/* * Simulated Ethernet Driver * * Copyright (C) 1999-2001, 2003 Hewlett-Packard Co * Stephane Eranian */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define SIMETH_RECV_MAX 10 /* * Maximum possible received frame for Ethernet. * We preallocate an sk_buff of that size to avoid costly * memcpy for temporary buffer into sk_buff. We do basically * what's done in other drivers, like eepro with a ring. * The difference is, of course, that we don't have real DMA !!! */ #define SIMETH_FRAME_SIZE ETH_FRAME_LEN #define SSC_NETDEV_PROBE 100 #define SSC_NETDEV_SEND 101 #define SSC_NETDEV_RECV 102 #define SSC_NETDEV_ATTACH 103 #define SSC_NETDEV_DETACH 104 #define NETWORK_INTR 8 struct simeth_local { struct net_device_stats stats; int simfd; /* descriptor in the simulator */ }; static int simeth_probe1(void); static int simeth_open(struct net_device *dev); static int simeth_close(struct net_device *dev); static int simeth_tx(struct sk_buff *skb, struct net_device *dev); static int simeth_rx(struct net_device *dev); static struct net_device_stats *simeth_get_stats(struct net_device *dev); static irqreturn_t simeth_interrupt(int irq, void *dev_id); static void set_multicast_list(struct net_device *dev); static int simeth_device_event(struct notifier_block *this,unsigned long event, void *ptr); static char *simeth_version="0.3"; /* * This variable is used to establish a mapping between the Linux/ia64 kernel * and the host linux kernel. * * As of today, we support only one card, even though most of the code * is ready for many more. The mapping is then: * linux/ia64 -> linux/x86 * eth0 -> eth1 * * In the future, we some string operations, we could easily support up * to 10 cards (0-9). * * The default mapping can be changed on the kernel command line by * specifying simeth=ethX (or whatever string you want). */ static char *simeth_device="eth0"; /* default host interface to use */ static volatile unsigned int card_count; /* how many cards "found" so far */ static int simeth_debug; /* set to 1 to get debug information */ /* * Used to catch IFF_UP & IFF_DOWN events */ static struct notifier_block simeth_dev_notifier = { simeth_device_event, NULL }; /* * Function used when using a kernel command line option. * * Format: simeth=interface_name (like eth0) */ static int __init simeth_setup(char *str) { simeth_device = str; return 1; } __setup("simeth=", simeth_setup); /* * Function used to probe for simeth devices when not installed * as a loadable module */ int __init simeth_probe (void) { int r; printk(KERN_INFO "simeth: v%s\n", simeth_version); r = simeth_probe1(); if (r == 0) register_netdevice_notifier(&simeth_dev_notifier); return r; } extern long ia64_ssc (long, long, long, long, int); extern void ia64_ssc_connect_irq (long intr, long irq); static inline int netdev_probe(char *name, unsigned char *ether) { return ia64_ssc(__pa(name), __pa(ether), 0,0, SSC_NETDEV_PROBE); } static inline int netdev_connect(int irq) { /* XXX Fix me * this does not support multiple cards * also no return value */ ia64_ssc_connect_irq(NETWORK_INTR, irq); return 0; } static inline int netdev_attach(int fd, int irq, unsigned int ipaddr) { /* this puts the host interface in the right mode (start interrupting) */ return ia64_ssc(fd, ipaddr, 0,0, SSC_NETDEV_ATTACH); } static inline int netdev_detach(int fd) { /* * inactivate the host interface (don't interrupt anymore) */ return ia64_ssc(fd, 0,0,0, SSC_NETDEV_DETACH); } static inline int netdev_send(int fd, unsigned char *buf, unsigned int len) { return ia64_ssc(fd, __pa(buf), len, 0, SSC_NETDEV_SEND); } static inline int netdev_read(int fd, unsigned char *buf, unsigned int len) { return ia64_ssc(fd, __pa(buf), len, 0, SSC_NETDEV_RECV); } /* * Function shared with module code, so cannot be in init section * * So far this function "detects" only one card (test_&_set) but