Commit | Line | Data |
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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> | |
35 | #include <linux/spinlock.h> | |
36 | #include <linux/slab.h> | |
aab8f11a | 37 | #include <linux/highmem.h> |
ab31523c GH |
38 | |
39 | #include <xen/xen.h> | |
40 | #include <xen/grant_table.h> | |
ca47ceaa | 41 | #include <xen/balloon.h> |
ab31523c | 42 | #include <xen/gntdev.h> |
bdc612dc | 43 | #include <xen/events.h> |
ab31523c GH |
44 | #include <asm/xen/hypervisor.h> |
45 | #include <asm/xen/hypercall.h> | |
46 | #include <asm/xen/page.h> | |
47 | ||
48 | MODULE_LICENSE("GPL"); | |
49 | MODULE_AUTHOR("Derek G. Murray <Derek.Murray@cl.cam.ac.uk>, " | |
50 | "Gerd Hoffmann <kraxel@redhat.com>"); | |
51 | MODULE_DESCRIPTION("User-space granted page access driver"); | |
52 | ||
ef91082e | 53 | static int limit = 1024*1024; |
ab31523c | 54 | module_param(limit, int, 0644); |
ef91082e DDG |
55 | MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by " |
56 | "the gntdev device"); | |
57 | ||
58 | static atomic_t pages_mapped = ATOMIC_INIT(0); | |
ab31523c | 59 | |
aab8f11a | 60 | static int use_ptemod; |
16a1d022 | 61 | #define populate_freeable_maps use_ptemod |
aab8f11a | 62 | |
ab31523c | 63 | struct gntdev_priv { |
16a1d022 | 64 | /* maps with visible offsets in the file descriptor */ |
ab31523c | 65 | struct list_head maps; |
16a1d022 DDG |
66 | /* maps that are not visible; will be freed on munmap. |
67 | * Only populated if populate_freeable_maps == 1 */ | |
68 | struct list_head freeable_maps; | |
69 | /* lock protects maps and freeable_maps */ | |
ab31523c GH |
70 | spinlock_t lock; |
71 | struct mm_struct *mm; | |
72 | struct mmu_notifier mn; | |
73 | }; | |
74 | ||
bdc612dc DDG |
75 | struct unmap_notify { |
76 | int flags; | |
77 | /* Address relative to the start of the grant_map */ | |
78 | int addr; | |
79 | int event; | |
80 | }; | |
81 | ||
ab31523c GH |
82 | struct grant_map { |
83 | struct list_head next; | |
ab31523c GH |
84 | struct vm_area_struct *vma; |
85 | int index; | |
86 | int count; | |
87 | int flags; | |
68b025c8 | 88 | atomic_t users; |
bdc612dc | 89 | struct unmap_notify notify; |
ab31523c GH |
90 | struct ioctl_gntdev_grant_ref *grants; |
91 | struct gnttab_map_grant_ref *map_ops; | |
92 | struct gnttab_unmap_grant_ref *unmap_ops; | |
0930bba6 | 93 | struct gnttab_map_grant_ref *kmap_ops; |
a12b4eb3 | 94 | struct page **pages; |
ab31523c GH |
95 | }; |
96 | ||
aab8f11a DDG |
97 | static int unmap_grant_pages(struct grant_map *map, int offset, int pages); |
98 | ||
ab31523c GH |
99 | /* ------------------------------------------------------------------ */ |
100 | ||
101 | static void gntdev_print_maps(struct gntdev_priv *priv, | |
102 | char *text, int text_index) | |
103 | { | |
104 | #ifdef DEBUG | |
105 | struct grant_map *map; | |
106 | ||
ef91082e | 107 | pr_debug("%s: maps list (priv %p)\n", __func__, priv); |
ab31523c GH |
108 | list_for_each_entry(map, &priv->maps, next) |
109 | pr_debug(" index %2d, count %2d %s\n", | |
110 | map->index, map->count, | |
111 | map->index == text_index && text ? text : ""); | |
112 | #endif | |
113 | } | |
114 | ||
a67baeb7 DV |
115 | static void gntdev_free_map(struct grant_map *map) |
116 | { | |
117 | if (map == NULL) | |
118 | return; | |
119 | ||
120 | if (map->pages) | |
121 | free_xenballooned_pages(map->count, map->pages); | |
122 | kfree(map->pages); | |
123 | kfree(map->grants); | |
124 | kfree(map->map_ops); | |
125 | kfree(map->unmap_ops); | |
126 | kfree(map->kmap_ops); | |
127 | kfree(map); | |
128 | } | |
129 | ||
ab31523c GH |
130 | static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count) |
131 | { | |
132 | struct grant_map *add; | |
a12b4eb3 | 133 | int i; |
