Ralf Baechle wrote:
+/* module parameters */
+
+static int param_set_ethaddr(const char *val, struct kernel_param *kp)
+{
+       static const char fmt[] = "%2hhx:%2hhx:%2hhx:%2hhx:%2hhx:%2hhx";
+       unsigned char * const cc = (unsigned char *) kp->arg;
+
+       if (!val) return -EINVAL;
+
+       return (6 == sscanf(val, fmt, &cc[0], &cc[1], &cc[2], &cc[3],
+                           &cc[4], &cc[5])) ? 0 : -EINVAL;
+}
+
+static int param_get_ethaddr(char *buffer, struct kernel_param *kp)
+{
+       static const char fmt[] = "%02x:%02x:%02x:%02x:%02x:%02x";
+       const unsigned char * const cc = (unsigned char *) kp->arg;
+
+       return scnprintf(buffer, 18, fmt,
+                        cc[0], cc[1], cc[2], cc[3], cc[4], cc[5]);
+}
+
+#define param_check_ethaddr(name, p) __param_check(name, *p, unsigned char)

kill this, it is settable via ifconfig already


+enum {
+       speed_10m = 0x0,
+       speed_100m = 0x1,
+       speed_1g = 0x2
+};
+
+static int autoneg = 1;
+static unsigned int speed = speed_1g;
+static int full_duplex = 1;
+static unsigned char hwaddr[6] = {0x00, 0x30, 0x53, 0x00, 0x00, 0x00};
+
+module_param(autoneg, bool, 0444);
+module_param(full_duplex, bool, 0444);
+module_param(speed, uint, 0444);
+module_param(hwaddr, ethaddr, 0444);

kill all this, use ethtool


+/* XDMA descriptors */
+typedef struct {
+       volatile u64    cpu_part;
+       volatile u64    xdma_part;
+} rx_desc_t;
+
+typedef volatile u64 tx_desc_t;

volatile inevitably implies that the programmer was too lazy with barriers such.

Remove 'volatile', and make sure it still works.  If not, debug...


+/* Port specific data structure */
+typedef struct {
+       unsigned int                    port_num;
+       unsigned int                    irq_phy;
+       u8                              port_mac_addr[6];
+
+       /* Statistics */
+       spinlock_t                      stat_lock;
+       struct timer_list               stat_timer;
+
+       /* Tx next descriptor pointer */
+       int                             tx_next_desc;
+
+       /* SKB queues */
+       struct sk_buff_head             rx_queue;
+       struct sk_buff_head             tx_queue;
+
+       /* XDMA descriptor area */
+       rx_desc_t                       * rx_desc_area;
+       tx_desc_t                       * tx_desc_area;
+
+       /* DMA structures and handles */
+       dma_addr_t                      tx_dma;
+       dma_addr_t                      rx_dma;
+
+       /* Device lock */
+       spinlock_t                      lock;
+
+       unsigned int                    rx_ring_size;
+       unsigned int                    tx_ring_size;
+
+       struct net_device_stats         stats;
+
+       /* Tx and Rx coalescing */
+       unsigned long                   rx_int_coal;
+       unsigned long                   tx_int_coal;
+
+       /* NAPI work limit */
+       unsigned int                    rx_work_limit;
+
+       /* Values set from platform resources */
+       unsigned int                    slice;
+       unsigned int                    mdio_channel;
+       unsigned int                    rxfifo_start, rxfifo_len;
+       unsigned int                    txfifo_start, txfifo_len;
+       void __iomem *                  addr_xdma;
+       void __iomem *                  addr_mac;
+       void __iomem *                  addr_pktproc;
+       void __iomem *                  addr_mstat;
+       void __iomem *                  addr_fifo_rx;
+       void __iomem *                  addr_fifo_tx;
+       void  __iomem *                 addr_mdio;
+} rm9k_ge_port_info;
+

+static inline rx_desc_t * rm9k_ge_rxdesc_from_skb(const struct sk_buff * skb)
+{
+       rx_desc_t ** const d = (rx_desc_t **) skb->cb;
+       return *d;
+}
+
+
+
+static inline void
+rm9k_ge_rxdesc_to_skb(struct sk_buff * skb, rx_desc_t * desc)
+{
+       rx_desc_t ** const d = (rx_desc_t **) skb->cb;
+       *d = desc;
+}
+
+
+
+static inline tx_desc_t *
+rm9k_ge_txdesc_from_skb(const struct sk_buff * skb)
+{
+       tx_desc_t ** const d = (tx_desc_t **) skb->cb;
+       return *d;
+}
+
+
+
+static inline void
+rm9k_ge_txdesc_to_skb(struct sk_buff * skb, tx_desc_t * desc)
+{
+       tx_desc_t ** const d = (tx_desc_t **) skb->cb;
+       *d = desc;
+}

Don't use skb->cb for this stuff, that's not the intended usage. It will get stomped on.

Besides that, this is backwards from how other net drivers set things up: most net drivers create a list of descriptor information, and directly index the skb pointer from that.



+/*
+ * Change the MTU of the Ethernet Device
+ */
+static int rm9k_ge_change_mtu(struct net_device *netdev, int new_mtu)
+{
+       if ((new_mtu > ETH_DATA_LEN) || (new_mtu < 64))
+               return -EINVAL;
+
+       netdev->mtu = new_mtu;
+
+       if (netif_running(netdev)) {
+               rm9k_ge_port_info * const info = netdev_priv(netdev);
+
+               /* Rebuild the RX queue */
+               rm9k_ge_free_rx_queue(netdev);
+               gpi_writel(rm9k_eth_rx_frame_len(new_mtu),
+                          info->addr_mac + 0x0008);
+               gpi_writel(rm9k_eth_tx_frame_len(new_mtu),
+                          info->addr_mac + 0x0058);
+               rm9k_ge_setup_rx_queue(netdev);

Seems to need some sort of locking?


