Merge branch 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[linux-2.6-block.git] / drivers / xen / gntdev.c
CommitLineData
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>
1d314567 9 * (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
ab31523c
GH
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
21#undef DEBUG
22
283c0972
JP
23#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
24
ab31523c
GH
25#include <linux/module.h>
26#include <linux/kernel.h>
27#include <linux/init.h>
28#include <linux/miscdevice.h>
29#include <linux/fs.h>
ab31523c
GH
30#include <linux/uaccess.h>
31#include <linux/sched.h>
6e84f315 32#include <linux/sched/mm.h>
ab31523c
GH
33#include <linux/spinlock.h>
34#include <linux/slab.h>
aab8f11a 35#include <linux/highmem.h>
c5f7c5a9 36#include <linux/refcount.h>
975ef7ff
OA
37#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
38#include <linux/of_device.h>
39#endif
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 49
1d314567 50#include "gntdev-common.h"
932d6562
OA
51#ifdef CONFIG_XEN_GNTDEV_DMABUF
52#include "gntdev-dmabuf.h"
53#endif
1d314567 54
ab31523c
GH
55MODULE_LICENSE("GPL");
56MODULE_AUTHOR("Derek G. Murray <Derek.Murray@cl.cam.ac.uk>, "
57 "Gerd Hoffmann <kraxel@redhat.com>");
58MODULE_DESCRIPTION("User-space granted page access driver");
59
ef91082e 60static int limit = 1024*1024;
ab31523c 61module_param(limit, int, 0644);
ef91082e
DDG
62MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by "
63 "the gntdev device");
64
65static atomic_t pages_mapped = ATOMIC_INIT(0);
ab31523c 66
aab8f11a 67static int use_ptemod;
16a1d022 68#define populate_freeable_maps use_ptemod
aab8f11a 69
1d314567
OA
70static int unmap_grant_pages(struct gntdev_grant_map *map,
71 int offset, int pages);
aab8f11a 72
975ef7ff
OA
73static struct miscdevice gntdev_miscdev;
74
ab31523c
GH
75/* ------------------------------------------------------------------ */
76
1d314567
OA
77bool gntdev_account_mapped_pages(int count)
78{
79 return atomic_add_return(count, &pages_mapped) > limit;
80}
81
ab31523c
GH
82static void gntdev_print_maps(struct gntdev_priv *priv,
83 char *text, int text_index)
84{
85#ifdef DEBUG
1d314567 86 struct gntdev_grant_map *map;
ab31523c 87
ef91082e 88 pr_debug("%s: maps list (priv %p)\n", __func__, priv);
ab31523c
GH
89 list_for_each_entry(map, &priv->maps, next)
90 pr_debug(" index %2d, count %2d %s\n",
91 map->index, map->count,
92 map->index == text_index && text ? text : "");
93#endif
94}
95
1d314567 96static void gntdev_free_map(struct gntdev_grant_map *map)
a67baeb7
DV
97{
98 if (map == NULL)
99 return;
100
975ef7ff
OA
101#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
102 if (map->dma_vaddr) {
103 struct gnttab_dma_alloc_args args;
104
105 args.dev = map->dma_dev;
106 args.coherent = !!(map->dma_flags & GNTDEV_DMA_FLAG_COHERENT);
107 args.nr_pages = map->count;
108 args.pages = map->pages;
109 args.frames = map->frames;
110 args.vaddr = map->dma_vaddr;
111 args.dev_bus_addr = map->dma_bus_addr;
112
113 gnttab_dma_free_pages(&args);
114 } else
115#endif
a67baeb7 116 if (map->pages)
ff4b156f 117 gnttab_free_pages(map->count, map->pages);
975ef7ff
OA
118
119#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
120 kfree(map->frames);
121#endif
a67baeb7
DV
122 kfree(map->pages);
123 kfree(map->grants);
124 kfree(map->map_ops);
125 kfree(map->unmap_ops);
126 kfree(map->kmap_ops);
853d0289 127 kfree(map->kunmap_ops);
a67baeb7
DV
128 kfree(map);
129}
130
1d314567 131struct gntdev_grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count,
975ef7ff 132 int dma_flags)
ab31523c 133{
1d314567 134 struct gntdev_grant_map *add;
a12b4eb3 135 int i;
ab31523c 136
1d314567 137 add = kzalloc(sizeof(*add), GFP_KERNEL);
ab31523c
GH
138 if (NULL == add)
139 return NULL;
140
fc6e0c3b
DC
141 add->grants = kcalloc(count, sizeof(add->grants[0]), GFP_KERNEL);
142 add->map_ops = kcalloc(count, sizeof(add->map_ops[0]), GFP_KERNEL);
143 add->unmap_ops = kcalloc(count, sizeof(add->unmap_ops[0]), GFP_KERNEL);
144 add->kmap_ops = kcalloc(count, sizeof(add->kmap_ops[0]), GFP_KERNEL);
853d0289 145 add->kunmap_ops = kcalloc(count, sizeof(add->kunmap_ops[0]), GFP_KERNEL);
fc6e0c3b 146 add->pages = kcalloc(count, sizeof(add->pages[0]), GFP_KERNEL);
a12b4eb3
SS
147 if (NULL == add->grants ||
148 NULL == add->map_ops ||
149 NULL == add->unmap_ops ||
0930bba6 150 NULL == add->kmap_ops ||
853d0289 151 NULL == add->kunmap_ops ||
a12b4eb3 152 NULL == add->pages)
ab31523c
GH
153 goto err;
154
975ef7ff
OA
155#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
156 add->dma_flags = dma_flags;
157
158 /*
159 * Check if this mapping is requested to be backed
160 * by a DMA buffer.
