wifi: cfg80211: Add Support to Set RTS Threshold for each Radio

Currently, setting RTS threshold is based on per-phy basis, i.e., all the
radios present in a wiphy will take RTS threshold value to be the one sent
from userspace. But each radio in a multi-radio wiphy can have different
RTS threshold requirements.

To extend support to set RTS threshold for each radio, get the radio for
which RTS threshold needs to be changed from the user. Use the attribute
in NL - NL80211_ATTR_WIPHY_RADIO_INDEX, to identify the radio of interest.
Create a new structure - wiphy_radio_cfg and add rts_threshold in it as a
u32 value to store RTS threshold of each radio in a wiphy and allocate
memory for it during wiphy register based on the wiphy.n_radio updated by
drivers. Pass radio id received from the user to mac80211 drivers along
with its corresponding RTS threshold.

Signed-off-by: Roopni Devanathan <quic_rdevanat@quicinc.com>
Link: https://patch.msgid.link/20250615082312.619639-3-quic_rdevanat@quicinc.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

2 files changed, 78 insertions, 3 deletions

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 5c3c72df0591..f3cd70757ef2 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -995,6 +995,24 @@ int wiphy_register(struct wiphy *wiphy)
 		 wiphy->max_num_akm_suites > CFG80211_MAX_NUM_AKM_SUITES)
 		return -EINVAL;
 
+	/* Allocate radio configuration space for multi-radio wiphy */
+	if (wiphy->n_radio > 0) {
+		int idx;
+
+		wiphy->radio_cfg = kcalloc(wiphy->n_radio,
+					   sizeof(*wiphy->radio_cfg),
+					   GFP_KERNEL);
+		if (!wiphy->radio_cfg)
+			return -ENOMEM;
+		/*
+		 * Initialize wiphy radio parameters to IEEE 802.11
+		 * MIB default values. RTS threshold is disabled by
+		 * default with the special -1 value.
+		 */
+		for (idx = 0; idx < wiphy->n_radio; idx++)
+			wiphy->radio_cfg[idx].rts_threshold = (u32)-1;
+	}
+
 	/* check and set up bitrates */
 	ieee80211_set_bitrate_flags(wiphy);
 
@@ -1222,6 +1240,7 @@ void cfg80211_dev_free(struct cfg80211_registered_device *rdev)
 
 void wiphy_free(struct wiphy *wiphy)
 {
+	kfree(wiphy->radio_cfg);
 	put_device(&wiphy->dev);
 }
 EXPORT_SYMBOL(wiphy_free);
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index b40978549790..b0176090182c 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -3609,6 +3609,33 @@ static int nl80211_set_channel(struct sk_buff *skb, struct genl_info *info)
 	return __nl80211_set_channel(rdev, netdev, info, link_id);
 }
 
+static int nl80211_set_wiphy_radio(struct genl_info *info,
+				   struct cfg80211_registered_device *rdev,
+				   int radio_idx)
+{
+	u32 rts_threshold = 0, old_rts, changed = 0;
+	int result;
+
+	if (!rdev->ops->set_wiphy_params)
+		return -EOPNOTSUPP;
+
+	if (info->attrs[NL80211_ATTR_WIPHY_RTS_THRESHOLD]) {
+		rts_threshold = nla_get_u32(
+				info->attrs[NL80211_ATTR_WIPHY_RTS_THRESHOLD]);
+		changed |= WIPHY_PARAM_RTS_THRESHOLD;
+	}
+
+	old_rts = rdev->wiphy.radio_cfg[radio_idx].rts_threshold;
+
+	rdev->wiphy.radio_cfg[radio_idx].rts_threshold = rts_threshold;
+
+	result = rdev_set_wiphy_params(rdev, radio_idx, changed);
+	if (result)
+		rdev->wiphy.radio_cfg[radio_idx].rts_threshold = old_rts;
+
+	return 0;
+}
+
 static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 {
 	struct cfg80211_registered_device *rdev = NULL;
@@ -3681,6 +3708,8 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 				info->attrs[NL80211_ATTR_WIPHY_RADIO_INDEX]);
 		if (radio_idx >= rdev->wiphy.n_radio)
 			return -EINVAL;
+
+		return nl80211_set_wiphy_radio(info, rdev, radio_idx);
 	}
 
