mwifiex: implement extended scan feature

In extended scan, host gets scan results through one or
multiple events instead of scan command response. Host will
send next scan command when all the events are received.

Legacy scan sometimes truncates scan results in a noisy
environment due to buffer length limitation. This issue
is addressed in extended scan.

Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 185 insertions, 6 deletions

diff --git a/drivers/net/wireless/mwifiex/scan.c b/drivers/net/wireless/mwifiex/scan.c
index 3633347f50f6..c548a7d4877d 100644
--- a/drivers/net/wireless/mwifiex/scan.c
+++ b/drivers/net/wireless/mwifiex/scan.c
@@ -595,7 +595,7 @@ mwifiex_scan_channel_list(struct mwifiex_private *priv,
 	struct mwifiex_chan_scan_param_set *tmp_chan_list;
 	struct mwifiex_chan_scan_param_set *start_chan;
 
-	u32 tlv_idx, rates_size;
+	u32 tlv_idx, rates_size, cmd_no;
 	u32 total_scan_time;
 	u32 done_early;
 	u8 radio_type;
@@ -733,9 +733,13 @@ mwifiex_scan_channel_list(struct mwifiex_private *priv,
 
 		/* Send the scan command to the firmware with the specified
 		   cfg */
-		ret = mwifiex_send_cmd_async(priv, HostCmd_CMD_802_11_SCAN,
-					     HostCmd_ACT_GEN_SET, 0,
-					     scan_cfg_out);
+		if (priv->adapter->ext_scan)
+			cmd_no = HostCmd_CMD_802_11_SCAN_EXT;
+		else
+			cmd_no = HostCmd_CMD_802_11_SCAN;
+
+		ret = mwifiex_send_cmd_async(priv, cmd_no, HostCmd_ACT_GEN_SET,
+					     0, scan_cfg_out);
 
 		/* rate IE is updated per scan command but same starting
 		 * pointer is used each time so that rate IE from earlier
@@ -786,6 +790,7 @@ mwifiex_config_scan(struct mwifiex_private *priv,
 	struct mwifiex_adapter *adapter = priv->adapter;
 	struct mwifiex_ie_types_num_probes *num_probes_tlv;
 	struct mwifiex_ie_types_wildcard_ssid_params *wildcard_ssid_tlv;
+	struct mwifiex_ie_types_bssid_list *bssid_tlv;
 	u8 *tlv_pos;
 	u32 num_probes;
 	u32 ssid_len;
@@ -848,6 +853,17 @@ mwifiex_config_scan(struct mwifiex_private *priv,
 		       user_scan_in->specific_bssid,
 		       sizeof(scan_cfg_out->specific_bssid));
 
+		if (adapter->ext_scan &&
+		    !is_zero_ether_addr(scan_cfg_out->specific_bssid)) {
+			bssid_tlv =
+				(struct mwifiex_ie_types_bssid_list *)tlv_pos;
+			bssid_tlv->header.type = cpu_to_le16(TLV_TYPE_BSSID);
+			bssid_tlv->header.len = cpu_to_le16(ETH_ALEN);
+			memcpy(bssid_tlv->bssid, user_scan_in->specific_bssid,
+			       ETH_ALEN);
+			tlv_pos += sizeof(struct mwifiex_ie_types_bssid_list);
+		}
+
 		for (i = 0; i < user_scan_in->num_ssids; i++) {
 			ssid_len = user_scan_in->ssid_list[i].ssid_len;
 
