1/*
2 * rionet - Ethernet driver over RapidIO messaging services
3 *
4 * Copyright 2005 MontaVista Software, Inc.
5 * Matt Porter <mporter@kernel.crashing.org>
6 *
7 * This program is free software; you can redistribute  it and/or modify it
8 * under  the terms of  the GNU General  Public License as published by the
9 * Free Software Foundation;  either version 2 of the  License, or (at your
10 * option) any later version.
11 */
12
13#include <linux/module.h>
14#include <linux/kernel.h>
15#include <linux/dma-mapping.h>
16#include <linux/delay.h>
17#include <linux/rio.h>
18#include <linux/rio_drv.h>
19#include <linux/slab.h>
20#include <linux/rio_ids.h>
21
22#include <linux/netdevice.h>
23#include <linux/etherdevice.h>
24#include <linux/skbuff.h>
25#include <linux/crc32.h>
26#include <linux/ethtool.h>
27
28#define DRV_NAME        "rionet"
29#define DRV_VERSION     "0.3"
30#define DRV_AUTHOR      "Matt Porter <mporter@kernel.crashing.org>"
31#define DRV_DESC        "Ethernet over RapidIO"
32
33MODULE_AUTHOR(DRV_AUTHOR);
34MODULE_DESCRIPTION(DRV_DESC);
35MODULE_LICENSE("GPL");
36
37#define RIONET_DEFAULT_MSGLEVEL \
38			(NETIF_MSG_DRV          | \
39			 NETIF_MSG_LINK         | \
40			 NETIF_MSG_RX_ERR       | \
41			 NETIF_MSG_TX_ERR)
42
43#define RIONET_DOORBELL_JOIN	0x1000
44#define RIONET_DOORBELL_LEAVE	0x1001
45
46#define RIONET_MAILBOX		0
47
48#define RIONET_TX_RING_SIZE	CONFIG_RIONET_TX_SIZE
49#define RIONET_RX_RING_SIZE	CONFIG_RIONET_RX_SIZE
50#define RIONET_MAX_NETS		8
51
52struct rionet_private {
53	struct rio_mport *mport;
54	struct sk_buff *rx_skb[RIONET_RX_RING_SIZE];
55	struct sk_buff *tx_skb[RIONET_TX_RING_SIZE];
56	int rx_slot;
57	int tx_slot;
58	int tx_cnt;
59	int ack_slot;
60	spinlock_t lock;
61	spinlock_t tx_lock;
62	u32 msg_enable;
63};
64
65struct rionet_peer {
66	struct list_head node;
67	struct rio_dev *rdev;
68	struct resource *res;
69};
70
71struct rionet_net {
72	struct net_device *ndev;
73	struct list_head peers;
74	struct rio_dev **active;
75	int nact;	/* number of active peers */
76};
77
78static struct rionet_net nets[RIONET_MAX_NETS];
79
80#define is_rionet_capable(src_ops, dst_ops)			\
81			((src_ops & RIO_SRC_OPS_DATA_MSG) &&	\
82			 (dst_ops & RIO_DST_OPS_DATA_MSG) &&	\
83			 (src_ops & RIO_SRC_OPS_DOORBELL) &&	\
84			 (dst_ops & RIO_DST_OPS_DOORBELL))
85#define dev_rionet_capable(dev) \
86	is_rionet_capable(dev->src_ops, dev->dst_ops)
87
88#define RIONET_MAC_MATCH(x)	(!memcmp((x), "\00\01\00\01", 4))
89#define RIONET_GET_DESTID(x)	((*((u8 *)x + 4) << 8) | *((u8 *)x + 5))
90
91static int rionet_rx_clean(struct net_device *ndev)
92{
93	int i;
94	int error = 0;
95	struct rionet_private *rnet = netdev_priv(ndev);
96	void *data;
97
98	i = rnet->rx_slot;
99
100	do {
101		if (!rnet->rx_skb[i])
102			continue;
103
104		if (!(data = rio_get_inb_message(rnet->mport, RIONET_MAILBOX)))
105			break;
106
107		rnet->rx_skb[i]->data = data;
108		skb_put(rnet->rx_skb[i], RIO_MAX_MSG_SIZE);
109		rnet->rx_skb[i]->protocol =
110		    eth_type_trans(rnet->rx_skb[i], ndev);
