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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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/* max_drivers - Maximum I2O drivers (OSMs) which could be registered */
22unsigned int i2o_max_drivers = I2O_MAX_DRIVERS;
23module_param_named(max_drivers, i2o_max_drivers, uint, 0);
24MODULE_PARM_DESC(max_drivers, "maximum number of OSM's to support");
25
26/* I2O drivers lock and array */
27static spinlock_t i2o_drivers_lock;
28static struct i2o_driver **i2o_drivers;
29
30/**
31 * i2o_bus_match - Tell if a I2O device class id match the class ids of
32 * the I2O driver (OSM)
33 *
34 * @dev: device which should be verified
35 * @drv: the driver to match against
36 *
37 * Used by the bus to check if the driver wants to handle the device.
38 *
39 * Returns 1 if the class ids of the driver match the class id of the
40 * device, otherwise 0.
41 */
42static int i2o_bus_match(struct device *dev, struct device_driver *drv)
43{
44 struct i2o_device *i2o_dev = to_i2o_device(dev);
45 struct i2o_driver *i2o_drv = to_i2o_driver(drv);
46 struct i2o_class_id *ids = i2o_drv->classes;
47
48 if (ids)
49 while (ids->class_id != I2O_CLASS_END) {
50 if (ids->class_id == i2o_dev->lct_data.class_id)
51 return 1;
52 ids++;
53 }
54 return 0;
55};
56
57/* I2O bus type */
58struct bus_type i2o_bus_type = {
59 .name = "i2o",
60 .match = i2o_bus_match,
61};
62
63/**
64 * i2o_driver_register - Register a I2O driver (OSM) in the I2O core
65 * @drv: I2O driver which should be registered
66 *
67 * Registers the OSM drv in the I2O core and creates an event queues if
68 * necessary.
69 *
70 * Returns 0 on success or negative error code on failure.
71 */
72int i2o_driver_register(struct i2o_driver *drv)
73{
74 struct i2o_controller *c;
75 int i;
76 int rc = 0;
77 unsigned long flags;
78
79 pr_debug("i2o: Register driver %s\n", drv->name);
80
81 if (drv->event) {
82 drv->event_queue = create_workqueue(drv->name);
83 if (!drv->event_queue) {
84 printk(KERN_ERR "i2o: Could not initialize event queue "
85 "for driver %s\n", drv->name);
86 return -EFAULT;
87 }
88 pr_debug("i2o: Event queue initialized for driver %s\n",
89 drv->name);
90 } else
91 drv->event_queue = NULL;
92
93 drv->driver.name = drv->name;
94 drv->driver.bus = &i2o_bus_type;
95
96 spin_lock_irqsave(&i2o_drivers_lock, flags);
97
98 for (i = 0; i2o_drivers[i]; i++)
99 if (i >= i2o_max_drivers) {
100 printk(KERN_ERR "i2o: too many drivers registered, "
101 "increase max_drivers\n");
102 spin_unlock_irqrestore(&i2o_drivers_lock, flags);
103 return -EFAULT;
104 }
105
106 drv->context = i;
107 i2o_drivers[i] = drv;
108
109 spin_unlock_irqrestore(&i2o_drivers_lock, flags);
110
111 pr_debug("i2o: driver %s gets context id %d\n", drv->name,
112 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 */
137void i2o_driver_unregister(struct i2o_driver *drv)
138{
139 struct i2o_controller *c;
140 unsigned long flags;
141
142 pr_debug("i2o: 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 pr_debug("i2o: 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 */
179int i2o_driver_dispatch(struct i2o_controller *c, u32 m,
180 struct i2o_message __iomem *msg)
181{
182 struct i2o_driver *drv;
183 u32 context = readl(&msg->u.s.icntxt);
184
185 if (likely(context < i2o_max_drivers)) {
186 spin_lock(&i2o_drivers_lock);
187 drv = i2o_drivers[context];
188 spin_unlock(&i2o_drivers_lock);
189
190 if (unlikely(!drv)) {
191 printk(KERN_WARNING "%s: Spurious reply to unknown "
192 "driver %d\n", c->name, context);
193 return -EIO;
194 }
195
196 if ((readl(&msg->u.head[1]) >> 24) == I2O_CMD_UTIL_EVT_REGISTER) {
197 struct i2o_device *dev, *tmp;
198 struct i2o_event *evt;
199 u16 size;
200 u16 tid;
201
202 tid = readl(&msg->u.head[1]) & 0x1fff;
203
204 pr_debug("%s: event received from device %d\n", c->name,
205 tid);
206
207 /* cut of header from message size (in 32-bit words) */
208 size = (readl(&msg->u.head[0]) >> 16) - 5;
209
210 evt = kmalloc(size * 4 + sizeof(*evt), GFP_ATOMIC);
211 if (!evt)
212 return -ENOMEM;
213 memset(evt, 0, size * 4 + sizeof(*evt));
214
215 evt->size = size;
216 memcpy_fromio(&evt->tcntxt, &msg->u.s.tcntxt,
217 (size + 2) * 4);
218
219 list_for_each_entry_safe(dev, tmp, &c->devices, list)
220 if (dev->lct_data.tid == tid) {
221 evt->i2o_dev = dev;
222 break;
223 }
224
225 INIT_WORK(&evt->work, (void (*)(void *))drv->event,
226 evt);
227 queue_work(drv->event_queue, &evt->work);
228 return 1;
229 }
230
231 if (likely(drv->reply))
232 return drv->reply(c, m, msg);
233 else
234 pr_debug("%s: Reply to driver %s, but no reply function"
235 " defined!\n", c->name, drv->name);
236 return -EIO;
237 } else
238 printk(KERN_WARNING "%s: Spurious reply to unknown driver "
239 "%d\n", c->name, readl(&msg->u.s.icntxt));
240 return -EIO;
241}
242
243/**
244 * i2o_driver_notify_controller_add_all - Send notify of added controller
245 * to all I2O drivers
246 *
247 * Send notifications to all registered drivers that a new controller was
248 * added.
