1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * comedi/comedi_fops.c 4 * comedi kernel module 5 * 6 * COMEDI - Linux Control and Measurement Device Interface 7 * Copyright (C) 1997-2007 David A. Schleef <ds@schleef.org> 8 * compat ioctls: 9 * Author: Ian Abbott, MEV Ltd. <abbotti@mev.co.uk> 10 * Copyright (C) 2007 MEV Ltd. <http://www.mev.co.uk/> 11 */ 12 13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 14 15 #include <linux/module.h> 16 #include <linux/errno.h> 17 #include <linux/kernel.h> 18 #include <linux/sched/signal.h> 19 #include <linux/fcntl.h> 20 #include <linux/delay.h> 21 #include <linux/mm.h> 22 #include <linux/slab.h> 23 #include <linux/poll.h> 24 #include <linux/device.h> 25 #include <linux/fs.h> 26 #include "comedidev.h" 27 #include <linux/cdev.h> 28 29 #include <linux/io.h> 30 #include <linux/uaccess.h> 31 #include <linux/compat.h> 32 33 #include "comedi_internal.h" 34 35 /* 36 * comedi_subdevice "runflags" 37 * COMEDI_SRF_RT: DEPRECATED: command is running real-time 38 * COMEDI_SRF_ERROR: indicates an COMEDI_CB_ERROR event has occurred 39 * since the last command was started 40 * COMEDI_SRF_RUNNING: command is running 41 * COMEDI_SRF_FREE_SPRIV: free s->private on detach 42 * 43 * COMEDI_SRF_BUSY_MASK: runflags that indicate the subdevice is "busy" 44 */ 45 #define COMEDI_SRF_RT BIT(1) 46 #define COMEDI_SRF_ERROR BIT(2) 47 #define COMEDI_SRF_RUNNING BIT(27) 48 #define COMEDI_SRF_FREE_SPRIV BIT(31) 49 50 #define COMEDI_SRF_BUSY_MASK (COMEDI_SRF_ERROR | COMEDI_SRF_RUNNING) 51 52 /** 53 * struct comedi_file - Per-file private data for COMEDI device 54 * @dev: COMEDI device. 55 * @read_subdev: Current "read" subdevice. 56 * @write_subdev: Current "write" subdevice. 57 * @last_detach_count: Last known detach count. 58 * @last_attached: Last known attached/detached state. 59 */ 60 struct comedi_file { 61 struct comedi_device *dev; 62 struct comedi_subdevice *read_subdev; 63 struct comedi_subdevice *write_subdev; 64 unsigned int last_detach_count; 65 unsigned int last_attached:1; 66 }; 67 68 #define COMEDI_NUM_MINORS 0x100 69 #define COMEDI_NUM_SUBDEVICE_MINORS \ 70 (COMEDI_NUM_MINORS - COMEDI_NUM_BOARD_MINORS) 71 72 static unsigned short comedi_num_legacy_minors; 73 module_param(comedi_num_legacy_minors, ushort, 0444); 74 MODULE_PARM_DESC(comedi_num_legacy_minors, 75 "number of comedi minor devices to reserve for non-auto-configured devices (default 0)" 76 ); 77 78 unsigned int comedi_default_buf_size_kb = CONFIG_COMEDI_DEFAULT_BUF_SIZE_KB; 79 module_param(comedi_default_buf_size_kb, uint, 0644); 80 MODULE_PARM_DESC(comedi_default_buf_size_kb, 81 "default asynchronous buffer size in KiB (default " 82 __MODULE_STRING(CONFIG_COMEDI_DEFAULT_BUF_SIZE_KB) ")"); 83 84 unsigned int comedi_default_buf_maxsize_kb = 85 CONFIG_COMEDI_DEFAULT_BUF_MAXSIZE_KB; 86 module_param(comedi_default_buf_maxsize_kb, uint, 0644); 87 MODULE_PARM_DESC(comedi_default_buf_maxsize_kb, 88 "default maximum size of asynchronous buffer in KiB (default " 89 __MODULE_STRING(CONFIG_COMEDI_DEFAULT_BUF_MAXSIZE_KB) ")"); 90 91 static DEFINE_MUTEX(comedi_board_minor_table_lock); 92 static struct comedi_device 93 *comedi_board_minor_table[COMEDI_NUM_BOARD_MINORS]; 94 95 static DEFINE_MUTEX(comedi_subdevice_minor_table_lock); 96 /* Note: indexed by minor - COMEDI_NUM_BOARD_MINORS. */ 97 static struct comedi_subdevice 98 *comedi_subdevice_minor_table[COMEDI_NUM_SUBDEVICE_MINORS]; 99 100 static struct class *comedi_class; 101 static struct cdev comedi_cdev; 102 103 static void comedi_device_init(struct comedi_device *dev) 104 { 105 kref_init(&dev->refcount); 106 spin_lock_init(&dev->spinlock); 107 mutex_init(&dev->mutex); 108 init_rwsem(&dev->attach_lock); 109 dev->minor = -1; 110 } 111 112 static void comedi_dev_kref_release(struct kref *kref) 113 { 114 struct comedi_device *dev = 115 container_of(kref, struct comedi_device, refcount); 116 117 mutex_destroy(&dev->mutex); 118 put_device(dev->class_dev); 119 kfree(dev); 120 } 121 122 /** 123 * comedi_dev_put() - Release a use of a COMEDI device 124 * @dev: COMEDI device. 125 * 126 * Must be called when a user of a COMEDI device is finished with it. 127 * When the last user of the COMEDI device calls this function, the 128 * COMEDI device is destroyed. 129 * 130 * Return: 1 if the COMEDI device is destroyed by this call or @dev is 131 * NULL, otherwise return 0. Callers must not assume the COMEDI 132 * device is still valid if this function returns 0. 133 */ 134 int comedi_dev_put(struct comedi_device *dev) 135 { 136 if (dev) 137 return kref_put(&dev->refcount, comedi_dev_kref_release); 138 return 1; 139 } 140 EXPORT_SYMBOL_GPL(comedi_dev_put); 141 142 static struct comedi_device *comedi_dev_get(struct comedi_device *dev) 143 { 144 if (dev) 145 kref_get(&dev->refcount); 146 return dev; 147 } 148 149 static void comedi_device_cleanup(struct comedi_device *dev) 150 { 151 struct module *driver_module = NULL; 152 153 if (!dev) 154 return; 155 mutex_lock(&dev->mutex); 156 if (dev->attached) 157 driver_module = dev->driver->module; 158 comedi_device_detach(dev); 159 if (driver_module && dev->use_count) 160 module_put(driver_module); 161 mutex_unlock(&dev->mutex); 162 } 163 164 static bool comedi_clear_board_dev(struct comedi_device *dev) 165 { 166 unsigned int i = dev->minor; 167 bool cleared = false; 168 169 lockdep_assert_held(&dev->mutex); 170 mutex_lock(&comedi_board_minor_table_lock); 171 if (dev == comedi_board_minor_table[i]) { 172 comedi_board_minor_table[i] = NULL; 173 cleared = true; 174 } 175 mutex_unlock(&comedi_board_minor_table_lock); 176 return cleared; 177 } 178 179 static struct comedi_device *comedi_clear_board_minor(unsigned int minor) 180 { 181 struct comedi_device *dev; 182 183 mutex_lock(&comedi_board_minor_table_lock); 184 dev = comedi_board_minor_table[minor]; 185 comedi_board_minor_table[minor] = NULL; 186 mutex_unlock(&comedi_board_minor_table_lock); 187 return dev; 188 } 189 190 static void comedi_free_board_dev(struct comedi_device *dev) 191 { 192 if (dev) { 193 comedi_device_cleanup(dev); 194 if (dev->class_dev) { 195 device_destroy(comedi_class, 196 MKDEV(COMEDI_MAJOR, dev->minor)); 197 } 198 comedi_dev_put(dev); 199 } 200 } 201 202 static struct comedi_subdevice * 203 comedi_subdevice_from_minor(const struct comedi_device *dev, unsigned int minor) 204 { 205 struct comedi_subdevice *s; 206 unsigned int i = minor - COMEDI_NUM_BOARD_MINORS; 207 208 mutex_lock(&comedi_subdevice_minor_table_lock); 209 s = comedi_subdevice_minor_table[i]; 210 if (s && s->device != dev) 211 s = NULL; 212 mutex_unlock(&comedi_subdevice_minor_table_lock); 213 return s; 214 } 215 216 static struct comedi_device *comedi_dev_get_from_board_minor(unsigned int minor) 217 { 218 struct comedi_device *dev; 219 220 mutex_lock(&comedi_board_minor_table_lock); 221 dev = comedi_dev_get(comedi_board_minor_table[minor]); 222 mutex_unlock(&comedi_board_minor_table_lock); 223 return dev; 224 } 225 226 static struct comedi_device * 227 comedi_dev_get_from_subdevice_minor(unsigned int minor) 228 { 229 struct comedi_device *dev; 230 struct comedi_subdevice *s; 231 unsigned int i = minor - COMEDI_NUM_BOARD_MINORS; 232 233 mutex_lock(&comedi_subdevice_minor_table_lock); 234 s = comedi_subdevice_minor_table[i]; 235 dev = comedi_dev_get(s ? s->device : NULL); 236 mutex_unlock(&comedi_subdevice_minor_table_lock); 237 return dev; 238 } 239 240 /** 241 * comedi_dev_get_from_minor() - Get COMEDI device by minor device number 242 * @minor: Minor device number. 243 * 244 * Finds the COMEDI device associated with the minor device number, if any, 245 * and increments its reference count. The COMEDI device is prevented from 246 * being freed until a matching call is made to comedi_dev_put(). 247 * 248 * Return: A pointer to the COMEDI device if it exists, with its usage 249 * reference incremented. Return NULL if no COMEDI device exists with the 250 * specified minor device number. 251 */ 252 struct comedi_device *comedi_dev_get_from_minor(unsigned int minor) 253 { 254 if (minor < COMEDI_NUM_BOARD_MINORS) 255 return comedi_dev_get_from_board_minor(minor); 256 257 return comedi_dev_get_from_subdevice_minor(minor); 258 } 259 EXPORT_SYMBOL_GPL(comedi_dev_get_from_minor); 260 261 static struct comedi_subdevice * 262 comedi_read_subdevice(const struct comedi_device *dev, unsigned int minor) 263 { 264 struct comedi_subdevice *s; 265 266 lockdep_assert_held(&dev->mutex); 267 if (minor >= COMEDI_NUM_BOARD_MINORS) { 268 s = comedi_subdevice_from_minor(dev, minor); 269 if (!s || (s->subdev_flags & SDF_CMD_READ)) 270 return s; 271 } 272 return dev->read_subdev; 273 } 274 275 static struct comedi_subdevice * 276 comedi_write_subdevice(const struct comedi_device *dev, unsigned int minor) 277 { 278 struct comedi_subdevice *s; 279 280 lockdep_assert_held(&dev->mutex); 281 if (minor >= COMEDI_NUM_BOARD_MINORS) { 282 s = comedi_subdevice_from_minor(dev, minor); 283 if (!s || (s->subdev_flags & SDF_CMD_WRITE)) 284 return s; 285 } 286 return dev->write_subdev; 287 } 288 289 static void comedi_file_reset(struct file *file) 290 { 291 struct comedi_file *cfp = file->private_data; 292 struct comedi_device *dev = cfp->dev; 293 struct comedi_subdevice *s, *read_s, *write_s; 294 unsigned int minor = iminor(file_inode(file)); 295 296 read_s = dev->read_subdev; 297 write_s = dev->write_subdev; 298 if (minor >= COMEDI_NUM_BOARD_MINORS) { 299 s = comedi_subdevice_from_minor(dev, minor); 300 if (!s || s->subdev_flags & SDF_CMD_READ) 301 read_s = s; 302 if (!s || s->subdev_flags & SDF_CMD_WRITE) 303 write_s = s; 304 } 305 cfp->last_attached = dev->attached; 306 cfp->last_detach_count = dev->detach_count; 307 WRITE_ONCE(cfp->read_subdev, read_s); 308 WRITE_ONCE(cfp->write_subdev, write_s); 309 } 310 311 static void comedi_file_check(struct file *file) 312 { 313 struct comedi_file *cfp = file->private_data; 314 struct comedi_device *dev = cfp->dev; 315 316 if (cfp->last_attached != dev->attached || 317 cfp->last_detach_count != dev->detach_count) 318 comedi_file_reset(file); 319 } 320 321 static struct comedi_subdevice *comedi_file_read_subdevice(struct file *file) 322 { 323 struct comedi_file *cfp = file->private_data; 324 325 comedi_file_check(file); 326 return READ_ONCE(cfp->read_subdev); 327 } 328 329 static struct comedi_subdevice *comedi_file_write_subdevice(struct file *file) 330 { 331 struct comedi_file *cfp = file->private_data; 332 333 comedi_file_check(file); 334 return READ_ONCE(cfp->write_subdev); 335 } 336 337 static int resize_async_buffer(struct comedi_device *dev, 338 struct comedi_subdevice *s, 339 unsigned int new_size) 340 { 341 struct comedi_async *async = s->async; 342 int retval; 343 344 lockdep_assert_held(&dev->mutex); 345 346 if (new_size > async->max_bufsize) 347 return -EPERM; 348 349 if (s->busy) { 350 dev_dbg(dev->class_dev, 351 "subdevice is busy, cannot resize buffer\n"); 352 return -EBUSY; 353 } 354 if (comedi_buf_is_mmapped(s)) { 355 dev_dbg(dev->class_dev, 356 "subdevice is mmapped, cannot resize buffer\n"); 357 return -EBUSY; 358 } 359 360 /* make sure buffer is an integral number of pages (we round up) */ 361 new_size = (new_size + PAGE_SIZE - 1) & PAGE_MASK; 362 363 retval = comedi_buf_alloc(dev, s, new_size); 364 if (retval < 0) 365 return retval; 366 367 if (s->buf_change) { 368 retval = s->buf_change(dev, s); 369 if (retval < 0) 370 return retval; 371 } 372 373 dev_dbg(dev->class_dev, "subd %d buffer resized to %i bytes\n", 374 s->index, async->prealloc_bufsz); 375 return 0; 376 } 377 378 /* sysfs attribute files */ 379 380 static ssize_t