515 lines
12 KiB
C
515 lines
12 KiB
C
/*
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* Simulated Ethernet Driver
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*
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* Copyright (C) 1999-2001, 2003 Hewlett-Packard Co
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* Stephane Eranian <eranian@hpl.hp.com>
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*/
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/types.h>
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#include <linux/in.h>
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#include <linux/string.h>
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#include <linux/init.h>
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#include <linux/errno.h>
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#include <linux/interrupt.h>
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#include <linux/netdevice.h>
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#include <linux/etherdevice.h>
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#include <linux/inetdevice.h>
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#include <linux/if_ether.h>
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#include <linux/if_arp.h>
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#include <linux/skbuff.h>
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#include <linux/notifier.h>
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#include <linux/bitops.h>
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#include <asm/system.h>
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#include <asm/irq.h>
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#include <asm/hpsim.h>
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#include "hpsim_ssc.h"
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#define SIMETH_RECV_MAX 10
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/*
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* Maximum possible received frame for Ethernet.
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* We preallocate an sk_buff of that size to avoid costly
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* memcpy for temporary buffer into sk_buff. We do basically
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* what's done in other drivers, like eepro with a ring.
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* The difference is, of course, that we don't have real DMA !!!
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*/
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#define SIMETH_FRAME_SIZE ETH_FRAME_LEN
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#define NETWORK_INTR 8
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struct simeth_local {
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struct net_device_stats stats;
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int simfd; /* descriptor in the simulator */
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};
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static int simeth_probe1(void);
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static int simeth_open(struct net_device *dev);
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static int simeth_close(struct net_device *dev);
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static int simeth_tx(struct sk_buff *skb, struct net_device *dev);
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static int simeth_rx(struct net_device *dev);
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static struct net_device_stats *simeth_get_stats(struct net_device *dev);
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static irqreturn_t simeth_interrupt(int irq, void *dev_id);
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static void set_multicast_list(struct net_device *dev);
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static int simeth_device_event(struct notifier_block *this,unsigned long event, void *ptr);
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static char *simeth_version="0.3";
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/*
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* This variable is used to establish a mapping between the Linux/ia64 kernel
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* and the host linux kernel.
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*
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* As of today, we support only one card, even though most of the code
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* is ready for many more. The mapping is then:
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* linux/ia64 -> linux/x86
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* eth0 -> eth1
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*
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* In the future, we some string operations, we could easily support up
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* to 10 cards (0-9).
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*
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* The default mapping can be changed on the kernel command line by
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* specifying simeth=ethX (or whatever string you want).
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*/
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static char *simeth_device="eth0"; /* default host interface to use */
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static volatile unsigned int card_count; /* how many cards "found" so far */
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static int simeth_debug; /* set to 1 to get debug information */
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/*
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* Used to catch IFF_UP & IFF_DOWN events
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*/
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static struct notifier_block simeth_dev_notifier = {
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simeth_device_event,
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NULL
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};
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/*
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* Function used when using a kernel command line option.
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*
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* Format: simeth=interface_name (like eth0)
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*/
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static int __init
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simeth_setup(char *str)
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{
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simeth_device = str;
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return 1;
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}
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__setup("simeth=", simeth_setup);
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/*
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* Function used to probe for simeth devices when not installed
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* as a loadable module
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*/
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int __init
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simeth_probe (void)
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{
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int r;
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printk(KERN_INFO "simeth: v%s\n", simeth_version);
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r = simeth_probe1();
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if (r == 0) register_netdevice_notifier(&simeth_dev_notifier);
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return r;
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}
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static inline int
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netdev_probe(char *name, unsigned char *ether)
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{
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return ia64_ssc(__pa(name), __pa(ether), 0,0, SSC_NETDEV_PROBE);
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}
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static inline int
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netdev_attach(int fd, int irq, unsigned int ipaddr)
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{
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/* this puts the host interface in the right mode (start interrupting) */
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return ia64_ssc(fd, ipaddr, 0,0, SSC_NETDEV_ATTACH);
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}
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static inline int
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netdev_detach(int fd)
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{
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/*
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* inactivate the host interface (don't interrupt anymore) */
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return ia64_ssc(fd, 0,0,0, SSC_NETDEV_DETACH);
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}
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static inline int
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netdev_send(int fd, unsigned char *buf, unsigned int len)
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{
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return ia64_ssc(fd, __pa(buf), len, 0, SSC_NETDEV_SEND);
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}
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static inline int
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netdev_read(int fd, unsigned char *buf, unsigned int len)
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{
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return ia64_ssc(fd, __pa(buf), len, 0, SSC_NETDEV_RECV);
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}
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static const struct net_device_ops simeth_netdev_ops = {
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.ndo_open = simeth_open,
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.ndo_stop = simeth_close,
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.ndo_start_xmit = simeth_tx,
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.ndo_get_stats = simeth_get_stats,
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.ndo_set_rx_mode = set_multicast_list, /* not yet used */
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};
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/*
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* Function shared with module code, so cannot be in init section
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*
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* So far this function "detects" only one card (test_&_set) but could
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* be extended easily.
