blob: 9ef54ebc1194d74281cd2545d72c6296f26fc313 [file] [log] [blame]
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -07001/******************************************************************************
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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090037#include <linux/slab.h>
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -070038#include <linux/vmalloc.h>
39#include <linux/uaccess.h>
Stefano Stabellini183d03c2010-05-17 17:08:21 +010040#include <linux/io.h>
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -070041
Jeremy Fitzhardinge1ccbf532009-10-06 15:11:14 -070042#include <xen/xen.h>
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -070043#include <xen/interface/xen.h>
44#include <xen/page.h>
45#include <xen/grant_table.h>
Stefano Stabellini183d03c2010-05-17 17:08:21 +010046#include <xen/interface/memory.h>
Jeremy Fitzhardingeecbf29c2008-12-16 12:37:07 -080047#include <asm/xen/hypercall.h>
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -070048
49#include <asm/pgtable.h>
50#include <asm/sync_bitops.h>
51
52
53/* External tools reserve first few grant table entries. */
54#define NR_RESERVED_ENTRIES 8
55#define GNTTAB_LIST_END 0xffffffff
56#define GREFS_PER_GRANT_FRAME (PAGE_SIZE / sizeof(struct grant_entry))
57
58static grant_ref_t **gnttab_list;
59static unsigned int nr_grant_frames;
60static unsigned int boot_max_nr_grant_frames;
61static int gnttab_free_count;
62static grant_ref_t gnttab_free_head;
63static DEFINE_SPINLOCK(gnttab_list_lock);
Stefano Stabellini183d03c2010-05-17 17:08:21 +010064unsigned long xen_hvm_resume_frames;
65EXPORT_SYMBOL_GPL(xen_hvm_resume_frames);
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -070066
67static struct grant_entry *shared;
68
69static struct gnttab_free_callback *gnttab_free_callback_list;
70
71static int gnttab_expand(unsigned int req_entries);
72
73#define RPP (PAGE_SIZE / sizeof(grant_ref_t))
74
75static inline grant_ref_t *__gnttab_entry(grant_ref_t entry)
76{
77 return &gnttab_list[(entry) / RPP][(entry) % RPP];
78}
79/* This can be used as an l-value */
80#define gnttab_entry(entry) (*__gnttab_entry(entry))
81
82static int get_free_entries(unsigned count)
83{
84 unsigned long flags;
85 int ref, rc;
86 grant_ref_t head;
87
88 spin_lock_irqsave(&gnttab_list_lock, flags);
89
90 if ((gnttab_free_count < count) &&
91 ((rc = gnttab_expand(count - gnttab_free_count)) < 0)) {
92 spin_unlock_irqrestore(&gnttab_list_lock, flags);
93 return rc;
94 }
95
96 ref = head = gnttab_free_head;
97 gnttab_free_count -= count;
98 while (count-- > 1)
99 head = gnttab_entry(head);
100 gnttab_free_head = gnttab_entry(head);
101 gnttab_entry(head) = GNTTAB_LIST_END;
102
103 spin_unlock_irqrestore(&gnttab_list_lock, flags);
104
105 return ref;
106}
107
108static void do_free_callbacks(void)
109{
110 struct gnttab_free_callback *callback, *next;
111
112 callback = gnttab_free_callback_list;
113 gnttab_free_callback_list = NULL;
114
115 while (callback != NULL) {
116 next = callback->next;
117 if (gnttab_free_count >= callback->count) {
118 callback->next = NULL;
119 callback->fn(callback->arg);
120 } else {
121 callback->next = gnttab_free_callback_list;
122 gnttab_free_callback_list = callback;
123 }
124 callback = next;
125 }
126}
127
128static inline void check_free_callbacks(void)
129{
130 if (unlikely(gnttab_free_callback_list))
131 do_free_callbacks();
132}
133
134static void put_free_entry(grant_ref_t ref)
135{
136 unsigned long flags;
137 spin_lock_irqsave(&gnttab_list_lock, flags);
138 gnttab_entry(ref) = gnttab_free_head;
139 gnttab_free_head = ref;
140 gnttab_free_count++;
141 check_free_callbacks();
142 spin_unlock_irqrestore(&gnttab_list_lock, flags);
143}
144
145static void update_grant_entry(grant_ref_t ref, domid_t domid,
146 unsigned long frame, unsigned flags)
147{
148 /*
149 * Introducing a valid entry into the grant table:
150 * 1. Write ent->domid.
