xref: /openbmc/linux/drivers/net/ethernet/sun/sunvnet.c (revision 455f9726)
1 /* sunvnet.c: Sun LDOM Virtual Network Driver.
2  *
3  * Copyright (C) 2007, 2008 David S. Miller <davem@davemloft.net>
4  */
5 
6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7 
8 #include <linux/module.h>
9 #include <linux/kernel.h>
10 #include <linux/types.h>
11 #include <linux/slab.h>
12 #include <linux/delay.h>
13 #include <linux/init.h>
14 #include <linux/netdevice.h>
15 #include <linux/ethtool.h>
16 #include <linux/etherdevice.h>
17 #include <linux/mutex.h>
18 
19 #include <asm/vio.h>
20 #include <asm/ldc.h>
21 
22 #include "sunvnet.h"
23 
24 #define DRV_MODULE_NAME		"sunvnet"
25 #define DRV_MODULE_VERSION	"1.0"
26 #define DRV_MODULE_RELDATE	"June 25, 2007"
27 
28 static char version[] =
29 	DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n";
30 MODULE_AUTHOR("David S. Miller (davem@davemloft.net)");
31 MODULE_DESCRIPTION("Sun LDOM virtual network driver");
32 MODULE_LICENSE("GPL");
33 MODULE_VERSION(DRV_MODULE_VERSION);
34 
35 /* Ordered from largest major to lowest */
36 static struct vio_version vnet_versions[] = {
37 	{ .major = 1, .minor = 0 },
38 };
39 
40 static inline u32 vnet_tx_dring_avail(struct vio_dring_state *dr)
41 {
42 	return vio_dring_avail(dr, VNET_TX_RING_SIZE);
43 }
44 
45 static int vnet_handle_unknown(struct vnet_port *port, void *arg)
46 {
47 	struct vio_msg_tag *pkt = arg;
48 
49 	pr_err("Received unknown msg [%02x:%02x:%04x:%08x]\n",
50 	       pkt->type, pkt->stype, pkt->stype_env, pkt->sid);
51 	pr_err("Resetting connection\n");
52 
53 	ldc_disconnect(port->vio.lp);
54 
55 	return -ECONNRESET;
56 }
57 
58 static int vnet_send_attr(struct vio_driver_state *vio)
59 {
60 	struct vnet_port *port = to_vnet_port(vio);
61 	struct net_device *dev = port->vp->dev;
62 	struct vio_net_attr_info pkt;
63 	int i;
64 
65 	memset(&pkt, 0, sizeof(pkt));
66 	pkt.tag.type = VIO_TYPE_CTRL;
67 	pkt.tag.stype = VIO_SUBTYPE_INFO;
68 	pkt.tag.stype_env = VIO_ATTR_INFO;
69 	pkt.tag.sid = vio_send_sid(vio);
70 	pkt.xfer_mode = VIO_DRING_MODE;
71 	pkt.addr_type = VNET_ADDR_ETHERMAC;
72 	pkt.ack_freq = 0;
73 	for (i = 0; i < 6; i++)
74 		pkt.addr |= (u64)dev->dev_addr[i] << ((5 - i) * 8);
75 	pkt.mtu = ETH_FRAME_LEN;
76 
77 	viodbg(HS, "SEND NET ATTR xmode[0x%x] atype[0x%x] addr[%llx] "
78 	       "ackfreq[%u] mtu[%llu]\n",
79 	       pkt.xfer_mode, pkt.addr_type,
80 	       (unsigned long long) pkt.addr,
81 	       pkt.ack_freq,
82 	       (unsigned long long) pkt.mtu);
83 
84 	return vio_ldc_send(vio, &pkt, sizeof(pkt));
85 }
86 
87 static int handle_attr_info(struct vio_driver_state *vio,
88 			    struct vio_net_attr_info *pkt)
89 {
90 	viodbg(HS, "GOT NET ATTR INFO xmode[0x%x] atype[0x%x] addr[%llx] "
91 	       "ackfreq[%u] mtu[%llu]\n",
92 	       pkt->xfer_mode, pkt->addr_type,
93 	       (unsigned long long) pkt->addr,
94 	       pkt->ack_freq,
95 	       (unsigned long long) pkt->mtu);
96 
97 	pkt->tag.sid = vio_send_sid(vio);
98 
99 	if (pkt->xfer_mode != VIO_DRING_MODE ||
100 	    pkt->addr_type != VNET_ADDR_ETHERMAC ||
101 	    pkt->mtu != ETH_FRAME_LEN) {
102 		viodbg(HS, "SEND NET ATTR NACK\n");
103 
104 		pkt->tag.stype = VIO_SUBTYPE_NACK;
105 
106 		(void) vio_ldc_send(vio, pkt, sizeof(*pkt));
107 
108 		return -ECONNRESET;
109 	} else {
110 		viodbg(HS, "SEND NET ATTR ACK\n");
111 
112 		pkt->tag.stype = VIO_SUBTYPE_ACK;
113 
114 		return vio_ldc_send(vio, pkt, sizeof(*pkt));
115 	}
116 
117 }
118 
119 static int handle_attr_ack(struct vio_driver_state *vio,
120 			   struct vio_net_attr_info *pkt)
121 {
122 	viodbg(HS, "GOT NET ATTR ACK\n");
123 
124 	return 0;
125 }
126 
127 static int handle_attr_nack(struct vio_driver_state *vio,
128 			    struct vio_net_attr_info *pkt)
129 {
130 	viodbg(HS, "GOT NET ATTR NACK\n");
131 
132 	return -ECONNRESET;
133 }
134 
135 static int vnet_handle_attr(struct vio_driver_state *vio, void *arg)
136 {
137 	struct vio_net_attr_info *pkt = arg;
138 
139 	switch (pkt->tag.stype) {
140 	case VIO_SUBTYPE_INFO:
141 		return handle_attr_info(vio, pkt);
142 
143 	case VIO_SUBTYPE_ACK:
144 		return handle_attr_ack(vio, pkt);
145 
146 	case VIO_SUBTYPE_NACK:
147 		return handle_attr_nack(vio, pkt);
148 
149 	default:
150 		return -ECONNRESET;
151 	}
152 }
153 
154 static void vnet_handshake_complete(struct vio_driver_state *vio)
155 {
156 	struct vio_dring_state *dr;
157 
158 	dr = &vio->drings[VIO_DRIVER_RX_RING];
159 	dr->snd_nxt = dr->rcv_nxt = 1;
160 
161 	dr = &vio->drings[VIO_DRIVER_TX_RING];
162 	dr->snd_nxt = dr->rcv_nxt = 1;
163 }
164 
165 /* The hypervisor interface that implements copying to/from imported
166  * memory from another domain requires that copies are done to 8-byte
167  * aligned buffers, and that the lengths of such copies are also 8-byte
168  * multiples.
