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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 | 58 | static int use_ptemod; |
16a1d022 | 59 | #define populate_freeable_maps use_ptemod |
aab8f11a | 60 | |
ab31523c | 61 | struct gntdev_priv { |
16a1d022 | 62 | /* maps with visible offsets in the file descriptor */ |
ab31523c | 63 | struct list_head maps; |
16a1d022 DDG |
64 | /* maps that are not visible; will be freed on munmap. |
65 | * Only populated if populate_freeable_maps == 1 */ | |
66 | struct list_head freeable_maps; | |
67 | /* lock protects maps and freeable_maps */ | |
32123973 | 68 | struct mutex lock; |
ab31523c GH |
69 | struct mm_struct *mm; |
70 | struct mmu_notifier mn; | |
71 | }; | |
72 | ||
bdc612dc DDG |
73 | struct unmap_notify { |
74 | int flags; | |
75 | /* Address relative to the start of the grant_map */ | |
76 | int addr; | |
77 | int event; | |
78 | }; | |
79 | ||
ab31523c GH |
80 | struct grant_map { |
81 | struct list_head next; | |
ab31523c GH |
82 | struct vm_area_struct *vma; |
83 | int index; | |
84 | int count; | |
85 | int flags; | |
68b025c8 | 86 | atomic_t users; |
bdc612dc | 87 | struct unmap_notify notify; |
ab31523c GH |
88 | struct ioctl_gntdev_grant_ref *grants; |
89 | struct gnttab_map_grant_ref *map_ops; | |
90 | struct gnttab_unmap_grant_ref *unmap_ops; | |
0930bba6 | 91 | struct gnttab_map_grant_ref *kmap_ops; |
a12b4eb3 | 92 | struct page **pages; |
ab31523c GH |
93 | }; |
94 | ||
aab8f11a DDG |
95 | static int unmap_grant_pages(struct grant_map *map, int offset, int pages); |
96 | ||
ab31523c GH |
97 | /* ------------------------------------------------------------------ */ |
98 | ||
99 | static void gntdev_print_maps(struct gntdev_priv *priv, | |
100 | char *text, int text_index) | |
101 | { | |
102 | #ifdef DEBUG | |
103 | struct grant_map *map; | |
104 | ||
ef91082e | 105 | pr_debug("%s: maps list (priv %p)\n", __func__, priv); |
ab31523c GH |
106 | list_for_each_entry(map, &priv->maps, next) |
107 | pr_debug(" index %2d, count %2d %s\n", | |
108 | map->index, map->count, | |
109 | map->index == text_index && text ? text : ""); | |
110 | #endif | |
111 | } | |
112 | ||
a67baeb7 DV |
113 | static void gntdev_free_map(struct grant_map *map) |
114 | { | |
115 | if (map == NULL) | |
116 | return; | |
117 | ||
118 | if (map->pages) | |
119 | free_xenballooned_pages(map->count, map->pages); | |
120 | kfree(map->pages); | |
121 | kfree(map->grants); | |
122 | kfree(map->map_ops); | |
123 | kfree(map->unmap_ops); | |
124 | kfree(map->kmap_ops); | |
125 | kfree(map); | |
126 | } | |
127 | ||
ab31523c GH |
128 | static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count) |
129 | { | |
130 | struct grant_map *add; | |
a12b4eb3 | 131 | int i; |
ab31523c GH |
132 | |
133 | add = kzalloc(sizeof(struct grant_map), GFP_KERNEL); | |
134 | if (NULL == add) | |
135 | return NULL; | |
136 | ||
fc6e0c3b DC |
137 | add->grants = kcalloc(count, sizeof(add->grants[0]), GFP_KERNEL); |
138 | add->map_ops = kcalloc(count, sizeof(add->map_ops[0]), GFP_KERNEL); | |
139 | add->unmap_ops = kcalloc(count, sizeof(add->unmap_ops[0]), GFP_KERNEL); | |
140 | add->kmap_ops = kcalloc(count, sizeof(add->kmap_ops[0]), GFP_KERNEL); | |
141 | add->pages = kcalloc(count, sizeof(add->pages[0]), GFP_KERNEL); | |
a12b4eb3 SS |
142 | if (NULL == add->grants || |
143 | NULL == add->map_ops || | |
144 | NULL == add->unmap_ops || | |
0930bba6 | 145 | NULL == add->kmap_ops || |
a12b4eb3 | 146 | NULL == add->pages) |
ab31523c GH |
147 | goto err; |
148 | ||
693394b8 | 149 | if (alloc_xenballooned_pages(count, add->pages, false /* lowmem */)) |
ca47ceaa DDG |
150 | goto err; |
151 | ||
a12b4eb3 | 152 | for (i = 0; i < count; i++) { |
