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/arch/ia64/hp/sim/simeth.c

https://bitbucket.org/evzijst/gittest
C | 530 lines | 292 code | 93 blank | 145 comment | 44 complexity | 0c30f851764c38179426d7c95cabe9b9 MD5 | raw file
  1/*
  2 * Simulated Ethernet Driver
  3 *
  4 * Copyright (C) 1999-2001, 2003 Hewlett-Packard Co
  5 *	Stephane Eranian <eranian@hpl.hp.com>
  6 */
  7#include <linux/config.h>
  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>
 24#include <asm/system.h>
 25#include <asm/irq.h>
 26
 27#define SIMETH_RECV_MAX	10
 28
 29/*
 30 * Maximum possible received frame for Ethernet.
 31 * We preallocate an sk_buff of that size to avoid costly
 32 * memcpy for temporary buffer into sk_buff. We do basically
 33 * what's done in other drivers, like eepro with a ring.
 34 * The difference is, of course, that we don't have real DMA !!!
 35 */
 36#define SIMETH_FRAME_SIZE	ETH_FRAME_LEN
 37
 38
 39#define SSC_NETDEV_PROBE		100
 40#define SSC_NETDEV_SEND			101
 41#define SSC_NETDEV_RECV			102
 42#define SSC_NETDEV_ATTACH		103
 43#define SSC_NETDEV_DETACH		104
 44
 45#define NETWORK_INTR			8
 46
 47struct simeth_local {
 48	struct net_device_stats stats;
 49	int 			simfd;	 /* descriptor in the simulator */
 50};
 51
 52static int simeth_probe1(void);
 53static int simeth_open(struct net_device *dev);
 54static int simeth_close(struct net_device *dev);
 55static int simeth_tx(struct sk_buff *skb, struct net_device *dev);
 56static int simeth_rx(struct net_device *dev);
 57static struct net_device_stats *simeth_get_stats(struct net_device *dev);
 58static irqreturn_t simeth_interrupt(int irq, void *dev_id, struct pt_regs * regs);
 59static void set_multicast_list(struct net_device *dev);
 60static int simeth_device_event(struct notifier_block *this,unsigned long event, void *ptr);
 61
 62static char *simeth_version="0.3";
 63
 64/*
 65 * This variable is used to establish a mapping between the Linux/ia64 kernel
 66 * and the host linux kernel.
 67 *
 68 * As of today, we support only one card, even though most of the code
 69 * is ready for many more. The mapping is then:
 70 *	linux/ia64 -> linux/x86
 71 * 	   eth0    -> eth1
 72 *
 73 * In the future, we some string operations, we could easily support up
 74 * to 10 cards (0-9).
 75 *
 76 * The default mapping can be changed on the kernel command line by
 77 * specifying simeth=ethX (or whatever string you want).
 78 */
 79static char *simeth_device="eth0";	 /* default host interface to use */
 80
 81
 82
 83static volatile unsigned int card_count; /* how many cards "found" so far */
 84static int simeth_debug;		/* set to 1 to get debug information */
 85
 86/*
 87 * Used to catch IFF_UP & IFF_DOWN events
 88 */
 89static struct notifier_block simeth_dev_notifier = {
 90	simeth_device_event,
 91	0
 92};
 93
 94
 95/*
 96 * Function used when using a kernel command line option.
