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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; | |
0930bba6 | 86 | struct gnttab_map_grant_ref *kmap_ops; |
a12b4eb3 | 87 | struct page **pages; |
ab31523c GH |
88 | }; |
89 | ||
aab8f11a DDG |
90 | static int unmap_grant_pages(struct grant_map *map, int offset, int pages); |
91 | ||
ab31523c GH |
92 | /* ------------------------------------------------------------------ */ |
93 | ||
94 | static void gntdev_print_maps(struct gntdev_priv *priv, | |
95 | char *text, int text_index) | |
96 | { | |
97 | #ifdef DEBUG | |
98 | struct grant_map *map; | |
99 | ||
ef91082e | 100 | pr_debug("%s: maps list (priv %p)\n", __func__, priv); |
ab31523c GH |
101 | list_for_each_entry(map, &priv->maps, next) |
102 | pr_debug(" index %2d, count %2d %s\n", | |
103 | map->index, map->count, | |
104 | map->index == text_index && text ? text : ""); | |
105 | #endif | |
106 | } | |
107 | ||
a67baeb7 DV |
108 | static void gntdev_free_map(struct grant_map *map) |
109 | { | |
110 | if (map == NULL) | |
111 | return; | |
112 | ||
113 | if (map->pages) | |
114 | free_xenballooned_pages(map->count, map->pages); | |
115 | kfree(map->pages); | |
116 | kfree(map->grants); | |
117 | kfree(map->map_ops); | |
118 | kfree(map->unmap_ops); | |
119 | kfree(map->kmap_ops); | |
120 | kfree(map); | |
121 | } | |
122 | ||
ab31523c GH |
123 | static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count) |
124 | { | |
125 | struct grant_map *add; | |
a12b4eb3 | 126 | int i; |
ab31523c GH |
127 | |
128 | add = kzalloc(sizeof(struct grant_map), GFP_KERNEL); | |
129 | if (NULL == add) | |
130 | return NULL; | |
131 | ||
fc6e0c3b DC |
132 | add->grants = kcalloc(count, sizeof(add->grants[0]), GFP_KERNEL); |
133 | add->map_ops = kcalloc(count, sizeof(add->map_ops[0]), GFP_KERNEL); | |
134 | add->unmap_ops = kcalloc(count, sizeof(add->unmap_ops[0]), GFP_KERNEL); | |
135 | add->kmap_ops = kcalloc(count, sizeof(add->kmap_ops[0]), GFP_KERNEL); | |
136 | add->pages = kcalloc(count, sizeof(add->pages[0]), GFP_KERNEL); | |
a12b4eb3 SS |
137 | if (NULL == add->grants || |
138 | NULL == add->map_ops || | |
139 | NULL == add->unmap_ops || | |
0930bba6 | 140 | NULL == add->kmap_ops || |
a12b4eb3 | 141 | NULL == add->pages) |
ab31523c GH |
142 | goto err; |
143 | ||
693394b8 | 144 | if (alloc_xenballooned_pages(count, add->pages, false /* lowmem */)) |
ca47ceaa DDG |
145 | goto err; |
146 | ||
a12b4eb3 | 147 | for (i = 0; i < count; i++) { |
77c35acb DDG |
148 | add->map_ops[i].handle = -1; |
149 | add->unmap_ops[i].handle = -1; | |
0930bba6 | 150 | add->kmap_ops[i].handle = -1; |
a12b4eb3 SS |
151 | } |
152 | ||
ab31523c GH |
153 | add->index = 0; |
154 | add->count = count; | |
68b025c8 | 155 | atomic_set(&add->users, 1); |
ab31523c | 156 | |
ab31523c GH |
157 | return add; |
158 | ||
159 | err: | |
a67baeb7 | 160 | gntdev_free_map(add); |
ab31523c GH |
161 | return NULL; |
162 | } | |
163 | ||
164 | static void gntdev_add_map(struct gntdev_priv *priv, struct grant_map *add) | |
165 | { | |
166 | struct grant_map *map; | |
167 | ||
168 | list_for_each_entry(map, &priv->maps, next) { | |
169 | if (add->index + add->count < map->index) { | |
170 | list_add_tail(&add->next, &map->next); | |
