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, fmt: "%s\n", mem->name);
55}
56
57static ssize_t map_addr_show(struct uio_mem *mem, char *buf)
58{
59 return sprintf(buf, fmt: "%pa\n", &mem->addr);
60}
61
62static ssize_t map_size_show(struct uio_mem *mem, char *buf)
63{
64 return sprintf(buf, fmt: "%pa\n", &mem->size);
65}
66
67static ssize_t map_offset_show(struct uio_mem *mem, char *buf)
68{
69 return sprintf(buf, fmt: "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(objp: 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, fmt: "%s\n", port->name);
139}
140
141static ssize_t portio_start_show(struct uio_port *port, char *buf)
142{
143 return sprintf(buf, fmt: "0x%lx\n", port->start);
144}
145
146static ssize_t portio_size_show(struct uio_port *port, char *buf)
147{
148 return sprintf(buf, fmt: "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, fmt: "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(objp: 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, fmt: "%s\n", idev->info->name);
230
231out:
232 mutex_unlock(lock: &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, fmt: "%s\n", idev->info->version);
251
252out:
253 mutex_unlock(lock: &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, fmt: "%u\n", (unsigned int)atomic_read(v: &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(name: "maps",
303 parent: &idev->dev.kobj);
304 if (!idev->map_dir) {
305 ret = -ENOMEM;
306 goto err_map;
307 }
308 }
309 map = kzalloc(size: sizeof(*map), GFP_KERNEL);
310 if (!map) {
311 ret = -ENOMEM;
312 goto err_map;
313 }
314 kobject_init(kobj: &map->kobj, ktype: &map_attr_type);
315 map->mem = mem;
316 mem->map = map;
317 ret = kobject_add(kobj: &map->kobj, parent: idev->map_dir, fmt: "map%d", mi);
318 if (ret)
319 goto err_map_kobj;
320 ret = kobject_uevent(kobj: &map->kobj, action: 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(name: "portio",
332 parent: &idev->dev.kobj);
333 if (!idev->portio_dir) {
334 ret = -ENOMEM;
335 goto err_portio;
336 }
337 }
338 portio = kzalloc(size: sizeof(*portio), GFP_KERNEL);
339 if (!portio) {
340 ret = -ENOMEM;
341 goto err_portio;
342 }
343 kobject_init(kobj: &portio->kobj, ktype: &portio_attr_type);
344 portio->port = port;
345 port->portio = portio;
346 ret = kobject_add(kobj: &portio->kobj, parent: idev->portio_dir,
347 fmt: "port%d", pi);
348 if (ret)
349 goto err_portio_kobj;
350 ret = kobject_uevent(kobj: &portio->kobj, action: 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(kobj: &portio->kobj);
364 }
365 kobject_put(kobj: 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(kobj: &map->kobj);
373 }
374 kobject_put(kobj: 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(kobj: &mem->map->kobj);
390 }
391 kobject_put(kobj: 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(kobj: &port->portio->kobj);
398 }
399 kobject_put(kobj: 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, ptr: idev, start: 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(lock: &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, id: minor);
423 mutex_unlock(lock: &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(v: &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, id: iminor(inode));
470 if (!idev) {
471 ret = -ENODEV;
472 mutex_unlock(lock: &minor_lock);
473 goto out;
474 }
475 get_device(dev: &idev->dev);
476 mutex_unlock(lock: &minor_lock);
477
478 if (!try_module_get(module: idev->owner)) {
479 ret = -ENODEV;
480 goto err_module_get;
481 }
482
483 listener = kmalloc(size: 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(v: &idev->event);
491 filep->private_data = listener;
492
493 mutex_lock(&idev->info_lock);
494 if (!idev->info) {
495 mutex_unlock(lock: &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(lock: &idev->info_lock);
503 if (ret)
504 goto err_infoopen;
505
506 return 0;
507
508err_infoopen:
509 kfree(objp: listener);
510
511err_alloc_listener:
512 module_put(module: idev->owner);
513
514err_module_get:
515 put_device(dev: &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(lock: &idev->info_lock);
539
540 module_put(module: idev->owner);
541 kfree(objp: listener);
542 put_device(dev: &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(lock: &idev->info_lock);
556
557 if (ret)
558 return ret;
559
560 poll_wait(filp: filep, wait_address: &idev->wait, p: wait);
561 if (listener->event_count != atomic_read(v: &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(wq_head: &idev->wait, wq_entry: &wait);
579
580 do {
581 mutex_lock(&idev->info_lock);
582 if (!idev->info || !idev->info->irq) {
583 retval = -EIO;
584 mutex_unlock(lock: &idev->info_lock);
585 break;
586 }
587 mutex_unlock(lock: &idev->info_lock);
588
589 set_current_state(TASK_INTERRUPTIBLE);
590
591 event_count = atomic_read(v: &idev->event);
592 if (event_count != listener->event_count) {
593 __set_current_state(TASK_RUNNING);
594 if (copy_to_user(to: buf, from: &event_count, n: 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(wq_head: &idev->wait, wq_entry: &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(to: &irq_on, from: buf, n: 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(lock: &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(vma: 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(lock: &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 addr: vma->vm_start,
758 pfn: mem->addr >> PAGE_SHIFT,
759 size: 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(lock: &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(kobj: &cdev->kobj, name: "%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(kobj: &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(class: &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(class: &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(objp: 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(size: 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(v: &idev->event, i: 0);
990
991 ret = uio_get_minor(idev);
992 if (ret) {
993 kfree(objp: idev);
994 return ret;
995 }
996
997 device_initialize(dev: &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(dev: &idev->dev, data: idev);
1003
1004 ret = dev_set_name(dev: &idev->dev, name: "uio%d", idev->minor);
1005 if (ret)
1006 goto err_device_create;
1007
1008 ret = device_add(dev: &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(irq: info->irq, handler: uio_interrupt,
1028 flags: info->irq_flags, name: info->name, dev: 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(dev: &idev->dev);
1041err_device_create:
1042 uio_free_minor(minor: idev->minor);
1043 put_device(dev: &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(info: *(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(res: ptr);
1077 return ret;
1078 }
1079
1080 devres_add(dev: parent, res: 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(lock: &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(dev: &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");
1135

source code of linux/drivers/uio/uio.c