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
44static DEFINE_SPINLOCK(opened_lock);
45static LIST_HEAD(opened);
46
47static DEFINE_SPINLOCK(devices_lock);
48static 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
57struct 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
67struct 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
101static 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
124static 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
151random:
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
159static 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
189static 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
195static 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
201static 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
206unsigned short tuntap_protocol(struct sk_buff *skb)
207{
208	return eth_type_trans(skb, skb->dev);
209}
210
211static 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
220static 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
271static 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
312static 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
348static void iss_net_timer(unsigned long priv)
349{
350	struct iss_net_private *lp = (struct iss_net_private *)priv;
351
352	iss_net_poll();
353	spin_lock(&lp->lock);
354	mod_timer(&lp->timer, jiffies + lp->timer_val);
355	spin_unlock(&lp->lock);
356}
357
358
359static 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_bh(&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_unlock_bh(&lp->lock);
380	spin_lock_bh(&opened_lock);
381	list_add(&lp->opened_list, &opened);
382	spin_unlock_bh(&opened_lock);
383	spin_lock_bh(&lp->lock);
384
385	init_timer(&lp->timer);
386	lp->timer_val = ISS_NET_TIMER_VALUE;
387	lp->timer.data = (unsigned long) lp;
388	lp->timer.function = iss_net_timer;
389	mod_timer(&lp->timer, jiffies + lp->timer_val);
390
391out:
392	spin_unlock_bh(&lp->lock);
393	return err;
394}
395
396static int iss_net_close(struct net_device *dev)
397{
398	struct iss_net_private *lp = netdev_priv(dev);
399	netif_stop_queue(dev);
400	spin_lock_bh(&lp->lock);
401
402	spin_lock(&opened_lock);
403	list_del(&opened);
404	spin_unlock(&opened_lock);
405
406	del_timer_sync(&lp->timer);
407
408	lp->tp.close(lp);
409
410	spin_unlock_bh(&lp->lock);
411	return 0;
412}
413
414static int iss_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
415{
416	struct iss_net_private *lp = netdev_priv(dev);
417	int len;
418
419	netif_stop_queue(dev);
420	spin_lock_bh(&lp->lock);
421
422	len = lp->tp.write(lp, &skb);
423
424	if (len == skb->len) {
425		lp->stats.tx_packets++;
426		lp->stats.tx_bytes += skb->len;
427		dev->trans_start = jiffies;
428		netif_start_queue(dev);
429
430		/* this is normally done in the interrupt when tx finishes */
431		netif_wake_queue(dev);
432
433	} else if (len == 0) {
434		netif_start_queue(dev);
435		lp->stats.tx_dropped++;
436
437	} else {
438		netif_start_queue(dev);
439		pr_err("%s: %s failed(%d)\n", dev->name, __func__, len);
440	}
441
442	spin_unlock_bh(&lp->lock);
443
444	dev_kfree_skb(skb);
445	return NETDEV_TX_OK;
446}
447
448
449static struct net_device_stats *iss_net_get_stats(struct net_device *dev)
450{
451	struct iss_net_private *lp = netdev_priv(dev);
452	return &lp->stats;
453}
454
455static void iss_net_set_multicast_list(struct net_device *dev)
456{
457}
458
459static void iss_net_tx_timeout(struct net_device *dev)
460{
461}
462
463static int iss_net_set_mac(struct net_device *dev, void *addr)
464{
465	struct iss_net_private *lp = netdev_priv(dev);
466	struct sockaddr *hwaddr = addr;
467
468	if (!is_valid_ether_addr(hwaddr->sa_data))
469		return -EADDRNOTAVAIL;
470	spin_lock_bh(&lp->lock);
471	memcpy(dev->dev_addr, hwaddr->sa_data, ETH_ALEN);
472	spin_unlock_bh(&lp->lock);
473	return 0;
474}
475
476static int iss_net_change_mtu(struct net_device *dev, int new_mtu)
477{
478	return -EINVAL;
479}
480
481void iss_net_user_timer_expire(unsigned long _conn)
482{
483}
484
485
486static struct platform_driver iss_net_driver = {
487	.driver = {
488		.name  = DRIVER_NAME,
489	},
490};
491
492static int driver_registered;
493
494static const struct net_device_ops iss_netdev_ops = {
495	.ndo_open		= iss_net_open,
496	.ndo_stop		= iss_net_close,
497	.ndo_get_stats		= iss_net_get_stats,
498	.ndo_start_xmit		= iss_net_start_xmit,
499	.ndo_validate_addr	= eth_validate_addr,
500	.ndo_change_mtu		= iss_net_change_mtu,
501	.ndo_set_mac_address	= iss_net_set_mac,
502	.ndo_tx_timeout		= iss_net_tx_timeout,
503	.ndo_set_rx_mode	= iss_net_set_multicast_list,
504};
505
506static int iss_net_configure(int index, char *init)
507{
508	struct net_device *dev;
509	struct iss_net_private *lp;
510	int err;
511
512	dev = alloc_etherdev(sizeof(*lp));
513	if (dev == NULL) {
514		pr_err("eth_configure: failed to allocate device\n");
515		return 1;
516	}
517
518	/* Initialize private element. */
519
520	lp = netdev_priv(dev);
521	*lp = (struct iss_net_private) {
522		.device_list		= LIST_HEAD_INIT(lp->device_list),
523		.opened_list		= LIST_HEAD_INIT(lp->opened_list),
524		.dev			= dev,
525		.index			= index,
526	};
527
528	spin_lock_init(&lp->lock);
529	/*
530	 * If this name ends up conflicting with an existing registered
531	 * netdevice, that is OK, register_netdev{,ice}() will notice this
532	 * and fail.
