64130227574f8cf32aec2113139f99eb6b5de699
[linux-3.10.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 a I2O device class id match the class ids of
38  *                      the I2O driver (OSM)
39  *
40  *      @dev: device which should be verified
41  *      @drv: the driver to match against
42  *
43  *      Used by the bus to check if the driver wants to handle the device.
44  *
45  *      Returns 1 if the class ids of the driver match the class id of the
46  *      device, otherwise 0.
47  */
48 static int i2o_bus_match(struct device *dev, struct device_driver *drv)
49 {
50         struct i2o_device *i2o_dev = to_i2o_device(dev);
51         struct i2o_driver *i2o_drv = to_i2o_driver(drv);
52         struct i2o_class_id *ids = i2o_drv->classes;
53
54         if (ids)
55                 while (ids->class_id != I2O_CLASS_END) {
56                         if (ids->class_id == i2o_dev->lct_data.class_id)
57                                 return 1;
58                         ids++;
59                 }
60         return 0;
61 };
62
63 /* I2O bus type */
64 struct bus_type i2o_bus_type = {
65         .name = "i2o",
66         .match = i2o_bus_match,
67         .dev_attrs = i2o_device_attrs
68 };
69
70 /**
71  *      i2o_driver_register - Register a I2O driver (OSM) in the I2O core
72  *      @drv: I2O driver which should be registered
73  *
74  *      Registers the OSM drv in the I2O core and creates an event queues if
75  *      necessary.
76  *
77  *      Returns 0 on success or negative error code on failure.
78  */
79 int i2o_driver_register(struct i2o_driver *drv)
80 {
81         struct i2o_controller *c;
82         int i;
83         int rc = 0;
84         unsigned long flags;
85
86         osm_debug("Register driver %s\n", drv->name);
87
88         if (drv->event) {
89                 drv->event_queue = create_workqueue(drv->name);
90                 if (!drv->event_queue) {
91                         osm_err("Could not initialize event queue for driver "
92                                 "%s\n", drv->name);
93                         return -EFAULT;
94                 }
95                 osm_debug("Event queue initialized for driver %s\n", drv->name);
96         } else
97                 drv->event_queue = NULL;
98
99         drv->driver.name = drv->name;
100         drv->driver.bus = &i2o_bus_type;
101
102         spin_lock_irqsave(&i2o_drivers_lock, flags);
103
104         for (i = 0; i2o_drivers[i]; i++)
105                 if (i >= i2o_max_drivers) {
106                         osm_err("too many drivers registered, increase "
107                                 "max_drivers\n");
108                         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
109                         return -EFAULT;
110                 }
111
112         drv->context = i;
113         i2o_drivers[i] = drv;
114
115         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
116
117         osm_debug("driver %s gets context id %d\n", drv->name, drv->context);
118
119         list_for_each_entry(c, &i2o_controllers, list) {
120                 struct i2o_device *i2o_dev;
121
122                 i2o_driver_notify_controller_add(drv, c);
123                 list_for_each_entry(i2o_dev, &c->devices, list)
124                     i2o_driver_notify_device_add(drv, i2o_dev);
125         }
126
127         rc = driver_register(&drv->driver);
128         if (rc)
129                 destroy_workqueue(drv->event_queue);
130
131         return rc;
132 };
133
134 /**
135  *      i2o_driver_unregister - Unregister a I2O driver (OSM) from the I2O core
136  *      @drv: I2O driver which should be unregistered
137  *
138  *      Unregisters the OSM drv from the I2O core and cleanup event queues if
139  *      necessary.
