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 if (map->pages) { 200 if (!use_ptemod) 201 unmap_grant_pages(map, 0, map->count); 202 203 free_xenballooned_pages(map->count, map->pages); 204 } 205 kfree(map->pages); 206 kfree(map->grants); 207 kfree(map->map_ops); 208 kfree(map->unmap_ops); 209 kfree(map); 210 } 211 212 /* ------------------------------------------------------------------ */ 213 214 static int find_grant_ptes(pte_t *pte, pgtable_t token, 215 unsigned long addr, void *data) 216 { 217 struct grant_map *map = data; 218 unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT; 219 int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte; 220 u64 pte_maddr; 221 222 BUG_ON(pgnr >= map->count); 223 pte_maddr = arbitrary_virt_to_machine(pte).maddr; 224 225 gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, flags, 226 map->grants[pgnr].ref, 227 map->grants[pgnr].domid); 228 gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags, 229 -1 /* handle */); 230 return 0; 231 } 232 233 static int map_grant_pages(struct grant_map *map) 234 { 235 int i, err = 0; 236 237 if (!use_ptemod) { 238 /* Note: it could already be mapped */ 239 if (map->map_ops[0].handle != -1) 240 return 0; 241 for (i = 0; i < map->count; i++) { 242 unsigned long addr = (unsigned long) 243 pfn_to_kaddr(page_to_pfn(map->pages[i])); 244 gnttab_set_map_op(&map->map_ops[i], addr, map->flags, 245 map->grants[i].ref, 246 map->grants[i].domid); 247 gnttab_set_unmap_op(&map->unmap_ops[i], addr, 248 map->flags, -1 /* handle */); 249 } 250 } else { 251 /* 252 * Setup the map_ops corresponding to the pte entries pointing 253 * to the kernel linear addresses of the struct pages. 254 * These ptes are completely different from the user ptes dealt 255 * with find_grant_ptes. 256 */ 257 for (i = 0; i < map->count; i++) { 258 unsigned level; 259 unsigned long address = (unsigned long) 260 pfn_to_kaddr(page_to_pfn(map->pages[i])); 261 pte_t *ptep; 262 u64 pte_maddr = 0; 263 BUG_ON(PageHighMem(map->pages[i])); 264 265 ptep = lookup_address(address, &level); 266 pte_maddr = arbitrary_virt_to_machine(ptep).maddr; 267 gnttab_set_map_op(&map->kmap_ops[i], pte_maddr, 268 map->flags | 269 GNTMAP_host_map | 270 GNTMAP_contains_pte, 271 map->grants[i].ref, 272 map->grants[i].domid); 273 } 274 } 275 276 pr_debug("map %d+%d\n", map->index, map->count); 277 err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL, 278 map->pages, map->count); 279 if (err) 280 return err; 281 282 for (i = 0; i < map->count; i++) { 283 if (map->map_ops[i].status) 284 err = -EINVAL; 285 else { 286 BUG_ON(map->map_ops[i].handle == -1); 287 map->unmap_ops[i].handle = map->map_ops[i].handle; 288 pr_debug("map handle=%d\n", map->map_ops[i].handle); 289 } 290 } 291 return err; 292 } 293 294 static int __unmap_grant_pages(struct grant_map *map, int offset, int pages) 295 { 296 int i, err = 0; 297 298 if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) { 299 int pgno = (map->notify.addr >> PAGE_SHIFT); 300 if (pgno >= offset && pgno < offset + pages && use_ptemod) { 301 void __user *tmp = (void __user *) 302 map->vma->vm_start + map->notify.addr; 303 err = copy_to_user(tmp, &err, 1); 304 if (err) 305 return -EFAULT; 306 map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE; 307 } else if (pgno >= offset && pgno < offset + pages) { 308 uint8_t *tmp = kmap(map->pages[pgno]); 309 tmp[map->notify.addr & (PAGE_SIZE-1)] = 0; 310 kunmap(map->pages[pgno]); 311 map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE; 312 } 313 } 314 315 err = gnttab_unmap_refs(map->unmap_ops + offset, map->pages + offset, pages); 316 if (err) 317 return err; 318 319 for (i = 0; i < pages; i++) { 320 if (map->unmap_ops[offset+i].status) 321 err = -EINVAL; 322 pr_debug("unmap handle=%d st=%d\n", 323 map->unmap_ops[offset+i].handle, 324 map->unmap_ops[offset+i].status); 325 map->unmap_ops[offset+i].handle = -1; 326 } 327 return err; 328 } 329 330 static int unmap_grant_pages(struct grant_map *map, int offset, int pages) 331 { 332 int range, err = 0; 333 334 pr_debug("unmap %d+%d [%d+%d]\n", map->index, map->count, offset, pages); 335 336 /* It is possible the requested range will have a "hole" where we 337 * already unmapped some of the grants. Only unmap valid ranges. 