summaryrefslogtreecommitdiffstats
path: root/arch/ia64/hp/sim/simeth.c
blob: 47afcc61f6e54235353e4f5c55d634395e08aa49 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
/*
 * 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);
}

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, 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 = 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;
	}

	if ((rc = assign_irq_vector(AUTO_ASSIGN)) < 0)
		panic("%s: out of interrupt vectors!\n", __func__);
	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_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);
OpenPOWER on IntegriCloud