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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#include <linux/dma-mapping.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 *map_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};
94ATTRIBUTE_GROUPS(map);
95
96static void map_release(struct kobject *kobj)
97{
98 struct uio_map *map = to_map(kobj);
99 kfree(map);
100}
101
102static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr,
103 char *buf)
104{
105 struct uio_map *map = to_map(kobj);
106 struct uio_mem *mem = map->mem;
107 struct map_sysfs_entry *entry;
108
109 entry = container_of(attr, struct map_sysfs_entry, attr);
110
111 if (!entry->show)
112 return -EIO;
113
114 return entry->show(mem, buf);
115}
116
117static const struct sysfs_ops map_sysfs_ops = {
118 .show = map_type_show,
119};
120
121static struct kobj_type map_attr_type = {
122 .release = map_release,
123 .sysfs_ops = &map_sysfs_ops,
124 .default_groups = map_groups,
125};
126
127struct uio_portio {
128 struct kobject kobj;
129 struct uio_port *port;
130};
131#define to_portio(portio) container_of(portio, struct uio_portio, kobj)
132
133static ssize_t portio_name_show(struct uio_port *port, char *buf)
134{
135 if (unlikely(!port->name))
136 port->name = "";
137
138 return sprintf(buf, "%s\n", port->name);
139}
140
141static ssize_t portio_start_show(struct uio_port *port, char *buf)
142{
143 return sprintf(buf, "0x%lx\n", port->start);
144}
145
146static ssize_t portio_size_show(struct uio_port *port, char *buf)
147{
148 return sprintf(buf, "0x%lx\n", port->size);
149}
150
151static ssize_t portio_porttype_show(struct uio_port *port, char *buf)
152{
153 const char *porttypes[] = {"none", "x86", "gpio", "other"};
154
155 if ((port->porttype < 0) || (port->porttype > UIO_PORT_OTHER))
156 return -EINVAL;
157
158 return sprintf(buf, "port_%s\n", porttypes[port->porttype]);
159}
160
161struct portio_sysfs_entry {
162 struct attribute attr;
163 ssize_t (*show)(struct uio_port *, char *);
164 ssize_t (*store)(struct uio_port *, const char *, size_t);
165};
166
167static struct portio_sysfs_entry portio_name_attribute =
168 __ATTR(name, S_IRUGO, portio_name_show, NULL);
169static struct portio_sysfs_entry portio_start_attribute =
170 __ATTR(start, S_IRUGO, portio_start_show, NULL);
171static struct portio_sysfs_entry portio_size_attribute =
172 __ATTR(size, S_IRUGO, portio_size_show, NULL);
173static struct portio_sysfs_entry portio_porttype_attribute =
174 __ATTR(porttype, S_IRUGO, portio_porttype_show, NULL);
175
176static struct attribute *portio_attrs[] = {
177 &portio_name_attribute.attr,
178 &portio_start_attribute.attr,
179 &portio_size_attribute.attr,
180 &portio_porttype_attribute.attr,
181 NULL,
182};
183ATTRIBUTE_GROUPS(portio);
184
185static void portio_release(struct kobject *kobj)
186{
187 struct uio_portio *portio = to_portio(kobj);
188 kfree(portio);
189}
190
191static ssize_t portio_type_show(struct kobject *kobj, struct attribute *attr,
192 char *buf)
193{
194 struct uio_portio *portio = to_portio(kobj);
195 struct uio_port *port = portio->port;
196 struct portio_sysfs_entry *entry;
197
198 entry = container_of(attr, struct portio_sysfs_entry, attr);
199
200 if (!entry->show)
201 return -EIO;
202
203 return entry->show(port, buf);
204}
205
206static const struct sysfs_ops portio_sysfs_ops = {
207 .show = portio_type_show,
208};
209
210static struct kobj_type portio_attr_type = {
211 .release = portio_release,
212 .sysfs_ops = &portio_sysfs_ops,
213 .default_groups = portio_groups,
214};
215
216static ssize_t name_show(struct device *dev,
217 struct device_attribute *attr, char *buf)
218{
219 struct uio_device *idev = dev_get_drvdata(dev);
220 int ret;
221
222 mutex_lock(&idev->info_lock);
223 if (!idev->info) {
224 ret = -EINVAL;
225 dev_err(dev, "the device has been unregistered\n");
226 goto out;
227 }
228
229 ret = sprintf(buf, "%s\n", idev->info->name);
230
231out:
232 mutex_unlock(&idev->info_lock);
233 return ret;
234}
235static DEVICE_ATTR_RO(name);
236
237static ssize_t version_show(struct device *dev,
238 struct device_attribute *attr, char *buf)
239{
240 struct uio_device *idev = dev_get_drvdata(dev);
241 int ret;
242
243 mutex_lock(&idev->info_lock);
244 if (!idev->info) {
245 ret = -EINVAL;
246 dev_err(dev, "the device has been unregistered\n");
247 goto out;
248 }
249
250 ret = sprintf(buf, "%s\n", idev->info->version);
251
252out:
253 mutex_unlock(&idev->info_lock);
254 return ret;
255}
256static DEVICE_ATTR_RO(version);
257
258static ssize_t event_show(struct device *dev,
259 struct device_attribute *attr, char *buf)
260{
261 struct uio_device *idev = dev_get_drvdata(dev);
262 return sprintf(buf, "%u\n", (unsigned int)atomic_read(&idev->event));
263}
264static DEVICE_ATTR_RO(event);
265
266static struct attribute *uio_attrs[] = {
267 &dev_attr_name.attr,
268 &dev_attr_version.attr,
269 &dev_attr_event.attr,
270 NULL,
271};
272ATTRIBUTE_GROUPS(uio);
273
274/* UIO class infrastructure */
275static struct class uio_class = {
276 .name = "uio",
277 .dev_groups = uio_groups,
278};
279
280static bool uio_class_registered;
281
282/*
283 * device functions
284 */
285static int uio_dev_add_attributes(struct uio_device *idev)
286{
287 int ret;
288 int mi, pi;
289 int map_found = 0;
290 int portio_found = 0;
291 struct uio_mem *mem;
292 struct uio_map *map;
293 struct uio_port *port;
294 struct uio_portio *portio;
295
296 for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
297 mem = &idev->info->mem[mi];
298 if (mem->size == 0)
299 break;
300 if (!map_found) {
301 map_found = 1;
302 idev->map_dir = kobject_create_and_add("maps",
303 &idev->dev.kobj);
304 if (!idev->map_dir) {
305 ret = -ENOMEM;
306 goto err_map;
307 }
308 }
