1 /*
2  *
3  * arch/xtensa/platforms/iss/network.c
4  *
5  * Platform specific initialization.
6  *
7  * Authors: Chris Zankel <chris@zankel.net>
8  * Based on work form the UML team.
9  *
10  * Copyright 2005 Tensilica Inc.
11  *
12  * This program is free software; you can redistribute  it and/or modify it
13  * under  the terms of  the GNU General  Public License as published by the
14  * Free Software Foundation;  either version 2 of the  License, or (at your
15  * option) any later version.
16  *
17  */
18 
19 #include <linux/list.h>
20 #include <linux/irq.h>
21 #include <linux/spinlock.h>
22 #include <linux/slab.h>
23 #include <linux/timer.h>
24 #include <linux/if_ether.h>
25 #include <linux/inetdevice.h>
26 #include <linux/init.h>
27 #include <linux/if_tun.h>
28 #include <linux/etherdevice.h>
29 #include <linux/interrupt.h>
30 #include <linux/ioctl.h>
31 #include <linux/bootmem.h>
32 #include <linux/ethtool.h>
33 #include <linux/rtnetlink.h>
34 #include <linux/platform_device.h>
35 
36 #include <platform/simcall.h>
37 
38 #define DRIVER_NAME "iss-netdev"
39 #define ETH_MAX_PACKET 1500
40 #define ETH_HEADER_OTHER 14
41 #define ISS_NET_TIMER_VALUE (HZ / 10)
42 
43 
44 static DEFINE_SPINLOCK(opened_lock);
45 static LIST_HEAD(opened);
46 
47 static DEFINE_SPINLOCK(devices_lock);
48 static LIST_HEAD(devices);
49 
50 /* ------------------------------------------------------------------------- */
51 
52 /* We currently only support the TUNTAP transport protocol. */
53 
54 #define TRANSPORT_TUNTAP_NAME "tuntap"
55 #define TRANSPORT_TUNTAP_MTU ETH_MAX_PACKET
56 
57 struct tuntap_info {
58 	char dev_name[IFNAMSIZ];
59 	int fd;
60 };
61 
62 /* ------------------------------------------------------------------------- */
63 
64 
65 /* This structure contains out private information for the driver. */
66 
67 struct iss_net_private {
68 	struct list_head device_list;
69 	struct list_head opened_list;
70 
71 	spinlock_t lock;
72 	struct net_device *dev;
73 	struct platform_device pdev;
74 	struct timer_list tl;
75 	struct net_device_stats stats;
76 
77 	struct timer_list timer;
78 	unsigned int timer_val;
79 
80 	int index;
81 	int mtu;
82 
83 	struct {
84 		union {
85 			struct tuntap_info tuntap;
86 		} info;
87 
88 		int (*open)(struct iss_net_private *lp);
89 		void (*close)(struct iss_net_private *lp);
90 		int (*read)(struct iss_net_private *lp, struct sk_buff **skb);
91 		int (*write)(struct iss_net_private *lp, struct sk_buff **skb);
92 		unsigned short (*protocol)(struct sk_buff *skb);
93 		int (*poll)(struct iss_net_private *lp);
94 	} tp;
95 
96 };
97 
98 /* ================================ HELPERS ================================ */
99 
100 
101 static char *split_if_spec(char *str, ...)