77c35acb DDG |
153 | add->map_ops[i].handle = -1; |
154 | add->unmap_ops[i].handle = -1; | |
0930bba6 | 155 | add->kmap_ops[i].handle = -1; |
a12b4eb3 SS |
156 | } |
157 | ||
ab31523c GH |
158 | add->index = 0; |
159 | add->count = count; | |
68b025c8 | 160 | atomic_set(&add->users, 1); |
ab31523c | 161 | |
ab31523c GH |
162 | return add; |
163 | ||
164 | err: | |
a67baeb7 | 165 | gntdev_free_map(add); |
ab31523c GH |
166 | return NULL; |
167 | } | |
168 | ||
169 | static void gntdev_add_map(struct gntdev_priv *priv, struct grant_map *add) | |
170 | { | |
171 | struct grant_map *map; | |
172 | ||
173 | list_for_each_entry(map, &priv->maps, next) { | |
174 | if (add->index + add->count < map->index) { | |
175 | list_add_tail(&add->next, &map->next); | |
176 | goto done; | |
177 | } | |
178 | add->index = map->index + map->count; | |
179 | } | |
180 | list_add_tail(&add->next, &priv->maps); | |
181 | ||
182 | done: | |
ab31523c GH |
183 | gntdev_print_maps(priv, "[new]", add->index); |
184 | } | |
185 | ||
186 | static struct grant_map *gntdev_find_map_index(struct gntdev_priv *priv, | |
187 | int index, int count) | |
188 | { | |
189 | struct grant_map *map; | |
190 | ||
191 | list_for_each_entry(map, &priv->maps, next) { | |
192 | if (map->index != index) | |
193 | continue; | |
bdc612dc | 194 | if (count && map->count != count) |
ab31523c GH |
195 | continue; |
196 | return map; | |
197 | } | |
198 | return NULL; | |
199 | } | |
200 | ||
16a1d022 | 201 | static void gntdev_put_map(struct gntdev_priv *priv, struct grant_map *map) |
ab31523c GH |
202 | { |
203 | if (!map) | |
204 | return; | |
a12b4eb3 | 205 | |
68b025c8 DDG |
206 | if (!atomic_dec_and_test(&map->users)) |
207 | return; | |
208 | ||
209 | atomic_sub(map->count, &pages_mapped); | |
210 | ||
0cc678f8 | 211 | if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) { |
bdc612dc | 212 | notify_remote_via_evtchn(map->notify.event); |
0cc678f8 DDG |
213 | evtchn_put(map->notify.event); |
214 | } | |
bdc612dc | 215 | |
16a1d022 | 216 | if (populate_freeable_maps && priv) { |
32123973 | 217 | mutex_lock(&priv->lock); |
16a1d022 | 218 | list_del(&map->next); |
32123973 | 219 | mutex_unlock(&priv->lock); |
16a1d022 DDG |
220 | } |
221 | ||
a67baeb7 DV |
222 | if (map->pages && !use_ptemod) |
223 | unmap_grant_pages(map, 0, map->count); | |
224 | gntdev_free_map(map); | |
ab31523c GH |
225 | } |
226 | ||
227 | /* ------------------------------------------------------------------ */ | |
228 | ||
229 | static int find_grant_ptes(pte_t *pte, pgtable_t token, | |
230 | unsigned long addr, void *data) | |
231 | { | |
232 | struct grant_map *map = data; | |
233 | unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT; | |
aab8f11a | 234 | int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte; |
ab31523c GH |
235 | u64 pte_maddr; |
236 | ||
237 | BUG_ON(pgnr >= map->count); | |
ba5d1012 JF |
238 | pte_maddr = arbitrary_virt_to_machine(pte).maddr; |
239 | ||
aab8f11a | 240 | gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, flags, |
ab31523c GH |
241 | map->grants[pgnr].ref, |
242 | map->grants[pgnr].domid); | |
aab8f11a | 243 | gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags, |
77c35acb | 244 | -1 /* handle */); |
ab31523c GH |
245 | return 0; |
246 | } | |
247 | ||
248 | static int map_grant_pages(struct grant_map *map) | |
249 | { | |
250 | int i, err = 0; | |
aab8f11a DDG |
251 | |
252 | if (!use_ptemod) { | |
12996fc3 | 253 | /* Note: it could already be mapped */ |
77c35acb | 254 | if (map->map_ops[0].handle != -1) |
12996fc3 | 255 | return 0; |
aab8f11a | 256 | for (i = 0; i < map->count; i++) { |
38eaeb0f | 257 | unsigned long addr = (unsigned long) |
