blob: d2efe823c20dd7fc317a1ffc0e12c283138e531d [file] [log] [blame]
Hans J. Kochbeafc542006-12-07 10:58:29 +01001/*
2 * drivers/uio/uio.c
3 *
4 * Copyright(C) 2005, Benedikt Spranger <b.spranger@linutronix.de>
5 * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
Hans J. Koch318af552010-10-30 00:36:47 +02006 * Copyright(C) 2006, Hans J. Koch <hjk@hansjkoch.de>
Hans J. Kochbeafc542006-12-07 10:58:29 +01007 * 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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090020#include <linux/slab.h>
Hans J. Kochbeafc542006-12-07 10:58:29 +010021#include <linux/mm.h>
22#include <linux/idr.h>
Alexey Dobriyand43c36d2009-10-07 17:09:06 +040023#include <linux/sched.h>
Hans J. Kochbeafc542006-12-07 10:58:29 +010024#include <linux/string.h>
25#include <linux/kobject.h>
Eric W. Biederman91960a42010-09-14 11:38:06 -070026#include <linux/cdev.h>
Hans J. Kochbeafc542006-12-07 10:58:29 +010027#include <linux/uio_driver.h>
28
Eric W. Biederman91960a42010-09-14 11:38:06 -070029#define UIO_MAX_DEVICES (1U << MINORBITS)
Hans J. Kochbeafc542006-12-07 10:58:29 +010030
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 int vma_count;
39 struct uio_info *info;
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000040 struct kobject *map_dir;
Hans J. Koche70c4122008-12-06 02:23:13 +010041 struct kobject *portio_dir;
Hans J. Kochbeafc542006-12-07 10:58:29 +010042};
43
44static int uio_major;
Eric W. Biederman91960a42010-09-14 11:38:06 -070045static struct cdev *uio_cdev;
Hans J. Kochbeafc542006-12-07 10:58:29 +010046static DEFINE_IDR(uio_idr);
Jan Engelhardt4f014692008-01-22 20:50:54 +010047static const struct file_operations uio_fops;
Hans J. Kochbeafc542006-12-07 10:58:29 +010048
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -060049/* Protect idr accesses */
50static DEFINE_MUTEX(minor_lock);
51
Hans J. Kochbeafc542006-12-07 10:58:29 +010052/*
53 * attributes
54 */
55
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000056struct uio_map {
57 struct kobject kobj;
58 struct uio_mem *mem;
Hans J. Kochbeafc542006-12-07 10:58:29 +010059};
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000060#define to_map(map) container_of(map, struct uio_map, kobj)
Hans J. Kochbeafc542006-12-07 10:58:29 +010061
Hans J. Koch82057792009-01-07 00:15:39 +010062static ssize_t map_name_show(struct uio_mem *mem, char *buf)
63{
64 if (unlikely(!mem->name))
65 mem->name = "";
66
67 return sprintf(buf, "%s\n", mem->name);
68}
69
Brandon Philips4f808bc2008-02-19 01:55:05 -080070static ssize_t map_addr_show(struct uio_mem *mem, char *buf)
Hans J. Kochbeafc542006-12-07 10:58:29 +010071{
Brandon Philips4f808bc2008-02-19 01:55:05 -080072 return sprintf(buf, "0x%lx\n", mem->addr);
Hans J. Kochbeafc542006-12-07 10:58:29 +010073}
74
Brandon Philips4f808bc2008-02-19 01:55:05 -080075static ssize_t map_size_show(struct uio_mem *mem, char *buf)
76{
77 return sprintf(buf, "0x%lx\n", mem->size);
78}
79
Hans J. Koche2b39df2008-09-18 23:53:18 +020080static ssize_t map_offset_show(struct uio_mem *mem, char *buf)
81{
82 return sprintf(buf, "0x%lx\n", mem->addr & ~PAGE_MASK);
83}
84
Hans J. Koche70c4122008-12-06 02:23:13 +010085struct map_sysfs_entry {
Brandon Philips4f808bc2008-02-19 01:55:05 -080086 struct attribute attr;
87 ssize_t (*show)(struct uio_mem *, char *);
88 ssize_t (*store)(struct uio_mem *, const char *, size_t);
89};
90
Hans J. Koch82057792009-01-07 00:15:39 +010091static struct map_sysfs_entry name_attribute =
92 __ATTR(name, S_IRUGO, map_name_show, NULL);
Hans J. Koche70c4122008-12-06 02:23:13 +010093static struct map_sysfs_entry addr_attribute =
Brandon Philips4f808bc2008-02-19 01:55:05 -080094 __ATTR(addr, S_IRUGO, map_addr_show, NULL);
Hans J. Koche70c4122008-12-06 02:23:13 +010095static struct map_sysfs_entry size_attribute =
Brandon Philips4f808bc2008-02-19 01:55:05 -080096 __ATTR(size, S_IRUGO, map_size_show, NULL);
Hans J. Koche70c4122008-12-06 02:23:13 +010097static struct map_sysfs_entry offset_attribute =
