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1 | /* |
2 | * drivers/uio/uio.c |
3 | * |
4 | * Copyright(C) 2005, Benedikt Spranger <b.spranger@linutronix.de> |
5 | * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de> |
6 | * Copyright(C) 2006, Hans J. Koch <hjk@linutronix.de> |
7 | * Copyright(C) 2006, Greg Kroah-Hartman <greg@kroah.com> |
8 | * |
9 | * Userspace IO |
10 | * |
11 | * Base Functions |
12 | * |
13 | * Licensed under the GPLv2 only. |
14 | */ |
15 | |
16 | #include <linux/module.h> |
17 | #include <linux/init.h> |
18 | #include <linux/poll.h> |
19 | #include <linux/device.h> |
20 | #include <linux/slab.h> |
21 | #include <linux/mm.h> |
22 | #include <linux/idr.h> |
23 | #include <linux/sched.h> |
24 | #include <linux/string.h> |
25 | #include <linux/kobject.h> |
26 | #include <linux/uio_driver.h> |
27 | |
28 | #define UIO_MAX_DEVICES 255 |
29 | |
30 | struct uio_device { |
31 | struct module *owner; |
32 | struct device *dev; |
33 | int minor; |
34 | atomic_t event; |
35 | struct fasync_struct *async_queue; |
36 | wait_queue_head_t wait; |
37 | int vma_count; |
38 | struct uio_info *info; |
39 | struct kobject *map_dir; |
40 | struct kobject *portio_dir; |
41 | }; |
42 | |
43 | static int uio_major; |
44 | static DEFINE_IDR(uio_idr); |
45 | static const struct file_operations uio_fops; |
46 | |
47 | /* UIO class infrastructure */ |
48 | static struct uio_class { |
49 | struct kref kref; |
50 | struct class *class; |
51 | } *uio_class; |
52 | |
53 | /* Protect idr accesses */ |
54 | static DEFINE_MUTEX(minor_lock); |
55 | |
56 | /* |
57 | * attributes |
58 | */ |
59 | |
60 | struct uio_map { |
61 | struct kobject kobj; |
62 | struct uio_mem *mem; |
63 | }; |
64 | #define to_map(map) container_of(map, struct uio_map, kobj) |
65 | |
66 | static ssize_t map_name_show(struct uio_mem *mem, char *buf) |
67 | { |
68 | if (unlikely(!mem->name)) |
69 | mem->name = ""; |
70 | |
71 | return sprintf(buf, "%s\n", mem->name); |
72 | } |
73 | |
74 | static ssize_t map_addr_show(struct uio_mem *mem, char *buf) |
75 | { |
76 | return sprintf(buf, "0x%lx\n", mem->addr); |
77 | } |
78 | |
79 | static ssize_t map_size_show(struct uio_mem *mem, char *buf) |
80 | { |
81 | return sprintf(buf, "0x%lx\n", mem->size); |
82 | } |
83 | |
84 | static ssize_t map_offset_show(struct uio_mem *mem, char *buf) |
85 | { |
86 | return sprintf(buf, "0x%lx\n", mem->addr & ~PAGE_MASK); |
87 | } |
88 | |
89 | struct map_sysfs_entry { |
90 | struct attribute attr; |
91 | ssize_t (*show)(struct uio_mem *, char *); |
92 | ssize_t (*store)(struct uio_mem *, const char *, size_t); |
93 | }; |
94 | |
95 | static struct map_sysfs_entry name_attribute = |
96 | __ATTR(name, S_IRUGO, map_name_show, NULL); |
97 | static struct map_sysfs_entry addr_attribute = |
98 | __ATTR(addr, S_IRUGO, map_addr_show, NULL); |
99 | static struct map_sysfs_entry size_attribute = |
100 | __ATTR(size, S_IRUGO, map_size_show, NULL); |
101 | static struct map_sysfs_entry offset_attribute = |
102 | __ATTR(offset, S_IRUGO, map_offset_show, NULL); |
103 | |
104 | static struct attribute *attrs[] = { |
105 | &name_attribute.attr, |
106 | &addr_attribute.attr, |
107 | &size_attribute.attr, |
108 | &offset_attribute.attr, |
109 | NULL, /* need to NULL terminate the list of attributes */ |
110 | }; |
111 | |
