[net-next-2.6.git] / arch / ia64 / hp / sim / simeth.c

/*
 * Simulated Ethernet Driver
 *
 * Copyright (C) 1999-2001, 2003 Hewlett-Packard Co
 *	Stephane Eranian <eranian@hpl.hp.com>
 */
#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 <linux/bitops.h>
#include <asm/system.h>
#include <asm/irq.h>
#include <asm/hpsim.h>

#include "hpsim_ssc.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 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;
}

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 (dev->nd_net != &init_net)
		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
		 */
		skb_copy_to_linear_data(skb, 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);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Simulated Ethernet Driver
	3	*
	4	* Copyright (C) 1999-2001, 2003 Hewlett-Packard Co
	5	* Stephane Eranian <eranian@hpl.hp.com>
	6	*/
1da177e4 LT	7	#include <linux/kernel.h>
	8	#include <linux/sched.h>
	9	#include <linux/types.h>
	10	#include <linux/in.h>
	11	#include <linux/string.h>
	12	#include <linux/init.h>
	13	#include <linux/errno.h>
	14	#include <linux/interrupt.h>
	15	#include <linux/netdevice.h>
	16	#include <linux/etherdevice.h>
	17	#include <linux/inetdevice.h>
	18	#include <linux/if_ether.h>
	19	#include <linux/if_arp.h>
	20	#include <linux/skbuff.h>
	21	#include <linux/notifier.h>
	22	#include <linux/bitops.h>
	23	#include <asm/system.h>
	24	#include <asm/irq.h>
7b3166db PC	25	#include <asm/hpsim.h>
	26
	27	#include "hpsim_ssc.h"
1da177e4 LT	28
	29	#define SIMETH_RECV_MAX 10
	30
	31	/*
	32	* Maximum possible received frame for Ethernet.
	33	* We preallocate an sk_buff of that size to avoid costly
	34	* memcpy for temporary buffer into sk_buff. We do basically
	35	* what's done in other drivers, like eepro with a ring.
	36	* The difference is, of course, that we don't have real DMA !!!
	37	*/
	38	#define SIMETH_FRAME_SIZE ETH_FRAME_LEN
	39
	40
1da177e4 LT	41	#define NETWORK_INTR 8
	42
	43	struct simeth_local {
	44	struct net_device_stats stats;
	45	int simfd; /* descriptor in the simulator */
	46	};
	47
	48	static int simeth_probe1(void);
	49	static int simeth_open(struct net_device *dev);
	50	static int simeth_close(struct net_device *dev);
	51	static int simeth_tx(struct sk_buff skb, struct net_device dev);
	52	static int simeth_rx(struct net_device *dev);
	53	static struct net_device_stats simeth_get_stats(struct net_device dev);
5dcded1b	54	static irqreturn_t simeth_interrupt(int irq, void *dev_id);
1da177e4 LT	55	static void set_multicast_list(struct net_device *dev);
	56	static int simeth_device_event(struct notifier_block this,unsigned long event, void ptr);
	57
	58	static char *simeth_version="0.3";
	59
	60	/*
	61	* This variable is used to establish a mapping between the Linux/ia64 kernel
	62	* and the host linux kernel.
	63	*
	64	* As of today, we support only one card, even though most of the code
	65	* is ready for many more. The mapping is then:
	66	* linux/ia64 -> linux/x86
	67	* eth0 -> eth1
	68	*
	69	* In the future, we some string operations, we could easily support up
	70	* to 10 cards (0-9).
	71	*
	72	* The default mapping can be changed on the kernel command line by
	73	* specifying simeth=ethX (or whatever string you want).
	74	*/
	75	static char simeth_device="eth0"; / default host interface to use */
	76
	77
	78
	79	static volatile unsigned int card_count; /* how many cards "found" so far */
	80	static int simeth_debug; /* set to 1 to get debug information */
	81
	82	/*
	83	* Used to catch IFF_UP & IFF_DOWN events
	84	*/
	85	static struct notifier_block simeth_dev_notifier = {
	86	simeth_device_event,
cfa7fd72	87	NULL
1da177e4 LT	88	};
	89
	90
	91	/*
	92	* Function used when using a kernel command line option.
