1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *
4 * arch/xtensa/platforms/iss/network.c
5 *
6 * Platform specific initialization.
7 *
8 * Authors: Chris Zankel <chris@zankel.net>
9 * Based on work form the UML team.
10 *
11 * Copyright 2005 Tensilica Inc.
12 */
13
14#define pr_fmt(fmt) "%s: " fmt, __func__
15
16#include <linux/list.h>
17#include <linux/irq.h>
18#include <linux/spinlock.h>
19#include <linux/slab.h>
20#include <linux/timer.h>
21#include <linux/if_ether.h>
22#include <linux/inetdevice.h>
23#include <linux/init.h>
24#include <linux/if_tun.h>
25#include <linux/etherdevice.h>
26#include <linux/interrupt.h>
27#include <linux/ioctl.h>
28#include <linux/memblock.h>
29#include <linux/ethtool.h>
30#include <linux/rtnetlink.h>
31#include <linux/platform_device.h>
32
33#include <platform/simcall.h>
34
35#define DRIVER_NAME "iss-netdev"
36#define ETH_MAX_PACKET 1500
37#define ETH_HEADER_OTHER 14
38#define ISS_NET_TIMER_VALUE (HZ / 10)
39
40/* ------------------------------------------------------------------------- */
41
42/* We currently only support the TUNTAP transport protocol. */
43
44#define TRANSPORT_TUNTAP_NAME "tuntap"
45#define TRANSPORT_TUNTAP_MTU ETH_MAX_PACKET
46
47struct tuntap_info {
48 char dev_name[IFNAMSIZ];
49 int fd;
50};
51
52/* ------------------------------------------------------------------------- */
53
54
55struct iss_net_private;
56
57struct iss_net_ops {
58 int (*open)(struct iss_net_private *lp);
59 void (*close)(struct iss_net_private *lp);
60 int (*read)(struct iss_net_private *lp, struct sk_buff **skb);
61 int (*write)(struct iss_net_private *lp, struct sk_buff **skb);
62 unsigned short (*protocol)(struct sk_buff *skb);
63 int (*poll)(struct iss_net_private *lp);
64};
65
66/* This structure contains out private information for the driver. */
67
68struct iss_net_private {
69 spinlock_t lock;
70 struct net_device *dev;
71 struct platform_device pdev;
72 struct timer_list tl;
73 struct rtnl_link_stats64 stats;
74
75 struct timer_list timer;
76 unsigned int timer_val;
77
78 int index;
79 int mtu;
80
81 struct {
82 union {
83 struct tuntap_info tuntap;
84 } info;
85
86 const struct iss_net_ops *net_ops;
87 } tp;
88
89};
90
91/* ================================ HELPERS ================================ */
92
93
94static char *split_if_spec(char *str, ...)
95{
96 char **arg, *end;
97 va_list ap;
98
99 va_start(ap, str);
100 while ((arg = va_arg(ap, char**)) != NULL) {
101 if (*str == '\0') {
102 va_end(ap);
103 return NULL;
104 }
105 end = strchr(str, ',');
106 if (end != str)
107 *arg = str;
108 if (end == NULL) {
109 va_end(ap);
110 return NULL;
111 }
112 *end++ = '\0';
113 str = end;
114 }
115 va_end(ap);
116 return str;
117}
118
119/* Set Ethernet address of the specified device. */
120
121static void setup_etheraddr(struct net_device *dev, char *str)
122{
123 u8 addr[ETH_ALEN];
124
125 if (str == NULL)
126 goto random;
127
128 if (!mac_pton(s: str, mac: addr)) {
