blob: 65bf0676d54afc785107822f51a696ae373a2702 [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
Hans J. Kochbeafc542006-12-07 10:58:29 +010031static int uio_major;
Eric W. Biederman91960a42010-09-14 11:38:06 -070032static struct cdev *uio_cdev;
Hans J. Kochbeafc542006-12-07 10:58:29 +010033static DEFINE_IDR(uio_idr);
Jan Engelhardt4f014692008-01-22 20:50:54 +010034static const struct file_operations uio_fops;
Hans J. Kochbeafc542006-12-07 10:58:29 +010035
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -060036/* Protect idr accesses */
37static DEFINE_MUTEX(minor_lock);
38
Hans J. Kochbeafc542006-12-07 10:58:29 +010039/*
40 * attributes
41 */
42
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000043struct uio_map {
44 struct kobject kobj;
45 struct uio_mem *mem;
Hans J. Kochbeafc542006-12-07 10:58:29 +010046};
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000047#define to_map(map) container_of(map, struct uio_map, kobj)
Hans J. Kochbeafc542006-12-07 10:58:29 +010048
Hans J. Koch82057792009-01-07 00:15:39 +010049static 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
Brandon Philips4f808bc2008-02-19 01:55:05 -080057static ssize_t map_addr_show(struct uio_mem *mem, char *buf)
Hans J. Kochbeafc542006-12-07 10:58:29 +010058{
Cristian Stoicae0f11472014-10-09 15:00:27 +030059 return sprintf(buf, "%pa\n", &mem->addr);
Hans J. Kochbeafc542006-12-07 10:58:29 +010060}
61
Brandon Philips4f808bc2008-02-19 01:55:05 -080062static ssize_t map_size_show(struct uio_mem *mem, char *buf)
63{
Cristian Stoicae0f11472014-10-09 15:00:27 +030064 return sprintf(buf, "%pa\n", &mem->size);
Brandon Philips4f808bc2008-02-19 01:55:05 -080065}
66
Hans J. Koche2b39df2008-09-18 23:53:18 +020067static ssize_t map_offset_show(struct uio_mem *mem, char *buf)
68{
Kai Jiang27a90702011-10-17 20:50:20 +020069 return sprintf(buf, "0x%llx\n", (unsigned long long)mem->addr & ~PAGE_MASK);
Hans J. Koche2b39df2008-09-18 23:53:18 +020070}
71
Hans J. Koche70c4122008-12-06 02:23:13 +010072struct map_sysfs_entry {
Brandon Philips4f808bc2008-02-19 01:55:05 -080073 struct attribute attr;
74 ssize_t (*show)(struct uio_mem *, char *);
75 ssize_t (*store)(struct uio_mem *, const char *, size_t);
76};
77
Hans J. Koch82057792009-01-07 00:15:39 +010078static struct map_sysfs_entry name_attribute =
79 __ATTR(name, S_IRUGO, map_name_show, NULL);
Hans J. Koche70c4122008-12-06 02:23:13 +010080static struct map_sysfs_entry addr_attribute =
Brandon Philips4f808bc2008-02-19 01:55:05 -080081 __ATTR(addr, S_IRUGO, map_addr_show, NULL);
Hans J. Koche70c4122008-12-06 02:23:13 +010082static struct map_sysfs_entry size_attribute =
Brandon Philips4f808bc2008-02-19 01:55:05 -080083 __ATTR(size, S_IRUGO, map_size_show, NULL);
Hans J. Koche70c4122008-12-06 02:23:13 +010084static struct map_sysfs_entry offset_attribute =
Hans J. Koche2b39df2008-09-18 23:53:18 +020085 __ATTR(offset, S_IRUGO, map_offset_show, NULL);
Hans J. Kochbeafc542006-12-07 10:58:29 +010086
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000087static struct attribute *attrs[] = {
Hans J. Koch82057792009-01-07 00:15:39 +010088 &name_attribute.attr,
Brandon Philips4f808bc2008-02-19 01:55:05 -080089 &addr_attribute.attr,
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000090 &size_attribute.attr,
Hans J. Koche2b39df2008-09-18 23:53:18 +020091 &offset_attribute.attr,
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000092 NULL, /* need to NULL terminate the list of attributes */
Hans J. Kochbeafc542006-12-07 10:58:29 +010093};
94
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000095static void map_release(struct kobject *kobj)
96{
97 struct uio_map *map = to_map(kobj);
98 kfree(map);
99}
100
Brandon Philips4f808bc2008-02-19 01:55:05 -0800101static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr,
102 char *buf)
103{
104 struct uio_map *map = to_map(kobj);
105 struct uio_mem *mem = map->mem;
Hans J. Koche70c4122008-12-06 02:23:13 +0100106 struct map_sysfs_entry *entry;
Brandon Philips4f808bc2008-02-19 01:55:05 -0800107
Hans J. Koche70c4122008-12-06 02:23:13 +0100108 entry = container_of(attr, struct map_sysfs_entry, attr);
Brandon Philips4f808bc2008-02-19 01:55:05 -0800109
110 if (!entry->show)
111 return -EIO;
112
113 return entry->show(mem, buf);
114}
115
Emese Revfy52cf25d2010-01-19 02:58:23 +0100116static const struct sysfs_ops map_sysfs_ops = {
