1// SPDX-License-Identifier: GPL-2.0
2/* sunvnet.c: Sun LDOM Virtual Network Driver.
3 *
4 * Copyright (C) 2007, 2008 David S. Miller <davem@davemloft.net>
5 * Copyright (C) 2016-2017 Oracle. All rights reserved.
6 */
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#define CREATE_TRACE_POINTS
21#include <trace/events/sunvnet.h>
22
23#if IS_ENABLED(CONFIG_IPV6)
24#include <linux/icmpv6.h>
25#endif
26
27#include <net/ip.h>
28#include <net/icmp.h>
29#include <net/route.h>
30
31#include <asm/vio.h>
32#include <asm/ldc.h>
33
34#include "sunvnet_common.h"
35
36/* Heuristic for the number of times to exponentially backoff and
37 * retry sending an LDC trigger when EAGAIN is encountered
38 */
39#define	VNET_MAX_RETRIES	10
40
41MODULE_AUTHOR("David S. Miller (davem@davemloft.net)");
42MODULE_DESCRIPTION("Sun LDOM virtual network support library");
43MODULE_LICENSE("GPL");
44MODULE_VERSION("1.1");
45
46static int __vnet_tx_trigger(struct vnet_port *port, u32 start);
47
48static inline u32 vnet_tx_dring_avail(struct vio_dring_state *dr)
49{
50	return vio_dring_avail(dr, VNET_TX_RING_SIZE);
51}
52
53static int vnet_handle_unknown(struct vnet_port *port, void *arg)
54{
55	struct vio_msg_tag *pkt = arg;
56
57	pr_err("Received unknown msg [%02x:%02x:%04x:%08x]\n",
58	       pkt->type, pkt->stype, pkt->stype_env, pkt->sid);
59	pr_err("Resetting connection\n");
60
61	ldc_disconnect(port->vio.lp);
62
63	return -ECONNRESET;
64}
65
66static int vnet_port_alloc_tx_ring(struct vnet_port *port);
67
68int sunvnet_send_attr_common(struct vio_driver_state *vio)
69{
70	struct vnet_port *port = to_vnet_port(vio);
71	struct net_device *dev = VNET_PORT_TO_NET_DEVICE(port);
72	struct vio_net_attr_info pkt;
73	int framelen = ETH_FRAME_LEN;
74	int i, err;
75
76	err = vnet_port_alloc_tx_ring(to_vnet_port(vio));
77	if (err)
78		return err;
79
80	memset(&pkt, 0, sizeof(pkt));
81	pkt.tag.type = VIO_TYPE_CTRL;
82	pkt.tag.stype = VIO_SUBTYPE_INFO;
83	pkt.tag.stype_env = VIO_ATTR_INFO;
84	pkt.tag.sid = vio_send_sid(vio);
85	if (vio_version_before(vio, 1, 2))
86		pkt.xfer_mode = VIO_DRING_MODE;
87	else
88		pkt.xfer_mode = VIO_NEW_DRING_MODE;
89	pkt.addr_type = VNET_ADDR_ETHERMAC;
90	pkt.ack_freq = 0;
91	for (i = 0; i < 6; i++)
92		pkt.addr |= (u64)dev->dev_addr[i] << ((5 - i) * 8);
93	if (vio_version_after(vio, 1, 3)) {
94		if (port->rmtu) {
95			port->rmtu = min(VNET_MAXPACKET, port->rmtu);
96			pkt.mtu = port->rmtu;
97		} else {
98			port->rmtu = VNET_MAXPACKET;
99			pkt.mtu = port->rmtu;
100		}
101		if (vio_version_after_eq(vio, 1, 6))
102			pkt.options = VIO_TX_DRING;
103	} else if (vio_version_before(vio, 1, 3)) {
104		pkt.mtu = framelen;
105	} else { /* v1.3 */
106		pkt.mtu = framelen + VLAN_HLEN;
107	}
108
109	pkt.cflags = 0;
110	if (vio_version_after_eq(vio, 1, 7) && port->tso) {
111		pkt.cflags |= VNET_LSO_IPV4_CAPAB;
112		if (!port->tsolen)
113			port->tsolen = VNET_MAXTSO;
114		pkt.ipv4_lso_maxlen = port->tsolen;
115	}
116
117	pkt.plnk_updt = PHYSLINK_UPDATE_NONE;
118
119	viodbg(HS, "SEND NET ATTR xmode[0x%x] atype[0x%x] addr[%llx] "
120	       "ackfreq[%u] plnk_updt[0x%02x] opts[0x%02x] mtu[%llu] "
121	       "cflags[0x%04x] lso_max[%u]\n",
122	       pkt.xfer_mode, pkt.addr_type,
123	       (unsigned long long)pkt.addr,
124	       pkt.ack_freq, pkt.plnk_updt, pkt.options,
125	       (unsigned long long)pkt.mtu, pkt.cflags, pkt.ipv4_lso_maxlen);
126
127	return vio_ldc_send(vio, &pkt, sizeof(pkt));
128}
129EXPORT_SYMBOL_GPL(sunvnet_send_attr_common);
130
131static int handle_attr_info(struct vio_driver_state *vio,
132			    struct vio_net_attr_info *pkt)
133{
134	struct vnet_port *port = to_vnet_port(vio);
135	u64	localmtu;
136	u8	xfer_mode;
137
138	viodbg(HS, "GOT NET ATTR xmode[0x%x] atype[0x%x] addr[%llx] "
139	       "ackfreq[%u] plnk_updt[0x%02x] opts[0x%02x] mtu[%llu] "
140	       " (rmtu[%llu]) cflags[0x%04x] lso_max[%u]\n",
141	       pkt->xfer_mode, pkt->addr_type,
142	       (unsigned long long)pkt->addr,
143	       pkt->ack_freq, pkt->plnk_updt, pkt->options,
144	       (unsigned long long)pkt->mtu, port->rmtu, pkt->cflags,
145	       pkt->ipv4_lso_maxlen);
146
147	pkt->tag.sid = vio_send_sid(vio);
148
149	xfer_mode = pkt->xfer_mode;
150	/* for version < 1.2, VIO_DRING_MODE = 0x3 and no bitmask */
151	if (vio_version_before(vio, 1, 2) && xfer_mode == VIO_DRING_MODE)
152		xfer_mode = VIO_NEW_DRING_MODE;
153
154	/* MTU negotiation:
155	 *	< v1.3 - ETH_FRAME_LEN exactly
156	 *	> v1.3 - MIN(pkt.mtu, VNET_MAXPACKET, port->rmtu) and change
157	 *			pkt->mtu for ACK
158	 *	= v1.3 - ETH_FRAME_LEN + VLAN_HLEN exactly
159	 */
160	if (vio_version_before(vio, 1, 3)) {
161		localmtu = ETH_FRAME_LEN;
162	} else if (vio_version_after(vio, 1, 3)) {
163		localmtu = port->rmtu ? port->rmtu : VNET_MAXPACKET;
164		localmtu = min(pkt->mtu, localmtu);
165		pkt->mtu = localmtu;
166	} else { /* v1.3 */
167		localmtu = ETH_FRAME_LEN + VLAN_HLEN;
168	}
169	port->rmtu = localmtu;
170
171	/* LSO negotiation */
172	if (vio_version_after_eq(vio, 1, 7))
173		port->tso &= !!(pkt->cflags & VNET_LSO_IPV4_CAPAB);
174	else
175		port->tso = false;
176	if (port->tso) {
177		if (!port->tsolen)
178			port->tsolen = VNET_MAXTSO;
179		port->tsolen = min(port->tsolen, pkt->ipv4_lso_maxlen);
180		if (port->tsolen < VNET_MINTSO) {
181			port->tso = false;
182			port->tsolen = 0;
183			pkt->cflags &= ~VNET_LSO_IPV4_CAPAB;
184		}
185		pkt->ipv4_lso_maxlen = port->tsolen;
186	} else {
187		pkt->cflags &= ~VNET_LSO_IPV4_CAPAB;
188		pkt->ipv4_lso_maxlen = 0;
189		port->tsolen = 0;
190	}
191
192	/* for version >= 1.6, ACK packet mode we support */
193	if (vio_version_after_eq(vio, 1, 6)) {
194		pkt->xfer_mode = VIO_NEW_DRING_MODE;
195		pkt->options = VIO_TX_DRING;
196	}
197
198	if (!(xfer_mode | VIO_NEW_DRING_MODE) ||
199	    pkt->addr_type != VNET_ADDR_ETHERMAC ||
200	    pkt->mtu != localmtu) {
201		viodbg(HS, "SEND NET ATTR NACK\n");
202
203		pkt->tag.stype = VIO_SUBTYPE_NACK;
204
205		(void)vio_ldc_send(vio, pkt, sizeof(*pkt));
206
207		return -ECONNRESET;
208	}
209
210	viodbg(HS, "SEND NET ATTR ACK xmode[0x%x] atype[0x%x] "
211	       "addr[%llx] ackfreq[%u] plnk_updt[0x%02x] opts[0x%02x] "
212	       "mtu[%llu] (rmtu[%llu]) cflags[0x%04x] lso_max[%u]\n",
213	       pkt->xfer_mode, pkt->addr_type,
214	       (unsigned long long)pkt->addr,
215	       pkt->ack_freq, pkt->plnk_updt, pkt->options,
216	       (unsigned long long)pkt->mtu, port->rmtu, pkt->cflags,
217	       pkt->ipv4_lso_maxlen);
218
219	pkt->tag.stype = VIO_SUBTYPE_ACK;
220
221	return vio_ldc_send(vio, pkt, sizeof(*pkt));
222}
223
224static int handle_attr_ack(struct vio_driver_state *vio,
225			   struct vio_net_attr_info *pkt)