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*
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* Return:
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* - -ENODEV is no device found
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* - -ENOMEM is no more memory
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* - 0 otherwise
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*/
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static int
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simeth_probe1(void)
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{
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unsigned char mac_addr[ETH_ALEN];
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struct simeth_local *local;
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struct net_device *dev;
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int fd, i, err, rc;
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/*
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* XXX Fix me
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* let's support just one card for now
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*/
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if (test_and_set_bit(0, &card_count))
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return -ENODEV;
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/*
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* check with the simulator for the device
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*/
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fd = netdev_probe(simeth_device, mac_addr);
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if (fd == -1)
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return -ENODEV;
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dev = alloc_etherdev(sizeof(struct simeth_local));
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if (!dev)
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return -ENOMEM;
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memcpy(dev->dev_addr, mac_addr, sizeof(mac_addr));
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local = netdev_priv(dev);
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local->simfd = fd; /* keep track of underlying file descriptor */
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dev->netdev_ops = &simeth_netdev_ops;
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err = register_netdev(dev);
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if (err) {
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free_netdev(dev);
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return err;
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}
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/*
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* attach the interrupt in the simulator, this does enable interrupts
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* until a netdev_attach() is called
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*/
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if ((rc = hpsim_get_irq(NETWORK_INTR)) < 0)
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panic("%s: out of interrupt vectors!\n", __func__);
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dev->irq = rc;
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printk(KERN_INFO "%s: hosteth=%s simfd=%d, HwAddr",
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dev->name, simeth_device, local->simfd);
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for(i = 0; i < ETH_ALEN; i++) {
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printk(" %2.2x", dev->dev_addr[i]);
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}
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printk(", IRQ %d\n", dev->irq);
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return 0;
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}
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/*
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* actually binds the device to an interrupt vector
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*/
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static int
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simeth_open(struct net_device *dev)
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{
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if (request_irq(dev->irq, simeth_interrupt, 0, "simeth", dev)) {
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printk(KERN_WARNING "simeth: unable to get IRQ %d.\n", dev->irq);
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return -EAGAIN;
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}
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netif_start_queue(dev);
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return 0;
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}
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/* copied from lapbether.c */
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static __inline__ int dev_is_ethdev(struct net_device *dev)
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{
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return ( dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5));
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}
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/*
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* Handler for IFF_UP or IFF_DOWN
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*
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* The reason for that is that we don't want to be interrupted when the
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* interface is down. There is no way to unconnect in the simualtor. Instead
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* we use this function to shutdown packet processing in the frame filter
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* in the simulator. Thus no interrupts are generated
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*
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*
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* That's also the place where we pass the IP address of this device to the
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* simulator so that that we can start filtering packets for it
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*
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* There may be a better way of doing this, but I don't know which yet.
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*/
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static int
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simeth_device_event(struct notifier_block *this,unsigned long event, void *ptr)
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{
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struct net_device *dev = ptr;
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struct simeth_local *local;
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struct in_device *in_dev;
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struct in_ifaddr **ifap = NULL;
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struct in_ifaddr *ifa = NULL;
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int r;
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if ( ! dev ) {
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printk(KERN_WARNING "simeth_device_event dev=0\n");
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return NOTIFY_DONE;
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}
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if (dev_net(dev) != &init_net)
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return NOTIFY_DONE;
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if ( event != NETDEV_UP && event != NETDEV_DOWN ) return NOTIFY_DONE;
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/*
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* Check whether or not it's for an ethernet device
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*
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* XXX Fixme: This works only as long as we support one
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* type of ethernet device.
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*/
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if ( !dev_is_ethdev(dev) ) return NOTIFY_DONE;
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if ((in_dev=dev->ip_ptr) != NULL) {
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for (ifap=&in_dev->ifa_list; (ifa=*ifap) != NULL; ifap=&ifa->ifa_next)
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if (strcmp(dev->name, ifa->ifa_label) == 0) break;
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}
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if ( ifa == NULL ) {
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printk(KERN_ERR "simeth_open: can't find device %s's ifa\n", dev->name);
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return NOTIFY_DONE;
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}
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printk(KERN_INFO "simeth_device_event: %s ipaddr=0x%x\n",
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dev->name, ntohl(ifa->ifa_local));
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/*
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* XXX Fix me
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* if the device was up, and we're simply reconfiguring it, not sure
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* we get DOWN then UP.
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*/
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local = netdev_priv(dev);
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/* now do it for real */
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r = event == NETDEV_UP ?
