ath10k: start using sk_buff_head
authorMichal Kazior <michal.kazior@tieto.com>
Tue, 18 Nov 2014 07:24:47 +0000 (09:24 +0200)
committerKalle Valo <kvalo@qca.qualcomm.com>
Thu, 20 Nov 2014 13:43:00 +0000 (15:43 +0200)
Instead of using manual sk_buff linking via ->next
use sk_buff_head. It's more robust, cleaner and
there's plenty of helper functions in kernel
already to manage sk_buff_head.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
drivers/net/wireless/ath/ath10k/htt_rx.c

index 52c6306..f988a8d 100644 (file)
@@ -301,27 +301,15 @@ static inline struct sk_buff *ath10k_htt_rx_netbuf_pop(struct ath10k_htt *htt)
        return msdu;
 }
 
-static void ath10k_htt_rx_free_msdu_chain(struct sk_buff *skb)
-{
-       struct sk_buff *next;
-
-       while (skb) {
-               next = skb->next;
-               dev_kfree_skb_any(skb);
-               skb = next;
-       }
-}
-
 /* return: < 0 fatal error, 0 - non chained msdu, 1 chained msdu */
 static int ath10k_htt_rx_amsdu_pop(struct ath10k_htt *htt,
                                   u8 **fw_desc, int *fw_desc_len,
-                                  struct sk_buff **head_msdu,
-                                  struct sk_buff **tail_msdu,
+                                  struct sk_buff_head *amsdu,
                                   u32 *attention)
 {
        struct ath10k *ar = htt->ar;
        int msdu_len, msdu_chaining = 0;
-       struct sk_buff *msdu, *next;
+       struct sk_buff *msdu;
        struct htt_rx_desc *rx_desc;
 
        lockdep_assert_held(&htt->rx_ring.lock);
@@ -331,10 +319,19 @@ static int ath10k_htt_rx_amsdu_pop(struct ath10k_htt *htt,
                return -1;
        }
 
-       msdu = *head_msdu = ath10k_htt_rx_netbuf_pop(htt);
-       while (msdu) {
+       for (;;) {
                int last_msdu, msdu_len_invalid, msdu_chained;
 
+               msdu = ath10k_htt_rx_netbuf_pop(htt);
+               if (!msdu) {
+                       ath10k_err(ar, "failed to pop msdu\n");
+                       __skb_queue_purge(amsdu);
+                       htt->rx_confused = true;
+                       break;
+               }
+
+               __skb_queue_tail(amsdu, msdu);
+
                rx_desc = (struct htt_rx_desc *)msdu->data;
 
                /* FIXME: we must report msdu payload since this is what caller
@@ -352,10 +349,8 @@ static int ath10k_htt_rx_amsdu_pop(struct ath10k_htt *htt,
                 */
                if (!(__le32_to_cpu(rx_desc->attention.flags)
                                & RX_ATTENTION_FLAGS_MSDU_DONE)) {
-                       ath10k_htt_rx_free_msdu_chain(*head_msdu);
-                       *head_msdu = NULL;
-                       msdu = NULL;
-                       ath10k_err(ar, "htt rx stopped. cannot recover\n");
+                       ath10k_err(ar, "popped an incomplete msdu\n");
+                       __skb_queue_purge(amsdu);
                        htt->rx_confused = true;
                        break;
                }
@@ -421,25 +416,20 @@ static int ath10k_htt_rx_amsdu_pop(struct ath10k_htt *htt,
                skb_put(msdu, min(msdu_len, HTT_RX_MSDU_SIZE));
                msdu_len -= msdu->len;
 
-               /* FIXME: Do chained buffers include htt_rx_desc or not? */
+               /* Note: Chained buffers do not contain rx descriptor */
                while (msdu_chained--) {
-                       struct sk_buff *next = ath10k_htt_rx_netbuf_pop(htt);
-
-                       if (!next) {
+                       msdu = ath10k_htt_rx_netbuf_pop(htt);
+                       if (!msdu) {
                                ath10k_warn(ar, "failed to pop chained msdu\n");
-                               ath10k_htt_rx_free_msdu_chain(*head_msdu);
-                               *head_msdu = NULL;
-                               msdu = NULL;
+                               __skb_queue_purge(amsdu);
                                htt->rx_confused = true;
                                break;
                        }
 