171 | goto done; | |
172 | } | |
173 | add->index = map->index + map->count; | |
174 | } | |
175 | list_add_tail(&add->next, &priv->maps); | |
176 | ||
177 | done: | |
ab31523c GH |
178 | gntdev_print_maps(priv, "[new]", add->index); |
179 | } | |
180 | ||
181 | static struct grant_map *gntdev_find_map_index(struct gntdev_priv *priv, | |
182 | int index, int count) | |
183 | { | |
184 | struct grant_map *map; | |
185 | ||
186 | list_for_each_entry(map, &priv->maps, next) { | |
187 | if (map->index != index) | |
188 | continue; | |
bdc612dc | 189 | if (count && map->count != count) |
ab31523c GH |
190 | continue; |
191 | return map; | |
192 | } | |
193 | return NULL; | |
194 | } | |
195 | ||
68b025c8 | 196 | static void gntdev_put_map(struct grant_map *map) |
ab31523c GH |
197 | { |
198 | if (!map) | |
199 | return; | |
a12b4eb3 | 200 | |
68b025c8 DDG |
201 | if (!atomic_dec_and_test(&map->users)) |
202 | return; | |
203 | ||
204 | atomic_sub(map->count, &pages_mapped); | |
205 | ||
0cc678f8 | 206 | if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) { |
bdc612dc | 207 | notify_remote_via_evtchn(map->notify.event); |
0cc678f8 DDG |
208 | evtchn_put(map->notify.event); |
209 | } | |
bdc612dc | 210 | |
a67baeb7 DV |
211 | if (map->pages && !use_ptemod) |
212 | unmap_grant_pages(map, 0, map->count); | |
213 | gntdev_free_map(map); | |
ab31523c GH |
214 | } |
215 | ||
216 | /* ------------------------------------------------------------------ */ | |
217 | ||
218 | static int find_grant_ptes(pte_t *pte, pgtable_t token, | |
219 | unsigned long addr, void *data) | |
220 | { | |
221 | struct grant_map *map = data; | |
222 | unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT; | |
aab8f11a | 223 | int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte; |
ab31523c GH |
224 | u64 pte_maddr; |
225 | ||
226 | BUG_ON(pgnr >= map->count); | |
ba5d1012 JF |
227 | pte_maddr = arbitrary_virt_to_machine(pte).maddr; |
228 | ||
aab8f11a | 229 | gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, flags, |
ab31523c GH |
230 | map->grants[pgnr].ref, |
231 | map->grants[pgnr].domid); | |
aab8f11a | 232 | gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags, |
77c35acb | 233 | -1 /* handle */); |
ab31523c GH |
234 | return 0; |
235 | } | |
236 | ||
237 | static int map_grant_pages(struct grant_map *map) | |
238 | { | |
239 | int i, err = 0; | |
aab8f11a DDG |
240 | |
241 | if (!use_ptemod) { | |
12996fc3 | 242 | /* Note: it could already be mapped */ |
77c35acb | 243 | if (map->map_ops[0].handle != -1) |
12996fc3 | 244 | return 0; |
aab8f11a | 245 | for (i = 0; i < map->count; i++) { |
38eaeb0f | 246 | unsigned long addr = (unsigned long) |
aab8f11a DDG |
247 | pfn_to_kaddr(page_to_pfn(map->pages[i])); |
248 | gnttab_set_map_op(&map->map_ops[i], addr, map->flags, | |
249 | map->grants[i].ref, | |
250 | map->grants[i].domid); | |
251 | gnttab_set_unmap_op(&map->unmap_ops[i], addr, | |
77c35acb | 252 | map->flags, -1 /* handle */); |
aab8f11a | 253 | } |
0930bba6 SS |
254 | } else { |
255 | /* | |
256 | * Setup the map_ops corresponding to the pte entries pointing | |
257 | * to the kernel linear addresses of the struct pages. | |
258 | * These ptes are completely different from the user ptes dealt | |