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netdev_attach(local->simfd, dev->irq, ntohl(ifa->ifa_local)):
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netdev_detach(local->simfd);
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printk(KERN_INFO "simeth: netdev_attach/detach: event=%s ->%d\n",
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event == NETDEV_UP ? "attach":"detach", r);
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return NOTIFY_DONE;
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}
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static int
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simeth_close(struct net_device *dev)
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{
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netif_stop_queue(dev);
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free_irq(dev->irq, dev);
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return 0;
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}
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/*
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* Only used for debug
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*/
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static void
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frame_print(unsigned char *from, unsigned char *frame, int len)
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{
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int i;
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printk("%s: (%d) %02x", from, len, frame[0] & 0xff);
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for(i=1; i < 6; i++ ) {
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printk(":%02x", frame[i] &0xff);
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}
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printk(" %2x", frame[6] &0xff);
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for(i=7; i < 12; i++ ) {
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printk(":%02x", frame[i] &0xff);
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}
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printk(" [%02x%02x]\n", frame[12], frame[13]);
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for(i=14; i < len; i++ ) {
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printk("%02x ", frame[i] &0xff);
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if ( (i%10)==0) printk("\n");
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}
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printk("\n");
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}
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/*
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* Function used to transmit of frame, very last one on the path before
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* going to the simulator.
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*/
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static int
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simeth_tx(struct sk_buff *skb, struct net_device *dev)
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{
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struct simeth_local *local = netdev_priv(dev);
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#if 0
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/* ensure we have at least ETH_ZLEN bytes (min frame size) */
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unsigned int length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN;
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/* Where do the extra padding bytes comes from inthe skbuff ? */
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#else
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/* the real driver in the host system is going to take care of that
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* or maybe it's the NIC itself.
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*/
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unsigned int length = skb->len;
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#endif
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local->stats.tx_bytes += skb->len;
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local->stats.tx_packets++;
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if (simeth_debug > 5) frame_print("simeth_tx", skb->data, length);
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netdev_send(local->simfd, skb->data, length);
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/*
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* we are synchronous on write, so we don't simulate a
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* trasnmit complete interrupt, thus we don't need to arm a tx
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*/
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dev_kfree_skb(skb);
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return NETDEV_TX_OK;
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}
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static inline struct sk_buff *
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make_new_skb(struct net_device *dev)
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{
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struct sk_buff *nskb;
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/*
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* The +2 is used to make sure that the IP header is nicely
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* aligned (on 4byte boundary I assume 14+2=16)
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*/
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nskb = dev_alloc_skb(SIMETH_FRAME_SIZE + 2);
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if ( nskb == NULL ) {
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printk(KERN_NOTICE "%s: memory squeeze. dropping packet.\n", dev->name);
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return NULL;
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}
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skb_reserve(nskb, 2); /* Align IP on 16 byte boundaries */
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skb_put(nskb,SIMETH_FRAME_SIZE);
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return nskb;
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}
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/*
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* called from interrupt handler to process a received frame
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*/
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static int
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simeth_rx(struct net_device *dev)
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{
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struct simeth_local *local;
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struct sk_buff *skb;
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int len;
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int rcv_count = SIMETH_RECV_MAX;
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local = netdev_priv(dev);
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/*
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* the loop concept has been borrowed from other drivers
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* looks to me like it's a throttling thing to avoid pushing to many
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* packets at one time into the stack. Making sure we can process them
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* upstream and make forward progress overall
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*/
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do {
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if ( (skb=make_new_skb(dev)) == NULL ) {
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printk(KERN_NOTICE "%s: memory squeeze. dropping packet.\n", dev->name);
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local->stats.rx_dropped++;
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return 0;
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}
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/*
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* Read only one frame at a time
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*/
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len = netdev_read(local->simfd, skb->data, SIMETH_FRAME_SIZE);
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if ( len == 0 ) {
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if ( simeth_debug > 0 ) printk(KERN_WARNING "%s: count=%d netdev_read=0\n",
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dev->name, SIMETH_RECV_MAX-rcv_count);
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break;
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}
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#if 0
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/*
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* XXX Fix me
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* Should really do a csum+copy here
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*/
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skb_copy_to_linear_data(skb, frame, len);
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#endif
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skb->protocol = eth_type_trans(skb, dev);
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if ( simeth_debug > 6 ) frame_print("simeth_rx", skb->data, len);
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/*
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* push the packet up & trigger software interrupt
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*/
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netif_rx(skb);
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local->stats.rx_packets++;
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local->stats.rx_bytes += len;
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} while ( --rcv_count );
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return len; /* 0 = nothing left to read, otherwise, we can try again */
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}
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/*
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* Interrupt handler (Yes, we can do it too !!!)
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*/
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static irqreturn_t
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simeth_interrupt(int irq, void *dev_id)
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{
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struct net_device *dev = dev_id;
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/*
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* very simple loop because we get interrupts only when receiving
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*/
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while (simeth_rx(dev));
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return IRQ_HANDLED;
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}
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static struct net_device_stats *
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simeth_get_stats(struct net_device *dev)
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{
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struct simeth_local *local = netdev_priv(dev);
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return &local->stats;
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}
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/* fake multicast ability */
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static void
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set_multicast_list(struct net_device *dev)
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{
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printk(KERN_WARNING "%s: set_multicast_list called\n", dev->name);
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}
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__initcall(simeth_probe);
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