226{
227	viodbg(HS, "GOT NET ATTR ACK\n");
228
229	return 0;
230}
231
232static int handle_attr_nack(struct vio_driver_state *vio,
233			    struct vio_net_attr_info *pkt)
234{
235	viodbg(HS, "GOT NET ATTR NACK\n");
236
237	return -ECONNRESET;
238}
239
240int sunvnet_handle_attr_common(struct vio_driver_state *vio, void *arg)
241{
242	struct vio_net_attr_info *pkt = arg;
243
244	switch (pkt->tag.stype) {
245	case VIO_SUBTYPE_INFO:
246		return handle_attr_info(vio, pkt);
247
248	case VIO_SUBTYPE_ACK:
249		return handle_attr_ack(vio, pkt);
250
251	case VIO_SUBTYPE_NACK:
252		return handle_attr_nack(vio, pkt);
253
254	default:
255		return -ECONNRESET;
256	}
257}
258EXPORT_SYMBOL_GPL(sunvnet_handle_attr_common);
259
260void sunvnet_handshake_complete_common(struct vio_driver_state *vio)
261{
262	struct vio_dring_state *dr;
263
264	dr = &vio->drings[VIO_DRIVER_RX_RING];
265	dr->rcv_nxt = 1;
266	dr->snd_nxt = 1;
267
268	dr = &vio->drings[VIO_DRIVER_TX_RING];
269	dr->rcv_nxt = 1;
270	dr->snd_nxt = 1;
271}
272EXPORT_SYMBOL_GPL(sunvnet_handshake_complete_common);
273
274/* The hypervisor interface that implements copying to/from imported
275 * memory from another domain requires that copies are done to 8-byte
276 * aligned buffers, and that the lengths of such copies are also 8-byte
277 * multiples.
278 *
279 * So we align skb->data to an 8-byte multiple and pad-out the data
280 * area so we can round the copy length up to the next multiple of
281 * 8 for the copy.
282 *
283 * The transmitter puts the actual start of the packet 6 bytes into
284 * the buffer it sends over, so that the IP headers after the ethernet
285 * header are aligned properly.  These 6 bytes are not in the descriptor
286 * length, they are simply implied.  This offset is represented using
287 * the VNET_PACKET_SKIP macro.
288 */
289static struct sk_buff *alloc_and_align_skb(struct net_device *dev,
290					   unsigned int len)
291{
292	struct sk_buff *skb;
293	unsigned long addr, off;
294
295	skb = netdev_alloc_skb(dev, len + VNET_PACKET_SKIP + 8 + 8);
296	if (unlikely(!skb))
297		return NULL;
298
299	addr = (unsigned long)skb->data;
300	off = ((addr + 7UL) & ~7UL) - addr;
301	if (off)
302		skb_reserve(skb, off);
303
304	return skb;
305}
306
307static inline void vnet_fullcsum_ipv4(struct sk_buff *skb)
308{
309	struct iphdr *iph = ip_hdr(skb);
310	int offset = skb_transport_offset(skb);
311
312	if (skb->protocol != htons(ETH_P_IP))
313		return;
314	if (iph->protocol != IPPROTO_TCP &&
315	    iph->protocol != IPPROTO_UDP)
316		return;
317	skb->ip_summed = CHECKSUM_NONE;
318	skb->csum_level = 1;
319	skb->csum = 0;
320	if (iph->protocol == IPPROTO_TCP) {
321		struct tcphdr *ptcp = tcp_hdr(skb);
322
323		ptcp->check = 0;
324		skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
325		ptcp->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
326						skb->len - offset, IPPROTO_TCP,
327						skb->csum);
328	} else if (iph->protocol == IPPROTO_UDP) {
329		struct udphdr *pudp = udp_hdr(skb);
330
331		pudp->check = 0;
332		skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
333		pudp->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
334						skb->len - offset, IPPROTO_UDP,
335						skb->csum);
336	}
337}
338
339#if IS_ENABLED(CONFIG_IPV6)
340static inline void vnet_fullcsum_ipv6(struct sk_buff *skb)
341{
342	struct ipv6hdr *ip6h = ipv6_hdr(skb);
343	int offset = skb_transport_offset(skb);
344
345	if (skb->protocol != htons(ETH_P_IPV6))
346		return;
347	if (ip6h->nexthdr != IPPROTO_TCP &&
348	    ip6h->nexthdr != IPPROTO_UDP)
349		return;
350	skb->ip_summed = CHECKSUM_NONE;
351	skb->csum_level = 1;
352	skb->csum = 0;
353	if (ip6h->nexthdr == IPPROTO_TCP) {
354		struct tcphdr *ptcp = tcp_hdr(skb);
355
356		ptcp->check = 0;
357		skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
358		ptcp->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
359					      skb->len - offset, IPPROTO_TCP,
360					      skb->csum);
361	} else if (ip6h->nexthdr == IPPROTO_UDP) {
362		struct udphdr *pudp = udp_hdr(skb);
363
364		pudp->check = 0;
365		skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
366		pudp->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
367					      skb->len - offset, IPPROTO_UDP,
368					      skb->csum);
369	}
370}
371#endif
372
373static int vnet_rx_one(struct vnet_port *port, struct vio_net_desc *desc)
374{
375	struct net_device *dev = VNET_PORT_TO_NET_DEVICE(port);
376	unsigned int len = desc->size;
377	unsigned int copy_len;
378	struct sk_buff *skb;
379	int maxlen;
380	int err;
381
382	err = -EMSGSIZE;
383	if (port->tso && port->tsolen > port->rmtu)
384		maxlen = port->tsolen;
385	else
386		maxlen = port->rmtu;
387	if (unlikely(len < ETH_ZLEN || len > maxlen)) {
388		dev->stats.rx_length_errors++;
389		goto out_dropped;
390	}
391
392	skb = alloc_and_align_skb(dev, len);
393	err = -ENOMEM;
394	if (unlikely(!skb)) {
395		dev->stats.rx_missed_errors++;
396		goto out_dropped;
397	}
398
399	copy_len = (len + VNET_PACKET_SKIP + 7U) & ~7U;
400	skb_put(skb, copy_len);
401	err = ldc_copy(port->vio.lp, LDC_COPY_IN,
402		       skb->data, copy_len, 0,
403		       desc->cookies, desc->ncookies);
404	if (unlikely(err < 0)) {
405		dev->stats.rx_frame_errors++;
406		goto out_free_skb;
407	}
408
409	skb_pull(skb, VNET_PACKET_SKIP);
410	skb_trim(skb, len);
411	skb->protocol = eth_type_trans(skb, dev);
412
413	if (vio_version_after_eq(&port->vio, 1, 8)) {
414		struct vio_net_dext *dext = vio_net_ext(desc);
415
416		skb_reset_network_header(skb);
417
418		if (dext->flags & VNET_PKT_HCK_IPV4_HDRCKSUM) {
419			if (skb->protocol == ETH_P_IP) {
420				struct iphdr *iph = ip_hdr(skb);
421
422				iph->check = 0;
423				ip_send_check(iph);
424			}
425		}
426		if ((dext->flags & VNET_PKT_HCK_FULLCKSUM) &&
427		    skb->ip_summed == CHECKSUM_NONE) {
428			if (skb->protocol == htons(ETH_P_IP)) {
429				struct iphdr *iph = ip_hdr(skb);
430				int ihl = iph->ihl * 4;
431
432				skb_set_transport_header(skb, ihl);
433				vnet_fullcsum_ipv4(skb);
434#if IS_ENABLED(CONFIG_IPV6)
435			} else if (skb->protocol == htons(ETH_P_IPV6)) {
436				skb_set_transport_header(skb,
437							 sizeof(struct ipv6hdr));
438				vnet_fullcsum_ipv6(skb);
439#endif
440			}
441		}
442		if (dext->flags & VNET_PKT_HCK_IPV4_HDRCKSUM_OK) {
443			skb->ip_summed = CHECKSUM_PARTIAL;
444			skb->csum_level = 0;
445			if (dext->flags & VNET_PKT_HCK_FULLCKSUM_OK)
446				skb->csum_level = 1;
447		}
448	}
449
450	skb->ip_summed = port->switch_port ? CHECKSUM_NONE : CHECKSUM_PARTIAL;
451
452	if (unlikely(is_multicast_ether_addr(eth_hdr(skb)->h_dest)))
453		dev->stats.multicast++;
454	dev->stats.rx_packets++;
