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 "wimax-internal.h"
  36
  37 #define D_SUBMODULE op_reset
  38 #include "debug-levels.h"
  39
  40
  41 /**
  42  * wimax_reset - Reset a WiMAX device
  43  *
  44  * @wimax_dev: WiMAX device descriptor
  45  *
  46  * Returns:
  47  *
  48  * %0 if ok and a warm reset was done (the device still exists in
  49  * the system).
  50  *
  51  * -%ENODEV if a cold/bus reset had to be done (device has
  52  * disconnected and reconnected, so current handle is not valid
  53  * any more).
  54  *
  55  * -%EINVAL if the device is not even registered.
  56  *
  57  * Any other negative error code shall be considered as
  58  * non-recoverable.
  59  *
  60  * Description:
  61  *
  62  * Called when wanting to reset the device for any reason. Device is
  63  * taken back to power on status.
  64  *
  65  * This call blocks; on successful return, the device has completed the
  66  * reset process and is ready to operate.
  67  */
  68 int wimax_reset(struct wimax_dev *wimax_dev)
  69 {
  70         int result = -EINVAL;
  71         struct device *dev = wimax_dev_to_dev(wimax_dev);
  72         enum wimax_st state;
  73
  74         might_sleep();
  75         d_fnstart(3, dev, "(wimax_dev %p)\n", wimax_dev);
  76         mutex_lock(&wimax_dev->mutex);
  77         dev_hold(wimax_dev->net_dev);
  78         state = wimax_dev->state;
  79         mutex_unlock(&wimax_dev->mutex);
  80
  81         if (state >= WIMAX_ST_DOWN) {
  82                 mutex_lock(&wimax_dev->mutex_reset);
  83                 result = wimax_dev->op_reset(wimax_dev);
  84                 mutex_unlock(&wimax_dev->mutex_reset);
  85         }
  86         dev_put(wimax_dev->net_dev);
  87
  88         d_fnend(3, dev, "(wimax_dev %p) = %d\n", wimax_dev, result);
  89         return result;
  90 }
  91 EXPORT_SYMBOL(wimax_reset);
  92
  93
  94 static const struct nla_policy wimax_gnl_reset_policy[WIMAX_GNL_ATTR_MAX + 1] = {
  95         [WIMAX_GNL_RESET_IFIDX] = {
  96                 .type = NLA_U32,
  97         },
  98 };
  99
 100
 101 /*
 102  * Exporting to user space over generic netlink
 103  *
 104  * Parse the reset command from user space, return error code.
 105  *
 106  * No attributes.
 107  */
 108 static
 109 int wimax_gnl_doit_reset(struct sk_buff *skb, struct genl_info *info)
 110 {
 111         int result, ifindex;
 112         struct wimax_dev *wimax_dev;
 113
 114         d_fnstart(3, NULL, "(skb %p info %p)\n", skb, info);
 115         result = -ENODEV;
 116         if (info->attrs[WIMAX_GNL_RESET_IFIDX] == NULL) {
 117                 printk(KERN_ERR "WIMAX_GNL_OP_RFKILL: can't find IFIDX "
 118                         "attribute\n");
 119                 goto error_no_wimax_dev;
 120         }
 121         ifindex = nla_get_u32(info->attrs[WIMAX_GNL_RESET_IFIDX]);
 122         wimax_dev = wimax_dev_get_by_genl_info(info, ifindex);
 123         if (wimax_dev == NULL)
 124                 goto error_no_wimax_dev;
 125         /* Execute the operation and send the result back to user space */
 126         result = wimax_reset(wimax_dev);
 127         dev_put(wimax_dev->net_dev);
 128 error_no_wimax_dev:
 129         d_fnend(3, NULL, "(skb %p info %p) = %d\n", skb, info, result);
 130         return result;
 131 }
 132
 133
 134 struct genl_ops wimax_gnl_reset = {
 135         .cmd = WIMAX_GNL_OP_RESET,
 136         .flags = GENL_ADMIN_PERM,
 137         .policy = wimax_gnl_reset_policy,
 138         .doit = wimax_gnl_doit_reset,
 139         .dumpit = NULL,
 140 };