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 <linux/comedi/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 cdev comedi_cdev;
101
comedi_device_init(struct comedi_device * dev)102 static void comedi_device_init(struct comedi_device *dev)
103 {
104 kref_init(&dev->refcount);
105 spin_lock_init(&dev->spinlock);
106 mutex_init(&dev->mutex);
107 init_rwsem(&dev->attach_lock);
108 dev->minor = -1;
109 }
110
comedi_dev_kref_release(struct kref * kref)111 static void comedi_dev_kref_release(struct kref *kref)
112 {
113 struct comedi_device *dev =
114 container_of(kref, struct comedi_device, refcount);
115
116 mutex_destroy(&dev->mutex);
117 put_device(dev->class_dev);
118 kfree(dev);
119 }
120
121 /**
122 * comedi_dev_put() - Release a use of a COMEDI device
123 * @dev: COMEDI device.
124 *
125 * Must be called when a user of a COMEDI device is finished with it.
126 * When the last user of the COMEDI device calls this function, the
127 * COMEDI device is destroyed.
128 *
129 * Return: 1 if the COMEDI device is destroyed by this call or @dev is
130 * NULL, otherwise return 0. Callers must not assume the COMEDI
131 * device is still valid if this function returns 0.
132 */
comedi_dev_put(struct comedi_device * dev)133 int comedi_dev_put(struct comedi_device *dev)
134 {
135 if (dev)
136 return kref_put(&dev->refcount, comedi_dev_kref_release);
137 return 1;
138 }
139 EXPORT_SYMBOL_GPL(comedi_dev_put);
140
comedi_dev_get(struct comedi_device * dev)141 static struct comedi_device *comedi_dev_get(struct comedi_device *dev)
142 {
143 if (dev)
144 kref_get(&dev->refcount);
145 return dev;
146 }
147
comedi_device_cleanup(struct comedi_device * dev)148 static void comedi_device_cleanup(struct comedi_device *dev)
149 {
150 struct module *driver_module = NULL;
151
152 if (!dev)
153 return;
154 mutex_lock(&dev->mutex);
155 if (dev->attached)
156 driver_module = dev->driver->module;
157 comedi_device_detach(dev);
158 if (driver_module && dev->use_count)
159 module_put(driver_module);
160 mutex_unlock(&dev->mutex);
161 }
162
comedi_clear_board_dev(struct comedi_device * dev)163 static bool comedi_clear_board_dev(struct comedi_device *dev)
164 {
165 unsigned int i = dev->minor;
166 bool cleared = false;
167
168 lockdep_assert_held(&dev->mutex);
169 mutex_lock(&comedi_board_minor_table_lock);
170 if (dev == comedi_board_minor_table[i]) {
171 comedi_board_minor_table[i] = NULL;
172 cleared = true;
173 }
174 mutex_unlock(&comedi_board_minor_table_lock);
175 return cleared;
176 }
177
comedi_clear_board_minor(unsigned int minor)178 static struct comedi_device *comedi_clear_board_minor(unsigned int minor)
179 {
180 struct comedi_device *dev;
181
182 mutex_lock(&comedi_board_minor_table_lock);
183 dev = comedi_board_minor_table[minor];
184 comedi_board_minor_table[minor] = NULL;
185 mutex_unlock(&comedi_board_minor_table_lock);
186 return dev;
187 }
188
189 static struct comedi_subdevice *
comedi_subdevice_from_minor(const struct comedi_device * dev,unsigned int minor)190 comedi_subdevice_from_minor(const struct comedi_device *dev, unsigned int minor)
191 {
192 struct comedi_subdevice *s;
193 unsigned int i = minor - COMEDI_NUM_BOARD_MINORS;
194
195 mutex_lock(&comedi_subdevice_minor_table_lock);
196 s = comedi_subdevice_minor_table[i];
197 if (s && s->device != dev)
198 s = NULL;
199 mutex_unlock(&comedi_subdevice_minor_table_lock);
200 return s;
201 }
202
comedi_dev_get_from_board_minor(unsigned int minor)203 static struct comedi_device *comedi_dev_get_from_board_minor(unsigned int minor)
204 {
205 struct comedi_device *dev;
206
207 mutex_lock(&comedi_board_minor_table_lock);
208 dev = comedi_dev_get(comedi_board_minor_table[minor]);
209 mutex_unlock(&comedi_board_minor_table_lock);
210 return dev;
211 }
212
213 static struct comedi_device *
comedi_dev_get_from_subdevice_minor(unsigned int minor)214 comedi_dev_get_from_subdevice_minor(unsigned int minor)
215 {
216 struct comedi_device *dev;
217 struct comedi_subdevice *s;
218 unsigned int i = minor - COMEDI_NUM_BOARD_MINORS;
219
220 mutex_lock(&comedi_subdevice_minor_table_lock);
221 s = comedi_subdevice_minor_table[i];
222 dev = comedi_dev_get(s ? s->device : NULL);
223 mutex_unlock(&comedi_subdevice_minor_table_lock);
224 return dev;
225 }
226
227 /**
228 * comedi_dev_get_from_minor() - Get COMEDI device by minor device number
229 * @minor: Minor device number.
230 *
231 * Finds the COMEDI device associated with the minor device number, if any,
232 * and increments its reference count. The COMEDI device is prevented from
233 * being freed until a matching call is made to comedi_dev_put().
234 *
235 * Return: A pointer to the COMEDI device if it exists, with its usage
236 * reference incremented. Return NULL if no COMEDI device exists with the
237 * specified minor device number.
238 */
comedi_dev_get_from_minor(unsigned int minor)239 struct comedi_device *comedi_dev_get_from_minor(unsigned int minor)
240 {
241 if (minor < COMEDI_NUM_BOARD_MINORS)
242 return comedi_dev_get_from_board_minor(minor);
243
244 return comedi_dev_get_from_subdevice_minor(minor);
245 }
246 EXPORT_SYMBOL_GPL(comedi_dev_get_from_minor);
247
248 static struct comedi_subdevice *
comedi_read_subdevice(const struct comedi_device * dev,unsigned int minor)249 comedi_read_subdevice(const struct comedi_device *dev, unsigned int minor)
250 {
251 struct comedi_subdevice *s;
252
253 lockdep_assert_held(&dev->mutex);
254 if (minor >= COMEDI_NUM_BOARD_MINORS) {
255 s = comedi_subdevice_from_minor(dev, minor);
256 if (!s || (s->subdev_flags & SDF_CMD_READ))
257 return s;
258 }
259 return dev->read_subdev;
260 }
261
262 static struct comedi_subdevice *
comedi_write_subdevice(const struct comedi_device * dev,unsigned int minor)263 comedi_write_subdevice(const struct comedi_device *dev, unsigned int minor)
264 {
265 struct comedi_subdevice *s;
266
267 lockdep_assert_held(&dev->mutex);
268 if (minor >= COMEDI_NUM_BOARD_MINORS) {
269 s = comedi_subdevice_from_minor(dev, minor);
270 if (!s || (s->subdev_flags & SDF_CMD_WRITE))
271 return s;
272 }
273 return dev->write_subdev;
274 }
275
comedi_file_reset(struct file * file)276 static void comedi_file_reset(struct file *file)
277 {
278 struct comedi_file *cfp = file->private_data;
279 struct comedi_device *dev = cfp->dev;
280 struct comedi_subdevice *s, *read_s, *write_s;
281 unsigned int minor = iminor(file_inode(file));
282
283 read_s = dev->read_subdev;
284 write_s = dev->write_subdev;
285 if (minor >= COMEDI_NUM_BOARD_MINORS) {
286 s = comedi_subdevice_from_minor(dev, minor);
287 if (!s || s->subdev_flags & SDF_CMD_READ)
288 read_s = s;
289 if (!s || s->subdev_flags & SDF_CMD_WRITE)
290 write_s = s;
291 }
292 cfp->last_attached = dev->attached;
293 cfp->last_detach_count = dev->detach_count;
294 WRITE_ONCE(cfp->read_subdev, read_s);
295 WRITE_ONCE(cfp->write_subdev, write_s);
296 }
297
comedi_file_check(struct file * file)298 static void comedi_file_check(struct file *file)
299 {
300 struct comedi_file *cfp = file->private_data;
301 struct comedi_device *dev = cfp->dev;
302
303 if (cfp->last_attached != dev->attached ||
304 cfp->last_detach_count != dev->detach_count)
305 comedi_file_reset(file);
306 }
307
comedi_file_read_subdevice(struct file * file)308 static struct comedi_subdevice *comedi_file_read_subdevice(struct file *file)
309 {
310 struct comedi_file *cfp = file->private_data;
311
312 comedi_file_check(file);
313 return READ_ONCE(cfp->read_subdev);
314 }
315
comedi_file_write_subdevice(struct file * file)316 static struct comedi_subdevice *comedi_file_write_subdevice(struct file *file)
317 {
318 struct comedi_file *cfp = file->private_data;
319
320 comedi_file_check(file);
321 return READ_ONCE(cfp->write_subdev);
322 }
323
resize_async_buffer(struct comedi_device * dev,struct comedi_subdevice * s,unsigned int new_size)324 static int resize_async_buffer(struct comedi_device *dev,
325 struct comedi_subdevice *s,
326 unsigned int new_size)
327 {
328 struct comedi_async *async = s->async;
329 int retval;
330
331 lockdep_assert_held(&dev->mutex);
332
333 if (new_size > async->max_bufsize)
334 return -EPERM;
335
336 if (s->busy) {
337 dev_dbg(dev->class_dev,
338 "subdevice is busy, cannot resize buffer\n");
339 return -EBUSY;
340 }
341 if (comedi_buf_is_mmapped(s)) {
342 dev_dbg(dev->class_dev,
343 "subdevice is mmapped, cannot resize buffer\n");
344 return -EBUSY;
345 }
346
347 /* make sure buffer is an integral number of pages (we round up) */
348 new_size = (new_size + PAGE_SIZE - 1) & PAGE_MASK;
349
350 retval = comedi_buf_alloc(dev, s, new_size);
351 if (retval < 0)
352 return retval;
353
354 if (s->buf_change) {
355 retval = s->buf_change(dev, s);
356 if (retval < 0)
357 return retval;
358 }
359
360 dev_dbg(dev->class_dev, "subd %d buffer resized to %i bytes\n",
361 s->index, async->prealloc_bufsz);
362 return 0;
363 }
364
365 /* sysfs attribute files */
366
max_read_buffer_kb_show(struct device * csdev,struct device_attribute * attr,char * buf)367 static ssize_t max_read_buffer_kb_show(struct device *csdev,
368 struct device_attribute *attr, char *buf)
369 {
370 unsigned int minor = MINOR(csdev->devt);
371 struct comedi_device *dev;
372 struct comedi_subdevice *s;
373 unsigned int size = 0;
374
375 dev = comedi_dev_get_from_minor(minor);
376 if (!dev)
377 return -ENODEV;
378
379 mutex_lock(&dev->mutex);
380 s = comedi_read_subdevice(dev, minor);
381 if (s && (s->subdev_flags & SDF_CMD_READ) && s->async)
382 size = s->async->max_bufsize / 1024;
383 mutex_unlock(&dev->mutex);
384
385 comedi_dev_put(dev);
386 return sysfs_emit(buf, "%u\n", size);
387 }
388
max_read_buffer_kb_store(struct device * csdev,struct device_attribute * attr,const char * buf,size_t count)389 static ssize_t max_read_buffer_kb_store(struct device *csdev,
390 struct device_attribute *attr,
391 const char *buf, size_t count)
392 {
393 unsigned int minor = MINOR(csdev->devt);
394 struct comedi_device *dev;
395 struct comedi_subdevice *s;
396 unsigned int size;
397 int err;
398
399 err = kstrtouint(buf, 10, &size);
400 if (err)
401 return err;
402 if (size > (UINT_MAX / 1024))
403 return -EINVAL;
404 size *= 1024;
405
406 dev = comedi_dev_get_from_minor(minor);
407 if (!dev)
408 return -ENODEV;
409
410 mutex_lock(&dev->mutex);
411 s = comedi_read_subdevice(dev, minor);
412 if (s && (s->subdev_flags & SDF_CMD_READ) && s->async)
413 s->async->max_bufsize = size;
414 else
415 err = -EINVAL;
416 mutex_unlock(&dev->mutex);
417
418 comedi_dev_put(dev);
419 return err ? err : count;
420 }
421 static DEVICE_ATTR_RW(max_read_buffer_kb);
422
read_buffer_kb_show(struct device * csdev,struct device_attribute * attr,char * buf)423 static ssize_t read_buffer_kb_show(struct device *csdev,
424 struct device_attribute *attr, char *buf)
425 {
426 unsigned int minor = MINOR(csdev->devt);
427 struct comedi_device *dev;
428 struct comedi_subdevice *s;
429 unsigned int size = 0;
430
431 dev = comedi_dev_get_from_minor(minor);
432 if (!dev)
433 return -ENODEV;
434
435 mutex_lock(&dev->mutex);
436 s = comedi_read_subdevice(dev, minor);
437 if (s && (s->subdev_flags & SDF_CMD_READ) && s->async)
438 size = s->async->prealloc_bufsz / 1024;
439 mutex_unlock(&dev->mutex);
440
441 comedi_dev_put(dev);
442 return sysfs_emit(buf, "%u\n", size);
443 }
444
read_buffer_kb_store(struct device * csdev,struct device_attribute * attr,const char * buf,size_t count)445 static ssize_t read_buffer_kb_store(struct device *csdev,
446 struct device_attribute *attr,
447 const char *buf, size_t count)
448 {
449 unsigned int minor = MINOR(csdev->devt);
450 struct comedi_device *dev;
451 struct comedi_subdevice *s;
452 unsigned int size;
453 int err;
454
455 err = kstrtouint(buf, 10, &size);
456 if (err)
457 return err;
458 if (size > (UINT_MAX / 1024))
459 return -EINVAL;
460 size *= 1024;
461
462 dev = comedi_dev_get_from_minor(minor);
463 if (!dev)
464 return -ENODEV;
465
466 mutex_lock(&dev->mutex);
467 s = comedi_read_subdevice(dev, minor);
468 if (s && (s->subdev_flags & SDF_CMD_READ) && s->async)
469 err = resize_async_buffer(dev, s, size);
470 else
