ath10k: adjust the RX packet pad offset at QCA99X0 4addr mode

The QCA99X0 4 addresses RX packets pad 2 bytes at the beginning of
MSDU instead the end of ieee80211 header to keep alignment. The currently RX
data path can't parse the header correctly in this case. This patch fixes it
for QCA99X0.

Signed-off-by: Yanbo Li <yanbol@qca.qualcomm.com>
[kvalo@qca.qualcomm.com: checkpatch fixes and naming changes]
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath10k/core.c

@@ -58,6 +58,7 @@ static const struct ath10k_hw_params ath10k_hw_params_list[] = {
 		.otp_exe_param = 0,
 		.channel_counters_freq_hz = 88000,
 		.max_probe_resp_desc_thres = 0,
+		.hw_4addr_pad = ATH10K_HW_4ADDR_PAD_AFTER,
 		.fw = {
 			.dir = QCA988X_HW_2_0_FW_DIR,
 			.fw = QCA988X_HW_2_0_FW_FILE,
@@ -75,6 +76,7 @@ static const struct ath10k_hw_params ath10k_hw_params_list[] = {
 		.otp_exe_param = 0,
 		.channel_counters_freq_hz = 88000,
 		.max_probe_resp_desc_thres = 0,
+		.hw_4addr_pad = ATH10K_HW_4ADDR_PAD_AFTER,
 		.fw = {
 			.dir = QCA6174_HW_2_1_FW_DIR,
 			.fw = QCA6174_HW_2_1_FW_FILE,
@@ -92,6 +94,7 @@ static const struct ath10k_hw_params ath10k_hw_params_list[] = {
 		.otp_exe_param = 0,
 		.channel_counters_freq_hz = 88000,
 		.max_probe_resp_desc_thres = 0,
+		.hw_4addr_pad = ATH10K_HW_4ADDR_PAD_AFTER,
 		.fw = {
 			.dir = QCA6174_HW_3_0_FW_DIR,
 			.fw = QCA6174_HW_3_0_FW_FILE,
@@ -109,6 +112,7 @@ static const struct ath10k_hw_params ath10k_hw_params_list[] = {
 		.otp_exe_param = 0,
 		.channel_counters_freq_hz = 88000,
 		.max_probe_resp_desc_thres = 0,
+		.hw_4addr_pad = ATH10K_HW_4ADDR_PAD_AFTER,
 		.fw = {
 			/* uses same binaries as hw3.0 */
 			.dir = QCA6174_HW_3_0_FW_DIR,
@@ -128,6 +132,7 @@ static const struct ath10k_hw_params ath10k_hw_params_list[] = {
 		.continuous_frag_desc = true,
 		.channel_counters_freq_hz = 150000,
 		.max_probe_resp_desc_thres = 24,
+		.hw_4addr_pad = ATH10K_HW_4ADDR_PAD_BEFORE,
 		.fw = {
 			.dir = QCA99X0_HW_2_0_FW_DIR,
 			.fw = QCA99X0_HW_2_0_FW_FILE,

drivers/net/wireless/ath/ath10k/core.h

@@ -668,6 +668,9 @@ struct ath10k {
 		 */
 		u32 max_probe_resp_desc_thres;
 
+		/* The padding bytes's location is different on various chips */
+		enum ath10k_hw_4addr_pad hw_4addr_pad;
+
 		struct ath10k_hw_params_fw {
 			const char *dir;
 			const char *fw;

drivers/net/wireless/ath/ath10k/htt_rx.c

@@ -1114,7 +1114,20 @@ static void ath10k_htt_rx_h_undecap_nwifi(struct ath10k *ar,
 	 */
 
 	/* pull decapped header and copy SA & DA */
-	hdr = (struct ieee80211_hdr *)msdu->data;
+	if ((ar->hw_params.hw_4addr_pad == ATH10K_HW_4ADDR_PAD_BEFORE) &&
+	    ieee80211_has_a4(((struct ieee80211_hdr *)first_hdr)->frame_control)) {
+		/* The QCA99X0 4 address mode pad 2 bytes at the
+		 * beginning of MSDU
+		 */
+		hdr = (struct ieee80211_hdr *)(msdu->data + 2);
+		/* The skb length need be extended 2 as the 2 bytes at the tail
+		 * be excluded due to the padding
+		 */
+		skb_put(msdu, 2);
+	} else {
+		hdr = (struct ieee80211_hdr *)(msdu->data);
+	}
+
 	hdr_len = ath10k_htt_rx_nwifi_hdrlen(ar, hdr);
 	ether_addr_copy(da, ieee80211_get_DA(hdr));
 	ether_addr_copy(sa, ieee80211_get_SA(hdr));

drivers/net/wireless/ath/ath10k/hw.h

@@ -304,6 +304,11 @@ enum ath10k_hw_rate_cck {
 	ATH10K_HW_RATE_CCK_SP_2M,
 };
 
+enum ath10k_hw_4addr_pad {
+	ATH10K_HW_4ADDR_PAD_AFTER,
+	ATH10K_HW_4ADDR_PAD_BEFORE,
+};
+
 /* Target specific defines for MAIN firmware */
 #define TARGET_NUM_VDEVS			8
 #define TARGET_NUM_PEER_AST			2