Brandon Philips4f808bc2008-02-19 01:55:05 -0800117 .show = map_type_show,
118};
119
Hans J. Kochbeafc542006-12-07 10:58:29 +0100120static struct kobj_type map_attr_type = {
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000121 .release = map_release,
Hans J. Koche70c4122008-12-06 02:23:13 +0100122 .sysfs_ops = &map_sysfs_ops,
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000123 .default_attrs = attrs,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100124};
125
Hans J. Koche70c4122008-12-06 02:23:13 +0100126struct uio_portio {
127 struct kobject kobj;
128 struct uio_port *port;
129};
130#define to_portio(portio) container_of(portio, struct uio_portio, kobj)
131
Hans J. Koch82057792009-01-07 00:15:39 +0100132static ssize_t portio_name_show(struct uio_port *port, char *buf)
133{
134 if (unlikely(!port->name))
135 port->name = "";
136
137 return sprintf(buf, "%s\n", port->name);
138}
139
Hans J. Koche70c4122008-12-06 02:23:13 +0100140static ssize_t portio_start_show(struct uio_port *port, char *buf)
141{
142 return sprintf(buf, "0x%lx\n", port->start);
143}
144
145static ssize_t portio_size_show(struct uio_port *port, char *buf)
146{
147 return sprintf(buf, "0x%lx\n", port->size);
148}
149
150static ssize_t portio_porttype_show(struct uio_port *port, char *buf)
151{
152 const char *porttypes[] = {"none", "x86", "gpio", "other"};
153
154 if ((port->porttype < 0) || (port->porttype > UIO_PORT_OTHER))
155 return -EINVAL;
156
157 return sprintf(buf, "port_%s\n", porttypes[port->porttype]);
158}
159
160struct portio_sysfs_entry {
161 struct attribute attr;
162 ssize_t (*show)(struct uio_port *, char *);
163 ssize_t (*store)(struct uio_port *, const char *, size_t);
164};
165
Hans J. Koch82057792009-01-07 00:15:39 +0100166static struct portio_sysfs_entry portio_name_attribute =
167 __ATTR(name, S_IRUGO, portio_name_show, NULL);
Hans J. Koche70c4122008-12-06 02:23:13 +0100168static struct portio_sysfs_entry portio_start_attribute =
169 __ATTR(start, S_IRUGO, portio_start_show, NULL);
170static struct portio_sysfs_entry portio_size_attribute =
171 __ATTR(size, S_IRUGO, portio_size_show, NULL);
172static struct portio_sysfs_entry portio_porttype_attribute =
173 __ATTR(porttype, S_IRUGO, portio_porttype_show, NULL);
174
175static struct attribute *portio_attrs[] = {
Hans J. Koch82057792009-01-07 00:15:39 +0100176 &portio_name_attribute.attr,
Hans J. Koche70c4122008-12-06 02:23:13 +0100177 &portio_start_attribute.attr,
178 &portio_size_attribute.attr,
179 &portio_porttype_attribute.attr,
180 NULL,
181};
182
183static void portio_release(struct kobject *kobj)
184{
185 struct uio_portio *portio = to_portio(kobj);
186 kfree(portio);
187}
188
189static ssize_t portio_type_show(struct kobject *kobj, struct attribute *attr,
190 char *buf)
191{
192 struct uio_portio *portio = to_portio(kobj);
193 struct uio_port *port = portio->port;
194 struct portio_sysfs_entry *entry;
195
196 entry = container_of(attr, struct portio_sysfs_entry, attr);
197
198 if (!entry->show)
199 return -EIO;
200
201 return entry->show(port, buf);
202}
203
Emese Revfy52cf25d2010-01-19 02:58:23 +0100204static const struct sysfs_ops portio_sysfs_ops = {
Hans J. Koche70c4122008-12-06 02:23:13 +0100205 .show = portio_type_show,
206};
207
208static struct kobj_type portio_attr_type = {
209 .release = portio_release,
210 .sysfs_ops = &portio_sysfs_ops,
211 .default_attrs = portio_attrs,
212};
213
Greg Kroah-Hartmanc9dce922013-07-24 15:05:23 -0700214static ssize_t name_show(struct device *dev,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100215 struct device_attribute *attr, char *buf)
216{
217 struct uio_device *idev = dev_get_drvdata(dev);
Eric W. Biederman70a91562010-09-14 11:36:54 -0700218 return sprintf(buf, "%s\n", idev->info->name);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100219}
Greg Kroah-Hartmanc9dce922013-07-24 15:05:23 -0700220static DEVICE_ATTR_RO(name);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100221
Greg Kroah-Hartmanc9dce922013-07-24 15:05:23 -0700222static ssize_t version_show(struct device *dev,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100223 struct device_attribute *attr, char *buf)
224{
225 struct uio_device *idev = dev_get_drvdata(dev);
Eric W. Biederman70a91562010-09-14 11:36:54 -0700226 return sprintf(buf, "%s\n", idev->info->version);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100227}