111		error = netif_rx(rnet->rx_skb[i]);
112
113		if (error == NET_RX_DROP) {
114			ndev->stats.rx_dropped++;
115		} else {
116			ndev->stats.rx_packets++;
117			ndev->stats.rx_bytes += RIO_MAX_MSG_SIZE;
118		}
119
120	} while ((i = (i + 1) % RIONET_RX_RING_SIZE) != rnet->rx_slot);
121
122	return i;
123}
124
125static void rionet_rx_fill(struct net_device *ndev, int end)
126{
127	int i;
128	struct rionet_private *rnet = netdev_priv(ndev);
129
130	i = rnet->rx_slot;
131	do {
132		rnet->rx_skb[i] = dev_alloc_skb(RIO_MAX_MSG_SIZE);
133
134		if (!rnet->rx_skb[i])
135			break;
136
137		rio_add_inb_buffer(rnet->mport, RIONET_MAILBOX,
138				   rnet->rx_skb[i]->data);
139	} while ((i = (i + 1) % RIONET_RX_RING_SIZE) != end);
140
141	rnet->rx_slot = i;
142}
143
144static int rionet_queue_tx_msg(struct sk_buff *skb, struct net_device *ndev,
145			       struct rio_dev *rdev)
146{
147	struct rionet_private *rnet = netdev_priv(ndev);
148
149	rio_add_outb_message(rnet->mport, rdev, 0, skb->data, skb->len);
150	rnet->tx_skb[rnet->tx_slot] = skb;
151
152	ndev->stats.tx_packets++;
153	ndev->stats.tx_bytes += skb->len;
154
155	if (++rnet->tx_cnt == RIONET_TX_RING_SIZE)
156		netif_stop_queue(ndev);
157
158	++rnet->tx_slot;
159	rnet->tx_slot &= (RIONET_TX_RING_SIZE - 1);
160
161	if (netif_msg_tx_queued(rnet))
162		printk(KERN_INFO "%s: queued skb len %8.8x\n", DRV_NAME,
163		       skb->len);
164
165	return 0;
166}
167
168static int rionet_start_xmit(struct sk_buff *skb, struct net_device *ndev)
169{
170	int i;
171	struct rionet_private *rnet = netdev_priv(ndev);
172	struct ethhdr *eth = (struct ethhdr *)skb->data;
173	u16 destid;
174	unsigned long flags;
175	int add_num = 1;
176
177	local_irq_save(flags);
178	if (!spin_trylock(&rnet->tx_lock)) {
179		local_irq_restore(flags);
180		return NETDEV_TX_LOCKED;
181	}
182
183	if (is_multicast_ether_addr(eth->h_dest))
184		add_num = nets[rnet->mport->id].nact;
185
186	if ((rnet->tx_cnt + add_num) > RIONET_TX_RING_SIZE) {
187		netif_stop_queue(ndev);
188		spin_unlock_irqrestore(&rnet->tx_lock, flags);
189		printk(KERN_ERR "%s: BUG! Tx Ring full when queue awake!\n",
190		       ndev->name);
191		return NETDEV_TX_BUSY;
192	}
193
194	if (is_multicast_ether_addr(eth->h_dest)) {
195		int count = 0;
196
197		for (i = 0; i < RIO_MAX_ROUTE_ENTRIES(rnet->mport->sys_size);
198				i++)
199			if (nets[rnet->mport->id].active[i]) {
200				rionet_queue_tx_msg(skb, ndev,
201					nets[rnet->mport->id].active[i]);
202				if (count)
203					atomic_inc(&skb->users);
204				count++;
205			}
206	} else if (RIONET_MAC_MATCH(eth->h_dest)) {
207		destid = RIONET_GET_DESTID(eth->h_dest);
208		if (nets[rnet->mport->id].active[destid])
209			rionet_queue_tx_msg(skb, ndev,
210					nets[rnet->mport->id].active[destid]);
211		else {
212			/*
213			 * If the target device was removed from the list of
214			 * active peers but we still have TX packets targeting
215			 * it just report sending a packet to the target
216			 * (without actual packet transfer).
