blob: 99d8151c824adbff0611a16f493dde6e6927de4c [file] [log] [blame]
Gerd Hoffmannab315232010-12-14 18:40:46 +00001/******************************************************************************
2 * gntdev.c
3 *
4 * Device for accessing (in user-space) pages that have been granted by other
5 * domains.
6 *
7 * Copyright (c) 2006-2007, D G Murray.
8 * (c) 2009 Gerd Hoffmann <kraxel@redhat.com>
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20#undef DEBUG
21
22#include <linux/module.h>
23#include <linux/kernel.h>
24#include <linux/init.h>
25#include <linux/miscdevice.h>
26#include <linux/fs.h>
27#include <linux/mm.h>
28#include <linux/mman.h>
29#include <linux/mmu_notifier.h>
30#include <linux/types.h>
31#include <linux/uaccess.h>
32#include <linux/sched.h>
33#include <linux/spinlock.h>
34#include <linux/slab.h>
Daniel De Graafaab8f112011-02-03 12:19:02 -050035#include <linux/highmem.h>
Gerd Hoffmannab315232010-12-14 18:40:46 +000036
37#include <xen/xen.h>
38#include <xen/grant_table.h>
Daniel De Graafca47cea2011-03-09 18:07:34 -050039#include <xen/balloon.h>
Gerd Hoffmannab315232010-12-14 18:40:46 +000040#include <xen/gntdev.h>
Daniel De Graafbdc612d2011-02-03 12:19:04 -050041#include <xen/events.h>
Gerd Hoffmannab315232010-12-14 18:40:46 +000042#include <asm/xen/hypervisor.h>
43#include <asm/xen/hypercall.h>
44#include <asm/xen/page.h>
45
46MODULE_LICENSE("GPL");
47MODULE_AUTHOR("Derek G. Murray <Derek.Murray@cl.cam.ac.uk>, "
48 "Gerd Hoffmann <kraxel@redhat.com>");
49MODULE_DESCRIPTION("User-space granted page access driver");
50
Daniel De Graafef910822011-02-03 12:18:59 -050051static int limit = 1024*1024;
Gerd Hoffmannab315232010-12-14 18:40:46 +000052module_param(limit, int, 0644);
Daniel De Graafef910822011-02-03 12:18:59 -050053MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by "
54 "the gntdev device");
55
56static atomic_t pages_mapped = ATOMIC_INIT(0);
Gerd Hoffmannab315232010-12-14 18:40:46 +000057
Daniel De Graafaab8f112011-02-03 12:19:02 -050058static int use_ptemod;
59
Gerd Hoffmannab315232010-12-14 18:40:46 +000060struct gntdev_priv {
61 struct list_head maps;
Gerd Hoffmannab315232010-12-14 18:40:46 +000062 /* lock protects maps from concurrent changes */
63 spinlock_t lock;
64 struct mm_struct *mm;
65 struct mmu_notifier mn;
66};
67
Daniel De Graafbdc612d2011-02-03 12:19:04 -050068struct unmap_notify {
69 int flags;
70 /* Address relative to the start of the grant_map */
71 int addr;
72 int event;
73};
74
Gerd Hoffmannab315232010-12-14 18:40:46 +000075struct grant_map {
76 struct list_head next;
Gerd Hoffmannab315232010-12-14 18:40:46 +000077 struct vm_area_struct *vma;
78 int index;
79 int count;
80 int flags;
Daniel De Graaf68b025c2011-02-03 12:19:01 -050081 atomic_t users;
Daniel De Graafbdc612d2011-02-03 12:19:04 -050082 struct unmap_notify notify;
Gerd Hoffmannab315232010-12-14 18:40:46 +000083 struct ioctl_gntdev_grant_ref *grants;
84 struct gnttab_map_grant_ref *map_ops;
85 struct gnttab_unmap_grant_ref *unmap_ops;
Stefano Stabellini0930bba2011-09-29 11:57:56 +010086 struct gnttab_map_grant_ref *kmap_ops;
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +000087 struct page **pages;
Gerd Hoffmannab315232010-12-14 18:40:46 +000088};
89
Daniel De Graafaab8f112011-02-03 12:19:02 -050090static int unmap_grant_pages(struct grant_map *map, int offset, int pages);
91
Gerd Hoffmannab315232010-12-14 18:40:46 +000092/* ------------------------------------------------------------------ */
93
94static void gntdev_print_maps(struct gntdev_priv *priv,
95 char *text, int text_index)
96{
97#ifdef DEBUG
98 struct grant_map *map;