 97 *
 98 * Format: simeth=interface_name (like eth0)
 99 */
100static int __init
101simeth_setup(char *str)
102{
103	simeth_device = str;
104	return 1;
105}
106
107__setup("simeth=", simeth_setup);
108
109/*
110 * Function used to probe for simeth devices when not installed
111 * as a loadable module
112 */
113
114int __init
115simeth_probe (void)
116{
117	int r;
118
119	printk(KERN_INFO "simeth: v%s\n", simeth_version);
120
121	r = simeth_probe1();
122
123	if (r == 0) register_netdevice_notifier(&simeth_dev_notifier);
124
125	return r;
126}
127
128extern long ia64_ssc (long, long, long, long, int);
129extern void ia64_ssc_connect_irq (long intr, long irq);
130
131static inline int
132netdev_probe(char *name, unsigned char *ether)
133{
134	return ia64_ssc(__pa(name), __pa(ether), 0,0, SSC_NETDEV_PROBE);
135}
136
137
138static inline int
139netdev_connect(int irq)
140{
141	/* XXX Fix me
142	 * this does not support multiple cards
143	 * also no return value
144	 */
145	ia64_ssc_connect_irq(NETWORK_INTR, irq);
146	return 0;
147}
148
149static inline int
150netdev_attach(int fd, int irq, unsigned int ipaddr)
151{
152	/* this puts the host interface in the right mode (start interrupting) */
153	return ia64_ssc(fd, ipaddr, 0,0, SSC_NETDEV_ATTACH);
154}
155
156
157static inline int
158netdev_detach(int fd)
159{
160	/*
161	 * inactivate the host interface (don't interrupt anymore) */
162	return ia64_ssc(fd, 0,0,0, SSC_NETDEV_DETACH);
163}
164
165static inline int
166netdev_send(int fd, unsigned char *buf, unsigned int len)
167{
168	return ia64_ssc(fd, __pa(buf), len, 0, SSC_NETDEV_SEND);
169}
170
171static inline int
172netdev_read(int fd, unsigned char *buf, unsigned int len)
173{
174	return ia64_ssc(fd, __pa(buf), len, 0, SSC_NETDEV_RECV);
175}
176
177/*
178 * Function shared with module code, so cannot be in init section
179 *
180 * So far this function "detects" only one card (test_&_set) but could
181 * be extended easily.
182 *
183 * Return:
184 * 	- -ENODEV is no device found
185 *	- -ENOMEM is no more memory
186 *	- 0 otherwise
187 */
188static int
189simeth_probe1(void)
190{
191	unsigned char mac_addr[ETH_ALEN];
192	struct simeth_local *local;
193	struct net_device *dev;
194	int fd, i, err;
195
196	/*
197	 * XXX Fix me
198	 * let's support just one card for now
199	 */
200	if (test_and_set_bit(0, &card_count))
201		return -ENODEV;
202
203	/*
204	 * check with the simulator for the device
205	 */
206	fd = netdev_probe(simeth_device, mac_addr);
207	if (fd == -1)
208		return -ENODEV;
209
210	dev = alloc_etherdev(sizeof(struct simeth_local));
211	if (!dev)
212		return -ENOMEM;
213
214	memcpy(dev->dev_addr, mac_addr, sizeof(mac_addr));
215
216	local = dev->priv;
217	local->simfd = fd; /* keep track of underlying file descriptor */
218
219	dev->open		= simeth_open;
220	dev->stop		= simeth_close;
221	dev->hard_start_xmit	= simeth_tx;
222	dev->get_stats		= simeth_get_stats;
223	dev->set_multicast_list = set_multicast_list; /* no yet used */
224
225	err = register_netdev(dev);
226	if (err) {
227		free_netdev(dev);
228		return err;
229	}
230
231	dev->irq = assign_irq_vector(AUTO_ASSIGN);
232
233	/*
234	 * attach the interrupt in the simulator, this does enable interrupts
235	 * until a netdev_attach() is called
236	 */
237	netdev_connect(dev->irq);
238
239	printk(KERN_INFO "%s: hosteth=%s simfd=%d, HwAddr",
240	       dev->name, simeth_device, local->simfd);
241	for(i = 0; i < ETH_ALEN; i++) {
242		printk(" %2.2x", dev->dev_addr[i]);
243	}
244	printk(", IRQ %d\n", dev->irq);
245
246	return 0;
247}
248
249/*
250 * actually binds the device to an interrupt vector
251 */
252static int
253simeth_open(struct net_device *dev)
254{
255	if (request_irq(dev->irq, simeth_interrupt, 0, "simeth", dev)) {
256		printk(KERN_WARNING "simeth: unable to get IRQ %d.\n", dev->irq);
257		return -EAGAIN;
258	}
259
260	netif_start_queue(dev);
261
262	return 0;
263}
264
265/* copied from lapbether.c */
266static __inline__ int dev_is_ethdev(struct net_device *dev)
267{
268       return ( dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5));
269}
270
271
272/*
273 * Handler for IFF_UP or IFF_DOWN
274 *
275 * The reason for that is that we don't want to be interrupted when the
276 * interface is down. There is no way to unconnect in the simualtor. Instead
277 * we use this function to shutdown packet processing in the frame filter
278 * in the simulator. Thus no interrupts are generated
279 *
280 *
281 * That's also the place where we pass the IP address of this device to the
282 * simulator so that that we can start filtering packets for it
283 *
284 * There may be a better way of doing this, but I don't know which yet.