	93	*
	94	* Format: simeth=interface_name (like eth0)
	95	*/
	96	static int __init
	97	simeth_setup(char *str)
	98	{
	99	simeth_device = str;
	100	return 1;
	101	}
	102
	103	__setup("simeth=", simeth_setup);
	104
	105	/*
	106	* Function used to probe for simeth devices when not installed
	107	* as a loadable module
	108	*/
	109
	110	int __init
	111	simeth_probe (void)
	112	{
	113	int r;
	114
	115	printk(KERN_INFO "simeth: v%s\n", simeth_version);
	116
	117	r = simeth_probe1();
	118
	119	if (r == 0) register_netdevice_notifier(&simeth_dev_notifier);
	120
	121	return r;
	122	}
	123
1da177e4 LT	124	static inline int
	125	netdev_probe(char name, unsigned char ether)
	126	{
	127	return ia64_ssc(__pa(name), __pa(ether), 0,0, SSC_NETDEV_PROBE);
	128	}
	129
	130
	131	static inline int
	132	netdev_connect(int irq)
	133	{
	134	/* XXX Fix me
	135	* this does not support multiple cards
	136	* also no return value
	137	*/
	138	ia64_ssc_connect_irq(NETWORK_INTR, irq);
	139	return 0;
	140	}
	141
	142	static inline int
	143	netdev_attach(int fd, int irq, unsigned int ipaddr)
	144	{
	145	/* this puts the host interface in the right mode (start interrupting) */
	146	return ia64_ssc(fd, ipaddr, 0,0, SSC_NETDEV_ATTACH);
	147	}
	148
	149
	150	static inline int
	151	netdev_detach(int fd)
	152	{
	153	/*
	154	* inactivate the host interface (don't interrupt anymore) */
	155	return ia64_ssc(fd, 0,0,0, SSC_NETDEV_DETACH);
	156	}
	157
	158	static inline int
	159	netdev_send(int fd, unsigned char *buf, unsigned int len)
	160	{
	161	return ia64_ssc(fd, __pa(buf), len, 0, SSC_NETDEV_SEND);
	162	}
	163
	164	static inline int
	165	netdev_read(int fd, unsigned char *buf, unsigned int len)
	166	{
	167	return ia64_ssc(fd, __pa(buf), len, 0, SSC_NETDEV_RECV);
	168	}
	169
	170	/*
	171	* Function shared with module code, so cannot be in init section
	172	*
	173	* So far this function "detects" only one card (test_&_set) but could
	174	* be extended easily.
	175	*
	176	* Return:
	177	* - -ENODEV is no device found
	178	* - -ENOMEM is no more memory
	179	* - 0 otherwise
	180	*/
	181	static int
	182	simeth_probe1(void)
	183	{
	184	unsigned char mac_addr[ETH_ALEN];
	185	struct simeth_local *local;
	186	struct net_device *dev;
3b5cc090	187	int fd, i, err, rc;
1da177e4 LT	188
	189	/*
	190	* XXX Fix me
	191	* let's support just one card for now
	192	*/
	193	if (test_and_set_bit(0, &card_count))
	194	return -ENODEV;
	195
	196	/*
	197	* check with the simulator for the device
	198	*/
	199	fd = netdev_probe(simeth_device, mac_addr);
	200	if (fd == -1)
	201	return -ENODEV;
	202
	203	dev = alloc_etherdev(sizeof(struct simeth_local));
	204	if (!dev)
	205	return -ENOMEM;
	206
	207	memcpy(dev->dev_addr, mac_addr, sizeof(mac_addr));
	208
	209	local = dev->priv;
	210	local->simfd = fd; /* keep track of underlying file descriptor */
	211
	212	dev->open = simeth_open;
	213	dev->stop = simeth_close;
	214	dev->hard_start_xmit = simeth_tx;
	215	dev->get_stats = simeth_get_stats;
	216	dev->set_multicast_list = set_multicast_list; /* no yet used */
	217
	218	err = register_netdev(dev);
	219	if (err) {
	220	free_netdev(dev);
	221	return err;
	222	}
	223
3b5cc090 KK	224	if ((rc = assign_irq_vector(AUTO_ASSIGN)) < 0)
	225	panic("%s: out of interrupt vectors!\n", __FUNCTION__);
	226	dev->irq = rc;
1da177e4 LT	227
	228	/*
	229	* attach the interrupt in the simulator, this does enable interrupts
	230	* until a netdev_attach() is called
	231	*/
	232	netdev_connect(dev->irq);
	233
	234	printk(KERN_INFO "%s: hosteth=%s simfd=%d, HwAddr",
	235	dev->name, simeth_device, local->simfd);
	236	for(i = 0; i < ETH_ALEN; i++) {
	237	printk(" %2.2x", dev->dev_addr[i]);
	238	}
	239	printk(", IRQ %d\n", dev->irq);
	240
	241	return 0;
	242	}
	243
	244	/*
	245	* actually binds the device to an interrupt vector
	246	*/
	247	static int
	248	simeth_open(struct net_device *dev)
	249	{
	250	if (request_irq(dev->irq, simeth_interrupt, 0, "simeth", dev)) {
	251	printk(KERN_WARNING "simeth: unable to get IRQ %d.\n", dev->irq);
	252	return -EAGAIN;
	253	}
	254
	255	netif_start_queue(dev);
	256
	257	return 0;
	258	}
	259
	260	/* copied from lapbether.c */
	261	static __inline__ int dev_is_ethdev(struct net_device *dev)
	262	{
	263	return ( dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5));
	264	}
	265
	266
	267	/*
	268	* Handler for IFF_UP or IFF_DOWN
	269	*
	270	* The reason for that is that we don't want to be interrupted when the
	271	* interface is down. There is no way to unconnect in the simualtor. Instead
	272	* we use this function to shutdown packet processing in the frame filter
	273	* in the simulator. Thus no interrupts are generated
	274	*
	275	*
	276	* That's also the place where we pass the IP address of this device to the
	277	* simulator so that that we can start filtering packets for it
	278	*
	279	* There may be a better way of doing this, but I don't know which yet.