+static int rm9k_ge_xdma_ints(u32 mask)
+{
+       static spinlock_t intflg_lock = SPIN_LOCK_UNLOCKED;
+       u32 flg;
+
+       /*
+        * The interrupt decoding below assumes that the 'low priority core'
+        * feature of the RM9000 is not used!
+        */
+       switch (smp_processor_id()) {
+               case 0:
+                       spin_lock(&intflg_lock);
+                       flg = titan_readl(0x0048) & titan_readl(0x0038)
+                                         & mask;
+                       if (flg)
+                               titan_writel(flg, 0x0048);
+                       spin_unlock(&intflg_lock);
+                       break;
+
+               case 1:
+                       spin_lock(&intflg_lock);
+                       flg = titan_readl(0x004c) & titan_readl(0x003c)
+                                         & mask;
+                       if (flg)
+                               titan_writel(flg, 0x004c);
+                       spin_unlock(&intflg_lock);
+                       break;
+
+               default:
+                       flg = 0;
+                       break;
+       }
+
+       return flg != 0;
+}
+
+
+
+/*
+ * Tx Timeout function
+ */
+static void rm9k_ge_tx_timeout(struct net_device *netdev)
+{
+       rm9k_ge_port_info * const info = netdev_priv(netdev);
+       u32 reg;
+
+       /* Stop the tx queue */
+       netif_stop_queue(netdev);
+
+       /* Reset the tx xdma */
+       spin_lock(&info->tx_queue.lock);
+       info->stats.tx_errors += skb_queue_len(&info->tx_queue);
+       reg = gpi_readl(info->addr_xdma + 0x0000);
+       gpi_writel(reg | 0x80000000, info->addr_xdma + 0x0000);
+       iob();
+       spin_unlock(&info->tx_queue.lock);
+
+       /* Flush the tx queue */
+       __skb_queue_purge(&info->tx_queue);
+       info->tx_next_desc = 0;
+
+       /* Restart the tx xdma channel */
+       gpi_writel(reg & ~0x80000000, info->addr_xdma + 0x0000);
+       iob();
+
+       /* Restart the tx queue */
+       printk(KERN_ERR "%s: TX timeout - queue flushed\n", netdev->name);
+       netif_start_queue(netdev);
+}
+
+
+
+static struct sk_buff *rm9k_ge_get_tx_skb(rm9k_ge_port_info * info)
+{
+       struct sk_buff * s;
+
+       spin_lock(&info->tx_queue.lock);
+       s = skb_queue_len(&info->tx_queue) > gpi_readl(info->addr_xdma + 
0x0004) ?
+       __skb_dequeue(&info->tx_queue) : NULL;
+       spin_unlock(&info->tx_queue.lock);
+       return s;
+}
+
+
+
+
+
+static irqreturn_t rm9k_ge_main_int_handler(int irq, void *dev_id,
+                                           struct pt_regs *regs)
+{
+       u32 reg;
+       struct net_device * const netdev = (struct net_device *) dev_id;
+       rm9k_ge_port_info * const info = netdev_priv(netdev);
+       const u32 eth_int_cause_error = gpi_readl(info->addr_xdma + 0x000c);
+       const int int_tx = rm9k_ge_xdma_ints(0x1 << (info->slice * 8 + 1)),
+                 int_rx = rm9k_ge_xdma_ints(0x1 << (info->slice * 8 + 0));
+
+       if (!int_tx && !int_rx && !eth_int_cause_error)
+               return IRQ_NONE;
+
+       /* Handle Tx first */
+       if (int_tx) {
+               struct sk_buff *skb;
+
+               while (skb = rm9k_ge_get_tx_skb(info), skb != NULL) {
+                       tx_desc_t * const desc =
+                               rm9k_ge_txdesc_from_skb(skb);
+
+                       dma_unmap_single(netdev->class_dev.dev,
+                                        *desc & 0x00000000ffffffffull,
+                                        skb->len, DMA_TO_DEVICE);
+                       dev_kfree_skb_irq(skb);
+               }
+
+               if (netif_queue_stopped(netdev))
+                       netif_start_queue(netdev);
+       }
+
+       /* Handle the Rx next */
+       if (int_rx) {
+               if (netif_rx_schedule_prep(netdev)) {
+                       /* Disable Tx and Rx */
+                       lock_titan_regs();
+                       reg = titan_readl(0x0058);
+                       reg &= ~(0x1 << (info->slice * 8));
+                       titan_writel(reg, 0x0058);
+                       unlock_titan_regs();
+                       __netif_rx_schedule(netdev);
+               }
+       }
+
+       /* Handle error interrupts */
+       if (eth_int_cause_error && (eth_int_cause_error != 0x2)) {
+               printk(KERN_ERR
+                       "XDMA Channel Error : %x  on port %d\n",
+                       eth_int_cause_error, info->slice);
+
+               printk(KERN_ERR
+                      "XDMA GDI Hardware error : %x  on port %d\n",
+                      titan_readl(0x5008), info->slice);
+
+               printk(KERN_ERR
+                       "XDMA currently has %d Rx descriptors \n",
+                       gpi_readl(info->addr_xdma +0x0008));
+
+               printk(KERN_ERR
+                       "XDMA currently has prefetcted %d Rx descriptors \n",
+                       gpi_readl(info->addr_xdma + 0x001c));
+
+               gpi_writel(eth_int_cause_error, info->addr_xdma + 0x000c);
+       }
+       return IRQ_HANDLED;
+}
+
+static irqreturn_t rm9k_ge_phy_int_handler(int irq, void *dev_id,
+                                          struct pt_regs *regs)
+{
+       struct net_device * const netdev = (struct net_device *) dev_id;
+       u16 phy_intstat;
+
+       /*
+        * PHY interrupt to inform abt the changes. Reading the
+        * PHY Status register will clear the interrupt
+        */
+       rm9k_ge_mdio_read(PHY_ADDR, RM9K_GE_MDIO_PHY_INTSTAT, &phy_intstat);
+
+       if (phy_intstat & 0x0010) {
+               rm9k_ge_port_info * const info = netdev_priv(netdev);
+               /* Autonegotiation completed */
+               static const u16 val[8] =
+                       { 0x1000, 0x0000, 0x1100, 0x0100,
+                         0x1201, 0x0201, 0x1201, 0x0201 };

magic numbers



+               u16 phy_reg = 0;
+               int i;
+
+               gpi_writel(0x00000000, info->addr_mac + 0x014c);
+               rm9k_ge_mdio_read(PHY_ADDR, RM9K_GE_MDIO_PHY_STATUS, &phy_reg);
+               i = ((phy_reg >> 1) & 0x1) | ((phy_reg >> 2) & 0x6);
+
+               wmb();
+               gpi_writel(val[i], info->addr_mac + 0x0150);
+               wmb();
+               gpi_writel(0x00000003, info->addr_mac + 0x014c);
+               iob();

author desperately needs to read memory-barriers doc...

and investigate write posting.


+               netif_carrier_on(netdev);
+               pr_debug("%s: autonegotiation completed\n", netdev->name);
+       } else {
+               u16 val;
+               rm9k_ge_mdio_read(PHY_ADDR, RM9K_GE_MDIO_PHY_STATUS, &val);
+
+               if (val & 0x0004) {
+                       pr_debug("%s: carrier detected\n", netdev->name);
+                       if (!autoneg)
+                               netif_carrier_on(netdev);
+               } else {
+                       netif_carrier_off(netdev);
+                       pr_debug("%s: carrier lost\n", netdev->name);
+               }
+       }
+
+       rm9k_ge_mdio_write(PHY_ADDR, RM9K_GE_MDIO_PHY_INTCLEAR, phy_intstat);
+       return IRQ_HANDLED;
+}
+
+/*
+ * Multicast and Promiscuous mode set. The
+ * set_multi entry point is called whenever the
+ * multicast address list or the network interface
+ * flags are updated.
+ */
+static void rm9k_ge_set_multi(struct net_device *netdev)
+{
+       rm9k_ge_port_info * const info = netdev_priv(netdev);
+       u32 reg;
+
+       reg = gpi_readl(info->addr_pktproc + 0x0124);
+
+       if (netdev->flags & IFF_PROMISC) {
+               reg |= 0x2;
+       }
+       else if (netdev->flags & IFF_ALLMULTI) {
+               reg |= 0x401; /* Use the 64-bit Multicast Hash bin */
+       }
+       else {
+               reg = 0x2;

doesn't this code turn on promisc, even in unicast situations?


+       gpi_writel(reg, info->addr_pktproc + 0x0124);
+       if (reg & 0x01) {
+               gpi_writel(0xffff, info->addr_pktproc + 0x0110);
+               gpi_writel(0xffff, info->addr_pktproc + 0x0114);
+               gpi_writel(0xffff, info->addr_pktproc + 0x0118);
+               gpi_writel(0xffff, info->addr_pktproc + 0x011c);

magic numbers, and no comments.  WTF does this code actually do?

Seems like a broken way to program the multicast filter, to me.



