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 #include <linux/dma-mapping.h> 28 29 #define UIO_MAX_DEVICES (1U << MINORBITS) 30 31 static int uio_major; 32 static struct cdev *uio_cdev; 33 static DEFINE_IDR(uio_idr); 34 static const struct file_operations uio_fops; 35 36 /* Protect idr accesses */ 37 static DEFINE_MUTEX(minor_lock); 38 39 /* 40 * attributes 41 */ 42 43 struct uio_map { 44 struct kobject kobj; 45 struct uio_mem *mem; 46 }; 47 #define to_map(map) container_of(map, struct uio_map, kobj) 48 49 static ssize_t map_name_show(struct uio_mem *mem, char *buf) 50 { 51 if (unlikely(!mem->name)) 52 mem->name = ""; 53 54 return sprintf(buf, "%s\n", mem->name); 55 } 56 57 static ssize_t map_addr_show(struct uio_mem *mem, char *buf) 58 { 59 return sprintf(buf, "%pa\n", &mem->addr); 60 } 61 62 static ssize_t map_size_show(struct uio_mem *mem, char *buf) 63 { 64 return sprintf(buf, "%pa\n", &mem->size); 65 } 66 67 static ssize_t map_offset_show(struct uio_mem *mem, char *buf) 68 { 69 return sprintf(buf, "0x%llx\n", (unsigned long long)mem->offs); 70 } 71 72 struct map_sysfs_entry { 73 struct attribute attr; 74 ssize_t (*show)(struct uio_mem *, char *); 75 ssize_t (*store)(struct uio_mem *, const char *, size_t); 76 }; 77 78 static struct map_sysfs_entry name_attribute = 79 __ATTR(name, S_IRUGO, map_name_show, NULL); 80 static struct map_sysfs_entry addr_attribute = 81 __ATTR(addr, S_IRUGO, map_addr_show, NULL); 82 static struct map_sysfs_entry size_attribute = 83 __ATTR(size, S_IRUGO, map_size_show, NULL); 84 static struct map_sysfs_entry offset_attribute = 85 __ATTR(offset, S_IRUGO, map_offset_show, NULL); 86 87 static struct attribute *map_attrs[] = { 88 &name_attribute.attr, 89 &addr_attribute.attr, 90 &size_attribute.attr, 91 &offset_attribute.attr, 92 NULL, /* need to NULL terminate the list of attributes */ 93 }; 94 ATTRIBUTE_GROUPS(map); 95 96 static void map_release(struct kobject *kobj) 97 { 98 struct uio_map *map = to_map(kobj); 99 kfree(map); 100 } 101 102 static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr, 103 char *buf) 104 { 105 struct uio_map *map = to_map(kobj); 106 struct uio_mem *mem = map->mem; 107 struct map_sysfs_entry *entry; 108 109 entry = container_of(attr, struct map_sysfs_entry, attr); 110 111 if (!entry->show) 112 return -EIO; 113 114 return entry->show(mem, buf); 115 } 116 117 static const struct sysfs_ops map_sysfs_ops = { 118 .show = map_type_show, 119 }; 120 121 static struct kobj_type map_attr_type = { 122 .release = map_release, 123 .sysfs_ops = &map_sysfs_ops, 124 .default_groups = map_groups, 125 }; 126 127 struct uio_portio { 128 struct kobject kobj; 129 struct uio_port *port; 130 }; 131 #define to_portio(portio) container_of(portio, struct uio_portio, kobj) 132 133 static ssize_t portio_name_show(struct uio_port *port, char *buf) 134 { 135 if (unlikely(!port->name)) 136 port->name = ""; 137 138 return sprintf(buf, "%s\n", port->name); 139 } 140 141 static ssize_t portio_start_show(struct uio_port *port, char *buf) 142 { 143 return sprintf(buf, "0x%lx\n", port->start); 144 } 145 146 static ssize_t portio_size_show(struct uio_port *port, char *buf) 147 { 148 return sprintf(buf, "0x%lx\n", port->size); 149 } 150 151 static ssize_t portio_porttype_show(struct uio_port *port, char *buf) 152 { 153 const char *porttypes[] = {"none", "x86", "gpio", "other"}; 154 155 if ((port->porttype < 0) || (port->porttype > UIO_PORT_OTHER)) 156 return -EINVAL; 157 158 return sprintf(buf, "port_%s\n", porttypes[port->porttype]); 159 } 160 161 struct portio_sysfs_entry { 162 struct attribute attr; 163 ssize_t (*show)(struct uio_port *, char *); 164 ssize_t (*store)(struct uio_port *, const char *, size_t); 165 }; 166 167 static struct portio_sysfs_entry portio_name_attribute = 168 __ATTR(name, S_IRUGO, portio_name_show, NULL); 169 static struct portio_sysfs_entry portio_start_attribute = 170 __ATTR(start, S_IRUGO, portio_start_show, NULL); 171 static struct portio_sysfs_entry portio_size_attribute = 172 __ATTR(size, S_IRUGO, portio_size_show, NULL); 173 static struct portio_sysfs_entry portio_porttype_attribute = 174 __ATTR(porttype, S_IRUGO, portio_porttype_show, NULL); 175 176 static struct attribute *portio_attrs[] = { 177 &portio_name_attribute.attr, 178 &portio_start_attribute.attr, 179 &portio_size_attribute.attr, 180 &portio_porttype_attribute.attr, 181 NULL, 182 }; 183 ATTRIBUTE_GROUPS(portio); 184 185 static void portio_release(struct kobject *kobj) 186 { 187 struct uio_portio *portio = to_portio(kobj); 188 kfree(portio); 189 } 190 191 static ssize_t portio_type_show(struct kobject *kobj, struct attribute *attr, 192 char *buf) 193 { 194 struct uio_portio *portio = to_portio(kobj); 195 struct uio_port *port = portio->port; 196 struct portio_sysfs_entry *entry; 197 198 entry = container_of(attr, struct portio_sysfs_entry, attr); 199 200 if (!entry->show) 201 return -EIO; 202 203 return entry->show(port, buf); 204 } 205 206 static const struct sysfs_ops portio_sysfs_ops = { 207 .show = portio_type_show, 208 }; 209 210 static struct kobj_type portio_attr_type = { 211 .release = portio_release, 212 .sysfs_ops = &portio_sysfs_ops, 213 .default_groups = portio_groups, 214 }; 215 216 static ssize_t name_show(struct device *dev, 217 struct device_attribute *attr, char *buf) 218 { 219 struct uio_device *idev = dev_get_drvdata(dev); 220 int ret; 221 222 mutex_lock(&idev->info_lock); 223 if (!idev->info) { 224 ret = -EINVAL; 225 dev_err(dev, "the device has been unregistered\n"); 226 goto out; 227 } 228 229 ret = sprintf(buf, "%s\n", idev->info->name); 230 231 out: 232 mutex_unlock(&idev->info_lock); 233 return ret; 234 } 235 static DEVICE_ATTR_RO(name); 236 237 static ssize_t version_show(struct device *dev, 238 struct device_attribute *attr, char *buf) 239 { 240 struct uio_device *idev = dev_get_drvdata(dev); 241 int ret; 242 243 mutex_lock(&idev->info_lock); 244 if (!idev->info) { 245 ret = -EINVAL; 246 dev_err(dev, "the device has been unregistered\n"); 247 goto out; 248 } 249 250 ret = sprintf(buf, "%s\n", idev->info->version); 251 252 out: 253 mutex_unlock(&idev->info_lock); 254 return ret; 255 } 256 static DEVICE_ATTR_RO(version); 257 258 static ssize_t event_show(struct device *dev, 259 struct device_attribute *attr, char *buf) 260 { 261 struct uio_device *idev = dev_get_drvdata(dev); 262 return sprintf(buf, "%u\n", (unsigned int)atomic_read(&idev->event)); 263 } 264 static DEVICE_ATTR_RO(event); 265 266 static struct attribute *uio_attrs[] = { 267 &dev_attr_name.attr, 268 &dev_attr_version.attr, 269 &dev_attr_event.attr, 270 NULL, 271 }; 272 ATTRIBUTE_GROUPS(uio); 273 274 /* UIO class infrastructure */ 275 static struct class uio_class = { 276 .name = "uio", 277 .dev_groups = uio_groups, 278 }; 279 