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 */
28static unsigned int i2o_max_drivers = I2O_MAX_DRIVERS;
29module_param_named(max_drivers, i2o_max_drivers, uint, 0);
30MODULE_PARM_DESC(max_drivers, "maximum number of OSM's to support");
31
32/* I2O drivers lock and array */
33static spinlock_t i2o_drivers_lock;
34static 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 */
46static 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 */
62struct 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 */
77int 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 */
143void 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 */
185int 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 */
258void 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 */
278void 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 */
297void 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 */
316void 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 */
336int __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 */
367void i2o_driver_exit(void)
368{
369	bus_unregister(&i2o_bus_type);
370	kfree(i2o_drivers);
371};
372
373EXPORT_SYMBOL(i2o_driver_register);
374EXPORT_SYMBOL(i2o_driver_unregister);
375EXPORT_SYMBOL(i2o_driver_notify_controller_add_all);
376EXPORT_SYMBOL(i2o_driver_notify_controller_remove_all);
377EXPORT_SYMBOL(i2o_driver_notify_device_add_all);
378EXPORT_SYMBOL(i2o_driver_notify_device_remove_all);
379