+ * Open the network device
+ */
+static int rm9k_ge_open(struct net_device *netdev)
+{
+       rm9k_ge_port_info * const info = netdev_priv(netdev);
+       static const char irqerr[] =
+               KERN_ERR "%s: failed to set up irq %u - error %d\n";
+       int res;
+       u32 reg, xdma_initval;
+       u16 phy_reg;
+       unsigned long end;
+
+       /* Check, if slice in GMII/MII (not TBI) mode */
+       reg = titan_readl(0x0010);
+       if (~reg & (0x100 << info->slice)) {

magic numbers


+               printk(KERN_ERR "Ethernet slice #%u wrong mode\n",
+               info->slice);
+               return -EINVAL;
+       }
+
+       /* Compute the XDMA channel initialization value */
+       xdma_initval = 0x440;
+
+       switch (info->tx_ring_size) {
+               case 512:
+                       break;
+               case 256:
+                       xdma_initval |= 0x10000000;
+                       break;
+               case 128:
+                       xdma_initval |= 0x20000000;
+                       break;
+               case 64:
+                       xdma_initval |= 0x30000000;
+                       break;
+               default:
+                       return -EINVAL;
+       }
+
+       switch (info->rx_ring_size) {
+               case 512:
+                       break;
+               case 256:
+                       xdma_initval |= 0x00010000;
+                       break;
+               case 128:
+                       xdma_initval |= 0x00020000;
+                       break;
+               case 64:
+                       xdma_initval |= 0x00030000;
+                       break;
+               default:
+                       return -EINVAL;
+       }
+
+       /* Set up the GPI interrupt */
+       res = request_irq(netdev->irq, rm9k_ge_main_int_handler,
+                    SA_INTERRUPT | SA_SAMPLE_RANDOM | SA_SHIRQ,
+                    netdev->name, netdev);
+
+       if (res) {
+               printk(irqerr, netdev->name, netdev->irq, -res);
+               return res;
+       }
+
+       /* Set up the PHY interrupt */
+       res = request_irq(info->irq_phy, rm9k_ge_phy_int_handler,
+                    SA_INTERRUPT | SA_SAMPLE_RANDOM,
+                    netdev->name, netdev);
+
+       if (res) {
+               free_irq(netdev->irq, netdev);
+               printk(irqerr, netdev->name, info->irq_phy, -res);
+               return res;
+       }
+
+       /* Set the MAC Address */
+       memcpy(info->port_mac_addr, netdev->dev_addr, ETH_ALEN);
+
+       rm9k_ge_update_afx(info);
+
+       /* Enable the slice */
+       lock_titan_regs();
+       reg = titan_readl(0x0004);
+       reg &= ~(0x30000 << (info->slice * 2));    /* enable slice */
+       reg |= 0x3 << (info->slice * 2);       /* disable DLLs */
+       titan_writel(reg, 0x0004);
+       unlock_titan_regs();
+
+       /* Set up the Tx descriptor ring */
+       gpi_writel((u32) info->tx_dma, info->addr_xdma + 0x0014);
+       info->tx_next_desc = 0;
+
+       /* IR register for the XDMA: no Rx_OOD */
+       gpi_writel(0x80068000, info->addr_xdma + 0x0010);
+
+       /* Start the XDMA controller */
+       gpi_writel(xdma_initval, info->addr_xdma + 0x0000);
+
+       /* Set up the Rx skb queue */
+       res = rm9k_ge_setup_rx_queue(netdev);
+       if (res)
+               return res;
+
+       /* Rx FIFO BAV2,BAV and DAV settings */
+       reg = (info->rxfifo_len << 10) | info->rxfifo_start;
+       gpi_writel(0x100000 | reg, info->addr_fifo_rx + 0x0000);
+       gpi_writel((0x10 << 20) | (0x10 << 10) | 0x1,
+                  info->addr_fifo_rx + 0x0004);
+       gpi_writel(0x200000 | reg, info->addr_fifo_rx + 0x0000);
+
+       /* Tx FIFO BAV2, BAV and DAV settings */
+       reg = (info->txfifo_len << 10) | info->txfifo_start;
+       gpi_writel(0x100000 | reg, info->addr_fifo_tx + 0x0000);
+       gpi_writel((0x1 << 20) | (0x1 << 10) | 0x10,
+                  info->addr_fifo_tx + 0x0004);
+       gpi_writel(0x200000 | reg, info->addr_fifo_tx + 0x0000);

magic numbers galore


+       if (hw_hdr_align) {
+               /*
+                * TRTG block enable
+                * This is the 1.2 revision of the chip. It has a fix for the
+                * IP header alignment. Now, the IP header begins at an
+                * aligned address and this wont need an extra copy in the
+                * driver. This performance drawback existed in the previous
+                * versions of the silicon.
+                */
+               reg = gpi_readl(info->addr_pktproc + 0x003c);
+               reg |= 0x40000000;
+               gpi_writel(reg, info->addr_pktproc + 0x003c);
+
+               reg |= 0x04000000;
+               gpi_writel(reg, info->addr_pktproc + 0x003c);
+               udelay(7);
+               reg &= ~0x04000000;
+               gpi_writel(reg, info->addr_pktproc + 0x003c);
+               udelay(2);

memory barriers / write posting


+               /* Priority & start of range to checksum */
+               gpi_writel(0x00010010 + ((ETH_HLEN + NET_IP_ALIGN) << 8),
+                          info->addr_pktproc + 0x0038);
+
+       } else {
+               /* Priority & start of range to checksum */
+               gpi_writel(0x00010010 + (ETH_HLEN << 8),
+                          info->addr_pktproc + 0x0038);
+       }
+
+       gpi_writel(0x00008001, info->addr_pktproc + 0x0000);
+
+       gpi_writel(0x00000000, info->addr_mac + 0x0028);
+       gpi_writel(0x00000000, info->addr_mac + 0x014c);
+       wmb();
+
+       /* Start the Tx activity */
+       gpi_writel(0xe1b7, info->addr_mac + 0x0044);
+       gpi_writel(rm9k_eth_tx_frame_len(netdev->mtu), info->addr_mac + 0x0058);
+       gpi_writel(RM9K_GE_TMAC_OPTIONS | 0x1, info->addr_mac + 0x0040);
+
+       /* Destination Address drop bit */
+       gpi_writel(0x0009, info->addr_mac + 0x0004);
+       gpi_writel(0x3, info->addr_mac + 0x0018);
+       gpi_writel(rm9k_eth_rx_frame_len(netdev->mtu), info->addr_mac + 0x0008);
+
+       /* Start the Rx activity */
+       gpi_writel(RM9K_GE_RMAC_OPTIONS | 0x1, info->addr_mac + 0x0000);
+
+       lock_titan_regs();
+
+       /* Enable the info->slice interrupts */
+       reg = titan_readl(0x0050);
+       titan_writel(reg | (0x1f << (info->slice * 5)), 0x0050);
+
+       /* Enable the Interrupts for Tx and Rx */
+       reg = titan_readl(0x0058);
+       reg |= 0x3 << (info->slice * 8);
+       titan_writel(reg, 0x0058);
+
+       unlock_titan_regs();
+
+       /* Start the MDIO */
+       rm9k_ge_init_mdio(info->addr_mdio, info->mdio_channel);
+
+       /* Reset the PHY */
+       end = jiffies + HZ;
+       rm9k_ge_mdio_write(PHY_ADDR, RM9K_GE_MDIO_PHY_BMCR, 0x8000);
+       while (time_before(jiffies, end)) {
+               rm9k_ge_mdio_read(PHY_ADDR, RM9K_GE_MDIO_PHY_BMCR, &phy_reg);
+               if (~phy_reg & 0x8000)
+                       break;
+               yield();
+       }
+       if (unlikely(phy_reg & 0x8000)) {
+               free_irq(info->irq_phy, netdev);
+               free_irq(netdev->irq, netdev);
+               printk(KERN_ERR "%s: PHY reset timed out\n", netdev->name);
+               return -ETIME;
+       }
+
+       /* Set up the PHY */
+       if (autoneg) {
+               /* Force the connection to be re-negotiated. */
+               rm9k_ge_mdio_write(PHY_ADDR, RM9K_GE_MDIO_PHY_BMCR, 0x1000);
+               rm9k_ge_mdio_write(PHY_ADDR, RM9K_GE_MDIO_PHY_INTMASK, 0x4010);
+       } else {
+               u32 mac_val = full_duplex ? 0x00000000 : 0x00001000;
+               phy_reg = full_duplex ? 0x0100 : 0x0000;
+
+               switch (speed) {
+                       case speed_1g:
+                               mac_val |= 0x00000200;
+                               phy_reg |= 0x0040;
+                               break;
+                       case speed_100m:
+                               mac_val |= 0x00000100;
+                               phy_reg |= 0x2000;
+                               break;
+               }
+               gpi_writel(mac_val, info->addr_mac + 0x0150);
+               rm9k_ge_mdio_write(PHY_ADDR, RM9K_GE_MDIO_PHY_BMCR, phy_reg);
+               rm9k_ge_mdio_write(PHY_ADDR, RM9K_GE_MDIO_PHY_INTMASK, 0x4000);
+       }
+
+       gpi_writel(0x00000003, info->addr_mac + 0x014c);
+
+       rm9k_ge_mdio_read(PHY_ADDR, RM9K_GE_MDIO_PHY_STATUS, &phy_reg);
+       if (phy_reg & 0x0004) {
+               pr_debug("%s: link is up\n", netdev->name);
+               netif_carrier_on(netdev);
+       } else {
+               pr_debug("%s: link is down\n", netdev->name);
+               netif_carrier_off(netdev);
+       }
+
+       /* Set up statistics gathering */
+       rm9k_ge_update_stats(netdev);
+       mod_timer(&info->stat_timer, jiffies + HZ * 600);
+
+       return 0;
+}
+
+
+
+/*
+ * Close the network device
+ */
+static int rm9k_ge_stop(struct net_device *netdev)
+{
+       rm9k_ge_port_info * const info = netdev_priv(netdev);
+       u32 reg;
+
+       del_timer(&info->stat_timer);

del_timer_sync()