ab31523c GH |
134 | |
135 | add = kzalloc(sizeof(struct grant_map), GFP_KERNEL); | |
136 | if (NULL == add) | |
137 | return NULL; | |
138 | ||
fc6e0c3b DC |
139 | add->grants = kcalloc(count, sizeof(add->grants[0]), GFP_KERNEL); |
140 | add->map_ops = kcalloc(count, sizeof(add->map_ops[0]), GFP_KERNEL); | |
141 | add->unmap_ops = kcalloc(count, sizeof(add->unmap_ops[0]), GFP_KERNEL); | |
142 | add->kmap_ops = kcalloc(count, sizeof(add->kmap_ops[0]), GFP_KERNEL); | |
143 | add->pages = kcalloc(count, sizeof(add->pages[0]), GFP_KERNEL); | |
a12b4eb3 SS |
144 | if (NULL == add->grants || |
145 | NULL == add->map_ops || | |
146 | NULL == add->unmap_ops || | |
0930bba6 | 147 | NULL == add->kmap_ops || |
a12b4eb3 | 148 | NULL == add->pages) |
ab31523c GH |
149 | goto err; |
150 | ||
693394b8 | 151 | if (alloc_xenballooned_pages(count, add->pages, false /* lowmem */)) |
ca47ceaa DDG |
152 | goto err; |
153 | ||
a12b4eb3 | 154 | for (i = 0; i < count; i++) { |
77c35acb DDG |
155 | add->map_ops[i].handle = -1; |
156 | add->unmap_ops[i].handle = -1; | |
0930bba6 | 157 | add->kmap_ops[i].handle = -1; |
a12b4eb3 SS |
158 | } |
159 | ||
ab31523c GH |
160 | add->index = 0; |
161 | add->count = count; | |
68b025c8 | 162 | atomic_set(&add->users, 1); |
ab31523c | 163 | |
ab31523c GH |
164 | return add; |
165 | ||
166 | err: | |
a67baeb7 | 167 | gntdev_free_map(add); |
ab31523c GH |
168 | return NULL; |
169 | } | |
170 | ||
171 | static void gntdev_add_map(struct gntdev_priv *priv, struct grant_map *add) | |
172 | { | |
173 | struct grant_map *map; | |
174 | ||
175 | list_for_each_entry(map, &priv->maps, next) { | |
176 | if (add->index + add->count < map->index) { | |
177 | list_add_tail(&add->next, &map->next); | |
178 | goto done; | |
179 | } | |
180 | add->index = map->index + map->count; | |
181 | } | |
182 | list_add_tail(&add->next, &priv->maps); | |
183 | ||
184 | done: | |
ab31523c GH |
185 | gntdev_print_maps(priv, "[new]", add->index); |
186 | } | |
187 | ||
188 | static struct grant_map *gntdev_find_map_index(struct gntdev_priv *priv, | |
189 | int index, int count) | |
190 | { | |
191 | struct grant_map *map; | |
192 | ||
193 | list_for_each_entry(map, &priv->maps, next) { | |
194 | if (map->index != index) | |
195 | continue; | |
bdc612dc | 196 | if (count && map->count != count) |
ab31523c GH |
197 | continue; |
198 | return map; | |
199 | } | |
200 | return NULL; | |
201 | } | |
202 | ||
16a1d022 | 203 | static void gntdev_put_map(struct gntdev_priv *priv, struct grant_map *map) |
ab31523c GH |
204 | { |
205 | if (!map) | |
206 | return; | |
a12b4eb3 | 207 | |
68b025c8 DDG |
208 | if (!atomic_dec_and_test(&map->users)) |
209 | return; | |
210 | ||
211 | atomic_sub(map->count, &pages_mapped); | |
212 | ||
0cc678f8 | 213 | if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) { |
bdc612dc | 214 | notify_remote_via_evtchn(map->notify.event); |
0cc678f8 DDG |
215 | evtchn_put(map->notify.event); |
216 | } | |
bdc612dc | 217 | |
16a1d022 DDG |
218 | if (populate_freeable_maps && priv) { |
219 | spin_lock(&priv->lock); | |
220 | list_del(&map->next); | |
221 | spin_unlock(&priv->lock); | |
222 | } | |
223 | ||
a67baeb7 DV |
224 | if (map->pages && !use_ptemod) |
225 | unmap_grant_pages(map, 0, map->count); | |
226 | gntdev_free_map(map); | |
ab31523c GH |
227 | } |
228 | ||
229 | /* ------------------------------------------------------------------ */ | |
230 | ||
231 | static int find_grant_ptes(pte_t *pte, pgtable_t token, | |
232 | unsigned long addr, void *data) | |
233 | { | |
234 | struct grant_map *map = data; | |
235 | unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT; | |
aab8f11a | 236 | int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte; |
ab31523c GH |
