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20#undef DEBUG
21
22#include <linux/module.h>
23#include <linux/kernel.h>
24#include <linux/init.h>
25#include <linux/miscdevice.h>
26#include <linux/fs.h>
27#include <linux/mm.h>
28#include <linux/mman.h>
29#include <linux/mmu_notifier.h>
30#include <linux/types.h>
31#include <linux/uaccess.h>
32#include <linux/sched.h>
33#include <linux/spinlock.h>
34#include <linux/slab.h>
35#include <linux/highmem.h>
36
37#include <xen/xen.h>
38#include <xen/grant_table.h>
39#include <xen/balloon.h>
40#include <xen/gntdev.h>
41#include <xen/events.h>
42#include <asm/xen/hypervisor.h>
43#include <asm/xen/hypercall.h>
44#include <asm/xen/page.h>
45
46MODULE_LICENSE("GPL");
47MODULE_AUTHOR("Derek G. Murray <Derek.Murray@cl.cam.ac.uk>, "
48 "Gerd Hoffmann <kraxel@redhat.com>");
49MODULE_DESCRIPTION("User-space granted page access driver");
50
51static int limit = 1024*1024;
52module_param(limit, int, 0644);
53MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by "
54 "the gntdev device");
55
56static atomic_t pages_mapped = ATOMIC_INIT(0);
57
58static int use_ptemod;
59#define populate_freeable_maps use_ptemod
60
61struct gntdev_priv {
62
63 struct list_head maps;
64
65
66 struct list_head freeable_maps;
67
68 spinlock_t lock;
69 struct mm_struct *mm;
70 struct mmu_notifier mn;
71};
72
73struct unmap_notify {
74 int flags;
75
76 int addr;
77 int event;
78};
79
80struct grant_map {
81 struct list_head next;
82 struct vm_area_struct *vma;
83 int index;
84 int count;
85 int flags;
86 atomic_t users;
87 struct unmap_notify notify;
88 struct ioctl_gntdev_grant_ref *grants;
89 struct gnttab_map_grant_ref *map_ops;
90 struct gnttab_unmap_grant_ref *unmap_ops;
91 struct gnttab_map_grant_ref *kmap_ops;
92 struct page **pages;
93};
94
95static int unmap_grant_pages(struct grant_map *map, int offset, int pages);
96
97
98
99static void gntdev_print_maps(struct gntdev_priv *priv,
100 char *text, int text_index)
101{
102#ifdef DEBUG
103 struct grant_map *map;
104
105 pr_debug("%s: maps list (priv %p)\n", __func__, priv);
106 list_for_each_entry(map, &priv->maps, next)
107 pr_debug(" index %2d, count %2d %s\n",
108 map->index, map->count,
109 map->index == text_index && text ? text : "");
110#endif
111}
112
113static void gntdev_free_map(struct grant_map *map)
114{
115 if (map == NULL)
116 return;
117
118 if (map->pages)
119 free_xenballooned_pages(map->count, map->pages);
120 kfree(map->pages);
121 kfree(map->grants);
122 kfree(map->map_ops);
123 kfree(map->unmap_ops);
124 kfree(map->kmap_ops);
125 kfree(map);
126}
127
128static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
129{
130 struct grant_map *add;
131 int i;
132
133 add = kzalloc(sizeof(struct grant_map), GFP_KERNEL);
134 if (NULL == add)
135 return NULL;
136
137 add->grants = kcalloc(count, sizeof(add->grants[0]), GFP_KERNEL);
138 add->map_ops = kcalloc(count, sizeof(add->map_ops[0]), GFP_KERNEL);
139 add->unmap_ops = kcalloc(count, sizeof(add->unmap_ops[0]), GFP_KERNEL);
140 add->kmap_ops = kcalloc(count, sizeof(add->kmap_ops[0]), GFP_KERNEL);
141 add->pages = kcalloc(count, sizeof(add->pages[0]), GFP_KERNEL);
142 if (NULL == add->grants ||
143 NULL == add->map_ops ||
144 NULL == add->unmap_ops ||
145 NULL == add->kmap_ops ||
146 NULL == add->pages)
147 goto err;
148
149 if (alloc_xenballooned_pages(count, add->pages, false ))
150 goto err;
151
152 for (i = 0; i < count; i++) {
153 add->map_ops[i].handle = -1;