99
Daniel De Graafef910822011-02-03 12:18:59 -0500100 pr_debug("%s: maps list (priv %p)\n", __func__, priv);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000101 list_for_each_entry(map, &priv->maps, next)
102 pr_debug(" index %2d, count %2d %s\n",
103 map->index, map->count,
104 map->index == text_index && text ? text : "");
105#endif
106}
107
108static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
109{
110 struct grant_map *add;
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +0000111 int i;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000112
113 add = kzalloc(sizeof(struct grant_map), GFP_KERNEL);
114 if (NULL == add)
115 return NULL;
116
Dan Carpenterfc6e0c32011-11-04 21:23:32 +0300117 add->grants = kcalloc(count, sizeof(add->grants[0]), GFP_KERNEL);
118 add->map_ops = kcalloc(count, sizeof(add->map_ops[0]), GFP_KERNEL);
119 add->unmap_ops = kcalloc(count, sizeof(add->unmap_ops[0]), GFP_KERNEL);
120 add->kmap_ops = kcalloc(count, sizeof(add->kmap_ops[0]), GFP_KERNEL);
121 add->pages = kcalloc(count, sizeof(add->pages[0]), GFP_KERNEL);
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +0000122 if (NULL == add->grants ||
123 NULL == add->map_ops ||
124 NULL == add->unmap_ops ||
Stefano Stabellini0930bba2011-09-29 11:57:56 +0100125 NULL == add->kmap_ops ||
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +0000126 NULL == add->pages)
Gerd Hoffmannab315232010-12-14 18:40:46 +0000127 goto err;
128
Stefano Stabellini693394b2011-09-29 11:57:55 +0100129 if (alloc_xenballooned_pages(count, add->pages, false /* lowmem */))
Daniel De Graafca47cea2011-03-09 18:07:34 -0500130 goto err;
131
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +0000132 for (i = 0; i < count; i++) {
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500133 add->map_ops[i].handle = -1;
134 add->unmap_ops[i].handle = -1;
Stefano Stabellini0930bba2011-09-29 11:57:56 +0100135 add->kmap_ops[i].handle = -1;
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +0000136 }
137
Gerd Hoffmannab315232010-12-14 18:40:46 +0000138 add->index = 0;
139 add->count = count;
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500140 atomic_set(&add->users, 1);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000141
Gerd Hoffmannab315232010-12-14 18:40:46 +0000142 return add;
143
144err:
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +0000145 kfree(add->pages);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000146 kfree(add->grants);
147 kfree(add->map_ops);
148 kfree(add->unmap_ops);
Stefano Stabellini0930bba2011-09-29 11:57:56 +0100149 kfree(add->kmap_ops);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000150 kfree(add);
151 return NULL;
152}
153
154static void gntdev_add_map(struct gntdev_priv *priv, struct grant_map *add)
155{
156 struct grant_map *map;
157
158 list_for_each_entry(map, &priv->maps, next) {
159 if (add->index + add->count < map->index) {
160 list_add_tail(&add->next, &map->next);
161 goto done;
162 }
163 add->index = map->index + map->count;
164 }
165 list_add_tail(&add->next, &priv->maps);
166
167done:
Gerd Hoffmannab315232010-12-14 18:40:46 +0000168 gntdev_print_maps(priv, "[new]", add->index);
169}
170
171static struct grant_map *gntdev_find_map_index(struct gntdev_priv *priv,
172 int index, int count)
173{
174 struct grant_map *map;
175
176 list_for_each_entry(map, &priv->maps, next) {
177 if (map->index != index)
178 continue;
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500179 if (count && map->count != count)
Gerd Hoffmannab315232010-12-14 18:40:46 +0000180 continue;
181 return map;
182 }
