i2o: remove extraneous kernel-doc
[linux-2.6.git] / drivers / message / i2o / driver.c
1 /*
2  *      Functions to handle I2O drivers (OSMs) and I2O bus type for sysfs
3  *
4  *      Copyright (C) 2004      Markus Lidel <Markus.Lidel@shadowconnect.com>
5  *
6  *      This program is free software; you can redistribute it and/or modify it
7  *      under the terms of the GNU General Public License as published by the
8  *      Free Software Foundation; either version 2 of the License, or (at your
9  *      option) any later version.
10  *
11  *      Fixes/additions:
12  *              Markus Lidel <Markus.Lidel@shadowconnect.com>
13  *                      initial version.
14  */
15
16 #include <linux/device.h>
17 #include <linux/module.h>
18 #include <linux/rwsem.h>
19 #include <linux/i2o.h>
20 #include <linux/workqueue.h>
21 #include <linux/string.h>
22 #include <linux/slab.h>
23 #include "core.h"
24
25 #define OSM_NAME        "i2o"
26
27 /* max_drivers - Maximum I2O drivers (OSMs) which could be registered */
28 static unsigned int i2o_max_drivers = I2O_MAX_DRIVERS;
29 module_param_named(max_drivers, i2o_max_drivers, uint, 0);
30 MODULE_PARM_DESC(max_drivers, "maximum number of OSM's to support");
31
32 /* I2O drivers lock and array */
33 static spinlock_t i2o_drivers_lock;
34 static struct i2o_driver **i2o_drivers;
35
36 /**
37  *      i2o_bus_match - Tell if I2O device class id matches the class ids of the I2O driver (OSM)
38  *      @dev: device which should be verified
39  *      @drv: the driver to match against
40  *
41  *      Used by the bus to check if the driver wants to handle the device.
42  *
43  *      Returns 1 if the class ids of the driver match the class id of the
44  *      device, otherwise 0.
45  */
46 static int i2o_bus_match(struct device *dev, struct device_driver *drv)
47 {
48         struct i2o_device *i2o_dev = to_i2o_device(dev);
49         struct i2o_driver *i2o_drv = to_i2o_driver(drv);
50         struct i2o_class_id *ids = i2o_drv->classes;
51
52         if (ids)
53                 while (ids->class_id != I2O_CLASS_END) {
54                         if (ids->class_id == i2o_dev->lct_data.class_id)
55                                 return 1;
56                         ids++;
57                 }
58         return 0;
59 };
60
61 /* I2O bus type */
62 struct bus_type i2o_bus_type = {
63         .name = "i2o",
64         .match = i2o_bus_match,
65         .dev_attrs = i2o_device_attrs
66 };
67
68 /**
69  *      i2o_driver_register - Register a I2O driver (OSM) in the I2O core
70  *      @drv: I2O driver which should be registered
71  *
72  *      Registers the OSM drv in the I2O core and creates an event queues if
73  *      necessary.
74  *
75  *      Returns 0 on success or negative error code on failure.
76  */
77 int i2o_driver_register(struct i2o_driver *drv)
78 {
79         struct i2o_controller *c;
80         int i;
81         int rc = 0;
82         unsigned long flags;
83
84         osm_debug("Register driver %s\n", drv->name);
85
86         if (drv->event) {
87                 drv->event_queue = create_workqueue(drv->name);
88                 if (!drv->event_queue) {
89                         osm_err("Could not initialize event queue for driver "
90                                 "%s\n", drv->name);
91                         return -EFAULT;
92                 }
93                 osm_debug("Event queue initialized for driver %s\n", drv->name);
94         } else
95                 drv->event_queue = NULL;
96
97         drv->driver.name = drv->name;
98         drv->driver.bus = &i2o_bus_type;
99
100         spin_lock_irqsave(&i2o_drivers_lock, flags);
101
102         for (i = 0; i2o_drivers[i]; i++)
103                 if (i >= i2o_max_drivers) {
104                         osm_err("too many drivers registered, increase "
105                                 "max_drivers\n");
106                         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
107                         return -EFAULT;
108                 }
109
110         drv->context = i;
111         i2o_drivers[i] = drv;
112
113         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
114
115         osm_debug("driver %s gets context id %d\n", drv->name, drv->context);
116
117         list_for_each_entry(c, &i2o_controllers, list) {
118                 struct i2o_device *i2o_dev;
119
120                 i2o_driver_notify_controller_add(drv, c);
121                 list_for_each_entry(i2o_dev, &c->devices, list)
122                     i2o_driver_notify_device_add(drv, i2o_dev);
123         }
124
125         rc = driver_register(&drv->driver);
126         if (rc) {
127                 if (drv->event) {
128                         destroy_workqueue(drv->event_queue);
129                         drv->event_queue = NULL;
130                 }
131         }
132
133         return rc;
134 };
135
136 /**
137  *      i2o_driver_unregister - Unregister a I2O driver (OSM) from the I2O core
138  *      @drv: I2O driver which should be unregistered
139  *
140  *      Unregisters the OSM drv from the I2O core and cleanup event queues if
141  *      necessary.