Hans J. Koche2b39df2008-09-18 23:53:18 +020098 __ATTR(offset, S_IRUGO, map_offset_show, NULL);
Hans J. Kochbeafc542006-12-07 10:58:29 +010099
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000100static struct attribute *attrs[] = {
Hans J. Koch82057792009-01-07 00:15:39 +0100101 &name_attribute.attr,
Brandon Philips4f808bc2008-02-19 01:55:05 -0800102 &addr_attribute.attr,
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000103 &size_attribute.attr,
Hans J. Koche2b39df2008-09-18 23:53:18 +0200104 &offset_attribute.attr,
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000105 NULL, /* need to NULL terminate the list of attributes */
Hans J. Kochbeafc542006-12-07 10:58:29 +0100106};
107
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000108static void map_release(struct kobject *kobj)
109{
110 struct uio_map *map = to_map(kobj);
111 kfree(map);
112}
113
Brandon Philips4f808bc2008-02-19 01:55:05 -0800114static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr,
115 char *buf)
116{
117 struct uio_map *map = to_map(kobj);
118 struct uio_mem *mem = map->mem;
Hans J. Koche70c4122008-12-06 02:23:13 +0100119 struct map_sysfs_entry *entry;
Brandon Philips4f808bc2008-02-19 01:55:05 -0800120
Hans J. Koche70c4122008-12-06 02:23:13 +0100121 entry = container_of(attr, struct map_sysfs_entry, attr);
Brandon Philips4f808bc2008-02-19 01:55:05 -0800122
123 if (!entry->show)
124 return -EIO;
125
126 return entry->show(mem, buf);
127}
128
Emese Revfy52cf25d2010-01-19 02:58:23 +0100129static const struct sysfs_ops map_sysfs_ops = {
Brandon Philips4f808bc2008-02-19 01:55:05 -0800130 .show = map_type_show,
131};
132
Hans J. Kochbeafc542006-12-07 10:58:29 +0100133static struct kobj_type map_attr_type = {
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000134 .release = map_release,
Hans J. Koche70c4122008-12-06 02:23:13 +0100135 .sysfs_ops = &map_sysfs_ops,
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000136 .default_attrs = attrs,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100137};
138
Hans J. Koche70c4122008-12-06 02:23:13 +0100139struct uio_portio {
140 struct kobject kobj;
141 struct uio_port *port;
142};
143#define to_portio(portio) container_of(portio, struct uio_portio, kobj)
144
Hans J. Koch82057792009-01-07 00:15:39 +0100145static ssize_t portio_name_show(struct uio_port *port, char *buf)
146{
147 if (unlikely(!port->name))
148 port->name = "";
149
150 return sprintf(buf, "%s\n", port->name);
151}
152
Hans J. Koche70c4122008-12-06 02:23:13 +0100153static ssize_t portio_start_show(struct uio_port *port, char *buf)
154{
155 return sprintf(buf, "0x%lx\n", port->start);
156}
157
158static ssize_t portio_size_show(struct uio_port *port, char *buf)
159{
160 return sprintf(buf, "0x%lx\n", port->size);
161}
162
163static ssize_t portio_porttype_show(struct uio_port *port, char *buf)
164{
165 const char *porttypes[] = {"none", "x86", "gpio", "other"};
166
167 if ((port->porttype < 0) || (port->porttype > UIO_PORT_OTHER))
168 return -EINVAL;
169
170 return sprintf(buf, "port_%s\n", porttypes[port->porttype]);
171}
172
173struct portio_sysfs_entry {
174 struct attribute attr;
175 ssize_t (*show)(struct uio_port *, char *);
176 ssize_t (*store)(struct uio_port *, const char *, size_t);
177};
178
Hans J. Koch82057792009-01-07 00:15:39 +0100179static struct portio_sysfs_entry portio_name_attribute =
180 __ATTR(name, S_IRUGO, portio_name_show, NULL);
Hans J. Koche70c4122008-12-06 02:23:13 +0100181static struct portio_sysfs_entry portio_start_attribute =
182 __ATTR(start, S_IRUGO, portio_start_show, NULL);
183static struct portio_sysfs_entry portio_size_attribute =
184 __ATTR(size, S_IRUGO, portio_size_show, NULL);
185static struct portio_sysfs_entry portio_porttype_attribute =
186 __ATTR(porttype, S_IRUGO, portio_porttype_show, NULL);
187
188static struct attribute *portio_attrs[] = {
Hans J. Koch82057792009-01-07 00:15:39 +0100189 &portio_name_attribute.attr,