112 | static void map_release(struct kobject *kobj) |
113 | { |
114 | struct uio_map *map = to_map(kobj); |
115 | kfree(map); |
116 | } |
117 | |
118 | static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr, |
119 | char *buf) |
120 | { |
121 | struct uio_map *map = to_map(kobj); |
122 | struct uio_mem *mem = map->mem; |
123 | struct map_sysfs_entry *entry; |
124 | |
125 | entry = container_of(attr, struct map_sysfs_entry, attr); |
126 | |
127 | if (!entry->show) |
128 | return -EIO; |
129 | |
130 | return entry->show(mem, buf); |
131 | } |
132 | |
133 | static const struct sysfs_ops map_sysfs_ops = { |
134 | .show = map_type_show, |
135 | }; |
136 | |
137 | static struct kobj_type map_attr_type = { |
138 | .release = map_release, |
139 | .sysfs_ops = &map_sysfs_ops, |
140 | .default_attrs = attrs, |
141 | }; |
142 | |
143 | struct uio_portio { |
144 | struct kobject kobj; |
145 | struct uio_port *port; |
146 | }; |
147 | #define to_portio(portio) container_of(portio, struct uio_portio, kobj) |
148 | |
149 | static ssize_t portio_name_show(struct uio_port *port, char *buf) |
150 | { |
151 | if (unlikely(!port->name)) |
152 | port->name = ""; |
153 | |
154 | return sprintf(buf, "%s\n", port->name); |
155 | } |
156 | |
157 | static ssize_t portio_start_show(struct uio_port *port, char *buf) |
158 | { |
159 | return sprintf(buf, "0x%lx\n", port->start); |
160 | } |
161 | |
162 | static ssize_t portio_size_show(struct uio_port *port, char *buf) |
163 | { |
164 | return sprintf(buf, "0x%lx\n", port->size); |
165 | } |
166 | |
167 | static ssize_t portio_porttype_show(struct uio_port *port, char *buf) |
168 | { |
169 | const char *porttypes[] = {"none", "x86", "gpio", "other"}; |
170 | |
171 | if ((port->porttype < 0) || (port->porttype > UIO_PORT_OTHER)) |
172 | return -EINVAL; |
173 | |
174 | return sprintf(buf, "port_%s\n", porttypes[port->porttype]); |
175 | } |
176 | |
177 | struct portio_sysfs_entry { |
178 | struct attribute attr; |
179 | ssize_t (*show)(struct uio_port *, char *); |
180 | ssize_t (*store)(struct uio_port *, const char *, size_t); |
181 | }; |
182 | |
183 | static struct portio_sysfs_entry portio_name_attribute = |
184 | __ATTR(name, S_IRUGO, portio_name_show, NULL); |
185 | static struct portio_sysfs_entry portio_start_attribute = |
186 | __ATTR(start, S_IRUGO, portio_start_show, NULL); |
187 | static struct portio_sysfs_entry portio_size_attribute = |
188 | __ATTR(size, S_IRUGO, portio_size_show, NULL); |
189 | static struct portio_sysfs_entry portio_porttype_attribute = |
190 | __ATTR(porttype, S_IRUGO, portio_porttype_show, NULL); |
191 | |
192 | static struct attribute *portio_attrs[] = { |
193 | &portio_name_attribute.attr, |
194 | &portio_start_attribute.attr, |
195 | &portio_size_attribute.attr, |
196 | &portio_porttype_attribute.attr, |
197 | NULL, |
198 | }; |
199 | |
200 | static void portio_release(struct kobject *kobj) |
201 | { |
202 | struct uio_portio *portio = to_portio(kobj); |
203 | kfree(portio); |
204 | } |
205 | |
206 | static ssize_t portio_type_show(struct kobject *kobj, struct attribute *attr, |
207 | char *buf) |
208 | { |
209 | struct uio_portio *portio = to_portio(kobj); |
210 | struct uio_port *port = portio->port; |
211 | struct portio_sysfs_entry *entry; |
212 | |
213 | entry = container_of(attr, struct portio_sysfs_entry, attr); |
214 | |