142  */
143 void i2o_driver_unregister(struct i2o_driver *drv)
144 {
145         struct i2o_controller *c;
146         unsigned long flags;
147
148         osm_debug("unregister driver %s\n", drv->name);
149
150         driver_unregister(&drv->driver);
151
152         list_for_each_entry(c, &i2o_controllers, list) {
153                 struct i2o_device *i2o_dev;
154
155                 list_for_each_entry(i2o_dev, &c->devices, list)
156                     i2o_driver_notify_device_remove(drv, i2o_dev);
157
158                 i2o_driver_notify_controller_remove(drv, c);
159         }
160
161         spin_lock_irqsave(&i2o_drivers_lock, flags);
162         i2o_drivers[drv->context] = NULL;
163         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
164
165         if (drv->event_queue) {
166                 destroy_workqueue(drv->event_queue);
167                 drv->event_queue = NULL;
168                 osm_debug("event queue removed for %s\n", drv->name);
169         }
170 };
171
172 /**
173  *      i2o_driver_dispatch - dispatch an I2O reply message
174  *      @c: I2O controller of the message
175  *      @m: I2O message number
176  *
177  *      The reply is delivered to the driver from which the original message
178  *      was. This function is only called from interrupt context.
179  *
180  *      Returns 0 on success and the message should not be flushed. Returns > 0
181  *      on success and if the message should be flushed afterwords. Returns
182  *      negative error code on failure (the message will be flushed too).
183  */
184 int i2o_driver_dispatch(struct i2o_controller *c, u32 m)
185 {
186         struct i2o_driver *drv;
187         struct i2o_message *msg = i2o_msg_out_to_virt(c, m);
188         u32 context = le32_to_cpu(msg->u.s.icntxt);
189         unsigned long flags;
190
191         if (unlikely(context >= i2o_max_drivers)) {
192                 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
193                          context);
194                 return -EIO;
195         }
196
197         spin_lock_irqsave(&i2o_drivers_lock, flags);
198         drv = i2o_drivers[context];
199         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
200
201         if (unlikely(!drv)) {
202                 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
203                          context);
204                 return -EIO;
205         }
206
207         if ((le32_to_cpu(msg->u.head[1]) >> 24) == I2O_CMD_UTIL_EVT_REGISTER) {
208                 struct i2o_device *dev, *tmp;
209                 struct i2o_event *evt;
210                 u16 size;
211                 u16 tid = le32_to_cpu(msg->u.head[1]) & 0xfff;
212
213                 osm_debug("event received from device %d\n", tid);
214
215                 if (!drv->event)
216                         return -EIO;
217
218                 /* cut of header from message size (in 32-bit words) */
219                 size = (le32_to_cpu(msg->u.head[0]) >> 16) - 5;
220
221                 evt = kzalloc(size * 4 + sizeof(*evt), GFP_ATOMIC);
222                 if (!evt)
223                         return -ENOMEM;
224
225                 evt->size = size;
226                 evt->tcntxt = le32_to_cpu(msg->u.s.tcntxt);
227                 evt->event_indicator = le32_to_cpu(msg->body[0]);
228                 memcpy(&evt->data, &msg->body[1], size * 4);
229
230                 list_for_each_entry_safe(dev, tmp, &c->devices, list)
231                     if (dev->lct_data.tid == tid) {
232                         evt->i2o_dev = dev;
233                         break;
234                 }
235
236                 INIT_WORK(&evt->work, drv->event);
237                 queue_work(drv->event_queue, &evt->work);
238                 return 1;
239         }
240
241         if (unlikely(!drv->reply)) {
242                 osm_debug("%s: Reply to driver %s, but no reply function"
243                           " defined!\n", c->name, drv->name);
244                 return -EIO;
245         }
246
247         return drv->reply(c, m, msg);
248 }
249
250 /**
251  *      i2o_driver_notify_controller_add_all - Send notify of added controller
252  *      @c: newly added controller
253  *
254  *      Send notifications to all registered drivers that a new controller was
255  *      added.
