1/*
2 * Linux WiMAX
3 * Implement and export a method for resetting a WiMAX device
4 *
5 *
6 * Copyright (C) 2008 Intel Corporation <linux-wimax@intel.com>
7 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License version
11 * 2 as published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21 * 02110-1301, USA.
22 *
23 *
24 * This implements a simple synchronous call to reset a WiMAX device.
25 *
26 * Resets aim at being warm, keeping the device handles active;
27 * however, when that fails, it falls back to a cold reset (that will
28 * disconnect and reconnect the device).
29 */
30
31#include <net/wimax.h>
32#include <net/genetlink.h>
33#include <linux/wimax.h>
34#include <linux/security.h>
35#include <linux/export.h>
36#include "wimax-internal.h"
37
38#define D_SUBMODULE op_reset
39#include "debug-levels.h"
40
41
42/**
43 * wimax_reset - Reset a WiMAX device
44 *
45 * @wimax_dev: WiMAX device descriptor
46 *
47 * Returns:
48 *
49 * %0 if ok and a warm reset was done (the device still exists in
50 * the system).
51 *
52 * -%ENODEV if a cold/bus reset had to be done (device has
53 * disconnected and reconnected, so current handle is not valid
54 * any more).
55 *
56 * -%EINVAL if the device is not even registered.
57 *
58 * Any other negative error code shall be considered as
59 * non-recoverable.
60 *
61 * Description:
62 *
63 * Called when wanting to reset the device for any reason. Device is
64 * taken back to power on status.
65 *
66 * This call blocks; on successful return, the device has completed the
67 * reset process and is ready to operate.
68 */
69int wimax_reset(struct wimax_dev *wimax_dev)
70{
71	int result = -EINVAL;
72	struct device *dev = wimax_dev_to_dev(wimax_dev);
73	enum wimax_st state;
74
75	might_sleep();
76	d_fnstart(3, dev, "(wimax_dev %p)\n", wimax_dev);
77	mutex_lock(&wimax_dev->mutex);
78	dev_hold(wimax_dev->net_dev);
79	state = wimax_dev->state;
80	mutex_unlock(&wimax_dev->mutex);
81
82	if (state >= WIMAX_ST_DOWN) {
83		mutex_lock(&wimax_dev->mutex_reset);
84		result = wimax_dev->op_reset(wimax_dev);
85		mutex_unlock(&wimax_dev->mutex_reset);
86	}
87	dev_put(wimax_dev->net_dev);
88
89	d_fnend(3, dev, "(wimax_dev %p) = %d\n", wimax_dev, result);
90	return result;
91}
92EXPORT_SYMBOL(wimax_reset);
93
94
95/*
96 * Exporting to user space over generic netlink
97 *
98 * Parse the reset command from user space, return error code.
99 *
100 * No attributes.
101 */
102int wimax_gnl_doit_reset(struct sk_buff *skb, struct genl_info *info)
103{
104	int result, ifindex;
105	struct wimax_dev *wimax_dev;
106
107	d_fnstart(3, NULL, "(skb %p info %p)\n", skb, info);
108	result = -ENODEV;
109	if (info->attrs[WIMAX_GNL_RESET_IFIDX] == NULL) {
110		pr_err("WIMAX_GNL_OP_RFKILL: can't find IFIDX attribute\n");
111		goto error_no_wimax_dev;
112	}
113	ifindex = nla_get_u32(info->attrs[WIMAX_GNL_RESET_IFIDX]);
114	wimax_dev = wimax_dev_get_by_genl_info(info, ifindex);
115	if (wimax_dev == NULL)
116		goto error_no_wimax_dev;
117	/* Execute the operation and send the result back to user space */
118	result = wimax_reset(wimax_dev);
119	dev_put(wimax_dev->net_dev);
120error_no_wimax_dev:
121	d_fnend(3, NULL, "(skb %p info %p) = %d\n", skb, info, result);
122	return result;
123}
124