259 | * with find_grant_ptes. | |
260 | */ | |
261 | for (i = 0; i < map->count; i++) { | |
262 | unsigned level; | |
263 | unsigned long address = (unsigned long) | |
264 | pfn_to_kaddr(page_to_pfn(map->pages[i])); | |
265 | pte_t *ptep; | |
266 | u64 pte_maddr = 0; | |
267 | BUG_ON(PageHighMem(map->pages[i])); | |
268 | ||
269 | ptep = lookup_address(address, &level); | |
270 | pte_maddr = arbitrary_virt_to_machine(ptep).maddr; | |
271 | gnttab_set_map_op(&map->kmap_ops[i], pte_maddr, | |
272 | map->flags | | |
273 | GNTMAP_host_map | | |
274 | GNTMAP_contains_pte, | |
275 | map->grants[i].ref, | |
276 | map->grants[i].domid); | |
277 | } | |
aab8f11a | 278 | } |
ab31523c GH |
279 | |
280 | pr_debug("map %d+%d\n", map->index, map->count); | |
0930bba6 SS |
281 | err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL, |
282 | map->pages, map->count); | |
ab31523c GH |
283 | if (err) |
284 | return err; | |
285 | ||
286 | for (i = 0; i < map->count; i++) { | |
287 | if (map->map_ops[i].status) | |
288 | err = -EINVAL; | |
77c35acb DDG |
289 | else { |
290 | BUG_ON(map->map_ops[i].handle == -1); | |
291 | map->unmap_ops[i].handle = map->map_ops[i].handle; | |
292 | pr_debug("map handle=%d\n", map->map_ops[i].handle); | |
293 | } | |
ab31523c GH |
294 | } |
295 | return err; | |
296 | } | |
297 | ||
b57c1869 | 298 | static int __unmap_grant_pages(struct grant_map *map, int offset, int pages) |
ab31523c GH |
299 | { |
300 | int i, err = 0; | |
301 | ||
bdc612dc DDG |
302 | if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) { |
303 | int pgno = (map->notify.addr >> PAGE_SHIFT); | |
0ea22f07 | 304 | if (pgno >= offset && pgno < offset + pages && use_ptemod) { |
f4ee4af4 DDG |
305 | void __user *tmp = (void __user *) |
306 | map->vma->vm_start + map->notify.addr; | |
9960be97 DDG |
307 | err = copy_to_user(tmp, &err, 1); |
308 | if (err) | |
12f0258d | 309 | return -EFAULT; |
0ea22f07 DDG |
310 | map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE; |
311 | } else if (pgno >= offset && pgno < offset + pages) { | |
bdc612dc DDG |
312 | uint8_t *tmp = kmap(map->pages[pgno]); |
313 | tmp[map->notify.addr & (PAGE_SIZE-1)] = 0; | |
314 | kunmap(map->pages[pgno]); | |
315 | map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE; | |
316 | } | |
317 | } | |
318 | ||
2fc136ee SS |
319 | err = gnttab_unmap_refs(map->unmap_ops + offset, |
320 | use_ptemod ? map->kmap_ops + offset : NULL, map->pages + offset, | |
321 | pages); | |
ab31523c GH |
322 | if (err) |
323 | return err; | |
324 | ||
325 | for (i = 0; i < pages; i++) { | |
326 | if (map->unmap_ops[offset+i].status) | |
327 | err = -EINVAL; | |
77c35acb DDG |
328 | pr_debug("unmap handle=%d st=%d\n", |
329 | map->unmap_ops[offset+i].handle, | |
330 | map->unmap_ops[offset+i].status); | |
331 | map->unmap_ops[offset+i].handle = -1; | |
ab31523c GH |
332 | } |
333 | return err; | |
334 | } | |
335 | ||
b57c1869 DDG |
336 | static int unmap_grant_pages(struct grant_map *map, int offset, int pages) |
337 | { | |
338 | int range, err = 0; | |
339 | ||
340 | pr_debug("unmap %d+%d [%d+%d]\n", map->index, map->count, offset, pages); | |
341 | ||
342 | /* It is possible the requested range will have a "hole" where we | |
343 | * already unmapped some of the grants. Only unmap valid ranges. | |
