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Commit b0aa75f0 authored by Johannes Berg's avatar Johannes Berg
Browse files

ieee80211: add new VHT capability fields/parsing 



IEEE 802.11-2016 extended the VHT capability fields to allow
indicating the number of spatial streams depending on the
actually used bandwidth, add support for decoding this.

Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 34fb190e

include/linux/ieee80211.h

+33 −2
Original line number Diff line number Diff line
@@ -1460,13 +1460,16 @@ struct ieee80211_ht_operation { 
 *	STA can receive. Rate expressed in units of 1 Mbps.

 *	If this field is 0 this value should not be used to

 *	consider the highest RX data rate supported.

 *	The top 3 bits of this field are reserved.

 *	The top 3 bits of this field indicate the Maximum NSTS,total

 *	(a beamformee capability.)

 * @tx_mcs_map: TX MCS map 2 bits for each stream, total 8 streams

 * @tx_highest: Indicates highest long GI VHT PPDU data rate

 *	STA can transmit. Rate expressed in units of 1 Mbps.

 *	If this field is 0 this value should not be used to

 *	consider the highest TX data rate supported.

 *	The top 3 bits of this field are reserved.

 *	The top 2 bits of this field are reserved, the

 *	3rd bit from the top indiciates VHT Extended NSS BW

 *	Capability.

 */

struct ieee80211_vht_mcs_info {

	__le16 rx_mcs_map;
@@ -1475,6 +1478,13 @@ struct ieee80211_vht_mcs_info { 
	__le16 tx_highest;

} __packed;



/* for rx_highest */

#define IEEE80211_VHT_MAX_NSTS_TOTAL_SHIFT	13

#define IEEE80211_VHT_MAX_NSTS_TOTAL_MASK	(7 << IEEE80211_VHT_MAX_NSTS_TOTAL_SHIFT)



/* for tx_highest */

#define IEEE80211_VHT_EXT_NSS_BW_CAPABLE	(1 << 13)



/**

 * enum ieee80211_vht_mcs_support - VHT MCS support definitions

 * @IEEE80211_VHT_MCS_SUPPORT_0_7: MCSes 0-7 are supported for the
@@ -1650,6 +1660,7 @@ struct ieee80211_mu_edca_param_set { 
#define IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ		0x00000004

#define IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ	0x00000008

#define IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK			0x0000000C

#define IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_SHIFT			2

#define IEEE80211_VHT_CAP_RXLDPC				0x00000010

#define IEEE80211_VHT_CAP_SHORT_GI_80				0x00000020

#define IEEE80211_VHT_CAP_SHORT_GI_160				0x00000040
@@ -1678,6 +1689,26 @@ struct ieee80211_mu_edca_param_set { 
#define IEEE80211_VHT_CAP_VHT_LINK_ADAPTATION_VHT_MRQ_MFB	0x0c000000

#define IEEE80211_VHT_CAP_RX_ANTENNA_PATTERN			0x10000000

#define IEEE80211_VHT_CAP_TX_ANTENNA_PATTERN			0x20000000

#define IEEE80211_VHT_CAP_EXT_NSS_BW_SHIFT			30

#define IEEE80211_VHT_CAP_EXT_NSS_BW_MASK			0xc0000000



/**

 * ieee80211_get_vht_max_nss - return max NSS for a given bandwidth/MCS

 * @cap: VHT capabilities of the peer

 * @bw: bandwidth to use

 * @mcs: MCS index to use

 * @ext_nss_bw_capable: indicates whether or not the local transmitter

 *	(rate scaling algorithm) can deal with the new logic

 *	(dot11VHTExtendedNSSBWCapable)

 *

 * Due to the VHT Extended NSS Bandwidth Support, the maximum NSS can

 * vary for a given BW/MCS. This function parses the data.

 *

 * Note: This function is exported by cfg80211.

 */

int ieee80211_get_vht_max_nss(struct ieee80211_vht_cap *cap,

			      enum ieee80211_vht_chanwidth bw,

			      int mcs, bool ext_nss_bw_capable);



/* 802.11ax HE MAC capabilities */

#define IEEE80211_HE_MAC_CAP0_HTC_HE				0x01

net/wireless/util.c

+109 −0
Original line number Diff line number Diff line
@@ -5,17 +5,20 @@ 
 * Copyright 2007-2009	Johannes Berg <johannes@sipsolutions.net>