Greg Kroah-Hartmanc9dce922013-07-24 15:05:23 -0700228static DEVICE_ATTR_RO(version);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100229
Greg Kroah-Hartmanc9dce922013-07-24 15:05:23 -0700230static ssize_t event_show(struct device *dev,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100231 struct device_attribute *attr, char *buf)
232{
233 struct uio_device *idev = dev_get_drvdata(dev);
Eric W. Biederman70a91562010-09-14 11:36:54 -0700234 return sprintf(buf, "%u\n", (unsigned int)atomic_read(&idev->event));
Hans J. Kochbeafc542006-12-07 10:58:29 +0100235}
Greg Kroah-Hartmanc9dce922013-07-24 15:05:23 -0700236static DEVICE_ATTR_RO(event);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100237
Greg Kroah-Hartmanc9dce922013-07-24 15:05:23 -0700238static struct attribute *uio_attrs[] = {
239 &dev_attr_name.attr,
240 &dev_attr_version.attr,
241 &dev_attr_event.attr,
242 NULL,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100243};
Greg Kroah-Hartmanc9dce922013-07-24 15:05:23 -0700244ATTRIBUTE_GROUPS(uio);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100245
Eric W. Biedermanc66fdab2010-09-14 11:38:36 -0700246/* UIO class infrastructure */
247static struct class uio_class = {
248 .name = "uio",
Greg Kroah-Hartmanc9dce922013-07-24 15:05:23 -0700249 .dev_groups = uio_groups,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100250};
251
252/*
253 * device functions
254 */
255static int uio_dev_add_attributes(struct uio_device *idev)
256{
257 int ret;
Hans J. Koche70c4122008-12-06 02:23:13 +0100258 int mi, pi;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100259 int map_found = 0;
Hans J. Koche70c4122008-12-06 02:23:13 +0100260 int portio_found = 0;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100261 struct uio_mem *mem;
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000262 struct uio_map *map;
Hans J. Koche70c4122008-12-06 02:23:13 +0100263 struct uio_port *port;
264 struct uio_portio *portio;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100265
Hans J. Kochbeafc542006-12-07 10:58:29 +0100266 for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
267 mem = &idev->info->mem[mi];
268 if (mem->size == 0)
269 break;
270 if (!map_found) {
271 map_found = 1;
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000272 idev->map_dir = kobject_create_and_add("maps",
273 &idev->dev->kobj);
274 if (!idev->map_dir)
Hans J. Koche70c4122008-12-06 02:23:13 +0100275 goto err_map;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100276 }
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000277 map = kzalloc(sizeof(*map), GFP_KERNEL);
278 if (!map)
Cong Ding75f0aef2013-10-25 00:25:53 -0700279 goto err_map_kobj;
Greg Kroah-Hartmanf9cb0742007-12-17 23:05:35 -0700280 kobject_init(&map->kobj, &map_attr_type);
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000281 map->mem = mem;
282 mem->map = map;
Greg Kroah-Hartmanb2d6db52007-12-17 23:05:35 -0700283 ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100284 if (ret)
Cong Ding75f0aef2013-10-25 00:25:53 -0700285 goto err_map_kobj;
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000286 ret = kobject_uevent(&map->kobj, KOBJ_ADD);
287 if (ret)
Hans J. Koche70c4122008-12-06 02:23:13 +0100288 goto err_map;
289 }
290
291 for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) {
292 port = &idev->info->port[pi];
293 if (port->size == 0)
294 break;
295 if (!portio_found) {
296 portio_found = 1;
297 idev->portio_dir = kobject_create_and_add("portio",
298 &idev->dev->kobj);
299 if (!idev->portio_dir)
300 goto err_portio;
301 }
302 portio = kzalloc(sizeof(*portio), GFP_KERNEL);
303 if (!portio)
Cong Ding75f0aef2013-10-25 00:25:53 -0700304 goto err_portio_kobj;
Hans J. Koche70c4122008-12-06 02:23:13 +0100305 kobject_init(&portio->kobj, &portio_attr_type);
306 portio->port = port;
307 port->portio = portio;
308 ret = kobject_add(&portio->kobj, idev->portio_dir,
309 "port%d", pi);
310 if (ret)
Cong Ding75f0aef2013-10-25 00:25:53 -0700311 goto err_portio_kobj;
Hans J. Koche70c4122008-12-06 02:23:13 +0100312 ret = kobject_uevent(&portio->kobj, KOBJ_ADD);
313 if (ret)
314 goto err_portio;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100315 }
316
317 return 0;
318
Hans J. Koche70c4122008-12-06 02:23:13 +0100319err_portio:
Cong Ding75f0aef2013-10-25 00:25:53 -0700320 pi--;
321err_portio_kobj:
322 for (; pi >= 0; pi--) {
Hans J. Koche70c4122008-12-06 02:23:13 +0100323 port = &idev->info->port[pi];
324 portio = port->portio;
325 kobject_put(&portio->kobj);
326 }
327 kobject_put(idev->portio_dir);
328err_map:
Cong Ding75f0aef2013-10-25 00:25:53 -0700329 mi--;
330err_map_kobj:
331 for (; mi >= 0; mi--) {
Hans J. Kochbeafc542006-12-07 10:58:29 +0100332 mem = &idev->info->mem[mi];
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000333 map = mem->map;
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800334 kobject_put(&map->kobj);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100335 }
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800336 kobject_put(idev->map_dir);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100337 dev_err(idev->dev, "error creating sysfs files (%d)\n", ret);
338 return ret;
339}
340
341static void uio_dev_del_attributes(struct uio_device *idev)
342{
Hans J. Koche70c4122008-12-06 02:23:13 +0100343 int i;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100344 struct uio_mem *mem;
Hans J. Koche70c4122008-12-06 02:23:13 +0100345 struct uio_port *port;
346
347 for (i = 0; i < MAX_UIO_MAPS; i++) {
348 mem = &idev->info->mem[i];
Hans J. Kochbeafc542006-12-07 10:58:29 +0100349 if (mem->size == 0)
350 break;
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800351 kobject_put(&mem->map->kobj);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100352 }
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800353 kobject_put(idev->map_dir);
Hans J. Koche70c4122008-12-06 02:23:13 +0100354
355 for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) {
356 port = &idev->info->port[i];
357 if (port->size == 0)
358 break;
359 kobject_put(&port->portio->kobj);
360 }
361 kobject_put(idev->portio_dir);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100362}
363
364static int uio_get_minor(struct uio_device *idev)
365{
Hans J. Kochbeafc542006-12-07 10:58:29 +0100366 int retval = -ENOMEM;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100367
368 mutex_lock(&minor_lock);
Tejun Heo6d770932013-02-27 17:04:47 -0800369 retval = idr_alloc(&uio_idr, idev, 0, UIO_MAX_DEVICES, GFP_KERNEL);
370 if (retval >= 0) {
371 idev->minor = retval;
Damian Hobson-Garcia5ed05052013-03-26 10:31:22 +0900372 retval = 0;
Tejun Heo6d770932013-02-27 17:04:47 -0800373 } else if (retval == -ENOSPC) {
Hillf Dantonc6edc422011-03-31 20:38:47 +0800374 dev_err(idev->dev, "too many uio devices\n");
375 retval = -EINVAL;
Hillf Dantonc6edc422011-03-31 20:38:47 +0800376 }
Hans J. Kochbeafc542006-12-07 10:58:29 +0100377 mutex_unlock(&minor_lock);
378 return retval;
379}
380
381static void uio_free_minor(struct uio_device *idev)
382{
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -0600383 mutex_lock(&minor_lock);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100384 idr_remove(&uio_idr, idev->minor);
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -0600385 mutex_unlock(&minor_lock);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100386}
387
388/**
389 * uio_event_notify - trigger an interrupt event
390 * @info: UIO device capabilities
391 */
392void uio_event_notify(struct uio_info *info)
393{
394 struct uio_device *idev = info->uio_dev;
395
396 atomic_inc(&idev->event);
397 wake_up_interruptible(&idev->wait);
398 kill_fasync(&idev->async_queue, SIGIO, POLL_IN);
399}
400EXPORT_SYMBOL_GPL(uio_event_notify);
401
402/**
403 * uio_interrupt - hardware interrupt handler
404 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer
405 * @dev_id: Pointer to the devices uio_device structure
406 */
407static irqreturn_t uio_interrupt(int irq, void *dev_id)
408{
409 struct uio_device *idev = (struct uio_device *)dev_id;
410 irqreturn_t ret = idev->info->handler(irq, idev->info);
411
412 if (ret == IRQ_HANDLED)
413 uio_event_notify(idev->info);
414
415 return ret;
416}
417
418struct uio_listener {
419 struct uio_device *dev;
420 s32 event_count;
421};
422
423static int uio_open(struct inode *inode, struct file *filep)
424{
425 struct uio_device *idev;
426 struct uio_listener *listener;
427 int ret = 0;
428
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -0600429 mutex_lock(&minor_lock);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100430 idev = idr_find(&uio_idr, iminor(inode));
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -0600431 mutex_unlock(&minor_lock);
