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 */
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_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 */
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 = 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;
131out:
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 */
147void 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 */
188int 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 */
261void 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 */
281void 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 */
300void 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 */
319void 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 */
339int __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 */
370void i2o_driver_exit(void)
371{
372	bus_unregister(&i2o_bus_type);
373	kfree(i2o_drivers);
374};
375
376EXPORT_SYMBOL(i2o_driver_register);
377EXPORT_SYMBOL(i2o_driver_unregister);
378EXPORT_SYMBOL(i2o_driver_notify_controller_add_all);
379EXPORT_SYMBOL(i2o_driver_notify_controller_remove_all);
380EXPORT_SYMBOL(i2o_driver_notify_device_add_all);
381EXPORT_SYMBOL(i2o_driver_notify_device_remove_all);
382