344 | */ | |
345 | while (pages && !err) { | |
77c35acb | 346 | while (pages && map->unmap_ops[offset].handle == -1) { |
b57c1869 DDG |
347 | offset++; |
348 | pages--; | |
349 | } | |
350 | range = 0; | |
351 | while (range < pages) { | |
77c35acb | 352 | if (map->unmap_ops[offset+range].handle == -1) { |
b57c1869 DDG |
353 | range--; |
354 | break; | |
355 | } | |
356 | range++; | |
357 | } | |
358 | err = __unmap_grant_pages(map, offset, range); | |
359 | offset += range; | |
360 | pages -= range; | |
361 | } | |
362 | ||
363 | return err; | |
364 | } | |
365 | ||
ab31523c GH |
366 | /* ------------------------------------------------------------------ */ |
367 | ||
d79647ae DDG |
368 | static void gntdev_vma_open(struct vm_area_struct *vma) |
369 | { | |
370 | struct grant_map *map = vma->vm_private_data; | |
371 | ||
372 | pr_debug("gntdev_vma_open %p\n", vma); | |
373 | atomic_inc(&map->users); | |
374 | } | |
375 | ||
ab31523c GH |
376 | static void gntdev_vma_close(struct vm_area_struct *vma) |
377 | { | |
378 | struct grant_map *map = vma->vm_private_data; | |
379 | ||
d79647ae | 380 | pr_debug("gntdev_vma_close %p\n", vma); |
ab31523c GH |
381 | map->vma = NULL; |
382 | vma->vm_private_data = NULL; | |
68b025c8 | 383 | gntdev_put_map(map); |
ab31523c GH |
384 | } |
385 | ||
ab31523c | 386 | static struct vm_operations_struct gntdev_vmops = { |
d79647ae | 387 | .open = gntdev_vma_open, |
ab31523c | 388 | .close = gntdev_vma_close, |
ab31523c GH |
389 | }; |
390 | ||
391 | /* ------------------------------------------------------------------ */ | |
392 | ||
393 | static void mn_invl_range_start(struct mmu_notifier *mn, | |
394 | struct mm_struct *mm, | |
395 | unsigned long start, unsigned long end) | |
396 | { | |
397 | struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); | |
398 | struct grant_map *map; | |
399 | unsigned long mstart, mend; | |
400 | int err; | |
401 | ||
402 | spin_lock(&priv->lock); | |
403 | list_for_each_entry(map, &priv->maps, next) { | |
404 | if (!map->vma) | |
405 | continue; | |
ab31523c GH |
406 | if (map->vma->vm_start >= end) |
407 | continue; | |
408 | if (map->vma->vm_end <= start) | |
409 | continue; | |
410 | mstart = max(start, map->vma->vm_start); | |
411 | mend = min(end, map->vma->vm_end); | |
412 | pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n", | |
413 | map->index, map->count, | |
414 | map->vma->vm_start, map->vma->vm_end, | |
415 | start, end, mstart, mend); | |
416 | err = unmap_grant_pages(map, | |
417 | (mstart - map->vma->vm_start) >> PAGE_SHIFT, | |
418 | (mend - mstart) >> PAGE_SHIFT); | |
419 | WARN_ON(err); | |
420 | } | |
421 | spin_unlock(&priv->lock); | |
422 | } | |
423 | ||
424 | static void mn_invl_page(struct mmu_notifier *mn, | |
425 | struct mm_struct *mm, | |
426 | unsigned long address) | |
427 | { | |
428 | mn_invl_range_start(mn, mm, address, address + PAGE_SIZE); | |
429 | } | |
430 | ||
431 | static void mn_release(struct mmu_notifier *mn, | |
432 | struct mm_struct *mm) | |
433 | { | |
434 | struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); | |
435 | struct grant_map *map; | |
436 | int err; | |
437 | ||
438 | spin_lock(&priv->lock); | |
439 | list_for_each_entry(map, &priv->maps, next) { | |
