ath10k: cleanup RX decap handling

Simplify decapping code and make it easier to
understand.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

1 files changed, 28 insertions, 26 deletions

diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
index 617df96e4ffd..cdb4e6da7cc2 100644
--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -669,11 +669,16 @@ static void ath10k_htt_rx_amsdu(struct ath10k_htt *htt,
 
                 switch (fmt) {
                 case RX_MSDU_DECAP_RAW:
+                        /* remove trailing FCS */
                         skb_trim(skb, skb->len - FCS_LEN);
                         break;
                 case RX_MSDU_DECAP_NATIVE_WIFI:
+                        /* nothing to do */
                         break;
                 case RX_MSDU_DECAP_ETHERNET2_DIX:
+                        /* strip ethernet header and insert decapped 802.11
+                         * header, amsdu subframe header and rfc1042 header */
+
                         len = 0;
                         len += sizeof(struct rfc1042_hdr);
                         len += sizeof(struct amsdu_subframe_hdr);
@@ -683,6 +688,8 @@ static void ath10k_htt_rx_amsdu(struct ath10k_htt *htt,
                         memcpy(skb_push(skb, hdr_len), hdr, hdr_len);
                         break;
                 case RX_MSDU_DECAP_8023_SNAP_LLC:
+                        /* insert decapped 802.11 header making a singly
+                         * A-MSDU */
                         memcpy(skb_push(skb, hdr_len), hdr, hdr_len);
                         break;
                 }
@@ -706,6 +713,8 @@ static void ath10k_htt_rx_msdu(struct ath10k_htt *htt, struct htt_rx_info *info)
         struct ieee80211_hdr *hdr;
         enum rx_msdu_decap_format fmt;
         enum htt_rx_mpdu_encrypt_type enctype;
+        int hdr_len;
+        void *rfc1042;
 
         /* This shouldn't happen. If it does than it may be a FW bug. */
         if (skb->next) {
@@ -719,46 +728,39 @@ static void ath10k_htt_rx_msdu(struct ath10k_htt *htt, struct htt_rx_info *info)
                         RX_MSDU_START_INFO1_DECAP_FORMAT);
         enctype = MS(__le32_to_cpu(rxd->mpdu_start.info0),
                         RX_MPDU_START_INFO0_ENCRYPT_TYPE);
-        hdr = (void *)skb->data - RX_HTT_HDR_STATUS_LEN;
+        hdr = (struct ieee80211_hdr *)rxd->rx_hdr_status;
+        hdr_len = ieee80211_hdrlen(hdr->frame_control);
 
         skb->ip_summed = ath10k_htt_rx_get_csum_state(skb);
 
         switch (fmt) {
         case RX_MSDU_DECAP_RAW:
                 /* remove trailing FCS */
-                skb_trim(skb, skb->len - 4);
+                skb_trim(skb, skb->len - FCS_LEN);
                 break;
         case RX_MSDU_DECAP_NATIVE_WIFI:
                 /* nothing to do here */
                 break;
         case RX_MSDU_DECAP_ETHERNET2_DIX:
-                /* macaddr[6] + macaddr[6] + ethertype[2] */
-                skb_pull(skb, 6 + 6 + 2);
-                break;
-        case RX_MSDU_DECAP_8023_SNAP_LLC:
-                /* macaddr[6] + macaddr[6] + len[2] */
-                /* we don't need this for non-A-MSDU */
-                skb_pull(skb, 6 + 6 + 2);
-                break;
-        }
-
-        if (fmt == RX_MSDU_DECAP_ETHERNET2_DIX) {
-                void *llc;
-                int llclen;
+                /* strip ethernet header and insert decapped 802.11 header and
+                 * rfc1042 header */
 
-                llclen = 8;
-                llc  = hdr;
-                llc += roundup(ieee80211_hdrlen(hdr->frame_control), 4);
-                llc += roundup(ath10k_htt_rx_crypto_param_len(enctype), 4);
+                rfc1042 = hdr;
+                rfc1042 += roundup(hdr_len, 4);
+                rfc1042 += roundup(ath10k_htt_rx_crypto_param_len(enctype), 4);
 
-                skb_push(skb, llclen);
-                memcpy(skb->data, llc, llclen);
-        }
+                skb_pull(skb, sizeof(struct ethhdr));
+                memcpy(skb_push(skb, sizeof(struct rfc1042_hdr)),
+                       rfc1042, sizeof(struct rfc1042_hdr));
+                memcpy(skb_push(skb, hdr_len), hdr, hdr_len);
+                break;
+        case RX_MSDU_DECAP_8023_SNAP_LLC:
+                /* remove A-MSDU subframe header and insert
+                 * decapped 802.11 header. rfc1042 header is already there */
 
-        if (fmt >= RX_MSDU_DECAP_ETHERNET2_DIX) {
-                int len = ieee80211_hdrlen(hdr->frame_control);
-                skb_push(skb, len);
-                memcpy(skb->data, hdr, len);
+                skb_pull(skb, sizeof(struct amsdu_subframe_hdr));
+                memcpy(skb_push(skb, hdr_len), hdr, hdr_len);
+                break;
         }
 
         info->skb = skb;