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;