285 */
286static int
287simeth_device_event(struct notifier_block *this,unsigned long event, void *ptr)
288{
289	struct net_device *dev = ptr;
290	struct simeth_local *local;
291	struct in_device *in_dev;
292	struct in_ifaddr **ifap = NULL;
293	struct in_ifaddr *ifa = NULL;
294	int r;
295
296
297	if ( ! dev ) {
298		printk(KERN_WARNING "simeth_device_event dev=0\n");
299		return NOTIFY_DONE;
300	}
301
302	if ( event != NETDEV_UP && event != NETDEV_DOWN ) return NOTIFY_DONE;
303
304	/*
305	 * Check whether or not it's for an ethernet device
306	 *
307	 * XXX Fixme: This works only as long as we support one
308	 * type of ethernet device.
309	 */
310	if ( !dev_is_ethdev(dev) ) return NOTIFY_DONE;
311
312	if ((in_dev=dev->ip_ptr) != NULL) {
313		for (ifap=&in_dev->ifa_list; (ifa=*ifap) != NULL; ifap=&ifa->ifa_next)
314			if (strcmp(dev->name, ifa->ifa_label) == 0) break;
315	}
316	if ( ifa == NULL ) {
317		printk(KERN_ERR "simeth_open: can't find device %s's ifa\n", dev->name);
318		return NOTIFY_DONE;
319	}
320
321	printk(KERN_INFO "simeth_device_event: %s ipaddr=0x%x\n",
322	       dev->name, htonl(ifa->ifa_local));
323
324	/*
325	 * XXX Fix me
326	 * if the device was up, and we're simply reconfiguring it, not sure
327	 * we get DOWN then UP.
328	 */
329
330	local = dev->priv;
331	/* now do it for real */
332	r = event == NETDEV_UP ?
333		netdev_attach(local->simfd, dev->irq, htonl(ifa->ifa_local)):
334		netdev_detach(local->simfd);
335
336	printk(KERN_INFO "simeth: netdev_attach/detach: event=%s ->%d\n",
337	       event == NETDEV_UP ? "attach":"detach", r);
338
339	return NOTIFY_DONE;
340}
341
342static int
343simeth_close(struct net_device *dev)
344{
345	netif_stop_queue(dev);
346
347	free_irq(dev->irq, dev);
348
349	return 0;
350}
351
352/*
353 * Only used for debug
354 */
355static void
356frame_print(unsigned char *from, unsigned char *frame, int len)
357{
358	int i;
359
360	printk("%s: (%d) %02x", from, len, frame[0] & 0xff);
361	for(i=1; i < 6; i++ ) {
362		printk(":%02x", frame[i] &0xff);
363	}
364	printk(" %2x", frame[6] &0xff);
365	for(i=7; i < 12; i++ ) {
366		printk(":%02x", frame[i] &0xff);
367	}
368	printk(" [%02x%02x]\n", frame[12], frame[13]);
369
370	for(i=14; i < len; i++ ) {
371		printk("%02x ", frame[i] &0xff);
372		if ( (i%10)==0) printk("\n");
373	}
374	printk("\n");
375}
376
377
378/*
379 * Function used to transmit of frame, very last one on the path before
380 * going to the simulator.
381 */
382static int
383simeth_tx(struct sk_buff *skb, struct net_device *dev)
384{
385	struct simeth_local *local = dev->priv;
386
387#if 0
388	/* ensure we have at least ETH_ZLEN bytes (min frame size) */
389	unsigned int length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN;
390	/* Where do the extra padding bytes comes from inthe skbuff ? */
391#else
392	/* the real driver in the host system is going to take care of that
393	 * or maybe it's the NIC itself.
