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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 | ||
283c0972 JP |
22 | #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt |
23 | ||
ab31523c GH |
24 | #include <linux/module.h> |
25 | #include <linux/kernel.h> | |
26 | #include <linux/init.h> | |
27 | #include <linux/miscdevice.h> | |
28 | #include <linux/fs.h> | |
29 | #include <linux/mm.h> | |
30 | #include <linux/mman.h> | |
31 | #include <linux/mmu_notifier.h> | |
32 | #include <linux/types.h> | |
33 | #include <linux/uaccess.h> | |
34 | #include <linux/sched.h> | |
6e84f315 | 35 | #include <linux/sched/mm.h> |
ab31523c GH |
36 | #include <linux/spinlock.h> |
37 | #include <linux/slab.h> | |
aab8f11a | 38 | #include <linux/highmem.h> |
c5f7c5a9 | 39 | #include <linux/refcount.h> |
ab31523c GH |
40 | |
41 | #include <xen/xen.h> | |
42 | #include <xen/grant_table.h> | |
ca47ceaa | 43 | #include <xen/balloon.h> |
ab31523c | 44 | #include <xen/gntdev.h> |
bdc612dc | 45 | #include <xen/events.h> |
a9fd60e2 | 46 | #include <xen/page.h> |
ab31523c GH |
47 | #include <asm/xen/hypervisor.h> |
48 | #include <asm/xen/hypercall.h> | |
ab31523c GH |
49 | |
50 | MODULE_LICENSE("GPL"); | |
51 | MODULE_AUTHOR("Derek G. Murray <Derek.Murray@cl.cam.ac.uk>, " | |
52 | "Gerd Hoffmann <kraxel@redhat.com>"); | |
53 | MODULE_DESCRIPTION("User-space granted page access driver"); | |
54 | ||
ef91082e | 55 | static int limit = 1024*1024; |
ab31523c | 56 | module_param(limit, int, 0644); |
ef91082e DDG |
57 | MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by " |
58 | "the gntdev device"); | |
59 | ||
60 | static atomic_t pages_mapped = ATOMIC_INIT(0); | |
ab31523c | 61 | |
aab8f11a | 62 | static int use_ptemod; |
16a1d022 | 63 | #define populate_freeable_maps use_ptemod |
aab8f11a | 64 | |
ab31523c | 65 | struct gntdev_priv { |
16a1d022 | 66 | /* maps with visible offsets in the file descriptor */ |
ab31523c | 67 | struct list_head maps; |
16a1d022 DDG |
68 | /* maps that are not visible; will be freed on munmap. |
69 | * Only populated if populate_freeable_maps == 1 */ | |
70 | struct list_head freeable_maps; | |
71 | /* lock protects maps and freeable_maps */ | |
1401c00e | 72 | struct mutex lock; |
ab31523c GH |
73 | struct mm_struct *mm; |
74 | struct mmu_notifier mn; | |
75 | }; | |
76 | ||
bdc612dc DDG |
77 | struct unmap_notify { |
78 | int flags; | |
79 | /* Address relative to the start of the grant_map */ | |
80 | int addr; | |
81 | int event; | |
82 | }; | |
83 | ||
ab31523c GH |
84 | struct grant_map { |
85 | struct list_head next; | |
ab31523c GH |
86 | struct vm_area_struct *vma; |
87 | int index; | |
88 | int count; | |
89 | int flags; | |
c5f7c5a9 | 90 | refcount_t users; |
bdc612dc | 91 | struct unmap_notify notify; |
ab31523c GH |
92 | struct ioctl_gntdev_grant_ref *grants; |
93 | struct gnttab_map_grant_ref *map_ops; | |
94 | struct gnttab_unmap_grant_ref *unmap_ops; | |
0930bba6 | 95 | struct gnttab_map_grant_ref *kmap_ops; |
853d0289 | 96 | struct gnttab_unmap_grant_ref *kunmap_ops; |
a12b4eb3 | 97 | struct page **pages; |
dab069c6 | 98 | unsigned long pages_vm_start; |
ab31523c GH |
99 | }; |
100 | ||
aab8f11a DDG |
101 | static int unmap_grant_pages(struct grant_map *map, int offset, int pages); |
102 | ||
ab31523c GH |
103 | /* ------------------------------------------------------------------ */ |
104 | ||
105 | static void gntdev_print_maps(struct gntdev_priv *priv, | |
106 | char *text, int text_index) | |
107 | { | |
108 | #ifdef DEBUG | |
109 | struct grant_map *map; | |
110 | ||
ef91082e | 111 | pr_debug("%s: maps list (priv %p)\n", __func__, priv); |
ab31523c GH |
112 | list_for_each_entry(map, &priv->maps, next) |
113 | pr_debug(" index %2d, count %2d %s\n", | |
114 | map->index, map->count, | |
115 | map->index == text_index && text ? text : ""); | |
116 | #endif | |
117 | } | |
118 | ||
a67baeb7 DV |
119 | static void gntdev_free_map(struct grant_map *map) |
120 | { | |
121 | if (map == NULL) | |
122 | return; | |
123 | ||
124 | if (map->pages) | |
ff4b156f | 125 | gnttab_free_pages(map->count, map->pages); |
a67baeb7 DV |
126 | kfree(map->pages); |
127 | kfree(map->grants); | |
128 | kfree(map->map_ops); | |
129 | kfree(map->unmap_ops); | |
130 | kfree(map->kmap_ops); | |
853d0289 | 131 | kfree(map->kunmap_ops); |
a67baeb7 DV |
132 | kfree(map); |
133 | } | |
134 | ||
ab31523c GH |
135 | static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count) |
136 | { | |
137 | struct grant_map *add; | |
a12b4eb3 | 138 | int i; |
ab31523c GH |
139 | |
140 | add = kzalloc(sizeof(struct grant_map), GFP_KERNEL); | |
141 | if (NULL == add) | |
142 | return NULL; | |
143 | ||
fc6e0c3b DC |
144 | add->grants = kcalloc(count, sizeof(add->grants[0]), GFP_KERNEL); |
145 | add->map_ops = kcalloc(count, sizeof(add->map_ops[0]), GFP_KERNEL); | |
146 | add->unmap_ops = kcalloc(count, sizeof(add->unmap_ops[0]), GFP_KERNEL); | |
