linux-stable/net/mac80211/wme.c
Felix Fietkau 1974da8b31 mac80211: when using iTXQ, select the queue in ieee80211_subif_start_xmit
When using iTXQ, the network stack does not need the real queue number, since
mac80211 is using its internal queues anyway. In that case we can defer
selecting the queue and remove a redundant station lookup in the tx path to save
some CPU cycles.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-04-26 13:02:11 +02:00

286 lines
6.4 KiB
C

/*
* Copyright 2004, Instant802 Networks, Inc.
* Copyright 2013-2014 Intel Mobile Communications GmbH
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/module.h>
#include <linux/if_arp.h>
#include <linux/types.h>
#include <net/ip.h>
#include <net/pkt_sched.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "wme.h"
/* Default mapping in classifier to work with default
* queue setup.
*/
const int ieee802_1d_to_ac[8] = {
IEEE80211_AC_BE,
IEEE80211_AC_BK,
IEEE80211_AC_BK,
IEEE80211_AC_BE,
IEEE80211_AC_VI,
IEEE80211_AC_VI,
IEEE80211_AC_VO,
IEEE80211_AC_VO
};
static int wme_downgrade_ac(struct sk_buff *skb)
{
switch (skb->priority) {
case 6:
case 7:
skb->priority = 5; /* VO -> VI */
return 0;
case 4:
case 5:
skb->priority = 3; /* VI -> BE */
return 0;
case 0:
case 3:
skb->priority = 2; /* BE -> BK */
return 0;
default:
return -1;
}
}
/**
* ieee80211_fix_reserved_tid - return the TID to use if this one is reserved
* @tid: the assumed-reserved TID
*
* Returns: the alternative TID to use, or 0 on error
*/
static inline u8 ieee80211_fix_reserved_tid(u8 tid)
{
switch (tid) {
case 0:
return 3;
case 1:
return 2;
case 2:
return 1;
case 3:
return 0;
case 4:
return 5;
case 5:
return 4;
case 6:
return 7;
case 7:
return 6;
}
return 0;
}
static u16 ieee80211_downgrade_queue(struct ieee80211_sub_if_data *sdata,
struct sta_info *sta, struct sk_buff *skb)
{
struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
/* in case we are a client verify acm is not set for this ac */
while (sdata->wmm_acm & BIT(skb->priority)) {
int ac = ieee802_1d_to_ac[skb->priority];
if (ifmgd->tx_tspec[ac].admitted_time &&
skb->priority == ifmgd->tx_tspec[ac].up)
return ac;
if (wme_downgrade_ac(skb)) {
/*
* This should not really happen. The AP has marked all
* lower ACs to require admission control which is not
* a reasonable configuration. Allow the frame to be
* transmitted using AC_BK as a workaround.
*/
break;
}
}
/* Check to see if this is a reserved TID */
if (sta && sta->reserved_tid == skb->priority)
skb->priority = ieee80211_fix_reserved_tid(skb->priority);
/* look up which queue to use for frames with this 1d tag */
return ieee802_1d_to_ac[skb->priority];
}
/* Indicate which queue to use for this fully formed 802.11 frame */
u16 ieee80211_select_queue_80211(struct ieee80211_sub_if_data *sdata,
struct sk_buff *skb,
struct ieee80211_hdr *hdr)
{
struct ieee80211_local *local = sdata->local;
u8 *p;
if (local->hw.queues < IEEE80211_NUM_ACS)
return 0;
if (!ieee80211_is_data(hdr->frame_control)) {
skb->priority = 7;
return ieee802_1d_to_ac[skb->priority];
}
if (!ieee80211_is_data_qos(hdr->frame_control)) {
skb->priority = 0;
return ieee802_1d_to_ac[skb->priority];
}
p = ieee80211_get_qos_ctl(hdr);
skb->priority = *p & IEEE80211_QOS_CTL_TAG1D_MASK;
return ieee80211_downgrade_queue(sdata, NULL, skb);
}
u16 __ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
struct sta_info *sta, struct sk_buff *skb)
{
struct mac80211_qos_map *qos_map;
bool qos;
/* all mesh/ocb stations are required to support WME */
if (sdata->vif.type == NL80211_IFTYPE_MESH_POINT ||
sdata->vif.type == NL80211_IFTYPE_OCB)
qos = true;
else if (sta)
qos = sta->sta.wme;
else
qos = false;
if (!qos) {
skb->priority = 0; /* required for correct WPA/11i MIC */
return IEEE80211_AC_BE;
}
if (skb->protocol == sdata->control_port_protocol) {
skb->priority = 7;
goto downgrade;
}
/* use the data classifier to determine what 802.1d tag the
* data frame has */
qos_map = rcu_dereference(sdata->qos_map);
skb->priority = cfg80211_classify8021d(skb, qos_map ?