161 */
162 if (dma_flags & (GNTDEV_DMA_FLAG_WC | GNTDEV_DMA_FLAG_COHERENT)) {
163 struct gnttab_dma_alloc_args args;
164
165 add->frames = kcalloc(count, sizeof(add->frames[0]),
166 GFP_KERNEL);
167 if (!add->frames)
168 goto err;
169
170 /* Remember the device, so we can free DMA memory. */
171 add->dma_dev = priv->dma_dev;
172
173 args.dev = priv->dma_dev;
174 args.coherent = !!(dma_flags & GNTDEV_DMA_FLAG_COHERENT);
175 args.nr_pages = count;
176 args.pages = add->pages;
177 args.frames = add->frames;
178
179 if (gnttab_dma_alloc_pages(&args))
180 goto err;
181
182 add->dma_vaddr = args.vaddr;
183 add->dma_bus_addr = args.dev_bus_addr;
184 } else
185#endif
ff4b156f 186 if (gnttab_alloc_pages(count, add->pages))
ca47ceaa
DDG
187 goto err;
188
a12b4eb3 189 for (i = 0; i < count; i++) {
77c35acb
DDG
190 add->map_ops[i].handle = -1;
191 add->unmap_ops[i].handle = -1;
0930bba6 192 add->kmap_ops[i].handle = -1;
853d0289 193 add->kunmap_ops[i].handle = -1;
a12b4eb3
SS
194 }
195
ab31523c
GH
196 add->index = 0;
197 add->count = count;
c5f7c5a9 198 refcount_set(&add->users, 1);
ab31523c 199
ab31523c
GH
200 return add;
201
202err:
a67baeb7 203 gntdev_free_map(add);
ab31523c
GH
204 return NULL;
205}
206
1d314567 207void gntdev_add_map(struct gntdev_priv *priv, struct gntdev_grant_map *add)
ab31523c 208{
1d314567 209 struct gntdev_grant_map *map;
ab31523c
GH
210
211 list_for_each_entry(map, &priv->maps, next) {
212 if (add->index + add->count < map->index) {
213 list_add_tail(&add->next, &map->next);
214 goto done;
215 }
216 add->index = map->index + map->count;
217 }
218 list_add_tail(&add->next, &priv->maps);
219
220done:
ab31523c
GH
221 gntdev_print_maps(priv, "[new]", add->index);
222}
223
1d314567
OA
224static struct gntdev_grant_map *gntdev_find_map_index(struct gntdev_priv *priv,
225 int index, int count)
ab31523c 226{
1d314567 227 struct gntdev_grant_map *map;
ab31523c
GH
228
229 list_for_each_entry(map, &priv->maps, next) {
230 if (map->index != index)
231 continue;
bdc612dc 232 if (count && map->count != count)
ab31523c
GH
233 continue;
234 return map;
235 }
236 return NULL;
237}
238
1d314567 239void gntdev_put_map(struct gntdev_priv *priv, struct gntdev_grant_map *map)
ab31523c
GH
240{
241 if (!map)
242 return;
a12b4eb3 243
c5f7c5a9 244 if (!refcount_dec_and_test(&map->users))
68b025c8
DDG
245 return;
246
247 atomic_sub(map->count, &pages_mapped);
248
0cc678f8 249 if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) {
bdc612dc 250 notify_remote_via_evtchn(map->notify.event);
0cc678f8
DDG
251 evtchn_put(map->notify.event);
252 }
bdc612dc 253
16a1d022 254 if (populate_freeable_maps && priv) {
1401c00e 255 mutex_lock(&priv->lock);
16a1d022 256 list_del(&map->next);
1401c00e 257 mutex_unlock(&priv->lock);
16a1d022
DDG
258 }
259
a67baeb7
DV
260 if (map->pages && !use_ptemod)
261 unmap_grant_pages(map, 0, map->count);
262 gntdev_free_map(map);
ab31523c
GH
263}
264
265/* ------------------------------------------------------------------ */
266
8b1e0f81 267static int find_grant_ptes(pte_t *pte, unsigned long addr, void *data)
ab31523c 268{
1d314567 269 struct gntdev_grant_map *map = data;
ab31523c 270 unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT;
aab8f11a 271 int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte;
ab31523c
GH
272 u64 pte_maddr;
273
274 BUG_ON(pgnr >= map->count);
ba5d1012
JF
275 pte_maddr = arbitrary_virt_to_machine(pte).maddr;
276
923b2919
DV
277 /*
278 * Set the PTE as special to force get_user_pages_fast() fall
279 * back to the slow path. If this is not supported as part of
280 * the grant map, it will be done afterwards.
281 */
282 if (xen_feature(XENFEAT_gnttab_map_avail_bits))
283 flags |= (1 << _GNTMAP_guest_avail0);
284
aab8f11a 285 gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, flags,
ab31523c
GH
286 map->grants[pgnr].ref,
287 map->grants[pgnr].domid);
aab8f11a 288 gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags,
77c35acb 289 -1 /* handle */);
ab31523c
GH
290 return 0;
291}
292
923b2919 293#ifdef CONFIG_X86
8b1e0f81 294static int set_grant_ptes_as_special(pte_t *pte, unsigned long addr, void *data)
923b2919
DV
295{
296 set_pte_at(current->mm, addr, pte, pte_mkspecial(*pte));
297 return 0;
298}
299#endif
300
1d314567 301int gntdev_map_grant_pages(struct gntdev_grant_map *map)
ab31523c
GH
302{
303 int i, err = 0;
aab8f11a
DDG
304
305 if (!use_ptemod) {
12996fc3 306 /* Note: it could already be mapped */
77c35acb 307 if (map->map_ops[0].handle != -1)
12996fc3 308 return 0;
aab8f11a 309 for (i = 0; i < map->count; i++) {
38eaeb0f 310 unsigned long addr = (unsigned long)
aab8f11a
DDG
311 pfn_to_kaddr(page_to_pfn(map->pages[i]));
312 gnttab_set_map_op(&map->map_ops[i], addr, map->flags,
313 map->grants[i].ref,
314 map->grants[i].domid);
315 gnttab_set_unmap_op(&map->unmap_ops[i], addr,
77c35acb 316 map->flags, -1 /* handle */);
aab8f11a 317 }
0930bba6
SS
318 } else {
319 /*
320 * Setup the map_ops corresponding to the pte entries pointing
321 * to the kernel linear addresses of the struct pages.