147 | add->kmap_ops = kcalloc(count, sizeof(add->kmap_ops[0]), GFP_KERNEL); | |
853d0289 | 148 | add->kunmap_ops = kcalloc(count, sizeof(add->kunmap_ops[0]), GFP_KERNEL); |
fc6e0c3b | 149 | add->pages = kcalloc(count, sizeof(add->pages[0]), GFP_KERNEL); |
a12b4eb3 SS |
150 | if (NULL == add->grants || |
151 | NULL == add->map_ops || | |
152 | NULL == add->unmap_ops || | |
0930bba6 | 153 | NULL == add->kmap_ops || |
853d0289 | 154 | NULL == add->kunmap_ops || |
a12b4eb3 | 155 | NULL == add->pages) |
ab31523c GH |
156 | goto err; |
157 | ||
ff4b156f | 158 | if (gnttab_alloc_pages(count, add->pages)) |
ca47ceaa DDG |
159 | goto err; |
160 | ||
a12b4eb3 | 161 | for (i = 0; i < count; i++) { |
77c35acb DDG |
162 | add->map_ops[i].handle = -1; |
163 | add->unmap_ops[i].handle = -1; | |
0930bba6 | 164 | add->kmap_ops[i].handle = -1; |
853d0289 | 165 | add->kunmap_ops[i].handle = -1; |
a12b4eb3 SS |
166 | } |
167 | ||
ab31523c GH |
168 | add->index = 0; |
169 | add->count = count; | |
c5f7c5a9 | 170 | refcount_set(&add->users, 1); |
ab31523c | 171 | |
ab31523c GH |
172 | return add; |
173 | ||
174 | err: | |
a67baeb7 | 175 | gntdev_free_map(add); |
ab31523c GH |
176 | return NULL; |
177 | } | |
178 | ||
179 | static void gntdev_add_map(struct gntdev_priv *priv, struct grant_map *add) | |
180 | { | |
181 | struct grant_map *map; | |
182 | ||
183 | list_for_each_entry(map, &priv->maps, next) { | |
184 | if (add->index + add->count < map->index) { | |
185 | list_add_tail(&add->next, &map->next); | |
186 | goto done; | |
187 | } | |
188 | add->index = map->index + map->count; | |
189 | } | |
190 | list_add_tail(&add->next, &priv->maps); | |
191 | ||
192 | done: | |
ab31523c GH |
193 | gntdev_print_maps(priv, "[new]", add->index); |
194 | } | |
195 | ||
196 | static struct grant_map *gntdev_find_map_index(struct gntdev_priv *priv, | |
197 | int index, int count) | |
198 | { | |
199 | struct grant_map *map; | |
200 | ||
201 | list_for_each_entry(map, &priv->maps, next) { | |
202 | if (map->index != index) | |
203 | continue; | |
bdc612dc | 204 | if (count && map->count != count) |
ab31523c GH |
205 | continue; |
206 | return map; | |
207 | } | |
208 | return NULL; | |
209 | } | |
210 | ||
16a1d022 | 211 | static void gntdev_put_map(struct gntdev_priv *priv, struct grant_map *map) |
ab31523c GH |
212 | { |
213 | if (!map) | |
214 | return; | |
a12b4eb3 | 215 | |
c5f7c5a9 | 216 | if (!refcount_dec_and_test(&map->users)) |
68b025c8 DDG |
217 | return; |
218 | ||
219 | atomic_sub(map->count, &pages_mapped); | |
220 | ||
0cc678f8 | 221 | if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) { |
bdc612dc | 222 | notify_remote_via_evtchn(map->notify.event); |
0cc678f8 DDG |
223 | evtchn_put(map->notify.event); |
224 | } | |
bdc612dc | 225 | |
16a1d022 | 226 | if (populate_freeable_maps && priv) { |
1401c00e | 227 | mutex_lock(&priv->lock); |
16a1d022 | 228 | list_del(&map->next); |
1401c00e | 229 | mutex_unlock(&priv->lock); |
16a1d022 DDG |
230 | } |
231 | ||
a67baeb7 DV |
232 | if (map->pages && !use_ptemod) |
233 | unmap_grant_pages(map, 0, map->count); | |
234 | gntdev_free_map(map); | |
ab31523c GH |
235 | } |
236 | ||
237 | /* ------------------------------------------------------------------ */ | |
238 | ||
239 | static int find_grant_ptes(pte_t *pte, pgtable_t token, | |
240 | unsigned long addr, void *data) | |
241 | { | |
242 | struct grant_map *map = data; | |
243 | unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT; | |
aab8f11a | 244 | int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte; |
ab31523c GH |
245 | u64 pte_maddr; |
246 | ||
247 | BUG_ON(pgnr >= map->count); | |
ba5d1012 JF |
248 | pte_maddr = arbitrary_virt_to_machine(pte).maddr; |
249 | ||
923b2919 DV |
250 | /* |
251 | * Set the PTE as special to force get_user_pages_fast() fall | |
252 | * back to the slow path. If this is not supported as part of | |
253 | * the grant map, it will be done afterwards. | |
254 | */ | |
255 | if (xen_feature(XENFEAT_gnttab_map_avail_bits)) | |
256 | flags |= (1 << _GNTMAP_guest_avail0); | |
257 | ||
aab8f11a | 258 | gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, flags, |
ab31523c GH |
259 | map->grants[pgnr].ref, |
260 | map->grants[pgnr].domid); | |
aab8f11a | 261 | gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags, |
77c35acb | 262 | -1 /* handle */); |
ab31523c GH |
263 | return 0; |
264 | } | |
265 | ||
923b2919 DV |
266 | #ifdef CONFIG_X86 |
267 | static int set_grant_ptes_as_special(pte_t *pte, pgtable_t token, | |
268 | unsigned long addr, void *data) | |
269 | { | |
270 | set_pte_at(current->mm, addr, pte, pte_mkspecial(*pte)); | |
271 | return 0; | |
272 | } | |
273 | #endif | |
274 | ||
ab31523c GH |
275 | static int map_grant_pages(struct grant_map *map) |
276 | { | |
277 | int i, err = 0; | |
aab8f11a DDG |
278 | |
279 | if (!use_ptemod) { | |
12996fc3 | 280 | /* Note: it could already be mapped */ |
77c35acb | 281 | if (map->map_ops[0].handle != -1) |
12996fc3 | 282 | return 0; |
