Loading...
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@hansjkoch.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/signal.h>
24#include <linux/string.h>
25#include <linux/kobject.h>
26#include <linux/cdev.h>
27#include <linux/uio_driver.h>
28
29#define UIO_MAX_DEVICES (1U << MINORBITS)
30
31static int uio_major;
32static struct cdev *uio_cdev;
33static DEFINE_IDR(uio_idr);
34static const struct file_operations uio_fops;
35
36/* Protect idr accesses */
37static DEFINE_MUTEX(minor_lock);
38
39/*
40 * attributes
41 */
42
43struct uio_map {
44 struct kobject kobj;
45 struct uio_mem *mem;
46};
47#define to_map(map) container_of(map, struct uio_map, kobj)
48
49static ssize_t map_name_show(struct uio_mem *mem, char *buf)
50{
51 if (unlikely(!mem->name))
52 mem->name = "";
53
54 return sprintf(buf, "%s\n", mem->name);
55}
56
57static ssize_t map_addr_show(struct uio_mem *mem, char *buf)
58{
59 return sprintf(buf, "%pa\n", &mem->addr);
60}
61
62static ssize_t map_size_show(struct uio_mem *mem, char *buf)
63{
64 return sprintf(buf, "%pa\n", &mem->size);
65}
66
67static ssize_t map_offset_show(struct uio_mem *mem, char *buf)
68{
69 return sprintf(buf, "0x%llx\n", (unsigned long long)mem->offs);
70}
71
72struct map_sysfs_entry {
73 struct attribute attr;
74 ssize_t (*show)(struct uio_mem *, char *);
75 ssize_t (*store)(struct uio_mem *, const char *, size_t);
76};
77
78static struct map_sysfs_entry name_attribute =
79 __ATTR(name, S_IRUGO, map_name_show, NULL);
80static struct map_sysfs_entry addr_attribute =
81 __ATTR(addr, S_IRUGO, map_addr_show, NULL);
82static struct map_sysfs_entry size_attribute =
83 __ATTR(size, S_IRUGO, map_size_show, NULL);
84static struct map_sysfs_entry offset_attribute =
85 __ATTR(offset, S_IRUGO, map_offset_show, NULL);
86
87static struct attribute *attrs[] = {
88 &name_attribute.attr,
89 &addr_attribute.attr,
90 &size_attribute.attr,
91 &offset_attribute.attr,
92 NULL, /* need to NULL terminate the list of attributes */
93};
94
95static void map_release(struct kobject *kobj)
96{
97 struct uio_map *map = to_map(kobj);
98 kfree(map);
99}
100
101static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr,
102 char *buf)
103{
104 struct uio_map *map = to_map(kobj);
105 struct uio_mem *mem = map->mem;
106 struct map_sysfs_entry *entry;
107
108 entry = container_of(attr, struct map_sysfs_entry, attr);
109
110 if (!entry->show)
111 return -EIO;
112
113 return entry->show(mem, buf);
114}
115
116static const struct sysfs_ops map_sysfs_ops = {
117 .show = map_type_show,
118};
119
120static struct kobj_type map_attr_type = {
121 .release = map_release,
122 .sysfs_ops = &map_sysfs_ops,
123 .default_attrs = attrs,
124};
125
126struct uio_portio {
127 struct kobject kobj;
128 struct uio_port *port;
129};
130#define to_portio(portio) container_of(portio, struct uio_portio, kobj)
131
132static ssize_t portio_name_show(struct uio_port *port, char *buf)
133{
134 if (unlikely(!port->name))
135 port->name = "";
136
137 return sprintf(buf, "%s\n", port->name);
138}
139
140static ssize_t portio_start_show(struct uio_port *port, char *buf)
141{
142 return sprintf(buf, "0x%lx\n", port->start);
143}
144
145static ssize_t portio_size_show(struct uio_port *port, char *buf)
146{
147 return sprintf(buf, "0x%lx\n", port->size);
148}
149
150static ssize_t portio_porttype_show(struct uio_port *port, char *buf)
151{
152 const char *porttypes[] = {"none", "x86", "gpio", "other"};
153
154 if ((port->porttype < 0) || (port->porttype > UIO_PORT_OTHER))
155 return -EINVAL;
156
157 return sprintf(buf, "port_%s\n", porttypes[port->porttype]);
158}
159
160struct portio_sysfs_entry {
161 struct attribute attr;
162 ssize_t (*show)(struct uio_port *, char *);
163 ssize_t (*store)(struct uio_port *, const char *, size_t);
164};
165
166static struct portio_sysfs_entry portio_name_attribute =
167 __ATTR(name, S_IRUGO, portio_name_show, NULL);
168static struct portio_sysfs_entry portio_start_attribute =
169 __ATTR(start, S_IRUGO, portio_start_show, NULL);
170static struct portio_sysfs_entry portio_size_attribute =
171 __ATTR(size, S_IRUGO, portio_size_show, NULL);
172static struct portio_sysfs_entry portio_porttype_attribute =
173 __ATTR(porttype, S_IRUGO, portio_porttype_show, NULL);
174
175static struct attribute *portio_attrs[] = {
176 &portio_name_attribute.attr,
177 &portio_start_attribute.attr,
178 &portio_size_attribute.attr,
179 &portio_porttype_attribute.attr,
180 NULL,
181};
182
183static void portio_release(struct kobject *kobj)
184{
185 struct uio_portio *portio = to_portio(kobj);
186 kfree(portio);
187}
188
189static ssize_t portio_type_show(struct kobject *kobj, struct attribute *attr,
190 char *buf)
191{
192 struct uio_portio *portio = to_portio(kobj);
193 struct uio_port *port = portio->port;
194 struct portio_sysfs_entry *entry;
195
196 entry = container_of(attr, struct portio_sysfs_entry, attr);
197
198 if (!entry->show)
199 return -EIO;
200
201 return entry->show(port, buf);
202}
203
204static const struct sysfs_ops portio_sysfs_ops = {
205 .show = portio_type_show,
206};
207
208static struct kobj_type portio_attr_type = {
209 .release = portio_release,
210 .sysfs_ops = &portio_sysfs_ops,
211 .default_attrs = portio_attrs,
212};
213
214static ssize_t name_show(struct device *dev,
215 struct device_attribute *attr, char *buf)
216{
217 struct uio_device *idev = dev_get_drvdata(dev);
218 return sprintf(buf, "%s\n", idev->info->name);
219}
220static DEVICE_ATTR_RO(name);
221
222static ssize_t version_show(struct device *dev,
223 struct device_attribute *attr, char *buf)
224{
225 struct uio_device *idev = dev_get_drvdata(dev);
226 return sprintf(buf, "%s\n", idev->info->version);
227}
228static DEVICE_ATTR_RO(version);
229
230static ssize_t event_show(struct device *dev,
231 struct device_attribute *attr, char *buf)
232{
233 struct uio_device *idev = dev_get_drvdata(dev);
234 return sprintf(buf, "%u\n", (unsigned int)atomic_read(&idev->event));
235}
236static DEVICE_ATTR_RO(event);
237
238static struct attribute *uio_attrs[] = {
239 &dev_attr_name.attr,
240 &dev_attr_version.attr,
241 &dev_attr_event.attr,
242 NULL,
243};
244ATTRIBUTE_GROUPS(uio);
245
246/* UIO class infrastructure */
247static struct class uio_class = {
248 .name = "uio",
249 .dev_groups = uio_groups,
250};
251
252/*
253 * device functions
254 */
255static int uio_dev_add_attributes(struct uio_device *idev)
256{
257 int ret;
258 int mi, pi;
259 int map_found = 0;
260 int portio_found = 0;
261 struct uio_mem *mem;