217			 */
218			dev_kfree_skb_any(skb);
219			ndev->stats.tx_packets++;
220			ndev->stats.tx_bytes += skb->len;
221		}
222	}
223
224	spin_unlock_irqrestore(&rnet->tx_lock, flags);
225
226	return NETDEV_TX_OK;
227}
228
229static void rionet_dbell_event(struct rio_mport *mport, void *dev_id, u16 sid, u16 tid,
230			       u16 info)
231{
232	struct net_device *ndev = dev_id;
233	struct rionet_private *rnet = netdev_priv(ndev);
234	struct rionet_peer *peer;
235
236	if (netif_msg_intr(rnet))
237		printk(KERN_INFO "%s: doorbell sid %4.4x tid %4.4x info %4.4x",
238		       DRV_NAME, sid, tid, info);
239	if (info == RIONET_DOORBELL_JOIN) {
240		if (!nets[rnet->mport->id].active[sid]) {
241			list_for_each_entry(peer,
242					   &nets[rnet->mport->id].peers, node) {
243				if (peer->rdev->destid == sid) {
244					nets[rnet->mport->id].active[sid] =
245								peer->rdev;
246					nets[rnet->mport->id].nact++;
247				}
248			}
249			rio_mport_send_doorbell(mport, sid,
250						RIONET_DOORBELL_JOIN);
251		}
252	} else if (info == RIONET_DOORBELL_LEAVE) {
253		nets[rnet->mport->id].active[sid] = NULL;
254		nets[rnet->mport->id].nact--;
255	} else {
256		if (netif_msg_intr(rnet))
257			printk(KERN_WARNING "%s: unhandled doorbell\n",
258			       DRV_NAME);
259	}
260}
261
262static void rionet_inb_msg_event(struct rio_mport *mport, void *dev_id, int mbox, int slot)
263{
264	int n;
265	struct net_device *ndev = dev_id;
266	struct rionet_private *rnet = netdev_priv(ndev);
267
268	if (netif_msg_intr(rnet))
269		printk(KERN_INFO "%s: inbound message event, mbox %d slot %d\n",
270		       DRV_NAME, mbox, slot);
271
272	spin_lock(&rnet->lock);
273	if ((n = rionet_rx_clean(ndev)) != rnet->rx_slot)
274		rionet_rx_fill(ndev, n);
275	spin_unlock(&rnet->lock);
276}
277
278static void rionet_outb_msg_event(struct rio_mport *mport, void *dev_id, int mbox, int slot)
279{
280	struct net_device *ndev = dev_id;
281	struct rionet_private *rnet = netdev_priv(ndev);
282
283	spin_lock(&rnet->tx_lock);
284
285	if (netif_msg_intr(rnet))
286		printk(KERN_INFO
287		       "%s: outbound message event, mbox %d slot %d\n",
288		       DRV_NAME, mbox, slot);
289
290	while (rnet->tx_cnt && (rnet->ack_slot != slot)) {
291		/* dma unmap single */
292		dev_kfree_skb_irq(rnet->tx_skb[rnet->ack_slot]);
293		rnet->tx_skb[rnet->ack_slot] = NULL;
294		++rnet->ack_slot;
295		rnet->ack_slot &= (RIONET_TX_RING_SIZE - 1);
296		rnet->tx_cnt--;
297	}
298
299	if (rnet->tx_cnt < RIONET_TX_RING_SIZE)
300		netif_wake_queue(ndev);
301
302	spin_unlock(&rnet->tx_lock);
303}
304
305static int rionet_open(struct net_device *ndev)
306{
307	int i, rc = 0;
308	struct rionet_peer *peer, *tmp;
309	struct rionet_private *rnet = netdev_priv(ndev);
310
311	if (netif_msg_ifup(rnet))
312		printk(KERN_INFO "%s: open\n", DRV_NAME);
313
314	if ((rc = rio_request_inb_dbell(rnet->mport,
315					(void *)ndev,
316					RIONET_DOORBELL_JOIN,
317					RIONET_DOORBELL_LEAVE,
318					rionet_dbell_event)) < 0)
319		goto out;
320
321	if ((rc = rio_request_inb_mbox(rnet->mport,
322				       (void *)ndev,