aab8f11a | 283 | for (i = 0; i < map->count; i++) { |
38eaeb0f | 284 | unsigned long addr = (unsigned long) |
aab8f11a DDG |
285 | pfn_to_kaddr(page_to_pfn(map->pages[i])); |
286 | gnttab_set_map_op(&map->map_ops[i], addr, map->flags, | |
287 | map->grants[i].ref, | |
288 | map->grants[i].domid); | |
289 | gnttab_set_unmap_op(&map->unmap_ops[i], addr, | |
77c35acb | 290 | map->flags, -1 /* handle */); |
aab8f11a | 291 | } |
0930bba6 SS |
292 | } else { |
293 | /* | |
294 | * Setup the map_ops corresponding to the pte entries pointing | |
295 | * to the kernel linear addresses of the struct pages. | |
296 | * These ptes are completely different from the user ptes dealt | |
297 | * with find_grant_ptes. | |
298 | */ | |
299 | for (i = 0; i < map->count; i++) { | |
0930bba6 SS |
300 | unsigned long address = (unsigned long) |
301 | pfn_to_kaddr(page_to_pfn(map->pages[i])); | |
0930bba6 SS |
302 | BUG_ON(PageHighMem(map->pages[i])); |
303 | ||
ee072640 SS |
304 | gnttab_set_map_op(&map->kmap_ops[i], address, |
305 | map->flags | GNTMAP_host_map, | |
0930bba6 SS |
306 | map->grants[i].ref, |
307 | map->grants[i].domid); | |
853d0289 DV |
308 | gnttab_set_unmap_op(&map->kunmap_ops[i], address, |
309 | map->flags | GNTMAP_host_map, -1); | |
0930bba6 | 310 | } |
aab8f11a | 311 | } |
ab31523c GH |
312 | |
313 | pr_debug("map %d+%d\n", map->index, map->count); | |
e85fc980 KRW |
314 | err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL, |
315 | map->pages, map->count); | |
ab31523c GH |
316 | if (err) |
317 | return err; | |
318 | ||
319 | for (i = 0; i < map->count; i++) { | |
853d0289 | 320 | if (map->map_ops[i].status) { |
ab31523c | 321 | err = -EINVAL; |
853d0289 | 322 | continue; |
77c35acb | 323 | } |
853d0289 DV |
324 | |
325 | map->unmap_ops[i].handle = map->map_ops[i].handle; | |
326 | if (use_ptemod) | |
327 | map->kunmap_ops[i].handle = map->kmap_ops[i].handle; | |
ab31523c GH |
328 | } |
329 | return err; | |
330 | } | |
331 | ||
b57c1869 | 332 | static int __unmap_grant_pages(struct grant_map *map, int offset, int pages) |
ab31523c GH |
333 | { |
334 | int i, err = 0; | |
74528225 | 335 | struct gntab_unmap_queue_data unmap_data; |
ab31523c | 336 | |
bdc612dc DDG |
337 | if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) { |
338 | int pgno = (map->notify.addr >> PAGE_SHIFT); | |
1affa98d DDG |
339 | if (pgno >= offset && pgno < offset + pages) { |
340 | /* No need for kmap, pages are in lowmem */ | |
341 | uint8_t *tmp = pfn_to_kaddr(page_to_pfn(map->pages[pgno])); | |
bdc612dc | 342 | tmp[map->notify.addr & (PAGE_SIZE-1)] = 0; |
bdc612dc DDG |
343 | map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE; |
344 | } | |
345 | } | |
346 | ||
74528225 JH |
347 | unmap_data.unmap_ops = map->unmap_ops + offset; |
348 | unmap_data.kunmap_ops = use_ptemod ? map->kunmap_ops + offset : NULL; | |
349 | unmap_data.pages = map->pages + offset; | |
350 | unmap_data.count = pages; | |
351 | ||
b44166cd BL |
352 | err = gnttab_unmap_refs_sync(&unmap_data); |
353 | if (err) | |
354 | return err; | |
ab31523c GH |
355 | |
356 | for (i = 0; i < pages; i++) { | |
357 | if (map->unmap_ops[offset+i].status) | |
358 | err = -EINVAL; | |
77c35acb DDG |
359 | pr_debug("unmap handle=%d st=%d\n", |
360 | map->unmap_ops[offset+i].handle, | |
361 | map->unmap_ops[offset+i].status); | |
362 | map->unmap_ops[offset+i].handle = -1; | |
ab31523c GH |
363 | } |
364 | return err; | |
365 | } | |
366 | ||
b57c1869 DDG |
367 | static int unmap_grant_pages(struct grant_map *map, int offset, int pages) |
368 | { | |
369 | int range, err = 0; | |
370 | ||
371 | pr_debug("unmap %d+%d [%d+%d]\n", map->index, map->count, offset, pages); | |
372 | ||
373 | /* It is possible the requested range will have a "hole" where we | |
374 | * already unmapped some of the grants. Only unmap valid ranges. | |
375 | */ | |
376 | while (pages && !err) { | |
77c35acb | 377 | while (pages && map->unmap_ops[offset].handle == -1) { |
b57c1869 DDG |
378 | offset++; |
379 | pages--; | |
380 | } | |
381 | range = 0; | |
382 | while (range < pages) { | |
951a0102 | 383 | if (map->unmap_ops[offset+range].handle == -1) |
b57c1869 | 384 | break; |
b57c1869 DDG |
385 | range++; |
386 | } | |
387 | err = __unmap_grant_pages(map, offset, range); | |
388 | offset += range; | |
389 | pages -= range; | |
390 | } | |
391 | ||
392 | return err; | |
393 | } | |
394 | ||
ab31523c GH |
395 | /* ------------------------------------------------------------------ */ |
396 | ||
d79647ae DDG |
397 | static void gntdev_vma_open(struct vm_area_struct *vma) |
398 | { | |
399 | struct grant_map *map = vma->vm_private_data; | |
400 | ||
401 | pr_debug("gntdev_vma_open %p\n", vma); | |
c5f7c5a9 | 402 | refcount_inc(&map->users); |
d79647ae DDG |
403 | } |
404 | ||
ab31523c GH |
405 | static void gntdev_vma_close(struct vm_area_struct *vma) |
406 | { | |
407 | struct grant_map *map = vma->vm_private_data; | |
16a1d022 DDG |