Hans J. Koche70c4122008-12-06 02:23:13 +0100190 &portio_start_attribute.attr,
191 &portio_size_attribute.attr,
192 &portio_porttype_attribute.attr,
193 NULL,
194};
195
196static void portio_release(struct kobject *kobj)
197{
198 struct uio_portio *portio = to_portio(kobj);
199 kfree(portio);
200}
201
202static ssize_t portio_type_show(struct kobject *kobj, struct attribute *attr,
203 char *buf)
204{
205 struct uio_portio *portio = to_portio(kobj);
206 struct uio_port *port = portio->port;
207 struct portio_sysfs_entry *entry;
208
209 entry = container_of(attr, struct portio_sysfs_entry, attr);
210
211 if (!entry->show)
212 return -EIO;
213
214 return entry->show(port, buf);
215}
216
Emese Revfy52cf25d2010-01-19 02:58:23 +0100217static const struct sysfs_ops portio_sysfs_ops = {
Hans J. Koche70c4122008-12-06 02:23:13 +0100218 .show = portio_type_show,
219};
220
221static struct kobj_type portio_attr_type = {
222 .release = portio_release,
223 .sysfs_ops = &portio_sysfs_ops,
224 .default_attrs = portio_attrs,
225};
226
Hans J. Kochbeafc542006-12-07 10:58:29 +0100227static ssize_t show_name(struct device *dev,
228 struct device_attribute *attr, char *buf)
229{
230 struct uio_device *idev = dev_get_drvdata(dev);
Eric W. Biederman70a91562010-09-14 11:36:54 -0700231 return sprintf(buf, "%s\n", idev->info->name);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100232}
Hans J. Kochbeafc542006-12-07 10:58:29 +0100233
234static ssize_t show_version(struct device *dev,
235 struct device_attribute *attr, char *buf)
236{
237 struct uio_device *idev = dev_get_drvdata(dev);
Eric W. Biederman70a91562010-09-14 11:36:54 -0700238 return sprintf(buf, "%s\n", idev->info->version);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100239}
Hans J. Kochbeafc542006-12-07 10:58:29 +0100240
241static ssize_t show_event(struct device *dev,
242 struct device_attribute *attr, char *buf)
243{
244 struct uio_device *idev = dev_get_drvdata(dev);
Eric W. Biederman70a91562010-09-14 11:36:54 -0700245 return sprintf(buf, "%u\n", (unsigned int)atomic_read(&idev->event));
Hans J. Kochbeafc542006-12-07 10:58:29 +0100246}
Hans J. Kochbeafc542006-12-07 10:58:29 +0100247
Eric W. Biedermanc66fdab2010-09-14 11:38:36 -0700248static struct device_attribute uio_class_attributes[] = {
249 __ATTR(name, S_IRUGO, show_name, NULL),
250 __ATTR(version, S_IRUGO, show_version, NULL),
251 __ATTR(event, S_IRUGO, show_event, NULL),
252 {}
Hans J. Kochbeafc542006-12-07 10:58:29 +0100253};
254
Eric W. Biedermanc66fdab2010-09-14 11:38:36 -0700255/* UIO class infrastructure */
256static struct class uio_class = {
257 .name = "uio",
258 .dev_attrs = uio_class_attributes,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100259};
260
261/*
262 * device functions
263 */
264static int uio_dev_add_attributes(struct uio_device *idev)
265{
266 int ret;
Hans J. Koche70c4122008-12-06 02:23:13 +0100267 int mi, pi;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100268 int map_found = 0;
Hans J. Koche70c4122008-12-06 02:23:13 +0100269 int portio_found = 0;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100270 struct uio_mem *mem;
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000271 struct uio_map *map;
Hans J. Koche70c4122008-12-06 02:23:13 +0100272 struct uio_port *port;
273 struct uio_portio *portio;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100274
Hans J. Kochbeafc542006-12-07 10:58:29 +0100275 for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
276 mem = &idev->info->mem[mi];
277 if (mem->size == 0)
278 break;
279 if (!map_found) {
280 map_found = 1;
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000281 idev->map_dir = kobject_create_and_add("maps",
282 &idev->dev->kobj);
283 if (!idev->map_dir)
Hans J. Koche70c4122008-12-06 02:23:13 +0100284 goto err_map;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100285 }
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000286 map = kzalloc(sizeof(*map), GFP_KERNEL);
287 if (!map)
