wifi: ath12k: enforce vdev limit in ath12k_mac_vdev_create()

[ Upstream commit 448bf7b ]

Currently, vdev limit check is performed only in
ath12k_mac_assign_vif_to_vdev(). If the host has already created
maximum number of vdevs for the radio (ar) and a scan request
arrives for the same radio, ath12k_mac_initiate_hw_scan() attempts
to create a vdev without checking the limit, causing firmware asserts.

Centralize the vdev limit guard by moving the check into
ath12k_mac_vdev_create() so that all callers obey the limit.
While doing this, update the condition from
`num_created_vdevs > (TARGET_NUM_VDEVS(ab) - 1)` to
`num_created_vdevs >= TARGET_NUM_VDEVS(ab)` for clarity and to
eliminate unnecessary arithmetic.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.4.1-00199-QCAHKSWPL_SILICONZ-1

Fixes: 0d6e673 ("wifi: ath12k: scan statemachine changes for single wiphy")
Fixes: 4938ba7 ("wifi: ath12k: modify remain on channel for single wiphy")
Signed-off-by: Rameshkumar Sundaram <rameshkumar.sundaram@oss.qualcomm.com>
Reviewed-by: Vasanthakumar Thiagarajan <vasanthakumar.thiagarajan@oss.qualcomm.com>
Link: https://patch.msgid.link/20251026182254.1399650-2-rameshkumar.sundaram@oss.qualcomm.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: Rameshkumar Sundaram

drivers/net/wireless/ath/ath12k/mac.c

@@ -9687,6 +9687,12 @@ int ath12k_mac_vdev_create(struct ath12k *ar, struct ath12k_link_vif *arvif)
 	if (vif->type == NL80211_IFTYPE_MONITOR && ar->monitor_vdev_created)
 		return -EINVAL;
 
+	if (ar->num_created_vdevs >= TARGET_NUM_VDEVS(ab)) {
+		ath12k_warn(ab, "failed to create vdev, reached max vdev limit %d\n",
+			    TARGET_NUM_VDEVS(ab));
+		return -ENOSPC;
+	}
+
 	link_id = arvif->link_id;
 
 	if (link_id < IEEE80211_MLD_MAX_NUM_LINKS) {
@@ -10046,12 +10052,6 @@ static struct ath12k *ath12k_mac_assign_vif_to_vdev(struct ieee80211_hw *hw,
 	if (arvif->is_created)
 		goto flush;
 
-	if (ar->num_created_vdevs > (TARGET_NUM_VDEVS(ab) - 1)) {
-		ath12k_warn(ab, "failed to create vdev, reached max vdev limit %d\n",
-			    TARGET_NUM_VDEVS(ab));
-		goto unlock;
-	}
-
 	ret = ath12k_mac_vdev_create(ar, arvif);
 	if (ret) {
 		ath12k_warn(ab, "failed to create vdev %pM ret %d", vif->addr, ret);