xref: /linux/drivers/net/ethernet/sun/sunvnet.c (revision 957e3facd147510f2cf8780e38606f1d707f0e33)
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 #include <linux/highmem.h>
19 #include <linux/if_vlan.h>
20 
21 #if IS_ENABLED(CONFIG_IPV6)
22 #include <linux/icmpv6.h>
23 #endif
24 
25 #include <net/ip.h>
26 #include <net/icmp.h>
27 #include <net/route.h>
28 
29 #include <asm/vio.h>
30 #include <asm/ldc.h>
31 
32 #include "sunvnet.h"
33 
34 #define DRV_MODULE_NAME		"sunvnet"
35 #define DRV_MODULE_VERSION	"1.0"
36 #define DRV_MODULE_RELDATE	"June 25, 2007"
37 
38 static char version[] =
39 	DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n";
40 MODULE_AUTHOR("David S. Miller (davem@davemloft.net)");
41 MODULE_DESCRIPTION("Sun LDOM virtual network driver");
42 MODULE_LICENSE("GPL");
43 MODULE_VERSION(DRV_MODULE_VERSION);
44 
45 #define	VNET_MAX_TXQS		16
46 
47 /* Heuristic for the number of times to exponentially backoff and
48  * retry sending an LDC trigger when EAGAIN is encountered
49  */
50 #define	VNET_MAX_RETRIES	10
51 
52 static int __vnet_tx_trigger(struct vnet_port *port, u32 start);
53 
54 /* Ordered from largest major to lowest */
55 static struct vio_version vnet_versions[] = {
56 	{ .major = 1, .minor = 8 },
57 	{ .major = 1, .minor = 7 },
58 	{ .major = 1, .minor = 6 },
59 	{ .major = 1, .minor = 0 },
60 };
61 
62 static inline u32 vnet_tx_dring_avail(struct vio_dring_state *dr)
63 {
64 	return vio_dring_avail(dr, VNET_TX_RING_SIZE);
65 }
66 
67 static int vnet_handle_unknown(struct vnet_port *port, void *arg)
68 {
69 	struct vio_msg_tag *pkt = arg;
70 
71 	pr_err("Received unknown msg [%02x:%02x:%04x:%08x]\n",
72 	       pkt->type, pkt->stype, pkt->stype_env, pkt->sid);
73 	pr_err("Resetting connection\n");
74 
75 	ldc_disconnect(port->vio.lp);
76 
77 	return -ECONNRESET;
78 }
79 
80 static int vnet_port_alloc_tx_ring(struct vnet_port *port);
81 
82 static int vnet_send_attr(struct vio_driver_state *vio)
83 {
84 	struct vnet_port *port = to_vnet_port(vio);
85 	struct net_device *dev = port->vp->dev;
86 	struct vio_net_attr_info pkt;
87 	int framelen = ETH_FRAME_LEN;
88 	int i, err;
89 
90 	err = vnet_port_alloc_tx_ring(to_vnet_port(vio));
91 	if (err)
92 		return err;
93 
94 	memset(&pkt, 0, sizeof(pkt));
95 	pkt.tag.type = VIO_TYPE_CTRL;
96 	pkt.tag.stype = VIO_SUBTYPE_INFO;
97 	pkt.tag.stype_env = VIO_ATTR_INFO;
98 	pkt.tag.sid = vio_send_sid(vio);
99 	if (vio_version_before(vio, 1, 2))
100 		pkt.xfer_mode = VIO_DRING_MODE;
101 	else
102 		pkt.xfer_mode = VIO_NEW_DRING_MODE;
103 	pkt.addr_type = VNET_ADDR_ETHERMAC;
104 	pkt.ack_freq = 0;
105 	for (i = 0; i < 6; i++)
106 		pkt.addr |= (u64)dev->dev_addr[i] << ((5 - i) * 8);
107 	if (vio_version_after(vio, 1, 3)) {
108 		if (port->rmtu) {
109 			port->rmtu = min(VNET_MAXPACKET, port->rmtu);
110 			pkt.mtu = port->rmtu;
111 		} else {
112 			port->rmtu = VNET_MAXPACKET;
113 			pkt.mtu = port->rmtu;
114 		}
115 		if (vio_version_after_eq(vio, 1, 6))
116 			pkt.options = VIO_TX_DRING;
117 	} else if (vio_version_before(vio, 1, 3)) {
118 		pkt.mtu = framelen;
119 	} else { /* v1.3 */
120 		pkt.mtu = framelen + VLAN_HLEN;
121 	}
122 
123 	pkt.cflags = 0;
124 	if (vio_version_after_eq(vio, 1, 7) && port->tso) {
125 		pkt.cflags |= VNET_LSO_IPV4_CAPAB;
126 		if (!port->tsolen)
127 			port->tsolen = VNET_MAXTSO;
128 		pkt.ipv4_lso_maxlen = port->tsolen;
129 	}
130 
131 	pkt.plnk_updt = PHYSLINK_UPDATE_NONE;
132 
133 	viodbg(HS, "SEND NET ATTR xmode[0x%x] atype[0x%x] addr[%llx] "
134 	       "ackfreq[%u] plnk_updt[0x%02x] opts[0x%02x] mtu[%llu] "
135 	       "cflags[0x%04x] lso_max[%u]\n",
136 	       pkt.xfer_mode, pkt.addr_type,
137 	       (unsigned long long)pkt.addr,
138 	       pkt.ack_freq, pkt.plnk_updt, pkt.options,
139 	       (unsigned long long)pkt.mtu, pkt.cflags, pkt.ipv4_lso_maxlen);
140 
141 
142 	return vio_ldc_send(vio, &pkt, sizeof(pkt));
143 }
144 
145 static int handle_attr_info(struct vio_driver_state *vio,
146 			    struct vio_net_attr_info *pkt)
147 {
148 	struct vnet_port *port = to_vnet_port(vio);
149 	u64	localmtu;
150 	u8	xfer_mode;
151 
152 	viodbg(HS, "GOT NET ATTR xmode[0x%x] atype[0x%x] addr[%llx] "
153 	       "ackfreq[%u] plnk_updt[0x%02x] opts[0x%02x] mtu[%llu] "
154 	       " (rmtu[%llu]) cflags[0x%04x] lso_max[%u]\n",
155 	       pkt->xfer_mode, pkt->addr_type,
156 	       (unsigned long long)pkt->addr,
157 	       pkt->ack_freq, pkt->plnk_updt, pkt->options,
158 	       (unsigned long long)pkt->mtu, port->rmtu, pkt->cflags,
159 	       pkt->ipv4_lso_maxlen);
160 
161 	pkt->tag.sid = vio_send_sid(vio);
162 
163 	xfer_mode = pkt->xfer_mode;
164 	/* for version < 1.2, VIO_DRING_MODE = 0x3 and no bitmask */
165 	if (vio_version_before(vio, 1, 2) && xfer_mode == VIO_DRING_MODE)
166 		xfer_mode = VIO_NEW_DRING_MODE;
167 
168 	/* MTU negotiation:
169 	 *	< v1.3 - ETH_FRAME_LEN exactly
170 	 *	> v1.3 - MIN(pkt.mtu, VNET_MAXPACKET, port->rmtu) and change
171 	 *			pkt->mtu for ACK
172 	 *	= v1.3 - ETH_FRAME_LEN + VLAN_HLEN exactly
173 	 */
174 	if (vio_version_before(vio, 1, 3)) {
175 		localmtu = ETH_FRAME_LEN;
176 	} else if (vio_version_after(vio, 1, 3)) {
177 		localmtu = port->rmtu ? port->rmtu : VNET_MAXPACKET;
178 		localmtu = min(pkt->mtu, localmtu);
179 		pkt->mtu = localmtu;
180 	} else { /* v1.3 */
181 		localmtu = ETH_FRAME_LEN + VLAN_HLEN;
182 	}
183 	port->rmtu = localmtu;
184 
185 	/* LSO negotiation */
186 	if (vio_version_after_eq(vio, 1, 7))
187 		port->tso &= !!(pkt->cflags & VNET_LSO_IPV4_CAPAB);
188 	else
189 		port->tso = false;
190 	if (port->tso) {
191 		if (!port->tsolen)
192 			port->tsolen = VNET_MAXTSO;
193 		port->tsolen = min(port->tsolen, pkt->ipv4_lso_maxlen);
194 		if (port->tsolen < VNET_MINTSO) {
195 			port->tso = false;
196 			port->tsolen = 0;
197 			pkt->cflags &= ~VNET_LSO_IPV4_CAPAB;
198 		}
199 		pkt->ipv4_lso_maxlen = port->tsolen;
200 	} else {
201 		pkt->cflags &= ~VNET_LSO_IPV4_CAPAB;
202 		pkt->ipv4_lso_maxlen = 0;
203 	}
204 
205 	/* for version >= 1.6, ACK packet mode we support */
206 	if (vio_version_after_eq(vio, 1, 6)) {
207 		pkt->xfer_mode = VIO_NEW_DRING_MODE;
208 		pkt->options = VIO_TX_DRING;
209 	}
210 
211 	if (!(xfer_mode | VIO_NEW_DRING_MODE) ||
212 	    pkt->addr_type != VNET_ADDR_ETHERMAC ||
213 	    pkt->mtu != localmtu) {
214 		viodbg(HS, "SEND NET ATTR NACK\n");
215 
216 		pkt->tag.stype = VIO_SUBTYPE_NACK;
217 
218 		(void) vio_ldc_send(vio, pkt, sizeof(*pkt));
219 
220 		return -ECONNRESET;
221 	} else {
222 		viodbg(HS, "SEND NET ATTR ACK xmode[0x%x] atype[0x%x] "
223 		       "addr[%llx] ackfreq[%u] plnk_updt[0x%02x] opts[0x%02x] "
224 		       "mtu[%llu] (rmtu[%llu]) cflags[0x%04x] lso_max[%u]\n",
225 		       pkt->xfer_mode, pkt->addr_type,
226 		       (unsigned long long)pkt->addr,
227 		       pkt->ack_freq, pkt->plnk_updt, pkt->options,
228 		       (unsigned long long)pkt->mtu, port->rmtu, pkt->cflags,
229 		       pkt->ipv4_lso_maxlen);
230 
231 		pkt->tag.stype = VIO_SUBTYPE_ACK;
232 
233 		return vio_ldc_send(vio, pkt, sizeof(*pkt));
234 	}
235 
236 }
237 
238 static int handle_attr_ack(struct vio_driver_state *vio,
239 			   struct vio_net_attr_info *pkt)
240 {
241 	viodbg(HS, "GOT NET ATTR ACK\n");
242 
243 	return 0;
244 }
245 
246 static int handle_attr_nack(struct vio_driver_state *vio,
247 			    struct vio_net_attr_info *pkt)
248 {
249 	viodbg(HS, "GOT NET ATTR NACK\n");
250 
251 	return -ECONNRESET;
252 }
253 
254 static int vnet_handle_attr(struct vio_driver_state *vio, void *arg)
255 {
256 	struct vio_net_attr_info *pkt = arg;
257 
258 	switch (pkt->tag.stype) {
259 	case VIO_SUBTYPE_INFO:
260 		return handle_attr_info(vio, pkt);
261 
262 	case VIO_SUBTYPE_ACK:
263 		return handle_attr_ack(vio, pkt);
264 
265 	case VIO_SUBTYPE_NACK:
266 		return handle_attr_nack(vio, pkt);
267 
268 	default:
269 		return -ECONNRESET;
270 	}
271 }
272 
273 static void vnet_handshake_complete(struct vio_driver_state *vio)
274 {
275 	struct vio_dring_state *dr;
276 
277 	dr = &vio->drings[VIO_DRIVER_RX_RING];
278 	dr->snd_nxt = dr->rcv_nxt = 1;
279 
280 	dr = &vio->drings[VIO_DRIVER_TX_RING];
281 	dr->snd_nxt = dr->rcv_nxt = 1;
282 }
283 
284 /* The hypervisor interface that implements copying to/from imported
285  * memory from another domain requires that copies are done to 8-byte
286  * aligned buffers, and that the lengths of such copies are also 8-byte
287  * multiples.