Hans J. Koche70c4122008-12-06 02:23:13 +0100288 goto err_map;
Greg Kroah-Hartmanf9cb0742007-12-17 23:05:35 -0700289 kobject_init(&map->kobj, &map_attr_type);
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000290 map->mem = mem;
291 mem->map = map;
Greg Kroah-Hartmanb2d6db52007-12-17 23:05:35 -0700292 ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100293 if (ret)
Hans J. Koche70c4122008-12-06 02:23:13 +0100294 goto err_map;
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000295 ret = kobject_uevent(&map->kobj, KOBJ_ADD);
296 if (ret)
Hans J. Koche70c4122008-12-06 02:23:13 +0100297 goto err_map;
298 }
299
300 for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) {
301 port = &idev->info->port[pi];
302 if (port->size == 0)
303 break;
304 if (!portio_found) {
305 portio_found = 1;
306 idev->portio_dir = kobject_create_and_add("portio",
307 &idev->dev->kobj);
308 if (!idev->portio_dir)
309 goto err_portio;
310 }
311 portio = kzalloc(sizeof(*portio), GFP_KERNEL);
312 if (!portio)
313 goto err_portio;
314 kobject_init(&portio->kobj, &portio_attr_type);
315 portio->port = port;
316 port->portio = portio;
317 ret = kobject_add(&portio->kobj, idev->portio_dir,
318 "port%d", pi);
319 if (ret)
320 goto err_portio;
321 ret = kobject_uevent(&portio->kobj, KOBJ_ADD);
322 if (ret)
323 goto err_portio;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100324 }
325
326 return 0;
327
Hans J. Koche70c4122008-12-06 02:23:13 +0100328err_portio:
329 for (pi--; pi >= 0; pi--) {
330 port = &idev->info->port[pi];
331 portio = port->portio;
332 kobject_put(&portio->kobj);
333 }
334 kobject_put(idev->portio_dir);
335err_map:
Hans J. Kochbeafc542006-12-07 10:58:29 +0100336 for (mi--; mi>=0; mi--) {
337 mem = &idev->info->mem[mi];
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000338 map = mem->map;
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800339 kobject_put(&map->kobj);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100340 }
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800341 kobject_put(idev->map_dir);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100342 dev_err(idev->dev, "error creating sysfs files (%d)\n", ret);
343 return ret;
344}
345
346static void uio_dev_del_attributes(struct uio_device *idev)
347{
Hans J. Koche70c4122008-12-06 02:23:13 +0100348 int i;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100349 struct uio_mem *mem;
Hans J. Koche70c4122008-12-06 02:23:13 +0100350 struct uio_port *port;
351
352 for (i = 0; i < MAX_UIO_MAPS; i++) {
353 mem = &idev->info->mem[i];
Hans J. Kochbeafc542006-12-07 10:58:29 +0100354 if (mem->size == 0)
355 break;
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800356 kobject_put(&mem->map->kobj);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100357 }
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800358 kobject_put(idev->map_dir);
Hans J. Koche70c4122008-12-06 02:23:13 +0100359
360 for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) {
361 port = &idev->info->port[i];
362 if (port->size == 0)
363 break;
364 kobject_put(&port->portio->kobj);
365 }
366 kobject_put(idev->portio_dir);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100367}
368
369static int uio_get_minor(struct uio_device *idev)
370{
Hans J. Kochbeafc542006-12-07 10:58:29 +0100371 int retval = -ENOMEM;
372 int id;
373
374 mutex_lock(&minor_lock);
375 if (idr_pre_get(&uio_idr, GFP_KERNEL) == 0)
376 goto exit;
377
378 retval = idr_get_new(&uio_idr, idev, &id);
379 if (retval < 0) {
380 if (retval == -EAGAIN)
381 retval = -ENOMEM;
382 goto exit;
383 }
Hillf Dantonc6edc422011-03-31 20:38:47 +0800384 if (id < UIO_MAX_DEVICES) {
385 idev->minor = id;
386 } else {
387 dev_err(idev->dev, "too many uio devices\n");
388 retval = -EINVAL;
389 idr_remove(&uio_idr, id);
390 }
Hans J. Kochbeafc542006-12-07 10:58:29 +0100391exit:
392 mutex_unlock(&minor_lock);
393 return retval;
394}
395
396static void uio_free_minor(struct uio_device *idev)
397{
