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 const 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 const 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_handler - 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_handler(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 ret = IRQ_WAKE_THREAD; 453 454 return ret; 455 } 456 457 /** 458 * uio_interrupt_thread - irq thread handler 459 * @irq: IRQ number 460 * @dev_id: Pointer to the devices uio_device structure 461 */ 462 static irqreturn_t uio_interrupt_thread(int irq, void *dev_id) 463 { 464 struct uio_device *idev = (struct uio_device *)dev_id; 465 466 uio_event_notify(idev->info); 467 468 return IRQ_HANDLED; 469 } 470 471 struct uio_listener { 472 struct uio_device *dev; 473 s32 event_count; 474 }; 475 476 static int uio_open(struct inode *inode, struct file *filep) 477 { 478 struct uio_device *idev; 479 struct uio_listener *listener; 480 int ret = 0; 481 482 mutex_lock(&minor_lock); 483 idev = idr_find(&uio_idr, iminor(inode)); 484 if (!idev) { 485 ret = -ENODEV; 486 mutex_unlock(&minor_lock); 487 goto out; 488 } 489 get_device(&idev->dev); 490 mutex_unlock(&minor_lock); 491 492 if (!try_module_get(idev->owner)) { 493 ret = -ENODEV; 494 goto err_module_get; 495 } 496 497 listener = kmalloc(sizeof(*listener), GFP_KERNEL); 498 if (!listener) { 499 ret = -ENOMEM; 500 goto err_alloc_listener; 501 } 502 503 listener->dev = idev; 504 listener->event_count = atomic_read(&idev->event); 505 filep->private_data = listener; 506 507 mutex_lock(&idev->info_lock); 508 if (!idev->info) { 509 mutex_unlock(&idev->info_lock); 510 ret = -EINVAL; 511 goto err_infoopen; 512 } 513 514 if (idev->info->open) 515 ret = idev->info->open(idev->info, inode); 516 mutex_unlock(&idev->info_lock); 517 if (ret) 518 goto err_infoopen; 519 520 return 0; 521 522 err_infoopen: 523 kfree(listener); 524 525 err_alloc_listener: 526 module_put(idev->owner); 527 528 err_module_get: 529 put_device(&idev->dev); 530 531 out: 532 return ret; 533 } 534 535 static int uio_fasync(int fd, struct file *filep, int on) 536 { 537 struct uio_listener *listener = filep->private_data; 538 struct uio_device *idev = listener->dev; 539 540 return fasync_helper(fd, filep, on, &idev->async_queue); 541 } 542 543 static int uio_release(struct inode *inode, struct file *filep) 544 { 545 int ret = 0; 546 struct uio_listener *listener = filep->private_data; 547 struct uio_device *idev = listener->dev; 548 549 mutex_lock(&idev->info_lock); 550 if (idev->info && idev->info->release) 551 ret = idev->info->release(idev->info, inode); 552 mutex_unlock(&idev->info_lock); 553 554 module_put(idev->owner); 555 kfree(listener); 556 put_device(&idev->dev); 557 return ret; 558 } 559 560 static __poll_t uio_poll(struct file *filep, poll_table *wait) 561 { 562 struct uio_listener *listener = filep->private_data; 563 struct uio_device *idev = listener->dev; 564 __poll_t ret = 0; 565 566 mutex_lock(&idev->info_lock); 567 if (!idev->info || !idev->info->irq) 568 ret = -EIO; 569 mutex_unlock(&idev->info_lock); 570 571 if (ret) 572 return ret; 573 574 poll_wait(filep, &idev->wait, wait); 575 if (listener->event_count != atomic_read(&idev->event)) 576 return EPOLLIN | EPOLLRDNORM; 577 return 0; 578 } 579 580 static ssize_t uio_read(struct file *filep, char __user *buf, 581 size_t count, loff_t *ppos) 582 { 583 