max_read_buffer_kb_show(struct device *csdev, 381 struct device_attribute *attr, char *buf) 382 { 383 unsigned int minor = MINOR(csdev->devt); 384 struct comedi_device *dev; 385 struct comedi_subdevice *s; 386 unsigned int size = 0; 387 388 dev = comedi_dev_get_from_minor(minor); 389 if (!dev) 390 return -ENODEV; 391 392 mutex_lock(&dev->mutex); 393 s = comedi_read_subdevice(dev, minor); 394 if (s && (s->subdev_flags & SDF_CMD_READ) && s->async) 395 size = s->async->max_bufsize / 1024; 396 mutex_unlock(&dev->mutex); 397 398 comedi_dev_put(dev); 399 return snprintf(buf, PAGE_SIZE, "%u\n", size); 400 } 401 402 static ssize_t max_read_buffer_kb_store(struct device *csdev, 403 struct device_attribute *attr, 404 const char *buf, size_t count) 405 { 406 unsigned int minor = MINOR(csdev->devt); 407 struct comedi_device *dev; 408 struct comedi_subdevice *s; 409 unsigned int size; 410 int err; 411 412 err = kstrtouint(buf, 10, &size); 413 if (err) 414 return err; 415 if (size > (UINT_MAX / 1024)) 416 return -EINVAL; 417 size *= 1024; 418 419 dev = comedi_dev_get_from_minor(minor); 420 if (!dev) 421 return -ENODEV; 422 423 mutex_lock(&dev->mutex); 424 s = comedi_read_subdevice(dev, minor); 425 if (s && (s->subdev_flags & SDF_CMD_READ) && s->async) 426 s->async->max_bufsize = size; 427 else 428 err = -EINVAL; 429 mutex_unlock(&dev->mutex); 430 431 comedi_dev_put(dev); 432 return err ? err : count; 433 } 434 static DEVICE_ATTR_RW(max_read_buffer_kb); 435 436 static ssize_t read_buffer_kb_show(struct device *csdev, 437 struct device_attribute *attr, char *buf) 438 { 439 unsigned int minor = MINOR(csdev->devt); 440 struct comedi_device *dev; 441 struct comedi_subdevice *s; 442 unsigned int size = 0; 443 444 dev = comedi_dev_get_from_minor(minor); 445 if (!dev) 446 return -ENODEV; 447 448 mutex_lock(&dev->mutex); 449 s = comedi_read_subdevice(dev, minor); 450 if (s && (s->subdev_flags & SDF_CMD_READ) && s->async) 451 size = s->async->prealloc_bufsz / 1024; 452 mutex_unlock(&dev->mutex); 453 454 comedi_dev_put(dev); 455 return snprintf(buf, PAGE_SIZE, "%u\n", size); 456 } 457 458 static ssize_t read_buffer_kb_store(struct device *csdev, 459 struct device_attribute *attr, 460 const char *buf, size_t count) 461 { 462 unsigned int minor = MINOR(csdev->devt); 463 struct comedi_device *dev; 464 struct comedi_subdevice *s; 465 unsigned int size; 466 int err; 467 468 err = kstrtouint(buf, 10, &size); 469 if (err) 470 return err; 471 if (size > (UINT_MAX / 1024)) 472 return -EINVAL; 473 size *= 1024; 474 475 dev = comedi_dev_get_from_minor(minor); 476 if (!dev) 477 return -ENODEV; 478 479 mutex_lock(&dev->mutex); 480 s = comedi_read_subdevice(dev, minor); 481 if (s && (s->subdev_flags & SDF_CMD_READ) && s->async) 482 err = resize_async_buffer(dev, s, size); 483 else 484 err = -EINVAL; 485 mutex_unlock(&dev->mutex); 486 487 comedi_dev_put(dev); 488 return err ? err : count; 489 } 490 static DEVICE_ATTR_RW(read_buffer_kb); 491 492 static ssize_t max_write_buffer_kb_show(struct device *csdev, 493 struct device_attribute *attr, 494 char *buf) 495 { 496 unsigned int minor = MINOR(csdev->devt); 497 struct comedi_device *dev; 498 struct comedi_subdevice *s; 499 unsigned int size = 0; 500 501 dev = comedi_dev_get_from_minor(minor); 502 if (!dev) 503 return -ENODEV; 504 505 mutex_lock(&dev->mutex); 506 s = comedi_write_subdevice(dev, minor); 507 if (s && (s->subdev_flags & SDF_CMD_WRITE) && s->async) 508 size = s->async->max_bufsize / 1024; 509 mutex_unlock(&dev->mutex); 510 511 comedi_dev_put(dev); 512 return snprintf(buf, PAGE_SIZE, "%u\n", size); 513 } 514 515 static ssize_t max_write_buffer_kb_store(struct device *csdev, 516 struct device_attribute *attr, 517 const char *buf, size_t count) 518 { 519 unsigned int minor = MINOR(csdev->devt); 520 struct comedi_device *dev; 521 struct comedi_subdevice *s; 522 unsigned int size; 523 int err; 524 525 err = kstrtouint(buf, 10, &size); 526 if (err) 527 return err; 528 if (size > (UINT_MAX / 1024)) 529 return -EINVAL; 530 size *= 1024; 531 532 dev = comedi_dev_get_from_minor(minor); 533 if (!dev) 534 return -ENODEV; 535 536 mutex_lock(&dev->mutex); 537 s = comedi_write_subdevice(dev, minor); 538 if (s && (s->subdev_flags & SDF_CMD_WRITE) && s->async) 539 s->async->max_bufsize = size; 540 else 541 err = -EINVAL; 542 mutex_unlock(&dev->mutex); 543 544 comedi_dev_put(dev); 545 return err ? err : count; 546 } 547 static DEVICE_ATTR_RW(max_write_buffer_kb); 548 549 static ssize_t write_buffer_kb_show(struct device *csdev, 550 struct device_attribute *attr, char *buf) 551 { 552 unsigned int minor = MINOR(csdev->devt); 553 struct comedi_device *dev; 554 struct comedi_subdevice *s; 555 unsigned int size = 0; 556 557 dev = comedi_dev_get_from_minor(minor); 558 if (!dev) 559 return -ENODEV; 560 561 mutex_lock(&dev->mutex); 562 s = comedi_write_subdevice(dev, minor); 563 if (s && (s->subdev_flags & SDF_CMD_WRITE) && s->async) 564 size = s->async->prealloc_bufsz / 1024; 565 mutex_unlock(&dev->mutex); 566 567 comedi_dev_put(dev); 568 return snprintf(buf, PAGE_SIZE, "%u\n", size); 569 } 570 571 static ssize_t write_buffer_kb_store(struct device *csdev, 572 struct device_attribute *attr, 573 const char *buf, size_t count) 574 { 575 unsigned int minor = MINOR(csdev->devt); 576 struct comedi_device *dev; 577 struct comedi_subdevice *s; 578 unsigned int size; 579 int err; 580 581 err = kstrtouint(buf, 10, &size); 582 if (err) 583 return err; 584 if (size > (UINT_MAX / 1024)) 585 return -EINVAL; 586 size *= 1024; 587 588 dev = comedi_dev_get_from_minor(minor); 589 if (!dev) 590 return -ENODEV; 591 592 mutex_lock(&dev->mutex); 593 s = comedi_write_subdevice(dev, minor); 594 if (s && (s->subdev_flags & SDF_CMD_WRITE) && s->async) 595 err = resize_async_buffer(dev, s, size); 596 else 597 err = -EINVAL; 598 mutex_unlock(&dev->mutex); 599 600 comedi_dev_put(dev); 601 return err ? err : count; 602 } 603 static DEVICE_ATTR_RW(write_buffer_kb); 604 605 static struct attribute *comedi_dev_attrs[] = { 606 &dev_attr_max_read_buffer_kb.attr, 607 &dev_attr_read_buffer_kb.attr, 608 &dev_attr_max_write_buffer_kb.attr, 609 &dev_attr_write_buffer_kb.attr, 610 NULL, 611 }; 612 ATTRIBUTE_GROUPS(comedi_dev); 613 614 static void __comedi_clear_subdevice_runflags(struct comedi_subdevice *s, 615 unsigned int bits) 616 { 617 s->runflags &= ~bits; 618 } 619 620 static void __comedi_set_subdevice_runflags(struct comedi_subdevice *s, 621 unsigned int bits) 622 { 623 s->runflags |= bits; 624 } 625 626 static void comedi_update_subdevice_runflags(struct comedi_subdevice *s, 627 unsigned int mask, 628 unsigned int bits) 629 { 630 unsigned long flags; 631 632 spin_lock_irqsave(&s->spin_lock, flags); 633 __comedi_clear_subdevice_runflags(s, mask); 634 __comedi_set_subdevice_runflags(s, bits & mask); 635 spin_unlock_irqrestore(&s->spin_lock, flags); 636 } 637 638 static unsigned int __comedi_get_subdevice_runflags(struct comedi_subdevice *s) 639 { 640 return s->runflags; 641 } 642 643 static unsigned int comedi_get_subdevice_runflags(struct comedi_subdevice *s) 644 { 645 unsigned long flags; 646 unsigned int runflags; 647 648 spin_lock_irqsave(&s->spin_lock, flags); 649 runflags = __comedi_get_subdevice_runflags(s); 650 spin_unlock_irqrestore(&s->spin_lock, flags); 651 return runflags; 652 } 653 654 static bool comedi_is_runflags_running(unsigned int runflags) 655 { 656 return runflags & COMEDI_SRF_RUNNING; 657 } 658 659 static bool comedi_is_runflags_in_error(unsigned int runflags) 660 { 661 return runflags & COMEDI_SRF_ERROR; 662 } 663 664 /** 665 * comedi_is_subdevice_running() - Check if async command running on subdevice 666 * @s: COMEDI subdevice. 667 * 668 * Return: %true if an asynchronous COMEDI command is active on the 669 * subdevice, else %false. 670 */ 671 bool comedi_is_subdevice_running(struct comedi_subdevice *s) 672 { 673 unsigned int runflags = comedi_get_subdevice_runflags(s); 674 675 return comedi_is_runflags_running(runflags); 676 } 677 EXPORT_SYMBOL_GPL(comedi_is_subdevice_running); 678 679 static bool __comedi_is_subdevice_running(struct comedi_subdevice *s) 680 { 681 unsigned int runflags = __comedi_get_subdevice_runflags(s); 682 683 return comedi_is_runflags_running(runflags); 684 } 685 686 bool comedi_can_auto_free_spriv(struct comedi_subdevice *s) 687 { 688 unsigned int runflags = __comedi_get_subdevice_runflags(s); 689 690 return runflags & COMEDI_SRF_FREE_SPRIV; 691 } 692 693 /** 694 * comedi_set_spriv_auto_free() - Mark subdevice private data as freeable 695 * @s: COMEDI subdevice. 696 * 697 * Mark the subdevice as having a pointer to private data that can be 698 * automatically freed when the COMEDI device is detached from the low-level 699 * driver. 700 */ 701 void comedi_set_spriv_auto_free(struct comedi_subdevice *s) 702 { 703 __comedi_set_subdevice_runflags(s, COMEDI_SRF_FREE_SPRIV); 704 } 705 EXPORT_SYMBOL_GPL(comedi_set_spriv_auto_free); 706 707 /** 708 * comedi_alloc_spriv - Allocate memory for the subdevice private data 709 * @s: COMEDI subdevice. 710 * @size: Size of the memory to allocate. 711 * 712 * Allocate memory for the subdevice private data and point @s->private 713 * to it. The memory will be freed automatically when the COMEDI device 714 * is detached from the low-level driver. 715 * 716 * Return: A pointer to the allocated memory @s->private on success. 717 * Return NULL on failure. 718 */ 719 void *comedi_alloc_spriv(struct comedi_subdevice *s, size_t size) 720 { 721 s->private = kzalloc(size, GFP_KERNEL); 722 if (s->private) 723 comedi_set_spriv_auto_free(s); 724 return s->private; 725 } 726 EXPORT_SYMBOL_GPL(comedi_alloc_spriv); 727 728 /* 729 * This function restores a subdevice to an idle state. 730 */ 731 static void do_become_nonbusy(struct comedi_device *dev, 732 struct comedi_subdevice *s) 733 { 734 struct comedi_async *async = s->async; 735 736 lockdep_assert_held(&dev->mutex); 737 comedi_update_subdevice_runflags(s, COMEDI_SRF_RUNNING, 0); 738 if (async) { 739 comedi_buf_reset(s); 740 async->inttrig = NULL; 741 kfree(async->cmd.chanlist); 742 async->cmd.chanlist = NULL; 743 s->busy = NULL; 744 wake_up_interruptible_all(&async->wait_head); 745 } else { 746 dev_err(dev->class_dev, 747 "BUG: (?) %s called with async=NULL\n", __func__); 748 s->busy = NULL; 749 } 750 } 751 752 static int do_cancel(struct comedi_device *dev, struct comedi_subdevice *s) 753 { 754 int ret = 0; 755 756 lockdep_assert_held(&dev->mutex); 757 if (comedi_is_subdevice_running(s) && s->cancel) 758 ret = s->cancel(dev, s); 759 760 do_become_nonbusy(dev, s); 761 762 return ret; 763 } 764 765 void comedi_device_cancel_all(struct comedi_device *dev) 766 { 767 struct comedi_subdevice *s; 768 int i; 769 770 lockdep_assert_held(&dev->mutex); 771 if (!dev->attached) 772 return; 773 774 for (i = 0; i < dev->n_subdevices; i++) { 775 s = &dev->subdevices[i]; 776 if (s->async) 777 do_cancel(dev, s); 778 } 779 } 780 781 static int is_device_busy(struct comedi_device *dev) 782 { 783 struct comedi_subdevice *s; 784 int i; 785 786 lockdep_assert_held(&dev->mutex); 787 if (!dev->attached) 788 return 0; 789 790 for (i = 0; i < dev->n_subdevices; i++) { 791 s = &dev->subdevices[i]; 792 if (s->busy) 793 return 1; 794 if (s->async && comedi_buf_is_mmapped(s)) 795 return 1; 796 } 797 798 return 0; 799 } 800 801 /* 802 * COMEDI_DEVCONFIG ioctl 803 * attaches (and configures) or detaches a legacy device 804 * 805 * arg: 806 * pointer to comedi_devconfig structure (NULL if detaching) 807 * 808 * reads: 809 * comedi_devconfig structure (if attaching) 810 * 811 * writes: 812 * nothing 813 */ 814 