183 return NULL;
184}
185
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500186static void gntdev_put_map(struct grant_map *map)
Gerd Hoffmannab315232010-12-14 18:40:46 +0000187{
188 if (!map)
189 return;
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +0000190
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500191 if (!atomic_dec_and_test(&map->users))
192 return;
193
194 atomic_sub(map->count, &pages_mapped);
195
Daniel De Graaf0cc678f2011-10-27 17:58:49 -0400196 if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) {
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500197 notify_remote_via_evtchn(map->notify.event);
Daniel De Graaf0cc678f2011-10-27 17:58:49 -0400198 evtchn_put(map->notify.event);
199 }
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500200
Daniel De Graafaab8f112011-02-03 12:19:02 -0500201 if (map->pages) {
202 if (!use_ptemod)
203 unmap_grant_pages(map, 0, map->count);
204
Daniel De Graafca47cea2011-03-09 18:07:34 -0500205 free_xenballooned_pages(map->count, map->pages);
Daniel De Graafaab8f112011-02-03 12:19:02 -0500206 }
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +0000207 kfree(map->pages);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000208 kfree(map->grants);
209 kfree(map->map_ops);
210 kfree(map->unmap_ops);
211 kfree(map);
212}
213
214/* ------------------------------------------------------------------ */
215
216static int find_grant_ptes(pte_t *pte, pgtable_t token,
217 unsigned long addr, void *data)
218{
219 struct grant_map *map = data;
220 unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT;
Daniel De Graafaab8f112011-02-03 12:19:02 -0500221 int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000222 u64 pte_maddr;
223
224 BUG_ON(pgnr >= map->count);
Jeremy Fitzhardingeba5d1012010-12-08 10:54:32 -0800225 pte_maddr = arbitrary_virt_to_machine(pte).maddr;
226
Daniel De Graafaab8f112011-02-03 12:19:02 -0500227 gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, flags,
Gerd Hoffmannab315232010-12-14 18:40:46 +0000228 map->grants[pgnr].ref,
229 map->grants[pgnr].domid);
Daniel De Graafaab8f112011-02-03 12:19:02 -0500230 gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags,
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500231 -1 /* handle */);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000232 return 0;
233}
234
235static int map_grant_pages(struct grant_map *map)
236{
237 int i, err = 0;
Daniel De Graafaab8f112011-02-03 12:19:02 -0500238
239 if (!use_ptemod) {
Daniel De Graaf12996fc2011-02-09 16:11:32 -0500240 /* Note: it could already be mapped */
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500241 if (map->map_ops[0].handle != -1)
Daniel De Graaf12996fc2011-02-09 16:11:32 -0500242 return 0;
Daniel De Graafaab8f112011-02-03 12:19:02 -0500243 for (i = 0; i < map->count; i++) {
Ian Campbell38eaeb02011-03-08 16:56:43 +0000244 unsigned long addr = (unsigned long)
Daniel De Graafaab8f112011-02-03 12:19:02 -0500245 pfn_to_kaddr(page_to_pfn(map->pages[i]));
246 gnttab_set_map_op(&map->map_ops[i], addr, map->flags,
247 map->grants[i].ref,
248 map->grants[i].domid);
249 gnttab_set_unmap_op(&map->unmap_ops[i], addr,
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500250 map->flags, -1 /* handle */);
Daniel De Graafaab8f112011-02-03 12:19:02 -0500251 }
Stefano Stabellini0930bba2011-09-29 11:57:56 +0100252 } else {
253 /*
254 * Setup the map_ops corresponding to the pte entries pointing
255 * to the kernel linear addresses of the struct pages.
256 * These ptes are completely different from the user ptes dealt
257 * with find_grant_ptes.