102 {
103 	char **arg, *end;
104 	va_list ap;
105 
106 	va_start(ap, str);
107 	while ((arg = va_arg(ap, char**)) != NULL) {
108 		if (*str == '\0')
109 			return NULL;
110 		end = strchr(str, ',');
111 		if (end != str)
112 			*arg = str;
113 		if (end == NULL)
114 			return NULL;
115 		*end++ = '\0';
116 		str = end;
117 	}
118 	va_end(ap);
119 	return str;
120 }
121 
122 /* Set Ethernet address of the specified device. */
123 
124 static void setup_etheraddr(struct net_device *dev, char *str)
125 {
126 	unsigned char *addr = dev->dev_addr;
127 
128 	if (str == NULL)
129 		goto random;
130 
131 	if (!mac_pton(str, addr)) {
132 		pr_err("%s: failed to parse '%s' as an ethernet address\n",
133 		       dev->name, str);
134 		goto random;
135 	}
136 	if (is_multicast_ether_addr(addr)) {
137 		pr_err("%s: attempt to assign a multicast ethernet address\n",
138 		       dev->name);
139 		goto random;
140 	}
141 	if (!is_valid_ether_addr(addr)) {
142 		pr_err("%s: attempt to assign an invalid ethernet address\n",
143 		       dev->name);
144 		goto random;
145 	}
146 	if (!is_local_ether_addr(addr))
147 		pr_warn("%s: assigning a globally valid ethernet address\n",
148 			dev->name);
149 	return;
150 
151 random:
152 	pr_info("%s: choosing a random ethernet address\n",
153 		dev->name);
154 	eth_hw_addr_random(dev);
155 }
156 
157 /* ======================= TUNTAP TRANSPORT INTERFACE ====================== */
158 
159 static int tuntap_open(struct iss_net_private *lp)
160 {
161 	struct ifreq ifr;
162 	char *dev_name = lp->tp.info.tuntap.dev_name;
163 	int err = -EINVAL;
164 	int fd;
165 
166 	fd = simc_open("/dev/net/tun", 02, 0); /* O_RDWR */
167 	if (fd < 0) {
168 		pr_err("%s: failed to open /dev/net/tun, returned %d (errno = %d)\n",
169 		       lp->dev->name, fd, errno);
170 		return fd;
171 	}
172 
173 	memset(&ifr, 0, sizeof(ifr));
174 	ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
175 	strlcpy(ifr.ifr_name, dev_name, sizeof(ifr.ifr_name));
176 
177 	err = simc_ioctl(fd, TUNSETIFF, &ifr);
178 	if (err < 0) {
179 		pr_err("%s: failed to set interface %s, returned %d (errno = %d)\n",
180 		       lp->dev->name, dev_name, err, errno);
181 		simc_close(fd);
182 		return err;
183 	}
184 
185 	lp->tp.info.tuntap.fd = fd;
186 	return err;
187 }
188 
189 static void tuntap_close(struct iss_net_private *lp)
190 {
191 	simc_close(lp->tp.info.tuntap.fd);
192 	lp->tp.info.tuntap.fd = -1;
193 }
194 
195 static int tuntap_read(struct iss_net_private *lp, struct sk_buff **skb)
196 {
197 	return simc_read(lp->tp.info.tuntap.fd,
198 			(*skb)->data, (*skb)->dev->mtu + ETH_HEADER_OTHER);
199 }
200 
201 static int tuntap_write(struct iss_net_private *lp, struct sk_buff **skb)
202 {
203 	return simc_write(lp->tp.info.tuntap.fd, (*skb)->data, (*skb)->len);
204 }
205 
206 unsigned short tuntap_protocol(struct sk_buff *skb)
207 {
208 	return eth_type_trans(skb, skb->dev);
209 }
210 
211 static int tuntap_poll(struct iss_net_private *lp)
212 {
213 	return simc_poll(lp->tp.info.tuntap.fd);
214 }
215 
216 /*
217  * ethX=tuntap,[mac address],device name
218  */
219 
220 static int tuntap_probe(struct iss_net_private *lp, int index, char *init)
221 {
222 	struct net_device *dev = lp->dev;
223 	char *dev_name = NULL, *mac_str = NULL, *rem = NULL;
224 
225 	/* Transport should be 'tuntap': ethX=tuntap,mac,dev_name */
226 
227 	if (strncmp(init, TRANSPORT_TUNTAP_NAME,
228 		    sizeof(TRANSPORT_TUNTAP_NAME) - 1))
229 		return 0;
230 