static int do_devconfig_ioctl(struct comedi_device *dev, 815 struct comedi_devconfig __user *arg) 816 { 817 struct comedi_devconfig it; 818 819 lockdep_assert_held(&dev->mutex); 820 if (!capable(CAP_SYS_ADMIN)) 821 return -EPERM; 822 823 if (!arg) { 824 if (is_device_busy(dev)) 825 return -EBUSY; 826 if (dev->attached) { 827 struct module *driver_module = dev->driver->module; 828 829 comedi_device_detach(dev); 830 module_put(driver_module); 831 } 832 return 0; 833 } 834 835 if (copy_from_user(&it, arg, sizeof(it))) 836 return -EFAULT; 837 838 it.board_name[COMEDI_NAMELEN - 1] = 0; 839 840 if (it.options[COMEDI_DEVCONF_AUX_DATA_LENGTH]) { 841 dev_warn(dev->class_dev, 842 "comedi_config --init_data is deprecated\n"); 843 return -EINVAL; 844 } 845 846 if (dev->minor >= comedi_num_legacy_minors) 847 /* don't re-use dynamically allocated comedi devices */ 848 return -EBUSY; 849 850 /* This increments the driver module count on success. */ 851 return comedi_device_attach(dev, &it); 852 } 853 854 /* 855 * COMEDI_BUFCONFIG ioctl 856 * buffer configuration 857 * 858 * arg: 859 * pointer to comedi_bufconfig structure 860 * 861 * reads: 862 * comedi_bufconfig structure 863 * 864 * writes: 865 * modified comedi_bufconfig structure 866 */ 867 static int do_bufconfig_ioctl(struct comedi_device *dev, 868 struct comedi_bufconfig __user *arg) 869 { 870 struct comedi_bufconfig bc; 871 struct comedi_async *async; 872 struct comedi_subdevice *s; 873 int retval = 0; 874 875 lockdep_assert_held(&dev->mutex); 876 if (copy_from_user(&bc, arg, sizeof(bc))) 877 return -EFAULT; 878 879 if (bc.subdevice >= dev->n_subdevices) 880 return -EINVAL; 881 882 s = &dev->subdevices[bc.subdevice]; 883 async = s->async; 884 885 if (!async) { 886 dev_dbg(dev->class_dev, 887 "subdevice does not have async capability\n"); 888 bc.size = 0; 889 bc.maximum_size = 0; 890 goto copyback; 891 } 892 893 if (bc.maximum_size) { 894 if (!capable(CAP_SYS_ADMIN)) 895 return -EPERM; 896 897 async->max_bufsize = bc.maximum_size; 898 } 899 900 if (bc.size) { 901 retval = resize_async_buffer(dev, s, bc.size); 902 if (retval < 0) 903 return retval; 904 } 905 906 bc.size = async->prealloc_bufsz; 907 bc.maximum_size = async->max_bufsize; 908 909 copyback: 910 if (copy_to_user(arg, &bc, sizeof(bc))) 911 return -EFAULT; 912 913 return 0; 914 } 915 916 /* 917 * COMEDI_DEVINFO ioctl 918 * device info 919 * 920 * arg: 921 * pointer to comedi_devinfo structure 922 * 923 * reads: 924 * nothing 925 * 926 * writes: 927 * comedi_devinfo structure 928 */ 929 static int do_devinfo_ioctl(struct comedi_device *dev, 930 struct comedi_devinfo __user *arg, 931 struct file *file) 932 { 933 struct comedi_subdevice *s; 934 struct comedi_devinfo devinfo; 935 936 lockdep_assert_held(&dev->mutex); 937 memset(&devinfo, 0, sizeof(devinfo)); 938 939 /* fill devinfo structure */ 940 devinfo.version_code = COMEDI_VERSION_CODE; 941 devinfo.n_subdevs = dev->n_subdevices; 942 strscpy(devinfo.driver_name, dev->driver->driver_name, COMEDI_NAMELEN); 943 strscpy(devinfo.board_name, dev->board_name, COMEDI_NAMELEN); 944 945 s = comedi_file_read_subdevice(file); 946 if (s) 947 devinfo.read_subdevice = s->index; 948 else 949 devinfo.read_subdevice = -1; 950 951 s = comedi_file_write_subdevice(file); 952 if (s) 953 devinfo.write_subdevice = s->index; 954 else 955 devinfo.write_subdevice = -1; 956 957 if (copy_to_user(arg, &devinfo, sizeof(devinfo))) 958 return -EFAULT; 959 960 return 0; 961 } 962 963 /* 964 * COMEDI_SUBDINFO ioctl 965 * subdevices info 966 * 967 * arg: 968 * pointer to array of comedi_subdinfo structures 969 * 970 * reads: 971 * nothing 972 * 973 * writes: 974 * array of comedi_subdinfo structures 975 */ 976 static int do_subdinfo_ioctl(struct comedi_device *dev, 977 struct comedi_subdinfo __user *arg, void *file) 978 { 979 int ret, i; 980 struct comedi_subdinfo *tmp, *us; 981 struct comedi_subdevice *s; 982 983 lockdep_assert_held(&dev->mutex); 984 tmp = kcalloc(dev->n_subdevices, sizeof(*tmp), GFP_KERNEL); 985 if (!tmp) 986 return -ENOMEM; 987 988 /* fill subdinfo structs */ 989 for (i = 0; i < dev->n_subdevices; i++) { 990 s = &dev->subdevices[i]; 991 us = tmp + i; 992 993 us->type = s->type; 994 us->n_chan = s->n_chan; 995 us->subd_flags = s->subdev_flags; 996 if (comedi_is_subdevice_running(s)) 997 us->subd_flags |= SDF_RUNNING; 998 #define TIMER_nanosec 5 /* backwards compatibility */ 999 us->timer_type = TIMER_nanosec; 1000 us->len_chanlist = s->len_chanlist; 1001 us->maxdata = s->maxdata; 1002 if (s->range_table) { 1003 us->range_type = 1004 (i << 24) | (0 << 16) | (s->range_table->length); 1005 } else { 1006 us->range_type = 0; /* XXX */ 1007 } 1008 1009 if (s->busy) 1010 us->subd_flags |= SDF_BUSY; 1011 if (s->busy == file) 1012 us->subd_flags |= SDF_BUSY_OWNER; 1013 if (s->lock) 1014 us->subd_flags |= SDF_LOCKED; 1015 if (s->lock == file) 1016 us->subd_flags |= SDF_LOCK_OWNER; 1017 if (!s->maxdata && s->maxdata_list) 1018 us->subd_flags |= SDF_MAXDATA; 1019 if (s->range_table_list) 1020 us->subd_flags |= SDF_RANGETYPE; 1021 if (s->do_cmd) 1022 us->subd_flags |= SDF_CMD; 1023 1024 if (s->insn_bits != &insn_inval) 1025 us->insn_bits_support = COMEDI_SUPPORTED; 1026 else 1027 us->insn_bits_support = COMEDI_UNSUPPORTED; 1028 } 1029 1030 ret = copy_to_user(arg, tmp, dev->n_subdevices * sizeof(*tmp)); 1031 1032 kfree(tmp); 1033 1034 return ret ? -EFAULT : 0; 1035 } 1036 1037 /* 1038 * COMEDI_CHANINFO ioctl 1039 * subdevice channel info 1040 * 1041 * arg: 1042 * pointer to comedi_chaninfo structure 1043 * 1044 * reads: 1045 * comedi_chaninfo structure 1046 * 1047 * writes: 1048 * array of maxdata values to chaninfo->maxdata_list if requested 1049 * array of range table lengths to chaninfo->range_table_list if requested 1050 */ 1051 static int do_chaninfo_ioctl(struct comedi_device *dev, 1052 struct comedi_chaninfo *it) 1053 { 1054 struct comedi_subdevice *s; 1055 1056 lockdep_assert_held(&dev->mutex); 1057 1058 if (it->subdev >= dev->n_subdevices) 1059 return -EINVAL; 1060 s = &dev->subdevices[it->subdev]; 1061 1062 if (it->maxdata_list) { 1063 if (s->maxdata || !s->maxdata_list) 1064 return -EINVAL; 1065 if (copy_to_user(it->maxdata_list, s->maxdata_list, 1066 s->n_chan * sizeof(unsigned int))) 1067 return -EFAULT; 1068 } 1069 1070 if (it->flaglist) 1071 return -EINVAL; /* flaglist not supported */ 1072 1073 if (it->rangelist) { 1074 int i; 1075 1076 if (!s->range_table_list) 1077 return -EINVAL; 1078 for (i = 0; i < s->n_chan; i++) { 1079 int x; 1080 1081 x = (dev->minor << 28) | (it->subdev << 24) | (i << 16) | 1082 (s->range_table_list[i]->length); 1083 if (put_user(x, it->rangelist + i)) 1084 return -EFAULT; 1085 } 1086 } 1087 1088 return 0; 1089 } 1090 1091 /* 1092 * COMEDI_BUFINFO ioctl 1093 * buffer information 1094 * 1095 * arg: 1096 * pointer to comedi_bufinfo structure 1097 * 1098 * reads: 1099 * comedi_bufinfo structure 1100 * 1101 * writes: 1102 * modified comedi_bufinfo structure 1103 */ 1104 static int do_bufinfo_ioctl(struct comedi_device *dev, 1105 struct comedi_bufinfo __user *arg, void *file) 1106 { 1107 struct comedi_bufinfo bi; 1108 struct comedi_subdevice *s; 1109 struct comedi_async *async; 1110 unsigned int runflags; 1111 int retval = 0; 1112 bool become_nonbusy = false; 1113 1114 lockdep_assert_held(&dev->mutex); 1115 if (copy_from_user(&bi, arg, sizeof(bi))) 1116 return -EFAULT; 1117 1118 if (bi.subdevice >= dev->n_subdevices) 1119 return -EINVAL; 1120 1121 s = &dev->subdevices[bi.subdevice]; 1122 1123 async = s->async; 1124 1125 if (!async || s->busy != file) 1126 return -EINVAL; 1127 1128 runflags = comedi_get_subdevice_runflags(s); 1129 if (!(async->cmd.flags & CMDF_WRITE)) { 1130 /* command was set up in "read" direction */ 1131 if (bi.bytes_read) { 1132 comedi_buf_read_alloc(s, bi.bytes_read); 1133 bi.bytes_read = comedi_buf_read_free(s, bi.bytes_read); 1134 } 1135 /* 1136 * If nothing left to read, and command has stopped, and 1137 * {"read" position not updated or command stopped normally}, 1138 * then become non-busy. 1139 */ 1140 if (comedi_buf_read_n_available(s) == 0 && 1141 !comedi_is_runflags_running(runflags) && 1142 (bi.bytes_read == 0 || 1143 !comedi_is_runflags_in_error(runflags))) { 1144 become_nonbusy = true; 1145 if (comedi_is_runflags_in_error(runflags)) 1146 retval = -EPIPE; 1147 } 1148 bi.bytes_written = 0; 1149 } else { 1150 /* command was set up in "write" direction */ 1151 if (!comedi_is_runflags_running(runflags)) { 1152 bi.bytes_written = 0; 1153 become_nonbusy = true; 1154 if (comedi_is_runflags_in_error(runflags)) 1155 retval = -EPIPE; 1156 } else if (bi.bytes_written) { 1157 comedi_buf_write_alloc(s, bi.bytes_written); 1158 bi.bytes_written = 1159 comedi_buf_write_free(s, bi.bytes_written); 1160 } 1161 bi.bytes_read = 0; 1162 } 1163 1164 bi.buf_write_count = async->buf_write_count; 1165 bi.buf_write_ptr = async->buf_write_ptr; 1166 bi.buf_read_count = async->buf_read_count; 1167 bi.buf_read_ptr = async->buf_read_ptr; 1168 1169 if (become_nonbusy) 1170 do_become_nonbusy(dev, s); 1171 1172 if (retval) 1173 return retval; 1174 1175 if (copy_to_user(arg, &bi, sizeof(bi))) 1176 return -EFAULT; 1177 1178 return 0; 1179 } 1180 1181 static int check_insn_config_length(struct comedi_insn *insn, 1182 unsigned int *data) 1183 { 1184 if (insn->n < 1) 1185 return -EINVAL; 1186 1187 switch (data[0]) { 1188 case INSN_CONFIG_DIO_OUTPUT: 1189 case INSN_CONFIG_DIO_INPUT: 1190 case INSN_CONFIG_DISARM: 1191 case INSN_CONFIG_RESET: 1192 if (insn->n == 1) 1193 return 0; 1194 break; 1195 case INSN_CONFIG_ARM: 1196 case INSN_CONFIG_DIO_QUERY: 1197 case INSN_CONFIG_BLOCK_SIZE: 1198 case INSN_CONFIG_FILTER: 1199 case INSN_CONFIG_SERIAL_CLOCK: 1200 case INSN_CONFIG_BIDIRECTIONAL_DATA: 1201 case INSN_CONFIG_ALT_SOURCE: 1202 case INSN_CONFIG_SET_COUNTER_MODE: 1203 case INSN_CONFIG_8254_READ_STATUS: 1204 case INSN_CONFIG_SET_ROUTING: 1205 case INSN_CONFIG_GET_ROUTING: 1206 case INSN_CONFIG_GET_PWM_STATUS: 1207 case INSN_CONFIG_PWM_SET_PERIOD: 1208 case INSN_CONFIG_PWM_GET_PERIOD: 1209 if (insn->n == 2) 1210 return 0; 1211 break; 1212 case INSN_CONFIG_SET_GATE_SRC: 1213 case INSN_CONFIG_GET_GATE_SRC: 1214 case INSN_CONFIG_SET_CLOCK_SRC: 1215 case INSN_CONFIG_GET_CLOCK_SRC: 1216 case INSN_CONFIG_SET_OTHER_SRC: 1217 case INSN_CONFIG_GET_COUNTER_STATUS: 1218 case INSN_CONFIG_PWM_SET_H_BRIDGE: 1219 case INSN_CONFIG_PWM_GET_H_BRIDGE: 1220 case INSN_CONFIG_GET_HARDWARE_BUFFER_SIZE: 1221 if (insn->n == 3) 1222 return 0; 1223 break; 1224 case INSN_CONFIG_PWM_OUTPUT: 1225 case INSN_CONFIG_ANALOG_TRIG: 1226 case INSN_CONFIG_TIMER_1: 1227 if (insn->n == 5) 1228 return 0; 1229 break; 1230 case INSN_CONFIG_DIGITAL_TRIG: 1231 if (insn->n == 6) 1232 return 0; 1233 break; 1234 case INSN_CONFIG_GET_CMD_TIMING_CONSTRAINTS: 1235 if (insn->n >= 4) 1236 return 0; 1237 break; 1238 /* 1239 * by default we allow the insn since we don't have checks for 1240 * all possible cases yet 1241 */ 1242 default: 1243 pr_warn("No check for data length of config insn id %i is implemented\n", 1244 data[0]); 1245 pr_warn("Add a check to %s in %s\n", __func__, __FILE__); 1246 pr_warn("Assuming n=%i is correct\n", insn->n); 1247 return 0; 1248 } 1249 return -EINVAL; 1250 } 1251 1252 static int check_insn_device_config_length(struct comedi_insn *insn, 1253 unsigned int *data) 1254 { 1255 if (insn->n < 1) 1256 return -EINVAL; 1257 1258 switch (data[0]) { 1259 case INSN_DEVICE_CONFIG_TEST_ROUTE: 1260 case INSN_DEVICE_CONFIG_CONNECT_ROUTE: 1261 case INSN_DEVICE_CONFIG_DISCONNECT_ROUTE: 1262 if (insn->n == 3) 1263 return 0; 1264 break; 1265 case INSN_DEVICE_CONFIG_GET_ROUTES: 1266 /* 1267 * Big enough for config_id and the length of the userland 1268 * memory buffer. Additional length should be in factors of 2 1269 * to communicate any returned route pairs (source,destination). 