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ab31523c GH |
1 | /****************************************************************************** |
2 | * gntdev.c | |
3 | * | |
4 | * Device for accessing (in user-space) pages that have been granted by other | |
5 | * domains. | |
6 | * | |
7 | * Copyright (c) 2006-2007, D G Murray. | |
8 | * (c) 2009 Gerd Hoffmann <kraxel@redhat.com> | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
18 | */ | |
19 | ||
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> | |
aab8f11a | 35 | #include <linux/highmem.h> |
ab31523c GH |
36 | |
37 | #include <xen/xen.h> | |
38 | #include <xen/grant_table.h> | |
ca47ceaa | 39 | #include <xen/balloon.h> |
ab31523c | 40 | #include <xen/gntdev.h> |
bdc612dc | 41 | #include <xen/events.h> |
ab31523c GH |
42 | #include <asm/xen/hypervisor.h> |
43 | #include <asm/xen/hypercall.h> | |
44 | #include <asm/xen/page.h> | |
45 | ||
46 | MODULE_LICENSE("GPL"); | |
47 | MODULE_AUTHOR("Derek G. Murray <Derek.Murray@cl.cam.ac.uk>, " | |
48 | "Gerd Hoffmann <kraxel@redhat.com>"); | |
49 | MODULE_DESCRIPTION("User-space granted page access driver"); | |
50 | ||
ef91082e | 51 | static int limit = 1024*1024; |
ab31523c | 52 | module_param(limit, int, 0644); |
ef91082e DDG |
53 | MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by " |
54 | "the gntdev device"); | |
55 | ||
56 | static atomic_t pages_mapped = ATOMIC_INIT(0); | |
ab31523c | 57 | |
aab8f11a DDG |
58 | static int use_ptemod; |
59 | ||
ab31523c GH |
60 | struct gntdev_priv { |
61 | struct list_head maps; | |
ab31523c GH |
62 | /* lock protects maps from concurrent changes */ |
63 | spinlock_t lock; | |
64 | struct mm_struct *mm; | |
65 | struct mmu_notifier mn; | |
66 | }; | |
67 | ||
bdc612dc DDG |
68 | struct unmap_notify { |
69 | int flags; | |
70 | /* Address relative to the start of the grant_map */ | |
71 | int addr; | |
72 | int event; | |
73 | }; | |
74 | ||
ab31523c GH |
75 | struct grant_map { |
76 | struct list_head next; | |
ab31523c GH |
77 | struct vm_area_struct *vma; |
78 | int index; | |
79 | int count; | |
80 | int flags; | |
68b025c8 | 81 | atomic_t users; |
bdc612dc | 82 | struct unmap_notify notify; |
ab31523c GH |
83 | struct ioctl_gntdev_grant_ref *grants; |
84 | struct gnttab_map_grant_ref *map_ops; | |
85 | struct gnttab_unmap_grant_ref *unmap_ops; | |
a12b4eb3 | 86 | struct page **pages; |
ab31523c GH |
87 | }; |
88 | ||
aab8f11a DDG |
89 | static int unmap_grant_pages(struct grant_map *map, int offset, int pages); |
90 | ||
ab31523c GH |
91 | /* ------------------------------------------------------------------ */ |
92 | ||
93 | static void gntdev_print_maps(struct gntdev_priv *priv, | |
94 | char *text, int text_index) | |
95 | { | |
96 | #ifdef DEBUG | |
97 | struct grant_map *map; | |
98 | ||
ef91082e | 99 | pr_debug("%s: maps list (priv %p)\n", __func__, priv); |
ab31523c GH |
100 | list_for_each_entry(map, &priv->maps, next) |
101 | pr_debug(" index %2d, count %2d %s\n", | |
102 | map->index, map->count, | |
103 | map->index == text_index && text ? text : ""); | |
104 | #endif | |
105 | } | |
106 | ||
107 | static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count) | |
108 | { | |