288  *
289  * So we align skb->data to an 8-byte multiple and pad-out the data
290  * area so we can round the copy length up to the next multiple of
291  * 8 for the copy.
292  *
293  * The transmitter puts the actual start of the packet 6 bytes into
294  * the buffer it sends over, so that the IP headers after the ethernet
295  * header are aligned properly.  These 6 bytes are not in the descriptor
296  * length, they are simply implied.  This offset is represented using
297  * the VNET_PACKET_SKIP macro.
298  */
299 static struct sk_buff *alloc_and_align_skb(struct net_device *dev,
300 					   unsigned int len)
301 {
302 	struct sk_buff *skb = netdev_alloc_skb(dev, len+VNET_PACKET_SKIP+8+8);
303 	unsigned long addr, off;
304 
305 	if (unlikely(!skb))
306 		return NULL;
307 
308 	addr = (unsigned long) skb->data;
309 	off = ((addr + 7UL) & ~7UL) - addr;
310 	if (off)
311 		skb_reserve(skb, off);
312 
313 	return skb;
314 }
315 
316 static inline void vnet_fullcsum(struct sk_buff *skb)
317 {
318 	struct iphdr *iph = ip_hdr(skb);
319 	int offset = skb_transport_offset(skb);
320 
321 	if (skb->protocol != htons(ETH_P_IP))
322 		return;
323 	if (iph->protocol != IPPROTO_TCP &&
324 	    iph->protocol != IPPROTO_UDP)
325 		return;
326 	skb->ip_summed = CHECKSUM_NONE;
327 	skb->csum_level = 1;
328 	skb->csum = 0;
329 	if (iph->protocol == IPPROTO_TCP) {
330 		struct tcphdr *ptcp = tcp_hdr(skb);
331 
332 		ptcp->check = 0;
333 		skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
334 		ptcp->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
335 						skb->len - offset, IPPROTO_TCP,
336 						skb->csum);
337 	} else if (iph->protocol == IPPROTO_UDP) {
338 		struct udphdr *pudp = udp_hdr(skb);
339 
340 		pudp->check = 0;
341 		skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
342 		pudp->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
343 						skb->len - offset, IPPROTO_UDP,
344 						skb->csum);
345 	}
346 }
347 
348 static int vnet_rx_one(struct vnet_port *port, struct vio_net_desc *desc)
349 {
350 	struct net_device *dev = port->vp->dev;
351 	unsigned int len = desc->size;
352 	unsigned int copy_len;
353 	struct sk_buff *skb;
354 	int err;
355 
356 	err = -EMSGSIZE;
357 	if (unlikely(len < ETH_ZLEN || len > port->rmtu)) {
358 		dev->stats.rx_length_errors++;
359 		goto out_dropped;
360 	}
361 
362 	skb = alloc_and_align_skb(dev, len);
363 	err = -ENOMEM;
364 	if (unlikely(!skb)) {
365 		dev->stats.rx_missed_errors++;
366 		goto out_dropped;
367 	}
368 
369 	copy_len = (len + VNET_PACKET_SKIP + 7U) & ~7U;
370 	skb_put(skb, copy_len);
371 	err = ldc_copy(port->vio.lp, LDC_COPY_IN,
372 		       skb->data, copy_len, 0,
373 		       desc->cookies, desc->ncookies);
374 	if (unlikely(err < 0)) {
375 		dev->stats.rx_frame_errors++;
376 		goto out_free_skb;
377 	}
378 
379 	skb_pull(skb, VNET_PACKET_SKIP);
380 	skb_trim(skb, len);
381 	skb->protocol = eth_type_trans(skb, dev);
382 
383 	if (vio_version_after_eq(&port->vio, 1, 8)) {
384 		struct vio_net_dext *dext = vio_net_ext(desc);
385 
386 		if (dext->flags & VNET_PKT_HCK_IPV4_HDRCKSUM) {
387 			if (skb->protocol == ETH_P_IP) {
388 				struct iphdr *iph = (struct iphdr *)skb->data;
389 
390 				iph->check = 0;
391 				ip_send_check(iph);
392 			}
393 		}
394 		if ((dext->flags & VNET_PKT_HCK_FULLCKSUM) &&
395 		    skb->ip_summed == CHECKSUM_NONE)
396 			vnet_fullcsum(skb);
397 		if (dext->flags & VNET_PKT_HCK_IPV4_HDRCKSUM_OK) {
398 			skb->ip_summed = CHECKSUM_PARTIAL;
399 			skb->csum_level = 0;
400 			if (dext->flags & VNET_PKT_HCK_FULLCKSUM_OK)
401 				skb->csum_level = 1;
402 		}
403 	}
404 
405 	skb->ip_summed = port->switch_port ? CHECKSUM_NONE : CHECKSUM_PARTIAL;
406 
407 	dev->stats.rx_packets++;
408 	dev->stats.rx_bytes += len;
409 	napi_gro_receive(&port->napi, skb);
410 	return 0;
411 
412 out_free_skb:
413 	kfree_skb(skb);
414 
415 out_dropped:
416 	dev->stats.rx_dropped++;
417 	return err;
418 }
419 
420 static int vnet_send_ack(struct vnet_port *port, struct vio_dring_state *dr,
421 			 u32 start, u32 end, u8 vio_dring_state)
422 {
423 	struct vio_dring_data hdr = {
424 		.tag = {
425 			.type		= VIO_TYPE_DATA,
426 			.stype		= VIO_SUBTYPE_ACK,
427 			.stype_env	= VIO_DRING_DATA,
428 			.sid		= vio_send_sid(&port->vio),
429 		},
430 		.dring_ident		= dr->ident,
431 		.start_idx		= start,
432 		.end_idx		= end,
433 		.state			= vio_dring_state,
434 	};
435 	int err, delay;
436 	int retries = 0;
437 
438 	hdr.seq = dr->snd_nxt;
439 	delay = 1;
440 	do {
441 		err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
442 		if (err > 0) {
443 			dr->snd_nxt++;
444 			break;
445 		}
446 		udelay(delay);
447 		if ((delay <<= 1) > 128)
448 			delay = 128;
449 		if (retries++ > VNET_MAX_RETRIES) {
450 			pr_info("ECONNRESET %x:%x:%x:%x:%x:%x\n",
451 				port->raddr[0], port->raddr[1],
452 				port->raddr[2], port->raddr[3],
453 				port->raddr[4], port->raddr[5]);
454 			break;
455 		}
456 	} while (err == -EAGAIN);
457 
458 	if (err <= 0 && vio_dring_state == VIO_DRING_STOPPED) {
459 		port->stop_rx_idx = end;
460 		port->stop_rx = true;
461 	} else {
462 		port->stop_rx_idx = 0;
463 		port->stop_rx = false;
464 	}
465 
466 	return err;
467 }
468 
469 static u32 next_idx(u32 idx, struct vio_dring_state *dr)
470 {
471 	if (++idx == dr->num_entries)
472 		idx = 0;
473 	return idx;
474 }
475 
476 static u32 prev_idx(u32 idx, struct vio_dring_state *dr)
477 {
478 	if (idx == 0)
479 		idx = dr->num_entries - 1;
480 	else
481 		idx--;
482 
483 	return idx;
484 }
485 
486 static struct vio_net_desc *get_rx_desc(struct vnet_port *port,
487 					struct vio_dring_state *dr,
488 					u32 index)
489 {
490 	struct vio_net_desc *desc = port->vio.desc_buf;
491 	int err;
492 
493 	err = ldc_get_dring_entry(port->vio.lp, desc, dr->entry_size,
494 				  (index * dr->entry_size),
495 				  dr->cookies, dr->ncookies);
496 	if (err < 0)
497 		return ERR_PTR(err);
498 
499 	return desc;
500 }
501 
502 static int put_rx_desc(struct vnet_port *port,
503 		       struct vio_dring_state *dr,
504 		       struct vio_net_desc *desc,
505 		       u32 index)
506 {
507 	int err;
508 
509 	err = ldc_put_dring_entry(port->vio.lp, desc, dr->entry_size,
510 				  (index * dr->entry_size),
511 				  dr->cookies, dr->ncookies);
512 	if (err < 0)
513 		return err;
514 
515 	return 0;
516 }
517 
518 static int vnet_walk_rx_one(struct vnet_port *port,
519 			    struct vio_dring_state *dr,
520 			    u32 index, int *needs_ack)
521 {
522 	struct vio_net_desc *desc = get_rx_desc(port, dr, index);
523 	struct vio_driver_state *vio = &port->vio;
524 	int err;
525 
526 	BUG_ON(desc == NULL);
527 	if (IS_ERR(desc))
528 		return PTR_ERR(desc);
529 
530 	if (desc->hdr.state != VIO_DESC_READY)
531 		return 1;
532 
533 	rmb();
534 
535 	viodbg(DATA, "vio_walk_rx_one desc[%02x:%02x:%08x:%08x:%llx:%llx]\n",
536 	       desc->hdr.state, desc->hdr.ack,
537 	       desc->size, desc->ncookies,
538 	       desc->cookies[0].cookie_addr,
539 	       desc->cookies[0].cookie_size);
540 
541 	err = vnet_rx_one(port, desc);
542 	if (err == -ECONNRESET)
543 		return err;
544 	desc->hdr.state = VIO_DESC_DONE;
545 	err = put_rx_desc(port, dr, desc, index);
546 	if (err < 0)
547 		return err;
548 	*needs_ack = desc->hdr.ack;
549 	return 0;
550 }
551 
552 static int vnet_walk_rx(struct vnet_port *port, struct vio_dring_state *dr,
553 			u32 start, u32 end, int *npkts, int budget)
554 {
555 	struct vio_driver_state *vio = &port->vio;