Jonathan Corbetfbc8a812008-05-15 10:39:37 -0600432 if (!idev) {
433 ret = -ENODEV;
434 goto out;
435 }
Hans J. Kochbeafc542006-12-07 10:58:29 +0100436
Jonathan Corbetfbc8a812008-05-15 10:39:37 -0600437 if (!try_module_get(idev->owner)) {
438 ret = -ENODEV;
439 goto out;
440 }
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200441
Hans J. Kochbeafc542006-12-07 10:58:29 +0100442 listener = kmalloc(sizeof(*listener), GFP_KERNEL);
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200443 if (!listener) {
444 ret = -ENOMEM;
445 goto err_alloc_listener;
446 }
Hans J. Kochbeafc542006-12-07 10:58:29 +0100447
448 listener->dev = idev;
449 listener->event_count = atomic_read(&idev->event);
450 filep->private_data = listener;
451
452 if (idev->info->open) {
Hans J. Kochbeafc542006-12-07 10:58:29 +0100453 ret = idev->info->open(idev->info, inode);
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200454 if (ret)
455 goto err_infoopen;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100456 }
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200457 return 0;
458
459err_infoopen:
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200460 kfree(listener);
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200461
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -0600462err_alloc_listener:
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200463 module_put(idev->owner);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100464
Jonathan Corbetfbc8a812008-05-15 10:39:37 -0600465out:
Hans J. Kochbeafc542006-12-07 10:58:29 +0100466 return ret;
467}
468
469static int uio_fasync(int fd, struct file *filep, int on)
470{
471 struct uio_listener *listener = filep->private_data;
472 struct uio_device *idev = listener->dev;
473
474 return fasync_helper(fd, filep, on, &idev->async_queue);
475}
476
477static int uio_release(struct inode *inode, struct file *filep)
478{
479 int ret = 0;
480 struct uio_listener *listener = filep->private_data;
481 struct uio_device *idev = listener->dev;
482
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200483 if (idev->info->release)
Hans J. Kochbeafc542006-12-07 10:58:29 +0100484 ret = idev->info->release(idev->info, inode);
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200485
486 module_put(idev->owner);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100487 kfree(listener);
488 return ret;
489}
490
491static unsigned int uio_poll(struct file *filep, poll_table *wait)
492{
493 struct uio_listener *listener = filep->private_data;
494 struct uio_device *idev = listener->dev;
495
Eric W. Biederman6427a762010-09-14 11:37:36 -0700496 if (!idev->info->irq)
Hans J. Kochbeafc542006-12-07 10:58:29 +0100497 return -EIO;
498
499 poll_wait(filep, &idev->wait, wait);
500 if (listener->event_count != atomic_read(&idev->event))
501 return POLLIN | POLLRDNORM;
502 return 0;
503}
504
505static ssize_t uio_read(struct file *filep, char __user *buf,
506 size_t count, loff_t *ppos)
507{
508 struct uio_listener *listener = filep->private_data;
509 struct uio_device *idev = listener->dev;
510 DECLARE_WAITQUEUE(wait, current);
511 ssize_t retval;
512 s32 event_count;
513
Eric W. Biederman6427a762010-09-14 11:37:36 -0700514 if (!idev->info->irq)
Hans J. Kochbeafc542006-12-07 10:58:29 +0100515 return -EIO;
516
517 if (count != sizeof(s32))
518 return -EINVAL;
519
520 add_wait_queue(&idev->wait, &wait);
521
522 do {
523 set_current_state(TASK_INTERRUPTIBLE);
524
525 event_count = atomic_read(&idev->event);
526 if (event_count != listener->event_count) {
527 if (copy_to_user(buf, &event_count, count))
528 retval = -EFAULT;
529 else {
530 listener->event_count = event_count;
531 retval = count;
532 }
533 break;
534 }
535
536 if (filep->f_flags & O_NONBLOCK) {
537 retval = -EAGAIN;
538 break;
539 }
540
541 if (signal_pending(current)) {
542 retval = -ERESTARTSYS;
543 break;
544 }
545 schedule();
546 } while (1);
547
548 __set_current_state(TASK_RUNNING);
549 remove_wait_queue(&idev->wait, &wait);
550
551 return retval;
552}
553
Hans J. Koch328a14e2008-05-23 13:50:14 +0200554static ssize_t uio_write(struct file *filep, const char __user *buf,
555 size_t count, loff_t *ppos)
556{
557 struct uio_listener *listener = filep->private_data;
558 struct uio_device *idev = listener->dev;
559 ssize_t retval;
560 s32 irq_on;
561
Eric W. Biederman6427a762010-09-14 11:37:36 -0700562 if (!idev->info->irq)
