source: bootcd/isolinux/syslinux-6.03/gpxe/src/drivers/net/legacy.c

#include <stdint.h>
#include <stdio.h>
#include <errno.h>
#include <gpxe/if_ether.h>
#include <gpxe/netdevice.h>
#include <gpxe/ethernet.h>
#include <gpxe/iobuf.h>
#include <nic.h>

/*
 * Quick and dirty compatibility layer
 *
 * This should allow old-API PCI drivers to at least function until
 * they are updated.  It will not help non-PCI drivers.
 *
 * No drivers should rely on this code.  It will be removed asap.
 *
 */

FILE_LICENCE ( GPL2_OR_LATER );

struct nic nic;

static int legacy_registered = 0;

static int legacy_transmit ( struct net_device *netdev, struct io_buffer *iobuf ) {
        struct nic *nic = netdev->priv;
        struct ethhdr *ethhdr;

        DBG ( "Transmitting %zd bytes\n", iob_len ( iobuf ) );
        iob_pad ( iobuf, ETH_ZLEN );
        ethhdr = iobuf->data;
        iob_pull ( iobuf, sizeof ( *ethhdr ) );
        nic->nic_op->transmit ( nic, ( const char * ) ethhdr->h_dest,
                                ntohs ( ethhdr->h_protocol ),
                                iob_len ( iobuf ), iobuf->data );
        netdev_tx_complete ( netdev, iobuf );
        return 0;
}

static void legacy_poll ( struct net_device *netdev ) {
        struct nic *nic = netdev->priv;
        struct io_buffer *iobuf;

        iobuf = alloc_iob ( ETH_FRAME_LEN );
        if ( ! iobuf )
                return;

        nic->packet = iobuf->data;
        if ( nic->nic_op->poll ( nic, 1 ) ) {
                DBG ( "Received %d bytes\n", nic->packetlen );
                iob_put ( iobuf, nic->packetlen );
                netdev_rx ( netdev, iobuf );
        } else {
                free_iob ( iobuf );
        }
}

static int legacy_open ( struct net_device *netdev __unused ) {
        /* Nothing to do */
        return 0;
}

static void legacy_close ( struct net_device *netdev __unused ) {
        /* Nothing to do */
}

static void legacy_irq ( struct net_device *netdev __unused, int enable ) {
        struct nic *nic = netdev->priv;

        nic->nic_op->irq ( nic, ( enable ? ENABLE : DISABLE ) );
}

static struct net_device_operations legacy_operations = {
        .open           = legacy_open,
        .close          = legacy_close,
        .transmit       = legacy_transmit,
        .poll           = legacy_poll,
        .irq            = legacy_irq,
};

int legacy_probe ( void *hwdev,
                   void ( * set_drvdata ) ( void *hwdev, void *priv ),
                   struct device *dev,
                   int ( * probe ) ( struct nic *nic, void *hwdev ),
                   void ( * disable ) ( struct nic *nic, void *hwdev ) ) {
        struct net_device *netdev;
        int rc;

        if ( legacy_registered )
                return -EBUSY;
        
        netdev = alloc_etherdev ( 0 );
        if ( ! netdev )
                return -ENOMEM;
        netdev_init ( netdev, &legacy_operations );
        netdev->priv = &nic;
        memset ( &nic, 0, sizeof ( nic ) );
        set_drvdata ( hwdev, netdev );
        netdev->dev = dev;

        nic.node_addr = netdev->hw_addr;
        nic.irqno = dev->desc.irq;

        if ( ! probe ( &nic, hwdev ) ) {
                rc = -ENODEV;
                goto err_probe;
        }

        /* Overwrite the IRQ number.  Some legacy devices set
         * nic->irqno to 0 in the probe routine to indicate that they
         * don't support interrupts; doing this allows the timer
         * interrupt to be used instead.
         */
        dev->desc.irq = nic.irqno;

        /* Mark as link up; legacy devices don't handle link state */
        netdev_link_up ( netdev );

        if ( ( rc = register_netdev ( netdev ) ) != 0 )
                goto err_register;

        /* Do not remove this message */
        printf ( "WARNING: Using legacy NIC wrapper on %s\n",
                 netdev->ll_protocol->ntoa ( nic.node_addr ) );

        legacy_registered = 1;
        return 0;

 err_register:
        disable ( &nic, hwdev );
 err_probe:
        netdev_nullify ( netdev );
        netdev_put ( netdev );
        return rc;
}

void legacy_remove ( void *hwdev,
                     void * ( * get_drvdata ) ( void *hwdev ),
                     void ( * disable ) ( struct nic *nic, void *hwdev ) ) {
        struct net_device *netdev = get_drvdata ( hwdev );
        struct nic *nic = netdev->priv;

        unregister_netdev ( netdev );
        disable ( nic, hwdev );
        netdev_nullify ( netdev );
        netdev_put ( netdev );
        legacy_registered = 0;
}

int dummy_connect ( struct nic *nic __unused ) {
        return 1;
}

void dummy_irq ( struct nic *nic __unused, irq_action_t irq_action __unused ) {
        return;
}