262 struct uio_map *map;
263 struct uio_port *port;
264 struct uio_portio *portio;
265
266 for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
267 mem = &idev->info->mem[mi];
268 if (mem->size == 0)
269 break;
270 if (!map_found) {
271 map_found = 1;
272 idev->map_dir = kobject_create_and_add("maps",
273 &idev->dev->kobj);
274 if (!idev->map_dir) {
275 ret = -ENOMEM;
276 goto err_map;
277 }
278 }
279 map = kzalloc(sizeof(*map), GFP_KERNEL);
280 if (!map) {
281 ret = -ENOMEM;
282 goto err_map;
283 }
284 kobject_init(&map->kobj, &map_attr_type);
285 map->mem = mem;
286 mem->map = map;
287 ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi);
288 if (ret)
289 goto err_map_kobj;
290 ret = kobject_uevent(&map->kobj, KOBJ_ADD);
291 if (ret)
292 goto err_map_kobj;
293 }
294
295 for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) {
296 port = &idev->info->port[pi];
297 if (port->size == 0)
298 break;
299 if (!portio_found) {
300 portio_found = 1;
301 idev->portio_dir = kobject_create_and_add("portio",
302 &idev->dev->kobj);
303 if (!idev->portio_dir) {
304 ret = -ENOMEM;
305 goto err_portio;
306 }
307 }
308 portio = kzalloc(sizeof(*portio), GFP_KERNEL);
309 if (!portio) {
310 ret = -ENOMEM;
311 goto err_portio;
312 }
313 kobject_init(&portio->kobj, &portio_attr_type);
314 portio->port = port;
315 port->portio = portio;
316 ret = kobject_add(&portio->kobj, idev->portio_dir,
317 "port%d", pi);
318 if (ret)
319 goto err_portio_kobj;
320 ret = kobject_uevent(&portio->kobj, KOBJ_ADD);
321 if (ret)
322 goto err_portio_kobj;
323 }
324
325 return 0;
326
327err_portio:
328 pi--;
329err_portio_kobj:
330 for (; pi >= 0; pi--) {
331 port = &idev->info->port[pi];
332 portio = port->portio;
333 kobject_put(&portio->kobj);
334 }
335 kobject_put(idev->portio_dir);
336err_map:
337 mi--;
338err_map_kobj:
339 for (; mi >= 0; mi--) {
340 mem = &idev->info->mem[mi];
341 map = mem->map;
342 kobject_put(&map->kobj);
343 }
344 kobject_put(idev->map_dir);
345 dev_err(idev->dev, "error creating sysfs files (%d)\n", ret);
346 return ret;
347}
348
349static void uio_dev_del_attributes(struct uio_device *idev)
350{
351 int i;
352 struct uio_mem *mem;
353 struct uio_port *port;
354
355 for (i = 0; i < MAX_UIO_MAPS; i++) {
356 mem = &idev->info->mem[i];
357 if (mem->size == 0)
358 break;
359 kobject_put(&mem->map->kobj);
360 }
361 kobject_put(idev->map_dir);
362
363 for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) {
364 port = &idev->info->port[i];
365 if (port->size == 0)
366 break;
367 kobject_put(&port->portio->kobj);
368 }
369 kobject_put(idev->portio_dir);
370}
371
372static int uio_get_minor(struct uio_device *idev)
373{
374 int retval = -ENOMEM;
375
376 mutex_lock(&minor_lock);
377 retval = idr_alloc(&uio_idr, idev, 0, UIO_MAX_DEVICES, GFP_KERNEL);
378 if (retval >= 0) {
379 idev->minor = retval;
380 retval = 0;
381 } else if (retval == -ENOSPC) {
382 dev_err(idev->dev, "too many uio devices\n");
383 retval = -EINVAL;
384 }
385 mutex_unlock(&minor_lock);
386 return retval;
387}
388
389static void uio_free_minor(struct uio_device *idev)
390{
391 mutex_lock(&minor_lock);
392 idr_remove(&uio_idr, idev->minor);
393 mutex_unlock(&minor_lock);
394}
395
396/**
397 * uio_event_notify - trigger an interrupt event
398 * @info: UIO device capabilities
399 */
400void uio_event_notify(struct uio_info *info)
401{
402 struct uio_device *idev = info->uio_dev;
403
404 atomic_inc(&idev->event);
405 wake_up_interruptible(&idev->wait);
406 kill_fasync(&idev->async_queue, SIGIO, POLL_IN);
407}
408EXPORT_SYMBOL_GPL(uio_event_notify);
409
410/**
411 * uio_interrupt - hardware interrupt handler
412 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer
413 * @dev_id: Pointer to the devices uio_device structure
414 */
415static irqreturn_t uio_interrupt(int irq, void *dev_id)
416{
417 struct uio_device *idev = (struct uio_device *)dev_id;
418 irqreturn_t ret = idev->info->handler(irq, idev->info);
419
420 if (ret == IRQ_HANDLED)
421 uio_event_notify(idev->info);
422
423 return ret;
424}
425
426struct uio_listener {
427 struct uio_device *dev;
428 s32 event_count;
429};
430
431static int uio_open(struct inode *inode, struct file *filep)
432{
433 struct uio_device *idev;
434 struct uio_listener *listener;
435 int ret = 0;
436
437 mutex_lock(&minor_lock);
438 idev = idr_find(&uio_idr, iminor(inode));
439 mutex_unlock(&minor_lock);
440 if (!idev) {
441 ret = -ENODEV;
442 goto out;
443 }
444
445 if (!try_module_get(idev->owner)) {
446 ret = -ENODEV;
447 goto out;
448 }
449
450 listener = kmalloc(sizeof(*listener), GFP_KERNEL);
451 if (!listener) {
452 ret = -ENOMEM;
453 goto err_alloc_listener;
454 }
455
456 listener->dev = idev;
457 listener->event_count = atomic_read(&idev->event);
458 filep->private_data = listener;
459
460 if (idev->info->open) {
461 ret = idev->info->open(idev->info, inode);
462 if (ret)
463 goto err_infoopen;
464 }
465 return 0;
466
467err_infoopen:
468 kfree(listener);
469
470err_alloc_listener:
471 module_put(idev->owner);
472
473out:
474 return ret;
475}
476
477static int uio_fasync(int fd, struct file *filep, int on)
478{
479 struct uio_listener *listener = filep->private_data;
480 struct uio_device *idev = listener->dev;
481
482 return fasync_helper(fd, filep, on, &idev->async_queue);
483}
484
485static int uio_release(struct inode *inode, struct file *filep)
486{
487 int ret = 0;
488 struct uio_listener *listener = filep->private_data;
489 struct uio_device *idev = listener->dev;
490
491 if (idev->info->release)
492 ret = idev->info->release(idev->info, inode);
493
494 module_put(idev->owner);
495 kfree(listener);
496 return ret;
497}
498
499static __poll_t uio_poll(struct file *filep, poll_table *wait)
500{
501 struct uio_listener *listener = filep->private_data;
502 struct uio_device *idev = listener->dev;
503
504 if (!idev->info->irq)
505 return -EIO;
506
507 poll_wait(filep, &idev->wait, wait);
508 if (listener->event_count != atomic_read(&idev->event))
509 return EPOLLIN | EPOLLRDNORM;
510 return 0;
511}
512
513static ssize_t uio_read(struct file *filep, char __user *buf,
514 size_t count, loff_t *ppos)
515{
516 struct uio_listener *listener = filep->private_data;
517 struct uio_device *idev = listener->dev;
518 DECLARE_WAITQUEUE(wait, current);
519 ssize_t retval;
520 s32 event_count;
521
522 if (!idev->info->irq)
523 return -EIO;
524
525 if (count != sizeof(s32))
526 return -EINVAL;
527
528 add_wait_queue(&idev->wait, &wait);
529
530 do {
531 set_current_state(TASK_INTERRUPTIBLE);
532