323				       RIONET_MAILBOX,
324				       RIONET_RX_RING_SIZE,
325				       rionet_inb_msg_event)) < 0)
326		goto out;
327
328	if ((rc = rio_request_outb_mbox(rnet->mport,
329					(void *)ndev,
330					RIONET_MAILBOX,
331					RIONET_TX_RING_SIZE,
332					rionet_outb_msg_event)) < 0)
333		goto out;
334
335	/* Initialize inbound message ring */
336	for (i = 0; i < RIONET_RX_RING_SIZE; i++)
337		rnet->rx_skb[i] = NULL;
338	rnet->rx_slot = 0;
339	rionet_rx_fill(ndev, 0);
340
341	rnet->tx_slot = 0;
342	rnet->tx_cnt = 0;
343	rnet->ack_slot = 0;
344
345	netif_carrier_on(ndev);
346	netif_start_queue(ndev);
347
348	list_for_each_entry_safe(peer, tmp,
349				 &nets[rnet->mport->id].peers, node) {
350		if (!(peer->res = rio_request_outb_dbell(peer->rdev,
351							 RIONET_DOORBELL_JOIN,
352							 RIONET_DOORBELL_LEAVE)))
353		{
354			printk(KERN_ERR "%s: error requesting doorbells\n",
355			       DRV_NAME);
356			continue;
357		}
358
359		/* Send a join message */
360		rio_send_doorbell(peer->rdev, RIONET_DOORBELL_JOIN);
361	}
362
363      out:
364	return rc;
365}
366
367static int rionet_close(struct net_device *ndev)
368{
369	struct rionet_private *rnet = netdev_priv(ndev);
370	struct rionet_peer *peer, *tmp;
371	int i;
372
373	if (netif_msg_ifup(rnet))
374		printk(KERN_INFO "%s: close %s\n", DRV_NAME, ndev->name);
375
376	netif_stop_queue(ndev);
377	netif_carrier_off(ndev);
378
379	for (i = 0; i < RIONET_RX_RING_SIZE; i++)
380		kfree_skb(rnet->rx_skb[i]);
381
382	list_for_each_entry_safe(peer, tmp,
383				 &nets[rnet->mport->id].peers, node) {
384		if (nets[rnet->mport->id].active[peer->rdev->destid]) {
385			rio_send_doorbell(peer->rdev, RIONET_DOORBELL_LEAVE);
386			nets[rnet->mport->id].active[peer->rdev->destid] = NULL;
387		}
388		rio_release_outb_dbell(peer->rdev, peer->res);
389	}
390
391	rio_release_inb_dbell(rnet->mport, RIONET_DOORBELL_JOIN,
392			      RIONET_DOORBELL_LEAVE);
393	rio_release_inb_mbox(rnet->mport, RIONET_MAILBOX);
394	rio_release_outb_mbox(rnet->mport, RIONET_MAILBOX);
395
396	return 0;
397}
398
399static void rionet_remove_dev(struct device *dev, struct subsys_interface *sif)
400{
401	struct rio_dev *rdev = to_rio_dev(dev);
402	unsigned char netid = rdev->net->hport->id;
403	struct rionet_peer *peer, *tmp;
404
405	if (dev_rionet_capable(rdev)) {
406		list_for_each_entry_safe(peer, tmp, &nets[netid].peers, node) {
407			if (peer->rdev == rdev) {
408				if (nets[netid].active[rdev->destid]) {
409					nets[netid].active[rdev->destid] = NULL;
410					nets[netid].nact--;
411				}
412
413				list_del(&peer->node);
414				kfree(peer);
415				break;
416			}
417		}
418	}
419}
420
421static void rionet_get_drvinfo(struct net_device *ndev,
422			       struct ethtool_drvinfo *info)
423{
424	struct rionet_private *rnet = netdev_priv(ndev);
425
426	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
427	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
428	strlcpy(info->fw_version, "n/a", sizeof(info->fw_version));
429	strlcpy(info->bus_info, rnet->mport->name, sizeof(info->bus_info));
430}
431