231 	init += sizeof(TRANSPORT_TUNTAP_NAME) - 1;
232 	if (*init == ',') {
233 		rem = split_if_spec(init + 1, &mac_str, &dev_name);
234 		if (rem != NULL) {
235 			pr_err("%s: extra garbage on specification : '%s'\n",
236 			       dev->name, rem);
237 			return 0;
238 		}
239 	} else if (*init != '\0') {
240 		pr_err("%s: invalid argument: %s. Skipping device!\n",
241 		       dev->name, init);
242 		return 0;
243 	}
244 
245 	if (!dev_name) {
246 		pr_err("%s: missing tuntap device name\n", dev->name);
247 		return 0;
248 	}
249 
250 	strlcpy(lp->tp.info.tuntap.dev_name, dev_name,
251 		sizeof(lp->tp.info.tuntap.dev_name));
252 
253 	setup_etheraddr(dev, mac_str);
254 
255 	lp->mtu = TRANSPORT_TUNTAP_MTU;
256 
257 	lp->tp.info.tuntap.fd = -1;
258 
259 	lp->tp.open = tuntap_open;
260 	lp->tp.close = tuntap_close;
261 	lp->tp.read = tuntap_read;
262 	lp->tp.write = tuntap_write;
263 	lp->tp.protocol = tuntap_protocol;
264 	lp->tp.poll = tuntap_poll;
265 
266 	return 1;
267 }
268 
269 /* ================================ ISS NET ================================ */
270 
271 static int iss_net_rx(struct net_device *dev)
272 {
273 	struct iss_net_private *lp = netdev_priv(dev);
274 	int pkt_len;
275 	struct sk_buff *skb;
276 
277 	/* Check if there is any new data. */
278 
279 	if (lp->tp.poll(lp) == 0)
280 		return 0;
281 
282 	/* Try to allocate memory, if it fails, try again next round. */
283 
284 	skb = dev_alloc_skb(dev->mtu + 2 + ETH_HEADER_OTHER);
285 	if (skb == NULL) {
286 		lp->stats.rx_dropped++;
287 		return 0;
288 	}
289 
290 	skb_reserve(skb, 2);
291 
292 	/* Setup skb */
293 
294 	skb->dev = dev;
295 	skb_reset_mac_header(skb);
296 	pkt_len = lp->tp.read(lp, &skb);
297 	skb_put(skb, pkt_len);
298 
299 	if (pkt_len > 0) {
300 		skb_trim(skb, pkt_len);
301 		skb->protocol = lp->tp.protocol(skb);
302 
303 		lp->stats.rx_bytes += skb->len;
304 		lp->stats.rx_packets++;
305 		netif_rx_ni(skb);
306 		return pkt_len;
307 	}
308 	kfree_skb(skb);
309 	return pkt_len;
310 }
311 
312 static int iss_net_poll(void)
313 {
314 	struct list_head *ele;
315 	int err, ret = 0;
316 
317 	spin_lock(&opened_lock);
318 
319 	list_for_each(ele, &opened) {
320 		struct iss_net_private *lp;
321 
322 		lp = list_entry(ele, struct iss_net_private, opened_list);
323 
324 		if (!netif_running(lp->dev))
325 			break;
326 
327 		spin_lock(&lp->lock);
328 
329 		while ((err = iss_net_rx(lp->dev)) > 0)
330 			ret++;
331 
332 		spin_unlock(&lp->lock);
333 
334 		if (err < 0) {
335 			pr_err("Device '%s' read returned %d, shutting it down\n",
336 			       lp->dev->name, err);
337 			dev_close(lp->dev);
338 		} else {
339 			/* FIXME reactivate_fd(lp->fd, ISS_ETH_IRQ); */
340 		}
341 	}
342 
343 	spin_unlock(&opened_lock);
344 	return ret;
345 }
346 
347 
348 static void iss_net_timer(unsigned long priv)
349 {
350 	struct iss_net_private *lp = (struct iss_net_private *)priv;
351 
352 	spin_lock(&lp->lock);
353 	iss_net_poll();
354 	mod_timer(&lp->timer, jiffies + lp->timer_val);
355 	spin_unlock(&lp->lock);
356 }
357 
358 
359 static int iss_net_open(struct net_device *dev)
360 {
361 	struct iss_net_private *lp = netdev_priv(dev);
362 	int err;
363 
364 	spin_lock(&lp->lock);
365 
366 	err = lp->tp.open(lp);
367 	if (err < 0)
368 		goto out;
369 
370 	netif_start_queue(dev);
371 
372 	/* clear buffer - it can happen that the host side of the interface
373 	 * is full when we get here. In this case, new data is never queued,
374 	 * SIGIOs never arrive, and the net never works.