533 event_count = atomic_read(&idev->event);
534 if (event_count != listener->event_count) {
535 __set_current_state(TASK_RUNNING);
536 if (copy_to_user(buf, &event_count, count))
537 retval = -EFAULT;
538 else {
539 listener->event_count = event_count;
540 retval = count;
541 }
542 break;
543 }
544
545 if (filep->f_flags & O_NONBLOCK) {
546 retval = -EAGAIN;
547 break;
548 }
549
550 if (signal_pending(current)) {
551 retval = -ERESTARTSYS;
552 break;
553 }
554 schedule();
555 } while (1);
556
557 __set_current_state(TASK_RUNNING);
558 remove_wait_queue(&idev->wait, &wait);
559
560 return retval;
561}
562
563static ssize_t uio_write(struct file *filep, const char __user *buf,
564 size_t count, loff_t *ppos)
565{
566 struct uio_listener *listener = filep->private_data;
567 struct uio_device *idev = listener->dev;
568 ssize_t retval;
569 s32 irq_on;
570
571 if (!idev->info->irq)
572 return -EIO;
573
574 if (count != sizeof(s32))
575 return -EINVAL;
576
577 if (!idev->info->irqcontrol)
578 return -ENOSYS;
579
580 if (copy_from_user(&irq_on, buf, count))
581 return -EFAULT;
582
583 retval = idev->info->irqcontrol(idev->info, irq_on);
584
585 return retval ? retval : sizeof(s32);
586}
587
588static int uio_find_mem_index(struct vm_area_struct *vma)
589{
590 struct uio_device *idev = vma->vm_private_data;
591
592 if (vma->vm_pgoff < MAX_UIO_MAPS) {
593 if (idev->info->mem[vma->vm_pgoff].size == 0)
594 return -1;
595 return (int)vma->vm_pgoff;
596 }
597 return -1;
598}
599
600static int uio_vma_fault(struct vm_fault *vmf)
601{
602 struct uio_device *idev = vmf->vma->vm_private_data;
603 struct page *page;
604 unsigned long offset;
605 void *addr;
606
607 int mi = uio_find_mem_index(vmf->vma);
608 if (mi < 0)
609 return VM_FAULT_SIGBUS;
610
611 /*
612 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
613 * to use mem[N].
614 */
615 offset = (vmf->pgoff - mi) << PAGE_SHIFT;
616
617 addr = (void *)(unsigned long)idev->info->mem[mi].addr + offset;
618 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
619 page = virt_to_page(addr);
620 else
621 page = vmalloc_to_page(addr);
622 get_page(page);
623 vmf->page = page;
624 return 0;
625}
626
627static const struct vm_operations_struct uio_logical_vm_ops = {
628 .fault = uio_vma_fault,
629};
630
631static int uio_mmap_logical(struct vm_area_struct *vma)
632{
633 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
634 vma->vm_ops = &uio_logical_vm_ops;
635 return 0;
636}
637
638static const struct vm_operations_struct uio_physical_vm_ops = {
639#ifdef CONFIG_HAVE_IOREMAP_PROT
640 .access = generic_access_phys,
641#endif
642};
643
644static int uio_mmap_physical(struct vm_area_struct *vma)
645{
646 struct uio_device *idev = vma->vm_private_data;
647 int mi = uio_find_mem_index(vma);
648 struct uio_mem *mem;
649 if (mi < 0)
650 return -EINVAL;
651 mem = idev->info->mem + mi;
652
653 if (mem->addr & ~PAGE_MASK)
654 return -ENODEV;
655 if (vma->vm_end - vma->vm_start > mem->size)
656 return -EINVAL;
657
658 vma->vm_ops = &uio_physical_vm_ops;
659 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
660
661 /*
662 * We cannot use the vm_iomap_memory() helper here,
663 * because vma->vm_pgoff is the map index we looked
664 * up above in uio_find_mem_index(), rather than an
665 * actual page offset into the mmap.
666 *
667 * So we just do the physical mmap without a page
668 * offset.
669 */
670 return remap_pfn_range(vma,
671 vma->vm_start,
672 mem->addr >> PAGE_SHIFT,
673 vma->vm_end - vma->vm_start,
674 vma->vm_page_prot);
675}
676
677static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
678{
679 struct uio_listener *listener = filep->private_data;
680 struct uio_device *idev = listener->dev;
681 int mi;
682 unsigned long requested_pages, actual_pages;
683 int ret = 0;
684
685 if (vma->vm_end < vma->vm_start)
686 return -EINVAL;
687
688 vma->vm_private_data = idev;
689
690 mi = uio_find_mem_index(vma);
691 if (mi < 0)
692 return -EINVAL;
693
694 requested_pages = vma_pages(vma);
695 actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK)
696 + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
697 if (requested_pages > actual_pages)
698 return -EINVAL;
699
700 if (idev->info->mmap) {
701 ret = idev->info->mmap(idev->info, vma);
702 return ret;
703 }
704
705 switch (idev->info->mem[mi].memtype) {
706 case UIO_MEM_PHYS:
707 return uio_mmap_physical(vma);
708 case UIO_MEM_LOGICAL:
709 case UIO_MEM_VIRTUAL:
710 return uio_mmap_logical(vma);
711 default:
712 return -EINVAL;
713 }
714}
715
716static const struct file_operations uio_fops = {
717 .owner = THIS_MODULE,
718 .open = uio_open,
719 .release = uio_release,
720 .read = uio_read,
721 .write = uio_write,
722 .mmap = uio_mmap,
723 .poll = uio_poll,
724 .fasync = uio_fasync,
725 .llseek = noop_llseek,
726};
727
728static int uio_major_init(void)
729{
730 static const char name[] = "uio";
731 struct cdev *cdev = NULL;
732 dev_t uio_dev = 0;
733 int result;
734
735 result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name);
736 if (result)
737 goto out;
738
739 result = -ENOMEM;
740 cdev = cdev_alloc();
741 if (!cdev)
742 goto out_unregister;
743
744 cdev->owner = THIS_MODULE;
745 cdev->ops = &uio_fops;
746 kobject_set_name(&cdev->kobj, "%s", name);
747
748 result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES);
749 if (result)
750 goto out_put;
751
752 uio_major = MAJOR(uio_dev);
753 uio_cdev = cdev;
754 return 0;
755out_put:
756 kobject_put(&cdev->kobj);
757out_unregister:
758 unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES);
759out:
760 return result;
761}
762
763static void uio_major_cleanup(void)
764{
765 unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES);
766 cdev_del(uio_cdev);
767}
768
769static int init_uio_class(void)
770{
771 int ret;
772
773 /* This is the first time in here, set everything up properly */
774 ret = uio_major_init();
775 if (ret)
776 goto exit;
777
778 ret = class_register(&uio_class);
779 if (ret) {
780 printk(KERN_ERR "class_register failed for uio\n");
781 goto err_class_register;
782 }
783 return 0;
784
785err_class_register:
786 uio_major_cleanup();
787exit:
788 return ret;
789}
790
791static void release_uio_class(void)
792{
793 class_unregister(&uio_class);
794 uio_major_cleanup();
795}
796
797/**
798 * uio_register_device - register a new userspace IO device
799 * @owner: module that creates the new device
800 * @parent: parent device
801 * @info: UIO device capabilities
802 *
803 * returns zero on success or a negative error code.