237 | u64 pte_maddr; |
238 | ||
239 | BUG_ON(pgnr >= map->count); | |
ba5d1012 JF |
240 | pte_maddr = arbitrary_virt_to_machine(pte).maddr; |
241 | ||
aab8f11a | 242 | gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, flags, |
ab31523c GH |
243 | map->grants[pgnr].ref, |
244 | map->grants[pgnr].domid); | |
aab8f11a | 245 | gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags, |
77c35acb | 246 | -1 /* handle */); |
ab31523c GH |
247 | return 0; |
248 | } | |
249 | ||
250 | static int map_grant_pages(struct grant_map *map) | |
251 | { | |
252 | int i, err = 0; | |
aab8f11a DDG |
253 | |
254 | if (!use_ptemod) { | |
12996fc3 | 255 | /* Note: it could already be mapped */ |
77c35acb | 256 | if (map->map_ops[0].handle != -1) |
12996fc3 | 257 | return 0; |
aab8f11a | 258 | for (i = 0; i < map->count; i++) { |
38eaeb0f | 259 | unsigned long addr = (unsigned long) |
aab8f11a DDG |
260 | pfn_to_kaddr(page_to_pfn(map->pages[i])); |
261 | gnttab_set_map_op(&map->map_ops[i], addr, map->flags, | |
262 | map->grants[i].ref, | |
263 | map->grants[i].domid); | |
264 | gnttab_set_unmap_op(&map->unmap_ops[i], addr, | |
77c35acb | 265 | map->flags, -1 /* handle */); |
aab8f11a | 266 | } |
0930bba6 SS |
267 | } else { |
268 | /* | |
269 | * Setup the map_ops corresponding to the pte entries pointing | |
270 | * to the kernel linear addresses of the struct pages. | |
271 | * These ptes are completely different from the user ptes dealt | |
272 | * with find_grant_ptes. | |
273 | */ | |
274 | for (i = 0; i < map->count; i++) { | |
0930bba6 SS |
275 | unsigned long address = (unsigned long) |
276 | pfn_to_kaddr(page_to_pfn(map->pages[i])); | |
0930bba6 SS |
277 | BUG_ON(PageHighMem(map->pages[i])); |
278 | ||
ee072640 SS |
279 | gnttab_set_map_op(&map->kmap_ops[i], address, |
280 | map->flags | GNTMAP_host_map, | |
0930bba6 SS |
281 | map->grants[i].ref, |
282 | map->grants[i].domid); | |
283 | } | |
aab8f11a | 284 | } |
ab31523c GH |
285 | |
286 | pr_debug("map %d+%d\n", map->index, map->count); | |
0930bba6 SS |
287 | err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL, |
288 | map->pages, map->count); | |
ab31523c GH |
289 | if (err) |
290 | return err; | |
291 | ||
292 | for (i = 0; i < map->count; i++) { | |
293 | if (map->map_ops[i].status) | |
294 | err = -EINVAL; | |
77c35acb DDG |
295 | else { |
296 | BUG_ON(map->map_ops[i].handle == -1); | |
297 | map->unmap_ops[i].handle = map->map_ops[i].handle; | |
298 | pr_debug("map handle=%d\n", map->map_ops[i].handle); | |
299 | } | |
ab31523c GH |
300 | } |
301 | return err; | |
302 | } | |
303 | ||
b57c1869 | 304 | static int __unmap_grant_pages(struct grant_map *map, int offset, int pages) |
ab31523c GH |
305 | { |
306 | int i, err = 0; | |
307 | ||
bdc612dc DDG |
308 | if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) { |
309 | int pgno = (map->notify.addr >> PAGE_SHIFT); | |
1affa98d DDG |
310 | if (pgno >= offset && pgno < offset + pages) { |
311 | /* No need for kmap, pages are in lowmem */ | |
312 | uint8_t *tmp = pfn_to_kaddr(page_to_pfn(map->pages[pgno])); | |
bdc612dc | 313 | tmp[map->notify.addr & (PAGE_SIZE-1)] = 0; |
bdc612dc DDG |
314 | map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE; |
315 | } | |
316 | } | |
317 | ||
2fc136ee SS |
318 | err = gnttab_unmap_refs(map->unmap_ops + offset, |
319 | use_ptemod ? map->kmap_ops + offset : NULL, map->pages + offset, | |
320 | pages); | |
ab31523c GH |
321 | if (err) |
322 | return err; | |
323 | ||
324 | for (i = 0; i < pages; i++) { | |
325 | if (map->unmap_ops[offset+i].status) | |
326 | err = -EINVAL; | |
77c35acb DDG |
327 | pr_debug("unmap handle=%d st=%d\n", |
328 | map->unmap_ops[offset+i].handle, | |
329 | map->unmap_ops[offset+i].status); | |
330 | map->unmap_ops[offset+i].handle = -1; | |