471 err = -EINVAL;
472 mutex_unlock(&dev->mutex);
473
474 comedi_dev_put(dev);
475 return err ? err : count;
476 }
477 static DEVICE_ATTR_RW(read_buffer_kb);
478
max_write_buffer_kb_show(struct device * csdev,struct device_attribute * attr,char * buf)479 static ssize_t max_write_buffer_kb_show(struct device *csdev,
480 struct device_attribute *attr,
481 char *buf)
482 {
483 unsigned int minor = MINOR(csdev->devt);
484 struct comedi_device *dev;
485 struct comedi_subdevice *s;
486 unsigned int size = 0;
487
488 dev = comedi_dev_get_from_minor(minor);
489 if (!dev)
490 return -ENODEV;
491
492 mutex_lock(&dev->mutex);
493 s = comedi_write_subdevice(dev, minor);
494 if (s && (s->subdev_flags & SDF_CMD_WRITE) && s->async)
495 size = s->async->max_bufsize / 1024;
496 mutex_unlock(&dev->mutex);
497
498 comedi_dev_put(dev);
499 return sysfs_emit(buf, "%u\n", size);
500 }
501
max_write_buffer_kb_store(struct device * csdev,struct device_attribute * attr,const char * buf,size_t count)502 static ssize_t max_write_buffer_kb_store(struct device *csdev,
503 struct device_attribute *attr,
504 const char *buf, size_t count)
505 {
506 unsigned int minor = MINOR(csdev->devt);
507 struct comedi_device *dev;
508 struct comedi_subdevice *s;
509 unsigned int size;
510 int err;
511
512 err = kstrtouint(buf, 10, &size);
513 if (err)
514 return err;
515 if (size > (UINT_MAX / 1024))
516 return -EINVAL;
517 size *= 1024;
518
519 dev = comedi_dev_get_from_minor(minor);
520 if (!dev)
521 return -ENODEV;
522
523 mutex_lock(&dev->mutex);
524 s = comedi_write_subdevice(dev, minor);
525 if (s && (s->subdev_flags & SDF_CMD_WRITE) && s->async)
526 s->async->max_bufsize = size;
527 else
528 err = -EINVAL;
529 mutex_unlock(&dev->mutex);
530
531 comedi_dev_put(dev);
532 return err ? err : count;
533 }
534 static DEVICE_ATTR_RW(max_write_buffer_kb);
535
write_buffer_kb_show(struct device * csdev,struct device_attribute * attr,char * buf)536 static ssize_t write_buffer_kb_show(struct device *csdev,
537 struct device_attribute *attr, char *buf)
538 {
539 unsigned int minor = MINOR(csdev->devt);
540 struct comedi_device *dev;
541 struct comedi_subdevice *s;
542 unsigned int size = 0;
543
544 dev = comedi_dev_get_from_minor(minor);
545 if (!dev)
546 return -ENODEV;
547
548 mutex_lock(&dev->mutex);
549 s = comedi_write_subdevice(dev, minor);
550 if (s && (s->subdev_flags & SDF_CMD_WRITE) && s->async)
551 size = s->async->prealloc_bufsz / 1024;
552 mutex_unlock(&dev->mutex);
553
554 comedi_dev_put(dev);
555 return sysfs_emit(buf, "%u\n", size);
556 }
557
write_buffer_kb_store(struct device * csdev,struct device_attribute * attr,const char * buf,size_t count)558 static ssize_t write_buffer_kb_store(struct device *csdev,
559 struct device_attribute *attr,
560 const char *buf, size_t count)
561 {
562 unsigned int minor = MINOR(csdev->devt);
563 struct comedi_device *dev;
564 struct comedi_subdevice *s;
565 unsigned int size;
566 int err;
567
568 err = kstrtouint(buf, 10, &size);
569 if (err)
570 return err;
571 if (size > (UINT_MAX / 1024))
572 return -EINVAL;
573 size *= 1024;
574
575 dev = comedi_dev_get_from_minor(minor);
576 if (!dev)
577 return -ENODEV;
578
579 mutex_lock(&dev->mutex);
580 s = comedi_write_subdevice(dev, minor);
581 if (s && (s->subdev_flags & SDF_CMD_WRITE) && s->async)
582 err = resize_async_buffer(dev, s, size);
583 else
584 err = -EINVAL;
585 mutex_unlock(&dev->mutex);
586
587 comedi_dev_put(dev);
588 return err ? err : count;
589 }
590 static DEVICE_ATTR_RW(write_buffer_kb);
591
592 static struct attribute *comedi_dev_attrs[] = {
593 &dev_attr_max_read_buffer_kb.attr,
594 &dev_attr_read_buffer_kb.attr,
595 &dev_attr_max_write_buffer_kb.attr,
596 &dev_attr_write_buffer_kb.attr,
597 NULL,
598 };
599 ATTRIBUTE_GROUPS(comedi_dev);
600
601 static const struct class comedi_class = {
602 .name = "comedi",
603 .dev_groups = comedi_dev_groups,
604 };
605
comedi_free_board_dev(struct comedi_device * dev)606 static void comedi_free_board_dev(struct comedi_device *dev)
607 {
608 if (dev) {
609 comedi_device_cleanup(dev);
610 if (dev->class_dev) {
611 device_destroy(&comedi_class,
612 MKDEV(COMEDI_MAJOR, dev->minor));
613 }
614 comedi_dev_put(dev);
615 }
616 }
617
__comedi_clear_subdevice_runflags(struct comedi_subdevice * s,unsigned int bits)618 static void __comedi_clear_subdevice_runflags(struct comedi_subdevice *s,
619 unsigned int bits)
620 {
621 s->runflags &= ~bits;
622 }
623
__comedi_set_subdevice_runflags(struct comedi_subdevice * s,unsigned int bits)624 static void __comedi_set_subdevice_runflags(struct comedi_subdevice *s,
625 unsigned int bits)
626 {
627 s->runflags |= bits;
628 }
629
comedi_update_subdevice_runflags(struct comedi_subdevice * s,unsigned int mask,unsigned int bits)630 static void comedi_update_subdevice_runflags(struct comedi_subdevice *s,
631 unsigned int mask,
632 unsigned int bits)
633 {
634 unsigned long flags;
635
636 spin_lock_irqsave(&s->spin_lock, flags);
637 __comedi_clear_subdevice_runflags(s, mask);
638 __comedi_set_subdevice_runflags(s, bits & mask);
639 spin_unlock_irqrestore(&s->spin_lock, flags);
640 }
641
__comedi_get_subdevice_runflags(struct comedi_subdevice * s)642 static unsigned int __comedi_get_subdevice_runflags(struct comedi_subdevice *s)
643 {
644 return s->runflags;
645 }
646
comedi_get_subdevice_runflags(struct comedi_subdevice * s)647 static unsigned int comedi_get_subdevice_runflags(struct comedi_subdevice *s)
648 {
649 unsigned long flags;
650 unsigned int runflags;
651
652 spin_lock_irqsave(&s->spin_lock, flags);
653 runflags = __comedi_get_subdevice_runflags(s);
654 spin_unlock_irqrestore(&s->spin_lock, flags);
655 return runflags;
656 }
657
comedi_is_runflags_running(unsigned int runflags)658 static bool comedi_is_runflags_running(unsigned int runflags)
659 {
660 return runflags & COMEDI_SRF_RUNNING;
661 }
662
comedi_is_runflags_in_error(unsigned int runflags)663 static bool comedi_is_runflags_in_error(unsigned int runflags)
664 {
665 return runflags & COMEDI_SRF_ERROR;
666 }
667
668 /**
669 * comedi_is_subdevice_running() - Check if async command running on subdevice
670 * @s: COMEDI subdevice.
671 *
672 * Return: %true if an asynchronous COMEDI command is active on the
673 * subdevice, else %false.
674 */
comedi_is_subdevice_running(struct comedi_subdevice * s)675 bool comedi_is_subdevice_running(struct comedi_subdevice *s)
676 {
677 unsigned int runflags = comedi_get_subdevice_runflags(s);
678
679 return comedi_is_runflags_running(runflags);
680 }
681 EXPORT_SYMBOL_GPL(comedi_is_subdevice_running);
682
__comedi_is_subdevice_running(struct comedi_subdevice * s)683 static bool __comedi_is_subdevice_running(struct comedi_subdevice *s)
684 {
685 unsigned int runflags = __comedi_get_subdevice_runflags(s);
686
687 return comedi_is_runflags_running(runflags);
688 }
689
comedi_can_auto_free_spriv(struct comedi_subdevice * s)690 bool comedi_can_auto_free_spriv(struct comedi_subdevice *s)
691 {
692 unsigned int runflags = __comedi_get_subdevice_runflags(s);
693
694 return runflags & COMEDI_SRF_FREE_SPRIV;
695 }
696
697 /**
698 * comedi_set_spriv_auto_free() - Mark subdevice private data as freeable
699 * @s: COMEDI subdevice.
700 *
701 * Mark the subdevice as having a pointer to private data that can be
702 * automatically freed when the COMEDI device is detached from the low-level
703 * driver.
704 */
comedi_set_spriv_auto_free(struct comedi_subdevice * s)705 void comedi_set_spriv_auto_free(struct comedi_subdevice *s)
706 {
707 __comedi_set_subdevice_runflags(s, COMEDI_SRF_FREE_SPRIV);
708 }
709 EXPORT_SYMBOL_GPL(comedi_set_spriv_auto_free);
710
711 /**
712 * comedi_alloc_spriv - Allocate memory for the subdevice private data
713 * @s: COMEDI subdevice.
714 * @size: Size of the memory to allocate.
715 *
716 * Allocate memory for the subdevice private data and point @s->private
717 * to it. The memory will be freed automatically when the COMEDI device
718 * is detached from the low-level driver.
719 *
720 * Return: A pointer to the allocated memory @s->private on success.
721 * Return NULL on failure.
722 */
comedi_alloc_spriv(struct comedi_subdevice * s,size_t size)723 void *comedi_alloc_spriv(struct comedi_subdevice *s, size_t size)
724 {
725 s->private = kzalloc(size, GFP_KERNEL);
726 if (s->private)
727 comedi_set_spriv_auto_free(s);
728 return s->private;
729 }
730 EXPORT_SYMBOL_GPL(comedi_alloc_spriv);
731
732 /*
733 * This function restores a subdevice to an idle state.
734 */
do_become_nonbusy(struct comedi_device * dev,struct comedi_subdevice * s)735 static void do_become_nonbusy(struct comedi_device *dev,
736 struct comedi_subdevice *s)
737 {
738 struct comedi_async *async = s->async;
739
740 lockdep_assert_held(&dev->mutex);
741 comedi_update_subdevice_runflags(s, COMEDI_SRF_RUNNING, 0);
742 if (async) {
743 comedi_buf_reset(s);
744 async->inttrig = NULL;
745 kfree(async->cmd.chanlist);
746 async->cmd.chanlist = NULL;
747 s->busy = NULL;
748 wake_up_interruptible_all(&async->wait_head);
749 } else {
750 dev_err(dev->class_dev,
751 "BUG: (?) %s called with async=NULL\n", __func__);
752 s->busy = NULL;
753 }
754 }
755
do_cancel(struct comedi_device * dev,struct comedi_subdevice * s)756 static int do_cancel(struct comedi_device *dev, struct comedi_subdevice *s)
757 {
758 int ret = 0;
759
760 lockdep_assert_held(&dev->mutex);
761 if (comedi_is_subdevice_running(s) && s->cancel)
762 ret = s->cancel(dev, s);
763
764 do_become_nonbusy(dev, s);
765
766 return ret;
767 }
768
comedi_device_cancel_all(struct comedi_device * dev)769 void comedi_device_cancel_all(struct comedi_device *dev)
770 {
771 struct comedi_subdevice *s;
772 int i;
773
774 lockdep_assert_held(&dev->mutex);
775 if (!dev->attached)
776 return;
777
778 for (i = 0; i < dev->n_subdevices; i++) {
779 s = &dev->subdevices[i];
780 if (s->async)
781 do_cancel(dev, s);
782 }
783 }
784
is_device_busy(struct comedi_device * dev)785 static int is_device_busy(struct comedi_device *dev)
786 {
787 struct comedi_subdevice *s;
788 int i;
789
790 lockdep_assert_held(&dev->mutex);
791 if (!dev->attached)
792 return 0;
793
794 for (i = 0; i < dev->n_subdevices; i++) {
795 s = &dev->subdevices[i];
796 if (s->busy)
797 return 1;
798 if (s->async && comedi_buf_is_mmapped(s))
799 return 1;
800 }
801
802 return 0;
803 }
804
805 /*
806 * COMEDI_DEVCONFIG ioctl
807 * attaches (and configures) or detaches a legacy device
808 *
809 * arg:
810 * pointer to comedi_devconfig structure (NULL if detaching)
811 *
812 * reads:
813 * comedi_devconfig structure (if attaching)
814 *
815 * writes:
816 * nothing
817 */
do_devconfig_ioctl(struct comedi_device * dev,struct comedi_devconfig __user * arg)818 static int do_devconfig_ioctl(struct comedi_device *dev,
819 struct comedi_devconfig __user *arg)
820 {
821 struct comedi_devconfig it;
822
823 lockdep_assert_held(&dev->mutex);
824 if (!capable(CAP_SYS_ADMIN))
825 return -EPERM;
826
827 if (!arg) {
828 if (is_device_busy(dev))
829 return -EBUSY;
830 if (dev->attached) {
831 struct module *driver_module = dev->driver->module;
832
833 comedi_device_detach(dev);
834 module_put(driver_module);
835 }
836 return 0;
837 }
838
839 if (copy_from_user(&it, arg, sizeof(it)))
840 return -EFAULT;
841
842 it.board_name[COMEDI_NAMELEN - 1] = 0;
843
844 if (it.options[COMEDI_DEVCONF_AUX_DATA_LENGTH]) {
845 dev_warn(dev->class_dev,
846 "comedi_config --init_data is deprecated\n");
847 return -EINVAL;
848 }
849
850 if (dev->minor >= comedi_num_legacy_minors)
851 /* don't re-use dynamically allocated comedi devices */
852 return -EBUSY;
853
854 /* This increments the driver module count on success. */
855 return comedi_device_attach(dev, &it);
856 }
857
858 /*
859 * COMEDI_BUFCONFIG ioctl
860 * buffer configuration
861 *
862 * arg:
863 * pointer to comedi_bufconfig structure
864 *
865 * reads:
866 * comedi_bufconfig structure
867 *
868 * writes:
869 * modified comedi_bufconfig structure
870 */
do_bufconfig_ioctl(struct comedi_device * dev,struct comedi_bufconfig __user * arg)871 static int do_bufconfig_ioctl(struct comedi_device *dev,
872 struct comedi_bufconfig __user *arg)