556 	int ack_start = -1, ack_end = -1;
557 	bool send_ack = true;
558 
559 	end = (end == (u32) -1) ? prev_idx(start, dr) : next_idx(end, dr);
560 
561 	viodbg(DATA, "vnet_walk_rx start[%08x] end[%08x]\n", start, end);
562 
563 	while (start != end) {
564 		int ack = 0, err = vnet_walk_rx_one(port, dr, start, &ack);
565 		if (err == -ECONNRESET)
566 			return err;
567 		if (err != 0)
568 			break;
569 		(*npkts)++;
570 		if (ack_start == -1)
571 			ack_start = start;
572 		ack_end = start;
573 		start = next_idx(start, dr);
574 		if (ack && start != end) {
575 			err = vnet_send_ack(port, dr, ack_start, ack_end,
576 					    VIO_DRING_ACTIVE);
577 			if (err == -ECONNRESET)
578 				return err;
579 			ack_start = -1;
580 		}
581 		if ((*npkts) >= budget) {
582 			send_ack = false;
583 			break;
584 		}
585 	}
586 	if (unlikely(ack_start == -1))
587 		ack_start = ack_end = prev_idx(start, dr);
588 	if (send_ack) {
589 		port->napi_resume = false;
590 		return vnet_send_ack(port, dr, ack_start, ack_end,
591 				     VIO_DRING_STOPPED);
592 	} else  {
593 		port->napi_resume = true;
594 		port->napi_stop_idx = ack_end;
595 		return 1;
596 	}
597 }
598 
599 static int vnet_rx(struct vnet_port *port, void *msgbuf, int *npkts,
600 		   int budget)
601 {
602 	struct vio_dring_data *pkt = msgbuf;
603 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_RX_RING];
604 	struct vio_driver_state *vio = &port->vio;
605 
606 	viodbg(DATA, "vnet_rx stype_env[%04x] seq[%016llx] rcv_nxt[%016llx]\n",
607 	       pkt->tag.stype_env, pkt->seq, dr->rcv_nxt);
608 
609 	if (unlikely(pkt->tag.stype_env != VIO_DRING_DATA))
610 		return 0;
611 	if (unlikely(pkt->seq != dr->rcv_nxt)) {
612 		pr_err("RX out of sequence seq[0x%llx] rcv_nxt[0x%llx]\n",
613 		       pkt->seq, dr->rcv_nxt);
614 		return 0;
615 	}
616 
617 	if (!port->napi_resume)
618 		dr->rcv_nxt++;
619 
620 	/* XXX Validate pkt->start_idx and pkt->end_idx XXX */
621 
622 	return vnet_walk_rx(port, dr, pkt->start_idx, pkt->end_idx,
623 			    npkts, budget);
624 }
625 
626 static int idx_is_pending(struct vio_dring_state *dr, u32 end)
627 {
628 	u32 idx = dr->cons;
629 	int found = 0;
630 
631 	while (idx != dr->prod) {
632 		if (idx == end) {
633 			found = 1;
634 			break;
635 		}
636 		idx = next_idx(idx, dr);
637 	}
638 	return found;
639 }
640 
641 static int vnet_ack(struct vnet_port *port, void *msgbuf)
642 {
643 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
644 	struct vio_dring_data *pkt = msgbuf;
645 	struct net_device *dev;
646 	struct vnet *vp;
647 	u32 end;
648 	struct vio_net_desc *desc;
649 	struct netdev_queue *txq;
650 
651 	if (unlikely(pkt->tag.stype_env != VIO_DRING_DATA))
652 		return 0;
653 
654 	end = pkt->end_idx;
655 	vp = port->vp;
656 	dev = vp->dev;
657 	netif_tx_lock(dev);
658 	if (unlikely(!idx_is_pending(dr, end))) {
659 		netif_tx_unlock(dev);
660 		return 0;
661 	}
662 
663 	/* sync for race conditions with vnet_start_xmit() and tell xmit it
664 	 * is time to send a trigger.
665 	 */
666 	dr->cons = next_idx(end, dr);
667 	desc = vio_dring_entry(dr, dr->cons);
668 	if (desc->hdr.state == VIO_DESC_READY && !port->start_cons) {
669 		/* vnet_start_xmit() just populated this dring but missed
670 		 * sending the "start" LDC message to the consumer.
671 		 * Send a "start" trigger on its behalf.
672 		 */
673 		if (__vnet_tx_trigger(port, dr->cons) > 0)
674 			port->start_cons = false;
675 		else
676 			port->start_cons = true;
677 	} else {
678 		port->start_cons = true;
679 	}
680 	netif_tx_unlock(dev);
681 
682 	txq = netdev_get_tx_queue(dev, port->q_index);
683 	if (unlikely(netif_tx_queue_stopped(txq) &&
684 		     vnet_tx_dring_avail(dr) >= VNET_TX_WAKEUP_THRESH(dr)))
685 		return 1;
686 
687 	return 0;
688 }
689 
690 static int vnet_nack(struct vnet_port *port, void *msgbuf)
691 {
692 	/* XXX just reset or similar XXX */
693 	return 0;
694 }
695 
696 static int handle_mcast(struct vnet_port *port, void *msgbuf)
697 {
698 	struct vio_net_mcast_info *pkt = msgbuf;
699 
700 	if (pkt->tag.stype != VIO_SUBTYPE_ACK)
701 		pr_err("%s: Got unexpected MCAST reply [%02x:%02x:%04x:%08x]\n",
702 		       port->vp->dev->name,
703 		       pkt->tag.type,
704 		       pkt->tag.stype,
705 		       pkt->tag.stype_env,
706 		       pkt->tag.sid);
707 
708 	return 0;
709 }
710 
711 /* Got back a STOPPED LDC message on port. If the queue is stopped,
712  * wake it up so that we'll send out another START message at the
713  * next TX.
714  */
715 static void maybe_tx_wakeup(struct vnet_port *port)
716 {
717 	struct netdev_queue *txq;
718 
719 	txq = netdev_get_tx_queue(port->vp->dev, port->q_index);
720 	__netif_tx_lock(txq, smp_processor_id());
721 	if (likely(netif_tx_queue_stopped(txq))) {
722 		struct vio_dring_state *dr;
723 
724 		dr = &port->vio.drings[VIO_DRIVER_TX_RING];
725 		netif_tx_wake_queue(txq);
726 	}
727 	__netif_tx_unlock(txq);
728 }
729 
730 static inline bool port_is_up(struct vnet_port *vnet)
731 {
732 	struct vio_driver_state *vio = &vnet->vio;
733 
734 	return !!(vio->hs_state & VIO_HS_COMPLETE);
735 }
736 
737 static int vnet_event_napi(struct vnet_port *port, int budget)
738 {
739 	struct vio_driver_state *vio = &port->vio;
740 	int tx_wakeup, err;
741 	int npkts = 0;
742 	int event = (port->rx_event & LDC_EVENT_RESET);
743 
744 ldc_ctrl:
745 	if (unlikely(event == LDC_EVENT_RESET ||
746 		     event == LDC_EVENT_UP)) {
747 		vio_link_state_change(vio, event);
748 
749 		if (event == LDC_EVENT_RESET) {
750 			port->rmtu = 0;
751 			port->tso = true;
752 			port->tsolen = 0;
753 			vio_port_up(vio);
754 		}
755 		port->rx_event = 0;
756 		return 0;
757 	}
758 	/* We may have multiple LDC events in rx_event. Unroll send_events() */
759 	event = (port->rx_event & LDC_EVENT_UP);
760 	port->rx_event &= ~(LDC_EVENT_RESET|LDC_EVENT_UP);
761 	if (event == LDC_EVENT_UP)
762 		goto ldc_ctrl;
763 	event = port->rx_event;
764 	if (!(event & LDC_EVENT_DATA_READY))
765 		return 0;
766 
767 	/* we dont expect any other bits than RESET, UP, DATA_READY */
768 	BUG_ON(event != LDC_EVENT_DATA_READY);
769 
770 	tx_wakeup = err = 0;
771 	while (1) {
772 		union {
773 			struct vio_msg_tag tag;
774 			u64 raw[8];
775 		} msgbuf;
776 
777 		if (port->napi_resume) {
778 			struct vio_dring_data *pkt =
779 				(struct vio_dring_data *)&msgbuf;
780 			struct vio_dring_state *dr =
781 				&port->vio.drings[VIO_DRIVER_RX_RING];
782 
783 			pkt->tag.type = VIO_TYPE_DATA;
784 			pkt->tag.stype = VIO_SUBTYPE_INFO;
785 			pkt->tag.stype_env = VIO_DRING_DATA;
786 			pkt->seq = dr->rcv_nxt;
787 			pkt->start_idx = next_idx(port->napi_stop_idx, dr);
788 			pkt->end_idx = -1;
789 			goto napi_resume;
790 		}
791 		err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf));
792 		if (unlikely(err < 0)) {
793 			if (err == -ECONNRESET)
794 				vio_conn_reset(vio);
795 			break;
796 		}
797 		if (err == 0)
798 			break;
799 		viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n",
800 		       msgbuf.tag.type,
801 		       msgbuf.tag.stype,
802 		       msgbuf.tag.stype_env,
803 		       msgbuf.tag.sid);
804 		err = vio_validate_sid(vio, &msgbuf.tag);
805 		if (err < 0)
806 			break;
807 napi_resume:
808 		if (likely(msgbuf.tag.type == VIO_TYPE_DATA)) {
809 			if (msgbuf.tag.stype == VIO_SUBTYPE_INFO) {
810 				if (!port_is_up(port)) {
811 					/* failures like handshake_failure()
812 					 * may have cleaned up dring, but
813 					 * NAPI polling may bring us here.