154 add->unmap_ops[i].handle = -1;
155 add->kmap_ops[i].handle = -1;
156 }
157
158 add->index = 0;
159 add->count = count;
160 atomic_set(&add->users, 1);
161
162 return add;
163
164err:
165 gntdev_free_map(add);
166 return NULL;
167}
168
169static void gntdev_add_map(struct gntdev_priv *priv, struct grant_map *add)
170{
171 struct grant_map *map;
172
173 list_for_each_entry(map, &priv->maps, next) {
174 if (add->index + add->count < map->index) {
175 list_add_tail(&add->next, &map->next);
176 goto done;
177 }
178 add->index = map->index + map->count;
179 }
180 list_add_tail(&add->next, &priv->maps);
181
182done:
183 gntdev_print_maps(priv, "[new]", add->index);
184}
185
186static struct grant_map *gntdev_find_map_index(struct gntdev_priv *priv,
187 int index, int count)
188{
189 struct grant_map *map;
190
191 list_for_each_entry(map, &priv->maps, next) {
192 if (map->index != index)
193 continue;
194 if (count && map->count != count)
195 continue;
196 return map;
197 }
198 return NULL;
199}
200
201static void gntdev_put_map(struct gntdev_priv *priv, struct grant_map *map)
202{
203 if (!map)
204 return;
205
206 if (!atomic_dec_and_test(&map->users))
207 return;
208
209 atomic_sub(map->count, &pages_mapped);
210
211 if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) {
212 notify_remote_via_evtchn(map->notify.event);
213 evtchn_put(map->notify.event);
214 }
215
216 if (populate_freeable_maps && priv) {
217 spin_lock(&priv->lock);
218 list_del(&map->next);
219 spin_unlock(&priv->lock);
220 }
221
222 if (map->pages && !use_ptemod)
223 unmap_grant_pages(map, 0, map->count);
224 gntdev_free_map(map);
225}
226
227
228
229static int find_grant_ptes(pte_t *pte, pgtable_t token,
230 unsigned long addr, void *data)
231{
232 struct grant_map *map = data;
233 unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT;
234 int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte;
235 u64 pte_maddr;
236
237 BUG_ON(pgnr >= map->count);
238 pte_maddr = arbitrary_virt_to_machine(pte).maddr;
239
240 gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, flags,
241 map->grants[pgnr].ref,
242 map->grants[pgnr].domid);
243 gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags,
244 -1 );
245 return 0;
246}
247
248static int map_grant_pages(struct grant_map *map)
249{
250 int i, err = 0;
251
252 if (!use_ptemod) {
253
254 if (map->map_ops[0].handle != -1)
255 return 0;
256 for (i = 0; i < map->count; i++) {
257 unsigned long addr = (unsigned long)
258 pfn_to_kaddr(page_to_pfn(map->pages[i]));
259 gnttab_set_map_op(&map->map_ops[i], addr, map->flags,
260 map->grants[i].ref,
261 map->grants[i].domid);
262 gnttab_set_unmap_op(&map->unmap_ops[i], addr,
263 map->flags, -1 );
264 }
265 } else {
266
267
268
269
270
271
272 for (i = 0; i < map->count; i++) {
273 unsigned level;
274 unsigned long address = (unsigned long)
275 pfn_to_kaddr(page_to_pfn(map->pages[i]));
276 pte_t *ptep;
277 u64 pte_maddr = 0;
278 BUG_ON(PageHighMem(map->pages[i]));
279
280 ptep = lookup_address(address, &level);
281 pte_maddr = arbitrary_virt_to_machine(ptep).maddr;
282 gnttab_set_map_op(&map->kmap_ops[i], pte_maddr,
283 map->flags |
284 GNTMAP_host_map |
285 GNTMAP_contains_pte,
286 map->grants[i].ref,
287 map->grants[i].domid);
288 }
289 }
290
291 pr_debug("map %d+%d\n", map->index, map->count);
292 err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL,
293 map->pages, map->count);
294 if (err)
295 return err;
296
