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 "wimax-internal.h"
36
37 #define D_SUBMODULE op_reset
38 #include "debug-levels.h"
39
40
41 /**
42 * wimax_reset - Reset a WiMAX device
43 *
44 * @wimax_dev: WiMAX device descriptor
45 *
46 * Returns:
47 *
48 * %0 if ok and a warm reset was done (the device still exists in
49 * the system).
50 *
51 * -%ENODEV if a cold/bus reset had to be done (device has
52 * disconnected and reconnected, so current handle is not valid
53 * any more).
54 *
55 * -%EINVAL if the device is not even registered.
56 *
57 * Any other negative error code shall be considered as
58 * non-recoverable.
59 *
60 * Description:
61 *
62 * Called when wanting to reset the device for any reason. Device is
63 * taken back to power on status.
64 *
65 * This call blocks; on successful return, the device has completed the
66 * reset process and is ready to operate.
67 */
wimax_reset(struct wimax_dev * wimax_dev)68 int wimax_reset(struct wimax_dev *wimax_dev)
69 {
70 int result = -EINVAL;
71 struct device *dev = wimax_dev_to_dev(wimax_dev);
72 enum wimax_st state;
73
74 might_sleep();
75 d_fnstart(3, dev, "(wimax_dev %p)\n", wimax_dev);
76 mutex_lock(&wimax_dev->mutex);
77 dev_hold(wimax_dev->net_dev);
78 state = wimax_dev->state;
79 mutex_unlock(&wimax_dev->mutex);
80
81 if (state >= WIMAX_ST_DOWN) {
82 mutex_lock(&wimax_dev->mutex_reset);
83 result = wimax_dev->op_reset(wimax_dev);
84 mutex_unlock(&wimax_dev->mutex_reset);
85 }
86 dev_put(wimax_dev->net_dev);
87
88 d_fnend(3, dev, "(wimax_dev %p) = %d\n", wimax_dev, result);
89 return result;
90 }
91 EXPORT_SYMBOL(wimax_reset);
92
93
94 static const struct nla_policy wimax_gnl_reset_policy[WIMAX_GNL_ATTR_MAX + 1] = {
95 [WIMAX_GNL_RESET_IFIDX] = {
96 .type = NLA_U32,
97 },
98 };
99
100
101 /*
102 * Exporting to user space over generic netlink
103 *
104 * Parse the reset command from user space, return error code.
105 *
106 * No attributes.
107 */
108 static
wimax_gnl_doit_reset(struct sk_buff * skb,struct genl_info * info)109 int wimax_gnl_doit_reset(struct sk_buff *skb, struct genl_info *info)
110 {
111 int result, ifindex;
112 struct wimax_dev *wimax_dev;
113
114 d_fnstart(3, NULL, "(skb %p info %p)\n", skb, info);
115 result = -ENODEV;
116 if (info->attrs[WIMAX_GNL_RESET_IFIDX] == NULL) {
117 printk(KERN_ERR "WIMAX_GNL_OP_RFKILL: can't find IFIDX "
118 "attribute\n");
119 goto error_no_wimax_dev;
120 }
121 ifindex = nla_get_u32(info->attrs[WIMAX_GNL_RESET_IFIDX]);
122 wimax_dev = wimax_dev_get_by_genl_info(info, ifindex);
123 if (wimax_dev == NULL)
124 goto error_no_wimax_dev;
125 /* Execute the operation and send the result back to user space */
126 result = wimax_reset(wimax_dev);
127 dev_put(wimax_dev->net_dev);
128 error_no_wimax_dev:
129 d_fnend(3, NULL, "(skb %p info %p) = %d\n", skb, info, result);
130 return result;
131 }
132
133
134 struct genl_ops wimax_gnl_reset = {
135 .cmd = WIMAX_GNL_OP_RESET,
136 .flags = GENL_ADMIN_PERM,
137 .policy = wimax_gnl_reset_policy,
138 .doit = wimax_gnl_doit_reset,
139 .dumpit = NULL,
140 };
141