873 {
874 struct comedi_bufconfig bc;
875 struct comedi_async *async;
876 struct comedi_subdevice *s;
877 int retval = 0;
878
879 lockdep_assert_held(&dev->mutex);
880 if (copy_from_user(&bc, arg, sizeof(bc)))
881 return -EFAULT;
882
883 if (bc.subdevice >= dev->n_subdevices)
884 return -EINVAL;
885
886 s = &dev->subdevices[bc.subdevice];
887 async = s->async;
888
889 if (!async) {
890 dev_dbg(dev->class_dev,
891 "subdevice does not have async capability\n");
892 bc.size = 0;
893 bc.maximum_size = 0;
894 goto copyback;
895 }
896
897 if (bc.maximum_size) {
898 if (!capable(CAP_SYS_ADMIN))
899 return -EPERM;
900
901 async->max_bufsize = bc.maximum_size;
902 }
903
904 if (bc.size) {
905 retval = resize_async_buffer(dev, s, bc.size);
906 if (retval < 0)
907 return retval;
908 }
909
910 bc.size = async->prealloc_bufsz;
911 bc.maximum_size = async->max_bufsize;
912
913 copyback:
914 if (copy_to_user(arg, &bc, sizeof(bc)))
915 return -EFAULT;
916
917 return 0;
918 }
919
920 /*
921 * COMEDI_DEVINFO ioctl
922 * device info
923 *
924 * arg:
925 * pointer to comedi_devinfo structure
926 *
927 * reads:
928 * nothing
929 *
930 * writes:
931 * comedi_devinfo structure
932 */
do_devinfo_ioctl(struct comedi_device * dev,struct comedi_devinfo __user * arg,struct file * file)933 static int do_devinfo_ioctl(struct comedi_device *dev,
934 struct comedi_devinfo __user *arg,
935 struct file *file)
936 {
937 struct comedi_subdevice *s;
938 struct comedi_devinfo devinfo;
939
940 lockdep_assert_held(&dev->mutex);
941 memset(&devinfo, 0, sizeof(devinfo));
942
943 /* fill devinfo structure */
944 devinfo.version_code = COMEDI_VERSION_CODE;
945 devinfo.n_subdevs = dev->n_subdevices;
946 strscpy(devinfo.driver_name, dev->driver->driver_name, COMEDI_NAMELEN);
947 strscpy(devinfo.board_name, dev->board_name, COMEDI_NAMELEN);
948
949 s = comedi_file_read_subdevice(file);
950 if (s)
951 devinfo.read_subdevice = s->index;
952 else
953 devinfo.read_subdevice = -1;
954
955 s = comedi_file_write_subdevice(file);
956 if (s)
957 devinfo.write_subdevice = s->index;
958 else
959 devinfo.write_subdevice = -1;
960
961 if (copy_to_user(arg, &devinfo, sizeof(devinfo)))
962 return -EFAULT;
963
964 return 0;
965 }
966
967 /*
968 * COMEDI_SUBDINFO ioctl
969 * subdevices info
970 *
971 * arg:
972 * pointer to array of comedi_subdinfo structures
973 *
974 * reads:
975 * nothing
976 *
977 * writes:
978 * array of comedi_subdinfo structures
979 */
do_subdinfo_ioctl(struct comedi_device * dev,struct comedi_subdinfo __user * arg,void * file)980 static int do_subdinfo_ioctl(struct comedi_device *dev,
981 struct comedi_subdinfo __user *arg, void *file)
982 {
983 int ret, i;
984 struct comedi_subdinfo *tmp, *us;
985 struct comedi_subdevice *s;
986
987 lockdep_assert_held(&dev->mutex);
988 tmp = kcalloc(dev->n_subdevices, sizeof(*tmp), GFP_KERNEL);
989 if (!tmp)
990 return -ENOMEM;
991
992 /* fill subdinfo structs */
993 for (i = 0; i < dev->n_subdevices; i++) {
994 s = &dev->subdevices[i];
995 us = tmp + i;
996
997 us->type = s->type;
998 us->n_chan = s->n_chan;
999 us->subd_flags = s->subdev_flags;
1000 if (comedi_is_subdevice_running(s))
1001 us->subd_flags |= SDF_RUNNING;
1002 #define TIMER_nanosec 5 /* backwards compatibility */
1003 us->timer_type = TIMER_nanosec;
1004 us->len_chanlist = s->len_chanlist;
1005 us->maxdata = s->maxdata;
1006 if (s->range_table) {
1007 us->range_type =
1008 (i << 24) | (0 << 16) | (s->range_table->length);
1009 } else {
1010 us->range_type = 0; /* XXX */
1011 }
1012
1013 if (s->busy)
1014 us->subd_flags |= SDF_BUSY;
1015 if (s->busy == file)
1016 us->subd_flags |= SDF_BUSY_OWNER;
1017 if (s->lock)
1018 us->subd_flags |= SDF_LOCKED;
1019 if (s->lock == file)
1020 us->subd_flags |= SDF_LOCK_OWNER;
1021 if (!s->maxdata && s->maxdata_list)
1022 us->subd_flags |= SDF_MAXDATA;
1023 if (s->range_table_list)
1024 us->subd_flags |= SDF_RANGETYPE;
1025 if (s->do_cmd)
1026 us->subd_flags |= SDF_CMD;
1027
1028 if (s->insn_bits != &insn_inval)
1029 us->insn_bits_support = COMEDI_SUPPORTED;
1030 else
1031 us->insn_bits_support = COMEDI_UNSUPPORTED;
1032 }
1033
1034 ret = copy_to_user(arg, tmp, dev->n_subdevices * sizeof(*tmp));
1035
1036 kfree(tmp);
1037
1038 return ret ? -EFAULT : 0;
1039 }
1040
1041 /*
1042 * COMEDI_CHANINFO ioctl
1043 * subdevice channel info
1044 *
1045 * arg:
1046 * pointer to comedi_chaninfo structure
1047 *
1048 * reads:
1049 * comedi_chaninfo structure
1050 *
1051 * writes:
1052 * array of maxdata values to chaninfo->maxdata_list if requested
1053 * array of range table lengths to chaninfo->range_table_list if requested
1054 */
do_chaninfo_ioctl(struct comedi_device * dev,struct comedi_chaninfo * it)1055 static int do_chaninfo_ioctl(struct comedi_device *dev,
1056 struct comedi_chaninfo *it)
1057 {
1058 struct comedi_subdevice *s;
1059
1060 lockdep_assert_held(&dev->mutex);
1061
1062 if (it->subdev >= dev->n_subdevices)
1063 return -EINVAL;
1064 s = &dev->subdevices[it->subdev];
1065
1066 if (it->maxdata_list) {
1067 if (s->maxdata || !s->maxdata_list)
1068 return -EINVAL;
1069 if (copy_to_user(it->maxdata_list, s->maxdata_list,
1070 s->n_chan * sizeof(unsigned int)))
1071 return -EFAULT;
1072 }
1073
1074 if (it->flaglist)
1075 return -EINVAL; /* flaglist not supported */
1076
1077 if (it->rangelist) {
1078 int i;
1079
1080 if (!s->range_table_list)
1081 return -EINVAL;
1082 for (i = 0; i < s->n_chan; i++) {
1083 int x;
1084
1085 x = (dev->minor << 28) | (it->subdev << 24) | (i << 16) |
1086 (s->range_table_list[i]->length);
1087 if (put_user(x, it->rangelist + i))
1088 return -EFAULT;
1089 }
1090 }
1091
1092 return 0;
1093 }
1094
1095 /*
1096 * COMEDI_BUFINFO ioctl
1097 * buffer information
1098 *
1099 * arg:
1100 * pointer to comedi_bufinfo structure
1101 *
1102 * reads:
1103 * comedi_bufinfo structure
1104 *
1105 * writes:
1106 * modified comedi_bufinfo structure
1107 */
do_bufinfo_ioctl(struct comedi_device * dev,struct comedi_bufinfo __user * arg,void * file)1108 static int do_bufinfo_ioctl(struct comedi_device *dev,
1109 struct comedi_bufinfo __user *arg, void *file)
1110 {
1111 struct comedi_bufinfo bi;
1112 struct comedi_subdevice *s;
1113 struct comedi_async *async;
1114 unsigned int runflags;
1115 int retval = 0;
1116 bool become_nonbusy = false;
1117
1118 lockdep_assert_held(&dev->mutex);
1119 if (copy_from_user(&bi, arg, sizeof(bi)))
1120 return -EFAULT;
1121
1122 if (bi.subdevice >= dev->n_subdevices)
1123 return -EINVAL;
1124
1125 s = &dev->subdevices[bi.subdevice];
1126
1127 async = s->async;
1128
1129 if (!async || s->busy != file)
1130 return -EINVAL;
1131
1132 runflags = comedi_get_subdevice_runflags(s);
1133 if (!(async->cmd.flags & CMDF_WRITE)) {
1134 /* command was set up in "read" direction */
1135 if (bi.bytes_read) {
1136 comedi_buf_read_alloc(s, bi.bytes_read);
1137 bi.bytes_read = comedi_buf_read_free(s, bi.bytes_read);
1138 }
1139 /*
1140 * If nothing left to read, and command has stopped, and
1141 * {"read" position not updated or command stopped normally},
1142 * then become non-busy.
1143 */
1144 if (comedi_buf_read_n_available(s) == 0 &&
1145 !comedi_is_runflags_running(runflags) &&
1146 (bi.bytes_read == 0 ||
1147 !comedi_is_runflags_in_error(runflags))) {
1148 become_nonbusy = true;
1149 if (comedi_is_runflags_in_error(runflags))
1150 retval = -EPIPE;
1151 }
1152 bi.bytes_written = 0;
1153 } else {
1154 /* command was set up in "write" direction */
1155 if (!comedi_is_runflags_running(runflags)) {
1156 bi.bytes_written = 0;
1157 become_nonbusy = true;
1158 if (comedi_is_runflags_in_error(runflags))
1159 retval = -EPIPE;
1160 } else if (bi.bytes_written) {
1161 comedi_buf_write_alloc(s, bi.bytes_written);
1162 bi.bytes_written =
1163 comedi_buf_write_free(s, bi.bytes_written);
1164 }
1165 bi.bytes_read = 0;
1166 }
1167
1168 bi.buf_write_count = async->buf_write_count;
1169 bi.buf_write_ptr = async->buf_write_ptr;
1170 bi.buf_read_count = async->buf_read_count;
1171 bi.buf_read_ptr = async->buf_read_ptr;
1172
1173 if (become_nonbusy)
1174 do_become_nonbusy(dev, s);
1175
1176 if (retval)
1177 return retval;
1178
1179 if (copy_to_user(arg, &bi, sizeof(bi)))
1180 return -EFAULT;
1181
1182 return 0;
1183 }
1184
check_insn_config_length(struct comedi_insn * insn,unsigned int * data)1185 static int check_insn_config_length(struct comedi_insn *insn,
1186 unsigned int *data)
1187 {
1188 if (insn->n < 1)
1189 return -EINVAL;
1190
1191 switch (data[0]) {
1192 case INSN_CONFIG_DIO_OUTPUT:
1193 case INSN_CONFIG_DIO_INPUT:
1194 case INSN_CONFIG_DISARM:
1195 case INSN_CONFIG_RESET:
1196 if (insn->n == 1)
1197 return 0;
1198 break;
1199 case INSN_CONFIG_ARM:
1200 case INSN_CONFIG_DIO_QUERY:
1201 case INSN_CONFIG_BLOCK_SIZE:
1202 case INSN_CONFIG_FILTER:
1203 case INSN_CONFIG_SERIAL_CLOCK:
1204 case INSN_CONFIG_BIDIRECTIONAL_DATA:
1205 case INSN_CONFIG_ALT_SOURCE:
1206 case INSN_CONFIG_SET_COUNTER_MODE:
1207 case INSN_CONFIG_8254_READ_STATUS:
1208 case INSN_CONFIG_SET_ROUTING:
1209 case INSN_CONFIG_GET_ROUTING:
1210 case INSN_CONFIG_GET_PWM_STATUS:
1211 case INSN_CONFIG_PWM_SET_PERIOD:
1212 case INSN_CONFIG_PWM_GET_PERIOD:
1213 if (insn->n == 2)
1214 return 0;
1215 break;
1216 case INSN_CONFIG_SET_GATE_SRC:
1217 case INSN_CONFIG_GET_GATE_SRC:
1218 case INSN_CONFIG_SET_CLOCK_SRC:
1219 case INSN_CONFIG_GET_CLOCK_SRC:
1220 case INSN_CONFIG_SET_OTHER_SRC:
1221 case INSN_CONFIG_GET_COUNTER_STATUS:
1222 case INSN_CONFIG_GET_PWM_OUTPUT:
1223 case INSN_CONFIG_PWM_SET_H_BRIDGE:
1224 case INSN_CONFIG_PWM_GET_H_BRIDGE:
1225 case INSN_CONFIG_GET_HARDWARE_BUFFER_SIZE:
1226 if (insn->n == 3)
1227 return 0;
1228 break;
1229 case INSN_CONFIG_PWM_OUTPUT:
1230 case INSN_CONFIG_ANALOG_TRIG:
1231 case INSN_CONFIG_TIMER_1:
1232 if (insn->n == 5)
1233 return 0;
1234 break;
1235 case INSN_CONFIG_DIGITAL_TRIG:
1236 if (insn->n == 6)
1237 return 0;
1238 break;
1239 case INSN_CONFIG_GET_CMD_TIMING_CONSTRAINTS:
1240 if (insn->n >= 4)
1241 return 0;
1242 break;
1243 /*
1244 * by default we allow the insn since we don't have checks for
1245 * all possible cases yet
1246 */
1247 default:
1248 pr_warn("No check for data length of config insn id %i is implemented\n",
1249 data[0]);
1250 pr_warn("Add a check to %s in %s\n", __func__, __FILE__);
1251 pr_warn("Assuming n=%i is correct\n", insn->n);
1252 return 0;
1253 }
1254 return -EINVAL;
1255 }
1256
check_insn_device_config_length(struct comedi_insn * insn,unsigned int * data)1257 static int check_insn_device_config_length(struct comedi_insn *insn,
1258 unsigned int *data)
1259 {
1260 if (insn->n < 1)
1261 return -EINVAL;
1262
1263 switch (data[0]) {
1264 case INSN_DEVICE_CONFIG_TEST_ROUTE:
1265 case INSN_DEVICE_CONFIG_CONNECT_ROUTE:
1266 case INSN_DEVICE_CONFIG_DISCONNECT_ROUTE:
1267 if (insn->n == 3)
1268 return 0;
1269 break;
1270 case INSN_DEVICE_CONFIG_GET_ROUTES:
1271 /*
1272 * Big enough for config_id and the length of the userland
1273 * memory buffer. Additional length should be in factors of 2
1274 * to communicate any returned route pairs (source,destination).
1275 */
1276 if (insn->n >= 2)
1277 return 0;
1278 break;
1279 }
1280 return -EINVAL;
1281 }
1282
1283 /**
1284 * get_valid_routes() - Calls low-level driver get_valid_routes function to
1285 * either return a count of valid routes to user, or copy
1286 * of list of all valid device routes to buffer in
1287 * userspace.
1288 * @dev: comedi device pointer
1289 * @data: data from user insn call. The length of the data must be >= 2.
1290 * data[0] must contain the INSN_DEVICE_CONFIG config_id.
1291 * data[1](input) contains the number of _pairs_ for which memory is
1292 * allotted from the user. If the user specifies '0', then only
1293 * the number of pairs available is returned.
1294 * data[1](output) returns either the number of pairs available (if none
1295 * where requested) or the number of _pairs_ that are copied back
1296 * to the user.
1297 * data[2::2] returns each (source, destination) pair.
1298 *
1299 * Return: -EINVAL if low-level driver does not allocate and return routes as
1300 * expected. Returns 0 otherwise.