440 | if (!map->vma) | |
441 | continue; | |
442 | pr_debug("map %d+%d (%lx %lx)\n", | |
443 | map->index, map->count, | |
444 | map->vma->vm_start, map->vma->vm_end); | |
445 | err = unmap_grant_pages(map, /* offset */ 0, map->count); | |
446 | WARN_ON(err); | |
447 | } | |
448 | spin_unlock(&priv->lock); | |
449 | } | |
450 | ||
b8b0f559 | 451 | static struct mmu_notifier_ops gntdev_mmu_ops = { |
ab31523c GH |
452 | .release = mn_release, |
453 | .invalidate_page = mn_invl_page, | |
454 | .invalidate_range_start = mn_invl_range_start, | |
455 | }; | |
456 | ||
457 | /* ------------------------------------------------------------------ */ | |
458 | ||
459 | static int gntdev_open(struct inode *inode, struct file *flip) | |
460 | { | |
461 | struct gntdev_priv *priv; | |
462 | int ret = 0; | |
463 | ||
464 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); | |
465 | if (!priv) | |
466 | return -ENOMEM; | |
467 | ||
468 | INIT_LIST_HEAD(&priv->maps); | |
469 | spin_lock_init(&priv->lock); | |
ab31523c | 470 | |
aab8f11a DDG |
471 | if (use_ptemod) { |
472 | priv->mm = get_task_mm(current); | |
473 | if (!priv->mm) { | |
474 | kfree(priv); | |
475 | return -ENOMEM; | |
476 | } | |
477 | priv->mn.ops = &gntdev_mmu_ops; | |
478 | ret = mmu_notifier_register(&priv->mn, priv->mm); | |
479 | mmput(priv->mm); | |
ab31523c | 480 | } |
ab31523c GH |
481 | |
482 | if (ret) { | |
483 | kfree(priv); | |
484 | return ret; | |
485 | } | |
486 | ||
487 | flip->private_data = priv; | |
488 | pr_debug("priv %p\n", priv); | |
489 | ||
490 | return 0; | |
491 | } | |
492 | ||
493 | static int gntdev_release(struct inode *inode, struct file *flip) | |
494 | { | |
495 | struct gntdev_priv *priv = flip->private_data; | |
496 | struct grant_map *map; | |
ab31523c GH |
497 | |
498 | pr_debug("priv %p\n", priv); | |
499 | ||
ab31523c GH |
500 | while (!list_empty(&priv->maps)) { |
501 | map = list_entry(priv->maps.next, struct grant_map, next); | |
68b025c8 DDG |
502 | list_del(&map->next); |
503 | gntdev_put_map(map); | |
ab31523c | 504 | } |
ab31523c | 505 | |
aab8f11a DDG |
506 | if (use_ptemod) |
507 | mmu_notifier_unregister(&priv->mn, priv->mm); | |
ab31523c GH |
508 | kfree(priv); |
509 | return 0; | |
510 | } | |
511 | ||
512 | static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv, | |
513 | struct ioctl_gntdev_map_grant_ref __user *u) | |
514 | { | |
515 | struct ioctl_gntdev_map_grant_ref op; | |
516 | struct grant_map *map; | |
517 | int err; | |
518 | ||
519 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
520 | return -EFAULT; | |
521 | pr_debug("priv %p, add %d\n", priv, op.count); | |
522 | if (unlikely(op.count <= 0)) | |
523 | return -EINVAL; | |
ab31523c GH |
524 | |
525 | err = -ENOMEM; | |
526 | map = gntdev_alloc_map(priv, op.count); | |
527 | if (!map) | |
528 | return err; | |
ef91082e | 529 | |
68b025c8 DDG |
530 | if (unlikely(atomic_add_return(op.count, &pages_mapped) > limit)) { |
531 | pr_debug("can't map: over limit\n"); | |
532 | gntdev_put_map(map); | |
ab31523c GH |
533 | return err; |
534 | } | |
535 | ||
68b025c8 DDG |
536 | if (copy_from_user(map->grants, &u->refs, |
537 | sizeof(map->grants[0]) * op.count) != 0) { | |
538 | gntdev_put_map(map); | |
ef91082e DDG |