169  *
170  * So we align skb->data to an 8-byte multiple and pad-out the data
171  * area so we can round the copy length up to the next multiple of
172  * 8 for the copy.
173  *
174  * The transmitter puts the actual start of the packet 6 bytes into
175  * the buffer it sends over, so that the IP headers after the ethernet
176  * header are aligned properly.  These 6 bytes are not in the descriptor
177  * length, they are simply implied.  This offset is represented using
178  * the VNET_PACKET_SKIP macro.
179  */
180 static struct sk_buff *alloc_and_align_skb(struct net_device *dev,
181 					   unsigned int len)
182 {
183 	struct sk_buff *skb = netdev_alloc_skb(dev, len+VNET_PACKET_SKIP+8+8);
184 	unsigned long addr, off;
185 
186 	if (unlikely(!skb))
187 		return NULL;
188 
189 	addr = (unsigned long) skb->data;
190 	off = ((addr + 7UL) & ~7UL) - addr;
191 	if (off)
192 		skb_reserve(skb, off);
193 
194 	return skb;
195 }
196 
197 static int vnet_rx_one(struct vnet_port *port, unsigned int len,
198 		       struct ldc_trans_cookie *cookies, int ncookies)
199 {
200 	struct net_device *dev = port->vp->dev;
201 	unsigned int copy_len;
202 	struct sk_buff *skb;
203 	int err;
204 
205 	err = -EMSGSIZE;
206 	if (unlikely(len < ETH_ZLEN || len > ETH_FRAME_LEN)) {
207 		dev->stats.rx_length_errors++;
208 		goto out_dropped;
209 	}
210 
211 	skb = alloc_and_align_skb(dev, len);
212 	err = -ENOMEM;
213 	if (unlikely(!skb)) {
214 		dev->stats.rx_missed_errors++;
215 		goto out_dropped;
216 	}
217 
218 	copy_len = (len + VNET_PACKET_SKIP + 7U) & ~7U;
219 	skb_put(skb, copy_len);
220 	err = ldc_copy(port->vio.lp, LDC_COPY_IN,
221 		       skb->data, copy_len, 0,
222 		       cookies, ncookies);
223 	if (unlikely(err < 0)) {
224 		dev->stats.rx_frame_errors++;
225 		goto out_free_skb;
226 	}
227 
228 	skb_pull(skb, VNET_PACKET_SKIP);
229 	skb_trim(skb, len);
230 	skb->protocol = eth_type_trans(skb, dev);
231 
232 	dev->stats.rx_packets++;
233 	dev->stats.rx_bytes += len;
234 
235 	netif_rx(skb);
236 
237 	return 0;
238 
239 out_free_skb:
240 	kfree_skb(skb);
241 
242 out_dropped:
243 	dev->stats.rx_dropped++;
244 	return err;
245 }
246 
247 static int vnet_send_ack(struct vnet_port *port, struct vio_dring_state *dr,
248 			 u32 start, u32 end, u8 vio_dring_state)
249 {
250 	struct vio_dring_data hdr = {
251 		.tag = {
252 			.type		= VIO_TYPE_DATA,
253 			.stype		= VIO_SUBTYPE_ACK,
254 			.stype_env	= VIO_DRING_DATA,
255 			.sid		= vio_send_sid(&port->vio),
256 		},
257 		.dring_ident		= dr->ident,
258 		.start_idx		= start,
259 		.end_idx		= end,
260 		.state			= vio_dring_state,
261 	};
262 	int err, delay;
263 
264 	hdr.seq = dr->snd_nxt;
265 	delay = 1;
266 	do {
267 		err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
268 		if (err > 0) {
269 			dr->snd_nxt++;
270 			break;
271 		}
272 		udelay(delay);
273 		if ((delay <<= 1) > 128)
274 			delay = 128;
275 	} while (err == -EAGAIN);
276 
277 	return err;
278 }
279 
280 static u32 next_idx(u32 idx, struct vio_dring_state *dr)
281 {
282 	if (++idx == dr->num_entries)
283 		idx = 0;
284 	return idx;
285 }
286 
287 static u32 prev_idx(u32 idx, struct vio_dring_state *dr)
288 {
289 	if (idx == 0)
290 		idx = dr->num_entries - 1;
291 	else
292 		idx--;
293 
294 	return idx;
295 }
296 
297 static struct vio_net_desc *get_rx_desc(struct vnet_port *port,
298 					struct vio_dring_state *dr,
299 					u32 index)
300 {
301 	struct vio_net_desc *desc = port->vio.desc_buf;
302 	int err;
303 
304 	err = ldc_get_dring_entry(port->vio.lp, desc, dr->entry_size,
305 				  (index * dr->entry_size),
306 				  dr->cookies, dr->ncookies);
307 	if (err < 0)
308 		return ERR_PTR(err);
309 
310 	return desc;
311 }
312 
313 static int put_rx_desc(struct vnet_port *port,
314 		       struct vio_dring_state *dr,
315 		       struct vio_net_desc *desc,
316 		       u32 index)
317 {
318 	int err;
319 
320 	err = ldc_put_dring_entry(port->vio.lp, desc, dr->entry_size,
321 				  (index * dr->entry_size),
322 				  dr->cookies, dr->ncookies);
323 	if (err < 0)
324 		return err;
325 
326 	return 0;
327 }
328 
329 static int vnet_walk_rx_one(struct vnet_port *port,
330 			    struct vio_dring_state *dr,
331 			    u32 index, int *needs_ack)
332 {