814 					 */
815 					err = -ECONNRESET;
816 					break;
817 				}
818 				err = vnet_rx(port, &msgbuf, &npkts, budget);
819 				if (npkts >= budget)
820 					break;
821 				if (npkts == 0)
822 					break;
823 			} else if (msgbuf.tag.stype == VIO_SUBTYPE_ACK) {
824 				err = vnet_ack(port, &msgbuf);
825 				if (err > 0)
826 					tx_wakeup |= err;
827 			} else if (msgbuf.tag.stype == VIO_SUBTYPE_NACK) {
828 				err = vnet_nack(port, &msgbuf);
829 			}
830 		} else if (msgbuf.tag.type == VIO_TYPE_CTRL) {
831 			if (msgbuf.tag.stype_env == VNET_MCAST_INFO)
832 				err = handle_mcast(port, &msgbuf);
833 			else
834 				err = vio_control_pkt_engine(vio, &msgbuf);
835 			if (err)
836 				break;
837 		} else {
838 			err = vnet_handle_unknown(port, &msgbuf);
839 		}
840 		if (err == -ECONNRESET)
841 			break;
842 	}
843 	if (unlikely(tx_wakeup && err != -ECONNRESET))
844 		maybe_tx_wakeup(port);
845 	return npkts;
846 }
847 
848 static int vnet_poll(struct napi_struct *napi, int budget)
849 {
850 	struct vnet_port *port = container_of(napi, struct vnet_port, napi);
851 	struct vio_driver_state *vio = &port->vio;
852 	int processed = vnet_event_napi(port, budget);
853 
854 	if (processed < budget) {
855 		napi_complete(napi);
856 		port->rx_event &= ~LDC_EVENT_DATA_READY;
857 		vio_set_intr(vio->vdev->rx_ino, HV_INTR_ENABLED);
858 	}
859 	return processed;
860 }
861 
862 static void vnet_event(void *arg, int event)
863 {
864 	struct vnet_port *port = arg;
865 	struct vio_driver_state *vio = &port->vio;
866 
867 	port->rx_event |= event;
868 	vio_set_intr(vio->vdev->rx_ino, HV_INTR_DISABLED);
869 	napi_schedule(&port->napi);
870 
871 }
872 
873 static int __vnet_tx_trigger(struct vnet_port *port, u32 start)
874 {
875 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
876 	struct vio_dring_data hdr = {
877 		.tag = {
878 			.type		= VIO_TYPE_DATA,
879 			.stype		= VIO_SUBTYPE_INFO,
880 			.stype_env	= VIO_DRING_DATA,
881 			.sid		= vio_send_sid(&port->vio),
882 		},
883 		.dring_ident		= dr->ident,
884 		.start_idx		= start,
885 		.end_idx		= (u32) -1,
886 	};
887 	int err, delay;
888 	int retries = 0;
889 
890 	if (port->stop_rx) {
891 		err = vnet_send_ack(port,
892 				    &port->vio.drings[VIO_DRIVER_RX_RING],
893 				    port->stop_rx_idx, -1,
894 				    VIO_DRING_STOPPED);
895 		if (err <= 0)
896 			return err;
897 	}
898 
899 	hdr.seq = dr->snd_nxt;
900 	delay = 1;
901 	do {
902 		err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
903 		if (err > 0) {
904 			dr->snd_nxt++;
905 			break;
906 		}
907 		udelay(delay);
908 		if ((delay <<= 1) > 128)
909 			delay = 128;
910 		if (retries++ > VNET_MAX_RETRIES)
911 			break;
912 	} while (err == -EAGAIN);
913 
914 	return err;
915 }
916 
917 struct vnet_port *__tx_port_find(struct vnet *vp, struct sk_buff *skb)
918 {
919 	unsigned int hash = vnet_hashfn(skb->data);
920 	struct hlist_head *hp = &vp->port_hash[hash];
921 	struct vnet_port *port;
922 
923 	hlist_for_each_entry_rcu(port, hp, hash) {
924 		if (!port_is_up(port))
925 			continue;
926 		if (ether_addr_equal(port->raddr, skb->data))
927 			return port;
928 	}
929 	list_for_each_entry_rcu(port, &vp->port_list, list) {
930 		if (!port->switch_port)
931 			continue;
932 		if (!port_is_up(port))
933 			continue;
934 		return port;
935 	}
936 	return NULL;
937 }
938 
939 static struct sk_buff *vnet_clean_tx_ring(struct vnet_port *port,
940 					  unsigned *pending)
941 {
942 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
943 	struct sk_buff *skb = NULL;
944 	int i, txi;
945 
946 	*pending = 0;
947 
948 	txi = dr->prod-1;
949 	if (txi < 0)
950 		txi = VNET_TX_RING_SIZE-1;
951 
952 	for (i = 0; i < VNET_TX_RING_SIZE; ++i) {
953 		struct vio_net_desc *d;
954 
955 		d = vio_dring_entry(dr, txi);
956 
957 		if (d->hdr.state == VIO_DESC_DONE) {
958 			if (port->tx_bufs[txi].skb) {
959 				BUG_ON(port->tx_bufs[txi].skb->next);
960 
961 				port->tx_bufs[txi].skb->next = skb;
962 				skb = port->tx_bufs[txi].skb;
963 				port->tx_bufs[txi].skb = NULL;
964 
965 				ldc_unmap(port->vio.lp,
966 					  port->tx_bufs[txi].cookies,
967 					  port->tx_bufs[txi].ncookies);
968 			}
969 			d->hdr.state = VIO_DESC_FREE;
970 		} else if (d->hdr.state == VIO_DESC_READY) {
971 			(*pending)++;
972 		} else if (d->hdr.state == VIO_DESC_FREE) {
973 			break;
974 		}
975 		--txi;
976 		if (txi < 0)
977 			txi = VNET_TX_RING_SIZE-1;
978 	}
979 	return skb;
980 }
981 
982 static inline void vnet_free_skbs(struct sk_buff *skb)
983 {
984 	struct sk_buff *next;
985 
986 	while (skb) {
987 		next = skb->next;
988 		skb->next = NULL;
989 		dev_kfree_skb(skb);
990 		skb = next;
991 	}
992 }
993 
994 static void vnet_clean_timer_expire(unsigned long port0)
995 {
996 	struct vnet_port *port = (struct vnet_port *)port0;
997 	struct sk_buff *freeskbs;
998 	unsigned pending;
999 
1000 	netif_tx_lock(port->vp->dev);
1001 	freeskbs = vnet_clean_tx_ring(port, &pending);
1002 	netif_tx_unlock(port->vp->dev);
1003 
1004 	vnet_free_skbs(freeskbs);
1005 
1006 	if (pending)
1007 		(void)mod_timer(&port->clean_timer,
1008 				jiffies + VNET_CLEAN_TIMEOUT);
1009 	 else
1010 		del_timer(&port->clean_timer);
1011 }
1012 
1013 static inline int vnet_skb_map(struct ldc_channel *lp, struct sk_buff *skb,
1014 			       struct ldc_trans_cookie *cookies, int ncookies,
1015 			       unsigned int map_perm)
1016 {
1017 	int i, nc, err, blen;
1018 
1019 	/* header */
1020 	blen = skb_headlen(skb);
1021 	if (blen < ETH_ZLEN)
1022 		blen = ETH_ZLEN;
1023 	blen += VNET_PACKET_SKIP;
1024 	blen += 8 - (blen & 7);
1025 
1026 	err = ldc_map_single(lp, skb->data-VNET_PACKET_SKIP, blen, cookies,
1027 			     ncookies, map_perm);
1028 	if (err < 0)
1029 		return err;
1030 	nc = err;
1031 
1032 	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1033 		skb_frag_t *f = &skb_shinfo(skb)->frags[i];
1034 		u8 *vaddr;
1035 
1036 		if (nc < ncookies) {
1037 			vaddr = kmap_atomic(skb_frag_page(f));
1038 			blen = skb_frag_size(f);
1039 			blen += 8 - (blen & 7);
1040 			err = ldc_map_single(lp, vaddr + f->page_offset,
1041 					     blen, cookies + nc, ncookies - nc,
1042 					     map_perm);
1043 			kunmap_atomic(vaddr);
1044 		} else {
1045 			err = -EMSGSIZE;
1046 		}
1047 
1048 		if (err < 0) {
1049 			ldc_unmap(lp, cookies, nc);
1050 			return err;
1051 		}
1052 		nc += err;
1053 	}
1054 	return nc;
1055 }
1056 
1057 static inline struct sk_buff *vnet_skb_shape(struct sk_buff *skb, int ncookies)
1058 {
1059 	struct sk_buff *nskb;
1060 	int i, len, pad, docopy;
1061 
1062 	len = skb->len;
1063 	pad = 0;
1064 	if (len < ETH_ZLEN) {
1065 		pad += ETH_ZLEN - skb->len;
1066 		len += pad;
1067 	}
1068 	len += VNET_PACKET_SKIP;
1069 	pad += 8 - (len & 7);
1070 
1071 	/* make sure we have enough cookies and alignment in every frag */
1072 	docopy = skb_shinfo(skb)->nr_frags >= ncookies;
1073 	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1074 		skb_frag_t *f = &skb_shinfo(skb)->frags[i];
1075 
1076 		docopy |= f->page_offset & 7;
1077 	}
1078 	if (((unsigned long)skb->data & 7) != VNET_PACKET_SKIP ||
1079 	    skb_tailroom(skb) < pad ||
1080 	    skb_headroom(skb) < VNET_PACKET_SKIP || docopy) {