256  */
257 void i2o_driver_notify_controller_add_all(struct i2o_controller *c)
258 {
259         int i;
260         struct i2o_driver *drv;
261
262         for (i = 0; i < i2o_max_drivers; i++) {
263                 drv = i2o_drivers[i];
264
265                 if (drv)
266                         i2o_driver_notify_controller_add(drv, c);
267         }
268 }
269
270 /**
271  *      i2o_driver_notify_controller_remove_all - Send notify of removed controller
272  *      @c: controller that is being removed
273  *
274  *      Send notifications to all registered drivers that a controller was
275  *      removed.
276  */
277 void i2o_driver_notify_controller_remove_all(struct i2o_controller *c)
278 {
279         int i;
280         struct i2o_driver *drv;
281
282         for (i = 0; i < i2o_max_drivers; i++) {
283                 drv = i2o_drivers[i];
284
285                 if (drv)
286                         i2o_driver_notify_controller_remove(drv, c);
287         }
288 }
289
290 /**
291  *      i2o_driver_notify_device_add_all - Send notify of added device
292  *      @i2o_dev: newly added I2O device
293  *
294  *      Send notifications to all registered drivers that a device was added.
295  */
296 void i2o_driver_notify_device_add_all(struct i2o_device *i2o_dev)
297 {
298         int i;
299         struct i2o_driver *drv;
300
301         for (i = 0; i < i2o_max_drivers; i++) {
302                 drv = i2o_drivers[i];
303
304                 if (drv)
305                         i2o_driver_notify_device_add(drv, i2o_dev);
306         }
307 }
308
309 /**
310  *      i2o_driver_notify_device_remove_all - Send notify of removed device
311  *      @i2o_dev: device that is being removed
312  *
313  *      Send notifications to all registered drivers that a device was removed.
314  */
315 void i2o_driver_notify_device_remove_all(struct i2o_device *i2o_dev)
316 {
317         int i;
318         struct i2o_driver *drv;
319
320         for (i = 0; i < i2o_max_drivers; i++) {
321                 drv = i2o_drivers[i];
322
323                 if (drv)
324                         i2o_driver_notify_device_remove(drv, i2o_dev);
325         }
326 }
327
328 /**
329  *      i2o_driver_init - initialize I2O drivers (OSMs)
330  *
331  *      Registers the I2O bus and allocate memory for the array of OSMs.
332  *
333  *      Returns 0 on success or negative error code on failure.
334  */
335 int __init i2o_driver_init(void)
336 {
337         int rc = 0;
338
339         spin_lock_init(&i2o_drivers_lock);
340
341         if ((i2o_max_drivers < 2) || (i2o_max_drivers > 64)) {
342                 osm_warn("max_drivers set to %d, but must be >=2 and <= 64\n",
343                          i2o_max_drivers);
344                 i2o_max_drivers = I2O_MAX_DRIVERS;
345         }
346         osm_info("max drivers = %d\n", i2o_max_drivers);
347
348         i2o_drivers =
349             kcalloc(i2o_max_drivers, sizeof(*i2o_drivers), GFP_KERNEL);
350         if (!i2o_drivers)
351                 return -ENOMEM;
352
353         rc = bus_register(&i2o_bus_type);
354
355         if (rc < 0)
356                 kfree(i2o_drivers);
357
358         return rc;
359 };
360
361 /**
362  *      i2o_driver_exit - clean up I2O drivers (OSMs)
363  *
364  *      Unregisters the I2O bus and frees driver array.
365  */
366 void i2o_driver_exit(void)
367 {
368         bus_unregister(&i2o_bus_type);
369         kfree(i2o_drivers);
370 };
371
372 EXPORT_SYMBOL(i2o_driver_register);
373 EXPORT_SYMBOL(i2o_driver_unregister);
374 EXPORT_SYMBOL(i2o_driver_notify_controller_add_all);
375 EXPORT_SYMBOL(i2o_driver_notify_controller_remove_all);
376 EXPORT_SYMBOL(i2o_driver_notify_device_add_all);
377 EXPORT_SYMBOL(i2o_driver_notify_device_remove_all);