wifi: cfg80211: save power spectral density(psd) of regulatory rule

6 GHz regulatory domains introduces Power Spectral Density (PSD).
The PSD value of the regulatory rule should be taken into effect
for the ieee80211_channels falling into that particular regulatory
rule. Save the values in the channel which has PSD value and add
nl80211 attributes accordingly to handle it.
Co-developed-by: Aditya Kumar Singh <quic_adisi@quicinc.com>
Signed-off-by: Aditya Kumar Singh <quic_adisi@quicinc.com>
Signed-off-by: Wen Gong <quic_wgong@quicinc.com>
Link: https://lore.kernel.org/r/20230914082026.3709-1-quic_wgong@quicinc.com
[use hole in chan flags, reword docs]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/cfg80211.h

@@ -76,6 +76,8 @@ struct wiphy;
  * @IEEE80211_CHAN_DISABLED: This channel is disabled.
  * @IEEE80211_CHAN_NO_IR: do not initiate radiation, this includes
  *	sending probe requests or beaconing.
+ * @IEEE80211_CHAN_PSD: Power spectral density (in dBm) is set for this
+ *	channel.
  * @IEEE80211_CHAN_RADAR: Radar detection is required on this channel.
  * @IEEE80211_CHAN_NO_HT40PLUS: extension channel above this channel
  *	is not permitted.
@@ -119,7 +121,7 @@ struct wiphy;
 enum ieee80211_channel_flags {
 	IEEE80211_CHAN_DISABLED		= 1<<0,
 	IEEE80211_CHAN_NO_IR		= 1<<1,
-	/* hole at 1<<2 */
+	IEEE80211_CHAN_PSD		= 1<<2,
 	IEEE80211_CHAN_RADAR		= 1<<3,
 	IEEE80211_CHAN_NO_HT40PLUS	= 1<<4,
 	IEEE80211_CHAN_NO_HT40MINUS	= 1<<5,
@@ -171,6 +173,7 @@ enum ieee80211_channel_flags {
  *	on this channel.
  * @dfs_state_entered: timestamp (jiffies) when the dfs state was entered.
  * @dfs_cac_ms: DFS CAC time in milliseconds, this is valid for DFS channels.
+ * @psd: power spectral density (in dBm)
  */
 struct ieee80211_channel {
 	enum nl80211_band band;
@@ -187,6 +190,7 @@ struct ieee80211_channel {
 	enum nl80211_dfs_state dfs_state;
 	unsigned long dfs_state_entered;
 	unsigned int dfs_cac_ms;
+	s8 psd;
 };
 
 /**

include/net/regulatory.h

@@ -213,6 +213,7 @@ struct ieee80211_reg_rule {
 	u32 flags;
 	u32 dfs_cac_ms;
 	bool has_wmm;
+	s8 psd;
 };
 
 struct ieee80211_regdomain {

include/uapi/linux/nl80211.h

@@ -4215,6 +4215,8 @@ enum nl80211_wmm_rule {
  *	as the primary or any of the secondary channels isn't possible
  * @NL80211_FREQUENCY_ATTR_NO_EHT: EHT operation is not allowed on this channel
  *	in current regulatory domain.
+ * @NL80211_FREQUENCY_ATTR_PSD: Power spectral density (in dBm) that
+ *	is allowed on this channel in current regulatory domain.
  * @NL80211_FREQUENCY_ATTR_MAX: highest frequency attribute number
  *	currently defined
  * @__NL80211_FREQUENCY_ATTR_AFTER_LAST: internal use
@@ -4253,6 +4255,7 @@ enum nl80211_frequency_attr {
 	NL80211_FREQUENCY_ATTR_16MHZ,
 	NL80211_FREQUENCY_ATTR_NO_320MHZ,
 	NL80211_FREQUENCY_ATTR_NO_EHT,
+	NL80211_FREQUENCY_ATTR_PSD,
 
 	/* keep last */
 	__NL80211_FREQUENCY_ATTR_AFTER_LAST,
@@ -4353,6 +4356,8 @@ enum nl80211_reg_type {
  * 	a given frequency range. The value is in mBm (100 * dBm).
  * @NL80211_ATTR_DFS_CAC_TIME: DFS CAC time in milliseconds.
  *	If not present or 0 default CAC time will be used.
+ * @NL80211_ATTR_POWER_RULE_PSD: power spectral density (in dBm).
+ *	This could be negative.
  * @NL80211_REG_RULE_ATTR_MAX: highest regulatory rule attribute number
  *	currently defined
  * @__NL80211_REG_RULE_ATTR_AFTER_LAST: internal use
@@ -4370,6 +4375,8 @@ enum nl80211_reg_rule_attr {
 