322 * These ptes are completely different from the user ptes dealt
323 * with find_grant_ptes.
324 */
325 for (i = 0; i < map->count; i++) {
0930bba6
SS
326 unsigned long address = (unsigned long)
327 pfn_to_kaddr(page_to_pfn(map->pages[i]));
0930bba6
SS
328 BUG_ON(PageHighMem(map->pages[i]));
329
ee072640
SS
330 gnttab_set_map_op(&map->kmap_ops[i], address,
331 map->flags | GNTMAP_host_map,
0930bba6
SS
332 map->grants[i].ref,
333 map->grants[i].domid);
853d0289
DV
334 gnttab_set_unmap_op(&map->kunmap_ops[i], address,
335 map->flags | GNTMAP_host_map, -1);
0930bba6 336 }
aab8f11a 337 }
ab31523c
GH
338
339 pr_debug("map %d+%d\n", map->index, map->count);
e85fc980
KRW
340 err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL,
341 map->pages, map->count);
ab31523c
GH
342 if (err)
343 return err;
344
345 for (i = 0; i < map->count; i++) {
853d0289 346 if (map->map_ops[i].status) {
ab31523c 347 err = -EINVAL;
853d0289 348 continue;
77c35acb 349 }
853d0289
DV
350
351 map->unmap_ops[i].handle = map->map_ops[i].handle;
352 if (use_ptemod)
353 map->kunmap_ops[i].handle = map->kmap_ops[i].handle;
975ef7ff
OA
354#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
355 else if (map->dma_vaddr) {
356 unsigned long bfn;
357
358 bfn = pfn_to_bfn(page_to_pfn(map->pages[i]));
359 map->unmap_ops[i].dev_bus_addr = __pfn_to_phys(bfn);
360 }
361#endif
ab31523c
GH
362 }
363 return err;
364}
365
1d314567
OA
366static int __unmap_grant_pages(struct gntdev_grant_map *map, int offset,
367 int pages)
ab31523c
GH
368{
369 int i, err = 0;
74528225 370 struct gntab_unmap_queue_data unmap_data;
ab31523c 371
bdc612dc
DDG
372 if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) {
373 int pgno = (map->notify.addr >> PAGE_SHIFT);
1affa98d
DDG
374 if (pgno >= offset && pgno < offset + pages) {
375 /* No need for kmap, pages are in lowmem */
376 uint8_t *tmp = pfn_to_kaddr(page_to_pfn(map->pages[pgno]));
bdc612dc 377 tmp[map->notify.addr & (PAGE_SIZE-1)] = 0;
bdc612dc
DDG
378 map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE;
379 }
380 }
381
74528225
JH
382 unmap_data.unmap_ops = map->unmap_ops + offset;
383 unmap_data.kunmap_ops = use_ptemod ? map->kunmap_ops + offset : NULL;
384 unmap_data.pages = map->pages + offset;
385 unmap_data.count = pages;
386
b44166cd
BL
387 err = gnttab_unmap_refs_sync(&unmap_data);
388 if (err)
389 return err;
ab31523c
GH
390
391 for (i = 0; i < pages; i++) {
392 if (map->unmap_ops[offset+i].status)
393 err = -EINVAL;
77c35acb
DDG
394 pr_debug("unmap handle=%d st=%d\n",
395 map->unmap_ops[offset+i].handle,
396 map->unmap_ops[offset+i].status);
397 map->unmap_ops[offset+i].handle = -1;
ab31523c
GH
398 }
399 return err;
400}
401
1d314567
OA
402static int unmap_grant_pages(struct gntdev_grant_map *map, int offset,
403 int pages)
b57c1869
DDG
404{
405 int range, err = 0;
406
407 pr_debug("unmap %d+%d [%d+%d]\n", map->index, map->count, offset, pages);
408
409 /* It is possible the requested range will have a "hole" where we
410 * already unmapped some of the grants. Only unmap valid ranges.
411 */
412 while (pages && !err) {
77c35acb 413 while (pages && map->unmap_ops[offset].handle == -1) {
b57c1869
DDG
414 offset++;
415 pages--;
416 }
417 range = 0;
418 while (range < pages) {
951a0102 419 if (map->unmap_ops[offset+range].handle == -1)
b57c1869 420 break;
b57c1869
DDG
421 range++;
422 }
423 err = __unmap_grant_pages(map, offset, range);
424 offset += range;
425 pages -= range;
426 }
427
428 return err;
429}
430
ab31523c
GH
431/* ------------------------------------------------------------------ */
432
d79647ae
DDG
433static void gntdev_vma_open(struct vm_area_struct *vma)
434{
1d314567 435 struct gntdev_grant_map *map = vma->vm_private_data;
d79647ae
DDG
436
437 pr_debug("gntdev_vma_open %p\n", vma);
c5f7c5a9 438 refcount_inc(&map->users);
d79647ae
DDG
439}
440
ab31523c
GH
441static void gntdev_vma_close(struct vm_area_struct *vma)
442{
1d314567 443 struct gntdev_grant_map *map = vma->vm_private_data;
16a1d022
DDG
444 struct file *file = vma->vm_file;
445 struct gntdev_priv *priv = file->private_data;
ab31523c 446
d79647ae 447 pr_debug("gntdev_vma_close %p\n", vma);
2512f298 448 if (use_ptemod) {
2512f298
DDG
449 /* It is possible that an mmu notifier could be running
450 * concurrently, so take priv->lock to ensure that the vma won't
451 * vanishing during the unmap_grant_pages call, since we will
452 * spin here until that completes. Such a concurrent call will
453 * not do any unmapping, since that has been done prior to
454 * closing the vma, but it may still iterate the unmap_ops list.
