mac80211: add ability to parse CCFS2

With newer VHT implementations, it's necessary to look at the
HT operation's CCFS2 field to identify the actual bandwidth
used.

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

6 files changed, 50 insertions, 22 deletions

diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index f0f5fedb8caa..0d704e8d7078 100644
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -1070,7 +1070,9 @@ static void ieee80211_update_sta_info(struct ieee80211_sub_if_data *sdata,
                         struct ieee80211_vht_cap cap_ie;
                         struct ieee80211_sta_vht_cap cap = sta->sta.vht_cap;
 
-                        ieee80211_chandef_vht_oper(elems->vht_operation,
+                        ieee80211_chandef_vht_oper(&local->hw,
+                                                   elems->vht_operation,
+                                                   elems->ht_operation,
                                                    &chandef);
                         memcpy(&cap_ie, elems->vht_cap_elem, sizeof(cap_ie));
                         ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband,
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 08da90adeaea..f40a2167935f 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -2112,7 +2112,9 @@ u8 *ieee80211_add_wmm_info_ie(u8 *buf, u8 qosinfo);
 /* channel management */
 bool ieee80211_chandef_ht_oper(const struct ieee80211_ht_operation *ht_oper,
                                struct cfg80211_chan_def *chandef);
-bool ieee80211_chandef_vht_oper(const struct ieee80211_vht_operation *oper,
+bool ieee80211_chandef_vht_oper(struct ieee80211_hw *hw,
+                                const struct ieee80211_vht_operation *oper,
+                                const struct ieee80211_ht_operation *htop,
                                 struct cfg80211_chan_def *chandef);
 u32 ieee80211_chandef_downgrade(struct cfg80211_chan_def *c);
 
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index d51da26e9c18..8bad414c52ad 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2008, 2009 open80211s Ltd.
+ * Copyright (C) 2018 Intel Corporation
  * Authors:    Luis Carlos Cobo <luisca@cozybit.com>
  *             Javier Cardona <javier@cozybit.com>
  *
@@ -98,7 +99,9 @@ bool mesh_matches_local(struct ieee80211_sub_if_data *sdata,
         cfg80211_chandef_create(&sta_chan_def, sdata->vif.bss_conf.chandef.chan,
                                 NL80211_CHAN_NO_HT);
         ieee80211_chandef_ht_oper(ie->ht_operation, &sta_chan_def);
-        ieee80211_chandef_vht_oper(ie->vht_operation, &sta_chan_def);
+        ieee80211_chandef_vht_oper(&sdata->local->hw,
+                                   ie->vht_operation, ie->ht_operation,
+                                   &sta_chan_def);
 
         if (!cfg80211_chandef_compatible(&sdata->vif.bss_conf.chandef,
                                          &sta_chan_def))
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 3dbecae4be73..764a0f8e1dd1 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -220,7 +220,8 @@ ieee80211_determine_chantype(struct ieee80211_sub_if_data *sdata,
                 memcpy(&he_oper_vht_cap, he_oper->optional, 3);
                 he_oper_vht_cap.basic_mcs_set = cpu_to_le16(0);
 
-                if (!ieee80211_chandef_vht_oper(&he_oper_vht_cap,
+                if (!ieee80211_chandef_vht_oper(&sdata->local->hw,
+                                                &he_oper_vht_cap, ht_oper,
                                                 &vht_chandef)) {
                         if (!(ifmgd->flags & IEEE80211_STA_DISABLE_HE))
                                 sdata_info(sdata,
@@ -228,7 +229,8 @@ ieee80211_determine_chantype(struct ieee80211_sub_if_data *sdata,
                         ret = IEEE80211_STA_DISABLE_HE;
                         goto out;
                 }
-        } else if (!ieee80211_chandef_vht_oper(vht_oper, &vht_chandef)) {
+        } else if (!ieee80211_chandef_vht_oper(&sdata->local->hw, vht_oper,
+                                               ht_oper, &vht_chandef)) {
                 if (!(ifmgd->flags & IEEE80211_STA_DISABLE_VHT))
                         sdata_info(sdata,
                                    "AP VHT information is invalid, disable VHT\n");
diff --git a/net/mac80211/spectmgmt.c b/net/mac80211/spectmgmt.c
index 029334835747..4e4902bdbef8 100644
--- a/net/mac80211/spectmgmt.c
+++ b/net/mac80211/spectmgmt.c
@@ -144,6 +144,7 @@ int ieee80211_parse_ch_switch_ie(struct ieee80211_sub_if_data *sdata,
                                 wide_bw_chansw_ie->new_center_freq_seg1,
                         /* .basic_mcs_set doesn't matter */
                 };
+                struct ieee80211_ht_operation ht_oper = {};
 