280 static bool uio_class_registered; 281 282 /* 283 * device functions 284 */ 285 static int uio_dev_add_attributes(struct uio_device *idev) 286 { 287 int ret; 288 int mi, pi; 289 int map_found = 0; 290 int portio_found = 0; 291 struct uio_mem *mem; 292 struct uio_map *map; 293 struct uio_port *port; 294 struct uio_portio *portio; 295 296 for (mi = 0; mi < MAX_UIO_MAPS; mi++) { 297 mem = &idev->info->mem[mi]; 298 if (mem->size == 0) 299 break; 300 if (!map_found) { 301 map_found = 1; 302 idev->map_dir = kobject_create_and_add("maps", 303 &idev->dev.kobj); 304 if (!idev->map_dir) { 305 ret = -ENOMEM; 306 goto err_map; 307 } 308 } 309 map = kzalloc(sizeof(*map), GFP_KERNEL); 310 if (!map) { 311 ret = -ENOMEM; 312 goto err_map; 313 } 314 kobject_init(&map->kobj, &map_attr_type); 315 map->mem = mem; 316 mem->map = map; 317 ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi); 318 if (ret) 319 goto err_map_kobj; 320 ret = kobject_uevent(&map->kobj, KOBJ_ADD); 321 if (ret) 322 goto err_map_kobj; 323 } 324 325 for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) { 326 port = &idev->info->port[pi]; 327 if (port->size == 0) 328 break; 329 if (!portio_found) { 330 portio_found = 1; 331 idev->portio_dir = kobject_create_and_add("portio", 332 &idev->dev.kobj); 333 if (!idev->portio_dir) { 334 ret = -ENOMEM; 335 goto err_portio; 336 } 337 } 338 portio = kzalloc(sizeof(*portio), GFP_KERNEL); 339 if (!portio) { 340 ret = -ENOMEM; 341 goto err_portio; 342 } 343 kobject_init(&portio->kobj, &portio_attr_type); 344 portio->port = port; 345 port->portio = portio; 346 ret = kobject_add(&portio->kobj, idev->portio_dir, 347 "port%d", pi); 348 if (ret) 349 goto err_portio_kobj; 350 ret = kobject_uevent(&portio->kobj, KOBJ_ADD); 351 if (ret) 352 goto err_portio_kobj; 353 } 354 355 return 0; 356 357 err_portio: 358 pi--; 359 err_portio_kobj: 360 for (; pi >= 0; pi--) { 361 port = &idev->info->port[pi]; 362 portio = port->portio; 363 kobject_put(&portio->kobj); 364 } 365 kobject_put(idev->portio_dir); 366 err_map: 367 mi--; 368 err_map_kobj: 369 for (; mi >= 0; mi--) { 370 mem = &idev->info->mem[mi]; 371 map = mem->map; 372 kobject_put(&map->kobj); 373 } 374 kobject_put(idev->map_dir); 375 dev_err(&idev->dev, "error creating sysfs files (%d)\n", ret); 376 return ret; 377 } 378 379 static void uio_dev_del_attributes(struct uio_device *idev) 380 { 381 int i; 382 struct uio_mem *mem; 383 struct uio_port *port; 384 385 for (i = 0; i < MAX_UIO_MAPS; i++) { 386 mem = &idev->info->mem[i]; 387 if (mem->size == 0) 388 break; 389 kobject_put(&mem->map->kobj); 390 } 391 kobject_put(idev->map_dir); 392 393 for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) { 394 port = &idev->info->port[i]; 395 if (port->size == 0) 396 break; 397 kobject_put(&port->portio->kobj); 398 } 399 kobject_put(idev->portio_dir); 400 } 401 402 static int uio_get_minor(struct uio_device *idev) 403 { 404 int retval; 405 406 mutex_lock(&minor_lock); 407 retval = idr_alloc(&uio_idr, idev, 0, UIO_MAX_DEVICES, GFP_KERNEL); 408 if (retval >= 0) { 409 idev->minor = retval; 410 retval = 0; 411 } else if (retval == -ENOSPC) { 412 dev_err(&idev->dev, "too many uio devices\n"); 413 retval = -EINVAL; 414 } 415 mutex_unlock(&minor_lock); 416 return retval; 417 } 418 419 static void uio_free_minor(unsigned long minor) 420 { 421 mutex_lock(&minor_lock); 422 idr_remove(&uio_idr, minor); 