455 */
1401c00e 456 mutex_lock(&priv->lock);
2512f298 457 map->vma = NULL;
1401c00e 458 mutex_unlock(&priv->lock);
2512f298 459 }
ab31523c 460 vma->vm_private_data = NULL;
16a1d022 461 gntdev_put_map(priv, map);
ab31523c
GH
462}
463
dab069c6
DV
464static struct page *gntdev_vma_find_special_page(struct vm_area_struct *vma,
465 unsigned long addr)
466{
1d314567 467 struct gntdev_grant_map *map = vma->vm_private_data;
dab069c6
DV
468
469 return map->pages[(addr - map->pages_vm_start) >> PAGE_SHIFT];
470}
471
7cbea8dc 472static const struct vm_operations_struct gntdev_vmops = {
d79647ae 473 .open = gntdev_vma_open,
ab31523c 474 .close = gntdev_vma_close,
dab069c6 475 .find_special_page = gntdev_vma_find_special_page,
ab31523c
GH
476};
477
478/* ------------------------------------------------------------------ */
479
93065ac7
MH
480static bool in_range(struct gntdev_grant_map *map,
481 unsigned long start, unsigned long end)
482{
483 if (!map->vma)
484 return false;
485 if (map->vma->vm_start >= end)
486 return false;
487 if (map->vma->vm_end <= start)
488 return false;
489
490 return true;
491}
492
58a57569
MH
493static int unmap_if_in_range(struct gntdev_grant_map *map,
494 unsigned long start, unsigned long end,
495 bool blockable)
16a1d022
DDG
496{
497 unsigned long mstart, mend;
498 int err;
499
58a57569
MH
500 if (!in_range(map, start, end))
501 return 0;
502
503 if (!blockable)
504 return -EAGAIN;
505
16a1d022
DDG
506 mstart = max(start, map->vma->vm_start);
507 mend = min(end, map->vma->vm_end);
508 pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n",
509 map->index, map->count,
510 map->vma->vm_start, map->vma->vm_end,
511 start, end, mstart, mend);
512 err = unmap_grant_pages(map,
513 (mstart - map->vma->vm_start) >> PAGE_SHIFT,
514 (mend - mstart) >> PAGE_SHIFT);
515 WARN_ON(err);
58a57569
MH
516
517 return 0;
16a1d022
DDG
518}
519
93065ac7 520static int mn_invl_range_start(struct mmu_notifier *mn,
5d6527a7 521 const struct mmu_notifier_range *range)
ab31523c
GH
522{
523 struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
1d314567 524 struct gntdev_grant_map *map;
93065ac7
MH
525 int ret = 0;
526
dfcd6660 527 if (mmu_notifier_range_blockable(range))
93065ac7
MH
528 mutex_lock(&priv->lock);
529 else if (!mutex_trylock(&priv->lock))
530 return -EAGAIN;
ab31523c 531
ab31523c 532 list_for_each_entry(map, &priv->maps, next) {
5d6527a7 533 ret = unmap_if_in_range(map, range->start, range->end,
dfcd6660 534 mmu_notifier_range_blockable(range));
58a57569 535 if (ret)
93065ac7 536 goto out_unlock;
16a1d022
DDG
537 }
538 list_for_each_entry(map, &priv->freeable_maps, next) {
5d6527a7 539 ret = unmap_if_in_range(map, range->start, range->end,
dfcd6660 540 mmu_notifier_range_blockable(range));
58a57569 541 if (ret)
93065ac7 542 goto out_unlock;
ab31523c 543 }
93065ac7
MH
544
545out_unlock:
1401c00e 546 mutex_unlock(&priv->lock);
93065ac7
MH
547
548 return ret;
ab31523c
GH
549}
550
ab31523c
GH
551static void mn_release(struct mmu_notifier *mn,
552 struct mm_struct *mm)
553{
554 struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
1d314567 555 struct gntdev_grant_map *map;
ab31523c
GH
556 int err;
557
1401c00e 558 mutex_lock(&priv->lock);
ab31523c
GH
559 list_for_each_entry(map, &priv->maps, next) {
560 if (!map->vma)
561 continue;
562 pr_debug("map %d+%d (%lx %lx)\n",
563 map->index, map->count,
564 map->vma->vm_start, map->vma->vm_end);
565 err = unmap_grant_pages(map, /* offset */ 0, map->count);
566 WARN_ON(err);
567 }
16a1d022
DDG
568 list_for_each_entry(map, &priv->freeable_maps, next) {
569 if (!map->vma)
570 continue;
571 pr_debug("map %d+%d (%lx %lx)\n",
572 map->index, map->count,
573 map->vma->vm_start, map->vma->vm_end);
574 err = unmap_grant_pages(map, /* offset */ 0, map->count);
575 WARN_ON(err);
576 }
1401c00e 577 mutex_unlock(&priv->lock);
ab31523c
GH
578}
579
b9c0a92a 580static const struct mmu_notifier_ops gntdev_mmu_ops = {
ab31523c 581 .release = mn_release,
ab31523c
GH
582 .invalidate_range_start = mn_invl_range_start,
583};
584
585/* ------------------------------------------------------------------ */
586
587static int gntdev_open(struct inode *inode, struct file *flip)
588{
589 struct gntdev_priv *priv;
590 int ret = 0;
591
592 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
593 if (!priv)
594 return -ENOMEM;
595
596 INIT_LIST_HEAD(&priv->maps);
16a1d022 597 INIT_LIST_HEAD(&priv->freeable_maps);
1401c00e 598 mutex_init(&priv->lock);
ab31523c 599
932d6562 600#ifdef CONFIG_XEN_GNTDEV_DMABUF
fa13e665 601 priv->dmabuf_priv = gntdev_dmabuf_init(flip);
932d6562
OA
602 if (IS_ERR(priv->dmabuf_priv)) {
603 ret = PTR_ERR(priv->dmabuf_priv);
604 kfree(priv);
605 return ret;
606 }
607#endif
608
aab8f11a
DDG
609 if (use_ptemod) {
610 priv->mm = get_task_mm(current);
611 if (!priv->mm) {
612 kfree(priv);
613 return -ENOMEM;
614 }
615 priv->mn.ops = &gntdev_mmu_ops;
616 ret = mmu_notifier_register(&priv->mn, priv->mm);
617 mmput(priv->mm);
ab31523c 618 }
ab31523c
GH
619
620 if (ret) {
621 kfree(priv);
622 return ret;
623 }
624
625 flip->private_data = priv;
975ef7ff
OA
626#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
627 priv->dma_dev = gntdev_miscdev.this_device;
628
629 /*
630 * The device is not spawn from a device tree, so arch_setup_dma_ops
631 * is not called, thus leaving the device with dummy DMA ops.