297 for (i = 0; i < map->count; i++) {
298 if (map->map_ops[i].status)
299 err = -EINVAL;
300 else {
301 BUG_ON(map->map_ops[i].handle == -1);
302 map->unmap_ops[i].handle = map->map_ops[i].handle;
303 pr_debug("map handle=%d\n", map->map_ops[i].handle);
304 }
305 }
306 return err;
307}
308
309static int __unmap_grant_pages(struct grant_map *map, int offset, int pages)
310{
311 int i, err = 0;
312
313 if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) {
314 int pgno = (map->notify.addr >> PAGE_SHIFT);
315 if (pgno >= offset && pgno < offset + pages) {
316
317 uint8_t *tmp = pfn_to_kaddr(page_to_pfn(map->pages[pgno]));
318 tmp[map->notify.addr & (PAGE_SIZE-1)] = 0;
319 map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE;
320 }
321 }
322
323 err = gnttab_unmap_refs(map->unmap_ops + offset,
324 use_ptemod ? map->kmap_ops + offset : NULL, map->pages + offset,
325 pages);
326 if (err)
327 return err;
328
329 for (i = 0; i < pages; i++) {
330 if (map->unmap_ops[offset+i].status)
331 err = -EINVAL;
332 pr_debug("unmap handle=%d st=%d\n",
333 map->unmap_ops[offset+i].handle,
334 map->unmap_ops[offset+i].status);
335 map->unmap_ops[offset+i].handle = -1;
336 }
337 return err;
338}
339
340static int unmap_grant_pages(struct grant_map *map, int offset, int pages)
341{
342 int range, err = 0;
343
344 pr_debug("unmap %d+%d [%d+%d]\n", map->index, map->count, offset, pages);
345
346
347
348
349 while (pages && !err) {
350 while (pages && map->unmap_ops[offset].handle == -1) {
351 offset++;
352 pages--;
353 }
354 range = 0;
355 while (range < pages) {
356 if (map->unmap_ops[offset+range].handle == -1) {
357 range--;
358 break;
359 }
360 range++;
361 }
362 err = __unmap_grant_pages(map, offset, range);
363 offset += range;
364 pages -= range;
365 }
366
367 return err;
368}
369
370
371
372static void gntdev_vma_open(struct vm_area_struct *vma)
373{
374 struct grant_map *map = vma->vm_private_data;
375
376 pr_debug("gntdev_vma_open %p\n", vma);
377 atomic_inc(&map->users);
378}
379
380static void gntdev_vma_close(struct vm_area_struct *vma)
381{
382 struct grant_map *map = vma->vm_private_data;
383 struct file *file = vma->vm_file;
384 struct gntdev_priv *priv = file->private_data;
385
386 pr_debug("gntdev_vma_close %p\n", vma);
387 if (use_ptemod) {
388
389
390
391
392
393
394
395 spin_lock(&priv->lock);
396 map->vma = NULL;
397 spin_unlock(&priv->lock);
398 }
399 vma->vm_private_data = NULL;
400 gntdev_put_map(priv, map);
401}
402
403static struct vm_operations_struct gntdev_vmops = {
404 .open = gntdev_vma_open,
405 .close = gntdev_vma_close,
406};
407
408
409
410static void unmap_if_in_range(struct grant_map *map,
411 unsigned long start, unsigned long end)
412{
413 unsigned long mstart, mend;
414 int err;
415
416 if (!map->vma)
417 return;
418 if (map->vma->vm_start >= end)
419 return;
420 if (map->vma->vm_end <= start)
421 return;
422 mstart = max(start, map->vma->vm_start);
423 mend = min(end, map->vma->vm_end);
424 pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n",
425 map->index, map->count,
426 map->vma->vm_start, map->vma->vm_end,
427 start, end, mstart, mend);
428 err = unmap_grant_pages(map,
429 (mstart - map->vma->vm_start) >> PAGE_SHIFT,
430 (mend - mstart) >> PAGE_SHIFT);
431 WARN_ON(err);
432}
433
434static void mn_invl_range_start(struct mmu_notifier *mn,
435 struct mm_struct *mm,
436 unsigned long start, unsigned long end)
437{
438 struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