could * be extended easily. * * Return: * - -ENODEV is no device found * - -ENOMEM is no more memory * - 0 otherwise */ static int simeth_probe1(void) { unsigned char mac_addr[ETH_ALEN]; struct simeth_local *local; struct net_device *dev; int fd, i, err, rc; /* * XXX Fix me * let's support just one card for now */ if (test_and_set_bit(0, &card_count)) return -ENODEV; /* * check with the simulator for the device */ fd = netdev_probe(simeth_device, mac_addr); if (fd == -1) return -ENODEV; dev = alloc_etherdev(sizeof(struct simeth_local)); if (!dev) return -ENOMEM; memcpy(dev->dev_addr, mac_addr, sizeof(mac_addr)); local = dev->priv; local->simfd = fd; /* keep track of underlying file descriptor */ dev->open = simeth_open; dev->stop = simeth_close; dev->hard_start_xmit = simeth_tx; dev->get_stats = simeth_get_stats; dev->set_multicast_list = set_multicast_list; /* no yet used */ err = register_netdev(dev); if (err) { free_netdev(dev); return err; } if ((rc = assign_irq_vector(AUTO_ASSIGN)) < 0) panic("%s: out of interrupt vectors!\n", __FUNCTION__); dev->irq = rc; /* * attach the interrupt in the simulator, this does enable interrupts * until a netdev_attach() is called */ netdev_connect(dev->irq); printk(KERN_INFO "%s: hosteth=%s simfd=%d, HwAddr", dev->name, simeth_device, local->simfd); for(i = 0; i < ETH_ALEN; i++) { printk(" %2.2x", dev->dev_addr[i]); } printk(", IRQ %d\n", dev->irq); return 0; } /* * actually binds the device to an interrupt vector */ static int simeth_open(struct net_device *dev) { if (request_irq(dev->irq, simeth_interrupt, 0, "simeth", dev)) { printk(KERN_WARNING "simeth: unable to get IRQ %d.\n", dev->irq); return -EAGAIN; } netif_start_queue(dev); return 0; } /* copied from lapbether.c */ static __inline__ int dev_is_ethdev(struct net_device *dev) { return ( dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5)); } /* * Handler for IFF_UP or IFF_DOWN * * The reason for that is that we don't want to be interrupted when the * interface is down. There is no way to unconnect in the simualtor. Instead * we use this function to shutdown packet processing in the frame filter * in the simulator. Thus no interrupts are generated * * * That's also the place where we pass the IP address of this device to the * simulator so that that we can start filtering packets for it * * There may be a better way of doing this, but I don't know which yet. */ static int simeth_device_event(struct notifier_block *this,unsigned long event, void *ptr) { struct net_device *dev = ptr; struct simeth_local *local; struct in_device *in_dev; struct in_ifaddr **ifap = NULL; struct in_ifaddr *ifa = NULL; int r; if ( ! dev ) { printk(KERN_WARNING "simeth_device_event dev=0\n"); return NOTIFY_DONE; } if ( event != NETDEV_UP && event != NETDEV_DOWN ) return NOTIFY_DONE; /* * Check whether or not it's for an ethernet device * * XXX Fixme: This works only as long as we support one * type of ethernet device. */ if ( !dev_is_ethdev(dev) ) return NOTIFY_DONE; if ((in_dev=dev->ip_ptr) != NULL) { for (ifap=&in_dev->ifa_list; (ifa=*ifap) != NULL; ifap=&ifa->ifa_next) if (strcmp(dev->name, ifa->ifa_label) == 0) break; } if ( ifa == NULL ) { printk(KERN_ERR "simeth_open: can't find device %s's ifa\n", dev->name); return NOTIFY_DONE; } printk(KERN_INFO "simeth_device_event: %s ipaddr=0x%x\n", dev->name, ntohl(ifa->ifa_local)); /* * XXX Fix me * if the device was up, and we're simply reconfiguring it, not sure * we get DOWN then UP. */ local = dev->priv; /* now do it for real */ r = event == NETDEV_UP ? netdev_attach(local->simfd, dev->irq, ntohl(ifa->ifa_local)): netdev_detach(local->simfd); printk(KERN_INFO "simeth: netdev_attach/detach: event=%s ->%d\n", event == NETDEV_UP ? "attach":"detach", r); return NOTIFY_DONE; } static int simeth_close(struct net_device *dev) { netif_stop_queue(dev); free_irq(dev->irq, dev); return 