632 * Fix this by calling of_dma_configure() with a NULL node to set
633 * default DMA ops.
634 */
635 of_dma_configure(priv->dma_dev, NULL, true);
636#endif
ab31523c
GH
637 pr_debug("priv %p\n", priv);
638
639 return 0;
640}
641
642static int gntdev_release(struct inode *inode, struct file *flip)
643{
644 struct gntdev_priv *priv = flip->private_data;
1d314567 645 struct gntdev_grant_map *map;
ab31523c
GH
646
647 pr_debug("priv %p\n", priv);
648
30b03d05 649 mutex_lock(&priv->lock);
ab31523c 650 while (!list_empty(&priv->maps)) {
1d314567
OA
651 map = list_entry(priv->maps.next,
652 struct gntdev_grant_map, next);
68b025c8 653 list_del(&map->next);
16a1d022 654 gntdev_put_map(NULL /* already removed */, map);
ab31523c 655 }
16a1d022 656 WARN_ON(!list_empty(&priv->freeable_maps));
30b03d05 657 mutex_unlock(&priv->lock);
ab31523c 658
932d6562
OA
659#ifdef CONFIG_XEN_GNTDEV_DMABUF
660 gntdev_dmabuf_fini(priv->dmabuf_priv);
661#endif
662
aab8f11a
DDG
663 if (use_ptemod)
664 mmu_notifier_unregister(&priv->mn, priv->mm);
932d6562 665
ab31523c
GH
666 kfree(priv);
667 return 0;
668}
669
670static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv,
671 struct ioctl_gntdev_map_grant_ref __user *u)
672{
673 struct ioctl_gntdev_map_grant_ref op;
1d314567 674 struct gntdev_grant_map *map;
ab31523c
GH
675 int err;
676
677 if (copy_from_user(&op, u, sizeof(op)) != 0)
678 return -EFAULT;
679 pr_debug("priv %p, add %d\n", priv, op.count);
680 if (unlikely(op.count <= 0))
681 return -EINVAL;
ab31523c
GH
682
683 err = -ENOMEM;
975ef7ff 684 map = gntdev_alloc_map(priv, op.count, 0 /* This is not a dma-buf. */);
ab31523c
GH
685 if (!map)
686 return err;
ef91082e 687
1d314567 688 if (unlikely(gntdev_account_mapped_pages(op.count))) {
68b025c8 689 pr_debug("can't map: over limit\n");
16a1d022 690 gntdev_put_map(NULL, map);
ab31523c
GH
691 return err;
692 }
693
68b025c8
DDG
694 if (copy_from_user(map->grants, &u->refs,
695 sizeof(map->grants[0]) * op.count) != 0) {
16a1d022
DDG
696 gntdev_put_map(NULL, map);
697 return -EFAULT;
ef91082e
DDG
698 }
699
1401c00e 700 mutex_lock(&priv->lock);
ab31523c
GH
701 gntdev_add_map(priv, map);
702 op.index = map->index << PAGE_SHIFT;
1401c00e 703 mutex_unlock(&priv->lock);
ab31523c 704
68b025c8
DDG
705 if (copy_to_user(u, &op, sizeof(op)) != 0)
706 return -EFAULT;
707
ab31523c
GH
708 return 0;
709}
710
711static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv,
712 struct ioctl_gntdev_unmap_grant_ref __user *u)
713{
714 struct ioctl_gntdev_unmap_grant_ref op;
1d314567 715 struct gntdev_grant_map *map;
ab31523c
GH
716 int err = -ENOENT;
717
718 if (copy_from_user(&op, u, sizeof(op)) != 0)
719 return -EFAULT;
720 pr_debug("priv %p, del %d+%d\n", priv, (int)op.index, (int)op.count);
721
1401c00e 722 mutex_lock(&priv->lock);
ab31523c 723 map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count);
68b025c8
DDG
724 if (map) {
725 list_del(&map->next);
16a1d022
DDG
726 if (populate_freeable_maps)
727 list_add_tail(&map->next, &priv->freeable_maps);
68b025c8
DDG
728 err = 0;
729 }
1401c00e 730 mutex_unlock(&priv->lock);
1f1503ba 731 if (map)
16a1d022 732 gntdev_put_map(priv, map);
ab31523c
GH
733 return err;
734}
735
736static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv,
737 struct ioctl_gntdev_get_offset_for_vaddr __user *u)
738{
739 struct ioctl_gntdev_get_offset_for_vaddr op;
a879211b 740 struct vm_area_struct *vma;
1d314567 741 struct gntdev_grant_map *map;
2512f298 742 int rv = -EINVAL;
ab31523c
GH
743
744 if (copy_from_user(&op, u, sizeof(op)) != 0)
745 return -EFAULT;
746 pr_debug("priv %p, offset for vaddr %lx\n", priv, (unsigned long)op.vaddr);
747
2512f298 748 down_read(&current->mm->mmap_sem);
a879211b
DDG
749 vma = find_vma(current->mm, op.vaddr);
750 if (!vma || vma->vm_ops != &gntdev_vmops)
2512f298 751 goto out_unlock;
a879211b
DDG
752
753 map = vma->vm_private_data;
754 if (!map)
2512f298 755 goto out_unlock;
a879211b 756
ab31523c
GH
757 op.offset = map->index << PAGE_SHIFT;
758 op.count = map->count;
2512f298 759 rv = 0;
ab31523c 760
2512f298
DDG
761 out_unlock:
762 up_read(&current->mm->mmap_sem);
763
764 if (rv == 0 && copy_to_user(u, &op, sizeof(op)) != 0)
ab31523c 765 return -EFAULT;
2512f298 766 return rv;
ab31523c
GH
767}
768
bdc612dc
DDG
769static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u)
770{
771 struct ioctl_gntdev_unmap_notify op;
1d314567 772 struct gntdev_grant_map *map;
bdc612dc 773 int rc;
0cc678f8
DDG
774 int out_flags;
775 unsigned int out_event;
bdc612dc
DDG
776
777 if (copy_from_user(&op, u, sizeof(op)))
778 return -EFAULT;
779
780 if (op.action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT))
781 return -EINVAL;
782
0cc678f8
DDG
783 /* We need to grab a reference to the event channel we are going to use
784 * to send the notify before releasing the reference we may already have
785 * (if someone has called this ioctl twice). This is required so that
786 * it is possible to change the clear_byte part of the notification
787 * without disturbing the event channel part, which may now be the last
788 * reference to that event channel.
