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 static bool uio_class_registered; 278 279 /* 280 * device functions 281 */ 282 static int uio_dev_add_attributes(struct uio_device *idev) 283 { 284 int ret; 285 int mi, pi; 286 int map_found = 0; 287 int portio_found = 0; 288 struct uio_mem *mem; 289 struct uio_map *map; 290 struct uio_port *port; 291 struct uio_portio *portio; 292 293 for (mi = 0; mi < MAX_UIO_MAPS; mi++) { 294 mem = &idev->info->mem[mi]; 295 if (mem->size == 0) 296 break; 297 if (!map_found) { 298 map_found = 1; 299 idev->map_dir = kobject_create_and_add("maps", 300 &idev->dev.kobj); 301 if (!idev->map_dir) { 302 ret = -ENOMEM; 303 goto err_map; 304 } 305 } 306 map = kzalloc(sizeof(*map), GFP_KERNEL); 307 if (!map) { 308 ret = -ENOMEM; 309 goto err_map; 310 } 311 kobject_init(&map->kobj, &map_attr_type); 312 map->mem = mem; 313 mem->map = map; 314 ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi); 315 if (ret) 316 goto err_map_kobj; 317 ret = kobject_uevent(&map->kobj, KOBJ_ADD); 318 if (ret) 319 goto err_map_kobj; 320 } 321 322 for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) { 323 port = &idev->info->port[pi]; 324 if (port->size == 0) 325 break; 326 if (!portio_found) { 327 portio_found = 1; 328 idev->portio_dir = kobject_create_and_add("portio", 329 &idev->dev.kobj); 330 if (!idev->portio_dir) { 331 ret = -ENOMEM; 332 goto err_portio; 333 } 334 } 335 portio = kzalloc(sizeof(*portio), GFP_KERNEL); 336 if (!portio) { 337 ret = -ENOMEM; 338 goto err_portio; 339 } 340 kobject_init(&portio->kobj, &portio_attr_type); 341 portio->port = port; 342 port->portio = portio; 343 ret = kobject_add(&portio->kobj, idev->portio_dir, 344 "port%d", pi); 345 if (ret) 346 goto err_portio_kobj; 347 ret = kobject_uevent(&portio->kobj, KOBJ_ADD); 348 if (ret) 349 goto err_portio_kobj; 350 } 351 352 return 0; 353 354 err_portio: 355 pi--; 356 err_portio_kobj: 357 for (; pi >= 0; pi--) { 358 port = &idev->info->port[pi]; 359 portio = port->portio; 360 kobject_put(&portio->kobj); 361 } 362 kobject_put(idev->portio_dir); 363 err_map: 364 mi--; 365 err_map_kobj: 366 for (; mi >= 0; mi--) { 367 mem = &idev->info->mem[mi]; 368 map = mem->map; 369 kobject_put(&map->kobj); 370 } 371 kobject_put(idev->map_dir); 372 dev_err(&idev->dev, "error creating sysfs files (%d)\n", ret); 373 return ret; 374 } 375 376 static void uio_dev_del_attributes(struct uio_device *idev) 377 { 378 int i; 379 struct uio_mem *mem; 380 struct uio_port *port; 381 382 for (i = 0; i < MAX_UIO_MAPS; i++) { 383 mem = &idev->info->mem[i]; 384 if (mem->size == 0) 385 break; 386 kobject_put(&mem->map->kobj); 387 } 388 kobject_put(idev->map_dir); 389 390 for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) { 391 port = &idev->info->port[i]; 392 if (port->size == 0) 393 break; 394 kobject_put(&port->portio->kobj); 395 } 396 kobject_put(idev->portio_dir); 397 } 398 399 static int uio_get_minor(struct uio_device *idev) 400 { 401 int retval; 402 403 mutex_lock(&minor_lock); 404 retval = idr_alloc(&uio_idr, idev, 0, UIO_MAX_DEVICES, GFP_KERNEL); 405 if (retval >= 0) { 406 idev->minor = retval; 407 retval = 0; 408 } else if (retval == -ENOSPC) { 409 dev_err(&idev->dev, "too many uio devices\n"); 410 retval = -EINVAL; 411 } 412 mutex_unlock(&minor_lock); 413 return retval; 414 } 415 416 static void uio_free_minor(unsigned long minor) 417 { 418 mutex_lock(&minor_lock); 419 idr_remove(&uio_idr, minor); 420 mutex_unlock(&minor_lock); 421 } 422 423 /** 424 * uio_event_notify - trigger an interrupt event 425 * @info: UIO device