Hans J. Koch328a14e2008-05-23 13:50:14 +0200563 return -EIO;
564
565 if (count != sizeof(s32))
566 return -EINVAL;
567
568 if (!idev->info->irqcontrol)
569 return -ENOSYS;
570
571 if (copy_from_user(&irq_on, buf, count))
572 return -EFAULT;
573
574 retval = idev->info->irqcontrol(idev->info, irq_on);
575
576 return retval ? retval : sizeof(s32);
577}
578
Hans J. Kochbeafc542006-12-07 10:58:29 +0100579static int uio_find_mem_index(struct vm_area_struct *vma)
580{
Hans J. Kochbeafc542006-12-07 10:58:29 +0100581 struct uio_device *idev = vma->vm_private_data;
582
Hillf Dantonf0c554f2011-03-28 23:33:26 +0200583 if (vma->vm_pgoff < MAX_UIO_MAPS) {
584 if (idev->info->mem[vma->vm_pgoff].size == 0)
Hans J. Kochbeafc542006-12-07 10:58:29 +0100585 return -1;
Hillf Dantonf0c554f2011-03-28 23:33:26 +0200586 return (int)vma->vm_pgoff;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100587 }
588 return -1;
589}
590
Nick Piggina18b6302008-02-06 01:37:35 -0800591static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
Hans J. Kochbeafc542006-12-07 10:58:29 +0100592{
593 struct uio_device *idev = vma->vm_private_data;
Nick Piggina18b6302008-02-06 01:37:35 -0800594 struct page *page;
Andrew G. Harvey02683ff2008-09-24 01:10:02 +0200595 unsigned long offset;
Ben Hutchingse6418fc2013-10-27 21:53:40 +0000596 void *addr;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100597
598 int mi = uio_find_mem_index(vma);
599 if (mi < 0)
Nick Piggina18b6302008-02-06 01:37:35 -0800600 return VM_FAULT_SIGBUS;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100601
Andrew G. Harvey02683ff2008-09-24 01:10:02 +0200602 /*
603 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
604 * to use mem[N].
605 */
606 offset = (vmf->pgoff - mi) << PAGE_SHIFT;
607
Ben Hutchingse6418fc2013-10-27 21:53:40 +0000608 addr = (void *)(unsigned long)idev->info->mem[mi].addr + offset;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100609 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
Ben Hutchingse6418fc2013-10-27 21:53:40 +0000610 page = virt_to_page(addr);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100611 else
Ben Hutchingse6418fc2013-10-27 21:53:40 +0000612 page = vmalloc_to_page(addr);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100613 get_page(page);
Nick Piggina18b6302008-02-06 01:37:35 -0800614 vmf->page = page;
615 return 0;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100616}
617
Uwe Kleine-König72941512013-08-07 13:02:53 +0200618static const struct vm_operations_struct uio_logical_vm_ops = {
Nick Piggina18b6302008-02-06 01:37:35 -0800619 .fault = uio_vma_fault,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100620};
621
Uwe Kleine-König72941512013-08-07 13:02:53 +0200622static int uio_mmap_logical(struct vm_area_struct *vma)
623{
624 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
625 vma->vm_ops = &uio_logical_vm_ops;
Uwe Kleine-König72941512013-08-07 13:02:53 +0200626 return 0;
627}
628
629static const struct vm_operations_struct uio_physical_vm_ops = {
630#ifdef CONFIG_HAVE_IOREMAP_PROT
631 .access = generic_access_phys,
632#endif
633};
634
Hans J. Kochbeafc542006-12-07 10:58:29 +0100635static int uio_mmap_physical(struct vm_area_struct *vma)
636{
637 struct uio_device *idev = vma->vm_private_data;
638 int mi = uio_find_mem_index(vma);
Linus Torvalds7314e6132013-10-29 10:21:34 -0700639 struct uio_mem *mem;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100640 if (mi < 0)
641 return -EINVAL;
Linus Torvalds7314e6132013-10-29 10:21:34 -0700642 mem = idev->info->mem + mi;
643
Linus Torvaldsb6550282013-12-02 11:50:37 -0800644 if (mem->addr & ~PAGE_MASK)
645 return -ENODEV;
Greg Kroah-Hartmanb29f6802014-06-17 16:07:08 -0700646 if (vma->vm_end - vma->vm_start > mem->size)
Linus Torvalds7314e6132013-10-29 10:21:34 -0700647 return -EINVAL;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100648
Uwe Kleine-König72941512013-08-07 13:02:53 +0200649 vma->vm_ops = &uio_physical_vm_ops;
Jean-Samuel Chenardc9698d6b2008-03-14 11:28:36 +0100650 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
651
Linus Torvalds7314e6132013-10-29 10:21:34 -0700652 /*
653 * We cannot use the vm_iomap_memory() helper here,
654 * because vma->vm_pgoff is the map index we looked
655 * up above in uio_find_mem_index(), rather than an
656 * actual page offset into the mmap.
