diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/cxgb4vf/sge.c | 121 |
1 files changed, 74 insertions, 47 deletions
diff --git a/drivers/net/cxgb4vf/sge.c b/drivers/net/cxgb4vf/sge.c index 6a6e18b07248..ecf0770bf0ff 100644 --- a/drivers/net/cxgb4vf/sge.c +++ b/drivers/net/cxgb4vf/sge.c @@ -154,13 +154,14 @@ enum { */ RX_COPY_THRES = 256, RX_PULL_LEN = 128, -}; -/* - * Can't define this in the above enum because PKTSHIFT isn't a constant in - * the VF Driver ... - */ -#define RX_PKT_PULL_LEN (RX_PULL_LEN + PKTSHIFT) + /* + * Main body length for sk_buffs used for RX Ethernet packets with + * fragments. Should be >= RX_PULL_LEN but possibly bigger to give + * pskb_may_pull() some room. + */ + RX_SKB_LEN = 512, +}; /* * Software state per TX descriptor. @@ -1355,6 +1356,67 @@ out_free: } /** + * t4vf_pktgl_to_skb - build an sk_buff from a packet gather list + * @gl: the gather list + * @skb_len: size of sk_buff main body if it carries fragments + * @pull_len: amount of data to move to the sk_buff's main body + * + * Builds an sk_buff from the given packet gather list. Returns the + * sk_buff or %NULL if sk_buff allocation failed. + */ +struct sk_buff *t4vf_pktgl_to_skb(const struct pkt_gl *gl, + unsigned int skb_len, unsigned int pull_len) +{ + struct sk_buff *skb; + struct skb_shared_info *ssi; + + /* + * If the ingress packet is small enough, allocate an skb large enough + * for all of the data and copy it inline. Otherwise, allocate an skb + * with enough room to pull in the header and reference the rest of + * the data via the skb fragment list. + * + * Below we rely on RX_COPY_THRES being less than the smallest Rx + * buff! size, which is expected since buffers are at least + * PAGE_SIZEd. In this case packets up to RX_COPY_THRES have only one + * fragment. + */ + if (gl->tot_len <= RX_COPY_THRES) { + /* small packets have only one fragment */ + skb = alloc_skb(gl->tot_len, GFP_ATOMIC); + if (unlikely(!skb)) + goto out; + __skb_put(skb, gl->tot_len); + skb_copy_to_linear_data(skb, gl->va, gl->tot_len); + } else { + skb = alloc_skb(skb_len, GFP_ATOMIC); + if (unlikely(!skb)) + goto out; + __skb_put(skb, pull_len); + skb_copy_to_linear_data(skb, gl->va, pull_len); + + ssi = skb_shinfo(skb); + ssi->frags[0].page = gl->frags[0].page; + ssi->frags[0].page_offset = gl->frags[0].page_offset + pull_len; + ssi->frags[0].size = gl->frags[0].size - pull_len; + if (gl->nfrags > 1) + memcpy(&ssi->frags[1], &gl->frags[1], + (gl->nfrags-1) * sizeof(skb_frag_t)); + ssi->nr_frags = gl->nfrags; + + skb->len = gl->tot_len; + skb->data_len = skb->len - pull_len; + skb->truesize += skb->data_len; + + /* Get a reference for the last page, we don't own it */ + get_page(gl->frags[gl->nfrags - 1].page); + } + +out: + return skb; +} + +/** * t4vf_pktgl_free - free a packet gather list * @gl: the gather list * @@ -1463,10 +1525,8 @@ int t4vf_ethrx_handler(struct sge_rspq *rspq, const __be64 *rsp, { struct sk_buff *skb; struct port_info *pi; - struct skb_shared_info *ssi; const struct cpl_rx_pkt *pkt = (void *)&rsp[1]; bool csum_ok = pkt->csum_calc && !pkt->err_vec; - unsigned int len = be16_to_cpu(pkt->len); struct sge_eth_rxq *rxq = container_of(rspq, struct sge_eth_rxq, rspq); /* @@ -1481,42 +1541,14 @@ int t4vf_ethrx_handler(struct sge_rspq *rspq, const __be64 *rsp, } /* - * If the ingress packet is small enough, allocate an skb large enough - * for all of the data and copy it inline. Otherwise, allocate an skb - * with enough room to pull in the header and reference the rest of - * the data via the skb fragment list. + * Convert the Packet Gather List into an skb. */ - if (len <= RX_COPY_THRES) { - /* small packets have only one fragment */ - skb = alloc_skb(gl->frags[0].size, GFP_ATOMIC); - if (!skb) - goto nomem; - __skb_put(skb, gl->frags[0].size); - skb_copy_to_linear_data(skb, gl->va, gl->frags[0].size); - } else { - skb = alloc_skb(RX_PKT_PULL_LEN, GFP_ATOMIC); - if (!skb) - goto nomem; - __skb_put(skb, RX_PKT_PULL_LEN); - skb_copy_to_linear_data(skb, gl->va, RX_PKT_PULL_LEN); - - ssi = skb_shinfo(skb); - ssi->frags[0].page = gl->frags[0].page; - ssi->frags[0].page_offset = (gl->frags[0].page_offset + - RX_PKT_PULL_LEN); - ssi->frags[0].size = gl->frags[0].size - RX_PKT_PULL_LEN; - if (gl->nfrags > 1) - memcpy(&ssi->frags[1], &gl->frags[1], - (gl->nfrags-1) * sizeof(skb_frag_t)); - ssi->nr_frags = gl->nfrags; - skb->len = len + PKTSHIFT; - skb->data_len = skb->len - RX_PKT_PULL_LEN; - skb->truesize += skb->data_len; - - /* Get a reference for the last page, we don't own it */ - get_page(gl->frags[gl->nfrags - 1].page); + skb = t4vf_pktgl_to_skb(gl, RX_SKB_LEN, RX_PULL_LEN); + if (unlikely(!skb)) { + t4vf_pktgl_free(gl); + rxq->stats.rx_drops++; + return 0; } - __skb_pull(skb, PKTSHIFT); skb->protocol = eth_type_trans(skb, rspq->netdev); skb_record_rx_queue(skb, rspq->idx); @@ -1549,11 +1581,6 @@ int t4vf_ethrx_handler(struct sge_rspq *rspq, const __be64 *rsp, netif_receive_skb(skb); return 0; - -nomem: - t4vf_pktgl_free(gl); - rxq->stats.rx_drops++; - return 0; } /** |