net/mac802154/util.c

Source file repositories/reference/linux-study-clean/net/mac802154/util.c

File Facts

System
Linux kernel
Corpus path
net/mac802154/util.c
Extension
.c
Size
4734 bytes
Lines
174
Domain
Networking Core
Bucket
Sockets, Protocols, Packet Path, And Network Policy
Inferred role
Networking Core: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Networking stack implementation surface: socket APIs, protocol dispatch, packet flow, routing, filtering, and network namespaces.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
/*
 *
 * Authors:
 * Alexander Aring <aar@pengutronix.de>
 *
 * Based on: net/mac80211/util.c
 */

#include "ieee802154_i.h"
#include "driver-ops.h"

/* privid for wpan_phys to determine whether they belong to us or not */
const void *const mac802154_wpan_phy_privid = &mac802154_wpan_phy_privid;

/**
 * ieee802154_wake_queue - wake ieee802154 queue
 * @hw: main hardware object
 *
 * Tranceivers usually have either one transmit framebuffer or one framebuffer
 * for both transmitting and receiving. Hence, the core currently only handles
 * one frame at a time for each phy, which means we had to stop the queue to
 * avoid new skb to come during the transmission. The queue then needs to be
 * woken up after the operation.
 */
static void ieee802154_wake_queue(struct ieee802154_hw *hw)
{
	struct ieee802154_local *local = hw_to_local(hw);
	struct ieee802154_sub_if_data *sdata;

	rcu_read_lock();
	clear_bit(WPAN_PHY_FLAG_STATE_QUEUE_STOPPED, &local->phy->flags);
	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
		if (!sdata->dev)
			continue;

		netif_wake_queue(sdata->dev);
	}
	rcu_read_unlock();
}

/**
 * ieee802154_stop_queue - stop ieee802154 queue
 * @hw: main hardware object
 *
 * Tranceivers usually have either one transmit framebuffer or one framebuffer
 * for both transmitting and receiving. Hence, the core currently only handles
 * one frame at a time for each phy, which means we need to tell upper layers to
 * stop giving us new skbs while we are busy with the transmitted one. The queue
 * must then be stopped before transmitting.
 */
static void ieee802154_stop_queue(struct ieee802154_hw *hw)
{
	struct ieee802154_local *local = hw_to_local(hw);
	struct ieee802154_sub_if_data *sdata;

	rcu_read_lock();
	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
		if (!sdata->dev)
			continue;

		netif_stop_queue(sdata->dev);
	}
	rcu_read_unlock();
}

void ieee802154_hold_queue(struct ieee802154_local *local)
{
	unsigned long flags;

	spin_lock_irqsave(&local->phy->queue_lock, flags);
	if (!atomic_fetch_inc(&local->phy->hold_txs))
		ieee802154_stop_queue(&local->hw);
	spin_unlock_irqrestore(&local->phy->queue_lock, flags);
}

void ieee802154_release_queue(struct ieee802154_local *local)
{
	unsigned long flags;

	spin_lock_irqsave(&local->phy->queue_lock, flags);
	if (atomic_dec_and_test(&local->phy->hold_txs))
		ieee802154_wake_queue(&local->hw);
	spin_unlock_irqrestore(&local->phy->queue_lock, flags);
}

void ieee802154_disable_queue(struct ieee802154_local *local)
{
	struct ieee802154_sub_if_data *sdata;

Annotation

Implementation Notes