	280	*/
	281	static int
	282	simeth_device_event(struct notifier_block this,unsigned long event, void ptr)
	283	{
	284	struct net_device *dev = ptr;
	285	struct simeth_local *local;
	286	struct in_device *in_dev;
	287	struct in_ifaddr **ifap = NULL;
	288	struct in_ifaddr *ifa = NULL;
	289	int r;
	290
291
292	if ( ! dev ) {
293	printk(KERN_WARNING "simeth_device_event dev=0\n");
294	return NOTIFY_DONE;
295	}
296
e9dc8653 EB	297	if (dev->nd_net != &init_net)
	298	return NOTIFY_DONE;
	299
1da177e4 LT	300	if ( event != NETDEV_UP && event != NETDEV_DOWN ) return NOTIFY_DONE;
	301
	302	/*
	303	* Check whether or not it's for an ethernet device
	304	*
	305	* XXX Fixme: This works only as long as we support one
	306	* type of ethernet device.
	307	*/
	308	if ( !dev_is_ethdev(dev) ) return NOTIFY_DONE;
	309
	310	if ((in_dev=dev->ip_ptr) != NULL) {
	311	for (ifap=&in_dev->ifa_list; (ifa=*ifap) != NULL; ifap=&ifa->ifa_next)
	312	if (strcmp(dev->name, ifa->ifa_label) == 0) break;
	313	}
	314	if ( ifa == NULL ) {
	315	printk(KERN_ERR "simeth_open: can't find device %s's ifa\n", dev->name);
	316	return NOTIFY_DONE;
	317	}
	318
	319	printk(KERN_INFO "simeth_device_event: %s ipaddr=0x%x\n",
a144ea4b	320	dev->name, ntohl(ifa->ifa_local));
1da177e4 LT	321
	322	/*
	323	* XXX Fix me
	324	* if the device was up, and we're simply reconfiguring it, not sure
	325	* we get DOWN then UP.
	326	*/
	327
	328	local = dev->priv;
	329	/* now do it for real */
	330	r = event == NETDEV_UP ?
a144ea4b	331	netdev_attach(local->simfd, dev->irq, ntohl(ifa->ifa_local)):
1da177e4 LT	332	netdev_detach(local->simfd);
	333
	334	printk(KERN_INFO "simeth: netdev_attach/detach: event=%s ->%d\n",
	335	event == NETDEV_UP ? "attach":"detach", r);
	336
	337	return NOTIFY_DONE;
	338	}
	339
	340	static int
	341	simeth_close(struct net_device *dev)
	342	{
	343	netif_stop_queue(dev);
	344
	345	free_irq(dev->irq, dev);
	346
	347	return 0;
	348	}
	349
	350	/*
	351	* Only used for debug
	352	*/
	353	static void
	354	frame_print(unsigned char from, unsigned char frame, int len)
	355	{
	356	int i;
	357
	358	printk("%s: (%d) %02x", from, len, frame[0] & 0xff);
	359	for(i=1; i < 6; i++ ) {
	360	printk(":%02x", frame[i] &0xff);
	361	}
	362	printk(" %2x", frame[6] &0xff);
	363	for(i=7; i < 12; i++ ) {
	364	printk(":%02x", frame[i] &0xff);
	365	}
	366	printk(" [%02x%02x]\n", frame[12], frame[13]);
	367
	368	for(i=14; i < len; i++ ) {
	369	printk("%02x ", frame[i] &0xff);
	370	if ( (i%10)==0) printk("\n");
	371	}
	372	printk("\n");
	373	}
	374
	375
	376	/*
	377	* Function used to transmit of frame, very last one on the path before
	378	* going to the simulator.
	379	*/
	380	static int
	381	simeth_tx(struct sk_buff skb, struct net_device dev)
	382	{
	383	struct simeth_local *local = dev->priv;
	384
	385	#if 0
	386	/* ensure we have at least ETH_ZLEN bytes (min frame size) */
	387	unsigned int length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN;
	388	/* Where do the extra padding bytes comes from inthe skbuff ? */
	389	#else
	390	/* the real driver in the host system is going to take care of that
	391	* or maybe it's the NIC itself.