258 */
259 for (i = 0; i < map->count; i++) {
260 unsigned level;
261 unsigned long address = (unsigned long)
262 pfn_to_kaddr(page_to_pfn(map->pages[i]));
263 pte_t *ptep;
264 u64 pte_maddr = 0;
265 BUG_ON(PageHighMem(map->pages[i]));
266
267 ptep = lookup_address(address, &level);
268 pte_maddr = arbitrary_virt_to_machine(ptep).maddr;
269 gnttab_set_map_op(&map->kmap_ops[i], pte_maddr,
270 map->flags |
271 GNTMAP_host_map |
272 GNTMAP_contains_pte,
273 map->grants[i].ref,
274 map->grants[i].domid);
275 }
Daniel De Graafaab8f112011-02-03 12:19:02 -0500276 }
Gerd Hoffmannab315232010-12-14 18:40:46 +0000277
278 pr_debug("map %d+%d\n", map->index, map->count);
Stefano Stabellini0930bba2011-09-29 11:57:56 +0100279 err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL,
280 map->pages, map->count);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000281 if (err)
282 return err;
283
284 for (i = 0; i < map->count; i++) {
285 if (map->map_ops[i].status)
286 err = -EINVAL;
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500287 else {
288 BUG_ON(map->map_ops[i].handle == -1);
289 map->unmap_ops[i].handle = map->map_ops[i].handle;
290 pr_debug("map handle=%d\n", map->map_ops[i].handle);
291 }
Gerd Hoffmannab315232010-12-14 18:40:46 +0000292 }
293 return err;
294}
295
Daniel De Graafb57c1862011-02-09 15:12:00 -0500296static int __unmap_grant_pages(struct grant_map *map, int offset, int pages)
Gerd Hoffmannab315232010-12-14 18:40:46 +0000297{
298 int i, err = 0;
299
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500300 if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) {
301 int pgno = (map->notify.addr >> PAGE_SHIFT);
Daniel De Graaf0ea22f02011-02-08 09:14:06 -0500302 if (pgno >= offset && pgno < offset + pages && use_ptemod) {
Daniel De Graaff4ee4af2011-02-23 08:11:36 -0500303 void __user *tmp = (void __user *)
304 map->vma->vm_start + map->notify.addr;
Daniel De Graaf9960be92011-02-09 18:15:50 -0500305 err = copy_to_user(tmp, &err, 1);
306 if (err)
Dan Carpenter12f02582011-03-19 08:44:34 +0300307 return -EFAULT;
Daniel De Graaf0ea22f02011-02-08 09:14:06 -0500308 map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE;
309 } else if (pgno >= offset && pgno < offset + pages) {
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500310 uint8_t *tmp = kmap(map->pages[pgno]);
311 tmp[map->notify.addr & (PAGE_SIZE-1)] = 0;
312 kunmap(map->pages[pgno]);
313 map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE;
314 }
315 }
316
Daniel De Graaf7d17e842011-12-14 15:12:11 -0500317 err = gnttab_unmap_refs(map->unmap_ops + offset, map->pages + offset,
318 pages, true);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000319 if (err)
320 return err;
321
322 for (i = 0; i < pages; i++) {
323 if (map->unmap_ops[offset+i].status)
324 err = -EINVAL;
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500325 pr_debug("unmap handle=%d st=%d\n",
326 map->unmap_ops[offset+i].handle,
327 map->unmap_ops[offset+i].status);
328 map->unmap_ops[offset+i].handle = -1;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000329 }
330 return err;
331}
332
Daniel De Graafb57c1862011-02-09 15:12:00 -0500333static int unmap_grant_pages(struct grant_map *map, int offset, int pages)
334{
335 int range, err = 0;
336
337 pr_debug("unmap %d+%d [%d+%d]\n", map->index, map->count, offset, pages);
338
339 /* It is possible the requested range will have a "hole" where we
340 * already unmapped some of the grants. Only unmap valid ranges.
341 */
342 while (pages && !err) {
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500343 while (pages && map->unmap_ops[offset].handle == -1) {
Daniel De Graafb57c1862011-02-09 15:12:00 -0500344 offset++;
345 pages--;
346 }
347 range = 0;
348 while (range < pages) {
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500349 if (map->unmap_ops[offset+range].handle == -1) {
Daniel De Graafb57c1862011-02-09 15:12:00 -0500350 range--;
351 break;
352 }
353 range++;
354 }
355 err = __unmap_grant_pages(map, offset, range);
356 offset += range;
357 pages -= range;
358 }
359
360 return err;
361}
362
Gerd Hoffmannab315232010-12-14 18:40:46 +0000363/* ------------------------------------------------------------------ */
364
Daniel De Graafd79647a2011-03-07 15:18:57 -0500365static void gntdev_vma_open(struct vm_area_struct *vma)
366{
367 struct grant_map *map = vma->vm_private_data;
368
369 pr_debug("gntdev_vma_open %p\n", vma);
370 atomic_inc(&map->users);
371}
372
