[mirror_ubuntu-focal-kernel.git] / arch / ia64 / hp / sim / simeth.c

// SPDX-License-Identifier: GPL-2.0
/*
 * 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
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/*
	3	* Simulated Ethernet Driver
	4	*
	5	* Copyright (C) 1999-2001, 2003 Hewlett-Packard Co
	6	* Stephane Eranian <eranian@hpl.hp.com>
	7	*/
1da177e4 LT	8	#include <linux/kernel.h>
	9	#include <linux/sched.h>
	10	#include <linux/types.h>
	11	#include <linux/in.h>
	12	#include <linux/string.h>
	13	#include <linux/init.h>
	14	#include <linux/errno.h>
	15	#include <linux/interrupt.h>
	16	#include <linux/netdevice.h>
	17	#include <linux/etherdevice.h>
	18	#include <linux/inetdevice.h>
	19	#include <linux/if_ether.h>
	20	#include <linux/if_arp.h>
	21	#include <linux/skbuff.h>
	22	#include <linux/notifier.h>
	23	#include <linux/bitops.h>
1da177e4	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
1da177e4 LT	131	static inline int
	132	netdev_attach(int fd, int irq, unsigned int ipaddr)
	133	{
	134	/* this puts the host interface in the right mode (start interrupting) */
	135	return ia64_ssc(fd, ipaddr, 0,0, SSC_NETDEV_ATTACH);
	136	}
	137
	138
	139	static inline int
	140	netdev_detach(int fd)
	141	{
	142	/*
	143	* inactivate the host interface (don't interrupt anymore) */
	144	return ia64_ssc(fd, 0,0,0, SSC_NETDEV_DETACH);
	145	}
	146
	147	static inline int
	148	netdev_send(int fd, unsigned char *buf, unsigned int len)
	149	{
	150	return ia64_ssc(fd, __pa(buf), len, 0, SSC_NETDEV_SEND);
	151	}
	152
	153	static inline int
	154	netdev_read(int fd, unsigned char *buf, unsigned int len)
	155	{
	156	return ia64_ssc(fd, __pa(buf), len, 0, SSC_NETDEV_RECV);
	157	}
	158
f9867328 AD	159	static const struct net_device_ops simeth_netdev_ops = {
	160	.ndo_open = simeth_open,
	161	.ndo_stop = simeth_close,
	162	.ndo_start_xmit = simeth_tx,
	163	.ndo_get_stats = simeth_get_stats,
afc4b13d	164	.ndo_set_rx_mode = set_multicast_list, /* not yet used */
f9867328 AD	165
	166	};
	167
1da177e4 LT	168	/*
	169	* Function shared with module code, so cannot be in init section
	170	*
	171	* So far this function "detects" only one card (test_&_set) but could
	172	* be extended easily.
	173	*
	174	* Return:
	175	* - -ENODEV is no device found
	176	* - -ENOMEM is no more memory
	177	* - 0 otherwise
	178	*/
	179	static int
	180	simeth_probe1(void)
	181	{
	182	unsigned char mac_addr[ETH_ALEN];
	183	struct simeth_local *local;
	184	struct net_device *dev;
ff40a675	185	int fd, err, rc;
1da177e4 LT	186
	187	/*
	188	* XXX Fix me
	189	* let's support just one card for now
	190	*/
	191	if (test_and_set_bit(0, &card_count))
	192	return -ENODEV;
	193
	194	/*
	195	* check with the simulator for the device
	196	*/
	197	fd = netdev_probe(simeth_device, mac_addr);
	198	if (fd == -1)
	199	return -ENODEV;
	200
	201	dev = alloc_etherdev(sizeof(struct simeth_local));
	202	if (!dev)
	203	return -ENOMEM;
	204
	205	memcpy(dev->dev_addr, mac_addr, sizeof(mac_addr));
	206
28945dd4	207	local = netdev_priv(dev);
1da177e4 LT	208	local->simfd = fd; /* keep track of underlying file descriptor */
1da177e4 LT	209
f9867328	210	dev->netdev_ops = &simeth_netdev_ops;
1da177e4 LT	211
	212	err = register_netdev(dev);
	213	if (err) {
	214	free_netdev(dev);
	215	return err;
	216	}
	217
1da177e4 LT	218	/*
	219	* attach the interrupt in the simulator, this does enable interrupts
	220	* until a netdev_attach() is called
	221	*/
6efb6b77 JS	222	if ((rc = hpsim_get_irq(NETWORK_INTR)) < 0)
	223	panic("%s: out of interrupt vectors!\n", __func__);
	224	dev->irq = rc;
1da177e4	225
ff40a675 DK	226	printk(KERN_INFO "%s: hosteth=%s simfd=%d, HwAddr=%pm, IRQ %d\n",
ff40a675 DK	227	dev->name, simeth_device, local->simfd, dev->dev_addr, dev->irq);
1da177e4 LT	228
	229	return 0;
	230	}
	231
	232	/*
	233	* actually binds the device to an interrupt vector
	234	*/
	235	static int
	236	simeth_open(struct net_device *dev)
	237	{
	238	if (request_irq(dev->irq, simeth_interrupt, 0, "simeth", dev)) {
	239	printk(KERN_WARNING "simeth: unable to get IRQ %d.\n", dev->irq);
	240	return -EAGAIN;
	241	}
	242
	243	netif_start_queue(dev);
	244
	245	return 0;
	246	}
	247
	248	/* copied from lapbether.c */
	249	static __inline__ int dev_is_ethdev(struct net_device *dev)
	250	{
	251	return ( dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5));
	252	}
	253
	254
	255	/*
	256	* Handler for IFF_UP or IFF_DOWN
	257	*
	258	* The reason for that is that we don't want to be interrupted when the
	259	* interface is down. There is no way to unconnect in the simualtor. Instead
	260	* we use this function to shutdown packet processing in the frame filter
	261	* in the simulator. Thus no interrupts are generated
	262	*
	263	*
	264	* That's also the place where we pass the IP address of this device to the
	265	* simulator so that that we can start filtering packets for it
	266	*
	267	* There may be a better way of doing this, but I don't know which yet.