804 */
805int __uio_register_device(struct module *owner,
806 struct device *parent,
807 struct uio_info *info)
808{
809 struct uio_device *idev;
810 int ret = 0;
811
812 if (!parent || !info || !info->name || !info->version)
813 return -EINVAL;
814
815 info->uio_dev = NULL;
816
817 idev = devm_kzalloc(parent, sizeof(*idev), GFP_KERNEL);
818 if (!idev) {
819 return -ENOMEM;
820 }
821
822 idev->owner = owner;
823 idev->info = info;
824 init_waitqueue_head(&idev->wait);
825 atomic_set(&idev->event, 0);
826
827 ret = uio_get_minor(idev);
828 if (ret)
829 return ret;
830
831 idev->dev = device_create(&uio_class, parent,
832 MKDEV(uio_major, idev->minor), idev,
833 "uio%d", idev->minor);
834 if (IS_ERR(idev->dev)) {
835 printk(KERN_ERR "UIO: device register failed\n");
836 ret = PTR_ERR(idev->dev);
837 goto err_device_create;
838 }
839
840 ret = uio_dev_add_attributes(idev);
841 if (ret)
842 goto err_uio_dev_add_attributes;
843
844 info->uio_dev = idev;
845
846 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) {
847 /*
848 * Note that we deliberately don't use devm_request_irq
849 * here. The parent module can unregister the UIO device
850 * and call pci_disable_msi, which requires that this
851 * irq has been freed. However, the device may have open
852 * FDs at the time of unregister and therefore may not be
853 * freed until they are released.
854 */
855 ret = request_irq(info->irq, uio_interrupt,
856 info->irq_flags, info->name, idev);
857 if (ret)
858 goto err_request_irq;
859 }
860
861 return 0;
862
863err_request_irq:
864 uio_dev_del_attributes(idev);
865err_uio_dev_add_attributes:
866 device_destroy(&uio_class, MKDEV(uio_major, idev->minor));
867err_device_create:
868 uio_free_minor(idev);
869 return ret;
870}
871EXPORT_SYMBOL_GPL(__uio_register_device);
872
873/**
874 * uio_unregister_device - unregister a industrial IO device
875 * @info: UIO device capabilities
876 *
877 */
878void uio_unregister_device(struct uio_info *info)
879{
880 struct uio_device *idev;
881
882 if (!info || !info->uio_dev)
883 return;
884
885 idev = info->uio_dev;
886
887 uio_free_minor(idev);
888
889 uio_dev_del_attributes(idev);
890
891 if (info->irq && info->irq != UIO_IRQ_CUSTOM)
892 free_irq(info->irq, idev);
893
894 device_destroy(&uio_class, MKDEV(uio_major, idev->minor));
895
896 return;
897}
898EXPORT_SYMBOL_GPL(uio_unregister_device);
899
900static int __init uio_init(void)
901{
902 return init_uio_class();
903}
904
905static void __exit uio_exit(void)
906{
907 release_uio_class();
908 idr_destroy(&uio_idr);
909}
910
911module_init(uio_init)
912module_exit(uio_exit)
913MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * drivers/uio/uio.c
4 *
5 * Copyright(C) 2005, Benedikt Spranger <b.spranger@linutronix.de>
6 * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
7 * Copyright(C) 2006, Hans J. Koch <hjk@hansjkoch.de>
8 * Copyright(C) 2006, Greg Kroah-Hartman <greg@kroah.com>
9 *
10 * Userspace IO
11 *
12 * Base Functions
13 */
14
15#include <linux/module.h>
16#include <linux/init.h>
17#include <linux/poll.h>
18#include <linux/device.h>
19#include <linux/slab.h>
20#include <linux/mm.h>
21#include <linux/idr.h>
22#include <linux/sched/signal.h>
23#include <linux/string.h>
24#include <linux/kobject.h>
25#include <linux/cdev.h>
26#include <linux/uio_driver.h>
27
28#define UIO_MAX_DEVICES (1U << MINORBITS)
29
30static int uio_major;
31static struct cdev *uio_cdev;
32static DEFINE_IDR(uio_idr);
33static const struct file_operations uio_fops;
34
35/* Protect idr accesses */
36static DEFINE_MUTEX(minor_lock);
37
38/*
39 * attributes
40 */
41
42struct uio_map {
43 struct kobject kobj;
44 struct uio_mem *mem;
45};
46#define to_map(map) container_of(map, struct uio_map, kobj)
47
48static ssize_t map_name_show(struct uio_mem *mem, char *buf)
49{
50 if (unlikely(!mem->name))
51 mem->name = "";
52
53 return sprintf(buf, "%s\n", mem->name);
54}
55
56static ssize_t map_addr_show(struct uio_mem *mem, char *buf)
57{
58 return sprintf(buf, "%pa\n", &mem->addr);
59}
60
61static ssize_t map_size_show(struct uio_mem *mem, char *buf)
62{
63 return sprintf(buf, "%pa\n", &mem->size);
64}
65
66static ssize_t map_offset_show(struct uio_mem *mem, char *buf)
67{
68 return sprintf(buf, "0x%llx\n", (unsigned long long)mem->offs);
69}
70
71struct map_sysfs_entry {
72 struct attribute attr;
73 ssize_t (*show)(struct uio_mem *, char *);
74 ssize_t (*store)(struct uio_mem *, const char *, size_t);
75};
76
77static struct map_sysfs_entry name_attribute =
78 __ATTR(name, S_IRUGO, map_name_show, NULL);
79static struct map_sysfs_entry addr_attribute =
80 __ATTR(addr, S_IRUGO, map_addr_show, NULL);
81static struct map_sysfs_entry size_attribute =
82 __ATTR(size, S_IRUGO, map_size_show, NULL);
83static struct map_sysfs_entry offset_attribute =
84 __ATTR(offset, S_IRUGO, map_offset_show, NULL);
85
86static struct attribute *map_attrs[] = {
87 &name_attribute.attr,
88 &addr_attribute.attr,
89 &size_attribute.attr,
90 &offset_attribute.attr,
91 NULL, /* need to NULL terminate the list of attributes */
92};
93ATTRIBUTE_GROUPS(map);
94
95static void map_release(struct kobject *kobj)
96{
97 struct uio_map *map = to_map(kobj);
98 kfree(map);
99}
100
101static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr,
102 char *buf)
103{