533	 */
534	snprintf(dev->name, sizeof(dev->name), "eth%d", index);
535
536	/*
537	 * Try all transport protocols.
538	 * Note: more protocols can be added by adding '&& !X_init(lp, eth)'.
539	 */
540
541	if (!tuntap_probe(lp, index, init)) {
542		pr_err("%s: invalid arguments. Skipping device!\n",
543		       dev->name);
544		goto errout;
545	}
546
547	pr_info("Netdevice %d (%pM)\n", index, dev->dev_addr);
548
549	/* sysfs register */
550
551	if (!driver_registered) {
552		platform_driver_register(&iss_net_driver);
553		driver_registered = 1;
554	}
555
556	spin_lock(&devices_lock);
557	list_add(&lp->device_list, &devices);
558	spin_unlock(&devices_lock);
559
560	lp->pdev.id = index;
561	lp->pdev.name = DRIVER_NAME;
562	platform_device_register(&lp->pdev);
563	SET_NETDEV_DEV(dev, &lp->pdev.dev);
564
565	dev->netdev_ops = &iss_netdev_ops;
566	dev->mtu = lp->mtu;
567	dev->watchdog_timeo = (HZ >> 1);
568	dev->irq = -1;
569
570	rtnl_lock();
571	err = register_netdevice(dev);
572	rtnl_unlock();
573
574	if (err) {
575		pr_err("%s: error registering net device!\n", dev->name);
576		/* XXX: should we call ->remove() here? */
577		free_netdev(dev);
578		return 1;
579	}
580
581	init_timer(&lp->tl);
582	lp->tl.function = iss_net_user_timer_expire;
583
584	return 0;
585
586errout:
587	/* FIXME: unregister; free, etc.. */
588	return -EIO;
589}
590
591/* ------------------------------------------------------------------------- */
592
593/* Filled in during early boot */
594
595struct list_head eth_cmd_line = LIST_HEAD_INIT(eth_cmd_line);
596
597struct iss_net_init {
598	struct list_head list;
599	char *init;		/* init string */
600	int index;
601};
602
603/*
604 * Parse the command line and look for 'ethX=...' fields, and register all
605 * those fields. They will be later initialized in iss_net_init.
606 */
607
608#define ERR KERN_ERR "iss_net_setup: "
609
610static int __init iss_net_setup(char *str)
611{
612	struct iss_net_private *device = NULL;
613	struct iss_net_init *new;
614	struct list_head *ele;
615	char *end;
616	int rc;
617	unsigned n;
618
619	end = strchr(str, '=');
620	if (!end) {
621		printk(ERR "Expected '=' after device number\n");
622		return 1;
623	}
624	*end = 0;
625	rc = kstrtouint(str, 0, &n);
626	*end = '=';
627	if (rc < 0) {
628		printk(ERR "Failed to parse '%s'\n", str);
629		return 1;
630	}
631	str = end;
632
633	spin_lock(&devices_lock);
634
635	list_for_each(ele, &devices) {
636		device = list_entry(ele, struct iss_net_private, device_list);
637		if (device->index == n)
638			break;
639	}
640
641	spin_unlock(&devices_lock);
642
643	if (device && device->index == n) {
644		printk(ERR "Device %u already configured\n", n);
645		return 1;
646	}
647
648	new = alloc_bootmem(sizeof(*new));
649	if (new == NULL) {
650		printk(ERR "Alloc_bootmem failed\n");
651		return 1;
652	}
653
654	INIT_LIST_HEAD(&new->list);
655	new->index = n;
656	new->init = str + 1;
657
658	list_add_tail(&new->list, &eth_cmd_line);
659	return 1;
660}
661
662#undef ERR
663
664__setup("eth", iss_net_setup);
665
666/*
667 * Initialize all ISS Ethernet devices previously registered in iss_net_setup.
668 */
669
670static int iss_net_init(void)
671{
672	struct list_head *ele, *next;
673
674	/* Walk through all Ethernet devices specified in the command line. */
675
676	list_for_each_safe(ele, next, &eth_cmd_line) {
677		struct iss_net_init *eth;
678		eth = list_entry(ele, struct iss_net_init, list);
679		iss_net_configure(eth->index, eth->init);
680	}
681
682	return 1;
683}
684
685module_init(iss_net_init);
686
687