1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * drivers/uio/uio.c 4 * 5 * Copyright(C) 2005, Benedikt Spranger <b.spranger@linutronix.de> 6 * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de> 7 * Copyright(C) 2006, Hans J. Koch <hjk@hansjkoch.de> 8 * Copyright(C) 2006, Greg Kroah-Hartman <greg@kroah.com> 9 * 10 * Userspace IO 11 * 12 * Base Functions 13 */ 14 15 #include <linux/module.h> 16 #include <linux/init.h> 17 #include <linux/poll.h> 18 #include <linux/device.h> 19 #include <linux/slab.h> 20 #include <linux/mm.h> 21 #include <linux/idr.h> 22 #include <linux/sched/signal.h> 23 #include <linux/string.h> 24 #include <linux/kobject.h> 25 #include <linux/cdev.h> 26 #include <linux/uio_driver.h> 27 28 #define UIO_MAX_DEVICES (1U << MINORBITS) 29 30 static int uio_major; 31 static struct cdev *uio_cdev; 32 static DEFINE_IDR(uio_idr); 33 static const struct file_operations uio_fops; 34 35 /* Protect idr accesses */ 36 static DEFINE_MUTEX(minor_lock); 37 38 /* 39 * attributes 40 */ 41 42 struct uio_map { 43 struct kobject kobj; 44 struct uio_mem *mem; 45 }; 46 #define to_map(map) container_of(map, struct uio_map, kobj) 47 48 static ssize_t map_name_show(struct uio_mem *mem, char *buf) 49 { 50 if (unlikely(!mem->name)) 51 mem->name = ""; 52 53 return sprintf(buf, "%s\n", mem->name); 54 } 55 56 static ssize_t map_addr_show(struct uio_mem *mem, char *buf) 57 { 58 return sprintf(buf, "%pa\n", &mem->addr); 59 } 60 61 static ssize_t map_size_show(struct uio_mem *mem, char *buf) 62 { 63 return sprintf(buf, "%pa\n", &mem->size); 64 } 65 66 static ssize_t map_offset_show(struct uio_mem *mem, char *buf) 67 { 68 return sprintf(buf, "0x%llx\n", (unsigned long long)mem->offs); 69 } 70 71 struct map_sysfs_entry { 72 struct attribute attr; 73 ssize_t (*show)(struct uio_mem *, char *); 74 ssize_t (*store)(struct uio_mem *, const char *, size_t); 75 }; 76 77 static struct map_sysfs_entry name_attribute = 78 __ATTR(name, S_IRUGO, map_name_show, NULL); 79 static struct map_sysfs_entry addr_attribute = 80 __ATTR(addr, S_IRUGO, map_addr_show, NULL); 81 static struct map_sysfs_entry size_attribute = 82 __ATTR(size, S_IRUGO, map_size_show, NULL); 83 static struct map_sysfs_entry offset_attribute = 84 __ATTR(offset, S_IRUGO, map_offset_show, NULL); 85 86 static struct attribute *attrs[] = { 87 &name_attribute.attr, 88 &addr_attribute.attr, 89 &size_attribute.attr, 90 &offset_attribute.attr, 91 NULL, /* need to NULL terminate the list of attributes */ 92 }; 93 94 static void map_release(struct kobject *kobj) 95 { 96 struct uio_map *map = to_map(kobj); 97 kfree(map); 98 } 99 100 static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr, 101 char *buf) 102 { 103 struct uio_map *map = to_map(kobj); 104 struct uio_mem *mem = map->mem; 105 struct map_sysfs_entry *entry; 106 107 entry = container_of(attr, struct map_sysfs_entry, attr); 108 109 if (!entry->show) 110 return -EIO; 111 112 return entry->show(mem, buf); 113 } 114 115 static const struct sysfs_ops map_sysfs_ops = { 116 .show = map_type_show, 117 }; 118 119 static struct kobj_type map_attr_type = { 120 .release = map_release, 121 .sysfs_ops = &map_sysfs_ops, 122 .default_attrs = attrs, 123 }; 124 125 struct uio_portio { 126 struct kobject kobj; 127 struct uio_port *port; 128 }; 129 #define to_portio(portio) container_of(portio, struct uio_portio, kobj) 130 131 static ssize_t portio_name_show(struct uio_port *port, char *buf) 132 { 133 if (unlikely(!port->name)) 134 port->name = ""; 135 136 return sprintf(buf, "%s\n", port->name); 137 } 138 139 static ssize_t portio_start_show(struct