309 map = kzalloc(sizeof(*map), GFP_KERNEL);
310 if (!map) {
311 ret = -ENOMEM;
312 goto err_map;
313 }
314 kobject_init(&map->kobj, &map_attr_type);
315 map->mem = mem;
316 mem->map = map;
317 ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi);
318 if (ret)
319 goto err_map_kobj;
320 ret = kobject_uevent(&map->kobj, KOBJ_ADD);
321 if (ret)
322 goto err_map_kobj;
323 }
324
325 for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) {
326 port = &idev->info->port[pi];
327 if (port->size == 0)
328 break;
329 if (!portio_found) {
330 portio_found = 1;
331 idev->portio_dir = kobject_create_and_add("portio",
332 &idev->dev.kobj);
333 if (!idev->portio_dir) {
334 ret = -ENOMEM;
335 goto err_portio;
336 }
337 }
338 portio = kzalloc(sizeof(*portio), GFP_KERNEL);
339 if (!portio) {
340 ret = -ENOMEM;
341 goto err_portio;
342 }
343 kobject_init(&portio->kobj, &portio_attr_type);
344 portio->port = port;
345 port->portio = portio;
346 ret = kobject_add(&portio->kobj, idev->portio_dir,
347 "port%d", pi);
348 if (ret)
349 goto err_portio_kobj;
350 ret = kobject_uevent(&portio->kobj, KOBJ_ADD);
351 if (ret)
352 goto err_portio_kobj;
353 }
354
355 return 0;
356
357err_portio:
358 pi--;
359err_portio_kobj:
360 for (; pi >= 0; pi--) {
361 port = &idev->info->port[pi];
362 portio = port->portio;
363 kobject_put(&portio->kobj);
364 }
365 kobject_put(idev->portio_dir);
366err_map:
367 mi--;
368err_map_kobj:
369 for (; mi >= 0; mi--) {
370 mem = &idev->info->mem[mi];
371 map = mem->map;
372 kobject_put(&map->kobj);
373 }
374 kobject_put(idev->map_dir);
375 dev_err(&idev->dev, "error creating sysfs files (%d)\n", ret);
376 return ret;
377}
378
379static void uio_dev_del_attributes(struct uio_device *idev)
380{
381 int i;
382 struct uio_mem *mem;
383 struct uio_port *port;
384
385 for (i = 0; i < MAX_UIO_MAPS; i++) {
386 mem = &idev->info->mem[i];
387 if (mem->size == 0)
388 break;
389 kobject_put(&mem->map->kobj);
390 }
391 kobject_put(idev->map_dir);
392
393 for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) {
394 port = &idev->info->port[i];
395 if (port->size == 0)
396 break;
397 kobject_put(&port->portio->kobj);
398 }
399 kobject_put(idev->portio_dir);
400}
401
402static int uio_get_minor(struct uio_device *idev)
403{
404 int retval;
405
406 mutex_lock(&minor_lock);
407 retval = idr_alloc(&uio_idr, idev, 0, UIO_MAX_DEVICES, GFP_KERNEL);
408 if (retval >= 0) {
409 idev->minor = retval;
410 retval = 0;
411 } else if (retval == -ENOSPC) {
412 dev_err(&idev->dev, "too many uio devices\n");
413 retval = -EINVAL;
414 }
415 mutex_unlock(&minor_lock);
416 return retval;
417}
418
419static void uio_free_minor(unsigned long minor)
420{
421 mutex_lock(&minor_lock);
422 idr_remove(&uio_idr, minor);
423 mutex_unlock(&minor_lock);
424}
425
426/**
427 * uio_event_notify - trigger an interrupt event
428 * @info: UIO device capabilities
429 */
430void uio_event_notify(struct uio_info *info)
431{
432 struct uio_device *idev = info->uio_dev;
433
434 atomic_inc(&idev->event);
435 wake_up_interruptible(&idev->wait);
436 kill_fasync(&idev->async_queue, SIGIO, POLL_IN);
437}
438EXPORT_SYMBOL_GPL(uio_event_notify);
439
440/**
441 * uio_interrupt - hardware interrupt handler
442 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer
443 * @dev_id: Pointer to the devices uio_device structure
444 */
445static irqreturn_t uio_interrupt(int irq, void *dev_id)
446{
447 struct uio_device *idev = (struct uio_device *)dev_id;
448 irqreturn_t ret;
449
450 ret = idev->info->handler(irq, idev->info);
451 if (ret == IRQ_HANDLED)
452 uio_event_notify(idev->info);
453
454 return ret;
455}
456
457struct uio_listener {
458 struct uio_device *dev;
459 s32 event_count;
460};
461
462static int uio_open(struct inode *inode, struct file *filep)
463{
464 struct uio_device *idev;
465 struct uio_listener *listener;
466 int ret = 0;
467
468 mutex_lock(&minor_lock);
469 idev = idr_find(&uio_idr, iminor(inode));
470 if (!idev) {
471 ret = -ENODEV;
472 mutex_unlock(&minor_lock);
473 goto out;
474 }
475 get_device(&idev->dev);
476 mutex_unlock(&minor_lock);
477
478 if (!try_module_get(idev->owner)) {
479 ret = -ENODEV;
480 goto err_module_get;
481 }
482
483 listener = kmalloc(sizeof(*listener), GFP_KERNEL);
484 if (!listener) {
485 ret = -ENOMEM;
486 goto err_alloc_listener;
487 }
488
489 listener->dev = idev;
490 listener->event_count = atomic_read(&idev->event);
491 filep->private_data = listener;
492
493 mutex_lock(&idev->info_lock);
494 if (!idev->info) {
495 mutex_unlock(&idev->info_lock);
496 ret = -EINVAL;
497 goto err_infoopen;
498 }
499
500 if (idev->info->open)
501 ret = idev->info->open(idev->info, inode);
502 mutex_unlock(&idev->info_lock);
503 if (ret)
504 goto err_infoopen;
505
506 return 0;
507
508err_infoopen:
509 kfree(listener);
510
511err_alloc_listener:
512 module_put(idev->owner);
513
514err_module_get:
515 put_device(&idev->dev);
516
517out:
518 return ret;
519}
520
521static int uio_fasync(int fd, struct file *filep, int on)
522{
523 struct uio_listener *listener = filep->private_data;
524 struct uio_device *idev = listener->dev;
525
526 return fasync_helper(fd, filep, on, &idev->async_queue);
527}
528
529static int uio_release(struct inode *inode, struct file *filep)
530{
531 int ret = 0;
532 struct uio_listener *listener = filep->private_data;
533 struct uio_device *idev = listener->dev;
534
535 mutex_lock(&idev->info_lock);
536 if (idev->info && idev->info->release)
537 ret = idev->info->release(idev->info, inode);
538 mutex_unlock(&idev->info_lock);
539
540 module_put(idev->owner);
541 kfree(listener);
542 put_device(&idev->dev);
543 return ret;
544}
545
546static __poll_t uio_poll(struct file *filep, poll_table *wait)
547{
548 struct uio_listener *listener = filep->private_data;