 	if (info->attrs[NL80211_ATTR_WIPHY_TXQ_PARAMS]) {
@@ -3893,16 +3922,30 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 	if (changed) {
 		u8 old_retry_short, old_retry_long;
 		u32 old_frag_threshold, old_rts_threshold;
-		u8 old_coverage_class;
+		u8 old_coverage_class, i;
 		u32 old_txq_limit, old_txq_memory_limit, old_txq_quantum;
+		u32 *old_radio_rts_threshold = NULL;
 
 		if (!rdev->ops->set_wiphy_params)
 			return -EOPNOTSUPP;
 
+		if (rdev->wiphy.n_radio) {
+			old_radio_rts_threshold = kcalloc(rdev->wiphy.n_radio,
+							  sizeof(u32),
+							  GFP_KERNEL);
+			if (!old_radio_rts_threshold)
+				return -ENOMEM;
+		}
+
 		old_retry_short = rdev->wiphy.retry_short;
 		old_retry_long = rdev->wiphy.retry_long;
 		old_frag_threshold = rdev->wiphy.frag_threshold;
 		old_rts_threshold = rdev->wiphy.rts_threshold;
+		if (old_radio_rts_threshold) {
+			for (i = 0 ; i < rdev->wiphy.n_radio; i++)
+				old_radio_rts_threshold[i] =
+					rdev->wiphy.radio_cfg[i].rts_threshold;
+		}
 		old_coverage_class = rdev->wiphy.coverage_class;
 		old_txq_limit = rdev->wiphy.txq_limit;
 		old_txq_memory_limit = rdev->wiphy.txq_memory_limit;
@@ -3914,8 +3957,13 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 			rdev->wiphy.retry_long = retry_long;
 		if (changed & WIPHY_PARAM_FRAG_THRESHOLD)
 			rdev->wiphy.frag_threshold = frag_threshold;
-		if (changed & WIPHY_PARAM_RTS_THRESHOLD)
+		if ((changed & WIPHY_PARAM_RTS_THRESHOLD) &&
+		    old_radio_rts_threshold) {
 			rdev->wiphy.rts_threshold = rts_threshold;
+			for (i = 0 ; i < rdev->wiphy.n_radio; i++)
+				rdev->wiphy.radio_cfg[i].rts_threshold =
+					rdev->wiphy.rts_threshold;
+		}
 		if (changed & WIPHY_PARAM_COVERAGE_CLASS)
 			rdev->wiphy.coverage_class = coverage_class;
 		if (changed & WIPHY_PARAM_TXQ_LIMIT)
@@ -3931,12 +3979,20 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 			rdev->wiphy.retry_long = old_retry_long;
 			rdev->wiphy.frag_threshold = old_frag_threshold;
 			rdev->wiphy.rts_threshold = old_rts_threshold;
+			if (old_radio_rts_threshold) {
+				for (i = 0 ; i < rdev->wiphy.n_radio; i++)
+					rdev->wiphy.radio_cfg[i].rts_threshold =
+						old_radio_rts_threshold[i];
+			}
 			rdev->wiphy.coverage_class = old_coverage_class;
 			rdev->wiphy.txq_limit = old_txq_limit;
 			rdev->wiphy.txq_memory_limit = old_txq_memory_limit;
 			rdev->wiphy.txq_quantum = old_txq_quantum;
-			return result;
 		}
+
+		if (old_rts_threshold)
+			kfree(old_radio_rts_threshold);
+		return result;
 	}
 
 	return 0;