109 | struct grant_map *add; | |
a12b4eb3 | 110 | int i; |
ab31523c GH |
111 | |
112 | add = kzalloc(sizeof(struct grant_map), GFP_KERNEL); | |
113 | if (NULL == add) | |
114 | return NULL; | |
115 | ||
116 | add->grants = kzalloc(sizeof(add->grants[0]) * count, GFP_KERNEL); | |
117 | add->map_ops = kzalloc(sizeof(add->map_ops[0]) * count, GFP_KERNEL); | |
118 | add->unmap_ops = kzalloc(sizeof(add->unmap_ops[0]) * count, GFP_KERNEL); | |
a12b4eb3 SS |
119 | add->pages = kzalloc(sizeof(add->pages[0]) * count, GFP_KERNEL); |
120 | if (NULL == add->grants || | |
121 | NULL == add->map_ops || | |
122 | NULL == add->unmap_ops || | |
123 | NULL == add->pages) | |
ab31523c GH |
124 | goto err; |
125 | ||
ca47ceaa DDG |
126 | if (alloc_xenballooned_pages(count, add->pages)) |
127 | goto err; | |
128 | ||
a12b4eb3 | 129 | for (i = 0; i < count; i++) { |
77c35acb DDG |
130 | add->map_ops[i].handle = -1; |
131 | add->unmap_ops[i].handle = -1; | |
a12b4eb3 SS |
132 | } |
133 | ||
ab31523c GH |
134 | add->index = 0; |
135 | add->count = count; | |
68b025c8 | 136 | atomic_set(&add->users, 1); |
ab31523c | 137 | |
ab31523c GH |
138 | return add; |
139 | ||
140 | err: | |
a12b4eb3 | 141 | kfree(add->pages); |
ab31523c GH |
142 | kfree(add->grants); |
143 | kfree(add->map_ops); | |
144 | kfree(add->unmap_ops); | |
145 | kfree(add); | |
146 | return NULL; | |
147 | } | |
148 | ||
149 | static void gntdev_add_map(struct gntdev_priv *priv, struct grant_map *add) | |
150 | { | |
151 | struct grant_map *map; | |
152 | ||
153 | list_for_each_entry(map, &priv->maps, next) { | |
154 | if (add->index + add->count < map->index) { | |
155 | list_add_tail(&add->next, &map->next); | |
156 | goto done; | |
157 | } | |
158 | add->index = map->index + map->count; | |
159 | } | |
160 | list_add_tail(&add->next, &priv->maps); | |
161 | ||
162 | done: | |
ab31523c GH |
163 | gntdev_print_maps(priv, "[new]", add->index); |
164 | } | |
165 | ||
166 | static struct grant_map *gntdev_find_map_index(struct gntdev_priv *priv, | |
167 | int index, int count) | |
168 | { | |
169 | struct grant_map *map; | |
170 | ||
171 | list_for_each_entry(map, &priv->maps, next) { | |
172 | if (map->index != index) | |
173 | continue; | |
bdc612dc | 174 | if (count && map->count != count) |
ab31523c GH |
175 | continue; |
176 | return map; | |
177 | } | |
178 | return NULL; | |
179 | } | |
180 | ||
68b025c8 | 181 | static void gntdev_put_map(struct grant_map *map) |
ab31523c GH |
182 | { |
183 | if (!map) | |
184 | return; | |
a12b4eb3 | 185 | |
68b025c8 DDG |
186 | if (!atomic_dec_and_test(&map->users)) |
187 | return; | |
188 | ||
189 | atomic_sub(map->count, &pages_mapped); | |
190 | ||
bdc612dc DDG |
191 | if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) { |
192 | notify_remote_via_evtchn(map->notify.event); | |
193 | } | |
194 | ||
aab8f11a DDG |
195 | if (map->pages) { |
196 | if (!use_ptemod) | |
197 | unmap_grant_pages(map, 0, map->count); | |
198 | ||
ca47ceaa | 199 | free_xenballooned_pages(map->count, map->pages); |
aab8f11a | 200 | } |
a12b4eb3 | 201 | kfree(map->pages); |
ab31523c GH |
202 | kfree(map->grants); |
203 | kfree(map->map_ops); | |
204 | kfree(map->unmap_ops); | |