408 | struct file *file = vma->vm_file; |
409 | struct gntdev_priv *priv = file->private_data; | |
ab31523c | 410 | |
d79647ae | 411 | pr_debug("gntdev_vma_close %p\n", vma); |
2512f298 | 412 | if (use_ptemod) { |
2512f298 DDG |
413 | /* It is possible that an mmu notifier could be running |
414 | * concurrently, so take priv->lock to ensure that the vma won't | |
415 | * vanishing during the unmap_grant_pages call, since we will | |
416 | * spin here until that completes. Such a concurrent call will | |
417 | * not do any unmapping, since that has been done prior to | |
418 | * closing the vma, but it may still iterate the unmap_ops list. | |
419 | */ | |
1401c00e | 420 | mutex_lock(&priv->lock); |
2512f298 | 421 | map->vma = NULL; |
1401c00e | 422 | mutex_unlock(&priv->lock); |
2512f298 | 423 | } |
ab31523c | 424 | vma->vm_private_data = NULL; |
16a1d022 | 425 | gntdev_put_map(priv, map); |
ab31523c GH |
426 | } |
427 | ||
dab069c6 DV |
428 | static struct page *gntdev_vma_find_special_page(struct vm_area_struct *vma, |
429 | unsigned long addr) | |
430 | { | |
431 | struct grant_map *map = vma->vm_private_data; | |
432 | ||
433 | return map->pages[(addr - map->pages_vm_start) >> PAGE_SHIFT]; | |
434 | } | |
435 | ||
7cbea8dc | 436 | static const struct vm_operations_struct gntdev_vmops = { |
d79647ae | 437 | .open = gntdev_vma_open, |
ab31523c | 438 | .close = gntdev_vma_close, |
dab069c6 | 439 | .find_special_page = gntdev_vma_find_special_page, |
ab31523c GH |
440 | }; |
441 | ||
442 | /* ------------------------------------------------------------------ */ | |
443 | ||
16a1d022 DDG |
444 | static void unmap_if_in_range(struct grant_map *map, |
445 | unsigned long start, unsigned long end) | |
446 | { | |
447 | unsigned long mstart, mend; | |
448 | int err; | |
449 | ||
450 | if (!map->vma) | |
451 | return; | |
452 | if (map->vma->vm_start >= end) | |
453 | return; | |
454 | if (map->vma->vm_end <= start) | |
455 | return; | |
456 | mstart = max(start, map->vma->vm_start); | |
457 | mend = min(end, map->vma->vm_end); | |
458 | pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n", | |
459 | map->index, map->count, | |
460 | map->vma->vm_start, map->vma->vm_end, | |
461 | start, end, mstart, mend); | |
462 | err = unmap_grant_pages(map, | |
463 | (mstart - map->vma->vm_start) >> PAGE_SHIFT, | |
464 | (mend - mstart) >> PAGE_SHIFT); | |
465 | WARN_ON(err); | |
466 | } | |
467 | ||
ab31523c GH |
468 | static void mn_invl_range_start(struct mmu_notifier *mn, |
469 | struct mm_struct *mm, | |
470 | unsigned long start, unsigned long end) | |
471 | { | |
472 | struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); | |
473 | struct grant_map *map; | |
ab31523c | 474 | |
1401c00e | 475 | mutex_lock(&priv->lock); |
ab31523c | 476 | list_for_each_entry(map, &priv->maps, next) { |
16a1d022 DDG |
477 | unmap_if_in_range(map, start, end); |
478 | } | |
479 | list_for_each_entry(map, &priv->freeable_maps, next) { | |
480 | unmap_if_in_range(map, start, end); | |
ab31523c | 481 | } |
1401c00e | 482 | mutex_unlock(&priv->lock); |
ab31523c GH |
483 | } |
484 | ||
ab31523c GH |
485 | static void mn_release(struct mmu_notifier *mn, |
486 | struct mm_struct *mm) | |
487 | { | |
488 | struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); | |
489 | struct grant_map *map; | |
490 | int err; | |
491 | ||
1401c00e | 492 | mutex_lock(&priv->lock); |
ab31523c GH |
493 | list_for_each_entry(map, &priv->maps, next) { |
494 | if (!map->vma) | |
495 | continue; | |
496 | pr_debug("map %d+%d (%lx %lx)\n", | |
497 | map->index, map->count, | |
498 | map->vma->vm_start, map->vma->vm_end); | |
499 | err = unmap_grant_pages(map, /* offset */ 0, map->count); | |
500 | WARN_ON(err); | |
501 | } | |
16a1d022 DDG |
502 | list_for_each_entry(map, &priv->freeable_maps, next) { |
503 | if (!map->vma) | |
504 | continue; | |
505 | pr_debug("map %d+%d (%lx %lx)\n", | |
506 | map->index, map->count, | |
507 | map->vma->vm_start, map->vma->vm_end); | |
508 | err = unmap_grant_pages(map, /* offset */ 0, map->count); | |
509 | WARN_ON(err); | |
510 | } | |
1401c00e | 511 | mutex_unlock(&priv->lock); |
ab31523c GH |
512 | } |
513 | ||
b9c0a92a | 514 | static const struct mmu_notifier_ops gntdev_mmu_ops = { |
ab31523c | 515 | .release = mn_release, |
ab31523c GH |
516 | .invalidate_range_start = mn_invl_range_start, |
517 | }; | |
518 | ||
519 | /* ------------------------------------------------------------------ */ | |
520 | ||
521 | static int gntdev_open(struct inode *inode, struct file *flip) | |
522 | { | |
523 | struct gntdev_priv *priv; | |
524 | int ret = 0; | |
525 | ||
526 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); | |
527 | if (!priv) | |
528 | return -ENOMEM; | |
529 | ||
530 | INIT_LIST_HEAD(&priv->maps); | |
16a1d022 | 531 | INIT_LIST_HEAD(&priv->freeable_maps); |
1401c00e | 532 | mutex_init(&priv->lock); |
ab31523c | 533 | |
aab8f11a DDG |
534 | if (use_ptemod) { |