1270 */ 1271 if (insn->n >= 2) 1272 return 0; 1273 break; 1274 } 1275 return -EINVAL; 1276 } 1277 1278 /** 1279 * get_valid_routes() - Calls low-level driver get_valid_routes function to 1280 * either return a count of valid routes to user, or copy 1281 * of list of all valid device routes to buffer in 1282 * userspace. 1283 * @dev: comedi device pointer 1284 * @data: data from user insn call. The length of the data must be >= 2. 1285 * data[0] must contain the INSN_DEVICE_CONFIG config_id. 1286 * data[1](input) contains the number of _pairs_ for which memory is 1287 * allotted from the user. If the user specifies '0', then only 1288 * the number of pairs available is returned. 1289 * data[1](output) returns either the number of pairs available (if none 1290 * where requested) or the number of _pairs_ that are copied back 1291 * to the user. 1292 * data[2::2] returns each (source, destination) pair. 1293 * 1294 * Return: -EINVAL if low-level driver does not allocate and return routes as 1295 * expected. Returns 0 otherwise. 1296 */ 1297 static int get_valid_routes(struct comedi_device *dev, unsigned int *data) 1298 { 1299 lockdep_assert_held(&dev->mutex); 1300 data[1] = dev->get_valid_routes(dev, data[1], data + 2); 1301 return 0; 1302 } 1303 1304 static int parse_insn(struct comedi_device *dev, struct comedi_insn *insn, 1305 unsigned int *data, void *file) 1306 { 1307 struct comedi_subdevice *s; 1308 int ret = 0; 1309 int i; 1310 1311 lockdep_assert_held(&dev->mutex); 1312 if (insn->insn & INSN_MASK_SPECIAL) { 1313 /* a non-subdevice instruction */ 1314 1315 switch (insn->insn) { 1316 case INSN_GTOD: 1317 { 1318 struct timespec64 tv; 1319 1320 if (insn->n != 2) { 1321 ret = -EINVAL; 1322 break; 1323 } 1324 1325 ktime_get_real_ts64(&tv); 1326 /* unsigned data safe until 2106 */ 1327 data[0] = (unsigned int)tv.tv_sec; 1328 data[1] = tv.tv_nsec / NSEC_PER_USEC; 1329 ret = 2; 1330 1331 break; 1332 } 1333 case INSN_WAIT: 1334 if (insn->n != 1 || data[0] >= 100000) { 1335 ret = -EINVAL; 1336 break; 1337 } 1338 udelay(data[0] / 1000); 1339 ret = 1; 1340 break; 1341 case INSN_INTTRIG: 1342 if (insn->n != 1) { 1343 ret = -EINVAL; 1344 break; 1345 } 1346 if (insn->subdev >= dev->n_subdevices) { 1347 dev_dbg(dev->class_dev, 1348 "%d not usable subdevice\n", 1349 insn->subdev); 1350 ret = -EINVAL; 1351 break; 1352 } 1353 s = &dev->subdevices[insn->subdev]; 1354 if (!s->async) { 1355 dev_dbg(dev->class_dev, "no async\n"); 1356 ret = -EINVAL; 1357 break; 1358 } 1359 if (!s->async->inttrig) { 1360 dev_dbg(dev->class_dev, "no inttrig\n"); 1361 ret = -EAGAIN; 1362 break; 1363 } 1364 ret = s->async->inttrig(dev, s, data[0]); 1365 if (ret >= 0) 1366 ret = 1; 1367 break; 1368 case INSN_DEVICE_CONFIG: 1369 ret = check_insn_device_config_length(insn, data); 1370 if (ret) 1371 break; 1372 1373 if (data[0] == INSN_DEVICE_CONFIG_GET_ROUTES) { 1374 /* 1375 * data[1] should be the number of _pairs_ that 1376 * the memory can hold. 1377 */ 1378 data[1] = (insn->n - 2) / 2; 1379 ret = get_valid_routes(dev, data); 1380 break; 1381 } 1382 1383 /* other global device config instructions. */ 1384 ret = dev->insn_device_config(dev, insn, data); 1385 break; 1386 default: 1387 dev_dbg(dev->class_dev, "invalid insn\n"); 1388 ret = -EINVAL; 1389 break; 1390 } 1391 } else { 1392 /* a subdevice instruction */ 1393 unsigned int maxdata; 1394 1395 if (insn->subdev >= dev->n_subdevices) { 1396 dev_dbg(dev->class_dev, "subdevice %d out of range\n", 1397 insn->subdev); 1398 ret = -EINVAL; 1399 goto out; 1400 } 1401 s = &dev->subdevices[insn->subdev]; 1402 1403 if (s->type == COMEDI_SUBD_UNUSED) { 1404 dev_dbg(dev->class_dev, "%d not usable subdevice\n", 1405 insn->subdev); 1406 ret = -EIO; 1407 goto out; 1408 } 1409 1410 /* are we locked? (ioctl lock) */ 1411 if (s->lock && s->lock != file) { 1412 dev_dbg(dev->class_dev, "device locked\n"); 1413 ret = -EACCES; 1414 goto out; 1415 } 1416 1417 ret = comedi_check_chanlist(s, 1, &insn->chanspec); 1418 if (ret < 0) { 1419 ret = -EINVAL; 1420 dev_dbg(dev->class_dev, "bad chanspec\n"); 1421 goto out; 1422 } 1423 1424 if (s->busy) { 1425 ret = -EBUSY; 1426 goto out; 1427 } 1428 /* This looks arbitrary. It is. */ 1429 s->busy = parse_insn; 1430 switch (insn->insn) { 1431 case INSN_READ: 1432 ret = s->insn_read(dev, s, insn, data); 1433 if (ret == -ETIMEDOUT) { 1434 dev_dbg(dev->class_dev, 1435 "subdevice %d read instruction timed out\n", 1436 s->index); 1437 } 1438 break; 1439 case INSN_WRITE: 1440 maxdata = s->maxdata_list 1441 ? s->maxdata_list[CR_CHAN(insn->chanspec)] 1442 : s->maxdata; 1443 for (i = 0; i < insn->n; ++i) { 1444 if (data[i] > maxdata) { 1445 ret = -EINVAL; 1446 dev_dbg(dev->class_dev, 1447 "bad data value(s)\n"); 1448 break; 1449 } 1450 } 1451 if (ret == 0) { 1452 ret = s->insn_write(dev, s, insn, data); 1453 if (ret == -ETIMEDOUT) { 1454 dev_dbg(dev->class_dev, 1455 "subdevice %d write instruction timed out\n", 1456 s->index); 1457 } 1458 } 1459 break; 1460 case INSN_BITS: 1461 if (insn->n != 2) { 1462 ret = -EINVAL; 1463 } else { 1464 /* 1465 * Most drivers ignore the base channel in 1466 * insn->chanspec. Fix this here if 1467 * the subdevice has <= 32 channels. 1468 */ 1469 unsigned int orig_mask = data[0]; 1470 unsigned int shift = 0; 1471 1472 if (s->n_chan <= 32) { 1473 shift = CR_CHAN(insn->chanspec); 1474 if (shift > 0) { 1475 insn->chanspec = 0; 1476 data[0] <<= shift; 1477 data[1] <<= shift; 1478 } 1479 } 1480 ret = s->insn_bits(dev, s, insn, data); 1481 data[0] = orig_mask; 1482 if (shift > 0) 1483 data[1] >>= shift; 1484 } 1485 break; 1486 case INSN_CONFIG: 1487 ret = check_insn_config_length(insn, data); 1488 if (ret) 1489 break; 1490 ret = s->insn_config(dev, s, insn, data); 1491 break; 1492 default: 1493 ret = -EINVAL; 1494 break; 1495 } 1496 1497 s->busy = NULL; 1498 } 1499 1500 out: 1501 return ret; 1502 } 1503 1504 /* 1505 * COMEDI_INSNLIST ioctl 1506 * synchronous instruction list 1507 * 1508 * arg: 1509 * pointer to comedi_insnlist structure 1510 * 1511 * reads: 1512 * comedi_insnlist structure 1513 * array of comedi_insn structures from insnlist->insns pointer 1514 * data (for writes) from insns[].data pointers 1515 * 1516 * writes: 1517 * data (for reads) to insns[].data pointers 1518 */ 1519 /* arbitrary limits */ 1520 #define MIN_SAMPLES 16 1521 #define MAX_SAMPLES 65536 1522 static int do_insnlist_ioctl(struct comedi_device *dev, 1523 struct comedi_insn *insns, 1524 unsigned int n_insns, 1525 void *file) 1526 { 1527 unsigned int *data = NULL; 1528 unsigned int max_n_data_required = MIN_SAMPLES; 1529 int i = 0; 1530 int ret = 0; 1531 1532 lockdep_assert_held(&dev->mutex); 1533 1534 /* Determine maximum memory needed for all instructions. */ 1535 for (i = 0; i < n_insns; ++i) { 1536 if (insns[i].n > MAX_SAMPLES) { 1537 dev_dbg(dev->class_dev, 1538 "number of samples too large\n"); 1539 ret = -EINVAL; 1540 goto error; 1541 } 1542 max_n_data_required = max(max_n_data_required, insns[i].n); 1543 } 1544 1545 /* Allocate scratch space for all instruction data. */ 1546 data = kmalloc_array(max_n_data_required, sizeof(unsigned int), 1547 GFP_KERNEL); 1548 if (!data) { 1549 ret = -ENOMEM; 1550 goto error; 1551 } 1552 1553 for (i = 0; i < n_insns; ++i) { 1554 if (insns[i].insn & INSN_MASK_WRITE) { 1555 if (copy_from_user(data, insns[i].data, 1556 insns[i].n * sizeof(unsigned int))) { 1557 dev_dbg(dev->class_dev, 1558 "copy_from_user failed\n"); 1559 ret = -EFAULT; 1560 goto error; 1561 } 1562 } 1563 ret = parse_insn(dev, insns + i, data, file); 1564 if (ret < 0) 1565 goto error; 1566 if (insns[i].insn & INSN_MASK_READ) { 1567 if (copy_to_user(insns[i].data, data, 1568 insns[i].n * sizeof(unsigned int))) { 1569 dev_dbg(dev->class_dev, 1570 "copy_to_user failed\n"); 1571 ret = -EFAULT; 1572 goto error; 1573 } 1574 } 1575 if (need_resched()) 1576 schedule(); 1577 } 1578 1579 error: 1580 kfree(data); 1581 1582 if (ret < 0) 1583 return ret; 1584 return i; 1585 } 1586 1587 /* 1588 * COMEDI_INSN ioctl 1589 * synchronous instruction 1590 * 1591 * arg: 1592 * pointer to comedi_insn structure 1593 * 1594 * reads: 1595 * comedi_insn structure 1596 * data (for writes) from insn->data pointer 1597 * 1598 * writes: 1599 * data (for reads) to insn->data pointer 1600 */ 1601 static int do_insn_ioctl(struct comedi_device *dev, 1602 struct comedi_insn *insn, void *file) 1603 { 1604 unsigned int *data = NULL; 1605 unsigned int n_data = MIN_SAMPLES; 1606 int ret = 0; 1607 1608 lockdep_assert_held(&dev->mutex); 1609 1610 n_data = max(n_data, insn->n); 1611 1612 /* This is where the behavior of insn and insnlist deviate. */ 1613 if (insn->n > MAX_SAMPLES) { 1614 insn->n = MAX_SAMPLES; 1615 n_data = MAX_SAMPLES; 1616 } 1617 1618 data = kmalloc_array(n_data, sizeof(unsigned int), GFP_KERNEL); 1619 if (!data) { 1620 ret = -ENOMEM; 1621 goto error; 1622 } 1623 1624 if (insn->insn & INSN_MASK_WRITE) { 1625 if (copy_from_user(data, 1626 insn->data, 1627 insn->n * sizeof(unsigned int))) { 1628 ret = -EFAULT; 1629 goto error; 1630 } 1631 } 1632 ret = parse_insn(dev, insn, data, file); 1633 if (ret < 0) 1634 goto error; 1635 if (insn->insn & INSN_MASK_READ) { 1636 if (copy_to_user(insn->data, 1637 data, 1638 insn->n * sizeof(unsigned int))) { 1639 ret = -EFAULT; 1640 goto error; 1641 } 1642 } 1643 ret = insn->n; 1644 1645 error: 1646 kfree(data); 1647 1648 return ret; 1649 } 1650 1651 static int __comedi_get_user_cmd(struct comedi_device *dev, 1652 struct comedi_cmd *cmd) 1653 { 1654 struct comedi_subdevice *s; 1655 1656 lockdep_assert_held(&dev->mutex); 1657 if (cmd->subdev >= dev->n_subdevices) { 1658 dev_dbg(dev->class_dev, "%d no such subdevice\n", cmd->subdev); 1659 return -ENODEV; 1660 } 1661 1662 s = &dev->subdevices[cmd->subdev]; 1663 1664 if (s->type == COMEDI_SUBD_UNUSED) { 1665 dev_dbg(dev->class_dev, "%d not valid subdevice\n", 1666 cmd->subdev); 1667 return -EIO; 1668 } 1669 1670 if (!s->do_cmd || !s->do_cmdtest || !s->async) { 1671 dev_dbg(dev->class_dev, 1672 "subdevice %d does not support commands\n", 1673 cmd->subdev); 1674 return -EIO; 1675 } 1676 1677 /* make sure channel/gain list isn't too long */ 1678 if (cmd->chanlist_len > s->len_chanlist) { 1679 dev_dbg(dev->class_dev, "channel/gain list too long %d > %d\n", 1680 cmd->chanlist_len, s->len_chanlist); 1681 return -EINVAL; 1682 } 1683 1684 /* 1685 * Set the CMDF_WRITE flag to the correct state if the subdevice 1686 * supports only "read" commands or only "write" commands. 