549 struct uio_device *idev = listener->dev;
550 __poll_t ret = 0;
551
552 mutex_lock(&idev->info_lock);
553 if (!idev->info || !idev->info->irq)
554 ret = -EIO;
555 mutex_unlock(&idev->info_lock);
556
557 if (ret)
558 return ret;
559
560 poll_wait(filep, &idev->wait, wait);
561 if (listener->event_count != atomic_read(&idev->event))
562 return EPOLLIN | EPOLLRDNORM;
563 return 0;
564}
565
566static ssize_t uio_read(struct file *filep, char __user *buf,
567 size_t count, loff_t *ppos)
568{
569 struct uio_listener *listener = filep->private_data;
570 struct uio_device *idev = listener->dev;
571 DECLARE_WAITQUEUE(wait, current);
572 ssize_t retval = 0;
573 s32 event_count;
574
575 if (count != sizeof(s32))
576 return -EINVAL;
577
578 add_wait_queue(&idev->wait, &wait);
579
580 do {
581 mutex_lock(&idev->info_lock);
582 if (!idev->info || !idev->info->irq) {
583 retval = -EIO;
584 mutex_unlock(&idev->info_lock);
585 break;
586 }
587 mutex_unlock(&idev->info_lock);
588
589 set_current_state(TASK_INTERRUPTIBLE);
590
591 event_count = atomic_read(&idev->event);
592 if (event_count != listener->event_count) {
593 __set_current_state(TASK_RUNNING);
594 if (copy_to_user(buf, &event_count, count))
595 retval = -EFAULT;
596 else {
597 listener->event_count = event_count;
598 retval = count;
599 }
600 break;
601 }
602
603 if (filep->f_flags & O_NONBLOCK) {
604 retval = -EAGAIN;
605 break;
606 }
607
608 if (signal_pending(current)) {
609 retval = -ERESTARTSYS;
610 break;
611 }
612 schedule();
613 } while (1);
614
615 __set_current_state(TASK_RUNNING);
616 remove_wait_queue(&idev->wait, &wait);
617
618 return retval;
619}
620
621static ssize_t uio_write(struct file *filep, const char __user *buf,
622 size_t count, loff_t *ppos)
623{
624 struct uio_listener *listener = filep->private_data;
625 struct uio_device *idev = listener->dev;
626 ssize_t retval;
627 s32 irq_on;
628
629 if (count != sizeof(s32))
630 return -EINVAL;
631
632 if (copy_from_user(&irq_on, buf, count))
633 return -EFAULT;
634
635 mutex_lock(&idev->info_lock);
636 if (!idev->info) {
637 retval = -EINVAL;
638 goto out;
639 }
640
641 if (!idev->info->irq) {
642 retval = -EIO;
643 goto out;
644 }
645
646 if (!idev->info->irqcontrol) {
647 retval = -ENOSYS;
648 goto out;
649 }
650
651 retval = idev->info->irqcontrol(idev->info, irq_on);
652
653out:
654 mutex_unlock(&idev->info_lock);
655 return retval ? retval : sizeof(s32);
656}
657
658static int uio_find_mem_index(struct vm_area_struct *vma)
659{
660 struct uio_device *idev = vma->vm_private_data;
661
662 if (vma->vm_pgoff < MAX_UIO_MAPS) {
663 if (idev->info->mem[vma->vm_pgoff].size == 0)
664 return -1;
665 return (int)vma->vm_pgoff;
666 }
667 return -1;
668}
669
670static vm_fault_t uio_vma_fault(struct vm_fault *vmf)
671{
672 struct uio_device *idev = vmf->vma->vm_private_data;
673 struct page *page;
674 unsigned long offset;
675 void *addr;
676 vm_fault_t ret = 0;
677 int mi;
678
679 mutex_lock(&idev->info_lock);
680 if (!idev->info) {
681 ret = VM_FAULT_SIGBUS;
682 goto out;
683 }
684
685 mi = uio_find_mem_index(vmf->vma);
686 if (mi < 0) {
687 ret = VM_FAULT_SIGBUS;
688 goto out;
689 }
690
691 /*
692 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
693 * to use mem[N].
694 */
695 offset = (vmf->pgoff - mi) << PAGE_SHIFT;
696
697 addr = (void *)(unsigned long)idev->info->mem[mi].addr + offset;
698 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
699 page = virt_to_page(addr);
700 else
701 page = vmalloc_to_page(addr);
702 get_page(page);
703 vmf->page = page;
704
705out:
706 mutex_unlock(&idev->info_lock);
707
708 return ret;
709}
710
711static const struct vm_operations_struct uio_logical_vm_ops = {
712 .fault = uio_vma_fault,
713};
714
715static int uio_mmap_logical(struct vm_area_struct *vma)
716{
717 vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP);
718 vma->vm_ops = &uio_logical_vm_ops;
719 return 0;
720}
721
722static const struct vm_operations_struct uio_physical_vm_ops = {
723#ifdef CONFIG_HAVE_IOREMAP_PROT
724 .access = generic_access_phys,
725#endif
726};
727
728static int uio_mmap_physical(struct vm_area_struct *vma)
729{
730 struct uio_device *idev = vma->vm_private_data;
731 int mi = uio_find_mem_index(vma);
732 struct uio_mem *mem;
733
734 if (mi < 0)
735 return -EINVAL;
736 mem = idev->info->mem + mi;
737
738 if (mem->addr & ~PAGE_MASK)
739 return -ENODEV;
740 if (vma->vm_end - vma->vm_start > mem->size)
741 return -EINVAL;
742
743 vma->vm_ops = &uio_physical_vm_ops;
744 if (idev->info->mem[mi].memtype == UIO_MEM_PHYS)
745 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
746
747 /*
748 * We cannot use the vm_iomap_memory() helper here,
749 * because vma->vm_pgoff is the map index we looked
750 * up above in uio_find_mem_index(), rather than an
751 * actual page offset into the mmap.
752 *
753 * So we just do the physical mmap without a page
754 * offset.
755 */
756 return remap_pfn_range(vma,
757 vma->vm_start,
758 mem->addr >> PAGE_SHIFT,
759 vma->vm_end - vma->vm_start,
760 vma->vm_page_prot);
761}
762
763static int uio_mmap_dma_coherent(struct vm_area_struct *vma)
764{
765 struct uio_device *idev = vma->vm_private_data;
766 struct uio_mem *mem;
767 void *addr;
768 int ret = 0;
769 int mi;
770
771 mi = uio_find_mem_index(vma);
772 if (mi < 0)
773 return -EINVAL;
774
775 mem = idev->info->mem + mi;
776
777 if (mem->addr & ~PAGE_MASK)
778 return -ENODEV;
779 if (mem->dma_addr & ~PAGE_MASK)
780 return -ENODEV;
781 if (!mem->dma_device)
782 return -ENODEV;
783 if (vma->vm_end - vma->vm_start > mem->size)
784 return -EINVAL;
785
786 dev_warn(mem->dma_device,
787 "use of UIO_MEM_DMA_COHERENT is highly discouraged");
788
789 /*
790 * UIO uses offset to index into the maps for a device.
