |
8da7633f | 809 | unsigned int i; |
1429d46d | 810 | int ret; |
289b777e SS |
811 | |
812 | ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops, count); | |
87f1d40a JF |
813 | if (ret) |
814 | return ret; | |
815 | ||
8da7633f JH |
816 | for (i = 0; i < count; i++) |
817 | ClearPageForeign(pages[i]); | |
818 | ||
853d0289 | 819 | return clear_foreign_p2m_mapping(unmap_ops, kunmap_ops, pages, count); |
289b777e SS |
820 | } |
821 | EXPORT_SYMBOL_GPL(gnttab_unmap_refs); | |
822 | ||
3f9f1c67 JH |
823 | #define GNTTAB_UNMAP_REFS_DELAY 5 |
824 | ||
825 | static void __gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item); | |
826 | ||
827 | static void gnttab_unmap_work(struct work_struct *work) | |
828 | { | |
829 | struct gntab_unmap_queue_data | |
830 | *unmap_data = container_of(work, | |
831 | struct gntab_unmap_queue_data, | |
832 | gnttab_work.work); | |
833 | if (unmap_data->age != UINT_MAX) | |
834 | unmap_data->age++; | |
835 | __gnttab_unmap_refs_async(unmap_data); | |
836 | } | |
837 | ||
838 | static void __gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item) | |
839 | { | |
840 | int ret; | |
841 | int pc; | |
842 | ||
843 | for (pc = 0; pc < item->count; pc++) { | |
844 | if (page_count(item->pages[pc]) > 1) { | |
845 | unsigned long delay = GNTTAB_UNMAP_REFS_DELAY * (item->age + 1); | |
846 | schedule_delayed_work(&item->gnttab_work, | |
847 | msecs_to_jiffies(delay)); | |
848 | return; | |
849 | } | |
850 | } | |
851 | ||
852 | ret = gnttab_unmap_refs(item->unmap_ops, item->kunmap_ops, | |
853 | item->pages, item->count); | |
854 | item->done(ret, item); | |
855 | } | |
856 | ||
857 | void gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item) | |
858 | { | |
859 | INIT_DELAYED_WORK(&item->gnttab_work, gnttab_unmap_work); | |
860 | item->age = 0; | |
861 | ||
862 | __gnttab_unmap_refs_async(item); | |
863 | } | |
864 | EXPORT_SYMBOL_GPL(gnttab_unmap_refs_async); | |
865 | ||
ef32f892 | 866 | static int gnttab_map_frames_v1(xen_pfn_t *frames, unsigned int nr_gframes) |
0f9f5a95 AL |
867 | { |
868 | int rc; | |
869 | ||
870 | rc = arch_gnttab_map_shared(frames, nr_gframes, | |
871 | gnttab_max_grant_frames(), | |
872 | &gnttab_shared.addr); | |
873 | BUG_ON(rc); | |
874 | ||
875 | return 0; | |
876 | } | |
877 | ||
878 | static void gnttab_unmap_frames_v1(void) | |
879 | { | |
85ff6acb AL |
880 | arch_gnttab_unmap(gnttab_shared.addr, nr_grant_frames); |
881 | } | |
882 | ||
ad9a8612 JF |
883 | static int gnttab_map(unsigned int start_idx, unsigned int end_idx) |
884 | { | |
885 | struct gnttab_setup_table setup; | |
ef32f892 | 886 | xen_pfn_t *frames; |
ad9a8612 JF |
887 | unsigned int nr_gframes = end_idx + 1; |
888 | int rc; | |
889 | ||
6926f6d6 | 890 | if (xen_feature(XENFEAT_auto_translated_physmap)) { |
183d03cc SS |
891 | struct xen_add_to_physmap xatp; |
892 | unsigned int i = end_idx; | |
893 | rc = 0; | |
efaf30a3 | 894 | BUG_ON(xen_auto_xlat_grant_frames.count < nr_gframes); |
183d03cc SS |
895 | /* |
896 | * Loop backwards, so that the first hypercall has the largest | |
897 | * index, ensuring that the table will grow only once. | |
898 | */ | |
899 | do { | |
900 | xatp.domid = DOMID_SELF; | |
901 | xatp.idx = i; | |
902 | xatp.space = XENMAPSPACE_grant_table; | |
efaf30a3 | 903 | xatp.gpfn = xen_auto_xlat_grant_frames.pfn[i]; |
183d03cc SS |
904 | rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp); |