439 struct grant_map *map;
440
441 spin_lock(&priv->lock);
442 list_for_each_entry(map, &priv->maps, next) {
443 unmap_if_in_range(map, start, end);
444 }
445 list_for_each_entry(map, &priv->freeable_maps, next) {
446 unmap_if_in_range(map, start, end);
447 }
448 spin_unlock(&priv->lock);
449}
450
451static void mn_invl_page(struct mmu_notifier *mn,
452 struct mm_struct *mm,
453 unsigned long address)
454{
455 mn_invl_range_start(mn, mm, address, address + PAGE_SIZE);
456}
457
458static void mn_release(struct mmu_notifier *mn,
459 struct mm_struct *mm)
460{
461 struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
462 struct grant_map *map;
463 int err;
464
465 spin_lock(&priv->lock);
466 list_for_each_entry(map, &priv->maps, next) {
467 if (!map->vma)
468 continue;
469 pr_debug("map %d+%d (%lx %lx)\n",
470 map->index, map->count,
471 map->vma->vm_start, map->vma->vm_end);
472 err = unmap_grant_pages(map, 0, map->count);
473 WARN_ON(err);
474 }
475 list_for_each_entry(map, &priv->freeable_maps, next) {
476 if (!map->vma)
477 continue;
478 pr_debug("map %d+%d (%lx %lx)\n",
479 map->index, map->count,
480 map->vma->vm_start, map->vma->vm_end);
481 err = unmap_grant_pages(map, 0, map->count);
482 WARN_ON(err);
483 }
484 spin_unlock(&priv->lock);
485}
486
487static struct mmu_notifier_ops gntdev_mmu_ops = {
488 .release = mn_release,
489 .invalidate_page = mn_invl_page,
490 .invalidate_range_start = mn_invl_range_start,
491};
492
493
494
495static int gntdev_open(struct inode *inode, struct file *flip)
496{
497 struct gntdev_priv *priv;
498 int ret = 0;
499
500 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
501 if (!priv)
502 return -ENOMEM;
503
504 INIT_LIST_HEAD(&priv->maps);
505 INIT_LIST_HEAD(&priv->freeable_maps);
506 spin_lock_init(&priv->lock);
507
508 if (use_ptemod) {
509 priv->mm = get_task_mm(current);
510 if (!priv->mm) {
511 kfree(priv);
512 return -ENOMEM;
513 }
514 priv->mn.ops = &gntdev_mmu_ops;
515 ret = mmu_notifier_register(&priv->mn, priv->mm);
516 mmput(priv->mm);
517 }
518
519 if (ret) {
520 kfree(priv);
521 return ret;
522 }
523
524 flip->private_data = priv;
525 pr_debug("priv %p\n", priv);
526
527 return 0;
528}
529
530static int gntdev_release(struct inode *inode, struct file *flip)
531{
532 struct gntdev_priv *priv = flip->private_data;
533 struct grant_map *map;
534
535 pr_debug("priv %p\n", priv);
536
537 while (!list_empty(&priv->maps)) {
538 map = list_entry(priv->maps.next, struct grant_map, next);
539 list_del(&map->next);
540 gntdev_put_map(NULL , map);
541 }
542 WARN_ON(!list_empty(&priv->freeable_maps));
543
544 if (use_ptemod)
545 mmu_notifier_unregister(&priv->mn, priv->mm);
546 kfree(priv);
547 return 0;
548}
549
550static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv,
551 struct ioctl_gntdev_map_grant_ref __user *u)
552{
553 struct ioctl_gntdev_map_grant_ref op;
554 struct grant_map *map;
555 int err;
556
557 if (copy_from_user(&op, u, sizeof(op)) != 0)
558 return -EFAULT;
559 pr_debug("priv %p, add %d\n", priv, op.count);
560 if (unlikely(op.count <= 0))
561 return -EINVAL;
562
563 err = -ENOMEM;
564 map = gntdev_alloc_map(priv, op.count);
565 if (!map)
566 return err;
567
568 if (unlikely(atomic_add_return(op.count, &pages_mapped) > limit)) {
569 pr_debug("can't map: over limit\n");
570 gntdev_put_map(NULL, map);
571 return err;
572 }
573
574 if (copy_from_user(map->grants, &u->refs,
575 sizeof(map->grants[0]) * op.count) != 0) {