539 | return err; |
540 | } | |
541 | ||
ab31523c GH |
542 | spin_lock(&priv->lock); |
543 | gntdev_add_map(priv, map); | |
544 | op.index = map->index << PAGE_SHIFT; | |
545 | spin_unlock(&priv->lock); | |
546 | ||
68b025c8 DDG |
547 | if (copy_to_user(u, &op, sizeof(op)) != 0) |
548 | return -EFAULT; | |
549 | ||
ab31523c GH |
550 | return 0; |
551 | } | |
552 | ||
553 | static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv, | |
554 | struct ioctl_gntdev_unmap_grant_ref __user *u) | |
555 | { | |
556 | struct ioctl_gntdev_unmap_grant_ref op; | |
557 | struct grant_map *map; | |
558 | int err = -ENOENT; | |
559 | ||
560 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
561 | return -EFAULT; | |
562 | pr_debug("priv %p, del %d+%d\n", priv, (int)op.index, (int)op.count); | |
563 | ||
564 | spin_lock(&priv->lock); | |
565 | map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count); | |
68b025c8 DDG |
566 | if (map) { |
567 | list_del(&map->next); | |
68b025c8 DDG |
568 | err = 0; |
569 | } | |
ab31523c | 570 | spin_unlock(&priv->lock); |
1f1503ba DDG |
571 | if (map) |
572 | gntdev_put_map(map); | |
ab31523c GH |
573 | return err; |
574 | } | |
575 | ||
576 | static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv, | |
577 | struct ioctl_gntdev_get_offset_for_vaddr __user *u) | |
578 | { | |
579 | struct ioctl_gntdev_get_offset_for_vaddr op; | |
a879211b | 580 | struct vm_area_struct *vma; |
ab31523c GH |
581 | struct grant_map *map; |
582 | ||
583 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
584 | return -EFAULT; | |
585 | pr_debug("priv %p, offset for vaddr %lx\n", priv, (unsigned long)op.vaddr); | |
586 | ||
a879211b DDG |
587 | vma = find_vma(current->mm, op.vaddr); |
588 | if (!vma || vma->vm_ops != &gntdev_vmops) | |
ab31523c | 589 | return -EINVAL; |
a879211b DDG |
590 | |
591 | map = vma->vm_private_data; | |
592 | if (!map) | |
593 | return -EINVAL; | |
594 | ||
ab31523c GH |
595 | op.offset = map->index << PAGE_SHIFT; |
596 | op.count = map->count; | |
ab31523c GH |
597 | |
598 | if (copy_to_user(u, &op, sizeof(op)) != 0) | |
599 | return -EFAULT; | |
600 | return 0; | |
601 | } | |
602 | ||
bdc612dc DDG |
603 | static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u) |
604 | { | |
605 | struct ioctl_gntdev_unmap_notify op; | |
606 | struct grant_map *map; | |
607 | int rc; | |
0cc678f8 DDG |
608 | int out_flags; |
609 | unsigned int out_event; | |
bdc612dc DDG |
610 | |
611 | if (copy_from_user(&op, u, sizeof(op))) | |
612 | return -EFAULT; | |
613 | ||
614 | if (op.action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT)) | |
615 | return -EINVAL; | |
616 | ||
0cc678f8 DDG |
617 | /* We need to grab a reference to the event channel we are going to use |
618 | * to send the notify before releasing the reference we may already have | |
619 | * (if someone has called this ioctl twice). This is required so that | |
620 | * it is possible to change the clear_byte part of the notification | |
621 | * without disturbing the event channel part, which may now be the last | |
622 | * reference to that event channel. | |
623 | */ | |
624 | if (op.action & UNMAP_NOTIFY_SEND_EVENT) { | |
625 | if (evtchn_get(op.event_channel_port)) | |
626 | return -EINVAL; | |