aab8f11a DDG |
258 | pfn_to_kaddr(page_to_pfn(map->pages[i])); |
259 | gnttab_set_map_op(&map->map_ops[i], addr, map->flags, | |
260 | map->grants[i].ref, | |
261 | map->grants[i].domid); | |
262 | gnttab_set_unmap_op(&map->unmap_ops[i], addr, | |
77c35acb | 263 | map->flags, -1 /* handle */); |
aab8f11a | 264 | } |
0930bba6 SS |
265 | } else { |
266 | /* | |
267 | * Setup the map_ops corresponding to the pte entries pointing | |
268 | * to the kernel linear addresses of the struct pages. | |
269 | * These ptes are completely different from the user ptes dealt | |
270 | * with find_grant_ptes. | |
271 | */ | |
272 | for (i = 0; i < map->count; i++) { | |
273 | unsigned level; | |
274 | unsigned long address = (unsigned long) | |
275 | pfn_to_kaddr(page_to_pfn(map->pages[i])); | |
276 | pte_t *ptep; | |
277 | u64 pte_maddr = 0; | |
278 | BUG_ON(PageHighMem(map->pages[i])); | |
279 | ||
280 | ptep = lookup_address(address, &level); | |
281 | pte_maddr = arbitrary_virt_to_machine(ptep).maddr; | |
282 | gnttab_set_map_op(&map->kmap_ops[i], pte_maddr, | |
283 | map->flags | | |
284 | GNTMAP_host_map | | |
285 | GNTMAP_contains_pte, | |
286 | map->grants[i].ref, | |
287 | map->grants[i].domid); | |
288 | } | |
aab8f11a | 289 | } |
ab31523c GH |
290 | |
291 | pr_debug("map %d+%d\n", map->index, map->count); | |
0930bba6 SS |
292 | err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL, |
293 | map->pages, map->count); | |
ab31523c GH |
294 | if (err) |
295 | return err; | |
296 | ||
297 | for (i = 0; i < map->count; i++) { | |
298 | if (map->map_ops[i].status) | |
299 | err = -EINVAL; | |
77c35acb DDG |
300 | else { |
301 | BUG_ON(map->map_ops[i].handle == -1); | |
302 | map->unmap_ops[i].handle = map->map_ops[i].handle; | |
303 | pr_debug("map handle=%d\n", map->map_ops[i].handle); | |
304 | } | |
ab31523c GH |
305 | } |
306 | return err; | |
307 | } | |
308 | ||
b57c1869 | 309 | static int __unmap_grant_pages(struct grant_map *map, int offset, int pages) |
ab31523c GH |
310 | { |
311 | int i, err = 0; | |
312 | ||
bdc612dc DDG |
313 | if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) { |
314 | int pgno = (map->notify.addr >> PAGE_SHIFT); | |
1affa98d DDG |
315 | if (pgno >= offset && pgno < offset + pages) { |
316 | /* No need for kmap, pages are in lowmem */ | |
317 | uint8_t *tmp = pfn_to_kaddr(page_to_pfn(map->pages[pgno])); | |
bdc612dc | 318 | tmp[map->notify.addr & (PAGE_SIZE-1)] = 0; |
bdc612dc DDG |
319 | map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE; |
320 | } | |
321 | } | |
322 | ||
2fc136ee SS |
323 | err = gnttab_unmap_refs(map->unmap_ops + offset, |
324 | use_ptemod ? map->kmap_ops + offset : NULL, map->pages + offset, | |
325 | pages); | |
ab31523c GH |
326 | if (err) |
327 | return err; | |
328 | ||
329 | for (i = 0; i < pages; i++) { | |
330 | if (map->unmap_ops[offset+i].status) | |
331 | err = -EINVAL; | |
77c35acb DDG |
332 | pr_debug("unmap handle=%d st=%d\n", |
333 | map->unmap_ops[offset+i].handle, | |
334 | map->unmap_ops[offset+i].status); | |
335 | map->unmap_ops[offset+i].handle = -1; | |
ab31523c GH |
336 | } |
337 | return err; | |
338 | } | |
339 | ||
b57c1869 DDG |
340 | static int unmap_grant_pages(struct grant_map *map, int offset, int pages) |
341 | { | |
342 | int range, err = 0; | |
343 | ||
344 | pr_debug("unmap %d+%d [%d+%d]\n", map->index, map->count, offset, pages); | |
345 | ||
346 | /* It is possible the requested range will have a "hole" where we | |
347 | * already unmapped some of the grants. Only unmap valid ranges. | |
348 | */ | |
349 | while (pages && !err) { | |
77c35acb | 350 | while (pages && map->unmap_ops[offset].handle == -1) { |
b57c1869 DDG |