+       /* Reset the XDMA */
+       gpi_writel(0x80080000, info->addr_xdma + 0x0000);
+
+       /* Disable the GMII data paths */
+       gpi_writel(0x00000000, info->addr_mac + 0x014c);
+
+       /* Reset the FIFOs */
+       gpi_writel(0x00100000 | (info->rxfifo_len << 10) | info->rxfifo_start,
+                  info->addr_fifo_rx + 0x0000);
+       gpi_writel(0x00100000 | (info->txfifo_len << 10) | info->txfifo_start,
+                  info->addr_fifo_tx + 0x0000);
+
+       /* Reset the packet processor */
+       gpi_writel(0x00000001, info->addr_pktproc + 0x0000);
+
+       /* Reset RX and TX MACs */
+       gpi_writel(RM9K_GE_RMAC_OPTIONS, info->addr_mac + 0x0000);
+       gpi_writel(RM9K_GE_TMAC_OPTIONS, info->addr_mac + 0x0040);
+
+       /* Power down the PHY */
+       rm9k_ge_mdio_write(PHY_ADDR, RM9K_GE_MDIO_PHY_INTMASK, 0x0000);
+       rm9k_ge_mdio_write(PHY_ADDR, RM9K_GE_MDIO_PHY_BMCR, 0x0800);

magic numbers


+       rm9k_ge_cleanup_mdio(info->mdio_channel);
+
+       /* Disable the Tx and Rx interrupts */
+       lock_titan_regs();
+       reg = titan_readl(0x0058);
+       titan_writel(reg & ~(0xff << (info->slice * 8)), 0x0058);
+       iob();
+       unlock_titan_regs();
+
+       /* Release the interrupts */
+       free_irq(info->irq_phy, netdev);
+       free_irq(netdev->irq, netdev);
+
+       rm9k_ge_free_tx_queue(netdev);
+       rm9k_ge_free_rx_queue(netdev);
+
+       /* Disable the Tx and Rx interrupts */
+       lock_titan_regs();
+       reg = titan_readl(0x0058);
+       titan_writel(reg & ~(0xff << (info->slice * 8)), 0x0058);
+       unlock_titan_regs();
+
+       return 0;
+}
+
+
+
+/*
+ * Set up the skb queue for the RX direction
+ */
+static int rm9k_ge_setup_rx_queue(struct net_device * netdev)
+{
+       rm9k_ge_port_info * const info = netdev_priv(netdev);
+       struct sk_buff_head * const q = &info->rx_queue;
+       rx_desc_t * d;
+
+       if (!skb_queue_empty(q))
+               return -EBUSY;
+
+       spin_lock_irq(&q->lock);

spin_lock_irqsave is preferred -- much less fragile


+       for (d = info->rx_desc_area;
+            d < info->rx_desc_area + info->rx_ring_size;
+            d++) {
+               struct sk_buff * const s =
+                       alloc_skb(rm9k_eth_rx_frame_len(netdev->mtu), 
GFP_KERNEL);
+
+               if (!s) {
+                       __skb_queue_purge(q);
+                       spin_unlock_irq(&q->lock);
+                       return -ENOMEM;
+               }
+
+               d->cpu_part =
+                       dma_map_single(netdev->class_dev.dev, s->data,
+                                      rm9k_eth_rx_frame_len(netdev->mtu),
+                                      DMA_FROM_DEVICE);
+               d->xdma_part = RM9K_GE_RX_BUFFER_OWNED;
+               s->dev = netdev;
+               rm9k_ge_rxdesc_to_skb(s, d);
+               skb_queue_tail(q, s);
+       }
+
+       gpi_writel((unsigned long) info->rx_dma, info->addr_xdma + 0x0018);
+       gpi_writel(info->rx_ring_size, info->addr_xdma + 0x0008);
+       spin_unlock_irq(&q->lock);
+       return 0;
+}
+
+
+
+/*
+ * Free the RX queue
+ */
+static void rm9k_ge_free_rx_queue(struct net_device *netdev)
+{
+       rm9k_ge_port_info * const info = netdev_priv(netdev);
+       u32 reg;
+
+       /* Stop the RX DMA */
+       reg = gpi_readl(info->addr_xdma + 0x0000);
+       gpi_writel(reg | 0x000c0000, info->addr_xdma + 0x0000);
+
+       /* Disable the RMAC */
+       gpi_writel(RM9K_GE_RMAC_OPTIONS, info->addr_mac + 0x0000);
+       iob();
+
+       skb_queue_purge(&info->rx_queue);
+}
+
+
+
+/*
+ * Free the TX queue
+ */
+static void rm9k_ge_free_tx_queue(struct net_device *netdev)
+{
+       rm9k_ge_port_info * const info = netdev_priv(netdev);
+       u32 reg;
+
+       /* Stop the Tx DMA */
+       reg = gpi_readl(info->addr_xdma + 0x0000);
+       gpi_writel(reg | 0xc0000000, info->addr_xdma + 0x0000);
+
+       /* Disable the TMAC */
+       gpi_writel(RM9K_GE_TMAC_OPTIONS, info->addr_mac + 0x0040);
+       iob();
+
+       skb_queue_purge(&info->tx_queue);
+}
+
+
+
+/*
+ * Queue the packet for Tx. Currently no support for zero copy,
+ * checksum offload and Scatter Gather. The chip does support
+ * Scatter Gather only. But, that wont help here since zero copy
+ * requires support for Tx checksumming also.
+ */
+static int rm9k_ge_start_xmit(struct sk_buff *skb, struct net_device *netdev)
+{
+       rm9k_ge_port_info * const info = netdev_priv(netdev);
+
+       struct device *device = netdev->class_dev.dev;
+       const unsigned int curr_desc = info->tx_next_desc;
+       tx_desc_t * const tx_curr = info->tx_desc_area + curr_desc;
+
+       *tx_curr = dma_map_single(device, skb->data, skb->len, DMA_TO_DEVICE)
+                  | ((tx_desc_t) (skb->len & 0x00003fff) << 32)
+                  | (1ULL << 48)
+                  | (1ULL << 53)
+                  | (1ULL << 63);
+
+       rm9k_ge_txdesc_to_skb(skb, tx_curr);
+       skb_queue_tail(&info->tx_queue, skb);
+       info->tx_next_desc = (curr_desc + 1) % info->tx_ring_size;
+       gpi_writel(0x1, info->addr_xdma + 0x0004);
+       netdev->trans_start = jiffies;
+       pr_debug("%s: packet sent\n", netdev->name);

locking against TX completion?