 	NL80211_ATTR_DFS_CAC_TIME,
 
+	NL80211_ATTR_POWER_RULE_PSD,
+
 	/* keep last */
 	__NL80211_REG_RULE_ATTR_AFTER_LAST,
 	NL80211_REG_RULE_ATTR_MAX = __NL80211_REG_RULE_ATTR_AFTER_LAST - 1
@@ -4453,6 +4460,7 @@ enum nl80211_sched_scan_match_attr {
  * @NL80211_RRF_NO_HE: HE operation not allowed
  * @NL80211_RRF_NO_320MHZ: 320MHz operation not allowed
  * @NL80211_RRF_NO_EHT: EHT operation not allowed
+ * @NL80211_RRF_PSD: Ruleset has power spectral density value
  */
 enum nl80211_reg_rule_flags {
 	NL80211_RRF_NO_OFDM		= 1<<0,
@@ -4473,6 +4481,7 @@ enum nl80211_reg_rule_flags {
 	NL80211_RRF_NO_HE		= 1<<17,
 	NL80211_RRF_NO_320MHZ		= 1<<18,
 	NL80211_RRF_NO_EHT		= 1<<19,
+	NL80211_RRF_PSD			= 1<<20,
 };
 
 #define NL80211_RRF_PASSIVE_SCAN	NL80211_RRF_NO_IR

net/wireless/nl80211.c

@@ -1115,6 +1115,10 @@ static int nl80211_msg_put_channel(struct sk_buff *msg, struct wiphy *wiphy,
 	if (nla_put_u32(msg, NL80211_FREQUENCY_ATTR_OFFSET, chan->freq_offset))
 		goto nla_put_failure;
 
+	if ((chan->flags & IEEE80211_CHAN_PSD) &&
+	    nla_put_s8(msg, NL80211_FREQUENCY_ATTR_PSD, chan->psd))
+		goto nla_put_failure;
+
 	if ((chan->flags & IEEE80211_CHAN_DISABLED) &&
 	    nla_put_flag(msg, NL80211_FREQUENCY_ATTR_DISABLED))
 		goto nla_put_failure;
@@ -8529,6 +8533,11 @@ static int nl80211_put_regdom(const struct ieee80211_regdomain *regdom,
 				reg_rule->dfs_cac_ms))
 			goto nla_put_failure;
 
+		if ((reg_rule->flags & NL80211_RRF_PSD) &&
+		    nla_put_s8(msg, NL80211_ATTR_POWER_RULE_PSD,
+			       reg_rule->psd))
+			goto nla_put_failure;
+
 		nla_nest_end(msg, nl_reg_rule);
 	}
 

net/wireless/reg.c

@@ -1589,6 +1589,8 @@ static u32 map_regdom_flags(u32 rd_flags)
 		channel_flags |= IEEE80211_CHAN_NO_320MHZ;
 	if (rd_flags & NL80211_RRF_NO_EHT)
 		channel_flags |= IEEE80211_CHAN_NO_EHT;
+	if (rd_flags & NL80211_RRF_PSD)
+		channel_flags |= IEEE80211_CHAN_PSD;
 	return channel_flags;
 }
 
@@ -1795,6 +1797,9 @@ static void handle_channel_single_rule(struct wiphy *wiphy,
 				chan->dfs_cac_ms = reg_rule->dfs_cac_ms;
 		}
 
+		if (chan->flags & IEEE80211_CHAN_PSD)
+			chan->psd = reg_rule->psd;
+
 		return;
 	}
 
@@ -1815,6 +1820,9 @@ static void handle_channel_single_rule(struct wiphy *wiphy,
 			chan->dfs_cac_ms = IEEE80211_DFS_MIN_CAC_TIME_MS;
 	}
 
+	if (chan->flags & IEEE80211_CHAN_PSD)
+		chan->psd = reg_rule->psd;
+
 	if (chan->orig_mpwr) {
 		/*
 		 * Devices that use REGULATORY_COUNTRY_IE_FOLLOW_POWER
@@ -1884,6 +1892,12 @@ static void handle_channel_adjacent_rules(struct wiphy *wiphy,
 							 rrule2->dfs_cac_ms);
 		}
 
+		if ((rrule1->flags & NL80211_RRF_PSD) &&
+		    (rrule2->flags & NL80211_RRF_PSD))
+			chan->psd = min_t(s8, rrule1->psd, rrule2->psd);
+		else
+			chan->flags &= ~NL80211_RRF_PSD;
+
 		return;
 	}
 
@@ -2570,6 +2584,9 @@ static void handle_channel_custom(struct wiphy *wiphy,
 			chan->dfs_cac_ms = IEEE80211_DFS_MIN_CAC_TIME_MS;
 	}
 
+	if (chan->flags & IEEE80211_CHAN_PSD)
+		chan->psd = reg_rule->psd;
+
 	chan->max_power = chan->max_reg_power;
 }