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 * @msg: I2O message to be delivered
177 *
178 * The reply is delivered to the driver from which the original message
179 * was. This function is only called from interrupt context.
180 *
181 * Returns 0 on success and the message should not be flushed. Returns > 0
182 * on success and if the message should be flushed afterwords. Returns
183 * negative error code on failure (the message will be flushed too).
184 */
185 int i2o_driver_dispatch(struct i2o_controller *c, u32 m)
186 {
187 struct i2o_driver *drv;
188 struct i2o_message *msg = i2o_msg_out_to_virt(c, m);
189 u32 context = le32_to_cpu(msg->u.s.icntxt);
190 unsigned long flags;
191
192 if (unlikely(context >= i2o_max_drivers)) {
193 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
194 context);
195 return -EIO;
196 }
197
198 spin_lock_irqsave(&i2o_drivers_lock, flags);
199 drv = i2o_drivers[context];
200 spin_unlock_irqrestore(&i2o_drivers_lock, flags);
201
202 if (unlikely(!drv)) {
203 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
204 context);
205 return -EIO;
206 }
207
208 if ((le32_to_cpu(msg->u.head[1]) >> 24) == I2O_CMD_UTIL_EVT_REGISTER) {
209 struct i2o_device *dev, *tmp;
210 struct i2o_event *evt;
211 u16 size;
212 u16 tid = le32_to_cpu(msg->u.head[1]) & 0xfff;
213
214 osm_debug("event received from device %d\n", tid);
215
216 if (!drv->event)
217 return -EIO;
218
219 /* cut of header from message size (in 32-bit words) */
220 size = (le32_to_cpu(msg->u.head[0]) >> 16) - 5;
221
222 evt = kzalloc(size * 4 + sizeof(*evt), GFP_ATOMIC);
223 if (!evt)
224 return -ENOMEM;
225
226 evt->size = size;
227 evt->tcntxt = le32_to_cpu(msg->u.s.tcntxt);
228 evt->event_indicator = le32_to_cpu(msg->body[0]);
229 memcpy(&evt->data, &msg->body[1], size * 4);
230
231 list_for_each_entry_safe(dev, tmp, &c->devices, list)
232 if (dev->lct_data.tid == tid) {
233 evt->i2o_dev = dev;
234 break;
235 }
236
237 INIT_WORK(&evt->work, drv->event);
238 queue_work(drv->event_queue, &evt->work);
239 return 1;
240 }
241
242 if (unlikely(!drv->reply)) {
243 osm_debug("%s: Reply to driver %s, but no reply function"
244 " defined!\n", c->name, drv->name);
245 return -EIO;
246 }
247
248 return drv->reply(c, m, msg);
249 }
250
251 /**
252 * i2o_driver_notify_controller_add_all - Send notify of added controller
253 * @c: newly added controller
254 *
255 * Send notifications to all registered drivers that a new controller was
256 * added.
257 */
258 void i2o_driver_notify_controller_add_all(struct i2o_controller *c)
259 {
260 int i;
261 struct i2o_driver *drv;
262
263 for (i = 0; i < i2o_max_drivers; i++) {
264 drv = i2o_drivers[i];
265
266 if (drv)
267 i2o_driver_notify_controller_add(drv, c);
268 }
269 }
270
271 /**
272 * i2o_driver_notify_controller_remove_all - Send notify of removed controller
273 * @c: controller that is being removed
274 *
275 * Send notifications to all registered drivers that a controller was
276 * removed.
277 */
278 void i2o_driver_notify_controller_remove_all(struct i2o_controller *c)
279 {
280 int i;
281 struct i2o_driver *drv;
282
283 for (i = 0; i < i2o_max_drivers; i++) {
284 drv = i2o_drivers[i];
285
286 if (drv)
287 i2o_driver_notify_controller_remove(drv, c);
288 }
289 }
290
291 /**
292 * i2o_driver_notify_device_add_all - Send notify of added device
293 * @i2o_dev: newly added I2O device
294 *
295 * Send notifications to all registered drivers that a device was added.
296 */
297 void i2o_driver_notify_device_add_all(struct i2o_device *i2o_dev)
298 {
299 int i;
300 struct i2o_driver *drv;
301
302 for (i = 0; i < i2o_max_drivers; i++) {
303 drv = i2o_drivers[i];
304
305 if (drv)
306 i2o_driver_notify_device_add(drv, i2o_dev);
307 }
308 }
309
310 /**
311 * i2o_driver_notify_device_remove_all - Send notify of removed device
312 * @i2o_dev: device that is being removed
313 *
314 * Send notifications to all registered drivers that a device was removed.
315 */
316 void i2o_driver_notify_device_remove_all(struct i2o_device *i2o_dev)
317 {
318 int i;
319 struct i2o_driver *drv;
320
321 for (i = 0; i < i2o_max_drivers; i++) {
322 drv = i2o_drivers[i];
323
324 if (drv)
325 i2o_driver_notify_device_remove(drv, i2o_dev);
326 }
327 }
328
329 /**
330 * i2o_driver_init - initialize I2O drivers (OSMs)
331 *
332 * Registers the I2O bus and allocate memory for the array of OSMs.
333 *
334 * Returns 0 on success or negative error code on failure.
335 */
336 int __init i2o_driver_init(void)
337 {
338 int rc = 0;
339
340 spin_lock_init(&i2o_drivers_lock);
341
342 if ((i2o_max_drivers < 2) || (i2o_max_drivers > 64)) {
343 osm_warn("max_drivers set to %d, but must be >=2 and <= 64\n",
344 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 kcalloc(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 frees driver array.
366 */
367 void 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);
379
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