205 | kfree(map); | |
206 | } | |
207 | ||
208 | /* ------------------------------------------------------------------ */ | |
209 | ||
210 | static int find_grant_ptes(pte_t *pte, pgtable_t token, | |
211 | unsigned long addr, void *data) | |
212 | { | |
213 | struct grant_map *map = data; | |
214 | unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT; | |
aab8f11a | 215 | int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte; |
ab31523c GH |
216 | u64 pte_maddr; |
217 | ||
218 | BUG_ON(pgnr >= map->count); | |
ba5d1012 JF |
219 | pte_maddr = arbitrary_virt_to_machine(pte).maddr; |
220 | ||
aab8f11a | 221 | gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, flags, |
ab31523c GH |
222 | map->grants[pgnr].ref, |
223 | map->grants[pgnr].domid); | |
aab8f11a | 224 | gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags, |
77c35acb | 225 | -1 /* handle */); |
ab31523c GH |
226 | return 0; |
227 | } | |
228 | ||
229 | static int map_grant_pages(struct grant_map *map) | |
230 | { | |
231 | int i, err = 0; | |
aab8f11a DDG |
232 | |
233 | if (!use_ptemod) { | |
12996fc3 | 234 | /* Note: it could already be mapped */ |
77c35acb | 235 | if (map->map_ops[0].handle != -1) |
12996fc3 | 236 | return 0; |
aab8f11a | 237 | for (i = 0; i < map->count; i++) { |
38eaeb0f | 238 | unsigned long addr = (unsigned long) |
aab8f11a DDG |
239 | pfn_to_kaddr(page_to_pfn(map->pages[i])); |
240 | gnttab_set_map_op(&map->map_ops[i], addr, map->flags, | |
241 | map->grants[i].ref, | |
242 | map->grants[i].domid); | |
243 | gnttab_set_unmap_op(&map->unmap_ops[i], addr, | |
77c35acb | 244 | map->flags, -1 /* handle */); |
aab8f11a DDG |
245 | } |
246 | } | |
ab31523c GH |
247 | |
248 | pr_debug("map %d+%d\n", map->index, map->count); | |
a12b4eb3 | 249 | err = gnttab_map_refs(map->map_ops, map->pages, map->count); |
ab31523c GH |
250 | if (err) |
251 | return err; | |
252 | ||
253 | for (i = 0; i < map->count; i++) { | |
254 | if (map->map_ops[i].status) | |
255 | err = -EINVAL; | |
77c35acb DDG |
256 | else { |
257 | BUG_ON(map->map_ops[i].handle == -1); | |
258 | map->unmap_ops[i].handle = map->map_ops[i].handle; | |
259 | pr_debug("map handle=%d\n", map->map_ops[i].handle); | |
260 | } | |
ab31523c GH |
261 | } |
262 | return err; | |
263 | } | |
264 | ||
b57c1869 | 265 | static int __unmap_grant_pages(struct grant_map *map, int offset, int pages) |
ab31523c GH |
266 | { |
267 | int i, err = 0; | |
268 | ||
bdc612dc DDG |
269 | if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) { |
270 | int pgno = (map->notify.addr >> PAGE_SHIFT); | |
0ea22f07 | 271 | if (pgno >= offset && pgno < offset + pages && use_ptemod) { |
f4ee4af4 DDG |
272 | void __user *tmp = (void __user *) |
273 | map->vma->vm_start + map->notify.addr; | |
9960be97 DDG |
274 | err = copy_to_user(tmp, &err, 1); |
275 | if (err) | |
12f0258d | 276 | return -EFAULT; |
0ea22f07 DDG |
277 | map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE; |
278 | } else if (pgno >= offset && pgno < offset + pages) { | |
bdc612dc DDG |
279 | uint8_t *tmp = kmap(map->pages[pgno]); |
280 | tmp[map->notify.addr & (PAGE_SIZE-1)] = 0; | |
281 | kunmap(map->pages[pgno]); | |
282 | map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE; | |
