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 *map_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 ATTRIBUTE_GROUPS(map); 94 95 static void map_release(struct kobject *kobj) 96 { 97 struct uio_map *map = to_map(kobj); 98 kfree(map); 99 } 100 101 static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr, 102 char *buf) 103 { 104 struct uio_map *map = to_map(kobj); 105 struct uio_mem *mem = map->mem; 106 struct map_sysfs_entry *entry; 107 108 entry = container_of(attr, struct map_sysfs_entry, attr); 109 110 if (!entry->show) 111 return -EIO; 112 113 return entry->show(mem, buf); 114 } 115 116 static const struct sysfs_ops map_sysfs_ops = { 117 .show = map_type_show, 118 }; 119 120 static struct kobj_type map_attr_type = { 121 .release = map_release, 122 .sysfs_ops = &map_sysfs_ops, 123 .default_groups = map_groups, 124 }; 125 126 struct uio_portio { 127 struct kobject kobj; 128 struct uio_port *port; 129 }; 130 #define to_portio(portio) container_of(portio, struct uio_portio, kobj) 131 132 static ssize_t portio_name_show(struct uio_port *port, char *buf) 133 { 134 if (unlikely(!port->name)) 135 port->name = ""; 136 137 return sprintf(buf, "%s\n", port->name); 138 } 139 140 static ssize_t portio_start_show(struct uio_port *port, char *buf) 141 { 142 return sprintf(buf, "0x%lx\n", port->start); 143 } 144 145 static ssize_t portio_size_show(struct uio_port *port, char *buf) 146 { 147 return sprintf(buf, "0x%lx\n", port->size); 148 } 149 150 static ssize_t portio_porttype_show(struct uio_port *port, char *buf) 151 { 152 const char *porttypes[] = {"none", "x86", "gpio", "other"}; 153 154 if ((port->porttype < 0) || (port->porttype > UIO_PORT_OTHER)) 155 return -EINVAL; 156 157 return sprintf(buf, "port_%s\n", porttypes[port->porttype]); 158 } 159 160 struct portio_sysfs_entry { 161 struct attribute attr; 162 ssize_t (*show)(struct uio_port *, char *); 163 ssize_t (*store)(struct uio_port *, const char *, size_t); 164 }; 165 166 static struct portio_sysfs_entry portio_name_attribute = 167 __ATTR(name, S_IRUGO, portio_name_show, NULL); 168 static struct portio_sysfs_entry portio_start_attribute = 169 __ATTR(start, S_IRUGO, portio_start_show, NULL); 170 static struct portio_sysfs_entry portio_size_attribute = 171 __ATTR(size, S_IRUGO, portio_size_show, NULL); 172 static struct portio_sysfs_entry portio_porttype_attribute = 173 __ATTR(porttype, S_IRUGO, portio_porttype_show, NULL); 174 175 static struct attribute *portio_attrs[] = { 176 &portio_name_attribute.attr, 177 &portio_start_attribute.attr, 178 &portio_size_attribute.attr, 179 &portio_porttype_attribute.attr, 180 NULL, 181 }; 182 ATTRIBUTE_GROUPS(portio); 183 184 static void portio_release(struct kobject *kobj) 185 { 186 struct uio_portio *portio = to_portio(kobj); 187 kfree(portio); 188 } 189 190 static ssize_t portio_type_show(struct kobject *kobj, struct attribute *attr, 191 char *buf) 192 { 193 struct uio_portio *portio = to_portio(kobj); 194 struct uio_port *port = portio->port; 195 struct portio_sysfs_entry *entry; 196 197 entry = container_of(attr, struct portio_sysfs_entry, attr); 198 199 if (!entry->show) 200 return -EIO; 201 202 return entry->show(port, buf); 203 } 204 205 static const struct sysfs_ops portio_sysfs_ops = { 206 .show = portio_type_show, 207 }; 208 209 static struct kobj_type portio_attr_type = { 210 .release = portio_release, 211 .sysfs_ops = &portio_sysfs_ops, 212 .default_groups = portio_groups, 213 }; 214 215 static ssize_t name_show(struct device *dev, 216 struct device_attribute *attr, char *buf) 217 { 218 struct uio_device *idev = dev_get_drvdata(dev); 219 int ret; 220 221 mutex_lock(&idev->info_lock); 222 if (!idev->info) { 223 ret = -EINVAL; 224 dev_err(dev, "the device has been unregistered\n"); 225 goto out; 226 } 227 228 ret = sprintf(buf, "%s\n", idev->info->name); 229 230 out: 231 mutex_unlock(&idev->info_lock); 232 return ret; 233 } 234 static DEVICE_ATTR_RO(name); 235 236 static ssize_t version_show(struct device *dev, 237 struct device_attribute *attr, char *buf) 238 { 239 struct uio_device *idev = dev_get_drvdata(dev); 240 int ret; 241 242 mutex_lock(&idev->info_lock); 243 if (!idev->info) { 244 ret = -EINVAL; 245 dev_err(dev, "the device has been unregistered\n"); 246 goto out; 247 } 248 249 ret = sprintf(buf, "%s\n", idev->info->version); 250 251 out: 252 mutex_unlock(&idev->info_lock); 253 return ret; 254 } 255 static DEVICE_ATTR_RO(version); 256 257 static ssize_t event_show(struct device *dev, 258 struct device_attribute *attr, char *buf) 259 { 260 struct uio_device *idev = dev_get_drvdata(dev); 261 return sprintf(buf, "%u\n", (unsigned int)atomic_read(&idev->event)); 262 } 263 static DEVICE_ATTR_RO(event); 264 265 static struct attribute *uio_attrs[] = { 266 &dev_attr_name.attr, 267 &dev_attr_version.attr, 268 &dev_attr_event.attr, 269 NULL, 270 }; 271 ATTRIBUTE_GROUPS(uio); 272 273 /* UIO class infrastructure */ 274 static struct class uio_class = { 275 .name = "uio", 276 .dev_groups = uio_groups, 277 }; 278 279 static bool uio_class_registered; 280 281 /* 282 * device functions 283 */ 284 static int uio_dev_add_attributes(struct uio_device *idev) 285 { 286 int ret; 287 int mi, pi; 288 int map_found = 0; 289 int portio_found = 0; 290 struct uio_mem *mem; 291 struct uio_map *map; 292 struct uio_port *port; 293 struct uio_portio *portio; 294 295 for (mi = 0; mi < MAX_UIO_MAPS; mi++) { 296 mem = &idev->info->mem[mi]; 297 if (mem->size == 0) 298 break; 299 if (!map_found) { 300 map_found = 1; 301 idev->map_dir = kobject_create_and_add("maps", 302 &idev->dev.kobj); 303 if (!idev->map_dir) { 304 ret = -ENOMEM; 305 goto err_map; 306 } 307 } 308 map = kzalloc(sizeof(*map), GFP_KERNEL); 309 if (!map) { 310 ret = -ENOMEM; 311 goto err_map; 312 } 313 kobject_init(&map->kobj, &map_attr_type); 314 map->mem = mem; 315 mem->map = map; 316 ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi); 317 if (ret) 318 goto err_map_kobj; 319 ret = kobject_uevent(&map->kobj, KOBJ_ADD); 320 if (ret) 321 goto err_map_kobj; 322 } 323 324 for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) { 325 port = &idev->info->port[pi]; 326 if (port->size == 0) 327 break; 328 if (!portio_found) { 329 portio_found = 1; 330 idev->portio_dir = kobject_create_and_add("portio", 331 &idev->dev.kobj); 332 if (!idev->portio_dir) { 333 ret = -ENOMEM; 334 goto err_portio; 335 } 336 } 337 portio = kzalloc(sizeof(*portio), GFP_KERNEL); 338 if (!portio) { 339 ret = -ENOMEM; 340 goto err_portio; 341 } 342 kobject_init(&portio->kobj, &portio_attr_type); 343 portio->port = port; 344 port->portio = portio; 345 ret = kobject_add(&portio->kobj, idev->portio_dir, 346 "port%d", pi); 347 if (ret) 348 goto err_portio_kobj; 349 ret = kobject_uevent(&portio->kobj, KOBJ_ADD); 350 if (ret) 351 goto err_portio_kobj; 352 } 353 354 return 0; 355 356 err_portio: 357 pi--; 358 err_portio_kobj: 359 for (; pi >= 0; pi--) { 360 