iwlwiif: mvm: refactor iwl_mvm_notify_rx_queue

Instead of allocating memory for which we have an upper
limit, use a small buffer on stack.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/intel/iwlwifi/fw/api/rx.h

@@ -776,7 +776,6 @@ struct iwl_rss_config_cmd {
 	u8 indirection_table[IWL_RSS_INDIRECTION_TABLE_SIZE];
 } __packed; /* RSS_CONFIG_CMD_API_S_VER_1 */
 
-#define IWL_MULTI_QUEUE_SYNC_MSG_MAX_SIZE 128
 #define IWL_MULTI_QUEUE_SYNC_SENDER_POS 0
 #define IWL_MULTI_QUEUE_SYNC_SENDER_MSK 0xf
 

drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c

@@ -465,18 +465,20 @@ static bool iwl_mvm_is_dup(struct ieee80211_sta *sta, int queue,
 int iwl_mvm_notify_rx_queue(struct iwl_mvm *mvm, u32 rxq_mask,
 			    const u8 *data, u32 count)
 {
-	struct iwl_rxq_sync_cmd *cmd;
+	u8 buf[sizeof(struct iwl_rxq_sync_cmd) +
+	       sizeof(struct iwl_mvm_rss_sync_notif)];
+	struct iwl_rxq_sync_cmd *cmd = (void *)buf;
 	u32 data_size = sizeof(*cmd) + count;
 	int ret;
 
-	/* should be DWORD aligned */
-	if (WARN_ON(count & 3 || count > IWL_MULTI_QUEUE_SYNC_MSG_MAX_SIZE))
+	/*
+	 * size must be a multiple of DWORD
+	 * Ensure we don't overflow buf
+	 */
+	if (WARN_ON(count & 3 ||
+		    count > sizeof(struct iwl_mvm_rss_sync_notif)))
 		return -EINVAL;
 
-	cmd = kzalloc(data_size, GFP_KERNEL);
-	if (!cmd)
-		return -ENOMEM;
-
 	cmd->rxq_mask = cpu_to_le32(rxq_mask);
 	cmd->count =  cpu_to_le32(count);
 	cmd->flags = 0;
@@ -487,7 +489,6 @@ int iwl_mvm_notify_rx_queue(struct iwl_mvm *mvm, u32 rxq_mask,
 					   TRIGGER_RX_QUEUES_NOTIF_CMD),
 				   0, data_size, cmd);
 
-	kfree(cmd);
 	return ret;
 }