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 *
177 * The reply is delivered to the driver from which the original message
178 * was. This function is only called from interrupt context.
179 *
180 * Returns 0 on success and the message should not be flushed. Returns > 0
181 * on success and if the message should be flushed afterwords. Returns
182 * negative error code on failure (the message will be flushed too).
183 */
184 int i2o_driver_dispatch(struct i2o_controller *c, u32 m)
185 {
186 struct i2o_driver *drv;
187 struct i2o_message *msg = i2o_msg_out_to_virt(c, m);
188 u32 context = le32_to_cpu(msg->u.s.icntxt);
189 unsigned long flags;
190
191 if (unlikely(context >= i2o_max_drivers)) {
192 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
193 context);
194 return -EIO;
195 }
196
197 spin_lock_irqsave(&i2o_drivers_lock, flags);
198 drv = i2o_drivers[context];
199 spin_unlock_irqrestore(&i2o_drivers_lock, flags);
200
201 if (unlikely(!drv)) {
202 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
203 context);
204 return -EIO;
205 }
206
207 if ((le32_to_cpu(msg->u.head[1]) >> 24) == I2O_CMD_UTIL_EVT_REGISTER) {
208 struct i2o_device *dev, *tmp;
209 struct i2o_event *evt;
210 u16 size;
211 u16 tid = le32_to_cpu(msg->u.head[1]) & 0xfff;
212
213 osm_debug("event received from device %d\n", tid);
214
215 if (!drv->event)
216 return -EIO;
217
218 /* cut of header from message size (in 32-bit words) */
219 size = (le32_to_cpu(msg->u.head[0]) >> 16) - 5;
220
221 evt = kzalloc(size * 4 + sizeof(*evt), GFP_ATOMIC);
222 if (!evt)
223 return -ENOMEM;
224
225 evt->size = size;
226 evt->tcntxt = le32_to_cpu(msg->u.s.tcntxt);
227 evt->event_indicator = le32_to_cpu(msg->body[0]);
228 memcpy(&evt->data, &msg->body[1], size * 4);
229
230 list_for_each_entry_safe(dev, tmp, &c->devices, list)
231 if (dev->lct_data.tid == tid) {
232 evt->i2o_dev = dev;
233 break;
234 }
235
236 INIT_WORK(&evt->work, drv->event);
237 queue_work(drv->event_queue, &evt->work);
238 return 1;
239 }
240
241 if (unlikely(!drv->reply)) {
242 osm_debug("%s: Reply to driver %s, but no reply function"
243 " defined!\n", c->name, drv->name);
244 return -EIO;
245 }
246
247 return drv->reply(c, m, msg);
248 }
249
250 /**
251 * i2o_driver_notify_controller_add_all - Send notify of added controller
252 * @c: newly added controller
253 *
254 * Send notifications to all registered drivers that a new controller was
255 * added.
256 */
257 void i2o_driver_notify_controller_add_all(struct i2o_controller *c)
258 {
259 int i;
260 struct i2o_driver *drv;
261
262 for (i = 0; i < i2o_max_drivers; i++) {
263 drv = i2o_drivers[i];
264
265 if (drv)
266 i2o_driver_notify_controller_add(drv, c);
267 }
268 }
269
270 /**
271 * i2o_driver_notify_controller_remove_all - Send notify of removed controller
272 * @c: controller that is being removed
273 *
274 * Send notifications to all registered drivers that a controller was
275 * removed.
276 */
277 void i2o_driver_notify_controller_remove_all(struct i2o_controller *c)
278 {
279 int i;
280 struct i2o_driver *drv;
281
282 for (i = 0; i < i2o_max_drivers; i++) {
283 drv = i2o_drivers[i];
284
285 if (drv)
286 i2o_driver_notify_controller_remove(drv, c);
287 }
288 }
289
290 /**
291 * i2o_driver_notify_device_add_all - Send notify of added device
292 * @i2o_dev: newly added I2O device
293 *
294 * Send notifications to all registered drivers that a device was added.
295 */
296 void i2o_driver_notify_device_add_all(struct i2o_device *i2o_dev)
297 {
298 int i;
299 struct i2o_driver *drv;
300
301 for (i = 0; i < i2o_max_drivers; i++) {
302 drv = i2o_drivers[i];
303
304 if (drv)
305 i2o_driver_notify_device_add(drv, i2o_dev);
306 }
307 }
308
309 /**
310 * i2o_driver_notify_device_remove_all - Send notify of removed device
311 * @i2o_dev: device that is being removed
312 *
313 * Send notifications to all registered drivers that a device was removed.
314 */
315 void i2o_driver_notify_device_remove_all(struct i2o_device *i2o_dev)
316 {
317 int i;
318 struct i2o_driver *drv;
319
320 for (i = 0; i < i2o_max_drivers; i++) {
321 drv = i2o_drivers[i];
322
323 if (drv)
324 i2o_driver_notify_device_remove(drv, i2o_dev);
325 }
326 }
327
328 /**
329 * i2o_driver_init - initialize I2O drivers (OSMs)
330 *
331 * Registers the I2O bus and allocate memory for the array of OSMs.
332 *
333 * Returns 0 on success or negative error code on failure.
334 */
335 int __init i2o_driver_init(void)
336 {
337 int rc = 0;
338
339 spin_lock_init(&i2o_drivers_lock);
340
341 if ((i2o_max_drivers < 2) || (i2o_max_drivers > 64)) {
342 osm_warn("max_drivers set to %d, but must be >=2 and <= 64\n",
343 i2o_max_drivers);
344 i2o_max_drivers = I2O_MAX_DRIVERS;
345 }
346 osm_info("max drivers = %d\n", i2o_max_drivers);
347
348 i2o_drivers =
349 kcalloc(i2o_max_drivers, sizeof(*i2o_drivers), GFP_KERNEL);
350 if (!i2o_drivers)
351 return -ENOMEM;
352
353 rc = bus_register(&i2o_bus_type);
354
355 if (rc < 0)
356 kfree(i2o_drivers);
357
358 return rc;
359 };
360
361 /**
362 * i2o_driver_exit - clean up I2O drivers (OSMs)
363 *
364 * Unregisters the I2O bus and frees driver array.
365 */
366 void i2o_driver_exit(void)
367 {
368 bus_unregister(&i2o_bus_type);
369 kfree(i2o_drivers);
370 };
371
372 EXPORT_SYMBOL(i2o_driver_register);
373 EXPORT_SYMBOL(i2o_driver_unregister);
374 EXPORT_SYMBOL(i2o_driver_notify_controller_add_all);
375 EXPORT_SYMBOL(i2o_driver_notify_controller_remove_all);
376 EXPORT_SYMBOL(i2o_driver_notify_device_add_all);
377 EXPORT_SYMBOL(i2o_driver_notify_device_remove_all);
378
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