576 gntdev_put_map(NULL, map);
577 return -EFAULT;
578 }
579
580 spin_lock(&priv->lock);
581 gntdev_add_map(priv, map);
582 op.index = map->index << PAGE_SHIFT;
583 spin_unlock(&priv->lock);
584
585 if (copy_to_user(u, &op, sizeof(op)) != 0)
586 return -EFAULT;
587
588 return 0;
589}
590
591static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv,
592 struct ioctl_gntdev_unmap_grant_ref __user *u)
593{
594 struct ioctl_gntdev_unmap_grant_ref op;
595 struct grant_map *map;
596 int err = -ENOENT;
597
598 if (copy_from_user(&op, u, sizeof(op)) != 0)
599 return -EFAULT;
600 pr_debug("priv %p, del %d+%d\n", priv, (int)op.index, (int)op.count);
601
602 spin_lock(&priv->lock);
603 map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count);
604 if (map) {
605 list_del(&map->next);
606 if (populate_freeable_maps)
607 list_add_tail(&map->next, &priv->freeable_maps);
608 err = 0;
609 }
610 spin_unlock(&priv->lock);
611 if (map)
612 gntdev_put_map(priv, map);
613 return err;
614}
615
616static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv,
617 struct ioctl_gntdev_get_offset_for_vaddr __user *u)
618{
619 struct ioctl_gntdev_get_offset_for_vaddr op;
620 struct vm_area_struct *vma;
621 struct grant_map *map;
622 int rv = -EINVAL;
623
624 if (copy_from_user(&op, u, sizeof(op)) != 0)
625 return -EFAULT;
626 pr_debug("priv %p, offset for vaddr %lx\n", priv, (unsigned long)op.vaddr);
627
628 down_read(¤t->mm->mmap_sem);
629 vma = find_vma(current->mm, op.vaddr);
630 if (!vma || vma->vm_ops != &gntdev_vmops)
631 goto out_unlock;
632
633 map = vma->vm_private_data;
634 if (!map)
635 goto out_unlock;
636
637 op.offset = map->index << PAGE_SHIFT;
638 op.count = map->count;
639 rv = 0;
640
641 out_unlock:
642 up_read(¤t->mm->mmap_sem);
643
644 if (rv == 0 && copy_to_user(u, &op, sizeof(op)) != 0)
645 return -EFAULT;
646 return rv;
647}
648
649static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u)
650{
651 struct ioctl_gntdev_unmap_notify op;
652 struct grant_map *map;
653 int rc;
654 int out_flags;
655 unsigned int out_event;
656
657 if (copy_from_user(&op, u, sizeof(op)))
658 return -EFAULT;
659
660 if (op.action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT))
661 return -EINVAL;
662
663
664
665
666
667
668
669
670 if (op.action & UNMAP_NOTIFY_SEND_EVENT) {
671 if (evtchn_get(op.event_channel_port))
672 return -EINVAL;
673 }
674
675 out_flags = op.action;
676 out_event = op.event_channel_port;
677
678 spin_lock(&priv->lock);
679
680 list_for_each_entry(map, &priv->maps, next) {
681 uint64_t begin = map->index << PAGE_SHIFT;
682 uint64_t end = (map->index + map->count) << PAGE_SHIFT;
683 if (op.index >= begin && op.index < end)
684 goto found;
685 }
686 rc = -ENOENT;
687 goto unlock_out;
688
689 found:
690 if ((op.action & UNMAP_NOTIFY_CLEAR_BYTE) &&
691 (map->flags & GNTMAP_readonly)) {
692 rc = -EINVAL;
693 goto unlock_out;
694 }
695
696 out_flags = map->notify.flags;
697 out_event = map->notify.event;
698
699 map->notify.flags = op.action;
700 map->notify.addr = op.index - (map->index << PAGE_SHIFT);
701 map->notify.event = op.event_channel_port;
702
703 rc = 0;
704
705 unlock_out:
706 spin_unlock(&priv->lock);
707
708
709 if (out_flags & UNMAP_NOTIFY_SEND_EVENT)
710 evtchn_put(out_event);
711
712 return rc;
713}
714
715static long gntdev_ioctl(struct file *flip,
716 unsigned int cmd, unsigned long arg)
717{
718 struct gntdev_priv *priv = flip->private_data;
719 void __user *ptr = (void __user *)arg;