333 	struct vio_net_desc *desc = get_rx_desc(port, dr, index);
334 	struct vio_driver_state *vio = &port->vio;
335 	int err;
336 
337 	if (IS_ERR(desc))
338 		return PTR_ERR(desc);
339 
340 	viodbg(DATA, "vio_walk_rx_one desc[%02x:%02x:%08x:%08x:%llx:%llx]\n",
341 	       desc->hdr.state, desc->hdr.ack,
342 	       desc->size, desc->ncookies,
343 	       desc->cookies[0].cookie_addr,
344 	       desc->cookies[0].cookie_size);
345 
346 	if (desc->hdr.state != VIO_DESC_READY)
347 		return 1;
348 	err = vnet_rx_one(port, desc->size, desc->cookies, desc->ncookies);
349 	if (err == -ECONNRESET)
350 		return err;
351 	desc->hdr.state = VIO_DESC_DONE;
352 	err = put_rx_desc(port, dr, desc, index);
353 	if (err < 0)
354 		return err;
355 	*needs_ack = desc->hdr.ack;
356 	return 0;
357 }
358 
359 static int vnet_walk_rx(struct vnet_port *port, struct vio_dring_state *dr,
360 			u32 start, u32 end)
361 {
362 	struct vio_driver_state *vio = &port->vio;
363 	int ack_start = -1, ack_end = -1;
364 
365 	end = (end == (u32) -1) ? prev_idx(start, dr) : next_idx(end, dr);
366 
367 	viodbg(DATA, "vnet_walk_rx start[%08x] end[%08x]\n", start, end);
368 
369 	while (start != end) {
370 		int ack = 0, err = vnet_walk_rx_one(port, dr, start, &ack);
371 		if (err == -ECONNRESET)
372 			return err;
373 		if (err != 0)
374 			break;
375 		if (ack_start == -1)
376 			ack_start = start;
377 		ack_end = start;
378 		start = next_idx(start, dr);
379 		if (ack && start != end) {
380 			err = vnet_send_ack(port, dr, ack_start, ack_end,
381 					    VIO_DRING_ACTIVE);
382 			if (err == -ECONNRESET)
383 				return err;
384 			ack_start = -1;
385 		}
386 	}
387 	if (unlikely(ack_start == -1))
388 		ack_start = ack_end = prev_idx(start, dr);
389 	return vnet_send_ack(port, dr, ack_start, ack_end, VIO_DRING_STOPPED);
390 }
391 
392 static int vnet_rx(struct vnet_port *port, void *msgbuf)
393 {
394 	struct vio_dring_data *pkt = msgbuf;
395 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_RX_RING];
396 	struct vio_driver_state *vio = &port->vio;
397 
398 	viodbg(DATA, "vnet_rx stype_env[%04x] seq[%016llx] rcv_nxt[%016llx]\n",
399 	       pkt->tag.stype_env, pkt->seq, dr->rcv_nxt);
400 
401 	if (unlikely(pkt->tag.stype_env != VIO_DRING_DATA))
402 		return 0;
403 	if (unlikely(pkt->seq != dr->rcv_nxt)) {
404 		pr_err("RX out of sequence seq[0x%llx] rcv_nxt[0x%llx]\n",
405 		       pkt->seq, dr->rcv_nxt);
406 		return 0;
407 	}
408 
409 	dr->rcv_nxt++;
410 
411 	/* XXX Validate pkt->start_idx and pkt->end_idx XXX */
412 
413 	return vnet_walk_rx(port, dr, pkt->start_idx, pkt->end_idx);
414 }
415 
416 static int idx_is_pending(struct vio_dring_state *dr, u32 end)
417 {
418 	u32 idx = dr->cons;
419 	int found = 0;
420 
421 	while (idx != dr->prod) {
422 		if (idx == end) {
423 			found = 1;
424 			break;
425 		}
426 		idx = next_idx(idx, dr);
427 	}
428 	return found;
429 }
430 
431 static int vnet_ack(struct vnet_port *port, void *msgbuf)
432 {
433 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
434 	struct vio_dring_data *pkt = msgbuf;
435 	struct net_device *dev;
436 	struct vnet *vp;
437 	u32 end;
438 
439 	if (unlikely(pkt->tag.stype_env != VIO_DRING_DATA))
440 		return 0;
441 
442 	end = pkt->end_idx;
443 	if (unlikely(!idx_is_pending(dr, end)))
444 		return 0;
445 
446 	dr->cons = next_idx(end, dr);
447 
448 	vp = port->vp;
449 	dev = vp->dev;
450 	if (unlikely(netif_queue_stopped(dev) &&
451 		     vnet_tx_dring_avail(dr) >= VNET_TX_WAKEUP_THRESH(dr)))
452 		return 1;
453 
454 	return 0;
455 }
456 
457 static int vnet_nack(struct vnet_port *port, void *msgbuf)
458 {
459 	/* XXX just reset or similar XXX */
460 	return 0;
461 }
462 
463 static int handle_mcast(struct vnet_port *port, void *msgbuf)
464 {
465 	struct vio_net_mcast_info *pkt = msgbuf;
466 
467 	if (pkt->tag.stype != VIO_SUBTYPE_ACK)
468 		pr_err("%s: Got unexpected MCAST reply [%02x:%02x:%04x:%08x]\n",
469 		       port->vp->dev->name,
470 		       pkt->tag.type,
471 		       pkt->tag.stype,
472 		       pkt->tag.stype_env,
473 		       pkt->tag.sid);
474 
475 	return 0;
476 }
477 
478 static void maybe_tx_wakeup(struct vnet *vp)
479 {
480 	struct net_device *dev = vp->dev;
481 
482 	netif_tx_lock(dev);
483 	if (likely(netif_queue_stopped(dev))) {