                 /* default, for the case of IEEE80211_VHT_CHANWIDTH_USE_HT,
                  * to the previously parsed chandef
@@ -151,7 +152,9 @@ int ieee80211_parse_ch_switch_ie(struct ieee80211_sub_if_data *sdata,
                 new_vht_chandef = csa_ie->chandef;
 
                 /* ignore if parsing fails */
-                if (!ieee80211_chandef_vht_oper(&vht_oper, &new_vht_chandef))
+                if (!ieee80211_chandef_vht_oper(&sdata->local->hw,
+                                                &vht_oper, &ht_oper,
+                                                &new_vht_chandef))
                         new_vht_chandef.chan = NULL;
 
                 if (sta_flags & IEEE80211_STA_DISABLE_80P80MHZ &&
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index b51fdcb5adf9..36a3c2ada515 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -2757,49 +2757,65 @@ bool ieee80211_chandef_ht_oper(const struct ieee80211_ht_operation *ht_oper,
         return true;
 }
 
-bool ieee80211_chandef_vht_oper(const struct ieee80211_vht_operation *oper,
+bool ieee80211_chandef_vht_oper(struct ieee80211_hw *hw,
+                                const struct ieee80211_vht_operation *oper,
+                                const struct ieee80211_ht_operation *htop,
                                 struct cfg80211_chan_def *chandef)
 {
         struct cfg80211_chan_def new = *chandef;
-        int cf1, cf2;
+        int cf0, cf1;
+        int ccfs0, ccfs1, ccfs2;
+        int ccf0, ccf1;
 
-        if (!oper)
+        if (!oper || !htop)
                 return false;
 
-        cf1 = ieee80211_channel_to_frequency(oper->center_freq_seg0_idx,
-                                             chandef->chan->band);
-        cf2 = ieee80211_channel_to_frequency(oper->center_freq_seg1_idx,
-                                             chandef->chan->band);
+        ccfs0 = oper->center_freq_seg0_idx;
+        ccfs1 = oper->center_freq_seg1_idx;
+        ccfs2 = (le16_to_cpu(htop->operation_mode) &
+                                IEEE80211_HT_OP_MODE_CCFS2_MASK)
+                        >> IEEE80211_HT_OP_MODE_CCFS2_SHIFT;
+
+        /* when parsing (and we know how to) CCFS1 and CCFS2 are equivalent */
+        ccf0 = ccfs0;
+        ccf1 = ccfs1;
+        if (!ccfs1 && ieee80211_hw_check(hw, SUPPORTS_VHT_EXT_NSS_BW))
+                ccf1 = ccfs2;
+
+        cf0 = ieee80211_channel_to_frequency(ccf0, chandef->chan->band);
+        cf1 = ieee80211_channel_to_frequency(ccf1, chandef->chan->band);
 
         switch (oper->chan_width) {
         case IEEE80211_VHT_CHANWIDTH_USE_HT:
+                /* just use HT information directly */
                 break;
         case IEEE80211_VHT_CHANWIDTH_80MHZ:
                 new.width = NL80211_CHAN_WIDTH_80;
-                new.center_freq1 = cf1;
+                new.center_freq1 = cf0;
                 /* If needed, adjust based on the newer interop workaround. */
-                if (oper->center_freq_seg1_idx) {
+                if (ccf1) {
                         unsigned int diff;
 
-                        diff = abs(oper->center_freq_seg1_idx -
-                                   oper->center_freq_seg0_idx);
+                        diff = abs(ccf1 - ccf0);
                         if (diff == 8) {
                                 new.width = NL80211_CHAN_WIDTH_160;
-                                new.center_freq1 = cf2;
+                                new.center_freq1 = cf1;
                         } else if (diff > 8) {
                                 new.width = NL80211_CHAN_WIDTH_80P80;
-                                new.center_freq2 = cf2;
+                                new.center_freq2 = cf1;
                         }
                 }
                 break;
         case IEEE80211_VHT_CHANWIDTH_160MHZ:
+                /* deprecated encoding */
                 new.width = NL80211_CHAN_WIDTH_160;
-                new.center_freq1 = cf1;
+                new.center_freq1 = cf0;
                 break;
         case IEEE80211_VHT_CHANWIDTH_80P80MHZ:
+                /* deprecated encoding */
                 new.width = NL80211_CHAN_WIDTH_80P80;
-                new.center_freq1 = cf1;
-                new.center_freq2 = cf2;
+                new.center_freq1 = cf0;
+                new.center_freq2 = cf1;
                 break;
         default:
                 return false;