1301 */
get_valid_routes(struct comedi_device * dev,unsigned int * data)1302 static int get_valid_routes(struct comedi_device *dev, unsigned int *data)
1303 {
1304 lockdep_assert_held(&dev->mutex);
1305 data[1] = dev->get_valid_routes(dev, data[1], data + 2);
1306 return 0;
1307 }
1308
parse_insn(struct comedi_device * dev,struct comedi_insn * insn,unsigned int * data,void * file)1309 static int parse_insn(struct comedi_device *dev, struct comedi_insn *insn,
1310 unsigned int *data, void *file)
1311 {
1312 struct comedi_subdevice *s;
1313 int ret = 0;
1314 int i;
1315
1316 lockdep_assert_held(&dev->mutex);
1317 if (insn->insn & INSN_MASK_SPECIAL) {
1318 /* a non-subdevice instruction */
1319
1320 switch (insn->insn) {
1321 case INSN_GTOD:
1322 {
1323 struct timespec64 tv;
1324
1325 if (insn->n != 2) {
1326 ret = -EINVAL;
1327 break;
1328 }
1329
1330 ktime_get_real_ts64(&tv);
1331 /* unsigned data safe until 2106 */
1332 data[0] = (unsigned int)tv.tv_sec;
1333 data[1] = tv.tv_nsec / NSEC_PER_USEC;
1334 ret = 2;
1335
1336 break;
1337 }
1338 case INSN_WAIT:
1339 if (insn->n != 1 || data[0] >= 100000) {
1340 ret = -EINVAL;
1341 break;
1342 }
1343 udelay(data[0] / 1000);
1344 ret = 1;
1345 break;
1346 case INSN_INTTRIG:
1347 if (insn->n != 1) {
1348 ret = -EINVAL;
1349 break;
1350 }
1351 if (insn->subdev >= dev->n_subdevices) {
1352 dev_dbg(dev->class_dev,
1353 "%d not usable subdevice\n",
1354 insn->subdev);
1355 ret = -EINVAL;
1356 break;
1357 }
1358 s = &dev->subdevices[insn->subdev];
1359 if (!s->async) {
1360 dev_dbg(dev->class_dev, "no async\n");
1361 ret = -EINVAL;
1362 break;
1363 }
1364 if (!s->async->inttrig) {
1365 dev_dbg(dev->class_dev, "no inttrig\n");
1366 ret = -EAGAIN;
1367 break;
1368 }
1369 ret = s->async->inttrig(dev, s, data[0]);
1370 if (ret >= 0)
1371 ret = 1;
1372 break;
1373 case INSN_DEVICE_CONFIG:
1374 ret = check_insn_device_config_length(insn, data);
1375 if (ret)
1376 break;
1377
1378 if (data[0] == INSN_DEVICE_CONFIG_GET_ROUTES) {
1379 /*
1380 * data[1] should be the number of _pairs_ that
1381 * the memory can hold.
1382 */
1383 data[1] = (insn->n - 2) / 2;
1384 ret = get_valid_routes(dev, data);
1385 break;
1386 }
1387
1388 /* other global device config instructions. */
1389 ret = dev->insn_device_config(dev, insn, data);
1390 break;
1391 default:
1392 dev_dbg(dev->class_dev, "invalid insn\n");
1393 ret = -EINVAL;
1394 break;
1395 }
1396 } else {
1397 /* a subdevice instruction */
1398 unsigned int maxdata;
1399
1400 if (insn->subdev >= dev->n_subdevices) {
1401 dev_dbg(dev->class_dev, "subdevice %d out of range\n",
1402 insn->subdev);
1403 ret = -EINVAL;
1404 goto out;
1405 }
1406 s = &dev->subdevices[insn->subdev];
1407
1408 if (s->type == COMEDI_SUBD_UNUSED) {
1409 dev_dbg(dev->class_dev, "%d not usable subdevice\n",
1410 insn->subdev);
1411 ret = -EIO;
1412 goto out;
1413 }
1414
1415 /* are we locked? (ioctl lock) */
1416 if (s->lock && s->lock != file) {
1417 dev_dbg(dev->class_dev, "device locked\n");
1418 ret = -EACCES;
1419 goto out;
1420 }
1421
1422 ret = comedi_check_chanlist(s, 1, &insn->chanspec);
1423 if (ret < 0) {
1424 ret = -EINVAL;
1425 dev_dbg(dev->class_dev, "bad chanspec\n");
1426 goto out;
1427 }
1428
1429 if (s->busy) {
1430 ret = -EBUSY;
1431 goto out;
1432 }
1433 /* This looks arbitrary. It is. */
1434 s->busy = parse_insn;
1435 switch (insn->insn) {
1436 case INSN_READ:
1437 ret = s->insn_read(dev, s, insn, data);
1438 if (ret == -ETIMEDOUT) {
1439 dev_dbg(dev->class_dev,
1440 "subdevice %d read instruction timed out\n",
1441 s->index);
1442 }
1443 break;
1444 case INSN_WRITE:
1445 maxdata = s->maxdata_list
1446 ? s->maxdata_list[CR_CHAN(insn->chanspec)]
1447 : s->maxdata;
1448 for (i = 0; i < insn->n; ++i) {
1449 if (data[i] > maxdata) {
1450 ret = -EINVAL;
1451 dev_dbg(dev->class_dev,
1452 "bad data value(s)\n");
1453 break;
1454 }
1455 }
1456 if (ret == 0) {
1457 ret = s->insn_write(dev, s, insn, data);
1458 if (ret == -ETIMEDOUT) {
1459 dev_dbg(dev->class_dev,
1460 "subdevice %d write instruction timed out\n",
1461 s->index);
1462 }
1463 }
1464 break;
1465 case INSN_BITS:
1466 if (insn->n != 2) {
1467 ret = -EINVAL;
1468 } else {
1469 /*
1470 * Most drivers ignore the base channel in
1471 * insn->chanspec. Fix this here if
1472 * the subdevice has <= 32 channels.
1473 */
1474 unsigned int orig_mask = data[0];
1475 unsigned int shift = 0;
1476
1477 if (s->n_chan <= 32) {
1478 shift = CR_CHAN(insn->chanspec);
1479 if (shift > 0) {
1480 insn->chanspec = 0;
1481 data[0] <<= shift;
1482 data[1] <<= shift;
1483 }
1484 }
1485 ret = s->insn_bits(dev, s, insn, data);
1486 data[0] = orig_mask;
1487 if (shift > 0)
1488 data[1] >>= shift;
1489 }
1490 break;
1491 case INSN_CONFIG:
1492 ret = check_insn_config_length(insn, data);
1493 if (ret)
1494 break;
1495 ret = s->insn_config(dev, s, insn, data);
1496 break;
1497 default:
1498 ret = -EINVAL;
1499 break;
1500 }
1501
1502 s->busy = NULL;
1503 }
1504
1505 out:
1506 return ret;
1507 }
1508
1509 /*
1510 * COMEDI_INSNLIST ioctl
1511 * synchronous instruction list
1512 *
1513 * arg:
1514 * pointer to comedi_insnlist structure
1515 *
1516 * reads:
1517 * comedi_insnlist structure
1518 * array of comedi_insn structures from insnlist->insns pointer
1519 * data (for writes) from insns[].data pointers
1520 *
1521 * writes:
1522 * data (for reads) to insns[].data pointers
1523 */
1524 /* arbitrary limits */
1525 #define MIN_SAMPLES 16
1526 #define MAX_SAMPLES 65536
do_insnlist_ioctl(struct comedi_device * dev,struct comedi_insn * insns,unsigned int n_insns,void * file)1527 static int do_insnlist_ioctl(struct comedi_device *dev,
1528 struct comedi_insn *insns,
1529 unsigned int n_insns,
1530 void *file)
1531 {
1532 unsigned int *data = NULL;
1533 unsigned int max_n_data_required = MIN_SAMPLES;
1534 int i = 0;
1535 int ret = 0;
1536
1537 lockdep_assert_held(&dev->mutex);
1538
1539 /* Determine maximum memory needed for all instructions. */
1540 for (i = 0; i < n_insns; ++i) {
1541 if (insns[i].n > MAX_SAMPLES) {
1542 dev_dbg(dev->class_dev,
1543 "number of samples too large\n");
1544 ret = -EINVAL;
1545 goto error;
1546 }
1547 max_n_data_required = max(max_n_data_required, insns[i].n);
1548 }
1549
1550 /* Allocate scratch space for all instruction data. */
1551 data = kmalloc_array(max_n_data_required, sizeof(unsigned int),
1552 GFP_KERNEL);
1553 if (!data) {
1554 ret = -ENOMEM;
1555 goto error;
1556 }
1557
1558 for (i = 0; i < n_insns; ++i) {
1559 if (insns[i].insn & INSN_MASK_WRITE) {
1560 if (copy_from_user(data, insns[i].data,
1561 insns[i].n * sizeof(unsigned int))) {
1562 dev_dbg(dev->class_dev,
1563 "copy_from_user failed\n");
1564 ret = -EFAULT;
1565 goto error;
1566 }
1567 }
1568 ret = parse_insn(dev, insns + i, data, file);
1569 if (ret < 0)
1570 goto error;
1571 if (insns[i].insn & INSN_MASK_READ) {
1572 if (copy_to_user(insns[i].data, data,
1573 insns[i].n * sizeof(unsigned int))) {
1574 dev_dbg(dev->class_dev,
1575 "copy_to_user failed\n");
1576 ret = -EFAULT;
1577 goto error;
1578 }
1579 }
1580 if (need_resched())
1581 schedule();
1582 }
1583
1584 error:
1585 kfree(data);
1586
1587 if (ret < 0)
1588 return ret;
1589 return i;
1590 }
1591
1592 /*
1593 * COMEDI_INSN ioctl
1594 * synchronous instruction
1595 *
1596 * arg:
1597 * pointer to comedi_insn structure
1598 *
1599 * reads:
1600 * comedi_insn structure
1601 * data (for writes) from insn->data pointer
1602 *
1603 * writes:
1604 * data (for reads) to insn->data pointer
1605 */
do_insn_ioctl(struct comedi_device * dev,struct comedi_insn * insn,void * file)1606 static int do_insn_ioctl(struct comedi_device *dev,
1607 struct comedi_insn *insn, void *file)
1608 {
1609 unsigned int *data = NULL;
1610 unsigned int n_data = MIN_SAMPLES;
1611 int ret = 0;
1612
1613 lockdep_assert_held(&dev->mutex);
1614
1615 n_data = max(n_data, insn->n);
1616
1617 /* This is where the behavior of insn and insnlist deviate. */
1618 if (insn->n > MAX_SAMPLES) {
1619 insn->n = MAX_SAMPLES;
1620 n_data = MAX_SAMPLES;
1621 }
1622
1623 data = kmalloc_array(n_data, sizeof(unsigned int), GFP_KERNEL);
1624 if (!data) {
1625 ret = -ENOMEM;
1626 goto error;
1627 }
1628
1629 if (insn->insn & INSN_MASK_WRITE) {
1630 if (copy_from_user(data,
1631 insn->data,
1632 insn->n * sizeof(unsigned int))) {
1633 ret = -EFAULT;
1634 goto error;
1635 }
1636 }
1637 ret = parse_insn(dev, insn, data, file);
1638 if (ret < 0)
1639 goto error;
1640 if (insn->insn & INSN_MASK_READ) {
1641 if (copy_to_user(insn->data,
1642 data,
1643 insn->n * sizeof(unsigned int))) {
1644 ret = -EFAULT;
1645 goto error;
1646 }
1647 }
1648 ret = insn->n;
1649
1650 error:
1651 kfree(data);
1652
1653 return ret;
1654 }
1655
__comedi_get_user_cmd(struct comedi_device * dev,struct comedi_cmd * cmd)1656 static int __comedi_get_user_cmd(struct comedi_device *dev,
1657 struct comedi_cmd *cmd)
1658 {
1659 struct comedi_subdevice *s;
1660
1661 lockdep_assert_held(&dev->mutex);
1662 if (cmd->subdev >= dev->n_subdevices) {
1663 dev_dbg(dev->class_dev, "%d no such subdevice\n", cmd->subdev);
1664 return -ENODEV;
1665 }
1666
1667 s = &dev->subdevices[cmd->subdev];
1668
1669 if (s->type == COMEDI_SUBD_UNUSED) {
1670 dev_dbg(dev->class_dev, "%d not valid subdevice\n",
1671 cmd->subdev);
1672 return -EIO;
1673 }
1674
1675 if (!s->do_cmd || !s->do_cmdtest || !s->async) {
1676 dev_dbg(dev->class_dev,
1677 "subdevice %d does not support commands\n",
1678 cmd->subdev);
1679 return -EIO;
1680 }
1681
1682 /* make sure channel/gain list isn't too long */
1683 if (cmd->chanlist_len > s->len_chanlist) {
1684 dev_dbg(dev->class_dev, "channel/gain list too long %d > %d\n",
1685 cmd->chanlist_len, s->len_chanlist);
1686 return -EINVAL;
1687 }
1688
1689 /*
1690 * Set the CMDF_WRITE flag to the correct state if the subdevice
1691 * supports only "read" commands or only "write" commands.
1692 */
1693 switch (s->subdev_flags & (SDF_CMD_READ | SDF_CMD_WRITE)) {
1694 case SDF_CMD_READ:
1695 cmd->flags &= ~CMDF_WRITE;
1696 break;
1697 case SDF_CMD_WRITE:
1698 cmd->flags |= CMDF_WRITE;
1699 break;
1700 default:
1701 break;
1702 }
1703
1704 return 0;
1705 }
1706
__comedi_get_user_chanlist(struct comedi_device * dev,struct comedi_subdevice * s,unsigned int __user * user_chanlist,struct comedi_cmd * cmd)1707 static int __comedi_get_user_chanlist(struct comedi_device *dev,
1708 struct comedi_subdevice *s,
1709 unsigned int __user *user_chanlist,
1710 struct comedi_cmd *cmd)
1711 {
1712 unsigned int *chanlist;
1713 int ret;
1714
1715 lockdep_assert_held(&dev->mutex);
1716 cmd->chanlist = NULL;
1717 chanlist = memdup_array_user(user_chanlist,
1718 cmd->chanlist_len, sizeof(unsigned int));
1719 if (IS_ERR(chanlist))
1720 return PTR_ERR(chanlist);
1721
1722 /* make sure each element in channel/gain list is valid */
1723 ret = comedi_check_chanlist(s, cmd->chanlist_len, chanlist);
1724 if (ret < 0) {
1725 kfree(chanlist);
1726 return ret;
1727 }
1728
1729 cmd->chanlist = chanlist;
1730
1731 return 0;
1732 }
1733
1734 /*
1735 * COMEDI_CMD ioctl
1736 * asynchronous acquisition command set-up
1737 *
1738 * arg:
1739 * pointer to comedi_cmd structure
1740 *
1741 * reads:
1742 * comedi_cmd structure
1743 * channel/range list from cmd->chanlist pointer
1744 *
1745 * writes:
1746 * possibly modified comedi_cmd structure (when -EAGAIN returned)
1747 */
do_cmd_ioctl(struct comedi_device * dev,struct comedi_cmd * cmd,bool * copy,void * file)1748 static int do_cmd_ioctl(struct comedi_device *dev,
1749 struct comedi_cmd *cmd, bool *copy, void *file)
1750 {
1751 struct comedi_subdevice *s;
1752 struct comedi_async *async;
1753 unsigned int __user *user_chanlist;
1754 int ret;
1755
1756 lockdep_assert_held(&dev->mutex);
1757
1758 /* do some simple cmd validation */
1759 ret = __comedi_get_user_cmd(dev, cmd);
1760 if (ret)
1761 return ret;
1762
1763 /* save user's chanlist pointer so it can be restored later */
1764 user_chanlist = (unsigned int __user *)cmd->chanlist;
1765
1766 s = &dev->subdevices[cmd->subdev];
1767 async = s->async;
1768
1769 /* are we locked? (ioctl lock) */
1770 if (s->lock && s->lock != file) {
1771 dev_dbg(dev->class_dev, "subdevice locked\n");
1772 return -EACCES;
1773 }
1774
1775 /* are we busy? */
1776 if (s->busy) {
1777 dev_dbg(dev->class_dev, "subdevice busy\n");
1778 return -EBUSY;
1779 }
1780
1781 /* make sure channel/gain list isn't too short */
1782 if (cmd->chanlist_len < 1) {
1783 dev_dbg(dev->class_dev, "channel/gain list too short %u < 1\n",
1784 cmd->chanlist_len);
1785 return -EINVAL;
1786 }
1787
1788 async->cmd = *cmd;
1789 async->cmd.data = NULL;
1790
1791 /* load channel/gain list */
1792 ret = __comedi_get_user_chanlist(dev, s, user_chanlist, &async->cmd);
1793 if (ret)
1794 goto cleanup;
1795
1796 ret = s->do_cmdtest(dev, s, &async->cmd);
1797
1798 if (async->cmd.flags & CMDF_BOGUS || ret) {
1799 dev_dbg(dev->class_dev, "test returned %d\n", ret);
1800 *cmd = async->cmd;
1801 /* restore chanlist pointer before copying back */
1802 cmd->chanlist = (unsigned int __force *)user_chanlist;
1803 cmd->data = NULL;
1804 *copy = true;
1805 ret = -EAGAIN;
1806 goto cleanup;
1807 }
1808
1809 if (!async->prealloc_bufsz) {
1810 ret = -ENOMEM;
1811 dev_dbg(dev->class_dev, "no buffer (?)\n");
1812 goto cleanup;
1813 }
1814
1815 comedi_buf_reset(s);
1816
1817 async->cb_mask = COMEDI_CB_BLOCK | COMEDI_CB_CANCEL_MASK;
1818 if (async->cmd.flags & CMDF_WAKE_EOS)
1819 async->cb_mask |= COMEDI_CB_EOS;
1820
1821 comedi_update_subdevice_runflags(s, COMEDI_SRF_BUSY_MASK,
1822 COMEDI_SRF_RUNNING);
1823
1824 /*
1825 * Set s->busy _after_ setting COMEDI_SRF_RUNNING flag to avoid
1826 * race with comedi_read() or comedi_write().
