blob: 1ec2d31f2639c7b9958e1163c4724bc5bd97279e [file] [log] [blame]
Hans J. Kochbeafc542006-12-07 10:58:29 +01001/*
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/mm.h>
21#include <linux/idr.h>
22#include <linux/string.h>
23#include <linux/kobject.h>
24#include <linux/uio_driver.h>
25
26#define UIO_MAX_DEVICES 255
27
28struct uio_device {
29 struct module *owner;
30 struct device *dev;
31 int minor;
32 atomic_t event;
33 struct fasync_struct *async_queue;
34 wait_queue_head_t wait;
35 int vma_count;
36 struct uio_info *info;
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000037 struct kobject *map_dir;
Hans J. Kochbeafc542006-12-07 10:58:29 +010038};
39
40static int uio_major;
41static DEFINE_IDR(uio_idr);
42static struct file_operations uio_fops;
43
44/* UIO class infrastructure */
45static struct uio_class {
46 struct kref kref;
47 struct class *class;
48} *uio_class;
49
50/*
51 * attributes
52 */
53
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000054struct uio_map {
55 struct kobject kobj;
56 struct uio_mem *mem;
Hans J. Kochbeafc542006-12-07 10:58:29 +010057};
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000058#define to_map(map) container_of(map, struct uio_map, kobj)
Hans J. Kochbeafc542006-12-07 10:58:29 +010059
Hans J. Kochbeafc542006-12-07 10:58:29 +010060
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000061static ssize_t map_attr_show(struct kobject *kobj, struct kobj_attribute *attr,
Hans J. Kochbeafc542006-12-07 10:58:29 +010062 char *buf)
63{
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000064 struct uio_map *map = to_map(kobj);
65 struct uio_mem *mem = map->mem;
Hans J. Kochbeafc542006-12-07 10:58:29 +010066
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000067 if (strncmp(attr->attr.name, "addr", 4) == 0)
Hans J. Kochbeafc542006-12-07 10:58:29 +010068 return sprintf(buf, "0x%lx\n", mem->addr);
69
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000070 if (strncmp(attr->attr.name, "size", 4) == 0)
Hans J. Kochbeafc542006-12-07 10:58:29 +010071 return sprintf(buf, "0x%lx\n", mem->size);
72
73 return -ENODEV;
74}
75
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000076static struct kobj_attribute attr_attribute =
77 __ATTR(addr, S_IRUGO, map_attr_show, NULL);
78static struct kobj_attribute size_attribute =
79 __ATTR(size, S_IRUGO, map_attr_show, NULL);
Hans J. Kochbeafc542006-12-07 10:58:29 +010080
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000081static struct attribute *attrs[] = {
82 &attr_attribute.attr,
83 &size_attribute.attr,
84 NULL, /* need to NULL terminate the list of attributes */
Hans J. Kochbeafc542006-12-07 10:58:29 +010085};
86
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000087static void map_release(struct kobject *kobj)
88{
89 struct uio_map *map = to_map(kobj);
90 kfree(map);
91}
92
Hans J. Kochbeafc542006-12-07 10:58:29 +010093static struct kobj_type map_attr_type = {
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000094 .release = map_release,
95 .default_attrs = attrs,
Hans J. Kochbeafc542006-12-07 10:58:29 +010096};
97
98static ssize_t show_name(struct device *dev,
99 struct device_attribute *attr, char *buf)
100{
101 struct uio_device *idev = dev_get_drvdata(dev);
102 if (idev)
103 return sprintf(buf, "%s\n", idev->info->name);
104 else
105 return -ENODEV;
106}
107static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
108
109static ssize_t show_version(struct device *dev,
110 struct device_attribute *attr, char *buf)
111{
112 struct uio_device *idev = dev_get_drvdata(dev);
113 if (idev)
114 return sprintf(buf, "%s\n", idev->info->version);
115 else
116 return -ENODEV;
117}
118static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);
119
120static ssize_t show_event(struct device *dev,
121 struct device_attribute *attr, char *buf)
122{
123 struct uio_device *idev = dev_get_drvdata(dev);
124 if (idev)
125 return sprintf(buf, "%u\n",
126 (unsigned int)atomic_read(&idev->event));
127 else
128 return -ENODEV;
129}
130static DEVICE_ATTR(event, S_IRUGO, show_event, NULL);
