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 "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 */
i2o_bus_match(struct device * dev,struct device_driver * drv)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_groups = i2o_device_groups,
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 */
i2o_driver_register(struct i2o_driver * drv)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 = alloc_workqueue("%s", WQ_MEM_RECLAIM, 1,
88 drv->name);
89 if (!drv->event_queue) {
90 osm_err("Could not initialize event queue for driver "
91 "%s\n", drv->name);
92 return -EFAULT;
93 }
94 osm_debug("Event queue initialized for driver %s\n", drv->name);
95 } else
96 drv->event_queue = NULL;
97
98 drv->driver.name = drv->name;
99 drv->driver.bus = &i2o_bus_type;
100
101 spin_lock_irqsave(&i2o_drivers_lock, flags);
102
103 for (i = 0; i2o_drivers[i]; i++)
104 if (i >= i2o_max_drivers) {
105 osm_err("too many drivers registered, increase max_drivers\n");
106 spin_unlock_irqrestore(&i2o_drivers_lock, flags);
107 rc = -EFAULT;
108 goto out;
109 }
110
111 drv->context = i;
112 i2o_drivers[i] = drv;
113
114 spin_unlock_irqrestore(&i2o_drivers_lock, flags);
115
116 osm_debug("driver %s gets context id %d\n", drv->name, drv->context);
117
118 list_for_each_entry(c, &i2o_controllers, list) {
119 struct i2o_device *i2o_dev;
120
121 i2o_driver_notify_controller_add(drv, c);
122 list_for_each_entry(i2o_dev, &c->devices, list)
123 i2o_driver_notify_device_add(drv, i2o_dev);
124 }
125
126 rc = driver_register(&drv->driver);
127 if (rc)
128 goto out;
129
130 return 0;
131 out:
132 if (drv->event_queue) {
133 destroy_workqueue(drv->event_queue);
134 drv->event_queue = NULL;
135 }
136
137 return rc;
138 };
139
140 /**
141 * i2o_driver_unregister - Unregister a I2O driver (OSM) from the I2O core
142 * @drv: I2O driver which should be unregistered
143 *
144 * Unregisters the OSM drv from the I2O core and cleanup event queues if
145 * necessary.
146 */
i2o_driver_unregister(struct i2o_driver * drv)147 void i2o_driver_unregister(struct i2o_driver *drv)
148 {
149 struct i2o_controller *c;
150 unsigned long flags;
151
152 osm_debug("unregister driver %s\n", drv->name);
153
154 driver_unregister(&drv->driver);
155
156 list_for_each_entry(c, &i2o_controllers, list) {
157 struct i2o_device *i2o_dev;
158
159 list_for_each_entry(i2o_dev, &c->devices, list)
160 i2o_driver_notify_device_remove(drv, i2o_dev);
161
162 i2o_driver_notify_controller_remove(drv, c);
163 }
164
165 spin_lock_irqsave(&i2o_drivers_lock, flags);
166 i2o_drivers[drv->context] = NULL;
167 spin_unlock_irqrestore(&i2o_drivers_lock, flags);
168
169 if (drv->event_queue) {
170 destroy_workqueue(drv->event_queue);
171 drv->event_queue = NULL;
172 osm_debug("event queue removed for %s\n", drv->name);
173 }
174 };
175
176 /**
177 * i2o_driver_dispatch - dispatch an I2O reply message
178 * @c: I2O controller of the message
179 * @m: I2O message number
180 *
181 * The reply is delivered to the driver from which the original message
182 * was. This function is only called from interrupt context.
183 *
184 * Returns 0 on success and the message should not be flushed. Returns > 0
185 * on success and if the message should be flushed afterwords. Returns
186 * negative error code on failure (the message will be flushed too).
187 */
i2o_driver_dispatch(struct i2o_controller * c,u32 m)188 int i2o_driver_dispatch(struct i2o_controller *c, u32 m)
189 {
190 struct i2o_driver *drv;
191 struct i2o_message *msg = i2o_msg_out_to_virt(c, m);
192 u32 context = le32_to_cpu(msg->u.s.icntxt);
193 unsigned long flags;
194
195 if (unlikely(context >= i2o_max_drivers)) {
196 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
197 context);
198 return -EIO;
199 }
200
201 spin_lock_irqsave(&i2o_drivers_lock, flags);
202 drv = i2o_drivers[context];
203 spin_unlock_irqrestore(&i2o_drivers_lock, flags);
204
205 if (unlikely(!drv)) {
206 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
207 context);
208 return -EIO;
209 }
210
211 if ((le32_to_cpu(msg->u.head[1]) >> 24) == I2O_CMD_UTIL_EVT_REGISTER) {
212 struct i2o_device *dev, *tmp;
213 struct i2o_event *evt;
214 u16 size;
215 u16 tid = le32_to_cpu(msg->u.head[1]) & 0xfff;
216
217 osm_debug("event received from device %d\n", tid);
218
219 if (!drv->event)
220 return -EIO;
221
222 /* cut of header from message size (in 32-bit words) */
223 size = (le32_to_cpu(msg->u.head[0]) >> 16) - 5;
224
225 evt = kzalloc(size * 4 + sizeof(*evt), GFP_ATOMIC);
226 if (!evt)
227 return -ENOMEM;
228
229 evt->size = size;
230 evt->tcntxt = le32_to_cpu(msg->u.s.tcntxt);
231 evt->event_indicator = le32_to_cpu(msg->body[0]);
232 memcpy(&evt->data, &msg->body[1], size * 4);
233
234 list_for_each_entry_safe(dev, tmp, &c->devices, list)
235 if (dev->lct_data.tid == tid) {
236 evt->i2o_dev = dev;
237 break;
238 }
239
240 INIT_WORK(&evt->work, drv->event);
241 queue_work(drv->event_queue, &evt->work);
242 return 1;
243 }
244
245 if (unlikely(!drv->reply)) {
246 osm_debug("%s: Reply to driver %s, but no reply function defined!\n",
247 c->name, drv->name);
248 return -EIO;
249 }
250
251 return drv->reply(c, m, msg);
252 }
253
254 /**
255 * i2o_driver_notify_controller_add_all - Send notify of added controller
256 * @c: newly added controller
257 *
258 * Send notifications to all registered drivers that a new controller was
259 * added.