484 		struct vnet_port *port;
485 		int wake = 1;
486 
487 		list_for_each_entry(port, &vp->port_list, list) {
488 			struct vio_dring_state *dr;
489 
490 			dr = &port->vio.drings[VIO_DRIVER_TX_RING];
491 			if (vnet_tx_dring_avail(dr) <
492 			    VNET_TX_WAKEUP_THRESH(dr)) {
493 				wake = 0;
494 				break;
495 			}
496 		}
497 		if (wake)
498 			netif_wake_queue(dev);
499 	}
500 	netif_tx_unlock(dev);
501 }
502 
503 static void vnet_event(void *arg, int event)
504 {
505 	struct vnet_port *port = arg;
506 	struct vio_driver_state *vio = &port->vio;
507 	unsigned long flags;
508 	int tx_wakeup, err;
509 
510 	spin_lock_irqsave(&vio->lock, flags);
511 
512 	if (unlikely(event == LDC_EVENT_RESET ||
513 		     event == LDC_EVENT_UP)) {
514 		vio_link_state_change(vio, event);
515 		spin_unlock_irqrestore(&vio->lock, flags);
516 
517 		if (event == LDC_EVENT_RESET)
518 			vio_port_up(vio);
519 		return;
520 	}
521 
522 	if (unlikely(event != LDC_EVENT_DATA_READY)) {
523 		pr_warning("Unexpected LDC event %d\n", event);
524 		spin_unlock_irqrestore(&vio->lock, flags);
525 		return;
526 	}
527 
528 	tx_wakeup = err = 0;
529 	while (1) {
530 		union {
531 			struct vio_msg_tag tag;
532 			u64 raw[8];
533 		} msgbuf;
534 
535 		err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf));
536 		if (unlikely(err < 0)) {
537 			if (err == -ECONNRESET)
538 				vio_conn_reset(vio);
539 			break;
540 		}
541 		if (err == 0)
542 			break;
543 		viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n",
544 		       msgbuf.tag.type,
545 		       msgbuf.tag.stype,
546 		       msgbuf.tag.stype_env,
547 		       msgbuf.tag.sid);
548 		err = vio_validate_sid(vio, &msgbuf.tag);
549 		if (err < 0)
550 			break;
551 
552 		if (likely(msgbuf.tag.type == VIO_TYPE_DATA)) {
553 			if (msgbuf.tag.stype == VIO_SUBTYPE_INFO) {
554 				err = vnet_rx(port, &msgbuf);
555 			} else if (msgbuf.tag.stype == VIO_SUBTYPE_ACK) {
556 				err = vnet_ack(port, &msgbuf);
557 				if (err > 0)
558 					tx_wakeup |= err;
559 			} else if (msgbuf.tag.stype == VIO_SUBTYPE_NACK) {
560 				err = vnet_nack(port, &msgbuf);
561 			}
562 		} else if (msgbuf.tag.type == VIO_TYPE_CTRL) {
563 			if (msgbuf.tag.stype_env == VNET_MCAST_INFO)
564 				err = handle_mcast(port, &msgbuf);
565 			else
566 				err = vio_control_pkt_engine(vio, &msgbuf);
567 			if (err)
568 				break;
569 		} else {
570 			err = vnet_handle_unknown(port, &msgbuf);
571 		}
572 		if (err == -ECONNRESET)
573 			break;
574 	}
575 	spin_unlock(&vio->lock);
576 	if (unlikely(tx_wakeup && err != -ECONNRESET))
577 		maybe_tx_wakeup(port->vp);
578 	local_irq_restore(flags);
579 }
580 
581 static int __vnet_tx_trigger(struct vnet_port *port)
582 {
583 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
584 	struct vio_dring_data hdr = {
585 		.tag = {
586 			.type		= VIO_TYPE_DATA,
587 			.stype		= VIO_SUBTYPE_INFO,
588 			.stype_env	= VIO_DRING_DATA,
589 			.sid		= vio_send_sid(&port->vio),
590 		},
591 		.dring_ident		= dr->ident,
592 		.start_idx		= dr->prod,
593 		.end_idx		= (u32) -1,
594 	};
595 	int err, delay;
596 
597 	hdr.seq = dr->snd_nxt;
598 	delay = 1;
599 	do {
600 		err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
601 		if (err > 0) {
602 			dr->snd_nxt++;
603 			break;
604 		}
605 		udelay(delay);
606 		if ((delay <<= 1) > 128)
607 			delay = 128;
608 	} while (err == -EAGAIN);
609 
610 	return err;
611 }
612 
613 static inline bool port_is_up(struct vnet_port *vnet)
614 {
615 	struct vio_driver_state *vio = &vnet->vio;
616 
617 	return !!(vio->hs_state & VIO_HS_COMPLETE);
618 }
619 
620 struct vnet_port *__tx_port_find(struct vnet *vp, struct sk_buff *skb)
621 {
622 	unsigned int hash = vnet_hashfn(skb->data);
623 	struct hlist_head *hp = &vp->port_hash[hash];
624 	struct vnet_port *port;
625 
626 	hlist_for_each_entry(port, hp, hash) {
627 		if (!port_is_up(port))
628 			continue;
629 		if (ether_addr_equal(port->raddr, skb->data))
630 			return port;
631 	}
632 	list_for_each_entry(port, &vp->port_list, list) {
633 		if (!port->switch_port)
634 			continue;
635 		if (!port_is_up(port))
636 			continue;
637 		return port;
638 	}
639 	return NULL;
640 }
641 
642 struct vnet_port *tx_port_find(struct vnet *vp, struct sk_buff *skb)