535 | priv->mm = get_task_mm(current); | |
536 | if (!priv->mm) { | |
537 | kfree(priv); | |
538 | return -ENOMEM; | |
539 | } | |
540 | priv->mn.ops = &gntdev_mmu_ops; | |
541 | ret = mmu_notifier_register(&priv->mn, priv->mm); | |
542 | mmput(priv->mm); | |
ab31523c | 543 | } |
ab31523c GH |
544 | |
545 | if (ret) { | |
546 | kfree(priv); | |
547 | return ret; | |
548 | } | |
549 | ||
550 | flip->private_data = priv; | |
551 | pr_debug("priv %p\n", priv); | |
552 | ||
553 | return 0; | |
554 | } | |
555 | ||
556 | static int gntdev_release(struct inode *inode, struct file *flip) | |
557 | { | |
558 | struct gntdev_priv *priv = flip->private_data; | |
559 | struct grant_map *map; | |
ab31523c GH |
560 | |
561 | pr_debug("priv %p\n", priv); | |
562 | ||
30b03d05 | 563 | mutex_lock(&priv->lock); |
ab31523c GH |
564 | while (!list_empty(&priv->maps)) { |
565 | map = list_entry(priv->maps.next, struct grant_map, next); | |
68b025c8 | 566 | list_del(&map->next); |
16a1d022 | 567 | gntdev_put_map(NULL /* already removed */, map); |
ab31523c | 568 | } |
16a1d022 | 569 | WARN_ON(!list_empty(&priv->freeable_maps)); |
30b03d05 | 570 | mutex_unlock(&priv->lock); |
ab31523c | 571 | |
aab8f11a DDG |
572 | if (use_ptemod) |
573 | mmu_notifier_unregister(&priv->mn, priv->mm); | |
ab31523c GH |
574 | kfree(priv); |
575 | return 0; | |
576 | } | |
577 | ||
578 | static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv, | |
579 | struct ioctl_gntdev_map_grant_ref __user *u) | |
580 | { | |
581 | struct ioctl_gntdev_map_grant_ref op; | |
582 | struct grant_map *map; | |
583 | int err; | |
584 | ||
585 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
586 | return -EFAULT; | |
587 | pr_debug("priv %p, add %d\n", priv, op.count); | |
588 | if (unlikely(op.count <= 0)) | |
589 | return -EINVAL; | |
ab31523c GH |
590 | |
591 | err = -ENOMEM; | |
592 | map = gntdev_alloc_map(priv, op.count); | |
593 | if (!map) | |
594 | return err; | |
ef91082e | 595 | |
68b025c8 DDG |
596 | if (unlikely(atomic_add_return(op.count, &pages_mapped) > limit)) { |
597 | pr_debug("can't map: over limit\n"); | |
16a1d022 | 598 | gntdev_put_map(NULL, map); |
ab31523c GH |
599 | return err; |
600 | } | |
601 | ||
68b025c8 DDG |
602 | if (copy_from_user(map->grants, &u->refs, |
603 | sizeof(map->grants[0]) * op.count) != 0) { | |
16a1d022 DDG |
604 | gntdev_put_map(NULL, map); |
605 | return -EFAULT; | |
ef91082e DDG |
606 | } |
607 | ||
1401c00e | 608 | mutex_lock(&priv->lock); |
ab31523c GH |
609 | gntdev_add_map(priv, map); |
610 | op.index = map->index << PAGE_SHIFT; | |
1401c00e | 611 | mutex_unlock(&priv->lock); |
ab31523c | 612 | |
68b025c8 DDG |
613 | if (copy_to_user(u, &op, sizeof(op)) != 0) |
614 | return -EFAULT; | |
615 | ||
ab31523c GH |
616 | return 0; |
617 | } | |
618 | ||
619 | static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv, | |
620 | struct ioctl_gntdev_unmap_grant_ref __user *u) | |
621 | { | |
622 | struct ioctl_gntdev_unmap_grant_ref op; | |
623 | struct grant_map *map; | |
624 | int err = -ENOENT; | |
625 | ||
626 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
627 | return -EFAULT; | |
628 | pr_debug("priv %p, del %d+%d\n", priv, (int)op.index, (int)op.count); | |
629 | ||
1401c00e | 630 | mutex_lock(&priv->lock); |
ab31523c | 631 | map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count); |
68b025c8 DDG |
632 | if (map) { |
633 | list_del(&map->next); | |
16a1d022 DDG |
634 | if (populate_freeable_maps) |
635 | list_add_tail(&map->next, &priv->freeable_maps); | |
68b025c8 DDG |
636 | err = 0; |
637 | } | |
1401c00e | 638 | mutex_unlock(&priv->lock); |
1f1503ba | 639 | if (map) |
16a1d022 | 640 | gntdev_put_map(priv, map); |
ab31523c GH |
641 | return err; |
642 | } | |
643 | ||
644 | static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv, | |
645 | struct ioctl_gntdev_get_offset_for_vaddr __user *u) | |
646 | { | |
647 | struct ioctl_gntdev_get_offset_for_vaddr op; | |
a879211b | 648 | struct vm_area_struct *vma; |
ab31523c | 649 | struct grant_map *map; |
2512f298 | 650 | int rv = -EINVAL; |
ab31523c GH |
651 | |
652 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
653 | return -EFAULT; | |
654 | pr_debug("priv %p, offset for vaddr %lx\n", priv, (unsigned long)op.vaddr); | |
655 | ||
2512f298 | 656 | down_read(¤t->mm->mmap_sem); |
a879211b DDG |
657 | vma = find_vma(current->mm, op.vaddr); |
658 | if (!vma || vma->vm_ops != &gntdev_vmops) | |
2512f298 | 659 | goto out_unlock; |
a879211b DDG |
660 | |
661 | map = vma->vm_private_data; | |
662 | if (!map) | |
2512f298 | 663 | goto out_unlock; |
a879211b | 664 | |
ab31523c GH |
665 | op.offset = map->index << PAGE_SHIFT; |
666 | op.count = map->count; | |
2512f298 | 667 | rv = 0; |
ab31523c | 668 | |
2512f298 DDG |
669 | out_unlock: |
670 | up_read(¤t->mm->mmap_sem); | |
671 | ||
672 | if (rv == 0 && copy_to_user(u, &op, sizeof(op)) != 0) | |
ab31523c | 673 | return -EFAULT; |
2512f298 | 674 | return rv; |
ab31523c GH |