1081 		int start = 0, offset;
1082 		__wsum csum;
1083 
1084 		len = skb->len > ETH_ZLEN ? skb->len : ETH_ZLEN;
1085 		nskb = alloc_and_align_skb(skb->dev, len);
1086 		if (nskb == NULL) {
1087 			dev_kfree_skb(skb);
1088 			return NULL;
1089 		}
1090 		skb_reserve(nskb, VNET_PACKET_SKIP);
1091 
1092 		nskb->protocol = skb->protocol;
1093 		offset = skb_mac_header(skb) - skb->data;
1094 		skb_set_mac_header(nskb, offset);
1095 		offset = skb_network_header(skb) - skb->data;
1096 		skb_set_network_header(nskb, offset);
1097 		offset = skb_transport_header(skb) - skb->data;
1098 		skb_set_transport_header(nskb, offset);
1099 
1100 		offset = 0;
1101 		nskb->csum_offset = skb->csum_offset;
1102 		nskb->ip_summed = skb->ip_summed;
1103 
1104 		if (skb->ip_summed == CHECKSUM_PARTIAL)
1105 			start = skb_checksum_start_offset(skb);
1106 		if (start) {
1107 			struct iphdr *iph = ip_hdr(nskb);
1108 			int offset = start + nskb->csum_offset;
1109 
1110 			if (skb_copy_bits(skb, 0, nskb->data, start)) {
1111 				dev_kfree_skb(nskb);
1112 				dev_kfree_skb(skb);
1113 				return NULL;
1114 			}
1115 			*(__sum16 *)(skb->data + offset) = 0;
1116 			csum = skb_copy_and_csum_bits(skb, start,
1117 						      nskb->data + start,
1118 						      skb->len - start, 0);
1119 			if (iph->protocol == IPPROTO_TCP ||
1120 			    iph->protocol == IPPROTO_UDP) {
1121 				csum = csum_tcpudp_magic(iph->saddr, iph->daddr,
1122 							 skb->len - start,
1123 							 iph->protocol, csum);
1124 			}
1125 			*(__sum16 *)(nskb->data + offset) = csum;
1126 
1127 			nskb->ip_summed = CHECKSUM_NONE;
1128 		} else if (skb_copy_bits(skb, 0, nskb->data, skb->len)) {
1129 			dev_kfree_skb(nskb);
1130 			dev_kfree_skb(skb);
1131 			return NULL;
1132 		}
1133 		(void)skb_put(nskb, skb->len);
1134 		if (skb_is_gso(skb)) {
1135 			skb_shinfo(nskb)->gso_size = skb_shinfo(skb)->gso_size;
1136 			skb_shinfo(nskb)->gso_type = skb_shinfo(skb)->gso_type;
1137 		}
1138 		dev_kfree_skb(skb);
1139 		skb = nskb;
1140 	}
1141 	return skb;
1142 }
1143 
1144 static u16
1145 vnet_select_queue(struct net_device *dev, struct sk_buff *skb,
1146 		  void *accel_priv, select_queue_fallback_t fallback)
1147 {
1148 	struct vnet *vp = netdev_priv(dev);
1149 	struct vnet_port *port = __tx_port_find(vp, skb);
1150 
1151 	if (port == NULL)
1152 		return 0;
1153 	return port->q_index;
1154 }
1155 
1156 static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev);
1157 
1158 static int vnet_handle_offloads(struct vnet_port *port, struct sk_buff *skb)
1159 {
1160 	struct net_device *dev = port->vp->dev;
1161 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
1162 	struct sk_buff *segs;
1163 	int maclen, datalen;
1164 	int status;
1165 	int gso_size, gso_type, gso_segs;
1166 	int hlen = skb_transport_header(skb) - skb_mac_header(skb);
1167 	int proto = IPPROTO_IP;
1168 
1169 	if (skb->protocol == htons(ETH_P_IP))
1170 		proto = ip_hdr(skb)->protocol;
1171 	else if (skb->protocol == htons(ETH_P_IPV6))
1172 		proto = ipv6_hdr(skb)->nexthdr;
1173 
1174 	if (proto == IPPROTO_TCP)
1175 		hlen += tcp_hdr(skb)->doff * 4;
1176 	else if (proto == IPPROTO_UDP)
1177 		hlen += sizeof(struct udphdr);
1178 	else {
1179 		pr_err("vnet_handle_offloads GSO with unknown transport "
1180 		       "protocol %d tproto %d\n", skb->protocol, proto);
1181 		hlen = 128; /* XXX */
1182 	}
1183 	datalen = port->tsolen - hlen;
1184 
1185 	gso_size = skb_shinfo(skb)->gso_size;
1186 	gso_type = skb_shinfo(skb)->gso_type;
1187 	gso_segs = skb_shinfo(skb)->gso_segs;
1188 
1189 	if (port->tso && gso_size < datalen)
1190 		gso_segs = DIV_ROUND_UP(skb->len - hlen, datalen);
1191 
1192 	if (unlikely(vnet_tx_dring_avail(dr) < gso_segs)) {
1193 		struct netdev_queue *txq;
1194 
1195 		txq  = netdev_get_tx_queue(dev, port->q_index);
1196 		netif_tx_stop_queue(txq);
1197 		if (vnet_tx_dring_avail(dr) < skb_shinfo(skb)->gso_segs)
1198 			return NETDEV_TX_BUSY;
1199 		netif_tx_wake_queue(txq);
1200 	}
1201 
1202 	maclen = skb_network_header(skb) - skb_mac_header(skb);
1203 	skb_pull(skb, maclen);
1204 
1205 	if (port->tso && gso_size < datalen) {
1206 		/* segment to TSO size */
1207 		skb_shinfo(skb)->gso_size = datalen;
1208 		skb_shinfo(skb)->gso_segs = gso_segs;
1209 
1210 		segs = skb_gso_segment(skb, dev->features & ~NETIF_F_TSO);
1211 
1212 		/* restore gso_size & gso_segs */
1213 		skb_shinfo(skb)->gso_size = gso_size;
1214 		skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len - hlen,
1215 							 gso_size);
1216 	} else
1217 		segs = skb_gso_segment(skb, dev->features & ~NETIF_F_TSO);
1218 	if (IS_ERR(segs)) {
1219 		dev->stats.tx_dropped++;
1220 		return NETDEV_TX_OK;
1221 	}
1222 
1223 	skb_push(skb, maclen);
1224 	skb_reset_mac_header(skb);
1225 
1226 	status = 0;
1227 	while (segs) {
1228 		struct sk_buff *curr = segs;
1229 
1230 		segs = segs->next;
1231 		curr->next = NULL;
1232 		if (port->tso && curr->len > dev->mtu) {
1233 			skb_shinfo(curr)->gso_size = gso_size;
1234 			skb_shinfo(curr)->gso_type = gso_type;
1235 			skb_shinfo(curr)->gso_segs =
1236 				DIV_ROUND_UP(curr->len - hlen, gso_size);
1237 		} else
1238 			skb_shinfo(curr)->gso_size = 0;
1239 
1240 		skb_push(curr, maclen);
1241 		skb_reset_mac_header(curr);
1242 		memcpy(skb_mac_header(curr), skb_mac_header(skb),
1243 		       maclen);
1244 		curr->csum_start = skb_transport_header(curr) - curr->head;
1245 		if (ip_hdr(curr)->protocol == IPPROTO_TCP)
1246 			curr->csum_offset = offsetof(struct tcphdr, check);
1247 		else if (ip_hdr(curr)->protocol == IPPROTO_UDP)
1248 			curr->csum_offset = offsetof(struct udphdr, check);
1249 
1250 		if (!(status & NETDEV_TX_MASK))
1251 			status = vnet_start_xmit(curr, dev);
1252 		if (status & NETDEV_TX_MASK)
1253 			dev_kfree_skb_any(curr);
1254 	}
1255 
1256 	if (!(status & NETDEV_TX_MASK))
1257 		dev_kfree_skb_any(skb);
1258 	return status;
1259 }
1260 
1261 static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
1262 {
1263 	struct vnet *vp = netdev_priv(dev);
1264 	struct vnet_port *port = NULL;
1265 	struct vio_dring_state *dr;
1266 	struct vio_net_desc *d;
1267 	unsigned int len;
1268 	struct sk_buff *freeskbs = NULL;
1269 	int i, err, txi;
1270 	unsigned pending = 0;
1271 	struct netdev_queue *txq;
1272 
1273 	rcu_read_lock();
1274 	port = __tx_port_find(vp, skb);
1275 	if (unlikely(!port)) {
1276 		rcu_read_unlock();
1277 		goto out_dropped;
1278 	}
1279 
1280 	if (skb_is_gso(skb) && skb->len > port->tsolen) {
1281 		err = vnet_handle_offloads(port, skb);
1282 		rcu_read_unlock();
1283 		return err;
1284 	}
1285 
1286 	if (!skb_is_gso(skb) && skb->len > port->rmtu) {
1287 		unsigned long localmtu = port->rmtu - ETH_HLEN;
1288 
1289 		if (vio_version_after_eq(&port->vio, 1, 3))
1290 			localmtu -= VLAN_HLEN;
1291 
1292 		if (skb->protocol == htons(ETH_P_IP)) {
1293 			struct flowi4 fl4;
1294 			struct rtable *rt = NULL;
1295 
1296 			memset(&fl4, 0, sizeof(fl4));
1297 			fl4.flowi4_oif = dev->ifindex;
1298 			fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos);
1299 			fl4.daddr = ip_hdr(skb)->daddr;
1300 			fl4.saddr = ip_hdr(skb)->saddr;
1301 