643 {
644 	struct vnet_port *ret;
645 	unsigned long flags;
646 
647 	spin_lock_irqsave(&vp->lock, flags);
648 	ret = __tx_port_find(vp, skb);
649 	spin_unlock_irqrestore(&vp->lock, flags);
650 
651 	return ret;
652 }
653 
654 static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
655 {
656 	struct vnet *vp = netdev_priv(dev);
657 	struct vnet_port *port = tx_port_find(vp, skb);
658 	struct vio_dring_state *dr;
659 	struct vio_net_desc *d;
660 	unsigned long flags;
661 	unsigned int len;
662 	void *tx_buf;
663 	int i, err;
664 
665 	if (unlikely(!port))
666 		goto out_dropped;
667 
668 	spin_lock_irqsave(&port->vio.lock, flags);
669 
670 	dr = &port->vio.drings[VIO_DRIVER_TX_RING];
671 	if (unlikely(vnet_tx_dring_avail(dr) < 2)) {
672 		if (!netif_queue_stopped(dev)) {
673 			netif_stop_queue(dev);
674 
675 			/* This is a hard error, log it. */
676 			netdev_err(dev, "BUG! Tx Ring full when queue awake!\n");
677 			dev->stats.tx_errors++;
678 		}
679 		spin_unlock_irqrestore(&port->vio.lock, flags);
680 		return NETDEV_TX_BUSY;
681 	}
682 
683 	d = vio_dring_cur(dr);
684 
685 	tx_buf = port->tx_bufs[dr->prod].buf;
686 	skb_copy_from_linear_data(skb, tx_buf + VNET_PACKET_SKIP, skb->len);
687 
688 	len = skb->len;
689 	if (len < ETH_ZLEN) {
690 		len = ETH_ZLEN;
691 		memset(tx_buf+VNET_PACKET_SKIP+skb->len, 0, len - skb->len);
692 	}
693 
694 	d->hdr.ack = VIO_ACK_ENABLE;
695 	d->size = len;
696 	d->ncookies = port->tx_bufs[dr->prod].ncookies;
697 	for (i = 0; i < d->ncookies; i++)
698 		d->cookies[i] = port->tx_bufs[dr->prod].cookies[i];
699 
700 	/* This has to be a non-SMP write barrier because we are writing
701 	 * to memory which is shared with the peer LDOM.
702 	 */
703 	wmb();
704 
705 	d->hdr.state = VIO_DESC_READY;
706 
707 	err = __vnet_tx_trigger(port);
708 	if (unlikely(err < 0)) {
709 		netdev_info(dev, "TX trigger error %d\n", err);
710 		d->hdr.state = VIO_DESC_FREE;
711 		dev->stats.tx_carrier_errors++;
712 		goto out_dropped_unlock;
713 	}
714 
715 	dev->stats.tx_packets++;
716 	dev->stats.tx_bytes += skb->len;
717 
718 	dr->prod = (dr->prod + 1) & (VNET_TX_RING_SIZE - 1);
719 	if (unlikely(vnet_tx_dring_avail(dr) < 2)) {
720 		netif_stop_queue(dev);
721 		if (vnet_tx_dring_avail(dr) > VNET_TX_WAKEUP_THRESH(dr))
722 			netif_wake_queue(dev);
723 	}
724 
725 	spin_unlock_irqrestore(&port->vio.lock, flags);
726 
727 	dev_kfree_skb(skb);
728 
729 	return NETDEV_TX_OK;
730 
731 out_dropped_unlock:
732 	spin_unlock_irqrestore(&port->vio.lock, flags);
733 
734 out_dropped:
735 	dev_kfree_skb(skb);
736 	dev->stats.tx_dropped++;
737 	return NETDEV_TX_OK;
738 }
739 
740 static void vnet_tx_timeout(struct net_device *dev)
741 {
742 	/* XXX Implement me XXX */
743 }
744 
745 static int vnet_open(struct net_device *dev)
746 {
747 	netif_carrier_on(dev);
748 	netif_start_queue(dev);
749 
750 	return 0;
751 }
752 
753 static int vnet_close(struct net_device *dev)
754 {
755 	netif_stop_queue(dev);
756 	netif_carrier_off(dev);
757 
758 	return 0;
759 }
760 
761 static struct vnet_mcast_entry *__vnet_mc_find(struct vnet *vp, u8 *addr)
762 {
763 	struct vnet_mcast_entry *m;
764 
765 	for (m = vp->mcast_list; m; m = m->next) {
766 		if (ether_addr_equal(m->addr, addr))
767 			return m;
768 	}
769 	return NULL;
770 }
771 
772 static void __update_mc_list(struct vnet *vp, struct net_device *dev)
773 {
774 	struct netdev_hw_addr *ha;
775 
776 	netdev_for_each_mc_addr(ha, dev) {
777 		struct vnet_mcast_entry *m;
778 
779 		m = __vnet_mc_find(vp, ha->addr);
780 		if (m) {
781 			m->hit = 1;
782 			continue;
783 		}
784 
785 		if (!m) {
786 			m = kzalloc(sizeof(*m), GFP_ATOMIC);
787 			if (!m)
788 				continue;
789 			memcpy(m->addr, ha->addr, ETH_ALEN);
790 			m->hit = 1;
791 
792 			m->next = vp->mcast_list;
793 			vp->mcast_list = m;
794 		}
795 	}
796 }
797 
798 static void __send_mc_list(struct vnet *vp, struct vnet_port *port)
799 {
800 	struct vio_net_mcast_info info;
801 	struct vnet_mcast_entry *m, **pp;
802 	int n_addrs;
803 
804 	memset(&info, 0, sizeof(info));
805 
806 	info.tag.type = VIO_TYPE_CTRL;
807 	info.tag.stype = VIO_SUBTYPE_INFO;
808 	info.tag.stype_env = VNET_MCAST_INFO;
809 	info.tag.sid = vio_send_sid(&port->vio);
810 	info.set = 1;
811 