455	dev->stats.rx_bytes += len;
456	port->stats.rx_packets++;
457	port->stats.rx_bytes += len;
458	napi_gro_receive(&port->napi, skb);
459	return 0;
460
461out_free_skb:
462	kfree_skb(skb);
463
464out_dropped:
465	dev->stats.rx_dropped++;
466	return err;
467}
468
469static int vnet_send_ack(struct vnet_port *port, struct vio_dring_state *dr,
470			 u32 start, u32 end, u8 vio_dring_state)
471{
472	struct vio_dring_data hdr = {
473		.tag = {
474			.type		= VIO_TYPE_DATA,
475			.stype		= VIO_SUBTYPE_ACK,
476			.stype_env	= VIO_DRING_DATA,
477			.sid		= vio_send_sid(&port->vio),
478		},
479		.dring_ident		= dr->ident,
480		.start_idx		= start,
481		.end_idx		= end,
482		.state			= vio_dring_state,
483	};
484	int err, delay;
485	int retries = 0;
486
487	hdr.seq = dr->snd_nxt;
488	delay = 1;
489	do {
490		err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
491		if (err > 0) {
492			dr->snd_nxt++;
493			break;
494		}
495		udelay(delay);
496		if ((delay <<= 1) > 128)
497			delay = 128;
498		if (retries++ > VNET_MAX_RETRIES) {
499			pr_info("ECONNRESET %x:%x:%x:%x:%x:%x\n",
500				port->raddr[0], port->raddr[1],
501				port->raddr[2], port->raddr[3],
502				port->raddr[4], port->raddr[5]);
503			break;
504		}
505	} while (err == -EAGAIN);
506
507	if (err <= 0 && vio_dring_state == VIO_DRING_STOPPED) {
508		port->stop_rx_idx = end;
509		port->stop_rx = true;
510	} else {
511		port->stop_rx_idx = 0;
512		port->stop_rx = false;
513	}
514
515	return err;
516}
517
518static struct vio_net_desc *get_rx_desc(struct vnet_port *port,
519					struct vio_dring_state *dr,
520					u32 index)
521{
522	struct vio_net_desc *desc = port->vio.desc_buf;
523	int err;
524
525	err = ldc_get_dring_entry(port->vio.lp, desc, dr->entry_size,
526				  (index * dr->entry_size),
527				  dr->cookies, dr->ncookies);
528	if (err < 0)
529		return ERR_PTR(err);
530
531	return desc;
532}
533
534static int put_rx_desc(struct vnet_port *port,
535		       struct vio_dring_state *dr,
536		       struct vio_net_desc *desc,
537		       u32 index)
538{
539	int err;
540
541	err = ldc_put_dring_entry(port->vio.lp, desc, dr->entry_size,
542				  (index * dr->entry_size),
543				  dr->cookies, dr->ncookies);
544	if (err < 0)
545		return err;
546
547	return 0;
548}
549
550static int vnet_walk_rx_one(struct vnet_port *port,
551			    struct vio_dring_state *dr,
552			    u32 index, int *needs_ack)
553{
554	struct vio_net_desc *desc = get_rx_desc(port, dr, index);
555	struct vio_driver_state *vio = &port->vio;
556	int err;
557
558	BUG_ON(!desc);
559	if (IS_ERR(desc))
560		return PTR_ERR(desc);
561
562	if (desc->hdr.state != VIO_DESC_READY)
563		return 1;
564
565	dma_rmb();
566
567	viodbg(DATA, "vio_walk_rx_one desc[%02x:%02x:%08x:%08x:%llx:%llx]\n",
568	       desc->hdr.state, desc->hdr.ack,
569	       desc->size, desc->ncookies,
570	       desc->cookies[0].cookie_addr,
571	       desc->cookies[0].cookie_size);
572
573	err = vnet_rx_one(port, desc);
574	if (err == -ECONNRESET)
575		return err;
576	trace_vnet_rx_one(port->vio._local_sid, port->vio._peer_sid,
577			  index, desc->hdr.ack);
578	desc->hdr.state = VIO_DESC_DONE;
579	err = put_rx_desc(port, dr, desc, index);
580	if (err < 0)
581		return err;
582	*needs_ack = desc->hdr.ack;
583	return 0;
584}
585
586static int vnet_walk_rx(struct vnet_port *port, struct vio_dring_state *dr,
587			u32 start, u32 end, int *npkts, int budget)
588{
589	struct vio_driver_state *vio = &port->vio;
590	int ack_start = -1, ack_end = -1;
591	bool send_ack = true;
592
593	end = (end == (u32)-1) ? vio_dring_prev(dr, start)
594			       : vio_dring_next(dr, end);
595
596	viodbg(DATA, "vnet_walk_rx start[%08x] end[%08x]\n", start, end);
597
598	while (start != end) {
599		int ack = 0, err = vnet_walk_rx_one(port, dr, start, &ack);
600
601		if (err == -ECONNRESET)
602			return err;
603		if (err != 0)
604			break;
605		(*npkts)++;
606		if (ack_start == -1)
607			ack_start = start;
608		ack_end = start;
609		start = vio_dring_next(dr, start);
610		if (ack && start != end) {
611			err = vnet_send_ack(port, dr, ack_start, ack_end,
612					    VIO_DRING_ACTIVE);
613			if (err == -ECONNRESET)
614				return err;
615			ack_start = -1;
616		}
617		if ((*npkts) >= budget) {
618			send_ack = false;
619			break;
620		}
621	}
622	if (unlikely(ack_start == -1)) {
623		ack_end = vio_dring_prev(dr, start);
624		ack_start = ack_end;
625	}
626	if (send_ack) {
627		port->napi_resume = false;
628		trace_vnet_tx_send_stopped_ack(port->vio._local_sid,
629					       port->vio._peer_sid,
630					       ack_end, *npkts);
631		return vnet_send_ack(port, dr, ack_start, ack_end,
632				     VIO_DRING_STOPPED);
633	} else  {
634		trace_vnet_tx_defer_stopped_ack(port->vio._local_sid,
635						port->vio._peer_sid,
636						ack_end, *npkts);
637		port->napi_resume = true;
638		port->napi_stop_idx = ack_end;
639		return 1;
640	}
641}
642
643static int vnet_rx(struct vnet_port *port, void *msgbuf, int *npkts,
644		   int budget)
645{
646	struct vio_dring_data *pkt = msgbuf;
647	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_RX_RING];
648	struct vio_driver_state *vio = &port->vio;
649
650	viodbg(DATA, "vnet_rx stype_env[%04x] seq[%016llx] rcv_nxt[%016llx]\n",
651	       pkt->tag.stype_env, pkt->seq, dr->rcv_nxt);
652
653	if (unlikely(pkt->tag.stype_env != VIO_DRING_DATA))
654		return 0;
655	if (unlikely(pkt->seq != dr->rcv_nxt)) {
656		pr_err("RX out of sequence seq[0x%llx] rcv_nxt[0x%llx]\n",
657		       pkt->seq, dr->rcv_nxt);
658		return 0;
659	}
660
661	if (!port->napi_resume)
662		dr->rcv_nxt++;
663
664	/* XXX Validate pkt->start_idx and pkt->end_idx XXX */
665
666	return vnet_walk_rx(port, dr, pkt->start_idx, pkt->end_idx,
667			    npkts, budget);
668}
669
670static int idx_is_pending(struct vio_dring_state *dr, u32 end)
671{
672	u32 idx = dr->cons;
673	int found = 0;
674
675	while (idx != dr->prod) {
676		if (idx == end) {
677			found = 1;
678			break;
679		}
680		idx = vio_dring_next(dr, idx);
681	}
682	return found;
683}
684
685static int vnet_ack(struct vnet_port *port, void *msgbuf)
686{
687	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
688	struct vio_dring_data *pkt = msgbuf;
689	struct net_device *dev;
690	u32 end;
691	struct vio_net_desc *desc;
692	struct netdev_queue *txq;
693
694	if (unlikely(pkt->tag.stype_env != VIO_DRING_DATA))
695		return 0;
696
697	end = pkt->end_idx;
698	dev = VNET_PORT_TO_NET_DEVICE(port);
699	netif_tx_lock(dev);
700	if (unlikely(!idx_is_pending(dr, end))) {
701		netif_tx_unlock(dev);
702		return 0;
703	}
704
705	/* sync for race conditions with vnet_start_xmit() and tell xmit it
706	 * is time to send a trigger.