151 * 2. Write ent->frame:
152 * GTF_permit_access: Frame to which access is permitted.
153 * GTF_accept_transfer: Pseudo-phys frame slot being filled by new
154 * frame, or zero if none.
155 * 3. Write memory barrier (WMB).
156 * 4. Write ent->flags, inc. valid type.
157 */
158 shared[ref].frame = frame;
159 shared[ref].domid = domid;
160 wmb();
161 shared[ref].flags = flags;
162}
163
164/*
165 * Public grant-issuing interface functions
166 */
167void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid,
168 unsigned long frame, int readonly)
169{
170 update_grant_entry(ref, domid, frame,
171 GTF_permit_access | (readonly ? GTF_readonly : 0));
172}
173EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_ref);
174
175int gnttab_grant_foreign_access(domid_t domid, unsigned long frame,
176 int readonly)
177{
178 int ref;
179
180 ref = get_free_entries(1);
181 if (unlikely(ref < 0))
182 return -ENOSPC;
183
184 gnttab_grant_foreign_access_ref(ref, domid, frame, readonly);
185
186 return ref;
187}
188EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access);
189
190int gnttab_query_foreign_access(grant_ref_t ref)
191{
192 u16 nflags;
193
194 nflags = shared[ref].flags;
195
196 return (nflags & (GTF_reading|GTF_writing));
197}
198EXPORT_SYMBOL_GPL(gnttab_query_foreign_access);
199
200int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly)
201{
202 u16 flags, nflags;
203
204 nflags = shared[ref].flags;
205 do {
206 flags = nflags;
207 if (flags & (GTF_reading|GTF_writing)) {
208 printk(KERN_ALERT "WARNING: g.e. still in use!\n");
209 return 0;
210 }
211 } while ((nflags = sync_cmpxchg(&shared[ref].flags, flags, 0)) != flags);
212
213 return 1;
214}
215EXPORT_SYMBOL_GPL(gnttab_end_foreign_access_ref);
216
217void gnttab_end_foreign_access(grant_ref_t ref, int readonly,
218 unsigned long page)
219{
220 if (gnttab_end_foreign_access_ref(ref, readonly)) {
221 put_free_entry(ref);
222 if (page != 0)
223 free_page(page);
224 } else {
225 /* XXX This needs to be fixed so that the ref and page are
226 placed on a list to be freed up later. */
227 printk(KERN_WARNING
228 "WARNING: leaking g.e. and page still in use!\n");
229 }
230}
231EXPORT_SYMBOL_GPL(gnttab_end_foreign_access);
232
233int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn)
234{
235 int ref;
236
237 ref = get_free_entries(1);
238 if (unlikely(ref < 0))
239 return -ENOSPC;
240 gnttab_grant_foreign_transfer_ref(ref, domid, pfn);
241
242 return ref;
243}
244EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer);
245
246void gnttab_grant_foreign_transfer_ref(grant_ref_t ref, domid_t domid,
247 unsigned long pfn)
248{
249 update_grant_entry(ref, domid, pfn, GTF_accept_transfer);
250}
251EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer_ref);
252
253unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref)
254{
255 unsigned long frame;
256 u16 flags;
257
258 /*
259 * If a transfer is not even yet started, try to reclaim the grant
260 * reference and return failure (== 0).