789 */
790 if (op.action & UNMAP_NOTIFY_SEND_EVENT) {
791 if (evtchn_get(op.event_channel_port))
792 return -EINVAL;
793 }
794
795 out_flags = op.action;
796 out_event = op.event_channel_port;
797
1401c00e 798 mutex_lock(&priv->lock);
bdc612dc
DDG
799
800 list_for_each_entry(map, &priv->maps, next) {
801 uint64_t begin = map->index << PAGE_SHIFT;
802 uint64_t end = (map->index + map->count) << PAGE_SHIFT;
803 if (op.index >= begin && op.index < end)
804 goto found;
805 }
806 rc = -ENOENT;
807 goto unlock_out;
808
809 found:
9960be97
DDG
810 if ((op.action & UNMAP_NOTIFY_CLEAR_BYTE) &&
811 (map->flags & GNTMAP_readonly)) {
812 rc = -EINVAL;
813 goto unlock_out;
814 }
815
0cc678f8
DDG
816 out_flags = map->notify.flags;
817 out_event = map->notify.event;
818
bdc612dc
DDG
819 map->notify.flags = op.action;
820 map->notify.addr = op.index - (map->index << PAGE_SHIFT);
821 map->notify.event = op.event_channel_port;
0cc678f8 822
bdc612dc 823 rc = 0;
0cc678f8 824
bdc612dc 825 unlock_out:
1401c00e 826 mutex_unlock(&priv->lock);
0cc678f8
DDG
827
828 /* Drop the reference to the event channel we did not save in the map */
829 if (out_flags & UNMAP_NOTIFY_SEND_EVENT)
830 evtchn_put(out_event);
831
bdc612dc
DDG
832 return rc;
833}
834
36ae220a 835#define GNTDEV_COPY_BATCH 16
a4cdb556
DV
836
837struct gntdev_copy_batch {
838 struct gnttab_copy ops[GNTDEV_COPY_BATCH];
839 struct page *pages[GNTDEV_COPY_BATCH];
840 s16 __user *status[GNTDEV_COPY_BATCH];
841 unsigned int nr_ops;
842 unsigned int nr_pages;
843};
844
845static int gntdev_get_page(struct gntdev_copy_batch *batch, void __user *virt,
846 bool writeable, unsigned long *gfn)
847{
848 unsigned long addr = (unsigned long)virt;
849 struct page *page;
850 unsigned long xen_pfn;
851 int ret;
852
73b0140b 853 ret = get_user_pages_fast(addr, 1, writeable ? FOLL_WRITE : 0, &page);
a4cdb556
DV
854 if (ret < 0)
855 return ret;
856
857 batch->pages[batch->nr_pages++] = page;
858
859 xen_pfn = page_to_xen_pfn(page) + XEN_PFN_DOWN(addr & ~PAGE_MASK);
860 *gfn = pfn_to_gfn(xen_pfn);
861
862 return 0;
863}
864
865static void gntdev_put_pages(struct gntdev_copy_batch *batch)
866{
867 unsigned int i;
868
869 for (i = 0; i < batch->nr_pages; i++)
870 put_page(batch->pages[i]);
871 batch->nr_pages = 0;
872}
873
874static int gntdev_copy(struct gntdev_copy_batch *batch)
875{
876 unsigned int i;
877
878 gnttab_batch_copy(batch->ops, batch->nr_ops);
879 gntdev_put_pages(batch);
880
881 /*
882 * For each completed op, update the status if the op failed
883 * and all previous ops for the segment were successful.
884 */
885 for (i = 0; i < batch->nr_ops; i++) {
886 s16 status = batch->ops[i].status;
887 s16 old_status;
888
889 if (status == GNTST_okay)
890 continue;
891
892 if (__get_user(old_status, batch->status[i]))
893 return -EFAULT;
894
895 if (old_status != GNTST_okay)
896 continue;
897
898 if (__put_user(status, batch->status[i]))
899 return -EFAULT;
900 }
901
902 batch->nr_ops = 0;
903 return 0;
904}
905
906static int gntdev_grant_copy_seg(struct gntdev_copy_batch *batch,
907 struct gntdev_grant_copy_segment *seg,
908 s16 __user *status)
909{
910 uint16_t copied = 0;
911
912 /*
913 * Disallow local -> local copies since there is only space in
914 * batch->pages for one page per-op and this would be a very
915 * expensive memcpy().