@@ -1579,7 +1595,7 @@ done:
 static int
 mwifiex_parse_single_response_buf(struct mwifiex_private *priv, u8 **bss_info,
 				  u32 *bytes_left, u64 fw_tsf, u8 *radio_type,
-				  bool ext_scan)
+				  bool ext_scan, s32 rssi_val)
 {
 	struct mwifiex_adapter *adapter = priv->adapter;
 	struct mwifiex_chan_freq_power *cfp;
@@ -1642,6 +1658,8 @@ mwifiex_parse_single_response_buf(struct mwifiex_private *priv, u8 **bss_info,
 		current_ptr += sizeof(u8);
 		curr_bcn_bytes -= sizeof(u8);
 		dev_dbg(adapter->dev, "info: InterpretIE: RSSI=%d\n", rssi);
+	} else {
+		rssi = rssi_val;
 	}
 
 	bcn_param = (struct mwifiex_fixed_bcn_param *)current_ptr;
@@ -1914,7 +1932,7 @@ int mwifiex_ret_802_11_scan(struct mwifiex_private *priv,
 		ret = mwifiex_parse_single_response_buf(priv, &bss_info,
 							&bytes_left,
 							le64_to_cpu(fw_tsf),
-							radio_type, false);
+							radio_type, false, 0);
 		if (ret)
 			goto check_next_scan;
 	}
@@ -1925,6 +1943,167 @@ check_next_scan:
 }
 