1302 			rt = ip_route_output_key(dev_net(dev), &fl4);
1303 			rcu_read_unlock();
1304 			if (!IS_ERR(rt)) {
1305 				skb_dst_set(skb, &rt->dst);
1306 				icmp_send(skb, ICMP_DEST_UNREACH,
1307 					  ICMP_FRAG_NEEDED,
1308 					  htonl(localmtu));
1309 			}
1310 		}
1311 #if IS_ENABLED(CONFIG_IPV6)
1312 		else if (skb->protocol == htons(ETH_P_IPV6))
1313 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, localmtu);
1314 #endif
1315 		goto out_dropped;
1316 	}
1317 
1318 	skb = vnet_skb_shape(skb, 2);
1319 
1320 	if (unlikely(!skb))
1321 		goto out_dropped;
1322 
1323 	if (skb->ip_summed == CHECKSUM_PARTIAL)
1324 		vnet_fullcsum(skb);
1325 
1326 	dr = &port->vio.drings[VIO_DRIVER_TX_RING];
1327 	i = skb_get_queue_mapping(skb);
1328 	txq = netdev_get_tx_queue(dev, i);
1329 	if (unlikely(vnet_tx_dring_avail(dr) < 1)) {
1330 		if (!netif_tx_queue_stopped(txq)) {
1331 			netif_tx_stop_queue(txq);
1332 
1333 			/* This is a hard error, log it. */
1334 			netdev_err(dev, "BUG! Tx Ring full when queue awake!\n");
1335 			dev->stats.tx_errors++;
1336 		}
1337 		rcu_read_unlock();
1338 		return NETDEV_TX_BUSY;
1339 	}
1340 
1341 	d = vio_dring_cur(dr);
1342 
1343 	txi = dr->prod;
1344 
1345 	freeskbs = vnet_clean_tx_ring(port, &pending);
1346 
1347 	BUG_ON(port->tx_bufs[txi].skb);
1348 
1349 	len = skb->len;
1350 	if (len < ETH_ZLEN)
1351 		len = ETH_ZLEN;
1352 
1353 	err = vnet_skb_map(port->vio.lp, skb, port->tx_bufs[txi].cookies, 2,
1354 			   (LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_RW));
1355 	if (err < 0) {
1356 		netdev_info(dev, "tx buffer map error %d\n", err);
1357 		goto out_dropped;
1358 	}
1359 
1360 	port->tx_bufs[txi].skb = skb;
1361 	skb = NULL;
1362 	port->tx_bufs[txi].ncookies = err;
1363 
1364 	/* We don't rely on the ACKs to free the skb in vnet_start_xmit(),
1365 	 * thus it is safe to not set VIO_ACK_ENABLE for each transmission:
1366 	 * the protocol itself does not require it as long as the peer
1367 	 * sends a VIO_SUBTYPE_ACK for VIO_DRING_STOPPED.
1368 	 *
1369 	 * An ACK for every packet in the ring is expensive as the
1370 	 * sending of LDC messages is slow and affects performance.
1371 	 */
1372 	d->hdr.ack = VIO_ACK_DISABLE;
1373 	d->size = len;
1374 	d->ncookies = port->tx_bufs[txi].ncookies;
1375 	for (i = 0; i < d->ncookies; i++)
1376 		d->cookies[i] = port->tx_bufs[txi].cookies[i];
1377 	if (vio_version_after_eq(&port->vio, 1, 7)) {
1378 		struct vio_net_dext *dext = vio_net_ext(d);
1379 
1380 		memset(dext, 0, sizeof(*dext));
1381 		if (skb_is_gso(port->tx_bufs[txi].skb)) {
1382 			dext->ipv4_lso_mss = skb_shinfo(port->tx_bufs[txi].skb)
1383 					     ->gso_size;
1384 			dext->flags |= VNET_PKT_IPV4_LSO;
1385 		}
1386 		if (vio_version_after_eq(&port->vio, 1, 8) &&
1387 		    !port->switch_port) {
1388 			dext->flags |= VNET_PKT_HCK_IPV4_HDRCKSUM_OK;
1389 			dext->flags |= VNET_PKT_HCK_FULLCKSUM_OK;
1390 		}
1391 	}
1392 
1393 	/* This has to be a non-SMP write barrier because we are writing
1394 	 * to memory which is shared with the peer LDOM.
1395 	 */
1396 	wmb();
1397 
1398 	d->hdr.state = VIO_DESC_READY;
1399 
1400 	/* Exactly one ldc "start" trigger (for dr->cons) needs to be sent
1401 	 * to notify the consumer that some descriptors are READY.
1402 	 * After that "start" trigger, no additional triggers are needed until
1403 	 * a DRING_STOPPED is received from the consumer. The dr->cons field
1404 	 * (set up by vnet_ack()) has the value of the next dring index
1405 	 * that has not yet been ack-ed. We send a "start" trigger here
1406 	 * if, and only if, start_cons is true (reset it afterward). Conversely,
1407 	 * vnet_ack() should check if the dring corresponding to cons
1408 	 * is marked READY, but start_cons was false.
1409 	 * If so, vnet_ack() should send out the missed "start" trigger.
1410 	 *
1411 	 * Note that the wmb() above makes sure the cookies et al. are
1412 	 * not globally visible before the VIO_DESC_READY, and that the
1413 	 * stores are ordered correctly by the compiler. The consumer will
1414 	 * not proceed until the VIO_DESC_READY is visible assuring that
1415 	 * the consumer does not observe anything related to descriptors
1416 	 * out of order. The HV trap from the LDC start trigger is the
1417 	 * producer to consumer announcement that work is available to the
1418 	 * consumer
1419 	 */
1420 	if (!port->start_cons)
1421 		goto ldc_start_done; /* previous trigger suffices */
1422 
1423 	err = __vnet_tx_trigger(port, dr->cons);
1424 	if (unlikely(err < 0)) {
1425 		netdev_info(dev, "TX trigger error %d\n", err);
1426 		d->hdr.state = VIO_DESC_FREE;
1427 		dev->stats.tx_carrier_errors++;
1428 		goto out_dropped;
1429 	}
1430 
1431 ldc_start_done:
1432 	port->start_cons = false;
1433 
1434 	dev->stats.tx_packets++;
1435 	dev->stats.tx_bytes += port->tx_bufs[txi].skb->len;
1436 
1437 	dr->prod = (dr->prod + 1) & (VNET_TX_RING_SIZE - 1);
1438 	if (unlikely(vnet_tx_dring_avail(dr) < 1)) {
1439 		netif_tx_stop_queue(txq);
1440 		if (vnet_tx_dring_avail(dr) > VNET_TX_WAKEUP_THRESH(dr))
1441 			netif_tx_wake_queue(txq);
1442 	}
1443 
1444 	(void)mod_timer(&port->clean_timer, jiffies + VNET_CLEAN_TIMEOUT);
1445 	rcu_read_unlock();
1446 
1447 	vnet_free_skbs(freeskbs);
1448 
1449 	return NETDEV_TX_OK;
1450 
1451 out_dropped:
1452 	if (pending)
1453 		(void)mod_timer(&port->clean_timer,
1454 				jiffies + VNET_CLEAN_TIMEOUT);
1455 	else if (port)
1456 		del_timer(&port->clean_timer);
1457 	if (port)
1458 		rcu_read_unlock();
1459 	if (skb)
1460 		dev_kfree_skb(skb);
1461 	vnet_free_skbs(freeskbs);
1462 	dev->stats.tx_dropped++;
1463 	return NETDEV_TX_OK;
1464 }
1465 
1466 static void vnet_tx_timeout(struct net_device *dev)
1467 {
1468 	/* XXX Implement me XXX */
1469 }
1470 
1471 static int vnet_open(struct net_device *dev)
1472 {
1473 	netif_carrier_on(dev);
1474 	netif_tx_start_all_queues(dev);
1475 
1476 	return 0;
1477 }
1478 
1479 static int vnet_close(struct net_device *dev)
1480 {
1481 	netif_tx_stop_all_queues(dev);
1482 	netif_carrier_off(dev);
1483 
1484 	return 0;
1485 }
1486 
1487 static struct vnet_mcast_entry *__vnet_mc_find(struct vnet *vp, u8 *addr)
1488 {
1489 	struct vnet_mcast_entry *m;
1490 
1491 	for (m = vp->mcast_list; m; m = m->next) {
1492 		if (ether_addr_equal(m->addr, addr))
1493 			return m;
1494 	}
1495 	return NULL;
1496 }
1497 
1498 static void __update_mc_list(struct vnet *vp, struct net_device *dev)
1499 {
1500 	struct netdev_hw_addr *ha;
1501 
1502 	netdev_for_each_mc_addr(ha, dev) {
1503 		struct vnet_mcast_entry *m;
1504 
1505 		m = __vnet_mc_find(vp, ha->addr);
1506 		if (m) {
1507 			m->hit = 1;
1508 			continue;
1509 		}
1510 
1511 		if (!m) {
1512 			m = kzalloc(sizeof(*m), GFP_ATOMIC);
1513 			if (!m)
1514 				continue;
1515 			memcpy(m->addr, ha->addr, ETH_ALEN);
1516 			m->hit = 1;
1517 
1518 			m->next = vp->mcast_list;
1519 			vp->mcast_list = m;
1520 		}
1521 	}
1522 }
1523 
1524 static void __send_mc_list(struct vnet *vp, struct vnet_port *port)
1525 {
1526 	struct vio_net_mcast_info info;
1527 	struct vnet_mcast_entry *m, **pp;
1528 	int n_addrs;
1529 
1530 	memset(&info, 0, sizeof(info));
1531 
