1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20#undef DEBUG
21
22#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
23
24#include <linux/module.h>
25#include <linux/kernel.h>
26#include <linux/init.h>
27#include <linux/miscdevice.h>
28#include <linux/fs.h>
29#include <linux/mm.h>
30#include <linux/mman.h>
31#include <linux/mmu_notifier.h>
32#include <linux/types.h>
33#include <linux/uaccess.h>
34#include <linux/sched.h>
35#include <linux/spinlock.h>
36#include <linux/slab.h>
37#include <linux/highmem.h>
38
39#include <xen/xen.h>
40#include <xen/grant_table.h>
41#include <xen/balloon.h>
42#include <xen/gntdev.h>
43#include <xen/events.h>
44#include <asm/xen/hypervisor.h>
45#include <asm/xen/hypercall.h>
46#include <asm/xen/page.h>
47
48MODULE_LICENSE("GPL");
49MODULE_AUTHOR("Derek G. Murray <Derek.Murray@cl.cam.ac.uk>, "
50 "Gerd Hoffmann <kraxel@redhat.com>");
51MODULE_DESCRIPTION("User-space granted page access driver");
52
53static int limit = 1024*1024;
54module_param(limit, int, 0644);
55MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by "
56 "the gntdev device");
57
58static atomic_t pages_mapped = ATOMIC_INIT(0);
59
60static int use_ptemod;
61#define populate_freeable_maps use_ptemod
62
63struct gntdev_priv {
64
65 struct list_head maps;
66
67
68 struct list_head freeable_maps;
69
70 spinlock_t lock;
71 struct mm_struct *mm;
72 struct mmu_notifier mn;
73};
74
75struct unmap_notify {
76 int flags;
77
78 int addr;
79 int event;
80};
81
82struct grant_map {
83 struct list_head next;
84 struct vm_area_struct *vma;
85 int index;
86 int count;
87 int flags;
88 atomic_t users;
89 struct unmap_notify notify;
90 struct ioctl_gntdev_grant_ref *grants;
91 struct gnttab_map_grant_ref *map_ops;
92 struct gnttab_unmap_grant_ref *unmap_ops;
93 struct gnttab_map_grant_ref *kmap_ops;
94 struct page **pages;
95};
96
97static int unmap_grant_pages(struct grant_map *map, int offset, int pages);
98
99
100
101static void gntdev_print_maps(struct gntdev_priv *priv,
102 char *text, int text_index)
103{
104#ifdef DEBUG
105 struct grant_map *map;
106
107 pr_debug("%s: maps list (priv %p)\n", __func__, priv);
108 list_for_each_entry(map, &priv->maps, next)
109 pr_debug(" index %2d, count %2d %s\n",
110 map->index, map->count,
111 map->index == text_index && text ? text : "");
112#endif
113}
114
115static void gntdev_free_map(struct grant_map *map)
116{
117 if (map == NULL)
118 return;
119
120 if (map->pages)
121 free_xenballooned_pages(map->count, map->pages);
122 kfree(map->pages);
123 kfree(map->grants);
124 kfree(map->map_ops);
125 kfree(map->unmap_ops);
126 kfree(map->kmap_ops);
127 kfree(map);
128}
129
130static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
131{
132 struct grant_map *add;
133 int i;
134
135 add = kzalloc(sizeof(struct grant_map), GFP_KERNEL);
136 if (NULL == add)
137 return NULL;
138
139 add->grants = kcalloc(count, sizeof(add->grants[0]), GFP_KERNEL);
140 add->map_ops = kcalloc(count, sizeof(add->map_ops[0]), GFP_KERNEL);
141 add->unmap_ops = kcalloc(count, sizeof(add->unmap_ops[0]), GFP_KERNEL);
142 add->kmap_ops = kcalloc(count, sizeof(add->kmap_ops[0]), GFP_KERNEL);
143 add->pages = kcalloc(count, sizeof(add->pages[0]), GFP_KERNEL);
144 if (NULL == add->grants ||
145 NULL == add->map_ops ||
146 NULL == add->unmap_ops ||
147 NULL == add->kmap_ops ||
148 NULL == add->pages)
149 goto err;
150
151 if (alloc_xenballooned_pages(count, add->pages, false ))