uio_port *port, char *buf) 140 { 141 return sprintf(buf, "0x%lx\n", port->start); 142 } 143 144 static ssize_t portio_size_show(struct uio_port *port, char *buf) 145 { 146 return sprintf(buf, "0x%lx\n", port->size); 147 } 148 149 static ssize_t portio_porttype_show(struct uio_port *port, char *buf) 150 { 151 const char *porttypes[] = {"none", "x86", "gpio", "other"}; 152 153 if ((port->porttype < 0) || (port->porttype > UIO_PORT_OTHER)) 154 return -EINVAL; 155 156 return sprintf(buf, "port_%s\n", porttypes[port->porttype]); 157 } 158 159 struct portio_sysfs_entry { 160 struct attribute attr; 161 ssize_t (*show)(struct uio_port *, char *); 162 ssize_t (*store)(struct uio_port *, const char *, size_t); 163 }; 164 165 static struct portio_sysfs_entry portio_name_attribute = 166 __ATTR(name, S_IRUGO, portio_name_show, NULL); 167 static struct portio_sysfs_entry portio_start_attribute = 168 __ATTR(start, S_IRUGO, portio_start_show, NULL); 169 static struct portio_sysfs_entry portio_size_attribute = 170 __ATTR(size, S_IRUGO, portio_size_show, NULL); 171 static struct portio_sysfs_entry portio_porttype_attribute = 172 __ATTR(porttype, S_IRUGO, portio_porttype_show, NULL); 173 174 static struct attribute *portio_attrs[] = { 175 &portio_name_attribute.attr, 176 &portio_start_attribute.attr, 177 &portio_size_attribute.attr, 178 &portio_porttype_attribute.attr, 179 NULL, 180 }; 181 182 static void portio_release(struct kobject *kobj) 183 { 184 struct uio_portio *portio = to_portio(kobj); 185 kfree(portio); 186 } 187 188 static ssize_t portio_type_show(struct kobject *kobj, struct attribute *attr, 189 char *buf) 190 { 191 struct uio_portio *portio = to_portio(kobj); 192 struct uio_port *port = portio->port; 193 struct portio_sysfs_entry *entry; 194 195 entry = container_of(attr, struct portio_sysfs_entry, attr); 196 197 if (!entry->show) 198 return -EIO; 199 200 return entry->show(port, buf); 201 } 202 203 static const struct sysfs_ops portio_sysfs_ops = { 204 .show = portio_type_show, 205 }; 206 207 static struct kobj_type portio_attr_type = { 208 .release = portio_release, 209 .sysfs_ops = &portio_sysfs_ops, 210 .default_attrs = portio_attrs, 211 }; 212 213 static ssize_t name_show(struct device *dev, 214 struct device_attribute *attr, char *buf) 215 { 216 struct uio_device *idev = dev_get_drvdata(dev); 217 int ret; 218 219 mutex_lock(&idev->info_lock); 220 if (!idev->info) { 221 ret = -EINVAL; 222 dev_err(dev, "the device has been unregistered\n"); 223 goto out; 224 } 225 226 ret = sprintf(buf, "%s\n", idev->info->name); 227 228 out: 229 mutex_unlock(&idev->info_lock); 230 return ret; 231 } 232 static DEVICE_ATTR_RO(name); 233 234 static ssize_t version_show(struct device *dev, 235 struct device_attribute *attr, char *buf) 236 { 237 struct uio_device *idev = dev_get_drvdata(dev); 238 int ret; 239 240 mutex_lock(&idev->info_lock); 241 if (!idev->info) { 242 ret = -EINVAL; 243 dev_err(dev, "the device has been unregistered\n"); 244 goto out; 245 } 246 247 ret = sprintf(buf, "%s\n", idev->info->version); 248 249 out: 250 mutex_unlock(&idev->info_lock); 251 return ret; 252 } 253 static DEVICE_ATTR_RO(version); 254 255 static ssize_t event_show(struct device *dev, 256 struct device_attribute *attr, char *buf) 257 { 258 struct uio_device *idev = dev_get_drvdata(dev); 259 return sprintf(buf, "%u\n", (unsigned int)atomic_read(&idev->event)); 260 } 261 static DEVICE_ATTR_RO(event); 262 263 static struct attribute *uio_attrs[] = { 264 &dev_attr_name.attr, 265 &dev_attr_version.attr, 266 &dev_attr_event.attr, 267 NULL, 268 }; 269 