wifi: cfg80211: split control freq check from chandef check

In order to introduce NPCA later, split the control frequency
check out of cfg80211_chandef_valid().

Link: https://patch.msgid.link/20260303152641.11b31e4878a7.I534669506008e12ffcd6c115161777e528fdc838@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 54 insertions, 44 deletions

diff --git a/net/wireless/chan.c b/net/wireless/chan.c
index d9d4e043bb39..e3c18a4392bb 100644
--- a/net/wireless/chan.c
+++ b/net/wireless/chan.c
@@ -6,7 +6,7 @@
  *
  * Copyright 2009	Johannes Berg <johannes@sipsolutions.net>
  * Copyright 2013-2014  Intel Mobile Communications GmbH
- * Copyright 2018-2025	Intel Corporation
+ * Copyright 2018-2026	Intel Corporation
  */
 
 #include <linux/export.h>
@@ -339,6 +339,58 @@ static bool cfg80211_valid_center_freq(u32 center,
 	return (center - bw / 2 - 5945) % step == 0;
 }
 
+static bool
+cfg80211_chandef_valid_control_freq(const struct cfg80211_chan_def *chandef,
+				    u32 control_freq)
+{
+	switch (chandef->width) {
+	case NL80211_CHAN_WIDTH_5:
+	case NL80211_CHAN_WIDTH_10:
+	case NL80211_CHAN_WIDTH_20:
+	case NL80211_CHAN_WIDTH_20_NOHT:
+	case NL80211_CHAN_WIDTH_1:
+	case NL80211_CHAN_WIDTH_2:
+	case NL80211_CHAN_WIDTH_4:
+	case NL80211_CHAN_WIDTH_8:
+	case NL80211_CHAN_WIDTH_16:
+		/* checked separately */
+		break;
+	case NL80211_CHAN_WIDTH_320:
+		if (chandef->center_freq1 == control_freq + 150 ||
+		    chandef->center_freq1 == control_freq + 130 ||
+		    chandef->center_freq1 == control_freq + 110 ||
+		    chandef->center_freq1 == control_freq + 90 ||
+		    chandef->center_freq1 == control_freq - 90 ||
+		    chandef->center_freq1 == control_freq - 110 ||
+		    chandef->center_freq1 == control_freq - 130 ||
+		    chandef->center_freq1 == control_freq - 150)
+			break;
+		fallthrough;
+	case NL80211_CHAN_WIDTH_160:
+		if (chandef->center_freq1 == control_freq + 70 ||
+		    chandef->center_freq1 == control_freq + 50 ||
+		    chandef->center_freq1 == control_freq - 50 ||
+		    chandef->center_freq1 == control_freq - 70)
+			break;
+		fallthrough;
+	case NL80211_CHAN_WIDTH_80P80:
+	case NL80211_CHAN_WIDTH_80:
+		if (chandef->center_freq1 == control_freq + 30 ||
+		    chandef->center_freq1 == control_freq - 30)
+			break;
+		fallthrough;
+	case NL80211_CHAN_WIDTH_40:
+		if (chandef->center_freq1 == control_freq + 10 ||
+		    chandef->center_freq1 == control_freq - 10)
+			break;
+		fallthrough;
+	default:
+		return false;
+	}
+
+	return true;
+}
+
 bool cfg80211_chandef_valid(const struct cfg80211_chan_def *chandef)
 {
 	u32 control_freq, control_freq_khz, start_khz, end_khz;
@@ -393,50 +445,8 @@ bool cfg80211_chandef_valid(const struct cfg80211_chan_def *chandef)
 		break;
 	}
 
-	switch (chandef->width) {
-	case NL80211_CHAN_WIDTH_5:
-	case NL80211_CHAN_WIDTH_10:
-	case NL80211_CHAN_WIDTH_20:
-	case NL80211_CHAN_WIDTH_20_NOHT:
-	case NL80211_CHAN_WIDTH_1:
-	case NL80211_CHAN_WIDTH_2:
-	case NL80211_CHAN_WIDTH_4:
-	case NL80211_CHAN_WIDTH_8:
-	case NL80211_CHAN_WIDTH_16:
-		/* all checked above */
-		break;
-	case NL80211_CHAN_WIDTH_320:
-		if (chandef->center_freq1 == control_freq + 150 ||
-		    chandef->center_freq1 == control_freq + 130 ||
-		    chandef->center_freq1 == control_freq + 110 ||
-		    chandef->center_freq1 == control_freq + 90 ||
-		    chandef->center_freq1 == control_freq - 90 ||
-		    chandef->center_freq1 == control_freq - 110 ||
-		    chandef->center_freq1 == control_freq - 130 ||
-		    chandef->center_freq1 == control_freq - 150)
-			break;
-		fallthrough;
-	case NL80211_CHAN_WIDTH_160:
-		if (chandef->center_freq1 == control_freq + 70 ||
-		    chandef->center_freq1 == control_freq + 50 ||
-		    chandef->center_freq1 == control_freq - 50 ||
-		    chandef->center_freq1 == control_freq - 70)
-			break;
-		fallthrough;
-	case NL80211_CHAN_WIDTH_80P80:
-	case NL80211_CHAN_WIDTH_80:
-		if (chandef->center_freq1 == control_freq + 30 ||
-		    chandef->center_freq1 == control_freq - 30)
-			break;
-		fallthrough;
-	case NL80211_CHAN_WIDTH_40:
-		if (chandef->center_freq1 == control_freq + 10 ||
-		    chandef->center_freq1 == control_freq - 10)
-			break;
-		fallthrough;
-	default:
+	if (!cfg80211_chandef_valid_control_freq(chandef, control_freq))
 		return false;
-	}
 
 	if (!cfg80211_valid_center_freq(chandef->center_freq1, chandef->width))
 		return false;