131
132static struct attribute *uio_attrs[] = {
133 &dev_attr_name.attr,
134 &dev_attr_version.attr,
135 &dev_attr_event.attr,
136 NULL,
137};
138
139static struct attribute_group uio_attr_grp = {
140 .attrs = uio_attrs,
141};
142
143/*
144 * device functions
145 */
146static int uio_dev_add_attributes(struct uio_device *idev)
147{
148 int ret;
149 int mi;
150 int map_found = 0;
151 struct uio_mem *mem;
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000152 struct uio_map *map;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100153
154 ret = sysfs_create_group(&idev->dev->kobj, &uio_attr_grp);
155 if (ret)
156 goto err_group;
157
158 for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
159 mem = &idev->info->mem[mi];
160 if (mem->size == 0)
161 break;
162 if (!map_found) {
163 map_found = 1;
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000164 idev->map_dir = kobject_create_and_add("maps",
165 &idev->dev->kobj);
166 if (!idev->map_dir)
167 goto err;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100168 }
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000169 map = kzalloc(sizeof(*map), GFP_KERNEL);
170 if (!map)
171 goto err;
172 kobject_init_ng(&map->kobj, &map_attr_type);
173 map->mem = mem;
174 mem->map = map;
Greg Kroah-Hartmanb2d6db52007-12-17 23:05:35 -0700175 ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100176 if (ret)
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000177 goto err;
178 ret = kobject_uevent(&map->kobj, KOBJ_ADD);
179 if (ret)
180 goto err;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100181 }
182
183 return 0;
184
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000185err:
Hans J. Kochbeafc542006-12-07 10:58:29 +0100186 for (mi--; mi>=0; mi--) {
187 mem = &idev->info->mem[mi];
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000188 map = mem->map;
189 kobject_unregister(&map->kobj);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100190 }
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000191 kobject_unregister(idev->map_dir);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100192 sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp);
193err_group:
194 dev_err(idev->dev, "error creating sysfs files (%d)\n", ret);
195 return ret;
196}
197
198static void uio_dev_del_attributes(struct uio_device *idev)
199{
200 int mi;
201 struct uio_mem *mem;
202 for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
203 mem = &idev->info->mem[mi];
204 if (mem->size == 0)
205 break;
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000206 kobject_unregister(&mem->map->kobj);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100207 }
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000208 kobject_unregister(idev->map_dir);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100209 sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp);
210}
211
212static int uio_get_minor(struct uio_device *idev)
213{
214 static DEFINE_MUTEX(minor_lock);
215 int retval = -ENOMEM;
216 int id;
217
218 mutex_lock(&minor_lock);
219 if (idr_pre_get(&uio_idr, GFP_KERNEL) == 0)
220 goto exit;
221
222 retval = idr_get_new(&uio_idr, idev, &id);
223 if (retval < 0) {
224 if (retval == -EAGAIN)
225 retval = -ENOMEM;
226 goto exit;
227 }
228 idev->minor = id & MAX_ID_MASK;
229exit:
230 mutex_unlock(&minor_lock);
231 return retval;
232}
233
234static void uio_free_minor(struct uio_device *idev)
235{
236 idr_remove(&uio_idr, idev->minor);
237}
238
239/**
240 * uio_event_notify - trigger an interrupt event
241 * @info: UIO device capabilities
242 */
243void uio_event_notify(struct uio_info *info)
244{
245 struct uio_device *idev = info->uio_dev;
246
247 atomic_inc(&idev->event);
248 wake_up_interruptible(&idev->wait);
249 kill_fasync(&idev->async_queue, SIGIO, POLL_IN);
250}
251EXPORT_SYMBOL_GPL(uio_event_notify);
252
253/**
254 * uio_interrupt - hardware interrupt handler
255 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer
256 * @dev_id: Pointer to the devices uio_device structure
257 */