215 | if (!entry->show) |
216 | return -EIO; |
217 | |
218 | return entry->show(port, buf); |
219 | } |
220 | |
221 | static const struct sysfs_ops portio_sysfs_ops = { |
222 | .show = portio_type_show, |
223 | }; |
224 | |
225 | static struct kobj_type portio_attr_type = { |
226 | .release = portio_release, |
227 | .sysfs_ops = &portio_sysfs_ops, |
228 | .default_attrs = portio_attrs, |
229 | }; |
230 | |
231 | static ssize_t show_name(struct device *dev, |
232 | struct device_attribute *attr, char *buf) |
233 | { |
234 | struct uio_device *idev = dev_get_drvdata(dev); |
235 | if (idev) |
236 | return sprintf(buf, "%s\n", idev->info->name); |
237 | else |
238 | return -ENODEV; |
239 | } |
240 | static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); |
241 | |
242 | static ssize_t show_version(struct device *dev, |
243 | struct device_attribute *attr, char *buf) |
244 | { |
245 | struct uio_device *idev = dev_get_drvdata(dev); |
246 | if (idev) |
247 | return sprintf(buf, "%s\n", idev->info->version); |
248 | else |
249 | return -ENODEV; |
250 | } |
251 | static DEVICE_ATTR(version, S_IRUGO, show_version, NULL); |
252 | |
253 | static ssize_t show_event(struct device *dev, |
254 | struct device_attribute *attr, char *buf) |
255 | { |
256 | struct uio_device *idev = dev_get_drvdata(dev); |
257 | if (idev) |
258 | return sprintf(buf, "%u\n", |
259 | (unsigned int)atomic_read(&idev->event)); |
260 | else |
261 | return -ENODEV; |
262 | } |
263 | static DEVICE_ATTR(event, S_IRUGO, show_event, NULL); |
264 | |
265 | static struct attribute *uio_attrs[] = { |
266 | &dev_attr_name.attr, |
267 | &dev_attr_version.attr, |
268 | &dev_attr_event.attr, |
269 | NULL, |
270 | }; |
271 | |
272 | static struct attribute_group uio_attr_grp = { |
273 | .attrs = uio_attrs, |
274 | }; |
275 | |
276 | /* |
277 | * device functions |
278 | */ |
279 | static int uio_dev_add_attributes(struct uio_device *idev) |
280 | { |
281 | int ret; |
282 | int mi, pi; |
283 | int map_found = 0; |
284 | int portio_found = 0; |
285 | struct uio_mem *mem; |
286 | struct uio_map *map; |
287 | struct uio_port *port; |
288 | struct uio_portio *portio; |
289 | |
290 | ret = sysfs_create_group(&idev->dev->kobj, &uio_attr_grp); |
291 | if (ret) |
292 | goto err_group; |
293 | |
294 | for (mi = 0; mi < MAX_UIO_MAPS; mi++) { |
295 | mem = &idev->info->mem[mi]; |
296 | if (mem->size == 0) |
297 | break; |
298 | if (!map_found) { |
299 | map_found = 1; |
300 | idev->map_dir = kobject_create_and_add("maps", |
301 | &idev->dev->kobj); |
302 | if (!idev->map_dir) |
303 | goto err_map; |
304 | } |
305 | map = kzalloc(sizeof(*map), GFP_KERNEL); |
306 | if (!map) |
307 | goto err_map; |
308 | kobject_init(&map->kobj, &map_attr_type); |
309 | map->mem = mem; |
310 | mem->map = map; |
311 | ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi); |
312 | if (ret) |
313 | goto err_map; |
314 | ret = kobject_uevent(&map->kobj, KOBJ_ADD); |
315 | if (ret) |
316 | goto err_map; |
317 | } |
318 | |
319 | for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) { |
320 | port = &idev->info->port[pi]; |
321 | if (port->size == 0) |
322 | break; |
323 | if (!portio_found) { |
324 | portio_found = 1; |
325 | idev->portio_dir = kobject_create_and_add("portio", |
326 | &idev->dev->kobj); |
327 | if (!idev->portio_dir) |
328 | goto err_portio; |