812 	n_addrs = 0;
813 	for (m = vp->mcast_list; m; m = m->next) {
814 		if (m->sent)
815 			continue;
816 		m->sent = 1;
817 		memcpy(&info.mcast_addr[n_addrs * ETH_ALEN],
818 		       m->addr, ETH_ALEN);
819 		if (++n_addrs == VNET_NUM_MCAST) {
820 			info.count = n_addrs;
821 
822 			(void) vio_ldc_send(&port->vio, &info,
823 					    sizeof(info));
824 			n_addrs = 0;
825 		}
826 	}
827 	if (n_addrs) {
828 		info.count = n_addrs;
829 		(void) vio_ldc_send(&port->vio, &info, sizeof(info));
830 	}
831 
832 	info.set = 0;
833 
834 	n_addrs = 0;
835 	pp = &vp->mcast_list;
836 	while ((m = *pp) != NULL) {
837 		if (m->hit) {
838 			m->hit = 0;
839 			pp = &m->next;
840 			continue;
841 		}
842 
843 		memcpy(&info.mcast_addr[n_addrs * ETH_ALEN],
844 		       m->addr, ETH_ALEN);
845 		if (++n_addrs == VNET_NUM_MCAST) {
846 			info.count = n_addrs;
847 			(void) vio_ldc_send(&port->vio, &info,
848 					    sizeof(info));
849 			n_addrs = 0;
850 		}
851 
852 		*pp = m->next;
853 		kfree(m);
854 	}
855 	if (n_addrs) {
856 		info.count = n_addrs;
857 		(void) vio_ldc_send(&port->vio, &info, sizeof(info));
858 	}
859 }
860 
861 static void vnet_set_rx_mode(struct net_device *dev)
862 {
863 	struct vnet *vp = netdev_priv(dev);
864 	struct vnet_port *port;
865 	unsigned long flags;
866 
867 	spin_lock_irqsave(&vp->lock, flags);
868 	if (!list_empty(&vp->port_list)) {
869 		port = list_entry(vp->port_list.next, struct vnet_port, list);
870 
871 		if (port->switch_port) {
872 			__update_mc_list(vp, dev);
873 			__send_mc_list(vp, port);
874 		}
875 	}
876 	spin_unlock_irqrestore(&vp->lock, flags);
877 }
878 
879 static int vnet_change_mtu(struct net_device *dev, int new_mtu)
880 {
881 	if (new_mtu != ETH_DATA_LEN)
882 		return -EINVAL;
883 
884 	dev->mtu = new_mtu;
885 	return 0;
886 }
887 
888 static int vnet_set_mac_addr(struct net_device *dev, void *p)
889 {
890 	return -EINVAL;
891 }
892 
893 static void vnet_get_drvinfo(struct net_device *dev,
894 			     struct ethtool_drvinfo *info)
895 {
896 	strlcpy(info->driver, DRV_MODULE_NAME, sizeof(info->driver));
897 	strlcpy(info->version, DRV_MODULE_VERSION, sizeof(info->version));
898 }
899 
900 static u32 vnet_get_msglevel(struct net_device *dev)
901 {
902 	struct vnet *vp = netdev_priv(dev);
903 	return vp->msg_enable;
904 }
905 
906 static void vnet_set_msglevel(struct net_device *dev, u32 value)
907 {
908 	struct vnet *vp = netdev_priv(dev);
909 	vp->msg_enable = value;
910 }
911 
912 static const struct ethtool_ops vnet_ethtool_ops = {
913 	.get_drvinfo		= vnet_get_drvinfo,
914 	.get_msglevel		= vnet_get_msglevel,
915 	.set_msglevel		= vnet_set_msglevel,
916 	.get_link		= ethtool_op_get_link,
917 };
918 
919 static void vnet_port_free_tx_bufs(struct vnet_port *port)
920 {
921 	struct vio_dring_state *dr;
922 	int i;
923 
924 	dr = &port->vio.drings[VIO_DRIVER_TX_RING];
925 	if (dr->base) {
926 		ldc_free_exp_dring(port->vio.lp, dr->base,
927 				   (dr->entry_size * dr->num_entries),
928 				   dr->cookies, dr->ncookies);
929 		dr->base = NULL;
930 		dr->entry_size = 0;
931 		dr->num_entries = 0;
932 		dr->pending = 0;
933 		dr->ncookies = 0;
934 	}
935 
936 	for (i = 0; i < VNET_TX_RING_SIZE; i++) {
937 		void *buf = port->tx_bufs[i].buf;
938 
939 		if (!buf)
940 			continue;
941 
942 		ldc_unmap(port->vio.lp,
943 			  port->tx_bufs[i].cookies,
944 			  port->tx_bufs[i].ncookies);
945 
946 		kfree(buf);
947 		port->tx_bufs[i].buf = NULL;
948 	}
949 }
950 
951 static int vnet_port_alloc_tx_bufs(struct vnet_port *port)
952 {
953 	struct vio_dring_state *dr;
954 	unsigned long len;
955 	int i, err, ncookies;
956 	void *dring;
957 
958 	for (i = 0; i < VNET_TX_RING_SIZE; i++) {
959 		void *buf = kzalloc(ETH_FRAME_LEN + 8, GFP_KERNEL);
960 		int map_len = (ETH_FRAME_LEN + 7) & ~7;
961 
962 		err = -ENOMEM;
963 		if (!buf)
964 			goto err_out;
965 
966 		err = -EFAULT;
967 		if ((unsigned long)buf & (8UL - 1)) {
968 			pr_err("TX buffer misaligned\n");
969 			kfree(buf);
970 			goto err_out;
971 		}
972 
973 		err = ldc_map_single(port->vio.lp, buf, map_len,
974 				     port->tx_bufs[i].cookies, 2,
975 				     (LDC_MAP_SHADOW |
976 				      LDC_MAP_DIRECT |
977 				      LDC_MAP_RW));
978 		if (err < 0) {
979 			kfree(buf);