140  */
141 void i2o_driver_unregister(struct i2o_driver *drv)
142 {
143         struct i2o_controller *c;
144         unsigned long flags;
145
146         osm_debug("unregister driver %s\n", drv->name);
147
148         driver_unregister(&drv->driver);
149
150         list_for_each_entry(c, &i2o_controllers, list) {
151                 struct i2o_device *i2o_dev;
152
153                 list_for_each_entry(i2o_dev, &c->devices, list)
154                     i2o_driver_notify_device_remove(drv, i2o_dev);
155
156                 i2o_driver_notify_controller_remove(drv, c);
157         }
158
159         spin_lock_irqsave(&i2o_drivers_lock, flags);
160         i2o_drivers[drv->context] = NULL;
161         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
162
163         if (drv->event_queue) {
164                 destroy_workqueue(drv->event_queue);
165                 drv->event_queue = NULL;
166                 osm_debug("event queue removed for %s\n", drv->name);
167         }
168 };
169
170 /**
171  *      i2o_driver_dispatch - dispatch an I2O reply message
172  *      @c: I2O controller of the message
173  *      @m: I2O message number
174  *      @msg: I2O message to be delivered
175  *
176  *      The reply is delivered to the driver from which the original message
177  *      was. This function is only called from interrupt context.
178  *
179  *      Returns 0 on success and the message should not be flushed. Returns > 0
180  *      on success and if the message should be flushed afterwords. Returns
181  *      negative error code on failure (the message will be flushed too).
182  */
183 int i2o_driver_dispatch(struct i2o_controller *c, u32 m)
184 {
185         struct i2o_driver *drv;
186         struct i2o_message *msg = i2o_msg_out_to_virt(c, m);
187         u32 context = le32_to_cpu(msg->u.s.icntxt);
188         unsigned long flags;
189
190         if (unlikely(context >= i2o_max_drivers)) {
191                 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
192                          context);
193                 return -EIO;
194         }
195
196         spin_lock_irqsave(&i2o_drivers_lock, flags);
197         drv = i2o_drivers[context];
198         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
199
200         if (unlikely(!drv)) {
201                 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
202                          context);
203                 return -EIO;
204         }
205
206         if ((le32_to_cpu(msg->u.head[1]) >> 24) == I2O_CMD_UTIL_EVT_REGISTER) {
207                 struct i2o_device *dev, *tmp;
208                 struct i2o_event *evt;
209                 u16 size;
210                 u16 tid = le32_to_cpu(msg->u.head[1]) & 0xfff;
211
212                 osm_debug("event received from device %d\n", tid);
213
214                 if (!drv->event)
215                         return -EIO;
216
217                 /* cut of header from message size (in 32-bit words) */
218                 size = (le32_to_cpu(msg->u.head[0]) >> 16) - 5;
219
220                 evt = kzalloc(size * 4 + sizeof(*evt), GFP_ATOMIC);
221                 if (!evt)
222                         return -ENOMEM;
223
224                 evt->size = size;
225                 evt->tcntxt = le32_to_cpu(msg->u.s.tcntxt);
226                 evt->event_indicator = le32_to_cpu(msg->body[0]);
227                 memcpy(&evt->data, &msg->body[1], size * 4);
228
229                 list_for_each_entry_safe(dev, tmp, &c->devices, list)
230                     if (dev->lct_data.tid == tid) {
231                         evt->i2o_dev = dev;
232                         break;
233                 }
234
235                 INIT_WORK(&evt->work, (void (*)(void *))drv->event, evt);
236                 queue_work(drv->event_queue, &evt->work);
237                 return 1;
238         }
239
240         if (unlikely(!drv->reply)) {
241                 osm_debug("%s: Reply to driver %s, but no reply function"
242                           " defined!\n", c->name, drv->name);
243                 return -EIO;
244         }
245
246         return drv->reply(c, m, msg);
247 }
248
249 /**
250  *      i2o_driver_notify_controller_add_all - Send notify of added controller
251  *                                             to all I2O drivers
252  *
253  *      Send notifications to all registered drivers that a new controller was
254  *      added.
