op-reset.c

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/*
 * Linux WiMAX
 * Implement and export a method for resetting a WiMAX device
 *
 *
 * Copyright (C) 2008 Intel Corporation <[email protected]>
 * Inaky Perez-Gonzalez <[email protected]>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 *
 * This implements a simple synchronous call to reset a WiMAX device.
 *
 * Resets aim at being warm, keeping the device handles active;
 * however, when that fails, it falls back to a cold reset (that will
 * disconnect and reconnect the device).
 */

#include <net/wimax.h>
#include <net/genetlink.h>
#include <linux/wimax.h>
#include <linux/security.h>
#include <linux/export.h>
#include "wimax-internal.h"

#define D_SUBMODULE op_reset
#include "debug-levels.h"


int wimax_reset(struct wimax_dev *wimax_dev)
{
    int result = -EINVAL;
    struct device *dev = wimax_dev_to_dev(wimax_dev);
    enum wimax_st state;

    might_sleep();
    d_fnstart(3, dev, "(wimax_dev %p)\n", wimax_dev);
    mutex_lock(&wimax_dev->mutex);
    dev_hold(wimax_dev->net_dev);
    state = wimax_dev->state;
    mutex_unlock(&wimax_dev->mutex);

    if (state >= WIMAX_ST_DOWN) {
        mutex_lock(&wimax_dev->mutex_reset);
        result = wimax_dev->op_reset(wimax_dev);
        mutex_unlock(&wimax_dev->mutex_reset);
    }
    dev_put(wimax_dev->net_dev);

    d_fnend(3, dev, "(wimax_dev %p) = %d\n", wimax_dev, result);
    return result;
}
EXPORT_SYMBOL(wimax_reset);


static const struct nla_policy wimax_gnl_reset_policy[WIMAX_GNL_ATTR_MAX + 1] = {
    [WIMAX_GNL_RESET_IFIDX] = {
        .type = NLA_U32,
    },
};


/*
 * Exporting to user space over generic netlink
 *
 * Parse the reset command from user space, return error code.
 *
 * No attributes.
 */
static
int wimax_gnl_doit_reset(struct sk_buff *skb, struct genl_info *info)
{
    int result, ifindex;
    struct wimax_dev *wimax_dev;

    d_fnstart(3, NULL, "(skb %p info %p)\n", skb, info);
    result = -ENODEV;
    if (info->attrs[WIMAX_GNL_RESET_IFIDX] == NULL) {
        printk(KERN_ERR "WIMAX_GNL_OP_RFKILL: can't find IFIDX "
            "attribute\n");
        goto error_no_wimax_dev;
    }
    ifindex = nla_get_u32(info->attrs[WIMAX_GNL_RESET_IFIDX]);
    wimax_dev = wimax_dev_get_by_genl_info(info, ifindex);
    if (wimax_dev == NULL)
        goto error_no_wimax_dev;
    /* Execute the operation and send the result back to user space */
    result = wimax_reset(wimax_dev);
    dev_put(wimax_dev->net_dev);
error_no_wimax_dev:
    d_fnend(3, NULL, "(skb %p info %p) = %d\n", skb, info, result);
    return result;
}


struct genl_ops wimax_gnl_reset = {
    .cmd = WIMAX_GNL_OP_RESET,
    .flags = GENL_ADMIN_PERM,
    .policy = wimax_gnl_reset_policy,
    .doit = wimax_gnl_doit_reset,
    .dumpit = NULL,
};