ATTRIBUTE_GROUPS(uio); 270 271 /* UIO class infrastructure */ 272 static struct class uio_class = { 273 .name = "uio", 274 .dev_groups = uio_groups, 275 }; 276 277 /* 278 * device functions 279 */ 280 static int uio_dev_add_attributes(struct uio_device *idev) 281 { 282 int ret; 283 int mi, pi; 284 int map_found = 0; 285 int portio_found = 0; 286 struct uio_mem *mem; 287 struct uio_map *map; 288 struct uio_port *port; 289 struct uio_portio *portio; 290 291 for (mi = 0; mi < MAX_UIO_MAPS; mi++) { 292 mem = &idev->info->mem[mi]; 293 if (mem->size == 0) 294 break; 295 if (!map_found) { 296 map_found = 1; 297 idev->map_dir = kobject_create_and_add("maps", 298 &idev->dev.kobj); 299 if (!idev->map_dir) { 300 ret = -ENOMEM; 301 goto err_map; 302 } 303 } 304 map = kzalloc(sizeof(*map), GFP_KERNEL); 305 if (!map) { 306 ret = -ENOMEM; 307 goto err_map; 308 } 309 kobject_init(&map->kobj, &map_attr_type); 310 map->mem = mem; 311 mem->map = map; 312 ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi); 313 if (ret) 314 goto err_map_kobj; 315 ret = kobject_uevent(&map->kobj, KOBJ_ADD); 316 if (ret) 317 goto err_map_kobj; 318 } 319 320 for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) { 321 port = &idev->info->port[pi]; 322 if (port->size == 0) 323 break; 324 if (!portio_found) { 325 portio_found = 1; 326 idev->portio_dir = kobject_create_and_add("portio", 327 &idev->dev.kobj); 328 if (!idev->portio_dir) { 329 ret = -ENOMEM; 330 goto err_portio; 331 } 332 } 333 portio = kzalloc(sizeof(*portio), GFP_KERNEL); 334 if (!portio) { 335 ret = -ENOMEM; 336 goto err_portio; 337 } 338 kobject_init(&portio->kobj, &portio_attr_type); 339 portio->port = port; 340 port->portio = portio; 341 ret = kobject_add(&portio->kobj, idev->portio_dir, 342 "port%d", pi); 343 if (ret) 344 goto err_portio_kobj; 345 ret = kobject_uevent(&portio->kobj, KOBJ_ADD); 346 if (ret) 347 goto err_portio_kobj; 348 } 349 350 return 0; 351 352 err_portio: 353 pi--; 354 err_portio_kobj: 355 for (; pi >= 0; pi--) { 356 port = &idev->info->port[pi]; 357 portio = port->portio; 358 kobject_put(&portio->kobj); 359 } 360 kobject_put(idev->portio_dir); 361 err_map: 362 mi--; 363 err_map_kobj: 364 for (; mi >= 0; mi--) { 365 mem = &idev->info->mem[mi]; 366 map = mem->map; 367 kobject_put(&map->kobj); 368 } 369 kobject_put(idev->map_dir); 370 dev_err(&idev->dev, "error creating sysfs files (%d)\n", ret); 371 return ret; 372 } 373 374 static void uio_dev_del_attributes(struct uio_device *idev) 375 { 376 int i; 377 struct uio_mem *mem; 378 struct uio_port *port; 379 380 for (i = 0; i < MAX_UIO_MAPS; i++) { 381 mem = &idev->info->mem[i]; 382 if (mem->size == 0) 383 break; 384 kobject_put(&mem->map->kobj); 385 } 386 kobject_put(idev->map_dir); 387 388 for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) { 389 port = &idev->info->port[i]; 390 if (port->size == 0) 391 break; 392 kobject_put(&port->portio->kobj); 393 } 394 kobject_put(idev->portio_dir); 395 } 396 397 static int uio_get_minor(struct uio_device *idev) 398 { 399 int retval = -ENOMEM; 400 401 mutex_lock(&minor_lock); 402 retval = idr_alloc(&uio_idr, idev, 0, UIO_MAX_DEVICES, GFP_KERNEL); 403 if (retval >= 0) { 404 idev->minor = retval; 405 retval = 0; 406 } else if (retval == -ENOSPC) { 407 dev_err(&idev->dev, "too many uio devices\n"); 408 retval = -EINVAL; 409 } 410 mutex_unlock(&minor_lock); 411 return retval; 412 } 413 414 static void uio_free_minor(struct uio_device *idev) 415 { 416 mutex_lock(&minor_lock); 417 idr_remove(&uio_idr, idev->minor); 418 mutex_unlock(&minor_lock); 419 } 420 421 /** 422 * uio_event_notify - trigger an interrupt event 423 * @info: UIO device capabilities 424 */ 425 void uio_event_notify(struct uio_info *info) 426 { 427 struct uio_device *idev = info->uio_dev; 428 429 atomic_inc(&idev->event); 430 wake_up_interruptible(&idev->wait); 431 kill_fasync(&idev->async_queue, SIGIO, POLL_IN); 432 } 433 EXPORT_SYMBOL_GPL(uio_event_notify); 434 435 /** 436 * uio_interrupt - hardware interrupt handler 437 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer 438 * @dev_id: Pointer to the devices uio_device structure 439 */ 440 static irqreturn_t uio_interrupt(int irq, void *dev_id) 441 { 442 struct uio_device *idev = (struct uio_device *)dev_id; 443 irqreturn_t ret; 444 445 mutex_lock(&idev->info_lock); 446 447 ret = idev->info->handler(irq, idev->info); 448 if (ret == IRQ_HANDLED) 449 uio_event_notify(idev->info); 450 451 mutex_unlock(&idev->info_lock); 452 return ret; 453 } 454 455 struct uio_listener { 456 struct uio_device *dev; 457 s32 event_count; 458 }; 459 460 static int uio_open(struct inode *inode, struct file *filep) 461 { 462 struct uio_device *idev; 463 struct uio_listener *listener; 464 int ret = 0; 465 466 mutex_lock(&minor_lock); 467 idev = idr_find(&uio_idr, iminor(inode)); 468 mutex_unlock(&minor_lock); 469 if (!idev) { 470 ret = -ENODEV; 471 goto out; 472 } 473 474 get_device(&idev->dev); 475 476 if (!try_module_get(idev->owner)) { 477 ret = -ENODEV; 478 goto err_module_get; 479 } 480 481 listener = kmalloc(sizeof(*listener), GFP_KERNEL); 482 if (!listener) { 483 ret = -ENOMEM; 484 goto err_alloc_listener; 485 } 486 487 listener->dev = idev; 488 listener->event_count = atomic_read(&idev->event); 489 filep->private_data = listener; 490 491 mutex_lock(&idev->info_lock); 492 if (!idev->info) { 493 mutex_unlock(&idev->info_lock); 494 ret = -EINVAL; 495 goto err_alloc_listener; 496 } 497 498 if (idev->info && idev->info->open) 499 ret = idev->info->open(idev->info, inode); 500 mutex_unlock(&idev->info_lock); 501 if (ret) 502 goto err_infoopen; 503 504 return 0; 505 506 err_infoopen: 507 kfree(listener); 508 509 err_alloc_listener: 510 module_put(idev->owner); 511 512 err_module_get: 513 put_device(&idev->dev); 514 515 out: 516 return ret; 517 } 518 519 static int uio_fasync(int fd, struct file *filep, int on) 520 { 521 struct uio_listener *listener = filep->private_data; 522 struct uio_device *idev = listener->dev; 523 524 return fasync_helper(fd, filep, on, &idev->async_queue); 525 } 526 527 static int uio_release(struct inode *inode, struct file *filep) 528 { 529 int ret = 0; 530 struct uio_listener *listener = filep->private_data; 531 struct uio_device *idev = listener->dev; 532 533 mutex_lock(&idev->info_lock); 534 if (idev->info && idev->info->release) 535 ret = idev->info->release(idev->info, inode); 536 mutex_unlock(&idev->info_lock); 537 538 module_put(idev->owner); 539 kfree(listener); 540 put_device(&idev->dev); 541 return ret; 542 } 543 544 static __poll_t uio_poll(struct file *filep, poll_table *wait) 545 { 546 struct uio_listener *listener = filep->private_data; 547 struct uio_device *idev = listener->dev; 548 __poll_t ret = 0; 549 550 mutex_lock(&idev->info_lock); 551 if (!idev->info || !idev->info->irq) 552 ret = -EIO; 553 mutex_unlock(&idev->info_lock); 554 555 if (ret) 556 return ret; 557 558 poll_wait(filep, &idev->wait, wait); 559 if (listener->event_count != atomic_read(&idev->event)) 560 return EPOLLIN | EPOLLRDNORM; 561 return 0; 562 } 563 564 static ssize_t uio_read(struct file *filep, char __user *buf, 565 size_t count, loff_t *ppos) 566 { 567 struct uio_listener *listener = filep->private_data; 568 struct uio_device *idev = listener->dev; 569 DECLARE_WAITQUEUE(wait, current); 570 ssize_t retval = 0; 571 s32 event_count; 572 573 mutex_lock(&idev->info_lock); 574 if (!idev->info || !idev->info->irq) 575 retval = -EIO; 576 mutex_unlock(&idev->info_lock); 577 578 if (retval) 579 return retval; 580 581 if (count != sizeof(s32)) 582 return -EINVAL; 583 584 add_wait_queue(&idev->wait, &wait); 585 586 do { 587 set_current_state(TASK_INTERRUPTIBLE); 588 589 event_count = atomic_read(&idev->event); 590 if (event_count != listener->event_count) { 591 __set_current_state(TASK_RUNNING); 592 if (copy_to_user(buf, &event_count, count)) 593 retval = -EFAULT; 594 else { 595 listener->event_count = event_count; 596 retval = count; 597 } 598 break; 599 } 600 601 if (filep->f_flags & O_NONBLOCK) { 602 retval = -EAGAIN; 603 break; 604 } 605 606 if (signal_pending(current)) { 607 retval = -ERESTARTSYS; 608 break; 609 } 610 schedule(); 611 } while (1); 612 613 __set_current_state(TASK_RUNNING); 614 remove_wait_queue(&idev->wait, &wait); 615 616 return retval; 617 } 618 619 static ssize_t uio_write(struct file *filep, const char __user *buf, 620 size_t count, loff_t *ppos) 621 { 622 struct uio_listener *listener = filep->private_data; 623 struct uio_device *idev = listener->dev; 624 ssize_t retval; 625 s32 irq_on; 626 627 if (count != sizeof(s32)) 628 return -EINVAL; 629 630 if (copy_from_user(&irq_on, buf, count)) 631 return -EFAULT; 632 633 mutex_lock(&idev->info_lock); 634 if (!idev->info) { 635 retval = -EINVAL; 636 goto out; 637 } 638 639 if (!idev->info || !idev->info->irq) { 640 retval = -EIO; 641 goto out; 642 } 643 644 if (!idev->info->irqcontrol) { 645 retval = -ENOSYS; 646 goto out; 647 } 648 649 retval = idev->info->irqcontrol(idev->info, irq_on); 650 651 out: 652 mutex_unlock(&idev->info_lock); 653 return retval ? retval : sizeof(s32); 654 } 655 656 static int uio_find_mem_index(struct vm_area_struct *vma) 657 { 658 struct uio_device *idev = vma->vm_private_data; 659 660 if (vma->vm_pgoff < MAX_UIO_MAPS) { 661 if (idev->info->mem[vma->vm_pgoff].size == 0) 662 return -1; 663 return (int)vma->vm_pgoff; 664 } 665 return -1; 666 } 667 668 static vm_fault_t uio_vma_fault(struct vm_fault *vmf) 669 { 670 struct uio_device *idev = vmf->vma->vm_private_data; 671 struct page *page; 672 unsigned long offset; 673 void *addr; 674 int ret = 0; 675 int mi; 676 677 mutex_lock(&idev->info_lock); 678 if (!idev->info) { 679 ret = VM_FAULT_SIGBUS; 680 goto out; 681 } 682 683 mi = uio_find_mem_index(vmf->vma); 684 if (mi < 0) { 685 ret = VM_FAULT_SIGBUS; 686 goto out; 687 } 688 689 /* 690 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE 691 * to use mem[N]. 692 */ 693 offset = (vmf->pgoff - mi) << PAGE_SHIFT; 694 695 addr = (void *)(unsigned long)idev->info->mem[mi].addr + offset; 696 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL) 697 page = virt_to_page(addr); 698 else 699 page = vmalloc_to_page(addr); 700 get_page(page); 701 vmf->page = page; 702 703 out: 704 mutex_unlock(&idev->info_lock); 705 706 return ret; 707 } 708 709 static const struct vm_operations_struct uio_logical_vm_ops = { 710 .fault = uio_vma_fault, 711 }; 712 713 static int uio_mmap_logical(struct vm_area_struct *vma) 714 { 715 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; 716 vma->vm_ops = &uio_logical_vm_ops; 717 return 0; 718 } 719 720 static const struct vm_operations_struct uio_physical_vm_ops = { 721 #ifdef CONFIG_HAVE_IOREMAP_PROT 722 .access = generic_access_phys, 723 #endif 724 }; 725 726 static int uio_mmap_physical(struct