linux/net/mac80211/vht.c
Johannes Berg d2941df8fb mac80211: recalculate min channel width on VHT opmode changes
When an associated station changes its VHT operating mode this
can/will affect the bandwidth it's using, and consequently we
must recalculate the minimum bandwidth we need to use. Failure
to do so can lead to one of two scenarios:
 1) we use a too high bandwidth, this is benign
 2) we use a too narrow bandwidth, causing rate control and
    actual PHY configuration to be out of sync, which can in
    turn cause problems/crashes

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2017-01-11 16:35:05 +01:00

561 lines
16 KiB
C

/*
* VHT handling
*
* Portions of this file
* Copyright(c) 2015 - 2016 Intel Deutschland 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/ieee80211.h>
#include <linux/export.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "rate.h"
static void __check_vhtcap_disable(struct ieee80211_sub_if_data *sdata,
struct ieee80211_sta_vht_cap *vht_cap,
u32 flag)
{
__le32 le_flag = cpu_to_le32(flag);
if (sdata->u.mgd.vht_capa_mask.vht_cap_info & le_flag &&
!(sdata->u.mgd.vht_capa.vht_cap_info & le_flag))
vht_cap->cap &= ~flag;
}
void ieee80211_apply_vhtcap_overrides(struct ieee80211_sub_if_data *sdata,
struct ieee80211_sta_vht_cap *vht_cap)
{
int i;
u16 rxmcs_mask, rxmcs_cap, rxmcs_n, txmcs_mask, txmcs_cap, txmcs_n;
if (!vht_cap->vht_supported)
return;
if (sdata->vif.type != NL80211_IFTYPE_STATION)
return;
__check_vhtcap_disable(sdata, vht_cap,
IEEE80211_VHT_CAP_RXLDPC);
__check_vhtcap_disable(sdata, vht_cap,
IEEE80211_VHT_CAP_SHORT_GI_80);
__check_vhtcap_disable(sdata, vht_cap,
IEEE80211_VHT_CAP_SHORT_GI_160);
__check_vhtcap_disable(sdata, vht_cap,
IEEE80211_VHT_CAP_TXSTBC);
__check_vhtcap_disable(sdata, vht_cap,
IEEE80211_VHT_CAP_SU_BEAMFORMER_CAPABLE);
__check_vhtcap_disable(sdata, vht_cap,
IEEE80211_VHT_CAP_SU_BEAMFORMEE_CAPABLE);
__check_vhtcap_disable(sdata, vht_cap,
IEEE80211_VHT_CAP_RX_ANTENNA_PATTERN);
__check_vhtcap_disable(sdata, vht_cap,
IEEE80211_VHT_CAP_TX_ANTENNA_PATTERN);
/* Allow user to decrease AMPDU length exponent */
if (sdata->u.mgd.vht_capa_mask.vht_cap_info &
cpu_to_le32(IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK)) {
u32 cap, n;
n = le32_to_cpu(sdata->u.mgd.vht_capa.vht_cap_info) &
IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK;
n >>= IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_SHIFT;
cap = vht_cap->cap & IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK;
cap >>= IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_SHIFT;
if (n < cap) {
vht_cap->cap &=
~IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK;
vht_cap->cap |=
n << IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_SHIFT;
}
}
/* Allow the user to decrease MCSes */
rxmcs_mask =
le16_to_cpu(sdata->u.mgd.vht_capa_mask.supp_mcs.rx_mcs_map);
rxmcs_n = le16_to_cpu(sdata->u.mgd.vht_capa.supp_mcs.rx_mcs_map);
rxmcs_n &= rxmcs_mask;
rxmcs_cap = le16_to_cpu(vht_cap->vht_mcs.rx_mcs_map);
txmcs_mask =
le16_to_cpu(sdata->u.mgd.vht_capa_mask.supp_mcs.tx_mcs_map);
txmcs_n = le16_to_cpu(sdata->u.mgd.vht_capa.supp_mcs.tx_mcs_map);