104 struct uio_map *map = to_map(kobj);
105 struct uio_mem *mem = map->mem;
106 struct map_sysfs_entry *entry;
107
108 entry = container_of(attr, struct map_sysfs_entry, attr);
109
110 if (!entry->show)
111 return -EIO;
112
113 return entry->show(mem, buf);
114}
115
116static const struct sysfs_ops map_sysfs_ops = {
117 .show = map_type_show,
118};
119
120static struct kobj_type map_attr_type = {
121 .release = map_release,
122 .sysfs_ops = &map_sysfs_ops,
123 .default_groups = map_groups,
124};
125
126struct uio_portio {
127 struct kobject kobj;
128 struct uio_port *port;
129};
130#define to_portio(portio) container_of(portio, struct uio_portio, kobj)
131
132static ssize_t portio_name_show(struct uio_port *port, char *buf)
133{
134 if (unlikely(!port->name))
135 port->name = "";
136
137 return sprintf(buf, "%s\n", port->name);
138}
139
140static ssize_t portio_start_show(struct uio_port *port, char *buf)
141{
142 return sprintf(buf, "0x%lx\n", port->start);
143}
144
145static ssize_t portio_size_show(struct uio_port *port, char *buf)
146{
147 return sprintf(buf, "0x%lx\n", port->size);
148}
149
150static ssize_t portio_porttype_show(struct uio_port *port, char *buf)
151{
152 const char *porttypes[] = {"none", "x86", "gpio", "other"};
153
154 if ((port->porttype < 0) || (port->porttype > UIO_PORT_OTHER))
155 return -EINVAL;
156
157 return sprintf(buf, "port_%s\n", porttypes[port->porttype]);
158}
159
160struct portio_sysfs_entry {
161 struct attribute attr;
162 ssize_t (*show)(struct uio_port *, char *);
163 ssize_t (*store)(struct uio_port *, const char *, size_t);
164};
165
166static struct portio_sysfs_entry portio_name_attribute =
167 __ATTR(name, S_IRUGO, portio_name_show, NULL);
168static struct portio_sysfs_entry portio_start_attribute =
169 __ATTR(start, S_IRUGO, portio_start_show, NULL);
170static struct portio_sysfs_entry portio_size_attribute =
171 __ATTR(size, S_IRUGO, portio_size_show, NULL);
172static struct portio_sysfs_entry portio_porttype_attribute =
173 __ATTR(porttype, S_IRUGO, portio_porttype_show, NULL);
174
175static struct attribute *portio_attrs[] = {
176 &portio_name_attribute.attr,
177 &portio_start_attribute.attr,
178 &portio_size_attribute.attr,
179 &portio_porttype_attribute.attr,
180 NULL,
181};
182ATTRIBUTE_GROUPS(portio);
183
184static void portio_release(struct kobject *kobj)
185{
186 struct uio_portio *portio = to_portio(kobj);
187 kfree(portio);
188}
189
190static ssize_t portio_type_show(struct kobject *kobj, struct attribute *attr,
191 char *buf)
192{
193 struct uio_portio *portio = to_portio(kobj);
194 struct uio_port *port = portio->port;
195 struct portio_sysfs_entry *entry;
196
197 entry = container_of(attr, struct portio_sysfs_entry, attr);
198
199 if (!entry->show)
200 return -EIO;
201
202 return entry->show(port, buf);
203}
204
205static const struct sysfs_ops portio_sysfs_ops = {
206 .show = portio_type_show,
207};
208
209static struct kobj_type portio_attr_type = {
210 .release = portio_release,
211 .sysfs_ops = &portio_sysfs_ops,
212 .default_groups = portio_groups,
213};
214
215static ssize_t name_show(struct device *dev,
216 struct device_attribute *attr, char *buf)
217{
218 struct uio_device *idev = dev_get_drvdata(dev);
219 int ret;
220
221 mutex_lock(&idev->info_lock);
222 if (!idev->info) {
223 ret = -EINVAL;
224 dev_err(dev, "the device has been unregistered\n");
225 goto out;
226 }
227
228 ret = sprintf(buf, "%s\n", idev->info->name);
229
230out:
231 mutex_unlock(&idev->info_lock);
232 return ret;
233}
234static DEVICE_ATTR_RO(name);
235
236static ssize_t version_show(struct device *dev,
237 struct device_attribute *attr, char *buf)
238{
239 struct uio_device *idev = dev_get_drvdata(dev);
240 int ret;
241
242 mutex_lock(&idev->info_lock);
243 if (!idev->info) {
244 ret = -EINVAL;
245 dev_err(dev, "the device has been unregistered\n");
246 goto out;
247 }
248
249 ret = sprintf(buf, "%s\n", idev->info->version);
250
251out:
252 mutex_unlock(&idev->info_lock);
253 return ret;
254}
255static DEVICE_ATTR_RO(version);
256
257static ssize_t event_show(struct device *dev,
258 struct device_attribute *attr, char *buf)
259{
260 struct uio_device *idev = dev_get_drvdata(dev);
261 return sprintf(buf, "%u\n", (unsigned int)atomic_read(&idev->event));
262}
263static DEVICE_ATTR_RO(event);
264
265static struct attribute *uio_attrs[] = {
266 &dev_attr_name.attr,
267 &dev_attr_version.attr,
268 &dev_attr_event.attr,
269 NULL,
270};
271ATTRIBUTE_GROUPS(uio);
272
273/* UIO class infrastructure */
274static struct class uio_class = {
275 .name = "uio",
276 .dev_groups = uio_groups,
277};
278
279static bool uio_class_registered;
280
281/*
282 * device functions
283 */
284static int uio_dev_add_attributes(struct uio_device *idev)
285{
286 int ret;
287 int mi, pi;
288 int map_found = 0;
289 int portio_found = 0;
290 struct uio_mem *mem;
291 struct uio_map *map;
292 struct uio_port *port;
293 struct uio_portio *portio;
294
295 for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
296 mem = &idev->info->mem[mi];
297 if (mem->size == 0)
298 break;
299 if (!map_found) {
300 map_found = 1;
301 idev->map_dir = kobject_create_and_add("maps",
302 &idev->dev.kobj);
303 if (!idev->map_dir) {
304 ret = -ENOMEM;
305 goto err_map;
306 }
307 }
308 map = kzalloc(sizeof(*map), GFP_KERNEL);