329 | } |
330 | portio = kzalloc(sizeof(*portio), GFP_KERNEL); |
331 | if (!portio) |
332 | goto err_portio; |
333 | kobject_init(&portio->kobj, &portio_attr_type); |
334 | portio->port = port; |
335 | port->portio = portio; |
336 | ret = kobject_add(&portio->kobj, idev->portio_dir, |
337 | "port%d", pi); |
338 | if (ret) |
339 | goto err_portio; |
340 | ret = kobject_uevent(&portio->kobj, KOBJ_ADD); |
341 | if (ret) |
342 | goto err_portio; |
343 | } |
344 | |
345 | return 0; |
346 | |
347 | err_portio: |
348 | for (pi--; pi >= 0; pi--) { |
349 | port = &idev->info->port[pi]; |
350 | portio = port->portio; |
351 | kobject_put(&portio->kobj); |
352 | } |
353 | kobject_put(idev->portio_dir); |
354 | err_map: |
355 | for (mi--; mi>=0; mi--) { |
356 | mem = &idev->info->mem[mi]; |
357 | map = mem->map; |
358 | kobject_put(&map->kobj); |
359 | } |
360 | kobject_put(idev->map_dir); |
361 | sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp); |
362 | err_group: |
363 | dev_err(idev->dev, "error creating sysfs files (%d)\n", ret); |
364 | return ret; |
365 | } |
366 | |
367 | static void uio_dev_del_attributes(struct uio_device *idev) |
368 | { |
369 | int i; |
370 | struct uio_mem *mem; |
371 | struct uio_port *port; |
372 | |
373 | for (i = 0; i < MAX_UIO_MAPS; i++) { |
374 | mem = &idev->info->mem[i]; |
375 | if (mem->size == 0) |
376 | break; |
377 | kobject_put(&mem->map->kobj); |
378 | } |
379 | kobject_put(idev->map_dir); |
380 | |
381 | for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) { |
382 | port = &idev->info->port[i]; |
383 | if (port->size == 0) |
384 | break; |
385 | kobject_put(&port->portio->kobj); |
386 | } |
387 | kobject_put(idev->portio_dir); |
388 | |
389 | sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp); |
390 | } |
391 | |
392 | static int uio_get_minor(struct uio_device *idev) |
393 | { |
394 | int retval = -ENOMEM; |
395 | int id; |
396 | |
397 | mutex_lock(&minor_lock); |
398 | if (idr_pre_get(&uio_idr, GFP_KERNEL) == 0) |
399 | goto exit; |
400 | |
401 | retval = idr_get_new(&uio_idr, idev, &id); |
402 | if (retval < 0) { |
403 | if (retval == -EAGAIN) |
404 | retval = -ENOMEM; |
405 | goto exit; |
406 | } |
407 | idev->minor = id & MAX_ID_MASK; |
408 | exit: |
409 | mutex_unlock(&minor_lock); |
410 | return retval; |
411 | } |
412 | |
413 | static void uio_free_minor(struct uio_device *idev) |
414 | { |
415 | mutex_lock(&minor_lock); |
416 | idr_remove(&uio_idr, idev->minor); |
417 | mutex_unlock(&minor_lock); |
418 | } |
419 | |
420 | /** |
421 | * uio_event_notify - trigger an interrupt event |
422 | * @info: UIO device capabilities |
423 | */ |
424 | void uio_event_notify(struct uio_info *info) |
425 | { |
426 | struct uio_device *idev = info->uio_dev; |
427 | |
428 | atomic_inc(&idev->event); |
429 | wake_up_interruptible(&idev->wait); |
430 | kill_fasync(&idev->async_queue, SIGIO, POLL_IN); |
431 | } |
432 | EXPORT_SYMBOL_GPL(uio_event_notify); |
433 | |
434 | /** |
435 | * uio_interrupt - hardware interrupt handler |
436 | * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer |
437 | * @dev_id: Pointer to the devices uio_device structure |
438 | */ |
439 | static irqreturn_t uio_interrupt(int irq, void *dev_id) |
440 | { |
441 | struct uio_device *idev = (struct uio_device *)dev_id; |
442 | irqreturn_t ret = idev->info->handler(irq, idev->info); |