port = &idev->info->port[pi]; 361 portio = port->portio; 362 kobject_put(&portio->kobj); 363 } 364 kobject_put(idev->portio_dir); 365 err_map: 366 mi--; 367 err_map_kobj: 368 for (; mi >= 0; mi--) { 369 mem = &idev->info->mem[mi]; 370 map = mem->map; 371 kobject_put(&map->kobj); 372 } 373 kobject_put(idev->map_dir); 374 dev_err(&idev->dev, "error creating sysfs files (%d)\n", ret); 375 return ret; 376 } 377 378 static void uio_dev_del_attributes(struct uio_device *idev) 379 { 380 int i; 381 struct uio_mem *mem; 382 struct uio_port *port; 383 384 for (i = 0; i < MAX_UIO_MAPS; i++) { 385 mem = &idev->info->mem[i]; 386 if (mem->size == 0) 387 break; 388 kobject_put(&mem->map->kobj); 389 } 390 kobject_put(idev->map_dir); 391 392 for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) { 393 port = &idev->info->port[i]; 394 if (port->size == 0) 395 break; 396 kobject_put(&port->portio->kobj); 397 } 398 kobject_put(idev->portio_dir); 399 } 400 401 static int uio_get_minor(struct uio_device *idev) 402 { 403 int retval; 404 405 mutex_lock(&minor_lock); 406 retval = idr_alloc(&uio_idr, idev, 0, UIO_MAX_DEVICES, GFP_KERNEL); 407 if (retval >= 0) { 408 idev->minor = retval; 409 retval = 0; 410 } else if (retval == -ENOSPC) { 411 dev_err(&idev->dev, "too many uio devices\n"); 412 retval = -EINVAL; 413 } 414 mutex_unlock(&minor_lock); 415 return retval; 416 } 417 418 static void uio_free_minor(unsigned long minor) 419 { 420 mutex_lock(&minor_lock); 421 idr_remove(&uio_idr, minor); 422 mutex_unlock(&minor_lock); 423 } 424 425 /** 426 * uio_event_notify - trigger an interrupt event 427 * @info: UIO device capabilities 428 */ 429 void uio_event_notify(struct uio_info *info) 430 { 431 struct uio_device *idev = info->uio_dev; 432 433 atomic_inc(&idev->event); 434 wake_up_interruptible(&idev->wait); 435 kill_fasync(&idev->async_queue, SIGIO, POLL_IN); 436 } 437 EXPORT_SYMBOL_GPL(uio_event_notify); 438 439 /** 440 * uio_interrupt - hardware interrupt handler 441 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer 442 * @dev_id: Pointer to the devices uio_device structure 443 */ 444 static irqreturn_t uio_interrupt(int irq, void *dev_id) 445 { 446 struct uio_device *idev = (struct uio_device *)dev_id; 447 irqreturn_t ret; 448 449 ret = idev->info->handler(irq, idev->info); 450 if (ret == IRQ_HANDLED) 451 uio_event_notify(idev->info); 452 453 return ret; 454 } 455 456 struct uio_listener { 457 struct uio_device *dev; 458 s32 event_count; 459 }; 460 461 static int uio_open(struct inode *inode, struct file *filep) 462 { 463 struct uio_device *idev; 464 struct uio_listener *listener; 465 int ret = 0; 466 467 mutex_lock(&minor_lock); 468 idev = idr_find(&uio_idr, iminor(inode)); 469 mutex_unlock(&minor_lock); 470 if (!idev) { 471 ret = -ENODEV; 472 goto out; 473 } 474 475 get_device(&idev->dev); 476 477 if (!try_module_get(idev->owner)) { 478 ret = -ENODEV; 479 goto err_module_get; 480 } 481 482 listener = kmalloc(sizeof(*listener), GFP_KERNEL); 483 if (!listener) { 484 ret = -ENOMEM; 485 goto err_alloc_listener; 486 } 487 488 listener->dev = idev; 489 listener->event_count = atomic_read(&idev->event); 490 filep->private_data = listener; 491 492 mutex_lock(&idev->info_lock); 493 if (!idev->info) { 494 mutex_unlock(&idev->info_lock); 495 ret = -EINVAL; 496 goto err_infoopen; 497 } 498 499 if (idev->info->open) 500 ret = idev->info->open(idev->info, inode); 501 mutex_unlock(&idev->info_lock); 502 if (ret) 503 goto