791 * We need to clear vm_pgoff for dma_mmap_coherent.
792 */
793 vma->vm_pgoff = 0;
794
795 addr = (void *)(uintptr_t)mem->addr;
796 ret = dma_mmap_coherent(mem->dma_device,
797 vma,
798 addr,
799 mem->dma_addr,
800 vma->vm_end - vma->vm_start);
801 vma->vm_pgoff = mi;
802
803 return ret;
804}
805
806static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
807{
808 struct uio_listener *listener = filep->private_data;
809 struct uio_device *idev = listener->dev;
810 int mi;
811 unsigned long requested_pages, actual_pages;
812 int ret = 0;
813
814 if (vma->vm_end < vma->vm_start)
815 return -EINVAL;
816
817 vma->vm_private_data = idev;
818
819 mutex_lock(&idev->info_lock);
820 if (!idev->info) {
821 ret = -EINVAL;
822 goto out;
823 }
824
825 mi = uio_find_mem_index(vma);
826 if (mi < 0) {
827 ret = -EINVAL;
828 goto out;
829 }
830
831 requested_pages = vma_pages(vma);
832 actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK)
833 + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
834 if (requested_pages > actual_pages) {
835 ret = -EINVAL;
836 goto out;
837 }
838
839 if (idev->info->mmap) {
840 ret = idev->info->mmap(idev->info, vma);
841 goto out;
842 }
843
844 switch (idev->info->mem[mi].memtype) {
845 case UIO_MEM_IOVA:
846 case UIO_MEM_PHYS:
847 ret = uio_mmap_physical(vma);
848 break;
849 case UIO_MEM_LOGICAL:
850 case UIO_MEM_VIRTUAL:
851 ret = uio_mmap_logical(vma);
852 break;
853 case UIO_MEM_DMA_COHERENT:
854 ret = uio_mmap_dma_coherent(vma);
855 break;
856 default:
857 ret = -EINVAL;
858 }
859
860 out:
861 mutex_unlock(&idev->info_lock);
862 return ret;
863}
864
865static const struct file_operations uio_fops = {
866 .owner = THIS_MODULE,
867 .open = uio_open,
868 .release = uio_release,
869 .read = uio_read,
870 .write = uio_write,
871 .mmap = uio_mmap,
872 .poll = uio_poll,
873 .fasync = uio_fasync,
874 .llseek = noop_llseek,
875};
876
877static int uio_major_init(void)
878{
879 static const char name[] = "uio";
880 struct cdev *cdev = NULL;
881 dev_t uio_dev = 0;
882 int result;
883
884 result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name);
885 if (result)
886 goto out;
887
888 result = -ENOMEM;
889 cdev = cdev_alloc();
890 if (!cdev)
891 goto out_unregister;
892
893 cdev->owner = THIS_MODULE;
894 cdev->ops = &uio_fops;
895 kobject_set_name(&cdev->kobj, "%s", name);
896
897 result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES);
898 if (result)
899 goto out_put;
900
901 uio_major = MAJOR(uio_dev);
902 uio_cdev = cdev;
903 return 0;
904out_put:
905 kobject_put(&cdev->kobj);
906out_unregister:
907 unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES);
908out:
909 return result;
910}
911
912static void uio_major_cleanup(void)
913{
914 unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES);
915 cdev_del(uio_cdev);
916}
917
918static int init_uio_class(void)
919{
920 int ret;
921
922 /* This is the first time in here, set everything up properly */
923 ret = uio_major_init();
924 if (ret)
925 goto exit;
926
927 ret = class_register(&uio_class);
928 if (ret) {
929 printk(KERN_ERR "class_register failed for uio\n");
930 goto err_class_register;
931 }
932
933 uio_class_registered = true;
934
935 return 0;
936
937err_class_register:
938 uio_major_cleanup();
939exit:
940 return ret;
941}
942
943static void release_uio_class(void)
944{
945 uio_class_registered = false;
946 class_unregister(&uio_class);
947 uio_major_cleanup();
948}
949
950static void uio_device_release(struct device *dev)
951{
952 struct uio_device *idev = dev_get_drvdata(dev);
953
954 kfree(idev);
955}
956
957/**
958 * __uio_register_device - register a new userspace IO device
959 * @owner: module that creates the new device
960 * @parent: parent device
961 * @info: UIO device capabilities
962 *
963 * returns zero on success or a negative error code.
964 */
965int __uio_register_device(struct module *owner,
966 struct device *parent,
967 struct uio_info *info)
968{
969 struct uio_device *idev;
970 int ret = 0;
971
972 if (!uio_class_registered)
973 return -EPROBE_DEFER;
974
975 if (!parent || !info || !info->name || !info->version)
976 return -EINVAL;
977
978 info->uio_dev = NULL;
979
980 idev = kzalloc(sizeof(*idev), GFP_KERNEL);
981 if (!idev) {
982 return -ENOMEM;
983 }
984
985 idev->owner = owner;
986 idev->info = info;
987 mutex_init(&idev->info_lock);
988 init_waitqueue_head(&idev->wait);
989 atomic_set(&idev->event, 0);
990
991 ret = uio_get_minor(idev);
992 if (ret) {
993 kfree(idev);
994 return ret;
995 }
996
997 device_initialize(&idev->dev);
998 idev->dev.devt = MKDEV(uio_major, idev->minor);
999 idev->dev.class = &uio_class;
1000 idev->dev.parent = parent;
1001 idev->dev.release = uio_device_release;
1002 dev_set_drvdata(&idev->dev, idev);
1003
1004 ret = dev_set_name(&idev->dev, "uio%d", idev->minor);
1005 if (ret)
1006 goto err_device_create;
1007
1008 ret = device_add(&idev->dev);
1009 if (ret)
1010 goto err_device_create;
1011
1012 ret = uio_dev_add_attributes(idev);
1013 if (ret)
1014 goto err_uio_dev_add_attributes;
1015
1016 info->uio_dev = idev;
1017
1018 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) {
1019 /*
1020 * Note that we deliberately don't use devm_request_irq
1021 * here. The parent module can unregister the UIO device
1022 * and call pci_disable_msi, which requires that this
1023 * irq has been freed. However, the device may have open
1024 * FDs at the time of unregister and therefore may not be
1025 * freed until they are released.