vm_area_struct *vma) 727 { 728 struct uio_device *idev = vma->vm_private_data; 729 int mi = uio_find_mem_index(vma); 730 struct uio_mem *mem; 731 732 if (mi < 0) 733 return -EINVAL; 734 mem = idev->info->mem + mi; 735 736 if (mem->addr & ~PAGE_MASK) 737 return -ENODEV; 738 if (vma->vm_end - vma->vm_start > mem->size) 739 return -EINVAL; 740 741 vma->vm_ops = &uio_physical_vm_ops; 742 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 743 744 /* 745 * We cannot use the vm_iomap_memory() helper here, 746 * because vma->vm_pgoff is the map index we looked 747 * up above in uio_find_mem_index(), rather than an 748 * actual page offset into the mmap. 749 * 750 * So we just do the physical mmap without a page 751 * offset. 752 */ 753 return remap_pfn_range(vma, 754 vma->vm_start, 755 mem->addr >> PAGE_SHIFT, 756 vma->vm_end - vma->vm_start, 757 vma->vm_page_prot); 758 } 759 760 static int uio_mmap(struct file *filep, struct vm_area_struct *vma) 761 { 762 struct uio_listener *listener = filep->private_data; 763 struct uio_device *idev = listener->dev; 764 int mi; 765 unsigned long requested_pages, actual_pages; 766 int ret = 0; 767 768 if (vma->vm_end < vma->vm_start) 769 return -EINVAL; 770 771 vma->vm_private_data = idev; 772 773 mutex_lock(&idev->info_lock); 774 if (!idev->info) { 775 ret = -EINVAL; 776 goto out; 777 } 778 779 mi = uio_find_mem_index(vma); 780 if (mi < 0) { 781 ret = -EINVAL; 782 goto out; 783 } 784 785 requested_pages = vma_pages(vma); 786 actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK) 787 + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT; 788 if (requested_pages > actual_pages) { 789 ret = -EINVAL; 790 goto out; 791 } 792 793 if (idev->info->mmap) { 794 ret = idev->info->mmap(idev->info, vma); 795 goto out; 796 } 797 798 switch (idev->info->mem[mi].memtype) { 799 case UIO_MEM_PHYS: 800 ret = uio_mmap_physical(vma); 801 break; 802 case UIO_MEM_LOGICAL: 803 case UIO_MEM_VIRTUAL: 804 ret = uio_mmap_logical(vma); 805 break; 806 default: 807 ret = -EINVAL; 808 } 809 810 out: 811 mutex_unlock(&idev->info_lock); 812 return ret; 813 } 814 815 static const struct file_operations uio_fops = { 816 .owner = THIS_MODULE, 817 .open = uio_open, 818 .release = uio_release, 819 .read = uio_read, 820 .write = uio_write, 821 .mmap = uio_mmap, 822 .poll = uio_poll, 823 .fasync = uio_fasync, 824 .llseek = noop_llseek, 825 }; 826 827 static int uio_major_init(void) 828 { 829 static const char name[] = "uio"; 830 struct cdev *cdev = NULL; 831 dev_t uio_dev = 0; 832 int result; 833 834 result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name); 835 if (result) 836 goto out; 837 838 result = -ENOMEM; 839 cdev = cdev_alloc(); 840 if (!cdev) 841 goto out_unregister; 842 843 cdev->owner = THIS_MODULE; 844 cdev->ops = &uio_fops; 845 kobject_set_name(&cdev->kobj, "%s", name); 846 847 result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES); 848 if (result) 849 goto out_put; 850 851 uio_major = MAJOR(uio_dev); 852 uio_cdev = cdev; 853 return 0; 854 out_put: 855 kobject_put(&cdev->kobj); 856 out_unregister: 857 unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES); 858 out: 859 return result; 860 } 861 862 static void uio_major_cleanup(void) 863 { 864 unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES); 865 cdev_del(uio_cdev); 866 } 867 868 static int init_uio_class(void) 869 { 870 int ret; 871 872 /* This is the first time in here, set everything up properly */ 873 ret = uio_major_init(); 874 if (ret) 875 goto exit; 876 877 ret = class_register(&uio_class); 878 if (ret) { 879 