nl80211/cfg80211: add VHT MCS support

Add support for reporting and calculating VHT MCSes.

Note that I'm not completely sure that the bitrate
calculations are correct, nor that they can't be
simplified.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

2 files changed, 116 insertions, 16 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 15158a3..d038fa4 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -2890,29 +2890,52 @@ static bool nl80211_put_sta_rate(struct sk_buff *msg, struct rate_info *info,
 
 	rate = nla_nest_start(msg, attr);
 	if (!rate)
-		goto nla_put_failure;
+		return false;
 
 	/* cfg80211_calculate_bitrate will return 0 for mcs >= 32 */
 	bitrate = cfg80211_calculate_bitrate(info);
 	/* report 16-bit bitrate only if we can */
 	bitrate_compat = bitrate < (1UL << 16) ? bitrate : 0;
-	if ((bitrate > 0 &&
-	     nla_put_u32(msg, NL80211_RATE_INFO_BITRATE32, bitrate)) ||
-	    (bitrate_compat > 0 &&
-	     nla_put_u16(msg, NL80211_RATE_INFO_BITRATE, bitrate_compat)) ||
-	    ((info->flags & RATE_INFO_FLAGS_MCS) &&
-	     nla_put_u8(msg, NL80211_RATE_INFO_MCS, info->mcs)) ||
-	    ((info->flags & RATE_INFO_FLAGS_40_MHZ_WIDTH) &&
-	     nla_put_flag(msg, NL80211_RATE_INFO_40_MHZ_WIDTH)) ||
-	    ((info->flags & RATE_INFO_FLAGS_SHORT_GI) &&
-	     nla_put_flag(msg, NL80211_RATE_INFO_SHORT_GI)))
-		goto nla_put_failure;
+	if (bitrate > 0 &&
+	    nla_put_u32(msg, NL80211_RATE_INFO_BITRATE32, bitrate))
+		return false;
+	if (bitrate_compat > 0 &&
+	    nla_put_u16(msg, NL80211_RATE_INFO_BITRATE, bitrate_compat))
+		return false;
+
+	if (info->flags & RATE_INFO_FLAGS_MCS) {
+		if (nla_put_u8(msg, NL80211_RATE_INFO_MCS, info->mcs))
+			return false;
+		if (info->flags & RATE_INFO_FLAGS_40_MHZ_WIDTH &&
+		    nla_put_flag(msg, NL80211_RATE_INFO_40_MHZ_WIDTH))
+			return false;
+		if (info->flags & RATE_INFO_FLAGS_SHORT_GI &&
+		    nla_put_flag(msg, NL80211_RATE_INFO_SHORT_GI))
+			return false;
+	} else if (info->flags & RATE_INFO_FLAGS_VHT_MCS) {
+		if (nla_put_u8(msg, NL80211_RATE_INFO_VHT_MCS, info->mcs))
+			return false;
+		if (nla_put_u8(msg, NL80211_RATE_INFO_VHT_NSS, info->nss))
+			return false;
+		if (info->flags & RATE_INFO_FLAGS_40_MHZ_WIDTH &&
+		    nla_put_flag(msg, NL80211_RATE_INFO_40_MHZ_WIDTH))
+			return false;
+		if (info->flags & RATE_INFO_FLAGS_80_MHZ_WIDTH &&
+		    nla_put_flag(msg, NL80211_RATE_INFO_80_MHZ_WIDTH))
+			return false;
+		if (info->flags & RATE_INFO_FLAGS_80P80_MHZ_WIDTH &&
+		    nla_put_flag(msg, NL80211_RATE_INFO_80P80_MHZ_WIDTH))
+			return false;
+		if (info->flags & RATE_INFO_FLAGS_160_MHZ_WIDTH &&
+		    nla_put_flag(msg, NL80211_RATE_INFO_160_MHZ_WIDTH))
+			return false;
+		if (info->flags & RATE_INFO_FLAGS_SHORT_GI &&
+		    nla_put_flag(msg, NL80211_RATE_INFO_SHORT_GI))
+			return false;
+	}
 
 	nla_nest_end(msg, rate);
 	return true;
-
-nla_put_failure:
-	return false;
 }
 
 static int nl80211_send_station(struct sk_buff *msg, u32 portid, u32 seq,
@@ -5475,6 +5498,11 @@ static int nl80211_join_ibss(struct sk_buff *skb, struct genl_info *info)
 	if (!cfg80211_reg_can_beacon(&rdev->wiphy, &ibss.chandef))
 		return -EINVAL;
 