309 if (!map) {
310 ret = -ENOMEM;
311 goto err_map;
312 }
313 kobject_init(&map->kobj, &map_attr_type);
314 map->mem = mem;
315 mem->map = map;
316 ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi);
317 if (ret)
318 goto err_map_kobj;
319 ret = kobject_uevent(&map->kobj, KOBJ_ADD);
320 if (ret)
321 goto err_map_kobj;
322 }
323
324 for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) {
325 port = &idev->info->port[pi];
326 if (port->size == 0)
327 break;
328 if (!portio_found) {
329 portio_found = 1;
330 idev->portio_dir = kobject_create_and_add("portio",
331 &idev->dev.kobj);
332 if (!idev->portio_dir) {
333 ret = -ENOMEM;
334 goto err_portio;
335 }
336 }
337 portio = kzalloc(sizeof(*portio), GFP_KERNEL);
338 if (!portio) {
339 ret = -ENOMEM;
340 goto err_portio;
341 }
342 kobject_init(&portio->kobj, &portio_attr_type);
343 portio->port = port;
344 port->portio = portio;
345 ret = kobject_add(&portio->kobj, idev->portio_dir,
346 "port%d", pi);
347 if (ret)
348 goto err_portio_kobj;
349 ret = kobject_uevent(&portio->kobj, KOBJ_ADD);
350 if (ret)
351 goto err_portio_kobj;
352 }
353
354 return 0;
355
356err_portio:
357 pi--;
358err_portio_kobj:
359 for (; pi >= 0; pi--) {
360 port = &idev->info->port[pi];
361 portio = port->portio;
362 kobject_put(&portio->kobj);
363 }
364 kobject_put(idev->portio_dir);
365err_map:
366 mi--;
367err_map_kobj:
368 for (; mi >= 0; mi--) {
369 mem = &idev->info->mem[mi];
370 map = mem->map;
371 kobject_put(&map->kobj);
372 }
373 kobject_put(idev->map_dir);
374 dev_err(&idev->dev, "error creating sysfs files (%d)\n", ret);
375 return ret;
376}
377
378static void uio_dev_del_attributes(struct uio_device *idev)
379{
380 int i;
381 struct uio_mem *mem;
382 struct uio_port *port;
383
384 for (i = 0; i < MAX_UIO_MAPS; i++) {
385 mem = &idev->info->mem[i];
386 if (mem->size == 0)
387 break;
388 kobject_put(&mem->map->kobj);
389 }
390 kobject_put(idev->map_dir);
391
392 for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) {
393 port = &idev->info->port[i];
394 if (port->size == 0)
395 break;
396 kobject_put(&port->portio->kobj);
397 }
398 kobject_put(idev->portio_dir);
399}
400
401static int uio_get_minor(struct uio_device *idev)
402{
403 int retval;
404
405 mutex_lock(&minor_lock);
406 retval = idr_alloc(&uio_idr, idev, 0, UIO_MAX_DEVICES, GFP_KERNEL);
407 if (retval >= 0) {
408 idev->minor = retval;
409 retval = 0;
410 } else if (retval == -ENOSPC) {
411 dev_err(&idev->dev, "too many uio devices\n");
412 retval = -EINVAL;
413 }
414 mutex_unlock(&minor_lock);
415 return retval;
416}
417
418static void uio_free_minor(unsigned long minor)
419{
420 mutex_lock(&minor_lock);
421 idr_remove(&uio_idr, minor);
422 mutex_unlock(&minor_lock);
423}
424
425/**
426 * uio_event_notify - trigger an interrupt event
427 * @info: UIO device capabilities
428 */
429void uio_event_notify(struct uio_info *info)
430{
431 struct uio_device *idev = info->uio_dev;
432
433 atomic_inc(&idev->event);
434 wake_up_interruptible(&idev->wait);
435 kill_fasync(&idev->async_queue, SIGIO, POLL_IN);
436}
437EXPORT_SYMBOL_GPL(uio_event_notify);
438
439/**
440 * uio_interrupt - hardware interrupt handler
441 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer
442 * @dev_id: Pointer to the devices uio_device structure
443 */
444static irqreturn_t uio_interrupt(int irq, void *dev_id)
445{
446 struct uio_device *idev = (struct uio_device *)dev_id;
447 irqreturn_t ret;
448
449 ret = idev->info->handler(irq, idev->info);
450 if (ret == IRQ_HANDLED)
451 uio_event_notify(idev->info);
452
453 return ret;
454}
455
456struct uio_listener {
457 struct uio_device *dev;
458 s32 event_count;
459};
460
461static int uio_open(struct inode *inode, struct file *filep)
462{
463 struct uio_device *idev;
464 struct uio_listener *listener;
465 int ret = 0;
466
467 mutex_lock(&minor_lock);
468 idev = idr_find(&uio_idr, iminor(inode));
469 if (!idev) {
470 ret = -ENODEV;
471 mutex_unlock(&minor_lock);
472 goto out;
473 }
474 get_device(&idev->dev);
475 mutex_unlock(&minor_lock);
476
477 if (!try_module_get(idev->owner)) {
478 ret = -ENODEV;
479 goto err_module_get;
480 }
481
482 listener = kmalloc(sizeof(*listener), GFP_KERNEL);
483 if (!listener) {
484 ret = -ENOMEM;
485 goto err_alloc_listener;
486 }
487
488 listener->dev = idev;
489 listener->event_count = atomic_read(&idev->event);
490 filep->private_data = listener;
491
492 mutex_lock(&idev->info_lock);
493 if (!idev->info) {
494 mutex_unlock(&idev->info_lock);
495 ret = -EINVAL;
496 goto err_infoopen;
497 }
498
499 if (idev->info->open)
500 ret = idev->info->open(idev->info, inode);
501 mutex_unlock(&idev->info_lock);
502 if (ret)
503 goto err_infoopen;
504
505 return 0;
506
507err_infoopen:
508 kfree(listener);
509
510err_alloc_listener:
511 module_put(idev->owner);
512
513err_module_get:
514 put_device(&idev->dev);
515
516out:
517 return ret;
518}
519
520static int uio_fasync(int fd, struct file *filep, int on)
521{
522 struct uio_listener *listener = filep->private_data;
523 struct uio_device *idev = listener->dev;
524
525 return fasync_helper(fd, filep, on, &idev->async_queue);
526}
527
528static int uio_release(struct inode *inode, struct file *filep)
529{
530 int ret = 0;
531 struct uio_listener *listener = filep->private_data;
532 struct uio_device *idev = listener->dev;