1827 */
1828 s->busy = file;
1829 ret = s->do_cmd(dev, s);
1830 if (ret == 0)
1831 return 0;
1832
1833 cleanup:
1834 do_become_nonbusy(dev, s);
1835
1836 return ret;
1837 }
1838
1839 /*
1840 * COMEDI_CMDTEST ioctl
1841 * asynchronous acquisition command testing
1842 *
1843 * arg:
1844 * pointer to comedi_cmd structure
1845 *
1846 * reads:
1847 * comedi_cmd structure
1848 * channel/range list from cmd->chanlist pointer
1849 *
1850 * writes:
1851 * possibly modified comedi_cmd structure
1852 */
do_cmdtest_ioctl(struct comedi_device * dev,struct comedi_cmd * cmd,bool * copy,void * file)1853 static int do_cmdtest_ioctl(struct comedi_device *dev,
1854 struct comedi_cmd *cmd, bool *copy, void *file)
1855 {
1856 struct comedi_subdevice *s;
1857 unsigned int __user *user_chanlist;
1858 int ret;
1859
1860 lockdep_assert_held(&dev->mutex);
1861
1862 /* do some simple cmd validation */
1863 ret = __comedi_get_user_cmd(dev, cmd);
1864 if (ret)
1865 return ret;
1866
1867 /* save user's chanlist pointer so it can be restored later */
1868 user_chanlist = (unsigned int __user *)cmd->chanlist;
1869
1870 s = &dev->subdevices[cmd->subdev];
1871
1872 /* user_chanlist can be NULL for COMEDI_CMDTEST ioctl */
1873 if (user_chanlist) {
1874 /* load channel/gain list */
1875 ret = __comedi_get_user_chanlist(dev, s, user_chanlist, cmd);
1876 if (ret)
1877 return ret;
1878 }
1879
1880 ret = s->do_cmdtest(dev, s, cmd);
1881
1882 kfree(cmd->chanlist); /* free kernel copy of user chanlist */
1883
1884 /* restore chanlist pointer before copying back */
1885 cmd->chanlist = (unsigned int __force *)user_chanlist;
1886 *copy = true;
1887
1888 return ret;
1889 }
1890
1891 /*
1892 * COMEDI_LOCK ioctl
1893 * lock subdevice
1894 *
1895 * arg:
1896 * subdevice number
1897 *
1898 * reads:
1899 * nothing
1900 *
1901 * writes:
1902 * nothing
1903 */
do_lock_ioctl(struct comedi_device * dev,unsigned long arg,void * file)1904 static int do_lock_ioctl(struct comedi_device *dev, unsigned long arg,
1905 void *file)
1906 {
1907 int ret = 0;
1908 unsigned long flags;
1909 struct comedi_subdevice *s;
1910
1911 lockdep_assert_held(&dev->mutex);
1912 if (arg >= dev->n_subdevices)
1913 return -EINVAL;
1914 s = &dev->subdevices[arg];
1915
1916 spin_lock_irqsave(&s->spin_lock, flags);
1917 if (s->busy || s->lock)
1918 ret = -EBUSY;
1919 else
1920 s->lock = file;
1921 spin_unlock_irqrestore(&s->spin_lock, flags);
1922
1923 return ret;
1924 }
1925
1926 /*
1927 * COMEDI_UNLOCK ioctl
1928 * unlock subdevice
1929 *
1930 * arg:
1931 * subdevice number
1932 *
1933 * reads:
1934 * nothing
1935 *
1936 * writes:
1937 * nothing
1938 */
do_unlock_ioctl(struct comedi_device * dev,unsigned long arg,void * file)1939 static int do_unlock_ioctl(struct comedi_device *dev, unsigned long arg,
1940 void *file)
1941 {
1942 struct comedi_subdevice *s;
1943
1944 lockdep_assert_held(&dev->mutex);
1945 if (arg >= dev->n_subdevices)
1946 return -EINVAL;
1947 s = &dev->subdevices[arg];
1948
1949 if (s->busy)
1950 return -EBUSY;
1951
1952 if (s->lock && s->lock != file)
1953 return -EACCES;
1954
1955 if (s->lock == file)
1956 s->lock = NULL;
1957
1958 return 0;
1959 }
1960
1961 /*
1962 * COMEDI_CANCEL ioctl
1963 * cancel asynchronous acquisition
1964 *
1965 * arg:
1966 * subdevice number
1967 *
1968 * reads:
1969 * nothing
1970 *
1971 * writes:
1972 * nothing
1973 */
do_cancel_ioctl(struct comedi_device * dev,unsigned long arg,void * file)1974 static int do_cancel_ioctl(struct comedi_device *dev, unsigned long arg,
1975 void *file)
1976 {
1977 struct comedi_subdevice *s;
1978
1979 lockdep_assert_held(&dev->mutex);
1980 if (arg >= dev->n_subdevices)
1981 return -EINVAL;
1982 s = &dev->subdevices[arg];
1983 if (!s->async)
1984 return -EINVAL;
1985
1986 if (!s->busy)
1987 return 0;
1988
1989 if (s->busy != file)
1990 return -EBUSY;
1991
1992 return do_cancel(dev, s);
1993 }
1994
1995 /*
1996 * COMEDI_POLL ioctl
1997 * instructs driver to synchronize buffers
1998 *
1999 * arg:
2000 * subdevice number
2001 *
2002 * reads:
2003 * nothing
2004 *
2005 * writes:
2006 * nothing
2007 */
do_poll_ioctl(struct comedi_device * dev,unsigned long arg,void * file)2008 static int do_poll_ioctl(struct comedi_device *dev, unsigned long arg,
2009 void *file)
2010 {
2011 struct comedi_subdevice *s;
2012
2013 lockdep_assert_held(&dev->mutex);
2014 if (arg >= dev->n_subdevices)
2015 return -EINVAL;
2016 s = &dev->subdevices[arg];
2017
2018 if (!s->busy)
2019 return 0;
2020
2021 if (s->busy != file)
2022 return -EBUSY;
2023
2024 if (s->poll)
2025 return s->poll(dev, s);
2026
2027 return -EINVAL;
2028 }
2029
2030 /*
2031 * COMEDI_SETRSUBD ioctl
2032 * sets the current "read" subdevice on a per-file basis
2033 *
2034 * arg:
2035 * subdevice number
2036 *
2037 * reads:
2038 * nothing
2039 *
2040 * writes:
2041 * nothing
2042 */
do_setrsubd_ioctl(struct comedi_device * dev,unsigned long arg,struct file * file)2043 static int do_setrsubd_ioctl(struct comedi_device *dev, unsigned long arg,
2044 struct file *file)
2045 {
2046 struct comedi_file *cfp = file->private_data;
2047 struct comedi_subdevice *s_old, *s_new;
2048
2049 lockdep_assert_held(&dev->mutex);
2050 if (arg >= dev->n_subdevices)
2051 return -EINVAL;
2052
2053 s_new = &dev->subdevices[arg];
2054 s_old = comedi_file_read_subdevice(file);
2055 if (s_old == s_new)
2056 return 0; /* no change */
2057
2058 if (!(s_new->subdev_flags & SDF_CMD_READ))
2059 return -EINVAL;
2060
2061 /*
2062 * Check the file isn't still busy handling a "read" command on the
2063 * old subdevice (if any).
2064 */
2065 if (s_old && s_old->busy == file && s_old->async &&
2066 !(s_old->async->cmd.flags & CMDF_WRITE))
2067 return -EBUSY;
2068
2069 WRITE_ONCE(cfp->read_subdev, s_new);
2070 return 0;
2071 }
2072
2073 /*
2074 * COMEDI_SETWSUBD ioctl
2075 * sets the current "write" subdevice on a per-file basis
2076 *
2077 * arg:
2078 * subdevice number
2079 *
2080 * reads:
2081 * nothing
2082 *
2083 * writes:
2084 * nothing
2085 */
do_setwsubd_ioctl(struct comedi_device * dev,unsigned long arg,struct file * file)2086 static int do_setwsubd_ioctl(struct comedi_device *dev, unsigned long arg,
2087 struct file *file)
2088 {
2089 struct comedi_file *cfp = file->private_data;
2090 struct comedi_subdevice *s_old, *s_new;
2091
2092 lockdep_assert_held(&dev->mutex);
2093 if (arg >= dev->n_subdevices)
2094 return -EINVAL;
2095
2096 s_new = &dev->subdevices[arg];
2097 s_old = comedi_file_write_subdevice(file);
2098 if (s_old == s_new)
2099 return 0; /* no change */
2100
2101 if (!(s_new->subdev_flags & SDF_CMD_WRITE))
2102 return -EINVAL;
2103
2104 /*
2105 * Check the file isn't still busy handling a "write" command on the
2106 * old subdevice (if any).
2107 */
2108 if (s_old && s_old->busy == file && s_old->async &&
2109 (s_old->async->cmd.flags & CMDF_WRITE))
2110 return -EBUSY;
2111
2112 WRITE_ONCE(cfp->write_subdev, s_new);
2113 return 0;
2114 }
2115
comedi_unlocked_ioctl(struct file * file,unsigned int cmd,unsigned long arg)2116 static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd,
2117 unsigned long arg)
2118 {
2119 unsigned int minor = iminor(file_inode(file));
2120 struct comedi_file *cfp = file->private_data;
2121 struct comedi_device *dev = cfp->dev;
2122 int rc;
2123
2124 mutex_lock(&dev->mutex);
2125
2126 /*
2127 * Device config is special, because it must work on
2128 * an unconfigured device.
2129 */
2130 if (cmd == COMEDI_DEVCONFIG) {
2131 if (minor >= COMEDI_NUM_BOARD_MINORS) {
2132 /* Device config not appropriate on non-board minors. */
2133 rc = -ENOTTY;
2134 goto done;
2135 }
2136 rc = do_devconfig_ioctl(dev,
2137 (struct comedi_devconfig __user *)arg);
2138 if (rc == 0) {
2139 if (arg == 0 &&
2140 dev->minor >= comedi_num_legacy_minors) {
2141 /*
2142 * Successfully unconfigured a dynamically
2143 * allocated device. Try and remove it.
