diff options
author | Johannes Berg <johannes.berg@intel.com> | 2018-08-31 11:31:16 +0300 |
---|---|---|
committer | Johannes Berg <johannes.berg@intel.com> | 2018-09-05 11:03:14 +0300 |
commit | b0aa75f0b1b2e6bc77128fab36c8ed87e84917cc (patch) | |
tree | a1572f027b5a2ea13af2897a530ba9cfa50af215 /net | |
parent | 34fb190ec0e2284ef44b34ead88bc192b1212286 (diff) | |
download | linux-b0aa75f0b1b2e6bc77128fab36c8ed87e84917cc.tar.xz |
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: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net')
-rw-r--r-- | net/wireless/util.c | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/net/wireless/util.c b/net/wireless/util.c index 4293f980e9c4..ef14d80ca03e 100644 --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -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); |