905 | if (rc != 0) { | |
283c0972 JP |
906 | pr_warn("grant table add_to_physmap failed, err=%d\n", |
907 | rc); | |
183d03cc SS |
908 | break; |
909 | } | |
910 | } while (i-- > start_idx); | |
911 | ||
912 | return rc; | |
913 | } | |
914 | ||
85ff6acb AL |
915 | /* No need for kzalloc as it is initialized in following hypercall |
916 | * GNTTABOP_setup_table. | |
917 | */ | |
ad9a8612 JF |
918 | frames = kmalloc(nr_gframes * sizeof(unsigned long), GFP_ATOMIC); |
919 | if (!frames) | |
920 | return -ENOMEM; | |
921 | ||
922 | setup.dom = DOMID_SELF; | |
923 | setup.nr_frames = nr_gframes; | |
87e27cf6 | 924 | set_xen_guest_handle(setup.frame_list, frames); |
ad9a8612 JF |
925 | |
926 | rc = HYPERVISOR_grant_table_op(GNTTABOP_setup_table, &setup, 1); | |
927 | if (rc == -ENOSYS) { | |
928 | kfree(frames); | |
929 | return -ENOSYS; | |
930 | } | |
931 | ||
932 | BUG_ON(rc || setup.status); | |
933 | ||
0f9f5a95 | 934 | rc = gnttab_interface->map_frames(frames, nr_gframes); |
ad9a8612 JF |
935 | |
936 | kfree(frames); | |
937 | ||
0f9f5a95 AL |
938 | return rc; |
939 | } | |
940 | ||
941 | static struct gnttab_ops gnttab_v1_ops = { | |
942 | .map_frames = gnttab_map_frames_v1, | |
943 | .unmap_frames = gnttab_unmap_frames_v1, | |
944 | .update_entry = gnttab_update_entry_v1, | |
945 | .end_foreign_access_ref = gnttab_end_foreign_access_ref_v1, | |
946 | .end_foreign_transfer_ref = gnttab_end_foreign_transfer_ref_v1, | |
947 | .query_foreign_access = gnttab_query_foreign_access_v1, | |
948 | }; | |
949 | ||
950 | static void gnttab_request_version(void) | |
951 | { | |
438b33c7 DV |
952 | /* Only version 1 is used, which will always be available. */ |
953 | grant_table_version = 1; | |
954 | grefs_per_grant_frame = PAGE_SIZE / sizeof(struct grant_entry_v1); | |
955 | gnttab_interface = &gnttab_v1_ops; | |
85ff6acb | 956 | |
283c0972 | 957 | pr_info("Grant tables using version %d layout\n", grant_table_version); |
ad9a8612 JF |
958 | } |
959 | ||
d0b4d64a | 960 | static int gnttab_setup(void) |
ad9a8612 | 961 | { |
183d03cc SS |
962 | unsigned int max_nr_gframes; |
963 | ||
964 | max_nr_gframes = gnttab_max_grant_frames(); | |
965 | if (max_nr_gframes < nr_grant_frames) | |
ad9a8612 | 966 | return -ENOSYS; |
183d03cc | 967 | |
45684753 | 968 | if (xen_feature(XENFEAT_auto_translated_physmap) && gnttab_shared.addr == NULL) { |
efaf30a3 | 969 | gnttab_shared.addr = xen_auto_xlat_grant_frames.vaddr; |
0f9f5a95 | 970 | if (gnttab_shared.addr == NULL) { |
efaf30a3 KRW |
971 | pr_warn("gnttab share frames (addr=0x%08lx) is not mapped!\n", |
972 | (unsigned long)xen_auto_xlat_grant_frames.vaddr); | |
183d03cc SS |
973 | return -ENOMEM; |
974 | } | |
975 | } | |
45684753 | 976 | return gnttab_map(0, nr_grant_frames - 1); |
ad9a8612 JF |
977 | } |
978 | ||
d0b4d64a MW |
979 | int gnttab_resume(void) |
980 | { | |
981 | gnttab_request_version(); | |
982 | return gnttab_setup(); | |
983 | } | |
984 | ||
0e91398f | 985 | int gnttab_suspend(void) |
ad9a8612 | 986 | { |
13cd36a3 DV |
987 | if (!xen_feature(XENFEAT_auto_translated_physmap)) |
988 | gnttab_interface->unmap_frames(); | |
ad9a8612 JF |
989 | return 0; |
990 | } | |
991 | ||
992 | static int gnttab_expand(unsigned int req_entries) | |
993 | { | |
994 | int rc; | |
995 | unsigned int cur, extra; | |
996 | ||
d0b4d64a | 997 | BUG_ON(grefs_per_grant_frame == 0); |
