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