[mirror_ubuntu-zesty-kernel.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/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_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);
}

static const struct net_device_ops simeth_netdev_ops = {
	.ndo_open		= simeth_open,
	.ndo_stop		= simeth_close,
	.ndo_start_xmit		= simeth_tx,
	.ndo_get_stats		= simeth_get_stats,
	.ndo_set_rx_mode	= set_multicast_list, /* not yet used */

};

/*
 * 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, 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 = netdev_priv(dev);
	local->simfd = fd; /* keep track of underlying file descriptor */

	dev->netdev_ops = &simeth_netdev_ops;

	err = register_netdev(dev);
	if (err) {
		free_netdev(dev);
		return err;
	}

	/*
	 * attach the interrupt in the simulator, this does enable interrupts
	 * until a netdev_attach() is called
	 */
	if ((rc = hpsim_get_irq(NETWORK_INTR)) < 0)
		panic("%s: out of interrupt vectors!\n", __func__);
	dev->irq = rc;

	printk(KERN_INFO "%s: hosteth=%s simfd=%d, HwAddr=%pm, IRQ %d\n",
	       dev->name, simeth_device, local->simfd, dev->dev_addr, 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 = netdev_notifier_info_to_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_net(dev) != &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 = netdev_priv(dev);
	/* 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 = netdev_priv(dev);

#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 NETDEV_TX_OK;
}

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 = netdev_priv(dev);
	/*
	 * 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;

	/*
	 * 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 = netdev_priv(dev);