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -0600398 mutex_lock(&minor_lock);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100399 idr_remove(&uio_idr, idev->minor);
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -0600400 mutex_unlock(&minor_lock);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100401}
402
403/**
404 * uio_event_notify - trigger an interrupt event
405 * @info: UIO device capabilities
406 */
407void uio_event_notify(struct uio_info *info)
408{
409 struct uio_device *idev = info->uio_dev;
410
411 atomic_inc(&idev->event);
412 wake_up_interruptible(&idev->wait);
413 kill_fasync(&idev->async_queue, SIGIO, POLL_IN);
414}
415EXPORT_SYMBOL_GPL(uio_event_notify);
416
417/**
418 * uio_interrupt - hardware interrupt handler
419 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer
420 * @dev_id: Pointer to the devices uio_device structure
421 */
422static irqreturn_t uio_interrupt(int irq, void *dev_id)
423{
424 struct uio_device *idev = (struct uio_device *)dev_id;
425 irqreturn_t ret = idev->info->handler(irq, idev->info);
426
427 if (ret == IRQ_HANDLED)
428 uio_event_notify(idev->info);
429
430 return ret;
431}
432
433struct uio_listener {
434 struct uio_device *dev;
435 s32 event_count;
436};
437
438static int uio_open(struct inode *inode, struct file *filep)
439{
440 struct uio_device *idev;
441 struct uio_listener *listener;
442 int ret = 0;
443
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -0600444 mutex_lock(&minor_lock);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100445 idev = idr_find(&uio_idr, iminor(inode));
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -0600446 mutex_unlock(&minor_lock);
Jonathan Corbetfbc8a812008-05-15 10:39:37 -0600447 if (!idev) {
448 ret = -ENODEV;
449 goto out;
450 }
Hans J. Kochbeafc542006-12-07 10:58:29 +0100451
Jonathan Corbetfbc8a812008-05-15 10:39:37 -0600452 if (!try_module_get(idev->owner)) {
453 ret = -ENODEV;
454 goto out;
455 }
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200456
Hans J. Kochbeafc542006-12-07 10:58:29 +0100457 listener = kmalloc(sizeof(*listener), GFP_KERNEL);
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200458 if (!listener) {
459 ret = -ENOMEM;
460 goto err_alloc_listener;
461 }
Hans J. Kochbeafc542006-12-07 10:58:29 +0100462
463 listener->dev = idev;
464 listener->event_count = atomic_read(&idev->event);
465 filep->private_data = listener;
466
467 if (idev->info->open) {
Hans J. Kochbeafc542006-12-07 10:58:29 +0100468 ret = idev->info->open(idev->info, inode);
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200469 if (ret)
470 goto err_infoopen;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100471 }
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200472 return 0;
473
474err_infoopen:
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200475 kfree(listener);
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200476
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -0600477err_alloc_listener:
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200478 module_put(idev->owner);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100479
Jonathan Corbetfbc8a812008-05-15 10:39:37 -0600480out:
Hans J. Kochbeafc542006-12-07 10:58:29 +0100481 return ret;
482}
483
484static int uio_fasync(int fd, struct file *filep, int on)
485{
486 struct uio_listener *listener = filep->private_data;
487 struct uio_device *idev = listener->dev;
488
489 return fasync_helper(fd, filep, on, &idev->async_queue);
490}
491
492static int uio_release(struct inode *inode, struct file *filep)
493{
494 int ret = 0;
495 struct uio_listener *listener = filep->private_data;
496 struct uio_device *idev = listener->dev;
497
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200498 if (idev->info->release)
Hans J. Kochbeafc542006-12-07 10:58:29 +0100499 ret = idev->info->release(idev->info, inode);
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200500
501 module_put(idev->owner);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100502 kfree(listener);
