aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorDaniel Hellstrom <daniel@gaisler.com>2014-09-05 07:13:48 -0400
committerDavid S. Miller <davem@davemloft.net>2014-09-06 00:57:09 -0400
commite1743a16a043f3d6b707730e46ba33ca931fb553 (patch)
tree4efe72f85939140ee111c5992743a24f8bc66a27
parentc99d667e852766afc755fa4430be64bb94e5ea1c (diff)
greth: moved TX ring cleaning to NAPI rx poll func
This patch does not affect the 10/100 GRETH MAC. Before all GBit GRETH TX descriptor ring cleaning was done in start_xmit(), when descriptor list became full it activated TX interrupt to start the NAPI rx poll function to do TX ring cleaning. With this patch the TX descriptor ring is always cleaned from the NAPI rx poll function, triggered via TX or RX interrupt. Otherwise we could end up in TX frames being sent but not reported to the stack being sent. On the 10/100 GRETH this is not an issue since the SKB is copied&aligned into private buffers so that the SKB can be freed directly on start_xmit() Signed-off-by: Daniel Hellstrom <daniel@gaisler.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/ethernet/aeroflex/greth.c86
-rw-r--r--drivers/net/ethernet/aeroflex/greth.h2
2 files changed, 49 insertions, 39 deletions
diff --git a/drivers/net/ethernet/aeroflex/greth.c b/drivers/net/ethernet/aeroflex/greth.c
index 23578dfee249..3005155e412b 100644
--- a/drivers/net/ethernet/aeroflex/greth.c
+++ b/drivers/net/ethernet/aeroflex/greth.c
@@ -123,6 +123,12 @@ static inline void greth_enable_tx(struct greth_private *greth)
123 GRETH_REGORIN(greth->regs->control, GRETH_TXEN); 123 GRETH_REGORIN(greth->regs->control, GRETH_TXEN);
124} 124}
125 125
126static inline void greth_enable_tx_and_irq(struct greth_private *greth)
127{
128 wmb(); /* BDs must been written to memory before enabling TX */
129 GRETH_REGORIN(greth->regs->control, GRETH_TXEN | GRETH_TXI);
130}
131
126static inline void greth_disable_tx(struct greth_private *greth) 132static inline void greth_disable_tx(struct greth_private *greth)
127{ 133{
128 GRETH_REGANDIN(greth->regs->control, ~GRETH_TXEN); 134 GRETH_REGANDIN(greth->regs->control, ~GRETH_TXEN);
@@ -447,29 +453,30 @@ out:
447 return err; 453 return err;
448} 454}
449 455
456static inline u16 greth_num_free_bds(u16 tx_last, u16 tx_next)
457{
458 if (tx_next < tx_last)
459 return (tx_last - tx_next) - 1;
460 else
461 return GRETH_TXBD_NUM - (tx_next - tx_last) - 1;
462}
450 463
451static netdev_tx_t 464static netdev_tx_t
452greth_start_xmit_gbit(struct sk_buff *skb, struct net_device *dev) 465greth_start_xmit_gbit(struct sk_buff *skb, struct net_device *dev)
453{ 466{
454 struct greth_private *greth = netdev_priv(dev); 467 struct greth_private *greth = netdev_priv(dev);
455 struct greth_bd *bdp; 468 struct greth_bd *bdp;
456 u32 status = 0, dma_addr, ctrl; 469 u32 status, dma_addr;
457 int curr_tx, nr_frags, i, err = NETDEV_TX_OK; 470 int curr_tx, nr_frags, i, err = NETDEV_TX_OK;
458 unsigned long flags; 471 unsigned long flags;
472 u16 tx_last;
459 473
460 nr_frags = skb_shinfo(skb)->nr_frags; 474 nr_frags = skb_shinfo(skb)->nr_frags;
475 tx_last = greth->tx_last;
476 rmb(); /* tx_last is updated by the poll task */
461 477
462 /* Clean TX Ring */ 478 if (greth_num_free_bds(tx_last, greth->tx_next) < nr_frags + 1) {
463 greth_clean_tx_gbit(dev);
464
465 if (greth->tx_free < nr_frags + 1) {
466 spin_lock_irqsave(&greth->devlock, flags);/*save from poll/irq*/
467 ctrl = GRETH_REGLOAD(greth->regs->control);
468 /* Enable TX IRQ only if not already in poll() routine */
469 if (ctrl & GRETH_RXI)
470 GRETH_REGSAVE(greth->regs->control, ctrl | GRETH_TXI);