720
721 switch (cmd) {
722 case IOCTL_GNTDEV_MAP_GRANT_REF:
723 return gntdev_ioctl_map_grant_ref(priv, ptr);
724
725 case IOCTL_GNTDEV_UNMAP_GRANT_REF:
726 return gntdev_ioctl_unmap_grant_ref(priv, ptr);
727
728 case IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR:
729 return gntdev_ioctl_get_offset_for_vaddr(priv, ptr);
730
731 case IOCTL_GNTDEV_SET_UNMAP_NOTIFY:
732 return gntdev_ioctl_notify(priv, ptr);
733
734 default:
735 pr_debug("priv %p, unknown cmd %x\n", priv, cmd);
736 return -ENOIOCTLCMD;
737 }
738
739 return 0;
740}
741
742static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
743{
744 struct gntdev_priv *priv = flip->private_data;
745 int index = vma->vm_pgoff;
746 int count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
747 struct grant_map *map;
748 int i, err = -EINVAL;
749
750 if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED))
751 return -EINVAL;
752
753 pr_debug("map %d+%d at %lx (pgoff %lx)\n",
754 index, count, vma->vm_start, vma->vm_pgoff);
755
756 spin_lock(&priv->lock);
757 map = gntdev_find_map_index(priv, index, count);
758 if (!map)
759 goto unlock_out;
760 if (use_ptemod && map->vma)
761 goto unlock_out;
762 if (use_ptemod && priv->mm != vma->vm_mm) {
763 printk(KERN_WARNING "Huh? Other mm?\n");
764 goto unlock_out;
765 }
766
767 atomic_inc(&map->users);
768
769 vma->vm_ops = &gntdev_vmops;
770
771 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
772
773 if (use_ptemod)
774 vma->vm_flags |= VM_DONTCOPY;
775
776 vma->vm_private_data = map;
777
778 if (use_ptemod)
779 map->vma = vma;
780
781 if (map->flags) {
782 if ((vma->vm_flags & VM_WRITE) &&
783 (map->flags & GNTMAP_readonly))
784 goto out_unlock_put;
785 } else {
786 map->flags = GNTMAP_host_map;
787 if (!(vma->vm_flags & VM_WRITE))
788 map->flags |= GNTMAP_readonly;
789 }
790
791 spin_unlock(&priv->lock);
792
793 if (use_ptemod) {
794 err = apply_to_page_range(vma->vm_mm, vma->vm_start,
795 vma->vm_end - vma->vm_start,
796 find_grant_ptes, map);
797 if (err) {
798 printk(KERN_WARNING "find_grant_ptes() failure.\n");
799 goto out_put_map;
800 }
801 }
802
803 err = map_grant_pages(map);
804 if (err)
805 goto out_put_map;
806
807 if (!use_ptemod) {
808 for (i = 0; i < count; i++) {
809 err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE,
810 map->pages[i]);
811 if (err)
812 goto out_put_map;
813 }
814 }
815
816 return 0;
817
818unlock_out:
819 spin_unlock(&priv->lock);
820 return err;
821
822out_unlock_put:
823 spin_unlock(&priv->lock);
824out_put_map:
825 if (use_ptemod)
826 map->vma = NULL;
827 gntdev_put_map(priv, map);
828 return err;
829}
830
831static const struct file_operations gntdev_fops = {
832 .owner = THIS_MODULE,
833 .open = gntdev_open,
834 .release = gntdev_release,
835 .mmap = gntdev_mmap,
836 .unlocked_ioctl = gntdev_ioctl
837};
838
839static struct miscdevice gntdev_miscdev = {
840 .minor = MISC_DYNAMIC_MINOR,
841 .name = "xen/gntdev",
842 .fops = &gntdev_fops,
843};
844
845
846
847static int __init gntdev_init(void)
848{
849 int err;
850
851 if (!xen_domain())
852 return -ENODEV;
853
854 use_ptemod = xen_pv_domain();
855
856 err = misc_register(&gntdev_miscdev);
857 if (err != 0) {
858 printk(KERN_ERR "Could not register gntdev device\n");
859 return err;
860 }
861 return 0;
862}
863
864static void __exit gntdev_exit(void)
865{
866 misc_deregister(&gntdev_miscdev);
867}
868
869module_init(gntdev_init);
870module_exit(gntdev_exit);
871
872
873