152 goto err;
153
154 for (i = 0; i < count; i++) {
155 add->map_ops[i].handle = -1;
156 add->unmap_ops[i].handle = -1;
157 add->kmap_ops[i].handle = -1;
158 }
159
160 add->index = 0;
161 add->count = count;
162 atomic_set(&add->users, 1);
163
164 return add;
165
166err:
167 gntdev_free_map(add);
168 return NULL;
169}
170
171static void gntdev_add_map(struct gntdev_priv *priv, struct grant_map *add)
172{
173 struct grant_map *map;
174
175 list_for_each_entry(map, &priv->maps, next) {
176 if (add->index + add->count < map->index) {
177 list_add_tail(&add->next, &map->next);
178 goto done;
179 }
180 add->index = map->index + map->count;
181 }
182 list_add_tail(&add->next, &priv->maps);
183
184done:
185 gntdev_print_maps(priv, "[new]", add->index);
186}
187
188static struct grant_map *gntdev_find_map_index(struct gntdev_priv *priv,
189 int index, int count)
190{
191 struct grant_map *map;
192
193 list_for_each_entry(map, &priv->maps, next) {
194 if (map->index != index)
195 continue;
196 if (count && map->count != count)
197 continue;
198 return map;
199 }
200 return NULL;
201}
202
203static void gntdev_put_map(struct gntdev_priv *priv, struct grant_map *map)
204{
205 if (!map)
206 return;
207
208 if (!atomic_dec_and_test(&map->users))
209 return;
210
211 atomic_sub(map->count, &pages_mapped);
212
213 if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) {
214 notify_remote_via_evtchn(map->notify.event);
215 evtchn_put(map->notify.event);
216 }
217
218 if (populate_freeable_maps && priv) {
219 spin_lock(&priv->lock);
220 list_del(&map->next);
221 spin_unlock(&priv->lock);
222 }
223
224 if (map->pages && !use_ptemod)
225 unmap_grant_pages(map, 0, map->count);
226 gntdev_free_map(map);
227}
228
229
230
231static int find_grant_ptes(pte_t *pte, pgtable_t token,
232 unsigned long addr, void *data)
233{
234 struct grant_map *map = data;
235 unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT;
236 int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte;
237 u64 pte_maddr;
238
239 BUG_ON(pgnr >= map->count);
240 pte_maddr = arbitrary_virt_to_machine(pte).maddr;
241
242 gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, flags,
243 map->grants[pgnr].ref,
244 map->grants[pgnr].domid);
245 gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags,
246 -1 );
247 return 0;
248}
249
250static int map_grant_pages(struct grant_map *map)
251{
252 int i, err = 0;
253
254 if (!use_ptemod) {
255
256 if (map->map_ops[0].handle != -1)
257 return 0;
258 for (i = 0; i < map->count; i++) {
259 unsigned long addr = (unsigned long)
260 pfn_to_kaddr(page_to_pfn(map->pages[i]));
261 gnttab_set_map_op(&map->map_ops[i], addr, map->flags,
262 map->grants[i].ref,
263 map->grants[i].domid);
264 gnttab_set_unmap_op(&map->unmap_ops[i], addr,
265 map->flags, -1 );
266 }
267 } else {
268
269
270
271
272
273
274 for (i = 0; i < map->count; i++) {
275 unsigned long address = (unsigned long)
276 pfn_to_kaddr(page_to_pfn(map->pages[i]));
277 BUG_ON(PageHighMem(map->pages[i]));
278
279 gnttab_set_map_op(&map->kmap_ops[i], address,
280 map->flags | GNTMAP_host_map,
281 map->grants[i].ref,
282 map->grants[i].domid);
283 }
284 }
285
286 pr_debug("map %d+%d\n", map->index, map->count);
287 err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL,
288 map->pages, map->count);
289 if (err)
290 return err;
291
292 for (i = 0; i < map->count; i++) {
293 if (map->map_ops[i].status)
294 err = -EINVAL;
