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>

1 files changed, 73 insertions, 1 deletions

diff --git a/net/wireless/util.c b/net/wireless/util.c
index db61fe8a6b6..3cce6e48621 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))