ab31523c GH |
331 | } |
332 | return err; | |
333 | } | |
334 | ||
b57c1869 DDG |
335 | static int unmap_grant_pages(struct grant_map *map, int offset, int pages) |
336 | { | |
337 | int range, err = 0; | |
338 | ||
339 | pr_debug("unmap %d+%d [%d+%d]\n", map->index, map->count, offset, pages); | |
340 | ||
341 | /* It is possible the requested range will have a "hole" where we | |
342 | * already unmapped some of the grants. Only unmap valid ranges. | |
343 | */ | |
344 | while (pages && !err) { | |
77c35acb | 345 | while (pages && map->unmap_ops[offset].handle == -1) { |
b57c1869 DDG |
346 | offset++; |
347 | pages--; | |
348 | } | |
349 | range = 0; | |
350 | while (range < pages) { | |
77c35acb | 351 | if (map->unmap_ops[offset+range].handle == -1) { |
b57c1869 DDG |
352 | range--; |
353 | break; | |
354 | } | |
355 | range++; | |
356 | } | |
357 | err = __unmap_grant_pages(map, offset, range); | |
358 | offset += range; | |
359 | pages -= range; | |
360 | } | |
361 | ||
362 | return err; | |
363 | } | |
364 | ||
ab31523c GH |
365 | /* ------------------------------------------------------------------ */ |
366 | ||
d79647ae DDG |
367 | static void gntdev_vma_open(struct vm_area_struct *vma) |
368 | { | |
369 | struct grant_map *map = vma->vm_private_data; | |
370 | ||
371 | pr_debug("gntdev_vma_open %p\n", vma); | |
372 | atomic_inc(&map->users); | |
373 | } | |
374 | ||
ab31523c GH |
375 | static void gntdev_vma_close(struct vm_area_struct *vma) |
376 | { | |
377 | struct grant_map *map = vma->vm_private_data; | |
16a1d022 DDG |
378 | struct file *file = vma->vm_file; |
379 | struct gntdev_priv *priv = file->private_data; | |
ab31523c | 380 | |
d79647ae | 381 | pr_debug("gntdev_vma_close %p\n", vma); |
2512f298 | 382 | if (use_ptemod) { |
2512f298 DDG |
383 | /* It is possible that an mmu notifier could be running |
384 | * concurrently, so take priv->lock to ensure that the vma won't | |
385 | * vanishing during the unmap_grant_pages call, since we will | |
386 | * spin here until that completes. Such a concurrent call will | |
387 | * not do any unmapping, since that has been done prior to | |
388 | * closing the vma, but it may still iterate the unmap_ops list. | |
389 | */ | |
390 | spin_lock(&priv->lock); | |
391 | map->vma = NULL; | |
392 | spin_unlock(&priv->lock); | |
393 | } | |
ab31523c | 394 | vma->vm_private_data = NULL; |
16a1d022 | 395 | gntdev_put_map(priv, map); |
ab31523c GH |
396 | } |
397 | ||
ab31523c | 398 | static struct vm_operations_struct gntdev_vmops = { |
d79647ae | 399 | .open = gntdev_vma_open, |
ab31523c | 400 | .close = gntdev_vma_close, |
ab31523c GH |
401 | }; |
402 | ||
403 | /* ------------------------------------------------------------------ */ | |
404 | ||
16a1d022 DDG |
405 | static void unmap_if_in_range(struct grant_map *map, |
406 | unsigned long start, unsigned long end) | |
407 | { | |
408 | unsigned long mstart, mend; | |
409 | int err; | |
410 | ||
411 | if (!map->vma) | |
412 | return; | |
413 | if (map->vma->vm_start >= end) | |
414 | return; | |
415 | if (map->vma->vm_end <= start) | |
416 | return; | |
417 | mstart = max(start, map->vma->vm_start); | |
418 | mend = min(end, map->vma->vm_end); | |
419 | pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n", | |
420 | map->index, map->count, | |
421 | map->vma->vm_start, map->vma->vm_end, | |
422 | start, end, mstart, mend); | |
423 | err = unmap_grant_pages(map, | |
424 | (mstart - map->vma->vm_start) >> PAGE_SHIFT, | |
425 | (mend - mstart) >> PAGE_SHIFT); | |
426 | WARN_ON(err); | |
427 | } | |
428 | ||
ab31523c GH |
429 | static void mn_invl_range_start(struct mmu_notifier *mn, |
430 | struct mm_struct *mm, | |
431 | unsigned long start, unsigned long end) | |