627 | } | |
628 | ||
629 | out_flags = op.action; | |
630 | out_event = op.event_channel_port; | |
631 | ||
bdc612dc DDG |
632 | spin_lock(&priv->lock); |
633 | ||
634 | list_for_each_entry(map, &priv->maps, next) { | |
635 | uint64_t begin = map->index << PAGE_SHIFT; | |
636 | uint64_t end = (map->index + map->count) << PAGE_SHIFT; | |
637 | if (op.index >= begin && op.index < end) | |
638 | goto found; | |
639 | } | |
640 | rc = -ENOENT; | |
641 | goto unlock_out; | |
642 | ||
643 | found: | |
9960be97 DDG |
644 | if ((op.action & UNMAP_NOTIFY_CLEAR_BYTE) && |
645 | (map->flags & GNTMAP_readonly)) { | |
646 | rc = -EINVAL; | |
647 | goto unlock_out; | |
648 | } | |
649 | ||
0cc678f8 DDG |
650 | out_flags = map->notify.flags; |
651 | out_event = map->notify.event; | |
652 | ||
bdc612dc DDG |
653 | map->notify.flags = op.action; |
654 | map->notify.addr = op.index - (map->index << PAGE_SHIFT); | |
655 | map->notify.event = op.event_channel_port; | |
0cc678f8 | 656 | |
bdc612dc | 657 | rc = 0; |
0cc678f8 | 658 | |
bdc612dc DDG |
659 | unlock_out: |
660 | spin_unlock(&priv->lock); | |
0cc678f8 DDG |
661 | |
662 | /* Drop the reference to the event channel we did not save in the map */ | |
663 | if (out_flags & UNMAP_NOTIFY_SEND_EVENT) | |
664 | evtchn_put(out_event); | |
665 | ||
bdc612dc DDG |
666 | return rc; |
667 | } | |
668 | ||
ab31523c GH |
669 | static long gntdev_ioctl(struct file *flip, |
670 | unsigned int cmd, unsigned long arg) | |
671 | { | |
672 | struct gntdev_priv *priv = flip->private_data; | |
673 | void __user *ptr = (void __user *)arg; | |
674 | ||
675 | switch (cmd) { | |
676 | case IOCTL_GNTDEV_MAP_GRANT_REF: | |
677 | return gntdev_ioctl_map_grant_ref(priv, ptr); | |
678 | ||
679 | case IOCTL_GNTDEV_UNMAP_GRANT_REF: | |
680 | return gntdev_ioctl_unmap_grant_ref(priv, ptr); | |
681 | ||
682 | case IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR: | |
683 | return gntdev_ioctl_get_offset_for_vaddr(priv, ptr); | |
684 | ||
bdc612dc DDG |
685 | case IOCTL_GNTDEV_SET_UNMAP_NOTIFY: |
686 | return gntdev_ioctl_notify(priv, ptr); | |
687 | ||
ab31523c GH |
688 | default: |
689 | pr_debug("priv %p, unknown cmd %x\n", priv, cmd); | |
690 | return -ENOIOCTLCMD; | |
691 | } | |
692 | ||
693 | return 0; | |
694 | } | |
695 | ||
696 | static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) | |
697 | { | |
698 | struct gntdev_priv *priv = flip->private_data; | |
699 | int index = vma->vm_pgoff; | |
700 | int count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; | |
701 | struct grant_map *map; | |
aab8f11a | 702 | int i, err = -EINVAL; |
ab31523c GH |
703 | |
704 | if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED)) | |
705 | return -EINVAL; | |
706 | ||
707 | pr_debug("map %d+%d at %lx (pgoff %lx)\n", | |
708 | index, count, vma->vm_start, vma->vm_pgoff); | |
709 | ||
710 | spin_lock(&priv->lock); | |
711 | map = gntdev_find_map_index(priv, index, count); | |
712 | if (!map) | |
713 | goto unlock_out; | |
aab8f11a | 714 | if (use_ptemod && map->vma) |
ab31523c | 715 | goto unlock_out; |
aab8f11a | 716 | if (use_ptemod && priv->mm != vma->vm_mm) { |
ab31523c GH |
717 | printk(KERN_WARNING "Huh? Other mm?\n"); |
718 | goto unlock_out; | |
719 | } | |
720 | ||
68b025c8 DDG |