443 | |
444 | if (ret == IRQ_HANDLED) |
445 | uio_event_notify(idev->info); |
446 | |
447 | return ret; |
448 | } |
449 | |
450 | struct uio_listener { |
451 | struct uio_device *dev; |
452 | s32 event_count; |
453 | }; |
454 | |
455 | static int uio_open(struct inode *inode, struct file *filep) |
456 | { |
457 | struct uio_device *idev; |
458 | struct uio_listener *listener; |
459 | int ret = 0; |
460 | |
461 | mutex_lock(&minor_lock); |
462 | idev = idr_find(&uio_idr, iminor(inode)); |
463 | mutex_unlock(&minor_lock); |
464 | if (!idev) { |
465 | ret = -ENODEV; |
466 | goto out; |
467 | } |
468 | |
469 | if (!try_module_get(idev->owner)) { |
470 | ret = -ENODEV; |
471 | goto out; |
472 | } |
473 | |
474 | listener = kmalloc(sizeof(*listener), GFP_KERNEL); |
475 | if (!listener) { |
476 | ret = -ENOMEM; |
477 | goto err_alloc_listener; |
478 | } |
479 | |
480 | listener->dev = idev; |
481 | listener->event_count = atomic_read(&idev->event); |
482 | filep->private_data = listener; |
483 | |
484 | if (idev->info->open) { |
485 | ret = idev->info->open(idev->info, inode); |
486 | if (ret) |
487 | goto err_infoopen; |
488 | } |
489 | return 0; |
490 | |
491 | err_infoopen: |
492 | kfree(listener); |
493 | |
494 | err_alloc_listener: |
495 | module_put(idev->owner); |
496 | |
497 | out: |
498 | return ret; |
499 | } |
500 | |
501 | static int uio_fasync(int fd, struct file *filep, int on) |
502 | { |
503 | struct uio_listener *listener = filep->private_data; |
504 | struct uio_device *idev = listener->dev; |
505 | |
506 | return fasync_helper(fd, filep, on, &idev->async_queue); |
507 | } |
508 | |
509 | static int uio_release(struct inode *inode, struct file *filep) |
510 | { |
511 | int ret = 0; |
512 | struct uio_listener *listener = filep->private_data; |
513 | struct uio_device *idev = listener->dev; |
514 | |
515 | if (idev->info->release) |
516 | ret = idev->info->release(idev->info, inode); |
517 | |
518 | module_put(idev->owner); |
519 | kfree(listener); |
520 | return ret; |
521 | } |
522 | |
523 | static unsigned int uio_poll(struct file *filep, poll_table *wait) |
524 | { |
525 | struct uio_listener *listener = filep->private_data; |
526 | struct uio_device *idev = listener->dev; |
527 | |
528 | if (idev->info->irq == UIO_IRQ_NONE) |
529 | return -EIO; |
530 | |
531 | poll_wait(filep, &idev->wait, wait); |
532 | if (listener->event_count != atomic_read(&idev->event)) |
533 | return POLLIN | POLLRDNORM; |
534 | return 0; |
535 | } |
536 | |
537 | static ssize_t uio_read(struct file *filep, char __user *buf, |
538 | size_t count, loff_t *ppos) |
539 | { |
540 | struct uio_listener *listener = filep->private_data; |
541 | struct uio_device *idev = listener->dev; |
542 | DECLARE_WAITQUEUE(wait, current); |
543 | ssize_t retval; |
544 | s32 event_count; |
545 | |
546 | if (idev->info->irq == UIO_IRQ_NONE) |
547 | return -EIO; |
548 | |
549 | if (count != sizeof(s32)) |
550 | return -EINVAL; |
551 | |
552 | add_wait_queue(&idev->wait, &wait); |
553 | |
554 | do { |
555 | set_current_state(TASK_INTERRUPTIBLE); |
556 | |
557 | event_count = atomic_read(&idev->event); |
558 | if (event_count != listener->event_count) { |
559 | if (copy_to_user(buf, &event_count, count)) |
560 | retval = -EFAULT; |
561 | else { |
562 | listener->event_count = event_count; |