533
534 mutex_lock(&idev->info_lock);
535 if (idev->info && idev->info->release)
536 ret = idev->info->release(idev->info, inode);
537 mutex_unlock(&idev->info_lock);
538
539 module_put(idev->owner);
540 kfree(listener);
541 put_device(&idev->dev);
542 return ret;
543}
544
545static __poll_t uio_poll(struct file *filep, poll_table *wait)
546{
547 struct uio_listener *listener = filep->private_data;
548 struct uio_device *idev = listener->dev;
549 __poll_t ret = 0;
550
551 mutex_lock(&idev->info_lock);
552 if (!idev->info || !idev->info->irq)
553 ret = -EIO;
554 mutex_unlock(&idev->info_lock);
555
556 if (ret)
557 return ret;
558
559 poll_wait(filep, &idev->wait, wait);
560 if (listener->event_count != atomic_read(&idev->event))
561 return EPOLLIN | EPOLLRDNORM;
562 return 0;
563}
564
565static ssize_t uio_read(struct file *filep, char __user *buf,
566 size_t count, loff_t *ppos)
567{
568 struct uio_listener *listener = filep->private_data;
569 struct uio_device *idev = listener->dev;
570 DECLARE_WAITQUEUE(wait, current);
571 ssize_t retval = 0;
572 s32 event_count;
573
574 if (count != sizeof(s32))
575 return -EINVAL;
576
577 add_wait_queue(&idev->wait, &wait);
578
579 do {
580 mutex_lock(&idev->info_lock);
581 if (!idev->info || !idev->info->irq) {
582 retval = -EIO;
583 mutex_unlock(&idev->info_lock);
584 break;
585 }
586 mutex_unlock(&idev->info_lock);
587
588 set_current_state(TASK_INTERRUPTIBLE);
589
590 event_count = atomic_read(&idev->event);
591 if (event_count != listener->event_count) {
592 __set_current_state(TASK_RUNNING);
593 if (copy_to_user(buf, &event_count, count))
594 retval = -EFAULT;
595 else {
596 listener->event_count = event_count;
597 retval = count;
598 }
599 break;
600 }
601
602 if (filep->f_flags & O_NONBLOCK) {
603 retval = -EAGAIN;
604 break;
605 }
606
607 if (signal_pending(current)) {
608 retval = -ERESTARTSYS;
609 break;
610 }
611 schedule();
612 } while (1);
613
614 __set_current_state(TASK_RUNNING);
615 remove_wait_queue(&idev->wait, &wait);
616
617 return retval;
618}
619
620static ssize_t uio_write(struct file *filep, const char __user *buf,
621 size_t count, loff_t *ppos)
622{
623 struct uio_listener *listener = filep->private_data;
624 struct uio_device *idev = listener->dev;
625 ssize_t retval;
626 s32 irq_on;
627
628 if (count != sizeof(s32))
629 return -EINVAL;
630
631 if (copy_from_user(&irq_on, buf, count))
632 return -EFAULT;
633
634 mutex_lock(&idev->info_lock);
635 if (!idev->info) {
636 retval = -EINVAL;
637 goto out;
638 }
639
640 if (!idev->info->irq) {
641 retval = -EIO;
642 goto out;
643 }
644
645 if (!idev->info->irqcontrol) {
646 retval = -ENOSYS;
647 goto out;
648 }
649
650 retval = idev->info->irqcontrol(idev->info, irq_on);
651
652out:
653 mutex_unlock(&idev->info_lock);
654 return retval ? retval : sizeof(s32);
655}
656
657static int uio_find_mem_index(struct vm_area_struct *vma)
658{
659 struct uio_device *idev = vma->vm_private_data;
660
661 if (vma->vm_pgoff < MAX_UIO_MAPS) {
662 if (idev->info->mem[vma->vm_pgoff].size == 0)
663 return -1;
664 return (int)vma->vm_pgoff;
665 }
666 return -1;
667}
668
669static vm_fault_t uio_vma_fault(struct vm_fault *vmf)
670{
671 struct uio_device *idev = vmf->vma->vm_private_data;
672 struct page *page;
673 unsigned long offset;
674 void *addr;
675 vm_fault_t ret = 0;
676 int mi;
677
678 mutex_lock(&idev->info_lock);
679 if (!idev->info) {
680 ret = VM_FAULT_SIGBUS;
681 goto out;
682 }
683
684 mi = uio_find_mem_index(vmf->vma);
685 if (mi < 0) {
686 ret = VM_FAULT_SIGBUS;
687 goto out;
688 }
689
690 /*
691 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
692 * to use mem[N].
693 */
694 offset = (vmf->pgoff - mi) << PAGE_SHIFT;
695
696 addr = (void *)(unsigned long)idev->info->mem[mi].addr + offset;
697 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
698 page = virt_to_page(addr);
699 else
700 page = vmalloc_to_page(addr);
701 get_page(page);
702 vmf->page = page;
703
704out:
705 mutex_unlock(&idev->info_lock);
706
707 return ret;
708}
709
710static const struct vm_operations_struct uio_logical_vm_ops = {
711 .fault = uio_vma_fault,
712};
713
714static int uio_mmap_logical(struct vm_area_struct *vma)
715{
716 vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP);
717 vma->vm_ops = &uio_logical_vm_ops;
718 return 0;
719}
720
721static const struct vm_operations_struct uio_physical_vm_ops = {
722#ifdef CONFIG_HAVE_IOREMAP_PROT
723 .access = generic_access_phys,
724#endif
725};
726
727static int uio_mmap_physical(struct vm_area_struct *vma)
728{
729 struct uio_device *idev = vma->vm_private_data;
730 int mi = uio_find_mem_index(vma);
731 struct uio_mem *mem;
732
733 if (mi < 0)
734 return -EINVAL;
735 mem = idev->info->mem + mi;
736
737 if (mem->addr & ~PAGE_MASK)
738 return -ENODEV;
739 if (vma->vm_end - vma->vm_start > mem->size)
740 return -EINVAL;
741
742 vma->vm_ops = &uio_physical_vm_ops;
743 if (idev->info->mem[mi].memtype == UIO_MEM_PHYS)
744 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
745
746 /*
747 * We cannot use the vm_iomap_memory() helper here,
748 * because vma->vm_pgoff is the map index we looked
749 * up above in uio_find_mem_index(), rather than an
750 * actual page offset into the mmap.
751 *
752 * So we just do the physical mmap without a page
753 * offset.