432 | { | |
433 | struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); | |
434 | struct grant_map *map; | |
ab31523c GH |
435 | |
436 | spin_lock(&priv->lock); | |
437 | list_for_each_entry(map, &priv->maps, next) { | |
16a1d022 DDG |
438 | unmap_if_in_range(map, start, end); |
439 | } | |
440 | list_for_each_entry(map, &priv->freeable_maps, next) { | |
441 | unmap_if_in_range(map, start, end); | |
ab31523c GH |
442 | } |
443 | spin_unlock(&priv->lock); | |
444 | } | |
445 | ||
446 | static void mn_invl_page(struct mmu_notifier *mn, | |
447 | struct mm_struct *mm, | |
448 | unsigned long address) | |
449 | { | |
450 | mn_invl_range_start(mn, mm, address, address + PAGE_SIZE); | |
451 | } | |
452 | ||
453 | static void mn_release(struct mmu_notifier *mn, | |
454 | struct mm_struct *mm) | |
455 | { | |
456 | struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); | |
457 | struct grant_map *map; | |
458 | int err; | |
459 | ||
460 | spin_lock(&priv->lock); | |
461 | list_for_each_entry(map, &priv->maps, next) { | |
462 | if (!map->vma) | |
463 | continue; | |
464 | pr_debug("map %d+%d (%lx %lx)\n", | |
465 | map->index, map->count, | |
466 | map->vma->vm_start, map->vma->vm_end); | |
467 | err = unmap_grant_pages(map, /* offset */ 0, map->count); | |
468 | WARN_ON(err); | |
469 | } | |
16a1d022 DDG |
470 | list_for_each_entry(map, &priv->freeable_maps, next) { |
471 | if (!map->vma) | |
472 | continue; | |
473 | pr_debug("map %d+%d (%lx %lx)\n", | |
474 | map->index, map->count, | |
475 | map->vma->vm_start, map->vma->vm_end); | |
476 | err = unmap_grant_pages(map, /* offset */ 0, map->count); | |
477 | WARN_ON(err); | |
478 | } | |
ab31523c GH |
479 | spin_unlock(&priv->lock); |
480 | } | |
481 | ||
b8b0f559 | 482 | static struct mmu_notifier_ops gntdev_mmu_ops = { |
ab31523c GH |
483 | .release = mn_release, |
484 | .invalidate_page = mn_invl_page, | |
485 | .invalidate_range_start = mn_invl_range_start, | |
486 | }; | |
487 | ||
488 | /* ------------------------------------------------------------------ */ | |
489 | ||
490 | static int gntdev_open(struct inode *inode, struct file *flip) | |
491 | { | |
492 | struct gntdev_priv *priv; | |
493 | int ret = 0; | |
494 | ||
495 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); | |
496 | if (!priv) | |
497 | return -ENOMEM; | |
498 | ||
499 | INIT_LIST_HEAD(&priv->maps); | |
16a1d022 | 500 | INIT_LIST_HEAD(&priv->freeable_maps); |
ab31523c | 501 | spin_lock_init(&priv->lock); |
ab31523c | 502 | |
aab8f11a DDG |
503 | if (use_ptemod) { |
504 | priv->mm = get_task_mm(current); | |
505 | if (!priv->mm) { | |
506 | kfree(priv); | |
507 | return -ENOMEM; | |
508 | } | |
509 | priv->mn.ops = &gntdev_mmu_ops; | |
510 | ret = mmu_notifier_register(&priv->mn, priv->mm); | |
511 | mmput(priv->mm); | |
ab31523c | 512 | } |
ab31523c GH |
513 | |
514 | if (ret) { | |
515 | kfree(priv); | |
516 | return ret; | |
517 | } | |
518 | ||
519 | flip->private_data = priv; | |
520 | pr_debug("priv %p\n", priv); | |
521 | ||
522 | return 0; | |
523 | } | |
524 | ||
525 | static int gntdev_release(struct inode *inode, struct file *flip) | |
526 | { | |
527 | struct gntdev_priv *priv = flip->private_data; | |
528 | struct grant_map *map; | |
ab31523c GH |
529 | |
530 | pr_debug("priv %p\n", priv); | |
531 | ||
ab31523c GH |
532 | while (!list_empty(&priv->maps)) { |
533 | map = list_entry(priv->maps.next, struct grant_map, next); | |
68b025c8 | 534 | list_del(&map->next); |
16a1d022 | 535 | gntdev_put_map(NULL /* already removed */, map); |
ab31523c | 536 | } |
16a1d022 | 537 | WARN_ON(!list_empty(&priv->freeable_maps)); |
ab31523c | 538 | |
aab8f11a DDG |
539 | if (use_ptemod) |
540 | mmu_notifier_unregister(&priv->mn, priv->mm); | |
ab31523c GH |