err_infoopen; 504 505 return 0; 506 507 err_infoopen: 508 kfree(listener); 509 510 err_alloc_listener: 511 module_put(idev->owner); 512 513 err_module_get: 514 put_device(&idev->dev); 515 516 out: 517 return ret; 518 } 519 520 static int uio_fasync(int fd, struct file *filep, int on) 521 { 522 struct uio_listener *listener = filep->private_data; 523 struct uio_device *idev = listener->dev; 524 525 return fasync_helper(fd, filep, on, &idev->async_queue); 526 } 527 528 static int uio_release(struct inode *inode, struct file *filep) 529 { 530 int ret = 0; 531 struct uio_listener *listener = filep->private_data; 532 struct uio_device *idev = listener->dev; 533 534 mutex_lock(&idev->info_lock); 535 if (idev->info && idev->info->release) 536 ret = idev->info->release(idev->info, inode); 537 mutex_unlock(&idev->info_lock); 538 539 module_put(idev->owner); 540 kfree(listener); 541 put_device(&idev->dev); 542 return ret; 543 } 544 545 static __poll_t uio_poll(struct file *filep, poll_table *wait) 546 { 547 struct uio_listener *listener = filep->private_data; 548 struct uio_device *idev = listener->dev; 549 __poll_t ret = 0; 550 551 mutex_lock(&idev->info_lock); 552 if (!idev->info || !idev->info->irq) 553 ret = -EIO; 554 mutex_unlock(&idev->info_lock); 555 556 if (ret) 557 return ret; 558 559 poll_wait(filep, &idev->wait, wait); 560 if (listener->event_count != atomic_read(&idev->event)) 561 return EPOLLIN | EPOLLRDNORM; 562 return 0; 563 } 564 565 static ssize_t uio_read(struct file *filep, char __user *buf, 566 size_t count, loff_t *ppos) 567 { 568 struct uio_listener *listener = filep->private_data; 569 struct uio_device *idev = listener->dev; 570 DECLARE_WAITQUEUE(wait, current); 571 ssize_t retval = 0; 572 s32 event_count; 573 574 if (count != sizeof(s32)) 575 return -EINVAL; 576 577 add_wait_queue(&idev->wait, &wait); 578 579 do { 580 mutex_lock(&idev->info_lock); 581 if (!idev->info || !idev->info->irq) { 582 retval = -EIO; 583 mutex_unlock(&idev->info_lock); 584 break; 585 } 586 mutex_unlock(&idev->info_lock); 587 588 set_current_state(TASK_INTERRUPTIBLE); 589 590 event_count = atomic_read(&idev->event); 591 if (event_count != listener->event_count) { 592 __set_current_state(TASK_RUNNING); 593 if (copy_to_user(buf, &event_count, count)) 594 retval = -EFAULT; 595 else { 596 listener->event_count = event_count; 597 retval = count; 598 } 599 break; 600 } 601 602 if (filep->f_flags & O_NONBLOCK) { 603 retval = -EAGAIN; 604 break; 605 } 606 607 if (signal_pending(current)) { 608 retval = -ERESTARTSYS; 609 break; 610 } 611 schedule(); 612 } while (1); 613 614 __set_current_state(TASK_RUNNING); 615 remove_wait_queue(&idev->wait, &wait); 616 617 return retval; 618 } 619 620 static ssize_t uio_write(struct file *filep, const char __user *buf, 621 size_t count, loff_t *ppos) 622 { 623 struct uio_listener *listener = filep->private_data; 624 struct uio_device *idev = listener->dev; 625 ssize_t retval; 626 s32 irq_on; 627 628 if (count != sizeof(s32)) 629 return -EINVAL; 630 631 if (copy_from_user(&irq_on, buf, count)) 632 return -EFAULT; 633 634 mutex_lock(&idev->info_lock); 635 if (!idev->info) { 636 retval = -EINVAL; 637 goto out; 638 } 639 640 if (!idev->info->irq) { 641 retval = -EIO; 642 goto out; 643 } 644 645 if (!idev->info->irqcontrol) { 646 retval = -ENOSYS; 647 goto out; 648 } 649 650 retval = idev->info->irqcontrol(idev->info, irq_on); 651 652 out: 653 mutex_unlock(&idev->info_lock); 654 