707	 */
708	trace_vnet_rx_stopped_ack(port->vio._local_sid,
709				  port->vio._peer_sid, end);
710	dr->cons = vio_dring_next(dr, end);
711	desc = vio_dring_entry(dr, dr->cons);
712	if (desc->hdr.state == VIO_DESC_READY && !port->start_cons) {
713		/* vnet_start_xmit() just populated this dring but missed
714		 * sending the "start" LDC message to the consumer.
715		 * Send a "start" trigger on its behalf.
716		 */
717		if (__vnet_tx_trigger(port, dr->cons) > 0)
718			port->start_cons = false;
719		else
720			port->start_cons = true;
721	} else {
722		port->start_cons = true;
723	}
724	netif_tx_unlock(dev);
725
726	txq = netdev_get_tx_queue(dev, port->q_index);
727	if (unlikely(netif_tx_queue_stopped(txq) &&
728		     vnet_tx_dring_avail(dr) >= VNET_TX_WAKEUP_THRESH(dr)))
729		return 1;
730
731	return 0;
732}
733
734static int vnet_nack(struct vnet_port *port, void *msgbuf)
735{
736	/* XXX just reset or similar XXX */
737	return 0;
738}
739
740static int handle_mcast(struct vnet_port *port, void *msgbuf)
741{
742	struct vio_net_mcast_info *pkt = msgbuf;
743	struct net_device *dev = VNET_PORT_TO_NET_DEVICE(port);
744
745	if (pkt->tag.stype != VIO_SUBTYPE_ACK)
746		pr_err("%s: Got unexpected MCAST reply [%02x:%02x:%04x:%08x]\n",
747		       dev->name,
748		       pkt->tag.type,
749		       pkt->tag.stype,
750		       pkt->tag.stype_env,
751		       pkt->tag.sid);
752
753	return 0;
754}
755
756/* If the queue is stopped, wake it up so that we'll
757 * send out another START message at the next TX.
758 */
759static void maybe_tx_wakeup(struct vnet_port *port)
760{
761	struct netdev_queue *txq;
762
763	txq = netdev_get_tx_queue(VNET_PORT_TO_NET_DEVICE(port),
764				  port->q_index);
765	__netif_tx_lock(txq, smp_processor_id());
766	if (likely(netif_tx_queue_stopped(txq)))
767		netif_tx_wake_queue(txq);
768	__netif_tx_unlock(txq);
769}
770
771bool sunvnet_port_is_up_common(struct vnet_port *vnet)
772{
773	struct vio_driver_state *vio = &vnet->vio;
774
775	return !!(vio->hs_state & VIO_HS_COMPLETE);
776}
777EXPORT_SYMBOL_GPL(sunvnet_port_is_up_common);
778
779static int vnet_event_napi(struct vnet_port *port, int budget)
780{
781	struct net_device *dev = VNET_PORT_TO_NET_DEVICE(port);
782	struct vio_driver_state *vio = &port->vio;
783	int tx_wakeup, err;
784	int npkts = 0;
785
786	/* we don't expect any other bits */
787	BUG_ON(port->rx_event & ~(LDC_EVENT_DATA_READY |
788				  LDC_EVENT_RESET |
789				  LDC_EVENT_UP));
790
791	/* RESET takes precedent over any other event */
792	if (port->rx_event & LDC_EVENT_RESET) {
793		/* a link went down */
794
795		if (port->vsw == 1) {
796			netif_tx_stop_all_queues(dev);
797			netif_carrier_off(dev);
798		}
799
800		vio_link_state_change(vio, LDC_EVENT_RESET);
801		vnet_port_reset(port);
802		vio_port_up(vio);
803
804		/* If the device is running but its tx queue was
805		 * stopped (due to flow control), restart it.
806		 * This is necessary since vnet_port_reset()
807		 * clears the tx drings and thus we may never get
808		 * back a VIO_TYPE_DATA ACK packet - which is
809		 * the normal mechanism to restart the tx queue.
810		 */
811		if (netif_running(dev))
812			maybe_tx_wakeup(port);
813
814		port->rx_event = 0;
815		port->stats.event_reset++;
816		return 0;
817	}
818
819	if (port->rx_event & LDC_EVENT_UP) {
820		/* a link came up */
821
822		if (port->vsw == 1) {
823			netif_carrier_on(port->dev);
824			netif_tx_start_all_queues(port->dev);
825		}
826
827		vio_link_state_change(vio, LDC_EVENT_UP);
828		port->rx_event = 0;
829		port->stats.event_up++;
830		return 0;
831	}
832
833	err = 0;
834	tx_wakeup = 0;
835	while (1) {
836		union {
837			struct vio_msg_tag tag;
838			u64 raw[8];
839		} msgbuf;
840
841		if (port->napi_resume) {
842			struct vio_dring_data *pkt =
843				(struct vio_dring_data *)&msgbuf;
844			struct vio_dring_state *dr =
845				&port->vio.drings[VIO_DRIVER_RX_RING];
846
847			pkt->tag.type = VIO_TYPE_DATA;
848			pkt->tag.stype = VIO_SUBTYPE_INFO;
849			pkt->tag.stype_env = VIO_DRING_DATA;
850			pkt->seq = dr->rcv_nxt;
851			pkt->start_idx = vio_dring_next(dr,
852							port->napi_stop_idx);
853			pkt->end_idx = -1;
854		} else {
855			err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf));
856			if (unlikely(err < 0)) {
857				if (err == -ECONNRESET)
858					vio_conn_reset(vio);
859				break;
860			}
861			if (err == 0)
862				break;
863			viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n",
864			       msgbuf.tag.type,
865			       msgbuf.tag.stype,
866			       msgbuf.tag.stype_env,
867			       msgbuf.tag.sid);
868			err = vio_validate_sid(vio, &msgbuf.tag);
869			if (err < 0)
870				break;
871		}
872
873		if (likely(msgbuf.tag.type == VIO_TYPE_DATA)) {
874			if (msgbuf.tag.stype == VIO_SUBTYPE_INFO) {
875				if (!sunvnet_port_is_up_common(port)) {
876					/* failures like handshake_failure()
877					 * may have cleaned up dring, but
878					 * NAPI polling may bring us here.
