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