295 else {
296 BUG_ON(map->map_ops[i].handle == -1);
297 map->unmap_ops[i].handle = map->map_ops[i].handle;
298 pr_debug("map handle=%d\n", map->map_ops[i].handle);
299 }
300 }
301 return err;
302}
303
304static int __unmap_grant_pages(struct grant_map *map, int offset, int pages)
305{
306 int i, err = 0;
307
308 if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) {
309 int pgno = (map->notify.addr >> PAGE_SHIFT);
310 if (pgno >= offset && pgno < offset + pages) {
311
312 uint8_t *tmp = pfn_to_kaddr(page_to_pfn(map->pages[pgno]));
313 tmp[map->notify.addr & (PAGE_SIZE-1)] = 0;
314 map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE;
315 }
316 }
317
318 err = gnttab_unmap_refs(map->unmap_ops + offset,
319 use_ptemod ? map->kmap_ops + offset : NULL, map->pages + offset,
320 pages);
321 if (err)
322 return err;
323
324 for (i = 0; i < pages; i++) {
325 if (map->unmap_ops[offset+i].status)
326 err = -EINVAL;
327 pr_debug("unmap handle=%d st=%d\n",
328 map->unmap_ops[offset+i].handle,
329 map->unmap_ops[offset+i].status);
330 map->unmap_ops[offset+i].handle = -1;
331 }
332 return err;
333}
334
335static int unmap_grant_pages(struct grant_map *map, int offset, int pages)
336{
337 int range, err = 0;
338
339 pr_debug("unmap %d+%d [%d+%d]\n", map->index, map->count, offset, pages);
340
341
342
343
344 while (pages && !err) {
345 while (pages && map->unmap_ops[offset].handle == -1) {
346 offset++;
347 pages--;
348 }
349 range = 0;
350 while (range < pages) {
351 if (map->unmap_ops[offset+range].handle == -1) {
352 range--;
353 break;
354 }
355 range++;
356 }
357 err = __unmap_grant_pages(map, offset, range);
358 offset += range;
359 pages -= range;
360 }
361
362 return err;
363}
364
365
366
367static void gntdev_vma_open(struct vm_area_struct *vma)
368{
369 struct grant_map *map = vma->vm_private_data;
370
371 pr_debug("gntdev_vma_open %p\n", vma);
372 atomic_inc(&map->users);
373}
374
375static void gntdev_vma_close(struct vm_area_struct *vma)
376{
377 struct grant_map *map = vma->vm_private_data;
378 struct file *file = vma->vm_file;
379 struct gntdev_priv *priv = file->private_data;
380
381 pr_debug("gntdev_vma_close %p\n", vma);
382 if (use_ptemod) {
383
384
385
386
387
388
389
390 spin_lock(&priv->lock);
391 map->vma = NULL;
392 spin_unlock(&priv->lock);
393 }
394 vma->vm_private_data = NULL;
395 gntdev_put_map(priv, map);
396}
397
398static struct vm_operations_struct gntdev_vmops = {
399 .open = gntdev_vma_open,
400 .close = gntdev_vma_close,
401};
402
403
404
405static void unmap_if_in_range(struct grant_map *map,
406 unsigned long start, unsigned long end)
407{
408 unsigned long mstart, mend;
409 int err;
410
411 if (!map->vma)
412 return;
413 if (map->vma->vm_start >= end)
414 return;
415 if (map->vma->vm_end <= start)
416 return;
417 mstart = max(start, map->vma->vm_start);
418 mend = min(end, map->vma->vm_end);
419 pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n",
420 map->index, map->count,
421 map->vma->vm_start, map->vma->vm_end,
422 start, end, mstart, mend);
423 err = unmap_grant_pages(map,
424 (mstart - map->vma->vm_start) >> PAGE_SHIFT,
425 (mend - mstart) >> PAGE_SHIFT);
426 WARN_ON(err);
427}
428
429static void mn_invl_range_start(struct mmu_notifier *mn,
430 struct mm_struct *mm,
431 unsigned long start, unsigned long end)
432{
433 struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
434 struct grant_map *map;
435
436 spin_lock(&priv->lock);