+static struct sk_buff * rm9k_ge_get_rx_skb(rm9k_ge_port_info * info)
+{
+       unsigned long flg;
+       struct sk_buff * s;
+
+       spin_lock_irqsave(&info->rx_queue.lock, flg);
+       s = skb_peek(&info->rx_queue);
+       if (s) {
+               const rx_desc_t * const desc =
+                       rm9k_ge_rxdesc_from_skb(s);
+               s = (desc->xdma_part & RM9K_GE_RX_BUFFER_OWNED)
+                       ? NULL : __skb_dequeue(&info->rx_queue);
+       }
+       spin_unlock_irqrestore(&info->rx_queue.lock, flg);
+

rx queue rarely needs a lock


+#define        TX_THRESHOLD    4
+
+/*
+ * Receive packets and send them to the kernel.
+ */
+static int rm9k_ge_receive_queue(struct net_device *netdev, unsigned int max)
+{
+       rm9k_ge_port_info * const info = netdev_priv(netdev);
+       unsigned long received_packets = 0;
+
+       while (info->rx_work_limit) {
+               static const unsigned int error_mask =
+                       (0x1 << 27) | (0x1 << 20) | (0x1 << 19) | (0x1 << 15);
+               struct sk_buff * skb_reuse;
+               unsigned int len, cmd_sts, checksum;
+               rx_desc_t * desc;
+
+               struct sk_buff * skb = rm9k_ge_get_rx_skb(info);
+               if (!skb)
+                       break;
+
+               info->rx_work_limit--;
+               pr_debug("%s: packet received\n", netdev->name);
+
+               desc = rm9k_ge_rxdesc_from_skb(skb);
+               dma_unmap_single(netdev->class_dev.dev, desc->cpu_part,
+                                rm9k_eth_rx_frame_len(netdev->mtu),
+                                DMA_FROM_DEVICE);
+               len = (desc->xdma_part >> 32) & 0x7fff;
+               cmd_sts = desc->xdma_part >> 32;
+               checksum = ntohs((desc->xdma_part >> 16) & 0x0000ffff);
+
+               if (cmd_sts & error_mask) {
+                       info->stats.rx_errors++;
+                       desc->cpu_part =
+                               dma_map_single(netdev->class_dev.dev,
+                                              skb->data,
+                                              
rm9k_eth_rx_frame_len(netdev->mtu),
+                                              DMA_FROM_DEVICE);
+                       desc->xdma_part = RM9K_GE_RX_BUFFER_OWNED;
+                       skb_queue_tail(&info->rx_queue, skb);
+                       gpi_writel(1, info->addr_xdma + 0x0008);
+                       continue;
+               }
+
+               received_packets++;
+
+               if (hw_hdr_align) {
+                       /* Hardware header alignment supported */
+                       skb_reuse = 
alloc_skb(rm9k_eth_rx_frame_len(netdev->mtu),
+                                             GFP_ATOMIC);
+                       if (skb_reuse) {
+                               skb_reserve(skb, NET_IP_ALIGN);
+                               skb_put(skb, len - NET_IP_ALIGN);
+                       } else {
+                               skb_reuse = skb;
+                               skb = NULL;
+                       }
+               } else {
+                       /* Header alignment must be done in software */
+                       skb_reuse = skb;
+
+                       skb = alloc_skb(len + NET_IP_ALIGN, GFP_ATOMIC);

dev_alloc_skb()


+                       if (skb) {
+                               skb->dev = netdev;
+                               skb_reserve(skb, NET_IP_ALIGN);
+                               skb_put(skb, len);
+                               memcpy(skb->data, skb_reuse->data, len);
+                       }
+               }
+
+               if (skb) {
+                       skb->ip_summed = CHECKSUM_HW;
+                       skb->csum = checksum;
+                       skb->protocol = eth_type_trans(skb, netdev);
+                       netif_receive_skb(skb);
+               } else {
+                       info->stats.rx_dropped++;
+               }
+
+               desc->cpu_part =
+                       dma_map_single(netdev->class_dev.dev, skb_reuse->data,
+                                      rm9k_eth_rx_frame_len(netdev->mtu),
+                                      DMA_FROM_DEVICE);
+               desc->xdma_part = RM9K_GE_RX_BUFFER_OWNED;
+               skb_reuse->dev = netdev;
+               rm9k_ge_rxdesc_to_skb(skb_reuse, desc);
+               skb_queue_tail(&info->rx_queue, skb_reuse);
+               gpi_writel(1, info->addr_xdma + 0x0008);
+       }
+
+       return received_packets;
+}
+
+
+
+/*
+ * Main function to handle the polling for Rx side NAPI.
+ * Receive interrupts have been disabled at this point.
+ */
+static int rm9k_ge_poll(struct net_device *netdev, int *budget)
+{
+       rm9k_ge_port_info * const info = netdev_priv(netdev);
+       int work_done = 0;
+       unsigned long flags;
+       u32 reg;
+       const u32 mask = 0x1 << (info->slice * 8);
+
+       info->rx_work_limit = *budget;
+       if (info->rx_work_limit > netdev->quota)
+               info->rx_work_limit = netdev->quota;
+
+       do {
+               work_done += rm9k_ge_receive_queue(netdev, 0);
+
+               /* Out of quota and there is work to be done */
+               if (info->rx_work_limit < 0) {
+                       *budget -= work_done;
+                       netdev->quota -= work_done;
+                       return 1;
+               }
+
+               reg = (titan_readl(0x0048) | titan_readl(0x004c)) & mask;
+               titan_writel(reg, 0x0048);
+               titan_writel(reg, 0x004c);
+       } while (reg);
+
+       /*
+        * No more packets on the poll list. Turn the interrupts
+        * back on and we should be able to catch the new
+        * packets in the interrupt handler
+        */
+       if (!work_done)
+               work_done = 1;
+
+       *budget -= work_done;
+       netdev->quota -= work_done;
+
+       spin_lock_irqsave(&info->lock, flags);
+
+       /* Remove us from the poll list */
+       netif_rx_complete(netdev);
+
+       spin_unlock_irqrestore(&info->lock, flags);
+
+       /* Re-enable interrupts */
+       lock_titan_regs();
+       reg = titan_readl(0x0058);
+       titan_writel(reg | mask, 0x0058);
+       unlock_titan_regs();
+
+       return 0;
+}
+
+
+
+static inline unsigned long long rm9k_ge_sctr(void __iomem * p)
+{
+       return  ((unsigned long long) (gpi_readl(p + 8) & 0x0000ffff) << 32)
+               | ((unsigned long long) (gpi_readl(p + 4) & 0x0000ffff) << 16)
+               | (gpi_readl(p) & 0x0000ffff);
+}
+
+
+
+static void rm9k_ge_update_stats(struct net_device *netdev)
+{
+       unsigned long flg;
+       unsigned long long good_rx_frames, total_rx_frames;
+       rm9k_ge_port_info * const info = netdev_priv(netdev);
+       struct net_device_stats * const s = &info->stats;
+
+       spin_lock_irqsave(&info->stat_lock, flg);
+
+       /* Latch and clear counters */
+       gpi_writel(0x00000022, info->addr_mstat + 0x0028);
+       iob();
+
+       good_rx_frames = rm9k_ge_sctr(info->addr_mstat + 0x0040),
+       total_rx_frames = rm9k_ge_sctr(info->addr_mstat + 0x0060);
+
+       s->rx_packets += good_rx_frames;
+       s->rx_bytes += rm9k_ge_sctr(info->addr_mstat + 0x0050);
+       s->rx_errors +=  total_rx_frames - good_rx_frames;
+       s->multicast += rm9k_ge_sctr(info->addr_mstat + 0x00a0);
+       s->rx_crc_errors += rm9k_ge_sctr(info->addr_mstat + 0x00e0);
+       s->rx_frame_errors += rm9k_ge_sctr(info->addr_mstat + 0x00f0);
+       s->rx_length_errors += rm9k_ge_sctr(info->addr_mstat + 0x0120)
+                               + rm9k_ge_sctr(info->addr_mstat + 0x0130)
+                               + rm9k_ge_sctr(info->addr_mstat + 0x0140)
+                               + rm9k_ge_sctr(info->addr_mstat + 0x0150)
+                               + rm9k_ge_sctr(info->addr_mstat + 0x0160);
+
+       s->tx_packets += rm9k_ge_sctr(info->addr_mstat + 0x0250);
+       s->tx_bytes += rm9k_ge_sctr(info->addr_mstat + 0x0260);
+
+       spin_unlock_irqrestore(&info->stat_lock, flg);
+       mod_timer(&info->stat_timer, jiffies + HZ * 600);
+}
+
+
+
+/*
+ * Update the MAC address. Note that we have to write the
+ * address in three station registers, 16 bits each. And this
+ * has to be done for TMAC and RMAC
+ */
+static void rm9k_ge_update_mac_address(struct net_device *netdev)
+{
+       rm9k_ge_port_info *const info = netdev_priv(netdev);
+       u8 p_addr[6];
+
+       memcpy(info->port_mac_addr, netdev->dev_addr, ETH_ALEN);
+       memcpy(p_addr, netdev->dev_addr, ETH_ALEN);
+
+       /* Update the Address Filtering Match tables */
+       rm9k_ge_update_afx(info);
+
+       pr_debug("%s: station MAC : %d %d %d %d %d %d\n",
+                netdev->name,
+                p_addr[5], p_addr[4], p_addr[3],
+                p_addr[2], p_addr[1], p_addr[0]);
+
+       /* Set the MAC address here for TMAC and RMAC */
+       gpi_writel((p_addr[5] << 8) | p_addr[4], info->addr_mac + 0x004c);
+       gpi_writel((p_addr[3] << 8) | p_addr[2], info->addr_mac + 0x0050);
+       gpi_writel((p_addr[1] << 8) | p_addr[0], info->addr_mac + 0x0054);
+
+       gpi_writel((p_addr[5] << 8) | p_addr[4], info->addr_mac + 0x000c);
+       gpi_writel((p_addr[3] << 8) | p_addr[2], info->addr_mac + 0x0010);
+       gpi_writel((p_addr[1] << 8) | p_addr[0], info->addr_mac + 0x0014);


