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}