423 mutex_unlock(&minor_lock); 424 } 425 426 /** 427 * uio_event_notify - trigger an interrupt event 428 * @info: UIO device capabilities 429 */ 430 void uio_event_notify(struct uio_info *info) 431 { 432 struct uio_device *idev = info->uio_dev; 433 434 atomic_inc(&idev->event); 435 wake_up_interruptible(&idev->wait); 436 kill_fasync(&idev->async_queue, SIGIO, POLL_IN); 437 } 438 EXPORT_SYMBOL_GPL(uio_event_notify); 439 440 /** 441 * uio_interrupt - hardware interrupt handler 442 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer 443 * @dev_id: Pointer to the devices uio_device structure 444 */ 445 static irqreturn_t uio_interrupt(int irq, void *dev_id) 446 { 447 struct uio_device *idev = (struct uio_device *)dev_id; 448 irqreturn_t ret; 449 450 ret = idev->info->handler(irq, idev->info); 451 if (ret == IRQ_HANDLED) 452 uio_event_notify(idev->info); 453 454 return ret; 455 } 456 457 struct uio_listener { 458 struct uio_device *dev; 459 s32 event_count; 460 }; 461 462 static int uio_open(struct inode *inode, struct file *filep) 463 { 464 struct uio_device *idev; 465 struct uio_listener *listener; 466 int ret = 0; 467 468 mutex_lock(&minor_lock); 469 idev = idr_find(&uio_idr, iminor(inode)); 470 if (!idev) { 471 ret = -ENODEV; 472 mutex_unlock(&minor_lock); 473 goto out; 474 } 475 get_device(&idev->dev); 476 mutex_unlock(&minor_lock); 477 478 if (!try_module_get(idev->owner)) { 479 ret = -ENODEV; 480 goto err_module_get; 481 } 482 483 listener = kmalloc(sizeof(*listener), GFP_KERNEL); 484 if (!listener) { 485 ret = -ENOMEM; 486 goto err_alloc_listener; 487 } 488 489 listener->dev = idev; 490 listener->event_count = atomic_read(&idev->event); 491 filep->private_data = listener; 492 493 mutex_lock(&idev->info_lock); 494 if (!idev->info) { 495 mutex_unlock(&idev->info_lock); 496 ret = -EINVAL; 497 goto err_infoopen; 498 } 499 500 if (idev->info->open) 501 ret = idev->info->open(idev->info, inode); 502 mutex_unlock(&idev->info_lock); 503 if (ret) 504 goto err_infoopen; 505 506 return 0; 507 508 err_infoopen: 509 kfree(listener); 510 511 err_alloc_listener: 512 module_put(idev->owner); 513 514 err_module_get: 515 put_device(&idev->dev); 516 517 out: 518 return ret; 519 } 520 521 static int uio_fasync(int fd, struct file *filep, int on) 522 { 523 struct uio_listener *listener = filep->private_data; 524 struct uio_device *idev = listener->dev; 525 526 return fasync_helper(fd, filep, on, &idev->async_queue); 527 } 528 529 static int uio_release(struct inode *inode, struct file *filep) 530 { 531 int ret = 0; 532 struct uio_listener *listener = filep->private_data; 533 struct uio_device *idev = listener->dev; 534 535 mutex_lock(&idev->info_lock); 536 if (idev->info && idev->info->release) 537 ret = idev->info->release(idev->info, inode); 538 mutex_unlock(&idev->info_lock); 539 540 module_put(idev->owner); 541 kfree(listener); 542 put_device(&idev->dev); 543 return ret; 544 } 545 546 static __poll_t uio_poll(struct file *filep, poll_table *wait) 547 { 548 struct uio_listener *listener = filep->private_data; 549 struct uio_device *idev = listener->dev; 550 __poll_t ret = 0; 551 552 mutex_lock(&idev->info_lock); 553 if (!idev->info || !idev->info->irq) 554 ret = -EIO; 555 mutex_unlock(&idev->info_lock); 556 557 if (ret) 558 return ret; 559 560 poll_wait(filep, &idev->wait, wait); 561 if (listener->event_count != atomic_read(&idev->event)) 