657 *
658 * So we just do the physical mmap without a page
659 * offset.
660 */
Hans J. Kochbeafc542006-12-07 10:58:29 +0100661 return remap_pfn_range(vma,
662 vma->vm_start,
Linus Torvalds7314e6132013-10-29 10:21:34 -0700663 mem->addr >> PAGE_SHIFT,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100664 vma->vm_end - vma->vm_start,
665 vma->vm_page_prot);
666}
667
Hans J. Kochbeafc542006-12-07 10:58:29 +0100668static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
669{
670 struct uio_listener *listener = filep->private_data;
671 struct uio_device *idev = listener->dev;
672 int mi;
673 unsigned long requested_pages, actual_pages;
674 int ret = 0;
675
676 if (vma->vm_end < vma->vm_start)
677 return -EINVAL;
678
679 vma->vm_private_data = idev;
680
681 mi = uio_find_mem_index(vma);
682 if (mi < 0)
683 return -EINVAL;
684
Libin52c2dad2013-07-03 15:01:27 -0700685 requested_pages = vma_pages(vma);
Ian Abbott6da2d372009-02-24 17:22:59 +0000686 actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK)
687 + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100688 if (requested_pages > actual_pages)
689 return -EINVAL;
690
691 if (idev->info->mmap) {
Hans J. Kochbeafc542006-12-07 10:58:29 +0100692 ret = idev->info->mmap(idev->info, vma);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100693 return ret;
694 }
695
696 switch (idev->info->mem[mi].memtype) {
697 case UIO_MEM_PHYS:
698 return uio_mmap_physical(vma);
699 case UIO_MEM_LOGICAL:
700 case UIO_MEM_VIRTUAL:
701 return uio_mmap_logical(vma);
702 default:
703 return -EINVAL;
704 }
705}
706
Jan Engelhardt4f014692008-01-22 20:50:54 +0100707static const struct file_operations uio_fops = {
Hans J. Kochbeafc542006-12-07 10:58:29 +0100708 .owner = THIS_MODULE,
709 .open = uio_open,
710 .release = uio_release,
711 .read = uio_read,
Hans J. Koch328a14e2008-05-23 13:50:14 +0200712 .write = uio_write,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100713 .mmap = uio_mmap,
714 .poll = uio_poll,
715 .fasync = uio_fasync,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200716 .llseek = noop_llseek,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100717};
718
719static int uio_major_init(void)
720{
Eric W. Biederman91960a42010-09-14 11:38:06 -0700721 static const char name[] = "uio";
722 struct cdev *cdev = NULL;
723 dev_t uio_dev = 0;
724 int result;
725
726 result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name);
727 if (result)
728 goto out;
729
730 result = -ENOMEM;
731 cdev = cdev_alloc();
732 if (!cdev)
733 goto out_unregister;
734
735 cdev->owner = THIS_MODULE;
736 cdev->ops = &uio_fops;
737 kobject_set_name(&cdev->kobj, "%s", name);
738
739 result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES);
740 if (result)
741 goto out_put;
742
743 uio_major = MAJOR(uio_dev);
744 uio_cdev = cdev;
Wanlong Gaod80df1c2011-08-20 12:12:08 +0800745 return 0;
Eric W. Biederman91960a42010-09-14 11:38:06 -0700746out_put:
747 kobject_put(&cdev->kobj);
748out_unregister:
749 unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES);
Wanlong Gaod80df1c2011-08-20 12:12:08 +0800750out:
751 return result;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100752}
753
754static void uio_major_cleanup(void)
755{
Eric W. Biederman91960a42010-09-14 11:38:06 -0700756 unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES);
757 cdev_del(uio_cdev);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100758}
759
760static int init_uio_class(void)
761{
Eric W. Biederman3d4f9d72010-09-14 11:36:27 -0700762 int ret;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100763
764 /* This is the first time in here, set everything up properly */
765 ret = uio_major_init();
766 if (ret)
767 goto exit;
768
Eric W. Biedermanc66fdab2010-09-14 11:38:36 -0700769 ret = class_register(&uio_class);
770 if (ret) {
771 printk(KERN_ERR "class_register failed for uio\n");
772 goto err_class_register;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100773 }
774 return 0;
775
Eric W. Biedermanc66fdab2010-09-14 11:38:36 -0700776err_class_register:
Hans J. Kochbeafc542006-12-07 10:58:29 +0100777 uio_major_cleanup();
778exit:
779 return ret;
780}
781
Eric W. Biederman3d4f9d72010-09-14 11:36:27 -0700782static void release_uio_class(void)
Hans J. Kochbeafc542006-12-07 10:58:29 +0100783{
Eric W. Biedermanc66fdab2010-09-14 11:38:36 -0700784 class_unregister(&uio_class);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100785 uio_major_cleanup();
Hans J. Kochbeafc542006-12-07 10:58:29 +0100786}
787
788/**
789 * uio_register_device - register a new userspace IO device
790 * @owner: module that creates the new device
791 * @parent: parent device
792 * @info: UIO device capabilities
793 *
794 * returns zero on success or a negative error code.