258static irqreturn_t uio_interrupt(int irq, void *dev_id)
259{
260 struct uio_device *idev = (struct uio_device *)dev_id;
261 irqreturn_t ret = idev->info->handler(irq, idev->info);
262
263 if (ret == IRQ_HANDLED)
264 uio_event_notify(idev->info);
265
266 return ret;
267}
268
269struct uio_listener {
270 struct uio_device *dev;
271 s32 event_count;
272};
273
274static int uio_open(struct inode *inode, struct file *filep)
275{
276 struct uio_device *idev;
277 struct uio_listener *listener;
278 int ret = 0;
279
280 idev = idr_find(&uio_idr, iminor(inode));
281 if (!idev)
282 return -ENODEV;
283
284 listener = kmalloc(sizeof(*listener), GFP_KERNEL);
285 if (!listener)
286 return -ENOMEM;
287
288 listener->dev = idev;
289 listener->event_count = atomic_read(&idev->event);
290 filep->private_data = listener;
291
292 if (idev->info->open) {
293 if (!try_module_get(idev->owner))
294 return -ENODEV;
295 ret = idev->info->open(idev->info, inode);
296 module_put(idev->owner);
297 }
298
299 if (ret)
300 kfree(listener);
301
302 return ret;
303}
304
305static int uio_fasync(int fd, struct file *filep, int on)
306{
307 struct uio_listener *listener = filep->private_data;
308 struct uio_device *idev = listener->dev;
309
310 return fasync_helper(fd, filep, on, &idev->async_queue);
311}
312
313static int uio_release(struct inode *inode, struct file *filep)
314{
315 int ret = 0;
316 struct uio_listener *listener = filep->private_data;
317 struct uio_device *idev = listener->dev;
318
319 if (idev->info->release) {
320 if (!try_module_get(idev->owner))
321 return -ENODEV;
322 ret = idev->info->release(idev->info, inode);
323 module_put(idev->owner);
324 }
325 if (filep->f_flags & FASYNC)
326 ret = uio_fasync(-1, filep, 0);
327 kfree(listener);
328 return ret;
329}
330
331static unsigned int uio_poll(struct file *filep, poll_table *wait)
332{
333 struct uio_listener *listener = filep->private_data;
334 struct uio_device *idev = listener->dev;
335
336 if (idev->info->irq == UIO_IRQ_NONE)
337 return -EIO;
338
339 poll_wait(filep, &idev->wait, wait);
340 if (listener->event_count != atomic_read(&idev->event))
341 return POLLIN | POLLRDNORM;
342 return 0;
343}
344
345static ssize_t uio_read(struct file *filep, char __user *buf,
346 size_t count, loff_t *ppos)
347{
348 struct uio_listener *listener = filep->private_data;
349 struct uio_device *idev = listener->dev;
350 DECLARE_WAITQUEUE(wait, current);
351 ssize_t retval;
352 s32 event_count;
353
354 if (idev->info->irq == UIO_IRQ_NONE)
355 return -EIO;
356
357 if (count != sizeof(s32))
358 return -EINVAL;
359
360 add_wait_queue(&idev->wait, &wait);
361
362 do {
363 set_current_state(TASK_INTERRUPTIBLE);
364
365 event_count = atomic_read(&idev->event);
366 if (event_count != listener->event_count) {
367 if (copy_to_user(buf, &event_count, count))
368 retval = -EFAULT;
369 else {
370 listener->event_count = event_count;
371 retval = count;
372 }
373 break;
374 }
375
376 if (filep->f_flags & O_NONBLOCK) {
377 retval = -EAGAIN;
378 break;
379 }
380
381 if (signal_pending(current)) {
382 retval = -ERESTARTSYS;
383 break;
384 }
385 schedule();
386 } while (1);
387
388 __set_current_state(TASK_RUNNING);
389 remove_wait_queue(&idev->wait, &wait);
390
391 return retval;
392}
393
394static int uio_find_mem_index(struct vm_area_struct *vma)
395{
396 int mi;
397 struct uio_device *idev = vma->vm_private_data;
398
399 for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
400 if (idev->info->mem[mi].size == 0)
401 return -1;
402 if (vma->vm_pgoff == mi)
403 return mi;
404 }
405 return -1;
406}
407
408static void uio_vma_open(struct vm_area_struct *vma)
409{
410 struct uio_device *idev = vma->vm_private_data;
411 idev->vma_count++;
412}
413
414static void uio_vma_close(struct vm_area_struct *vma)
415{
416 struct uio_device *idev = vma->vm_private_data;
417 idev->vma_count--;
418}
419
420static struct page *uio_vma_nopage(struct vm_area_struct *vma,
421 unsigned long address, int *type)
422{
423 struct uio_device *idev = vma->vm_private_data;