1026 */
1027 ret = request_irq(info->irq, uio_interrupt,
1028 info->irq_flags, info->name, idev);
1029 if (ret) {
1030 info->uio_dev = NULL;
1031 goto err_request_irq;
1032 }
1033 }
1034
1035 return 0;
1036
1037err_request_irq:
1038 uio_dev_del_attributes(idev);
1039err_uio_dev_add_attributes:
1040 device_del(&idev->dev);
1041err_device_create:
1042 uio_free_minor(idev->minor);
1043 put_device(&idev->dev);
1044 return ret;
1045}
1046EXPORT_SYMBOL_GPL(__uio_register_device);
1047
1048static void devm_uio_unregister_device(struct device *dev, void *res)
1049{
1050 uio_unregister_device(*(struct uio_info **)res);
1051}
1052
1053/**
1054 * __devm_uio_register_device - Resource managed uio_register_device()
1055 * @owner: module that creates the new device
1056 * @parent: parent device
1057 * @info: UIO device capabilities
1058 *
1059 * returns zero on success or a negative error code.
1060 */
1061int __devm_uio_register_device(struct module *owner,
1062 struct device *parent,
1063 struct uio_info *info)
1064{
1065 struct uio_info **ptr;
1066 int ret;
1067
1068 ptr = devres_alloc(devm_uio_unregister_device, sizeof(*ptr),
1069 GFP_KERNEL);
1070 if (!ptr)
1071 return -ENOMEM;
1072
1073 *ptr = info;
1074 ret = __uio_register_device(owner, parent, info);
1075 if (ret) {
1076 devres_free(ptr);
1077 return ret;
1078 }
1079
1080 devres_add(parent, ptr);
1081
1082 return 0;
1083}
1084EXPORT_SYMBOL_GPL(__devm_uio_register_device);
1085
1086/**
1087 * uio_unregister_device - unregister a industrial IO device
1088 * @info: UIO device capabilities
1089 *
1090 */
1091void uio_unregister_device(struct uio_info *info)
1092{
1093 struct uio_device *idev;
1094 unsigned long minor;
1095
1096 if (!info || !info->uio_dev)
1097 return;
1098
1099 idev = info->uio_dev;
1100 minor = idev->minor;
1101
1102 mutex_lock(&idev->info_lock);
1103 uio_dev_del_attributes(idev);
1104
1105 if (info->irq && info->irq != UIO_IRQ_CUSTOM)
1106 free_irq(info->irq, idev);
1107
1108 idev->info = NULL;
1109 mutex_unlock(&idev->info_lock);
1110
1111 wake_up_interruptible(&idev->wait);
1112 kill_fasync(&idev->async_queue, SIGIO, POLL_HUP);
1113
1114 uio_free_minor(minor);
1115 device_unregister(&idev->dev);
1116
1117 return;
1118}
1119EXPORT_SYMBOL_GPL(uio_unregister_device);
1120
1121static int __init uio_init(void)
1122{
1123 return init_uio_class();
1124}
1125
1126static void __exit uio_exit(void)
1127{
1128 release_uio_class();
1129 idr_destroy(&uio_idr);
1130}
1131
1132module_init(uio_init)
1133module_exit(uio_exit)
1134MODULE_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
31struct uio_device {
32 struct module *owner;
33 struct device *dev;
34 int minor;
35 atomic_t event;
36 struct fasync_struct *async_queue;
37 wait_queue_head_t wait;
38 struct uio_info *info;
39 struct kobject *map_dir;
40 struct kobject *portio_dir;
41};
42
43static int uio_major;
44static struct cdev *uio_cdev;
45static DEFINE_IDR(uio_idr);
46static const struct file_operations uio_fops;
47
48/* Protect idr accesses */
49static DEFINE_MUTEX(minor_lock);
50
51/*
52 * attributes
53 */
54
55struct uio_map {
56 struct kobject kobj;
57 struct uio_mem *mem;
58};
59#define to_map(map) container_of(map, struct uio_map, kobj)
60
61static ssize_t map_name_show(struct uio_mem *mem, char *buf)
62{
63 if (unlikely(!mem->name))
64 mem->name = "";
65
66 return sprintf(buf, "%s\n", mem->name);
67}
68
69static ssize_t map_addr_show(struct uio_mem *mem, char *buf)
70{
71 return sprintf(buf, "0x%llx\n", (unsigned long long)mem->addr);
72}
73
74static ssize_t map_size_show(struct uio_mem *mem, char *buf)
75{
76 return sprintf(buf, "0x%lx\n", mem->size);
77}
78
79static ssize_t map_offset_show(struct uio_mem *mem, char *buf)
80{
81 return sprintf(buf, "0x%llx\n", (unsigned long long)mem->addr & ~PAGE_MASK);
82}
83
84struct map_sysfs_entry {
85 struct attribute attr;
86 ssize_t (*show)(struct uio_mem *, char *);
87 ssize_t (*store)(struct uio_mem *, const char *, size_t);
88};
89
90static struct map_sysfs_entry name_attribute =
91 __ATTR(name, S_IRUGO, map_name_show, NULL);
92static struct map_sysfs_entry addr_attribute =
93 __ATTR(addr, S_IRUGO, map_addr_show, NULL);
94static struct map_sysfs_entry size_attribute =
95 __ATTR(size, S_IRUGO, map_size_show, NULL);
96static struct map_sysfs_entry offset_attribute =
97 __ATTR(offset, S_IRUGO, map_offset_show, NULL);
98
99static struct attribute *attrs[] = {
100 &name_attribute.attr,
101 &addr_attribute.attr,
102 &size_attribute.attr,
103 &offset_attribute.attr,
104 NULL, /* need to NULL terminate the list of attributes */
105};
106
107static void map_release(struct kobject *kobj)
108{
109 struct uio_map *map = to_map(kobj);
110 kfree(map);
111}
112
113static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr,
114 char *buf)
115{
116 struct uio_map *map = to_map(kobj);
117 struct uio_mem *mem = map->mem;
118 struct map_sysfs_entry *entry;
119
120 entry = container_of(attr, struct map_sysfs_entry, attr);
121
122 if (!entry->show)
123 return -EIO;
124
125 return entry->show(mem, buf);
126}
127
128static const struct sysfs_ops map_sysfs_ops = {
129 .show = map_type_show,
130};
131
132static struct kobj_type map_attr_type = {
133 .release = map_release,
134 .sysfs_ops = &map_sysfs_ops,
135 .default_attrs = attrs,
136};
137
138struct uio_portio {
139 struct kobject kobj;
140 struct uio_port *port;
141};
142#define to_portio(portio) container_of(portio, struct uio_portio, kobj)
143
144static ssize_t portio_name_show(struct uio_port *port, char *buf)
145{
146 if (unlikely(!port->name))
147 port->name = "";
148
149 return sprintf(buf, "%s\n", port->name);
150}
151
152static ssize_t portio_start_show(struct uio_port *port, char *buf)
153{