675 | } |
676 | ||
bdc612dc DDG |
677 | static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u) |
678 | { | |
679 | struct ioctl_gntdev_unmap_notify op; | |
680 | struct grant_map *map; | |
681 | int rc; | |
0cc678f8 DDG |
682 | int out_flags; |
683 | unsigned int out_event; | |
bdc612dc DDG |
684 | |
685 | if (copy_from_user(&op, u, sizeof(op))) | |
686 | return -EFAULT; | |
687 | ||
688 | if (op.action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT)) | |
689 | return -EINVAL; | |
690 | ||
0cc678f8 DDG |
691 | /* We need to grab a reference to the event channel we are going to use |
692 | * to send the notify before releasing the reference we may already have | |
693 | * (if someone has called this ioctl twice). This is required so that | |
694 | * it is possible to change the clear_byte part of the notification | |
695 | * without disturbing the event channel part, which may now be the last | |
696 | * reference to that event channel. | |
697 | */ | |
698 | if (op.action & UNMAP_NOTIFY_SEND_EVENT) { | |
699 | if (evtchn_get(op.event_channel_port)) | |
700 | return -EINVAL; | |
701 | } | |
702 | ||
703 | out_flags = op.action; | |
704 | out_event = op.event_channel_port; | |
705 | ||
1401c00e | 706 | mutex_lock(&priv->lock); |
bdc612dc DDG |
707 | |
708 | list_for_each_entry(map, &priv->maps, next) { | |
709 | uint64_t begin = map->index << PAGE_SHIFT; | |
710 | uint64_t end = (map->index + map->count) << PAGE_SHIFT; | |
711 | if (op.index >= begin && op.index < end) | |
712 | goto found; | |
713 | } | |
714 | rc = -ENOENT; | |
715 | goto unlock_out; | |
716 | ||
717 | found: | |
9960be97 DDG |
718 | if ((op.action & UNMAP_NOTIFY_CLEAR_BYTE) && |
719 | (map->flags & GNTMAP_readonly)) { | |
720 | rc = -EINVAL; | |
721 | goto unlock_out; | |
722 | } | |
723 | ||
0cc678f8 DDG |
724 | out_flags = map->notify.flags; |
725 | out_event = map->notify.event; | |
726 | ||
bdc612dc DDG |
727 | map->notify.flags = op.action; |
728 | map->notify.addr = op.index - (map->index << PAGE_SHIFT); | |
729 | map->notify.event = op.event_channel_port; | |
0cc678f8 | 730 | |
bdc612dc | 731 | rc = 0; |
0cc678f8 | 732 | |
bdc612dc | 733 | unlock_out: |
1401c00e | 734 | mutex_unlock(&priv->lock); |
0cc678f8 DDG |
735 | |
736 | /* Drop the reference to the event channel we did not save in the map */ | |
737 | if (out_flags & UNMAP_NOTIFY_SEND_EVENT) | |
738 | evtchn_put(out_event); | |
739 | ||
bdc612dc DDG |
740 | return rc; |
741 | } | |
742 | ||
36ae220a | 743 | #define GNTDEV_COPY_BATCH 16 |
a4cdb556 DV |
744 | |
745 | struct gntdev_copy_batch { | |
746 | struct gnttab_copy ops[GNTDEV_COPY_BATCH]; | |
747 | struct page *pages[GNTDEV_COPY_BATCH]; | |
748 | s16 __user *status[GNTDEV_COPY_BATCH]; | |
749 | unsigned int nr_ops; | |
750 | unsigned int nr_pages; | |
751 | }; | |
752 | ||
753 | static int gntdev_get_page(struct gntdev_copy_batch *batch, void __user *virt, | |
754 | bool writeable, unsigned long *gfn) | |
755 | { | |
756 | unsigned long addr = (unsigned long)virt; | |
757 | struct page *page; | |
758 | unsigned long xen_pfn; | |
759 | int ret; | |
760 | ||
761 | ret = get_user_pages_fast(addr, 1, writeable, &page); | |
762 | if (ret < 0) | |
763 | return ret; | |
764 | ||
765 | batch->pages[batch->nr_pages++] = page; | |
766 | ||
767 | xen_pfn = page_to_xen_pfn(page) + XEN_PFN_DOWN(addr & ~PAGE_MASK); | |
768 | *gfn = pfn_to_gfn(xen_pfn); | |
769 | ||
770 | return 0; | |
771 | } | |
772 | ||
773 | static void gntdev_put_pages(struct gntdev_copy_batch *batch) | |
774 | { | |
775 | unsigned int i; | |
776 | ||
777 | for (i = 0; i < batch->nr_pages; i++) | |
778 | put_page(batch->pages[i]); | |
779 | batch->nr_pages = 0; | |
780 | } | |
781 | ||
782 | static int gntdev_copy(struct gntdev_copy_batch *batch) | |
783 | { | |
784 | unsigned int i; | |
785 | ||
786 | gnttab_batch_copy(batch->ops, batch->nr_ops); | |
787 | gntdev_put_pages(batch); | |
788 | ||
789 | /* | |
790 | * For each completed op, update the status if the op failed | |
791 | * and all previous ops for the segment were successful. | |
792 | */ | |
793 | for (i = 0; i < batch->nr_ops; i++) { | |
794 | s16 status = batch->ops[i].status; | |
795 | s16 old_status; | |
796 | ||
797 | if (status == GNTST_okay) | |
798 | continue; | |
799 | ||
800 | if (__get_user(old_status, batch->status[i])) | |
801 | return -EFAULT; | |
802 | ||
803 | if (old_status != GNTST_okay) | |
804 | continue; | |
805 | ||
806 | if (__put_user(status, batch->status[i])) | |
807 | return -EFAULT; | |
808 | } | |
809 | ||
810 | batch->nr_ops = 0; | |
811 | return 0; | |
812 | } | |
813 | ||
814 | static int gntdev_grant_copy_seg(struct gntdev_copy_batch *batch, | |
815 | struct gntdev_grant_copy_segment *seg, | |
816 | s16 __user *status) | |
817 | { | |
818 | uint16_t copied = 0; | |
819 | ||
820 | /* | |
821 | * Disallow local -> local copies since there is only space in | |
822 | * batch->pages for one page per-op and this would be a very | |