283 | } | |
284 | } | |
285 | ||
0ea22f07 | 286 | err = gnttab_unmap_refs(map->unmap_ops + offset, map->pages + offset, pages); |
ab31523c GH |
287 | if (err) |
288 | return err; | |
289 | ||
290 | for (i = 0; i < pages; i++) { | |
291 | if (map->unmap_ops[offset+i].status) | |
292 | err = -EINVAL; | |
77c35acb DDG |
293 | pr_debug("unmap handle=%d st=%d\n", |
294 | map->unmap_ops[offset+i].handle, | |
295 | map->unmap_ops[offset+i].status); | |
296 | map->unmap_ops[offset+i].handle = -1; | |
ab31523c GH |
297 | } |
298 | return err; | |
299 | } | |
300 | ||
b57c1869 DDG |
301 | static int unmap_grant_pages(struct grant_map *map, int offset, int pages) |
302 | { | |
303 | int range, err = 0; | |
304 | ||
305 | pr_debug("unmap %d+%d [%d+%d]\n", map->index, map->count, offset, pages); | |
306 | ||
307 | /* It is possible the requested range will have a "hole" where we | |
308 | * already unmapped some of the grants. Only unmap valid ranges. | |
309 | */ | |
310 | while (pages && !err) { | |
77c35acb | 311 | while (pages && map->unmap_ops[offset].handle == -1) { |
b57c1869 DDG |
312 | offset++; |
313 | pages--; | |
314 | } | |
315 | range = 0; | |
316 | while (range < pages) { | |
77c35acb | 317 | if (map->unmap_ops[offset+range].handle == -1) { |
b57c1869 DDG |
318 | range--; |
319 | break; | |
320 | } | |
321 | range++; | |
322 | } | |
323 | err = __unmap_grant_pages(map, offset, range); | |
324 | offset += range; | |
325 | pages -= range; | |
326 | } | |
327 | ||
328 | return err; | |
329 | } | |
330 | ||
ab31523c GH |
331 | /* ------------------------------------------------------------------ */ |
332 | ||
d79647ae DDG |
333 | static void gntdev_vma_open(struct vm_area_struct *vma) |
334 | { | |
335 | struct grant_map *map = vma->vm_private_data; | |
336 | ||
337 | pr_debug("gntdev_vma_open %p\n", vma); | |
338 | atomic_inc(&map->users); | |
339 | } | |
340 | ||
ab31523c GH |
341 | static void gntdev_vma_close(struct vm_area_struct *vma) |
342 | { | |
343 | struct grant_map *map = vma->vm_private_data; | |
344 | ||
d79647ae | 345 | pr_debug("gntdev_vma_close %p\n", vma); |
ab31523c GH |
346 | map->vma = NULL; |
347 | vma->vm_private_data = NULL; | |
68b025c8 | 348 | gntdev_put_map(map); |
ab31523c GH |
349 | } |
350 | ||
ab31523c | 351 | static struct vm_operations_struct gntdev_vmops = { |
d79647ae | 352 | .open = gntdev_vma_open, |
ab31523c | 353 | .close = gntdev_vma_close, |
ab31523c GH |
354 | }; |
355 | ||
356 | /* ------------------------------------------------------------------ */ | |
357 | ||
358 | static void mn_invl_range_start(struct mmu_notifier *mn, | |
359 | struct mm_struct *mm, | |
360 | unsigned long start, unsigned long end) | |
361 | { | |
362 | struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); | |
363 | struct grant_map *map; | |
364 | unsigned long mstart, mend; | |
365 | int err; | |
366 | ||
367 | spin_lock(&priv->lock); | |
368 | list_for_each_entry(map, &priv->maps, next) { | |
369 | if (!map->vma) | |
370 | continue; | |
ab31523c GH |
371 | if (map->vma->vm_start >= end) |
372 | continue; | |
373 | if (map->vma->vm_end <= start) | |
374 | continue; | |
375 | mstart = max(start, map->vma->vm_start); | |