563 | retval = count; |
564 | } |
565 | break; |
566 | } |
567 | |
568 | if (filep->f_flags & O_NONBLOCK) { |
569 | retval = -EAGAIN; |
570 | break; |
571 | } |
572 | |
573 | if (signal_pending(current)) { |
574 | retval = -ERESTARTSYS; |
575 | break; |
576 | } |
577 | schedule(); |
578 | } while (1); |
579 | |
580 | __set_current_state(TASK_RUNNING); |
581 | remove_wait_queue(&idev->wait, &wait); |
582 | |
583 | return retval; |
584 | } |
585 | |
586 | static ssize_t uio_write(struct file *filep, const char __user *buf, |
587 | size_t count, loff_t *ppos) |
588 | { |
589 | struct uio_listener *listener = filep->private_data; |
590 | struct uio_device *idev = listener->dev; |
591 | ssize_t retval; |
592 | s32 irq_on; |
593 | |
594 | if (idev->info->irq == UIO_IRQ_NONE) |
595 | return -EIO; |
596 | |
597 | if (count != sizeof(s32)) |
598 | return -EINVAL; |
599 | |
600 | if (!idev->info->irqcontrol) |
601 | return -ENOSYS; |
602 | |
603 | if (copy_from_user(&irq_on, buf, count)) |
604 | return -EFAULT; |
605 | |
606 | retval = idev->info->irqcontrol(idev->info, irq_on); |
607 | |
608 | return retval ? retval : sizeof(s32); |
609 | } |
610 | |
611 | static int uio_find_mem_index(struct vm_area_struct *vma) |
612 | { |
613 | int mi; |
614 | struct uio_device *idev = vma->vm_private_data; |
615 | |
616 | for (mi = 0; mi < MAX_UIO_MAPS; mi++) { |
617 | if (idev->info->mem[mi].size == 0) |
618 | return -1; |
619 | if (vma->vm_pgoff == mi) |
620 | return mi; |
621 | } |
622 | return -1; |
623 | } |
624 | |
625 | static void uio_vma_open(struct vm_area_struct *vma) |
626 | { |
627 | struct uio_device *idev = vma->vm_private_data; |
628 | idev->vma_count++; |
629 | } |
630 | |
631 | static void uio_vma_close(struct vm_area_struct *vma) |
632 | { |
633 | struct uio_device *idev = vma->vm_private_data; |
634 | idev->vma_count--; |
635 | } |
636 | |
637 | static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
638 | { |
639 | struct uio_device *idev = vma->vm_private_data; |
640 | struct page *page; |
641 | unsigned long offset; |
642 | |
643 | int mi = uio_find_mem_index(vma); |
644 | if (mi < 0) |
645 | return VM_FAULT_SIGBUS; |
646 | |
647 | /* |
648 | * We need to subtract mi because userspace uses offset = N*PAGE_SIZE |
649 | * to use mem[N]. |
650 | */ |
651 | offset = (vmf->pgoff - mi) << PAGE_SHIFT; |
652 | |
653 | if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL) |
654 | page = virt_to_page(idev->info->mem[mi].addr + offset); |
655 | else |
656 | page = vmalloc_to_page((void *)idev->info->mem[mi].addr |
657 | + offset); |
658 | get_page(page); |
659 | vmf->page = page; |
660 | return 0; |
661 | } |
662 | |
663 | static const struct vm_operations_struct uio_vm_ops = { |
664 | .open = uio_vma_open, |
665 | .close = uio_vma_close, |
666 | .fault = uio_vma_fault, |
667 | }; |
668 | |
669 | static int uio_mmap_physical(struct vm_area_struct *vma) |
670 | { |
671 | struct uio_device *idev = vma->vm_private_data; |
672 | int mi = uio_find_mem_index(vma); |
673 | if (mi < 0) |
674 | return -EINVAL; |
675 | |
676 | vma->vm_flags |= VM_IO | VM_RESERVED; |
677 | |
678 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); |
679 | |
680 | return remap_pfn_range(vma, |
681 | vma->vm_start, |
682 | idev->info->mem[mi].addr >> PAGE_SHIFT, |
683 | vma->vm_end - vma->vm_start, |