129 pr_err("%s: failed to parse '%s' as an ethernet address\n",
130 dev->name, str);
131 goto random;
132 }
133 if (is_multicast_ether_addr(addr)) {
134 pr_err("%s: attempt to assign a multicast ethernet address\n",
135 dev->name);
136 goto random;
137 }
138 if (!is_valid_ether_addr(addr)) {
139 pr_err("%s: attempt to assign an invalid ethernet address\n",
140 dev->name);
141 goto random;
142 }
143 if (!is_local_ether_addr(addr))
144 pr_warn("%s: assigning a globally valid ethernet address\n",
145 dev->name);
146 eth_hw_addr_set(dev, addr);
147 return;
148
149random:
150 pr_info("%s: choosing a random ethernet address\n",
151 dev->name);
152 eth_hw_addr_random(dev);
153}
154
155/* ======================= TUNTAP TRANSPORT INTERFACE ====================== */
156
157static int tuntap_open(struct iss_net_private *lp)
158{
159 struct ifreq ifr;
160 char *dev_name = lp->tp.info.tuntap.dev_name;
161 int err = -EINVAL;
162 int fd;
163
164 fd = simc_open("/dev/net/tun", 02, 0); /* O_RDWR */
165 if (fd < 0) {
166 pr_err("%s: failed to open /dev/net/tun, returned %d (errno = %d)\n",
167 lp->dev->name, fd, errno);
168 return fd;
169 }
170
171 memset(&ifr, 0, sizeof(ifr));
172 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
173 strscpy(ifr.ifr_name, dev_name, sizeof(ifr.ifr_name));
174
175 err = simc_ioctl(fd, TUNSETIFF, &ifr);
176 if (err < 0) {
177 pr_err("%s: failed to set interface %s, returned %d (errno = %d)\n",
178 lp->dev->name, dev_name, err, errno);
179 simc_close(fd);
180 return err;
181 }
182
183 lp->tp.info.tuntap.fd = fd;
184 return err;
185}
186
187static void tuntap_close(struct iss_net_private *lp)
188{
189 simc_close(lp->tp.info.tuntap.fd);
190 lp->tp.info.tuntap.fd = -1;
191}
192
193static int tuntap_read(struct iss_net_private *lp, struct sk_buff **skb)
194{
195 return simc_read(lp->tp.info.tuntap.fd,
196 (*skb)->data, (*skb)->dev->mtu + ETH_HEADER_OTHER);
197}
198
199static int tuntap_write(struct iss_net_private *lp, struct sk_buff **skb)
200{
201 return simc_write(lp->tp.info.tuntap.fd, (*skb)->data, (*skb)->len);
202}
203
204static unsigned short tuntap_protocol(struct sk_buff *skb)
205{
206 return eth_type_trans(skb, dev: skb->dev);
207}
208
209static int tuntap_poll(struct iss_net_private *lp)
210{
211 return simc_poll(lp->tp.info.tuntap.fd);
212}
213
214static const struct iss_net_ops tuntap_ops = {
215 .open = tuntap_open,
216 .close = tuntap_close,
217 .read = tuntap_read,
218 .write = tuntap_write,
219 .protocol = tuntap_protocol,
220 .poll = tuntap_poll,
221};
222
223/*
224 * ethX=tuntap,[mac address],device name
225 */
226
227static int tuntap_probe(struct iss_net_private *lp, int index, char *init)
228{
229 struct net_device *dev = lp->dev;
230 char *dev_name = NULL, *mac_str = NULL, *rem = NULL;
231
232 /* Transport should be 'tuntap': ethX=tuntap,mac,dev_name */
233
234 if (strncmp(init, TRANSPORT_TUNTAP_NAME,
235 sizeof(TRANSPORT_TUNTAP_NAME) - 1))
236 return 0;
237
238 init += sizeof(TRANSPORT_TUNTAP_NAME) - 1;