879					 */
880					err = -ECONNRESET;
881					break;
882				}
883				err = vnet_rx(port, &msgbuf, &npkts, budget);
884				if (npkts >= budget)
885					break;
886				if (npkts == 0)
887					break;
888			} else if (msgbuf.tag.stype == VIO_SUBTYPE_ACK) {
889				err = vnet_ack(port, &msgbuf);
890				if (err > 0)
891					tx_wakeup |= err;
892			} else if (msgbuf.tag.stype == VIO_SUBTYPE_NACK) {
893				err = vnet_nack(port, &msgbuf);
894			}
895		} else if (msgbuf.tag.type == VIO_TYPE_CTRL) {
896			if (msgbuf.tag.stype_env == VNET_MCAST_INFO)
897				err = handle_mcast(port, &msgbuf);
898			else
899				err = vio_control_pkt_engine(vio, &msgbuf);
900			if (err)
901				break;
902		} else {
903			err = vnet_handle_unknown(port, &msgbuf);
904		}
905		if (err == -ECONNRESET)
906			break;
907	}
908	if (unlikely(tx_wakeup && err != -ECONNRESET))
909		maybe_tx_wakeup(port);
910	return npkts;
911}
912
913int sunvnet_poll_common(struct napi_struct *napi, int budget)
914{
915	struct vnet_port *port = container_of(napi, struct vnet_port, napi);
916	struct vio_driver_state *vio = &port->vio;
917	int processed = vnet_event_napi(port, budget);
918
919	if (processed < budget) {
920		napi_complete_done(napi, processed);
921		port->rx_event &= ~LDC_EVENT_DATA_READY;
922		vio_set_intr(vio->vdev->rx_ino, HV_INTR_ENABLED);
923	}
924	return processed;
925}
926EXPORT_SYMBOL_GPL(sunvnet_poll_common);
927
928void sunvnet_event_common(void *arg, int event)
929{
930	struct vnet_port *port = arg;
931	struct vio_driver_state *vio = &port->vio;
932
933	port->rx_event |= event;
934	vio_set_intr(vio->vdev->rx_ino, HV_INTR_DISABLED);
935	napi_schedule(&port->napi);
936}
937EXPORT_SYMBOL_GPL(sunvnet_event_common);
938
939static int __vnet_tx_trigger(struct vnet_port *port, u32 start)
940{
941	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
942	struct vio_dring_data hdr = {
943		.tag = {
944			.type		= VIO_TYPE_DATA,
945			.stype		= VIO_SUBTYPE_INFO,
946			.stype_env	= VIO_DRING_DATA,
947			.sid		= vio_send_sid(&port->vio),
948		},
949		.dring_ident		= dr->ident,
950		.start_idx		= start,
951		.end_idx		= (u32)-1,
952	};
953	int err, delay;
954	int retries = 0;
955
956	if (port->stop_rx) {
957		trace_vnet_tx_pending_stopped_ack(port->vio._local_sid,
958						  port->vio._peer_sid,
959						  port->stop_rx_idx, -1);
960		err = vnet_send_ack(port,
961				    &port->vio.drings[VIO_DRIVER_RX_RING],
962				    port->stop_rx_idx, -1,
963				    VIO_DRING_STOPPED);
964		if (err <= 0)
965			return err;
966	}
967
968	hdr.seq = dr->snd_nxt;
969	delay = 1;
970	do {
971		err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
972		if (err > 0) {
973			dr->snd_nxt++;
974			break;
975		}
976		udelay(delay);
977		if ((delay <<= 1) > 128)
978			delay = 128;
979		if (retries++ > VNET_MAX_RETRIES)
980			break;
981	} while (err == -EAGAIN);
982	trace_vnet_tx_trigger(port->vio._local_sid,
983			      port->vio._peer_sid, start, err);
984
985	return err;
986}
987
988static struct sk_buff *vnet_clean_tx_ring(struct vnet_port *port,
989					  unsigned *pending)
990{
991	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
992	struct sk_buff *skb = NULL;
993	int i, txi;
994
995	*pending = 0;
996
997	txi = dr->prod;
998	for (i = 0; i < VNET_TX_RING_SIZE; ++i) {
999		struct vio_net_desc *d;
1000
1001		--txi;
1002		if (txi < 0)
1003			txi = VNET_TX_RING_SIZE - 1;
1004
1005		d = vio_dring_entry(dr, txi);
1006
1007		if (d->hdr.state == VIO_DESC_READY) {
1008			(*pending)++;
1009			continue;
1010		}
1011		if (port->tx_bufs[txi].skb) {
1012			if (d->hdr.state != VIO_DESC_DONE)
1013				pr_notice("invalid ring buffer state %d\n",
1014					  d->hdr.state);
1015			BUG_ON(port->tx_bufs[txi].skb->next);
1016
1017			port->tx_bufs[txi].skb->next = skb;
1018			skb = port->tx_bufs[txi].skb;
1019			port->tx_bufs[txi].skb = NULL;
1020
1021			ldc_unmap(port->vio.lp,
1022				  port->tx_bufs[txi].cookies,
1023				  port->tx_bufs[txi].ncookies);
1024		} else if (d->hdr.state == VIO_DESC_FREE) {
1025			break;
1026		}
1027		d->hdr.state = VIO_DESC_FREE;
1028	}
1029	return skb;
1030}
1031
1032static inline void vnet_free_skbs(struct sk_buff *skb)
1033{
1034	struct sk_buff *next;
1035
1036	while (skb) {
1037		next = skb->next;
1038		skb->next = NULL;
1039		dev_kfree_skb(skb);
1040		skb = next;
1041	}
1042}
1043
1044void sunvnet_clean_timer_expire_common(struct timer_list *t)
1045{
1046	struct vnet_port *port = from_timer(port, t, clean_timer);
1047	struct sk_buff *freeskbs;
1048	unsigned pending;
1049
1050	netif_tx_lock(VNET_PORT_TO_NET_DEVICE(port));
1051	freeskbs = vnet_clean_tx_ring(port, &pending);
1052	netif_tx_unlock(VNET_PORT_TO_NET_DEVICE(port));
1053
1054	vnet_free_skbs(freeskbs);
1055
1056	if (pending)
1057		(void)mod_timer(&port->clean_timer,
1058				jiffies + VNET_CLEAN_TIMEOUT);
1059	 else
1060		del_timer(&port->clean_timer);
1061}
1062EXPORT_SYMBOL_GPL(sunvnet_clean_timer_expire_common);
1063
1064static inline int vnet_skb_map(struct ldc_channel *lp, struct sk_buff *skb,
1065			       struct ldc_trans_cookie *cookies, int ncookies,
1066			       unsigned int map_perm)
1067{
1068	int i, nc, err, blen;
1069
1070	/* header */
1071	blen = skb_headlen(skb);
1072	if (blen < ETH_ZLEN)
1073		blen = ETH_ZLEN;
1074	blen += VNET_PACKET_SKIP;
1075	blen += 8 - (blen & 7);
1076
1077	err = ldc_map_single(lp, skb->data - VNET_PACKET_SKIP, blen, cookies,
1078			     ncookies, map_perm);
1079	if (err < 0)
1080		return err;
1081	nc = err;
1082
1083	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1084		skb_frag_t *f = &skb_shinfo(skb)->frags[i];
1085		u8 *vaddr;
1086
1087		if (nc < ncookies) {
1088			vaddr = kmap_atomic(skb_frag_page(f));
1089			blen = skb_frag_size(f);
1090			blen += 8 - (blen & 7);
1091			err = ldc_map_single(lp, vaddr + skb_frag_off(f),
1092					     blen, cookies + nc, ncookies - nc,
1093					     map_perm);
1094			kunmap_atomic(vaddr);
1095		} else {
1096			err = -EMSGSIZE;
1097		}
1098
1099		if (err < 0) {
1100			ldc_unmap(lp, cookies, nc);
1101			return err;
1102		}
1103		nc += err;
1104	}
1105	return nc;
1106}
1107
1108static inline struct sk_buff *vnet_skb_shape(struct sk_buff *skb, int ncookies)
1109{
1110	struct sk_buff *nskb;
1111	int i, len, pad, docopy;
1112
1113	len = skb->len;
1114	pad = 0;
1115	if (len < ETH_ZLEN) {
1116		pad += ETH_ZLEN - skb->len;
1117		len += pad;
1118	}
1119	len += VNET_PACKET_SKIP;
1120	pad += 8 - (len & 7);
1121
1122	/* make sure we have enough cookies and alignment in every frag */
1123	docopy = skb_shinfo(skb)->nr_frags >= ncookies;
1124	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1125		skb_frag_t *f = &skb_shinfo(skb)->frags[i];
1126
1127		docopy |= skb_frag_off(f) & 7;
1128	}
1129	if (((unsigned long)skb->data & 7) != VNET_PACKET_SKIP ||
1130	    skb_tailroom(skb) < pad ||
1131	    skb_headroom(skb) < VNET_PACKET_SKIP || docopy) {
1132		int start = 0, offset;
1133		__wsum csum;
1134
1135		len = skb->len > ETH_ZLEN ? skb->len : ETH_ZLEN;
1136		nskb = alloc_and_align_skb(skb->dev, len);
1137		if (!nskb) {
1138			dev_kfree_skb(skb);
1139			return NULL;
1140		}
1141		skb_reserve(nskb, VNET_PACKET_SKIP);
1142
1143		nskb->protocol = skb->protocol;
1144		offset = skb_mac_header(skb) - skb->data;
1145		skb_set_mac_header(nskb, offset);
1146		offset = skb_network_header(skb) - skb->data;
1147		skb_set_network_header(nskb, offset);
1148		offset = skb_transport_header(skb) - skb->data;
1149		skb_set_transport_header(nskb, offset);
1150
1151		offset = 0;
1152		nskb->csum_offset = skb->csum_offset;
1153		nskb->ip_summed = skb->ip_summed;
1154
1155		if (skb->ip_summed == CHECKSUM_PARTIAL)
1156			start = skb_checksum_start_offset(skb);
1157		if (start) {
1158			int offset = start + nskb->csum_offset;
1159
1160			/* copy the headers, no csum here */
1161			if (skb_copy_bits(skb, 0, nskb->data, start)) {
1162				dev_kfree_skb(nskb);
1163				dev_kfree_skb(skb);
1164				return NULL;
1165			}
