1 /****************************************************************************** 2 * gntdev.c 3 * 4 * Device for accessing (in user-space) pages that have been granted by other 5 * domains. 6 * 7 * Copyright (c) 2006-2007, D G Murray. 8 * (c) 2009 Gerd Hoffmann <kraxel@redhat.com> 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18 */ 19 20 #undef DEBUG 21 22 #include <linux/module.h> 23 #include <linux/kernel.h> 24 #include <linux/init.h> 25 #include <linux/miscdevice.h> 26 #include <linux/fs.h> 27 #include <linux/mm.h> 28 #include <linux/mman.h> 29 #include <linux/mmu_notifier.h> 30 #include <linux/types.h> 31 #include <linux/uaccess.h> 32 #include <linux/sched.h> 33 #include <linux/spinlock.h> 34 #include <linux/slab.h> 35 #include <linux/highmem.h> 36 37 #include <xen/xen.h> 38 #include <xen/grant_table.h> 39 #include <xen/balloon.h> 40 #include <xen/gntdev.h> 41 #include <xen/events.h> 42 #include <asm/xen/hypervisor.h> 43 #include <asm/xen/hypercall.h> 44 #include <asm/xen/page.h> 45 46 MODULE_LICENSE("GPL"); 47 MODULE_AUTHOR("Derek G. Murray <Derek.Murray@cl.cam.ac.uk>, " 48 "Gerd Hoffmann <kraxel@redhat.com>"); 49 MODULE_DESCRIPTION("User-space granted page access driver"); 50 51 static int limit = 1024*1024; 52 module_param(limit, int, 0644); 53 MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by " 54 "the gntdev device"); 55 56 static atomic_t pages_mapped = ATOMIC_INIT(0); 57 58 static int use_ptemod; 59 60 struct gntdev_priv { 61 struct list_head maps; 62 /* lock protects maps from concurrent changes */ 63 spinlock_t lock; 64 struct mm_struct *mm; 65 struct mmu_notifier mn; 66 }; 67 68 struct unmap_notify { 69 int flags; 70 /* Address relative to the start of the grant_map */ 71 int addr; 72 int event; 73 }; 74 75 struct grant_map { 76 struct list_head next; 77 struct vm_area_struct *vma; 78 int index; 79 int count; 80 int flags; 81 atomic_t users; 82 struct unmap_notify notify; 83 struct ioctl_gntdev_grant_ref *grants; 84 struct gnttab_map_grant_ref *map_ops; 85 struct gnttab_unmap_grant_ref *unmap_ops; 86 struct gnttab_map_grant_ref *kmap_ops; 87 struct page **pages; 88 }; 89 90 static int unmap_grant_pages(struct grant_map *map, int offset, int pages); 91 92 /* ------------------------------------------------------------------ */ 93 94 static void gntdev_print_maps(struct gntdev_priv *priv, 95 char *text, int text_index) 96 { 97 #ifdef DEBUG 98 struct grant_map *map; 99 100 pr_debug("%s: maps list (priv %p)\n", __func__, priv); 101 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 } 107 108 static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count) 109 { 110 struct grant_map *add; 111 int i; 112 113 add = kzalloc(sizeof(struct grant_map), GFP_KERNEL); 114 if (NULL == add) 115 return NULL; 116 117 add->grants = kzalloc(sizeof(add->grants[0]) * count, GFP_KERNEL); 118 add->map_ops = kzalloc(sizeof(add->map_ops[0]) * count, GFP_KERNEL); 119 add->unmap_ops = kzalloc(sizeof(add->unmap_ops[0]) * count, GFP_KERNEL); 120 add->kmap_ops = kzalloc(sizeof(add->kmap_ops[0]) * count, GFP_KERNEL); 121 add->pages = kzalloc(sizeof(add->pages[0]) * count, GFP_KERNEL); 122 if (NULL == add->grants || 123 NULL == add->map_ops || 124 NULL == add->unmap_ops || 125 NULL == add->kmap_ops || 126 NULL == add->pages) 127 goto err; 128 129 if (alloc_xenballooned_pages(count, add->pages, false /* lowmem */)) 130 goto err; 131 132 for (i = 0; i < count; i++) { 133 add->map_ops[i].handle = -1; 134 add->unmap_ops[i].handle = -1; 135 add->kmap_ops[i].handle = -1; 136 } 137 138 add->index = 0; 139 add->count = count; 140 atomic_set(&add->users, 1); 141 142 return add; 143 144 err: 145 kfree(add->pages); 146 kfree(add->grants); 147 kfree(add->map_ops); 148 kfree(add->unmap_ops); 149 kfree(add->kmap_ops); 150 kfree(add); 151 return NULL; 152 } 153 154 static 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); 166 167 done: 168 gntdev_print_maps(priv, "[new]", add->index); 169 } 170 171 static 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; 179 if (count && map->count != count) 180 continue; 181 return map; 182 } 183 return NULL; 184 } 185 186 static void gntdev_put_map(struct grant_map *map) 187 { 188 if (!map) 189 return; 190 191 if (!atomic_dec_and_test(&map->users)) 192 return; 193 194 atomic_sub(map->count, &pages_mapped); 195 196 if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) { 197 notify_remote_via_evtchn(map->notify.event); 198 } 199 200 if (map->pages) { 201 if (!use_ptemod) 202 unmap_grant_pages(map, 0, map->count); 203 204 free_xenballooned_pages(map->count, map->pages); 205 } 206 kfree(map->pages); 207 kfree(map->grants); 208 kfree(map->map_ops); 209 kfree(map->unmap_ops); 210 kfree(map); 211 } 212 213 /* ------------------------------------------------------------------ */ 214 215 static int find_grant_ptes(pte_t *pte, pgtable_t token, 216 unsigned long addr, void *data) 217 { 218 struct grant_map *map = data; 219 unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT; 220 int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte; 221 u64 pte_maddr; 222 223 BUG_ON(pgnr >= map->count); 224 pte_maddr = arbitrary_virt_to_machine(pte).maddr; 225 226 gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, flags, 227 map->grants[pgnr].ref, 228 map->grants[pgnr].domid); 229 gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags, 230 -1 /* handle */); 231 return 0; 232 } 233 234 static int map_grant_pages(struct grant_map *map) 235 { 236 int i, err = 0; 237 238 if (!use_ptemod) { 239 /* Note: it could already be mapped */ 240 if (map->map_ops[0].handle != -1) 241 return 0; 242 for (i = 0; i < map->count; i++) { 243 unsigned long addr = (unsigned long) 244 pfn_to_kaddr(page_to_pfn(map->pages[i])); 245 gnttab_set_map_op(&map->map_ops[i], addr, map->flags, 246 map->grants[i].ref, 247 map->grants[i].domid); 248 gnttab_set_unmap_op(&map->unmap_ops[i], addr, 249 map->flags, -1 /* handle */); 250 } 251 } else { 252 /* 253 * Setup the map_ops corresponding to the pte entries pointing 254 * to the kernel linear addresses of the struct pages. 255 * These ptes are completely different from the user ptes dealt 256 * with find_grant_ptes. 257 */ 258 for (i = 0; i < map->count; i++) { 259 unsigned level; 260 unsigned long address = (unsigned long) 261 pfn_to_kaddr(page_to_pfn(map->pages[i])); 262 pte_t *ptep; 263 u64 pte_maddr = 0; 264 BUG_ON(PageHighMem(map->pages[i])); 265 266 ptep = lookup_address(address, &level); 267 pte_maddr = arbitrary_virt_to_machine(ptep).maddr; 268 gnttab_set_map_op(&map->kmap_ops[i], pte_maddr, 269 map->flags | 270 GNTMAP_host_map | 271 GNTMAP_contains_pte, 272 map->grants[i].ref, 273 map->grants[i].domid); 