338 */ 339 while (pages && !err) { 340 while (pages && map->unmap_ops[offset].handle == -1) { 341 offset++; 342 pages--; 343 } 344 range = 0; 345 while (range < pages) { 346 if (map->unmap_ops[offset+range].handle == -1) { 347 range--; 348 break; 349 } 350 range++; 351 } 352 err = __unmap_grant_pages(map, offset, range); 353 offset += range; 354 pages -= range; 355 } 356 357 return err; 358 } 359 360 /* ------------------------------------------------------------------ */ 361 362 static void gntdev_vma_open(struct vm_area_struct *vma) 363 { 364 struct grant_map *map = vma->vm_private_data; 365 366 pr_debug("gntdev_vma_open %p\n", vma); 367 atomic_inc(&map->users); 368 } 369 370 static void gntdev_vma_close(struct vm_area_struct *vma) 371 { 372 struct grant_map *map = vma->vm_private_data; 373 374 pr_debug("gntdev_vma_close %p\n", vma); 375 map->vma = NULL; 376 vma->vm_private_data = NULL; 377 gntdev_put_map(map); 378 } 379 380 static struct vm_operations_struct gntdev_vmops = { 381 .open = gntdev_vma_open, 382 .close = gntdev_vma_close, 383 }; 384 385 /* ------------------------------------------------------------------ */ 386 387 static void mn_invl_range_start(struct mmu_notifier *mn, 388 struct mm_struct *mm, 389 unsigned long start, unsigned long end) 390 { 391 struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); 392 struct grant_map *map; 393 unsigned long mstart, mend; 394 int err; 395 396 spin_lock(&priv->lock); 397 list_for_each_entry(map, &priv->maps, next) { 398 if (!map->vma) 399 continue; 400 if (map->vma->vm_start >= end) 401 continue; 402 if (map->vma->vm_end <= start) 403 continue; 404 mstart = max(start, map->vma->vm_start); 405 mend = min(end, map->vma->vm_end); 406 pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n", 407 map->index, map->count, 408 map->vma->vm_start, map->vma->vm_end, 409 start, end, mstart, mend); 410 err = unmap_grant_pages(map, 411 (mstart - map->vma->vm_start) >> PAGE_SHIFT, 412 (mend - mstart) >> PAGE_SHIFT); 413 WARN_ON(err); 414 } 415 spin_unlock(&priv->lock); 416 } 417 418 static void mn_invl_page(struct mmu_notifier *mn, 419 struct mm_struct *mm, 420 unsigned long address) 421 { 422 mn_invl_range_start(mn, mm, address, address + PAGE_SIZE); 423 } 424 425 static void mn_release(struct mmu_notifier *mn, 426 struct mm_struct *mm) 427 { 428 struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); 429 struct grant_map *map; 430 int err; 431 432 spin_lock(&priv->lock); 433 list_for_each_entry(map, &priv->maps, next) { 434 if (!map->vma) 435 continue; 436 pr_debug("map %d+%d (%lx %lx)\n", 437 map->index, map->count, 438 map->vma->vm_start, map->vma->vm_end); 439 err = unmap_grant_pages(map, /* offset */ 0, map->count); 440 WARN_ON(err); 441 } 442 spin_unlock(&priv->lock); 443 } 444 445 struct mmu_notifier_ops gntdev_mmu_ops = { 446 .release = mn_release, 447 .invalidate_page = mn_invl_page, 448 .invalidate_range_start = mn_invl_range_start, 449 }; 450 451 /* ------------------------------------------------------------------ */ 452 453 static int gntdev_open(struct inode *inode, struct file *flip) 454 { 455 struct gntdev_priv *priv; 456 int ret = 0; 457 458 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 459 if (!priv) 460 return -ENOMEM; 461 462 INIT_LIST_HEAD(&priv->maps); 463 spin_lock_init(&priv->lock); 464 465 if (use_ptemod) { 466 priv->mm = get_task_mm(current); 467 if (!priv->mm) { 468 kfree(priv); 469 return -ENOMEM; 470 } 471 priv->mn.ops = &gntdev_mmu_ops; 472 ret = mmu_notifier_register(&priv->mn, priv->mm); 473 