printk(KERN_ERR "class_register failed for uio\n"); 880 goto err_class_register; 881 } 882 return 0; 883 884 err_class_register: 885 uio_major_cleanup(); 886 exit: 887 return ret; 888 } 889 890 static void release_uio_class(void) 891 { 892 class_unregister(&uio_class); 893 uio_major_cleanup(); 894 } 895 896 static void uio_device_release(struct device *dev) 897 { 898 struct uio_device *idev = dev_get_drvdata(dev); 899 900 kfree(idev); 901 } 902 903 /** 904 * uio_register_device - register a new userspace IO device 905 * @owner: module that creates the new device 906 * @parent: parent device 907 * @info: UIO device capabilities 908 * 909 * returns zero on success or a negative error code. 910 */ 911 int __uio_register_device(struct module *owner, 912 struct device *parent, 913 struct uio_info *info) 914 { 915 struct uio_device *idev; 916 int ret = 0; 917 918 if (!parent || !info || !info->name || !info->version) 919 return -EINVAL; 920 921 info->uio_dev = NULL; 922 923 idev = kzalloc(sizeof(*idev), GFP_KERNEL); 924 if (!idev) { 925 return -ENOMEM; 926 } 927 928 idev->owner = owner; 929 idev->info = info; 930 mutex_init(&idev->info_lock); 931 init_waitqueue_head(&idev->wait); 932 atomic_set(&idev->event, 0); 933 934 ret = uio_get_minor(idev); 935 if (ret) 936 return ret; 937 938 idev->dev.devt = MKDEV(uio_major, idev->minor); 939 idev->dev.class = &uio_class; 940 idev->dev.parent = parent; 941 idev->dev.release = uio_device_release; 942 dev_set_drvdata(&idev->dev, idev); 943 944 ret = dev_set_name(&idev->dev, "uio%d", idev->minor); 945 if (ret) 946 goto err_device_create; 947 948 ret = device_register(&idev->dev); 949 if (ret) 950 goto err_device_create; 951 952 ret = uio_dev_add_attributes(idev); 953 if (ret) 954 goto err_uio_dev_add_attributes; 955 956 info->uio_dev = idev; 957 958 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) { 959 /* 960 * Note that we deliberately don't use devm_request_irq 961 * here. The parent module can unregister the UIO device 962 * and call pci_disable_msi, which requires that this 963 * irq has been freed. However, the device may have open 964 * FDs at the time of unregister and therefore may not be 965 * freed until they are released. 966 */ 967 ret = request_threaded_irq(info->irq, NULL, uio_interrupt, 968 info->irq_flags, info->name, idev); 969 970 if (ret) 971 goto err_request_irq; 972 } 973 974 return 0; 975 976 err_request_irq: 977 uio_dev_del_attributes(idev); 978 err_uio_dev_add_attributes: 979 device_unregister(&idev->dev); 980 err_device_create: 981 uio_free_minor(idev); 982 return ret; 983 } 984 EXPORT_SYMBOL_GPL(__uio_register_device); 985 986 /** 987 * uio_unregister_device - unregister a industrial IO device 988 * @info: UIO device capabilities 989 * 990 */ 991 void uio_unregister_device(struct uio_info *info) 992 { 993 struct uio_device *idev; 994 995 if (!info || !info->uio_dev) 996 return; 997 998 idev = info->uio_dev; 999 1000 uio_free_minor(idev); 1001 1002 mutex_lock(&idev->info_lock); 1003 uio_dev_del_attributes(idev); 1004 1005 if (info->irq && info->irq != UIO_IRQ_CUSTOM) 1006 free_irq(info->irq, idev); 1007 1008 idev->info = NULL; 1009 mutex_unlock(&idev->info_lock); 1010 1011 device_unregister(&idev->dev); 1012 1013 return; 1014 } 1015 EXPORT_SYMBOL_GPL(uio_unregister_device); 1016 1017 static int __init uio_init(void) 1018 { 1019 return init_uio_class(); 1020 } 1021 1022 static void __exit uio_exit(void) 1023 { 1024 release_uio_class(); 1025 idr_destroy(&uio_idr); 1026 } 1027 1028 module_init(uio_init) 1029 module_exit(uio_exit) 1030 MODULE_LICENSE("GPL v2"); 1031