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