503 return ret;
504}
505
506static unsigned int uio_poll(struct file *filep, poll_table *wait)
507{
508 struct uio_listener *listener = filep->private_data;
509 struct uio_device *idev = listener->dev;
510
Eric W. Biederman6427a762010-09-14 11:37:36 -0700511 if (!idev->info->irq)
Hans J. Kochbeafc542006-12-07 10:58:29 +0100512 return -EIO;
513
514 poll_wait(filep, &idev->wait, wait);
515 if (listener->event_count != atomic_read(&idev->event))
516 return POLLIN | POLLRDNORM;
517 return 0;
518}
519
520static ssize_t uio_read(struct file *filep, char __user *buf,
521 size_t count, loff_t *ppos)
522{
523 struct uio_listener *listener = filep->private_data;
524 struct uio_device *idev = listener->dev;
525 DECLARE_WAITQUEUE(wait, current);
526 ssize_t retval;
527 s32 event_count;
528
Eric W. Biederman6427a762010-09-14 11:37:36 -0700529 if (!idev->info->irq)
Hans J. Kochbeafc542006-12-07 10:58:29 +0100530 return -EIO;
531
532 if (count != sizeof(s32))
533 return -EINVAL;
534
535 add_wait_queue(&idev->wait, &wait);
536
537 do {
538 set_current_state(TASK_INTERRUPTIBLE);
539
540 event_count = atomic_read(&idev->event);
541 if (event_count != listener->event_count) {
542 if (copy_to_user(buf, &event_count, count))
543 retval = -EFAULT;
544 else {
545 listener->event_count = event_count;
546 retval = count;
547 }
548 break;
549 }
550
551 if (filep->f_flags & O_NONBLOCK) {
552 retval = -EAGAIN;
553 break;
554 }
555
556 if (signal_pending(current)) {
557 retval = -ERESTARTSYS;
558 break;
559 }
560 schedule();
561 } while (1);
562
563 __set_current_state(TASK_RUNNING);
564 remove_wait_queue(&idev->wait, &wait);
565
566 return retval;
567}
568
Hans J. Koch328a14e2008-05-23 13:50:14 +0200569static ssize_t uio_write(struct file *filep, const char __user *buf,
570 size_t count, loff_t *ppos)
571{
572 struct uio_listener *listener = filep->private_data;
573 struct uio_device *idev = listener->dev;
574 ssize_t retval;
575 s32 irq_on;
576
Eric W. Biederman6427a762010-09-14 11:37:36 -0700577 if (!idev->info->irq)
Hans J. Koch328a14e2008-05-23 13:50:14 +0200578 return -EIO;
579
580 if (count != sizeof(s32))
581 return -EINVAL;
582
583 if (!idev->info->irqcontrol)
584 return -ENOSYS;
585
586 if (copy_from_user(&irq_on, buf, count))
587 return -EFAULT;
588
589 retval = idev->info->irqcontrol(idev->info, irq_on);
590
591 return retval ? retval : sizeof(s32);
592}
593
Hans J. Kochbeafc542006-12-07 10:58:29 +0100594static int uio_find_mem_index(struct vm_area_struct *vma)
595{
Hans J. Kochbeafc542006-12-07 10:58:29 +0100596 struct uio_device *idev = vma->vm_private_data;
597
Hillf Dantonf0c554f2011-03-28 23:33:26 +0200598 if (vma->vm_pgoff < MAX_UIO_MAPS) {
599 if (idev->info->mem[vma->vm_pgoff].size == 0)
Hans J. Kochbeafc542006-12-07 10:58:29 +0100600 return -1;
Hillf Dantonf0c554f2011-03-28 23:33:26 +0200601 return (int)vma->vm_pgoff;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100602 }
603 return -1;
604}
605
606static void uio_vma_open(struct vm_area_struct *vma)
607{
608 struct uio_device *idev = vma->vm_private_data;
609 idev->vma_count++;
610}
611
612static void uio_vma_close(struct vm_area_struct *vma)
613{
614 struct uio_device *idev = vma->vm_private_data;
615 idev->vma_count--;
616}
617
Nick Piggina18b6302008-02-06 01:37:35 -0800618static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
Hans J. Kochbeafc542006-12-07 10:58:29 +0100619{
620 struct uio_device *idev = vma->vm_private_data;
Nick Piggina18b6302008-02-06 01:37:35 -0800621 struct page *page;
Andrew G. Harvey02683ff2008-09-24 01:10:02 +0200622 unsigned long offset;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100623
624 int mi = uio_find_mem_index(vma);
625 if (mi < 0)
Nick Piggina18b6302008-02-06 01:37:35 -0800626 return VM_FAULT_SIGBUS;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100627
Andrew G. Harvey02683ff2008-09-24 01:10:02 +0200628 /*
629 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
630 * to use mem[N].