	268	*/
	269	static int
	270	simeth_device_event(struct notifier_block this,unsigned long event, void ptr)
	271	{
351638e7	272	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1da177e4 LT	273	struct simeth_local *local;
	274	struct in_device *in_dev;
	275	struct in_ifaddr **ifap = NULL;
	276	struct in_ifaddr *ifa = NULL;
	277	int r;
	278
	279
	280	if ( ! dev ) {
	281	printk(KERN_WARNING "simeth_device_event dev=0\n");
	282	return NOTIFY_DONE;
	283	}
	284
c346dca1	285	if (dev_net(dev) != &init_net)
e9dc8653 EB	286	return NOTIFY_DONE;
e9dc8653 EB	287
1da177e4 LT	288	if ( event != NETDEV_UP && event != NETDEV_DOWN ) return NOTIFY_DONE;
	289
	290	/*
	291	* Check whether or not it's for an ethernet device
	292	*
	293	* XXX Fixme: This works only as long as we support one
	294	* type of ethernet device.
	295	*/
	296	if ( !dev_is_ethdev(dev) ) return NOTIFY_DONE;
	297
	298	if ((in_dev=dev->ip_ptr) != NULL) {
	299	for (ifap=&in_dev->ifa_list; (ifa=*ifap) != NULL; ifap=&ifa->ifa_next)
	300	if (strcmp(dev->name, ifa->ifa_label) == 0) break;
	301	}
	302	if ( ifa == NULL ) {
	303	printk(KERN_ERR "simeth_open: can't find device %s's ifa\n", dev->name);
	304	return NOTIFY_DONE;
	305	}
	306
	307	printk(KERN_INFO "simeth_device_event: %s ipaddr=0x%x\n",
a144ea4b	308	dev->name, ntohl(ifa->ifa_local));
1da177e4 LT	309
	310	/*
	311	* XXX Fix me
	312	* if the device was up, and we're simply reconfiguring it, not sure
	313	* we get DOWN then UP.
	314	*/
	315
28945dd4	316	local = netdev_priv(dev);
1da177e4 LT	317	/* now do it for real */
1da177e4 LT	318	r = event == NETDEV_UP ?
a144ea4b	319	netdev_attach(local->simfd, dev->irq, ntohl(ifa->ifa_local)):
1da177e4 LT	320	netdev_detach(local->simfd);
	321
	322	printk(KERN_INFO "simeth: netdev_attach/detach: event=%s ->%d\n",
	323	event == NETDEV_UP ? "attach":"detach", r);
	324
	325	return NOTIFY_DONE;
	326	}
	327
	328	static int
	329	simeth_close(struct net_device *dev)
	330	{
	331	netif_stop_queue(dev);
	332
	333	free_irq(dev->irq, dev);
	334
	335	return 0;
	336	}
	337
	338	/*
	339	* Only used for debug
	340	*/
	341	static void
	342	frame_print(unsigned char from, unsigned char frame, int len)
	343	{
	344	int i;
	345
	346	printk("%s: (%d) %02x", from, len, frame[0] & 0xff);
	347	for(i=1; i < 6; i++ ) {
	348	printk(":%02x", frame[i] &0xff);
	349	}
	350	printk(" %2x", frame[6] &0xff);
	351	for(i=7; i < 12; i++ ) {
	352	printk(":%02x", frame[i] &0xff);
	353	}
	354	printk(" [%02x%02x]\n", frame[12], frame[13]);
	355
	356	for(i=14; i < len; i++ ) {
	357	printk("%02x ", frame[i] &0xff);
	358	if ( (i%10)==0) printk("\n");
	359	}
	360	printk("\n");
	361	}
	362
	363
	364	/*
	365	* Function used to transmit of frame, very last one on the path before
	366	* going to the simulator.