471 netif_stop_queue(dev); 479 netif_stop_queue(dev);
472 spin_unlock_irqrestore(&greth->devlock, flags);
473 err = NETDEV_TX_BUSY; 480 err = NETDEV_TX_BUSY;
474 goto out; 481 goto out;
475 } 482 }
@@ -488,6 +495,8 @@ greth_start_xmit_gbit(struct sk_buff *skb, struct net_device *dev)
488 /* Linear buf */ 495 /* Linear buf */
489 if (nr_frags != 0) 496 if (nr_frags != 0)
490 status = GRETH_TXBD_MORE; 497 status = GRETH_TXBD_MORE;
498 else
499 status = GRETH_BD_IE;
491 500
492 if (skb->ip_summed == CHECKSUM_PARTIAL) 501 if (skb->ip_summed == CHECKSUM_PARTIAL)
493 status |= GRETH_TXBD_CSALL; 502 status |= GRETH_TXBD_CSALL;
@@ -545,14 +554,12 @@ greth_start_xmit_gbit(struct sk_buff *skb, struct net_device *dev)
545 554
546 /* Enable the descriptor chain by enabling the first descriptor */ 555 /* Enable the descriptor chain by enabling the first descriptor */
547 bdp = greth->tx_bd_base + greth->tx_next; 556 bdp = greth->tx_bd_base + greth->tx_next;
548 greth_write_bd(&bdp->stat, greth_read_bd(&bdp->stat) | GRETH_BD_EN); 557 greth_write_bd(&bdp->stat,
549 greth->tx_next = curr_tx; 558 greth_read_bd(&bdp->stat) | GRETH_BD_EN);
550 greth->tx_free -= nr_frags + 1;
551
552 wmb();
553 559
554 spin_lock_irqsave(&greth->devlock, flags); /*save from poll/irq*/ 560 spin_lock_irqsave(&greth->devlock, flags); /*save from poll/irq*/
555 greth_enable_tx(greth); 561 greth->tx_next = curr_tx;
562 greth_enable_tx_and_irq(greth);
556 spin_unlock_irqrestore(&greth->devlock, flags); 563 spin_unlock_irqrestore(&greth->devlock, flags);
557 564
558 return NETDEV_TX_OK; 565 return NETDEV_TX_OK;
@@ -648,7 +655,6 @@ static void greth_clean_tx(struct net_device *dev)
648 if (greth->tx_free > 0) { 655 if (greth->tx_free > 0) {
649 netif_wake_queue(dev); 656 netif_wake_queue(dev);
650 } 657 }
651
652} 658}
653 659
654static inline void greth_update_tx_stats(struct net_device *dev, u32 stat) 660static inline void greth_update_tx_stats(struct net_device *dev, u32 stat)
@@ -670,20 +676,22 @@ static void greth_clean_tx_gbit(struct net_device *dev)
670{ 676{
671 struct greth_private *greth; 677 struct greth_private *greth;
672 struct greth_bd *bdp, *bdp_last_frag; 678 struct greth_bd *bdp, *bdp_last_frag;
673 struct sk_buff *skb; 679 struct sk_buff *skb = NULL;
674 u32 stat; 680 u32 stat;
675 int nr_frags, i; 681 int nr_frags, i;
682 u16 tx_last;
676 683
677 greth = netdev_priv(dev); 684 greth = netdev_priv(dev);
685 tx_last = greth->tx_last;
678 686
679 while (greth->tx_free < GRETH_TXBD_NUM) { 687 while (tx_last != greth->tx_next) {
680 688
681 skb = greth->tx_skbuff[greth->tx_last]; 689 skb = greth->tx_skbuff[tx_last];
682 690
683 nr_frags = skb_shinfo(skb)->nr_frags; 691 nr_frags = skb_shinfo(skb)->nr_frags;
684 692
685 /* We only clean fully completed SKBs */ 693 /* We only clean fully completed SKBs */
686 bdp_last_frag = greth->tx_bd_base + SKIP_TX(greth->tx_last, nr_frags); 694 bdp_last_frag = greth->tx_bd_base + SKIP_TX(tx_last, nr_frags);
687 695
688 GRETH_REGSAVE(greth->regs->status, GRETH_INT_TE | GRETH_INT_TX); 696 GRETH_REGSAVE(greth->regs->status, GRETH_INT_TE | GRETH_INT_TX);
689 mb(); 697 mb();
@@ -692,14 +700,14 @@ static void greth_clean_tx_gbit(struct net_device *dev)
692 if (stat & GRETH_BD_EN) 700 if (stat & GRETH_BD_EN)
693 break; 701 break;
694 702
695 greth->tx_skbuff[greth->tx_last] = NULL; 703 greth->tx_skbuff[tx_last] = NULL;
696 704
697 greth_update_tx_stats(dev, stat); 705 greth_update_tx_stats(dev, stat);
698 dev->stats.tx_bytes += skb->len; 706 dev->stats.tx_bytes += skb->len;
699 707
700 bdp = greth->tx_bd_base + greth->tx_last; 708 bdp = greth->tx_bd_base + tx_last;