return retval ? retval : sizeof(s32); 655 } 656 657 static int uio_find_mem_index(struct vm_area_struct *vma) 658 { 659 struct uio_device *idev = vma->vm_private_data; 660 661 if (vma->vm_pgoff < MAX_UIO_MAPS) { 662 if (idev->info->mem[vma->vm_pgoff].size == 0) 663 return -1; 664 return (int)vma->vm_pgoff; 665 } 666 return -1; 667 } 668 669 static vm_fault_t uio_vma_fault(struct vm_fault *vmf) 670 { 671 struct uio_device *idev = vmf->vma->vm_private_data; 672 struct page *page; 673 unsigned long offset; 674 void *addr; 675 vm_fault_t ret = 0; 676 int mi; 677 678 mutex_lock(&idev->info_lock); 679 if (!idev->info) { 680 ret = VM_FAULT_SIGBUS; 681 goto out; 682 } 683 684 mi = uio_find_mem_index(vmf->vma); 685 if (mi < 0) { 686 ret = VM_FAULT_SIGBUS; 687 goto out; 688 } 689 690 /* 691 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE 692 * to use mem[N]. 693 */ 694 offset = (vmf->pgoff - mi) << PAGE_SHIFT; 695 696 addr = (void *)(unsigned long)idev->info->mem[mi].addr + offset; 697 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL) 698 page = virt_to_page(addr); 699 else 700 page = vmalloc_to_page(addr); 701 get_page(page); 702 vmf->page = page; 703 704 out: 705 mutex_unlock(&idev->info_lock); 706 707 return ret; 708 } 709 710 static const struct vm_operations_struct uio_logical_vm_ops = { 711 .fault = uio_vma_fault, 712 }; 713 714 static int uio_mmap_logical(struct vm_area_struct *vma) 715 { 716 vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP); 717 vma->vm_ops = &uio_logical_vm_ops; 718 return 0; 719 } 720 721 static const struct vm_operations_struct uio_physical_vm_ops = { 722 #ifdef CONFIG_HAVE_IOREMAP_PROT 723 .access = generic_access_phys, 724 #endif 725 }; 726 727 static int uio_mmap_physical(struct vm_area_struct *vma) 728 { 729 struct uio_device *idev = vma->vm_private_data; 730 int mi = uio_find_mem_index(vma); 731 struct uio_mem *mem; 732 733 if (mi < 0) 734 return -EINVAL; 735 mem = idev->info->mem + mi; 736 737 if (mem->addr & ~PAGE_MASK) 738 return -ENODEV; 739 if (vma->vm_end - vma->vm_start > mem->size) 740 return -EINVAL; 741 742 vma->vm_ops = &uio_physical_vm_ops; 743 if (idev->info->mem[mi].memtype == UIO_MEM_PHYS) 744 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 745 746 /* 747 * We cannot use the vm_iomap_memory() helper here, 748 * because vma->vm_pgoff is the map index we looked 749 * up above in uio_find_mem_index(), rather than an 750 * actual page offset into the mmap. 751 * 752 * So we just do the physical mmap without a page 753 * offset. 754 */ 755 return remap_pfn_range(vma, 756 vma->vm_start, 757 mem->addr >> PAGE_SHIFT, 758 vma->vm_end - vma->vm_start, 759 vma->vm_page_prot); 760 } 761 762 static int uio_mmap(struct file *filep, struct vm_area_struct *vma) 763 { 764 struct uio_listener *listener = filep->private_data; 765 struct uio_device *idev = listener->dev; 766 int mi; 767 unsigned long requested_pages, actual_pages; 768 int ret = 0; 769 770 if (vma->vm_end < vma->vm_start) 771 return -EINVAL; 772 773 vma->vm_private_data = idev; 774 775 mutex_lock(&idev->info_lock); 776 if (!idev->info) { 777 ret = -EINVAL; 778 goto out; 779 } 780 781 mi = uio_find_mem_index(vma); 782 if (mi < 0) { 783 ret = -EINVAL; 784 goto out; 785 } 786 787 requested_pages = vma_pages(vma); 788 actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK) 789 + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT; 790 if (requested_pages > actual_pages) { 791 ret = -EINVAL; 792 goto out; 793 } 794 795 if (idev->info->mmap) { 796 ret = idev->info->mmap(idev->info, vma); 797 goto out; 798 } 799 800 switch (idev->info->mem[mi].memtype) { 801 case UIO_MEM_IOVA: 802 case UIO_MEM_PHYS: 803 ret = uio_mmap_physical(vma); 804 break; 805 case UIO_MEM_LOGICAL: 806 case UIO_MEM_VIRTUAL: 807 ret = uio_mmap_logical(vma); 808 break; 809 default: 810 ret = -EINVAL; 811 } 812 813 out: 814 mutex_unlock(&idev->info_lock); 815 return ret; 816 } 817 818 static const struct file_operations uio_fops = { 819 .owner = THIS_MODULE, 820 .open = uio_open, 821 .release = uio_release, 822 .read = uio_read, 823 .write = uio_write, 824 .mmap = uio_mmap, 825 .poll = uio_poll, 826 .fasync = uio_fasync, 827 .llseek = noop_llseek, 828 }; 829 830 static int uio_major_init(void) 831 { 832 static const char name[] = "uio"; 833 struct cdev *cdev = NULL; 834 dev_t uio_dev = 0; 835 int result; 836 837 result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name); 838 if (result) 839 goto out; 840 841 result = -ENOMEM; 842 cdev = cdev_alloc(); 843 if (!cdev) 844 goto out_unregister; 845 846 cdev->owner = THIS_MODULE; 847 cdev->ops = &uio_fops; 848 kobject_set_name(&cdev->kobj, "%s", name); 849 850 result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES); 851 if (result) 852 goto out_put; 853 854 uio_major = MAJOR(uio_dev); 855 uio_cdev = cdev; 856 return 0; 857 out_put: 858 kobject_put(&cdev->kobj); 859 out_unregister: 860 unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES); 861 out: 862 return result; 863 } 864 865 static void uio_major_cleanup(void) 866 { 867 unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES); 868 cdev_del(uio_cdev); 869 } 870 871 static int init_uio_class(void) 872 { 873 int ret; 874 875 /* This is the first time in here, set everything up properly */ 876 ret = uio_major_init(); 877 if (ret) 878 goto exit; 879 880 ret = class_register(&uio_class); 881 if (ret) { 882 printk(KERN_ERR "class_register failed for uio\n"); 883 goto err_class_register; 884 } 885 886 uio_class_registered = true; 887 888 return 0; 889 890 err_class_register: 891 uio_major_cleanup(); 892 exit: 893 return ret; 894 } 895 896 static void release_uio_class(void) 897 { 898 uio_class_registered = false; 899 class_unregister(&uio_class); 900 uio_major_cleanup(); 901 } 902 903 static void uio_device_release(struct device *dev) 904 { 905 struct uio_device *idev = dev_get_drvdata(dev); 906 907 kfree(idev); 908 } 909 910 /** 911 * __uio_register_device - register a new userspace IO device 912 * @owner: module that creates the new device 913 * @parent: parent device 914 * @info: UIO device capabilities 915 * 916 * returns zero on success or a negative error code. 917 */ 918 int __uio_register_device(struct module *owner, 919 struct device *parent, 920 struct uio_info *info) 921 { 922 struct uio_device *idev; 923 int ret = 0; 924 925 if (!uio_class_registered) 926 return -EPROBE_DEFER; 927 928 if (!parent || !info || !info->name || !info->version) 929 return -EINVAL; 930 931 info->uio_dev = NULL; 932 933 idev = kzalloc(sizeof(*idev), GFP_KERNEL); 934 if (!idev) { 935 return -ENOMEM; 936 } 937 938 idev->owner = owner; 939 idev->info = info; 940 mutex_init(&idev->info_lock); 941 init_waitqueue_head(&idev->wait); 942 atomic_set(&idev->event, 0); 943 944 ret = uio_get_minor(idev); 945 if (ret) { 946 kfree(idev); 947 return ret; 948 } 949 950 device_initialize(&idev->dev); 951 idev->dev.devt = MKDEV(uio_major, idev->minor); 952 idev->dev.class = &uio_class; 953 idev->dev.parent = parent; 954 idev->dev.release = uio_device_release; 955 dev_set_drvdata(&idev->dev, idev); 956 957 ret = dev_set_name(&idev->dev, "uio%d", idev->minor); 958 if (ret) 959 goto err_device_create; 960 961 ret = device_add(&idev->dev); 962 if (ret) 963 goto err_device_create; 964 965 ret = uio_dev_add_attributes(idev); 966 if (ret) 967 goto err_uio_dev_add_attributes; 968 969 info->uio_dev = idev; 970 971 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) { 972 /* 973 * Note that we deliberately don't use devm_request_irq 974 * here. The parent module can unregister the UIO device 975 * and call pci_disable_msi, which requires that this 976 * irq has been freed. However, the device may have open 977 * FDs at the time of unregister and therefore may not be 978 * freed until they are released. 979 */ 980 ret = request_irq(info->irq, uio_interrupt, 981 info->irq_flags, info->name, idev); 982 if (ret) { 983 info->uio_dev = NULL; 984 goto err_request_irq; 985 } 986 } 987 988 return 0; 989 990 err_request_irq: 991 uio_dev_del_attributes(idev); 992 err_uio_dev_add_attributes: 993 device_del(&idev->dev); 994 err_device_create: 995 uio_free_minor(idev->minor); 996 put_device(&idev->dev); 997 return ret; 998 } 999 EXPORT_SYMBOL_GPL(__uio_register_device); 1000 1001 static void devm_uio_unregister_device(struct device *dev, void *res) 1002 { 1003 uio_unregister_device(*(struct uio_info **)res); 1004 } 1005 1006 /** 1007 * __devm_uio_register_device - Resource managed uio_register_device() 1008 * @owner: module that creates the new device 1009 * @parent: parent device 1010 * @info: UIO device capabilities 1011 * 1012 * returns zero on success or a negative error code. 1013 */ 1014 int __devm_uio_register_device(struct module *owner, 1015 struct device *parent, 1016 struct uio_info *info) 1017 { 1018 struct uio_info **ptr; 1019 int ret; 1020 1021 ptr = devres_alloc(devm_uio_unregister_device, sizeof(*ptr), 1022 GFP_KERNEL); 1023 if (!ptr) 1024 return -ENOMEM; 1025 1026 *ptr = info; 1027 ret = __uio_register_device(owner, parent, info); 1028 if (ret) { 1029 devres_free(ptr); 1030 return ret; 1031 } 1032 1033 devres_add(parent, ptr); 1034 1035 return 0; 1036 } 1037 EXPORT_SYMBOL_GPL(__devm_uio_register_device); 1038 1039 /** 1040 * uio_unregister_device - unregister a industrial IO device 1041 * @info: UIO device capabilities 1042 * 1043 */ 1044 void uio_unregister_device(struct uio_info *info) 1045 { 1046 struct uio_device *idev; 1047 unsigned long minor; 1048 1049 if (!info || !info->uio_dev) 1050 return; 1051 1052 idev = info->uio_dev; 1053 minor = idev->minor; 1054 1055 mutex_lock(&idev->info_lock); 1056 uio_dev_del_attributes(idev); 1057 1058 if (info->irq && info->irq != UIO_IRQ_CUSTOM) 1059 free_irq(info->irq, idev); 1060 1061 idev->info = NULL; 1062 mutex_unlock(&idev->info_lock); 1063 1064 wake_up_interruptible(&idev->wait); 1065 kill_fasync(&idev->async_queue, SIGIO, POLL_HUP); 1066 1067 device_unregister(&idev->dev); 1068 1069 uio_free_minor(minor); 1070 1071 return; 1072 } 1073 EXPORT_SYMBOL_GPL(uio_unregister_device); 1074 1075 static int __init uio_init(void) 1076 { 1077 return init_uio_class(); 1078 } 1079 1080 static void __exit uio_exit(void) 1081 { 1082 release_uio_class(); 1083 idr_destroy(&uio_idr); 1084 } 1085 1086 module_init(uio_init) 1087 module_exit(uio_exit) 1088 MODULE_LICENSE("GPL v2"); 1089