	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>
1da177e4	23	#include <asm/irq.h>
7b3166db PC	24	#include <asm/hpsim.h>
	25
	26	#include "hpsim_ssc.h"
1da177e4 LT	27
	28	#define SIMETH_RECV_MAX 10
	29
	30	/*
	31	* Maximum possible received frame for Ethernet.
	32	* We preallocate an sk_buff of that size to avoid costly
	33	* memcpy for temporary buffer into sk_buff. We do basically
	34	* what's done in other drivers, like eepro with a ring.
	35	* The difference is, of course, that we don't have real DMA !!!
	36	*/
	37	#define SIMETH_FRAME_SIZE ETH_FRAME_LEN
	38
	39
1da177e4 LT	40	#define NETWORK_INTR 8
	41
	42	struct simeth_local {
	43	struct net_device_stats stats;
	44	int simfd; /* descriptor in the simulator */
	45	};
	46
	47	static int simeth_probe1(void);
	48	static int simeth_open(struct net_device *dev);
	49	static int simeth_close(struct net_device *dev);
	50	static int simeth_tx(struct sk_buff skb, struct net_device dev);
	51	static int simeth_rx(struct net_device *dev);
	52	static struct net_device_stats simeth_get_stats(struct net_device dev);
5dcded1b	53	static irqreturn_t simeth_interrupt(int irq, void *dev_id);
1da177e4 LT	54	static void set_multicast_list(struct net_device *dev);
	55	static int simeth_device_event(struct notifier_block this,unsigned long event, void ptr);
	56
	57	static char *simeth_version="0.3";
	58
	59	/*
	60	* This variable is used to establish a mapping between the Linux/ia64 kernel
	61	* and the host linux kernel.
	62	*
	63	* As of today, we support only one card, even though most of the code
	64	* is ready for many more. The mapping is then:
	65	* linux/ia64 -> linux/x86
	66	* eth0 -> eth1
	67	*
	68	* In the future, we some string operations, we could easily support up
	69	* to 10 cards (0-9).
	70	*
	71	* The default mapping can be changed on the kernel command line by
	72	* specifying simeth=ethX (or whatever string you want).
	73	*/
	74	static char simeth_device="eth0"; / default host interface to use */
	75
	76
	77
	78	static volatile unsigned int card_count; /* how many cards "found" so far */
	79	static int simeth_debug; /* set to 1 to get debug information */
	80
	81	/*
	82	* Used to catch IFF_UP & IFF_DOWN events
	83	*/
	84	static struct notifier_block simeth_dev_notifier = {
	85	simeth_device_event,
cfa7fd72	86	NULL
1da177e4 LT	87	};
	88
	89
	90	/*
	91	* Function used when using a kernel command line option.
	92	*
	93	* Format: simeth=interface_name (like eth0)
	94	*/
	95	static int __init
	96	simeth_setup(char *str)
	97	{
	98	simeth_device = str;
	99	return 1;
	100	}
	101
	102	__setup("simeth=", simeth_setup);
	103
	104	/*
	105	* Function used to probe for simeth devices when not installed
	106	* as a loadable module
	107	*/
	108
	109	int __init
	110	simeth_probe (void)
	111	{
	112	int r;
	113
	114	printk(KERN_INFO "simeth: v%s\n", simeth_version);
	115
	116	r = simeth_probe1();
	117
	118	if (r == 0) register_netdevice_notifier(&simeth_dev_notifier);
	119
	120	return r;
	121	}
	122
1da177e4 LT	123	static inline int
	124	netdev_probe(char name, unsigned char ether)
	125	{
	126	return ia64_ssc(__pa(name), __pa(ether), 0,0, SSC_NETDEV_PROBE);
	127	}
	128
	129
1da177e4 LT	130	static inline int
	131	netdev_attach(int fd, int irq, unsigned int ipaddr)
	132	{
	133	/* this puts the host interface in the right mode (start interrupting) */
	134	return ia64_ssc(fd, ipaddr, 0,0, SSC_NETDEV_ATTACH);
	135	}
	136
	137
	138	static inline int
	139	netdev_detach(int fd)
	140	{
	141	/*
	142	* inactivate the host interface (don't interrupt anymore) */
	143	return ia64_ssc(fd, 0,0,0, SSC_NETDEV_DETACH);
	144	}
	145
	146	static inline int
	147	netdev_send(int fd, unsigned char *buf, unsigned int len)
	148	{
	149	return ia64_ssc(fd, __pa(buf), len, 0, SSC_NETDEV_SEND);
	150	}
	151
	152	static inline int
	153	netdev_read(int fd, unsigned char *buf, unsigned int len)
	154	{
	155	return ia64_ssc(fd, __pa(buf), len, 0, SSC_NETDEV_RECV);
	156	}
	157
f9867328 AD	158	static const struct net_device_ops simeth_netdev_ops = {
	159	.ndo_open = simeth_open,
	160	.ndo_stop = simeth_close,
	161	.ndo_start_xmit = simeth_tx,
	162	.ndo_get_stats = simeth_get_stats,
afc4b13d	163	.ndo_set_rx_mode = set_multicast_list, /* not yet used */
f9867328 AD	164
	165	};
	166
1da177e4 LT	167	/*
	168	* Function shared with module code, so cannot be in init section
	169	*
	170	* So far this function "detects" only one card (test_&_set) but could
	171	* be extended easily.
	172	*
	173	* Return:
	174	* - -ENODEV is no device found
	175	* - -ENOMEM is no more memory
	176	* - 0 otherwise
	177	*/
	178	static int
	179	simeth_probe1(void)
	180	{
	181	unsigned char mac_addr[ETH_ALEN];