823 | * expensive memcpy(). | |
824 | */ | |
825 | if (!(seg->flags & (GNTCOPY_source_gref | GNTCOPY_dest_gref))) | |
826 | return -EINVAL; | |
827 | ||
828 | /* Can't cross page if source/dest is a grant ref. */ | |
829 | if (seg->flags & GNTCOPY_source_gref) { | |
830 | if (seg->source.foreign.offset + seg->len > XEN_PAGE_SIZE) | |
831 | return -EINVAL; | |
832 | } | |
833 | if (seg->flags & GNTCOPY_dest_gref) { | |
834 | if (seg->dest.foreign.offset + seg->len > XEN_PAGE_SIZE) | |
835 | return -EINVAL; | |
836 | } | |
837 | ||
838 | if (put_user(GNTST_okay, status)) | |
839 | return -EFAULT; | |
840 | ||
841 | while (copied < seg->len) { | |
842 | struct gnttab_copy *op; | |
843 | void __user *virt; | |
844 | size_t len, off; | |
845 | unsigned long gfn; | |
846 | int ret; | |
847 | ||
848 | if (batch->nr_ops >= GNTDEV_COPY_BATCH) { | |
849 | ret = gntdev_copy(batch); | |
850 | if (ret < 0) | |
851 | return ret; | |
852 | } | |
853 | ||
854 | len = seg->len - copied; | |
855 | ||
856 | op = &batch->ops[batch->nr_ops]; | |
857 | op->flags = 0; | |
858 | ||
859 | if (seg->flags & GNTCOPY_source_gref) { | |
860 | op->source.u.ref = seg->source.foreign.ref; | |
861 | op->source.domid = seg->source.foreign.domid; | |
862 | op->source.offset = seg->source.foreign.offset + copied; | |
863 | op->flags |= GNTCOPY_source_gref; | |
864 | } else { | |
865 | virt = seg->source.virt + copied; | |
866 | off = (unsigned long)virt & ~XEN_PAGE_MASK; | |
867 | len = min(len, (size_t)XEN_PAGE_SIZE - off); | |
868 | ||
869 | ret = gntdev_get_page(batch, virt, false, &gfn); | |
870 | if (ret < 0) | |
871 | return ret; | |
872 | ||
873 | op->source.u.gmfn = gfn; | |
874 | op->source.domid = DOMID_SELF; | |
875 | op->source.offset = off; | |
876 | } | |
877 | ||
878 | if (seg->flags & GNTCOPY_dest_gref) { | |
879 | op->dest.u.ref = seg->dest.foreign.ref; | |
880 | op->dest.domid = seg->dest.foreign.domid; | |
881 | op->dest.offset = seg->dest.foreign.offset + copied; | |
882 | op->flags |= GNTCOPY_dest_gref; | |
883 | } else { | |
884 | virt = seg->dest.virt + copied; | |
885 | off = (unsigned long)virt & ~XEN_PAGE_MASK; | |
886 | len = min(len, (size_t)XEN_PAGE_SIZE - off); | |
887 | ||
888 | ret = gntdev_get_page(batch, virt, true, &gfn); | |
889 | if (ret < 0) | |
890 | return ret; | |
891 | ||
892 | op->dest.u.gmfn = gfn; | |
893 | op->dest.domid = DOMID_SELF; | |
894 | op->dest.offset = off; | |
895 | } | |
896 | ||
897 | op->len = len; | |
898 | copied += len; | |
899 | ||
900 | batch->status[batch->nr_ops] = status; | |
901 | batch->nr_ops++; | |
902 | } | |
903 | ||
904 | return 0; | |
905 | } | |
906 | ||
907 | static long gntdev_ioctl_grant_copy(struct gntdev_priv *priv, void __user *u) | |
908 | { | |
909 | struct ioctl_gntdev_grant_copy copy; | |
910 | struct gntdev_copy_batch batch; | |
911 | unsigned int i; | |
912 | int ret = 0; | |
913 | ||
914 | if (copy_from_user(©, u, sizeof(copy))) | |
915 | return -EFAULT; | |
916 | ||
917 | batch.nr_ops = 0; | |
918 | batch.nr_pages = 0; | |
919 | ||
920 | for (i = 0; i < copy.count; i++) { | |
921 | struct gntdev_grant_copy_segment seg; | |
922 | ||
923 | if (copy_from_user(&seg, ©.segments[i], sizeof(seg))) { | |
924 | ret = -EFAULT; | |
925 | goto out; | |
926 | } | |
927 | ||
928 | ret = gntdev_grant_copy_seg(&batch, &seg, ©.segments[i].status); | |
929 | if (ret < 0) | |
930 | goto out; | |
931 | ||
932 | cond_resched(); | |
933 | } | |
934 | if (batch.nr_ops) | |
935 | ret = gntdev_copy(&batch); | |
936 | return ret; | |
937 | ||
938 | out: | |
939 | gntdev_put_pages(&batch); | |
940 | return ret; | |
941 | } | |
942 | ||
ab31523c GH |
943 | static long gntdev_ioctl(struct file *flip, |
944 | unsigned int cmd, unsigned long arg) | |
945 | { | |
946 | struct gntdev_priv *priv = flip->private_data; | |
947 | void __user *ptr = (void __user *)arg; | |
948 | ||
949 | switch (cmd) { | |
950 | case IOCTL_GNTDEV_MAP_GRANT_REF: | |
951 | return gntdev_ioctl_map_grant_ref(priv, ptr); | |
952 | ||
953 | case IOCTL_GNTDEV_UNMAP_GRANT_REF: | |
954 | return gntdev_ioctl_unmap_grant_ref(priv, ptr); | |
955 | ||
956 | case IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR: | |
957 | return gntdev_ioctl_get_offset_for_vaddr(priv, ptr); | |
958 | ||
bdc612dc DDG |
959 | case IOCTL_GNTDEV_SET_UNMAP_NOTIFY: |
960 | return gntdev_ioctl_notify(priv, ptr); | |
961 | ||
a4cdb556 DV |
962 | case IOCTL_GNTDEV_GRANT_COPY: |
963 | return gntdev_ioctl_grant_copy(priv, ptr); | |
964 | ||
ab31523c GH |
965 | default: |
966 | pr_debug("priv %p, unknown cmd %x\n", priv, cmd); | |
967 | return -ENOIOCTLCMD; | |
968 | } | |
969 | ||
970 | return 0; | |
971 | } | |
972 | ||
973 | static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) | |
974 | { | |
975 | struct gntdev_priv *priv = flip->private_data; | |
976 | int index = vma->vm_pgoff; | |
c7ebf9d9 | 977 | int count = vma_pages(vma); |
ab31523c | 978 | struct grant_map *map; |
aab8f11a | 979 | int i, err = -EINVAL; |