Gerd Hoffmannab315232010-12-14 18:40:46 +0000373static void gntdev_vma_close(struct vm_area_struct *vma)
374{
375 struct grant_map *map = vma->vm_private_data;
376
Daniel De Graafd79647a2011-03-07 15:18:57 -0500377 pr_debug("gntdev_vma_close %p\n", vma);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000378 map->vma = NULL;
379 vma->vm_private_data = NULL;
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500380 gntdev_put_map(map);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000381}
382
Gerd Hoffmannab315232010-12-14 18:40:46 +0000383static struct vm_operations_struct gntdev_vmops = {
Daniel De Graafd79647a2011-03-07 15:18:57 -0500384 .open = gntdev_vma_open,
Gerd Hoffmannab315232010-12-14 18:40:46 +0000385 .close = gntdev_vma_close,
Gerd Hoffmannab315232010-12-14 18:40:46 +0000386};
387
388/* ------------------------------------------------------------------ */
389
390static void mn_invl_range_start(struct mmu_notifier *mn,
391 struct mm_struct *mm,
392 unsigned long start, unsigned long end)
393{
394 struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
395 struct grant_map *map;
396 unsigned long mstart, mend;
397 int err;
398
399 spin_lock(&priv->lock);
400 list_for_each_entry(map, &priv->maps, next) {
401 if (!map->vma)
402 continue;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000403 if (map->vma->vm_start >= end)
404 continue;
405 if (map->vma->vm_end <= start)
406 continue;
407 mstart = max(start, map->vma->vm_start);
408 mend = min(end, map->vma->vm_end);
409 pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n",
410 map->index, map->count,
411 map->vma->vm_start, map->vma->vm_end,
412 start, end, mstart, mend);
413 err = unmap_grant_pages(map,
414 (mstart - map->vma->vm_start) >> PAGE_SHIFT,
415 (mend - mstart) >> PAGE_SHIFT);
416 WARN_ON(err);
417 }
418 spin_unlock(&priv->lock);
419}
420
421static void mn_invl_page(struct mmu_notifier *mn,
422 struct mm_struct *mm,
423 unsigned long address)
424{
425 mn_invl_range_start(mn, mm, address, address + PAGE_SIZE);
426}
427
428static void mn_release(struct mmu_notifier *mn,
429 struct mm_struct *mm)
430{
431 struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
432 struct grant_map *map;
433 int err;
434
435 spin_lock(&priv->lock);
436 list_for_each_entry(map, &priv->maps, next) {
437 if (!map->vma)
438 continue;
439 pr_debug("map %d+%d (%lx %lx)\n",
440 map->index, map->count,
441 map->vma->vm_start, map->vma->vm_end);
442 err = unmap_grant_pages(map, /* offset */ 0, map->count);
443 WARN_ON(err);
444 }
445 spin_unlock(&priv->lock);
446}
447
448struct mmu_notifier_ops gntdev_mmu_ops = {
449 .release = mn_release,
450 .invalidate_page = mn_invl_page,
451 .invalidate_range_start = mn_invl_range_start,
452};
453
454/* ------------------------------------------------------------------ */
455
456static int gntdev_open(struct inode *inode, struct file *flip)
457{
458 struct gntdev_priv *priv;
459 int ret = 0;
460
461 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
462 if (!priv)
463 return -ENOMEM;
464
465 INIT_LIST_HEAD(&priv->maps);
466 spin_lock_init(&priv->lock);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000467
Daniel De Graafaab8f112011-02-03 12:19:02 -0500468 if (use_ptemod) {
469 priv->mm = get_task_mm(current);
470 if (!priv->mm) {
471 kfree(priv);
472 return -ENOMEM;
473 }
474 priv->mn.ops = &gntdev_mmu_ops;
475 ret = mmu_notifier_register(&priv->mn, priv->mm);
476 mmput(priv->mm);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000477 }
Gerd Hoffmannab315232010-12-14 18:40:46 +0000478
479 if (ret) {
480 kfree(priv);
481 return ret;
482 }
483
484 flip->private_data = priv;
485 pr_debug("priv %p\n", priv);
486
487 return 0;
488}
489
490static int gntdev_release(struct inode *inode, struct file *flip)
491{
492 struct gntdev_priv *priv = flip->private_data;
493 struct grant_map *map;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000494
495 pr_debug("priv %p\n", priv);
496
Gerd Hoffmannab315232010-12-14 18:40:46 +0000497 while (!list_empty(&priv->maps)) {
498 map = list_entry(priv->maps.next, struct grant_map, next);
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500499 list_del(&map->next);
500 gntdev_put_map(map);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000501 }
Gerd Hoffmannab315232010-12-14 18:40:46 +0000502
Daniel De Graafaab8f112011-02-03 12:19:02 -0500503 if (use_ptemod)
504 mmu_notifier_unregister(&priv->mn, priv->mm);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000505 kfree(priv);