2144 */
2145 if (comedi_clear_board_dev(dev)) {
2146 mutex_unlock(&dev->mutex);
2147 comedi_free_board_dev(dev);
2148 return rc;
2149 }
2150 }
2151 }
2152 goto done;
2153 }
2154
2155 if (!dev->attached) {
2156 dev_dbg(dev->class_dev, "no driver attached\n");
2157 rc = -ENODEV;
2158 goto done;
2159 }
2160
2161 switch (cmd) {
2162 case COMEDI_BUFCONFIG:
2163 rc = do_bufconfig_ioctl(dev,
2164 (struct comedi_bufconfig __user *)arg);
2165 break;
2166 case COMEDI_DEVINFO:
2167 rc = do_devinfo_ioctl(dev, (struct comedi_devinfo __user *)arg,
2168 file);
2169 break;
2170 case COMEDI_SUBDINFO:
2171 rc = do_subdinfo_ioctl(dev,
2172 (struct comedi_subdinfo __user *)arg,
2173 file);
2174 break;
2175 case COMEDI_CHANINFO: {
2176 struct comedi_chaninfo it;
2177
2178 if (copy_from_user(&it, (void __user *)arg, sizeof(it)))
2179 rc = -EFAULT;
2180 else
2181 rc = do_chaninfo_ioctl(dev, &it);
2182 break;
2183 }
2184 case COMEDI_RANGEINFO: {
2185 struct comedi_rangeinfo it;
2186
2187 if (copy_from_user(&it, (void __user *)arg, sizeof(it)))
2188 rc = -EFAULT;
2189 else
2190 rc = do_rangeinfo_ioctl(dev, &it);
2191 break;
2192 }
2193 case COMEDI_BUFINFO:
2194 rc = do_bufinfo_ioctl(dev,
2195 (struct comedi_bufinfo __user *)arg,
2196 file);
2197 break;
2198 case COMEDI_LOCK:
2199 rc = do_lock_ioctl(dev, arg, file);
2200 break;
2201 case COMEDI_UNLOCK:
2202 rc = do_unlock_ioctl(dev, arg, file);
2203 break;
2204 case COMEDI_CANCEL:
2205 rc = do_cancel_ioctl(dev, arg, file);
2206 break;
2207 case COMEDI_CMD: {
2208 struct comedi_cmd cmd;
2209 bool copy = false;
2210
2211 if (copy_from_user(&cmd, (void __user *)arg, sizeof(cmd))) {
2212 rc = -EFAULT;
2213 break;
2214 }
2215 rc = do_cmd_ioctl(dev, &cmd, ©, file);
2216 if (copy && copy_to_user((void __user *)arg, &cmd, sizeof(cmd)))
2217 rc = -EFAULT;
2218 break;
2219 }
2220 case COMEDI_CMDTEST: {
2221 struct comedi_cmd cmd;
2222 bool copy = false;
2223
2224 if (copy_from_user(&cmd, (void __user *)arg, sizeof(cmd))) {
2225 rc = -EFAULT;
2226 break;
2227 }
2228 rc = do_cmdtest_ioctl(dev, &cmd, ©, file);
2229 if (copy && copy_to_user((void __user *)arg, &cmd, sizeof(cmd)))
2230 rc = -EFAULT;
2231 break;
2232 }
2233 case COMEDI_INSNLIST: {
2234 struct comedi_insnlist insnlist;
2235 struct comedi_insn *insns = NULL;
2236
2237 if (copy_from_user(&insnlist, (void __user *)arg,
2238 sizeof(insnlist))) {
2239 rc = -EFAULT;
2240 break;
2241 }
2242 insns = kcalloc(insnlist.n_insns, sizeof(*insns), GFP_KERNEL);
2243 if (!insns) {
2244 rc = -ENOMEM;
2245 break;
2246 }
2247 if (copy_from_user(insns, insnlist.insns,
2248 sizeof(*insns) * insnlist.n_insns)) {
2249 rc = -EFAULT;
2250 kfree(insns);
2251 break;
2252 }
2253 rc = do_insnlist_ioctl(dev, insns, insnlist.n_insns, file);
2254 kfree(insns);
2255 break;
2256 }
2257 case COMEDI_INSN: {
2258 struct comedi_insn insn;
2259
2260 if (copy_from_user(&insn, (void __user *)arg, sizeof(insn)))
2261 rc = -EFAULT;
2262 else
2263 rc = do_insn_ioctl(dev, &insn, file);
2264 break;
2265 }
2266 case COMEDI_POLL:
2267 rc = do_poll_ioctl(dev, arg, file);
2268 break;
2269 case COMEDI_SETRSUBD:
2270 rc = do_setrsubd_ioctl(dev, arg, file);
2271 break;
2272 case COMEDI_SETWSUBD:
2273 rc = do_setwsubd_ioctl(dev, arg, file);
2274 break;
2275 default:
2276 rc = -ENOTTY;
2277 break;
2278 }
2279
2280 done:
2281 mutex_unlock(&dev->mutex);
2282 return rc;
2283 }
2284
comedi_vm_open(struct vm_area_struct * area)2285 static void comedi_vm_open(struct vm_area_struct *area)
2286 {
2287 struct comedi_buf_map *bm;
2288
2289 bm = area->vm_private_data;
2290 comedi_buf_map_get(bm);
2291 }
2292
comedi_vm_close(struct vm_area_struct * area)2293 static void comedi_vm_close(struct vm_area_struct *area)
2294 {
2295 struct comedi_buf_map *bm;
2296
2297 bm = area->vm_private_data;
2298 comedi_buf_map_put(bm);
2299 }
2300
comedi_vm_access(struct vm_area_struct * vma,unsigned long addr,void * buf,int len,int write)2301 static int comedi_vm_access(struct vm_area_struct *vma, unsigned long addr,
2302 void *buf, int len, int write)
2303 {
2304 struct comedi_buf_map *bm = vma->vm_private_data;
2305 unsigned long offset =
2306 addr - vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT);
2307
2308 if (len < 0)
2309 return -EINVAL;
2310 if (len > vma->vm_end - addr)
2311 len = vma->vm_end - addr;
2312 return comedi_buf_map_access(bm, offset, buf, len, write);
2313 }
2314
2315 static const struct vm_operations_struct comedi_vm_ops = {
2316 .open = comedi_vm_open,
2317 .close = comedi_vm_close,
2318 .access = comedi_vm_access,
2319 };
2320
comedi_mmap(struct file * file,struct vm_area_struct * vma)2321 static int comedi_mmap(struct file *file, struct vm_area_struct *vma)
2322 {
2323 struct comedi_file *cfp = file->private_data;
2324 struct comedi_device *dev = cfp->dev;
2325 struct comedi_subdevice *s;
2326 struct comedi_async *async;
2327 struct comedi_buf_map *bm = NULL;
2328 struct comedi_buf_page *buf;
2329 unsigned long start = vma->vm_start;
2330 unsigned long size;
2331 int n_pages;
2332 int i;
2333 int retval = 0;
2334
2335 /*
2336 * 'trylock' avoids circular dependency with current->mm->mmap_lock
2337 * and down-reading &dev->attach_lock should normally succeed without
2338 * contention unless the device is in the process of being attached
2339 * or detached.
2340 */
2341 if (!down_read_trylock(&dev->attach_lock))
2342 return -EAGAIN;
2343
2344 if (!dev->attached) {
2345 dev_dbg(dev->class_dev, "no driver attached\n");
2346 retval = -ENODEV;
2347 goto done;
2348 }
2349
2350 if (vma->vm_flags & VM_WRITE)
2351 s = comedi_file_write_subdevice(file);
2352 else
2353 s = comedi_file_read_subdevice(file);
2354 if (!s) {
2355 retval = -EINVAL;
2356 goto done;
2357 }
2358
2359 async = s->async;
2360 if (!async) {
2361 retval = -EINVAL;
2362 goto done;
2363 }
2364
2365 if (vma->vm_pgoff != 0) {
2366 dev_dbg(dev->class_dev, "mmap() offset must be 0.\n");
2367 retval = -EINVAL;
2368 goto done;
2369 }
2370
2371 size = vma->vm_end - vma->vm_start;
2372 if (size > async->prealloc_bufsz) {
2373 retval = -EFAULT;
2374 goto done;
2375 }
2376 if (offset_in_page(size)) {
2377 retval = -EFAULT;
2378 goto done;
2379 }
2380
2381 n_pages = vma_pages(vma);
2382
2383 /* get reference to current buf map (if any) */
2384 bm = comedi_buf_map_from_subdev_get(s);
2385 if (!bm || n_pages > bm->n_pages) {
2386 retval = -EINVAL;
2387 goto done;
2388 }
2389 if (bm->dma_dir != DMA_NONE) {
2390 /*
2391 * DMA buffer was allocated as a single block.
2392 * Address is in page_list[0].
2393 */
2394 buf = &bm->page_list[0];
2395 retval = dma_mmap_coherent(bm->dma_hw_dev, vma, buf->virt_addr,
2396 buf->dma_addr, n_pages * PAGE_SIZE);
2397 } else {
2398 for (i = 0; i < n_pages; ++i) {
2399 unsigned long pfn;
2400
2401 buf = &bm->page_list[i];
2402 pfn = page_to_pfn(virt_to_page(buf->virt_addr));
2403 retval = remap_pfn_range(vma, start, pfn, PAGE_SIZE,
2404 PAGE_SHARED);
2405 if (retval)
2406 break;
2407
2408 start += PAGE_SIZE;
2409 }
2410 }
2411
2412 if (retval == 0) {
2413 vma->vm_ops = &comedi_vm_ops;
2414 vma->vm_private_data = bm;
2415
2416 vma->vm_ops->open(vma);
2417 }
2418
2419 done:
2420 up_read(&dev->attach_lock);
2421 comedi_buf_map_put(bm); /* put reference to buf map - okay if NULL */
2422 return retval;
2423 }
2424
comedi_poll(struct file * file,poll_table * wait)2425 static __poll_t comedi_poll(struct file *file, poll_table *wait)
2426 {
2427 __poll_t mask = 0;
2428 struct comedi_file *cfp = file->private_data;
2429 struct comedi_device *dev = cfp->dev;
2430 struct comedi_subdevice *s, *s_read;
2431
2432 down_read(&dev->attach_lock);
2433
2434 if (!dev->attached) {
2435 dev_dbg(dev->class_dev, "no driver attached\n");
2436 goto done;
2437 }
2438
2439 s = comedi_file_read_subdevice(file);
2440 s_read = s;
2441 if (s && s->async) {
2442 poll_wait(file, &s->async->wait_head, wait);
2443 if (s->busy != file || !comedi_is_subdevice_running(s) ||
2444 (s->async->cmd.flags & CMDF_WRITE) ||
2445 comedi_buf_read_n_available(s) > 0)
2446 mask |= EPOLLIN | EPOLLRDNORM;
2447 }
2448
2449 s = comedi_file_write_subdevice(file);
2450 if (s && s->async) {
2451 unsigned int bps = comedi_bytes_per_sample(s);
2452
2453 if (s != s_read)
2454 poll_wait(file, &s->async->wait_head, wait);
2455 if (s->busy != file || !comedi_is_subdevice_running(s) ||
2456 !(s->async->cmd.flags & CMDF_WRITE) ||
2457 comedi_buf_write_n_available(s) >= bps)
2458 mask |= EPOLLOUT | EPOLLWRNORM;
2459 }
2460
2461 done:
2462 up_read(&dev->attach_lock);
2463 return mask;
2464 }
2465
comedi_write(struct file * file,const char __user * buf,size_t nbytes,loff_t * offset)2466 static ssize_t comedi_write(struct file *file, const char __user *buf,
2467 size_t nbytes, loff_t *offset)
2468 {
2469 struct comedi_subdevice *s;
2470 struct comedi_async *async;
2471 unsigned int n, m;
2472 ssize_t count = 0;
2473 int retval = 0;
2474 DECLARE_WAITQUEUE(wait, current);
2475 struct comedi_file *cfp = file->private_data;
2476 struct comedi_device *dev = cfp->dev;
2477 bool become_nonbusy = false;
2478 bool attach_locked;
2479 unsigned int old_detach_count;
2480
2481 /* Protect against device detachment during operation. */
2482 down_read(&dev->attach_lock);
2483 attach_locked = true;
2484 old_detach_count = dev->detach_count;
2485
2486 if (!dev->attached) {
2487 dev_dbg(dev->class_dev, "no driver attached\n");
2488 retval = -ENODEV;
2489 goto out;
2490 }
2491
2492 s = comedi_file_write_subdevice(file);
2493 if (!s || !s->async) {
2494 retval = -EIO;
2495 goto out;
2496 }
2497
2498 async = s->async;
2499 if (s->busy != file || !(async->cmd.flags & CMDF_WRITE)) {
2500 retval = -EINVAL;
2501 goto out;
2502 }
2503
2504 add_wait_queue(&async->wait_head, &wait);
2505 while (count == 0 && !retval) {
2506 unsigned int runflags;
2507 unsigned int wp, n1, n2;
2508
2509 set_current_state(TASK_INTERRUPTIBLE);
2510
2511 runflags = comedi_get_subdevice_runflags(s);
2512 if (!comedi_is_runflags_running(runflags)) {
2513 if (comedi_is_runflags_in_error(runflags))
2514 retval = -EPIPE;
2515 if (retval || nbytes)
2516 become_nonbusy = true;
2517 break;
2518 }
2519 if (nbytes == 0)
2520 break;
2521
2522 /* Allocate all free buffer space. */
2523 comedi_buf_write_alloc(s, async->prealloc_bufsz);
2524 m = comedi_buf_write_n_allocated(s);
2525 n = min_t(size_t, m, nbytes);
2526
2527 if (n == 0) {
2528 if (file->f_flags & O_NONBLOCK) {
2529 retval = -EAGAIN;
2530 break;
2531 }
2532 schedule();
2533 if (signal_pending(current)) {
2534 retval = -ERESTARTSYS;
2535 break;
2536 }
2537 if (s->busy != file ||
2538 !(async->cmd.flags & CMDF_WRITE)) {
2539 retval = -EINVAL;
2540 break;
2541 }
2542 continue;
2543 }
2544
2545 set_current_state(TASK_RUNNING);
2546 wp = async->buf_write_ptr;
2547 n1 = min(n, async->prealloc_bufsz - wp);
2548 n2 = n - n1;
2549 m = copy_from_user(async->prealloc_buf + wp, buf, n1);
2550 if (m)
2551 m += n2;
2552 else if (n2)
2553 m = copy_from_user(async->prealloc_buf, buf + n1, n2);
2554 if (m) {
2555 n -= m;
2556 retval = -EFAULT;
2557 }
2558 comedi_buf_write_free(s, n);
2559
2560 count += n;
2561 nbytes -= n;
2562
2563 buf += n;
2564 }
2565 remove_wait_queue(&async->wait_head, &wait);
2566 set_current_state(TASK_RUNNING);
2567 if (become_nonbusy && count == 0) {
2568 struct comedi_subdevice *new_s;
2569
2570 /*
2571 * To avoid deadlock, cannot acquire dev->mutex
2572 * while dev->attach_lock is held.
2573 */
2574 up_read(&dev->attach_lock);
2575 attach_locked = false;
2576 mutex_lock(&dev->mutex);
2577 /*
2578 * Check device hasn't become detached behind our back.
2579 * Checking dev->detach_count is unchanged ought to be
2580 * sufficient (unless there have been 2**32 detaches in the
2581 * meantime!), but check the subdevice pointer as well just in
2582 * case.
2583 *
2584 * Also check the subdevice is still in a suitable state to
2585 * become non-busy in case it changed behind our back.
2586 */
2587 new_s = comedi_file_write_subdevice(file);
2588 if (dev->attached && old_detach_count == dev->detach_count &&
2589 s == new_s && new_s->async == async && s->busy == file &&
2590 (async->cmd.flags & CMDF_WRITE) &&
2591 !comedi_is_subdevice_running(s))
2592 do_become_nonbusy(dev, s);
2593 mutex_unlock(&dev->mutex);
2594 }
2595 out:
2596 if (attach_locked)
2597 up_read(&dev->attach_lock);
2598
2599 return count ? count : retval;
2600 }
2601
comedi_read(struct file * file,char __user * buf,size_t nbytes,loff_t * offset)2602 static ssize_t comedi_read(struct file *file, char __user *buf, size_t nbytes,
2603 loff_t *offset)
2604 {
2605 struct comedi_subdevice *s;
2606 struct comedi_async *async;
2607 unsigned int n, m;
2608 ssize_t count = 0;
2609 int retval = 0;
2610 DECLARE_WAITQUEUE(wait, current);
2611 struct comedi_file *cfp = file->private_data;
2612 struct comedi_device *dev = cfp->dev;
2613 unsigned int old_detach_count;
2614 bool become_nonbusy = false;
2615 bool attach_locked;
2616
2617 /* Protect against device detachment during operation. */
2618 down_read(&dev->attach_lock);
2619 attach_locked = true;
2620 old_detach_count = dev->detach_count;
2621
2622 if (!dev->attached) {
2623 dev_dbg(dev->class_dev, "no driver attached\n");
2624 retval = -ENODEV;
2625 goto out;
2626 }
2627
2628 s = comedi_file_read_subdevice(file);
2629 if (!s || !s->async) {
2630 retval = -EIO;
2631 goto out;
2632 }
2633
2634 async = s->async;
2635 if (s->busy != file || (async->cmd.flags & CMDF_WRITE)) {
2636 retval = -EINVAL;
2637 goto out;
2638 }
2639
2640 add_wait_queue(&async->wait_head, &wait);
2641 while (count == 0 && !retval) {
2642 unsigned int rp, n1, n2;
2643
2644 set_current_state(TASK_INTERRUPTIBLE);
2645
2646 m = comedi_buf_read_n_available(s);
2647 n = min_t(size_t, m, nbytes);
2648
2649 if (n == 0) {
2650 unsigned int runflags =
2651 comedi_get_subdevice_runflags(s);
2652
2653 if (!comedi_is_runflags_running(runflags)) {
2654 if (comedi_is_runflags_in_error(runflags))
2655 retval = -EPIPE;
2656 if (retval || nbytes)
2657 become_nonbusy = true;
2658 break;
2659 }
2660 if (nbytes == 0)
2661 break;
2662 if (file->f_flags & O_NONBLOCK) {
2663 retval = -EAGAIN;
2664 break;
2665 }
2666 schedule();
2667 if (signal_pending(current)) {
2668 retval = -ERESTARTSYS;
2669 break;
2670 }
2671 if (s->busy != file ||
2672 (async->cmd.flags & CMDF_WRITE)) {
2673 retval = -EINVAL;
2674 break;
2675 }
2676 continue;
2677 }
2678
2679 set_current_state(TASK_RUNNING);
2680 rp = async->buf_read_ptr;
2681 n1 = min(n, async->prealloc_bufsz - rp);
2682 n2 = n - n1;
2683 m = copy_to_user(buf, async->prealloc_buf + rp, n1);
2684 if (m)
2685 m += n2;
2686 else if (n2)
2687 m = copy_to_user(buf + n1, async->prealloc_buf, n2);
2688 if (m) {
2689 n -= m;
2690 retval = -EFAULT;
2691 }
2692
2693 comedi_buf_read_alloc(s, n);
2694 comedi_buf_read_free(s, n);
2695
2696 count += n;
2697 nbytes -= n;
2698
2699 buf += n;
2700 }
2701 remove_wait_queue(&async->wait_head, &wait);
2702 set_current_state(TASK_RUNNING);
2703 if (become_nonbusy && count == 0) {
2704 struct comedi_subdevice *new_s;
2705
2706 /*
2707 * To avoid deadlock, cannot acquire dev->mutex
2708 * while dev->attach_lock is held.