351 | offset++; |
352 | pages--; | |
353 | } | |
354 | range = 0; | |
355 | while (range < pages) { | |
77c35acb | 356 | if (map->unmap_ops[offset+range].handle == -1) { |
b57c1869 DDG |
357 | range--; |
358 | break; | |
359 | } | |
360 | range++; | |
361 | } | |
362 | err = __unmap_grant_pages(map, offset, range); | |
363 | offset += range; | |
364 | pages -= range; | |
365 | } | |
366 | ||
367 | return err; | |
368 | } | |
369 | ||
ab31523c GH |
370 | /* ------------------------------------------------------------------ */ |
371 | ||
d79647ae DDG |
372 | static void gntdev_vma_open(struct vm_area_struct *vma) |
373 | { | |
374 | struct grant_map *map = vma->vm_private_data; | |
375 | ||
376 | pr_debug("gntdev_vma_open %p\n", vma); | |
377 | atomic_inc(&map->users); | |
378 | } | |
379 | ||
ab31523c GH |
380 | static void gntdev_vma_close(struct vm_area_struct *vma) |
381 | { | |
382 | struct grant_map *map = vma->vm_private_data; | |
16a1d022 DDG |
383 | struct file *file = vma->vm_file; |
384 | struct gntdev_priv *priv = file->private_data; | |
ab31523c | 385 | |
d79647ae | 386 | pr_debug("gntdev_vma_close %p\n", vma); |
2512f298 | 387 | if (use_ptemod) { |
2512f298 DDG |
388 | /* It is possible that an mmu notifier could be running |
389 | * concurrently, so take priv->lock to ensure that the vma won't | |
390 | * vanishing during the unmap_grant_pages call, since we will | |
391 | * spin here until that completes. Such a concurrent call will | |
392 | * not do any unmapping, since that has been done prior to | |
393 | * closing the vma, but it may still iterate the unmap_ops list. | |
394 | */ | |
32123973 | 395 | mutex_lock(&priv->lock); |
2512f298 | 396 | map->vma = NULL; |
32123973 | 397 | mutex_unlock(&priv->lock); |
2512f298 | 398 | } |
ab31523c | 399 | vma->vm_private_data = NULL; |
16a1d022 | 400 | gntdev_put_map(priv, map); |
ab31523c GH |
401 | } |
402 | ||
ab31523c | 403 | static struct vm_operations_struct gntdev_vmops = { |
d79647ae | 404 | .open = gntdev_vma_open, |
ab31523c | 405 | .close = gntdev_vma_close, |
ab31523c GH |
406 | }; |
407 | ||
408 | /* ------------------------------------------------------------------ */ | |
409 | ||
16a1d022 DDG |
410 | static void unmap_if_in_range(struct grant_map *map, |
411 | unsigned long start, unsigned long end) | |
412 | { | |
413 | unsigned long mstart, mend; | |
414 | int err; | |
415 | ||
416 | if (!map->vma) | |
417 | return; | |
418 | if (map->vma->vm_start >= end) | |
419 | return; | |
420 | if (map->vma->vm_end <= start) | |
421 | return; | |
422 | mstart = max(start, map->vma->vm_start); | |
423 | mend = min(end, map->vma->vm_end); | |
424 | pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n", | |
425 | map->index, map->count, | |
426 | map->vma->vm_start, map->vma->vm_end, | |
427 | start, end, mstart, mend); | |
428 | err = unmap_grant_pages(map, | |
429 | (mstart - map->vma->vm_start) >> PAGE_SHIFT, | |
430 | (mend - mstart) >> PAGE_SHIFT); | |
431 | WARN_ON(err); | |
432 | } | |
433 | ||
ab31523c GH |
434 | static void mn_invl_range_start(struct mmu_notifier *mn, |
435 | struct mm_struct *mm, | |
436 | unsigned long start, unsigned long end) | |
437 | { | |
438 | struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); | |
439 | struct grant_map *map; | |
ab31523c | 440 | |
32123973 | 441 | mutex_lock(&priv->lock); |
ab31523c | 442 | list_for_each_entry(map, &priv->maps, next) { |
16a1d022 DDG |
443 | unmap_if_in_range(map, start, end); |
444 | } | |
445 | list_for_each_entry(map, &priv->freeable_maps, next) { | |
446 | unmap_if_in_range(map, start, end); | |
ab31523c | 447 | } |
32123973 | 448 | mutex_unlock(&priv->lock); |
ab31523c GH |
449 | } |