txmcs_n &= txmcs_mask;
txmcs_cap = le16_to_cpu(vht_cap->vht_mcs.tx_mcs_map);
for (i = 0; i < 8; i++) {
u8 m, n, c;
m = (rxmcs_mask >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
n = (rxmcs_n >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
c = (rxmcs_cap >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
if (m && ((c != IEEE80211_VHT_MCS_NOT_SUPPORTED && n < c) ||
n == IEEE80211_VHT_MCS_NOT_SUPPORTED)) {
rxmcs_cap &= ~(3 << 2*i);
rxmcs_cap |= (rxmcs_n & (3 << 2*i));
}
m = (txmcs_mask >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
n = (txmcs_n >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
c = (txmcs_cap >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
if (m && ((c != IEEE80211_VHT_MCS_NOT_SUPPORTED && n < c) ||
n == IEEE80211_VHT_MCS_NOT_SUPPORTED)) {
txmcs_cap &= ~(3 << 2*i);
txmcs_cap |= (txmcs_n & (3 << 2*i));
}
}
vht_cap->vht_mcs.rx_mcs_map = cpu_to_le16(rxmcs_cap);
vht_cap->vht_mcs.tx_mcs_map = cpu_to_le16(txmcs_cap);
}
void
ieee80211_vht_cap_ie_to_sta_vht_cap(struct ieee80211_sub_if_data *sdata,
struct ieee80211_supported_band *sband,
const struct ieee80211_vht_cap *vht_cap_ie,
struct sta_info *sta)
{
struct ieee80211_sta_vht_cap *vht_cap = &sta->sta.vht_cap;
struct ieee80211_sta_vht_cap own_cap;
u32 cap_info, i;
bool have_80mhz;
memset(vht_cap, 0, sizeof(*vht_cap));
if (!sta->sta.ht_cap.ht_supported)
return;
if (!vht_cap_ie || !sband->vht_cap.vht_supported)
return;
/* Allow VHT if at least one channel on the sband supports 80 MHz */
have_80mhz = false;
for (i = 0; i < sband->n_channels; i++) {
if (sband->channels[i].flags & (IEEE80211_CHAN_DISABLED |
IEEE80211_CHAN_NO_80MHZ))
continue;
have_80mhz = true;
break;
}
if (!have_80mhz)
return;
/*
* A VHT STA must support 40 MHz, but if we verify that here
* then we break a few things - some APs (e.g. Netgear R6300v2
* and others based on the BCM4360 chipset) will unset this
* capability bit when operating in 20 MHz.
*/
vht_cap->vht_supported = true;
own_cap = sband->vht_cap;
/*
* If user has specified capability overrides, take care
* of that if the station we're setting up is the AP that
* we advertised a restricted capability set to. Override
* our own capabilities and then use those below.
*/
if (sdata->vif.type == NL80211_IFTYPE_STATION &&
!test_sta_flag(sta, WLAN_STA_TDLS_PEER))
ieee80211_apply_vhtcap_overrides(sdata, &own_cap);
/* take some capabilities as-is */
cap_info = le32_to_cpu(vht_cap_ie->vht_cap_info);
vht_cap->cap = cap_info;
vht_cap->cap &= IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_3895 |
IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_7991 |
IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_11454 |
IEEE80211_VHT_CAP_RXLDPC |
IEEE80211_VHT_CAP_VHT_TXOP_PS |
IEEE80211_VHT_CAP_HTC_VHT |
IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK |
IEEE80211_VHT_CAP_VHT_LINK_ADAPTATION_VHT_UNSOL_MFB |
IEEE80211_VHT_CAP_VHT_LINK_ADAPTATION_VHT_MRQ_MFB |
IEEE80211_VHT_CAP_RX_ANTENNA_PATTERN |
IEEE80211_VHT_CAP_TX_ANTENNA_PATTERN;
/* and some based on our own capabilities */
switch (own_cap.cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK) {
case IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ:
vht_cap->cap |= cap_info &
IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ;
break;
case IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ:
vht_cap->cap |= cap_info &
IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
break;
default:
/* nothing */
break;
}
/* symmetric capabilities */
vht_cap->cap |= cap_info & own_cap.cap &
(IEEE80211_VHT_CAP_SHORT_GI_80 |
IEEE80211_VHT_CAP_SHORT_GI_160);
/* remaining ones */
if (own_cap.cap & IEEE80211_VHT_CAP_SU_BEAMFORMEE_CAPABLE)
vht_cap->cap |= cap_info &
(IEEE80211_VHT_CAP_SU_BEAMFORMER_CAPABLE |
IEEE80211_VHT_CAP_SOUNDING_DIMENSIONS_MASK);
if (own_cap.cap & IEEE80211_VHT_CAP_SU_BEAMFORMER_CAPABLE)
vht_cap->cap |= cap_info &
(IEEE80211_VHT_CAP_SU_BEAMFORMEE_CAPABLE |
IEEE80211_VHT_CAP_BEAMFORMEE_STS_MASK);
if (own_cap.cap & IEEE80211_VHT_CAP_MU_BEAMFORMER_CAPABLE)
vht_cap->cap |= cap_info &
IEEE80211_VHT_CAP_MU_BEAMFORMEE_CAPABLE;
if (own_cap.cap & IEEE80211_VHT_CAP_MU_BEAMFORMEE_CAPABLE)
vht_cap->cap |= cap_info &
IEEE80211_VHT_CAP_MU_BEAMFORMER_CAPABLE;
if (own_cap.cap & IEEE80211_VHT_CAP_TXSTBC)
vht_cap->cap |= cap_info & IEEE80211_VHT_CAP_RXSTBC_MASK;
if (own_cap.cap & IEEE80211_VHT_CAP_RXSTBC_MASK)
vht_cap->cap |= cap_info & IEEE80211_VHT_CAP_TXSTBC;
/* Copy peer MCS info, the driver might need them. */
memcpy(&vht_cap->vht_mcs, &vht_cap_ie->supp_mcs,
sizeof(struct ieee80211_vht_mcs_info));
/* but also restrict MCSes */
for (i = 0; i < 8; i++) {
u16 own_rx, own_tx, peer_rx, peer_tx;
own_rx = le16_to_cpu(own_cap.vht_mcs.rx_mcs_map);
own_rx = (own_rx >> i * 2) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
own_tx = le16_to_cpu(own_cap.vht_mcs.tx_mcs_map);
own_tx = (own_tx >> i * 2) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
peer_rx = le16_to_cpu(vht_cap->vht_mcs.rx_mcs_map);
peer_rx = (peer_rx >> i * 2) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
peer_tx = le16_to_cpu(vht_cap->vht_mcs.tx_mcs_map);
peer_tx = (peer_tx >> i * 2) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
if (peer_tx != IEEE80211_VHT_MCS_NOT_SUPPORTED) {
if (own_rx == IEEE80211_VHT_MCS_NOT_SUPPORTED)
peer_tx = IEEE80211_VHT_MCS_NOT_SUPPORTED;
else if (own_rx < peer_tx)
peer_tx = own_rx;
}
if (peer_rx != IEEE80211_VHT_MCS_NOT_SUPPORTED) {
if (own_tx == IEEE80211_VHT_MCS_NOT_SUPPORTED)
peer_rx = IEEE80211_VHT_MCS_NOT_SUPPORTED;
else if (own_tx < peer_rx)
peer_rx = own_tx;
}
vht_cap->vht_mcs.rx_mcs_map &=
~cpu_to_le16(IEEE80211_VHT_MCS_NOT_SUPPORTED << i * 2);
vht_cap->vht_mcs.rx_mcs_map |= cpu_to_le16(peer_rx << i * 2);
vht_cap->vht_mcs.tx_mcs_map &=
~cpu_to_le16(IEEE80211_VHT_MCS_NOT_SUPPORTED << i * 2);
vht_cap->vht_mcs.tx_mcs_map |= cpu_to_le16(peer_tx << i * 2);
}
/*
* This is a workaround for VHT-enabled STAs which break the spec
* and have the VHT-MCS Rx map filled in with value 3 for all eight
* spacial streams, an example is AR9462.
*
* As per spec, in section 22.1.1 Introduction to the VHT PHY
* A VHT STA shall support at least single spactial stream VHT-MCSs
* 0 to 7 (transmit and receive) in all supported channel widths.
