qcacld-3.0: Select valid channel after pcl selection fails

When SAP works in ACS mode, it needs to restart with a safe channel
if current channel is unsafe. Sometimes no channel is selected from
pcl channels. SAP can't just pick up one safe channel because the
channel may be DFS channel while SAP may disable DFS master capability.
SAP should select one valid channel for LTE COEX.

Change-Id: I303165f82b5c2a8d06447df4ba23fdcba5b1083c
CRs-Fixed: 2415007

core/sap/inc/sap_api.h

@@ -1375,6 +1375,32 @@ QDF_STATUS wlansap_update_owe_info(struct sap_context *sap_ctx,
 				   uint8_t *peer, const uint8_t *ie,
 				   uint32_t ie_len, uint16_t owe_status);
 
+/**
+ * wlansap_filter_ch_based_acs() -filter out channel based on acs
+ * @sap_ctx: sap context
+ * @ch_list: pointer to channel list
+ * @ch_cnt: channel number of channel list
+ *
+ * Return: QDF_STATUS
+ */
+QDF_STATUS wlansap_filter_ch_based_acs(struct sap_context *sap_ctx,
+				       uint8_t *ch_list,
+				       uint32_t *ch_cnt);
+
+/**
+ * wlansap_get_safe_channel_from_pcl_and_acs_range() - Get safe channel for SAP
+ * restart
+ * @sap_ctx: sap context
+ *
+ * Get a safe channel to restart SAP. PCL already takes into account the
+ * unsafe channels. So, the PCL is validated with the ACS range to provide
+ * a safe channel for the SAP to restart.
+ *
+ * Return: Channel number to restart SAP in case of success. In case of any
+ * failure, the channel number returned is zero.
+ */
+uint8_t
+wlansap_get_safe_channel_from_pcl_and_acs_range(struct sap_context *sap_ctx);
 #ifdef __cplusplus
 }
 #endif

core/sap/src/sap_module.c

@@ -2690,3 +2690,167 @@ QDF_STATUS wlansap_update_owe_info(struct sap_context *sap_ctx,
 