1687 */ 1688 switch (s->subdev_flags & (SDF_CMD_READ | SDF_CMD_WRITE)) { 1689 case SDF_CMD_READ: 1690 cmd->flags &= ~CMDF_WRITE; 1691 break; 1692 case SDF_CMD_WRITE: 1693 cmd->flags |= CMDF_WRITE; 1694 break; 1695 default: 1696 break; 1697 } 1698 1699 return 0; 1700 } 1701 1702 static int __comedi_get_user_chanlist(struct comedi_device *dev, 1703 struct comedi_subdevice *s, 1704 unsigned int __user *user_chanlist, 1705 struct comedi_cmd *cmd) 1706 { 1707 unsigned int *chanlist; 1708 int ret; 1709 1710 lockdep_assert_held(&dev->mutex); 1711 cmd->chanlist = NULL; 1712 chanlist = memdup_user(user_chanlist, 1713 cmd->chanlist_len * sizeof(unsigned int)); 1714 if (IS_ERR(chanlist)) 1715 return PTR_ERR(chanlist); 1716 1717 /* make sure each element in channel/gain list is valid */ 1718 ret = comedi_check_chanlist(s, cmd->chanlist_len, chanlist); 1719 if (ret < 0) { 1720 kfree(chanlist); 1721 return ret; 1722 } 1723 1724 cmd->chanlist = chanlist; 1725 1726 return 0; 1727 } 1728 1729 /* 1730 * COMEDI_CMD ioctl 1731 * asynchronous acquisition command set-up 1732 * 1733 * arg: 1734 * pointer to comedi_cmd structure 1735 * 1736 * reads: 1737 * comedi_cmd structure 1738 * channel/range list from cmd->chanlist pointer 1739 * 1740 * writes: 1741 * possibly modified comedi_cmd structure (when -EAGAIN returned) 1742 */ 1743 static int do_cmd_ioctl(struct comedi_device *dev, 1744 struct comedi_cmd *cmd, bool *copy, void *file) 1745 { 1746 struct comedi_subdevice *s; 1747 struct comedi_async *async; 1748 unsigned int __user *user_chanlist; 1749 int ret; 1750 1751 lockdep_assert_held(&dev->mutex); 1752 1753 /* do some simple cmd validation */ 1754 ret = __comedi_get_user_cmd(dev, cmd); 1755 if (ret) 1756 return ret; 1757 1758 /* save user's chanlist pointer so it can be restored later */ 1759 user_chanlist = (unsigned int __user *)cmd->chanlist; 1760 1761 s = &dev->subdevices[cmd->subdev]; 1762 async = s->async; 1763 1764 /* are we locked? (ioctl lock) */ 1765 if (s->lock && s->lock != file) { 1766 dev_dbg(dev->class_dev, "subdevice locked\n"); 1767 return -EACCES; 1768 } 1769 1770 /* are we busy? */ 1771 if (s->busy) { 1772 dev_dbg(dev->class_dev, "subdevice busy\n"); 1773 return -EBUSY; 1774 } 1775 1776 /* make sure channel/gain list isn't too short */ 1777 if (cmd->chanlist_len < 1) { 1778 dev_dbg(dev->class_dev, "channel/gain list too short %u < 1\n", 1779 cmd->chanlist_len); 1780 return -EINVAL; 1781 } 1782 1783 async->cmd = *cmd; 1784 async->cmd.data = NULL; 1785 1786 /* load channel/gain list */ 1787 ret = __comedi_get_user_chanlist(dev, s, user_chanlist, &async->cmd); 1788 if (ret) 1789 goto cleanup; 1790 1791 ret = s->do_cmdtest(dev, s, &async->cmd); 1792 1793 if (async->cmd.flags & CMDF_BOGUS || ret) { 1794 dev_dbg(dev->class_dev, "test returned %d\n", ret); 1795 *cmd = async->cmd; 1796 /* restore chanlist pointer before copying back */ 1797 cmd->chanlist = (unsigned int __force *)user_chanlist; 1798 cmd->data = NULL; 1799 *copy = true; 1800 ret = -EAGAIN; 1801 goto cleanup; 1802 } 1803 1804 if (!async->prealloc_bufsz) { 1805 ret = -ENOMEM; 1806 dev_dbg(dev->class_dev, "no buffer (?)\n"); 1807 goto cleanup; 1808 } 1809 1810 comedi_buf_reset(s); 1811 1812 async->cb_mask = COMEDI_CB_BLOCK | COMEDI_CB_CANCEL_MASK; 1813 if (async->cmd.flags & CMDF_WAKE_EOS) 1814 async->cb_mask |= COMEDI_CB_EOS; 1815 1816 comedi_update_subdevice_runflags(s, COMEDI_SRF_BUSY_MASK, 1817 COMEDI_SRF_RUNNING); 1818 1819 /* 1820 * Set s->busy _after_ setting COMEDI_SRF_RUNNING flag to avoid 1821 * race with comedi_read() or comedi_write(). 1822 */ 1823 s->busy = file; 1824 ret = s->do_cmd(dev, s); 1825 if (ret == 0) 1826 return 0; 1827 1828 cleanup: 1829 do_become_nonbusy(dev, s); 1830 1831 return ret; 1832 } 1833 1834 /* 1835 * COMEDI_CMDTEST ioctl 1836 * asynchronous acquisition command testing 1837 * 1838 * arg: 1839 * pointer to comedi_cmd structure 1840 * 1841 * reads: 1842 * comedi_cmd structure 1843 * channel/range list from cmd->chanlist pointer 1844 * 1845 * writes: 1846 * possibly modified comedi_cmd structure 1847 */ 1848 static int do_cmdtest_ioctl(struct comedi_device *dev, 1849 struct comedi_cmd *cmd, bool *copy, void *file) 1850 { 1851 struct comedi_subdevice *s; 1852 unsigned int __user *user_chanlist; 1853 int ret; 1854 1855 lockdep_assert_held(&dev->mutex); 1856 1857 /* do some simple cmd validation */ 1858 ret = __comedi_get_user_cmd(dev, cmd); 1859 if (ret) 1860 return ret; 1861 1862 /* save user's chanlist pointer so it can be restored later */ 1863 user_chanlist = (unsigned int __user *)cmd->chanlist; 1864 1865 s = &dev->subdevices[cmd->subdev]; 1866 1867 /* user_chanlist can be NULL for COMEDI_CMDTEST ioctl */ 1868 if (user_chanlist) { 1869 /* load channel/gain list */ 1870 ret = __comedi_get_user_chanlist(dev, s, user_chanlist, cmd); 1871 if (ret) 1872 return ret; 1873 } 1874 1875 ret = s->do_cmdtest(dev, s, cmd); 1876 1877 kfree(cmd->chanlist); /* free kernel copy of user chanlist */ 1878 1879 /* restore chanlist pointer before copying back */ 1880 cmd->chanlist = (unsigned int __force *)user_chanlist; 1881 *copy = true; 1882 1883 return ret; 1884 } 1885 1886 /* 1887 * COMEDI_LOCK ioctl 1888 * lock subdevice 1889 * 1890 * arg: 1891 * subdevice number 1892 * 1893 * reads: 1894 * nothing 1895 * 1896 * writes: 1897 * nothing 1898 */ 1899 static int do_lock_ioctl(struct comedi_device *dev, unsigned long arg, 1900 void *file) 1901 { 1902 int ret = 0; 1903 unsigned long flags; 1904 struct comedi_subdevice *s; 1905 1906 lockdep_assert_held(&dev->mutex); 1907 if (arg >= dev->n_subdevices) 1908 return -EINVAL; 1909 s = &dev->subdevices[arg]; 1910 1911 spin_lock_irqsave(&s->spin_lock, flags); 1912 if (s->busy || s->lock) 1913 ret = -EBUSY; 1914 else 1915 s->lock = file; 1916 spin_unlock_irqrestore(&s->spin_lock, flags); 1917 1918 return ret; 1919 } 1920 1921 /* 1922 * COMEDI_UNLOCK ioctl 1923 * unlock subdevice 1924 * 1925 * arg: 1926 * subdevice number 1927 * 1928 * reads: 1929 * nothing 1930 * 1931 * writes: 1932 * nothing 1933 */ 1934 static int do_unlock_ioctl(struct comedi_device *dev, unsigned long arg, 1935 void *file) 1936 { 1937 struct comedi_subdevice *s; 1938 1939 lockdep_assert_held(&dev->mutex); 1940 if (arg >= dev->n_subdevices) 1941 return -EINVAL; 1942 s = &dev->subdevices[arg]; 1943 1944 if (s->busy) 1945 return -EBUSY; 1946 1947 if (s->lock && s->lock != file) 1948 return -EACCES; 1949 1950 if (s->lock == file) 1951 s->lock = NULL; 1952 1953 return 0; 1954 } 1955 1956 /* 1957 * COMEDI_CANCEL ioctl 1958 * cancel asynchronous acquisition 1959 * 1960 * arg: 1961 * subdevice number 1962 * 1963 * reads: 1964 * nothing 1965 * 1966 * writes: 1967 * nothing 1968 */ 1969 static int do_cancel_ioctl(struct comedi_device *dev, unsigned long arg, 1970 void *file) 1971 { 1972 struct comedi_subdevice *s; 1973 1974 lockdep_assert_held(&dev->mutex); 1975 if (arg >= dev->n_subdevices) 1976 return -EINVAL; 1977 s = &dev->subdevices[arg]; 1978 if (!s->async) 1979 return -EINVAL; 1980 1981 if (!s->busy) 1982 return 0; 1983 1984 if (s->busy != file) 1985 return -EBUSY; 1986 1987 return do_cancel(dev, s); 1988 } 1989 1990 /* 1991 * COMEDI_POLL ioctl 1992 * instructs driver to synchronize buffers 1993 * 1994 * arg: 1995 * subdevice number 1996 * 1997 * reads: 1998 * nothing 1999 * 2000 * writes: 2001 * nothing 2002 */ 2003 static int do_poll_ioctl(struct comedi_device *dev, unsigned long arg, 2004 void *file) 2005 { 2006 struct comedi_subdevice *s; 2007 2008 lockdep_assert_held(&dev->mutex); 2009 if (arg >= dev->n_subdevices) 2010 return -EINVAL; 2011 s = &dev->subdevices[arg]; 2012 2013 if (!s->busy) 2014 return 0; 2015 2016 if (s->busy != file) 2017 return -EBUSY; 2018 2019 if (s->poll) 2020 return s->poll(dev, s); 2021 2022 return -EINVAL; 2023 } 2024 2025 /* 2026 * COMEDI_SETRSUBD ioctl 2027 * sets the current "read" subdevice on a per-file basis 2028 * 2029 * arg: 2030 * subdevice number 2031 * 2032 * reads: 2033 * nothing 2034 * 2035 * writes: 2036 * nothing 2037 */ 2038 static int do_setrsubd_ioctl(struct comedi_device *dev, unsigned long arg, 2039 struct file *file) 2040 { 2041 struct comedi_file *cfp = file->private_data; 2042 struct comedi_subdevice *s_old, *s_new; 2043 2044 lockdep_assert_held(&dev->mutex); 2045 if (arg >= dev->n_subdevices) 2046 return -EINVAL; 2047 2048 s_new = &dev->subdevices[arg]; 2049 s_old = comedi_file_read_subdevice(file); 2050 if (s_old == s_new) 2051 return 0; /* no change */ 2052 2053 if (!(s_new->subdev_flags & SDF_CMD_READ)) 2054 return -EINVAL; 2055 2056 /* 2057 * Check the file isn't still busy handling a "read" command on the 2058 * old subdevice (if any). 2059 */ 2060 if (s_old && s_old->busy == file && s_old->async && 2061 !(s_old->async->cmd.flags & CMDF_WRITE)) 2062 return -EBUSY; 2063 2064 WRITE_ONCE(cfp->read_subdev, s_new); 2065 return 0; 2066 } 2067 2068 /* 2069 * COMEDI_SETWSUBD ioctl 2070 * sets the current "write" subdevice on a per-file basis 2071 * 2072 * arg: 2073 * subdevice number 2074 * 2075 * reads: 2076 * nothing 2077 * 2078 * writes: 2079 * nothing 2080 */ 2081 static int do_setwsubd_ioctl(struct comedi_device *dev, unsigned long arg, 2082 struct file *file) 2083 { 2084 struct comedi_file *cfp = file->private_data; 2085 struct comedi_subdevice *s_old, *s_new; 2086 2087 lockdep_assert_held(&dev->mutex); 2088 if (arg >= dev->n_subdevices) 2089 return -EINVAL; 2090 2091 s_new = &dev->subdevices[arg]; 2092 s_old = comedi_file_write_subdevice(file); 2093 if (s_old == s_new) 2094 return 0; /* no change */ 2095 2096 if (!(s_new->subdev_flags & SDF_CMD_WRITE)) 2097 return -EINVAL; 2098 2099 /* 2100 * Check the file isn't still busy handling a "write" command on the 2101 * old subdevice (if any). 2102 */ 2103 if (s_old && s_old->busy == file && s_old->async && 2104 (s_old->async->cmd.flags & CMDF_WRITE)) 2105 return -EBUSY; 2106 2107 WRITE_ONCE(cfp->write_subdev, s_new); 2108 return 0; 2109 } 2110 2111 static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd, 2112 unsigned long arg) 2113 { 2114 unsigned int minor = iminor(file_inode(file)); 2115 struct comedi_file *cfp = file->private_data; 2116 struct comedi_device *dev = cfp->dev; 2117 int rc; 2118 2119 mutex_lock(&dev->mutex); 2120 2121 /* 2122 * Device config is special, because it must work on 2123 * an unconfigured device. 2124 */ 2125 if (cmd == COMEDI_DEVCONFIG) { 2126 if (minor >= COMEDI_NUM_BOARD_MINORS) { 2127 /* Device config not appropriate on non-board minors. */ 2128 rc = -ENOTTY; 2129 goto done; 2130 } 2131 rc = do_devconfig_ioctl(dev, 2132 (struct comedi_devconfig __user *)arg); 2133 if (rc == 0) { 2134 if (arg == 0 && 2135 dev->minor >= comedi_num_legacy_minors) { 2136 /* 2137 * Successfully unconfigured a dynamically 2138 * allocated device. Try and remove it. 2139 */ 2140 if (comedi_clear_board_dev(dev)) { 2141 mutex_unlock(&dev->mutex); 2142 comedi_free_board_dev(dev); 2143 return rc; 2144 } 2145 } 2146 } 2147 goto done; 2148 } 2149 2150 if (!dev->attached) { 2151 dev_dbg(dev->class_dev, "no driver attached\n"); 2152 rc = -ENODEV; 2153 goto done; 2154 } 2155 2156 switch (cmd) { 2157 case COMEDI_BUFCONFIG: 2158 rc = do_bufconfig_ioctl(dev, 2159 (struct comedi_bufconfig __user *)arg); 2160 break; 2161 case COMEDI_DEVINFO: 2162 rc = do_devinfo_ioctl(dev, (struct comedi_devinfo __user *)arg, 2163 file); 2164 break; 2165 case COMEDI_SUBDINFO: 2166 rc = do_subdinfo_ioctl(dev, 2167 (struct comedi_subdinfo __user *)arg, 2168 file); 2169 break; 2170 case COMEDI_CHANINFO: { 2171 struct comedi_chaninfo it; 2172 2173 if (copy_from_user(&it, (void __user *)arg, sizeof(it))) 2174 rc = -EFAULT; 2175 else 2176 rc = do_chaninfo_ioctl(dev, &it); 2177 break; 2178 } 2179 case COMEDI_RANGEINFO: { 2180 struct comedi_rangeinfo it; 2181 2182 if (copy_from_user(&it, (void __user *)arg, sizeof(it))) 2183 rc = -EFAULT; 2184 else 2185 rc = do_rangeinfo_ioctl(dev, &it); 2186 break; 2187 } 2188 case COMEDI_BUFINFO: 2189 rc = do_bufinfo_ioctl(dev, 2190 (struct comedi_bufinfo __user *)arg, 2191 file); 2192 break; 2193 case COMEDI_LOCK: 2194 rc = do_lock_ioctl(dev, arg, file); 2195 break; 2196 case COMEDI_UNLOCK: 2197 rc = do_unlock_ioctl(dev, arg, file); 2198 break; 2199 case COMEDI_CANCEL: 2200 rc = do_cancel_ioctl(dev, arg, file); 2201 break; 2202 case COMEDI_CMD: { 2203 struct comedi_cmd cmd; 2204 bool copy = false; 2205 2206 if (copy_from_user(&cmd, (void __user *)arg, sizeof(cmd))) { 2207 rc = -EFAULT; 2208 break; 2209 } 2210 rc = do_cmd_ioctl(dev, &cmd, ©, file); 