-                       skb_trim(next, 0);
-                       skb_put(next, min(msdu_len, HTT_RX_BUF_SIZE));
-                       msdu_len -= next->len;
-
-                       msdu->next = next;
-                       msdu = next;
+                       __skb_queue_tail(amsdu, msdu);
+                       skb_trim(msdu, 0);
+                       skb_put(msdu, min(msdu_len, HTT_RX_BUF_SIZE));
+                       msdu_len -= msdu->len;
                        msdu_chaining = 1;
                }
 
@@ -448,18 +438,12 @@ static int ath10k_htt_rx_amsdu_pop(struct ath10k_htt *htt,
 
                trace_ath10k_htt_rx_desc(ar, &rx_desc->attention,
                                         sizeof(*rx_desc) - sizeof(u32));
-               if (last_msdu) {
-                       msdu->next = NULL;
-                       break;
-               }
 
-               next = ath10k_htt_rx_netbuf_pop(htt);
-               msdu->next = next;
-               msdu = next;
+               if (last_msdu)
+                       break;
        }
-       *tail_msdu = msdu;
 
-       if (*head_msdu == NULL)
+       if (skb_queue_empty(amsdu))
                msdu_chaining = -1;
 
        /*
@@ -915,11 +899,11 @@ static int ath10k_htt_rx_nwifi_hdrlen(struct ieee80211_hdr *hdr)
 
 static void ath10k_htt_rx_amsdu(struct ath10k_htt *htt,
                                struct ieee80211_rx_status *rx_status,
-                               struct sk_buff *skb_in)
+                               struct sk_buff_head *amsdu)
 {
        struct ath10k *ar = htt->ar;
        struct htt_rx_desc *rxd;
-       struct sk_buff *skb = skb_in;
+       struct sk_buff *skb;
        struct sk_buff *first;
        enum rx_msdu_decap_format fmt;
        enum htt_rx_mpdu_encrypt_type enctype;
@@ -927,7 +911,9 @@ static void ath10k_htt_rx_amsdu(struct ath10k_htt *htt,
        u8 hdr_buf[64], da[ETH_ALEN], sa[ETH_ALEN], *qos;
        unsigned int hdr_len;
 
-       rxd = (void *)skb->data - sizeof(*rxd);
+       first = skb_peek(amsdu);
+
+       rxd = (void *)first->data - sizeof(*rxd);
        enctype = MS(__le32_to_cpu(rxd->mpdu_start.info0),
                     RX_MPDU_START_INFO0_ENCRYPT_TYPE);
 
@@ -936,8 +922,7 @@ static void ath10k_htt_rx_amsdu(struct ath10k_htt *htt,
        memcpy(hdr_buf, hdr, hdr_len);
        hdr = (struct ieee80211_hdr *)hdr_buf;
 
-       first = skb;
-       while (skb) {
+       while ((skb = __skb_dequeue(amsdu))) {
                void *decap_hdr;
                int len;
 
@@ -1005,18 +990,15 @@ static void ath10k_htt_rx_amsdu(struct ath10k_htt *htt,
                        break;
                }
 
-               skb_in = skb;
-               ath10k_htt_rx_h_protected(htt, rx_status, skb_in, enctype, fmt,
+               ath10k_htt_rx_h_protected(htt, rx_status, skb, enctype, fmt,
                                          false);
-               skb = skb->next;
-               skb_in->next = NULL;
 
-               if (skb)
-                       rx_status->flag |= RX_FLAG_AMSDU_MORE;
-               else
+               if (skb_queue_empty(amsdu))
                        rx_status->flag &= ~RX_FLAG_AMSDU_MORE;
+               else
+                       rx_status->flag |= RX_FLAG_AMSDU_MORE;
 
-               ath10k_process_rx(htt->ar, rx_status, skb_in);
+               ath10k_process_rx(htt->ar, rx_status, skb);
        }
 
