1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Linux WiMAX
4 * Implement and export a method for resetting a WiMAX device
5 *
6 * Copyright (C) 2008 Intel Corporation <linux-wimax@intel.com>
7 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
8 *
9 * This implements a simple synchronous call to reset a WiMAX device.
10 *
11 * Resets aim at being warm, keeping the device handles active;
12 * however, when that fails, it falls back to a cold reset (that will
13 * disconnect and reconnect the device).
14 */
15
16 #include <net/wimax.h>
17 #include <net/genetlink.h>
18 #include <linux/wimax.h>
19 #include <linux/security.h>
20 #include <linux/export.h>
21 #include "wimax-internal.h"
22
23 #define D_SUBMODULE op_reset
24 #include "debug-levels.h"
25
26
27 /**
28 * wimax_reset - Reset a WiMAX device
29 *
30 * @wimax_dev: WiMAX device descriptor
31 *
32 * Returns:
33 *
34 * %0 if ok and a warm reset was done (the device still exists in
35 * the system).
36 *
37 * -%ENODEV if a cold/bus reset had to be done (device has
38 * disconnected and reconnected, so current handle is not valid
39 * any more).
40 *
41 * -%EINVAL if the device is not even registered.
42 *
43 * Any other negative error code shall be considered as
44 * non-recoverable.
45 *
46 * Description:
47 *
48 * Called when wanting to reset the device for any reason. Device is
49 * taken back to power on status.
50 *
51 * This call blocks; on successful return, the device has completed the
52 * reset process and is ready to operate.
53 */
wimax_reset(struct wimax_dev * wimax_dev)54 int wimax_reset(struct wimax_dev *wimax_dev)
55 {
56 int result = -EINVAL;
57 struct device *dev = wimax_dev_to_dev(wimax_dev);
58 enum wimax_st state;
59
60 might_sleep();
61 d_fnstart(3, dev, "(wimax_dev %p)\n", wimax_dev);
62 mutex_lock(&wimax_dev->mutex);
63 dev_hold(wimax_dev->net_dev);
64 state = wimax_dev->state;
65 mutex_unlock(&wimax_dev->mutex);
66
67 if (state >= WIMAX_ST_DOWN) {
68 mutex_lock(&wimax_dev->mutex_reset);
69 result = wimax_dev->op_reset(wimax_dev);
70 mutex_unlock(&wimax_dev->mutex_reset);
71 }
72 dev_put(wimax_dev->net_dev);
73
74 d_fnend(3, dev, "(wimax_dev %p) = %d\n", wimax_dev, result);
75 return result;
76 }
77 EXPORT_SYMBOL(wimax_reset);
78
79
80 /*
81 * Exporting to user space over generic netlink
82 *
83 * Parse the reset command from user space, return error code.
84 *
85 * No attributes.
86 */
wimax_gnl_doit_reset(struct sk_buff * skb,struct genl_info * info)87 int wimax_gnl_doit_reset(struct sk_buff *skb, struct genl_info *info)
88 {
89 int result, ifindex;
90 struct wimax_dev *wimax_dev;
91
92 d_fnstart(3, NULL, "(skb %p info %p)\n", skb, info);
93 result = -ENODEV;
94 if (info->attrs[WIMAX_GNL_RESET_IFIDX] == NULL) {
95 pr_err("WIMAX_GNL_OP_RFKILL: can't find IFIDX attribute\n");
96 goto error_no_wimax_dev;
97 }
98 ifindex = nla_get_u32(info->attrs[WIMAX_GNL_RESET_IFIDX]);
99 wimax_dev = wimax_dev_get_by_genl_info(info, ifindex);
100 if (wimax_dev == NULL)
101 goto error_no_wimax_dev;
102 /* Execute the operation and send the result back to user space */
103 result = wimax_reset(wimax_dev);
104 dev_put(wimax_dev->net_dev);
105 error_no_wimax_dev:
106 d_fnend(3, NULL, "(skb %p info %p) = %d\n", skb, info, result);
107 return result;
108 }
109