From 4f1d97262d58e0f493d03de4938bce736ac3cf3d Mon Sep 17 00:00:00 2001 From: Rahul Lakkireddy Date: Fri, 15 May 2020 22:41:03 +0530 Subject: [PATCH] cxgb4: improve credits recovery in TC-MQPRIO Tx path Request credit update for every half credits consumed, including the current request. Also, avoid re-trying to post packets when there are no credits left. The credit update reply via interrupt will eventually restore the credits and will invoke the Tx path again. Signed-off-by: Rahul Lakkireddy Signed-off-by: David S. Miller --- drivers/net/ethernet/chelsio/cxgb4/sge.c | 40 +++++++++++++++++++++----------- 1 file changed, 26 insertions(+), 14 deletions(-) diff --git a/drivers/net/ethernet/chelsio/cxgb4/sge.c b/drivers/net/ethernet/chelsio/cxgb4/sge.c index 6516c45..1359158 100644 --- a/drivers/net/ethernet/chelsio/cxgb4/sge.c +++ b/drivers/net/ethernet/chelsio/cxgb4/sge.c @@ -2091,10 +2091,9 @@ static inline u8 ethofld_calc_tx_flits(struct adapter *adap, return flits + nsgl; } -static inline void *write_eo_wr(struct adapter *adap, - struct sge_eosw_txq *eosw_txq, - struct sk_buff *skb, struct fw_eth_tx_eo_wr *wr, - u32 hdr_len, u32 wrlen) +static void *write_eo_wr(struct adapter *adap, struct sge_eosw_txq *eosw_txq, + struct sk_buff *skb, struct fw_eth_tx_eo_wr *wr, + u32 hdr_len, u32 wrlen) { const struct skb_shared_info *ssi = skb_shinfo(skb); struct cpl_tx_pkt_core *cpl; @@ -2113,7 +2112,8 @@ static inline void *write_eo_wr(struct adapter *adap, immd_len += hdr_len; if (!eosw_txq->ncompl || - eosw_txq->last_compl >= adap->params.ofldq_wr_cred / 2) { + (eosw_txq->last_compl + wrlen16) >= + (adap->params.ofldq_wr_cred / 2)) { compl = true; eosw_txq->ncompl++; eosw_txq->last_compl = 0; @@ -2153,8 +2153,8 @@ static inline void *write_eo_wr(struct adapter *adap, return cpl; } -static void ethofld_hard_xmit(struct net_device *dev, - struct sge_eosw_txq *eosw_txq) +static int ethofld_hard_xmit(struct net_device *dev, + struct sge_eosw_txq *eosw_txq) { struct port_info *pi = netdev2pinfo(dev); struct adapter *adap = netdev2adap(dev); @@ -2167,8 +2167,8 @@ static void ethofld_hard_xmit(struct net_device *dev, bool skip_eotx_wr = false; struct tx_sw_desc *d; struct sk_buff *skb; + int left, ret = 0; u8 flits, ndesc; - int left; eohw_txq = &adap->sge.eohw_txq[eosw_txq->hwqid]; spin_lock(&eohw_txq->lock); @@ -2198,11 +2198,19 @@ static void ethofld_hard_xmit(struct net_device *dev, wrlen = flits * 8; wrlen16 = DIV_ROUND_UP(wrlen, 16); - /* If there are no CPL credits, then wait for credits - * to come back and retry again + left = txq_avail(&eohw_txq->q) - ndesc; + + /* If there are no descriptors left in hardware queues or no + * CPL credits left in software queues, then wait for them + * to come back and retry again. Note that we always request + * for credits update via interrupt for every half credits + * consumed. So, the interrupt will eventually restore the + * credits and invoke the Tx path again. */ - if (unlikely(wrlen16 > eosw_txq->cred)) + if (unlikely(left < 0 || wrlen16 > eosw_txq->cred)) { + ret = -ENOMEM; goto out_unlock; + } if (unlikely(skip_eotx_wr)) { start = (u64 *)wr; @@ -2231,7 +2239,8 @@ write_wr_headers: sgl = (u64 *)inline_tx_skb_header(skb, &eohw_txq->q, (void *)start, hdr_len); if (data_len) { - if (unlikely(cxgb4_map_skb(adap->pdev_dev, skb, d->addr))) { + ret = cxgb4_map_skb(adap->pdev_dev, skb, d->addr); + if (unlikely(ret)) { memset(d->addr, 0, sizeof(d->addr)); eohw_txq->mapping_err++; goto out_unlock; @@ -2277,12 +2286,13 @@ write_wr_headers: out_unlock: spin_unlock(&eohw_txq->lock); + return ret; } static void ethofld_xmit(struct net_device *dev, struct sge_eosw_txq *eosw_txq) { struct sk_buff *skb; - int pktcount; + int pktcount, ret; switch (eosw_txq->state) { case CXGB4_EO_STATE_ACTIVE: @@ -2307,7 +2317,9 @@ static void ethofld_xmit(struct net_device *dev, struct sge_eosw_txq *eosw_txq) continue; } - ethofld_hard_xmit(dev, eosw_txq); + ret = ethofld_hard_xmit(dev, eosw_txq); + if (ret) + break; } } -- 2.7.4