Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
[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 <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                 destroy_workqueue(drv->event_queue);
128
129         return rc;
130 };
131
132 /**
133  *      i2o_driver_unregister - Unregister a I2O driver (OSM) from the I2O core
134  *      @drv: I2O driver which should be unregistered
135  *
136  *      Unregisters the OSM drv from the I2O core and cleanup event queues if
137  *      necessary.
138  */
139 void i2o_driver_unregister(struct i2o_driver *drv)
140 {
141         struct i2o_controller *c;
142         unsigned long flags;
143
144         osm_debug("unregister driver %s\n", drv->name);
145
146         driver_unregister(&drv->driver);
147
148         list_for_each_entry(c, &i2o_controllers, list) {
149                 struct i2o_device *i2o_dev;
150
151                 list_for_each_entry(i2o_dev, &c->devices, list)
152                     i2o_driver_notify_device_remove(drv, i2o_dev);
153
154                 i2o_driver_notify_controller_remove(drv, c);
155         }
156
157         spin_lock_irqsave(&i2o_drivers_lock, flags);
158         i2o_drivers[drv->context] = NULL;
159         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
160
161         if (drv->event_queue) {
162                 destroy_workqueue(drv->event_queue);
163                 drv->event_queue = NULL;
164                 osm_debug("event queue removed for %s\n", drv->name);
165         }
166 };
167
168 /**
169  *      i2o_driver_dispatch - dispatch an I2O reply message
170  *      @c: I2O controller of the message
171  *      @m: I2O message number
172  *      @msg: I2O message to be delivered
173  *
174  *      The reply is delivered to the driver from which the original message
175  *      was. This function is only called from interrupt context.
176  *
177  *      Returns 0 on success and the message should not be flushed. Returns > 0
178  *      on success and if the message should be flushed afterwords. Returns
179  *      negative error code on failure (the message will be flushed too).
180  */
181 int i2o_driver_dispatch(struct i2o_controller *c, u32 m)
182 {
183         struct i2o_driver *drv;
184         struct i2o_message *msg = i2o_msg_out_to_virt(c, m);
185         u32 context = le32_to_cpu(msg->u.s.icntxt);
186         unsigned long flags;
187
188         if (unlikely(context >= i2o_max_drivers)) {
189                 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
190                          context);
191                 return -EIO;
192         }
193
194         spin_lock_irqsave(&i2o_drivers_lock, flags);
195         drv = i2o_drivers[context];
196         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
197
198         if (unlikely(!drv)) {
199                 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
200                          context);
201                 return -EIO;
202         }
203
204         if ((le32_to_cpu(msg->u.head[1]) >> 24) == I2O_CMD_UTIL_EVT_REGISTER) {
205                 struct i2o_device *dev, *tmp;
206                 struct i2o_event *evt;
207                 u16 size;
208                 u16 tid = le32_to_cpu(msg->u.head[1]) & 0xfff;
209
210                 osm_debug("event received from device %d\n", tid);
211
212                 if (!drv->event)
213                         return -EIO;
214
215                 /* cut of header from message size (in 32-bit words) */
216                 size = (le32_to_cpu(msg->u.head[0]) >> 16) - 5;
217
218                 evt = kzalloc(size * 4 + sizeof(*evt), GFP_ATOMIC);
219                 if (!evt)
220                         return -ENOMEM;
221
222                 evt->size = size;
223                 evt->tcntxt = le32_to_cpu(msg->u.s.tcntxt);
224                 evt->event_indicator = le32_to_cpu(msg->body[0]);
225                 memcpy(&evt->data, &msg->body[1], size * 4);
226
227                 list_for_each_entry_safe(dev, tmp, &c->devices, list)
228                     if (dev->lct_data.tid == tid) {
229                         evt->i2o_dev = dev;
230                         break;
231                 }
232
233                 INIT_WORK(&evt->work, drv->event);
234                 queue_work(drv->event_queue, &evt->work);
235                 return 1;
236         }
237
238         if (unlikely(!drv->reply)) {
239                 osm_debug("%s: Reply to driver %s, but no reply function"
240                           " defined!\n", c->name, drv->name);
241                 return -EIO;
242         }
243
244         return drv->reply(c, m, msg);
245 }
246
247 /**
248  *      i2o_driver_notify_controller_add_all - Send notify of added controller
249  *      @c: newly added controller
250  *
251  *      Send notifications to all registered drivers that a new controller was
252  *      added.
253  */
254 void i2o_driver_notify_controller_add_all(struct i2o_controller *c)
255 {
256         int i;
257         struct i2o_driver *drv;
258
259         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
260                 drv = i2o_drivers[i];
261
262                 if (drv)
263                         i2o_driver_notify_controller_add(drv, c);
264         }
265 }
266
267 /**
268  *      i2o_driver_notify_controller_remove_all - Send notify of removed controller
269  *      @c: controller that is being removed
270  *
271  *      Send notifications to all registered drivers that a controller was
272  *      removed.
273  */
274 void i2o_driver_notify_controller_remove_all(struct i2o_controller *c)
275 {
276         int i;
277         struct i2o_driver *drv;
278
279         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
280                 drv = i2o_drivers[i];
281
282                 if (drv)
283                         i2o_driver_notify_controller_remove(drv, c);
284         }
285 }
286
287 /**
288  *      i2o_driver_notify_device_add_all - Send notify of added device
289  *      @i2o_dev: newly added I2O device
290  *
291  *      Send notifications to all registered drivers that a device was added.
292  */
293 void i2o_driver_notify_device_add_all(struct i2o_device *i2o_dev)
294 {
295         int i;
296         struct i2o_driver *drv;
297
298         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
299                 drv = i2o_drivers[i];
300
301                 if (drv)
302                         i2o_driver_notify_device_add(drv, i2o_dev);
303         }
304 }
305
306 /**
307  *      i2o_driver_notify_device_remove_all - Send notify of removed device
308  *      @i2o_dev: device that is being removed
309  *
310  *      Send notifications to all registered drivers that a device was removed.
311  */
312 void i2o_driver_notify_device_remove_all(struct i2o_device *i2o_dev)
313 {
314         int i;
315         struct i2o_driver *drv;
316
317         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
318                 drv = i2o_drivers[i];
319
320                 if (drv)
321                         i2o_driver_notify_device_remove(drv, i2o_dev);
322         }
323 }
324
325 /**
326  *      i2o_driver_init - initialize I2O drivers (OSMs)
327  *
328  *      Registers the I2O bus and allocate memory for the array of OSMs.
329  *
330  *      Returns 0 on success or negative error code on failure.
331  */
332 int __init i2o_driver_init(void)
333 {
334         int rc = 0;
335
336         spin_lock_init(&i2o_drivers_lock);
337
338         if ((i2o_max_drivers < 2) || (i2o_max_drivers > 64) ||
339             ((i2o_max_drivers ^ (i2o_max_drivers - 1)) !=
340              (2 * i2o_max_drivers - 1))) {
341                 osm_warn("max_drivers set to %d, but must be >=2 and <= 64 and "
342                          "a power of 2\n", i2o_max_drivers);
343                 i2o_max_drivers = I2O_MAX_DRIVERS;
344         }
345         osm_info("max drivers = %d\n", i2o_max_drivers);
346
347         i2o_drivers =
348             kzalloc(i2o_max_drivers * sizeof(*i2o_drivers), GFP_KERNEL);
349         if (!i2o_drivers)
350                 return -ENOMEM;
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 frees driver array.
364  */
365 void 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);