631 */
632 offset = (vmf->pgoff - mi) << PAGE_SHIFT;
633
Hans J. Kochbeafc542006-12-07 10:58:29 +0100634 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
Andrew G. Harvey02683ff2008-09-24 01:10:02 +0200635 page = virt_to_page(idev->info->mem[mi].addr + offset);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100636 else
Andrew G. Harvey02683ff2008-09-24 01:10:02 +0200637 page = vmalloc_to_page((void *)idev->info->mem[mi].addr
638 + offset);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100639 get_page(page);
Nick Piggina18b6302008-02-06 01:37:35 -0800640 vmf->page = page;
641 return 0;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100642}
643
Alexey Dobriyanf0f37e22009-09-27 22:29:37 +0400644static const struct vm_operations_struct uio_vm_ops = {
Hans J. Kochbeafc542006-12-07 10:58:29 +0100645 .open = uio_vma_open,
646 .close = uio_vma_close,
Nick Piggina18b6302008-02-06 01:37:35 -0800647 .fault = uio_vma_fault,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100648};
649
650static int uio_mmap_physical(struct vm_area_struct *vma)
651{
652 struct uio_device *idev = vma->vm_private_data;
653 int mi = uio_find_mem_index(vma);
654 if (mi < 0)
655 return -EINVAL;
656
657 vma->vm_flags |= VM_IO | VM_RESERVED;
658
Jean-Samuel Chenardc9698d6b2008-03-14 11:28:36 +0100659 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
660
Hans J. Kochbeafc542006-12-07 10:58:29 +0100661 return remap_pfn_range(vma,
662 vma->vm_start,
663 idev->info->mem[mi].addr >> PAGE_SHIFT,
664 vma->vm_end - vma->vm_start,
665 vma->vm_page_prot);
666}
667
668static int uio_mmap_logical(struct vm_area_struct *vma)
669{
670 vma->vm_flags |= VM_RESERVED;
671 vma->vm_ops = &uio_vm_ops;
672 uio_vma_open(vma);
673 return 0;
674}
675
676static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
677{
678 struct uio_listener *listener = filep->private_data;
679 struct uio_device *idev = listener->dev;
680 int mi;
681 unsigned long requested_pages, actual_pages;
682 int ret = 0;
683
684 if (vma->vm_end < vma->vm_start)
685 return -EINVAL;
686
687 vma->vm_private_data = idev;
688
689 mi = uio_find_mem_index(vma);
690 if (mi < 0)
691 return -EINVAL;
692
693 requested_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
Ian Abbott6da2d372009-02-24 17:22:59 +0000694 actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK)
695 + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100696 if (requested_pages > actual_pages)
697 return -EINVAL;
698
699 if (idev->info->mmap) {
Hans J. Kochbeafc542006-12-07 10:58:29 +0100700 ret = idev->info->mmap(idev->info, vma);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100701 return ret;
702 }
703
704 switch (idev->info->mem[mi].memtype) {
705 case UIO_MEM_PHYS:
706 return uio_mmap_physical(vma);
707 case UIO_MEM_LOGICAL:
708 case UIO_MEM_VIRTUAL:
709 return uio_mmap_logical(vma);
710 default:
711 return -EINVAL;
712 }
713}
714
Jan Engelhardt4f014692008-01-22 20:50:54 +0100715static const struct file_operations uio_fops = {
Hans J. Kochbeafc542006-12-07 10:58:29 +0100716 .owner = THIS_MODULE,
717 .open = uio_open,
718 .release = uio_release,
719 .read = uio_read,
Hans J. Koch328a14e2008-05-23 13:50:14 +0200720 .write = uio_write,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100721 .mmap = uio_mmap,
722 .poll = uio_poll,
723 .fasync = uio_fasync,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200724 .llseek = noop_llseek,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100725};
726
727static int uio_major_init(void)
728{
Eric W. Biederman91960a42010-09-14 11:38:06 -0700729 static const char name[] = "uio";
730 struct cdev *cdev = NULL;
731 dev_t uio_dev = 0;
732 int result;
733
734 result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name);
735 if (result)
736 goto out;
737
738 result = -ENOMEM;
739 cdev = cdev_alloc();
740 if (!cdev)
741 goto out_unregister;
742
743 cdev->owner = THIS_MODULE;
744 cdev->ops = &uio_fops;
745 kobject_set_name(&cdev->kobj, "%s", name);
746
747 result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES);
748 if (result)
749 goto out_put;
750
751 uio_major = MAJOR(uio_dev);
752 uio_cdev = cdev;
753 result = 0;
754out:
755 return result;
756out_put:
757 kobject_put(&cdev->kobj);
758out_unregister:
759 unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES);
760 goto out;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100761}
762
763static void uio_major_cleanup(void)
764{
Eric W. Biederman91960a42010-09-14 11:38:06 -0700765 unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES);
766 cdev_del(uio_cdev);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100767}
768
769static int init_uio_class(void)
770{
Eric W. Biederman3d4f9d72010-09-14 11:36:27 -0700771 int ret;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100772
773 /* This is the first time in here, set everything up properly */
774 ret = uio_major_init();
775 if (ret)
776 goto exit;
777
Eric W. Biedermanc66fdab2010-09-14 11:38:36 -0700778 ret = class_register(&uio_class);
779 if (ret) {
780 printk(KERN_ERR "class_register failed for uio\n");
781 goto err_class_register;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100782 }
783 return 0;
784
Eric W. Biedermanc66fdab2010-09-14 11:38:36 -0700785err_class_register:
Hans J. Kochbeafc542006-12-07 10:58:29 +0100786 uio_major_cleanup();
787exit:
788 return ret;
789}
790
Eric W. Biederman3d4f9d72010-09-14 11:36:27 -0700791static void release_uio_class(void)
Hans J. Kochbeafc542006-12-07 10:58:29 +0100792{
Eric W. Biedermanc66fdab2010-09-14 11:38:36 -0700793 class_unregister(&uio_class);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100794 uio_major_cleanup();
Hans J. Kochbeafc542006-12-07 10:58:29 +0100795}
796
797/**
798 * uio_register_device - register a new userspace IO device
799 * @owner: module that creates the new device
800 * @parent: parent device
801 * @info: UIO device capabilities
802 *
803 * returns zero on success or a negative error code.