506 return 0;
507}
508
509static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv,
510 struct ioctl_gntdev_map_grant_ref __user *u)
511{
512 struct ioctl_gntdev_map_grant_ref op;
513 struct grant_map *map;
514 int err;
515
516 if (copy_from_user(&op, u, sizeof(op)) != 0)
517 return -EFAULT;
518 pr_debug("priv %p, add %d\n", priv, op.count);
519 if (unlikely(op.count <= 0))
520 return -EINVAL;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000521
522 err = -ENOMEM;
523 map = gntdev_alloc_map(priv, op.count);
524 if (!map)
525 return err;
Daniel De Graafef910822011-02-03 12:18:59 -0500526
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500527 if (unlikely(atomic_add_return(op.count, &pages_mapped) > limit)) {
528 pr_debug("can't map: over limit\n");
529 gntdev_put_map(map);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000530 return err;
531 }
532
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500533 if (copy_from_user(map->grants, &u->refs,
534 sizeof(map->grants[0]) * op.count) != 0) {
535 gntdev_put_map(map);
Daniel De Graafef910822011-02-03 12:18:59 -0500536 return err;
537 }
538
Gerd Hoffmannab315232010-12-14 18:40:46 +0000539 spin_lock(&priv->lock);
540 gntdev_add_map(priv, map);
541 op.index = map->index << PAGE_SHIFT;
542 spin_unlock(&priv->lock);
543
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500544 if (copy_to_user(u, &op, sizeof(op)) != 0)
545 return -EFAULT;
546
Gerd Hoffmannab315232010-12-14 18:40:46 +0000547 return 0;
548}
549
550static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv,
551 struct ioctl_gntdev_unmap_grant_ref __user *u)
552{
553 struct ioctl_gntdev_unmap_grant_ref op;
554 struct grant_map *map;
555 int err = -ENOENT;
556
557 if (copy_from_user(&op, u, sizeof(op)) != 0)
558 return -EFAULT;
559 pr_debug("priv %p, del %d+%d\n", priv, (int)op.index, (int)op.count);
560
561 spin_lock(&priv->lock);
562 map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count);
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500563 if (map) {
564 list_del(&map->next);
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500565 err = 0;
566 }
Gerd Hoffmannab315232010-12-14 18:40:46 +0000567 spin_unlock(&priv->lock);
Daniel De Graaf1f1503b2011-10-11 15:16:06 -0400568 if (map)
569 gntdev_put_map(map);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000570 return err;
571}
572
573static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv,
574 struct ioctl_gntdev_get_offset_for_vaddr __user *u)
575{
576 struct ioctl_gntdev_get_offset_for_vaddr op;
Daniel De Graafa8792112011-02-03 12:19:00 -0500577 struct vm_area_struct *vma;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000578 struct grant_map *map;
579
580 if (copy_from_user(&op, u, sizeof(op)) != 0)
581 return -EFAULT;
582 pr_debug("priv %p, offset for vaddr %lx\n", priv, (unsigned long)op.vaddr);
583
Daniel De Graafa8792112011-02-03 12:19:00 -0500584 vma = find_vma(current->mm, op.vaddr);
585 if (!vma || vma->vm_ops != &gntdev_vmops)
Gerd Hoffmannab315232010-12-14 18:40:46 +0000586 return -EINVAL;
Daniel De Graafa8792112011-02-03 12:19:00 -0500587
588 map = vma->vm_private_data;
589 if (!map)
590 return -EINVAL;
591
Gerd Hoffmannab315232010-12-14 18:40:46 +0000592 op.offset = map->index << PAGE_SHIFT;
593 op.count = map->count;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000594
595 if (copy_to_user(u, &op, sizeof(op)) != 0)
596 return -EFAULT;
597 return 0;
598}
599
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500600static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u)
601{
602 struct ioctl_gntdev_unmap_notify op;
603 struct grant_map *map;
604 int rc;
Daniel De Graaf0cc678f2011-10-27 17:58:49 -0400605 int out_flags;
606 unsigned int out_event;
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500607
608 if (copy_from_user(&op, u, sizeof(op)))
609 return -EFAULT;
610
611 if (op.action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT))
612 return -EINVAL;
613
Daniel De Graaf0cc678f2011-10-27 17:58:49 -0400614 /* We need to grab a reference to the event channel we are going to use
615 * to send the notify before releasing the reference we may already have
616 * (if someone has called this ioctl twice). This is required so that
617 * it is possible to change the clear_byte part of the notification
618 * without disturbing the event channel part, which may now be the last
619 * reference to that event channel.