2709 */
2710 up_read(&dev->attach_lock);
2711 attach_locked = false;
2712 mutex_lock(&dev->mutex);
2713 /*
2714 * Check device hasn't become detached behind our back.
2715 * Checking dev->detach_count is unchanged ought to be
2716 * sufficient (unless there have been 2**32 detaches in the
2717 * meantime!), but check the subdevice pointer as well just in
2718 * case.
2719 *
2720 * Also check the subdevice is still in a suitable state to
2721 * become non-busy in case it changed behind our back.
2722 */
2723 new_s = comedi_file_read_subdevice(file);
2724 if (dev->attached && old_detach_count == dev->detach_count &&
2725 s == new_s && new_s->async == async && s->busy == file &&
2726 !(async->cmd.flags & CMDF_WRITE) &&
2727 !comedi_is_subdevice_running(s) &&
2728 comedi_buf_read_n_available(s) == 0)
2729 do_become_nonbusy(dev, s);
2730 mutex_unlock(&dev->mutex);
2731 }
2732 out:
2733 if (attach_locked)
2734 up_read(&dev->attach_lock);
2735
2736 return count ? count : retval;
2737 }
2738
comedi_open(struct inode * inode,struct file * file)2739 static int comedi_open(struct inode *inode, struct file *file)
2740 {
2741 const unsigned int minor = iminor(inode);
2742 struct comedi_file *cfp;
2743 struct comedi_device *dev = comedi_dev_get_from_minor(minor);
2744 int rc;
2745
2746 if (!dev) {
2747 pr_debug("invalid minor number\n");
2748 return -ENODEV;
2749 }
2750
2751 cfp = kzalloc(sizeof(*cfp), GFP_KERNEL);
2752 if (!cfp) {
2753 comedi_dev_put(dev);
2754 return -ENOMEM;
2755 }
2756
2757 cfp->dev = dev;
2758
2759 mutex_lock(&dev->mutex);
2760 if (!dev->attached && !capable(CAP_SYS_ADMIN)) {
2761 dev_dbg(dev->class_dev, "not attached and not CAP_SYS_ADMIN\n");
2762 rc = -ENODEV;
2763 goto out;
2764 }
2765 if (dev->attached && dev->use_count == 0) {
2766 if (!try_module_get(dev->driver->module)) {
2767 rc = -ENXIO;
2768 goto out;
2769 }
2770 if (dev->open) {
2771 rc = dev->open(dev);
2772 if (rc < 0) {
2773 module_put(dev->driver->module);
2774 goto out;
2775 }
2776 }
2777 }
2778
2779 dev->use_count++;
2780 file->private_data = cfp;
2781 comedi_file_reset(file);
2782 rc = 0;
2783
2784 out:
2785 mutex_unlock(&dev->mutex);
2786 if (rc) {
2787 comedi_dev_put(dev);
2788 kfree(cfp);
2789 }
2790 return rc;
2791 }
2792
comedi_fasync(int fd,struct file * file,int on)2793 static int comedi_fasync(int fd, struct file *file, int on)
2794 {
2795 struct comedi_file *cfp = file->private_data;
2796 struct comedi_device *dev = cfp->dev;
2797
2798 return fasync_helper(fd, file, on, &dev->async_queue);
2799 }
2800
comedi_close(struct inode * inode,struct file * file)2801 static int comedi_close(struct inode *inode, struct file *file)
2802 {
2803 struct comedi_file *cfp = file->private_data;
2804 struct comedi_device *dev = cfp->dev;
2805 struct comedi_subdevice *s = NULL;
2806 int i;
2807
2808 mutex_lock(&dev->mutex);
2809
2810 if (dev->subdevices) {
2811 for (i = 0; i < dev->n_subdevices; i++) {
2812 s = &dev->subdevices[i];
2813
2814 if (s->busy == file)
2815 do_cancel(dev, s);
2816 if (s->lock == file)
2817 s->lock = NULL;
2818 }
2819 }
2820 if (dev->attached && dev->use_count == 1) {
2821 if (dev->close)
2822 dev->close(dev);
2823 module_put(dev->driver->module);
2824 }
2825
2826 dev->use_count--;
2827
2828 mutex_unlock(&dev->mutex);
2829 comedi_dev_put(dev);
2830 kfree(cfp);
2831
2832 return 0;
2833 }
2834
2835 #ifdef CONFIG_COMPAT
2836
2837 #define COMEDI32_CHANINFO _IOR(CIO, 3, struct comedi32_chaninfo_struct)
2838 #define COMEDI32_RANGEINFO _IOR(CIO, 8, struct comedi32_rangeinfo_struct)
2839 /*
2840 * N.B. COMEDI32_CMD and COMEDI_CMD 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_CMD _IOR(CIO, 9, struct comedi32_cmd_struct)
2844 /*
2845 * N.B. COMEDI32_CMDTEST and COMEDI_CMDTEST ought to use _IOWR, not _IOR.
2846 * It's too late to change it now, but it only affects the command number.
2847 */
2848 #define COMEDI32_CMDTEST _IOR(CIO, 10, struct comedi32_cmd_struct)
2849 #define COMEDI32_INSNLIST _IOR(CIO, 11, struct comedi32_insnlist_struct)
2850 #define COMEDI32_INSN _IOR(CIO, 12, struct comedi32_insn_struct)
2851
2852 struct comedi32_chaninfo_struct {
2853 unsigned int subdev;
2854 compat_uptr_t maxdata_list; /* 32-bit 'unsigned int *' */
2855 compat_uptr_t flaglist; /* 32-bit 'unsigned int *' */
2856 compat_uptr_t rangelist; /* 32-bit 'unsigned int *' */
2857 unsigned int unused[4];
2858 };
2859
2860 struct comedi32_rangeinfo_struct {
2861 unsigned int range_type;
2862 compat_uptr_t range_ptr; /* 32-bit 'void *' */
2863 };
2864
2865 struct comedi32_cmd_struct {
2866 unsigned int subdev;
2867 unsigned int flags;
2868 unsigned int start_src;
2869 unsigned int start_arg;
2870 unsigned int scan_begin_src;
2871 unsigned int scan_begin_arg;
2872 unsigned int convert_src;
2873 unsigned int convert_arg;
2874 unsigned int scan_end_src;
2875 unsigned int scan_end_arg;
2876 unsigned int stop_src;
2877 unsigned int stop_arg;
2878 compat_uptr_t chanlist; /* 32-bit 'unsigned int *' */
2879 unsigned int chanlist_len;
2880 compat_uptr_t data; /* 32-bit 'short *' */
2881 unsigned int data_len;
2882 };
2883
2884 struct comedi32_insn_struct {
2885 unsigned int insn;
2886 unsigned int n;
2887 compat_uptr_t data; /* 32-bit 'unsigned int *' */
2888 unsigned int subdev;
2889 unsigned int chanspec;
2890 unsigned int unused[3];
2891 };
2892
2893 struct comedi32_insnlist_struct {
2894 unsigned int n_insns;
2895 compat_uptr_t insns; /* 32-bit 'struct comedi_insn *' */
2896 };
2897
2898 /* Handle 32-bit COMEDI_CHANINFO ioctl. */
compat_chaninfo(struct file * file,unsigned long arg)2899 static int compat_chaninfo(struct file *file, unsigned long arg)
2900 {
2901 struct comedi_file *cfp = file->private_data;
2902 struct comedi_device *dev = cfp->dev;
2903 struct comedi32_chaninfo_struct chaninfo32;
2904 struct comedi_chaninfo chaninfo;
2905 int err;
2906
2907 if (copy_from_user(&chaninfo32, compat_ptr(arg), sizeof(chaninfo32)))
2908 return -EFAULT;
2909
2910 memset(&chaninfo, 0, sizeof(chaninfo));
2911 chaninfo.subdev = chaninfo32.subdev;
2912 chaninfo.maxdata_list = compat_ptr(chaninfo32.maxdata_list);
2913 chaninfo.flaglist = compat_ptr(chaninfo32.flaglist);
2914 chaninfo.rangelist = compat_ptr(chaninfo32.rangelist);
2915
2916 mutex_lock(&dev->mutex);
2917 err = do_chaninfo_ioctl(dev, &chaninfo);
2918 mutex_unlock(&dev->mutex);
2919 return err;
2920 }
2921
2922 /* Handle 32-bit COMEDI_RANGEINFO ioctl. */
compat_rangeinfo(struct file * file,unsigned long arg)2923 static int compat_rangeinfo(struct file *file, unsigned long arg)
2924 {
2925 struct comedi_file *cfp = file->private_data;
2926 struct comedi_device *dev = cfp->dev;
2927 struct comedi32_rangeinfo_struct rangeinfo32;
2928 struct comedi_rangeinfo rangeinfo;
2929 int err;
2930
2931 if (copy_from_user(&rangeinfo32, compat_ptr(arg), sizeof(rangeinfo32)))
2932 return -EFAULT;
2933 memset(&rangeinfo, 0, sizeof(rangeinfo));
2934 rangeinfo.range_type = rangeinfo32.range_type;
2935 rangeinfo.range_ptr = compat_ptr(rangeinfo32.range_ptr);
2936
2937 mutex_lock(&dev->mutex);
2938 err = do_rangeinfo_ioctl(dev, &rangeinfo);
2939 mutex_unlock(&dev->mutex);
2940 return err;
2941 }
2942
2943 /* Copy 32-bit cmd structure to native cmd structure. */
get_compat_cmd(struct comedi_cmd * cmd,struct comedi32_cmd_struct __user * cmd32)2944 static int get_compat_cmd(struct comedi_cmd *cmd,
2945 struct comedi32_cmd_struct __user *cmd32)
2946 {
2947 struct comedi32_cmd_struct v32;
2948
2949 if (copy_from_user(&v32, cmd32, sizeof(v32)))
2950 return -EFAULT;
2951
2952 cmd->subdev = v32.subdev;
2953 cmd->flags = v32.flags;
2954 cmd->start_src = v32.start_src;
2955 cmd->start_arg = v32.start_arg;
2956 cmd->scan_begin_src = v32.scan_begin_src;
2957 cmd->scan_begin_arg = v32.scan_begin_arg;
2958 cmd->convert_src = v32.convert_src;
2959 cmd->convert_arg = v32.convert_arg;
2960 cmd->scan_end_src = v32.scan_end_src;
2961 cmd->scan_end_arg = v32.scan_end_arg;
2962 cmd->stop_src = v32.stop_src;
2963 cmd->stop_arg = v32.stop_arg;
2964 cmd->chanlist = (unsigned int __force *)compat_ptr(v32.chanlist);
2965 cmd->chanlist_len = v32.chanlist_len;
2966 cmd->data = compat_ptr(v32.data);
2967 cmd->data_len = v32.data_len;
2968 return 0;
2969 }
2970
2971 /* Copy native cmd structure to 32-bit cmd structure. */
put_compat_cmd(struct comedi32_cmd_struct __user * cmd32,struct comedi_cmd * cmd)2972 static int put_compat_cmd(struct comedi32_cmd_struct __user *cmd32,
2973 struct comedi_cmd *cmd)
2974 {
2975 struct comedi32_cmd_struct v32;
2976
2977 memset(&v32, 0, sizeof(v32));
2978 v32.subdev = cmd->subdev;
2979 v32.flags = cmd->flags;
2980 v32.start_src = cmd->start_src;
2981 v32.start_arg = cmd->start_arg;
2982 v32.scan_begin_src = cmd->scan_begin_src;
2983 v32.scan_begin_arg = cmd->scan_begin_arg;
2984 v32.convert_src = cmd->convert_src;
2985 v32.convert_arg = cmd->convert_arg;
2986 v32.scan_end_src = cmd->scan_end_src;
2987 v32.scan_end_arg = cmd->scan_end_arg;
2988 v32.stop_src = cmd->stop_src;
2989 v32.stop_arg = cmd->stop_arg;
2990 /* Assume chanlist pointer is unchanged. */
2991 v32.chanlist = ptr_to_compat((unsigned int __user *)cmd->chanlist);
2992 v32.chanlist_len = cmd->chanlist_len;
2993 v32.data = ptr_to_compat(cmd->data);
2994 v32.data_len = cmd->data_len;
2995 if (copy_to_user(cmd32, &v32, sizeof(v32)))
2996 return -EFAULT;
2997 return 0;
2998 }
2999
3000 /* Handle 32-bit COMEDI_CMD ioctl. */
compat_cmd(struct file * file,unsigned long arg)3001 static int compat_cmd(struct file *file, unsigned long arg)
3002 {
3003 struct comedi_file *cfp = file->private_data;
3004 struct comedi_device *dev = cfp->dev;
3005 struct comedi_cmd cmd;
3006 bool copy = false;
3007 int rc, err;
3008
3009 rc = get_compat_cmd(&cmd, compat_ptr(arg));
3010 if (rc)
3011 return rc;
3012
3013 mutex_lock(&dev->mutex);
3014 rc = do_cmd_ioctl(dev, &cmd, ©, file);
3015 mutex_unlock(&dev->mutex);
3016 if (copy) {
3017 /* Special case: copy cmd back to user. */
3018 err = put_compat_cmd(compat_ptr(arg), &cmd);
3019 if (err)
3020 rc = err;
3021 }
3022 return rc;
3023 }
3024
3025 /* Handle 32-bit COMEDI_CMDTEST ioctl. */
compat_cmdtest(struct file * file,unsigned long arg)3026 static int compat_cmdtest(struct file *file, unsigned long arg)
3027 {
3028 struct comedi_file *cfp = file->private_data;
3029 struct comedi_device *dev = cfp->dev;
3030 struct comedi_cmd cmd;
3031 bool copy = false;
3032 int rc, err;
3033
3034 rc = get_compat_cmd(&cmd, compat_ptr(arg));
3035 if (rc)
3036 return rc;
3037
3038 mutex_lock(&dev->mutex);
3039 rc = do_cmdtest_ioctl(dev, &cmd, ©, file);
3040 mutex_unlock(&dev->mutex);
3041 if (copy) {
3042 err = put_compat_cmd(compat_ptr(arg), &cmd);
3043 if (err)
3044 rc = err;
3045 }
3046 return rc;
3047 }
3048
3049 /* Copy 32-bit insn structure to native insn structure. */
get_compat_insn(struct comedi_insn * insn,struct comedi32_insn_struct __user * insn32)3050 static int get_compat_insn(struct comedi_insn *insn,
3051 struct comedi32_insn_struct __user *insn32)
3052 {
3053 struct comedi32_insn_struct v32;
3054
3055 /* Copy insn structure. Ignore the unused members. */
3056 if (copy_from_user(&v32, insn32, sizeof(v32)))
3057 return -EFAULT;
3058 memset(insn, 0, sizeof(*insn));
3059 insn->insn = v32.insn;
3060 insn->n = v32.n;
3061 insn->data = compat_ptr(v32.data);
3062 insn->subdev = v32.subdev;
3063 insn->chanspec = v32.chanspec;
3064 return 0;
3065 }
3066
3067 /* Handle 32-bit COMEDI_INSNLIST ioctl. */
compat_insnlist(struct file * file,unsigned long arg)3068 static int compat_insnlist(struct file *file, unsigned long arg)
3069 {
3070 struct comedi_file *cfp = file->private_data;
3071 struct comedi_device *dev = cfp->dev;
3072 struct comedi32_insnlist_struct insnlist32;
3073 struct comedi32_insn_struct __user *insn32;
3074 struct comedi_insn *insns;
3075 unsigned int n;
3076 int rc;
3077
3078 if (copy_from_user(&insnlist32, compat_ptr(arg), sizeof(insnlist32)))
3079 return -EFAULT;
3080
3081 insns = kcalloc(insnlist32.n_insns, sizeof(*insns), GFP_KERNEL);
3082 if (!insns)
3083 return -ENOMEM;
3084
3085 /* Copy insn structures. */
3086 insn32 = compat_ptr(insnlist32.insns);
3087 for (n = 0; n < insnlist32.n_insns; n++) {
3088 rc = get_compat_insn(insns + n, insn32 + n);
3089 if (rc) {
3090 kfree(insns);
3091 return rc;
3092 }
3093 }
3094
3095 mutex_lock(&dev->mutex);
3096 rc = do_insnlist_ioctl(dev, insns, insnlist32.n_insns, file);
3097 mutex_unlock(&dev->mutex);
3098 kfree(insns);
3099 return rc;
3100 }
3101
3102 /* Handle 32-bit COMEDI_INSN ioctl. */
compat_insn(struct file * file,unsigned long arg)3103 static int compat_insn(struct file *file, unsigned long arg)
3104 {
3105 struct comedi_file *cfp = file->private_data;
3106 struct comedi_device *dev = cfp->dev;
3107 struct comedi_insn insn;
3108 int rc;
3109
3110 rc = get_compat_insn(&insn, (void __user *)arg);
3111 if (rc)
3112 return rc;
3113
3114 mutex_lock(&dev->mutex);
3115 rc = do_insn_ioctl(dev, &insn, file);
3116 mutex_unlock(&dev->mutex);
3117 return rc;
3118 }
3119
3120 /*
3121 * compat_ioctl file operation.