376 | mend = min(end, map->vma->vm_end); | |
377 | pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n", | |
378 | map->index, map->count, | |
379 | map->vma->vm_start, map->vma->vm_end, | |
380 | start, end, mstart, mend); | |
381 | err = unmap_grant_pages(map, | |
382 | (mstart - map->vma->vm_start) >> PAGE_SHIFT, | |
383 | (mend - mstart) >> PAGE_SHIFT); | |
384 | WARN_ON(err); | |
385 | } | |
386 | spin_unlock(&priv->lock); | |
387 | } | |
388 | ||
389 | static void mn_invl_page(struct mmu_notifier *mn, | |
390 | struct mm_struct *mm, | |
391 | unsigned long address) | |
392 | { | |
393 | mn_invl_range_start(mn, mm, address, address + PAGE_SIZE); | |
394 | } | |
395 | ||
396 | static void mn_release(struct mmu_notifier *mn, | |
397 | struct mm_struct *mm) | |
398 | { | |
399 | struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); | |
400 | struct grant_map *map; | |
401 | int err; | |
402 | ||
403 | spin_lock(&priv->lock); | |
404 | list_for_each_entry(map, &priv->maps, next) { | |
405 | if (!map->vma) | |
406 | continue; | |
407 | pr_debug("map %d+%d (%lx %lx)\n", | |
408 | map->index, map->count, | |
409 | map->vma->vm_start, map->vma->vm_end); | |
410 | err = unmap_grant_pages(map, /* offset */ 0, map->count); | |
411 | WARN_ON(err); | |
412 | } | |
413 | spin_unlock(&priv->lock); | |
414 | } | |
415 | ||
416 | struct mmu_notifier_ops gntdev_mmu_ops = { | |
417 | .release = mn_release, | |
418 | .invalidate_page = mn_invl_page, | |
419 | .invalidate_range_start = mn_invl_range_start, | |
420 | }; | |
421 | ||
422 | /* ------------------------------------------------------------------ */ | |
423 | ||
424 | static int gntdev_open(struct inode *inode, struct file *flip) | |
425 | { | |
426 | struct gntdev_priv *priv; | |
427 | int ret = 0; | |
428 | ||
429 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); | |
430 | if (!priv) | |
431 | return -ENOMEM; | |
432 | ||
433 | INIT_LIST_HEAD(&priv->maps); | |
434 | spin_lock_init(&priv->lock); | |
ab31523c | 435 | |
aab8f11a DDG |
436 | if (use_ptemod) { |
437 | priv->mm = get_task_mm(current); | |
438 | if (!priv->mm) { | |
439 | kfree(priv); | |
440 | return -ENOMEM; | |
441 | } | |
442 | priv->mn.ops = &gntdev_mmu_ops; | |
443 | ret = mmu_notifier_register(&priv->mn, priv->mm); | |
444 | mmput(priv->mm); | |
ab31523c | 445 | } |
ab31523c GH |
446 | |
447 | if (ret) { | |
448 | kfree(priv); | |
449 | return ret; | |
450 | } | |
451 | ||
452 | flip->private_data = priv; | |
453 | pr_debug("priv %p\n", priv); | |
454 | ||
455 | return 0; | |
456 | } | |
457 | ||
458 | static int gntdev_release(struct inode *inode, struct file *flip) | |
459 | { | |
460 | struct gntdev_priv *priv = flip->private_data; | |
461 | struct grant_map *map; | |
ab31523c GH |
462 | |
463 | pr_debug("priv %p\n", priv); | |
464 | ||
465 | spin_lock(&priv->lock); | |
466 | while (!list_empty(&priv->maps)) { | |
467 | map = list_entry(priv->maps.next, struct grant_map, next); | |
68b025c8 DDG |
468 | list_del(&map->next); |
469 | gntdev_put_map(map); | |
ab31523c GH |
470 | } |
471 | spin_unlock(&priv->lock); | |
472 | ||
aab8f11a DDG |
473 | if (use_ptemod) |
474 | mmu_notifier_unregister(&priv->mn, priv->mm); | |
