wifi: ath12k: defer dp_peer registration when firmware allocates MLD peer ID

For chips with host_alloc_ml_id=true (QCN9274 etc.), the host allocates
the MLD peer ID up front; ath12k_dp_peer_create() publishes the dp_peer
into dp_hw->dp_peers[] using that ID immediately. WCN7850/QCC2072 does
not work that way: the firmware picks the ID and only tells the host
afterwards via HTT_T2H_MSG_TYPE_MLO_RX_PEER_MAP, so the publication has
to be delayed until the event arrives.

Introduce ATH12K_MLO_PEER_ID_PENDING (0xFFFE) as a sentinel for "is_mlo,
but ID not yet known". On the firmware-allocates path:

  - ath12k_mac_op_sta_state(NOTEXIST->NONE) skips ath12k_peer_ml_alloc()
    and stores PENDING in ahsta->ml_peer_id and dp_params.peer_id;
  - ath12k_dp_peer_create() skips dp_peer registration until a real ID is
    known;
  - ath12k_peer_create() leaves peer->ml_id at INVALID so consumer sites
    do not treat PENDING as a real ID;
  - ath12k_peer_ml_free() and ath12k_mac_dp_peer_cleanup() skip the
    dp_peers[] write and the free_ml_peer_id_map clear when
    host_alloc_ml_id is false or the ID is still PENDING.

The HTT handler change that resolves the PENDING ID is added in a
follow-up patch.

Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c5-00302-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.115823.3

Signed-off-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>
Reviewed-by: Rameshkumar Sundaram <rameshkumar.sundaram@oss.qualcomm.com>
Link: https://patch.msgid.link/20260720-ath12k-fw-allocated-ml-peer-id-v2-7-630632758a80@oss.qualcomm.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>

4 files changed, 49 insertions, 17 deletions

diff --git a/drivers/net/wireless/ath/ath12k/core.h b/drivers/net/wireless/ath/ath12k/core.h
index 1f56474efbea..8769b41f5db5 100644
--- a/drivers/net/wireless/ath/ath12k/core.h
+++ b/drivers/net/wireless/ath/ath12k/core.h
@@ -72,6 +72,7 @@
 
 #define ATH12K_MAX_MLO_PEERS            256
 #define ATH12K_MLO_PEER_ID_INVALID      0xFFFF
+#define ATH12K_MLO_PEER_ID_PENDING      0xFFFE
 
 #define ATH12K_INVALID_RSSI_FULL -1
 #define ATH12K_INVALID_RSSI_EMPTY -128
diff --git a/drivers/net/wireless/ath/ath12k/dp_peer.c b/drivers/net/wireless/ath/ath12k/dp_peer.c
index a12073afc307..cd6a0eb207bd 100644
--- a/drivers/net/wireless/ath/ath12k/dp_peer.c
+++ b/drivers/net/wireless/ath/ath12k/dp_peer.c
@@ -475,7 +475,9 @@ int ath12k_dp_peer_create(struct ath12k_dp_hw *dp_hw, u8 *addr,
 	dp_peer->is_mlo = params->is_mlo;
 
 	/*
-	 * For MLO client, the host assigns the ML peer ID, so set peer_id in dp_peer
+	 * For MLO client, the ML peer ID, either known or PENDING, needs to be
+	 * initialized here since the following logic depends on it.
+	 *
 	 * For non-MLO client, host gets link peer ID from firmware and will be
 	 * assigned at the time of link peer creation
 	 */
@@ -491,13 +493,17 @@ int ath12k_dp_peer_create(struct ath12k_dp_hw *dp_hw, u8 *addr,
 	list_add(&dp_peer->list, &dp_hw->dp_peers_list);
 
 	/*
-	 * For MLO client, the peer_id for ath12k_dp_peer is allocated by host
-	 * and that peer_id is known at this point, and hence this ath12k_dp_peer
-	 * can be added to the RCU table using the peer_id.
-	 * For non-MLO client, this addition to RCU table shall be done at the
-	 * time of assignment of ath12k_dp_link_peer to ath12k_dp_peer.
+	 * For an MLO client whose ML peer ID is allocated by the host, the
+	 * peer_id is known here and the dp_peer can be added to the RCU
+	 * table using it. For an MLO client on chips where the firmware
+	 * allocates the ID, peer_id is ATH12K_MLO_PEER_ID_PENDING and the
+	 * RCU table publish is deferred to the
+	 * HTT_T2H_MSG_TYPE_MLO_RX_PEER_MAP handler. For a non-MLO client
+	 * the publish happens later, at the time of assignment of
+	 * ath12k_dp_link_peer to ath12k_dp_peer.
 	 */
-	if (dp_peer->is_mlo)
+	if (dp_peer->is_mlo &&
+	    dp_peer->peer_id != ATH12K_MLO_PEER_ID_PENDING)
 		rcu_assign_pointer(dp_hw->dp_peers[dp_peer->peer_id], dp_peer);
 
 	spin_unlock_bh(&dp_hw->peer_lock);
@@ -518,7 +524,8 @@ void ath12k_dp_peer_delete(struct ath12k_dp_hw *dp_hw, u8 *addr,
 		return;
 	}
 
