mac802154: rx: use tasklet instead workqueue

Tasklets have much less overhead than workqueues. This patch also
removes the heap allocation for the worker on receiving path.
Like mac80211 we should prefer use a tasklet here instead a workqueue to
getting fast out of interrupt context when ieee802154_rx_irqsafe is
called by driver. Like wireless inside the tasklet context we should
call netif_receive_skb instead netif_rx_ni anymore.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This commit is contained in:
Alexander Aring 2014-10-27 17:13:30 +01:00 committed by Marcel Holtmann
parent 61a2281458
commit c5c47e67bc
5 changed files with 47 additions and 41 deletions

View File

@ -202,6 +202,7 @@ void ieee802154_free_hw(struct ieee802154_hw *hw);
int ieee802154_register_hw(struct ieee802154_hw *hw);
void ieee802154_unregister_hw(struct ieee802154_hw *hw);
void ieee802154_rx(struct ieee802154_hw *hw, struct sk_buff *skb);
void ieee802154_rx_irqsafe(struct ieee802154_hw *hw, struct sk_buff *skb,
u8 lqi);

View File

@ -55,11 +55,18 @@ struct ieee802154_local {
* read them using any of protection methods.
*/
bool running;
struct tasklet_struct tasklet;
struct sk_buff_head skb_queue;
};
#define MAC802154_DEVICE_STOPPED 0x00
#define MAC802154_DEVICE_RUN 0x01
enum {
IEEE802154_RX_MSG = 1,
};
/* Slave interface definition.
*
* Slaves represent typical network interfaces available from userspace.

View File

@ -376,7 +376,7 @@ void mac802154_wpan_setup(struct net_device *dev)
static int mac802154_process_data(struct net_device *dev, struct sk_buff *skb)
{
return netif_rx_ni(skb);
return netif_receive_skb(skb);
}
static int

View File

@ -222,6 +222,29 @@ static int mac802154_set_frame_retries(struct wpan_phy *phy, s8 retries)
return local->ops->set_frame_retries(&local->hw, retries);
}
static void ieee802154_tasklet_handler(unsigned long data)
{
struct ieee802154_local *local = (struct ieee802154_local *)data;
struct sk_buff *skb;
while ((skb = skb_dequeue(&local->skb_queue))) {
switch (skb->pkt_type) {
case IEEE802154_RX_MSG:
/* Clear skb->pkt_type in order to not confuse kernel
* netstack.
*/
skb->pkt_type = 0;
ieee802154_rx(&local->hw, skb);
break;
default:
WARN(1, "mac802154: Packet is of unknown type %d\n",
skb->pkt_type);
kfree_skb(skb);
break;
}
}
}
struct ieee802154_hw *
ieee802154_alloc_hw(size_t priv_data_len, struct ieee802154_ops *ops)
{
@ -270,6 +293,12 @@ ieee802154_alloc_hw(size_t priv_data_len, struct ieee802154_ops *ops)
INIT_LIST_HEAD(&local->interfaces);
mutex_init(&local->iflist_mtx);
tasklet_init(&local->tasklet,
ieee802154_tasklet_handler,
(unsigned long)local);
skb_queue_head_init(&local->skb_queue);
return &local->hw;
}
EXPORT_SYMBOL(ieee802154_alloc_hw);
@ -371,6 +400,7 @@ void ieee802154_unregister_hw(struct ieee802154_hw *hw)
struct ieee802154_local *local = hw_to_local(hw);
struct ieee802154_sub_if_data *sdata, *next;
tasklet_kill(&local->tasklet);
flush_workqueue(local->workqueue);
destroy_workqueue(local->workqueue);

View File

@ -19,7 +19,6 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/workqueue.h>
#include <linux/netdevice.h>
#include <linux/crc-ccitt.h>
@ -28,30 +27,11 @@
#include "ieee802154_i.h"
/* The IEEE 802.15.4 standard defines 4 MAC packet types:
* - beacon frame
* - MAC command frame
* - acknowledgement frame
* - data frame
*
* and only the data frame should be pushed to the upper layers, other types
* are just internal MAC layer management information. So only data packets
* are going to be sent to the networking queue, all other will be processed
* right here by using the device workqueue.
*/
struct rx_work {
struct sk_buff *skb;
struct work_struct work;
struct ieee802154_hw *hw;
u8 lqi;
};
static void
mac802154_subif_rx(struct ieee802154_hw *hw, struct sk_buff *skb, u8 lqi)
mac802154_subif_rx(struct ieee802154_hw *hw, struct sk_buff *skb)
{
struct ieee802154_local *local = hw_to_local(hw);
mac_cb(skb)->lqi = lqi;
skb->protocol = htons(ETH_P_IEEE802154);
skb_reset_mac_header(skb);
@ -79,32 +59,20 @@ fail:
kfree_skb(skb);
}
static void mac802154_rx_worker(struct work_struct *work)
void ieee802154_rx(struct ieee802154_hw *hw, struct sk_buff *skb)
{
struct rx_work *rw = container_of(work, struct rx_work, work);
mac802154_subif_rx(rw->hw, rw->skb, rw->lqi);
kfree(rw);
mac802154_subif_rx(hw, skb);
}
EXPORT_SYMBOL(ieee802154_rx);
void
ieee802154_rx_irqsafe(struct ieee802154_hw *hw, struct sk_buff *skb, u8 lqi)
{
struct ieee802154_local *local = hw_to_local(hw);
struct rx_work *work;
if (!skb)
return;
work = kzalloc(sizeof(*work), GFP_ATOMIC);
if (!work)
return;
INIT_WORK(&work->work, mac802154_rx_worker);
work->skb = skb;
work->hw = hw;
work->lqi = lqi;
queue_work(local->workqueue, &work->work);
mac_cb(skb)->lqi = lqi;
skb->pkt_type = IEEE802154_RX_MSG;
skb_queue_tail(&local->skb_queue, skb);
tasklet_schedule(&local->tasklet);
}
EXPORT_SYMBOL(ieee802154_rx_irqsafe);