239 if (*init == ',') {
240 rem = split_if_spec(str: init + 1, &mac_str, &dev_name, NULL);
241 if (rem != NULL) {
242 pr_err("%s: extra garbage on specification : '%s'\n",
243 dev->name, rem);
244 return 0;
245 }
246 } else if (*init != '\0') {
247 pr_err("%s: invalid argument: %s. Skipping device!\n",
248 dev->name, init);
249 return 0;
250 }
251
252 if (!dev_name) {
253 pr_err("%s: missing tuntap device name\n", dev->name);
254 return 0;
255 }
256
257 strscpy(lp->tp.info.tuntap.dev_name, dev_name,
258 sizeof(lp->tp.info.tuntap.dev_name));
259
260 setup_etheraddr(dev, str: mac_str);
261
262 lp->mtu = TRANSPORT_TUNTAP_MTU;
263
264 lp->tp.info.tuntap.fd = -1;
265 lp->tp.net_ops = &tuntap_ops;
266
267 return 1;
268}
269
270/* ================================ ISS NET ================================ */
271
272static int iss_net_rx(struct net_device *dev)
273{
274 struct iss_net_private *lp = netdev_priv(dev);
275 int pkt_len;
276 struct sk_buff *skb;
277
278 /* Check if there is any new data. */
279
280 if (lp->tp.net_ops->poll(lp) == 0)
281 return 0;
282
283 /* Try to allocate memory, if it fails, try again next round. */
284
285 skb = dev_alloc_skb(length: dev->mtu + 2 + ETH_HEADER_OTHER);
286 if (skb == NULL) {
287 spin_lock_bh(lock: &lp->lock);
288 lp->stats.rx_dropped++;
289 spin_unlock_bh(lock: &lp->lock);
290 return 0;
291 }
292
293 skb_reserve(skb, len: 2);
294
295 /* Setup skb */
296
297 skb->dev = dev;
298 skb_reset_mac_header(skb);
299 pkt_len = lp->tp.net_ops->read(lp, &skb);
300 skb_put(skb, len: pkt_len);
301
302 if (pkt_len > 0) {
303 skb_trim(skb, len: pkt_len);
304 skb->protocol = lp->tp.net_ops->protocol(skb);
305
306 spin_lock_bh(lock: &lp->lock);
307 lp->stats.rx_bytes += skb->len;
308 lp->stats.rx_packets++;
309 spin_unlock_bh(lock: &lp->lock);
310 netif_rx(skb);
311 return pkt_len;
312 }
313 kfree_skb(skb);
314 return pkt_len;
315}
316
317static int iss_net_poll(struct iss_net_private *lp)
318{
319 int err, ret = 0;
320
321 if (!netif_running(dev: lp->dev))
322 return 0;
323
324 while ((err = iss_net_rx(dev: lp->dev)) > 0)
325 ret++;
326
327 if (err < 0) {
328 pr_err("Device '%s' read returned %d, shutting it down\n",
329 lp->dev->name, err);
330 dev_close(dev: lp->dev);
331 } else {
332 /* FIXME reactivate_fd(lp->fd, ISS_ETH_IRQ); */
333 }
334
335 return ret;
336}
337
338
339static void iss_net_timer(struct timer_list *t)
340{
341 struct iss_net_private *lp = timer_container_of(lp, t, timer);
342
343 iss_net_poll(lp);
344 mod_timer(timer: &lp->timer, expires: jiffies + lp->timer_val);
345}
346
347
348static int iss_net_open(struct net_device *dev)
349{
350 struct iss_net_private *lp = netdev_priv(dev);
351 int err;
352
353 err = lp->tp.net_ops->open(lp);
354 if (err < 0)
355 return err;
356
357 netif_start_queue(dev);
358
359 /* clear buffer - it can happen that the host side of the interface
360 * is full when we get here. In this case, new data is never queued,
361 * SIGIOs never arrive, and the net never works.