 * Copyright 2013-2014  Intel Mobile Communications GmbH

 * Copyright 2017	Intel Deutschland GmbH

 * Copyright (C) 2018 Intel Corporation

 */

#include <linux/export.h>

#include <linux/bitops.h>

#include <linux/etherdevice.h>

#include <linux/slab.h>

#include <linux/ieee80211.h>

#include <net/cfg80211.h>

#include <net/ip.h>

#include <net/dsfield.h>

#include <linux/if_vlan.h>

#include <linux/mpls.h>

#include <linux/gcd.h>

#include <linux/bitfield.h>

#include "core.h"

#include "rdev-ops.h"
@@ -1938,3 +1941,109 @@ void cfg80211_send_layer2_update(struct net_device *dev, const u8 *addr) 
	netif_rx_ni(skb);

}

EXPORT_SYMBOL(cfg80211_send_layer2_update);



int ieee80211_get_vht_max_nss(struct ieee80211_vht_cap *cap,

			      enum ieee80211_vht_chanwidth bw,

			      int mcs, bool ext_nss_bw_capable)

{

	u16 map = le16_to_cpu(cap->supp_mcs.rx_mcs_map);

	int max_vht_nss = 0;

	int ext_nss_bw;

	int supp_width;

	int i, mcs_encoding;



	if (map == 0xffff)

		return 0;



	if (WARN_ON(mcs > 9))

		return 0;

	if (mcs <= 7)

		mcs_encoding = 0;

	else if (mcs == 8)

		mcs_encoding = 1;

	else

		mcs_encoding = 2;



	/* find max_vht_nss for the given MCS */

	for (i = 7; i >= 0; i--) {

		int supp = (map >> (2 * i)) & 3;



		if (supp == 3)

			continue;



		if (supp >= mcs_encoding) {

			max_vht_nss = i;

			break;

		}

	}



	if (!(cap->supp_mcs.tx_mcs_map &

			cpu_to_le16(IEEE80211_VHT_EXT_NSS_BW_CAPABLE)))

		return max_vht_nss;



	ext_nss_bw = le32_get_bits(cap->vht_cap_info,

				   IEEE80211_VHT_CAP_EXT_NSS_BW_MASK);

	supp_width = le32_get_bits(cap->vht_cap_info,

				   IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK);



	/* if not capable, treat ext_nss_bw as 0 */

	if (!ext_nss_bw_capable)

		ext_nss_bw = 0;



	/* This is invalid */

	if (supp_width == 3)

		return 0;



	/* This is an invalid combination so pretend nothing is supported */

	if (supp_width == 2 && (ext_nss_bw == 1 || ext_nss_bw == 2))

		return 0;



	/*

	 * Cover all the special cases according to IEEE 802.11-2016

	 * Table 9-250. All other cases are either factor of 1 or not

	 * valid/supported.

	 */

	switch (bw) {

	case IEEE80211_VHT_CHANWIDTH_USE_HT:

	case IEEE80211_VHT_CHANWIDTH_80MHZ:

		if ((supp_width == 1 || supp_width == 2) &&

		    ext_nss_bw == 3)

			return 2 * max_vht_nss;

		break;

	case IEEE80211_VHT_CHANWIDTH_160MHZ:

		if (supp_width == 0 &&

		    (ext_nss_bw == 1 || ext_nss_bw == 2))

			return DIV_ROUND_UP(max_vht_nss, 2);

		if (supp_width == 0 &&

		    ext_nss_bw == 3)

			return DIV_ROUND_UP(3 * max_vht_nss, 4);

		if (supp_width == 1 &&

		    ext_nss_bw == 3)

			return 2 * max_vht_nss;

		break;

	case IEEE80211_VHT_CHANWIDTH_80P80MHZ:

		if (supp_width == 0 &&

		    (ext_nss_bw == 1 || ext_nss_bw == 2))

			return 0; /* not possible */

		if (supp_width == 0 &&

		    ext_nss_bw == 2)

			return DIV_ROUND_UP(max_vht_nss, 2);

		if (supp_width == 0 &&

		    ext_nss_bw == 3)

			return DIV_ROUND_UP(3 * max_vht_nss, 4);

		if (supp_width == 1 &&

		    ext_nss_bw == 0)

			return 0; /* not possible */

		if (supp_width == 1 &&

		    ext_nss_bw == 1)

			return DIV_ROUND_UP(max_vht_nss, 2);

		if (supp_width == 1 &&

		    ext_nss_bw == 2)

			return DIV_ROUND_UP(3 * max_vht_nss, 4);

		break;

	}



	/* not covered or invalid combination received */

	return max_vht_nss;

}

EXPORT_SYMBOL(ieee80211_get_vht_max_nss);