+ * Set the MAC address of the Ethernet device
+ */
+static int rm9k_ge_set_mac_address(struct net_device *netdev, void *addr)
+{
+       rm9k_ge_port_info * const info = netdev_priv(netdev);
+       struct sockaddr *sa = addr;
+
+       memcpy(netdev->dev_addr, sa->sa_data, netdev->addr_len);
+
+       spin_lock_irq(&info->lock);
+       rm9k_ge_update_mac_address(netdev);
+       spin_unlock_irq(&info->lock);
+
+       return 0;
+}
+
+#if defined(CONFIG_NET_POLL_CONTROLLER)
+/*
+ * Netpoll support
+ */
+static void rm9k_ge_netpoll(struct net_device *netdev)
+{
+       rm9k_ge_main_int_handler(netdev->irq, netdev, NULL);
+}
+#endif
+
+
+
+/*
+ * Get the Ethernet device stats
+ */
+static struct net_device_stats * rm9k_ge_get_stats(struct net_device *netdev)
+{
+       rm9k_ge_port_info * const info = netdev_priv(netdev);
+       rm9k_ge_update_stats(netdev);
+       return &info->stats;
+}
+
+/*
+ * Initialize the device as an Ethernet device
+ */
+static int __init rm9k_ge_probe(struct device *dev)
+{
+       int err;
+       unsigned int n_desc, n_rx, n_tx;
+       struct platform_device * pdv;
+       struct net_device * netdev;
+       rm9k_ge_port_info * info;
+       const struct resource
+               *rsrc_slice, *rsrc_phy, *rsrc_rxdma, *rsrc_txdma,
+               *rsrc_fifomem_rx, *rsrc_fifomem_tx, *rsrc_mac,
+               *rsrc_mstat, *rsrc_pktproc, *rsrc_xdma, *rsrc_mdio,
+               *rsrc_fifo_rx, *rsrc_fifo_tx, *rsrc_irq_main, *rsrc_irq_phy;
+
+       /* Get the platform dev. */
+       if (unlikely(dev->bus != &platform_bus_type)) {
+               err = -ENODEV;
+               goto out;
+       }
+
+       pdv = to_platform_device(dev);
+
+       rsrc_slice = rm9k_get_resource(pdv, 0, RM9K_GE_RESOURCE_GPI_SLICE);
+       rsrc_phy = rm9k_get_resource(pdv, IORESOURCE_MEM, RM9K_GE_RESOURCE_PHY);
+       rsrc_rxdma = rm9k_get_resource(pdv, IORESOURCE_MEM, 
RM9K_GE_RESOURCE_DMADESC_RX);
+       rsrc_txdma = rm9k_get_resource(pdv, IORESOURCE_MEM, 
RM9K_GE_RESOURCE_DMADESC_TX);
+       rsrc_fifomem_rx = rm9k_get_resource(pdv, 0,RM9K_GE_RESOURCE_FIFOMEM_RX);
+       rsrc_fifomem_tx = rm9k_get_resource(pdv, 0,RM9K_GE_RESOURCE_FIFOMEM_TX);
+       rsrc_mac = rm9k_get_resource(pdv, IORESOURCE_MEM, RM9K_GE_RESOURCE_MAC);
+       rsrc_mstat = rm9k_get_resource(pdv, IORESOURCE_MEM, 
RM9K_GE_RESOURCE_MSTAT);
+       rsrc_pktproc = rm9k_get_resource(pdv, IORESOURCE_MEM, 
RM9K_GE_RESOURCE_PKTPROC);
+       rsrc_xdma = rm9k_get_resource(pdv, IORESOURCE_MEM, 
RM9K_GE_RESOURCE_XDMA);
+       rsrc_mdio = rm9k_get_resource(pdv, 0, RM9K_GE_RESOURCE_MDIO_CHANNEL);
+       rsrc_fifo_rx = rm9k_get_resource(pdv, IORESOURCE_MEM, 
RM9K_GE_RESOURCE_FIFO_RX);
+       rsrc_fifo_tx = rm9k_get_resource(pdv, IORESOURCE_MEM, 
RM9K_GE_RESOURCE_FIFO_TX);
+       rsrc_irq_main = rm9k_get_resource(pdv, IORESOURCE_IRQ, 
RM9K_GE_RESOURCE_IRQ_MAIN);
+       rsrc_irq_phy = rm9k_get_resource(pdv, IORESOURCE_IRQ, 
RM9K_GE_RESOURCE_IRQ_PHY);
+
+       if (!rsrc_slice || !rsrc_phy || !rsrc_rxdma || !rsrc_fifo_rx
+           || !rsrc_fifo_tx || !rsrc_txdma || !rsrc_fifomem_rx
+           || !rsrc_mstat || !rsrc_fifomem_tx || !rsrc_mac || !rsrc_mdio
+           || !rsrc_pktproc || !rsrc_xdma || !rsrc_irq_main
+           || !rsrc_irq_phy) {
+               err = -ENODEV;
+               goto out;
+       }

leak, if some succeed but others fail


+       /* Compute RX and TX ring sizes */
+       n_desc = (rsrc_rxdma->end - rsrc_rxdma->start + 1) / sizeof (rx_desc_t);
+       switch (n_desc) {
+               case 64 ... 127:
+                       n_rx = 64;
+                       break;
+               case 128 ... 255:
+                       n_rx = 128;
+                       break;
+               case 256 ... 511:
+                       n_rx = 256;
+                       break;
+               default:
+                       n_rx = (n_desc >= 512) ? 512 : 0;
+                       break;
+       }
+
+       n_desc = (rsrc_txdma->end - rsrc_txdma->start + 1) / sizeof (tx_desc_t);
+       switch (n_desc) {
+               case 64 ... 127:
+                       n_tx = 64;
+                       break;
+               case 128 ... 255:
+                       n_tx = 128;
+                       break;
+               case 256 ... 511:
+                       n_tx = 256;
+                       break;
+               default:
+                       n_tx = (n_desc >= 512) ? 512 : 0;
+                       break;
+       }
+       if ((!n_rx || !n_tx)) {
+               err = -EINVAL;
+               goto out;
+       }
+
+       netdev = alloc_etherdev(sizeof(rm9k_ge_port_info)
+                               + (n_rx + n_tx) * sizeof (struct sk_buff *));

