wifi: cfg80211: separate NPCA validity from chandef validity

When considering both NPCA and DBE, it can appear that the
NPCA configuration is invalid, e.g. for an 80 MHz BSS channel
with DBE to 160 MHz:

     | primary channel
     |       NPCA primary channel
     |       |
     V       V
   | p |   | n |   |   |   |   |   |
   | BSS channel   |
   | DBE channel                   |

Now the NPCA primary channel is in the same half as the primary
channel, and the NPCA puncturing bitmap could be completely
invalid as a puncturing bitmap when considering the overall
channel.

Split out the validity checks from cfg80211_chandef_valid() to
a new cfg80211_chandef_npca_valid() function that just checks
the NPCA configuration against the BSS chandef.

Link: https://patch.msgid.link/20260428112708.1225df131557.If3a6afadcce05d215b72fd82175f72373a0f6d24@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 38 insertions, 21 deletions

diff --git a/net/wireless/chan.c b/net/wireless/chan.c
index 5289a4ddacd6..ed35b55b1b67 100644
--- a/net/wireless/chan.c
+++ b/net/wireless/chan.c
@@ -460,9 +460,6 @@ bool cfg80211_chandef_valid(const struct cfg80211_chan_def *chandef)
 		return false;
 
 	if (chandef->npca_chan) {
-		bool pri_upper, npca_upper;
-		u32 cf1;
-
 		switch (chandef->width) {
 		case NL80211_CHAN_WIDTH_80:
 		case NL80211_CHAN_WIDTH_160:
@@ -471,24 +468,6 @@ bool cfg80211_chandef_valid(const struct cfg80211_chan_def *chandef)
 		default:
 			return false;
 		}
-
-		if (!cfg80211_chandef_valid_control_freq(chandef,
-							 chandef->npca_chan->center_freq))
-			return false;
-
-		cf1 = chandef->center_freq1;
-		pri_upper = chandef->chan->center_freq > cf1;
-		npca_upper = chandef->npca_chan->center_freq > cf1;
-
-		if (pri_upper == npca_upper)
-			return false;
-
-		if (!valid_puncturing_bitmap(chandef,
-					     chandef->npca_chan->center_freq,
-					     chandef->npca_punctured) ||
-		    (chandef->punctured & chandef->npca_punctured) !=
-		    chandef->punctured)
-			return false;
 	} else if (chandef->npca_punctured) {
 		return false;
 	}
@@ -556,6 +535,44 @@ int cfg80211_chandef_primary(const struct cfg80211_chan_def *c,
 }
 EXPORT_SYMBOL(cfg80211_chandef_primary);
 
+bool cfg80211_chandef_npca_valid(struct wiphy *wiphy,
+				 const struct cfg80211_chan_def *chandef,
+				 const struct ieee80211_uhr_npca_info *npca)
+{
+	struct cfg80211_chan_def tmp = *chandef;
+	bool pri_upper, npca_upper;
+	u32 cf1;
+
+	if (chandef->npca_chan || chandef->npca_punctured)
+		return false;
+
+	if (!npca)
+		return true;
+
+	if (cfg80211_chandef_add_npca(wiphy, &tmp, npca))
+		return false;
+
+	if (!cfg80211_chandef_valid_control_freq(&tmp,
+						 tmp.npca_chan->center_freq))
+		return false;
+
+	cf1 = tmp.center_freq1;
+	pri_upper = tmp.chan->center_freq > cf1;
+	npca_upper = tmp.npca_chan->center_freq > cf1;
+
+	if (pri_upper == npca_upper)
+		return false;
+
+	if (!valid_puncturing_bitmap(&tmp,
+				     tmp.npca_chan->center_freq,
+				     tmp.npca_punctured) ||
+	    (tmp.punctured & tmp.npca_punctured) != tmp.punctured)
+		return false;
+
+	return true;
+}
+EXPORT_SYMBOL(cfg80211_chandef_npca_valid);
+
 int cfg80211_chandef_add_npca(struct wiphy *wiphy,
 			      struct cfg80211_chan_def *chandef,
 			      const struct ieee80211_uhr_npca_info *npca)