	182	struct simeth_local *local;
	183	struct net_device *dev;
ff40a675	184	int fd, err, rc;
1da177e4 LT	185
	186	/*
	187	* XXX Fix me
	188	* let's support just one card for now
	189	*/
	190	if (test_and_set_bit(0, &card_count))
	191	return -ENODEV;
	192
	193	/*
	194	* check with the simulator for the device
	195	*/
	196	fd = netdev_probe(simeth_device, mac_addr);
	197	if (fd == -1)
	198	return -ENODEV;
	199
	200	dev = alloc_etherdev(sizeof(struct simeth_local));
	201	if (!dev)
	202	return -ENOMEM;
	203
	204	memcpy(dev->dev_addr, mac_addr, sizeof(mac_addr));
	205
28945dd4	206	local = netdev_priv(dev);
1da177e4 LT	207	local->simfd = fd; /* keep track of underlying file descriptor */
1da177e4 LT	208
f9867328	209	dev->netdev_ops = &simeth_netdev_ops;
1da177e4 LT	210
	211	err = register_netdev(dev);
	212	if (err) {
	213	free_netdev(dev);
	214	return err;
	215	}
	216
1da177e4 LT	217	/*
	218	* attach the interrupt in the simulator, this does enable interrupts
	219	* until a netdev_attach() is called
	220	*/
6efb6b77 JS	221	if ((rc = hpsim_get_irq(NETWORK_INTR)) < 0)
	222	panic("%s: out of interrupt vectors!\n", __func__);
	223	dev->irq = rc;
1da177e4	224
ff40a675 DK	225	printk(KERN_INFO "%s: hosteth=%s simfd=%d, HwAddr=%pm, IRQ %d\n",
ff40a675 DK	226	dev->name, simeth_device, local->simfd, dev->dev_addr, dev->irq);
1da177e4 LT	227
	228	return 0;
	229	}
	230
	231	/*
	232	* actually binds the device to an interrupt vector
	233	*/
	234	static int
	235	simeth_open(struct net_device *dev)
	236	{
	237	if (request_irq(dev->irq, simeth_interrupt, 0, "simeth", dev)) {
	238	printk(KERN_WARNING "simeth: unable to get IRQ %d.\n", dev->irq);
	239	return -EAGAIN;
	240	}
	241
	242	netif_start_queue(dev);
	243
	244	return 0;
	245	}
	246
	247	/* copied from lapbether.c */
	248	static __inline__ int dev_is_ethdev(struct net_device *dev)
	249	{
	250	return ( dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5));
	251	}
	252
	253
	254	/*
	255	* Handler for IFF_UP or IFF_DOWN
	256	*
	257	* The reason for that is that we don't want to be interrupted when the
	258	* interface is down. There is no way to unconnect in the simualtor. Instead
	259	* we use this function to shutdown packet processing in the frame filter
	260	* in the simulator. Thus no interrupts are generated
	261	*
	262	*
	263	* That's also the place where we pass the IP address of this device to the
	264	* simulator so that that we can start filtering packets for it
	265	*
	266	* There may be a better way of doing this, but I don't know which yet.
	267	*/
	268	static int
	269	simeth_device_event(struct notifier_block this,unsigned long event, void ptr)
	270	{
351638e7	271	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1da177e4 LT	272	struct simeth_local *local;
	273	struct in_device *in_dev;
	274	struct in_ifaddr **ifap = NULL;
	275	struct in_ifaddr *ifa = NULL;
	276	int r;
	277
	278
	279	if ( ! dev ) {
	280	printk(KERN_WARNING "simeth_device_event dev=0\n");
	281	return NOTIFY_DONE;
	282	}
	283
c346dca1	284	if (dev_net(dev) != &init_net)
e9dc8653 EB	285	return NOTIFY_DONE;
e9dc8653 EB	286
1da177e4 LT	287	if ( event != NETDEV_UP && event != NETDEV_DOWN ) return NOTIFY_DONE;
	288
	289	/*
	290	* Check whether or not it's for an ethernet device
	291	*
	292	* XXX Fixme: This works only as long as we support one
	293	* type of ethernet device.
	294	*/
	295	if ( !dev_is_ethdev(dev) ) return NOTIFY_DONE;
	296
	297	if ((in_dev=dev->ip_ptr) != NULL) {
	298	for (ifap=&in_dev->ifa_list; (ifa=*ifap) != NULL; ifap=&ifa->ifa_next)
	299	if (strcmp(dev->name, ifa->ifa_label) == 0) break;
	300	}
	301	if ( ifa == NULL ) {
	302	printk(KERN_ERR "simeth_open: can't find device %s's ifa\n", dev->name);
	303	return NOTIFY_DONE;
	304	}
	305
	306	printk(KERN_INFO "simeth_device_event: %s ipaddr=0x%x\n",
a144ea4b	307	dev->name, ntohl(ifa->ifa_local));
1da177e4 LT	308
	309	/*
	310	* XXX Fix me
	311	* if the device was up, and we're simply reconfiguring it, not sure
	312	* we get DOWN then UP.
	313	*/
	314
28945dd4	315	local = netdev_priv(dev);
1da177e4 LT	316	/* now do it for real */
1da177e4 LT	317	r = event == NETDEV_UP ?
a144ea4b	318	netdev_attach(local->simfd, dev->irq, ntohl(ifa->ifa_local)):
1da177e4 LT	319	netdev_detach(local->simfd);
	320
	321	printk(KERN_INFO "simeth: netdev_attach/detach: event=%s ->%d\n",
	322	event == NETDEV_UP ? "attach":"detach", r);
	323
	324	return NOTIFY_DONE;
	325	}
	326
	327	static int
	328	simeth_close(struct net_device *dev)
	329	{
	330	netif_stop_queue(dev);
	331
	332	free_irq(dev->irq, dev);
	333
	334	return 0;
	335	}
	336
	337	/*
	338	* Only used for debug
	339	*/
	340	static void
	341	frame_print(unsigned char from, unsigned char frame, int len)