	367	*/
	368	static int
	369	simeth_tx(struct sk_buff skb, struct net_device dev)
	370	{
28945dd4	371	struct simeth_local *local = netdev_priv(dev);
1da177e4 LT	372
	373	#if 0
	374	/* ensure we have at least ETH_ZLEN bytes (min frame size) */
	375	unsigned int length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN;
	376	/* Where do the extra padding bytes comes from inthe skbuff ? */
	377	#else
	378	/* the real driver in the host system is going to take care of that
	379	* or maybe it's the NIC itself.
	380	*/
	381	unsigned int length = skb->len;
	382	#endif
	383
	384	local->stats.tx_bytes += skb->len;
	385	local->stats.tx_packets++;
	386
	387
	388	if (simeth_debug > 5) frame_print("simeth_tx", skb->data, length);
	389
	390	netdev_send(local->simfd, skb->data, length);
	391
	392	/*
	393	* we are synchronous on write, so we don't simulate a
	394	* trasnmit complete interrupt, thus we don't need to arm a tx
	395	*/
	396
	397	dev_kfree_skb(skb);
6ed10654	398	return NETDEV_TX_OK;
1da177e4 LT	399	}
	400
	401	static inline struct sk_buff *
	402	make_new_skb(struct net_device *dev)
	403	{
	404	struct sk_buff *nskb;
	405
	406	/*
	407	* The +2 is used to make sure that the IP header is nicely
	408	* aligned (on 4byte boundary I assume 14+2=16)
	409	*/
	410	nskb = dev_alloc_skb(SIMETH_FRAME_SIZE + 2);
	411	if ( nskb == NULL ) {
	412	printk(KERN_NOTICE "%s: memory squeeze. dropping packet.\n", dev->name);
	413	return NULL;
	414	}
1da177e4 LT	415
	416	skb_reserve(nskb, 2); /* Align IP on 16 byte boundaries */
	417
	418	skb_put(nskb,SIMETH_FRAME_SIZE);
	419
	420	return nskb;
	421	}
	422
	423	/*
	424	* called from interrupt handler to process a received frame
	425	*/
	426	static int
	427	simeth_rx(struct net_device *dev)
	428	{
	429	struct simeth_local *local;
	430	struct sk_buff *skb;
	431	int len;
	432	int rcv_count = SIMETH_RECV_MAX;
	433
28945dd4	434	local = netdev_priv(dev);
1da177e4 LT	435	/*
	436	* the loop concept has been borrowed from other drivers
	437	* looks to me like it's a throttling thing to avoid pushing to many
	438	* packets at one time into the stack. Making sure we can process them
	439	* upstream and make forward progress overall
	440	*/
	441	do {
	442	if ( (skb=make_new_skb(dev)) == NULL ) {
	443	printk(KERN_NOTICE "%s: memory squeeze. dropping packet.\n", dev->name);
	444	local->stats.rx_dropped++;
	445	return 0;
	446	}
	447	/*
	448	* Read only one frame at a time
	449	*/
	450	len = netdev_read(local->simfd, skb->data, SIMETH_FRAME_SIZE);
	451	if ( len == 0 ) {
	452	if ( simeth_debug > 0 ) printk(KERN_WARNING "%s: count=%d netdev_read=0\n",
	453	dev->name, SIMETH_RECV_MAX-rcv_count);
	454	break;
	455	}
	456	#if 0
	457	/*
	458	* XXX Fix me
	459	* Should really do a csum+copy here
	460	*/
27d7ff46	461	skb_copy_to_linear_data(skb, frame, len);
1da177e4 LT	462	#endif
	463	skb->protocol = eth_type_trans(skb, dev);
	464
	465	if ( simeth_debug > 6 ) frame_print("simeth_rx", skb->data, len);
	466
	467	/*
	468	* push the packet up & trigger software interrupt
	469	*/
	470	netif_rx(skb);
	471
	472	local->stats.rx_packets++;
	473	local->stats.rx_bytes += len;
	474
	475	} while ( --rcv_count );
	476
	477	return len; /* 0 = nothing left to read, otherwise, we can try again */
	478	}
	479
	480	/*
	481	* Interrupt handler (Yes, we can do it too !!!)
	482	*/
	483	static irqreturn_t
5dcded1b	484	simeth_interrupt(int irq, void *dev_id)
1da177e4 LT	485	{
	486	struct net_device *dev = dev_id;
	487
1da177e4 LT	488	/*
	489	* very simple loop because we get interrupts only when receiving
	490	*/
	491	while (simeth_rx(dev));
	492	return IRQ_HANDLED;
	493	}
	494
	495	static struct net_device_stats *
	496	simeth_get_stats(struct net_device *dev)
	497	{
28945dd4	498	struct simeth_local *local = netdev_priv(dev);
1da177e4 LT	499
	500	return &local->stats;
	501	}
	502
	503	/* fake multicast ability */
	504	static void
	505	set_multicast_list(struct net_device *dev)
	506	{
	507	printk(KERN_WARNING "%s: set_multicast_list called\n", dev->name);
	508	}
	509
	510	__initcall(simeth_probe);