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