980 			goto err_out;
981 		}
982 		port->tx_bufs[i].buf = buf;
983 		port->tx_bufs[i].ncookies = err;
984 	}
985 
986 	dr = &port->vio.drings[VIO_DRIVER_TX_RING];
987 
988 	len = (VNET_TX_RING_SIZE *
989 	       (sizeof(struct vio_net_desc) +
990 		(sizeof(struct ldc_trans_cookie) * 2)));
991 
992 	ncookies = VIO_MAX_RING_COOKIES;
993 	dring = ldc_alloc_exp_dring(port->vio.lp, len,
994 				    dr->cookies, &ncookies,
995 				    (LDC_MAP_SHADOW |
996 				     LDC_MAP_DIRECT |
997 				     LDC_MAP_RW));
998 	if (IS_ERR(dring)) {
999 		err = PTR_ERR(dring);
1000 		goto err_out;
1001 	}
1002 
1003 	dr->base = dring;
1004 	dr->entry_size = (sizeof(struct vio_net_desc) +
1005 			  (sizeof(struct ldc_trans_cookie) * 2));
1006 	dr->num_entries = VNET_TX_RING_SIZE;
1007 	dr->prod = dr->cons = 0;
1008 	dr->pending = VNET_TX_RING_SIZE;
1009 	dr->ncookies = ncookies;
1010 
1011 	return 0;
1012 
1013 err_out:
1014 	vnet_port_free_tx_bufs(port);
1015 
1016 	return err;
1017 }
1018 
1019 static LIST_HEAD(vnet_list);
1020 static DEFINE_MUTEX(vnet_list_mutex);
1021 
1022 static const struct net_device_ops vnet_ops = {
1023 	.ndo_open		= vnet_open,
1024 	.ndo_stop		= vnet_close,
1025 	.ndo_set_rx_mode	= vnet_set_rx_mode,
1026 	.ndo_set_mac_address	= vnet_set_mac_addr,
1027 	.ndo_validate_addr	= eth_validate_addr,
1028 	.ndo_tx_timeout		= vnet_tx_timeout,
1029 	.ndo_change_mtu		= vnet_change_mtu,
1030 	.ndo_start_xmit		= vnet_start_xmit,
1031 };
1032 
1033 static struct vnet *vnet_new(const u64 *local_mac)
1034 {
1035 	struct net_device *dev;
1036 	struct vnet *vp;
1037 	int err, i;
1038 
1039 	dev = alloc_etherdev(sizeof(*vp));
1040 	if (!dev)
1041 		return ERR_PTR(-ENOMEM);
1042 
1043 	for (i = 0; i < ETH_ALEN; i++)
1044 		dev->dev_addr[i] = (*local_mac >> (5 - i) * 8) & 0xff;
1045 
1046 	vp = netdev_priv(dev);
1047 
1048 	spin_lock_init(&vp->lock);
1049 	vp->dev = dev;
1050 
1051 	INIT_LIST_HEAD(&vp->port_list);
1052 	for (i = 0; i < VNET_PORT_HASH_SIZE; i++)
1053 		INIT_HLIST_HEAD(&vp->port_hash[i]);
1054 	INIT_LIST_HEAD(&vp->list);
1055 	vp->local_mac = *local_mac;
1056 
1057 	dev->netdev_ops = &vnet_ops;
1058 	dev->ethtool_ops = &vnet_ethtool_ops;
1059 	dev->watchdog_timeo = VNET_TX_TIMEOUT;
1060 
1061 	err = register_netdev(dev);
1062 	if (err) {
1063 		pr_err("Cannot register net device, aborting\n");
1064 		goto err_out_free_dev;
1065 	}
1066 
1067 	netdev_info(dev, "Sun LDOM vnet %pM\n", dev->dev_addr);
1068 
1069 	list_add(&vp->list, &vnet_list);
1070 
1071 	return vp;
1072 
1073 err_out_free_dev:
1074 	free_netdev(dev);
1075 
1076 	return ERR_PTR(err);
1077 }
1078 
1079 static struct vnet *vnet_find_or_create(const u64 *local_mac)
1080 {
1081 	struct vnet *iter, *vp;
1082 
1083 	mutex_lock(&vnet_list_mutex);
1084 	vp = NULL;
1085 	list_for_each_entry(iter, &vnet_list, list) {
1086 		if (iter->local_mac == *local_mac) {
1087 			vp = iter;
1088 			break;
1089 		}
1090 	}
1091 	if (!vp)
1092 		vp = vnet_new(local_mac);
1093 	mutex_unlock(&vnet_list_mutex);
1094 
1095 	return vp;
1096 }
1097 
1098 static void vnet_cleanup(void)
1099 {
1100 	struct vnet *vp;
1101 	struct net_device *dev;
1102 
1103 	mutex_lock(&vnet_list_mutex);
1104 	while (!list_empty(&vnet_list)) {
1105 		vp = list_first_entry(&vnet_list, struct vnet, list);
1106 		list_del(&vp->list);
1107 		dev = vp->dev;
1108 		/* vio_unregister_driver() should have cleaned up port_list */
1109 		BUG_ON(!list_empty(&vp->port_list));
1110 		unregister_netdev(dev);
1111 		free_netdev(dev);
1112 	}
1113 	mutex_unlock(&vnet_list_mutex);
1114 }
1115 
1116 static const char *local_mac_prop = "local-mac-address";
1117 
1118 static struct vnet *vnet_find_parent(struct mdesc_handle *hp,
1119 						u64 port_node)
1120 {
1121 	const u64 *local_mac = NULL;
1122 	u64 a;
1123 
1124 	mdesc_for_each_arc(a, hp, port_node, MDESC_ARC_TYPE_BACK) {
1125 		u64 target = mdesc_arc_target(hp, a);
1126 		const char *name;
1127 
1128 		name = mdesc_get_property(hp, target, "name", NULL);
1129 		if (!name || strcmp(name, "network"))
1130 			continue;
1131 
1132 		local_mac = mdesc_get_property(hp, target,
1133 					       local_mac_prop, NULL);
1134 		if (local_mac)
1135 			break;
1136 	}
1137 	if (!local_mac)
1138 		return ERR_PTR(-ENODEV);
1139 