261 */
262 while (!((flags = shared[ref].flags) & GTF_transfer_committed)) {
263 if (sync_cmpxchg(&shared[ref].flags, flags, 0) == flags)
264 return 0;
265 cpu_relax();
266 }
267
268 /* If a transfer is in progress then wait until it is completed. */
269 while (!(flags & GTF_transfer_completed)) {
270 flags = shared[ref].flags;
271 cpu_relax();
272 }
273
274 rmb(); /* Read the frame number /after/ reading completion status. */
275 frame = shared[ref].frame;
276 BUG_ON(frame == 0);
277
278 return frame;
279}
280EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer_ref);
281
282unsigned long gnttab_end_foreign_transfer(grant_ref_t ref)
283{
284 unsigned long frame = gnttab_end_foreign_transfer_ref(ref);
285 put_free_entry(ref);
286 return frame;
287}
288EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer);
289
290void gnttab_free_grant_reference(grant_ref_t ref)
291{
292 put_free_entry(ref);
293}
294EXPORT_SYMBOL_GPL(gnttab_free_grant_reference);
295
296void gnttab_free_grant_references(grant_ref_t head)
297{
298 grant_ref_t ref;
299 unsigned long flags;
300 int count = 1;
301 if (head == GNTTAB_LIST_END)
302 return;
303 spin_lock_irqsave(&gnttab_list_lock, flags);
304 ref = head;
305 while (gnttab_entry(ref) != GNTTAB_LIST_END) {
306 ref = gnttab_entry(ref);
307 count++;
308 }
309 gnttab_entry(ref) = gnttab_free_head;
310 gnttab_free_head = head;
311 gnttab_free_count += count;
312 check_free_callbacks();
313 spin_unlock_irqrestore(&gnttab_list_lock, flags);
314}
315EXPORT_SYMBOL_GPL(gnttab_free_grant_references);
316
317int gnttab_alloc_grant_references(u16 count, grant_ref_t *head)
318{
319 int h = get_free_entries(count);
320
321 if (h < 0)
322 return -ENOSPC;
323
324 *head = h;
325
326 return 0;
327}
328EXPORT_SYMBOL_GPL(gnttab_alloc_grant_references);
329
330int gnttab_empty_grant_references(const grant_ref_t *private_head)
331{
332 return (*private_head == GNTTAB_LIST_END);
333}
334EXPORT_SYMBOL_GPL(gnttab_empty_grant_references);
335
336int gnttab_claim_grant_reference(grant_ref_t *private_head)
337{
338 grant_ref_t g = *private_head;
339 if (unlikely(g == GNTTAB_LIST_END))
340 return -ENOSPC;
341 *private_head = gnttab_entry(g);
342 return g;
343}
344EXPORT_SYMBOL_GPL(gnttab_claim_grant_reference);
345
346void gnttab_release_grant_reference(grant_ref_t *private_head,
347 grant_ref_t release)
348{
349 gnttab_entry(release) = *private_head;
350 *private_head = release;
351}
352EXPORT_SYMBOL_GPL(gnttab_release_grant_reference);
353
354void gnttab_request_free_callback(struct gnttab_free_callback *callback,
355 void (*fn)(void *), void *arg, u16 count)
356{
357 unsigned long flags;
358 spin_lock_irqsave(&gnttab_list_lock, flags);
359 if (callback->next)
360 goto out;
361 callback->fn = fn;
362 callback->arg = arg;
363 callback->count = count;
364 callback->next = gnttab_free_callback_list;
365 gnttab_free_callback_list = callback;
366 check_free_callbacks();
367out:
368 spin_unlock_irqrestore(&gnttab_list_lock, flags);
369}
370EXPORT_SYMBOL_GPL(gnttab_request_free_callback);
371
372void gnttab_cancel_free_callback(struct gnttab_free_callback *callback)
373{
374 struct gnttab_free_callback **pcb;
375 unsigned long flags;
376
377 spin_lock_irqsave(&gnttab_list_lock, flags);
378 for (pcb = &gnttab_free_callback_list; *pcb; pcb = &(*pcb)->next) {
379 if (*pcb == callback) {