2211 if (copy && copy_to_user((void __user *)arg, &cmd, sizeof(cmd))) 2212 rc = -EFAULT; 2213 break; 2214 } 2215 case COMEDI_CMDTEST: { 2216 struct comedi_cmd cmd; 2217 bool copy = false; 2218 2219 if (copy_from_user(&cmd, (void __user *)arg, sizeof(cmd))) { 2220 rc = -EFAULT; 2221 break; 2222 } 2223 rc = do_cmdtest_ioctl(dev, &cmd, ©, file); 2224 if (copy && copy_to_user((void __user *)arg, &cmd, sizeof(cmd))) 2225 rc = -EFAULT; 2226 break; 2227 } 2228 case COMEDI_INSNLIST: { 2229 struct comedi_insnlist insnlist; 2230 struct comedi_insn *insns = NULL; 2231 2232 if (copy_from_user(&insnlist, (void __user *)arg, 2233 sizeof(insnlist))) { 2234 rc = -EFAULT; 2235 break; 2236 } 2237 insns = kcalloc(insnlist.n_insns, sizeof(*insns), GFP_KERNEL); 2238 if (!insns) { 2239 rc = -ENOMEM; 2240 break; 2241 } 2242 if (copy_from_user(insns, insnlist.insns, 2243 sizeof(*insns) * insnlist.n_insns)) { 2244 rc = -EFAULT; 2245 kfree(insns); 2246 break; 2247 } 2248 rc = do_insnlist_ioctl(dev, insns, insnlist.n_insns, file); 2249 kfree(insns); 2250 break; 2251 } 2252 case COMEDI_INSN: { 2253 struct comedi_insn insn; 2254 2255 if (copy_from_user(&insn, (void __user *)arg, sizeof(insn))) 2256 rc = -EFAULT; 2257 else 2258 rc = do_insn_ioctl(dev, &insn, file); 2259 break; 2260 } 2261 case COMEDI_POLL: 2262 rc = do_poll_ioctl(dev, arg, file); 2263 break; 2264 case COMEDI_SETRSUBD: 2265 rc = do_setrsubd_ioctl(dev, arg, file); 2266 break; 2267 case COMEDI_SETWSUBD: 2268 rc = do_setwsubd_ioctl(dev, arg, file); 2269 break; 2270 default: 2271 rc = -ENOTTY; 2272 break; 2273 } 2274 2275 done: 2276 mutex_unlock(&dev->mutex); 2277 return rc; 2278 } 2279 2280 static void comedi_vm_open(struct vm_area_struct *area) 2281 { 2282 struct comedi_buf_map *bm; 2283 2284 bm = area->vm_private_data; 2285 comedi_buf_map_get(bm); 2286 } 2287 2288 static void comedi_vm_close(struct vm_area_struct *area) 2289 { 2290 struct comedi_buf_map *bm; 2291 2292 bm = area->vm_private_data; 2293 comedi_buf_map_put(bm); 2294 } 2295 2296 static int comedi_vm_access(struct vm_area_struct *vma, unsigned long addr, 2297 void *buf, int len, int write) 2298 { 2299 struct comedi_buf_map *bm = vma->vm_private_data; 2300 unsigned long offset = 2301 addr - vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT); 2302 2303 if (len < 0) 2304 return -EINVAL; 2305 if (len > vma->vm_end - addr) 2306 len = vma->vm_end - addr; 2307 return comedi_buf_map_access(bm, offset, buf, len, write); 2308 } 2309 2310 static const struct vm_operations_struct comedi_vm_ops = { 2311 .open = comedi_vm_open, 2312 .close = comedi_vm_close, 2313 .access = comedi_vm_access, 2314 }; 2315 2316 static int comedi_mmap(struct file *file, struct vm_area_struct *vma) 2317 { 2318 struct comedi_file *cfp = file->private_data; 2319 struct comedi_device *dev = cfp->dev; 2320 struct comedi_subdevice *s; 2321 struct comedi_async *async; 2322 struct comedi_buf_map *bm = NULL; 2323 struct comedi_buf_page *buf; 2324 unsigned long start = vma->vm_start; 2325 unsigned long size; 2326 int n_pages; 2327 int i; 2328 int retval = 0; 2329 2330 /* 2331 * 'trylock' avoids circular dependency with current->mm->mmap_lock 2332 * and down-reading &dev->attach_lock should normally succeed without 2333 * contention unless the device is in the process of being attached 2334 * or detached. 2335 */ 2336 if (!down_read_trylock(&dev->attach_lock)) 2337 return -EAGAIN; 2338 2339 if (!dev->attached) { 2340 dev_dbg(dev->class_dev, "no driver attached\n"); 2341 retval = -ENODEV; 2342 goto done; 2343 } 2344 2345 if (vma->vm_flags & VM_WRITE) 2346 s = comedi_file_write_subdevice(file); 2347 else 2348 s = comedi_file_read_subdevice(file); 2349 if (!s) { 2350 retval = -EINVAL; 2351 goto done; 2352 } 2353 2354 async = s->async; 2355 if (!async) { 2356 retval = -EINVAL; 2357 goto done; 2358 } 2359 2360 if (vma->vm_pgoff != 0) { 2361 dev_dbg(dev->class_dev, "mmap() offset must be 0.\n"); 2362 retval = -EINVAL; 2363 goto done; 2364 } 2365 2366 size = vma->vm_end - vma->vm_start; 2367 if (size > async->prealloc_bufsz) { 2368 retval = -EFAULT; 2369 goto done; 2370 } 2371 if (offset_in_page(size)) { 2372 retval = -EFAULT; 2373 goto done; 2374 } 2375 2376 n_pages = vma_pages(vma); 2377 2378 /* get reference to current buf map (if any) */ 2379 bm = comedi_buf_map_from_subdev_get(s); 2380 if (!bm || n_pages > bm->n_pages) { 2381 retval = -EINVAL; 2382 goto done; 2383 } 2384 if (bm->dma_dir != DMA_NONE) { 2385 /* 2386 * DMA buffer was allocated as a single block. 2387 * Address is in page_list[0]. 2388 */ 2389 buf = &bm->page_list[0]; 2390 retval = dma_mmap_coherent(bm->dma_hw_dev, vma, buf->virt_addr, 2391 buf->dma_addr, n_pages * PAGE_SIZE); 2392 } else { 2393 for (i = 0; i < n_pages; ++i) { 2394 unsigned long pfn; 2395 2396 buf = &bm->page_list[i]; 2397 pfn = page_to_pfn(virt_to_page(buf->virt_addr)); 2398 retval = remap_pfn_range(vma, start, pfn, PAGE_SIZE, 2399 PAGE_SHARED); 2400 if (retval) 2401 break; 2402 2403 start += PAGE_SIZE; 2404 } 2405 } 2406 2407 if (retval == 0) { 2408 vma->vm_ops = &comedi_vm_ops; 2409 vma->vm_private_data = bm; 2410 2411 vma->vm_ops->open(vma); 2412 } 2413 2414 done: 2415 up_read(&dev->attach_lock); 2416 comedi_buf_map_put(bm); /* put reference to buf map - okay if NULL */ 2417 return retval; 2418 } 2419 2420 static __poll_t comedi_poll(struct file *file, poll_table *wait) 2421 { 2422 __poll_t mask = 0; 2423 struct comedi_file *cfp = file->private_data; 2424 struct comedi_device *dev = cfp->dev; 2425 struct comedi_subdevice *s, *s_read; 2426 2427 down_read(&dev->attach_lock); 2428 2429 if (!dev->attached) { 2430 dev_dbg(dev->class_dev, "no driver attached\n"); 2431 goto done; 2432 } 2433 2434 s = comedi_file_read_subdevice(file); 2435 s_read = s; 2436 if (s && s->async) { 2437 poll_wait(file, &s->async->wait_head, wait); 2438 if (s->busy != file || !comedi_is_subdevice_running(s) || 2439 (s->async->cmd.flags & CMDF_WRITE) || 2440 comedi_buf_read_n_available(s) > 0) 2441 mask |= EPOLLIN | EPOLLRDNORM; 2442 } 2443 2444 s = comedi_file_write_subdevice(file); 2445 if (s && s->async) { 2446 unsigned int bps = comedi_bytes_per_sample(s); 2447 2448 if (s != s_read) 2449 poll_wait(file, &s->async->wait_head, wait); 2450 if (s->busy != file || !comedi_is_subdevice_running(s) || 2451 !(s->async->cmd.flags & CMDF_WRITE) || 2452 comedi_buf_write_n_available(s) >= bps) 2453 mask |= EPOLLOUT | EPOLLWRNORM; 2454 } 2455 2456 done: 2457 up_read(&dev->attach_lock); 2458 return mask; 2459 } 2460 2461 static ssize_t comedi_write(struct file *file, const char __user *buf, 2462 size_t nbytes, loff_t *offset) 2463 { 2464 struct comedi_subdevice *s; 2465 struct comedi_async *async; 2466 unsigned int n, m; 2467 ssize_t count = 0; 2468 int retval = 0; 2469 DECLARE_WAITQUEUE(wait, current); 2470 struct comedi_file *cfp = file->private_data; 2471 struct comedi_device *dev = cfp->dev; 2472 bool become_nonbusy = false; 2473 bool attach_locked; 2474 unsigned int old_detach_count; 2475 2476 /* Protect against device detachment during operation. */ 2477 down_read(&dev->attach_lock); 2478 attach_locked = true; 2479 old_detach_count = dev->detach_count; 2480 2481 if (!dev->attached) { 2482 dev_dbg(dev->class_dev, "no driver attached\n"); 2483 retval = -ENODEV; 2484 goto out; 2485 } 2486 2487 s = comedi_file_write_subdevice(file); 2488 if (!s || !s->async) { 2489 retval = -EIO; 2490 goto out; 2491 } 2492 2493 async = s->async; 2494 if (s->busy != file || !(async->cmd.flags & CMDF_WRITE)) { 2495 retval = -EINVAL; 2496 goto out; 2497 } 2498 2499 add_wait_queue(&async->wait_head, &wait); 2500 while (count == 0 && !retval) { 2501 unsigned int runflags; 2502 unsigned int wp, n1, n2; 2503 2504 set_current_state(TASK_INTERRUPTIBLE); 2505 2506 runflags = comedi_get_subdevice_runflags(s); 2507 if (!comedi_is_runflags_running(runflags)) { 2508 if (comedi_is_runflags_in_error(runflags)) 2509 retval = -EPIPE; 2510 if (retval || nbytes) 2511 become_nonbusy = true; 2512 break; 2513 } 2514 if (nbytes == 0) 2515 break; 2516 2517 /* Allocate all free buffer space. */ 2518 comedi_buf_write_alloc(s, async->prealloc_bufsz); 2519 m = comedi_buf_write_n_allocated(s); 2520 n = min_t(size_t, m, nbytes); 2521 2522 if (n == 0) { 2523 if (file->f_flags & O_NONBLOCK) { 2524 retval = -EAGAIN; 2525 break; 2526 } 2527 schedule(); 2528 if (signal_pending(current)) { 2529 retval = -ERESTARTSYS; 2530 break; 2531 } 2532 if (s->busy != file || 2533 !(async->cmd.flags & CMDF_WRITE)) { 2534 retval = -EINVAL; 2535 break; 2536 } 2537 continue; 2538 } 2539 2540 set_current_state(TASK_RUNNING); 2541 wp = async->buf_write_ptr; 2542 n1 = min(n, async->prealloc_bufsz - wp); 2543 n2 = n - n1; 2544 m = copy_from_user(async->prealloc_buf + wp, buf, n1); 2545 if (m) 2546 m += n2; 2547 else if (n2) 2548 m = copy_from_user(async->prealloc_buf, buf + n1, n2); 2549 if (m) { 2550 n -= m; 2551 retval = -EFAULT; 2552 } 2553 comedi_buf_write_free(s, n); 2554 2555 count += n; 2556 nbytes -= n; 2557 2558 buf += n; 2559 } 2560 remove_wait_queue(&async->wait_head, &wait); 2561 set_current_state(TASK_RUNNING); 2562 if (become_nonbusy && count == 0) { 2563 struct comedi_subdevice *new_s; 2564 2565 /* 2566 * To avoid deadlock, cannot acquire dev->mutex 2567 * while dev->attach_lock is held. 2568 */ 2569 up_read(&dev->attach_lock); 2570 attach_locked = false; 2571 mutex_lock(&dev->mutex); 2572 /* 2573 * Check device hasn't become detached behind our back. 2574 * Checking dev->detach_count is unchanged ought to be 2575 * sufficient (unless there have been 2**32 detaches in the 2576 * meantime!), but check the subdevice pointer as well just in 2577 * case. 2578 * 2579 * Also check the subdevice is still in a suitable state to 2580 * become non-busy in case it changed behind our back. 2581 */ 2582 new_s = comedi_file_write_subdevice(file); 2583 if (dev->attached && old_detach_count == dev->detach_count && 2584 s == new_s && new_s->async == async && s->busy == file && 2585 (async->cmd.flags & CMDF_WRITE) && 2586 !comedi_is_subdevice_running(s)) 2587 do_become_nonbusy(dev, s); 2588 mutex_unlock(&dev->mutex); 2589 } 2590 out: 2591 if (attach_locked) 2592 up_read(&dev->attach_lock); 2593 2594 return count ? count : retval; 2595 } 2596 2597 static ssize_t comedi_read(struct file *file, char __user *buf, size_t nbytes, 2598 loff_t *offset) 2599 { 2600 struct comedi_subdevice *s; 2601 struct comedi_async *async; 2602 unsigned int n, m; 2603 ssize_t count = 0; 2604 int retval = 0; 2605 DECLARE_WAITQUEUE(wait, current); 2606 struct comedi_file *cfp = file->private_data; 2607 struct comedi_device *dev = cfp->dev; 2608 unsigned int old_detach_count; 2609 bool become_nonbusy = false; 2610 bool attach_locked; 2611 2612 /* Protect against device detachment during operation. */ 2613 down_read(&dev->attach_lock); 2614 attach_locked = true; 2615 old_detach_count = dev->detach_count; 2616 2617 if (!dev->attached) { 2618 dev_dbg(dev->class_dev, "no driver attached\n"); 2619 retval = -ENODEV; 2620 goto out; 2621 } 2622 2623 s = comedi_file_read_subdevice(file); 2624 if (!s || !s->async) { 2625 retval = -EIO; 2626 goto out; 2627 } 2628 2629 async = s->async; 2630 if (s->busy != file || (async->cmd.flags & CMDF_WRITE)) { 2631 retval = -EINVAL; 2632 goto out; 2633 } 2634 2635 add_wait_queue(&async->wait_head, &wait); 2636 while (count == 0 && !retval) { 2637 unsigned int rp, n1, n2; 2638 2639 set_current_state(TASK_INTERRUPTIBLE); 2640 2641 m = comedi_buf_read_n_available(s); 2642 n = min_t(size_t, m, nbytes); 2643 2644 if (n == 0) { 2645 unsigned int runflags = 2646 comedi_get_subdevice_runflags(s); 