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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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;
Kenji Kaneshige3b5cc092005-07-10 21:49:00 -0700194 int fd, i, err, rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195
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
Kenji Kaneshige3b5cc092005-07-10 21:49:00 -0700231 if ((rc = assign_irq_vector(AUTO_ASSIGN)) < 0)
232 panic("%s: out of interrupt vectors!\n", __FUNCTION__);
233 dev->irq = rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234
235 /*
236 * attach the interrupt in the simulator, this does enable interrupts
237 * until a netdev_attach() is called
238 */
239 netdev_connect(dev->irq);
240
241 printk(KERN_INFO "%s: hosteth=%s simfd=%d, HwAddr",
242 dev->name, simeth_device, local->simfd);
243 for(i = 0; i < ETH_ALEN; i++) {
244 printk(" %2.2x", dev->dev_addr[i]);
245 }
246 printk(", IRQ %d\n", dev->irq);
247
248 return 0;
249}
250
251/*
252 * actually binds the device to an interrupt vector
253 */
254static int
255simeth_open(struct net_device *dev)
256{
257 if (request_irq(dev->irq, simeth_interrupt, 0, "simeth", dev)) {
258 printk(KERN_WARNING "simeth: unable to get IRQ %d.\n", dev->irq);
259 return -EAGAIN;
260 }
261
262 netif_start_queue(dev);
263
264 return 0;
265}
266
267/* copied from lapbether.c */
268static __inline__ int dev_is_ethdev(struct net_device *dev)
269{
270 return ( dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5));
271}
272
273
274/*
275 * Handler for IFF_UP or IFF_DOWN
276 *
277 * The reason for that is that we don't want to be interrupted when the
278 * interface is down. There is no way to unconnect in the simualtor. Instead
279 * we use this function to shutdown packet processing in the frame filter
280 * in the simulator. Thus no interrupts are generated
281 *
282 *
283 * That's also the place where we pass the IP address of this device to the
284 * simulator so that that we can start filtering packets for it
285 *
286 * There may be a better way of doing this, but I don't know which yet.
287 */
288static int
289simeth_device_event(struct notifier_block *this,unsigned long event, void *ptr)
290{
291 struct net_device *dev = ptr;
292 struct simeth_local *local;
293 struct in_device *in_dev;
294 struct in_ifaddr **ifap = NULL;
295 struct in_ifaddr *ifa = NULL;
296 int r;
297
298
299 if ( ! dev ) {
300 printk(KERN_WARNING "simeth_device_event dev=0\n");
301 return NOTIFY_DONE;
302 }
303
304 if ( event != NETDEV_UP && event != NETDEV_DOWN ) return NOTIFY_DONE;
305
306 /*
307 * Check whether or not it's for an ethernet device
308 *
309 * XXX Fixme: This works only as long as we support one
310 * type of ethernet device.
311 */
312 if ( !dev_is_ethdev(dev) ) return NOTIFY_DONE;
313
314 if ((in_dev=dev->ip_ptr) != NULL) {
315 for (ifap=&in_dev->ifa_list; (ifa=*ifap) != NULL; ifap=&ifa->ifa_next)
316 if (strcmp(dev->name, ifa->ifa_label) == 0) break;
317 }
318 if ( ifa == NULL ) {
319 printk(KERN_ERR "simeth_open: can't find device %s's ifa\n", dev->name);
320 return NOTIFY_DONE;
321 }
322
323 printk(KERN_INFO "simeth_device_event: %s ipaddr=0x%x\n",
324 dev->name, htonl(ifa->ifa_local));
325
326 /*
327 * XXX Fix me
328 * if the device was up, and we're simply reconfiguring it, not sure
329 * we get DOWN then UP.
330 */
331
332 local = dev->priv;
333 /* now do it for real */
334 r = event == NETDEV_UP ?
335 netdev_attach(local->simfd, dev->irq, htonl(ifa->ifa_local)):
336 netdev_detach(local->simfd);
337
338 printk(KERN_INFO "simeth: netdev_attach/detach: event=%s ->%d\n",
339 event == NETDEV_UP ? "attach":"detach", r);
340
341 return NOTIFY_DONE;
342}
343
344static int
345simeth_close(struct net_device *dev)
346{
347 netif_stop_queue(dev);
348
349 free_irq(dev->irq, dev);
350
351 return 0;
352}
353
354/*
355 * Only used for debug
356 */
357static void
358frame_print(unsigned char *from, unsigned char *frame, int len)
359{
360 int i;
361
362 printk("%s: (%d) %02x", from, len, frame[0] & 0xff);
363 for(i=1; i < 6; i++ ) {
364 printk(":%02x", frame[i] &0xff);
365 }
366 printk(" %2x", frame[6] &0xff);
367 for(i=7; i < 12; i++ ) {
368 printk(":%02x", frame[i] &0xff);
369 }
370 printk(" [%02x%02x]\n", frame[12], frame[13]);
371
372 for(i=14; i < len; i++ ) {
373 printk("%02x ", frame[i] &0xff);
374 if ( (i%10)==0) printk("\n");
375 }
376 printk("\n");
377}
378
379
380/*
381 * Function used to transmit of frame, very last one on the path before
382 * going to the simulator.