721 | atomic_inc(&map->users); |
722 | ||
ab31523c GH |
723 | vma->vm_ops = &gntdev_vmops; |
724 | ||
314e51b9 | 725 | vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; |
d79647ae DDG |
726 | |
727 | if (use_ptemod) | |
e8e937be | 728 | vma->vm_flags |= VM_DONTCOPY; |
ab31523c GH |
729 | |
730 | vma->vm_private_data = map; | |
ab31523c | 731 | |
aab8f11a DDG |
732 | if (use_ptemod) |
733 | map->vma = vma; | |
734 | ||
12996fc3 DDG |
735 | if (map->flags) { |
736 | if ((vma->vm_flags & VM_WRITE) && | |
737 | (map->flags & GNTMAP_readonly)) | |
a93e20a8 | 738 | goto out_unlock_put; |
12996fc3 DDG |
739 | } else { |
740 | map->flags = GNTMAP_host_map; | |
741 | if (!(vma->vm_flags & VM_WRITE)) | |
742 | map->flags |= GNTMAP_readonly; | |
743 | } | |
ab31523c | 744 | |
f0a70c88 DDG |
745 | spin_unlock(&priv->lock); |
746 | ||
aab8f11a DDG |
747 | if (use_ptemod) { |
748 | err = apply_to_page_range(vma->vm_mm, vma->vm_start, | |
749 | vma->vm_end - vma->vm_start, | |
750 | find_grant_ptes, map); | |
751 | if (err) { | |
752 | printk(KERN_WARNING "find_grant_ptes() failure.\n"); | |
90b6f305 | 753 | goto out_put_map; |
aab8f11a | 754 | } |
ab31523c GH |
755 | } |
756 | ||
757 | err = map_grant_pages(map); | |
90b6f305 DDG |
758 | if (err) |
759 | goto out_put_map; | |
f0a70c88 | 760 | |
aab8f11a DDG |
761 | if (!use_ptemod) { |
762 | for (i = 0; i < count; i++) { | |
763 | err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE, | |
764 | map->pages[i]); | |
765 | if (err) | |
90b6f305 | 766 | goto out_put_map; |
aab8f11a DDG |
767 | } |
768 | } | |
769 | ||
f0a70c88 DDG |
770 | return 0; |
771 | ||
ab31523c GH |
772 | unlock_out: |
773 | spin_unlock(&priv->lock); | |
774 | return err; | |
90b6f305 | 775 | |
a93e20a8 DC |
776 | out_unlock_put: |
777 | spin_unlock(&priv->lock); | |
90b6f305 | 778 | out_put_map: |
84e4075d DDG |
779 | if (use_ptemod) |
780 | map->vma = NULL; | |
90b6f305 DDG |
781 | gntdev_put_map(map); |
782 | return err; | |
ab31523c GH |
783 | } |
784 | ||
785 | static const struct file_operations gntdev_fops = { | |
786 | .owner = THIS_MODULE, | |
787 | .open = gntdev_open, | |
788 | .release = gntdev_release, | |
789 | .mmap = gntdev_mmap, | |
790 | .unlocked_ioctl = gntdev_ioctl | |
791 | }; | |
792 | ||
793 | static struct miscdevice gntdev_miscdev = { | |
794 | .minor = MISC_DYNAMIC_MINOR, | |
795 | .name = "xen/gntdev", | |
796 | .fops = &gntdev_fops, | |
797 | }; | |
798 | ||
799 | /* ------------------------------------------------------------------ */ | |
800 | ||
801 | static int __init gntdev_init(void) | |
802 | { | |
803 | int err; | |
804 | ||
805 | if (!xen_domain()) | |
806 | return -ENODEV; | |
807 | ||
aab8f11a DDG |
808 | use_ptemod = xen_pv_domain(); |
809 | ||
ab31523c GH |
810 | err = misc_register(&gntdev_miscdev); |
811 | if (err != 0) { | |
812 | printk(KERN_ERR "Could not register gntdev device\n"); | |
813 | return err; | |
814 | } | |
815 | return 0; | |
816 | } | |
817 | ||
818 | static void __exit gntdev_exit(void) | |
819 | { | |
820 | misc_deregister(&gntdev_miscdev); | |
821 | } | |
822 | ||
823 | module_init(gntdev_init); | |
824 | module_exit(gntdev_exit); | |
825 | ||
826 | /* ------------------------------------------------------------------ */ |