*/
if (vht_cap->vht_mcs.rx_mcs_map == cpu_to_le16(0xFFFF)) {
vht_cap->vht_supported = false;
sdata_info(sdata, "Ignoring VHT IE from %pM due to invalid rx_mcs_map\n",
sta->addr);
return;
}
/* finally set up the bandwidth */
switch (vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK) {
case IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ:
case IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ:
sta->cur_max_bandwidth = IEEE80211_STA_RX_BW_160;
break;
default:
sta->cur_max_bandwidth = IEEE80211_STA_RX_BW_80;
}
sta->sta.bandwidth = ieee80211_sta_cur_vht_bw(sta);
/* If HT IE reported 3839 bytes only, stay with that size. */
if (sta->sta.max_amsdu_len == IEEE80211_MAX_MPDU_LEN_HT_3839)
return;
switch (vht_cap->cap & IEEE80211_VHT_CAP_MAX_MPDU_MASK) {
case IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_11454:
sta->sta.max_amsdu_len = IEEE80211_MAX_MPDU_LEN_VHT_11454;
break;
case IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_7991:
sta->sta.max_amsdu_len = IEEE80211_MAX_MPDU_LEN_VHT_7991;
break;
case IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_3895:
default:
sta->sta.max_amsdu_len = IEEE80211_MAX_MPDU_LEN_VHT_3895;
break;
}
}
enum ieee80211_sta_rx_bandwidth ieee80211_sta_cap_rx_bw(struct sta_info *sta)
{
struct ieee80211_sta_vht_cap *vht_cap = &sta->sta.vht_cap;
u32 cap_width;
if (!vht_cap->vht_supported)
return sta->sta.ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
IEEE80211_STA_RX_BW_40 :
IEEE80211_STA_RX_BW_20;
cap_width = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
if (cap_width == IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ ||
cap_width == IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
return IEEE80211_STA_RX_BW_160;
return IEEE80211_STA_RX_BW_80;
}
enum nl80211_chan_width ieee80211_sta_cap_chan_bw(struct sta_info *sta)
{
struct ieee80211_sta_vht_cap *vht_cap = &sta->sta.vht_cap;
u32 cap_width;
if (!vht_cap->vht_supported) {
if (!sta->sta.ht_cap.ht_supported)
return NL80211_CHAN_WIDTH_20_NOHT;
return sta->sta.ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
NL80211_CHAN_WIDTH_40 : NL80211_CHAN_WIDTH_20;
}
cap_width = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
if (cap_width == IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ)
return NL80211_CHAN_WIDTH_160;
else if (cap_width == IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
return NL80211_CHAN_WIDTH_80P80;
return NL80211_CHAN_WIDTH_80;
}
enum ieee80211_sta_rx_bandwidth
ieee80211_chan_width_to_rx_bw(enum nl80211_chan_width width)
{
switch (width) {
case NL80211_CHAN_WIDTH_20_NOHT:
case NL80211_CHAN_WIDTH_20:
return IEEE80211_STA_RX_BW_20;
case NL80211_CHAN_WIDTH_40:
return IEEE80211_STA_RX_BW_40;
case NL80211_CHAN_WIDTH_80:
return IEEE80211_STA_RX_BW_80;
case NL80211_CHAN_WIDTH_160:
case NL80211_CHAN_WIDTH_80P80:
return IEEE80211_STA_RX_BW_160;
default:
WARN_ON_ONCE(1);
return IEEE80211_STA_RX_BW_20;
}
}
enum ieee80211_sta_rx_bandwidth ieee80211_sta_cur_vht_bw(struct sta_info *sta)
{
struct ieee80211_sub_if_data *sdata = sta->sdata;
enum ieee80211_sta_rx_bandwidth bw;
enum nl80211_chan_width bss_width = sdata->vif.bss_conf.chandef.width;
bw = ieee80211_sta_cap_rx_bw(sta);
bw = min(bw, sta->cur_max_bandwidth);
bw = min(bw, ieee80211_chan_width_to_rx_bw(bss_width));
return bw;
}
void ieee80211_sta_set_rx_nss(struct sta_info *sta)
{
u8 ht_rx_nss = 0, vht_rx_nss = 0;
/* if we received a notification already don't overwrite it */
if (sta->sta.rx_nss)
return;
if (sta->sta.ht_cap.ht_supported) {
if (sta->sta.ht_cap.mcs.rx_mask[0])
ht_rx_nss++;
if (sta->sta.ht_cap.mcs.rx_mask[1])
ht_rx_nss++;
if (sta->sta.ht_cap.mcs.rx_mask[2])
ht_rx_nss++;
if (sta->sta.ht_cap.mcs.rx_mask[3])
ht_rx_nss++;