450 | ||
451 | static void mn_invl_page(struct mmu_notifier *mn, | |
452 | struct mm_struct *mm, | |
453 | unsigned long address) | |
454 | { | |
455 | mn_invl_range_start(mn, mm, address, address + PAGE_SIZE); | |
456 | } | |
457 | ||
458 | static void mn_release(struct mmu_notifier *mn, | |
459 | struct mm_struct *mm) | |
460 | { | |
461 | struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); | |
462 | struct grant_map *map; | |
463 | int err; | |
464 | ||
32123973 | 465 | mutex_lock(&priv->lock); |
ab31523c GH |
466 | list_for_each_entry(map, &priv->maps, next) { |
467 | if (!map->vma) | |
468 | continue; | |
469 | pr_debug("map %d+%d (%lx %lx)\n", | |
470 | map->index, map->count, | |
471 | map->vma->vm_start, map->vma->vm_end); | |
472 | err = unmap_grant_pages(map, /* offset */ 0, map->count); | |
473 | WARN_ON(err); | |
474 | } | |
16a1d022 DDG |
475 | list_for_each_entry(map, &priv->freeable_maps, next) { |
476 | if (!map->vma) | |
477 | continue; | |
478 | pr_debug("map %d+%d (%lx %lx)\n", | |
479 | map->index, map->count, | |
480 | map->vma->vm_start, map->vma->vm_end); | |
481 | err = unmap_grant_pages(map, /* offset */ 0, map->count); | |
482 | WARN_ON(err); | |
483 | } | |
32123973 | 484 | mutex_unlock(&priv->lock); |
ab31523c GH |
485 | } |
486 | ||
b8b0f559 | 487 | static struct mmu_notifier_ops gntdev_mmu_ops = { |
ab31523c GH |
488 | .release = mn_release, |
489 | .invalidate_page = mn_invl_page, | |
490 | .invalidate_range_start = mn_invl_range_start, | |
491 | }; | |
492 | ||
493 | /* ------------------------------------------------------------------ */ | |
494 | ||
495 | static int gntdev_open(struct inode *inode, struct file *flip) | |
496 | { | |
497 | struct gntdev_priv *priv; | |
498 | int ret = 0; | |
499 | ||
500 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); | |
501 | if (!priv) | |
502 | return -ENOMEM; | |
503 | ||
504 | INIT_LIST_HEAD(&priv->maps); | |
16a1d022 | 505 | INIT_LIST_HEAD(&priv->freeable_maps); |
32123973 | 506 | mutex_init(&priv->lock); |
ab31523c | 507 | |
aab8f11a DDG |
508 | if (use_ptemod) { |
509 | priv->mm = get_task_mm(current); | |
510 | if (!priv->mm) { | |
511 | kfree(priv); | |
512 | return -ENOMEM; | |
513 | } | |
514 | priv->mn.ops = &gntdev_mmu_ops; | |
515 | ret = mmu_notifier_register(&priv->mn, priv->mm); | |
516 | mmput(priv->mm); | |
ab31523c | 517 | } |
ab31523c GH |
518 | |
519 | if (ret) { | |
520 | kfree(priv); | |
521 | return ret; | |
522 | } | |
523 | ||
524 | flip->private_data = priv; | |
525 | pr_debug("priv %p\n", priv); | |
526 | ||
527 | return 0; | |
528 | } | |
529 | ||
530 | static int gntdev_release(struct inode *inode, struct file *flip) | |
531 | { | |
532 | struct gntdev_priv *priv = flip->private_data; | |
533 | struct grant_map *map; | |
ab31523c GH |
534 | |
535 | pr_debug("priv %p\n", priv); | |
536 | ||
9ae29834 | 537 | mutex_lock(&priv->lock); |
ab31523c GH |
538 | while (!list_empty(&priv->maps)) { |
539 | map = list_entry(priv->maps.next, struct grant_map, next); | |
68b025c8 | 540 | list_del(&map->next); |
16a1d022 | 541 | gntdev_put_map(NULL /* already removed */, map); |
ab31523c | 542 | } |
16a1d022 | 543 | WARN_ON(!list_empty(&priv->freeable_maps)); |
9ae29834 | 544 | mutex_unlock(&priv->lock); |
ab31523c | 545 | |
aab8f11a DDG |
546 | if (use_ptemod) |
547 | mmu_notifier_unregister(&priv->mn, priv->mm); | |
ab31523c GH |
548 | kfree(priv); |
549 | return 0; | |
550 | } | |
551 | ||
552 | static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv, | |
553 | struct ioctl_gntdev_map_grant_ref __user *u) | |
554 | { | |
555 | struct ioctl_gntdev_map_grant_ref op; | |
556 | struct grant_map *map; | |
557 | int err; | |
558 | ||
