From 36e24e2ee29e25480b4be4a9ea467f4739be22fb Mon Sep 17 00:00:00 2001 From: Duan Fugang-B38611 Date: Tue, 3 Sep 2013 10:41:18 +0800 Subject: [PATCH] net: fec: fix the error to get the previous BD entry Bug: error to get the previous BD entry. When the current BD is the first BD, the previous BD entry must be the last BD, not "bdp - 1" in current logic. V4: * Optimize fec_enet_get_nextdesc() for code clean. Replace "ex_new_bd - ring_size" with "ex_base". Replace "new_bd - ring_size" with "base". V3: * Restore the API name because David suggest to use fec_enet_ prefix for all function in fec driver. So, change next_bd() -> fec_enet_get_nextdesc() change pre_bd() -> fec_enet_get_prevdesc() * Reduce the two APIs parameters for easy to call. V2: * Add tx_ring_size and rx_ring_size to struct fec_enet_private. * Replace api fec_enet_get_nextdesc() with next_bd(). Replace api fec_enet_get_prevdesc() with pre_bd(). * Move all ring size check logic to next_bd() and pre_bd(), which simplifies the code redundancy. V1: * Add BD ring size check to get the previous BD entry in correctly. Reviewed-by: Li Frank Signed-off-by: Fugang Duan Acked-by: Frank Li Signed-off-by: David S. Miller --- drivers/net/ethernet/freescale/fec.h | 3 + drivers/net/ethernet/freescale/fec_main.c | 120 +++++++++++++--------- 2 files changed, 77 insertions(+), 46 deletions(-) diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h index ae236009f1a8..0120217a16dd 100644 --- a/drivers/net/ethernet/freescale/fec.h +++ b/drivers/net/ethernet/freescale/fec.h @@ -296,6 +296,9 @@ struct fec_enet_private { /* The ring entries to be free()ed */ struct bufdesc *dirty_tx; + unsigned short tx_ring_size; + unsigned short rx_ring_size; + struct platform_device *pdev; int opened; diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index c610a2716be4..fd90bf561d83 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -239,22 +239,57 @@ MODULE_PARM_DESC(macaddr, "FEC Ethernet MAC address"); static int mii_cnt; -static struct bufdesc *fec_enet_get_nextdesc(struct bufdesc *bdp, int is_ex) +static inline +struct bufdesc *fec_enet_get_nextdesc(struct bufdesc *bdp, struct fec_enet_private *fep) { - struct bufdesc_ex *ex = (struct bufdesc_ex *)bdp; - if (is_ex) - return (struct bufdesc *)(ex + 1); + struct bufdesc *new_bd = bdp + 1; + struct bufdesc_ex *ex_new_bd = (struct bufdesc_ex *)bdp + 1; + struct bufdesc_ex *ex_base; + struct bufdesc *base; + int ring_size; + + if (bdp >= fep->tx_bd_base) { + base = fep->tx_bd_base; + ring_size = fep->tx_ring_size; + ex_base = (struct bufdesc_ex *)fep->tx_bd_base; + } else { + base = fep->rx_bd_base; + ring_size = fep->rx_ring_size; + ex_base = (struct bufdesc_ex *)fep->rx_bd_base; + } + + if (fep->bufdesc_ex) + return (struct bufdesc *)((ex_new_bd >= (ex_base + ring_size)) ? + ex_base : ex_new_bd); else - return bdp + 1; + return (new_bd >= (base + ring_size)) ? + base : new_bd; } -static struct bufdesc *fec_enet_get_prevdesc(struct bufdesc *bdp, int is_ex) +static inline +struct bufdesc *fec_enet_get_prevdesc(struct bufdesc *bdp, struct fec_enet_private *fep) { - struct bufdesc_ex *ex = (struct bufdesc_ex *)bdp; - if (is_ex) - return (struct bufdesc *)(ex - 1); + struct bufdesc *new_bd = bdp - 1; + struct bufdesc_ex *ex_new_bd = (struct bufdesc_ex *)bdp - 1; + struct bufdesc_ex *ex_base; + struct bufdesc *base; + int ring_size; + + if (bdp >= fep->tx_bd_base) { + base = fep->tx_bd_base; + ring_size = fep->tx_ring_size; + ex_base = (struct bufdesc_ex *)fep->tx_bd_base; + } else { + base = fep->rx_bd_base; + ring_size = fep->rx_ring_size; + ex_base = (struct bufdesc_ex *)fep->rx_bd_base; + } + + if (fep->bufdesc_ex) + return (struct bufdesc *)((ex_new_bd < ex_base) ? + (ex_new_bd + ring_size) : ex_new_bd); else - return bdp - 1; + return (new_bd < base) ? (new_bd + ring_size) : new_bd; } static void *swap_buffer(void *bufaddr, int len) @@ -380,7 +415,7 @@ fec_enet_start_xmit(struct sk_buff *skb, struct net_device *ndev) } } - bdp_pre = fec_enet_get_prevdesc(bdp, fep->bufdesc_ex); + bdp_pre = fec_enet_get_prevdesc(bdp, fep); if ((id_entry->driver_data & FEC_QUIRK_ERR006358) && !(bdp_pre->cbd_sc & BD_ENET_TX_READY)) { fep->delay_work.trig_tx = true; @@ -389,10 +424,7 @@ fec_enet_start_xmit(struct sk_buff *skb, struct net_device *ndev) } /* If this was the last BD in the ring, start at the beginning again. */ - if (status & BD_ENET_TX_WRAP) - bdp = fep->tx_bd_base; - else - bdp = fec_enet_get_nextdesc(bdp, fep->bufdesc_ex); + bdp = fec_enet_get_nextdesc(bdp, fep); fep->cur_tx = bdp; @@ -417,18 +449,18 @@ static void fec_enet_bd_init(struct net_device *dev) /* Initialize the receive buffer descriptors. */ bdp = fep->rx_bd_base; - for (i = 0; i < RX_RING_SIZE; i++) { + for (i = 0; i < fep->rx_ring_size; i++) { /* Initialize the BD for every fragment in the page. */ if (bdp->cbd_bufaddr) bdp->cbd_sc = BD_ENET_RX_EMPTY; else bdp->cbd_sc = 0; - bdp = fec_enet_get_nextdesc(bdp, fep->bufdesc_ex); + bdp = fec_enet_get_nextdesc(bdp, fep); } /* Set the last buffer to wrap */ - bdp = fec_enet_get_prevdesc(bdp, fep->bufdesc_ex); + bdp = fec_enet_get_prevdesc(bdp, fep); bdp->cbd_sc |= BD_SC_WRAP; fep->cur_rx = fep->rx_bd_base; @@ -436,7 +468,7 @@ static void fec_enet_bd_init(struct net_device *dev) /* ...and the same for transmit */ bdp = fep->tx_bd_base; fep->cur_tx = bdp; - for (i = 0; i < TX_RING_SIZE; i++) { + for (i = 0; i < fep->tx_ring_size; i++) { /* Initialize the BD for every fragment in the page. */ bdp->cbd_sc = 0; @@ -445,11 +477,11 @@ static void fec_enet_bd_init(struct net_device *dev) fep->tx_skbuff[i] = NULL; } bdp->cbd_bufaddr = 0; - bdp = fec_enet_get_nextdesc(bdp, fep->bufdesc_ex); + bdp = fec_enet_get_nextdesc(bdp, fep); } /* Set the last buffer to wrap */ - bdp = fec_enet_get_prevdesc(bdp, fep->bufdesc_ex); + bdp = fec_enet_get_prevdesc(bdp, fep); bdp->cbd_sc |= BD_SC_WRAP; fep->dirty_tx = bdp; } @@ -510,10 +542,10 @@ fec_restart(struct net_device *ndev, int duplex) writel(fep->bd_dma, fep->hwp + FEC_R_DES_START); if (fep->bufdesc_ex) writel((unsigned long)fep->bd_dma + sizeof(struct bufdesc_ex) - * RX_RING_SIZE, fep->hwp + FEC_X_DES_START); + * fep->rx_ring_size, fep->hwp + FEC_X_DES_START); else writel((unsigned long)fep->bd_dma + sizeof(struct bufdesc) - * RX_RING_SIZE, fep->hwp + FEC_X_DES_START); + * fep->rx_ring_size, fep->hwp + FEC_X_DES_START); for (i = 0; i <= TX_RING_MOD_MASK; i++) { @@ -727,10 +759,7 @@ fec_enet_tx(struct net_device *ndev) bdp = fep->dirty_tx; /* get next bdp of dirty_tx */ - if (bdp->cbd_sc & BD_ENET_TX_WRAP) - bdp = fep->tx_bd_base; - else - bdp = fec_enet_get_nextdesc(bdp, fep->bufdesc_ex); + bdp = fec_enet_get_nextdesc(bdp, fep); while (((status = bdp->cbd_sc) & BD_ENET_TX_READY) == 