add some parens for increased readability


+       if (!netdev) {
+               err = -ENODEV;
+               goto out;
+       }
+
+       dev_set_drvdata(dev, netdev);
+       SET_NETDEV_DEV(netdev, dev);
+       netdev->irq = rsrc_irq_main->start;
+       netdev->open = rm9k_ge_open;
+       netdev->stop = rm9k_ge_stop;
+       netdev->hard_start_xmit = rm9k_ge_start_xmit;
+       netdev->get_stats = rm9k_ge_get_stats;
+       netdev->set_multicast_list = rm9k_ge_set_multi;
+       netdev->set_mac_address = rm9k_ge_set_mac_address;
+       netdev->mtu = ETH_DATA_LEN;
+#if defined(CONFIG_NET_POLL_CONTROLLER)
+       netdev->poll_controller = rm9k_ge_netpoll;
+#endif
+
+       /* Tx timeout */
+       netdev->tx_timeout = rm9k_ge_tx_timeout;
+       netdev->watchdog_timeo = 2 * HZ;
+
+       /* Set these to very high values */
+       netdev->poll = rm9k_ge_poll;
+       netdev->weight = 64;
+       netdev->base_addr = 0;
+
+       netdev->change_mtu = rm9k_ge_change_mtu;
+
+       info = netdev_priv(netdev);
+       spin_lock_init(&info->stat_lock);
+       init_timer(&info->stat_timer);
+       info->stat_timer.function = (void *) rm9k_ge_update_stats;
+       info->stat_timer.data = (unsigned long) netdev;
+
+       skb_queue_head_init(&info->rx_queue);
+       skb_queue_head_init(&info->tx_queue);
+
+       info->irq_phy = rsrc_irq_phy->start;
+       info->port_num = pdv->id;
+       info->slice = rsrc_slice->start;
+       info->mdio_channel = rsrc_mdio->start;
+
+       info->addr_mdio = ioremap_nocache(
+               rsrc_phy->start, rsrc_phy->end + 1 - rsrc_phy->start);

check for NULL return value, handle error


+       /* Set up RX descriptor ring */
+       info->rx_ring_size = n_rx;
+       info->rx_desc_area = (rx_desc_t *) ioremap_nocache(
+               rsrc_rxdma->start, n_rx * sizeof (rx_desc_t *));
+       info->rx_dma = (dma_addr_t) rsrc_rxdma->start;
+
+       /* Set up the TX descriptor ring */
+       info->tx_ring_size = n_tx;
+       info->tx_desc_area = (tx_desc_t *) ioremap_nocache(
+               rsrc_txdma->start, n_tx * sizeof (tx_desc_t *));
+       info->tx_dma = (dma_addr_t) rsrc_txdma->start;
+
+       /* Set up the RX and TX FIFOs */
+       info->rxfifo_start = rsrc_fifomem_rx->start;
+       info->rxfifo_len = rsrc_fifomem_rx->end + 1 - rsrc_fifomem_rx->start;
+       info->txfifo_start = rsrc_fifomem_tx->start;
+       info->txfifo_len = rsrc_fifomem_tx->end + 1 - rsrc_fifomem_tx->start;
+
+       info->addr_mac = ioremap_nocache(
+               rsrc_mac->start, rsrc_mac->end + 1 - rsrc_mac->start);
+       info->addr_pktproc = ioremap_nocache(
+               rsrc_pktproc->start,
+               rsrc_pktproc->end + 1 - rsrc_pktproc->start);
+       info->addr_xdma = ioremap_nocache(
+               rsrc_xdma->start, rsrc_xdma->end + 1 - rsrc_xdma->start);
+       info->addr_mstat = ioremap_nocache(
+               rsrc_mstat->start, rsrc_mstat->end + 1 - rsrc_mstat->start);
+       info->addr_fifo_rx = ioremap_nocache(
+               rsrc_fifo_rx->start,
+               rsrc_fifo_rx->end + 1 - rsrc_fifo_rx->start);
+       info->addr_fifo_tx = ioremap_nocache(
+               rsrc_fifo_tx->start,
+               rsrc_fifo_tx->end + 1 - rsrc_fifo_tx->start);

