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
 95static const struct nla_policy wimax_gnl_reset_policy[WIMAX_GNL_ATTR_MAX + 1] = {
 96	[WIMAX_GNL_RESET_IFIDX] = {
 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 */
109static
110int 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);
129error_no_wimax_dev:
130	d_fnend(3, NULL, "(skb %p info %p) = %d\n", skb, info, result);
131	return result;
132}
133
134
135struct genl_ops wimax_gnl_reset = {
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};