394	 */
395	unsigned int length = skb->len;
396#endif
397
398	local->stats.tx_bytes += skb->len;
399	local->stats.tx_packets++;
400
401
402	if (simeth_debug > 5) frame_print("simeth_tx", skb->data, length);
403
404	netdev_send(local->simfd, skb->data, length);
405
406	/*
407	 * we are synchronous on write, so we don't simulate a
408	 * trasnmit complete interrupt, thus we don't need to arm a tx
409	 */
410
411	dev_kfree_skb(skb);
412	return 0;
413}
414
415static inline struct sk_buff *
416make_new_skb(struct net_device *dev)
417{
418	struct sk_buff *nskb;
419
420	/*
421	 * The +2 is used to make sure that the IP header is nicely
422	 * aligned (on 4byte boundary I assume 14+2=16)
423	 */
424	nskb = dev_alloc_skb(SIMETH_FRAME_SIZE + 2);
425	if ( nskb == NULL ) {
426		printk(KERN_NOTICE "%s: memory squeeze. dropping packet.\n", dev->name);
427		return NULL;
428	}
429	nskb->dev = dev;
430
431	skb_reserve(nskb, 2);	/* Align IP on 16 byte boundaries */
432
433	skb_put(nskb,SIMETH_FRAME_SIZE);
434
435	return nskb;
436}
437
438/*
439 * called from interrupt handler to process a received frame
440 */
441static int
442simeth_rx(struct net_device *dev)
443{
444	struct simeth_local	*local;
445	struct sk_buff		*skb;
446	int			len;
447	int			rcv_count = SIMETH_RECV_MAX;
448
449	local = dev->priv;
450	/*
451	 * the loop concept has been borrowed from other drivers
452	 * looks to me like it's a throttling thing to avoid pushing to many
453	 * packets at one time into the stack. Making sure we can process them
454	 * upstream and make forward progress overall
455	 */
456	do {
457		if ( (skb=make_new_skb(dev)) == NULL ) {
458			printk(KERN_NOTICE "%s: memory squeeze. dropping packet.\n", dev->name);
459			local->stats.rx_dropped++;
460			return 0;
461		}
462		/*
463		 * Read only one frame at a time
464		 */
465		len = netdev_read(local->simfd, skb->data, SIMETH_FRAME_SIZE);
466		if ( len == 0 ) {
467			if ( simeth_debug > 0 ) printk(KERN_WARNING "%s: count=%d netdev_read=0\n",
468						       dev->name, SIMETH_RECV_MAX-rcv_count);
469			break;
470		}
471#if 0
472		/*
473		 * XXX Fix me
474		 * Should really do a csum+copy here
475		 */
476		memcpy(skb->data, frame, len);
477#endif
478		skb->protocol = eth_type_trans(skb, dev);
479
480		if ( simeth_debug > 6 ) frame_print("simeth_rx", skb->data, len);
481
482		/*
483		 * push the packet up & trigger software interrupt
484		 */
485		netif_rx(skb);
486
487		local->stats.rx_packets++;
488		local->stats.rx_bytes += len;
489
490	} while ( --rcv_count );
491
492	return len; /* 0 = nothing left to read, otherwise, we can try again */
493}
494
495/*
496 * Interrupt handler (Yes, we can do it too !!!)
497 */
498static irqreturn_t
499simeth_interrupt(int irq, void *dev_id, struct pt_regs * regs)
500{
501	struct net_device *dev = dev_id;
502
503	if ( dev == NULL ) {
504		printk(KERN_WARNING "simeth: irq %d for unknown device\n", irq);
505		return IRQ_NONE;
506	}
507
508	/*
509	 * very simple loop because we get interrupts only when receiving
510	 */
511	while (simeth_rx(dev));
512	return IRQ_HANDLED;
513}
514
515static struct net_device_stats *
516simeth_get_stats(struct net_device *dev)
517{
518	struct simeth_local *local = dev->priv;
519
520	return &local->stats;
521}
522
523/* fake multicast ability */
524static void
525set_multicast_list(struct net_device *dev)
526{
527	printk(KERN_WARNING "%s: set_multicast_list called\n", dev->name);
528}
529
530__initcall(simeth_probe);