2647 2648 if (!comedi_is_runflags_running(runflags)) { 2649 if (comedi_is_runflags_in_error(runflags)) 2650 retval = -EPIPE; 2651 if (retval || nbytes) 2652 become_nonbusy = true; 2653 break; 2654 } 2655 if (nbytes == 0) 2656 break; 2657 if (file->f_flags & O_NONBLOCK) { 2658 retval = -EAGAIN; 2659 break; 2660 } 2661 schedule(); 2662 if (signal_pending(current)) { 2663 retval = -ERESTARTSYS; 2664 break; 2665 } 2666 if (s->busy != file || 2667 (async->cmd.flags & CMDF_WRITE)) { 2668 retval = -EINVAL; 2669 break; 2670 } 2671 continue; 2672 } 2673 2674 set_current_state(TASK_RUNNING); 2675 rp = async->buf_read_ptr; 2676 n1 = min(n, async->prealloc_bufsz - rp); 2677 n2 = n - n1; 2678 m = copy_to_user(buf, async->prealloc_buf + rp, n1); 2679 if (m) 2680 m += n2; 2681 else if (n2) 2682 m = copy_to_user(buf + n1, async->prealloc_buf, n2); 2683 if (m) { 2684 n -= m; 2685 retval = -EFAULT; 2686 } 2687 2688 comedi_buf_read_alloc(s, n); 2689 comedi_buf_read_free(s, n); 2690 2691 count += n; 2692 nbytes -= n; 2693 2694 buf += n; 2695 } 2696 remove_wait_queue(&async->wait_head, &wait); 2697 set_current_state(TASK_RUNNING); 2698 if (become_nonbusy && count == 0) { 2699 struct comedi_subdevice *new_s; 2700 2701 /* 2702 * To avoid deadlock, cannot acquire dev->mutex 2703 * while dev->attach_lock is held. 2704 */ 2705 up_read(&dev->attach_lock); 2706 attach_locked = false; 2707 mutex_lock(&dev->mutex); 2708 /* 2709 * Check device hasn't become detached behind our back. 2710 * Checking dev->detach_count is unchanged ought to be 2711 * sufficient (unless there have been 2**32 detaches in the 2712 * meantime!), but check the subdevice pointer as well just in 2713 * case. 2714 * 2715 * Also check the subdevice is still in a suitable state to 2716 * become non-busy in case it changed behind our back. 2717 */ 2718 new_s = comedi_file_read_subdevice(file); 2719 if (dev->attached && old_detach_count == dev->detach_count && 2720 s == new_s && new_s->async == async && s->busy == file && 2721 !(async->cmd.flags & CMDF_WRITE) && 2722 !comedi_is_subdevice_running(s) && 2723 comedi_buf_read_n_available(s) == 0) 2724 do_become_nonbusy(dev, s); 2725 mutex_unlock(&dev->mutex); 2726 } 2727 out: 2728 if (attach_locked) 2729 up_read(&dev->attach_lock); 2730 2731 return count ? count : retval; 2732 } 2733 2734 static int comedi_open(struct inode *inode, struct file *file) 2735 { 2736 const unsigned int minor = iminor(inode); 2737 struct comedi_file *cfp; 2738 struct comedi_device *dev = comedi_dev_get_from_minor(minor); 2739 int rc; 2740 2741 if (!dev) { 2742 pr_debug("invalid minor number\n"); 2743 return -ENODEV; 2744 } 2745 2746 cfp = kzalloc(sizeof(*cfp), GFP_KERNEL); 2747 if (!cfp) { 2748 comedi_dev_put(dev); 2749 return -ENOMEM; 2750 } 2751 2752 cfp->dev = dev; 2753 2754 mutex_lock(&dev->mutex); 2755 if (!dev->attached && !capable(CAP_SYS_ADMIN)) { 2756 dev_dbg(dev->class_dev, "not attached and not CAP_SYS_ADMIN\n"); 2757 rc = -ENODEV; 2758 goto out; 2759 } 2760 if (dev->attached && dev->use_count == 0) { 2761 if (!try_module_get(dev->driver->module)) { 2762 rc = -ENXIO; 2763 goto out; 2764 } 2765 if (dev->open) { 2766 rc = dev->open(dev); 2767 if (rc < 0) { 2768 module_put(dev->driver->module); 2769 goto out; 2770 } 2771 } 2772 } 2773 2774 dev->use_count++; 2775 file->private_data = cfp; 2776 comedi_file_reset(file); 2777 rc = 0; 2778 2779 out: 2780 mutex_unlock(&dev->mutex); 2781 if (rc) { 2782 comedi_dev_put(dev); 2783 kfree(cfp); 2784 } 2785 return rc; 2786 } 2787 2788 static int comedi_fasync(int fd, struct file *file, int on) 2789 { 2790 struct comedi_file *cfp = file->private_data; 2791 struct comedi_device *dev = cfp->dev; 2792 2793 return fasync_helper(fd, file, on, &dev->async_queue); 2794 } 2795 2796 static int comedi_close(struct inode *inode, struct file *file) 2797 { 2798 struct comedi_file *cfp = file->private_data; 2799 struct comedi_device *dev = cfp->dev; 2800 struct comedi_subdevice *s = NULL; 2801 int i; 2802 2803 mutex_lock(&dev->mutex); 2804 2805 if (dev->subdevices) { 2806 for (i = 0; i < dev->n_subdevices; i++) { 2807 s = &dev->subdevices[i]; 2808 2809 if (s->busy == file) 2810 do_cancel(dev, s); 2811 if (s->lock == file) 2812 s->lock = NULL; 2813 } 2814 } 2815 if (dev->attached && dev->use_count == 1) { 2816 if (dev->close) 2817 dev->close(dev); 2818 module_put(dev->driver->module); 2819 } 2820 2821 dev->use_count--; 2822 2823 mutex_unlock(&dev->mutex); 2824 comedi_dev_put(dev); 2825 kfree(cfp); 2826 2827 return 0; 2828 } 2829 2830 #ifdef CONFIG_COMPAT 2831 2832 #define COMEDI32_CHANINFO _IOR(CIO, 3, struct comedi32_chaninfo_struct) 2833 #define COMEDI32_RANGEINFO _IOR(CIO, 8, struct comedi32_rangeinfo_struct) 2834 /* 2835 * N.B. COMEDI32_CMD and COMEDI_CMD ought to use _IOWR, not _IOR. 2836 * It's too late to change it now, but it only affects the command number. 2837 */ 2838 #define COMEDI32_CMD _IOR(CIO, 9, struct comedi32_cmd_struct) 2839 /* 2840 * N.B. COMEDI32_CMDTEST and COMEDI_CMDTEST ought to use _IOWR, not _IOR. 2841 * It's too late to change it now, but it only affects the command number. 2842 */ 2843 #define COMEDI32_CMDTEST _IOR(CIO, 10, struct comedi32_cmd_struct) 2844 #define COMEDI32_INSNLIST _IOR(CIO, 11, struct comedi32_insnlist_struct) 2845 #define COMEDI32_INSN _IOR(CIO, 12, struct comedi32_insn_struct) 2846 2847 struct comedi32_chaninfo_struct { 2848 unsigned int subdev; 2849 compat_uptr_t maxdata_list; /* 32-bit 'unsigned int *' */ 2850 compat_uptr_t flaglist; /* 32-bit 'unsigned int *' */ 2851 compat_uptr_t rangelist; /* 32-bit 'unsigned int *' */ 2852 unsigned int unused[4]; 2853 }; 2854 2855 struct comedi32_rangeinfo_struct { 2856 unsigned int range_type; 2857 compat_uptr_t range_ptr; /* 32-bit 'void *' */ 2858 }; 2859 2860 struct comedi32_cmd_struct { 2861 unsigned int subdev; 2862 unsigned int flags; 2863 unsigned int start_src; 2864 unsigned int start_arg; 2865 unsigned int scan_begin_src; 2866 unsigned int scan_begin_arg; 2867 unsigned int convert_src; 2868 unsigned int convert_arg; 2869 unsigned int scan_end_src; 2870 unsigned int scan_end_arg; 2871 unsigned int stop_src; 2872 unsigned int stop_arg; 2873 compat_uptr_t chanlist; /* 32-bit 'unsigned int *' */ 2874 unsigned int chanlist_len; 2875 compat_uptr_t data; /* 32-bit 'short *' */ 2876 unsigned int data_len; 2877 }; 2878 2879 struct comedi32_insn_struct { 2880 unsigned int insn; 2881 unsigned int n; 2882 compat_uptr_t data; /* 32-bit 'unsigned int *' */ 2883 unsigned int subdev; 2884 unsigned int chanspec; 2885 unsigned int unused[3]; 2886 }; 2887 2888 struct comedi32_insnlist_struct { 2889 unsigned int n_insns; 2890 compat_uptr_t insns; /* 32-bit 'struct comedi_insn *' */ 2891 }; 2892 2893 /* Handle 32-bit COMEDI_CHANINFO ioctl. */ 2894 static int compat_chaninfo(struct file *file, unsigned long arg) 2895 { 2896 struct comedi_file *cfp = file->private_data; 2897 struct comedi_device *dev = cfp->dev; 2898 struct comedi32_chaninfo_struct chaninfo32; 2899 struct comedi_chaninfo chaninfo; 2900 int err; 2901 2902 if (copy_from_user(&chaninfo32, compat_ptr(arg), sizeof(chaninfo32))) 2903 return -EFAULT; 2904 2905 memset(&chaninfo, 0, sizeof(chaninfo)); 2906 chaninfo.subdev = chaninfo32.subdev; 2907 chaninfo.maxdata_list = compat_ptr(chaninfo32.maxdata_list); 2908 chaninfo.flaglist = compat_ptr(chaninfo32.flaglist); 2909 chaninfo.rangelist = compat_ptr(chaninfo32.rangelist); 2910 2911 mutex_lock(&dev->mutex); 2912 err = do_chaninfo_ioctl(dev, &chaninfo); 2913 mutex_unlock(&dev->mutex); 2914 return err; 2915 } 2916 2917 /* Handle 32-bit COMEDI_RANGEINFO ioctl. */ 2918 static int compat_rangeinfo(struct file *file, unsigned long arg) 2919 { 2920 struct comedi_file *cfp = file->private_data; 2921 struct comedi_device *dev = cfp->dev; 2922 struct comedi32_rangeinfo_struct rangeinfo32; 2923 struct comedi_rangeinfo rangeinfo; 2924 int err; 2925 2926 if (copy_from_user(&rangeinfo32, compat_ptr(arg), sizeof(rangeinfo32))) 2927 return -EFAULT; 2928 memset(&rangeinfo, 0, sizeof(rangeinfo)); 2929 rangeinfo.range_type = rangeinfo32.range_type; 2930 rangeinfo.range_ptr = compat_ptr(rangeinfo32.range_ptr); 2931 2932 mutex_lock(&dev->mutex); 2933 err = do_rangeinfo_ioctl(dev, &rangeinfo); 2934 mutex_unlock(&dev->mutex); 2935 return err; 2936 } 2937 2938 /* Copy 32-bit cmd structure to native cmd structure. */ 2939 static int get_compat_cmd(struct comedi_cmd *cmd, 2940 struct comedi32_cmd_struct __user *cmd32) 2941 { 2942 struct comedi32_cmd_struct v32; 2943 2944 if (copy_from_user(&v32, cmd32, sizeof(v32))) 2945 return -EFAULT; 2946 2947 cmd->subdev = v32.subdev; 2948 cmd->flags = v32.flags; 2949 cmd->start_src = v32.start_src; 2950 cmd->start_arg = v32.start_arg; 2951 cmd->scan_begin_src = v32.scan_begin_src; 2952 cmd->scan_begin_arg = v32.scan_begin_arg; 2953 cmd->convert_src = v32.convert_src; 2954 cmd->convert_arg = v32.convert_arg; 2955 cmd->scan_end_src = v32.scan_end_src; 2956 cmd->scan_end_arg = v32.scan_end_arg; 2957 cmd->stop_src = v32.stop_src; 2958 cmd->stop_arg = v32.stop_arg; 2959 cmd->chanlist = (unsigned int __force *)compat_ptr(v32.chanlist); 2960 cmd->chanlist_len = v32.chanlist_len; 2961 cmd->data = compat_ptr(v32.data); 2962 cmd->data_len = v32.data_len; 2963 return 0; 2964 } 2965 2966 /* Copy native cmd structure to 32-bit cmd structure. */ 2967 static int put_compat_cmd(struct comedi32_cmd_struct __user *cmd32, 2968 struct comedi_cmd *cmd) 2969 { 2970 struct comedi32_cmd_struct v32; 2971 2972 memset(&v32, 0, sizeof(v32)); 2973 v32.subdev = cmd->subdev; 2974 v32.flags = cmd->flags; 2975 v32.start_src = cmd->start_src; 2976 v32.start_arg = cmd->start_arg; 2977 v32.scan_begin_src = cmd->scan_begin_src; 2978 v32.scan_begin_arg = cmd->scan_begin_arg; 2979 v32.convert_src = cmd->convert_src; 2980 v32.convert_arg = cmd->convert_arg; 2981 v32.scan_end_src = cmd->scan_end_src; 2982 v32.scan_end_arg = cmd->scan_end_arg; 2983 v32.stop_src = cmd->stop_src; 2984 v32.stop_arg = cmd->stop_arg; 2985 /* Assume chanlist pointer is unchanged. */ 2986 v32.chanlist = ptr_to_compat((unsigned int __user *)cmd->chanlist); 2987 v32.chanlist_len = cmd->chanlist_len; 2988 v32.data = ptr_to_compat(cmd->data); 2989 v32.data_len = cmd->data_len; 2990 if (copy_to_user(cmd32, &v32, sizeof(v32))) 2991 return -EFAULT; 2992 return 0; 2993 } 2994 2995 /* Handle 32-bit COMEDI_CMD ioctl. */ 2996 static int compat_cmd(struct file *file, unsigned long arg) 2997 { 2998 struct comedi_file *cfp = file->private_data; 2999 struct comedi_device *dev = cfp->dev; 3000 struct comedi_cmd cmd; 3001 bool copy = false; 3002 int rc, err; 3003 3004 rc = get_compat_cmd(&cmd, compat_ptr(arg)); 3005 if (rc) 3006 return rc; 3007 3008 mutex_lock(&dev->mutex); 3009 rc = do_cmd_ioctl(dev, &cmd, ©, file); 3010 mutex_unlock(&dev->mutex); 3011 if (copy) { 3012 /* Special case: copy cmd back to user. */ 3013 err = put_compat_cmd(compat_ptr(arg), &cmd); 3014 if (err) 3015 rc = err; 3016 } 3017 return rc; 3018 } 3019 3020 /* Handle 32-bit COMEDI_CMDTEST ioctl. */ 3021 static int compat_cmdtest(struct file *file, unsigned long arg) 3022 { 3023 struct comedi_file *cfp = file->private_data; 3024 struct comedi_device *dev = cfp->dev; 3025 struct comedi_cmd cmd; 3026 bool copy = false; 3027 int rc, err; 3028 3029 rc = get_compat_cmd(&cmd, compat_ptr(arg)); 3030 if (rc) 3031 return rc; 3032 3033 mutex_lock(&dev->mutex); 3034 rc = do_cmdtest_ioctl(dev, &cmd, ©, file); 3035 mutex_unlock(&dev->mutex); 3036 if (copy) { 3037 err = put_compat_cmd(compat_ptr(arg), &cmd); 3038 if (err) 3039 rc = err; 3040 } 3041 return rc; 3042 } 3043 3044 /* Copy 32-bit insn structure to native insn structure. */ 3045 static int get_compat_insn(struct comedi_insn *insn, 3046 struct comedi32_insn_struct __user *insn32) 3047 { 3048 struct comedi32_insn_struct v32; 3049 3050 /* Copy insn structure. Ignore the unused members. */ 3051 if (copy_from_user(&v32, insn32, sizeof(v32))) 3052 return -EFAULT; 3053 memset(insn, 0, sizeof(*insn)); 3054 insn->insn = v32.insn; 3055 insn->n = v32.n; 3056 insn->data = compat_ptr(v32.data); 3057 insn->subdev = v32.subdev; 3058 insn->chanspec = v32.chanspec; 3059 return 0; 3060 } 3061 3062 /* Handle 32-bit COMEDI_INSNLIST ioctl. */ 3063 static int compat_insnlist(struct file *file, unsigned long arg) 3064 { 3065 struct comedi_file *cfp = file->private_data; 3066 struct comedi_device *dev = cfp->dev; 3067 struct comedi32_insnlist_struct insnlist32; 3068 struct comedi32_insn_struct __user *insn32; 3069 struct comedi_insn *insns; 3070 unsigned int n; 3071 int rc; 3072 3073 if (copy_from_user(&insnlist32, compat_ptr(arg), sizeof(insnlist32))) 3074 return -EFAULT; 3075 3076 insns = kcalloc(insnlist32.n_insns, sizeof(*insns), GFP_KERNEL); 3077 if (!insns) 3078 return -ENOMEM; 3079 3080 /* Copy insn structures. */ 3081 insn32 = compat_ptr(insnlist32.insns); 3082 for (n = 0; n < insnlist32.n_insns; n++) { 3083 rc = get_compat_insn(insns + n, insn32 + n); 3084 if (rc) { 3085 kfree(insns); 3086 return rc; 3087 } 3088 } 3089 3090 mutex_lock(&dev->mutex); 3091 rc = do_insnlist_ioctl(dev, insns, insnlist32.n_insns, file); 3092 mutex_unlock(&dev->mutex); 3093 return rc; 3094 } 3095 3096 /* Handle 32-bit COMEDI_INSN ioctl. */ 3097 static int compat_insn(struct file *file, unsigned long arg) 3098 { 3099 struct comedi_file *cfp = file->private_data; 3100 struct comedi_device *dev = cfp->dev; 3101 struct comedi_insn insn; 3102 int rc; 3103 3104 rc = get_compat_insn(&insn, (void __user *)arg); 3105 if (rc) 3106 return rc; 3107 3108 mutex_lock(&dev->mutex); 3109 rc = do_insn_ioctl(dev, &insn, file); 3110 mutex_unlock(&dev->mutex); 3111 return rc; 3112 } 3113 3114 /* 3115 * compat_ioctl file operation. 3116 * 3117 * Returns -ENOIOCTLCMD for unrecognised ioctl codes. 3118 */ 3119 static long comedi_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 3120 { 3121 int rc; 3122 3123 switch (cmd) { 3124 case COMEDI_DEVCONFIG: 3125 case COMEDI_DEVINFO: 3126 case COMEDI_SUBDINFO: 3127 case COMEDI_BUFCONFIG: 3128 case COMEDI_BUFINFO: 3129 /* Just need to translate the pointer argument. */ 3130 arg = (unsigned long)compat_ptr(arg); 3131 rc = comedi_unlocked_ioctl(file, cmd, arg); 3132 break; 3133 case COMEDI_LOCK: 3134 case COMEDI_UNLOCK: 3135 case COMEDI_CANCEL: 3136 case COMEDI_POLL: 3137 case COMEDI_SETRSUBD: 3138 case COMEDI_SETWSUBD: 3139 /* No translation needed. */ 3140 rc = comedi_unlocked_ioctl(file, cmd, arg); 3141 break; 3142 case COMEDI32_CHANINFO: 3143 rc = compat_chaninfo(file, arg); 3144 break; 3145 case COMEDI32_RANGEINFO: 3146 rc = compat_rangeinfo(file, arg); 3147 break; 3148 case COMEDI32_CMD: 3149 rc = compat_cmd(file, arg); 3150 break; 3151 case COMEDI32_CMDTEST: 3152 rc = compat_cmdtest(file, arg); 3153 break; 3154 case COMEDI32_INSNLIST: 3155 rc = compat_insnlist(file, arg); 3156 break; 3157 case COMEDI32_INSN: 3158 rc = compat_insn(file, arg); 3159 break; 3160 default: 3161 rc = -ENOIOCTLCMD; 3162 break; 3163 } 3164 return rc; 3165 } 3166 #else 3167 #define comedi_compat_ioctl NULL 3168 #endif 3169 3170 static const struct file_operations comedi_fops = { 3171 .owner = THIS_MODULE, 3172 .unlocked_ioctl = comedi_unlocked_ioctl, 3173 .compat_ioctl = comedi_compat_ioctl, 3174 .open = comedi_open, 3175 .release = comedi_close, 3176 .read = comedi_read, 3177 .write = comedi_write, 3178 .mmap = comedi_mmap, 3179 .poll = comedi_poll, 3180 .fasync = comedi_fasync, 3181 .llseek = noop_llseek, 3182 }; 3183 3184 /** 3185 * comedi_event() - Handle events for asynchronous COMEDI command 3186 * @dev: COMEDI device. 3187 * @s: COMEDI subdevice. 3188 * Context: in_interrupt() (usually), @s->spin_lock spin-lock not held. 3189 * 3190 * If an asynchronous COMEDI command is active on the subdevice, process 3191 * any %COMEDI_CB_... event flags that have been set, usually by an 3192 * interrupt handler. These may change the run state of the asynchronous 3193 * command, wake a task, and/or send a %SIGIO signal. 3194 */ 3195 void comedi_event(struct comedi_device *dev, struct comedi_subdevice *s) 3196 { 3197 struct comedi_async *async = s->async; 3198 unsigned int events; 3199 int si_code = 0; 3200 unsigned long flags; 3201 3202 spin_lock_irqsave(&s->spin_lock, flags); 3203 3204 events = async->events; 3205 async->events = 0; 3206 if (!__comedi_is_subdevice_running(s)) { 3207 spin_unlock_irqrestore(&s->spin_lock, flags); 3208 return; 3209 } 3210 3211 if (events & COMEDI_CB_CANCEL_MASK) 3212 __comedi_clear_subdevice_runflags(s, COMEDI_SRF_RUNNING); 3213 3214 /* 3215 * Remember if an error event has occurred, so an error can be 3216 * returned the next time the user does a read() or write(). 3217 */ 3218 if (events & COMEDI_CB_ERROR_MASK) 3219 __comedi_set_subdevice_runflags(s, COMEDI_SRF_ERROR); 3220 3221 if (async->cb_mask & events) { 3222 wake_up_interruptible(&async->wait_head); 3223 si_code = async->cmd.flags & CMDF_WRITE ? POLL_OUT : POLL_IN; 3224 } 3225 3226 spin_unlock_irqrestore(&s->spin_lock, flags); 3227 3228 if (si_code) 3229 kill_fasync(&dev->async_queue, SIGIO, si_code); 3230 } 3231 EXPORT_SYMBOL_GPL(comedi_event); 3232 3233 /* Note: the ->mutex is pre-locked on successful return */ 3234 struct comedi_device *comedi_alloc_board_minor(struct device *hardware_device) 3235 { 3236 struct comedi_device *dev; 3237 struct device *csdev; 3238 unsigned int i; 3239 3240 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 3241 if (!dev) 3242 return ERR_PTR(-ENOMEM); 3243 comedi_device_init(dev); 3244 comedi_set_hw_dev(dev, hardware_device); 3245 mutex_lock(&dev->mutex); 3246 mutex_lock(&comedi_board_minor_table_lock); 3247 for (i = hardware_device ? comedi_num_legacy_minors : 0; 3248 i < COMEDI_NUM_BOARD_MINORS; ++i) { 3249 if (!comedi_board_minor_table[i]) { 3250 comedi_board_minor_table[i] = dev; 3251 break; 3252 } 3253 } 3254 mutex_unlock(&comedi_board_minor_table_lock); 3255 if (i == COMEDI_NUM_BOARD_MINORS) { 3256 mutex_unlock(&dev->mutex); 3257 comedi_device_cleanup(dev); 3258 comedi_dev_put(dev); 3259 dev_err(hardware_device, 3260 "ran out of minor numbers for board device files\n"); 3261 return ERR_PTR(-EBUSY); 3262 } 3263 dev->minor = i; 3264 csdev = device_create(comedi_class, hardware_device, 3265 MKDEV(COMEDI_MAJOR, i), NULL, "comedi%i", i); 3266 if (!IS_ERR(csdev)) 3267 dev->class_dev = get_device(csdev); 3268 3269 /* Note: dev->mutex needs to be unlocked by the caller. */ 3270 return dev; 3271 } 3272 3273 void comedi_release_hardware_device(struct device *hardware_device) 3274 { 3275 int minor; 3276 struct comedi_device *dev; 3277 3278 for (minor = comedi_num_legacy_minors; minor < COMEDI_NUM_BOARD_MINORS; 3279 minor++) { 3280 mutex_lock(&comedi_board_minor_table_lock); 3281 dev = comedi_board_minor_table[minor]; 3282 if (dev && dev->hw_dev == hardware_device) { 3283 comedi_board_minor_table[minor] = NULL; 3284 mutex_unlock(&comedi_board_minor_table_lock); 3285 comedi_free_board_dev(dev); 3286 break; 3287 } 3288 mutex_unlock(&comedi_board_minor_table_lock); 3289 } 3290 } 3291 3292 int comedi_alloc_subdevice_minor(struct comedi_subdevice *s) 3293 { 3294 struct comedi_device *dev = s->device; 3295 struct device *csdev; 3296 unsigned int i; 3297 3298 mutex_lock(&comedi_subdevice_minor_table_lock); 3299 for (i = 0; i < COMEDI_NUM_SUBDEVICE_MINORS; ++i) { 3300 if (!comedi_subdevice_minor_table[i]) { 3301 comedi_subdevice_minor_table[i] = s; 3302 break; 3303 } 3304 } 3305 mutex_unlock(&comedi_subdevice_minor_table_lock); 3306 if (i == COMEDI_NUM_SUBDEVICE_MINORS) { 3307 dev_err(dev->class_dev, 3308 "ran out of minor numbers for subdevice files\n"); 3309 return -EBUSY; 3310 } 3311 i += COMEDI_NUM_BOARD_MINORS; 3312 s->minor = i; 3313 csdev = device_create(comedi_class, dev->class_dev, 3314 MKDEV(COMEDI_MAJOR, i), NULL, "comedi%i_subd%i", 3315 dev->minor, s->index); 3316 if (!IS_ERR(csdev)) 3317 s->class_dev = csdev; 3318 3319 return 0; 3320 } 3321 3322 void comedi_free_subdevice_minor(struct comedi_subdevice *s) 3323 { 3324 unsigned int i; 3325 3326 if (!s) 3327 return; 3328 if (s->minor < COMEDI_NUM_BOARD_MINORS || 3329 s->minor >= COMEDI_NUM_MINORS) 3330 return; 3331 3332 i = s->minor - COMEDI_NUM_BOARD_MINORS; 3333 mutex_lock(&comedi_subdevice_minor_table_lock); 3334 if (s == comedi_subdevice_minor_table[i]) 3335 comedi_subdevice_minor_table[i] = NULL; 3336 mutex_unlock(&comedi_subdevice_minor_table_lock); 3337 if (s->class_dev) { 3338 device_destroy(comedi_class, MKDEV(COMEDI_MAJOR, s->minor)); 3339 s->class_dev = NULL; 3340 } 3341 } 3342 3343 static void comedi_cleanup_board_minors(void) 3344 { 3345 struct comedi_device *dev; 3346 unsigned int i; 3347 3348 for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) { 3349 dev = comedi_clear_board_minor(i); 3350 comedi_free_board_dev(dev); 3351 } 3352 } 3353 3354 static int __init comedi_init(void) 3355 { 3356 int i; 3357 int retval; 3358 3359 pr_info("version " COMEDI_RELEASE " - http://www.comedi.org\n"); 3360 3361 if (comedi_num_legacy_minors > COMEDI_NUM_BOARD_MINORS) { 3362 pr_err("invalid value for module parameter \"comedi_num_legacy_minors\". Valid values are 0 through %i.\n", 3363 COMEDI_NUM_BOARD_MINORS); 3364 return -EINVAL; 3365 } 3366 3367 retval = register_chrdev_region(MKDEV(COMEDI_MAJOR, 0), 3368 COMEDI_NUM_MINORS, "comedi"); 3369 if (retval) 3370 return retval; 3371 3372 cdev_init(&comedi_cdev, &comedi_fops); 3373 comedi_cdev.owner = THIS_MODULE; 3374 3375 retval = kobject_set_name(&comedi_cdev.kobj, "comedi"); 3376 if (retval) 3377 goto out_unregister_chrdev_region; 3378 3379 retval = cdev_add(&comedi_cdev, MKDEV(COMEDI_MAJOR, 0), 3380 COMEDI_NUM_MINORS); 3381 if (retval) 3382 goto out_unregister_chrdev_region; 3383 3384 comedi_class = class_create(THIS_MODULE, "comedi"); 3385 if (IS_ERR(comedi_class)) { 3386 retval = PTR_ERR(comedi_class); 3387 pr_err("failed to create class\n"); 3388 goto out_cdev_del; 3389 } 3390 3391 comedi_class->dev_groups = comedi_dev_groups; 3392 3393 /* create devices files for legacy/manual use */ 3394 for (i = 0; i < comedi_num_legacy_minors; i++) { 3395 struct comedi_device *dev; 3396 3397 dev = comedi_alloc_board_minor(NULL); 3398 if (IS_ERR(dev)) { 3399 retval = PTR_ERR(dev); 3400 goto out_cleanup_board_minors; 3401 } 3402 /* comedi_alloc_board_minor() locked the mutex */ 3403 lockdep_assert_held(&dev->mutex); 3404 mutex_unlock(&dev->mutex); 3405 } 3406 3407 /* XXX requires /proc interface */ 3408 comedi_proc_init(); 3409 3410 return 0; 3411 3412 out_cleanup_board_minors: 3413 comedi_cleanup_board_minors(); 3414 class_destroy(comedi_class); 3415 out_cdev_del: 3416 cdev_del(&comedi_cdev); 3417 out_unregister_chrdev_region: 3418 unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0), COMEDI_NUM_MINORS); 3419 return retval; 3420 } 3421 module_init(comedi_init); 3422 3423 static void __exit comedi_cleanup(void) 3424 { 3425 comedi_cleanup_board_minors(); 3426 class_destroy(comedi_class); 3427 cdev_del(&comedi_cdev); 3428 unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0), COMEDI_NUM_MINORS); 3429 3430 comedi_proc_cleanup(); 3431 } 3432 module_exit(comedi_cleanup); 3433 3434 MODULE_AUTHOR("https://www.comedi.org"); 3435 MODULE_DESCRIPTION("Comedi core module"); 3436 MODULE_LICENSE("GPL"); 3437