249 */
250void i2o_driver_notify_controller_add_all(struct i2o_controller *c)
251{
252 int i;
253 struct i2o_driver *drv;
254
255 for (i = 0; i < I2O_MAX_DRIVERS; i++) {
256 drv = i2o_drivers[i];
257
258 if (drv)
259 i2o_driver_notify_controller_add(drv, c);
260 }
261}
262
263/**
264 * i2o_driver_notify_controller_remove_all - Send notify of removed
265 * controller to all I2O drivers
266 *
267 * Send notifications to all registered drivers that a controller was
268 * removed.
269 */
270void i2o_driver_notify_controller_remove_all(struct i2o_controller *c)
271{
272 int i;
273 struct i2o_driver *drv;
274
275 for (i = 0; i < I2O_MAX_DRIVERS; i++) {
276 drv = i2o_drivers[i];
277
278 if (drv)
279 i2o_driver_notify_controller_remove(drv, c);
280 }
281}
282
283/**
284 * i2o_driver_notify_device_add_all - Send notify of added device to all
285 * I2O drivers
286 *
287 * Send notifications to all registered drivers that a device was added.
288 */
289void i2o_driver_notify_device_add_all(struct i2o_device *i2o_dev)
290{
291 int i;
292 struct i2o_driver *drv;
293
294 for (i = 0; i < I2O_MAX_DRIVERS; i++) {
295 drv = i2o_drivers[i];
296
297 if (drv)
298 i2o_driver_notify_device_add(drv, i2o_dev);
299 }
300}
301
302/**
303 * i2o_driver_notify_device_remove_all - Send notify of removed device to
304 * all I2O drivers
305 *
306 * Send notifications to all registered drivers that a device was removed.
307 */
308void i2o_driver_notify_device_remove_all(struct i2o_device *i2o_dev)
309{
310 int i;
311 struct i2o_driver *drv;
312
313 for (i = 0; i < I2O_MAX_DRIVERS; i++) {
314 drv = i2o_drivers[i];
315
316 if (drv)
317 i2o_driver_notify_device_remove(drv, i2o_dev);
318 }
319}
320
321/**
322 * i2o_driver_init - initialize I2O drivers (OSMs)
323 *
324 * Registers the I2O bus and allocate memory for the array of OSMs.
325 *
326 * Returns 0 on success or negative error code on failure.
327 */
328int __init i2o_driver_init(void)
329{
330 int rc = 0;
331
332 spin_lock_init(&i2o_drivers_lock);
333
334 if ((i2o_max_drivers < 2) || (i2o_max_drivers > 64) ||
335 ((i2o_max_drivers ^ (i2o_max_drivers - 1)) !=
336 (2 * i2o_max_drivers - 1))) {
337 printk(KERN_WARNING "i2o: max_drivers set to %d, but must be "
338 ">=2 and <= 64 and a power of 2\n", i2o_max_drivers);
339 i2o_max_drivers = I2O_MAX_DRIVERS;
340 }
341 printk(KERN_INFO "i2o: max drivers = %d\n", i2o_max_drivers);
342
343 i2o_drivers =
344 kmalloc(i2o_max_drivers * sizeof(*i2o_drivers), GFP_KERNEL);
345 if (!i2o_drivers)
346 return -ENOMEM;
347
348 memset(i2o_drivers, 0, i2o_max_drivers * sizeof(*i2o_drivers));
349
350 rc = bus_register(&i2o_bus_type);
351
352 if (rc < 0)
353 kfree(i2o_drivers);
354
355 return rc;
356};
357
358/**
359 * i2o_driver_exit - clean up I2O drivers (OSMs)
360 *
361 * Unregisters the I2O bus and free driver array.
362 */
363void __exit i2o_driver_exit(void)
364{
365 bus_unregister(&i2o_bus_type);
366 kfree(i2o_drivers);
367};
368
369EXPORT_SYMBOL(i2o_driver_register);
370EXPORT_SYMBOL(i2o_driver_unregister);
371EXPORT_SYMBOL(i2o_driver_notify_controller_add_all);
372EXPORT_SYMBOL(i2o_driver_notify_controller_remove_all);
373EXPORT_SYMBOL(i2o_driver_notify_device_add_all);
374EXPORT_SYMBOL(i2o_driver_notify_device_remove_all);