541 | kfree(priv); |
542 | return 0; | |
543 | } | |
544 | ||
545 | static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv, | |
546 | struct ioctl_gntdev_map_grant_ref __user *u) | |
547 | { | |
548 | struct ioctl_gntdev_map_grant_ref op; | |
549 | struct grant_map *map; | |
550 | int err; | |
551 | ||
552 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
553 | return -EFAULT; | |
554 | pr_debug("priv %p, add %d\n", priv, op.count); | |
555 | if (unlikely(op.count <= 0)) | |
556 | return -EINVAL; | |
ab31523c GH |
557 | |
558 | err = -ENOMEM; | |
559 | map = gntdev_alloc_map(priv, op.count); | |
560 | if (!map) | |
561 | return err; | |
ef91082e | 562 | |
68b025c8 DDG |
563 | if (unlikely(atomic_add_return(op.count, &pages_mapped) > limit)) { |
564 | pr_debug("can't map: over limit\n"); | |
16a1d022 | 565 | gntdev_put_map(NULL, map); |
ab31523c GH |
566 | return err; |
567 | } | |
568 | ||
68b025c8 DDG |
569 | if (copy_from_user(map->grants, &u->refs, |
570 | sizeof(map->grants[0]) * op.count) != 0) { | |
16a1d022 DDG |
571 | gntdev_put_map(NULL, map); |
572 | return -EFAULT; | |
ef91082e DDG |
573 | } |
574 | ||
ab31523c GH |
575 | spin_lock(&priv->lock); |
576 | gntdev_add_map(priv, map); | |
577 | op.index = map->index << PAGE_SHIFT; | |
578 | spin_unlock(&priv->lock); | |
579 | ||
68b025c8 DDG |
580 | if (copy_to_user(u, &op, sizeof(op)) != 0) |
581 | return -EFAULT; | |
582 | ||
ab31523c GH |
583 | return 0; |
584 | } | |
585 | ||
586 | static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv, | |
587 | struct ioctl_gntdev_unmap_grant_ref __user *u) | |
588 | { | |
589 | struct ioctl_gntdev_unmap_grant_ref op; | |
590 | struct grant_map *map; | |
591 | int err = -ENOENT; | |
592 | ||
593 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
594 | return -EFAULT; | |
595 | pr_debug("priv %p, del %d+%d\n", priv, (int)op.index, (int)op.count); | |
596 | ||
597 | spin_lock(&priv->lock); | |
598 | map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count); | |
68b025c8 DDG |
599 | if (map) { |
600 | list_del(&map->next); | |
16a1d022 DDG |
601 | if (populate_freeable_maps) |
602 | list_add_tail(&map->next, &priv->freeable_maps); | |
68b025c8 DDG |
603 | err = 0; |
604 | } | |
ab31523c | 605 | spin_unlock(&priv->lock); |
1f1503ba | 606 | if (map) |
16a1d022 | 607 | gntdev_put_map(priv, map); |
ab31523c GH |
608 | return err; |
609 | } | |
610 | ||
611 | static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv, | |
612 | struct ioctl_gntdev_get_offset_for_vaddr __user *u) | |
613 | { | |
614 | struct ioctl_gntdev_get_offset_for_vaddr op; | |
a879211b | 615 | struct vm_area_struct *vma; |
ab31523c | 616 | struct grant_map *map; |
2512f298 | 617 | int rv = -EINVAL; |
ab31523c GH |
618 | |
619 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
620 | return -EFAULT; | |
621 | pr_debug("priv %p, offset for vaddr %lx\n", priv, (unsigned long)op.vaddr); | |
622 | ||
2512f298 | 623 | down_read(¤t->mm->mmap_sem); |
a879211b DDG |
624 | vma = find_vma(current->mm, op.vaddr); |
625 | if (!vma || vma->vm_ops != &gntdev_vmops) | |
2512f298 | 626 | goto out_unlock; |
a879211b DDG |
627 | |
628 | map = vma->vm_private_data; | |
629 | if (!map) | |
2512f298 | 630 | goto out_unlock; |
a879211b | 631 | |
ab31523c GH |
632 | op.offset = map->index << PAGE_SHIFT; |
633 | op.count = map->count; | |
2512f298 | 634 | rv = 0; |
ab31523c | 635 | |
2512f298 DDG |
636 | out_unlock: |
637 | up_read(¤t->mm->mmap_sem); | |
638 | ||
639 | if (rv == 0 && copy_to_user(u, &op, sizeof(op)) != 0) | |
ab31523c | 640 | return -EFAULT; |
2512f298 | 641 | return rv; |
ab31523c GH |
642 | } |
643 | ||
bdc612dc DDG |
644 | static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u) |
645 | { | |