362 */
363 while ((err = iss_net_rx(dev)) > 0)
364 ;
365
366 timer_setup(&lp->timer, iss_net_timer, 0);
367 lp->timer_val = ISS_NET_TIMER_VALUE;
368 mod_timer(timer: &lp->timer, expires: jiffies + lp->timer_val);
369
370 return err;
371}
372
373static int iss_net_close(struct net_device *dev)
374{
375 struct iss_net_private *lp = netdev_priv(dev);
376
377 netif_stop_queue(dev);
378 timer_delete_sync(timer: &lp->timer);
379 lp->tp.net_ops->close(lp);
380
381 return 0;
382}
383
384static int iss_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
385{
386 struct iss_net_private *lp = netdev_priv(dev);
387 int len;
388
389 netif_stop_queue(dev);
390
391 len = lp->tp.net_ops->write(lp, &skb);
392
393 if (len == skb->len) {
394 spin_lock_bh(lock: &lp->lock);
395 lp->stats.tx_packets++;
396 lp->stats.tx_bytes += skb->len;
397 spin_unlock_bh(lock: &lp->lock);
398 netif_trans_update(dev);
399 netif_start_queue(dev);
400
401 /* this is normally done in the interrupt when tx finishes */
402 netif_wake_queue(dev);
403
404 } else if (len == 0) {
405 netif_start_queue(dev);
406 spin_lock_bh(lock: &lp->lock);
407 lp->stats.tx_dropped++;
408 spin_unlock_bh(lock: &lp->lock);
409
410 } else {
411 netif_start_queue(dev);
412 pr_err("%s: %s failed(%d)\n", dev->name, __func__, len);
413 }
414
415
416 dev_kfree_skb(skb);
417 return NETDEV_TX_OK;
418}
419
420
421static void iss_net_get_stats64(struct net_device *dev,
422 struct rtnl_link_stats64 *stats)
423{
424 struct iss_net_private *lp = netdev_priv(dev);
425
426 spin_lock_bh(lock: &lp->lock);
427 *stats = lp->stats;
428 spin_unlock_bh(lock: &lp->lock);
429}
430
431static void iss_net_set_multicast_list(struct net_device *dev)
432{
433}
434
435static void iss_net_tx_timeout(struct net_device *dev, unsigned int txqueue)
436{
437}
438
439static int iss_net_change_mtu(struct net_device *dev, int new_mtu)
440{
441 return -EINVAL;
442}
443
444static void iss_net_user_timer_expire(struct timer_list *unused)
445{
446}
447
448
449static struct platform_driver iss_net_driver = {
450 .driver = {
451 .name = DRIVER_NAME,
452 },
453};
454
455static int driver_registered;
456
457static const struct net_device_ops iss_netdev_ops = {
458 .ndo_open = iss_net_open,
459 .ndo_stop = iss_net_close,
460 .ndo_get_stats64 = iss_net_get_stats64,
461 .ndo_start_xmit = iss_net_start_xmit,
462 .ndo_validate_addr = eth_validate_addr,
463 .ndo_change_mtu = iss_net_change_mtu,
464 .ndo_set_mac_address = eth_mac_addr,
465 .ndo_tx_timeout = iss_net_tx_timeout,
466 .ndo_set_rx_mode = iss_net_set_multicast_list,
467};
468
469static void iss_net_pdev_release(struct device *dev)
470{
471 struct platform_device *pdev = to_platform_device(dev);
472 struct iss_net_private *lp =
473 container_of(pdev, struct iss_net_private, pdev);
474
475 free_netdev(dev: lp->dev);
476}
477
478static void iss_net_configure(int index, char *init)
479{
480 struct net_device *dev;
481 struct iss_net_private *lp;
482
483 dev = alloc_etherdev(sizeof(*lp));
484 if (dev == NULL) {
485 pr_err("eth_configure: failed to allocate device\n");
486 return;
487 }
488
489 /* Initialize private element. */
490
491 lp = netdev_priv(dev);
492 *lp = (struct iss_net_private) {
493 .dev = dev,
494 .index = index,
495 };
496
497 spin_lock_init(&lp->lock);
498 /*
499 * If this name ends up conflicting with an existing registered
500 * netdevice, that is OK, register_netdev{,ice}() will notice this
501 * and fail.
502 */
503 snprintf(buf: dev->name, size: sizeof(dev->name), fmt: "eth%d", index);
504
505 /*
506 * Try all transport protocols.
507 * Note: more protocols can be added by adding '&& !X_init(lp, eth)'.