0; } /* * Only used for debug */ static void frame_print(unsigned char *from, unsigned char *frame, int len) { int i; printk("%s: (%d) %02x", from, len, frame[0] & 0xff); for(i=1; i < 6; i++ ) { printk(":%02x", frame[i] &0xff); } printk(" %2x", frame[6] &0xff); for(i=7; i < 12; i++ ) { printk(":%02x", frame[i] &0xff); } printk(" [%02x%02x]\n", frame[12], frame[13]); for(i=14; i < len; i++ ) { printk("%02x ", frame[i] &0xff); if ( (i%10)==0) printk("\n"); } printk("\n"); } /* * Function used to transmit of frame, very last one on the path before * going to the simulator. */ static int simeth_tx(struct sk_buff *skb, struct net_device *dev) { struct simeth_local *local = dev->priv; #if 0 /* ensure we have at least ETH_ZLEN bytes (min frame size) */ unsigned int length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN; /* Where do the extra padding bytes comes from inthe skbuff ? */ #else /* the real driver in the host system is going to take care of that * or maybe it's the NIC itself. */ unsigned int length = skb->len; #endif local->stats.tx_bytes += skb->len; local->stats.tx_packets++; if (simeth_debug > 5) frame_print("simeth_tx", skb->data, length); netdev_send(local->simfd, skb->data, length); /* * we are synchronous on write, so we don't simulate a * trasnmit complete interrupt, thus we don't need to arm a tx */ dev_kfree_skb(skb); return 0; } static inline struct sk_buff * make_new_skb(struct net_device *dev) { struct sk_buff *nskb; /* * The +2 is used to make sure that the IP header is nicely * aligned (on 4byte boundary I assume 14+2=16) */ nskb = dev_alloc_skb(SIMETH_FRAME_SIZE + 2); if ( nskb == NULL ) { printk(KERN_NOTICE "%s: memory squeeze. dropping packet.\n", dev->name); return NULL; } skb_reserve(nskb, 2); /* Align IP on 16 byte boundaries */ skb_put(nskb,SIMETH_FRAME_SIZE); return nskb; } /* * called from interrupt handler to process a received frame */ static int simeth_rx(struct net_device *dev) { struct simeth_local *local; struct sk_buff *skb; int len; int rcv_count = SIMETH_RECV_MAX; local = dev->priv; /* * the loop concept has been borrowed from other drivers * looks to me like it's a throttling thing to avoid pushing to many * packets at one time into the stack. Making sure we can process them * upstream and make forward progress overall */ do { if ( (skb=make_new_skb(dev)) == NULL ) { printk(KERN_NOTICE "%s: memory squeeze. dropping packet.\n", dev->name); local->stats.rx_dropped++; return 0; } /* * Read only one frame at a time */ len = netdev_read(local->simfd, skb->data, SIMETH_FRAME_SIZE); if ( len == 0 ) { if ( simeth_debug > 0 ) printk(KERN_WARNING "%s: count=%d netdev_read=0\n", dev->name, SIMETH_RECV_MAX-rcv_count); break; } #if 0 /* * XXX Fix me * Should really do a csum+copy here */ memcpy(skb->data, frame, len); #endif skb->protocol = eth_type_trans(skb, dev); if ( simeth_debug > 6 ) frame_print("simeth_rx", skb->data, len); /* * push the packet up & trigger software interrupt */ netif_rx(skb); local->stats.rx_packets++; local->stats.rx_bytes += len; } while ( --rcv_count ); return len; /* 0 = nothing left to read, otherwise, we can try again */ } /* * Interrupt handler (Yes, we can do it too !!!) */ static irqreturn_t simeth_interrupt(int irq, void *dev_id) { struct net_device *dev = dev_id; if ( dev == NULL ) { printk(KERN_WARNING "simeth: irq %d for unknown device\n", irq); return IRQ_NONE; } /* * very simple loop because we get interrupts only when receiving */ while (simeth_rx(dev)); return IRQ_HANDLED; } static struct net_device_stats * simeth_get_stats(struct net_device *dev) { struct simeth_local *local = dev->priv; return &local->stats; } /* fake multicast ability */ static void set_multicast_list(struct net_device *dev) { printk(KERN_WARNING "%s: set_multicast_list called\n", dev->name); } __initcall(simeth_probe);