916 */
917 if (!(seg->flags & (GNTCOPY_source_gref | GNTCOPY_dest_gref)))
918 return -EINVAL;
919
920 /* Can't cross page if source/dest is a grant ref. */
921 if (seg->flags & GNTCOPY_source_gref) {
922 if (seg->source.foreign.offset + seg->len > XEN_PAGE_SIZE)
923 return -EINVAL;
924 }
925 if (seg->flags & GNTCOPY_dest_gref) {
926 if (seg->dest.foreign.offset + seg->len > XEN_PAGE_SIZE)
927 return -EINVAL;
928 }
929
930 if (put_user(GNTST_okay, status))
931 return -EFAULT;
932
933 while (copied < seg->len) {
934 struct gnttab_copy *op;
935 void __user *virt;
936 size_t len, off;
937 unsigned long gfn;
938 int ret;
939
940 if (batch->nr_ops >= GNTDEV_COPY_BATCH) {
941 ret = gntdev_copy(batch);
942 if (ret < 0)
943 return ret;
944 }
945
946 len = seg->len - copied;
947
948 op = &batch->ops[batch->nr_ops];
949 op->flags = 0;
950
951 if (seg->flags & GNTCOPY_source_gref) {
952 op->source.u.ref = seg->source.foreign.ref;
953 op->source.domid = seg->source.foreign.domid;
954 op->source.offset = seg->source.foreign.offset + copied;
955 op->flags |= GNTCOPY_source_gref;
956 } else {
957 virt = seg->source.virt + copied;
958 off = (unsigned long)virt & ~XEN_PAGE_MASK;
959 len = min(len, (size_t)XEN_PAGE_SIZE - off);
960
961 ret = gntdev_get_page(batch, virt, false, &gfn);
962 if (ret < 0)
963 return ret;
964
965 op->source.u.gmfn = gfn;
966 op->source.domid = DOMID_SELF;
967 op->source.offset = off;
968 }
969
970 if (seg->flags & GNTCOPY_dest_gref) {
971 op->dest.u.ref = seg->dest.foreign.ref;
972 op->dest.domid = seg->dest.foreign.domid;
973 op->dest.offset = seg->dest.foreign.offset + copied;
974 op->flags |= GNTCOPY_dest_gref;
975 } else {
976 virt = seg->dest.virt + copied;
977 off = (unsigned long)virt & ~XEN_PAGE_MASK;
978 len = min(len, (size_t)XEN_PAGE_SIZE - off);
979
980 ret = gntdev_get_page(batch, virt, true, &gfn);
981 if (ret < 0)
982 return ret;
983
984 op->dest.u.gmfn = gfn;
985 op->dest.domid = DOMID_SELF;
986 op->dest.offset = off;
987 }
988
989 op->len = len;
990 copied += len;
991
992 batch->status[batch->nr_ops] = status;
993 batch->nr_ops++;
994 }
995
996 return 0;
997}
998
999static long gntdev_ioctl_grant_copy(struct gntdev_priv *priv, void __user *u)
1000{
1001 struct ioctl_gntdev_grant_copy copy;
1002 struct gntdev_copy_batch batch;
1003 unsigned int i;
1004 int ret = 0;
1005
1006 if (copy_from_user(&copy, u, sizeof(copy)))
1007 return -EFAULT;
1008
1009 batch.nr_ops = 0;
1010 batch.nr_pages = 0;
1011
1012 for (i = 0; i < copy.count; i++) {
1013 struct gntdev_grant_copy_segment seg;
1014
1015 if (copy_from_user(&seg, &copy.segments[i], sizeof(seg))) {
1016 ret = -EFAULT;
1017 goto out;
1018 }
1019
1020 ret = gntdev_grant_copy_seg(&batch, &seg, &copy.segments[i].status);
1021 if (ret < 0)
1022 goto out;
1023
1024 cond_resched();
1025 }
1026 if (batch.nr_ops)
1027 ret = gntdev_copy(&batch);
1028 return ret;
1029
1030 out:
1031 gntdev_put_pages(&batch);
1032 return ret;
1033}
1034
ab31523c
GH
1035static long gntdev_ioctl(struct file *flip,
1036 unsigned int cmd, unsigned long arg)
1037{
1038 struct gntdev_priv *priv = flip->private_data;
1039 void __user *ptr = (void __user *)arg;
1040
1041 switch (cmd) {
1042 case IOCTL_GNTDEV_MAP_GRANT_REF:
1043 return gntdev_ioctl_map_grant_ref(priv, ptr);
1044
1045 case IOCTL_GNTDEV_UNMAP_GRANT_REF:
1046 return gntdev_ioctl_unmap_grant_ref(priv, ptr);
1047
1048 case IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR:
1049 return gntdev_ioctl_get_offset_for_vaddr(priv, ptr);
1050
bdc612dc
DDG
1051 case IOCTL_GNTDEV_SET_UNMAP_NOTIFY:
1052 return gntdev_ioctl_notify(priv, ptr);
1053
a4cdb556
DV
1054 case IOCTL_GNTDEV_GRANT_COPY:
1055 return gntdev_ioctl_grant_copy(priv, ptr);
1056
932d6562
OA
1057#ifdef CONFIG_XEN_GNTDEV_DMABUF
1058 case IOCTL_GNTDEV_DMABUF_EXP_FROM_REFS:
1059 return gntdev_ioctl_dmabuf_exp_from_refs(priv, use_ptemod, ptr);
1060
1061 case IOCTL_GNTDEV_DMABUF_EXP_WAIT_RELEASED:
1062 return gntdev_ioctl_dmabuf_exp_wait_released(priv, ptr);
1063
1064 case IOCTL_GNTDEV_DMABUF_IMP_TO_REFS:
1065 return gntdev_ioctl_dmabuf_imp_to_refs(priv, ptr);
1066
1067 case IOCTL_GNTDEV_DMABUF_IMP_RELEASE:
1068 return gntdev_ioctl_dmabuf_imp_release(priv, ptr);
1069#endif
1070
ab31523c
GH
1071 default:
1072 pr_debug("priv %p, unknown cmd %x\n", priv, cmd);
1073 return -ENOIOCTLCMD;
1074 }
1075
1076 return 0;
