[PATCH 1/7] cfg80211: save Power Spectral Density (PSD) of the regulatory rule

[Aditya Kumar Singh <quic_adisi@quicinc.com>]

From: Wen Gong <quic_wgong@quicinc.com>

6 GHz regulatory domain 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.

Signed-off-by: Wen Gong <quic_wgong@quicinc.com>
Co-developed-by: Aditya Kumar Singh <quic_adisi@quicinc.com>
Signed-off-by: Aditya Kumar Singh <quic_adisi@quicinc.com>
---
 include/net/cfg80211.h       |  5 +++++
 include/net/regulatory.h     |  1 +
 include/uapi/linux/nl80211.h |  9 +++++++++
 net/wireless/nl80211.c       | 18 ++++++++++++++++++
 net/wireless/reg.c           | 17 +++++++++++++++++
 5 files changed, 50 insertions(+)

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 140354f5f15b..600c080a280b 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -115,6 +115,8 @@ struct wiphy;
  *	This may be due to the driver or due to regulatory bandwidth
  *	restrictions.
  * @IEEE80211_CHAN_NO_EHT: EHT operation is not permitted on this channel.
+ * @IEEE80211_CHAN_PSD: power spectral density (in dBm)
+ *	on this channel
  */
 enum ieee80211_channel_flags {
 	IEEE80211_CHAN_DISABLED		= 1<<0,
@@ -138,6 +140,7 @@ enum ieee80211_channel_flags {
 	IEEE80211_CHAN_16MHZ		= 1<<18,
 	IEEE80211_CHAN_NO_320MHZ	= 1<<19,
 	IEEE80211_CHAN_NO_EHT		= 1<<20,
+	IEEE80211_CHAN_PSD              = 1<<21,
 };
 
 #define IEEE80211_CHAN_NO_HT40 \
@@ -171,6 +174,7 @@ 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 +191,7 @@ struct ieee80211_channel {
 	enum nl80211_dfs_state dfs_state;
 	unsigned long dfs_state_entered;
 	unsigned int dfs_cac_ms;
+	s8 psd;
 };
 
 /**
diff --git a/include/net/regulatory.h b/include/net/regulatory.h
index 47f06f6f5a67..ed20004fb6a9 100644
--- a/include/net/regulatory.h
+++ b/include/net/regulatory.h
@@ -221,6 +221,7 @@ struct ieee80211_reg_rule {
 	u32 flags;
 	u32 dfs_cac_ms;
 	bool has_wmm;
+	s8 psd;
 };
 
 struct ieee80211_regdomain {
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 279f9715919e..8c21136ac18c 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -4062,6 +4062,8 @@ 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)
+ *	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
@@ -4100,6 +4102,7 @@ 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,
@@ -4200,6 +4203,8 @@ 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
@@ -4217,6 +4222,8 @@ 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
@@ -4299,6 +4306,7 @@ enum nl80211_sched_scan_match_attr {
  * @NL80211_RRF_NO_160MHZ: 160MHz operation not allowed
  * @NL80211_RRF_NO_HE: HE operation not allowed
  * @NL80211_RRF_NO_320MHZ: 320MHz operation not allowed
+ * @NL80211_RRF_PSD: channel has power spectral density value
  */
 enum nl80211_reg_rule_flags {
 	NL80211_RRF_NO_OFDM		= 1<<0,
@@ -4318,6 +4326,7 @@ enum nl80211_reg_rule_flags {
 	NL80211_RRF_NO_160MHZ		= 1<<16,
 	NL80211_RRF_NO_HE		= 1<<17,
 	NL80211_RRF_NO_320MHZ		= 1<<18,
+	NL80211_RRF_PSD                 = 1<<19,
 };
 
 #define NL80211_RRF_PASSIVE_SCAN	NL80211_RRF_NO_IR
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index eda2ad029c90..afa8cd686e0e 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1096,6 +1096,10 @@ 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;
@@ -8168,6 +8172,11 @@ 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);
 	}
 
@@ -8341,6 +8350,7 @@ static const struct nla_policy reg_rule_policy[NL80211_REG_RULE_ATTR_MAX + 1] =
 	[NL80211_ATTR_POWER_RULE_MAX_ANT_GAIN]	= { .type = NLA_U32 },
 	[NL80211_ATTR_POWER_RULE_MAX_EIRP]	= { .type = NLA_U32 },
 	[NL80211_ATTR_DFS_CAC_TIME]		= { .type = NLA_U32 },
+	[NL80211_ATTR_POWER_RULE_PSD]		= { .type = NLA_S8 },
 };
 
 static int parse_reg_rule(struct nlattr *tb[],
@@ -8362,6 +8372,14 @@ static int parse_reg_rule(struct nlattr *tb[],
 
 	reg_rule->flags = nla_get_u32(tb[NL80211_ATTR_REG_RULE_FLAGS]);
 
+	if (reg_rule->flags & NL80211_RRF_PSD) {
+		if (!tb[NL80211_ATTR_POWER_RULE_PSD])
+			return -EINVAL;
+
+		reg_rule->psd =
+			nla_get_s8(tb[NL80211_ATTR_POWER_RULE_PSD]);
+	}
+
 	freq_range->start_freq_khz =
 		nla_get_u32(tb[NL80211_ATTR_FREQ_RANGE_START]);
 	freq_range->end_freq_khz =
diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index c7383ede794f..9a06aadba0d7 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -1619,6 +1619,8 @@ static u32 map_regdom_flags(u32 rd_flags)
 		channel_flags |= IEEE80211_CHAN_NO_HE;
 	if (rd_flags & NL80211_RRF_NO_320MHZ)
 		channel_flags |= IEEE80211_CHAN_NO_320MHZ;
+	if (rd_flags & NL80211_RRF_PSD)
+		channel_flags |= IEEE80211_CHAN_PSD;
 	return channel_flags;
 }
 
@@ -1825,6 +1827,9 @@ 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;
 	}
 
@@ -1845,6 +1850,9 @@ 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
@@ -1914,6 +1922,12 @@ 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;
 	}
 
@@ -2600,6 +2614,9 @@ 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;
 }
 
-- 
2.17.1