 /*
+ * This function prepares an extended scan command to be sent to the firmware
+ *
+ * This uses the scan command configuration sent to the command processing
+ * module in command preparation stage to configure a extended scan command
+ * structure to send to firmware.
+ */
+int mwifiex_cmd_802_11_scan_ext(struct mwifiex_private *priv,
+				struct host_cmd_ds_command *cmd,
+				void *data_buf)
+{
+	struct host_cmd_ds_802_11_scan_ext *ext_scan = &cmd->params.ext_scan;
+	struct mwifiex_scan_cmd_config *scan_cfg = data_buf;
+
+	memcpy(ext_scan->tlv_buffer, scan_cfg->tlv_buf, scan_cfg->tlv_buf_len);
+
+	cmd->command = cpu_to_le16(HostCmd_CMD_802_11_SCAN_EXT);
+
+	/* Size is equal to the sizeof(fixed portions) + the TLV len + header */
+	cmd->size = cpu_to_le16((u16)(sizeof(ext_scan->reserved)
+				      + scan_cfg->tlv_buf_len + S_DS_GEN));
+
+	return 0;
+}
+
+/* This function handles the command response of extended scan */
+int mwifiex_ret_802_11_scan_ext(struct mwifiex_private *priv)
+{
+	dev_dbg(priv->adapter->dev, "info: EXT scan returns successfully\n");
+	return 0;
+}
+
+/* This function This function handles the event extended scan report. It
+ * parses extended scan results and informs to cfg80211 stack.
+ */
+int mwifiex_handle_event_ext_scan_report(struct mwifiex_private *priv,
+					 void *buf)
+{
+	int ret = 0;
+	struct mwifiex_adapter *adapter = priv->adapter;
+	u8 *bss_info;
+	u32 bytes_left, bytes_left_for_tlv, idx;
+	u16 type, len;
+	struct mwifiex_ie_types_data *tlv;
+	struct mwifiex_ie_types_bss_scan_rsp *scan_rsp_tlv;
+	struct mwifiex_ie_types_bss_scan_info *scan_info_tlv;
+	u8 *radio_type;
+	u64 fw_tsf = 0;
+	s32 rssi = 0;
+	struct mwifiex_event_scan_result *event_scan = buf;
+	u8 num_of_set = event_scan->num_of_set;
+	u8 *scan_resp = buf + sizeof(struct mwifiex_event_scan_result);
+	u16 scan_resp_size = le16_to_cpu(event_scan->buf_size);
+
+	if (num_of_set > MWIFIEX_MAX_AP) {
+		dev_err(adapter->dev,
+			"EXT_SCAN: Invalid number of AP returned (%d)!!\n",
+			num_of_set);
+		ret = -1;
+		goto check_next_scan;
+	}
+
+	bytes_left = scan_resp_size;
+	dev_dbg(adapter->dev,
+		"EXT_SCAN: size %d, returned %d APs...",
+		scan_resp_size, num_of_set);
+
+	tlv = (struct mwifiex_ie_types_data *)scan_resp;
+
+	for (idx = 0; idx < num_of_set && bytes_left; idx++) {
+		type = le16_to_cpu(tlv->header.type);
+		len = le16_to_cpu(tlv->header.len);
+		if (bytes_left < sizeof(struct mwifiex_ie_types_header) + len) {
+			dev_err(adapter->dev, "EXT_SCAN: Error bytes left < TLV length\n");
+			break;
+		}
+		scan_rsp_tlv = NULL;
+		scan_info_tlv = NULL;
+		bytes_left_for_tlv = bytes_left;
+
+		/* BSS response TLV with beacon or probe response buffer
+		 * at the initial position of each descriptor
+		 */
+		if (type != TLV_TYPE_BSS_SCAN_RSP)
+			break;
+
+		bss_info = (u8 *)tlv;
+		scan_rsp_tlv = (struct mwifiex_ie_types_bss_scan_rsp *)tlv;
+		tlv = (struct mwifiex_ie_types_data *)(tlv->data + len);
+		bytes_left_for_tlv -=
+				(len + sizeof(struct mwifiex_ie_types_header));
+
+		while (bytes_left_for_tlv >=
+		       sizeof(struct mwifiex_ie_types_header) &&
+		       le16_to_cpu(tlv->header.type) != TLV_TYPE_BSS_SCAN_RSP) {
+			type = le16_to_cpu(tlv->header.type);
+			len = le16_to_cpu(tlv->header.len);
+			if (bytes_left_for_tlv <
+			    sizeof(struct mwifiex_ie_types_header) + len) {
+				dev_err(adapter->dev,
+					"EXT_SCAN: Error in processing TLV, bytes left < TLV length\n");
+				scan_rsp_tlv = NULL;
+				bytes_left_for_tlv = 0;
+				continue;
+			}
+			switch (type) {
+			case TLV_TYPE_BSS_SCAN_INFO:
+				scan_info_tlv =
+				  (struct mwifiex_ie_types_bss_scan_info *)tlv;
+				if (len !=
+				 sizeof(struct mwifiex_ie_types_bss_scan_info) -
+				 sizeof(struct mwifiex_ie_types_header)) {
+					bytes_left_for_tlv = 0;
+					continue;
+				}
+				break;
+			default:
+				break;
+			}
+			tlv = (struct mwifiex_ie_types_data *)(tlv->data + len);
+			bytes_left -=
+				(len + sizeof(struct mwifiex_ie_types_header));
+			bytes_left_for_tlv -=
+				(len + sizeof(struct mwifiex_ie_types_header));
+		}
+
+		if (!scan_rsp_tlv)
+			break;
+
+		/* Advance pointer to the beacon buffer length and
+		 * update the bytes count so that the function
+		 * wlan_interpret_bss_desc_with_ie() can handle the
+		 * scan buffer withut any change
+		 */
+		bss_info += sizeof(u16);
+		bytes_left -= sizeof(u16);
+
+		if (scan_info_tlv) {
+			rssi = (s32)(s16)(le16_to_cpu(scan_info_tlv->rssi));
+			rssi *= 100;           /* Convert dBm to mBm */
+			dev_dbg(adapter->dev,
+				"info: InterpretIE: RSSI=%d\n", rssi);
+			fw_tsf = le64_to_cpu(scan_info_tlv->tsf);
+			radio_type = &scan_info_tlv->radio_type;
+		} else {
+			radio_type = NULL;
+		}
+		ret = mwifiex_parse_single_response_buf(priv, &bss_info,
+							&bytes_left, fw_tsf,
+							radio_type, true, rssi);
+		if (ret)
+			goto check_next_scan;
+	}
+
+check_next_scan:
+	if (!event_scan->more_event)
+		mwifiex_check_next_scan_command(priv);
+
+	return ret;
+}
+
+/*
  * This function prepares command for background scan query.
  *
  * Preparation includes -