capabilities 426 */ 427 void uio_event_notify(struct uio_info *info) 428 { 429 struct uio_device *idev = info->uio_dev; 430 431 atomic_inc(&idev->event); 432 wake_up_interruptible(&idev->wait); 433 kill_fasync(&idev->async_queue, SIGIO, POLL_IN); 434 } 435 EXPORT_SYMBOL_GPL(uio_event_notify); 436 437 /** 438 * uio_interrupt - hardware interrupt handler 439 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer 440 * @dev_id: Pointer to the devices uio_device structure 441 */ 442 static irqreturn_t uio_interrupt(int irq, void *dev_id) 443 { 444 struct uio_device *idev = (struct uio_device *)dev_id; 445 irqreturn_t ret; 446 447 ret = idev->info->handler(irq, idev->info); 448 if (ret == IRQ_HANDLED) 449 uio_event_notify(idev->info); 450 451 return ret; 452 } 453 454 struct uio_listener { 455 struct uio_device *dev; 456 s32 event_count; 457 }; 458 459 static int uio_open(struct inode *inode, struct file *filep) 460 { 461 struct uio_device *idev; 462 struct uio_listener *listener; 463 int ret = 0; 464 465 mutex_lock(&minor_lock); 466 idev = idr_find(&uio_idr, iminor(inode)); 467 mutex_unlock(&minor_lock); 468 if (!idev) { 469 ret = -ENODEV; 470 goto out; 471 } 472 473 get_device(&idev->dev); 474 475 if (!try_module_get(idev->owner)) { 476 ret = -ENODEV; 477 goto err_module_get; 478 } 479 480 listener = kmalloc(sizeof(*listener), GFP_KERNEL); 481 if (!listener) { 482 ret = -ENOMEM; 483 goto err_alloc_listener; 484 } 485 486 listener->dev = idev; 487 listener->event_count = atomic_read(&idev->event); 488 filep->private_data = listener; 489 490 mutex_lock(&idev->info_lock); 491 if (!idev->info) { 492 mutex_unlock(&idev->info_lock); 493 ret = -EINVAL; 494 goto err_infoopen; 495 } 496 497 if (idev->info->open) 498 ret = idev->info->open(idev->info, inode); 499 mutex_unlock(&idev->info_lock); 500 if (ret) 501 goto err_infoopen; 502 503 return 0; 504 505 err_infoopen: 506 kfree(listener); 507 508 err_alloc_listener: 509 module_put(idev->owner); 510 511 err_module_get: 512 put_device(&idev->dev); 513 514 out: 515 return ret; 516 } 517 518 static int uio_fasync(int fd, struct file *filep, int on) 519 { 520 struct uio_listener *listener = filep->private_data; 521 struct uio_device *idev = listener->dev; 522 523 return fasync_helper(fd, filep, on, &idev->async_queue); 524 } 525 526 static int uio_release(struct inode *inode, struct file *filep) 527 { 528 int ret = 0; 529 struct uio_listener *listener = filep->private_data; 530 struct uio_device *idev = listener->dev; 531 532 mutex_lock(&idev->info_lock); 533 if (idev->info && idev->info->release) 534 ret = idev->info->release(idev->info, inode); 535 mutex_unlock(&idev->info_lock); 536 537 module_put(idev->owner); 538 kfree(listener); 539 put_device(&idev->dev); 540 return ret; 541 } 542 543 static __poll_t uio_poll(struct file *filep, poll_table *wait) 544 { 545 struct uio_listener *listener = filep->private_data; 546 struct uio_device *idev = listener->dev; 547 __poll_t ret = 0; 548 549 mutex_lock(&idev->info_lock); 550 if (!idev->info || !idev->info->irq) 551 ret = -EIO; 552 mutex_unlock(&idev->info_lock); 553 554 if (ret) 555 return ret; 556 557 poll_wait(filep, &idev->wait, wait); 558 if (listener->event_count != atomic_read(&idev->event)) 559 return EPOLLIN | EPOLLRDNORM; 560 return 0; 561 } 562 563 static ssize_t uio_read(struct file *filep, char __user *buf, 564 size_t count, loff_t *ppos) 565 { 566 struct uio_listener *listener = filep->private_data; 567 struct uio_device *idev = listener->dev; 568 DECLARE_WAITQUEUE(wait, current); 569 ssize_t retval = 0; 570 s32 event_count; 571 572 if (count != sizeof(s32)) 573 return -EINVAL; 574 575 add_wait_queue(&idev->wait, &wait); 576 577 do { 578 mutex_lock(&idev->info_lock); 579 if (!idev->info || !idev->info->irq) { 580 retval = -EIO; 581 mutex_unlock(&idev->info_lock); 582 break; 583 } 584 mutex_unlock(&idev->info_lock); 585 586 set_current_state(TASK_INTERRUPTIBLE); 587 588 event_count = atomic_read(&idev->event); 589 if (event_count != listener->event_count) { 590 __set_current_state(TASK_RUNNING); 591 if (copy_to_user(buf, &event_count, count)) 592 retval = -EFAULT; 593 else { 594 listener->event_count = event_count; 595 retval = count; 596 } 597 break; 598 } 599 600 if (filep->f_flags & O_NONBLOCK) { 601 retval = -EAGAIN; 602 break; 603 } 604 605 if (signal_pending(current)) { 606 retval = -ERESTARTSYS; 607 break; 608 } 609 schedule(); 610 } while (1); 611 612 __set_current_state(TASK_RUNNING); 613 remove_wait_queue(&idev->wait, &wait); 614 615 return retval; 616 } 617 618 static ssize_t uio_write(struct file *filep, const char __user *buf, 619 size_t count, loff_t *ppos) 620 { 621 struct uio_listener *listener = filep->private_data; 622 struct uio_device *idev = listener->dev; 623 ssize_t retval; 624 s32 irq_on; 625 626 if (count != sizeof(s32)) 627 return -EINVAL; 628 629 if (copy_from_user(&irq_on, buf, count)) 630 return -EFAULT; 631 632 mutex_lock(&idev->info_lock); 633 if (!idev->info) { 634 retval = -EINVAL; 635 goto out; 636 } 637 638 if (!idev->info->irq) { 639 retval = -EIO; 640 goto out; 641 } 642 643 if (!idev->info->irqcontrol) { 644 retval = -ENOSYS; 645 goto out; 646 } 647 648 retval = idev->info->irqcontrol(idev->info, irq_on); 649 650 out: 651 mutex_unlock(&idev->info_lock); 652 return retval ? retval : sizeof(s32); 653 } 654 655 static int uio_find_mem_index(struct vm_area_struct *vma) 656 { 657 struct uio_device *idev = vma->vm_private_data; 658 659 if (vma->vm_pgoff < MAX_UIO_MAPS) { 660 if (idev->info->mem[vma->vm_pgoff].size == 0) 661 return -1; 662 return (int)vma->vm_pgoff; 663 } 664 return -1; 665 } 666 667 static vm_fault_t uio_vma_fault(struct vm_fault *vmf) 668 { 669 struct uio_device *idev = vmf->vma->vm_private_data; 670 struct page *page; 671 unsigned long offset; 672 void *addr; 673 vm_fault_t ret = 0; 674 int mi; 675 676 mutex_lock(&idev->info_lock); 677 if (!idev->info) { 678 ret = VM_FAULT_SIGBUS; 679 goto out; 680 } 681 682 mi = uio_find_mem_index(vmf->vma); 683 if (mi < 0) { 684 ret = VM_FAULT_SIGBUS; 685 goto out; 686 } 687 688 /* 689 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE 690 * to use mem[N]. 691 */ 692 offset = (vmf->pgoff - mi) << PAGE_SHIFT; 693 694 addr = (void *)(unsigned long)idev->info->mem[mi].addr + offset; 695 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL) 696 page = virt_to_page(addr); 697 else 698 page = vmalloc_to_page(addr); 699 get_page(page); 700 vmf->page = page; 701 702 out: 703 mutex_unlock(&idev->info_lock); 704 705 return ret; 706 } 707 708 static const struct vm_operations_struct uio_logical_vm_ops = { 709 .fault = uio_vma_fault, 710 }; 711 712 static int uio_mmap_logical(struct vm_area_struct *vma) 713 { 714 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; 715 vma->vm_ops = &uio_logical_vm_ops; 716 return 0; 717 } 718 719 static const struct vm_operations_struct uio_physical_vm_ops = { 720 #ifdef CONFIG_HAVE_IOREMAP_PROT 721 .access = generic_access_phys, 722 #endif 723 }; 724 725 static int uio_mmap_physical(struct vm_area_struct *vma) 726 { 727 struct uio_device *idev = vma->vm_private_data; 728 int