255  */
256 void i2o_driver_notify_controller_add_all(struct i2o_controller *c)
257 {
258         int i;
259         struct i2o_driver *drv;
260
261         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
262                 drv = i2o_drivers[i];
263
264                 if (drv)
265                         i2o_driver_notify_controller_add(drv, c);
266         }
267 }
268
269 /**
270  *      i2o_driver_notify_controller_remove_all - Send notify of removed
271  *                                                controller to all I2O drivers
272  *
273  *      Send notifications to all registered drivers that a controller was
274  *      removed.
275  */
276 void i2o_driver_notify_controller_remove_all(struct i2o_controller *c)
277 {
278         int i;
279         struct i2o_driver *drv;
280
281         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
282                 drv = i2o_drivers[i];
283
284                 if (drv)
285                         i2o_driver_notify_controller_remove(drv, c);
286         }
287 }
288
289 /**
290  *      i2o_driver_notify_device_add_all - Send notify of added device to all
291  *                                         I2O drivers
292  *
293  *      Send notifications to all registered drivers that a device was added.
294  */
295 void i2o_driver_notify_device_add_all(struct i2o_device *i2o_dev)
296 {
297         int i;
298         struct i2o_driver *drv;
299
300         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
301                 drv = i2o_drivers[i];
302
303                 if (drv)
304                         i2o_driver_notify_device_add(drv, i2o_dev);
305         }
306 }
307
308 /**
309  *      i2o_driver_notify_device_remove_all - Send notify of removed device to
310  *                                            all I2O drivers
311  *
312  *      Send notifications to all registered drivers that a device was removed.
313  */
314 void i2o_driver_notify_device_remove_all(struct i2o_device *i2o_dev)
315 {
316         int i;
317         struct i2o_driver *drv;
318
319         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
320                 drv = i2o_drivers[i];
321
322                 if (drv)
323                         i2o_driver_notify_device_remove(drv, i2o_dev);
324         }
325 }
326
327 /**
328  *      i2o_driver_init - initialize I2O drivers (OSMs)
329  *
330  *      Registers the I2O bus and allocate memory for the array of OSMs.
331  *
332  *      Returns 0 on success or negative error code on failure.
333  */
334 int __init i2o_driver_init(void)
335 {
336         int rc = 0;
337
338         spin_lock_init(&i2o_drivers_lock);
339
340         if ((i2o_max_drivers < 2) || (i2o_max_drivers > 64) ||
341             ((i2o_max_drivers ^ (i2o_max_drivers - 1)) !=
342              (2 * i2o_max_drivers - 1))) {
343                 osm_warn("max_drivers set to %d, but must be >=2 and <= 64 and "
344                          "a power of 2\n", i2o_max_drivers);
345                 i2o_max_drivers = I2O_MAX_DRIVERS;
346         }
347         osm_info("max drivers = %d\n", i2o_max_drivers);
348
349         i2o_drivers =
350             kzalloc(i2o_max_drivers * sizeof(*i2o_drivers), GFP_KERNEL);
351         if (!i2o_drivers)
352                 return -ENOMEM;
353
354         rc = bus_register(&i2o_bus_type);
355
356         if (rc < 0)
357                 kfree(i2o_drivers);
358
359         return rc;
360 };
361
362 /**
363  *      i2o_driver_exit - clean up I2O drivers (OSMs)
364  *
365  *      Unregisters the I2O bus and free driver array.
366  */
367 void __exit i2o_driver_exit(void)
368 {
369         bus_unregister(&i2o_bus_type);
370         kfree(i2o_drivers);
371 };
372
373 EXPORT_SYMBOL(i2o_driver_register);
374 EXPORT_SYMBOL(i2o_driver_unregister);
375 EXPORT_SYMBOL(i2o_driver_notify_controller_add_all);
376 EXPORT_SYMBOL(i2o_driver_notify_controller_remove_all);
377 EXPORT_SYMBOL(i2o_driver_notify_device_add_all);
378 EXPORT_SYMBOL(i2o_driver_notify_device_remove_all);