559 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
560 | return -EFAULT; | |
561 | pr_debug("priv %p, add %d\n", priv, op.count); | |
562 | if (unlikely(op.count <= 0)) | |
563 | return -EINVAL; | |
ab31523c GH |
564 | |
565 | err = -ENOMEM; | |
566 | map = gntdev_alloc_map(priv, op.count); | |
567 | if (!map) | |
568 | return err; | |
ef91082e | 569 | |
68b025c8 DDG |
570 | if (unlikely(atomic_add_return(op.count, &pages_mapped) > limit)) { |
571 | pr_debug("can't map: over limit\n"); | |
16a1d022 | 572 | gntdev_put_map(NULL, map); |
ab31523c GH |
573 | return err; |
574 | } | |
575 | ||
68b025c8 DDG |
576 | if (copy_from_user(map->grants, &u->refs, |
577 | sizeof(map->grants[0]) * op.count) != 0) { | |
16a1d022 DDG |
578 | gntdev_put_map(NULL, map); |
579 | return -EFAULT; | |
ef91082e DDG |
580 | } |
581 | ||
32123973 | 582 | mutex_lock(&priv->lock); |
ab31523c GH |
583 | gntdev_add_map(priv, map); |
584 | op.index = map->index << PAGE_SHIFT; | |
32123973 | 585 | mutex_unlock(&priv->lock); |
ab31523c | 586 | |
68b025c8 DDG |
587 | if (copy_to_user(u, &op, sizeof(op)) != 0) |
588 | return -EFAULT; | |
589 | ||
ab31523c GH |
590 | return 0; |
591 | } | |
592 | ||
593 | static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv, | |
594 | struct ioctl_gntdev_unmap_grant_ref __user *u) | |
595 | { | |
596 | struct ioctl_gntdev_unmap_grant_ref op; | |
597 | struct grant_map *map; | |
598 | int err = -ENOENT; | |
599 | ||
600 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
601 | return -EFAULT; | |
602 | pr_debug("priv %p, del %d+%d\n", priv, (int)op.index, (int)op.count); | |
603 | ||
32123973 | 604 | mutex_lock(&priv->lock); |
ab31523c | 605 | map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count); |
68b025c8 DDG |
606 | if (map) { |
607 | list_del(&map->next); | |
16a1d022 DDG |
608 | if (populate_freeable_maps) |
609 | list_add_tail(&map->next, &priv->freeable_maps); | |
68b025c8 DDG |
610 | err = 0; |
611 | } | |
32123973 | 612 | mutex_unlock(&priv->lock); |
1f1503ba | 613 | if (map) |
16a1d022 | 614 | gntdev_put_map(priv, map); |
ab31523c GH |
615 | return err; |
616 | } | |
617 | ||
618 | static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv, | |
619 | struct ioctl_gntdev_get_offset_for_vaddr __user *u) | |
620 | { | |
621 | struct ioctl_gntdev_get_offset_for_vaddr op; | |
a879211b | 622 | struct vm_area_struct *vma; |
ab31523c | 623 | struct grant_map *map; |
2512f298 | 624 | int rv = -EINVAL; |
ab31523c GH |
625 | |
626 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
627 | return -EFAULT; | |
628 | pr_debug("priv %p, offset for vaddr %lx\n", priv, (unsigned long)op.vaddr); | |
629 | ||
2512f298 | 630 | down_read(¤t->mm->mmap_sem); |
a879211b DDG |
631 | vma = find_vma(current->mm, op.vaddr); |
632 | if (!vma || vma->vm_ops != &gntdev_vmops) | |
2512f298 | 633 | goto out_unlock; |
a879211b DDG |
634 | |
635 | map = vma->vm_private_data; | |
636 | if (!map) | |
2512f298 | 637 | goto out_unlock; |
a879211b | 638 | |
ab31523c GH |
639 | op.offset = map->index << PAGE_SHIFT; |
640 | op.count = map->count; | |
2512f298 | 641 | rv = 0; |
ab31523c | 642 | |
2512f298 DDG |
643 | out_unlock: |
644 | up_read(¤t->mm->mmap_sem); | |
645 | ||
646 | if (rv == 0 && copy_to_user(u, &op, sizeof(op)) != 0) | |
ab31523c | 647 | return -EFAULT; |
2512f298 | 648 | return rv; |
ab31523c GH |
649 | } |
650 | ||
bdc612dc DDG |
651 | static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u) |
652 | { | |
653 | struct ioctl_gntdev_unmap_notify op; | |
654 | struct grant_map *map; | |
655 | int rc; | |
0cc678f8 DDG |
656 | int out_flags; |
657 | unsigned int out_event; | |
bdc612dc DDG |
658 | |