432static u32 rionet_get_msglevel(struct net_device *ndev)
433{
434	struct rionet_private *rnet = netdev_priv(ndev);
435
436	return rnet->msg_enable;
437}
438
439static void rionet_set_msglevel(struct net_device *ndev, u32 value)
440{
441	struct rionet_private *rnet = netdev_priv(ndev);
442
443	rnet->msg_enable = value;
444}
445
446static const struct ethtool_ops rionet_ethtool_ops = {
447	.get_drvinfo = rionet_get_drvinfo,
448	.get_msglevel = rionet_get_msglevel,
449	.set_msglevel = rionet_set_msglevel,
450	.get_link = ethtool_op_get_link,
451};
452
453static const struct net_device_ops rionet_netdev_ops = {
454	.ndo_open		= rionet_open,
455	.ndo_stop		= rionet_close,
456	.ndo_start_xmit		= rionet_start_xmit,
457	.ndo_change_mtu		= eth_change_mtu,
458	.ndo_validate_addr	= eth_validate_addr,
459	.ndo_set_mac_address	= eth_mac_addr,
460};
461
462static int rionet_setup_netdev(struct rio_mport *mport, struct net_device *ndev)
463{
464	int rc = 0;
465	struct rionet_private *rnet;
466	u16 device_id;
467	const size_t rionet_active_bytes = sizeof(void *) *
468				RIO_MAX_ROUTE_ENTRIES(mport->sys_size);
469
470	nets[mport->id].active = (struct rio_dev **)__get_free_pages(GFP_KERNEL,
471						get_order(rionet_active_bytes));
472	if (!nets[mport->id].active) {
473		rc = -ENOMEM;
474		goto out;
475	}
476	memset((void *)nets[mport->id].active, 0, rionet_active_bytes);
477
478	/* Set up private area */
479	rnet = netdev_priv(ndev);
480	rnet->mport = mport;
481
482	/* Set the default MAC address */
483	device_id = rio_local_get_device_id(mport);
484	ndev->dev_addr[0] = 0x00;
485	ndev->dev_addr[1] = 0x01;
486	ndev->dev_addr[2] = 0x00;
487	ndev->dev_addr[3] = 0x01;
488	ndev->dev_addr[4] = device_id >> 8;
489	ndev->dev_addr[5] = device_id & 0xff;
490
491	ndev->netdev_ops = &rionet_netdev_ops;
492	ndev->mtu = RIO_MAX_MSG_SIZE - 14;
493	ndev->features = NETIF_F_LLTX;
494	SET_NETDEV_DEV(ndev, &mport->dev);
495	ndev->ethtool_ops = &rionet_ethtool_ops;
496
497	spin_lock_init(&rnet->lock);
498	spin_lock_init(&rnet->tx_lock);
499
500	rnet->msg_enable = RIONET_DEFAULT_MSGLEVEL;
501
502	rc = register_netdev(ndev);
503	if (rc != 0)
504		goto out;
505
506	printk(KERN_INFO "%s: %s %s Version %s, MAC %pM, %s\n",
507	       ndev->name,
508	       DRV_NAME,
509	       DRV_DESC,
510	       DRV_VERSION,
511	       ndev->dev_addr,
512	       mport->name);
513
514      out:
515	return rc;
516}
517
518static unsigned long net_table[RIONET_MAX_NETS/sizeof(unsigned long) + 1];
519
520static int rionet_add_dev(struct device *dev, struct subsys_interface *sif)
521{
522	int rc = -ENODEV;
523	u32 lsrc_ops, ldst_ops;
524	struct rionet_peer *peer;
525	struct net_device *ndev = NULL;
526	struct rio_dev *rdev = to_rio_dev(dev);
527	unsigned char netid = rdev->net->hport->id;
528	int oldnet;
529
530	if (netid >= RIONET_MAX_NETS)
531		return rc;
532
533	oldnet = test_and_set_bit(netid, net_table);
534
535	/*
536	 * If first time through this net, make sure local device is rionet
537	 * capable and setup netdev (this step will be skipped in later probes
538	 * on the same net).