375 	 */
376 	while ((err = iss_net_rx(dev)) > 0)
377 		;
378 
379 	spin_lock(&opened_lock);
380 	list_add(&lp->opened_list, &opened);
381 	spin_unlock(&opened_lock);
382 
383 	init_timer(&lp->timer);
384 	lp->timer_val = ISS_NET_TIMER_VALUE;
385 	lp->timer.data = (unsigned long) lp;
386 	lp->timer.function = iss_net_timer;
387 	mod_timer(&lp->timer, jiffies + lp->timer_val);
388 
389 out:
390 	spin_unlock(&lp->lock);
391 	return err;
392 }
393 
394 static int iss_net_close(struct net_device *dev)
395 {
396 	struct iss_net_private *lp = netdev_priv(dev);
397 	netif_stop_queue(dev);
398 	spin_lock(&lp->lock);
399 
400 	spin_lock(&opened_lock);
401 	list_del(&opened);
402 	spin_unlock(&opened_lock);
403 
404 	del_timer_sync(&lp->timer);
405 
406 	lp->tp.close(lp);
407 
408 	spin_unlock(&lp->lock);
409 	return 0;
410 }
411 
412 static int iss_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
413 {
414 	struct iss_net_private *lp = netdev_priv(dev);
415 	unsigned long flags;
416 	int len;
417 
418 	netif_stop_queue(dev);
419 	spin_lock_irqsave(&lp->lock, flags);
420 
421 	len = lp->tp.write(lp, &skb);
422 
423 	if (len == skb->len) {
424 		lp->stats.tx_packets++;
425 		lp->stats.tx_bytes += skb->len;
426 		dev->trans_start = jiffies;
427 		netif_start_queue(dev);
428 
429 		/* this is normally done in the interrupt when tx finishes */
430 		netif_wake_queue(dev);
431 
432 	} else if (len == 0) {
433 		netif_start_queue(dev);
434 		lp->stats.tx_dropped++;
435 
436 	} else {
437 		netif_start_queue(dev);
438 		pr_err("%s: %s failed(%d)\n", dev->name, __func__, len);
439 	}
440 
441 	spin_unlock_irqrestore(&lp->lock, flags);
442 
443 	dev_kfree_skb(skb);
444 	return NETDEV_TX_OK;
445 }
446 
447 
448 static struct net_device_stats *iss_net_get_stats(struct net_device *dev)
449 {
450 	struct iss_net_private *lp = netdev_priv(dev);
451 	return &lp->stats;
452 }
453 
454 static void iss_net_set_multicast_list(struct net_device *dev)
455 {
456 }
457 
458 static void iss_net_tx_timeout(struct net_device *dev)
459 {
460 }
461 
462 static int iss_net_set_mac(struct net_device *dev, void *addr)
463 {
464 	struct iss_net_private *lp = netdev_priv(dev);
465 	struct sockaddr *hwaddr = addr;
466 
467 	if (!is_valid_ether_addr(hwaddr->sa_data))
468 		return -EADDRNOTAVAIL;
469 	spin_lock(&lp->lock);
470 	memcpy(dev->dev_addr, hwaddr->sa_data, ETH_ALEN);
471 	spin_unlock(&lp->lock);
472 	return 0;
473 }
474 
475 static int iss_net_change_mtu(struct net_device *dev, int new_mtu)
476 {
477 	return -EINVAL;
478 }
479 
480 void iss_net_user_timer_expire(unsigned long _conn)
481 {
482 }
483 
484 
485 static struct platform_driver iss_net_driver = {
486 	.driver = {
487 		.name  = DRIVER_NAME,
488 	},
489 };
490 
491 static int driver_registered;
492 
493 static const struct net_device_ops iss_netdev_ops = {
494 	.ndo_open		= iss_net_open,
495 	.ndo_stop		= iss_net_close,
496 	.ndo_get_stats		= iss_net_get_stats,
497 	.ndo_start_xmit		= iss_net_start_xmit,
498 	.ndo_validate_addr	= eth_validate_addr,
499 	.ndo_change_mtu		= iss_net_change_mtu,
500 	.ndo_set_mac_address	= iss_net_set_mac,
501 	.ndo_tx_timeout		= iss_net_tx_timeout,
502 	.ndo_set_rx_mode	= iss_net_set_multicast_list,
503 };
504 
505 static int iss_net_configure(int index, char *init)
506 {
507 	struct net_device *dev;
508 	struct iss_net_private *lp;
509 	int err;
510 
511 	dev = alloc_etherdev(sizeof(*lp));
512 	if (dev == NULL) {
513 		pr_err("eth_configure: failed to allocate device\n");
514 		return 1;
515 	}
516 
517 	/* Initialize private element. */
518 
519 	lp = netdev_priv(dev);
520 	*lp = (struct iss_net_private) {
521 		.device_list		= LIST_HEAD_INIT(lp->device_list),
522 		.opened_list		= LIST_HEAD_INIT(lp->opened_list),
523 		.lock			= __SPIN_LOCK_UNLOCKED(lp.lock),
524 		.dev			= dev,
525 		.index			= index,
526 		};
527 
528 	/*
529 	 * If this name ends up conflicting with an existing registered
530 	 * netdevice, that is OK, register_netdev{,ice}() will notice this
531 	 * and fail.
532 	 */
533 	snprintf(dev->name, sizeof(dev->name), "eth%d", index);
534 
535 	/*
536 	 * Try all transport protocols.