562 return EPOLLIN | EPOLLRDNORM; 563 return 0; 564 } 565 566 static ssize_t uio_read(struct file *filep, char __user *buf, 567 size_t count, loff_t *ppos) 568 { 569 struct uio_listener *listener = filep->private_data; 570 struct uio_device *idev = listener->dev; 571 DECLARE_WAITQUEUE(wait, current); 572 ssize_t retval = 0; 573 s32 event_count; 574 575 if (count != sizeof(s32)) 576 return -EINVAL; 577 578 add_wait_queue(&idev->wait, &wait); 579 580 do { 581 mutex_lock(&idev->info_lock); 582 if (!idev->info || !idev->info->irq) { 583 retval = -EIO; 584 mutex_unlock(&idev->info_lock); 585 break; 586 } 587 mutex_unlock(&idev->info_lock); 588 589 set_current_state(TASK_INTERRUPTIBLE); 590 591 event_count = atomic_read(&idev->event); 592 if (event_count != listener->event_count) { 593 __set_current_state(TASK_RUNNING); 594 if (copy_to_user(buf, &event_count, count)) 595 retval = -EFAULT; 596 else { 597 listener->event_count = event_count; 598 retval = count; 599 } 600 break; 601 } 602 603 if (filep->f_flags & O_NONBLOCK) { 604 retval = -EAGAIN; 605 break; 606 } 607 608 if (signal_pending(current)) { 609 retval = -ERESTARTSYS; 610 break; 611 } 612 schedule(); 613 } while (1); 614 615 __set_current_state(TASK_RUNNING); 616 remove_wait_queue(&idev->wait, &wait); 617 618 return retval; 619 } 620 621 static ssize_t uio_write(struct file *filep, const char __user *buf, 622 size_t count, loff_t *ppos) 623 { 624 struct uio_listener *listener = filep->private_data; 625 struct uio_device *idev = listener->dev; 626 ssize_t retval; 627 s32 irq_on; 628 629 if (count != sizeof(s32)) 630 return -EINVAL; 631 632 if (copy_from_user(&irq_on, buf, count)) 633 return -EFAULT; 634 635 mutex_lock(&idev->info_lock); 636 if (!idev->info) { 637 retval = -EINVAL; 638 goto out; 639 } 640 641 if (!idev->info->irq) { 642 retval = -EIO; 643 goto out; 644 } 645 646 if (!idev->info->irqcontrol) { 647 retval = -ENOSYS; 648 goto out; 649 } 650 651 retval = idev->info->irqcontrol(idev->info, irq_on); 652 653 out: 654 mutex_unlock(&idev->info_lock); 655 return retval ? retval : sizeof(s32); 656 } 657 658 static int uio_find_mem_index(struct vm_area_struct *vma) 659 { 660 struct uio_device *idev = vma->vm_private_data; 661 662 if (vma->vm_pgoff < MAX_UIO_MAPS) { 663 if (idev->info->mem[vma->vm_pgoff].size == 0) 664 return -1; 665 return (int)vma->vm_pgoff; 666 } 667 return -1; 668 } 669 670 static vm_fault_t uio_vma_fault(struct vm_fault *vmf) 671 { 672 struct uio_device *idev = vmf->vma->vm_private_data; 673 struct page *page; 674 unsigned long offset; 675 void *addr; 676 vm_fault_t ret = 0; 677 int mi; 678 679 mutex_lock(&idev->info_lock); 680 if (!idev->info) { 681 ret = VM_FAULT_SIGBUS; 682 goto out; 683 } 684 685 mi = uio_find_mem_index(vmf->vma); 686 if (mi < 0) { 687 ret = VM_FAULT_SIGBUS; 688 goto out; 689 } 690 691 /* 692 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE 693 * to use mem[N]. 