0) { @@ -800,10 +829,7 @@ fec_enet_tx(struct net_device *ndev) fep->dirty_tx = bdp; /* Update pointer to next buffer descriptor to be transmitted */ - if (status & BD_ENET_TX_WRAP) - bdp = fep->tx_bd_base; - else - bdp = fec_enet_get_nextdesc(bdp, fep->bufdesc_ex); + bdp = fec_enet_get_nextdesc(bdp, fep); /* Since we have freed up a buffer, the ring is no longer full */ @@ -993,10 +1019,8 @@ rx_processing_done: } /* Update BD pointer to next entry */ - if (status & BD_ENET_RX_WRAP) - bdp = fep->rx_bd_base; - else - bdp = fec_enet_get_nextdesc(bdp, fep->bufdesc_ex); + bdp = fec_enet_get_nextdesc(bdp, fep); + /* Doing this here will keep the FEC running while we process * incoming frames. On a heavily loaded network, we should be * able to keep up at the expense of system resources. @@ -1662,7 +1686,7 @@ static void fec_enet_free_buffers(struct net_device *ndev) struct bufdesc *bdp; bdp = fep->rx_bd_base; - for (i = 0; i < RX_RING_SIZE; i++) { + for (i = 0; i < fep->rx_ring_size; i++) { skb = fep->rx_skbuff[i]; if (bdp->cbd_bufaddr) @@ -1670,11 +1694,11 @@ static void fec_enet_free_buffers(struct net_device *ndev) FEC_ENET_RX_FRSIZE, DMA_FROM_DEVICE); if (skb) dev_kfree_skb(skb); - bdp = fec_enet_get_nextdesc(bdp, fep->bufdesc_ex); + bdp = fec_enet_get_nextdesc(bdp, fep); } bdp = fep->tx_bd_base; - for (i = 0; i < TX_RING_SIZE; i++) + for (i = 0; i < fep->tx_ring_size; i++) kfree(fep->tx_bounce[i]); } @@ -1686,7 +1710,7 @@ static int fec_enet_alloc_buffers(struct net_device *ndev) struct bufdesc *bdp; bdp = fep->rx_bd_base; - for (i = 0; i < RX_RING_SIZE; i++) { + for (i = 0; i < fep->rx_ring_size; i++) { skb = netdev_alloc_skb(ndev, FEC_ENET_RX_FRSIZE); if (!skb) { fec_enet_free_buffers(ndev); @@ -1703,15 +1727,15 @@ static int fec_enet_alloc_buffers(struct net_device *ndev) ebdp->cbd_esc = BD_ENET_RX_INT; } - bdp = fec_enet_get_nextdesc(bdp, fep->bufdesc_ex); + bdp = fec_enet_get_nextdesc(bdp, fep); } /* Set the last buffer to wrap. */ - bdp = fec_enet_get_prevdesc(bdp, fep->bufdesc_ex); + bdp = fec_enet_get_prevdesc(bdp, fep); bdp->cbd_sc |= BD_SC_WRAP; bdp = fep->tx_bd_base; - for (i = 0; i < TX_RING_SIZE; i++) { + for (i = 0; i < fep->tx_ring_size; i++) { fep->tx_bounce[i] = kmalloc(FEC_ENET_TX_FRSIZE, GFP_KERNEL); bdp->cbd_sc = 0; @@ -1722,11 +1746,11 @@ static int fec_enet_alloc_buffers(struct net_device *ndev) ebdp->cbd_esc = BD_ENET_TX_INT; } - bdp = fec_enet_get_nextdesc(bdp, fep->bufdesc_ex); + bdp = fec_enet_get_nextdesc(bdp, fep); } /* Set the last buffer to wrap. */ - bdp = fec_enet_get_prevdesc(bdp, fep->bufdesc_ex); + bdp = fec_enet_get_prevdesc(bdp, fep); bdp->cbd_sc |= BD_SC_WRAP; return 0; @@ -1966,13 +1990,17 @@ static int fec_enet_init(struct net_device *ndev) /* Get the Ethernet address */ fec_get_mac(ndev); + /* init the tx & rx ring size */ + fep->tx_ring_size = TX_RING_SIZE; + fep->rx_ring_size = RX_RING_SIZE; + /* Set receive and transmit descriptor base. */ fep->rx_bd_base = cbd_base; if (fep->bufdesc_ex) fep->tx_bd_base = (struct bufdesc *) - (((struct bufdesc_ex *)cbd_base) + RX_RING_SIZE); + (((struct bufdesc_ex *)cbd_base) + fep->rx_ring_size); else - fep->tx_bd_base = cbd_base + RX_RING_SIZE; + fep->tx_bd_base = cbd_base + fep->rx_ring_size; /* The FEC Ethernet specific entries in the device structure */ ndev->watchdog_timeo = TX_TIMEOUT; -- 2.20.1