537 	 * Note: more protocols can be added by adding '&& !X_init(lp, eth)'.
538 	 */
539 
540 	if (!tuntap_probe(lp, index, init)) {
541 		pr_err("%s: invalid arguments. Skipping device!\n",
542 		       dev->name);
543 		goto errout;
544 	}
545 
546 	pr_info("Netdevice %d (%pM)\n", index, dev->dev_addr);
547 
548 	/* sysfs register */
549 
550 	if (!driver_registered) {
551 		platform_driver_register(&iss_net_driver);
552 		driver_registered = 1;
553 	}
554 
555 	spin_lock(&devices_lock);
556 	list_add(&lp->device_list, &devices);
557 	spin_unlock(&devices_lock);
558 
559 	lp->pdev.id = index;
560 	lp->pdev.name = DRIVER_NAME;
561 	platform_device_register(&lp->pdev);
562 	SET_NETDEV_DEV(dev, &lp->pdev.dev);
563 
564 	dev->netdev_ops = &iss_netdev_ops;
565 	dev->mtu = lp->mtu;
566 	dev->watchdog_timeo = (HZ >> 1);
567 	dev->irq = -1;
568 
569 	rtnl_lock();
570 	err = register_netdevice(dev);
571 	rtnl_unlock();
572 
573 	if (err) {
574 		pr_err("%s: error registering net device!\n", dev->name);
575 		/* XXX: should we call ->remove() here? */
576 		free_netdev(dev);
577 		return 1;
578 	}
579 
580 	init_timer(&lp->tl);
581 	lp->tl.function = iss_net_user_timer_expire;
582 
583 	return 0;
584 
585 errout:
586 	/* FIXME: unregister; free, etc.. */
587 	return -EIO;
588 }
589 
590 /* ------------------------------------------------------------------------- */
591 
592 /* Filled in during early boot */
593 
594 struct list_head eth_cmd_line = LIST_HEAD_INIT(eth_cmd_line);
595 
596 struct iss_net_init {
597 	struct list_head list;
598 	char *init;		/* init string */
599 	int index;
600 };
601 
602 /*
603  * Parse the command line and look for 'ethX=...' fields, and register all
604  * those fields. They will be later initialized in iss_net_init.
605  */
606 
607 #define ERR KERN_ERR "iss_net_setup: "
608 
609 static int __init iss_net_setup(char *str)
610 {
611 	struct iss_net_private *device = NULL;
612 	struct iss_net_init *new;
613 	struct list_head *ele;
614 	char *end;
615 	int rc;
616 	unsigned n;
617 
618 	end = strchr(str, '=');
619 	if (!end) {
620 		printk(ERR "Expected '=' after device number\n");
621 		return 1;
622 	}
623 	*end = 0;
624 	rc = kstrtouint(str, 0, &n);
625 	*end = '=';
626 	if (rc < 0) {
627 		printk(ERR "Failed to parse '%s'\n", str);
628 		return 1;
629 	}
630 	str = end;
631 
632 	spin_lock(&devices_lock);
633 
634 	list_for_each(ele, &devices) {
635 		device = list_entry(ele, struct iss_net_private, device_list);
636 		if (device->index == n)
637 			break;
638 	}
639 
640 	spin_unlock(&devices_lock);
641 
642 	if (device && device->index == n) {
643 		printk(ERR "Device %u already configured\n", n);
644 		return 1;
645 	}
646 
647 	new = alloc_bootmem(sizeof(*new));
648 	if (new == NULL) {
649 		printk(ERR "Alloc_bootmem failed\n");
650 		return 1;
651 	}
652 
653 	INIT_LIST_HEAD(&new->list);
654 	new->index = n;
655 	new->init = str + 1;
656 
657 	list_add_tail(&new->list, &eth_cmd_line);
658 	return 1;
659 }
660 
661 #undef ERR
662 
663 __setup("eth", iss_net_setup);
664 
665 /*
666  * Initialize all ISS Ethernet devices previously registered in iss_net_setup.
667  */
668 
669 static int iss_net_init(void)
670 {
671 	struct list_head *ele, *next;
672 
673 	/* Walk through all Ethernet devices specified in the command line. */
674 
675 	list_for_each_safe(ele, next, &eth_cmd_line) {
676 		struct iss_net_init *eth;
677 		eth = list_entry(ele, struct iss_net_init, list);
678 		iss_net_configure(eth->index, eth->init);
679 	}
680 
681 	return 1;
682 }
683 
684 module_init(iss_net_init);
685 
686