795 */
796int __uio_register_device(struct module *owner,
797 struct device *parent,
798 struct uio_info *info)
799{
800 struct uio_device *idev;
801 int ret = 0;
802
803 if (!parent || !info || !info->name || !info->version)
804 return -EINVAL;
805
806 info->uio_dev = NULL;
807
Michal Simeke6789cd2013-09-12 07:39:59 +0200808 idev = devm_kzalloc(parent, sizeof(*idev), GFP_KERNEL);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100809 if (!idev) {
Michal Simeke6789cd2013-09-12 07:39:59 +0200810 return -ENOMEM;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100811 }
812
813 idev->owner = owner;
814 idev->info = info;
815 init_waitqueue_head(&idev->wait);
816 atomic_set(&idev->event, 0);
817
818 ret = uio_get_minor(idev);
819 if (ret)
Michal Simeke6789cd2013-09-12 07:39:59 +0200820 return ret;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100821
Eric W. Biedermanc66fdab2010-09-14 11:38:36 -0700822 idev->dev = device_create(&uio_class, parent,
Greg Kroah-Hartmana9b12612008-07-21 20:03:34 -0700823 MKDEV(uio_major, idev->minor), idev,
824 "uio%d", idev->minor);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100825 if (IS_ERR(idev->dev)) {
826 printk(KERN_ERR "UIO: device register failed\n");
827 ret = PTR_ERR(idev->dev);
828 goto err_device_create;
829 }
Hans J. Kochbeafc542006-12-07 10:58:29 +0100830
831 ret = uio_dev_add_attributes(idev);
832 if (ret)
833 goto err_uio_dev_add_attributes;
834
835 info->uio_dev = idev;
836
Eric W. Biederman6427a762010-09-14 11:37:36 -0700837 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) {
Brian Russella0871462015-03-19 17:55:26 +0000838 /*
839 * Note that we deliberately don't use devm_request_irq
840 * here. The parent module can unregister the UIO device
841 * and call pci_disable_msi, which requires that this
842 * irq has been freed. However, the device may have open
843 * FDs at the time of unregister and therefore may not be
844 * freed until they are released.
845 */
846 ret = request_irq(info->irq, uio_interrupt,
Eric W. Biederman6427a762010-09-14 11:37:36 -0700847 info->irq_flags, info->name, idev);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100848 if (ret)
849 goto err_request_irq;
850 }
851
852 return 0;
853
854err_request_irq:
855 uio_dev_del_attributes(idev);
856err_uio_dev_add_attributes:
Eric W. Biedermanc66fdab2010-09-14 11:38:36 -0700857 device_destroy(&uio_class, MKDEV(uio_major, idev->minor));
Hans J. Kochbeafc542006-12-07 10:58:29 +0100858err_device_create:
859 uio_free_minor(idev);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100860 return ret;
861}
862EXPORT_SYMBOL_GPL(__uio_register_device);
863
864/**
865 * uio_unregister_device - unregister a industrial IO device
866 * @info: UIO device capabilities
867 *
868 */
869void uio_unregister_device(struct uio_info *info)
870{
871 struct uio_device *idev;
872
873 if (!info || !info->uio_dev)
874 return;
875
876 idev = info->uio_dev;
877
878 uio_free_minor(idev);
879
Hans J. Kochbeafc542006-12-07 10:58:29 +0100880 uio_dev_del_attributes(idev);
881
Brian Russella0871462015-03-19 17:55:26 +0000882 free_irq(idev->info->irq, idev);
883
Eric W. Biedermanc66fdab2010-09-14 11:38:36 -0700884 device_destroy(&uio_class, MKDEV(uio_major, idev->minor));
Hans J. Kochbeafc542006-12-07 10:58:29 +0100885
886 return;
887}
888EXPORT_SYMBOL_GPL(uio_unregister_device);
889
890static int __init uio_init(void)
891{
Eric W. Biederman3d4f9d72010-09-14 11:36:27 -0700892 return init_uio_class();
Hans J. Kochbeafc542006-12-07 10:58:29 +0100893}
894
895static void __exit uio_exit(void)
896{
Eric W. Biederman3d4f9d72010-09-14 11:36:27 -0700897 release_uio_class();
Hans J. Kochbeafc542006-12-07 10:58:29 +0100898}
899
900module_init(uio_init)
901module_exit(uio_exit)
902MODULE_LICENSE("GPL v2");