	342	{
	343	int i;
	344
	345	printk("%s: (%d) %02x", from, len, frame[0] & 0xff);
	346	for(i=1; i < 6; i++ ) {
	347	printk(":%02x", frame[i] &0xff);
	348	}
	349	printk(" %2x", frame[6] &0xff);
	350	for(i=7; i < 12; i++ ) {
	351	printk(":%02x", frame[i] &0xff);
	352	}
	353	printk(" [%02x%02x]\n", frame[12], frame[13]);
	354
	355	for(i=14; i < len; i++ ) {
	356	printk("%02x ", frame[i] &0xff);
	357	if ( (i%10)==0) printk("\n");
	358	}
	359	printk("\n");
	360	}
	361
	362
	363	/*
	364	* Function used to transmit of frame, very last one on the path before
	365	* going to the simulator.
	366	*/
	367	static int
	368	simeth_tx(struct sk_buff skb, struct net_device dev)
	369	{
28945dd4	370	struct simeth_local *local = netdev_priv(dev);
1da177e4 LT	371
	372	#if 0
	373	/* ensure we have at least ETH_ZLEN bytes (min frame size) */
	374	unsigned int length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN;
	375	/* Where do the extra padding bytes comes from inthe skbuff ? */
	376	#else
	377	/* the real driver in the host system is going to take care of that
	378	* or maybe it's the NIC itself.
	379	*/
	380	unsigned int length = skb->len;
	381	#endif
	382
	383	local->stats.tx_bytes += skb->len;
	384	local->stats.tx_packets++;
	385
	386
	387	if (simeth_debug > 5) frame_print("simeth_tx", skb->data, length);
	388
	389	netdev_send(local->simfd, skb->data, length);
	390
	391	/*
	392	* we are synchronous on write, so we don't simulate a
	393	* trasnmit complete interrupt, thus we don't need to arm a tx
	394	*/
	395
	396	dev_kfree_skb(skb);
6ed10654	397	return NETDEV_TX_OK;
1da177e4 LT	398	}
	399
	400	static inline struct sk_buff *
	401	make_new_skb(struct net_device *dev)
	402	{
	403	struct sk_buff *nskb;
	404
	405	/*
	406	* The +2 is used to make sure that the IP header is nicely
	407	* aligned (on 4byte boundary I assume 14+2=16)
	408	*/
	409	nskb = dev_alloc_skb(SIMETH_FRAME_SIZE + 2);
	410	if ( nskb == NULL ) {
	411	printk(KERN_NOTICE "%s: memory squeeze. dropping packet.\n", dev->name);
	412	return NULL;
	413	}
1da177e4 LT	414
	415	skb_reserve(nskb, 2); /* Align IP on 16 byte boundaries */
	416
	417	skb_put(nskb,SIMETH_FRAME_SIZE);
	418
	419	return nskb;
	420	}
	421
	422	/*
	423	* called from interrupt handler to process a received frame
	424	*/
	425	static int
	426	simeth_rx(struct net_device *dev)
	427	{
	428	struct simeth_local *local;
	429	struct sk_buff *skb;
	430	int len;
	431	int rcv_count = SIMETH_RECV_MAX;
	432
28945dd4	433	local = netdev_priv(dev);
1da177e4 LT	434	/*
	435	* the loop concept has been borrowed from other drivers
	436	* looks to me like it's a throttling thing to avoid pushing to many
	437	* packets at one time into the stack. Making sure we can process them
	438	* upstream and make forward progress overall
	439	*/
	440	do {
	441	if ( (skb=make_new_skb(dev)) == NULL ) {
	442	printk(KERN_NOTICE "%s: memory squeeze. dropping packet.\n", dev->name);
	443	local->stats.rx_dropped++;
	444	return 0;
	445	}
	446	/*
	447	* Read only one frame at a time
	448	*/
	449	len = netdev_read(local->simfd, skb->data, SIMETH_FRAME_SIZE);
	450	if ( len == 0 ) {
	451	if ( simeth_debug > 0 ) printk(KERN_WARNING "%s: count=%d netdev_read=0\n",
	452	dev->name, SIMETH_RECV_MAX-rcv_count);
	453	break;
	454	}
	455	#if 0
	456	/*
	457	* XXX Fix me
	458	* Should really do a csum+copy here
	459	*/
27d7ff46	460	skb_copy_to_linear_data(skb, frame, len);
1da177e4 LT	461	#endif
	462	skb->protocol = eth_type_trans(skb, dev);
	463
	464	if ( simeth_debug > 6 ) frame_print("simeth_rx", skb->data, len);
	465
	466	/*
	467	* push the packet up & trigger software interrupt
	468	*/
	469	netif_rx(skb);
	470
	471	local->stats.rx_packets++;
	472	local->stats.rx_bytes += len;
	473
	474	} while ( --rcv_count );
	475
	476	return len; /* 0 = nothing left to read, otherwise, we can try again */
	477	}
	478
	479	/*
	480	* Interrupt handler (Yes, we can do it too !!!)
	481	*/
	482	static irqreturn_t
5dcded1b	483	simeth_interrupt(int irq, void *dev_id)
1da177e4 LT	484	{
	485	struct net_device *dev = dev_id;
	486
1da177e4 LT	487	/*
	488	* very simple loop because we get interrupts only when receiving
	489	*/
	490	while (simeth_rx(dev));
	491	return IRQ_HANDLED;
	492	}
	493
	494	static struct net_device_stats *
	495	simeth_get_stats(struct net_device *dev)
	496	{
28945dd4	497	struct simeth_local *local = netdev_priv(dev);
1da177e4 LT	498
	499	return &local->stats;
	500	}
	501
	502	/* fake multicast ability */
	503	static void
	504	set_multicast_list(struct net_device *dev)
	505	{
	506	printk(KERN_WARNING "%s: set_multicast_list called\n", dev->name);
	507	}
	508
	509	__initcall(simeth_probe);