154 return sprintf(buf, "0x%lx\n", port->start);
155}
156
157static ssize_t portio_size_show(struct uio_port *port, char *buf)
158{
159 return sprintf(buf, "0x%lx\n", port->size);
160}
161
162static ssize_t portio_porttype_show(struct uio_port *port, char *buf)
163{
164 const char *porttypes[] = {"none", "x86", "gpio", "other"};
165
166 if ((port->porttype < 0) || (port->porttype > UIO_PORT_OTHER))
167 return -EINVAL;
168
169 return sprintf(buf, "port_%s\n", porttypes[port->porttype]);
170}
171
172struct portio_sysfs_entry {
173 struct attribute attr;
174 ssize_t (*show)(struct uio_port *, char *);
175 ssize_t (*store)(struct uio_port *, const char *, size_t);
176};
177
178static struct portio_sysfs_entry portio_name_attribute =
179 __ATTR(name, S_IRUGO, portio_name_show, NULL);
180static struct portio_sysfs_entry portio_start_attribute =
181 __ATTR(start, S_IRUGO, portio_start_show, NULL);
182static struct portio_sysfs_entry portio_size_attribute =
183 __ATTR(size, S_IRUGO, portio_size_show, NULL);
184static struct portio_sysfs_entry portio_porttype_attribute =
185 __ATTR(porttype, S_IRUGO, portio_porttype_show, NULL);
186
187static struct attribute *portio_attrs[] = {
188 &portio_name_attribute.attr,
189 &portio_start_attribute.attr,
190 &portio_size_attribute.attr,
191 &portio_porttype_attribute.attr,
192 NULL,
193};
194
195static void portio_release(struct kobject *kobj)
196{
197 struct uio_portio *portio = to_portio(kobj);
198 kfree(portio);
199}
200
201static ssize_t portio_type_show(struct kobject *kobj, struct attribute *attr,
202 char *buf)
203{
204 struct uio_portio *portio = to_portio(kobj);
205 struct uio_port *port = portio->port;
206 struct portio_sysfs_entry *entry;
207
208 entry = container_of(attr, struct portio_sysfs_entry, attr);
209
210 if (!entry->show)
211 return -EIO;
212
213 return entry->show(port, buf);
214}
215
216static const struct sysfs_ops portio_sysfs_ops = {
217 .show = portio_type_show,
218};
219
220static struct kobj_type portio_attr_type = {
221 .release = portio_release,
222 .sysfs_ops = &portio_sysfs_ops,
223 .default_attrs = portio_attrs,
224};
225
226static ssize_t name_show(struct device *dev,
227 struct device_attribute *attr, char *buf)
228{
229 struct uio_device *idev = dev_get_drvdata(dev);
230 return sprintf(buf, "%s\n", idev->info->name);
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 return sprintf(buf, "%s\n", idev->info->version);
239}
240static DEVICE_ATTR_RO(version);
241
242static ssize_t event_show(struct device *dev,
243 struct device_attribute *attr, char *buf)
244{
245 struct uio_device *idev = dev_get_drvdata(dev);
246 return sprintf(buf, "%u\n", (unsigned int)atomic_read(&idev->event));
247}
248static DEVICE_ATTR_RO(event);
249
250static struct attribute *uio_attrs[] = {
251 &dev_attr_name.attr,
252 &dev_attr_version.attr,
253 &dev_attr_event.attr,
254 NULL,
255};
256ATTRIBUTE_GROUPS(uio);
257
258/* UIO class infrastructure */
259static struct class uio_class = {
260 .name = "uio",
261 .dev_groups = uio_groups,
262};
263
264/*
265 * device functions
266 */
267static int uio_dev_add_attributes(struct uio_device *idev)
268{
269 int ret;
270 int mi, pi;
271 int map_found = 0;
272 int portio_found = 0;
273 struct uio_mem *mem;
274 struct uio_map *map;
275 struct uio_port *port;
276 struct uio_portio *portio;
277
278 for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
279 mem = &idev->info->mem[mi];
280 if (mem->size == 0)
281 break;
282 if (!map_found) {
283 map_found = 1;
284 idev->map_dir = kobject_create_and_add("maps",
285 &idev->dev->kobj);
286 if (!idev->map_dir)
287 goto err_map;
288 }
289 map = kzalloc(sizeof(*map), GFP_KERNEL);
290 if (!map)
291 goto err_map_kobj;
292 kobject_init(&map->kobj, &map_attr_type);
293 map->mem = mem;
294 mem->map = map;
295 ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi);
296 if (ret)
297 goto err_map_kobj;
298 ret = kobject_uevent(&map->kobj, KOBJ_ADD);
299 if (ret)
300 goto err_map;
301 }
302
303 for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) {
304 port = &idev->info->port[pi];
305 if (port->size == 0)
306 break;
307 if (!portio_found) {
308 portio_found = 1;
309 idev->portio_dir = kobject_create_and_add("portio",
310 &idev->dev->kobj);
311 if (!idev->portio_dir)
312 goto err_portio;
313 }
314 portio = kzalloc(sizeof(*portio), GFP_KERNEL);
315 if (!portio)
316 goto err_portio_kobj;
317 kobject_init(&portio->kobj, &portio_attr_type);
318 portio->port = port;
319 port->portio = portio;
320 ret = kobject_add(&portio->kobj, idev->portio_dir,
321 "port%d", pi);
322 if (ret)
323 goto err_portio_kobj;
324 ret = kobject_uevent(&portio->kobj, KOBJ_ADD);
325 if (ret)
326 goto err_portio;
327 }
328
329 return 0;
330
331err_portio:
332 pi--;
333err_portio_kobj:
334 for (; pi >= 0; pi--) {
335 port = &idev->info->port[pi];
336 portio = port->portio;
337 kobject_put(&portio->kobj);
338 }
339 kobject_put(idev->portio_dir);
340err_map:
341 mi--;
342err_map_kobj:
343 for (; mi >= 0; mi--) {
344 mem = &idev->info->mem[mi];
345 map = mem->map;
346 kobject_put(&map->kobj);
347 }
348 kobject_put(idev->map_dir);
349 dev_err(idev->dev, "error creating sysfs files (%d)\n", ret);
350 return ret;
351}
352
353static void uio_dev_del_attributes(struct uio_device *idev)
354{
355 int i;
356 struct uio_mem *mem;
357 struct uio_port *port;
358
359 for (i = 0; i < MAX_UIO_MAPS; i++) {
360 mem = &idev->info->mem[i];
361 if (mem->size == 0)
362 break;
363 kobject_put(&mem->map->kobj);
364 }
365 kobject_put(idev->map_dir);
366
367 for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) {
368 port = &idev->info->port[i];
369 if (port->size == 0)
370 break;
371 kobject_put(&port->portio->kobj);
372 }
373 kobject_put(idev->portio_dir);
374}
375