437 list_for_each_entry(map, &priv->maps, next) {
438 unmap_if_in_range(map, start, end);
439 }
440 list_for_each_entry(map, &priv->freeable_maps, next) {
441 unmap_if_in_range(map, start, end);
442 }
443 spin_unlock(&priv->lock);
444}
445
446static void mn_invl_page(struct mmu_notifier *mn,
447 struct mm_struct *mm,
448 unsigned long address)
449{
450 mn_invl_range_start(mn, mm, address, address + PAGE_SIZE);
451}
452
453static void mn_release(struct mmu_notifier *mn,
454 struct mm_struct *mm)
455{
456 struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
457 struct grant_map *map;
458 int err;
459
460 spin_lock(&priv->lock);
461 list_for_each_entry(map, &priv->maps, next) {
462 if (!map->vma)
463 continue;
464 pr_debug("map %d+%d (%lx %lx)\n",
465 map->index, map->count,
466 map->vma->vm_start, map->vma->vm_end);
467 err = unmap_grant_pages(map, 0, map->count);
468 WARN_ON(err);
469 }
470 list_for_each_entry(map, &priv->freeable_maps, next) {
471 if (!map->vma)
472 continue;
473 pr_debug("map %d+%d (%lx %lx)\n",
474 map->index, map->count,
475 map->vma->vm_start, map->vma->vm_end);
476 err = unmap_grant_pages(map, 0, map->count);
477 WARN_ON(err);
478 }
479 spin_unlock(&priv->lock);
480}
481
482static struct mmu_notifier_ops gntdev_mmu_ops = {
483 .release = mn_release,
484 .invalidate_page = mn_invl_page,
485 .invalidate_range_start = mn_invl_range_start,
486};
487
488
489
490static int gntdev_open(struct inode *inode, struct file *flip)
491{
492 struct gntdev_priv *priv;
493 int ret = 0;
494
495 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
496 if (!priv)
497 return -ENOMEM;
498
499 INIT_LIST_HEAD(&priv->maps);
500 INIT_LIST_HEAD(&priv->freeable_maps);
501 spin_lock_init(&priv->lock);
502
503 if (use_ptemod) {
504 priv->mm = get_task_mm(current);
505 if (!priv->mm) {
506 kfree(priv);
507 return -ENOMEM;
508 }
509 priv->mn.ops = &gntdev_mmu_ops;
510 ret = mmu_notifier_register(&priv->mn, priv->mm);
511 mmput(priv->mm);
512 }
513
514 if (ret) {
515 kfree(priv);
516 return ret;
517 }
518
519 flip->private_data = priv;
520 pr_debug("priv %p\n", priv);
521
522 return 0;
523}
524
525static int gntdev_release(struct inode *inode, struct file *flip)
526{
527 struct gntdev_priv *priv = flip->private_data;
528 struct grant_map *map;
529
530 pr_debug("priv %p\n", priv);
531
532 while (!list_empty(&priv->maps)) {
533 map = list_entry(priv->maps.next, struct grant_map, next);
534 list_del(&map->next);
535 gntdev_put_map(NULL , map);
536 }
537 WARN_ON(!list_empty(&priv->freeable_maps));
538
539 if (use_ptemod)
540 mmu_notifier_unregister(&priv->mn, priv->mm);
541 kfree(priv);
542 return 0;
543}
544
545static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv,
546 struct ioctl_gntdev_map_grant_ref __user *u)
547{
548 struct ioctl_gntdev_map_grant_ref op;
549 struct grant_map *map;
550 int err;
551
552 if (copy_from_user(&op, u, sizeof(op)) != 0)
553 return -EFAULT;
554 pr_debug("priv %p, add %d\n", priv, op.count);
555 if (unlikely(op.count <= 0))
556 return -EINVAL;
557
558 err = -ENOMEM;
559 map = gntdev_alloc_map(priv, op.count);
560 if (!map)
561 return err;
562
563 if (unlikely(atomic_add_return(op.count, &pages_mapped) > limit)) {
564 pr_debug("can't map: over limit\n");
565 gntdev_put_map(NULL, map);
566 return err;
567 }
568
569 if (copy_from_user(map->grants, &u->refs,
570 sizeof(map->grants[0]) * op.count) != 0) {
571 gntdev_put_map(NULL, map);
572 return -EFAULT;