	392	*/
	393	unsigned int length = skb->len;
	394	#endif
	395
396	local->stats.tx_bytes += skb->len;
397	local->stats.tx_packets++;
398
399
400	if (simeth_debug > 5) frame_print("simeth_tx", skb->data, length);
401
402	netdev_send(local->simfd, skb->data, length);
403
404	/*
405	* we are synchronous on write, so we don't simulate a
406	* trasnmit complete interrupt, thus we don't need to arm a tx
407	*/
408
409	dev_kfree_skb(skb);
410	return 0;
411	}
412
413	static inline struct sk_buff *
414	make_new_skb(struct net_device *dev)
415	{
416	struct sk_buff *nskb;
417
418	/*
419	* The +2 is used to make sure that the IP header is nicely
420	* aligned (on 4byte boundary I assume 14+2=16)
421	*/
422	nskb = dev_alloc_skb(SIMETH_FRAME_SIZE + 2);
423	if ( nskb == NULL ) {
424	printk(KERN_NOTICE "%s: memory squeeze. dropping packet.\n", dev->name);
425	return NULL;
426	}
1da177e4 LT	427
	428	skb_reserve(nskb, 2); /* Align IP on 16 byte boundaries */
	429
	430	skb_put(nskb,SIMETH_FRAME_SIZE);
	431
	432	return nskb;
	433	}
	434
	435	/*
	436	* called from interrupt handler to process a received frame
	437	*/
	438	static int
	439	simeth_rx(struct net_device *dev)
	440	{
	441	struct simeth_local *local;
	442	struct sk_buff *skb;
	443	int len;
	444	int rcv_count = SIMETH_RECV_MAX;
	445
	446	local = dev->priv;
	447	/*
	448	* the loop concept has been borrowed from other drivers
	449	* looks to me like it's a throttling thing to avoid pushing to many
	450	* packets at one time into the stack. Making sure we can process them
	451	* upstream and make forward progress overall
	452	*/
	453	do {
	454	if ( (skb=make_new_skb(dev)) == NULL ) {
	455	printk(KERN_NOTICE "%s: memory squeeze. dropping packet.\n", dev->name);
	456	local->stats.rx_dropped++;
	457	return 0;
	458	}
	459	/*
	460	* Read only one frame at a time
	461	*/
	462	len = netdev_read(local->simfd, skb->data, SIMETH_FRAME_SIZE);
	463	if ( len == 0 ) {
	464	if ( simeth_debug > 0 ) printk(KERN_WARNING "%s: count=%d netdev_read=0\n",
	465	dev->name, SIMETH_RECV_MAX-rcv_count);
	466	break;
	467	}
	468	#if 0
	469	/*
	470	* XXX Fix me
	471	* Should really do a csum+copy here
	472	*/
27d7ff46	473	skb_copy_to_linear_data(skb, frame, len);
1da177e4 LT	474	#endif
	475	skb->protocol = eth_type_trans(skb, dev);
	476
	477	if ( simeth_debug > 6 ) frame_print("simeth_rx", skb->data, len);
	478
	479	/*
	480	* push the packet up & trigger software interrupt
	481	*/
	482	netif_rx(skb);
	483
	484	local->stats.rx_packets++;
	485	local->stats.rx_bytes += len;
	486
	487	} while ( --rcv_count );
	488
	489	return len; /* 0 = nothing left to read, otherwise, we can try again */
	490	}
	491
	492	/*
	493	* Interrupt handler (Yes, we can do it too !!!)
	494	*/
	495	static irqreturn_t
5dcded1b	496	simeth_interrupt(int irq, void *dev_id)
1da177e4 LT	497	{
	498	struct net_device *dev = dev_id;
	499
	500	if ( dev == NULL ) {
	501	printk(KERN_WARNING "simeth: irq %d for unknown device\n", irq);
	502	return IRQ_NONE;
	503	}
	504
	505	/*
	506	* very simple loop because we get interrupts only when receiving
	507	*/
	508	while (simeth_rx(dev));
	509	return IRQ_HANDLED;
	510	}
	511
	512	static struct net_device_stats *
	513	simeth_get_stats(struct net_device *dev)
	514	{
	515	struct simeth_local *local = dev->priv;
	516
	517	return &local->stats;
	518	}
	519
	520	/* fake multicast ability */
	521	static void
	522	set_multicast_list(struct net_device *dev)
	523	{
	524	printk(KERN_WARNING "%s: set_multicast_list called\n", dev->name);
	525	}
	526
	527	__initcall(simeth_probe);