        /* FIXME: It might be nice to re-assemble the A-MSDU when there's a
@@ -1035,13 +1017,6 @@ static void ath10k_htt_rx_msdu(struct ath10k_htt *htt,
        int hdr_len;
        void *rfc1042;
 
-       /* This shouldn't happen. If it does than it may be a FW bug. */
-       if (skb->next) {
-               ath10k_warn(ar, "htt rx received chained non A-MSDU frame\n");
-               ath10k_htt_rx_free_msdu_chain(skb->next);
-               skb->next = NULL;
-       }
-
        rxd = (void *)skb->data - sizeof(*rxd);
        fmt = MS(__le32_to_cpu(rxd->msdu_start.info1),
                 RX_MSDU_START_INFO1_DECAP_FORMAT);
@@ -1127,10 +1102,9 @@ static int ath10k_htt_rx_get_csum_state(struct sk_buff *skb)
        return CHECKSUM_UNNECESSARY;
 }
 
-static int ath10k_unchain_msdu(struct sk_buff *msdu_head)
+static int ath10k_unchain_msdu(struct sk_buff_head *amsdu)
 {
-       struct sk_buff *next = msdu_head->next;
-       struct sk_buff *to_free = next;
+       struct sk_buff *skb, *first;
        int space;
        int total_len = 0;
 
@@ -1141,40 +1115,33 @@ static int ath10k_unchain_msdu(struct sk_buff *msdu_head)
         * skb?
         */
 
-       msdu_head->next = NULL;
+       first = __skb_dequeue(amsdu);
 
        /* Allocate total length all at once. */
-       while (next) {
-               total_len += next->len;
-               next = next->next;
-       }
+       skb_queue_walk(amsdu, skb)
+               total_len += skb->len;
 
-       space = total_len - skb_tailroom(msdu_head);
+       space = total_len - skb_tailroom(first);
        if ((space > 0) &&
-           (pskb_expand_head(msdu_head, 0, space, GFP_ATOMIC) < 0)) {
+           (pskb_expand_head(first, 0, space, GFP_ATOMIC) < 0)) {
                /* TODO:  bump some rx-oom error stat */
                /* put it back together so we can free the
                 * whole list at once.
                 */
-               msdu_head->next = to_free;
+               __skb_queue_head(amsdu, first);
                return -1;
        }
 
        /* Walk list again, copying contents into
         * msdu_head
         */
-       next = to_free;
-       while (next) {
-               skb_copy_from_linear_data(next, skb_put(msdu_head, next->len),
-                                         next->len);
-               next = next->next;
+       while ((skb = __skb_dequeue(amsdu))) {
+               skb_copy_from_linear_data(skb, skb_put(first, skb->len),
+                                         skb->len);
+               dev_kfree_skb_any(skb);
        }
 
-       /* If here, we have consolidated skb.  Free the
-        * fragments and pass the main skb on up the
-        * stack.
-        */
-       ath10k_htt_rx_free_msdu_chain(to_free);
+       __skb_queue_head(amsdu, first);
        return 0;
 }
 
@@ -1223,6 +1190,7 @@ static void ath10k_htt_rx_handler(struct ath10k_htt *htt,
        struct ath10k *ar = htt->ar;
        struct ieee80211_rx_status *rx_status = &htt->rx_status;
        struct htt_rx_indication_mpdu_range *mpdu_ranges;
+       struct sk_buff_head amsdu;
        struct ieee80211_hdr *hdr;
        int num_mpdu_ranges;
        u32 attention;
@@ -1271,35 +1239,28 @@ static void ath10k_htt_rx_handler(struct ath10k_htt *htt,
 
        for (i = 0; i < num_mpdu_ranges; i++) {
                for (j = 0; j < mpdu_ranges[i].mpdu_count; j++) {
-                       struct sk_buff *msdu_head, *msdu_tail;
-
                        attention = 0;
-                       msdu_head = NULL;
-                       msdu_tail = NULL;
-                       ret = ath10k_htt_rx_amsdu_pop(htt,
-                                                     &fw_desc,
-                                                     &fw_desc_len,
-                                                     &msdu_head,
-                                                     &msdu_tail,
+                       __skb_queue_head_init(&amsdu);
+                       ret = ath10k_htt_rx_amsdu_pop(htt, &fw_desc,
+                                                     &fw_desc_len, &amsdu,
                                                      &attention);
 