1166
1167			/* copy the rest, with csum calculation */
1168			*(__sum16 *)(skb->data + offset) = 0;
1169			csum = skb_copy_and_csum_bits(skb, start,
1170						      nskb->data + start,
1171						      skb->len - start);
1172
1173			/* add in the header checksums */
1174			if (skb->protocol == htons(ETH_P_IP)) {
1175				struct iphdr *iph = ip_hdr(nskb);
1176
1177				if (iph->protocol == IPPROTO_TCP ||
1178				    iph->protocol == IPPROTO_UDP) {
1179					csum = csum_tcpudp_magic(iph->saddr,
1180								 iph->daddr,
1181								 skb->len - start,
1182								 iph->protocol,
1183								 csum);
1184				}
1185			} else if (skb->protocol == htons(ETH_P_IPV6)) {
1186				struct ipv6hdr *ip6h = ipv6_hdr(nskb);
1187
1188				if (ip6h->nexthdr == IPPROTO_TCP ||
1189				    ip6h->nexthdr == IPPROTO_UDP) {
1190					csum = csum_ipv6_magic(&ip6h->saddr,
1191							       &ip6h->daddr,
1192							       skb->len - start,
1193							       ip6h->nexthdr,
1194							       csum);
1195				}
1196			}
1197
1198			/* save the final result */
1199			*(__sum16 *)(nskb->data + offset) = csum;
1200
1201			nskb->ip_summed = CHECKSUM_NONE;
1202		} else if (skb_copy_bits(skb, 0, nskb->data, skb->len)) {
1203			dev_kfree_skb(nskb);
1204			dev_kfree_skb(skb);
1205			return NULL;
1206		}
1207		(void)skb_put(nskb, skb->len);
1208		if (skb_is_gso(skb)) {
1209			skb_shinfo(nskb)->gso_size = skb_shinfo(skb)->gso_size;
1210			skb_shinfo(nskb)->gso_type = skb_shinfo(skb)->gso_type;
1211		}
1212		nskb->queue_mapping = skb->queue_mapping;
1213		dev_kfree_skb(skb);
1214		skb = nskb;
1215	}
1216	return skb;
1217}
1218
1219static netdev_tx_t
1220vnet_handle_offloads(struct vnet_port *port, struct sk_buff *skb,
1221		     struct vnet_port *(*vnet_tx_port)
1222		     (struct sk_buff *, struct net_device *))
1223{
1224	struct net_device *dev = VNET_PORT_TO_NET_DEVICE(port);
1225	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
1226	struct sk_buff *segs, *curr, *next;
1227	int maclen, datalen;
1228	int status;
1229	int gso_size, gso_type, gso_segs;
1230	int hlen = skb_transport_header(skb) - skb_mac_header(skb);
1231	int proto = IPPROTO_IP;
1232
1233	if (skb->protocol == htons(ETH_P_IP))
1234		proto = ip_hdr(skb)->protocol;
1235	else if (skb->protocol == htons(ETH_P_IPV6))
1236		proto = ipv6_hdr(skb)->nexthdr;
1237
1238	if (proto == IPPROTO_TCP) {
1239		hlen += tcp_hdr(skb)->doff * 4;
1240	} else if (proto == IPPROTO_UDP) {
1241		hlen += sizeof(struct udphdr);
1242	} else {
1243		pr_err("vnet_handle_offloads GSO with unknown transport "
1244		       "protocol %d tproto %d\n", skb->protocol, proto);
1245		hlen = 128; /* XXX */
1246	}
1247	datalen = port->tsolen - hlen;
1248
1249	gso_size = skb_shinfo(skb)->gso_size;
1250	gso_type = skb_shinfo(skb)->gso_type;
1251	gso_segs = skb_shinfo(skb)->gso_segs;
1252
1253	if (port->tso && gso_size < datalen)
1254		gso_segs = DIV_ROUND_UP(skb->len - hlen, datalen);
1255
1256	if (unlikely(vnet_tx_dring_avail(dr) < gso_segs)) {
1257		struct netdev_queue *txq;
1258
1259		txq  = netdev_get_tx_queue(dev, port->q_index);
1260		netif_tx_stop_queue(txq);
1261		if (vnet_tx_dring_avail(dr) < skb_shinfo(skb)->gso_segs)
1262			return NETDEV_TX_BUSY;
1263		netif_tx_wake_queue(txq);
1264	}
1265
1266	maclen = skb_network_header(skb) - skb_mac_header(skb);
1267	skb_pull(skb, maclen);
1268
1269	if (port->tso && gso_size < datalen) {
1270		if (skb_unclone(skb, GFP_ATOMIC))
1271			goto out_dropped;
1272
1273		/* segment to TSO size */
1274		skb_shinfo(skb)->gso_size = datalen;
1275		skb_shinfo(skb)->gso_segs = gso_segs;
1276	}
1277	segs = skb_gso_segment(skb, dev->features & ~NETIF_F_TSO);
1278	if (IS_ERR(segs))
1279		goto out_dropped;
1280
1281	skb_push(skb, maclen);
1282	skb_reset_mac_header(skb);
1283
1284	status = 0;
1285	skb_list_walk_safe(segs, curr, next) {
1286		skb_mark_not_on_list(curr);
1287		if (port->tso && curr->len > dev->mtu) {
1288			skb_shinfo(curr)->gso_size = gso_size;
1289			skb_shinfo(curr)->gso_type = gso_type;
1290			skb_shinfo(curr)->gso_segs =
1291				DIV_ROUND_UP(curr->len - hlen, gso_size);
1292		} else {
1293			skb_shinfo(curr)->gso_size = 0;
1294		}
1295
1296		skb_push(curr, maclen);
1297		skb_reset_mac_header(curr);
1298		memcpy(skb_mac_header(curr), skb_mac_header(skb),
1299		       maclen);
1300		curr->csum_start = skb_transport_header(curr) - curr->head;
1301		if (ip_hdr(curr)->protocol == IPPROTO_TCP)
1302			curr->csum_offset = offsetof(struct tcphdr, check);
1303		else if (ip_hdr(curr)->protocol == IPPROTO_UDP)
1304			curr->csum_offset = offsetof(struct udphdr, check);
1305
1306		if (!(status & NETDEV_TX_MASK))
1307			status = sunvnet_start_xmit_common(curr, dev,
1308							   vnet_tx_port);
1309		if (status & NETDEV_TX_MASK)
1310			dev_kfree_skb_any(curr);
1311	}
1312
1313	if (!(status & NETDEV_TX_MASK))
1314		dev_kfree_skb_any(skb);
1315	return status;
1316out_dropped:
1317	dev->stats.tx_dropped++;
1318	dev_kfree_skb_any(skb);
1319	return NETDEV_TX_OK;
1320}
1321
1322netdev_tx_t
1323sunvnet_start_xmit_common(struct sk_buff *skb, struct net_device *dev,
1324			  struct vnet_port *(*vnet_tx_port)
1325			  (struct sk_buff *, struct net_device *))
1326{
1327	struct vnet_port *port = NULL;
1328	struct vio_dring_state *dr;
1329	struct vio_net_desc *d;
1330	unsigned int len;
1331	struct sk_buff *freeskbs = NULL;
1332	int i, err, txi;
1333	unsigned pending = 0;
1334	struct netdev_queue *txq;
1335
1336	rcu_read_lock();
1337	port = vnet_tx_port(skb, dev);
1338	if (unlikely(!port))
1339		goto out_dropped;
1340
1341	if (skb_is_gso(skb) && skb->len > port->tsolen) {
1342		err = vnet_handle_offloads(port, skb, vnet_tx_port);
1343		rcu_read_unlock();
1344		return err;
1345	}
1346
1347	if (!skb_is_gso(skb) && skb->len > port->rmtu) {
1348		unsigned long localmtu = port->rmtu - ETH_HLEN;
1349
1350		if (vio_version_after_eq(&port->vio, 1, 3))
1351			localmtu -= VLAN_HLEN;
1352
1353		if (skb->protocol == htons(ETH_P_IP))
1354			icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
1355				      htonl(localmtu));
1356#if IS_ENABLED(CONFIG_IPV6)
1357		else if (skb->protocol == htons(ETH_P_IPV6))
1358			icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, localmtu);
1359#endif
1360		goto out_dropped;
1361	}
1362
1363	skb = vnet_skb_shape(skb, 2);
1364
1365	if (unlikely(!skb))
1366		goto out_dropped;
1367
1368	if (skb->ip_summed == CHECKSUM_PARTIAL) {
1369		if (skb->protocol == htons(ETH_P_IP))
1370			vnet_fullcsum_ipv4(skb);
1371#if IS_ENABLED(CONFIG_IPV6)
1372		else if (skb->protocol == htons(ETH_P_IPV6))
1373			vnet_fullcsum_ipv6(skb);
1374#endif
1375	}
1376
1377	dr = &port->vio.drings[VIO_DRIVER_TX_RING];
1378	i = skb_get_queue_mapping(skb);
1379	txq = netdev_get_tx_queue(dev, i);
1380	if (unlikely(vnet_tx_dring_avail(dr) < 1)) {
1381		if (!netif_tx_queue_stopped(txq)) {
1382			netif_tx_stop_queue(txq);
1383
1384			/* This is a hard error, log it. */
1385			netdev_err(dev, "BUG! Tx Ring full when queue awake!\n");
1386			dev->stats.tx_errors++;
1387		}
1388		rcu_read_unlock();
1389		return NETDEV_TX_BUSY;
1390	}
1391
1392	d = vio_dring_cur(dr);
1393
1394	txi = dr->prod;
1395
1396	freeskbs = vnet_clean_tx_ring(port, &pending);
1397
1398	BUG_ON(port->tx_bufs[txi].skb);
1399
1400	len = skb->len;
1401	if (len < ETH_ZLEN)
1402		len = ETH_ZLEN;
1403
1404	err = vnet_skb_map(port->vio.lp, skb, port->tx_bufs[txi].cookies, 2,
1405			   (LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_RW));
1406	if (err < 0) {
1407		netdev_info(dev, "tx buffer map error %d\n", err);
1408		goto out_dropped;
1409	}
1410
1411	port->tx_bufs[txi].skb = skb;
1412	skb = NULL;
1413	port->tx_bufs[txi].ncookies = err;
1414
1415	/* We don't rely on the ACKs to free the skb in vnet_start_xmit(),
1416	 * thus it is safe to not set VIO_ACK_ENABLE for each transmission:
1417	 * the protocol itself does not require it as long as the peer
1418	 * sends a VIO_SUBTYPE_ACK for VIO_DRING_STOPPED.