1077}
1078
1079static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
1080{
1081 struct gntdev_priv *priv = flip->private_data;
1082 int index = vma->vm_pgoff;
c7ebf9d9 1083 int count = vma_pages(vma);
1d314567 1084 struct gntdev_grant_map *map;
df9bde01 1085 int err = -EINVAL;
ab31523c
GH
1086
1087 if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED))
1088 return -EINVAL;
1089
1090 pr_debug("map %d+%d at %lx (pgoff %lx)\n",
1091 index, count, vma->vm_start, vma->vm_pgoff);
1092
1401c00e 1093 mutex_lock(&priv->lock);
ab31523c
GH
1094 map = gntdev_find_map_index(priv, index, count);
1095 if (!map)
1096 goto unlock_out;
aab8f11a 1097 if (use_ptemod && map->vma)
ab31523c 1098 goto unlock_out;
aab8f11a 1099 if (use_ptemod && priv->mm != vma->vm_mm) {
283c0972 1100 pr_warn("Huh? Other mm?\n");
ab31523c
GH
1101 goto unlock_out;
1102 }
1103
c5f7c5a9 1104 refcount_inc(&map->users);
68b025c8 1105
ab31523c
GH
1106 vma->vm_ops = &gntdev_vmops;
1107
30faaafd 1108 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP | VM_MIXEDMAP;
d79647ae
DDG
1109
1110 if (use_ptemod)
e8e937be 1111 vma->vm_flags |= VM_DONTCOPY;
ab31523c
GH
1112
1113 vma->vm_private_data = map;
ab31523c 1114
aab8f11a
DDG
1115 if (use_ptemod)
1116 map->vma = vma;
1117
12996fc3
DDG
1118 if (map->flags) {
1119 if ((vma->vm_flags & VM_WRITE) &&
1120 (map->flags & GNTMAP_readonly))
a93e20a8 1121 goto out_unlock_put;
12996fc3
DDG
1122 } else {
1123 map->flags = GNTMAP_host_map;
1124 if (!(vma->vm_flags & VM_WRITE))
1125 map->flags |= GNTMAP_readonly;
1126 }
ab31523c 1127
1401c00e 1128 mutex_unlock(&priv->lock);
f0a70c88 1129
aab8f11a 1130 if (use_ptemod) {
298d275d 1131 map->pages_vm_start = vma->vm_start;
aab8f11a
DDG
1132 err = apply_to_page_range(vma->vm_mm, vma->vm_start,
1133 vma->vm_end - vma->vm_start,
1134 find_grant_ptes, map);
1135 if (err) {
283c0972 1136 pr_warn("find_grant_ptes() failure.\n");
90b6f305 1137 goto out_put_map;
aab8f11a 1138 }
ab31523c
GH
1139 }
1140
1d314567 1141 err = gntdev_map_grant_pages(map);
90b6f305
DDG
1142 if (err)
1143 goto out_put_map;
f0a70c88 1144
aab8f11a 1145 if (!use_ptemod) {
8d1502f6 1146 err = vm_map_pages_zero(vma, map->pages, map->count);
df9bde01
SJ
1147 if (err)
1148 goto out_put_map;
923b2919
DV
1149 } else {
1150#ifdef CONFIG_X86
1151 /*
1152 * If the PTEs were not made special by the grant map
1153 * hypercall, do so here.
1154 *
1155 * This is racy since the mapping is already visible
1156 * to userspace but userspace should be well-behaved
1157 * enough to not touch it until the mmap() call
1158 * returns.
1159 */
1160 if (!xen_feature(XENFEAT_gnttab_map_avail_bits)) {
1161 apply_to_page_range(vma->vm_mm, vma->vm_start,
1162 vma->vm_end - vma->vm_start,
1163 set_grant_ptes_as_special, NULL);
1164 }
1165#endif
aab8f11a
DDG
1166 }
1167
f0a70c88
DDG
1168 return 0;
1169
ab31523c 1170unlock_out:
1401c00e 1171 mutex_unlock(&priv->lock);
ab31523c 1172 return err;
90b6f305 1173
a93e20a8 1174out_unlock_put:
1401c00e 1175 mutex_unlock(&priv->lock);
90b6f305 1176out_put_map:
cf2acf66 1177 if (use_ptemod) {
84e4075d 1178 map->vma = NULL;
cf2acf66
RL
1179 unmap_grant_pages(map, 0, map->count);
1180 }
16a1d022 1181 gntdev_put_map(priv, map);
90b6f305 1182 return err;
ab31523c
GH
1183}
1184
1185static const struct file_operations gntdev_fops = {
1186 .owner = THIS_MODULE,
1187 .open = gntdev_open,
1188 .release = gntdev_release,
1189 .mmap = gntdev_mmap,
1190 .unlocked_ioctl = gntdev_ioctl
1191};
1192
1193static struct miscdevice gntdev_miscdev = {
1194 .minor = MISC_DYNAMIC_MINOR,
1195 .name = "xen/gntdev",
1196 .fops = &gntdev_fops,
1197};
1198
1199/* ------------------------------------------------------------------ */
1200
1201static int __init gntdev_init(void)
1202{
1203 int err;
1204
1205 if (!xen_domain())
1206 return -ENODEV;
1207
6926f6d6 1208 use_ptemod = !xen_feature(XENFEAT_auto_translated_physmap);
aab8f11a 1209
ab31523c
GH
1210 err = misc_register(&gntdev_miscdev);
1211 if (err != 0) {
283c0972 1212 pr_err("Could not register gntdev device\n");
ab31523c
GH
1213 return err;
1214 }
1215 return 0;
1216}
1217
1218static void __exit gntdev_exit(void)
1219{
1220 misc_deregister(&gntdev_miscdev);
1221}
1222
1223module_init(gntdev_init);
1224module_exit(gntdev_exit);
1225
1226/* ------------------------------------------------------------------ */