                        if (ret < 0) {
                                ath10k_warn(ar, "failed to pop amsdu from htt rx ring %d\n",
                                            ret);
-                               ath10k_htt_rx_free_msdu_chain(msdu_head);
+                               __skb_queue_purge(&amsdu);
                                continue;
                        }
 
-                       if (!ath10k_htt_rx_amsdu_allowed(htt, msdu_head,
+                       if (!ath10k_htt_rx_amsdu_allowed(htt, skb_peek(&amsdu),
                                                         channel_set,
                                                         attention)) {
-                               ath10k_htt_rx_free_msdu_chain(msdu_head);
+                               __skb_queue_purge(&amsdu);
                                continue;
                        }
 
-                       if (ret > 0 &&
-                           ath10k_unchain_msdu(msdu_head) < 0) {
-                               ath10k_htt_rx_free_msdu_chain(msdu_head);
+                       if (ret > 0 && ath10k_unchain_msdu(&amsdu) < 0) {
+                               __skb_queue_purge(&amsdu);
                                continue;
                        }
 
@@ -1313,12 +1274,13 @@ static void ath10k_htt_rx_handler(struct ath10k_htt *htt,
                        else
                                rx_status->flag &= ~RX_FLAG_MMIC_ERROR;
 
-                       hdr = ath10k_htt_rx_skb_get_hdr(msdu_head);
+                       hdr = ath10k_htt_rx_skb_get_hdr(skb_peek(&amsdu));
 
                        if (ath10k_htt_rx_hdr_is_amsdu(hdr))
-                               ath10k_htt_rx_amsdu(htt, rx_status, msdu_head);
+                               ath10k_htt_rx_amsdu(htt, rx_status, &amsdu);
                        else
-                               ath10k_htt_rx_msdu(htt, rx_status, msdu_head);
+                               ath10k_htt_rx_msdu(htt, rx_status,
+                                                  __skb_dequeue(&amsdu));
                }
        }
 
@@ -1329,12 +1291,13 @@ static void ath10k_htt_rx_frag_handler(struct ath10k_htt *htt,
                                       struct htt_rx_fragment_indication *frag)
 {
        struct ath10k *ar = htt->ar;
-       struct sk_buff *msdu_head, *msdu_tail;
+       struct sk_buff *msdu;
        enum htt_rx_mpdu_encrypt_type enctype;
        struct htt_rx_desc *rxd;
        enum rx_msdu_decap_format fmt;
        struct ieee80211_rx_status *rx_status = &htt->rx_status;
        struct ieee80211_hdr *hdr;
+       struct sk_buff_head amsdu;
        int ret;
        bool tkip_mic_err;
        bool decrypt_err;
@@ -1346,13 +1309,11 @@ static void ath10k_htt_rx_frag_handler(struct ath10k_htt *htt,
        fw_desc_len = __le16_to_cpu(frag->fw_rx_desc_bytes);
        fw_desc = (u8 *)frag->fw_msdu_rx_desc;
 
-       msdu_head = NULL;
-       msdu_tail = NULL;
+       __skb_queue_head_init(&amsdu);
 
        spin_lock_bh(&htt->rx_ring.lock);
        ret = ath10k_htt_rx_amsdu_pop(htt, &fw_desc, &fw_desc_len,
-                                     &msdu_head, &msdu_tail,
-                                     &attention);
+                                     &amsdu, &attention);
        spin_unlock_bh(&htt->rx_ring.lock);
 
        tasklet_schedule(&htt->rx_replenish_task);
@@ -1362,15 +1323,23 @@ static void ath10k_htt_rx_frag_handler(struct ath10k_htt *htt,
        if (ret) {
                ath10k_warn(ar, "failed to pop amsdu from httr rx ring for fragmented rx %d\n",
                            ret);
-               ath10k_htt_rx_free_msdu_chain(msdu_head);
+               __skb_queue_purge(&amsdu);
                return;
        }
 
