Linux Kernel  3.7.1
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op-reset.c
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1 /*
2  * Linux WiMAX
3  * Implement and export a method for resetting a WiMAX device
4  *
5  *
6  * Copyright (C) 2008 Intel Corporation <[email protected]>
7  * Inaky Perez-Gonzalez <[email protected]>
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 
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 }
93 
94 
95 static const struct nla_policy wimax_gnl_reset_policy[WIMAX_GNL_ATTR_MAX + 1] = {
97  .type = NLA_U32,
98  },
99 };
100 
101 
102 /*
103  * Exporting to user space over generic netlink
104  *
105  * Parse the reset command from user space, return error code.
106  *
107  * No attributes.
108  */
109 static
110 int wimax_gnl_doit_reset(struct sk_buff *skb, struct genl_info *info)
111 {
112  int result, ifindex;
113  struct wimax_dev *wimax_dev;
114 
115  d_fnstart(3, NULL, "(skb %p info %p)\n", skb, info);
116  result = -ENODEV;
117  if (info->attrs[WIMAX_GNL_RESET_IFIDX] == NULL) {
118  printk(KERN_ERR "WIMAX_GNL_OP_RFKILL: can't find IFIDX "
119  "attribute\n");
120  goto error_no_wimax_dev;
121  }
122  ifindex = nla_get_u32(info->attrs[WIMAX_GNL_RESET_IFIDX]);
123  wimax_dev = wimax_dev_get_by_genl_info(info, ifindex);
124  if (wimax_dev == NULL)
125  goto error_no_wimax_dev;
126  /* Execute the operation and send the result back to user space */
127  result = wimax_reset(wimax_dev);
128  dev_put(wimax_dev->net_dev);
129 error_no_wimax_dev:
130  d_fnend(3, NULL, "(skb %p info %p) = %d\n", skb, info, result);
131  return result;
132 }
133 
134 
136  .cmd = WIMAX_GNL_OP_RESET,
137  .flags = GENL_ADMIN_PERM,
138  .policy = wimax_gnl_reset_policy,
139  .doit = wimax_gnl_doit_reset,
140  .dumpit = NULL,
141 };