patch-2.4.23 linux-2.4.23/arch/ia64/drivers/simeth.c

• Lines: 538
• Date: 2003-11-28 10:26:19.000000000 -0800
• Orig file: linux-2.4.22/arch/ia64/drivers/simeth.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.22/arch/ia64/drivers/simeth.c linux-2.4.23/arch/ia64/drivers/simeth.c
@@ -0,0 +1,537 @@
+/*
+ * Simulated Ethernet Driver
+ *
+ * Copyright (C) 1999-2001, 2003 Hewlett-Packard Co
+ *	Stephane Eranian <eranian@hpl.hp.com>
+ */
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <linux/in.h>
+#include <linux/string.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/inetdevice.h>
+#include <linux/if_ether.h>
+#include <linux/if_arp.h>
+#include <linux/skbuff.h>
+#include <linux/notifier.h>
+#include <asm/bitops.h>
+#include <asm/system.h>
+#include <asm/irq.h>
+
+#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 void simeth_interrupt(int irq, void *dev_id, struct pt_regs * regs);
+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,
+	0
+};
+
+
+/*
+ * 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;
+
+	/*
+	 * 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 = init_etherdev(NULL, sizeof(struct simeth_local));
+	if (!dev)
+		return -ENOMEM;
+
+	memcpy(dev->dev_addr, mac_addr, sizeof(mac_addr));
+
+	dev->irq = ia64_alloc_vector();
+
+	/*
+	 * attach the interrupt in the simulator, this does enable interrupts
+	 * until a netdev_attach() is called
+	 */
+	netdev_connect(dev->irq);
+
+	memset(dev->priv, 0, sizeof(struct simeth_local));
+
+	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 */
+
+	/* Fill in the fields of the device structure with ethernet-generic values. */
+	ether_setup(dev);
+
+	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 = (struct net_device *)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, htonl(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, htonl(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 = (struct simeth_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;
+	}
+	nskb->dev = dev;
+
+	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 = (struct simeth_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 void
+simeth_interrupt(int irq, void *dev_id, struct pt_regs * regs)
+{
+	struct net_device *dev = dev_id;
+
+	if ( dev == NULL ) {
+		printk(KERN_WARNING "simeth: irq %d for unknown device\n", irq);
+		return;
+	}
+
+	/*
+	 * very simple loop because we get interrupts only when receiving
+	 */
+	while (simeth_rx(dev));
+}
+
+static struct net_device_stats *
+simeth_get_stats(struct net_device *dev)
+{
+	struct simeth_local  *local = (struct simeth_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);
+}
+
+#ifdef CONFIG_NET_FASTROUTE
+static int
+simeth_accept_fastpath(struct net_device *dev, struct dst_entry *dst)
+{
+	printk(KERN_WARNING "%s: simeth_accept_fastpath called\n", dev->name);
+	return -1;
+}
+#endif
+
+__initcall(simeth_probe);