-	if (dp_peer->is_mlo)
+	if (dp_peer->is_mlo &&
+	    dp_peer->peer_id != ATH12K_MLO_PEER_ID_PENDING)
 		rcu_assign_pointer(dp_hw->dp_peers[dp_peer->peer_id], NULL);
 
 	list_del(&dp_peer->list);
diff --git a/drivers/net/wireless/ath/ath12k/mac.c b/drivers/net/wireless/ath/ath12k/mac.c
index 1004c290e5d0..760afe1c7f7a 100644
--- a/drivers/net/wireless/ath/ath12k/mac.c
+++ b/drivers/net/wireless/ath/ath12k/mac.c
@@ -1289,7 +1289,9 @@ void ath12k_mac_dp_peer_cleanup(struct ath12k_hw *ah)
 	spin_lock_bh(&dp_hw->peer_lock);
 	list_for_each_entry_safe(dp_peer, tmp, &dp_hw->dp_peers_list, list) {
 		if (dp_peer->is_mlo) {
-			rcu_assign_pointer(dp_hw->dp_peers[dp_peer->peer_id], NULL);
+			if (dp_peer->peer_id != ATH12K_MLO_PEER_ID_PENDING)
+				rcu_assign_pointer(dp_hw->dp_peers[dp_peer->peer_id],
+						   NULL);
 			ath12k_peer_ml_free(ah, ath12k_sta_to_ahsta(dp_peer->sta));
 		}
 
@@ -7750,11 +7752,19 @@ int ath12k_mac_op_sta_state(struct ieee80211_hw *hw,
 		/* ML sta */
 		if (sta->mlo && !ahsta->links_map &&
 		    (hweight16(sta->valid_links) == 1)) {
-			ahsta->ml_peer_id = ath12k_peer_ml_alloc(ah);
-			if (ahsta->ml_peer_id == ATH12K_MLO_PEER_ID_INVALID) {
-				ath12k_hw_warn(ah, "unable to allocate ML peer id for sta %pM",
-					       sta->addr);
-				goto exit;
+			if (ah->host_alloc_ml_id) {
+				ahsta->ml_peer_id = ath12k_peer_ml_alloc(ah);
+				if (ahsta->ml_peer_id == ATH12K_MLO_PEER_ID_INVALID) {
+					ath12k_hw_warn(ah, "unable to allocate ML peer id for sta %pM",
+						       sta->addr);
+					goto exit;
+				}
+			} else {
+				/*
+				 * firmware allocates the ML peer ID and notifies
+				 * the host via HTT_T2H_MSG_TYPE_MLO_RX_PEER_MAP
+				 */
+				ahsta->ml_peer_id = ATH12K_MLO_PEER_ID_PENDING;
 			}
 
 			dp_params.is_mlo = true;
diff --git a/drivers/net/wireless/ath/ath12k/peer.c b/drivers/net/wireless/ath/ath12k/peer.c
index 5dd7c6470219..ed0524ddff80 100644
--- a/drivers/net/wireless/ath/ath12k/peer.c
+++ b/drivers/net/wireless/ath/ath12k/peer.c
@@ -230,7 +230,16 @@ int ath12k_peer_create(struct ath12k *ar, struct ath12k_link_vif *arvif,
 		/* Fill ML info into created peer */
 		if (sta->mlo) {
 			ml_peer_id = ahsta->ml_peer_id;
-			peer->ml_id = ml_peer_id;
+			/*
+			 * For chips where firmware allocates the ML peer ID,
+			 * ml_peer_id is ATH12K_MLO_PEER_ID_PENDING here. The
+			 * MLO_RX_PEER_MAP HTT event handler fixes up
+			 * peer->ml_id once the ID is known.
+			 */
+			if (ml_peer_id == ATH12K_MLO_PEER_ID_PENDING)
+				peer->ml_id = ATH12K_MLO_PEER_ID_INVALID;
+			else
+				peer->ml_id = ml_peer_id;
 			ether_addr_copy(peer->ml_addr, sta->addr);
 
 			/* the assoc link is considered primary for now */
@@ -285,8 +294,13 @@ void ath12k_peer_ml_free(struct ath12k_hw *ah, struct ath12k_sta *ahsta)
 {
 	lockdep_assert_wiphy(ah->hw->wiphy);
 
-	if (ahsta->ml_peer_id <
-	    (ATH12K_MAX_MLO_PEERS | ATH12K_PEER_ML_ID_VALID))
+	/*
+	 * Only devices that allocate the ID on the host own a slot in
+	 * free_ml_peer_id_map.
+	 */
+	if (ah->host_alloc_ml_id &&
+	    (ahsta->ml_peer_id <
+	     (ATH12K_MAX_MLO_PEERS | ATH12K_PEER_ML_ID_VALID)))
 		clear_bit(ahsta->ml_peer_id & ~ATH12K_PEER_ML_ID_VALID,
 			  ah->free_ml_peer_id_map);
 	ahsta->ml_peer_id = ATH12K_MLO_PEER_ID_INVALID;