684 | vma->vm_page_prot); |
685 | } |
686 | |
687 | static int uio_mmap_logical(struct vm_area_struct *vma) |
688 | { |
689 | vma->vm_flags |= VM_RESERVED; |
690 | vma->vm_ops = &uio_vm_ops; |
691 | uio_vma_open(vma); |
692 | return 0; |
693 | } |
694 | |
695 | static int uio_mmap(struct file *filep, struct vm_area_struct *vma) |
696 | { |
697 | struct uio_listener *listener = filep->private_data; |
698 | struct uio_device *idev = listener->dev; |
699 | int mi; |
700 | unsigned long requested_pages, actual_pages; |
701 | int ret = 0; |
702 | |
703 | if (vma->vm_end < vma->vm_start) |
704 | return -EINVAL; |
705 | |
706 | vma->vm_private_data = idev; |
707 | |
708 | mi = uio_find_mem_index(vma); |
709 | if (mi < 0) |
710 | return -EINVAL; |
711 | |
712 | requested_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; |
713 | actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK) |
714 | + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT; |
715 | if (requested_pages > actual_pages) |
716 | return -EINVAL; |
717 | |
718 | if (idev->info->mmap) { |
719 | ret = idev->info->mmap(idev->info, vma); |
720 | return ret; |
721 | } |
722 | |
723 | switch (idev->info->mem[mi].memtype) { |
724 | case UIO_MEM_PHYS: |
725 | return uio_mmap_physical(vma); |
726 | case UIO_MEM_LOGICAL: |
727 | case UIO_MEM_VIRTUAL: |
728 | return uio_mmap_logical(vma); |
729 | default: |
730 | return -EINVAL; |
731 | } |
732 | } |
733 | |
734 | static const struct file_operations uio_fops = { |
735 | .owner = THIS_MODULE, |
736 | .open = uio_open, |
737 | .release = uio_release, |
738 | .read = uio_read, |
739 | .write = uio_write, |
740 | .mmap = uio_mmap, |
741 | .poll = uio_poll, |
742 | .fasync = uio_fasync, |
743 | }; |
744 | |
745 | static int uio_major_init(void) |
746 | { |
747 | uio_major = register_chrdev(0, "uio", &uio_fops); |
748 | if (uio_major < 0) |
749 | return uio_major; |
750 | return 0; |
751 | } |
752 | |
753 | static void uio_major_cleanup(void) |
754 | { |
755 | unregister_chrdev(uio_major, "uio"); |
756 | } |
757 | |
758 | static int init_uio_class(void) |
759 | { |
760 | int ret = 0; |
761 | |
762 | if (uio_class != NULL) { |
763 | kref_get(&uio_class->kref); |
764 | goto exit; |
765 | } |
766 | |
767 | /* This is the first time in here, set everything up properly */ |
768 | ret = uio_major_init(); |
769 | if (ret) |
770 | goto exit; |
771 | |
772 | uio_class = kzalloc(sizeof(*uio_class), GFP_KERNEL); |
773 | if (!uio_class) { |
774 | ret = -ENOMEM; |
775 | goto err_kzalloc; |
776 | } |
777 | |
778 | kref_init(&uio_class->kref); |
779 | uio_class->class = class_create(THIS_MODULE, "uio"); |
780 | if (IS_ERR(uio_class->class)) { |
781 | ret = IS_ERR(uio_class->class); |
782 | printk(KERN_ERR "class_create failed for uio\n"); |
783 | goto err_class_create; |
784 | } |
785 | return 0; |
786 | |
787 | err_class_create: |
788 | kfree(uio_class); |
789 | uio_class = NULL; |
790 | err_kzalloc: |
791 | uio_major_cleanup(); |
792 | exit: |
793 | return ret; |
794 | } |
795 | |
796 | static void release_uio_class(struct kref *kref) |
797 | { |
798 | /* Ok, we cheat as we know we only have one uio_class */ |
799 | class_destroy(uio_class->class); |
800 | kfree(uio_class); |
801 | uio_major_cleanup(); |
802 | uio_class = NULL; |
803 | } |
804 | |
805 | static void uio_class_destroy(void) |
806 | { |