260 */
i2o_driver_notify_controller_add_all(struct i2o_controller * c)261 void i2o_driver_notify_controller_add_all(struct i2o_controller *c)
262 {
263 int i;
264 struct i2o_driver *drv;
265
266 for (i = 0; i < i2o_max_drivers; i++) {
267 drv = i2o_drivers[i];
268
269 if (drv)
270 i2o_driver_notify_controller_add(drv, c);
271 }
272 }
273
274 /**
275 * i2o_driver_notify_controller_remove_all - Send notify of removed controller
276 * @c: controller that is being removed
277 *
278 * Send notifications to all registered drivers that a controller was
279 * removed.
280 */
i2o_driver_notify_controller_remove_all(struct i2o_controller * c)281 void i2o_driver_notify_controller_remove_all(struct i2o_controller *c)
282 {
283 int i;
284 struct i2o_driver *drv;
285
286 for (i = 0; i < i2o_max_drivers; i++) {
287 drv = i2o_drivers[i];
288
289 if (drv)
290 i2o_driver_notify_controller_remove(drv, c);
291 }
292 }
293
294 /**
295 * i2o_driver_notify_device_add_all - Send notify of added device
296 * @i2o_dev: newly added I2O device
297 *
298 * Send notifications to all registered drivers that a device was added.
299 */
i2o_driver_notify_device_add_all(struct i2o_device * i2o_dev)300 void i2o_driver_notify_device_add_all(struct i2o_device *i2o_dev)
301 {
302 int i;
303 struct i2o_driver *drv;
304
305 for (i = 0; i < i2o_max_drivers; i++) {
306 drv = i2o_drivers[i];
307
308 if (drv)
309 i2o_driver_notify_device_add(drv, i2o_dev);
310 }
311 }
312
313 /**
314 * i2o_driver_notify_device_remove_all - Send notify of removed device
315 * @i2o_dev: device that is being removed
316 *
317 * Send notifications to all registered drivers that a device was removed.
318 */
i2o_driver_notify_device_remove_all(struct i2o_device * i2o_dev)319 void i2o_driver_notify_device_remove_all(struct i2o_device *i2o_dev)
320 {
321 int i;
322 struct i2o_driver *drv;
323
324 for (i = 0; i < i2o_max_drivers; i++) {
325 drv = i2o_drivers[i];
326
327 if (drv)
328 i2o_driver_notify_device_remove(drv, i2o_dev);
329 }
330 }
331
332 /**
333 * i2o_driver_init - initialize I2O drivers (OSMs)
334 *
335 * Registers the I2O bus and allocate memory for the array of OSMs.
336 *
337 * Returns 0 on success or negative error code on failure.
338 */
i2o_driver_init(void)339 int __init i2o_driver_init(void)
340 {
341 int rc = 0;
342
343 spin_lock_init(&i2o_drivers_lock);
344
345 if ((i2o_max_drivers < 2) || (i2o_max_drivers > 64)) {
346 osm_warn("max_drivers set to %d, but must be >=2 and <= 64\n",
347 i2o_max_drivers);
348 i2o_max_drivers = I2O_MAX_DRIVERS;
349 }
350 osm_info("max drivers = %d\n", i2o_max_drivers);
351
352 i2o_drivers =
353 kcalloc(i2o_max_drivers, sizeof(*i2o_drivers), GFP_KERNEL);
354 if (!i2o_drivers)
355 return -ENOMEM;
356
357 rc = bus_register(&i2o_bus_type);
358
359 if (rc < 0)
360 kfree(i2o_drivers);
361
362 return rc;
363 };
364
365 /**
366 * i2o_driver_exit - clean up I2O drivers (OSMs)
367 *
368 * Unregisters the I2O bus and frees driver array.
369 */
i2o_driver_exit(void)370 void i2o_driver_exit(void)
371 {
372 bus_unregister(&i2o_bus_type);
373 kfree(i2o_drivers);
374 };
375
376 EXPORT_SYMBOL(i2o_driver_register);
377 EXPORT_SYMBOL(i2o_driver_unregister);
378 EXPORT_SYMBOL(i2o_driver_notify_controller_add_all);
379 EXPORT_SYMBOL(i2o_driver_notify_controller_remove_all);
380 EXPORT_SYMBOL(i2o_driver_notify_device_add_all);
381 EXPORT_SYMBOL(i2o_driver_notify_device_remove_all);
382