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