3122 *
3123 * Returns -ENOIOCTLCMD for unrecognised ioctl codes.
3124 */
comedi_compat_ioctl(struct file * file,unsigned int cmd,unsigned long arg)3125 static long comedi_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
3126 {
3127 int rc;
3128
3129 switch (cmd) {
3130 case COMEDI_DEVCONFIG:
3131 case COMEDI_DEVINFO:
3132 case COMEDI_SUBDINFO:
3133 case COMEDI_BUFCONFIG:
3134 case COMEDI_BUFINFO:
3135 /* Just need to translate the pointer argument. */
3136 arg = (unsigned long)compat_ptr(arg);
3137 rc = comedi_unlocked_ioctl(file, cmd, arg);
3138 break;
3139 case COMEDI_LOCK:
3140 case COMEDI_UNLOCK:
3141 case COMEDI_CANCEL:
3142 case COMEDI_POLL:
3143 case COMEDI_SETRSUBD:
3144 case COMEDI_SETWSUBD:
3145 /* No translation needed. */
3146 rc = comedi_unlocked_ioctl(file, cmd, arg);
3147 break;
3148 case COMEDI32_CHANINFO:
3149 rc = compat_chaninfo(file, arg);
3150 break;
3151 case COMEDI32_RANGEINFO:
3152 rc = compat_rangeinfo(file, arg);
3153 break;
3154 case COMEDI32_CMD:
3155 rc = compat_cmd(file, arg);
3156 break;
3157 case COMEDI32_CMDTEST:
3158 rc = compat_cmdtest(file, arg);
3159 break;
3160 case COMEDI32_INSNLIST:
3161 rc = compat_insnlist(file, arg);
3162 break;
3163 case COMEDI32_INSN:
3164 rc = compat_insn(file, arg);
3165 break;
3166 default:
3167 rc = -ENOIOCTLCMD;
3168 break;
3169 }
3170 return rc;
3171 }
3172 #else
3173 #define comedi_compat_ioctl NULL
3174 #endif
3175
3176 static const struct file_operations comedi_fops = {
3177 .owner = THIS_MODULE,
3178 .unlocked_ioctl = comedi_unlocked_ioctl,
3179 .compat_ioctl = comedi_compat_ioctl,
3180 .open = comedi_open,
3181 .release = comedi_close,
3182 .read = comedi_read,
3183 .write = comedi_write,
3184 .mmap = comedi_mmap,
3185 .poll = comedi_poll,
3186 .fasync = comedi_fasync,
3187 .llseek = noop_llseek,
3188 };
3189
3190 /**
3191 * comedi_event() - Handle events for asynchronous COMEDI command
3192 * @dev: COMEDI device.
3193 * @s: COMEDI subdevice.
3194 * Context: in_interrupt() (usually), @s->spin_lock spin-lock not held.
3195 *
3196 * If an asynchronous COMEDI command is active on the subdevice, process
3197 * any %COMEDI_CB_... event flags that have been set, usually by an
3198 * interrupt handler. These may change the run state of the asynchronous
3199 * command, wake a task, and/or send a %SIGIO signal.
3200 */
comedi_event(struct comedi_device * dev,struct comedi_subdevice * s)3201 void comedi_event(struct comedi_device *dev, struct comedi_subdevice *s)
3202 {
3203 struct comedi_async *async = s->async;
3204 unsigned int events;
3205 int si_code = 0;
3206 unsigned long flags;
3207
3208 spin_lock_irqsave(&s->spin_lock, flags);
3209
3210 events = async->events;
3211 async->events = 0;
3212 if (!__comedi_is_subdevice_running(s)) {
3213 spin_unlock_irqrestore(&s->spin_lock, flags);
3214 return;
3215 }
3216
3217 if (events & COMEDI_CB_CANCEL_MASK)
3218 __comedi_clear_subdevice_runflags(s, COMEDI_SRF_RUNNING);
3219
3220 /*
3221 * Remember if an error event has occurred, so an error can be
3222 * returned the next time the user does a read() or write().
3223 */
3224 if (events & COMEDI_CB_ERROR_MASK)
3225 __comedi_set_subdevice_runflags(s, COMEDI_SRF_ERROR);
3226
3227 if (async->cb_mask & events) {
3228 wake_up_interruptible(&async->wait_head);
3229 si_code = async->cmd.flags & CMDF_WRITE ? POLL_OUT : POLL_IN;
3230 }
3231
3232 spin_unlock_irqrestore(&s->spin_lock, flags);
3233
3234 if (si_code)
3235 kill_fasync(&dev->async_queue, SIGIO, si_code);
3236 }
3237 EXPORT_SYMBOL_GPL(comedi_event);
3238
3239 /* Note: the ->mutex is pre-locked on successful return */
comedi_alloc_board_minor(struct device * hardware_device)3240 struct comedi_device *comedi_alloc_board_minor(struct device *hardware_device)
3241 {
3242 struct comedi_device *dev;
3243 struct device *csdev;
3244 unsigned int i;
3245
3246 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
3247 if (!dev)
3248 return ERR_PTR(-ENOMEM);
3249 comedi_device_init(dev);
3250 comedi_set_hw_dev(dev, hardware_device);
3251 mutex_lock(&dev->mutex);
3252 mutex_lock(&comedi_board_minor_table_lock);
3253 for (i = hardware_device ? comedi_num_legacy_minors : 0;
3254 i < COMEDI_NUM_BOARD_MINORS; ++i) {
3255 if (!comedi_board_minor_table[i]) {
3256 comedi_board_minor_table[i] = dev;
3257 break;
3258 }
3259 }
3260 mutex_unlock(&comedi_board_minor_table_lock);
3261 if (i == COMEDI_NUM_BOARD_MINORS) {
3262 mutex_unlock(&dev->mutex);
3263 comedi_device_cleanup(dev);
3264 comedi_dev_put(dev);
3265 dev_err(hardware_device,
3266 "ran out of minor numbers for board device files\n");
3267 return ERR_PTR(-EBUSY);
3268 }
3269 dev->minor = i;
3270 csdev = device_create(&comedi_class, hardware_device,
3271 MKDEV(COMEDI_MAJOR, i), NULL, "comedi%i", i);
3272 if (!IS_ERR(csdev))
3273 dev->class_dev = get_device(csdev);
3274
3275 /* Note: dev->mutex needs to be unlocked by the caller. */
3276 return dev;
3277 }
3278
comedi_release_hardware_device(struct device * hardware_device)3279 void comedi_release_hardware_device(struct device *hardware_device)
3280 {
3281 int minor;
3282 struct comedi_device *dev;
3283
3284 for (minor = comedi_num_legacy_minors; minor < COMEDI_NUM_BOARD_MINORS;
3285 minor++) {
3286 mutex_lock(&comedi_board_minor_table_lock);
3287 dev = comedi_board_minor_table[minor];
3288 if (dev && dev->hw_dev == hardware_device) {
3289 comedi_board_minor_table[minor] = NULL;
3290 mutex_unlock(&comedi_board_minor_table_lock);
3291 comedi_free_board_dev(dev);
3292 break;
3293 }
3294 mutex_unlock(&comedi_board_minor_table_lock);
3295 }
3296 }
3297
comedi_alloc_subdevice_minor(struct comedi_subdevice * s)3298 int comedi_alloc_subdevice_minor(struct comedi_subdevice *s)
3299 {
3300 struct comedi_device *dev = s->device;
3301 struct device *csdev;
3302 unsigned int i;
3303
3304 mutex_lock(&comedi_subdevice_minor_table_lock);
3305 for (i = 0; i < COMEDI_NUM_SUBDEVICE_MINORS; ++i) {
3306 if (!comedi_subdevice_minor_table[i]) {
3307 comedi_subdevice_minor_table[i] = s;
3308 break;
3309 }
3310 }
3311 mutex_unlock(&comedi_subdevice_minor_table_lock);
3312 if (i == COMEDI_NUM_SUBDEVICE_MINORS) {
3313 dev_err(dev->class_dev,
3314 "ran out of minor numbers for subdevice files\n");
3315 return -EBUSY;
3316 }
3317 i += COMEDI_NUM_BOARD_MINORS;
3318 s->minor = i;
3319 csdev = device_create(&comedi_class, dev->class_dev,
3320 MKDEV(COMEDI_MAJOR, i), NULL, "comedi%i_subd%i",
3321 dev->minor, s->index);
3322 if (!IS_ERR(csdev))
3323 s->class_dev = csdev;
3324
3325 return 0;
3326 }
3327
comedi_free_subdevice_minor(struct comedi_subdevice * s)3328 void comedi_free_subdevice_minor(struct comedi_subdevice *s)
3329 {
3330 unsigned int i;
3331
3332 if (!s)
3333 return;
3334 if (s->minor < COMEDI_NUM_BOARD_MINORS ||
3335 s->minor >= COMEDI_NUM_MINORS)
3336 return;
3337
3338 i = s->minor - COMEDI_NUM_BOARD_MINORS;
3339 mutex_lock(&comedi_subdevice_minor_table_lock);
3340 if (s == comedi_subdevice_minor_table[i])
3341 comedi_subdevice_minor_table[i] = NULL;
3342 mutex_unlock(&comedi_subdevice_minor_table_lock);
3343 if (s->class_dev) {
3344 device_destroy(&comedi_class, MKDEV(COMEDI_MAJOR, s->minor));
3345 s->class_dev = NULL;
3346 }
3347 }
3348
comedi_cleanup_board_minors(void)3349 static void comedi_cleanup_board_minors(void)
3350 {
3351 struct comedi_device *dev;
3352 unsigned int i;
3353
3354 for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) {
3355 dev = comedi_clear_board_minor(i);
3356 comedi_free_board_dev(dev);
3357 }
3358 }
3359
comedi_init(void)3360 static int __init comedi_init(void)
3361 {
3362 int i;
3363 int retval;
3364
3365 pr_info("version " COMEDI_RELEASE " - http://www.comedi.org\n");
3366
3367 if (comedi_num_legacy_minors > COMEDI_NUM_BOARD_MINORS) {
3368 pr_err("invalid value for module parameter \"comedi_num_legacy_minors\". Valid values are 0 through %i.\n",
3369 COMEDI_NUM_BOARD_MINORS);
3370 return -EINVAL;
3371 }
3372
3373 retval = register_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
3374 COMEDI_NUM_MINORS, "comedi");
3375 if (retval)
3376 return retval;
3377
3378 cdev_init(&comedi_cdev, &comedi_fops);
3379 comedi_cdev.owner = THIS_MODULE;
3380
3381 retval = kobject_set_name(&comedi_cdev.kobj, "comedi");
3382 if (retval)
3383 goto out_unregister_chrdev_region;
3384
3385 retval = cdev_add(&comedi_cdev, MKDEV(COMEDI_MAJOR, 0),
3386 COMEDI_NUM_MINORS);
3387 if (retval)
3388 goto out_unregister_chrdev_region;
3389
3390 retval = class_register(&comedi_class);
3391 if (retval) {
3392 pr_err("failed to create class\n");
3393 goto out_cdev_del;
3394 }
3395
3396 /* create devices files for legacy/manual use */
3397 for (i = 0; i < comedi_num_legacy_minors; i++) {
3398 struct comedi_device *dev;
3399
3400 dev = comedi_alloc_board_minor(NULL);
3401 if (IS_ERR(dev)) {
3402 retval = PTR_ERR(dev);
3403 goto out_cleanup_board_minors;
3404 }
3405 /* comedi_alloc_board_minor() locked the mutex */
3406 lockdep_assert_held(&dev->mutex);
3407 mutex_unlock(&dev->mutex);
3408 }
3409
3410 /* XXX requires /proc interface */
3411 comedi_proc_init();
3412
3413 return 0;
3414
3415 out_cleanup_board_minors:
3416 comedi_cleanup_board_minors();
3417 class_unregister(&comedi_class);
3418 out_cdev_del:
3419 cdev_del(&comedi_cdev);
3420 out_unregister_chrdev_region:
3421 unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0), COMEDI_NUM_MINORS);
3422 return retval;
3423 }
3424 module_init(comedi_init);
3425
comedi_cleanup(void)3426 static void __exit comedi_cleanup(void)
3427 {
3428 comedi_cleanup_board_minors();
3429 class_unregister(&comedi_class);
3430 cdev_del(&comedi_cdev);
3431 unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0), COMEDI_NUM_MINORS);
3432
3433 comedi_proc_cleanup();
3434 }
3435 module_exit(comedi_cleanup);
3436
3437 MODULE_AUTHOR("https://www.comedi.org");
3438 MODULE_DESCRIPTION("Comedi core module");
3439 MODULE_LICENSE("GPL");
3440