659 | if (copy_from_user(&op, u, sizeof(op))) | |
660 | return -EFAULT; | |
661 | ||
662 | if (op.action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT)) | |
663 | return -EINVAL; | |
664 | ||
0cc678f8 DDG |
665 | /* We need to grab a reference to the event channel we are going to use |
666 | * to send the notify before releasing the reference we may already have | |
667 | * (if someone has called this ioctl twice). This is required so that | |
668 | * it is possible to change the clear_byte part of the notification | |
669 | * without disturbing the event channel part, which may now be the last | |
670 | * reference to that event channel. | |
671 | */ | |
672 | if (op.action & UNMAP_NOTIFY_SEND_EVENT) { | |
673 | if (evtchn_get(op.event_channel_port)) | |
674 | return -EINVAL; | |
675 | } | |
676 | ||
677 | out_flags = op.action; | |
678 | out_event = op.event_channel_port; | |
679 | ||
32123973 | 680 | mutex_lock(&priv->lock); |
bdc612dc DDG |
681 | |
682 | list_for_each_entry(map, &priv->maps, next) { | |
683 | uint64_t begin = map->index << PAGE_SHIFT; | |
684 | uint64_t end = (map->index + map->count) << PAGE_SHIFT; | |
685 | if (op.index >= begin && op.index < end) | |
686 | goto found; | |
687 | } | |
688 | rc = -ENOENT; | |
689 | goto unlock_out; | |
690 | ||
691 | found: | |
9960be97 DDG |
692 | if ((op.action & UNMAP_NOTIFY_CLEAR_BYTE) && |
693 | (map->flags & GNTMAP_readonly)) { | |
694 | rc = -EINVAL; | |
695 | goto unlock_out; | |
696 | } | |
697 | ||
0cc678f8 DDG |
698 | out_flags = map->notify.flags; |
699 | out_event = map->notify.event; | |
700 | ||
bdc612dc DDG |
701 | map->notify.flags = op.action; |
702 | map->notify.addr = op.index - (map->index << PAGE_SHIFT); | |
703 | map->notify.event = op.event_channel_port; | |
0cc678f8 | 704 | |
bdc612dc | 705 | rc = 0; |
0cc678f8 | 706 | |
bdc612dc | 707 | unlock_out: |
32123973 | 708 | mutex_unlock(&priv->lock); |
0cc678f8 DDG |
709 | |
710 | /* Drop the reference to the event channel we did not save in the map */ | |
711 | if (out_flags & UNMAP_NOTIFY_SEND_EVENT) | |
712 | evtchn_put(out_event); | |
713 | ||
bdc612dc DDG |
714 | return rc; |
715 | } | |
716 | ||
ab31523c GH |
717 | static long gntdev_ioctl(struct file *flip, |
718 | unsigned int cmd, unsigned long arg) | |
719 | { | |
720 | struct gntdev_priv *priv = flip->private_data; | |
721 | void __user *ptr = (void __user *)arg; | |
722 | ||
723 | switch (cmd) { | |
724 | case IOCTL_GNTDEV_MAP_GRANT_REF: | |
725 | return gntdev_ioctl_map_grant_ref(priv, ptr); | |
726 | ||
727 | case IOCTL_GNTDEV_UNMAP_GRANT_REF: | |
728 | return gntdev_ioctl_unmap_grant_ref(priv, ptr); | |
729 | ||
730 | case IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR: | |
731 | return gntdev_ioctl_get_offset_for_vaddr(priv, ptr); | |
732 | ||
bdc612dc DDG |
733 | case IOCTL_GNTDEV_SET_UNMAP_NOTIFY: |
734 | return gntdev_ioctl_notify(priv, ptr); | |
735 | ||
ab31523c GH |
736 | default: |
737 | pr_debug("priv %p, unknown cmd %x\n", priv, cmd); | |
738 | return -ENOIOCTLCMD; | |
739 | } | |
740 | ||
741 | return 0; | |
742 | } | |
743 | ||
744 | static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) | |
745 | { | |
746 | struct gntdev_priv *priv = flip->private_data; | |
747 | int index = vma->vm_pgoff; | |
748 | int count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; | |
749 | struct grant_map *map; | |
aab8f11a | 750 | int i, err = -EINVAL; |
ab31523c GH |
751 | |
752 | if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED)) | |
753 | return -EINVAL; | |
754 | ||
755 | pr_debug("map %d+%d at %lx (pgoff %lx)\n", | |
756 | index, count, vma->vm_start, vma->vm_pgoff); | |
757 | ||
32123973 | 758 | mutex_lock(&priv->lock); |
