qcacld-3.0: Optimize channel selection for NDI

The current algo maintains valid channel list for NDI from regulatory
channel list which leads to high space and time complexity.
As it is known that there are only three channels (144, 44, 6)
to support the NDI, so check for valid channel from these three
channels, instead of extracting from the channel list. If none of
above channels are valid, then take first valid channel from channel
list.
In this way, no need to maintain the channel list which helps to reduce
the time and space complexity.

Change-Id: I5dd2757ca952f4aaeb2a9ed74a47b4e547890245
CRs-Fixed: 3340778

core/hdd/src/wlan_hdd_nan_datapath.c

@@ -204,18 +204,11 @@ static bool hdd_is_ndp_allowed(struct hdd_context *hdd_ctx)
 }
 #endif /* NDP_SAP_CONCURRENCY_ENABLE */
 
-static void hdd_swap_frequencies(uint32_t *a, uint32_t *b)
-{
-	*b ^= *a;
-	*a ^= *b;
-	*b ^= *a;
-}
-
 /**
- * hdd_ndi_config_ch_list() - Configure the channel list for NDI start
+ * hdd_ndi_select_valid_freq() - Find the valid freq for NDI start
  * @hdd_ctx: hdd context
- * @ch_info: Buffer to fill supported channels, give preference to 5220 and 2437
- * to keep the legacy behavior intact
+ * @freq: pointer to freq, give preference to 5745, 5220 and 2437 to keep the
+ * legacy behavior intact
  *
  * Unlike traditional device modes, where the higher application
  * layer initiates connect / join / start, the NAN data
@@ -229,45 +222,47 @@ static void hdd_swap_frequencies(uint32_t *a, uint32_t *b)
  * start the NDI. Actual channel for NDP data transfer would be negotiated with
  * peer later.
  *
- * Return: SUCCESS if some valid channels are obtained
+ * Return: SUCCESS if valid channel is obtained
  */
-static QDF_STATUS
-hdd_ndi_config_ch_list(struct hdd_context *hdd_ctx,
-		       tCsrChannelInfo *ch_info)
+static QDF_STATUS hdd_ndi_select_valid_freq(struct hdd_context *hdd_ctx,
+					    uint32_t *freq)
 {
+	static const qdf_freq_t valid_freq[] = {NAN_SOCIAL_FREQ_5GHZ_UPPER_BAND,
+						NAN_SOCIAL_FREQ_5GHZ_LOWER_BAND,
+						NAN_SOCIAL_FREQ_2_4GHZ};
+	uint8_t i;
 	struct regulatory_channel *cur_chan_list;
-	int i = 0, swap_index = 0;
 	QDF_STATUS status;
 
-	ch_info->numOfChannels = 0;
+	for (i = 0; i < ARRAY_SIZE(valid_freq); i++) {
+		if (wlan_reg_is_freq_enabled(hdd_ctx->pdev, valid_freq[i],
+					     REG_CURRENT_PWR_MODE)) {
+			*freq = valid_freq[i];
+			return QDF_STATUS_SUCCESS;
+		}
+	}
+
 	cur_chan_list = qdf_mem_malloc(sizeof(*cur_chan_list) *
 							(NUM_CHANNELS + 2));
 	if (!cur_chan_list)
 		return QDF_STATUS_E_NOMEM;
 
 	status = ucfg_reg_get_current_chan_list(hdd_ctx->pdev, cur_chan_list);
-	if (status != QDF_STATUS_SUCCESS) {
+	if (QDF_IS_STATUS_ERROR(status)) {
 		hdd_err_rl("Failed to get the current channel list");
 		qdf_mem_free(cur_chan_list);
 		return QDF_STATUS_E_IO;
 	}
 
-	ch_info->freq_list = qdf_mem_malloc(sizeof(uint32_t) * NUM_CHANNELS);
-	if (!ch_info->freq_list) {
-		qdf_mem_free(cur_chan_list);
-		return QDF_STATUS_E_NOMEM;
-	}
-
 	for (i = 0; i < NUM_CHANNELS; i++) {
-		/**
+		/*
 		 * current channel list includes all channels. Exclude
 		 * disabled channels
 		 */
 		if (cur_chan_list[i].chan_flags & REGULATORY_CHAN_DISABLED ||
 		    cur_chan_list[i].chan_flags & REGULATORY_CHAN_RADAR)
 			continue;
-
-		/**
+		/*
 		 * do not include 6 GHz channels for now as NAN would need
 		 * 2.4 GHz and 5 GHz channels for discovery.
 		 * <TODO> Need to consider the 6GHz channels when there is a
@@ -277,52 +272,19 @@ hdd_ndi_config_ch_list(struct hdd_context *hdd_ctx,
 		if (wlan_reg_is_6ghz_chan_freq(cur_chan_list[i].center_freq))
 			continue;
 
