From: Masakazu Mokuno Date: Fri, 20 Jul 2007 08:24:56 +0000 (+0900) Subject: ps3: tx descriptor handling cleanup X-Git-Tag: v2.6.23-rc2~293^2~20 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=48544cc267da96a85e4d38aa1999a011229948d6;p=linux-2.6 ps3: tx descriptor handling cleanup gelic: TX descriptor handling cleanup - Emitted return value of NETDEV_TX_LOCKED when DMA map or kick failure. Now it would free the skb, update drop packet statistics and return OK. Requested from Jeff Garzik. - Enable tx queue if number of free descriptors are more than 2 - Fixed descriptor leak if dma map for second descriptor failed - Stopped calling xmit handler from interrupt handler in order to recheck tx queue. Instead, call appropriate helper functions. Signed-off-by: Masakazu Mokuno Signed-off-by: Jeff Garzik --- diff --git a/drivers/net/ps3_gelic_net.c b/drivers/net/ps3_gelic_net.c index f0610fba4c..143d7bdf78 100644 --- a/drivers/net/ps3_gelic_net.c +++ b/drivers/net/ps3_gelic_net.c @@ -408,22 +408,25 @@ static void gelic_net_release_tx_chain(struct gelic_net_card *card, int stop) break; case GELIC_NET_DESCR_COMPLETE: - card->netdev_stats.tx_packets++; - card->netdev_stats.tx_bytes += - tx_chain->tail->skb->len; + if (tx_chain->tail->skb) { + card->netdev_stats.tx_packets++; + card->netdev_stats.tx_bytes += + tx_chain->tail->skb->len; + } break; case GELIC_NET_DESCR_CARDOWNED: /* pending tx request */ default: /* any other value (== GELIC_NET_DESCR_NOT_IN_USE) */ - goto out; + if (!stop) + goto out; } gelic_net_release_tx_descr(card, tx_chain->tail); - release = 1; + release ++; } out: - if (!stop && release) + if (!stop && (2 < release)) netif_wake_queue(card->netdev); } @@ -660,19 +663,21 @@ static int gelic_net_prepare_tx_descr_v(struct gelic_net_card *card, { dma_addr_t buf[2]; unsigned int vlan_len; + struct gelic_net_descr *sec_descr = descr->next; if (skb->len < GELIC_NET_VLAN_POS) return -EINVAL; - memcpy(&descr->vlan, skb->data, GELIC_NET_VLAN_POS); + vlan_len = GELIC_NET_VLAN_POS; + memcpy(&descr->vlan, skb->data, vlan_len); if (card->vlan_index != -1) { + /* internal vlan tag used */ descr->vlan.h_vlan_proto = htons(ETH_P_8021Q); /* vlan 0x8100*/ descr->vlan.h_vlan_TCI = htons(card->vlan_id[card->vlan_index]); - vlan_len = GELIC_NET_VLAN_POS + VLAN_HLEN; /* VLAN_HLEN=4 */ - } else - vlan_len = GELIC_NET_VLAN_POS; /* no vlan tag */ + vlan_len += VLAN_HLEN; /* added for above two lines */ + } - /* first descr */ + /* map data area */ buf[0] = dma_map_single(ctodev(card), &descr->vlan, vlan_len, DMA_TO_DEVICE); @@ -683,20 +688,6 @@ static int gelic_net_prepare_tx_descr_v(struct gelic_net_card *card, return -ENOMEM; } - descr->buf_addr = buf[0]; - descr->buf_size = vlan_len; - descr->skb = skb; /* not used */ - descr->data_status = 0; - gelic_net_set_txdescr_cmdstat(descr, skb, 1); /* not the frame end */ - - /* second descr */ - card->tx_chain.head = card->tx_chain.head->next; - descr->next_descr_addr = descr->next->bus_addr; - descr = descr->next; - if (gelic_net_get_descr_status(descr) != GELIC_NET_DESCR_NOT_IN_USE) - /* XXX will be removed */ - dev_err(ctodev(card), "descr is not free!