380 *pcb = callback->next;
381 break;
382 }
383 }
384 spin_unlock_irqrestore(&gnttab_list_lock, flags);
385}
386EXPORT_SYMBOL_GPL(gnttab_cancel_free_callback);
387
388static int grow_gnttab_list(unsigned int more_frames)
389{
390 unsigned int new_nr_grant_frames, extra_entries, i;
Michael Abd-El-Malekbbc60c12008-04-04 02:33:48 -0700391 unsigned int nr_glist_frames, new_nr_glist_frames;
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -0700392
393 new_nr_grant_frames = nr_grant_frames + more_frames;
394 extra_entries = more_frames * GREFS_PER_GRANT_FRAME;
395
Michael Abd-El-Malekbbc60c12008-04-04 02:33:48 -0700396 nr_glist_frames = (nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP;
397 new_nr_glist_frames =
398 (new_nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP;
399 for (i = nr_glist_frames; i < new_nr_glist_frames; i++) {
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -0700400 gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_ATOMIC);
401 if (!gnttab_list[i])
402 goto grow_nomem;
403 }
404
405
406 for (i = GREFS_PER_GRANT_FRAME * nr_grant_frames;
407 i < GREFS_PER_GRANT_FRAME * new_nr_grant_frames - 1; i++)
408 gnttab_entry(i) = i + 1;
409
410 gnttab_entry(i) = gnttab_free_head;
411 gnttab_free_head = GREFS_PER_GRANT_FRAME * nr_grant_frames;
412 gnttab_free_count += extra_entries;
413
414 nr_grant_frames = new_nr_grant_frames;
415
416 check_free_callbacks();
417
418 return 0;
419
420grow_nomem:
Michael Abd-El-Malekbbc60c12008-04-04 02:33:48 -0700421 for ( ; i >= nr_glist_frames; i--)
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -0700422 free_page((unsigned long) gnttab_list[i]);
423 return -ENOMEM;
424}
425
426static unsigned int __max_nr_grant_frames(void)
427{
428 struct gnttab_query_size query;
429 int rc;
430
431 query.dom = DOMID_SELF;
432
433 rc = HYPERVISOR_grant_table_op(GNTTABOP_query_size, &query, 1);
434 if ((rc < 0) || (query.status != GNTST_okay))
435 return 4; /* Legacy max supported number of frames */
436
437 return query.max_nr_frames;
438}
439
Stefano Stabellini183d03c2010-05-17 17:08:21 +0100440unsigned int gnttab_max_grant_frames(void)
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -0700441{
442 unsigned int xen_max = __max_nr_grant_frames();
443
444 if (xen_max > boot_max_nr_grant_frames)
445 return boot_max_nr_grant_frames;
446 return xen_max;
447}
Stefano Stabellini183d03c2010-05-17 17:08:21 +0100448EXPORT_SYMBOL_GPL(gnttab_max_grant_frames);
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -0700449
Stefano Stabellini289b7772010-12-10 14:54:44 +0000450int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
451 struct page **pages, unsigned int count)
452{
453 int i, ret;
454 pte_t *pte;
455 unsigned long mfn;
456
457 ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map_ops, count);
Jeremy Fitzhardinge87f1d402010-12-13 14:42:30 +0000458 if (ret)
459 return ret;
Stefano Stabellini289b7772010-12-10 14:54:44 +0000460
461 for (i = 0; i < count; i++) {
462 /* m2p override only supported for GNTMAP_contains_pte mappings */
463 if (!(map_ops[i].flags & GNTMAP_contains_pte))
464 continue;
465 pte = (pte_t *) (mfn_to_virt(PFN_DOWN(map_ops[i].host_addr)) +
466 (map_ops[i].host_addr & ~PAGE_MASK));
467 mfn = pte_mfn(*pte);
Jeremy Fitzhardinge87f1d402010-12-13 14:42:30 +0000468 ret = m2p_add_override(mfn, pages[i]);