424 struct page* page = NOPAGE_SIGBUS;
425
426 int mi = uio_find_mem_index(vma);
427 if (mi < 0)
428 return page;
429
430 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
431 page = virt_to_page(idev->info->mem[mi].addr);
432 else
433 page = vmalloc_to_page((void*)idev->info->mem[mi].addr);
434 get_page(page);
435 if (type)
436 *type = VM_FAULT_MINOR;
437 return page;
438}
439
440static struct vm_operations_struct uio_vm_ops = {
441 .open = uio_vma_open,
442 .close = uio_vma_close,
443 .nopage = uio_vma_nopage,
444};
445
446static int uio_mmap_physical(struct vm_area_struct *vma)
447{
448 struct uio_device *idev = vma->vm_private_data;
449 int mi = uio_find_mem_index(vma);
450 if (mi < 0)
451 return -EINVAL;
452
453 vma->vm_flags |= VM_IO | VM_RESERVED;
454
455 return remap_pfn_range(vma,
456 vma->vm_start,
457 idev->info->mem[mi].addr >> PAGE_SHIFT,
458 vma->vm_end - vma->vm_start,
459 vma->vm_page_prot);
460}
461
462static int uio_mmap_logical(struct vm_area_struct *vma)
463{
464 vma->vm_flags |= VM_RESERVED;
465 vma->vm_ops = &uio_vm_ops;
466 uio_vma_open(vma);
467 return 0;
468}
469
470static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
471{
472 struct uio_listener *listener = filep->private_data;
473 struct uio_device *idev = listener->dev;
474 int mi;
475 unsigned long requested_pages, actual_pages;
476 int ret = 0;
477
478 if (vma->vm_end < vma->vm_start)
479 return -EINVAL;
480
481 vma->vm_private_data = idev;
482
483 mi = uio_find_mem_index(vma);
484 if (mi < 0)
485 return -EINVAL;
486
487 requested_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
488 actual_pages = (idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
489 if (requested_pages > actual_pages)
490 return -EINVAL;
491
492 if (idev->info->mmap) {
493 if (!try_module_get(idev->owner))
494 return -ENODEV;
495 ret = idev->info->mmap(idev->info, vma);
496 module_put(idev->owner);
497 return ret;
498 }
499
500 switch (idev->info->mem[mi].memtype) {
501 case UIO_MEM_PHYS:
502 return uio_mmap_physical(vma);
503 case UIO_MEM_LOGICAL:
504 case UIO_MEM_VIRTUAL:
505 return uio_mmap_logical(vma);
506 default:
507 return -EINVAL;
508 }
509}
510
511static struct file_operations uio_fops = {
512 .owner = THIS_MODULE,
513 .open = uio_open,
514 .release = uio_release,
515 .read = uio_read,
516 .mmap = uio_mmap,
517 .poll = uio_poll,
518 .fasync = uio_fasync,
519};
520
521static int uio_major_init(void)
522{
523 uio_major = register_chrdev(0, "uio", &uio_fops);
524 if (uio_major < 0)
525 return uio_major;
526 return 0;
527}
528
529static void uio_major_cleanup(void)
530{
531 unregister_chrdev(uio_major, "uio");
532}
533
534static int init_uio_class(void)
535{
536 int ret = 0;
537
538 if (uio_class != NULL) {
539 kref_get(&uio_class->kref);
540 goto exit;
541 }
542
543 /* This is the first time in here, set everything up properly */
544 ret = uio_major_init();
545 if (ret)
546 goto exit;
547
548 uio_class = kzalloc(sizeof(*uio_class), GFP_KERNEL);
549 if (!uio_class) {
550 ret = -ENOMEM;
551 goto err_kzalloc;
552 }
553
554 kref_init(&uio_class->kref);
555 uio_class->class = class_create(THIS_MODULE, "uio");
556 if (IS_ERR(uio_class->class)) {
557 ret = IS_ERR(uio_class->class);
558 printk(KERN_ERR "class_create failed for uio\n");
559 goto err_class_create;
560 }
561 return 0;
562
563err_class_create:
564 kfree(uio_class);
565 uio_class = NULL;
566err_kzalloc:
567 uio_major_cleanup();
568exit:
569 return ret;
570}
571
572static void release_uio_class(struct kref *kref)
573{
574 /* Ok, we cheat as we know we only have one uio_class */
575 class_destroy(uio_class->class);
576 kfree(uio_class);
577 uio_major_cleanup();
578 uio_class = NULL;
579}
580
581static void uio_class_destroy(void)
582{
583 if (uio_class)
584 kref_put(&uio_class->kref, release_uio_class);
585}
586
587/**
588 * uio_register_device - register a new userspace IO device
589 * @owner: module that creates the new device
590 * @parent: parent device
591 * @info: UIO device capabilities
592 *
593 * returns zero on success or a negative error code.