+	if (ibss.chandef.width > NL80211_CHAN_WIDTH_40)
+		return -EINVAL;
+	if (ibss.chandef.width != NL80211_CHAN_WIDTH_20_NOHT &&
+	    !(rdev->wiphy.features & NL80211_FEATURE_HT_IBSS))
+
 	ibss.channel_fixed = !!info->attrs[NL80211_ATTR_FREQ_FIXED];
 	ibss.privacy = !!info->attrs[NL80211_ATTR_PRIVACY];
 
diff --git a/net/wireless/util.c b/net/wireless/util.c
index db61fe8..3cce6e4 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -944,14 +944,86 @@ static u32 cfg80211_calculate_bitrate_60g(struct rate_info *rate)
 	return __mcs2bitrate[rate->mcs];
 }
 
+static u32 cfg80211_calculate_bitrate_vht(struct rate_info *rate)
+{
+	static const u32 base[4][10] = {
+		{   6500000,
+		   13000000,
+		   19500000,
+		   26000000,
+		   39000000,
+		   52000000,
+		   58500000,
+		   65000000,
+		   78000000,
+		   0,
+		},
+		{  13500000,
+		   27000000,
+		   40500000,
+		   54000000,
+		   81000000,
+		  108000000,
+		  121500000,
+		  135000000,
+		  162000000,
+		  180000000,
+		},
+		{  29300000,
+		   58500000,
+		   87800000,
+		  117000000,
+		  175500000,
+		  234000000,
+		  263300000,
+		  292500000,
+		  351000000,
+		  390000000,
+		},
+		{  58500000,
+		  117000000,
+		  175500000,
+		  234000000,
+		  351000000,
+		  468000000,
+		  526500000,
+		  585000000,
+		  702000000,
+		  780000000,
+		},
+	};
+	u32 bitrate;
+	int idx;
+
+	if (WARN_ON_ONCE(rate->mcs > 9))
+		return 0;
+
+	idx = rate->flags & (RATE_INFO_FLAGS_160_MHZ_WIDTH |
+			     RATE_INFO_FLAGS_80P80_MHZ_WIDTH) ? 3 :
+		  rate->flags & RATE_INFO_FLAGS_80_MHZ_WIDTH ? 2 :
+		  rate->flags & RATE_INFO_FLAGS_40_MHZ_WIDTH ? 1 : 0;
+
+	bitrate = base[idx][rate->mcs];
+	bitrate *= rate->nss;
+
+	if (rate->flags & RATE_INFO_FLAGS_SHORT_GI)
+		bitrate = (bitrate / 9) * 10;
+
+	/* do NOT round down here */
+	return (bitrate + 50000) / 100000;
+}
+
 u32 cfg80211_calculate_bitrate(struct rate_info *rate)
 {
 	int modulation, streams, bitrate;
 
-	if (!(rate->flags & RATE_INFO_FLAGS_MCS))
+	if (!(rate->flags & RATE_INFO_FLAGS_MCS) &&
+	    !(rate->flags & RATE_INFO_FLAGS_VHT_MCS))
 		return rate->legacy;
 	if (rate->flags & RATE_INFO_FLAGS_60G)
 		return cfg80211_calculate_bitrate_60g(rate);
+	if (rate->flags & RATE_INFO_FLAGS_VHT_MCS)
+		return cfg80211_calculate_bitrate_vht(rate);
 
 	/* the formula below does only work for MCS values smaller than 32 */
 	if (WARN_ON_ONCE(rate->mcs >= 32))