\n"); - buf[1] = dma_map_single(ctodev(card), skb->data + GELIC_NET_VLAN_POS, skb->len - GELIC_NET_VLAN_POS, DMA_TO_DEVICE); @@ -711,13 +702,24 @@ static int gelic_net_prepare_tx_descr_v(struct gelic_net_card *card, return -ENOMEM; } - descr->buf_addr = buf[1]; - descr->buf_size = skb->len - GELIC_NET_VLAN_POS; - descr->skb = skb; + /* first descr */ + descr->buf_addr = buf[0]; + descr->buf_size = vlan_len; + descr->skb = NULL; /* not used */ descr->data_status = 0; - descr->next_descr_addr = 0; /* terminate hw descr */ - gelic_net_set_txdescr_cmdstat(descr, skb, 0); + descr->next_descr_addr = descr->next->bus_addr; + gelic_net_set_txdescr_cmdstat(descr, skb, 1); /* not the frame end */ + /* second descr */ + sec_descr->buf_addr = buf[1]; + sec_descr->buf_size = skb->len - GELIC_NET_VLAN_POS; + sec_descr->skb = skb; + sec_descr->data_status = 0; + sec_descr->next_descr_addr = 0; /* terminate hw descr */ + gelic_net_set_txdescr_cmdstat(sec_descr, skb, 0); + + /* bump free descriptor pointer */ + card->tx_chain.head = sec_descr->next; return 0; } @@ -730,7 +732,7 @@ static int gelic_net_prepare_tx_descr_v(struct gelic_net_card *card, static int gelic_net_kick_txdma(struct gelic_net_card *card, struct gelic_net_descr *descr) { - int status = -ENXIO; + int status = 0; int count = 10; if (card->tx_dma_progress) @@ -764,47 +766,62 @@ static int gelic_net_kick_txdma(struct gelic_net_card *card, static int gelic_net_xmit(struct sk_buff *skb, struct net_device *netdev) { struct gelic_net_card *card = netdev_priv(netdev); - struct gelic_net_descr *descr = NULL; + struct gelic_net_descr *descr; int result; unsigned long flags; spin_lock_irqsave(&card->tx_dma_lock, flags); gelic_net_release_tx_chain(card, 0); - if (!skb) - goto kick; + descr = gelic_net_get_next_tx_descr(card); if (!descr) { + /* + * no more descriptors free + */ netif_stop_queue(netdev); spin_unlock_irqrestore(&card->tx_dma_lock, flags); return NETDEV_TX_BUSY; } - result = gelic_net_prepare_tx_descr_v(card, descr, skb); - - if (result) - goto error; - - card->tx_chain.head = card->tx_chain.head->next; - if (descr->prev) - descr->prev->next_descr_addr = descr->bus_addr; -kick: + result = gelic_net_prepare_tx_descr_v(card, descr, skb); + if (result) { + /* + * DMA map failed. As chanses are that failure + * would continue, just release skb and return + */ + card->netdev_stats.tx_dropped++; + dev_kfree_skb_any(skb); + spin_unlock_irqrestore(&card->tx_dma_lock, flags); + return NETDEV_TX_OK; + } + /* + * link this prepared descriptor to previous one + * to achieve high performance + */ + descr->prev->next_descr_addr = descr->bus_addr; /* * as hardware descriptor is modified in the above lines, * ensure that the hardware sees it */ wmb(); - if (gelic_net_kick_txdma(card, card->tx_chain.tail)) - goto error; + if (gelic_net_kick_txdma(card, descr)) { + /* + * kick failed. + * release descriptors which were just prepared + */ + card->netdev_stats.tx_dropped++; + gelic_net_release_tx_descr(card, descr); + gelic_net_release_tx_descr(card, descr->next); + card->tx_chain.tail = descr->next->next; + dev_info(ctodev(card), "%s: kick failure\n", __func__); + } else { + /* OK, DMA started/reserved */ + netdev->trans_start = jiffies; + } - netdev->trans_start = jiffies; spin_unlock_irqrestore(&card->tx_dma_lock, flags); return NETDEV_TX_OK; - -error: - card->netdev_stats.tx_dropped++; - spin_unlock_irqrestore(&card->tx_dma_lock, flags); - return NETDEV_TX_LOCKED; } /** @@ -1025,9 +1042,10 @@ static irqreturn_t gelic_net_interrupt(int irq, void *ptr) if (status & GELIC_NET_TXINT) { spin_lock_irqsave(&card->tx_dma_lock, flags); card->tx_dma_progress = 0; + gelic_net_release_tx_chain(card, 0); + /* kick outstanding tx descriptor if any */ + gelic_net_kick_txdma(card, card->tx_chain.tail); spin_unlock_irqrestore(&card->tx_dma_lock, flags); - /* start pending DMA */ - gelic_net_xmit(NULL, netdev); } return IRQ_HANDLED; }