620 */
621 if (op.action & UNMAP_NOTIFY_SEND_EVENT) {
622 if (evtchn_get(op.event_channel_port))
623 return -EINVAL;
624 }
625
626 out_flags = op.action;
627 out_event = op.event_channel_port;
628
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500629 spin_lock(&priv->lock);
630
631 list_for_each_entry(map, &priv->maps, next) {
632 uint64_t begin = map->index << PAGE_SHIFT;
633 uint64_t end = (map->index + map->count) << PAGE_SHIFT;
634 if (op.index >= begin && op.index < end)
635 goto found;
636 }
637 rc = -ENOENT;
638 goto unlock_out;
639
640 found:
Daniel De Graaf9960be92011-02-09 18:15:50 -0500641 if ((op.action & UNMAP_NOTIFY_CLEAR_BYTE) &&
642 (map->flags & GNTMAP_readonly)) {
643 rc = -EINVAL;
644 goto unlock_out;
645 }
646
Daniel De Graaf0cc678f2011-10-27 17:58:49 -0400647 out_flags = map->notify.flags;
648 out_event = map->notify.event;
649
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500650 map->notify.flags = op.action;
651 map->notify.addr = op.index - (map->index << PAGE_SHIFT);
652 map->notify.event = op.event_channel_port;
Daniel De Graaf0cc678f2011-10-27 17:58:49 -0400653
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500654 rc = 0;
Daniel De Graaf0cc678f2011-10-27 17:58:49 -0400655
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500656 unlock_out:
657 spin_unlock(&priv->lock);
Daniel De Graaf0cc678f2011-10-27 17:58:49 -0400658
659 /* Drop the reference to the event channel we did not save in the map */
660 if (out_flags & UNMAP_NOTIFY_SEND_EVENT)
661 evtchn_put(out_event);
662
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500663 return rc;
664}
665
Gerd Hoffmannab315232010-12-14 18:40:46 +0000666static long gntdev_ioctl(struct file *flip,
667 unsigned int cmd, unsigned long arg)
668{
669 struct gntdev_priv *priv = flip->private_data;
670 void __user *ptr = (void __user *)arg;
671
672 switch (cmd) {
673 case IOCTL_GNTDEV_MAP_GRANT_REF:
674 return gntdev_ioctl_map_grant_ref(priv, ptr);
675
676 case IOCTL_GNTDEV_UNMAP_GRANT_REF:
677 return gntdev_ioctl_unmap_grant_ref(priv, ptr);
678
679 case IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR:
680 return gntdev_ioctl_get_offset_for_vaddr(priv, ptr);
681
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500682 case IOCTL_GNTDEV_SET_UNMAP_NOTIFY:
683 return gntdev_ioctl_notify(priv, ptr);
684
Gerd Hoffmannab315232010-12-14 18:40:46 +0000685 default:
686 pr_debug("priv %p, unknown cmd %x\n", priv, cmd);
687 return -ENOIOCTLCMD;
688 }
689
690 return 0;
691}
692
693static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
694{
695 struct gntdev_priv *priv = flip->private_data;
696 int index = vma->vm_pgoff;
697 int count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
698 struct grant_map *map;
Daniel De Graafaab8f112011-02-03 12:19:02 -0500699 int i, err = -EINVAL;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000700
701 if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED))
702 return -EINVAL;
703
704 pr_debug("map %d+%d at %lx (pgoff %lx)\n",
705 index, count, vma->vm_start, vma->vm_pgoff);
706
707 spin_lock(&priv->lock);
708 map = gntdev_find_map_index(priv, index, count);
709 if (!map)
710 goto unlock_out;
Daniel De Graafaab8f112011-02-03 12:19:02 -0500711 if (use_ptemod && map->vma)
Gerd Hoffmannab315232010-12-14 18:40:46 +0000712 goto unlock_out;
Daniel De Graafaab8f112011-02-03 12:19:02 -0500713 if (use_ptemod && priv->mm != vma->vm_mm) {
Gerd Hoffmannab315232010-12-14 18:40:46 +0000714 printk(KERN_WARNING "Huh? Other mm?\n");
715 goto unlock_out;
716 }
717
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500718 atomic_inc(&map->users);