-		ch_info->freq_list[ch_info->numOfChannels++] =
-					cur_chan_list[i].center_freq;
-	}
-
-	if (!ch_info->numOfChannels) {
-		status = QDF_STATUS_E_NULL_VALUE;
-		qdf_mem_free(ch_info->freq_list);
-		goto end;
-	}
-
-	/**
-	 * Keep the valid channels in list in below order,
-	 * 149, 44, 6, rest of the channels
-	 */
-	for (i = ch_info->numOfChannels - 1; i >= 0; i--) {
-		if (ch_info->freq_list[i] != NAN_SOCIAL_FREQ_5GHZ_UPPER_BAND)
-			continue;
-		hdd_swap_frequencies(&ch_info->freq_list[i],
-				     &ch_info->freq_list[swap_index]);
-		swap_index++;
-		break;
-	}
-
-	for (i = ch_info->numOfChannels - 1; i >= 0; i--) {
-		if (ch_info->freq_list[i] != NAN_SOCIAL_FREQ_5GHZ_LOWER_BAND)
-			continue;
-
-		hdd_swap_frequencies(&ch_info->freq_list[i],
-				     &ch_info->freq_list[swap_index]);
-		swap_index++;
-		break;
-	}
-
-	for (i = ch_info->numOfChannels - 1; i >= 0; i--) {
-		if (ch_info->freq_list[i] != NAN_SOCIAL_FREQ_2_4GHZ)
-			continue;
-
-		hdd_swap_frequencies(&ch_info->freq_list[i],
-				     &ch_info->freq_list[swap_index]);
-		break;
+		/* extracting first valid channel from regulatory list */
+		if (wlan_reg_is_freq_enabled(hdd_ctx->pdev,
+					     cur_chan_list[i].center_freq,
+					     REG_CURRENT_PWR_MODE)) {
+			*freq = cur_chan_list[i].center_freq;
+			qdf_mem_free(cur_chan_list);
+			return QDF_STATUS_SUCCESS;
+		}
 	}
 
-end:
 	qdf_mem_free(cur_chan_list);
 
-	return status;
+	return QDF_STATUS_E_FAILURE;
 }
 
 /**
@@ -336,7 +298,7 @@ static int hdd_ndi_start_bss(struct hdd_adapter *adapter)
 	QDF_STATUS status;
 	struct bss_dot11_config dot11_cfg = {0};
 	struct start_bss_config ndi_bss_cfg = {0};
-	tCsrChannelInfo ch_info;
+	qdf_freq_t valid_freq = 0;
 	mac_handle_t mac_handle = hdd_adapter_get_mac_handle(adapter);
 	struct mac_context *mac = MAC_CONTEXT(mac_handle);
 	struct hdd_context *hdd_ctx;
@@ -344,14 +306,14 @@ static int hdd_ndi_start_bss(struct hdd_adapter *adapter)
 	hdd_enter();
 	hdd_ctx = WLAN_HDD_GET_CTX(adapter);
 
-	status = hdd_ndi_config_ch_list(hdd_ctx, &ch_info);
+	status = hdd_ndi_select_valid_freq(hdd_ctx, &valid_freq);
 	if (!QDF_IS_STATUS_SUCCESS(status)) {
 		hdd_err("Unable to retrieve channel list for NAN");
 		return -EINVAL;
 	}
 
 	dot11_cfg.vdev_id = adapter->vdev_id;
-	dot11_cfg.bss_op_ch_freq = ch_info.freq_list[0];
+	dot11_cfg.bss_op_ch_freq = valid_freq;
 	dot11_cfg.phy_mode = eCSR_DOT11_MODE_AUTO;
 	if (!wlan_vdev_id_is_open_cipher(mac->pdev, adapter->vdev_id))
 		dot11_cfg.privacy = 1;
@@ -387,11 +349,8 @@ static int hdd_ndi_start_bss(struct hdd_adapter *adapter)
 		/* change back to NotConnected */
 		hdd_conn_set_connection_state(adapter,
 					      eConnectionState_NotConnected);
-	} else {
-		hdd_info("sme_RoamConnect issued successfully for NDI");
 	}
 
-	qdf_mem_free(ch_info.freq_list);
 	hdd_exit();
 
 	return 0;