539	 */
540	if (!oldnet) {
541		rio_local_read_config_32(rdev->net->hport, RIO_SRC_OPS_CAR,
542					 &lsrc_ops);
543		rio_local_read_config_32(rdev->net->hport, RIO_DST_OPS_CAR,
544					 &ldst_ops);
545		if (!is_rionet_capable(lsrc_ops, ldst_ops)) {
546			printk(KERN_ERR
547			       "%s: local device %s is not network capable\n",
548			       DRV_NAME, rdev->net->hport->name);
549			goto out;
550		}
551
552		/* Allocate our net_device structure */
553		ndev = alloc_etherdev(sizeof(struct rionet_private));
554		if (ndev == NULL) {
555			rc = -ENOMEM;
556			goto out;
557		}
558		nets[netid].ndev = ndev;
559		rc = rionet_setup_netdev(rdev->net->hport, ndev);
560		if (rc) {
561			printk(KERN_ERR "%s: failed to setup netdev (rc=%d)\n",
562			       DRV_NAME, rc);
563			goto out;
564		}
565
566		INIT_LIST_HEAD(&nets[netid].peers);
567		nets[netid].nact = 0;
568	} else if (nets[netid].ndev == NULL)
569		goto out;
570
571	/*
572	 * If the remote device has mailbox/doorbell capabilities,
573	 * add it to the peer list.
574	 */
575	if (dev_rionet_capable(rdev)) {
576		if (!(peer = kmalloc(sizeof(struct rionet_peer), GFP_KERNEL))) {
577			rc = -ENOMEM;
578			goto out;
579		}
580		peer->rdev = rdev;
581		list_add_tail(&peer->node, &nets[netid].peers);
582	}
583
584	return 0;
585out:
586	return rc;
587}
588
589#ifdef MODULE
590static struct rio_device_id rionet_id_table[] = {
591	{RIO_DEVICE(RIO_ANY_ID, RIO_ANY_ID)},
592	{ 0, }	/* terminate list */
593};
594
595MODULE_DEVICE_TABLE(rapidio, rionet_id_table);
596#endif
597
598static struct subsys_interface rionet_interface = {
599	.name		= "rionet",
600	.subsys		= &rio_bus_type,
601	.add_dev	= rionet_add_dev,
602	.remove_dev	= rionet_remove_dev,
603};
604
605static int __init rionet_init(void)
606{
607	return subsys_interface_register(&rionet_interface);
608}
609
610static void __exit rionet_exit(void)
611{
612	struct rionet_private *rnet;
613	struct net_device *ndev;
614	struct rionet_peer *peer, *tmp;
615	int i;
616
617	for (i = 0; i < RIONET_MAX_NETS; i++) {
618		if (nets[i].ndev != NULL) {
619			ndev = nets[i].ndev;
620			rnet = netdev_priv(ndev);
621			unregister_netdev(ndev);
622
623			list_for_each_entry_safe(peer,
624						 tmp, &nets[i].peers, node) {
625				list_del(&peer->node);
626				kfree(peer);
627			}
628
629			free_pages((unsigned long)nets[i].active,
630				 get_order(sizeof(void *) *
631				 RIO_MAX_ROUTE_ENTRIES(rnet->mport->sys_size)));
632			nets[i].active = NULL;
633
634			free_netdev(ndev);
635		}
636	}
637
638	subsys_interface_unregister(&rionet_interface);
639}
640
641late_initcall(rionet_init);
642module_exit(rionet_exit);
643