1532 	info.tag.type = VIO_TYPE_CTRL;
1533 	info.tag.stype = VIO_SUBTYPE_INFO;
1534 	info.tag.stype_env = VNET_MCAST_INFO;
1535 	info.tag.sid = vio_send_sid(&port->vio);
1536 	info.set = 1;
1537 
1538 	n_addrs = 0;
1539 	for (m = vp->mcast_list; m; m = m->next) {
1540 		if (m->sent)
1541 			continue;
1542 		m->sent = 1;
1543 		memcpy(&info.mcast_addr[n_addrs * ETH_ALEN],
1544 		       m->addr, ETH_ALEN);
1545 		if (++n_addrs == VNET_NUM_MCAST) {
1546 			info.count = n_addrs;
1547 
1548 			(void) vio_ldc_send(&port->vio, &info,
1549 					    sizeof(info));
1550 			n_addrs = 0;
1551 		}
1552 	}
1553 	if (n_addrs) {
1554 		info.count = n_addrs;
1555 		(void) vio_ldc_send(&port->vio, &info, sizeof(info));
1556 	}
1557 
1558 	info.set = 0;
1559 
1560 	n_addrs = 0;
1561 	pp = &vp->mcast_list;
1562 	while ((m = *pp) != NULL) {
1563 		if (m->hit) {
1564 			m->hit = 0;
1565 			pp = &m->next;
1566 			continue;
1567 		}
1568 
1569 		memcpy(&info.mcast_addr[n_addrs * ETH_ALEN],
1570 		       m->addr, ETH_ALEN);
1571 		if (++n_addrs == VNET_NUM_MCAST) {
1572 			info.count = n_addrs;
1573 			(void) vio_ldc_send(&port->vio, &info,
1574 					    sizeof(info));
1575 			n_addrs = 0;
1576 		}
1577 
1578 		*pp = m->next;
1579 		kfree(m);
1580 	}
1581 	if (n_addrs) {
1582 		info.count = n_addrs;
1583 		(void) vio_ldc_send(&port->vio, &info, sizeof(info));
1584 	}
1585 }
1586 
1587 static void vnet_set_rx_mode(struct net_device *dev)
1588 {
1589 	struct vnet *vp = netdev_priv(dev);
1590 	struct vnet_port *port;
1591 
1592 	rcu_read_lock();
1593 	list_for_each_entry_rcu(port, &vp->port_list, list) {
1594 
1595 		if (port->switch_port) {
1596 			__update_mc_list(vp, dev);
1597 			__send_mc_list(vp, port);
1598 			break;
1599 		}
1600 	}
1601 	rcu_read_unlock();
1602 }
1603 
1604 static int vnet_change_mtu(struct net_device *dev, int new_mtu)
1605 {
1606 	if (new_mtu < 68 || new_mtu > 65535)
1607 		return -EINVAL;
1608 
1609 	dev->mtu = new_mtu;
1610 	return 0;
1611 }
1612 
1613 static int vnet_set_mac_addr(struct net_device *dev, void *p)
1614 {
1615 	return -EINVAL;
1616 }
1617 
1618 static void vnet_get_drvinfo(struct net_device *dev,
1619 			     struct ethtool_drvinfo *info)
1620 {
1621 	strlcpy(info->driver, DRV_MODULE_NAME, sizeof(info->driver));
1622 	strlcpy(info->version, DRV_MODULE_VERSION, sizeof(info->version));
1623 }
1624 
1625 static u32 vnet_get_msglevel(struct net_device *dev)
1626 {
1627 	struct vnet *vp = netdev_priv(dev);
1628 	return vp->msg_enable;
1629 }
1630 
1631 static void vnet_set_msglevel(struct net_device *dev, u32 value)
1632 {
1633 	struct vnet *vp = netdev_priv(dev);
1634 	vp->msg_enable = value;
1635 }
1636 
1637 static const struct ethtool_ops vnet_ethtool_ops = {
1638 	.get_drvinfo		= vnet_get_drvinfo,
1639 	.get_msglevel		= vnet_get_msglevel,
1640 	.set_msglevel		= vnet_set_msglevel,
1641 	.get_link		= ethtool_op_get_link,
1642 };
1643 
1644 static void vnet_port_free_tx_bufs(struct vnet_port *port)
1645 {
1646 	struct vio_dring_state *dr;
1647 	int i;
1648 
1649 	dr = &port->vio.drings[VIO_DRIVER_TX_RING];
1650 	if (dr->base) {
1651 		ldc_free_exp_dring(port->vio.lp, dr->base,
1652 				   (dr->entry_size * dr->num_entries),
1653 				   dr->cookies, dr->ncookies);
1654 		dr->base = NULL;
1655 		dr->entry_size = 0;
1656 		dr->num_entries = 0;
1657 		dr->pending = 0;
1658 		dr->ncookies = 0;
1659 	}
1660 
1661 	for (i = 0; i < VNET_TX_RING_SIZE; i++) {
1662 		struct vio_net_desc *d;
1663 		void *skb = port->tx_bufs[i].skb;
1664 
1665 		if (!skb)
1666 			continue;
1667 
1668 		d = vio_dring_entry(dr, i);
1669 		if (d->hdr.state == VIO_DESC_READY)
1670 			pr_warn("active transmit buffers freed\n");
1671 
1672 		ldc_unmap(port->vio.lp,
1673 			  port->tx_bufs[i].cookies,
1674 			  port->tx_bufs[i].ncookies);
1675 		dev_kfree_skb(skb);
1676 		port->tx_bufs[i].skb = NULL;
1677 		d->hdr.state = VIO_DESC_FREE;
1678 	}
1679 }
1680 
1681 static int vnet_port_alloc_tx_ring(struct vnet_port *port)
1682 {
1683 	struct vio_dring_state *dr;
1684 	unsigned long len, elen;
1685 	int i, err, ncookies;
1686 	void *dring;
1687 
1688 	dr = &port->vio.drings[VIO_DRIVER_TX_RING];
1689 
1690 	elen = sizeof(struct vio_net_desc) +
1691 	       sizeof(struct ldc_trans_cookie) * 2;
1692 	if (vio_version_after_eq(&port->vio, 1, 7))
1693 		elen += sizeof(struct vio_net_dext);
1694 	len = VNET_TX_RING_SIZE * elen;
1695 
1696 	ncookies = VIO_MAX_RING_COOKIES;
1697 	dring = ldc_alloc_exp_dring(port->vio.lp, len,
1698 				    dr->cookies, &ncookies,
1699 				    (LDC_MAP_SHADOW |
1700 				     LDC_MAP_DIRECT |
1701 				     LDC_MAP_RW));
1702 	if (IS_ERR(dring)) {
1703 		err = PTR_ERR(dring);
1704 		goto err_out;
1705 	}
1706 
1707 	dr->base = dring;
1708 	dr->entry_size = elen;
1709 	dr->num_entries = VNET_TX_RING_SIZE;
1710 	dr->prod = dr->cons = 0;
1711 	port->start_cons  = true; /* need an initial trigger */
1712 	dr->pending = VNET_TX_RING_SIZE;
1713 	dr->ncookies = ncookies;
1714 
1715 	for (i = 0; i < VNET_TX_RING_SIZE; ++i) {
1716 		struct vio_net_desc *d;
1717 
1718 		d = vio_dring_entry(dr, i);
1719 		d->hdr.state = VIO_DESC_FREE;
1720 	}
1721 	return 0;
1722 
1723 err_out:
1724 	vnet_port_free_tx_bufs(port);
1725 
1726 	return err;
1727 }
1728 
1729 #ifdef CONFIG_NET_POLL_CONTROLLER
1730 static void vnet_poll_controller(struct net_device *dev)
1731 {
1732 	struct vnet *vp = netdev_priv(dev);
1733 	struct vnet_port *port;
1734 	unsigned long flags;
1735 
1736 	spin_lock_irqsave(&vp->lock, flags);
1737 	if (!list_empty(&vp->port_list)) {
1738 		port = list_entry(vp->port_list.next, struct vnet_port, list);
1739 		napi_schedule(&port->napi);
1740 	}
1741 	spin_unlock_irqrestore(&vp->lock, flags);
1742 }
1743 #endif
1744 static LIST_HEAD(vnet_list);
1745 static DEFINE_MUTEX(vnet_list_mutex);
1746 
1747 static const struct net_device_ops vnet_ops = {
1748 	.ndo_open		= vnet_open,
1749 	.ndo_stop		= vnet_close,
1750 	.ndo_set_rx_mode	= vnet_set_rx_mode,
1751 	.ndo_set_mac_address	= vnet_set_mac_addr,
1752 	.ndo_validate_addr	= eth_validate_addr,
1753 	.ndo_tx_timeout		= vnet_tx_timeout,
1754 	.ndo_change_mtu		= vnet_change_mtu,
1755 	.ndo_start_xmit		= vnet_start_xmit,
1756 	.ndo_select_queue	= vnet_select_queue,
1757 #ifdef CONFIG_NET_POLL_CONTROLLER
1758 	.ndo_poll_controller	= vnet_poll_controller,
1759 #endif
1760 };
1761 
1762 static struct vnet *vnet_new(const u64 *local_mac)
1763 {
1764 	struct net_device *dev;
1765 	struct vnet *vp;
1766 	int err, i;
1767 
1768 	dev = alloc_etherdev_mqs(sizeof(*vp), VNET_MAX_TXQS, 1);
1769 	if (!dev)
1770 		return ERR_PTR(-ENOMEM);
1771 	dev->needed_headroom = VNET_PACKET_SKIP + 8;
1772 	dev->needed_tailroom = 8;
1773 
1774 	for (i = 0; i < ETH_ALEN; i++)
1775 		dev->dev_addr[i] = (*local_mac >> (5 - i) * 8) & 0xff;
1776 
1777 	vp = netdev_priv(dev);
1778 
1779 	spin_lock_init(&vp->lock);
1780 	vp->dev = dev;
1781 
1782 	INIT_LIST_HEAD(&vp->port_list);
1783 	for (i = 0; i < VNET_PORT_HASH_SIZE; i++)
1784 		INIT_HLIST_HEAD(&vp->port_hash[i]);
1785 	INIT_LIST_HEAD(&vp->list);
1786 	vp->local_mac = *local_mac;
1787 
1788 	dev->netdev_ops = &vnet_ops;
1789 	dev->ethtool_ops = &vnet_ethtool_ops;