594 */
595int __uio_register_device(struct module *owner,
596 struct device *parent,
597 struct uio_info *info)
598{
599 struct uio_device *idev;
600 int ret = 0;
601
602 if (!parent || !info || !info->name || !info->version)
603 return -EINVAL;
604
605 info->uio_dev = NULL;
606
607 ret = init_uio_class();
608 if (ret)
609 return ret;
610
611 idev = kzalloc(sizeof(*idev), GFP_KERNEL);
612 if (!idev) {
613 ret = -ENOMEM;
614 goto err_kzalloc;
615 }
616
617 idev->owner = owner;
618 idev->info = info;
619 init_waitqueue_head(&idev->wait);
620 atomic_set(&idev->event, 0);
621
622 ret = uio_get_minor(idev);
623 if (ret)
624 goto err_get_minor;
625
626 idev->dev = device_create(uio_class->class, parent,
627 MKDEV(uio_major, idev->minor),
628 "uio%d", idev->minor);
629 if (IS_ERR(idev->dev)) {
630 printk(KERN_ERR "UIO: device register failed\n");
631 ret = PTR_ERR(idev->dev);
632 goto err_device_create;
633 }
634 dev_set_drvdata(idev->dev, idev);
635
636 ret = uio_dev_add_attributes(idev);
637 if (ret)
638 goto err_uio_dev_add_attributes;
639
640 info->uio_dev = idev;
641
642 if (idev->info->irq >= 0) {
643 ret = request_irq(idev->info->irq, uio_interrupt,
644 idev->info->irq_flags, idev->info->name, idev);
645 if (ret)
646 goto err_request_irq;
647 }
648
649 return 0;
650
651err_request_irq:
652 uio_dev_del_attributes(idev);
653err_uio_dev_add_attributes:
654 device_destroy(uio_class->class, MKDEV(uio_major, idev->minor));
655err_device_create:
656 uio_free_minor(idev);
657err_get_minor:
658 kfree(idev);
659err_kzalloc:
660 uio_class_destroy();
661 return ret;
662}
663EXPORT_SYMBOL_GPL(__uio_register_device);
664
665/**
666 * uio_unregister_device - unregister a industrial IO device
667 * @info: UIO device capabilities
668 *
669 */
670void uio_unregister_device(struct uio_info *info)
671{
672 struct uio_device *idev;
673
674 if (!info || !info->uio_dev)
675 return;
676
677 idev = info->uio_dev;
678
679 uio_free_minor(idev);
680
681 if (info->irq >= 0)
682 free_irq(info->irq, idev);
683
684 uio_dev_del_attributes(idev);
685
686 dev_set_drvdata(idev->dev, NULL);
687 device_destroy(uio_class->class, MKDEV(uio_major, idev->minor));
688 kfree(idev);
689 uio_class_destroy();
690
691 return;
692}
693EXPORT_SYMBOL_GPL(uio_unregister_device);
694
695static int __init uio_init(void)
696{
697 return 0;
698}
699
700static void __exit uio_exit(void)
701{
702}
703
704module_init(uio_init)
705module_exit(uio_exit)
706MODULE_LICENSE("GPL v2");