ab31523c GH |
475 | kfree(priv); |
476 | return 0; | |
477 | } | |
478 | ||
479 | static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv, | |
480 | struct ioctl_gntdev_map_grant_ref __user *u) | |
481 | { | |
482 | struct ioctl_gntdev_map_grant_ref op; | |
483 | struct grant_map *map; | |
484 | int err; | |
485 | ||
486 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
487 | return -EFAULT; | |
488 | pr_debug("priv %p, add %d\n", priv, op.count); | |
489 | if (unlikely(op.count <= 0)) | |
490 | return -EINVAL; | |
ab31523c GH |
491 | |
492 | err = -ENOMEM; | |
493 | map = gntdev_alloc_map(priv, op.count); | |
494 | if (!map) | |
495 | return err; | |
ef91082e | 496 | |
68b025c8 DDG |
497 | if (unlikely(atomic_add_return(op.count, &pages_mapped) > limit)) { |
498 | pr_debug("can't map: over limit\n"); | |
499 | gntdev_put_map(map); | |
ab31523c GH |
500 | return err; |
501 | } | |
502 | ||
68b025c8 DDG |
503 | if (copy_from_user(map->grants, &u->refs, |
504 | sizeof(map->grants[0]) * op.count) != 0) { | |
505 | gntdev_put_map(map); | |
ef91082e DDG |
506 | return err; |
507 | } | |
508 | ||
ab31523c GH |
509 | spin_lock(&priv->lock); |
510 | gntdev_add_map(priv, map); | |
511 | op.index = map->index << PAGE_SHIFT; | |
512 | spin_unlock(&priv->lock); | |
513 | ||
68b025c8 DDG |
514 | if (copy_to_user(u, &op, sizeof(op)) != 0) |
515 | return -EFAULT; | |
516 | ||
ab31523c GH |
517 | return 0; |
518 | } | |
519 | ||
520 | static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv, | |
521 | struct ioctl_gntdev_unmap_grant_ref __user *u) | |
522 | { | |
523 | struct ioctl_gntdev_unmap_grant_ref op; | |
524 | struct grant_map *map; | |
525 | int err = -ENOENT; | |
526 | ||
527 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
528 | return -EFAULT; | |
529 | pr_debug("priv %p, del %d+%d\n", priv, (int)op.index, (int)op.count); | |
530 | ||
531 | spin_lock(&priv->lock); | |
532 | map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count); | |
68b025c8 DDG |
533 | if (map) { |
534 | list_del(&map->next); | |
535 | gntdev_put_map(map); | |
536 | err = 0; | |
537 | } | |
ab31523c | 538 | spin_unlock(&priv->lock); |
ab31523c GH |
539 | return err; |
540 | } | |
541 | ||
542 | static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv, | |
543 | struct ioctl_gntdev_get_offset_for_vaddr __user *u) | |
544 | { | |
545 | struct ioctl_gntdev_get_offset_for_vaddr op; | |
a879211b | 546 | struct vm_area_struct *vma; |
ab31523c GH |
547 | struct grant_map *map; |
548 | ||
549 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
550 | return -EFAULT; | |
551 | pr_debug("priv %p, offset for vaddr %lx\n", priv, (unsigned long)op.vaddr); | |
552 | ||
a879211b DDG |
553 | vma = find_vma(current->mm, op.vaddr); |
554 | if (!vma || vma->vm_ops != &gntdev_vmops) | |
ab31523c | 555 | return -EINVAL; |
a879211b DDG |
556 | |
557 | map = vma->vm_private_data; | |
558 | if (!map) | |
559 | return -EINVAL; | |
560 | ||
ab31523c GH |
561 | op.offset = map->index << PAGE_SHIFT; |
562 | op.count = map->count; | |
ab31523c GH |
563 | |
564 | if (copy_to_user(u, &op, sizeof(op)) != 0) | |
565 | return -EFAULT; | |
566 | return 0; | |
567 | } | |