 	return status;
 }
+
+QDF_STATUS wlansap_filter_ch_based_acs(struct sap_context *sap_ctx,
+				       uint8_t *ch_list,
+				       uint32_t *ch_cnt)
+{
+	size_t ch_index;
+	size_t target_ch_cnt = 0;
+
+	if (!sap_ctx || !ch_list || !ch_cnt) {
+		sap_err("NULL parameters");
+		return QDF_STATUS_E_FAULT;
+	}
+
+	for (ch_index = 0; ch_index < *ch_cnt; ch_index++) {
+		if (ch_list[ch_index] >= sap_ctx->acs_cfg->start_ch &&
+		    ch_list[ch_index] <= sap_ctx->acs_cfg->end_ch)
+			ch_list[target_ch_cnt++] = ch_list[ch_index];
+	}
+
+	*ch_cnt = target_ch_cnt;
+
+	return QDF_STATUS_SUCCESS;
+}
+
+#if defined(FEATURE_WLAN_CH_AVOID)
+/**
+ * wlansap_get_safe_channel() - Get safe channel from current regulatory
+ * @sap_ctx: Pointer to SAP context
+ *
+ * This function is used to get safe channel from current regulatory valid
+ * channels to restart SAP if failed to get safe channel from PCL.
+ *
+ * Return: Channel number to restart SAP in case of success. In case of any
+ * failure, the channel number returned is zero.
+ */
+static uint8_t
+wlansap_get_safe_channel(struct sap_context *sap_ctx)
+{
+	struct mac_context *mac;
+	struct sir_pcl_list pcl = {0};
+	QDF_STATUS status;
+	mac_handle_t mac_handle;
+
+	if (!sap_ctx) {
+		sap_err("NULL parameter");
+		return INVALID_CHANNEL_ID;
+	}
+
+	mac = sap_get_mac_context();
+	if (!mac) {
+		sap_err("Invalid MAC context");
+		return INVALID_CHANNEL_ID;
+	}
+	mac_handle = MAC_HANDLE(mac);
+
+	/* get the channel list for current domain */
+	status = policy_mgr_get_valid_chans(mac->psoc,
+					    pcl.pcl_list,
+					    &pcl.pcl_len);
+	if (QDF_IS_STATUS_ERROR(status)) {
+		sap_err("Error in getting valid channels");
+		return INVALID_CHANNEL_ID;
+	}
+
+	status = wlansap_filter_ch_based_acs(sap_ctx,
+					     pcl.pcl_list,
+					     &pcl.pcl_len);
+	if (QDF_IS_STATUS_ERROR(status)) {
+		sap_err("failed to filter ch from acs %d", status);
+		return INVALID_CHANNEL_ID;
+	}
+
+	if (pcl.pcl_len) {
+		status = policy_mgr_get_valid_chans_from_range(mac->psoc,
+							       pcl.pcl_list,
+							       &pcl.pcl_len,
+							       PM_SAP_MODE);
+		if (QDF_IS_STATUS_ERROR(status)) {
+			sap_err("failed to get valid channel: %d", status);
+			return INVALID_CHANNEL_ID;
+		}
+
+		if (pcl.pcl_len) {
+			sap_debug("select %d from valid channel list",
+				  pcl.pcl_list[0]);
+			return pcl.pcl_list[0];
+		}
+	}
+
+	return INVALID_CHANNEL_ID;
+}
+#else
+/**
+ * wlansap_get_safe_channel() - Get safe channel from current regulatory
+ * @sap_ctx: Pointer to SAP context
+ *
+ * This function is used to get safe channel from current regulatory valid
+ * channels to restart SAP if failed to get safe channel from PCL.
+ *
+ * Return: Channel number to restart SAP in case of success. In case of any
+ * failure, the channel number returned is zero.
+ */
+static uint8_t
+wlansap_get_safe_channel(struct sap_context *sap_ctx)
+{
+	return 0;
+}
+#endif
+
+uint8_t
+wlansap_get_safe_channel_from_pcl_and_acs_range(struct sap_context *sap_ctx)
+{
+	struct mac_context *mac;
+	struct sir_pcl_list pcl = {0};
+	QDF_STATUS status;
+	mac_handle_t mac_handle;
+
+	if (!sap_ctx) {
+		sap_err("NULL parameter");
+		return INVALID_CHANNEL_ID;
+	}
+
+	mac = sap_get_mac_context();
+	if (!mac) {
+		sap_err("Invalid MAC context");
+		return INVALID_CHANNEL_ID;
+	}
+	mac_handle = MAC_HANDLE(mac);
+
+	status = policy_mgr_get_pcl_for_existing_conn(
+			mac->psoc, PM_SAP_MODE, pcl.pcl_list, &pcl.pcl_len,
+			pcl.weight_list, QDF_ARRAY_SIZE(pcl.weight_list),
+			false);
+	if (QDF_IS_STATUS_ERROR(status)) {
+		sap_err("Get PCL failed");
+		return INVALID_CHANNEL_ID;
+	}
+
+	if (pcl.pcl_len) {
+		status = wlansap_filter_ch_based_acs(sap_ctx,
+						     pcl.pcl_list,
+						     &pcl.pcl_len);
+		if (QDF_IS_STATUS_ERROR(status)) {
+			sap_err("failed to filter ch from acs %d", status);
+			return INVALID_CHANNEL_ID;
+		}
+
+		if (pcl.pcl_len) {
+			sap_debug("select %d from valid channel list",
+				  pcl.pcl_list[0]);
+			return pcl.pcl_list[0];
+		}
+		sap_debug("no safe channel from PCL found in ACS range");
+	} else {
+		sap_debug("pcl length is zero!");
+	}
+
+	/*
+	 * In some scenarios, like hw dbs disabled, sap+sap case, if operating
+	 * channel is unsafe channel, the pcl may be empty, instead of return,
+	 * try to choose a safe channel from acs range.
+	 */
+	return wlansap_get_safe_channel(sap_ctx);
+}