646 | struct ioctl_gntdev_unmap_notify op; | |
647 | struct grant_map *map; | |
648 | int rc; | |
0cc678f8 DDG |
649 | int out_flags; |
650 | unsigned int out_event; | |
bdc612dc DDG |
651 | |
652 | if (copy_from_user(&op, u, sizeof(op))) | |
653 | return -EFAULT; | |
654 | ||
655 | if (op.action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT)) | |
656 | return -EINVAL; | |
657 | ||
0cc678f8 DDG |
658 | /* We need to grab a reference to the event channel we are going to use |
659 | * to send the notify before releasing the reference we may already have | |
660 | * (if someone has called this ioctl twice). This is required so that | |
661 | * it is possible to change the clear_byte part of the notification | |
662 | * without disturbing the event channel part, which may now be the last | |
663 | * reference to that event channel. | |
664 | */ | |
665 | if (op.action & UNMAP_NOTIFY_SEND_EVENT) { | |
666 | if (evtchn_get(op.event_channel_port)) | |
667 | return -EINVAL; | |
668 | } | |
669 | ||
670 | out_flags = op.action; | |
671 | out_event = op.event_channel_port; | |
672 | ||
bdc612dc DDG |
673 | spin_lock(&priv->lock); |
674 | ||
675 | list_for_each_entry(map, &priv->maps, next) { | |
676 | uint64_t begin = map->index << PAGE_SHIFT; | |
677 | uint64_t end = (map->index + map->count) << PAGE_SHIFT; | |
678 | if (op.index >= begin && op.index < end) | |
679 | goto found; | |
680 | } | |
681 | rc = -ENOENT; | |
682 | goto unlock_out; | |
683 | ||
684 | found: | |
9960be97 DDG |
685 | if ((op.action & UNMAP_NOTIFY_CLEAR_BYTE) && |
686 | (map->flags & GNTMAP_readonly)) { | |
687 | rc = -EINVAL; | |
688 | goto unlock_out; | |
689 | } | |
690 | ||
0cc678f8 DDG |
691 | out_flags = map->notify.flags; |
692 | out_event = map->notify.event; | |
693 | ||
bdc612dc DDG |
694 | map->notify.flags = op.action; |
695 | map->notify.addr = op.index - (map->index << PAGE_SHIFT); | |
696 | map->notify.event = op.event_channel_port; | |
0cc678f8 | 697 | |
bdc612dc | 698 | rc = 0; |
0cc678f8 | 699 | |
bdc612dc DDG |
700 | unlock_out: |
701 | spin_unlock(&priv->lock); | |
0cc678f8 DDG |
702 | |
703 | /* Drop the reference to the event channel we did not save in the map */ | |
704 | if (out_flags & UNMAP_NOTIFY_SEND_EVENT) | |
705 | evtchn_put(out_event); | |
706 | ||
bdc612dc DDG |
707 | return rc; |
708 | } | |
709 | ||
ab31523c GH |
710 | static long gntdev_ioctl(struct file *flip, |
711 | unsigned int cmd, unsigned long arg) | |
712 | { | |
713 | struct gntdev_priv *priv = flip->private_data; | |
714 | void __user *ptr = (void __user *)arg; | |
715 | ||
716 | switch (cmd) { | |
717 | case IOCTL_GNTDEV_MAP_GRANT_REF: | |
718 | return gntdev_ioctl_map_grant_ref(priv, ptr); | |
719 | ||
720 | case IOCTL_GNTDEV_UNMAP_GRANT_REF: | |
721 | return gntdev_ioctl_unmap_grant_ref(priv, ptr); | |
722 | ||
723 | case IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR: | |
724 | return gntdev_ioctl_get_offset_for_vaddr(priv, ptr); | |
725 | ||
bdc612dc DDG |
726 | case IOCTL_GNTDEV_SET_UNMAP_NOTIFY: |
727 | return gntdev_ioctl_notify(priv, ptr); | |
728 | ||
ab31523c GH |
729 | default: |
730 | pr_debug("priv %p, unknown cmd %x\n", priv, cmd); | |
731 | return -ENOIOCTLCMD; | |
732 | } | |
733 | ||
734 | return 0; | |
735 | } | |
736 | ||
737 | static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) | |
738 | { | |
739 | struct gntdev_priv *priv = flip->private_data; | |
740 | int index = vma->vm_pgoff; | |
741 | int count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; | |
742 | struct grant_map *map; | |
aab8f11a | 743 | int i, err = -EINVAL; |
ab31523c GH |
744 | |
745 | if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED)) | |
746 | return -EINVAL; | |
747 | ||
748 | pr_debug("map %d+%d at %lx (pgoff %lx)\n", | |
