s390/qeth: use napi_gro_frags() for SG skbs

For non-linear packets, get the skb for attaching the page fragments
from napi_get_frags() so that it can be recycled during GRO.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 8e2c058..b32b503 100644 (file)
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -5106,8 +5106,9 @@ static void qeth_l3_rebuild_skb(struct qeth_card *card, struct sk_buff *skb,
 #endif
 
 static void qeth_receive_skb(struct qeth_card *card, struct sk_buff *skb,
-                            struct qeth_hdr *hdr)
+                            struct qeth_hdr *hdr, bool uses_frags)
 {
+       struct napi_struct *napi = &card->napi;
        bool is_cso;
 
        switch (hdr->hdr.l2.id) {
@@ -5130,7 +5131,10 @@ static void qeth_receive_skb(struct qeth_card *card, struct sk_buff *skb,
                break;
        default:
                /* never happens */
-               dev_kfree_skb_any(skb);
+               if (uses_frags)
+                       napi_free_frags(napi);
+               else
+                       dev_kfree_skb_any(skb);
                return;
        }
 
@@ -5141,8 +5145,6 @@ static void qeth_receive_skb(struct qeth_card *card, struct sk_buff *skb,
                skb->ip_summed = CHECKSUM_NONE;
        }
 
-       skb->protocol = eth_type_trans(skb, skb->dev);
-
        QETH_CARD_STAT_ADD(card, rx_bytes, skb->len);
        QETH_CARD_STAT_INC(card, rx_packets);
        if (skb_is_nonlinear(skb)) {
@@ -5151,7 +5153,12 @@ static void qeth_receive_skb(struct qeth_card *card, struct sk_buff *skb,
                                   skb_shinfo(skb)->nr_frags);
        }
 
-       napi_gro_receive(&card->napi, skb);
+       if (uses_frags) {
+               napi_gro_frags(napi);
+       } else {
+               skb->protocol = eth_type_trans(skb, skb->dev);
+               napi_gro_receive(napi, skb);
+       }
 }
 
 static void qeth_create_skb_frag(struct sk_buff *skb, char *data, int data_len)
@@ -5177,7 +5184,9 @@ static int qeth_extract_skb(struct qeth_card *card,
 {
        struct qdio_buffer_element *element = *__element;
        struct qdio_buffer *buffer = qethbuffer->buffer;
+       struct napi_struct *napi = &card->napi;
        unsigned int linear_len = 0;
+       bool uses_frags = false;
        int offset = *__offset;
        bool use_rx_sg = false;
        unsigned int headroom;
@@ -5253,21 +5262,42 @@ next_packet:
                     !atomic_read(&card->force_alloc_skb) &&
                     !IS_OSN(card));
 
-       if (use_rx_sg && qethbuffer->rx_skb) {
+       if (use_rx_sg) {
                /* QETH_CQ_ENABLED only: */
-               skb = qethbuffer->rx_skb;
-               qethbuffer->rx_skb = NULL;
-       } else {
-               if (!use_rx_sg)
-                       linear_len = skb_len;
-               skb = napi_alloc_skb(&card->napi, linear_len + headroom);
+               if (qethbuffer->rx_skb) {
+                       skb = qethbuffer->rx_skb;
+                       qethbuffer->rx_skb = NULL;
+                       goto use_skb;
+               }
+
+               skb = napi_get_frags(napi);
+               if (!skb) {
+                       /* -ENOMEM, no point in falling back further. */
+                       QETH_CARD_STAT_INC(card, rx_dropped_nomem);
+                       goto walk_packet;
+               }
+
+               if (skb_tailroom(skb) >= linear_len + headroom) {
+                       uses_frags = true;
+                       goto use_skb;
+               }
+
+               netdev_info_once(card->dev,
+                                "Insufficient linear space in NAPI frags skb, need %u but have %u\n",
+                                linear_len + headroom, skb_tailroom(skb));
+               /* Shouldn't happen. Don't optimize, fall back to linear skb. */
        }
 
-       if (!skb)
+       linear_len = skb_len;
+       skb = napi_alloc_skb(napi, linear_len + headroom);
+       if (!skb) {
                QETH_CARD_STAT_INC(card, rx_dropped_nomem);
-       else if (headroom)
-               skb_reserve(skb, headroom);
+               goto walk_packet;
+       }
 
+use_skb:
+       if (headroom)
+               skb_reserve(skb, headroom);
 walk_packet:
        while (skb_len) {
                int data_len = min(skb_len, (int)(element->length - offset));
@@ -5300,7 +5330,10 @@ walk_packet:
                                QETH_CARD_TEXT(card, 4, "unexeob");
                                QETH_CARD_HEX(card, 2, buffer, sizeof(void *));
                                if (skb) {
-                                       dev_kfree_skb_any(skb);
+                                       if (uses_frags)
+                                               napi_free_frags(napi);
+                                       else
+                                               dev_kfree_skb_any(skb);
                                        QETH_CARD_STAT_INC(card,
                                                           rx_length_errors);
                                }
@@ -5318,7 +5351,7 @@ walk_packet:
        *__element = element;
        *__offset = offset;
 
-       qeth_receive_skb(card, skb, hdr);
+       qeth_receive_skb(card, skb, hdr, uses_frags);
        return 0;
 }