check all these for NULL, handle failure


+       spin_lock_init(&info->lock);
+
+       /* set MAC addresses */
+       memcpy(netdev->dev_addr, hwaddr, ETH_ALEN);
+
+       err = register_netdev(netdev);
+
+       if (err)
+               goto out_free_netdev;
+
+       return 0;
+
+out_free_netdev:
+       if (info->addr_mdio) iounmap(info->addr_mdio);
+       if (info->rx_desc_area) iounmap(info->rx_desc_area);
+       if (info->tx_desc_area) iounmap(info->tx_desc_area);
+       if (info->addr_mac) iounmap(info->addr_mac);
+       if (info->addr_pktproc) iounmap(info->addr_pktproc);
+       if (info->addr_xdma) iounmap(info->addr_xdma);
+       if (info->addr_mstat) iounmap(info->addr_mstat);
+       if (info->addr_fifo_rx) iounmap(info->addr_fifo_rx);
+       if (info->addr_fifo_tx) iounmap(info->addr_fifo_tx);
+       kfree(netdev);
+
+out:
+       return err;
+}
+
+static int __exit rm9k_ge_remove(struct device *dev)
+{
+       struct net_device * const netdev =
+               (struct net_device *) dev_get_drvdata(dev);
+       unregister_netdev(netdev);
+       free_netdev(netdev);
+       return 0;
+}
+
+static struct device_driver rm9k_ge_driver = {
+       .name   = RM9K_GE_NAME,
+       .bus    = &platform_bus_type,
+       .probe  = rm9k_ge_probe,
+       .remove = __exit_p(rm9k_ge_remove)
+};
+
+static void rm9k_ge_init_mdio(void * addr, unsigned int chan)
+{
+       u32 reg;
+
+       /* Take the MDIO channel out of reset */
+       lock_titan_regs();
+       reg = titan_readl(0x0004);
+       reg &= ~(0x1 << (11 + chan));
+       titan_writel(reg, 0x0004);
+       unlock_titan_regs();
+       iob();
+
+       if(rm9k_ge_mdio_setup(addr, 0x1f)) {
+               lock_titan_regs();
+               reg = titan_readl(0x0004);
+               reg |= 0x1 << (11 + chan);
+               titan_writel(reg, 0x0004);
+               unlock_titan_regs();
+               iob();
+       }
+}
+
+static void rm9k_ge_cleanup_mdio(unsigned int chan)
+{
+       u32 reg;
+       rm9k_ge_mdio_cleanup();
+
+       /* Reset the MDIO channel */
+       lock_titan_regs();
+       reg = titan_readl(0x0004);
+       reg |= 0x1 << (11 + chan);
+       titan_writel(reg, 0x0004);
+       unlock_titan_regs();
+}
+
+/*
+ * Register the Titan GE with the kernel
+ */
+static int __init rm9k_ge_init_module(void)
+{
+       unsigned int rev;
+
+       rev = read_c0_prid() & 0x000000ff;
+       hw_hdr_align = rev > 0x30;
+
+       if (driver_register(&rm9k_ge_driver)) {
+               printk(KERN_ERR "%s: Driver registration failed\n",
+                      rm9k_ge_name);
+               return 1;
+       }
+
+       printk(KERN_NOTICE "%s: RM9K Gigabit Ethernet Driver loaded "
+              "(H/W rev. %#04x)\n",
+              rm9k_ge_name, rev);
+       return 0;
+}
+
+/*
+ * Unregister the Titan GE from the kernel
+ */
+static void __exit rm9k_ge_cleanup_module(void)
+{
+       driver_unregister(&rm9k_ge_driver);
+}
+
+MODULE_AUTHOR("Thomas Koeller <[EMAIL PROTECTED]>");
+MODULE_DESCRIPTION("Rm9k gigabit ethernet driver");
+MODULE_LICENSE("GPL");
+
+MODULE_PARM_DESC(autoneg, "Enable speed/duplex autonegotiation (bool)");
+MODULE_PARM_DESC(full_duplex, "Force full/half duplex mode (bool)");
+MODULE_PARM_DESC(speed, "Force speed (0 - 10MBit, 1 - 100MBit, 2 - 1GBit)");
+MODULE_PARM_DESC(hwaddr, "Ethernet address (xx:xx:xx:xx:xx:xx)");
+
+module_init(rm9k_ge_init_module);
+module_exit(rm9k_ge_cleanup_module);
Index: linux-excite/drivers/net/rm9k_mdio.c
===================================================================
--- /dev/null   1970-01-01 00:00:00.000000000 +0000
+++ linux-excite/drivers/net/rm9k_mdio.c        2006-06-23 13:28:55.000000000 
+0100
@@ -0,0 +1,165 @@
+/*
+ * drivers/net/titan_mdio.c - Driver for Titan ethernet ports
+ *
+ * Copyright (C) 2003 PMC-Sierra Inc.
+ * Author : Manish Lachwani ([EMAIL PROTECTED])
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ *
+ * Management Data IO (MDIO) driver for the Titan GMII. Interacts with the 
Marvel PHY
+ * on the Titan. No support for the TBI as yet.
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/ioport.h>
+#include <asm/io.h>
+#include <asm/delay.h>
+
+#include "rm9k_mdio.h"
+
+#define MDIO_DEBUG
+
+#define gpi_readl(__a__)               __raw_readl((__a__))
+#define gpi_writel(__v__, __a__)       __raw_writel((__v__), (__a__))
+
+/*
+ * Local constants
+ */
+#define MAX_CLKA               1023
+#define MAX_PHY_DEV            31
+#define MAX_PHY_REG            31
+#define        READ_OPCODE             (0x2 << 8)
+#define WRITE_OPCODE           (0x1 << 8)
+#define MAX_MDIO_POLL          100
+
+/*
+ * Titan MDIO and SCMB register offsets
+ */
+#define SCMB_CONTROL                   0x00  /* SCMB Control */
+#define SCMB_CLKA                      0x04  /* SCMB Clock A */
+#define MDIO_COMMAND                   0x10  /* MDIO Command */
+#define MDIO_DEVICE_PORT_ADDRESS       0x14  /* MDIO Device and Port addrs */
+#define MDIO_DATA                      0x18  /* MDIO Data */
+#define MDIO_INTERRUPTS                        0x1c  /* MDIO Interrupts */
+
+void __iomem * base = NULL;
+
+/*
+ * Function to poll the MDIO
+ */
+static int mdio_poll(void)
+{
+       int i;
+
+       for (i = 0; i < MAX_MDIO_POLL; i++) {
+               if(!(gpi_readl(base + MDIO_COMMAND) & 0x8000))
+                       break;
+               udelay(10);
+       }
+
+       return i >= MAX_MDIO_POLL;
+}
+
+/*
+ * Initialize and configure the MDIO
+ */
+int rm9k_ge_mdio_setup(void __iomem * addr, unsigned int clka)
+{
+       if (base)
+               return -1;
+
+       base = addr;
+
+       /* Reset the SCMB and program into MDIO mode*/
+       gpi_writel(0x9000, base + SCMB_CONTROL);
+       wmb();
+       gpi_writel(0x1000, base + SCMB_CONTROL);
+       wmb();
+
+       /* CLK A */
+       gpi_writel(clka & 0x3ff, base + SCMB_CLKA);
+
+       pr_debug("%s(%p, %u)\n"
+                "\tSCMB_CONTROL (%p) = %#010x\n",
+                __func__, addr, clka, base + SCMB_CLKA,
+                gpi_readl(base + SCMB_CLKA));
+
+       return 0;
+}
+
+void rm9k_ge_mdio_cleanup(void)
+{
+       base = 0;
+}
+
+/*
+ * Read the MDIO register. This is what the individual parametes mean:
+ *
+ * dev_addr : PHY ID
+ * reg_addr : register offset
+ *
+ * See the spec for the Titan MAC. We operate in the Direct Mode.
+ */
+
+#define MAX_RETRIES    2
+
+int rm9k_ge_mdio_read(int dev_addr, int reg_addr, u16 *pdata)
+{
+       u32 val;
+       int retries;
+
+       for (retries = 0; retries < MAX_RETRIES; retries++) {
+               gpi_writel(((dev_addr << 8) & 0x1f00)
+                            | ( reg_addr & 0x001f) | 0x4000,
+                            base + MDIO_DEVICE_PORT_ADDRESS);
+                            wmb();
+               gpi_writel(READ_OPCODE | 0x1, base + MDIO_COMMAND);
+               if (mdio_poll())
+                       return -1;
+               *pdata = (unsigned int)
+                        (gpi_readl(base + MDIO_DATA) & 0x0000ffff);
+               val = gpi_readl(base + MDIO_INTERRUPTS);
+               if (~val & 0x2)
+                       return 0;
+               udelay(30);
+       }
+
+       return -1;
+}
+
+/*
+ * Write to the MDIO register
+ *
+ * dev_addr : PHY ID
+ * reg_addr : register that needs to be written to
+ *
+ */
+int rm9k_ge_mdio_write(int dev_addr, int reg_addr, u16 data)
+{
+       if (mdio_poll())
+               return -1;
+
+       gpi_writel(((dev_addr << 8) & 0x1f00)
+                    | (reg_addr & 0x001f) | 0x4000,
+                    base + MDIO_DEVICE_PORT_ADDRESS);
+       gpi_writel(data, base + MDIO_DATA);
+       wmb();
+       gpi_writel(WRITE_OPCODE | 0x1, base + MDIO_COMMAND);
+       if (mdio_poll())
+               return -1;
+
+       return  (gpi_readl(base + MDIO_INTERRUPTS) & 0x2) ? -1 : 0;
+}
Index: linux-excite/drivers/net/rm9k_mdio.h
===================================================================
--- /dev/null   1970-01-01 00:00:00.000000000 +0000
+++ linux-excite/drivers/net/rm9k_mdio.h        2006-06-23 13:28:55.000000000 
+0100
@@ -0,0 +1,36 @@
+/*
+ * MDIO used to interact with the PHY when using GMII/MII
+ */
+#ifndef _RM9K_MDIO_H
+#define _RM9K_MDIO_H
+
+#include <asm/types.h>
+
+
+/* GMII specific registers */
+#define RM9K_GE_MDIO_PHY_BMCR          0x00
+#define RM9K_GE_MDIO_PHY_BMSR          0x01
+#define RM9K_GE_MDIO_PHY_ID_HI         0x02
+#define RM9K_GE_MDIO_PHY_ID_LO         0x03
+#define        RM9K_PHY_AUTONEG_ADV            0x04
+#define        RM9K_PHY_LP_ABILITY             0x05
+#define        RM9K_GE_MDIO_MII_CTRL           0x09
+#define        RM9K_GE_MDIO_MII_EXTENDED       0x0f
+#define        RM9K_GE_MDIO_PHY_CTRL           0x10
+#define        RM9K_GE_MDIO_PHY_STATUS         0x11
+#define        RM9K_GE_MDIO_PHY_INTSTAT        0x14
+#define        RM9K_GE_MDIO_PHY_INTMASK        0x15
+#define        RM9K_GE_MDIO_PHY_INTCLEAR       0x17
+#define        RM9K_GE_MDIO_PHY_LED            0x18
+#define        RM9K_GE_MDIO_PHY_LED_OVER       0x19
+
+/*
+ * Function Prototypes
+ */
+int rm9k_ge_mdio_setup(void *, unsigned int);
+void rm9k_ge_mdio_cleanup(void);
+unsigned long rm9k_ge_mdio_ident_phy(int);
+int rm9k_ge_mdio_read(int, int, u16 *);
+int rm9k_ge_mdio_write(int, int, u16);
+
+#endif /* _RM9K_MDIO_H */


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