694 */ 695 offset = (vmf->pgoff - mi) << PAGE_SHIFT; 696 697 addr = (void *)(unsigned long)idev->info->mem[mi].addr + offset; 698 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL) 699 page = virt_to_page(addr); 700 else 701 page = vmalloc_to_page(addr); 702 get_page(page); 703 vmf->page = page; 704 705 out: 706 mutex_unlock(&idev->info_lock); 707 708 return ret; 709 } 710 711 static const struct vm_operations_struct uio_logical_vm_ops = { 712 .fault = uio_vma_fault, 713 }; 714 715 static int uio_mmap_logical(struct vm_area_struct *vma) 716 { 717 vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP); 718 vma->vm_ops = &uio_logical_vm_ops; 719 return 0; 720 } 721 722 static const struct vm_operations_struct uio_physical_vm_ops = { 723 #ifdef CONFIG_HAVE_IOREMAP_PROT 724 .access = generic_access_phys, 725 #endif 726 }; 727 728 static int uio_mmap_physical(struct vm_area_struct *vma) 729 { 730 struct uio_device *idev = vma->vm_private_data; 731 int mi = uio_find_mem_index(vma); 732 struct uio_mem *mem; 733 734 if (mi < 0) 735 return -EINVAL; 736 mem = idev->info->mem + mi; 737 738 if (mem->addr & ~PAGE_MASK) 739 return -ENODEV; 740 if (vma->vm_end - vma->vm_start > mem->size) 741 return -EINVAL; 742 743 vma->vm_ops = &uio_physical_vm_ops; 744 if (idev->info->mem[mi].memtype == UIO_MEM_PHYS) 745 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 746 747 /* 748 * We cannot use the vm_iomap_memory() helper here, 749 * because vma->vm_pgoff is the map index we looked 750 * up above in uio_find_mem_index(), rather than an 751 * actual page offset into the mmap. 752 * 753 * So we just do the physical mmap without a page 754 * offset. 755 */ 756 return remap_pfn_range(vma, 757 vma->vm_start, 758 mem->addr >> PAGE_SHIFT, 759 vma->vm_end - vma->vm_start, 760 vma->vm_page_prot); 761 } 762 763 static int uio_mmap_dma_coherent(struct vm_area_struct *vma) 764 { 765 struct uio_device *idev = vma->vm_private_data; 766 struct uio_mem *mem; 767 void *addr; 768 int ret = 0; 769 int mi; 770 771 mi = uio_find_mem_index(vma); 772 if (mi < 0) 773 return -EINVAL; 774 775 mem = idev->info->mem + mi; 776 777 if (mem->addr & ~PAGE_MASK) 778 return -ENODEV; 779 if (mem->dma_addr & ~PAGE_MASK) 780 return -ENODEV; 781 if (!mem->dma_device) 782 return -ENODEV; 783 if (vma->vm_end - vma->vm_start > mem->size) 784 return -EINVAL; 785 786 dev_warn(mem->dma_device, 787 "use of UIO_MEM_DMA_COHERENT is highly discouraged"); 788 789 /* 790 * UIO uses offset to index into the maps for a device. 791 * We need to clear vm_pgoff for dma_mmap_coherent. 792 */ 793 vma->vm_pgoff = 0; 794 795 addr = (void *)(uintptr_t)mem->addr; 796 ret = dma_mmap_coherent(mem->dma_device, 797 vma, 798 addr, 799 mem->dma_addr, 800 vma->vm_end - vma->vm_start); 801 vma->vm_pgoff = mi; 802 803 return ret; 804 } 805 806 static int uio_mmap(struct file *filep, struct vm_area_struct *vma) 807 { 808 struct uio_listener *listener = filep->private_data; 809 struct uio_device *idev = listener->dev; 810 int mi; 811 unsigned long requested_pages, actual_pages; 812 int ret = 0; 813 814 if (vma->vm_end < vma->vm_start) 815 return -EINVAL; 816 817 vma->vm_private_data = idev; 818 819 mutex_lock(&idev->info_lock); 820 if (!idev->info) { 821 ret = -EINVAL; 822 goto out; 823 } 824 825 mi = uio_find_mem_index(vma); 826 if (mi < 0) { 827 ret = -EINVAL; 828 goto out; 829 } 830 831 requested_pages = vma_pages(vma); 832 actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK) 833 + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT; 834 if (requested_pages > actual_pages) { 835 ret = -EINVAL; 836 goto out; 837 } 838 839 if (idev->info->mmap) { 840 ret = idev->info->mmap(idev->info, vma); 841 goto out; 842 } 843 844 switch (idev->info->mem[mi].memtype) { 845 case UIO_MEM_IOVA: 846 case UIO_MEM_PHYS: 847 ret = uio_mmap_physical(vma); 848 break; 