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