ab31523c GH |
759 | map = gntdev_find_map_index(priv, index, count); |
760 | if (!map) | |
761 | goto unlock_out; | |
aab8f11a | 762 | if (use_ptemod && map->vma) |
ab31523c | 763 | goto unlock_out; |
aab8f11a | 764 | if (use_ptemod && priv->mm != vma->vm_mm) { |
ab31523c GH |
765 | printk(KERN_WARNING "Huh? Other mm?\n"); |
766 | goto unlock_out; | |
767 | } | |
768 | ||
68b025c8 DDG |
769 | atomic_inc(&map->users); |
770 | ||
ab31523c GH |
771 | vma->vm_ops = &gntdev_vmops; |
772 | ||
28043279 | 773 | vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP | VM_IO; |
d79647ae DDG |
774 | |
775 | if (use_ptemod) | |
e8e937be | 776 | vma->vm_flags |= VM_DONTCOPY; |
ab31523c GH |
777 | |
778 | vma->vm_private_data = map; | |
ab31523c | 779 | |
aab8f11a DDG |
780 | if (use_ptemod) |
781 | map->vma = vma; | |
782 | ||
12996fc3 DDG |
783 | if (map->flags) { |
784 | if ((vma->vm_flags & VM_WRITE) && | |
785 | (map->flags & GNTMAP_readonly)) | |
a93e20a8 | 786 | goto out_unlock_put; |
12996fc3 DDG |
787 | } else { |
788 | map->flags = GNTMAP_host_map; | |
789 | if (!(vma->vm_flags & VM_WRITE)) | |
790 | map->flags |= GNTMAP_readonly; | |
791 | } | |
ab31523c | 792 | |
32123973 | 793 | mutex_unlock(&priv->lock); |
f0a70c88 | 794 | |
aab8f11a DDG |
795 | if (use_ptemod) { |
796 | err = apply_to_page_range(vma->vm_mm, vma->vm_start, | |
797 | vma->vm_end - vma->vm_start, | |
798 | find_grant_ptes, map); | |
799 | if (err) { | |
800 | printk(KERN_WARNING "find_grant_ptes() failure.\n"); | |
90b6f305 | 801 | goto out_put_map; |
aab8f11a | 802 | } |
ab31523c GH |
803 | } |
804 | ||
805 | err = map_grant_pages(map); | |
90b6f305 DDG |
806 | if (err) |
807 | goto out_put_map; | |
f0a70c88 | 808 | |
aab8f11a DDG |
809 | if (!use_ptemod) { |
810 | for (i = 0; i < count; i++) { | |
811 | err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE, | |
812 | map->pages[i]); | |
813 | if (err) | |
90b6f305 | 814 | goto out_put_map; |
aab8f11a DDG |
815 | } |
816 | } | |
817 | ||
f0a70c88 DDG |
818 | return 0; |
819 | ||
ab31523c | 820 | unlock_out: |
32123973 | 821 | mutex_unlock(&priv->lock); |
ab31523c | 822 | return err; |
90b6f305 | 823 | |
a93e20a8 | 824 | out_unlock_put: |
32123973 | 825 | mutex_unlock(&priv->lock); |
90b6f305 | 826 | out_put_map: |
84e4075d DDG |
827 | if (use_ptemod) |
828 | map->vma = NULL; | |
16a1d022 | 829 | gntdev_put_map(priv, map); |
90b6f305 | 830 | return err; |
ab31523c GH |
831 | } |
832 | ||
833 | static const struct file_operations gntdev_fops = { | |
834 | .owner = THIS_MODULE, | |
835 | .open = gntdev_open, | |
836 | .release = gntdev_release, | |
837 | .mmap = gntdev_mmap, | |
838 | .unlocked_ioctl = gntdev_ioctl | |
839 | }; | |
840 | ||
841 | static struct miscdevice gntdev_miscdev = { | |
842 | .minor = MISC_DYNAMIC_MINOR, | |
843 | .name = "xen/gntdev", | |
844 | .fops = &gntdev_fops, | |
845 | }; | |
846 | ||
847 | /* ------------------------------------------------------------------ */ | |
848 | ||
849 | static int __init gntdev_init(void) | |
850 | { | |
851 | int err; | |
852 | ||
853 | if (!xen_domain()) | |
854 | return -ENODEV; | |
855 | ||
aab8f11a DDG |
856 | use_ptemod = xen_pv_domain(); |
857 | ||
ab31523c GH |
858 | err = misc_register(&gntdev_miscdev); |
859 | if (err != 0) { | |
860 | printk(KERN_ERR "Could not register gntdev device\n"); | |
861 | return err; | |
862 | } | |
863 | return 0; | |
864 | } | |
865 | ||
866 | static void __exit gntdev_exit(void) | |
867 | { | |
868 | misc_deregister(&gntdev_miscdev); | |
869 | } | |
870 | ||
871 | module_init(gntdev_init); | |
872 | module_exit(gntdev_exit); | |
873 | ||
874 | /* ------------------------------------------------------------------ */ |