mi = uio_find_mem_index(vma); 729 struct uio_mem *mem; 730 731 if (mi < 0) 732 return -EINVAL; 733 mem = idev->info->mem + mi; 734 735 if (mem->addr & ~PAGE_MASK) 736 return -ENODEV; 737 if (vma->vm_end - vma->vm_start > mem->size) 738 return -EINVAL; 739 740 vma->vm_ops = &uio_physical_vm_ops; 741 if (idev->info->mem[mi].memtype == UIO_MEM_PHYS) 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_IOVA: 800 case UIO_MEM_PHYS: 801 ret = uio_mmap_physical(vma); 802 break; 803 case UIO_MEM_LOGICAL: 804 case UIO_MEM_VIRTUAL: 805 ret = uio_mmap_logical(vma); 806 break; 807 default: 808 ret = -EINVAL; 809 } 810 811 out: 812 mutex_unlock(&idev->info_lock); 813 return ret; 814 } 815 816 static const struct file_operations uio_fops = { 817 .owner = THIS_MODULE, 818 .open = uio_open, 819 .release = uio_release, 820 .read = uio_read, 821 .write = uio_write, 822 .mmap = uio_mmap, 823 .poll = uio_poll, 824 .fasync = uio_fasync, 825 .llseek = noop_llseek, 826 }; 827 828 static int uio_major_init(void) 829 { 830 static const char name[] = "uio"; 831 struct cdev *cdev = NULL; 832 dev_t uio_dev = 0; 833 int result; 834 835 result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name); 836 if (result) 837 goto out; 838 839 result = -ENOMEM; 840 cdev = cdev_alloc(); 841 if (!cdev) 842 goto out_unregister; 843 844 cdev->owner = THIS_MODULE; 845 cdev->ops = &uio_fops; 846 kobject_set_name(&cdev->kobj, "%s", name); 847 848 result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES); 849 if (result) 850 goto out_put; 851 852 uio_major = MAJOR(uio_dev); 853 uio_cdev = cdev; 854 return 0; 855 out_put: 856 kobject_put(&cdev->kobj); 857 out_unregister: 858 unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES); 859 out: 860 return result; 861 } 862 863 static void uio_major_cleanup(void) 864 { 865 unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES); 866 cdev_del(uio_cdev); 867 } 868 869 static int init_uio_class(void) 870 { 871 int ret; 872 873 /* This is the first time in here, set everything up properly */ 874 ret = uio_major_init(); 875 if (ret) 876 goto exit; 877 878 ret = class_register(&uio_class); 879 if (ret) { 880 printk(KERN_ERR "class_register failed for uio\n"); 881 goto err_class_register; 882 } 883 884 uio_class_registered = true; 885 886 return 0; 887 888 err_class_register: 889 uio_major_cleanup(); 890 exit: 891 return ret; 892 } 893 894 static void release_uio_class(void) 895 { 896 uio_class_registered = false; 897 class_unregister(&uio_class); 898 uio_major_cleanup(); 899 } 900 901 static void uio_device_release(struct device *dev) 902 { 903 struct uio_device *idev = dev_get_drvdata(dev); 904 905 kfree(idev); 906 } 907 908 /** 909 * __uio_register_device - register a new userspace IO device 910 * @owner: module that creates the new device 911 * @parent: parent device 912 * @info: UIO device capabilities 913 * 914 * returns zero on success or a negative error code. 915 */ 916 int __uio_register_device(struct module *owner, 917 struct device *parent, 918 struct uio_info *info) 919 { 920 struct uio_device *idev; 921 int ret = 0; 922 923 if (!uio_class_registered) 924 return -EPROBE_DEFER; 925 926 if (!parent || !info || !info->name || !info->version) 927 return -EINVAL; 928 929 info->uio_dev = NULL; 930 931 idev = kzalloc(sizeof(*idev), GFP_KERNEL); 932 if (!idev) { 933 return -ENOMEM; 934 } 935 936 idev->owner = owner; 937 idev->info = info; 938 mutex_init(&idev->info_lock); 939 init_waitqueue_head(&idev->wait); 940 atomic_set(&idev->event, 0); 941 942 ret = uio_get_minor(idev); 943 if (ret) { 944 kfree(idev); 945 return ret; 946 } 947 948 device_initialize(&idev->dev); 949 idev->dev.devt = MKDEV(uio_major, idev->minor); 950 idev->dev.class = &uio_class; 951 idev->dev.parent = parent; 952 idev->dev.release = uio_device_release; 953 dev_set_drvdata(&idev->dev, idev); 954 955 ret = dev_set_name(&idev->dev, "uio%d", idev->minor); 956 if (ret) 957 goto err_device_create; 958 959 ret = device_add(&idev->dev); 960 if (ret) 961 goto err_device_create; 962 963 ret = uio_dev_add_attributes(idev); 964 if (ret) 965 goto err_uio_dev_add_attributes; 966 967 info->uio_dev = idev; 968 969 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) { 970 /* 971 * Note that we deliberately don't use devm_request_irq 972 * here. The parent module can unregister the UIO device 973 * and call pci_disable_msi, which requires that this 974 * irq has been freed. However, the device may have open 975 * FDs at the time of unregister and therefore may not be 976 * freed until they are released. 977 */ 978 ret = request_irq(info->irq, uio_interrupt, 979 info->irq_flags, info->name, idev); 980 if (ret) { 981 info->uio_dev = NULL; 982 goto err_request_irq; 983 } 984 } 985 986 return 0; 987 988 err_request_irq: 989 uio_dev_del_attributes(idev); 990 err_uio_dev_add_attributes: 991 device_del(&idev->dev); 992 err_device_create: 993 uio_free_minor(idev->minor); 994 put_device(&idev->dev); 995 return ret; 996 } 997 EXPORT_SYMBOL_GPL(__uio_register_device); 998 999 static void devm_uio_unregister_device(struct device *dev, void *res) 1000 { 1001 uio_unregister_device(*(struct uio_info **)res); 1002 } 1003 1004 /** 1005 * __devm_uio_register_device - Resource managed uio_register_device() 1006 * @owner: module that creates the new device 1007 * @parent: parent device 1008 * @info: UIO device capabilities 1009 * 1010 * returns zero on success or a negative error code. 1011 */ 1012 int __devm_uio_register_device(struct module *owner, 1013 struct device *parent, 1014 struct uio_info *info) 1015 { 1016 struct uio_info **ptr; 1017 int ret; 1018 1019 ptr = devres_alloc(devm_uio_unregister_device, sizeof(*ptr), 1020 GFP_KERNEL); 1021 if (!ptr) 1022 return -ENOMEM; 1023 1024 *ptr = info; 1025 ret = __uio_register_device(owner, parent, info); 1026 if (ret) { 1027 devres_free(ptr); 1028 return ret; 1029 } 1030 1031 devres_add(parent, ptr); 1032 1033 return 0; 1034 } 1035 EXPORT_SYMBOL_GPL(__devm_uio_register_device); 1036 1037 /** 1038 * uio_unregister_device - unregister a industrial IO device 1039 * @info: UIO device capabilities 1040 * 1041 */ 1042 void uio_unregister_device(struct uio_info *info) 1043 { 1044 struct uio_device *idev; 1045 unsigned long minor; 1046 1047 if (!info || !info->uio_dev) 1048 return; 1049 1050 idev = info->uio_dev; 1051 minor = idev->minor; 1052 1053 mutex_lock(&idev->info_lock); 1054 uio_dev_del_attributes(idev); 1055 1056 if (info->irq && info->irq != UIO_IRQ_CUSTOM) 1057 free_irq(info->irq, idev); 1058 1059 idev->info = NULL; 1060 mutex_unlock(&idev->info_lock); 1061 1062 wake_up_interruptible(&idev->wait); 1063 kill_fasync(&idev->async_queue, SIGIO, POLL_HUP); 1064 1065 device_unregister(&idev->dev); 1066 1067 uio_free_minor(minor); 1068 1069 return; 1070 } 1071 EXPORT_SYMBOL_GPL(uio_unregister_device); 1072 1073 static int __init uio_init(void) 1074 { 1075 return init_uio_class(); 1076 } 1077 1078 static void __exit uio_exit(void) 1079 { 1080 release_uio_class(); 1081 idr_destroy(&uio_idr); 1082 } 1083 1084 module_init(uio_init) 1085 module_exit(uio_exit) 1086 MODULE_LICENSE("GPL v2"); 1087