ab31523c GH |
980 | |
981 | if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED)) | |
982 | return -EINVAL; | |
983 | ||
984 | pr_debug("map %d+%d at %lx (pgoff %lx)\n", | |
985 | index, count, vma->vm_start, vma->vm_pgoff); | |
986 | ||
1401c00e | 987 | mutex_lock(&priv->lock); |
ab31523c GH |
988 | map = gntdev_find_map_index(priv, index, count); |
989 | if (!map) | |
990 | goto unlock_out; | |
aab8f11a | 991 | if (use_ptemod && map->vma) |
ab31523c | 992 | goto unlock_out; |
aab8f11a | 993 | if (use_ptemod && priv->mm != vma->vm_mm) { |
283c0972 | 994 | pr_warn("Huh? Other mm?\n"); |
ab31523c GH |
995 | goto unlock_out; |
996 | } | |
997 | ||
c5f7c5a9 | 998 | refcount_inc(&map->users); |
68b025c8 | 999 | |
ab31523c GH |
1000 | vma->vm_ops = &gntdev_vmops; |
1001 | ||
30faaafd | 1002 | vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP | VM_MIXEDMAP; |
d79647ae DDG |
1003 | |
1004 | if (use_ptemod) | |
e8e937be | 1005 | vma->vm_flags |= VM_DONTCOPY; |
ab31523c GH |
1006 | |
1007 | vma->vm_private_data = map; | |
ab31523c | 1008 | |
aab8f11a DDG |
1009 | if (use_ptemod) |
1010 | map->vma = vma; | |
1011 | ||
12996fc3 DDG |
1012 | if (map->flags) { |
1013 | if ((vma->vm_flags & VM_WRITE) && | |
1014 | (map->flags & GNTMAP_readonly)) | |
a93e20a8 | 1015 | goto out_unlock_put; |
12996fc3 DDG |
1016 | } else { |
1017 | map->flags = GNTMAP_host_map; | |
1018 | if (!(vma->vm_flags & VM_WRITE)) | |
1019 | map->flags |= GNTMAP_readonly; | |
1020 | } | |
ab31523c | 1021 | |
1401c00e | 1022 | mutex_unlock(&priv->lock); |
f0a70c88 | 1023 | |
aab8f11a | 1024 | if (use_ptemod) { |
298d275d | 1025 | map->pages_vm_start = vma->vm_start; |
aab8f11a DDG |
1026 | err = apply_to_page_range(vma->vm_mm, vma->vm_start, |
1027 | vma->vm_end - vma->vm_start, | |
1028 | find_grant_ptes, map); | |
1029 | if (err) { | |
283c0972 | 1030 | pr_warn("find_grant_ptes() failure.\n"); |
90b6f305 | 1031 | goto out_put_map; |
aab8f11a | 1032 | } |
ab31523c GH |
1033 | } |
1034 | ||
1035 | err = map_grant_pages(map); | |
90b6f305 DDG |
1036 | if (err) |
1037 | goto out_put_map; | |
f0a70c88 | 1038 | |
aab8f11a DDG |
1039 | if (!use_ptemod) { |
1040 | for (i = 0; i < count; i++) { | |
1041 | err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE, | |
1042 | map->pages[i]); | |
1043 | if (err) | |
90b6f305 | 1044 | goto out_put_map; |
aab8f11a | 1045 | } |
923b2919 DV |
1046 | } else { |
1047 | #ifdef CONFIG_X86 | |
1048 | /* | |
1049 | * If the PTEs were not made special by the grant map | |
1050 | * hypercall, do so here. | |
1051 | * | |
1052 | * This is racy since the mapping is already visible | |
1053 | * to userspace but userspace should be well-behaved | |
1054 | * enough to not touch it until the mmap() call | |
1055 | * returns. | |
1056 | */ | |
1057 | if (!xen_feature(XENFEAT_gnttab_map_avail_bits)) { | |
1058 | apply_to_page_range(vma->vm_mm, vma->vm_start, | |
1059 | vma->vm_end - vma->vm_start, | |
1060 | set_grant_ptes_as_special, NULL); | |
1061 | } | |
1062 | #endif | |
aab8f11a DDG |
1063 | } |
1064 | ||
f0a70c88 DDG |
1065 | return 0; |
1066 | ||
ab31523c | 1067 | unlock_out: |
1401c00e | 1068 | mutex_unlock(&priv->lock); |
ab31523c | 1069 | return err; |
90b6f305 | 1070 | |
a93e20a8 | 1071 | out_unlock_put: |
1401c00e | 1072 | mutex_unlock(&priv->lock); |
90b6f305 | 1073 | out_put_map: |
cf2acf66 | 1074 | if (use_ptemod) { |
84e4075d | 1075 | map->vma = NULL; |
cf2acf66 RL |
1076 | unmap_grant_pages(map, 0, map->count); |
1077 | } | |
16a1d022 | 1078 | gntdev_put_map(priv, map); |
90b6f305 | 1079 | return err; |
ab31523c GH |
1080 | } |
1081 | ||
1082 | static const struct file_operations gntdev_fops = { | |
1083 | .owner = THIS_MODULE, | |
1084 | .open = gntdev_open, | |
1085 | .release = gntdev_release, | |
1086 | .mmap = gntdev_mmap, | |
1087 | .unlocked_ioctl = gntdev_ioctl | |
1088 | }; | |
1089 | ||
1090 | static struct miscdevice gntdev_miscdev = { | |
1091 | .minor = MISC_DYNAMIC_MINOR, | |
1092 | .name = "xen/gntdev", | |
1093 | .fops = &gntdev_fops, | |
1094 | }; | |
1095 | ||
1096 | /* ------------------------------------------------------------------ */ | |
1097 | ||
1098 | static int __init gntdev_init(void) | |
1099 | { | |
1100 | int err; | |
1101 | ||
1102 | if (!xen_domain()) | |
1103 | return -ENODEV; | |
1104 | ||
6926f6d6 | 1105 | use_ptemod = !xen_feature(XENFEAT_auto_translated_physmap); |
aab8f11a | 1106 | |
ab31523c GH |
1107 | err = misc_register(&gntdev_miscdev); |
1108 | if (err != 0) { | |
283c0972 | 1109 | pr_err("Could not register gntdev device\n"); |
ab31523c GH |
1110 | return err; |
1111 | } | |
1112 | return 0; | |
1113 | } | |
1114 | ||
1115 | static void __exit gntdev_exit(void) | |
1116 | { | |
1117 | misc_deregister(&gntdev_miscdev); | |
1118 | } | |
1119 | ||
1120 | module_init(gntdev_init); | |
1121 | module_exit(gntdev_exit); | |
1122 | ||
1123 | /* ------------------------------------------------------------------ */ |