274 } 275 } 276 277 pr_debug("map %d+%d\n", map->index, map->count); 278 err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL, 279 map->pages, map->count); 280 if (err) 281 return err; 282 283 for (i = 0; i < map->count; i++) { 284 if (map->map_ops[i].status) 285 err = -EINVAL; 286 else { 287 BUG_ON(map->map_ops[i].handle == -1); 288 map->unmap_ops[i].handle = map->map_ops[i].handle; 289 pr_debug("map handle=%d\n", map->map_ops[i].handle); 290 } 291 } 292 return err; 293 } 294 295 static int __unmap_grant_pages(struct grant_map *map, int offset, int pages) 296 { 297 int i, err = 0; 298 299 if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) { 300 int pgno = (map->notify.addr >> PAGE_SHIFT); 301 if (pgno >= offset && pgno < offset + pages && use_ptemod) { 302 void __user *tmp = (void __user *) 303 map->vma->vm_start + map->notify.addr; 304 err = copy_to_user(tmp, &err, 1); 305 if (err) 306 return -EFAULT; 307 map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE; 308 } else if (pgno >= offset && pgno < offset + pages) { 309 uint8_t *tmp = kmap(map->pages[pgno]); 310 tmp[map->notify.addr & (PAGE_SIZE-1)] = 0; 311 kunmap(map->pages[pgno]); 312 map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE; 313 } 314 } 315 316 err = gnttab_unmap_refs(map->unmap_ops + offset, map->pages + offset, pages); 317 if (err) 318 return err; 319 320 for (i = 0; i < pages; i++) { 321 if (map->unmap_ops[offset+i].status) 322 err = -EINVAL; 323 pr_debug("unmap handle=%d st=%d\n", 324 map->unmap_ops[offset+i].handle, 325 map->unmap_ops[offset+i].status); 326 map->unmap_ops[offset+i].handle = -1; 327 } 328 return err; 329 } 330 331 static int unmap_grant_pages(struct grant_map *map, int offset, int pages) 332 { 333 int range, err = 0; 334 335 pr_debug("unmap %d+%d [%d+%d]\n", map->index, map->count, offset, pages); 336 337 /* It is possible the requested range will have a "hole" where we 338 * already unmapped some of the grants. Only unmap valid ranges. 339 */ 340 while (pages && !err) { 341 while (pages && map->unmap_ops[offset].handle == -1) { 342 offset++; 343 pages--; 344 } 345 range = 0; 346 while (range < pages) { 347 if (map->unmap_ops[offset+range].handle == -1) { 348 range--; 349 break; 350 } 351 range++; 352 } 353 err = __unmap_grant_pages(map, offset, range); 354 offset += range; 355 pages -= range; 356 } 357 358 return err; 359 } 360 361 /* ------------------------------------------------------------------ */ 362 363 static void gntdev_vma_open(struct vm_area_struct *vma) 364 { 365 struct grant_map *map = vma->vm_private_data; 366 367 pr_debug("gntdev_vma_open %p\n", vma); 368 atomic_inc(&map->users); 369 } 370 371 static void gntdev_vma_close(struct vm_area_struct *vma) 372 { 373 struct grant_map *map = vma->vm_private_data; 374 375 pr_debug("gntdev_vma_close %p\n", vma); 376 map->vma = NULL; 377 vma->vm_private_data = NULL; 378 gntdev_put_map(map); 379 } 380 381 static struct vm_operations_struct gntdev_vmops = { 382 .open = gntdev_vma_open, 383 .close = gntdev_vma_close, 384 }; 385 386 /* ------------------------------------------------------------------ */ 387 388 static void mn_invl_range_start(struct mmu_notifier *mn, 389 struct mm_struct *mm, 390 unsigned long start, unsigned long end) 391 { 392 struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); 393 