1419	 *
1420	 * An ACK for every packet in the ring is expensive as the
1421	 * sending of LDC messages is slow and affects performance.
1422	 */
1423	d->hdr.ack = VIO_ACK_DISABLE;
1424	d->size = len;
1425	d->ncookies = port->tx_bufs[txi].ncookies;
1426	for (i = 0; i < d->ncookies; i++)
1427		d->cookies[i] = port->tx_bufs[txi].cookies[i];
1428	if (vio_version_after_eq(&port->vio, 1, 7)) {
1429		struct vio_net_dext *dext = vio_net_ext(d);
1430
1431		memset(dext, 0, sizeof(*dext));
1432		if (skb_is_gso(port->tx_bufs[txi].skb)) {
1433			dext->ipv4_lso_mss = skb_shinfo(port->tx_bufs[txi].skb)
1434					     ->gso_size;
1435			dext->flags |= VNET_PKT_IPV4_LSO;
1436		}
1437		if (vio_version_after_eq(&port->vio, 1, 8) &&
1438		    !port->switch_port) {
1439			dext->flags |= VNET_PKT_HCK_IPV4_HDRCKSUM_OK;
1440			dext->flags |= VNET_PKT_HCK_FULLCKSUM_OK;
1441		}
1442	}
1443
1444	/* This has to be a non-SMP write barrier because we are writing
1445	 * to memory which is shared with the peer LDOM.
1446	 */
1447	dma_wmb();
1448
1449	d->hdr.state = VIO_DESC_READY;
1450
1451	/* Exactly one ldc "start" trigger (for dr->cons) needs to be sent
1452	 * to notify the consumer that some descriptors are READY.
1453	 * After that "start" trigger, no additional triggers are needed until
1454	 * a DRING_STOPPED is received from the consumer. The dr->cons field
1455	 * (set up by vnet_ack()) has the value of the next dring index
1456	 * that has not yet been ack-ed. We send a "start" trigger here
1457	 * if, and only if, start_cons is true (reset it afterward). Conversely,
1458	 * vnet_ack() should check if the dring corresponding to cons
1459	 * is marked READY, but start_cons was false.
1460	 * If so, vnet_ack() should send out the missed "start" trigger.
1461	 *
1462	 * Note that the dma_wmb() above makes sure the cookies et al. are
1463	 * not globally visible before the VIO_DESC_READY, and that the
1464	 * stores are ordered correctly by the compiler. The consumer will
1465	 * not proceed until the VIO_DESC_READY is visible assuring that
1466	 * the consumer does not observe anything related to descriptors
1467	 * out of order. The HV trap from the LDC start trigger is the
1468	 * producer to consumer announcement that work is available to the
1469	 * consumer
1470	 */
1471	if (!port->start_cons) { /* previous trigger suffices */
1472		trace_vnet_skip_tx_trigger(port->vio._local_sid,
1473					   port->vio._peer_sid, dr->cons);
1474		goto ldc_start_done;
1475	}
1476
1477	err = __vnet_tx_trigger(port, dr->cons);
1478	if (unlikely(err < 0)) {
1479		netdev_info(dev, "TX trigger error %d\n", err);
1480		d->hdr.state = VIO_DESC_FREE;
1481		skb = port->tx_bufs[txi].skb;
1482		port->tx_bufs[txi].skb = NULL;
1483		dev->stats.tx_carrier_errors++;
1484		goto out_dropped;
1485	}
1486
1487ldc_start_done:
1488	port->start_cons = false;
1489
1490	dev->stats.tx_packets++;
1491	dev->stats.tx_bytes += port->tx_bufs[txi].skb->len;
1492	port->stats.tx_packets++;
1493	port->stats.tx_bytes += port->tx_bufs[txi].skb->len;
1494
1495	dr->prod = (dr->prod + 1) & (VNET_TX_RING_SIZE - 1);
1496	if (unlikely(vnet_tx_dring_avail(dr) < 1)) {
1497		netif_tx_stop_queue(txq);
1498		smp_rmb();
1499		if (vnet_tx_dring_avail(dr) > VNET_TX_WAKEUP_THRESH(dr))
1500			netif_tx_wake_queue(txq);
1501	}
1502
1503	(void)mod_timer(&port->clean_timer, jiffies + VNET_CLEAN_TIMEOUT);
1504	rcu_read_unlock();
1505
1506	vnet_free_skbs(freeskbs);
1507
1508	return NETDEV_TX_OK;
1509
1510out_dropped:
1511	if (pending)
1512		(void)mod_timer(&port->clean_timer,
1513				jiffies + VNET_CLEAN_TIMEOUT);
1514	else if (port)
1515		del_timer(&port->clean_timer);
1516	rcu_read_unlock();
1517	dev_kfree_skb(skb);
1518	vnet_free_skbs(freeskbs);
1519	dev->stats.tx_dropped++;
1520	return NETDEV_TX_OK;
1521}
1522EXPORT_SYMBOL_GPL(sunvnet_start_xmit_common);
1523
1524void sunvnet_tx_timeout_common(struct net_device *dev, unsigned int txqueue)
1525{
1526	/* XXX Implement me XXX */
1527}
1528EXPORT_SYMBOL_GPL(sunvnet_tx_timeout_common);
1529
1530int sunvnet_open_common(struct net_device *dev)
1531{
1532	netif_carrier_on(dev);
1533	netif_tx_start_all_queues(dev);
1534
1535	return 0;
1536}
1537EXPORT_SYMBOL_GPL(sunvnet_open_common);
1538
1539int sunvnet_close_common(struct net_device *dev)
1540{
1541	netif_tx_stop_all_queues(dev);
1542	netif_carrier_off(dev);
1543
1544	return 0;
1545}
1546EXPORT_SYMBOL_GPL(sunvnet_close_common);
1547
1548static struct vnet_mcast_entry *__vnet_mc_find(struct vnet *vp, u8 *addr)
1549{
1550	struct vnet_mcast_entry *m;
1551
1552	for (m = vp->mcast_list; m; m = m->next) {
1553		if (ether_addr_equal(m->addr, addr))
1554			return m;
1555	}
1556	return NULL;
1557}
1558
1559static void __update_mc_list(struct vnet *vp, struct net_device *dev)
1560{
1561	struct netdev_hw_addr *ha;
1562
1563	netdev_for_each_mc_addr(ha, dev) {
1564		struct vnet_mcast_entry *m;
1565
1566		m = __vnet_mc_find(vp, ha->addr);
1567		if (m) {
1568			m->hit = 1;
1569			continue;
1570		}
1571
1572		if (!m) {
1573			m = kzalloc(sizeof(*m), GFP_ATOMIC);
1574			if (!m)
1575				continue;
1576			memcpy(m->addr, ha->addr, ETH_ALEN);
1577			m->hit = 1;
1578
1579			m->next = vp->mcast_list;
1580			vp->mcast_list = m;
1581		}
1582	}
1583}
1584
1585static void __send_mc_list(struct vnet *vp, struct vnet_port *port)
1586{
1587	struct vio_net_mcast_info info;
1588	struct vnet_mcast_entry *m, **pp;
1589	int n_addrs;
1590
1591	memset(&info, 0, sizeof(info));
1592
1593	info.tag.type = VIO_TYPE_CTRL;
1594	info.tag.stype = VIO_SUBTYPE_INFO;
1595	info.tag.stype_env = VNET_MCAST_INFO;
1596	info.tag.sid = vio_send_sid(&port->vio);