804 */
805int __uio_register_device(struct module *owner,
806 struct device *parent,
807 struct uio_info *info)
808{
809 struct uio_device *idev;
810 int ret = 0;
811
812 if (!parent || !info || !info->name || !info->version)
813 return -EINVAL;
814
815 info->uio_dev = NULL;
816
Hans J. Kochbeafc542006-12-07 10:58:29 +0100817 idev = kzalloc(sizeof(*idev), GFP_KERNEL);
818 if (!idev) {
819 ret = -ENOMEM;
820 goto err_kzalloc;
821 }
822
823 idev->owner = owner;
824 idev->info = info;
825 init_waitqueue_head(&idev->wait);
826 atomic_set(&idev->event, 0);
827
828 ret = uio_get_minor(idev);
829 if (ret)
830 goto err_get_minor;
831
Eric W. Biedermanc66fdab2010-09-14 11:38:36 -0700832 idev->dev = device_create(&uio_class, parent,
Greg Kroah-Hartmana9b12612008-07-21 20:03:34 -0700833 MKDEV(uio_major, idev->minor), idev,
834 "uio%d", idev->minor);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100835 if (IS_ERR(idev->dev)) {
836 printk(KERN_ERR "UIO: device register failed\n");
837 ret = PTR_ERR(idev->dev);
838 goto err_device_create;
839 }
Hans J. Kochbeafc542006-12-07 10:58:29 +0100840
841 ret = uio_dev_add_attributes(idev);
842 if (ret)
843 goto err_uio_dev_add_attributes;
844
845 info->uio_dev = idev;
846
Eric W. Biederman6427a762010-09-14 11:37:36 -0700847 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) {
848 ret = request_irq(info->irq, uio_interrupt,
849 info->irq_flags, info->name, idev);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100850 if (ret)
851 goto err_request_irq;
852 }
853
854 return 0;
855
856err_request_irq:
857 uio_dev_del_attributes(idev);
858err_uio_dev_add_attributes:
Eric W. Biedermanc66fdab2010-09-14 11:38:36 -0700859 device_destroy(&uio_class, MKDEV(uio_major, idev->minor));
Hans J. Kochbeafc542006-12-07 10:58:29 +0100860err_device_create:
861 uio_free_minor(idev);
862err_get_minor:
863 kfree(idev);
864err_kzalloc:
Hans J. Kochbeafc542006-12-07 10:58:29 +0100865 return ret;
866}
867EXPORT_SYMBOL_GPL(__uio_register_device);
868
869/**
870 * uio_unregister_device - unregister a industrial IO device
871 * @info: UIO device capabilities
872 *
873 */
874void uio_unregister_device(struct uio_info *info)
875{
876 struct uio_device *idev;
877
878 if (!info || !info->uio_dev)
879 return;
880
881 idev = info->uio_dev;
882
883 uio_free_minor(idev);
884
Eric W. Biederman6427a762010-09-14 11:37:36 -0700885 if (info->irq && (info->irq != UIO_IRQ_CUSTOM))
Hans J. Kochbeafc542006-12-07 10:58:29 +0100886 free_irq(info->irq, idev);
887
888 uio_dev_del_attributes(idev);
889
Eric W. Biedermanc66fdab2010-09-14 11:38:36 -0700890 device_destroy(&uio_class, MKDEV(uio_major, idev->minor));
Hans J. Kochbeafc542006-12-07 10:58:29 +0100891 kfree(idev);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100892
893 return;
894}
895EXPORT_SYMBOL_GPL(uio_unregister_device);
896
897static int __init uio_init(void)
898{
Eric W. Biederman3d4f9d72010-09-14 11:36:27 -0700899 return init_uio_class();
Hans J. Kochbeafc542006-12-07 10:58:29 +0100900}
901
902static void __exit uio_exit(void)
903{
Eric W. Biederman3d4f9d72010-09-14 11:36:27 -0700904 release_uio_class();
Hans J. Kochbeafc542006-12-07 10:58:29 +0100905}
906
907module_init(uio_init)
908module_exit(uio_exit)
909MODULE_LICENSE("GPL v2");