568 | ||
bdc612dc DDG |
569 | static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u) |
570 | { | |
571 | struct ioctl_gntdev_unmap_notify op; | |
572 | struct grant_map *map; | |
573 | int rc; | |
574 | ||
575 | if (copy_from_user(&op, u, sizeof(op))) | |
576 | return -EFAULT; | |
577 | ||
578 | if (op.action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT)) | |
579 | return -EINVAL; | |
580 | ||
581 | spin_lock(&priv->lock); | |
582 | ||
583 | list_for_each_entry(map, &priv->maps, next) { | |
584 | uint64_t begin = map->index << PAGE_SHIFT; | |
585 | uint64_t end = (map->index + map->count) << PAGE_SHIFT; | |
586 | if (op.index >= begin && op.index < end) | |
587 | goto found; | |
588 | } | |
589 | rc = -ENOENT; | |
590 | goto unlock_out; | |
591 | ||
592 | found: | |
9960be97 DDG |
593 | if ((op.action & UNMAP_NOTIFY_CLEAR_BYTE) && |
594 | (map->flags & GNTMAP_readonly)) { | |
595 | rc = -EINVAL; | |
596 | goto unlock_out; | |
597 | } | |
598 | ||
bdc612dc DDG |
599 | map->notify.flags = op.action; |
600 | map->notify.addr = op.index - (map->index << PAGE_SHIFT); | |
601 | map->notify.event = op.event_channel_port; | |
602 | rc = 0; | |
603 | unlock_out: | |
604 | spin_unlock(&priv->lock); | |
605 | return rc; | |
606 | } | |
607 | ||
ab31523c GH |
608 | static long gntdev_ioctl(struct file *flip, |
609 | unsigned int cmd, unsigned long arg) | |
610 | { | |
611 | struct gntdev_priv *priv = flip->private_data; | |
612 | void __user *ptr = (void __user *)arg; | |
613 | ||
614 | switch (cmd) { | |
615 | case IOCTL_GNTDEV_MAP_GRANT_REF: | |
616 | return gntdev_ioctl_map_grant_ref(priv, ptr); | |
617 | ||
618 | case IOCTL_GNTDEV_UNMAP_GRANT_REF: | |
619 | return gntdev_ioctl_unmap_grant_ref(priv, ptr); | |
620 | ||
621 | case IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR: | |
622 | return gntdev_ioctl_get_offset_for_vaddr(priv, ptr); | |
623 | ||
bdc612dc DDG |
624 | case IOCTL_GNTDEV_SET_UNMAP_NOTIFY: |
625 | return gntdev_ioctl_notify(priv, ptr); | |
626 | ||
ab31523c GH |
627 | default: |
628 | pr_debug("priv %p, unknown cmd %x\n", priv, cmd); | |
629 | return -ENOIOCTLCMD; | |
630 | } | |
631 | ||
632 | return 0; | |
633 | } | |
634 | ||
635 | static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) | |
636 | { | |
637 | struct gntdev_priv *priv = flip->private_data; | |
638 | int index = vma->vm_pgoff; | |
639 | int count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; | |
640 | struct grant_map *map; | |
aab8f11a | 641 | int i, err = -EINVAL; |
ab31523c GH |
642 | |
643 | if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED)) | |
644 | return -EINVAL; | |
645 | ||
646 | pr_debug("map %d+%d at %lx (pgoff %lx)\n", | |
647 | index, count, vma->vm_start, vma->vm_pgoff); | |
648 | ||
649 | spin_lock(&priv->lock); | |
650 | map = gntdev_find_map_index(priv, index, count); | |
651 | if (!map) | |
652 | goto unlock_out; | |
aab8f11a | 653 | if (use_ptemod && map->vma) |
ab31523c | 654 | goto unlock_out; |
aab8f11a | 655 | if (use_ptemod && priv->mm != vma->vm_mm) { |
ab31523c GH |
656 | printk(KERN_WARNING "Huh? Other mm?\n"); |
657 | goto unlock_out; | |
658 | } | |
659 | ||
68b025c8 DDG |
660 | atomic_inc(&map->users); |