469 if (ret)
470 return ret;
Stefano Stabellini289b7772010-12-10 14:54:44 +0000471 }
472
473 return ret;
474}
475EXPORT_SYMBOL_GPL(gnttab_map_refs);
476
477int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
478 struct page **pages, unsigned int count)
479{
480 int i, ret;
481
482 ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops, count);
Jeremy Fitzhardinge87f1d402010-12-13 14:42:30 +0000483 if (ret)
484 return ret;
485
486 for (i = 0; i < count; i++) {
487 ret = m2p_remove_override(pages[i]);
488 if (ret)
489 return ret;
490 }
Stefano Stabellini289b7772010-12-10 14:54:44 +0000491
492 return ret;
493}
494EXPORT_SYMBOL_GPL(gnttab_unmap_refs);
495
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -0700496static int gnttab_map(unsigned int start_idx, unsigned int end_idx)
497{
498 struct gnttab_setup_table setup;
499 unsigned long *frames;
500 unsigned int nr_gframes = end_idx + 1;
501 int rc;
502
Stefano Stabellini183d03c2010-05-17 17:08:21 +0100503 if (xen_hvm_domain()) {
504 struct xen_add_to_physmap xatp;
505 unsigned int i = end_idx;
506 rc = 0;
507 /*
508 * Loop backwards, so that the first hypercall has the largest
509 * index, ensuring that the table will grow only once.
510 */
511 do {
512 xatp.domid = DOMID_SELF;
513 xatp.idx = i;
514 xatp.space = XENMAPSPACE_grant_table;
515 xatp.gpfn = (xen_hvm_resume_frames >> PAGE_SHIFT) + i;
516 rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp);
517 if (rc != 0) {
518 printk(KERN_WARNING
519 "grant table add_to_physmap failed, err=%d\n", rc);
520 break;
521 }
522 } while (i-- > start_idx);
523
524 return rc;
525 }
526
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -0700527 frames = kmalloc(nr_gframes * sizeof(unsigned long), GFP_ATOMIC);
528 if (!frames)
529 return -ENOMEM;
530
531 setup.dom = DOMID_SELF;
532 setup.nr_frames = nr_gframes;
Isaku Yamahata87e27cf2008-04-02 10:53:52 -0700533 set_xen_guest_handle(setup.frame_list, frames);
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -0700534
535 rc = HYPERVISOR_grant_table_op(GNTTABOP_setup_table, &setup, 1);
536 if (rc == -ENOSYS) {
537 kfree(frames);
538 return -ENOSYS;
539 }
540
541 BUG_ON(rc || setup.status);
542
Stefano Stabellini183d03c2010-05-17 17:08:21 +0100543 rc = arch_gnttab_map_shared(frames, nr_gframes, gnttab_max_grant_frames(),
Isaku Yamahata8d3d2102008-04-02 10:54:00 -0700544 &shared);
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -0700545 BUG_ON(rc);
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -0700546
547 kfree(frames);
548
549 return 0;
550}
551
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +0100552int gnttab_resume(void)
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -0700553{
Stefano Stabellini183d03c2010-05-17 17:08:21 +0100554 unsigned int max_nr_gframes;
555
556 max_nr_gframes = gnttab_max_grant_frames();
557 if (max_nr_gframes < nr_grant_frames)
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -0700558 return -ENOSYS;
Stefano Stabellini183d03c2010-05-17 17:08:21 +0100559
560 if (xen_pv_domain())
561 return gnttab_map(0, nr_grant_frames - 1);
562
563 if (!shared) {
564 shared = ioremap(xen_hvm_resume_frames, PAGE_SIZE * max_nr_gframes);
565 if (shared == NULL) {
566 printk(KERN_WARNING
567 "Failed to ioremap gnttab share frames!");
568 return -ENOMEM;
569 }
570 }
571