&qos_map->qos_map : NULL);
downgrade:
return ieee80211_downgrade_queue(sdata, sta, skb);
}
/* Indicate which queue to use. */
u16 ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
struct sk_buff *skb)
{
struct ieee80211_local *local = sdata->local;
struct sta_info *sta = NULL;
const u8 *ra = NULL;
u16 ret;
/* when using iTXQ, we can do this later */
if (local->ops->wake_tx_queue)
return 0;
if (local->hw.queues < IEEE80211_NUM_ACS || skb->len < 6) {
skb->priority = 0; /* required for correct WPA/11i MIC */
return 0;
}
rcu_read_lock();
switch (sdata->vif.type) {
case NL80211_IFTYPE_AP_VLAN:
sta = rcu_dereference(sdata->u.vlan.sta);
if (sta)
break;
/* fall through */
case NL80211_IFTYPE_AP:
ra = skb->data;
break;
case NL80211_IFTYPE_WDS:
ra = sdata->u.wds.remote_addr;
break;
case NL80211_IFTYPE_STATION:
/* might be a TDLS station */
sta = sta_info_get(sdata, skb->data);
if (sta)
break;
ra = sdata->u.mgd.bssid;
break;
case NL80211_IFTYPE_ADHOC:
ra = skb->data;
break;
default:
break;
}
if (!sta && ra && !is_multicast_ether_addr(ra))
sta = sta_info_get(sdata, ra);
ret = __ieee80211_select_queue(sdata, sta, skb);
rcu_read_unlock();
return ret;
}
/**
* ieee80211_set_qos_hdr - Fill in the QoS header if there is one.
*
* @sdata: local subif
* @skb: packet to be updated
*/
void ieee80211_set_qos_hdr(struct ieee80211_sub_if_data *sdata,
struct sk_buff *skb)
{
struct ieee80211_hdr *hdr = (void *)skb->data;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
u8 tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
u8 flags;
u8 *p;
if (!ieee80211_is_data_qos(hdr->frame_control))
return;
p = ieee80211_get_qos_ctl(hdr);
/* set up the first byte */
/*
* preserve everything but the TID and ACK policy
* (which we both write here)
*/
flags = *p & ~(IEEE80211_QOS_CTL_TID_MASK |
IEEE80211_QOS_CTL_ACK_POLICY_MASK);
if (is_multicast_ether_addr(hdr->addr1) ||
sdata->noack_map & BIT(tid)) {
flags |= IEEE80211_QOS_CTL_ACK_POLICY_NOACK;
info->flags |= IEEE80211_TX_CTL_NO_ACK;
}
*p = flags | tid;
/* set up the second byte */
p++;
if (ieee80211_vif_is_mesh(&sdata->vif)) {
/* preserve RSPI and Mesh PS Level bit */
*p &= ((IEEE80211_QOS_CTL_RSPI |
IEEE80211_QOS_CTL_MESH_PS_LEVEL) >> 8);
/* Nulls don't have a mesh header (frame body) */
if (!ieee80211_is_qos_nullfunc(hdr->frame_control))
*p |= (IEEE80211_QOS_CTL_MESH_CONTROL_PRESENT >> 8);
} else {
*p = 0;
}
}