573 }
574
575 spin_lock(&priv->lock);
576 gntdev_add_map(priv, map);
577 op.index = map->index << PAGE_SHIFT;
578 spin_unlock(&priv->lock);
579
580 if (copy_to_user(u, &op, sizeof(op)) != 0)
581 return -EFAULT;
582
583 return 0;
584}
585
586static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv,
587 struct ioctl_gntdev_unmap_grant_ref __user *u)
588{
589 struct ioctl_gntdev_unmap_grant_ref op;
590 struct grant_map *map;
591 int err = -ENOENT;
592
593 if (copy_from_user(&op, u, sizeof(op)) != 0)
594 return -EFAULT;
595 pr_debug("priv %p, del %d+%d\n", priv, (int)op.index, (int)op.count);
596
597 spin_lock(&priv->lock);
598 map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count);
599 if (map) {
600 list_del(&map->next);
601 if (populate_freeable_maps)
602 list_add_tail(&map->next, &priv->freeable_maps);
603 err = 0;
604 }
605 spin_unlock(&priv->lock);
606 if (map)
607 gntdev_put_map(priv, map);
608 return err;
609}
610
611static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv,
612 struct ioctl_gntdev_get_offset_for_vaddr __user *u)
613{
614 struct ioctl_gntdev_get_offset_for_vaddr op;
615 struct vm_area_struct *vma;
616 struct grant_map *map;
617 int rv = -EINVAL;
618
619 if (copy_from_user(&op, u, sizeof(op)) != 0)
620 return -EFAULT;
621 pr_debug("priv %p, offset for vaddr %lx\n", priv, (unsigned long)op.vaddr);
622
623 down_read(¤t->mm->mmap_sem);
624 vma = find_vma(current->mm, op.vaddr);
625 if (!vma || vma->vm_ops != &gntdev_vmops)
626 goto out_unlock;
627
628 map = vma->vm_private_data;
629 if (!map)
630 goto out_unlock;
631
632 op.offset = map->index << PAGE_SHIFT;
633 op.count = map->count;
634 rv = 0;
635
636 out_unlock:
637 up_read(¤t->mm->mmap_sem);
638
639 if (rv == 0 && copy_to_user(u, &op, sizeof(op)) != 0)
640 return -EFAULT;
641 return rv;
642}
643
644static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u)
645{
646 struct ioctl_gntdev_unmap_notify op;
647 struct grant_map *map;
648 int rc;
649 int out_flags;
650 unsigned int out_event;
651
652 if (copy_from_user(&op, u, sizeof(op)))
653 return -EFAULT;
654
655 if (op.action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT))
656 return -EINVAL;
657
658
659
660
661
662
663
664
665 if (op.action & UNMAP_NOTIFY_SEND_EVENT) {
666 if (evtchn_get(op.event_channel_port))
667 return -EINVAL;
668 }
669
670 out_flags = op.action;
671 out_event = op.event_channel_port;
672
673 spin_lock(&priv->lock);
674
675 list_for_each_entry(map, &priv->maps, next) {
676 uint64_t begin = map->index << PAGE_SHIFT;
677 uint64_t end = (map->index + map->count) << PAGE_SHIFT;
678 if (op.index >= begin && op.index < end)
679 goto found;
680 }
681 rc = -ENOENT;
682 goto unlock_out;
683
684 found:
685 if ((op.action & UNMAP_NOTIFY_CLEAR_BYTE) &&
686 (map->flags & GNTMAP_readonly)) {
687 rc = -EINVAL;
688 goto unlock_out;
689 }
690
691 out_flags = map->notify.flags;
692 out_event = map->notify.event;
693
694 map->notify.flags = op.action;
695 map->notify.addr = op.index - (map->index << PAGE_SHIFT);
696 map->notify.event = op.event_channel_port;
697
698 rc = 0;
699
700 unlock_out:
701 spin_unlock(&priv->lock);
702
703
704 if (out_flags & UNMAP_NOTIFY_SEND_EVENT)
705 evtchn_put(out_event);
706
707 return rc;
708}
709
710static long gntdev_ioctl(struct file *flip,
711 unsigned int cmd, unsigned long arg)
712{
713 struct gntdev_priv *priv = flip->private_data;
714 void __user *ptr = (void __user *)arg;
715