1597	info.set = 1;
1598
1599	n_addrs = 0;
1600	for (m = vp->mcast_list; m; m = m->next) {
1601		if (m->sent)
1602			continue;
1603		m->sent = 1;
1604		memcpy(&info.mcast_addr[n_addrs * ETH_ALEN],
1605		       m->addr, ETH_ALEN);
1606		if (++n_addrs == VNET_NUM_MCAST) {
1607			info.count = n_addrs;
1608
1609			(void)vio_ldc_send(&port->vio, &info,
1610					   sizeof(info));
1611			n_addrs = 0;
1612		}
1613	}
1614	if (n_addrs) {
1615		info.count = n_addrs;
1616		(void)vio_ldc_send(&port->vio, &info, sizeof(info));
1617	}
1618
1619	info.set = 0;
1620
1621	n_addrs = 0;
1622	pp = &vp->mcast_list;
1623	while ((m = *pp) != NULL) {
1624		if (m->hit) {
1625			m->hit = 0;
1626			pp = &m->next;
1627			continue;
1628		}
1629
1630		memcpy(&info.mcast_addr[n_addrs * ETH_ALEN],
1631		       m->addr, ETH_ALEN);
1632		if (++n_addrs == VNET_NUM_MCAST) {
1633			info.count = n_addrs;
1634			(void)vio_ldc_send(&port->vio, &info,
1635					   sizeof(info));
1636			n_addrs = 0;
1637		}
1638
1639		*pp = m->next;
1640		kfree(m);
1641	}
1642	if (n_addrs) {
1643		info.count = n_addrs;
1644		(void)vio_ldc_send(&port->vio, &info, sizeof(info));
1645	}
1646}
1647
1648void sunvnet_set_rx_mode_common(struct net_device *dev, struct vnet *vp)
1649{
1650	struct vnet_port *port;
1651
1652	rcu_read_lock();
1653	list_for_each_entry_rcu(port, &vp->port_list, list) {
1654		if (port->switch_port) {
1655			__update_mc_list(vp, dev);
1656			__send_mc_list(vp, port);
1657			break;
1658		}
1659	}
1660	rcu_read_unlock();
1661}
1662EXPORT_SYMBOL_GPL(sunvnet_set_rx_mode_common);
1663
1664int sunvnet_set_mac_addr_common(struct net_device *dev, void *p)
1665{
1666	return -EINVAL;
1667}
1668EXPORT_SYMBOL_GPL(sunvnet_set_mac_addr_common);
1669
1670void sunvnet_port_free_tx_bufs_common(struct vnet_port *port)
1671{
1672	struct vio_dring_state *dr;
1673	int i;
1674
1675	dr = &port->vio.drings[VIO_DRIVER_TX_RING];
1676
1677	if (!dr->base)
1678		return;
1679
1680	for (i = 0; i < VNET_TX_RING_SIZE; i++) {
1681		struct vio_net_desc *d;
1682		void *skb = port->tx_bufs[i].skb;
1683
1684		if (!skb)
1685			continue;
1686
1687		d = vio_dring_entry(dr, i);
1688
1689		ldc_unmap(port->vio.lp,
1690			  port->tx_bufs[i].cookies,
1691			  port->tx_bufs[i].ncookies);
1692		dev_kfree_skb(skb);
1693		port->tx_bufs[i].skb = NULL;
1694		d->hdr.state = VIO_DESC_FREE;
1695	}
1696	ldc_free_exp_dring(port->vio.lp, dr->base,
1697			   (dr->entry_size * dr->num_entries),
1698			   dr->cookies, dr->ncookies);
1699	dr->base = NULL;
1700	dr->entry_size = 0;
1701	dr->num_entries = 0;
1702	dr->pending = 0;
1703	dr->ncookies = 0;
1704}
1705EXPORT_SYMBOL_GPL(sunvnet_port_free_tx_bufs_common);
1706
1707void vnet_port_reset(struct vnet_port *port)
1708{
1709	del_timer(&port->clean_timer);
1710	sunvnet_port_free_tx_bufs_common(port);
1711	port->rmtu = 0;
1712	port->tso = (port->vsw == 0);  /* no tso in vsw, misbehaves in bridge */
1713	port->tsolen = 0;
1714}
1715EXPORT_SYMBOL_GPL(vnet_port_reset);
1716
1717static int vnet_port_alloc_tx_ring(struct vnet_port *port)
1718{
1719	struct vio_dring_state *dr;
1720	unsigned long len, elen;
1721	int i, err, ncookies;
1722	void *dring;
1723
1724	dr = &port->vio.drings[VIO_DRIVER_TX_RING];
1725
1726	elen = sizeof(struct vio_net_desc) +
1727	       sizeof(struct ldc_trans_cookie) * 2;
1728	if (vio_version_after_eq(&port->vio, 1, 7))
1729		elen += sizeof(struct vio_net_dext);
1730	len = VNET_TX_RING_SIZE * elen;
1731
1732	ncookies = VIO_MAX_RING_COOKIES;
1733	dring = ldc_alloc_exp_dring(port->vio.lp, len,
1734				    dr->cookies, &ncookies,
1735				    (LDC_MAP_SHADOW |
1736				     LDC_MAP_DIRECT |
1737				     LDC_MAP_RW));
1738	if (IS_ERR(dring)) {
1739		err = PTR_ERR(dring);
1740		goto err_out;
1741	}
1742
1743	dr->base = dring;
1744	dr->entry_size = elen;
1745	dr->num_entries = VNET_TX_RING_SIZE;
1746	dr->prod = 0;
1747	dr->cons = 0;
1748	port->start_cons  = true; /* need an initial trigger */
1749	dr->pending = VNET_TX_RING_SIZE;
1750	dr->ncookies = ncookies;
1751
1752	for (i = 0; i < VNET_TX_RING_SIZE; ++i) {
1753		struct vio_net_desc *d;
1754
1755		d = vio_dring_entry(dr, i);
1756		d->hdr.state = VIO_DESC_FREE;
1757	}
1758	return 0;
1759
1760err_out:
1761	sunvnet_port_free_tx_bufs_common(port);
1762
1763	return err;
1764}
1765
1766#ifdef CONFIG_NET_POLL_CONTROLLER
1767void sunvnet_poll_controller_common(struct net_device *dev, struct vnet *vp)
1768{
1769	struct vnet_port *port;
1770	unsigned long flags;
1771
1772	spin_lock_irqsave(&vp->lock, flags);
1773	if (!list_empty(&vp->port_list)) {
1774		port = list_entry(vp->port_list.next, struct vnet_port, list);
1775		napi_schedule(&port->napi);
1776	}
1777	spin_unlock_irqrestore(&vp->lock, flags);
1778}
1779EXPORT_SYMBOL_GPL(sunvnet_poll_controller_common);
1780#endif
1781
1782void sunvnet_port_add_txq_common(struct vnet_port *port)
1783{
1784	struct vnet *vp = port->vp;
1785	int smallest = 0;
1786	int i;
1787
1788	/* find the first least-used q
1789	 * When there are more ldoms than q's, we start to
1790	 * double up on ports per queue.
1791	 */
1792	for (i = 0; i < VNET_MAX_TXQS; i++) {
1793		if (vp->q_used[i] == 0) {
1794			smallest = i;
1795			break;
1796		}
1797		if (vp->q_used[i] < vp->q_used[smallest])
1798			smallest = i;
1799	}
1800
1801	vp->nports++;
1802	vp->q_used[smallest]++;
1803	port->q_index = smallest;
1804}
1805EXPORT_SYMBOL_GPL(sunvnet_port_add_txq_common);
1806
1807void sunvnet_port_rm_txq_common(struct vnet_port *port)
1808{
1809	port->vp->nports--;
1810	port->vp->q_used[port->q_index]--;
1811	port->q_index = 0;
1812}
1813EXPORT_SYMBOL_GPL(sunvnet_port_rm_txq_common);
1814