ad9a8612 | 998 | cur = nr_grant_frames; |
d0b4d64a MW |
999 | extra = ((req_entries + (grefs_per_grant_frame-1)) / |
1000 | grefs_per_grant_frame); | |
183d03cc | 1001 | if (cur + extra > gnttab_max_grant_frames()) |
ad9a8612 JF |
1002 | return -ENOSPC; |
1003 | ||
1004 | rc = gnttab_map(cur, cur + extra - 1); | |
1005 | if (rc == 0) | |
1006 | rc = grow_gnttab_list(extra); | |
1007 | ||
1008 | return rc; | |
1009 | } | |
1010 | ||
183d03cc | 1011 | int gnttab_init(void) |
ad9a8612 JF |
1012 | { |
1013 | int i; | |
162e3717 | 1014 | unsigned long max_nr_grant_frames; |
bbc60c18 | 1015 | unsigned int max_nr_glist_frames, nr_glist_frames; |
ad9a8612 | 1016 | unsigned int nr_init_grefs; |
6b5e7d9e | 1017 | int ret; |
ad9a8612 | 1018 | |
d0b4d64a | 1019 | gnttab_request_version(); |
162e3717 | 1020 | max_nr_grant_frames = gnttab_max_grant_frames(); |
ad9a8612 | 1021 | nr_grant_frames = 1; |
ad9a8612 JF |
1022 | |
1023 | /* Determine the maximum number of frames required for the | |
1024 | * grant reference free list on the current hypervisor. | |
1025 | */ | |
d0b4d64a | 1026 | BUG_ON(grefs_per_grant_frame == 0); |
162e3717 | 1027 | max_nr_glist_frames = (max_nr_grant_frames * |
d0b4d64a | 1028 | grefs_per_grant_frame / RPP); |
ad9a8612 JF |
1029 | |
1030 | gnttab_list = kmalloc(max_nr_glist_frames * sizeof(grant_ref_t *), | |
1031 | GFP_KERNEL); | |
1032 | if (gnttab_list == NULL) | |
1033 | return -ENOMEM; | |
1034 | ||
d0b4d64a | 1035 | nr_glist_frames = (nr_grant_frames * grefs_per_grant_frame + RPP - 1) / RPP; |
bbc60c18 | 1036 | for (i = 0; i < nr_glist_frames; i++) { |
ad9a8612 | 1037 | gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_KERNEL); |
6b5e7d9e JL |
1038 | if (gnttab_list[i] == NULL) { |
1039 | ret = -ENOMEM; | |
ad9a8612 | 1040 | goto ini_nomem; |
6b5e7d9e | 1041 | } |
ad9a8612 JF |
1042 | } |
1043 | ||
438b33c7 | 1044 | ret = arch_gnttab_init(max_nr_grant_frames); |
162e3717 DV |
1045 | if (ret < 0) |
1046 | goto ini_nomem; | |
1047 | ||
d0b4d64a | 1048 | if (gnttab_setup() < 0) { |
6b5e7d9e JL |
1049 | ret = -ENODEV; |
1050 | goto ini_nomem; | |
1051 | } | |
ad9a8612 | 1052 | |
d0b4d64a | 1053 | nr_init_grefs = nr_grant_frames * grefs_per_grant_frame; |
ad9a8612 JF |
1054 | |
1055 | for (i = NR_RESERVED_ENTRIES; i < nr_init_grefs - 1; i++) | |
1056 | gnttab_entry(i) = i + 1; | |
1057 | ||
1058 | gnttab_entry(nr_init_grefs - 1) = GNTTAB_LIST_END; | |
1059 | gnttab_free_count = nr_init_grefs - NR_RESERVED_ENTRIES; | |
1060 | gnttab_free_head = NR_RESERVED_ENTRIES; | |
1061 | ||
1062 | printk("Grant table initialized\n"); | |
1063 | return 0; | |
1064 | ||
1065 | ini_nomem: | |
1066 | for (i--; i >= 0; i--) | |
1067 | free_page((unsigned long)gnttab_list[i]); | |
1068 | kfree(gnttab_list); | |
6b5e7d9e | 1069 | return ret; |
ad9a8612 | 1070 | } |
183d03cc SS |
1071 | EXPORT_SYMBOL_GPL(gnttab_init); |
1072 | ||
345a5255 | 1073 | static int __gnttab_init(void) |
183d03cc SS |
1074 | { |
1075 | /* Delay grant-table initialization in the PV on HVM case */ | |
1076 | if (xen_hvm_domain()) | |
1077 | return 0; | |
1078 | ||
1079 | if (!xen_pv_domain()) | |
1080 | return -ENODEV; | |
1081 | ||
1082 | return gnttab_init(); | |
1083 | } | |
6926f6d6 KRW |
1084 | /* Starts after core_initcall so that xen_pvh_gnttab_setup can be called |
1085 | * beforehand to initialize xen_auto_xlat_grant_frames. */ | |
1086 | core_initcall_sync(__gnttab_init); |