508 */
509
510 if (!tuntap_probe(lp, index, init)) {
511 pr_err("%s: invalid arguments. Skipping device!\n",
512 dev->name);
513 goto err_free_netdev;
514 }
515
516 pr_info("Netdevice %d (%pM)\n", index, dev->dev_addr);
517
518 /* sysfs register */
519
520 if (!driver_registered) {
521 if (platform_driver_register(&iss_net_driver))
522 goto err_free_netdev;
523 driver_registered = 1;
524 }
525
526 lp->pdev.id = index;
527 lp->pdev.name = DRIVER_NAME;
528 lp->pdev.dev.release = iss_net_pdev_release;
529 if (platform_device_register(&lp->pdev))
530 goto err_free_netdev;
531 SET_NETDEV_DEV(dev, &lp->pdev.dev);
532
533 dev->netdev_ops = &iss_netdev_ops;
534 dev->mtu = lp->mtu;
535 dev->watchdog_timeo = (HZ >> 1);
536 dev->irq = -1;
537
538 rtnl_lock();
539 if (register_netdevice(dev)) {
540 rtnl_unlock();
541 pr_err("%s: error registering net device!\n", dev->name);
542 platform_device_unregister(&lp->pdev);
543 /* dev is freed by the iss_net_pdev_release callback */
544 return;
545 }
546 rtnl_unlock();
547
548 timer_setup(&lp->tl, iss_net_user_timer_expire, 0);
549
550 return;
551
552err_free_netdev:
553 free_netdev(dev);
554}
555
556/* ------------------------------------------------------------------------- */
557
558/* Filled in during early boot */
559
560struct list_head eth_cmd_line = LIST_HEAD_INIT(eth_cmd_line);
561
562struct iss_net_init {
563 struct list_head list;
564 char *init; /* init string */
565 int index;
566};
567
568/*
569 * Parse the command line and look for 'ethX=...' fields, and register all
570 * those fields. They will be later initialized in iss_net_init.
571 */
572
573static int __init iss_net_setup(char *str)
574{
575 struct iss_net_init *device = NULL;
576 struct iss_net_init *new;
577 struct list_head *ele;
578 char *end;
579 int rc;
580 unsigned n;
581
582 end = strchr(str, '=');
583 if (!end) {
584 pr_err("Expected '=' after device number\n");
585 return 1;
586 }
587 *end = 0;
588 rc = kstrtouint(s: str, base: 0, res: &n);
589 *end = '=';
590 if (rc < 0) {
591 pr_err("Failed to parse '%s'\n", str);
592 return 1;
593 }
594 str = end;
595
596 list_for_each(ele, &eth_cmd_line) {
597 device = list_entry(ele, struct iss_net_init, list);
598 if (device->index == n)
599 break;
600 }
601
602 if (device && device->index == n) {
603 pr_err("Device %u already configured\n", n);
604 return 1;
605 }
606
607 new = memblock_alloc(size: sizeof(*new), SMP_CACHE_BYTES);
608 if (new == NULL) {
609 pr_err("Alloc_bootmem failed\n");
610 return 1;
611 }
612
613 INIT_LIST_HEAD(list: &new->list);
614 new->index = n;
615 new->init = str + 1;
616
617 list_add_tail(new: &new->list, head: &eth_cmd_line);
618 return 1;
619}
620
621__setup("eth", iss_net_setup);
622
623/*
624 * Initialize all ISS Ethernet devices previously registered in iss_net_setup.
625 */
626
627static int iss_net_init(void)
628{
629 struct list_head *ele, *next;
630
631 /* Walk through all Ethernet devices specified in the command line. */
632
633 list_for_each_safe(ele, next, &eth_cmd_line) {
634 struct iss_net_init *eth;
635 eth = list_entry(ele, struct iss_net_init, list);
636 iss_net_configure(index: eth->index, init: eth->init);
637 }
638
639 return 1;
640}
641device_initcall(iss_net_init);
642

source code of linux/arch/xtensa/platforms/iss/network.c