376static int uio_get_minor(struct uio_device *idev)
377{
378 int retval = -ENOMEM;
379
380 mutex_lock(&minor_lock);
381 retval = idr_alloc(&uio_idr, idev, 0, UIO_MAX_DEVICES, GFP_KERNEL);
382 if (retval >= 0) {
383 idev->minor = retval;
384 retval = 0;
385 } else if (retval == -ENOSPC) {
386 dev_err(idev->dev, "too many uio devices\n");
387 retval = -EINVAL;
388 }
389 mutex_unlock(&minor_lock);
390 return retval;
391}
392
393static void uio_free_minor(struct uio_device *idev)
394{
395 mutex_lock(&minor_lock);
396 idr_remove(&uio_idr, idev->minor);
397 mutex_unlock(&minor_lock);
398}
399
400/**
401 * uio_event_notify - trigger an interrupt event
402 * @info: UIO device capabilities
403 */
404void uio_event_notify(struct uio_info *info)
405{
406 struct uio_device *idev = info->uio_dev;
407
408 atomic_inc(&idev->event);
409 wake_up_interruptible(&idev->wait);
410 kill_fasync(&idev->async_queue, SIGIO, POLL_IN);
411}
412EXPORT_SYMBOL_GPL(uio_event_notify);
413
414/**
415 * uio_interrupt - hardware interrupt handler
416 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer
417 * @dev_id: Pointer to the devices uio_device structure
418 */
419static irqreturn_t uio_interrupt(int irq, void *dev_id)
420{
421 struct uio_device *idev = (struct uio_device *)dev_id;
422 irqreturn_t ret = idev->info->handler(irq, idev->info);
423
424 if (ret == IRQ_HANDLED)
425 uio_event_notify(idev->info);
426
427 return ret;
428}
429
430struct uio_listener {
431 struct uio_device *dev;
432 s32 event_count;
433};
434
435static int uio_open(struct inode *inode, struct file *filep)
436{
437 struct uio_device *idev;
438 struct uio_listener *listener;
439 int ret = 0;
440
441 mutex_lock(&minor_lock);
442 idev = idr_find(&uio_idr, iminor(inode));
443 mutex_unlock(&minor_lock);
444 if (!idev) {
445 ret = -ENODEV;
446 goto out;
447 }
448
449 if (!try_module_get(idev->owner)) {
450 ret = -ENODEV;
451 goto out;
452 }
453
454 listener = kmalloc(sizeof(*listener), GFP_KERNEL);
455 if (!listener) {
456 ret = -ENOMEM;
457 goto err_alloc_listener;
458 }
459
460 listener->dev = idev;
461 listener->event_count = atomic_read(&idev->event);
462 filep->private_data = listener;
463
464 if (idev->info->open) {
465 ret = idev->info->open(idev->info, inode);
466 if (ret)
467 goto err_infoopen;
468 }
469 return 0;
470
471err_infoopen:
472 kfree(listener);
473
474err_alloc_listener:
475 module_put(idev->owner);
476
477out:
478 return ret;
479}
480
481static int uio_fasync(int fd, struct file *filep, int on)
482{
483 struct uio_listener *listener = filep->private_data;
484 struct uio_device *idev = listener->dev;
485
486 return fasync_helper(fd, filep, on, &idev->async_queue);
487}
488
489static int uio_release(struct inode *inode, struct file *filep)
490{
491 int ret = 0;
492 struct uio_listener *listener = filep->private_data;
493 struct uio_device *idev = listener->dev;
494
495 if (idev->info->release)
496 ret = idev->info->release(idev->info, inode);
497
498 module_put(idev->owner);
499 kfree(listener);
500 return ret;
501}
502
503static unsigned int uio_poll(struct file *filep, poll_table *wait)
504{
505 struct uio_listener *listener = filep->private_data;
506 struct uio_device *idev = listener->dev;
507
508 if (!idev->info->irq)
509 return -EIO;
510
511 poll_wait(filep, &idev->wait, wait);
512 if (listener->event_count != atomic_read(&idev->event))
513 return POLLIN | POLLRDNORM;
514 return 0;
515}
516
517static ssize_t uio_read(struct file *filep, char __user *buf,
518 size_t count, loff_t *ppos)
519{
520 struct uio_listener *listener = filep->private_data;
521 struct uio_device *idev = listener->dev;
522 DECLARE_WAITQUEUE(wait, current);
523 ssize_t retval;
524 s32 event_count;
525
526 if (!idev->info->irq)
527 return -EIO;
528
529 if (count != sizeof(s32))
530 return -EINVAL;
531
532 add_wait_queue(&idev->wait, &wait);
533
534 do {
535 set_current_state(TASK_INTERRUPTIBLE);
536
537 event_count = atomic_read(&idev->event);
538 if (event_count != listener->event_count) {
539 if (copy_to_user(buf, &event_count, count))
540 retval = -EFAULT;
541 else {
542 listener->event_count = event_count;
543 retval = count;
544 }
545 break;
546 }
547
548 if (filep->f_flags & O_NONBLOCK) {
549 retval = -EAGAIN;
550 break;
551 }
552
553 if (signal_pending(current)) {
554 retval = -ERESTARTSYS;
555 break;
556 }
557 schedule();
558 } while (1);
559
560 __set_current_state(TASK_RUNNING);
561 remove_wait_queue(&idev->wait, &wait);
562
563 return retval;
564}
565
566static ssize_t uio_write(struct file *filep, const char __user *buf,
567 size_t count, loff_t *ppos)
568{
569 struct uio_listener *listener = filep->private_data;
570 struct uio_device *idev = listener->dev;
571 ssize_t retval;
572 s32 irq_on;
573
574 if (!idev->info->irq)
575 return -EIO;
576
577 if (count != sizeof(s32))
578 return -EINVAL;
579
580 if (!idev->info->irqcontrol)
581 return -ENOSYS;
582
583 if (copy_from_user(&irq_on, buf, count))
584 return -EFAULT;
585
586 retval = idev->info->irqcontrol(idev->info, irq_on);
587
588 return retval ? retval : sizeof(s32);
589}
590
591static int uio_find_mem_index(struct vm_area_struct *vma)
592{
593 struct uio_device *idev = vma->vm_private_data;
594
595 if (vma->vm_pgoff < MAX_UIO_MAPS) {
596 if (idev->info->mem[vma->vm_pgoff].size == 0)
597 return -1;
598 return (int)vma->vm_pgoff;
599 }
600 return -1;
601}
602
603static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
604{
605 struct uio_device *idev = vma->vm_private_data;
606 struct page *page;
607 unsigned long offset;
608 void *addr;
609
610 int mi = uio_find_mem_index(vma);
611 if (mi < 0)
612 return VM_FAULT_SIGBUS;
613
614 /*
615 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
616 * to use mem[N].