struct uio_listener *listener = filep->private_data; 584 struct uio_device *idev = listener->dev; 585 DECLARE_WAITQUEUE(wait, current); 586 ssize_t retval = 0; 587 s32 event_count; 588 589 if (count != sizeof(s32)) 590 return -EINVAL; 591 592 add_wait_queue(&idev->wait, &wait); 593 594 do { 595 mutex_lock(&idev->info_lock); 596 if (!idev->info || !idev->info->irq) { 597 retval = -EIO; 598 mutex_unlock(&idev->info_lock); 599 break; 600 } 601 mutex_unlock(&idev->info_lock); 602 603 set_current_state(TASK_INTERRUPTIBLE); 604 605 event_count = atomic_read(&idev->event); 606 if (event_count != listener->event_count) { 607 __set_current_state(TASK_RUNNING); 608 if (copy_to_user(buf, &event_count, count)) 609 retval = -EFAULT; 610 else { 611 listener->event_count = event_count; 612 retval = count; 613 } 614 break; 615 } 616 617 if (filep->f_flags & O_NONBLOCK) { 618 retval = -EAGAIN; 619 break; 620 } 621 622 if (signal_pending(current)) { 623 retval = -ERESTARTSYS; 624 break; 625 } 626 schedule(); 627 } while (1); 628 629 __set_current_state(TASK_RUNNING); 630 remove_wait_queue(&idev->wait, &wait); 631 632 return retval; 633 } 634 635 static ssize_t uio_write(struct file *filep, const char __user *buf, 636 size_t count, loff_t *ppos) 637 { 638 struct uio_listener *listener = filep->private_data; 639 struct uio_device *idev = listener->dev; 640 ssize_t retval; 641 s32 irq_on; 642 643 if (count != sizeof(s32)) 644 return -EINVAL; 645 646 if (copy_from_user(&irq_on, buf, count)) 647 return -EFAULT; 648 649 mutex_lock(&idev->info_lock); 650 if (!idev->info) { 651 retval = -EINVAL; 652 goto out; 653 } 654 655 if (!idev->info->irq) { 656 retval = -EIO; 657 goto out; 658 } 659 660 if (!idev->info->irqcontrol) { 661 retval = -ENOSYS; 662 goto out; 663 } 664 665 retval = idev->info->irqcontrol(idev->info, irq_on); 666 667 out: 668 mutex_unlock(&idev->info_lock); 669 return retval ? retval : sizeof(s32); 670 } 671 672 static int uio_find_mem_index(struct vm_area_struct *vma) 673 { 674 struct uio_device *idev = vma->vm_private_data; 675 676 if (vma->vm_pgoff < MAX_UIO_MAPS) { 677 if (idev->info->mem[vma->vm_pgoff].size == 0) 678 return -1; 679 return (int)vma->vm_pgoff; 680 } 681 return -1; 682 } 683 684 static vm_fault_t uio_vma_fault(struct vm_fault *vmf) 685 { 686 struct uio_device *idev = vmf->vma->vm_private_data; 687 struct page *page; 688 unsigned long offset; 689 void *addr; 690 vm_fault_t ret = 0; 691 int mi; 692 693 mutex_lock(&idev->info_lock); 694 if (!idev->info) { 695 ret = VM_FAULT_SIGBUS; 696 goto out; 697 } 698 699 mi = uio_find_mem_index(vmf->vma); 700 if (mi < 0) { 701 ret = VM_FAULT_SIGBUS; 702 goto out; 703 } 704 705 /* 706 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE 707 * to use mem[N]. 708 */ 709 offset = (vmf->pgoff - mi) << PAGE_SHIFT; 710 711 addr = (void *)(unsigned long)idev->info->mem[mi].addr + offset; 712 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL) 713 page = virt_to_page(addr); 714 else 715 page = vmalloc_to_page(addr); 716 get_page(page); 717 vmf->page = page; 718 719 out: 720 mutex_unlock(&idev->info_lock); 721 722 return ret; 723 } 724 725 static const struct vm_operations_struct uio_logical_vm_ops = { 726 .fault = uio_vma_fault, 727 }; 728 729 static int uio_mmap_logical(struct vm_area_struct *vma) 730 { 731 vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP); 