xref: /kernel/linux/linux-5.10/net/wimax/op-reset.c (revision 8c2ecf20) 
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 */
54int 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}
77EXPORT_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 */
87int 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);
105error_no_wimax_dev:
106	d_fnend(3, NULL, "(skb %p info %p) = %d\n", skb, info, result);
107	return result;
108}
109