struct grant_map *map; 394 unsigned long mstart, mend; 395 int err; 396 397 spin_lock(&priv->lock); 398 list_for_each_entry(map, &priv->maps, next) { 399 if (!map->vma) 400 continue; 401 if (map->vma->vm_start >= end) 402 continue; 403 if (map->vma->vm_end <= start) 404 continue; 405 mstart = max(start, map->vma->vm_start); 406 mend = min(end, map->vma->vm_end); 407 pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n", 408 map->index, map->count, 409 map->vma->vm_start, map->vma->vm_end, 410 start, end, mstart, mend); 411 err = unmap_grant_pages(map, 412 (mstart - map->vma->vm_start) >> PAGE_SHIFT, 413 (mend - mstart) >> PAGE_SHIFT); 414 WARN_ON(err); 415 } 416 spin_unlock(&priv->lock); 417 } 418 419 static void mn_invl_page(struct mmu_notifier *mn, 420 struct mm_struct *mm, 421 unsigned long address) 422 { 423 mn_invl_range_start(mn, mm, address, address + PAGE_SIZE); 424 } 425 426 static void mn_release(struct mmu_notifier *mn, 427 struct mm_struct *mm) 428 { 429 struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); 430 struct grant_map *map; 431 int err; 432 433 spin_lock(&priv->lock); 434 list_for_each_entry(map, &priv->maps, next) { 435 if (!map->vma) 436 continue; 437 pr_debug("map %d+%d (%lx %lx)\n", 438 map->index, map->count, 439 map->vma->vm_start, map->vma->vm_end); 440 err = unmap_grant_pages(map, /* offset */ 0, map->count); 441 WARN_ON(err); 442 } 443 spin_unlock(&priv->lock); 444 } 445 446 struct mmu_notifier_ops gntdev_mmu_ops = { 447 .release = mn_release, 448 .invalidate_page = mn_invl_page, 449 .invalidate_range_start = mn_invl_range_start, 450 }; 451 452 /* ------------------------------------------------------------------ */ 453 454 static int gntdev_open(struct inode *inode, struct file *flip) 455 { 456 struct gntdev_priv *priv; 457 int ret = 0; 458 459 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 460 if (!priv) 461 return -ENOMEM; 462 463 INIT_LIST_HEAD(&priv->maps); 464 spin_lock_init(&priv->lock); 465 466 if (use_ptemod) { 467 priv->mm = get_task_mm(current); 468 if (!priv->mm) { 469 kfree(priv); 470 return -ENOMEM; 471 } 472 priv->mn.ops = &gntdev_mmu_ops; 473 ret = mmu_notifier_register(&priv->mn, priv->mm); 474 mmput(priv->mm); 475 } 476 477 if (ret) { 478 kfree(priv); 479 return ret; 480 } 481 482 flip->private_data = priv; 483 pr_debug("priv %p\n", priv); 484 485 return 0; 486 } 487 488 static int gntdev_release(struct inode *inode, struct file *flip) 489 { 490 struct gntdev_priv *priv = flip->private_data; 491 struct grant_map *map; 492 493 pr_debug("priv %p\n", priv); 494 495 while (!list_empty(&priv->maps)) { 496 map = list_entry(priv->maps.next, struct grant_map, next); 497 list_del(&map->next); 498 gntdev_put_map(map); 499 } 500 501 if (use_ptemod) 502 mmu_notifier_unregister(&priv->mn, priv->mm); 503 kfree(priv); 504 return 0; 505 } 506 507 static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv, 508 struct ioctl_gntdev_map_grant_ref __user *u) 509 { 510 struct ioctl_gntdev_map_grant_ref op; 511 struct grant_map *map; 512 int err; 513 514 if (copy_from_user(&op, u, sizeof(op)) != 0) 515 return -EFAULT; 516 pr_debug("priv %p, add %d\n", priv, op.count); 517 if (unlikely(op.count <= 0)) 518 return -EINVAL; 519 520 err = -ENOMEM; 521 map = gntdev_alloc_map(priv, op.count); 522 if (!map) 523 return err; 524 525 if (unlikely(atomic_add_return(op.count, &pages_mapped) > limit)) { 526 pr_debug("can't map: over limit\n"); 527 gntdev_put_map(map); 528 return err; 529 } 530 531 if (copy_from_user(map->grants, &u->refs, 532 sizeof(map->grants[0]) * op.count) != 0) { 533 gntdev_put_map(map); 534 return err; 535 } 536 537 spin_lock(&priv->lock); 538 gntdev_add_map(priv, map); 539 op.index = map->index << PAGE_SHIFT; 540 spin_unlock(&priv->lock); 541 542 if (copy_to_user(u, &op, sizeof(op)) != 0) 543 return -EFAULT; 544 545 return 0; 546 } 547 548 static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv, 549 struct ioctl_gntdev_unmap_grant_ref __user *u) 550 { 551 struct ioctl_gntdev_unmap_grant_ref op; 552 struct grant_map *map; 553 int err = -ENOENT; 554 555 if (copy_from_user(&op, u, sizeof(op)) != 0) 556 return -EFAULT; 557 pr_debug("priv %p, del %d+%d\n", priv, (int)op.index, (int)op.count); 558 559 spin_lock(&priv->lock); 560 map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count); 561 if (map) { 562 list_del(&map->next); 563 err = 0; 564 } 565 spin_unlock(&priv->lock); 566 if (map) 567 gntdev_put_map(map); 568 return err; 569 } 570 571 static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv, 572 struct ioctl_gntdev_get_offset_for_vaddr __user *u) 573 { 574 struct ioctl_gntdev_get_offset_for_vaddr op; 575 struct vm_area_struct *vma; 576 struct grant_map *map; 577 578 if (copy_from_user(&op, u, sizeof(op)) != 0) 579 return -EFAULT; 580 pr_debug("priv %p, offset for vaddr %lx\n", priv, (unsigned long)op.vaddr); 581 582 vma = find_vma(current->mm, op.vaddr); 583 if (!vma || vma->vm_ops != &gntdev_vmops) 584 return -EINVAL; 585 586 map = vma->vm_private_data; 587 if (!map) 588 return -EINVAL; 589 590 op.offset = map->index << PAGE_SHIFT; 591 op.count = map->count; 592 593 if (copy_to_user(u, &op, sizeof(op)) != 0) 594 return -EFAULT; 595 return 0; 596 } 597 598 static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u) 599 { 600 struct ioctl_gntdev_unmap_notify op; 601 struct grant_map *map; 602 int rc; 603 604 if (copy_from_user(&op, u, sizeof(op))) 605 return -EFAULT; 606 607 if (op.action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT)) 608 return -EINVAL; 609 610 spin_lock(&priv->lock); 611 612 list_for_each_entry(map, &priv->maps, next) { 613 uint64_t begin = map->index << PAGE_SHIFT; 614 uint64_t end = (map->index + map->count) << PAGE_SHIFT; 615 if (op.index >= begin && op.index < end) 616 goto found; 617 } 618 rc = -ENOENT; 619 goto unlock_out; 620 621 found: 622 if ((op.action & UNMAP_NOTIFY_CLEAR_BYTE) && 623 (map->flags & GNTMAP_readonly)) { 624 rc = -EINVAL; 625 goto unlock_out; 626 } 627 628 map->notify.flags = op.action; 629 map->notify.addr = op.index - (map->index << PAGE_SHIFT); 630 map->notify.event = op.event_channel_port; 631 rc = 0; 632 unlock_out: 633 spin_unlock(&priv->lock); 634 return rc; 635 } 636 637 static long gntdev_ioctl(struct file *flip, 638 unsigned int cmd, unsigned long arg) 639 { 640 struct gntdev_priv *priv = flip->private_data; 641 void __user *ptr = (void __user *)arg; 642 643 switch (cmd) { 644 case IOCTL_GNTDEV_MAP_GRANT_REF: 645 return gntdev_ioctl_map_grant_ref(priv, ptr); 646 647 case IOCTL_GNTDEV_UNMAP_GRANT_REF: 648 return gntdev_ioctl_unmap_grant_ref(priv, ptr); 649 650 case IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR: 