+       if (skb_queue_len(&amsdu) != 1) {
+               ath10k_warn(ar, "failed to pop frag amsdu: too many msdus\n");
+               __skb_queue_purge(&amsdu);
+               return;
+       }
+
+       msdu = __skb_dequeue(&amsdu);
+
        /* FIXME: implement signal strength */
        rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
 
-       hdr = (struct ieee80211_hdr *)msdu_head->data;
-       rxd = (void *)msdu_head->data - sizeof(*rxd);
+       hdr = (struct ieee80211_hdr *)msdu->data;
+       rxd = (void *)msdu->data - sizeof(*rxd);
        tkip_mic_err = !!(attention & RX_ATTENTION_FLAGS_TKIP_MIC_ERR);
        decrypt_err = !!(attention & RX_ATTENTION_FLAGS_DECRYPT_ERR);
        fmt = MS(__le32_to_cpu(rxd->msdu_start.info1),
@@ -1378,22 +1347,22 @@ static void ath10k_htt_rx_frag_handler(struct ath10k_htt *htt,
 
        if (fmt != RX_MSDU_DECAP_RAW) {
                ath10k_warn(ar, "we dont support non-raw fragmented rx yet\n");
-               dev_kfree_skb_any(msdu_head);
+               dev_kfree_skb_any(msdu);
                goto end;
        }
 
        enctype = MS(__le32_to_cpu(rxd->mpdu_start.info0),
                     RX_MPDU_START_INFO0_ENCRYPT_TYPE);
-       ath10k_htt_rx_h_protected(htt, rx_status, msdu_head, enctype, fmt,
+       ath10k_htt_rx_h_protected(htt, rx_status, msdu, enctype, fmt,
                                  true);
-       msdu_head->ip_summed = ath10k_htt_rx_get_csum_state(msdu_head);
+       msdu->ip_summed = ath10k_htt_rx_get_csum_state(msdu);
 
        if (tkip_mic_err)
                ath10k_warn(ar, "tkip mic error\n");
 
        if (decrypt_err) {
                ath10k_warn(ar, "decryption err in fragmented rx\n");
-               dev_kfree_skb_any(msdu_head);
+               dev_kfree_skb_any(msdu);
                goto end;
        }
 
@@ -1402,11 +1371,11 @@ static void ath10k_htt_rx_frag_handler(struct ath10k_htt *htt,
                paramlen = ath10k_htt_rx_crypto_param_len(ar, enctype);
 
                /* It is more efficient to move the header than the payload */
-               memmove((void *)msdu_head->data + paramlen,
-                       (void *)msdu_head->data,
+               memmove((void *)msdu->data + paramlen,
+                       (void *)msdu->data,
                        hdrlen);
-               skb_pull(msdu_head, paramlen);
-               hdr = (struct ieee80211_hdr *)msdu_head->data;
+               skb_pull(msdu, paramlen);
+               hdr = (struct ieee80211_hdr *)msdu->data;
        }
 
        /* remove trailing FCS */
@@ -1420,17 +1389,17 @@ static void ath10k_htt_rx_frag_handler(struct ath10k_htt *htt,
            enctype == HTT_RX_MPDU_ENCRYPT_TKIP_WPA)
                trim += MICHAEL_MIC_LEN;
 
-       if (trim > msdu_head->len) {
+       if (trim > msdu->len) {
                ath10k_warn(ar, "htt rx fragment: trailer longer than the frame itself? drop\n");
-               dev_kfree_skb_any(msdu_head);
+               dev_kfree_skb_any(msdu);
                goto end;
        }
 
-       skb_trim(msdu_head, msdu_head->len - trim);
+       skb_trim(msdu, msdu->len - trim);
 
        ath10k_dbg_dump(ar, ATH10K_DBG_HTT_DUMP, NULL, "htt rx frag mpdu: ",
-                       msdu_head->data, msdu_head->len);
-       ath10k_process_rx(htt->ar, rx_status, msdu_head);
+                       msdu->data, msdu->len);
+       ath10k_process_rx(htt->ar, rx_status, msdu);
 
 end:
        if (fw_desc_len > 0) {