572 gnttab_map(0, nr_grant_frames - 1);
573
574 return 0;
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -0700575}
576
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +0100577int gnttab_suspend(void)
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -0700578{
Isaku Yamahata8d3d2102008-04-02 10:54:00 -0700579 arch_gnttab_unmap_shared(shared, nr_grant_frames);
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -0700580 return 0;
581}
582
583static int gnttab_expand(unsigned int req_entries)
584{
585 int rc;
586 unsigned int cur, extra;
587
588 cur = nr_grant_frames;
589 extra = ((req_entries + (GREFS_PER_GRANT_FRAME-1)) /
590 GREFS_PER_GRANT_FRAME);
Stefano Stabellini183d03c2010-05-17 17:08:21 +0100591 if (cur + extra > gnttab_max_grant_frames())
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -0700592 return -ENOSPC;
593
594 rc = gnttab_map(cur, cur + extra - 1);
595 if (rc == 0)
596 rc = grow_gnttab_list(extra);
597
598 return rc;
599}
600
Stefano Stabellini183d03c2010-05-17 17:08:21 +0100601int gnttab_init(void)
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -0700602{
603 int i;
Michael Abd-El-Malekbbc60c12008-04-04 02:33:48 -0700604 unsigned int max_nr_glist_frames, nr_glist_frames;
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -0700605 unsigned int nr_init_grefs;
606
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -0700607 nr_grant_frames = 1;
608 boot_max_nr_grant_frames = __max_nr_grant_frames();
609
610 /* Determine the maximum number of frames required for the
611 * grant reference free list on the current hypervisor.
612 */
613 max_nr_glist_frames = (boot_max_nr_grant_frames *
Michael Abd-El-Malekbbc60c12008-04-04 02:33:48 -0700614 GREFS_PER_GRANT_FRAME / RPP);
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -0700615
616 gnttab_list = kmalloc(max_nr_glist_frames * sizeof(grant_ref_t *),
617 GFP_KERNEL);
618 if (gnttab_list == NULL)
619 return -ENOMEM;
620
Michael Abd-El-Malekbbc60c12008-04-04 02:33:48 -0700621 nr_glist_frames = (nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP;
622 for (i = 0; i < nr_glist_frames; i++) {
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -0700623 gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_KERNEL);
624 if (gnttab_list[i] == NULL)
625 goto ini_nomem;
626 }
627
628 if (gnttab_resume() < 0)
629 return -ENODEV;
630
631 nr_init_grefs = nr_grant_frames * GREFS_PER_GRANT_FRAME;
632
633 for (i = NR_RESERVED_ENTRIES; i < nr_init_grefs - 1; i++)
634 gnttab_entry(i) = i + 1;
635
636 gnttab_entry(nr_init_grefs - 1) = GNTTAB_LIST_END;
637 gnttab_free_count = nr_init_grefs - NR_RESERVED_ENTRIES;
638 gnttab_free_head = NR_RESERVED_ENTRIES;
639
640 printk("Grant table initialized\n");
641 return 0;
642
643 ini_nomem:
644 for (i--; i >= 0; i--)
645 free_page((unsigned long)gnttab_list[i]);
646 kfree(gnttab_list);
647 return -ENOMEM;
648}
Stefano Stabellini183d03c2010-05-17 17:08:21 +0100649EXPORT_SYMBOL_GPL(gnttab_init);
Jeremy Fitzhardingead9a8612007-07-17 18:37:06 -0700650
Stefano Stabellini183d03c2010-05-17 17:08:21 +0100651static int __devinit __gnttab_init(void)
652{
653 /* Delay grant-table initialization in the PV on HVM case */
654 if (xen_hvm_domain())
655 return 0;
656
657 if (!xen_pv_domain())
658 return -ENODEV;
659
660 return gnttab_init();
661}
662
663core_initcall(__gnttab_init);