749 | index, count, vma->vm_start, vma->vm_pgoff); | |
750 | ||
751 | spin_lock(&priv->lock); | |
752 | map = gntdev_find_map_index(priv, index, count); | |
753 | if (!map) | |
754 | goto unlock_out; | |
aab8f11a | 755 | if (use_ptemod && map->vma) |
ab31523c | 756 | goto unlock_out; |
aab8f11a | 757 | if (use_ptemod && priv->mm != vma->vm_mm) { |
283c0972 | 758 | pr_warn("Huh? Other mm?\n"); |
ab31523c GH |
759 | goto unlock_out; |
760 | } | |
761 | ||
68b025c8 DDG |
762 | atomic_inc(&map->users); |
763 | ||
ab31523c GH |
764 | vma->vm_ops = &gntdev_vmops; |
765 | ||
314e51b9 | 766 | vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; |
d79647ae DDG |
767 | |
768 | if (use_ptemod) | |
e8e937be | 769 | vma->vm_flags |= VM_DONTCOPY; |
ab31523c GH |
770 | |
771 | vma->vm_private_data = map; | |
ab31523c | 772 | |
aab8f11a DDG |
773 | if (use_ptemod) |
774 | map->vma = vma; | |
775 | ||
12996fc3 DDG |
776 | if (map->flags) { |
777 | if ((vma->vm_flags & VM_WRITE) && | |
778 | (map->flags & GNTMAP_readonly)) | |
a93e20a8 | 779 | goto out_unlock_put; |
12996fc3 DDG |
780 | } else { |
781 | map->flags = GNTMAP_host_map; | |
782 | if (!(vma->vm_flags & VM_WRITE)) | |
783 | map->flags |= GNTMAP_readonly; | |
784 | } | |
ab31523c | 785 | |
f0a70c88 DDG |
786 | spin_unlock(&priv->lock); |
787 | ||
aab8f11a DDG |
788 | if (use_ptemod) { |
789 | err = apply_to_page_range(vma->vm_mm, vma->vm_start, | |
790 | vma->vm_end - vma->vm_start, | |
791 | find_grant_ptes, map); | |
792 | if (err) { | |
283c0972 | 793 | pr_warn("find_grant_ptes() failure.\n"); |
90b6f305 | 794 | goto out_put_map; |
aab8f11a | 795 | } |
ab31523c GH |
796 | } |
797 | ||
798 | err = map_grant_pages(map); | |
90b6f305 DDG |
799 | if (err) |
800 | goto out_put_map; | |
f0a70c88 | 801 | |
aab8f11a DDG |
802 | if (!use_ptemod) { |
803 | for (i = 0; i < count; i++) { | |
804 | err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE, | |
805 | map->pages[i]); | |
806 | if (err) | |
90b6f305 | 807 | goto out_put_map; |
aab8f11a DDG |
808 | } |
809 | } | |
810 | ||
f0a70c88 DDG |
811 | return 0; |
812 | ||
ab31523c GH |
813 | unlock_out: |
814 | spin_unlock(&priv->lock); | |
815 | return err; | |
90b6f305 | 816 | |
a93e20a8 DC |
817 | out_unlock_put: |
818 | spin_unlock(&priv->lock); | |
90b6f305 | 819 | out_put_map: |
84e4075d DDG |
820 | if (use_ptemod) |
821 | map->vma = NULL; | |
16a1d022 | 822 | gntdev_put_map(priv, map); |
90b6f305 | 823 | return err; |
ab31523c GH |
824 | } |
825 | ||
826 | static const struct file_operations gntdev_fops = { | |
827 | .owner = THIS_MODULE, | |
828 | .open = gntdev_open, | |
829 | .release = gntdev_release, | |
830 | .mmap = gntdev_mmap, | |
831 | .unlocked_ioctl = gntdev_ioctl | |
832 | }; | |
833 | ||
834 | static struct miscdevice gntdev_miscdev = { | |
835 | .minor = MISC_DYNAMIC_MINOR, | |
836 | .name = "xen/gntdev", | |
837 | .fops = &gntdev_fops, | |
838 | }; | |
839 | ||
840 | /* ------------------------------------------------------------------ */ | |
841 | ||
842 | static int __init gntdev_init(void) | |
843 | { | |
844 | int err; | |
845 | ||
846 | if (!xen_domain()) | |
847 | return -ENODEV; | |
848 | ||
aab8f11a DDG |
849 | use_ptemod = xen_pv_domain(); |
850 | ||
ab31523c GH |
851 | err = misc_register(&gntdev_miscdev); |
852 | if (err != 0) { | |
283c0972 | 853 | pr_err("Could not register gntdev device\n"); |
ab31523c GH |
854 | return err; |
855 | } | |
856 | return 0; | |
857 | } | |
858 | ||
859 | static void __exit gntdev_exit(void) | |
860 | { | |
861 | misc_deregister(&gntdev_miscdev); | |
862 | } | |
863 | ||
864 | module_init(gntdev_init); | |
865 | module_exit(gntdev_exit); | |
866 | ||
867 | /* ------------------------------------------------------------------ */ |