732 vma->vm_ops = &uio_logical_vm_ops; 733 return 0; 734 } 735 736 static const struct vm_operations_struct uio_physical_vm_ops = { 737 #ifdef CONFIG_HAVE_IOREMAP_PROT 738 .access = generic_access_phys, 739 #endif 740 }; 741 742 static int uio_mmap_physical(struct vm_area_struct *vma) 743 { 744 struct uio_device *idev = vma->vm_private_data; 745 int mi = uio_find_mem_index(vma); 746 struct uio_mem *mem; 747 748 if (mi < 0) 749 return -EINVAL; 750 mem = idev->info->mem + mi; 751 752 if (mem->addr & ~PAGE_MASK) 753 return -ENODEV; 754 if (vma->vm_end - vma->vm_start > mem->size) 755 return -EINVAL; 756 757 vma->vm_ops = &uio_physical_vm_ops; 758 if (idev->info->mem[mi].memtype == UIO_MEM_PHYS) 759 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 760 761 /* 762 * We cannot use the vm_iomap_memory() helper here, 763 * because vma->vm_pgoff is the map index we looked 764 * up above in uio_find_mem_index(), rather than an 765 * actual page offset into the mmap. 766 * 767 * So we just do the physical mmap without a page 768 * offset. 769 */ 770 return remap_pfn_range(vma, 771 vma->vm_start, 772 mem->addr >> PAGE_SHIFT, 773 vma->vm_end - vma->vm_start, 774 vma->vm_page_prot); 775 } 776 777 static int uio_mmap_dma_coherent(struct vm_area_struct *vma) 778 { 779 struct uio_device *idev = vma->vm_private_data; 780 struct uio_mem *mem; 781 void *addr; 782 int ret = 0; 783 int mi; 784 785 mi = uio_find_mem_index(vma); 786 if (mi < 0) 787 return -EINVAL; 788 789 mem = idev->info->mem + mi; 790 791 if (mem->addr & ~PAGE_MASK) 792 return -ENODEV; 793 if (mem->dma_addr & ~PAGE_MASK) 794 return -ENODEV; 795 if (!mem->dma_device) 796 return -ENODEV; 797 if (vma->vm_end - vma->vm_start > mem->size) 798 return -EINVAL; 799 800 dev_warn(mem->dma_device, 801 "use of UIO_MEM_DMA_COHERENT is highly discouraged"); 802 803 /* 804 * UIO uses offset to index into the maps for a device. 805 * We need to clear vm_pgoff for dma_mmap_coherent. 806 */ 807 vma->vm_pgoff = 0; 808 809 addr = (void *)(uintptr_t)mem->addr; 810 ret = dma_mmap_coherent(mem->dma_device, 811 vma, 812 addr, 813 mem->dma_addr, 814 vma->vm_end - vma->vm_start); 815 vma->vm_pgoff = mi; 816 817 return ret; 818 } 819 820 static int uio_mmap(struct file *filep, struct vm_area_struct *vma) 821 { 822 struct uio_listener *listener = filep->private_data; 823 struct uio_device *idev = listener->dev; 824 int mi; 825 unsigned long requested_pages, actual_pages; 826 int ret = 0; 827 828 if (vma->vm_end < vma->vm_start) 829 return -EINVAL; 830 831 vma->vm_private_data = idev; 832 833 mutex_lock(&idev->info_lock); 834 if (!idev->info) { 835 ret = -EINVAL; 836 goto out; 837 } 838 839 mi = uio_find_mem_index(vma); 840 if (mi < 0) { 841 ret = -EINVAL; 842 goto out; 843 } 844 845 requested_pages = vma_pages(vma); 846 actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK) 847 + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT; 848 if (requested_pages > actual_pages) { 849 ret = -EINVAL; 850 goto out; 851 } 852 853 if (idev->info->mmap) { 854 ret = idev->info->mmap(idev->info, vma); 855 goto out; 856 } 857 858 switch (idev->info->mem[mi].memtype) { 859 case UIO_MEM_IOVA: 860 case UIO_MEM_PHYS: 861 ret = uio_mmap_physical(vma); 862 break; 863 case UIO_MEM_LOGICAL: 864 case UIO_MEM_VIRTUAL: 865 ret = uio_mmap_logical(vma); 866 break; 867 case UIO_MEM_DMA_COHERENT: 868 ret = uio_mmap_dma_coherent(vma); 869 break; 870 default: 871 ret = -EINVAL; 872 } 873 874 out: 875 mutex_unlock(&idev->info_lock); 876 return ret; 877 } 878 879 static const struct file_operations uio_fops = { 880 .owner = THIS_MODULE, 881 .open = uio_open, 882 .release = uio_release, 883 .read = uio_read, 884 .write = uio_write, 885 .mmap = uio_mmap, 886 .poll = uio_poll, 887 .fasync = uio_fasync, 888 .llseek = noop_llseek, 889 }; 890 891 static int uio_major_init(void) 892 { 893 static const char name[] = "uio"; 894 struct cdev *cdev = NULL; 895 dev_t uio_dev = 0; 896 int result; 897 898 result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name); 899 if (result) 900 goto out; 901 902 result = -ENOMEM; 903 cdev = cdev_alloc(); 904 if (!cdev) 905 goto out_unregister; 906 907 cdev->owner = THIS_MODULE; 908 cdev->ops = &uio_fops; 909 kobject_set_name(&cdev->kobj, "%s", name); 910 911 result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES); 912 if (result) 913 goto out_put; 914 915 uio_major = MAJOR(uio_dev); 916 uio_cdev = cdev; 917 return 0; 918 out_put: 919 kobject_put(&cdev->kobj); 920 out_unregister: 921 unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES); 922 out: 923 return result; 924 } 925 926 static void uio_major_cleanup(void) 927 { 928 unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES); 929 cdev_del(uio_cdev); 930 } 931 932 static int init_uio_class(void) 933 { 934 int ret; 935 936 /* This is the first time in here, set everything up properly */ 937 ret = uio_major_init(); 938 if (ret) 939 goto exit; 940 941 ret = class_register(&uio_class); 942 if (ret) { 943 printk(KERN_ERR "class_register failed for uio\n"); 944 goto err_class_register; 945 } 946 947 uio_class_registered = true; 948 949 return 0; 950 951 err_class_register: 952 uio_major_cleanup(); 953 exit: 954 return ret; 955 } 956 957 static void release_uio_class(void) 958 { 959 uio_class_registered = false; 960 class_unregister(&uio_class); 961 uio_major_cleanup(); 962 } 963 964 static void uio_device_release(struct device *dev) 965 { 966 struct uio_device *idev = dev_get_drvdata(dev); 967 968 kfree(idev); 969 } 970 971 /** 972 * __uio_register_device - register a new userspace IO device 973 * @owner: module that creates the new device 974 * @parent: parent device 975 * @info: UIO device capabilities 976 * 977 * returns zero on success or a negative error code. 978 */ 979 int __uio_register_device(struct module *owner, 980 struct device *parent, 981 struct uio_info *info) 982 { 983 struct uio_device *idev; 984 int ret = 0; 985 986 if (!uio_class_registered) 987 return -EPROBE_DEFER; 988 989 if (!parent || !info || !info->name || !info->version) 990 return -EINVAL; 991 992 info->uio_dev = NULL; 993 994 idev = kzalloc(sizeof(*idev), GFP_KERNEL); 995 if (!idev) { 996 return -ENOMEM; 997 } 998 999 idev->owner = owner; 1000 idev->info = info; 1001 mutex_init(&idev->info_lock); 1002 init_waitqueue_head(&idev->wait); 1003 atomic_set(&idev->event, 0); 1004 1005 ret = uio_get_minor(idev); 1006 if (ret) { 1007 kfree(idev); 1008 return ret; 1009 } 1010 1011 device_initialize(&idev->dev); 1012 idev->dev.devt = MKDEV(uio_major, idev->minor); 1013 idev->dev.class = &uio_class; 1014 idev->dev.parent = parent; 1015 idev->dev.release = uio_device_release; 1016 dev_set_drvdata(&idev->dev, idev); 1017 1018 ret = dev_set_name(&idev->dev, "uio%d", idev->minor); 1019 if (ret) 1020 goto err_device_create; 1021 1022 ret = device_add(&idev->dev); 1023 if (ret) 1024 goto err_device_create; 1025 1026 ret = uio_dev_add_attributes(idev); 1027 if (ret) 1028 goto err_uio_dev_add_attributes; 1029 1030 info->uio_dev = idev; 1031 1032 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) { 1033 /* 1034 * Note that we deliberately don't use devm_request_irq 1035 * here. The parent module can unregister the UIO device 1036 * and call pci_disable_msi, which requires that this 1037 * irq has been freed. However, the device may have open 1038 * FDs at the time of unregister and therefore may not be 1039 * freed until they are released. 1040 */ 1041 ret = request_threaded_irq(info->irq, uio_interrupt_handler, uio_interrupt_thread, 1042 info->irq_flags, info->name, idev); 1043 if (ret) { 1044 info->uio_dev = NULL; 1045 goto err_request_irq; 1046 } 1047 } 1048 1049 return 0; 1050 1051 err_request_irq: 1052 uio_dev_del_attributes(idev); 1053 err_uio_dev_add_attributes: 1054 device_del(&idev->dev); 1055 err_device_create: 1056 uio_free_minor(idev->minor); 1057 put_device(&idev->dev); 1058 return ret; 1059 } 1060 EXPORT_SYMBOL_GPL(__uio_register_device); 1061 1062 static void devm_uio_unregister_device(struct device *dev, void *res) 1063 { 1064 uio_unregister_device(*(struct uio_info **)res); 1065 } 1066 1067 /** 1068 * __devm_uio_register_device - Resource managed uio_register_device() 1069 * @owner: module that creates the new device 1070 * @parent: parent device 1071 * @info: UIO device capabilities 1072 * 1073 * returns zero on success or a negative error code. 1074 */ 1075 int __devm_uio_register_device(struct module *owner, 1076 struct device *parent, 1077 struct uio_info *info) 1078 { 1079 struct uio_info **ptr; 1080 int ret; 1081 1082 ptr = devres_alloc(devm_uio_unregister_device, sizeof(*ptr), 1083 GFP_KERNEL); 1084 if (!ptr) 1085 return -ENOMEM; 1086 1087 *ptr = info; 1088 ret = __uio_register_device(owner, parent, info); 1089 if (ret) { 1090 devres_free(ptr); 1091 return ret; 1092 } 1093 1094 devres_add(parent, ptr); 1095 1096 return 0; 1097 } 1098 EXPORT_SYMBOL_GPL(__devm_uio_register_device); 1099 1100 /** 1101 * uio_unregister_device - unregister a industrial IO device 1102 * @info: UIO device capabilities 1103 * 1104 */ 1105 void uio_unregister_device(struct uio_info *info) 1106 { 1107 struct uio_device *idev; 1108 unsigned long minor; 1109 1110 if (!info || !info->uio_dev) 1111 return; 1112 1113 idev = info->uio_dev; 1114 minor = idev->minor; 1115 1116 mutex_lock(&idev->info_lock); 1117 uio_dev_del_attributes(idev); 1118 1119 if (info->irq && info->irq != UIO_IRQ_CUSTOM) 1120 free_irq(info->irq, idev); 1121 1122 idev->info = NULL; 1123 mutex_unlock(&idev->info_lock); 1124 1125 wake_up_interruptible(&idev->wait); 1126 kill_fasync(&idev->async_queue, SIGIO, POLL_HUP); 1127 1128 uio_free_minor(minor); 1129 device_unregister(&idev->dev); 1130 1131 return; 1132 } 1133 EXPORT_SYMBOL_GPL(uio_unregister_device); 1134 1135 static int __init uio_init(void) 1136 { 1137 return init_uio_class(); 1138 } 1139 1140 static void __exit uio_exit(void) 1141 { 1142 release_uio_class(); 1143 idr_destroy(&uio_idr); 1144 } 1145 1146 module_init(uio_init) 1147 module_exit(uio_exit) 1148 MODULE_DESCRIPTION("Userspace IO core module"); 1149 MODULE_LICENSE("GPL v2"); 1150