1790 	dev->watchdog_timeo = VNET_TX_TIMEOUT;
1791 
1792 	dev->hw_features = NETIF_F_TSO | NETIF_F_GSO | NETIF_F_GSO_SOFTWARE |
1793 			   NETIF_F_HW_CSUM | NETIF_F_SG;
1794 	dev->features = dev->hw_features;
1795 
1796 	err = register_netdev(dev);
1797 	if (err) {
1798 		pr_err("Cannot register net device, aborting\n");
1799 		goto err_out_free_dev;
1800 	}
1801 
1802 	netdev_info(dev, "Sun LDOM vnet %pM\n", dev->dev_addr);
1803 
1804 	list_add(&vp->list, &vnet_list);
1805 
1806 	return vp;
1807 
1808 err_out_free_dev:
1809 	free_netdev(dev);
1810 
1811 	return ERR_PTR(err);
1812 }
1813 
1814 static struct vnet *vnet_find_or_create(const u64 *local_mac)
1815 {
1816 	struct vnet *iter, *vp;
1817 
1818 	mutex_lock(&vnet_list_mutex);
1819 	vp = NULL;
1820 	list_for_each_entry(iter, &vnet_list, list) {
1821 		if (iter->local_mac == *local_mac) {
1822 			vp = iter;
1823 			break;
1824 		}
1825 	}
1826 	if (!vp)
1827 		vp = vnet_new(local_mac);
1828 	mutex_unlock(&vnet_list_mutex);
1829 
1830 	return vp;
1831 }
1832 
1833 static void vnet_cleanup(void)
1834 {
1835 	struct vnet *vp;
1836 	struct net_device *dev;
1837 
1838 	mutex_lock(&vnet_list_mutex);
1839 	while (!list_empty(&vnet_list)) {
1840 		vp = list_first_entry(&vnet_list, struct vnet, list);
1841 		list_del(&vp->list);
1842 		dev = vp->dev;
1843 		/* vio_unregister_driver() should have cleaned up port_list */
1844 		BUG_ON(!list_empty(&vp->port_list));
1845 		unregister_netdev(dev);
1846 		free_netdev(dev);
1847 	}
1848 	mutex_unlock(&vnet_list_mutex);
1849 }
1850 
1851 static const char *local_mac_prop = "local-mac-address";
1852 
1853 static struct vnet *vnet_find_parent(struct mdesc_handle *hp,
1854 						u64 port_node)
1855 {
1856 	const u64 *local_mac = NULL;
1857 	u64 a;
1858 
1859 	mdesc_for_each_arc(a, hp, port_node, MDESC_ARC_TYPE_BACK) {
1860 		u64 target = mdesc_arc_target(hp, a);
1861 		const char *name;
1862 
1863 		name = mdesc_get_property(hp, target, "name", NULL);
1864 		if (!name || strcmp(name, "network"))
1865 			continue;
1866 
1867 		local_mac = mdesc_get_property(hp, target,
1868 					       local_mac_prop, NULL);
1869 		if (local_mac)
1870 			break;
1871 	}
1872 	if (!local_mac)
1873 		return ERR_PTR(-ENODEV);
1874 
1875 	return vnet_find_or_create(local_mac);
1876 }
1877 
1878 static struct ldc_channel_config vnet_ldc_cfg = {
1879 	.event		= vnet_event,
1880 	.mtu		= 64,
1881 	.mode		= LDC_MODE_UNRELIABLE,
1882 };
1883 
1884 static struct vio_driver_ops vnet_vio_ops = {
1885 	.send_attr		= vnet_send_attr,
1886 	.handle_attr		= vnet_handle_attr,
1887 	.handshake_complete	= vnet_handshake_complete,
1888 };
1889 
1890 static void print_version(void)
1891 {
1892 	printk_once(KERN_INFO "%s", version);
1893 }
1894 
1895 const char *remote_macaddr_prop = "remote-mac-address";
1896 
1897 static void
1898 vnet_port_add_txq(struct vnet_port *port)
1899 {
1900 	struct vnet *vp = port->vp;
1901 	int n;
1902 
1903 	n = vp->nports++;
1904 	n = n & (VNET_MAX_TXQS - 1);
1905 	port->q_index = n;
1906 	netif_tx_wake_queue(netdev_get_tx_queue(vp->dev, port->q_index));
1907 }
1908 
1909 static void
1910 vnet_port_rm_txq(struct vnet_port *port)
1911 {
1912 	port->vp->nports--;
1913 	netif_tx_stop_queue(netdev_get_tx_queue(port->vp->dev, port->q_index));
1914 }
1915 
1916 static int vnet_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
1917 {
1918 	struct mdesc_handle *hp;
1919 	struct vnet_port *port;
1920 	unsigned long flags;
1921 	struct vnet *vp;
1922 	const u64 *rmac;
1923 	int len, i, err, switch_port;
1924 
1925 	print_version();
1926 
1927 	hp = mdesc_grab();
1928 
1929 	vp = vnet_find_parent(hp, vdev->mp);
1930 	if (IS_ERR(vp)) {
1931 		pr_err("Cannot find port parent vnet\n");
1932 		err = PTR_ERR(vp);
1933 		goto err_out_put_mdesc;
1934 	}
1935 
1936 	rmac = mdesc_get_property(hp, vdev->mp, remote_macaddr_prop, &len);
1937 	err = -ENODEV;
1938 	if (!rmac) {
1939 		pr_err("Port lacks %s property\n", remote_macaddr_prop);
1940 		goto err_out_put_mdesc;
1941 	}
1942 
1943 	port = kzalloc(sizeof(*port), GFP_KERNEL);
1944 	err = -ENOMEM;
1945 	if (!port)
1946 		goto err_out_put_mdesc;
1947 
1948 	for (i = 0; i < ETH_ALEN; i++)
1949 		port->raddr[i] = (*rmac >> (5 - i) * 8) & 0xff;
1950 
1951 	port->vp = vp;
1952 
1953 	err = vio_driver_init(&port->vio, vdev, VDEV_NETWORK,
1954 			      vnet_versions, ARRAY_SIZE(vnet_versions),
1955 			      &vnet_vio_ops, vp->dev->name);
1956 	if (err)
1957 		goto err_out_free_port;
1958 
1959 	err = vio_ldc_alloc(&port->vio, &vnet_ldc_cfg, port);
1960 	if (err)
1961 		goto err_out_free_port;
1962 
1963 	netif_napi_add(port->vp->dev, &port->napi, vnet_poll, NAPI_POLL_WEIGHT);
1964 
1965 	INIT_HLIST_NODE(&port->hash);
1966 	INIT_LIST_HEAD(&port->list);
1967 
1968 	switch_port = 0;
1969 	if (mdesc_get_property(hp, vdev->mp, "switch-port", NULL) != NULL)
1970 		switch_port = 1;
1971 	port->switch_port = switch_port;
1972 	port->tso = true;
1973 	port->tsolen = 0;
1974 
1975 	spin_lock_irqsave(&vp->lock, flags);
1976 	if (switch_port)
1977 		list_add_rcu(&port->list, &vp->port_list);
1978 	else
1979 		list_add_tail_rcu(&port->list, &vp->port_list);
1980 	hlist_add_head_rcu(&port->hash,
1981 			   &vp->port_hash[vnet_hashfn(port->raddr)]);
1982 	vnet_port_add_txq(port);
1983 	spin_unlock_irqrestore(&vp->lock, flags);
1984 
1985 	dev_set_drvdata(&vdev->dev, port);
1986 
1987 	pr_info("%s: PORT ( remote-mac %pM%s )\n",
1988 		vp->dev->name, port->raddr, switch_port ? " switch-port" : "");
1989 
1990 	setup_timer(&port->clean_timer, vnet_clean_timer_expire,
1991 		    (unsigned long)port);
1992 
1993 	napi_enable(&port->napi);
1994 	vio_port_up(&port->vio);
1995 
1996 	mdesc_release(hp);
1997 
1998 	return 0;
1999 
2000 err_out_free_port:
2001 	kfree(port);
2002 
2003 err_out_put_mdesc:
2004 	mdesc_release(hp);
2005 	return err;
2006 }
2007 
2008 static int vnet_port_remove(struct vio_dev *vdev)
2009 {
2010 	struct vnet_port *port = dev_get_drvdata(&vdev->dev);
2011 
2012 	if (port) {
2013 
2014 		del_timer_sync(&port->vio.timer);
2015 
2016 		napi_disable(&port->napi);
2017 
2018 		list_del_rcu(&port->list);
2019 		hlist_del_rcu(&port->hash);
2020 
2021 		synchronize_rcu();
2022 		del_timer_sync(&port->clean_timer);
2023 		vnet_port_rm_txq(port);
2024 		netif_napi_del(&port->napi);
2025 		vnet_port_free_tx_bufs(port);
2026 		vio_ldc_free(&port->vio);
2027 
2028 		dev_set_drvdata(&vdev->dev, NULL);
2029 
2030 		kfree(port);
2031 
2032 	}
2033 	return 0;
2034 }
2035 
2036 static const struct vio_device_id vnet_port_match[] = {
2037 	{
2038 		.type = "vnet-port",
2039 	},
2040 	{},
2041 };
2042 MODULE_DEVICE_TABLE(vio, vnet_port_match);
2043 
2044 static struct vio_driver vnet_port_driver = {
2045 	.id_table	= vnet_port_match,
2046 	.probe		= vnet_port_probe,
2047 	.remove		= vnet_port_remove,
2048 	.name		= "vnet_port",
2049 };
2050 
2051 static int __init vnet_init(void)
2052 {
2053 	return vio_register_driver(&vnet_port_driver);
2054 }
2055 
2056 static void __exit vnet_exit(void)
2057 {
2058 	vio_unregister_driver(&vnet_port_driver);
2059 	vnet_cleanup();
2060 }
2061 
2062 module_init(vnet_init);
2063 module_exit(vnet_exit);
2064