617 */
618 offset = (vmf->pgoff - mi) << PAGE_SHIFT;
619
620 addr = (void *)(unsigned long)idev->info->mem[mi].addr + offset;
621 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
622 page = virt_to_page(addr);
623 else
624 page = vmalloc_to_page(addr);
625 get_page(page);
626 vmf->page = page;
627 return 0;
628}
629
630static const struct vm_operations_struct uio_logical_vm_ops = {
631 .fault = uio_vma_fault,
632};
633
634static int uio_mmap_logical(struct vm_area_struct *vma)
635{
636 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
637 vma->vm_ops = &uio_logical_vm_ops;
638 return 0;
639}
640
641static const struct vm_operations_struct uio_physical_vm_ops = {
642#ifdef CONFIG_HAVE_IOREMAP_PROT
643 .access = generic_access_phys,
644#endif
645};
646
647static int uio_mmap_physical(struct vm_area_struct *vma)
648{
649 struct uio_device *idev = vma->vm_private_data;
650 int mi = uio_find_mem_index(vma);
651 struct uio_mem *mem;
652 if (mi < 0)
653 return -EINVAL;
654 mem = idev->info->mem + mi;
655
656 if (mem->addr & ~PAGE_MASK)
657 return -ENODEV;
658 if (vma->vm_end - vma->vm_start > mem->size)
659 return -EINVAL;
660
661 vma->vm_ops = &uio_physical_vm_ops;
662 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
663
664 /*
665 * We cannot use the vm_iomap_memory() helper here,
666 * because vma->vm_pgoff is the map index we looked
667 * up above in uio_find_mem_index(), rather than an
668 * actual page offset into the mmap.
669 *
670 * So we just do the physical mmap without a page
671 * offset.
672 */
673 return remap_pfn_range(vma,
674 vma->vm_start,
675 mem->addr >> PAGE_SHIFT,
676 vma->vm_end - vma->vm_start,
677 vma->vm_page_prot);
678}
679
680static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
681{
682 struct uio_listener *listener = filep->private_data;
683 struct uio_device *idev = listener->dev;
684 int mi;
685 unsigned long requested_pages, actual_pages;
686 int ret = 0;
687
688 if (vma->vm_end < vma->vm_start)
689 return -EINVAL;
690
691 vma->vm_private_data = idev;
692
693 mi = uio_find_mem_index(vma);
694 if (mi < 0)
695 return -EINVAL;
696
697 requested_pages = vma_pages(vma);
698 actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK)
699 + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
700 if (requested_pages > actual_pages)
701 return -EINVAL;
702
703 if (idev->info->mmap) {
704 ret = idev->info->mmap(idev->info, vma);
705 return ret;
706 }
707
708 switch (idev->info->mem[mi].memtype) {
709 case UIO_MEM_PHYS:
710 return uio_mmap_physical(vma);
711 case UIO_MEM_LOGICAL:
712 case UIO_MEM_VIRTUAL:
713 return uio_mmap_logical(vma);
714 default:
715 return -EINVAL;
716 }
717}
718
719static const struct file_operations uio_fops = {
720 .owner = THIS_MODULE,
721 .open = uio_open,
722 .release = uio_release,
723 .read = uio_read,
724 .write = uio_write,
725 .mmap = uio_mmap,
726 .poll = uio_poll,
727 .fasync = uio_fasync,
728 .llseek = noop_llseek,
729};
730
731static int uio_major_init(void)
732{
733 static const char name[] = "uio";
734 struct cdev *cdev = NULL;
735 dev_t uio_dev = 0;
736 int result;
737
738 result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name);
739 if (result)
740 goto out;
741
742 result = -ENOMEM;
743 cdev = cdev_alloc();
744 if (!cdev)
745 goto out_unregister;
746
747 cdev->owner = THIS_MODULE;
748 cdev->ops = &uio_fops;
749 kobject_set_name(&cdev->kobj, "%s", name);
750
751 result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES);
752 if (result)
753 goto out_put;
754
755 uio_major = MAJOR(uio_dev);
756 uio_cdev = cdev;
757 return 0;
758out_put:
759 kobject_put(&cdev->kobj);
760out_unregister:
761 unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES);
762out:
763 return result;
764}
765
766static void uio_major_cleanup(void)
767{
768 unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES);
769 cdev_del(uio_cdev);
770}
771
772static int init_uio_class(void)
773{
774 int ret;
775
776 /* This is the first time in here, set everything up properly */
777 ret = uio_major_init();
778 if (ret)
779 goto exit;
780
781 ret = class_register(&uio_class);
782 if (ret) {
783 printk(KERN_ERR "class_register failed for uio\n");
784 goto err_class_register;
785 }
786 return 0;
787
788err_class_register:
789 uio_major_cleanup();
790exit:
791 return ret;
792}
793
794static void release_uio_class(void)
795{
796 class_unregister(&uio_class);
797 uio_major_cleanup();
798}
799
800/**
801 * uio_register_device - register a new userspace IO device
802 * @owner: module that creates the new device
803 * @parent: parent device
804 * @info: UIO device capabilities
805 *
806 * returns zero on success or a negative error code.
807 */
808int __uio_register_device(struct module *owner,
809 struct device *parent,
810 struct uio_info *info)
811{
812 struct uio_device *idev;
813 int ret = 0;
814
815 if (!parent || !info || !info->name || !info->version)
816 return -EINVAL;
817
818 info->uio_dev = NULL;
819
820 idev = devm_kzalloc(parent, sizeof(*idev), GFP_KERNEL);
821 if (!idev) {
822 return -ENOMEM;
823 }
824
825 idev->owner = owner;
826 idev->info = info;
827 init_waitqueue_head(&idev->wait);
828 atomic_set(&idev->event, 0);
829
830 ret = uio_get_minor(idev);
831 if (ret)
832 return ret;
833
834 idev->dev = device_create(&uio_class, parent,
835 MKDEV(uio_major, idev->minor), idev,
836 "uio%d", idev->minor);
837 if (IS_ERR(idev->dev)) {
838 printk(KERN_ERR "UIO: device register failed\n");
839 ret = PTR_ERR(idev->dev);
840 goto err_device_create;
841 }
842
843 ret = uio_dev_add_attributes(idev);
844 if (ret)
845 goto err_uio_dev_add_attributes;
846
847 info->uio_dev = idev;
848
849 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) {
850 ret = devm_request_irq(idev->dev, info->irq, uio_interrupt,
851 info->irq_flags, info->name, idev);
852 if (ret)
853 goto err_request_irq;
854 }
855
856 return 0;
857
858err_request_irq:
859 uio_dev_del_attributes(idev);
860err_uio_dev_add_attributes:
861 device_destroy(&uio_class, MKDEV(uio_major, idev->minor));
862err_device_create:
863 uio_free_minor(idev);
864 return ret;
865}
866EXPORT_SYMBOL_GPL(__uio_register_device);
867
868/**
869 * uio_unregister_device - unregister a industrial IO device
870 * @info: UIO device capabilities
871 *
872 */
873void uio_unregister_device(struct uio_info *info)
874{
875 struct uio_device *idev;
876
877 if (!info || !info->uio_dev)
878 return;
879
880 idev = info->uio_dev;
881
882 uio_free_minor(idev);
883
884 uio_dev_del_attributes(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}
901
902module_init(uio_init)
903module_exit(uio_exit)
904MODULE_LICENSE("GPL v2");