1140 	return vnet_find_or_create(local_mac);
1141 }
1142 
1143 static struct ldc_channel_config vnet_ldc_cfg = {
1144 	.event		= vnet_event,
1145 	.mtu		= 64,
1146 	.mode		= LDC_MODE_UNRELIABLE,
1147 };
1148 
1149 static struct vio_driver_ops vnet_vio_ops = {
1150 	.send_attr		= vnet_send_attr,
1151 	.handle_attr		= vnet_handle_attr,
1152 	.handshake_complete	= vnet_handshake_complete,
1153 };
1154 
1155 static void print_version(void)
1156 {
1157 	printk_once(KERN_INFO "%s", version);
1158 }
1159 
1160 const char *remote_macaddr_prop = "remote-mac-address";
1161 
1162 static int vnet_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
1163 {
1164 	struct mdesc_handle *hp;
1165 	struct vnet_port *port;
1166 	unsigned long flags;
1167 	struct vnet *vp;
1168 	const u64 *rmac;
1169 	int len, i, err, switch_port;
1170 
1171 	print_version();
1172 
1173 	hp = mdesc_grab();
1174 
1175 	vp = vnet_find_parent(hp, vdev->mp);
1176 	if (IS_ERR(vp)) {
1177 		pr_err("Cannot find port parent vnet\n");
1178 		err = PTR_ERR(vp);
1179 		goto err_out_put_mdesc;
1180 	}
1181 
1182 	rmac = mdesc_get_property(hp, vdev->mp, remote_macaddr_prop, &len);
1183 	err = -ENODEV;
1184 	if (!rmac) {
1185 		pr_err("Port lacks %s property\n", remote_macaddr_prop);
1186 		goto err_out_put_mdesc;
1187 	}
1188 
1189 	port = kzalloc(sizeof(*port), GFP_KERNEL);
1190 	err = -ENOMEM;
1191 	if (!port)
1192 		goto err_out_put_mdesc;
1193 
1194 	for (i = 0; i < ETH_ALEN; i++)
1195 		port->raddr[i] = (*rmac >> (5 - i) * 8) & 0xff;
1196 
1197 	port->vp = vp;
1198 
1199 	err = vio_driver_init(&port->vio, vdev, VDEV_NETWORK,
1200 			      vnet_versions, ARRAY_SIZE(vnet_versions),
1201 			      &vnet_vio_ops, vp->dev->name);
1202 	if (err)
1203 		goto err_out_free_port;
1204 
1205 	err = vio_ldc_alloc(&port->vio, &vnet_ldc_cfg, port);
1206 	if (err)
1207 		goto err_out_free_port;
1208 
1209 	err = vnet_port_alloc_tx_bufs(port);
1210 	if (err)
1211 		goto err_out_free_ldc;
1212 
1213 	INIT_HLIST_NODE(&port->hash);
1214 	INIT_LIST_HEAD(&port->list);
1215 
1216 	switch_port = 0;
1217 	if (mdesc_get_property(hp, vdev->mp, "switch-port", NULL) != NULL)
1218 		switch_port = 1;
1219 	port->switch_port = switch_port;
1220 
1221 	spin_lock_irqsave(&vp->lock, flags);
1222 	if (switch_port)
1223 		list_add(&port->list, &vp->port_list);
1224 	else
1225 		list_add_tail(&port->list, &vp->port_list);
1226 	hlist_add_head(&port->hash, &vp->port_hash[vnet_hashfn(port->raddr)]);
1227 	spin_unlock_irqrestore(&vp->lock, flags);
1228 
1229 	dev_set_drvdata(&vdev->dev, port);
1230 
1231 	pr_info("%s: PORT ( remote-mac %pM%s )\n",
1232 		vp->dev->name, port->raddr, switch_port ? " switch-port" : "");
1233 
1234 	vio_port_up(&port->vio);
1235 
1236 	mdesc_release(hp);
1237 
1238 	return 0;
1239 
1240 err_out_free_ldc:
1241 	vio_ldc_free(&port->vio);
1242 
1243 err_out_free_port:
1244 	kfree(port);
1245 
1246 err_out_put_mdesc:
1247 	mdesc_release(hp);
1248 	return err;
1249 }
1250 
1251 static int vnet_port_remove(struct vio_dev *vdev)
1252 {
1253 	struct vnet_port *port = dev_get_drvdata(&vdev->dev);
1254 
1255 	if (port) {
1256 		struct vnet *vp = port->vp;
1257 		unsigned long flags;
1258 
1259 		del_timer_sync(&port->vio.timer);
1260 
1261 		spin_lock_irqsave(&vp->lock, flags);
1262 		list_del(&port->list);
1263 		hlist_del(&port->hash);
1264 		spin_unlock_irqrestore(&vp->lock, flags);
1265 
1266 		vnet_port_free_tx_bufs(port);
1267 		vio_ldc_free(&port->vio);
1268 
1269 		dev_set_drvdata(&vdev->dev, NULL);
1270 
1271 		kfree(port);
1272 
1273 	}
1274 	return 0;
1275 }
1276 
1277 static const struct vio_device_id vnet_port_match[] = {
1278 	{
1279 		.type = "vnet-port",
1280 	},
1281 	{},
1282 };
1283 MODULE_DEVICE_TABLE(vio, vnet_port_match);
1284 
1285 static struct vio_driver vnet_port_driver = {
1286 	.id_table	= vnet_port_match,
1287 	.probe		= vnet_port_probe,
1288 	.remove		= vnet_port_remove,
1289 	.name		= "vnet_port",
1290 };
1291 
1292 static int __init vnet_init(void)
1293 {
1294 	return vio_register_driver(&vnet_port_driver);
1295 }
1296 
1297 static void __exit vnet_exit(void)
1298 {
1299 	vio_unregister_driver(&vnet_port_driver);
1300 	vnet_cleanup();
1301 }
1302 
1303 module_init(vnet_init);
1304 module_exit(vnet_exit);
1305