mmput(priv->mm); 474 } 475 476 if (ret) { 477 kfree(priv); 478 return ret; 479 } 480 481 flip->private_data = priv; 482 pr_debug("priv %p\n", priv); 483 484 return 0; 485 } 486 487 static int gntdev_release(struct inode *inode, struct file *flip) 488 { 489 struct gntdev_priv *priv = flip->private_data; 490 struct grant_map *map; 491 492 pr_debug("priv %p\n", priv); 493 494 while (!list_empty(&priv->maps)) { 495 map = list_entry(priv->maps.next, struct grant_map, next); 496 list_del(&map->next); 497 gntdev_put_map(map); 498 } 499 500 if (use_ptemod) 501 mmu_notifier_unregister(&priv->mn, priv->mm); 502 kfree(priv); 503 return 0; 504 } 505 506 static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv, 507 struct ioctl_gntdev_map_grant_ref __user *u) 508 { 509 struct ioctl_gntdev_map_grant_ref op; 510 struct grant_map *map; 511 int err; 512 513 if (copy_from_user(&op, u, sizeof(op)) != 0) 514 return -EFAULT; 515 pr_debug("priv %p, add %d\n", priv, op.count); 516 if (unlikely(op.count <= 0)) 517 return -EINVAL; 518 519 err = -ENOMEM; 520 map = gntdev_alloc_map(priv, op.count); 521 if (!map) 522 return err; 523 524 if (unlikely(atomic_add_return(op.count, &pages_mapped) > limit)) { 525 pr_debug("can't map: over limit\n"); 526 gntdev_put_map(map); 527 return err; 528 } 529 530 if (copy_from_user(map->grants, &u->refs, 531 sizeof(map->grants[0]) * op.count) != 0) { 532 gntdev_put_map(map); 533 return err; 534 } 535 536 spin_lock(&priv->lock); 537 gntdev_add_map(priv, map); 538 op.index = map->index << PAGE_SHIFT; 539 spin_unlock(&priv->lock); 540 541 if (copy_to_user(u, &op, sizeof(op)) != 0) 542 return -EFAULT; 543 544 return 0; 545 } 546 547 static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv, 548 struct ioctl_gntdev_unmap_grant_ref __user *u) 549 { 550 struct ioctl_gntdev_unmap_grant_ref op; 551 struct grant_map *map; 552 int err = -ENOENT; 553 554 if (copy_from_user(&op, u, sizeof(op)) != 0) 555 return -EFAULT; 556 pr_debug("priv %p, del %d+%d\n", priv, (int)op.index, (int)op.count); 557 558 spin_lock(&priv->lock); 559 map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count); 560 if (map) { 561 list_del(&map->next); 562 err = 0; 563 } 564 spin_unlock(&priv->lock); 565 if (map) 566 gntdev_put_map(map); 567 return err; 568 } 569 570 static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv, 571 struct ioctl_gntdev_get_offset_for_vaddr __user *u) 572 { 573 struct ioctl_gntdev_get_offset_for_vaddr op; 574 struct vm_area_struct *vma; 575 struct grant_map *map; 576 577 if (copy_from_user(&op, u, sizeof(op)) != 0) 578 return -EFAULT; 579 pr_debug("priv %p, offset for vaddr %lx\n", priv, (unsigned long)op.vaddr); 580 581 vma = find_vma(current->mm, op.vaddr); 582 if (!vma || vma->vm_ops != &gntdev_vmops) 583 return -EINVAL; 584 585 map = vma->vm_private_data; 586 if (!map) 587 return -EINVAL; 588 589 op.offset = map->index << PAGE_SHIFT; 590 op.count = map->count; 591 592 if (copy_to_user(u, &op, sizeof(op)) != 0) 593 return -EFAULT; 594 return 0; 595 } 596 597 static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u) 598 { 599 struct ioctl_gntdev_unmap_notify op; 600 struct grant_map *map; 601 int rc; 602 603 if (copy_from_user(&op, u, sizeof(op))) 604 return -EFAULT; 605 606 if (op.action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT)) 607 return -EINVAL; 608 609 spin_lock(&priv->lock); 610 611 list_for_each_entry(map, &priv->maps, next) { 612 uint64_t begin = map->index << PAGE_SHIFT; 613 uint64_t end = (map->index + map->count) << PAGE_SHIFT; 614 if (op.index >= begin && op.index < end) 615 goto found; 616 } 617 rc = -ENOENT; 618 goto unlock_out; 619 620 found: 621 if ((op.action & UNMAP_NOTIFY_CLEAR_BYTE) && 622 (map->flags & GNTMAP_readonly)) { 623 rc = -EINVAL; 624 goto unlock_out; 625 } 626 627 map->notify.flags = op.action; 628 map->notify.addr = op.index - (map->index << PAGE_SHIFT); 629 map->notify.event = op.event_channel_port; 630 rc = 0; 631 unlock_out: 632 spin_unlock(&priv->lock); 633 return rc; 634 } 635 636 static long gntdev_ioctl(struct file *flip, 637 unsigned int cmd, unsigned long arg) 638 { 639 struct gntdev_priv *priv = flip->private_data; 640 void __user *ptr = (void __user *)arg; 641 642 switch (cmd) { 643 case IOCTL_GNTDEV_MAP_GRANT_REF: 644 return gntdev_ioctl_map_grant_ref(priv, ptr); 645 646 case IOCTL_GNTDEV_UNMAP_GRANT_REF: 647 return gntdev_ioctl_unmap_grant_ref(priv, ptr); 648 649 case IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR: 650 return gntdev_ioctl_get_offset_for_vaddr(priv, ptr); 651 652 case IOCTL_GNTDEV_SET_UNMAP_NOTIFY: 653 return gntdev_ioctl_notify(priv, ptr); 654 655 default: 656 pr_debug("priv %p, unknown cmd %x\n", priv, cmd); 657 return -ENOIOCTLCMD; 658 } 659 660 return 0; 661 } 662 663 static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) 664 { 665 struct gntdev_priv *priv = flip->private_data; 666 int index = vma->vm_pgoff; 667 int count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; 668 struct grant_map *map; 669 int i, err = -EINVAL; 670 671 if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED)) 672 return -EINVAL; 673 674 pr_debug("map %d+%d at %lx (pgoff %lx)\n", 675 index, count, vma->vm_start, vma->vm_pgoff); 676 677 spin_lock(&priv->lock); 678 map = gntdev_find_map_index(priv, index, count); 679 if (!map) 680 goto unlock_out; 681 if (use_ptemod && map->vma) 682 goto unlock_out; 683 if (use_ptemod && priv->mm != vma->vm_mm) { 684 printk(KERN_WARNING "Huh? Other mm?\n"); 685 goto unlock_out; 686 } 687 688 atomic_inc(&map->users); 689 690 vma->vm_ops = &gntdev_vmops; 691 692 vma->vm_flags |= VM_RESERVED|VM_DONTEXPAND; 693 694 if (use_ptemod) 695 vma->vm_flags |= VM_DONTCOPY|VM_PFNMAP; 696 697 vma->vm_private_data = map; 698 699 if (use_ptemod) 700 map->vma = vma; 701 702 if (map->flags) { 703 if ((vma->vm_flags & VM_WRITE) && 704 (map->flags & GNTMAP_readonly)) 705 goto out_unlock_put; 706 } else { 707 map->flags = GNTMAP_host_map; 708 if (!(vma->vm_flags & VM_WRITE)) 709 map->flags |= GNTMAP_readonly; 710 } 711 712 spin_unlock(&priv->lock); 713 714 if (use_ptemod) { 715 err = apply_to_page_range(vma->vm_mm, vma->vm_start, 716 vma->vm_end - vma->vm_start, 717 find_grant_ptes, map); 718 if (err) { 719 printk(KERN_WARNING "find_grant_ptes() failure.\n"); 720 goto out_put_map; 721 } 722 } 723 724 err = map_grant_pages(map); 725 if (err) 726 goto out_put_map; 727 728 if (!use_ptemod) { 729 for (i = 0; i < count; i++) { 730 err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE, 731 map->pages[i]); 732 if (err) 733 goto out_put_map; 734 } 735 } 736 737 return 0; 738 739 unlock_out: 740 spin_unlock(&priv->lock); 741 return err; 742 743 out_unlock_put: 744 spin_unlock(&priv->lock); 745 out_put_map: 746 if (use_ptemod) 747 map->vma = NULL; 748 gntdev_put_map(map); 749 return err; 750 } 751 752 static const struct file_operations gntdev_fops = { 753 .owner = THIS_MODULE, 754 .open = gntdev_open, 755 .release = gntdev_release, 756 .mmap = gntdev_mmap, 757 .unlocked_ioctl = gntdev_ioctl 758 }; 759 760 static struct miscdevice gntdev_miscdev = { 761 .minor = MISC_DYNAMIC_MINOR, 762 .name = "xen/gntdev", 763 .fops = &gntdev_fops, 764 }; 765 766 /* ------------------------------------------------------------------ */ 767 768 static int __init gntdev_init(void) 769 { 770 int err; 771 772 if (!xen_domain()) 773 return -ENODEV; 774 775 use_ptemod = xen_pv_domain(); 776 777 err = misc_register(&gntdev_miscdev); 778 if (err != 0) { 779 printk(KERN_ERR "Could not register gntdev device\n"); 780 return err; 781 } 782 return 0; 783 } 784 785 static void __exit gntdev_exit(void) 786 { 787 misc_deregister(&gntdev_miscdev); 788 } 789 790 module_init(gntdev_init); 791 module_exit(gntdev_exit); 792 793 /* ------------------------------------------------------------------ */ 794