716 switch (cmd) {
717 case IOCTL_GNTDEV_MAP_GRANT_REF:
718 return gntdev_ioctl_map_grant_ref(priv, ptr);
719
720 case IOCTL_GNTDEV_UNMAP_GRANT_REF:
721 return gntdev_ioctl_unmap_grant_ref(priv, ptr);
722
723 case IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR:
724 return gntdev_ioctl_get_offset_for_vaddr(priv, ptr);
725
726 case IOCTL_GNTDEV_SET_UNMAP_NOTIFY:
727 return gntdev_ioctl_notify(priv, ptr);
728
729 default:
730 pr_debug("priv %p, unknown cmd %x\n", priv, cmd);
731 return -ENOIOCTLCMD;
732 }
733
734 return 0;
735}
736
737static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
738{
739 struct gntdev_priv *priv = flip->private_data;
740 int index = vma->vm_pgoff;
741 int count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
742 struct grant_map *map;
743 int i, err = -EINVAL;
744
745 if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED))
746 return -EINVAL;
747
748 pr_debug("map %d+%d at %lx (pgoff %lx)\n",
749 index, count, vma->vm_start, vma->vm_pgoff);
750
751 spin_lock(&priv->lock);
752 map = gntdev_find_map_index(priv, index, count);
753 if (!map)
754 goto unlock_out;
755 if (use_ptemod && map->vma)
756 goto unlock_out;
757 if (use_ptemod && priv->mm != vma->vm_mm) {
758 pr_warn("Huh? Other mm?\n");
759 goto unlock_out;
760 }
761
762 atomic_inc(&map->users);
763
764 vma->vm_ops = &gntdev_vmops;
765
766 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
767
768 if (use_ptemod)
769 vma->vm_flags |= VM_DONTCOPY;
770
771 vma->vm_private_data = map;
772
773 if (use_ptemod)
774 map->vma = vma;
775
776 if (map->flags) {
777 if ((vma->vm_flags & VM_WRITE) &&
778 (map->flags & GNTMAP_readonly))
779 goto out_unlock_put;
780 } else {
781 map->flags = GNTMAP_host_map;
782 if (!(vma->vm_flags & VM_WRITE))
783 map->flags |= GNTMAP_readonly;
784 }
785
786 spin_unlock(&priv->lock);
787
788 if (use_ptemod) {
789 err = apply_to_page_range(vma->vm_mm, vma->vm_start,
790 vma->vm_end - vma->vm_start,
791 find_grant_ptes, map);
792 if (err) {
793 pr_warn("find_grant_ptes() failure.\n");
794 goto out_put_map;
795 }
796 }
797
798 err = map_grant_pages(map);
799 if (err)
800 goto out_put_map;
801
802 if (!use_ptemod) {
803 for (i = 0; i < count; i++) {
804 err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE,
805 map->pages[i]);
806 if (err)
807 goto out_put_map;
808 }
809 }
810
811 return 0;
812
813unlock_out:
814 spin_unlock(&priv->lock);
815 return err;
816
817out_unlock_put:
818 spin_unlock(&priv->lock);
819out_put_map:
820 if (use_ptemod)
821 map->vma = NULL;
822 gntdev_put_map(priv, map);
823 return err;
824}
825
826static const struct file_operations gntdev_fops = {
827 .owner = THIS_MODULE,
828 .open = gntdev_open,
829 .release = gntdev_release,
830 .mmap = gntdev_mmap,
831 .unlocked_ioctl = gntdev_ioctl
832};
833
834static struct miscdevice gntdev_miscdev = {
835 .minor = MISC_DYNAMIC_MINOR,
836 .name = "xen/gntdev",
837 .fops = &gntdev_fops,
838};
839
840
841
842static int __init gntdev_init(void)
843{
844 int err;
845
846 if (!xen_domain())
847 return -ENODEV;
848
849 use_ptemod = !xen_feature(XENFEAT_auto_translated_physmap);
850
851 err = misc_register(&gntdev_miscdev);
852 if (err != 0) {
853 pr_err("Could not register gntdev device\n");
854 return err;
855 }
856 return 0;
857}
858
859static void __exit gntdev_exit(void)
860{
861 misc_deregister(&gntdev_miscdev);
862}
863
864module_init(gntdev_init);
865module_exit(gntdev_exit);
866
867
868