849 case UIO_MEM_LOGICAL: 850 case UIO_MEM_VIRTUAL: 851 ret = uio_mmap_logical(vma); 852 break; 853 case UIO_MEM_DMA_COHERENT: 854 ret = uio_mmap_dma_coherent(vma); 855 break; 856 default: 857 ret = -EINVAL; 858 } 859 860 out: 861 mutex_unlock(&idev->info_lock); 862 return ret; 863 } 864 865 static const struct file_operations uio_fops = { 866 .owner = THIS_MODULE, 867 .open = uio_open, 868 .release = uio_release, 869 .read = uio_read, 870 .write = uio_write, 871 .mmap = uio_mmap, 872 .poll = uio_poll, 873 .fasync = uio_fasync, 874 .llseek = noop_llseek, 875 }; 876 877 static int uio_major_init(void) 878 { 879 static const char name[] = "uio"; 880 struct cdev *cdev = NULL; 881 dev_t uio_dev = 0; 882 int result; 883 884 result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name); 885 if (result) 886 goto out; 887 888 result = -ENOMEM; 889 cdev = cdev_alloc(); 890 if (!cdev) 891 goto out_unregister; 892 893 cdev->owner = THIS_MODULE; 894 cdev->ops = &uio_fops; 895 kobject_set_name(&cdev->kobj, "%s", name); 896 897 result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES); 898 if (result) 899 goto out_put; 900 901 uio_major = MAJOR(uio_dev); 902 uio_cdev = cdev; 903 return 0; 904 out_put: 905 kobject_put(&cdev->kobj); 906 out_unregister: 907 unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES); 908 out: 909 return result; 910 } 911 912 static void uio_major_cleanup(void) 913 { 914 unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES); 915 cdev_del(uio_cdev); 916 } 917 918 static int init_uio_class(void) 919 { 920 int ret; 921 922 /* This is the first time in here, set everything up properly */ 923 ret = uio_major_init(); 924 if (ret) 925 goto exit; 926 927 ret = class_register(&uio_class); 928 if (ret) { 929 printk(KERN_ERR "class_register failed for uio\n"); 930 goto err_class_register; 931 } 932 933 uio_class_registered = true; 934 935 return 0; 936 937 err_class_register: 938 uio_major_cleanup(); 939 exit: 940 return ret; 941 } 942 943 static void release_uio_class(void) 944 { 945 uio_class_registered = false; 946 class_unregister(&uio_class); 947 uio_major_cleanup(); 948 } 949 950 static void uio_device_release(struct device *dev) 951 { 952 struct uio_device *idev = dev_get_drvdata(dev); 953 954 kfree(idev); 955 } 956 957 /** 958 * __uio_register_device - register a new userspace IO device 959 * @owner: module that creates the new device 960 * @parent: parent device 961 * @info: UIO device capabilities 962 * 963 * returns zero on success or a negative error code. 964 */ 965 int __uio_register_device(struct module *owner, 966 struct device *parent, 967 struct uio_info *info) 968 { 969 struct uio_device *idev; 970 int ret = 0; 971 972 if (!uio_class_registered) 973 return -EPROBE_DEFER; 974 975 if (!parent || !info || !info->name || !info->version) 976 return -EINVAL; 977 978 info->uio_dev = NULL; 979 980 idev = kzalloc(sizeof(*idev), GFP_KERNEL); 981 if (!idev) { 982 return -ENOMEM; 983 } 984 985 idev->owner = owner; 986 idev->info = info; 987 mutex_init(&idev->info_lock); 988 init_waitqueue_head(&idev->wait); 989 atomic_set(&idev->event, 0); 990 991 ret = uio_get_minor(idev); 992 if (ret) { 993 kfree(idev); 994 return ret; 995 } 996 997 device_initialize(&idev->dev); 998 idev->dev.devt = MKDEV(uio_major, idev->minor); 999 idev->dev.class = &uio_class; 1000 idev->dev.parent = parent; 1001 idev->dev.release = uio_device_release; 1002 dev_set_drvdata(&idev->dev, idev); 1003 1004 ret = dev_set_name(&idev->dev, "uio%d", idev->minor); 1005 if (ret) 1006 goto err_device_create; 1007 1008 ret = device_add(&idev->dev); 1009 if (ret) 1010 goto err_device_create; 1011 1012 ret = uio_dev_add_attributes(idev); 1013 if (ret) 1014 goto err_uio_dev_add_attributes; 1015 1016 info->uio_dev = idev; 1017 1018 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) { 1019 /* 1020 * Note that we deliberately don't use devm_request_irq 1021 * here. The parent module can unregister the UIO device 1022 * and call pci_disable_msi, which requires that this 1023 * irq has been freed. However, the device may have open 1024 * FDs at the time of unregister and therefore may not be 1025 * freed until they are released. 1026 */ 1027 ret = request_irq(info->irq, uio_interrupt, 1028 info->irq_flags, info->name, idev); 1029 if (ret) { 1030 info->uio_dev = NULL; 1031 goto err_request_irq; 1032 } 1033 } 1034 1035 return 0; 1036 1037 err_request_irq: 1038 uio_dev_del_attributes(idev); 1039 err_uio_dev_add_attributes: 1040 device_del(&idev->dev); 1041 err_device_create: 1042 uio_free_minor(idev->minor); 1043 put_device(&idev->dev); 1044 return ret; 1045 } 1046 EXPORT_SYMBOL_GPL(__uio_register_device); 1047 1048 static void devm_uio_unregister_device(struct device *dev, void *res) 1049 { 1050 uio_unregister_device(*(struct uio_info **)res); 1051 } 1052 1053 /** 1054 * __devm_uio_register_device - Resource managed uio_register_device() 1055 * @owner: module that creates the new device 1056 * @parent: parent device 1057 * @info: UIO device capabilities 1058 * 1059 * returns zero on success or a negative error code. 1060 */ 1061 int __devm_uio_register_device(struct module *owner, 1062 struct device *parent, 1063 struct uio_info *info) 1064 { 1065 struct uio_info **ptr; 1066 int ret; 1067 1068 ptr = devres_alloc(devm_uio_unregister_device, sizeof(*ptr), 1069 GFP_KERNEL); 1070 if (!ptr) 1071 return -ENOMEM; 1072 1073 *ptr = info; 1074 ret = __uio_register_device(owner, parent, info); 1075 if (ret) { 1076 devres_free(ptr); 1077 return ret; 1078 } 1079 1080 devres_add(parent, ptr); 1081 1082 return 0; 1083 } 1084 EXPORT_SYMBOL_GPL(__devm_uio_register_device); 1085 1086 /** 1087 * uio_unregister_device - unregister a industrial IO device 1088 * @info: UIO device capabilities 1089 * 1090 */ 1091 void uio_unregister_device(struct uio_info *info) 1092 { 1093 struct uio_device *idev; 1094 unsigned long minor; 1095 1096 if (!info || !info->uio_dev) 1097 return; 1098 1099 idev = info->uio_dev; 1100 minor = idev->minor; 1101 1102 mutex_lock(&idev->info_lock); 1103 uio_dev_del_attributes(idev); 1104 1105 if (info->irq && info->irq != UIO_IRQ_CUSTOM) 1106 free_irq(info->irq, idev); 1107 1108 idev->info = NULL; 1109 mutex_unlock(&idev->info_lock); 1110 1111 wake_up_interruptible(&idev->wait); 1112 kill_fasync(&idev->async_queue, SIGIO, POLL_HUP); 1113 1114 uio_free_minor(minor); 1115 device_unregister(&idev->dev); 1116 1117 return; 1118 } 1119 EXPORT_SYMBOL_GPL(uio_unregister_device); 1120 1121 static int __init uio_init(void) 1122 { 1123 return init_uio_class(); 1124 } 1125 1126 static void __exit uio_exit(void) 1127 { 1128 release_uio_class(); 1129 idr_destroy(&uio_idr); 1130 } 1131 1132 module_init(uio_init) 1133 module_exit(uio_exit) 1134 MODULE_LICENSE("GPL v2"); 1135