661 | ||
ab31523c GH |
662 | vma->vm_ops = &gntdev_vmops; |
663 | ||
d79647ae DDG |
664 | vma->vm_flags |= VM_RESERVED|VM_DONTEXPAND; |
665 | ||
666 | if (use_ptemod) | |
667 | vma->vm_flags |= VM_DONTCOPY|VM_PFNMAP; | |
ab31523c GH |
668 | |
669 | vma->vm_private_data = map; | |
ab31523c | 670 | |
aab8f11a DDG |
671 | if (use_ptemod) |
672 | map->vma = vma; | |
673 | ||
12996fc3 DDG |
674 | if (map->flags) { |
675 | if ((vma->vm_flags & VM_WRITE) && | |
676 | (map->flags & GNTMAP_readonly)) | |
a93e20a8 | 677 | goto out_unlock_put; |
12996fc3 DDG |
678 | } else { |
679 | map->flags = GNTMAP_host_map; | |
680 | if (!(vma->vm_flags & VM_WRITE)) | |
681 | map->flags |= GNTMAP_readonly; | |
682 | } | |
ab31523c | 683 | |
f0a70c88 DDG |
684 | spin_unlock(&priv->lock); |
685 | ||
aab8f11a DDG |
686 | if (use_ptemod) { |
687 | err = apply_to_page_range(vma->vm_mm, vma->vm_start, | |
688 | vma->vm_end - vma->vm_start, | |
689 | find_grant_ptes, map); | |
690 | if (err) { | |
691 | printk(KERN_WARNING "find_grant_ptes() failure.\n"); | |
90b6f305 | 692 | goto out_put_map; |
aab8f11a | 693 | } |
ab31523c GH |
694 | } |
695 | ||
696 | err = map_grant_pages(map); | |
90b6f305 DDG |
697 | if (err) |
698 | goto out_put_map; | |
f0a70c88 | 699 | |
aab8f11a DDG |
700 | if (!use_ptemod) { |
701 | for (i = 0; i < count; i++) { | |
702 | err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE, | |
703 | map->pages[i]); | |
704 | if (err) | |
90b6f305 | 705 | goto out_put_map; |
aab8f11a DDG |
706 | } |
707 | } | |
708 | ||
f0a70c88 DDG |
709 | return 0; |
710 | ||
ab31523c GH |
711 | unlock_out: |
712 | spin_unlock(&priv->lock); | |
713 | return err; | |
90b6f305 | 714 | |
a93e20a8 DC |
715 | out_unlock_put: |
716 | spin_unlock(&priv->lock); | |
90b6f305 | 717 | out_put_map: |
84e4075d DDG |
718 | if (use_ptemod) |
719 | map->vma = NULL; | |
90b6f305 DDG |
720 | gntdev_put_map(map); |
721 | return err; | |
ab31523c GH |
722 | } |
723 | ||
724 | static const struct file_operations gntdev_fops = { | |
725 | .owner = THIS_MODULE, | |
726 | .open = gntdev_open, | |
727 | .release = gntdev_release, | |
728 | .mmap = gntdev_mmap, | |
729 | .unlocked_ioctl = gntdev_ioctl | |
730 | }; | |
731 | ||
732 | static struct miscdevice gntdev_miscdev = { | |
733 | .minor = MISC_DYNAMIC_MINOR, | |
734 | .name = "xen/gntdev", | |
735 | .fops = &gntdev_fops, | |
736 | }; | |
737 | ||
738 | /* ------------------------------------------------------------------ */ | |
739 | ||
740 | static int __init gntdev_init(void) | |
741 | { | |
742 | int err; | |
743 | ||
744 | if (!xen_domain()) | |
745 | return -ENODEV; | |
746 | ||
aab8f11a DDG |
747 | use_ptemod = xen_pv_domain(); |
748 | ||
ab31523c GH |
749 | err = misc_register(&gntdev_miscdev); |
750 | if (err != 0) { | |
751 | printk(KERN_ERR "Could not register gntdev device\n"); | |
752 | return err; | |
753 | } | |
754 | return 0; | |
755 | } | |
756 | ||
757 | static void __exit gntdev_exit(void) | |
758 | { | |
759 | misc_deregister(&gntdev_miscdev); | |
760 | } | |
761 | ||
762 | module_init(gntdev_init); | |
763 | module_exit(gntdev_exit); | |
764 | ||
765 | /* ------------------------------------------------------------------ */ |