LXR linux/net/wimax/op-reset.c

   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};
 142