651 return gntdev_ioctl_get_offset_for_vaddr(priv, ptr); 652 653 case IOCTL_GNTDEV_SET_UNMAP_NOTIFY: 654 return gntdev_ioctl_notify(priv, ptr); 655 656 default: 657 pr_debug("priv %p, unknown cmd %x\n", priv, cmd); 658 return -ENOIOCTLCMD; 659 } 660 661 return 0; 662 } 663 664 static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) 665 { 666 struct gntdev_priv *priv = flip->private_data; 667 int index = vma->vm_pgoff; 668 int count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; 669 struct grant_map *map; 670 int i, err = -EINVAL; 671 672 if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED)) 673 return -EINVAL; 674 675 pr_debug("map %d+%d at %lx (pgoff %lx)\n", 676 index, count, vma->vm_start, vma->vm_pgoff); 677 678 spin_lock(&priv->lock); 679 map = gntdev_find_map_index(priv, index, count); 680 if (!map) 681 goto unlock_out; 682 if (use_ptemod && map->vma) 683 goto unlock_out; 684 if (use_ptemod && priv->mm != vma->vm_mm) { 685 printk(KERN_WARNING "Huh? Other mm?\n"); 686 goto unlock_out; 687 } 688 689 atomic_inc(&map->users); 690 691 vma->vm_ops = &gntdev_vmops; 692 693 vma->vm_flags |= VM_RESERVED|VM_DONTEXPAND; 694 695 if (use_ptemod) 696 vma->vm_flags |= VM_DONTCOPY|VM_PFNMAP; 697 698 vma->vm_private_data = map; 699 700 if (use_ptemod) 701 map->vma = vma; 702 703 if (map->flags) { 704 if ((vma->vm_flags & VM_WRITE) && 705 (map->flags & GNTMAP_readonly)) 706 goto out_unlock_put; 707 } else { 708 map->flags = GNTMAP_host_map; 709 if (!(vma->vm_flags & VM_WRITE)) 710 map->flags |= GNTMAP_readonly; 711 } 712 713 spin_unlock(&priv->lock); 714 715 if (use_ptemod) { 716 err = apply_to_page_range(vma->vm_mm, vma->vm_start, 717 vma->vm_end - vma->vm_start, 718 find_grant_ptes, map); 719 if (err) { 720 printk(KERN_WARNING "find_grant_ptes() failure.\n"); 721 goto out_put_map; 722 } 723 } 724 725 err = map_grant_pages(map); 726 if (err) 727 goto out_put_map; 728 729 if (!use_ptemod) { 730 for (i = 0; i < count; i++) { 731 err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE, 732 map->pages[i]); 733 if (err) 734 goto out_put_map; 735 } 736 } 737 738 return 0; 739 740 unlock_out: 741 spin_unlock(&priv->lock); 742 return err; 743 744 out_unlock_put: 745 spin_unlock(&priv->lock); 746 out_put_map: 747 if (use_ptemod) 748 map->vma = NULL; 749 gntdev_put_map(map); 750 return err; 751 } 752 753 static const struct file_operations gntdev_fops = { 754 .owner = THIS_MODULE, 755 .open = gntdev_open, 756 .release = gntdev_release, 757 .mmap = gntdev_mmap, 758 .unlocked_ioctl = gntdev_ioctl 759 }; 760 761 static struct miscdevice gntdev_miscdev = { 762 .minor = MISC_DYNAMIC_MINOR, 763 .name = "xen/gntdev", 764 .fops = &gntdev_fops, 765 }; 766 767 /* ------------------------------------------------------------------ */ 768 769 static int __init gntdev_init(void) 770 { 771 int err; 772 773 if (!xen_domain()) 774 return -ENODEV; 775 776 use_ptemod = xen_pv_domain(); 777 778 err = misc_register(&gntdev_miscdev); 779 if (err != 0) { 780 printk(KERN_ERR "Could not register gntdev device\n"); 781 return err; 782 } 783 return 0; 784 } 785 786 static void __exit gntdev_exit(void) 787 { 788 misc_deregister(&gntdev_miscdev); 789 } 790 791 module_init(gntdev_init); 792 module_exit(gntdev_exit); 793 794 /* ------------------------------------------------------------------ */ 795