754 */
755 return remap_pfn_range(vma,
756 vma->vm_start,
757 mem->addr >> PAGE_SHIFT,
758 vma->vm_end - vma->vm_start,
759 vma->vm_page_prot);
760}
761
762static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
763{
764 struct uio_listener *listener = filep->private_data;
765 struct uio_device *idev = listener->dev;
766 int mi;
767 unsigned long requested_pages, actual_pages;
768 int ret = 0;
769
770 if (vma->vm_end < vma->vm_start)
771 return -EINVAL;
772
773 vma->vm_private_data = idev;
774
775 mutex_lock(&idev->info_lock);
776 if (!idev->info) {
777 ret = -EINVAL;
778 goto out;
779 }
780
781 mi = uio_find_mem_index(vma);
782 if (mi < 0) {
783 ret = -EINVAL;
784 goto out;
785 }
786
787 requested_pages = vma_pages(vma);
788 actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK)
789 + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
790 if (requested_pages > actual_pages) {
791 ret = -EINVAL;
792 goto out;
793 }
794
795 if (idev->info->mmap) {
796 ret = idev->info->mmap(idev->info, vma);
797 goto out;
798 }
799
800 switch (idev->info->mem[mi].memtype) {
801 case UIO_MEM_IOVA:
802 case UIO_MEM_PHYS:
803 ret = uio_mmap_physical(vma);
804 break;
805 case UIO_MEM_LOGICAL:
806 case UIO_MEM_VIRTUAL:
807 ret = uio_mmap_logical(vma);
808 break;
809 default:
810 ret = -EINVAL;
811 }
812
813 out:
814 mutex_unlock(&idev->info_lock);
815 return ret;
816}
817
818static const struct file_operations uio_fops = {
819 .owner = THIS_MODULE,
820 .open = uio_open,
821 .release = uio_release,
822 .read = uio_read,
823 .write = uio_write,
824 .mmap = uio_mmap,
825 .poll = uio_poll,
826 .fasync = uio_fasync,
827 .llseek = noop_llseek,
828};
829
830static int uio_major_init(void)
831{
832 static const char name[] = "uio";
833 struct cdev *cdev = NULL;
834 dev_t uio_dev = 0;
835 int result;
836
837 result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name);
838 if (result)
839 goto out;
840
841 result = -ENOMEM;
842 cdev = cdev_alloc();
843 if (!cdev)
844 goto out_unregister;
845
846 cdev->owner = THIS_MODULE;
847 cdev->ops = &uio_fops;
848 kobject_set_name(&cdev->kobj, "%s", name);
849
850 result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES);
851 if (result)
852 goto out_put;
853
854 uio_major = MAJOR(uio_dev);
855 uio_cdev = cdev;
856 return 0;
857out_put:
858 kobject_put(&cdev->kobj);
859out_unregister:
860 unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES);
861out:
862 return result;
863}
864
865static void uio_major_cleanup(void)
866{
867 unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES);
868 cdev_del(uio_cdev);
869}
870
871static int init_uio_class(void)
872{
873 int ret;
874
875 /* This is the first time in here, set everything up properly */
876 ret = uio_major_init();
877 if (ret)
878 goto exit;
879
880 ret = class_register(&uio_class);
881 if (ret) {
882 printk(KERN_ERR "class_register failed for uio\n");
883 goto err_class_register;
884 }
885
886 uio_class_registered = true;
887
888 return 0;
889
890err_class_register:
891 uio_major_cleanup();
892exit:
893 return ret;
894}
895
896static void release_uio_class(void)
897{
898 uio_class_registered = false;
899 class_unregister(&uio_class);
900 uio_major_cleanup();
901}
902
903static void uio_device_release(struct device *dev)
904{
905 struct uio_device *idev = dev_get_drvdata(dev);
906
907 kfree(idev);
908}
909
910/**
911 * __uio_register_device - register a new userspace IO device
912 * @owner: module that creates the new device
913 * @parent: parent device
914 * @info: UIO device capabilities
915 *
916 * returns zero on success or a negative error code.
917 */
918int __uio_register_device(struct module *owner,
919 struct device *parent,
920 struct uio_info *info)
921{
922 struct uio_device *idev;
923 int ret = 0;
924
925 if (!uio_class_registered)
926 return -EPROBE_DEFER;
927
928 if (!parent || !info || !info->name || !info->version)
929 return -EINVAL;
930
931 info->uio_dev = NULL;
932
933 idev = kzalloc(sizeof(*idev), GFP_KERNEL);
934 if (!idev) {
935 return -ENOMEM;
936 }
937
938 idev->owner = owner;
939 idev->info = info;
940 mutex_init(&idev->info_lock);
941 init_waitqueue_head(&idev->wait);
942 atomic_set(&idev->event, 0);
943
944 ret = uio_get_minor(idev);
945 if (ret) {
946 kfree(idev);
947 return ret;
948 }
949
950 device_initialize(&idev->dev);
951 idev->dev.devt = MKDEV(uio_major, idev->minor);
952 idev->dev.class = &uio_class;
953 idev->dev.parent = parent;
954 idev->dev.release = uio_device_release;
955 dev_set_drvdata(&idev->dev, idev);
956
957 ret = dev_set_name(&idev->dev, "uio%d", idev->minor);
958 if (ret)
959 goto err_device_create;
960
961 ret = device_add(&idev->dev);
962 if (ret)
963 goto err_device_create;
964
965 ret = uio_dev_add_attributes(idev);
966 if (ret)
967 goto err_uio_dev_add_attributes;
968
969 info->uio_dev = idev;
970
971 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) {
972 /*
973 * Note that we deliberately don't use devm_request_irq
974 * here. The parent module can unregister the UIO device
975 * and call pci_disable_msi, which requires that this
976 * irq has been freed. However, the device may have open
977 * FDs at the time of unregister and therefore may not be
978 * freed until they are released.
979 */
980 ret = request_irq(info->irq, uio_interrupt,
981 info->irq_flags, info->name, idev);
982 if (ret) {
983 info->uio_dev = NULL;
984 goto err_request_irq;
985 }
986 }
987
988 return 0;
989
990err_request_irq:
991 uio_dev_del_attributes(idev);
992err_uio_dev_add_attributes:
993 device_del(&idev->dev);
994err_device_create:
995 uio_free_minor(idev->minor);
996 put_device(&idev->dev);
997 return ret;
998}
999EXPORT_SYMBOL_GPL(__uio_register_device);
1000
1001static void devm_uio_unregister_device(struct device *dev, void *res)
1002{
1003 uio_unregister_device(*(struct uio_info **)res);
1004}
1005
1006/**
1007 * __devm_uio_register_device - Resource managed uio_register_device()
1008 * @owner: module that creates the new device
1009 * @parent: parent device
1010 * @info: UIO device capabilities
1011 *
1012 * returns zero on success or a negative error code.
1013 */
1014int __devm_uio_register_device(struct module *owner,
1015 struct device *parent,
1016 struct uio_info *info)
1017{
1018 struct uio_info **ptr;
1019 int ret;
1020
1021 ptr = devres_alloc(devm_uio_unregister_device, sizeof(*ptr),
1022 GFP_KERNEL);
1023 if (!ptr)
1024 return -ENOMEM;
1025
1026 *ptr = info;
1027 ret = __uio_register_device(owner, parent, info);
1028 if (ret) {
1029 devres_free(ptr);
1030 return ret;
1031 }
1032
1033 devres_add(parent, ptr);
1034
1035 return 0;
1036}
1037EXPORT_SYMBOL_GPL(__devm_uio_register_device);
1038
1039/**
1040 * uio_unregister_device - unregister a industrial IO device
1041 * @info: UIO device capabilities
1042 *
1043 */
1044void uio_unregister_device(struct uio_info *info)
1045{
1046 struct uio_device *idev;
1047 unsigned long minor;
1048
1049 if (!info || !info->uio_dev)
1050 return;
1051
1052 idev = info->uio_dev;
1053 minor = idev->minor;
1054
1055 mutex_lock(&idev->info_lock);
1056 uio_dev_del_attributes(idev);
1057
1058 if (info->irq && info->irq != UIO_IRQ_CUSTOM)
1059 free_irq(info->irq, idev);
1060
1061 idev->info = NULL;
1062 mutex_unlock(&idev->info_lock);
1063
1064 wake_up_interruptible(&idev->wait);
1065 kill_fasync(&idev->async_queue, SIGIO, POLL_HUP);
1066
1067 uio_free_minor(minor);
1068 device_unregister(&idev->dev);
1069
1070 return;
1071}
1072EXPORT_SYMBOL_GPL(uio_unregister_device);
1073
1074static int __init uio_init(void)
1075{
1076 return init_uio_class();
1077}
1078
1079static void __exit uio_exit(void)
1080{
1081 release_uio_class();
1082 idr_destroy(&uio_idr);
1083}
1084
1085module_init(uio_init)
1086module_exit(uio_exit)
1087MODULE_LICENSE("GPL v2");