kernel_optimize_test/net/mac80211/ht.c
Johannes Berg ec034b208d mac80211: fix TX a-MPDU locking
During my quest to make mac80211 not have any RCU
warnings from sparse, I came across the a-MPDU code
again and it wasn't quite clear why it isn't racy.
So instead of assigning the tid_tx array with just
the spinlock held in ieee80211_start_tx_ba_session
use a separate temporary array protected only by
the spinlock and protect all assignments to the
"live" array by both the spinlock and the mutex so
that other code is easily verified to be correct.

Due to pointer assignment atomicity I don't think
this is a real issue, but I'm not sure, especially
on Alpha the current code might be problematic.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-05-16 14:10:40 -04:00

319 lines
9.4 KiB
C

/*
* HT handling
*
* Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
* Copyright 2002-2005, Instant802 Networks, Inc.
* Copyright 2005-2006, Devicescape Software, Inc.
* Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
* Copyright 2007, Michael Wu <flamingice@sourmilk.net>
* Copyright 2007-2010, Intel Corporation
*
* 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/ieee80211.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "rate.h"
void ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_supported_band *sband,
struct ieee80211_ht_cap *ht_cap_ie,
struct ieee80211_sta_ht_cap *ht_cap)
{
u8 ampdu_info, tx_mcs_set_cap;
int i, max_tx_streams;
BUG_ON(!ht_cap);
memset(ht_cap, 0, sizeof(*ht_cap));
if (!ht_cap_ie || !sband->ht_cap.ht_supported)
return;
ht_cap->ht_supported = true;
/*
* The bits listed in this expression should be
* the same for the peer and us, if the station
* advertises more then we can't use those thus
* we mask them out.
*/
ht_cap->cap = le16_to_cpu(ht_cap_ie->cap_info) &
(sband->ht_cap.cap |
~(IEEE80211_HT_CAP_LDPC_CODING |
IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
IEEE80211_HT_CAP_GRN_FLD |
IEEE80211_HT_CAP_SGI_20 |
IEEE80211_HT_CAP_SGI_40 |
IEEE80211_HT_CAP_DSSSCCK40));
/*
* The STBC bits are asymmetric -- if we don't have
* TX then mask out the peer's RX and vice versa.
*/
if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_TX_STBC))
ht_cap->cap &= ~IEEE80211_HT_CAP_RX_STBC;
if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_RX_STBC))
ht_cap->cap &= ~IEEE80211_HT_CAP_TX_STBC;
ampdu_info = ht_cap_ie->ampdu_params_info;
ht_cap->ampdu_factor =
ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
ht_cap->ampdu_density =
(ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
/* own MCS TX capabilities */
tx_mcs_set_cap = sband->ht_cap.mcs.tx_params;
/* Copy peer MCS TX capabilities, the driver might need them. */
ht_cap->mcs.tx_params = ht_cap_ie->mcs.tx_params;
/* can we TX with MCS rates? */
if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
return;
/* Counting from 0, therefore +1 */
if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
max_tx_streams =
((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
>> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
else
max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
/*
* 802.11n-2009 20.3.5 / 20.6 says:
* - indices 0 to 7 and 32 are single spatial stream
* - 8 to 31 are multiple spatial streams using equal modulation
* [8..15 for two streams, 16..23 for three and 24..31 for four]
* - remainder are multiple spatial streams using unequal modulation
*/
for (i = 0; i < max_tx_streams; i++)
ht_cap->mcs.rx_mask[i] =
sband->ht_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
i < IEEE80211_HT_MCS_MASK_LEN; i++)
ht_cap->mcs.rx_mask[i] =
sband->ht_cap.mcs.rx_mask[i] &
ht_cap_ie->mcs.rx_mask[i];
/* handle MCS rate 32 too */
if (sband->ht_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
ht_cap->mcs.rx_mask[32/8] |= 1;
}
void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta, bool tx)
{
int i;
cancel_work_sync(&sta->ampdu_mlme.work);
for (i = 0; i < STA_TID_NUM; i++) {
__ieee80211_stop_tx_ba_session(sta, i, WLAN_BACK_INITIATOR, tx);
__ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
WLAN_REASON_QSTA_LEAVE_QBSS, tx);
}
}
void ieee80211_ba_session_work(struct work_struct *work)
{
struct sta_info *sta =
container_of(work, struct sta_info, ampdu_mlme.work);
struct tid_ampdu_tx *tid_tx;
int tid;
/*
* When this flag is set, new sessions should be
* blocked, and existing sessions will be torn
* down by the code that set the flag, so this
* need not run.
*/
if (test_sta_flags(sta, WLAN_STA_BLOCK_BA))
return;
mutex_lock(&sta->ampdu_mlme.mtx);
for (tid = 0; tid < STA_TID_NUM; tid++) {
if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
___ieee80211_stop_rx_ba_session(
sta, tid, WLAN_BACK_RECIPIENT,
WLAN_REASON_QSTA_TIMEOUT, true);
tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
if (tid_tx) {
/*
* Assign it over to the normal tid_tx array
* where it "goes live".
*/
spin_lock_bh(&sta->lock);
sta->ampdu_mlme.tid_start_tx[tid] = NULL;
/* could there be a race? */
if (sta->ampdu_mlme.tid_tx[tid])
kfree(tid_tx);
else
ieee80211_assign_tid_tx(sta, tid, tid_tx);
spin_unlock_bh(&sta->lock);
ieee80211_tx_ba_session_handle_start(sta, tid);
continue;
}
tid_tx = sta->ampdu_mlme.tid_tx[tid];
if (tid_tx && test_and_clear_bit(HT_AGG_STATE_WANT_STOP,
&tid_tx->state))
___ieee80211_stop_tx_ba_session(sta, tid,
WLAN_BACK_INITIATOR,
true);
}
mutex_unlock(&sta->ampdu_mlme.mtx);
}
void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
const u8 *da, u16 tid,
u16 initiator, u16 reason_code)
{
struct ieee80211_local *local = sdata->local;
struct sk_buff *skb;
struct ieee80211_mgmt *mgmt;
u16 params;
skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
if (!skb) {
printk(KERN_ERR "%s: failed to allocate buffer "
"for delba frame\n", sdata->name);
return;
}
skb_reserve(skb, local->hw.extra_tx_headroom);
mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
memset(mgmt, 0, 24);
memcpy(mgmt->da, da, ETH_ALEN);
memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
if (sdata->vif.type == NL80211_IFTYPE_AP ||
sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
else if (sdata->vif.type == NL80211_IFTYPE_STATION)
memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
IEEE80211_STYPE_ACTION);
skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
mgmt->u.action.category = WLAN_CATEGORY_BACK;
mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
params = (u16)(initiator << 11); /* bit 11 initiator */
params |= (u16)(tid << 12); /* bit 15:12 TID number */
mgmt->u.action.u.delba.params = cpu_to_le16(params);
mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
ieee80211_tx_skb(sdata, skb);
}
void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
struct sta_info *sta,
struct ieee80211_mgmt *mgmt, size_t len)
{
u16 tid, params;
u16 initiator;
params = le16_to_cpu(mgmt->u.action.u.delba.params);
tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
#ifdef CONFIG_MAC80211_HT_DEBUG
if (net_ratelimit())
printk(KERN_DEBUG "delba from %pM (%s) tid %d reason code %d\n",
mgmt->sa, initiator ? "initiator" : "recipient", tid,
le16_to_cpu(mgmt->u.action.u.delba.reason_code));
#endif /* CONFIG_MAC80211_HT_DEBUG */
if (initiator == WLAN_BACK_INITIATOR)
__ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
true);
else
__ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
true);
}
int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
enum ieee80211_smps_mode smps, const u8 *da,
const u8 *bssid)
{
struct ieee80211_local *local = sdata->local;
struct sk_buff *skb;
struct ieee80211_mgmt *action_frame;
/* 27 = header + category + action + smps mode */
skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
if (!skb)
return -ENOMEM;
skb_reserve(skb, local->hw.extra_tx_headroom);
action_frame = (void *)skb_put(skb, 27);
memcpy(action_frame->da, da, ETH_ALEN);
memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
memcpy(action_frame->bssid, bssid, ETH_ALEN);
action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
IEEE80211_STYPE_ACTION);
action_frame->u.action.category = WLAN_CATEGORY_HT;
action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
switch (smps) {
case IEEE80211_SMPS_AUTOMATIC:
case IEEE80211_SMPS_NUM_MODES:
WARN_ON(1);
case IEEE80211_SMPS_OFF:
action_frame->u.action.u.ht_smps.smps_control =
WLAN_HT_SMPS_CONTROL_DISABLED;
break;
case IEEE80211_SMPS_STATIC:
action_frame->u.action.u.ht_smps.smps_control =
WLAN_HT_SMPS_CONTROL_STATIC;
break;
case IEEE80211_SMPS_DYNAMIC:
action_frame->u.action.u.ht_smps.smps_control =
WLAN_HT_SMPS_CONTROL_DYNAMIC;
break;
}
/* we'll do more on status of this frame */
IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
ieee80211_tx_skb(sdata, skb);
return 0;
}
void ieee80211_request_smps_work(struct work_struct *work)
{
struct ieee80211_sub_if_data *sdata =
container_of(work, struct ieee80211_sub_if_data,
u.mgd.request_smps_work);
mutex_lock(&sdata->u.mgd.mtx);
__ieee80211_request_smps(sdata, sdata->u.mgd.driver_smps_mode);
mutex_unlock(&sdata->u.mgd.mtx);
}
void ieee80211_request_smps(struct ieee80211_vif *vif,
enum ieee80211_smps_mode smps_mode)
{
struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
return;
if (WARN_ON(smps_mode == IEEE80211_SMPS_OFF))
smps_mode = IEEE80211_SMPS_AUTOMATIC;
sdata->u.mgd.driver_smps_mode = smps_mode;
ieee80211_queue_work(&sdata->local->hw,
&sdata->u.mgd.request_smps_work);
}
/* this might change ... don't want non-open drivers using it */
EXPORT_SYMBOL_GPL(ieee80211_request_smps);