383 */
384static int
385simeth_tx(struct sk_buff *skb, struct net_device *dev)
386{
387 struct simeth_local *local = dev->priv;
388
389#if 0
390 /* ensure we have at least ETH_ZLEN bytes (min frame size) */
391 unsigned int length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN;
392 /* Where do the extra padding bytes comes from inthe skbuff ? */
393#else
394 /* the real driver in the host system is going to take care of that
395 * or maybe it's the NIC itself.
396 */
397 unsigned int length = skb->len;
398#endif
399
400 local->stats.tx_bytes += skb->len;
401 local->stats.tx_packets++;
402
403
404 if (simeth_debug > 5) frame_print("simeth_tx", skb->data, length);
405
406 netdev_send(local->simfd, skb->data, length);
407
408 /*
409 * we are synchronous on write, so we don't simulate a
410 * trasnmit complete interrupt, thus we don't need to arm a tx
411 */
412
413 dev_kfree_skb(skb);
414 return 0;
415}
416
417static inline struct sk_buff *
418make_new_skb(struct net_device *dev)
419{
420 struct sk_buff *nskb;
421
422 /*
423 * The +2 is used to make sure that the IP header is nicely
424 * aligned (on 4byte boundary I assume 14+2=16)
425 */
426 nskb = dev_alloc_skb(SIMETH_FRAME_SIZE + 2);
427 if ( nskb == NULL ) {
428 printk(KERN_NOTICE "%s: memory squeeze. dropping packet.\n", dev->name);
429 return NULL;
430 }
431 nskb->dev = dev;
432
433 skb_reserve(nskb, 2); /* Align IP on 16 byte boundaries */
434
435 skb_put(nskb,SIMETH_FRAME_SIZE);
436
437 return nskb;
438}
439
440/*
441 * called from interrupt handler to process a received frame
442 */
443static int
444simeth_rx(struct net_device *dev)
445{
446 struct simeth_local *local;
447 struct sk_buff *skb;
448 int len;
449 int rcv_count = SIMETH_RECV_MAX;
450
451 local = dev->priv;
452 /*
453 * the loop concept has been borrowed from other drivers
454 * looks to me like it's a throttling thing to avoid pushing to many
455 * packets at one time into the stack. Making sure we can process them
456 * upstream and make forward progress overall
457 */
458 do {
459 if ( (skb=make_new_skb(dev)) == NULL ) {
460 printk(KERN_NOTICE "%s: memory squeeze. dropping packet.\n", dev->name);
461 local->stats.rx_dropped++;
462 return 0;
463 }
464 /*
465 * Read only one frame at a time
466 */
467 len = netdev_read(local->simfd, skb->data, SIMETH_FRAME_SIZE);
468 if ( len == 0 ) {
469 if ( simeth_debug > 0 ) printk(KERN_WARNING "%s: count=%d netdev_read=0\n",
470 dev->name, SIMETH_RECV_MAX-rcv_count);
471 break;
472 }
473#if 0
474 /*
475 * XXX Fix me
476 * Should really do a csum+copy here
477 */
478 memcpy(skb->data, frame, len);
479#endif
480 skb->protocol = eth_type_trans(skb, dev);
481
482 if ( simeth_debug > 6 ) frame_print("simeth_rx", skb->data, len);
483
484 /*
485 * push the packet up & trigger software interrupt
486 */
487 netif_rx(skb);
488
489 local->stats.rx_packets++;
490 local->stats.rx_bytes += len;
491
492 } while ( --rcv_count );
493
494 return len; /* 0 = nothing left to read, otherwise, we can try again */
495}
496
497/*
498 * Interrupt handler (Yes, we can do it too !!!)
499 */
500static irqreturn_t
501simeth_interrupt(int irq, void *dev_id, struct pt_regs * regs)
502{
503 struct net_device *dev = dev_id;
504
505 if ( dev == NULL ) {
506 printk(KERN_WARNING "simeth: irq %d for unknown device\n", irq);
507 return IRQ_NONE;
508 }
509
510 /*
511 * very simple loop because we get interrupts only when receiving
512 */
513 while (simeth_rx(dev));
514 return IRQ_HANDLED;
515}
516
517static struct net_device_stats *
518simeth_get_stats(struct net_device *dev)
519{
520 struct simeth_local *local = dev->priv;
521
522 return &local->stats;
523}
524
525/* fake multicast ability */
526static void
527set_multicast_list(struct net_device *dev)
528{
529 printk(KERN_WARNING "%s: set_multicast_list called\n", dev->name);
530}
531
532__initcall(simeth_probe);