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