719
Gerd Hoffmannab315232010-12-14 18:40:46 +0000720 vma->vm_ops = &gntdev_vmops;
721
Daniel De Graafd79647a2011-03-07 15:18:57 -0500722 vma->vm_flags |= VM_RESERVED|VM_DONTEXPAND;
723
724 if (use_ptemod)
725 vma->vm_flags |= VM_DONTCOPY|VM_PFNMAP;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000726
727 vma->vm_private_data = map;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000728
Daniel De Graafaab8f112011-02-03 12:19:02 -0500729 if (use_ptemod)
730 map->vma = vma;
731
Daniel De Graaf12996fc2011-02-09 16:11:32 -0500732 if (map->flags) {
733 if ((vma->vm_flags & VM_WRITE) &&
734 (map->flags & GNTMAP_readonly))
Dan Carpentera93e20a2011-03-19 08:45:43 +0300735 goto out_unlock_put;
Daniel De Graaf12996fc2011-02-09 16:11:32 -0500736 } else {
737 map->flags = GNTMAP_host_map;
738 if (!(vma->vm_flags & VM_WRITE))
739 map->flags |= GNTMAP_readonly;
740 }
Gerd Hoffmannab315232010-12-14 18:40:46 +0000741
Daniel De Graaff0a70c82011-01-07 11:51:47 +0000742 spin_unlock(&priv->lock);
743
Daniel De Graafaab8f112011-02-03 12:19:02 -0500744 if (use_ptemod) {
745 err = apply_to_page_range(vma->vm_mm, vma->vm_start,
746 vma->vm_end - vma->vm_start,
747 find_grant_ptes, map);
748 if (err) {
749 printk(KERN_WARNING "find_grant_ptes() failure.\n");
Daniel De Graaf90b6f302011-02-03 14:16:54 -0500750 goto out_put_map;
Daniel De Graafaab8f112011-02-03 12:19:02 -0500751 }
Gerd Hoffmannab315232010-12-14 18:40:46 +0000752 }
753
754 err = map_grant_pages(map);
Daniel De Graaf90b6f302011-02-03 14:16:54 -0500755 if (err)
756 goto out_put_map;
Daniel De Graaff0a70c82011-01-07 11:51:47 +0000757
Daniel De Graafaab8f112011-02-03 12:19:02 -0500758 if (!use_ptemod) {
759 for (i = 0; i < count; i++) {
760 err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE,
761 map->pages[i]);
762 if (err)
Daniel De Graaf90b6f302011-02-03 14:16:54 -0500763 goto out_put_map;
Daniel De Graafaab8f112011-02-03 12:19:02 -0500764 }
765 }
766
Daniel De Graaff0a70c82011-01-07 11:51:47 +0000767 return 0;
768
Gerd Hoffmannab315232010-12-14 18:40:46 +0000769unlock_out:
770 spin_unlock(&priv->lock);
771 return err;
Daniel De Graaf90b6f302011-02-03 14:16:54 -0500772
Dan Carpentera93e20a2011-03-19 08:45:43 +0300773out_unlock_put:
774 spin_unlock(&priv->lock);
Daniel De Graaf90b6f302011-02-03 14:16:54 -0500775out_put_map:
Daniel De Graaf84e40752011-02-09 15:11:59 -0500776 if (use_ptemod)
777 map->vma = NULL;
Daniel De Graaf90b6f302011-02-03 14:16:54 -0500778 gntdev_put_map(map);
779 return err;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000780}
781
782static const struct file_operations gntdev_fops = {
783 .owner = THIS_MODULE,
784 .open = gntdev_open,
785 .release = gntdev_release,
786 .mmap = gntdev_mmap,
787 .unlocked_ioctl = gntdev_ioctl
788};
789
790static struct miscdevice gntdev_miscdev = {
791 .minor = MISC_DYNAMIC_MINOR,
792 .name = "xen/gntdev",
793 .fops = &gntdev_fops,
794};
795
796/* ------------------------------------------------------------------ */
797
798static int __init gntdev_init(void)
799{
800 int err;
801
802 if (!xen_domain())
803 return -ENODEV;
804
Daniel De Graafaab8f112011-02-03 12:19:02 -0500805 use_ptemod = xen_pv_domain();
806
Gerd Hoffmannab315232010-12-14 18:40:46 +0000807 err = misc_register(&gntdev_miscdev);
808 if (err != 0) {
809 printk(KERN_ERR "Could not register gntdev device\n");
810 return err;
811 }
812 return 0;
813}
814
815static void __exit gntdev_exit(void)
816{
817 misc_deregister(&gntdev_miscdev);
818}
819
820module_init(gntdev_init);
821module_exit(gntdev_exit);
822
823/* ------------------------------------------------------------------ */