807 | if (uio_class) |
808 | kref_put(&uio_class->kref, release_uio_class); |
809 | } |
810 | |
811 | /** |
812 | * uio_register_device - register a new userspace IO device |
813 | * @owner: module that creates the new device |
814 | * @parent: parent device |
815 | * @info: UIO device capabilities |
816 | * |
817 | * returns zero on success or a negative error code. |
818 | */ |
819 | int __uio_register_device(struct module *owner, |
820 | struct device *parent, |
821 | struct uio_info *info) |
822 | { |
823 | struct uio_device *idev; |
824 | int ret = 0; |
825 | |
826 | if (!parent || !info || !info->name || !info->version) |
827 | return -EINVAL; |
828 | |
829 | info->uio_dev = NULL; |
830 | |
831 | ret = init_uio_class(); |
832 | if (ret) |
833 | return ret; |
834 | |
835 | idev = kzalloc(sizeof(*idev), GFP_KERNEL); |
836 | if (!idev) { |
837 | ret = -ENOMEM; |
838 | goto err_kzalloc; |
839 | } |
840 | |
841 | idev->owner = owner; |
842 | idev->info = info; |
843 | init_waitqueue_head(&idev->wait); |
844 | atomic_set(&idev->event, 0); |
845 | |
846 | ret = uio_get_minor(idev); |
847 | if (ret) |
848 | goto err_get_minor; |
849 | |
850 | idev->dev = device_create(uio_class->class, parent, |
851 | MKDEV(uio_major, idev->minor), idev, |
852 | "uio%d", idev->minor); |
853 | if (IS_ERR(idev->dev)) { |
854 | printk(KERN_ERR "UIO: device register failed\n"); |
855 | ret = PTR_ERR(idev->dev); |
856 | goto err_device_create; |
857 | } |
858 | |
859 | ret = uio_dev_add_attributes(idev); |
860 | if (ret) |
861 | goto err_uio_dev_add_attributes; |
862 | |
863 | info->uio_dev = idev; |
864 | |
865 | if (idev->info->irq >= 0) { |
866 | ret = request_irq(idev->info->irq, uio_interrupt, |
867 | idev->info->irq_flags, idev->info->name, idev); |
868 | if (ret) |
869 | goto err_request_irq; |
870 | } |
871 | |
872 | return 0; |
873 | |
874 | err_request_irq: |
875 | uio_dev_del_attributes(idev); |
876 | err_uio_dev_add_attributes: |
877 | device_destroy(uio_class->class, MKDEV(uio_major, idev->minor)); |
878 | err_device_create: |
879 | uio_free_minor(idev); |
880 | err_get_minor: |
881 | kfree(idev); |
882 | err_kzalloc: |
883 | uio_class_destroy(); |
884 | return ret; |
885 | } |
886 | EXPORT_SYMBOL_GPL(__uio_register_device); |
887 | |
888 | /** |
889 | * uio_unregister_device - unregister a industrial IO device |
890 | * @info: UIO device capabilities |
891 | * |
892 | */ |
893 | void uio_unregister_device(struct uio_info *info) |
894 | { |
895 | struct uio_device *idev; |
896 | |
897 | if (!info || !info->uio_dev) |
898 | return; |
899 | |
900 | idev = info->uio_dev; |
901 | |
902 | uio_free_minor(idev); |
903 | |
904 | if (info->irq >= 0) |
905 | free_irq(info->irq, idev); |
906 | |
907 | uio_dev_del_attributes(idev); |
908 | |
909 | dev_set_drvdata(idev->dev, NULL); |
910 | device_destroy(uio_class->class, MKDEV(uio_major, idev->minor)); |
911 | kfree(idev); |
912 | uio_class_destroy(); |
913 | |
914 | return; |
915 | } |
916 | EXPORT_SYMBOL_GPL(uio_unregister_device); |
917 | |
918 | static int __init uio_init(void) |
919 | { |
920 | return 0; |
921 | } |
922 | |
923 | static void __exit uio_exit(void) |
924 | { |
925 | } |
926 | |
927 | module_init(uio_init) |
928 | module_exit(uio_exit) |
929 | MODULE_LICENSE("GPL v2"); |
930 |
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