/* FIXME: consider rx_highest? */
}
if (sta->sta.vht_cap.vht_supported) {
int i;
u16 rx_mcs_map;
rx_mcs_map = le16_to_cpu(sta->sta.vht_cap.vht_mcs.rx_mcs_map);
for (i = 7; i >= 0; i--) {
u8 mcs = (rx_mcs_map >> (2 * i)) & 3;
if (mcs != IEEE80211_VHT_MCS_NOT_SUPPORTED) {
vht_rx_nss = i + 1;
break;
}
}
/* FIXME: consider rx_highest? */
}
ht_rx_nss = max(ht_rx_nss, vht_rx_nss);
sta->sta.rx_nss = max_t(u8, 1, ht_rx_nss);
}
u32 __ieee80211_vht_handle_opmode(struct ieee80211_sub_if_data *sdata,
struct sta_info *sta, u8 opmode,
enum nl80211_band band)
{
struct ieee80211_local *local = sdata->local;
struct ieee80211_supported_band *sband;
enum ieee80211_sta_rx_bandwidth new_bw;
u32 changed = 0;
u8 nss;
sband = local->hw.wiphy->bands[band];
/* ignore - no support for BF yet */
if (opmode & IEEE80211_OPMODE_NOTIF_RX_NSS_TYPE_BF)
return 0;
nss = opmode & IEEE80211_OPMODE_NOTIF_RX_NSS_MASK;
nss >>= IEEE80211_OPMODE_NOTIF_RX_NSS_SHIFT;
nss += 1;
if (sta->sta.rx_nss != nss) {
sta->sta.rx_nss = nss;
changed |= IEEE80211_RC_NSS_CHANGED;
}
switch (opmode & IEEE80211_OPMODE_NOTIF_CHANWIDTH_MASK) {
case IEEE80211_OPMODE_NOTIF_CHANWIDTH_20MHZ:
sta->cur_max_bandwidth = IEEE80211_STA_RX_BW_20;
break;
case IEEE80211_OPMODE_NOTIF_CHANWIDTH_40MHZ:
sta->cur_max_bandwidth = IEEE80211_STA_RX_BW_40;
break;
case IEEE80211_OPMODE_NOTIF_CHANWIDTH_80MHZ:
sta->cur_max_bandwidth = IEEE80211_STA_RX_BW_80;
break;
case IEEE80211_OPMODE_NOTIF_CHANWIDTH_160MHZ:
sta->cur_max_bandwidth = IEEE80211_STA_RX_BW_160;
break;
}
new_bw = ieee80211_sta_cur_vht_bw(sta);
if (new_bw != sta->sta.bandwidth) {
sta->sta.bandwidth = new_bw;
changed |= IEEE80211_RC_BW_CHANGED;
}
return changed;
}
void ieee80211_process_mu_groups(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt)
{
struct ieee80211_bss_conf *bss_conf = &sdata->vif.bss_conf;
if (!sdata->vif.mu_mimo_owner)
return;
if (!memcmp(mgmt->u.action.u.vht_group_notif.position,
bss_conf->mu_group.position, WLAN_USER_POSITION_LEN) &&
!memcmp(mgmt->u.action.u.vht_group_notif.membership,
bss_conf->mu_group.membership, WLAN_MEMBERSHIP_LEN))
return;
memcpy(bss_conf->mu_group.membership,
mgmt->u.action.u.vht_group_notif.membership,
WLAN_MEMBERSHIP_LEN);
memcpy(bss_conf->mu_group.position,
mgmt->u.action.u.vht_group_notif.position,
WLAN_USER_POSITION_LEN);
ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_MU_GROUPS);
}
void ieee80211_update_mu_groups(struct ieee80211_vif *vif,
const u8 *membership, const u8 *position)
{
struct ieee80211_bss_conf *bss_conf = &vif->bss_conf;
if (WARN_ON_ONCE(!vif->mu_mimo_owner))
return;
memcpy(bss_conf->mu_group.membership, membership, WLAN_MEMBERSHIP_LEN);
memcpy(bss_conf->mu_group.position, position, WLAN_USER_POSITION_LEN);
}
EXPORT_SYMBOL_GPL(ieee80211_update_mu_groups);
void ieee80211_vht_handle_opmode(struct ieee80211_sub_if_data *sdata,
struct sta_info *sta, u8 opmode,
enum nl80211_band band)
{
struct ieee80211_local *local = sdata->local;
struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
u32 changed = __ieee80211_vht_handle_opmode(sdata, sta, opmode, band);
if (changed > 0) {
ieee80211_recalc_min_chandef(sdata);
rate_control_rate_update(local, sband, sta, changed);
}
}
void ieee80211_get_vht_mask_from_cap(__le16 vht_cap,
u16 vht_mask[NL80211_VHT_NSS_MAX])
{
int i;
u16 mask, cap = le16_to_cpu(vht_cap);
for (i = 0; i < NL80211_VHT_NSS_MAX; i++) {
mask = (cap >> i * 2) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
switch (mask) {
case IEEE80211_VHT_MCS_SUPPORT_0_7:
vht_mask[i] = 0x00FF;
break;
case IEEE80211_VHT_MCS_SUPPORT_0_8:
vht_mask[i] = 0x01FF;
break;
case IEEE80211_VHT_MCS_SUPPORT_0_9:
vht_mask[i] = 0x03FF;
break;
case IEEE80211_VHT_MCS_NOT_SUPPORTED:
default:
vht_mask[i] = 0;
break;
}
}
}