701 709
702 greth->tx_last = NEXT_TX(greth->tx_last); 710 tx_last = NEXT_TX(tx_last);
703 711
704 dma_unmap_single(greth->dev, 712 dma_unmap_single(greth->dev,
705 greth_read_bd(&bdp->addr), 713 greth_read_bd(&bdp->addr),
@@ -708,21 +716,26 @@ static void greth_clean_tx_gbit(struct net_device *dev)
708 716
709 for (i = 0; i < nr_frags; i++) { 717 for (i = 0; i < nr_frags; i++) {
710 skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; 718 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
711 bdp = greth->tx_bd_base + greth->tx_last; 719 bdp = greth->tx_bd_base + tx_last;
712 720
713 dma_unmap_page(greth->dev, 721 dma_unmap_page(greth->dev,
714 greth_read_bd(&bdp->addr), 722 greth_read_bd(&bdp->addr),
715 skb_frag_size(frag), 723 skb_frag_size(frag),
716 DMA_TO_DEVICE); 724 DMA_TO_DEVICE);
717 725
718 greth->tx_last = NEXT_TX(greth->tx_last); 726 tx_last = NEXT_TX(tx_last);
719 } 727 }
720 greth->tx_free += nr_frags+1;
721 dev_kfree_skb(skb); 728 dev_kfree_skb(skb);
722 } 729 }
730 if (skb) { /* skb is set only if the above while loop was entered */
731 wmb();
732 greth->tx_last = tx_last;
723 733
724 if (netif_queue_stopped(dev) && (greth->tx_free > (MAX_SKB_FRAGS+1))) 734 if (netif_queue_stopped(dev) &&
725 netif_wake_queue(dev); 735 (greth_num_free_bds(tx_last, greth->tx_next) >
736 (MAX_SKB_FRAGS+1)))
737 netif_wake_queue(dev);
738 }
726} 739}
727 740
728static int greth_rx(struct net_device *dev, int limit) 741static int greth_rx(struct net_device *dev, int limit)
@@ -965,16 +978,12 @@ static int greth_poll(struct napi_struct *napi, int budget)
965 greth = container_of(napi, struct greth_private, napi); 978 greth = container_of(napi, struct greth_private, napi);
966 979
967restart_txrx_poll: 980restart_txrx_poll:
968 if (netif_queue_stopped(greth->netdev)) {
969 if (greth->gbit_mac)
970 greth_clean_tx_gbit(greth->netdev);
971 else
972 greth_clean_tx(greth->netdev);
973 }
974
975 if (greth->gbit_mac) { 981 if (greth->gbit_mac) {
982 greth_clean_tx_gbit(greth->netdev);
976 work_done += greth_rx_gbit(greth->netdev, budget - work_done); 983 work_done += greth_rx_gbit(greth->netdev, budget - work_done);
977 } else { 984 } else {
985 if (netif_queue_stopped(greth->netdev))
986 greth_clean_tx(greth->netdev);
978 work_done += greth_rx(greth->netdev, budget - work_done); 987 work_done += greth_rx(greth->netdev, budget - work_done);
979 } 988 }
980 989
@@ -983,7 +992,8 @@ restart_txrx_poll:
983 spin_lock_irqsave(&greth->devlock, flags); 992 spin_lock_irqsave(&greth->devlock, flags);
984 993
985 ctrl = GRETH_REGLOAD(greth->regs->control); 994 ctrl = GRETH_REGLOAD(greth->regs->control);
986 if (netif_queue_stopped(greth->netdev)) { 995 if ((greth->gbit_mac && (greth->tx_last != greth->tx_next)) ||
996 (!greth->gbit_mac && netif_queue_stopped(greth->netdev))) {
987 GRETH_REGSAVE(greth->regs->control, 997 GRETH_REGSAVE(greth->regs->control,
988 ctrl | GRETH_TXI | GRETH_RXI); 998 ctrl | GRETH_TXI | GRETH_RXI);
989 mask = GRETH_INT_RX | GRETH_INT_RE | 999 mask = GRETH_INT_RX | GRETH_INT_RE |
diff --git a/drivers/net/ethernet/aeroflex/greth.h b/drivers/net/ethernet/aeroflex/greth.h
index 232a622a85b7..ae16ac94daf8 100644
--- a/drivers/net/ethernet/aeroflex/greth.h
+++ b/drivers/net/ethernet/aeroflex/greth.h
@@ -107,7 +107,7 @@ struct greth_private {
107 107
108 u16 tx_next; 108 u16 tx_next;
109 u16 tx_last; 109 u16 tx_last;
110 u16 tx_free; 110 u16 tx_free; /* only used on 10/100Mbit */
111 u16 rx_cur; 111 u16 rx_cur;
112 112
113 struct greth_regs *regs; /* Address of controller registers. */ 113 struct greth_regs *regs; /* Address of controller registers. */