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 + f->page_offset,
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 |= f->page_offset & 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, 0);
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 int vnet_handle_offloads(struct vnet_port *port, struct sk_buff *skb,
1220				struct vnet_port *(*vnet_tx_port)
1221				(struct sk_buff *, struct net_device *))
 
1222{
1223	struct net_device *dev = VNET_PORT_TO_NET_DEVICE(port);
1224	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
1225	struct sk_buff *segs;
1226	int maclen, datalen;
1227	int status;
1228	int gso_size, gso_type, gso_segs;
1229	int hlen = skb_transport_header(skb) - skb_mac_header(skb);
1230	int proto = IPPROTO_IP;
1231
1232	if (skb->protocol == htons(ETH_P_IP))
1233		proto = ip_hdr(skb)->protocol;
1234	else if (skb->protocol == htons(ETH_P_IPV6))
1235		proto = ipv6_hdr(skb)->nexthdr;
1236
1237	if (proto == IPPROTO_TCP) {
1238		hlen += tcp_hdr(skb)->doff * 4;
1239	} else if (proto == IPPROTO_UDP) {
1240		hlen += sizeof(struct udphdr);
1241	} else {
1242		pr_err("vnet_handle_offloads GSO with unknown transport "
1243		       "protocol %d tproto %d\n", skb->protocol, proto);
1244		hlen = 128; /* XXX */
1245	}
1246	datalen = port->tsolen - hlen;
1247
1248	gso_size = skb_shinfo(skb)->gso_size;
1249	gso_type = skb_shinfo(skb)->gso_type;
1250	gso_segs = skb_shinfo(skb)->gso_segs;
1251
1252	if (port->tso && gso_size < datalen)
1253		gso_segs = DIV_ROUND_UP(skb->len - hlen, datalen);
1254
1255	if (unlikely(vnet_tx_dring_avail(dr) < gso_segs)) {
1256		struct netdev_queue *txq;
1257
1258		txq  = netdev_get_tx_queue(dev, port->q_index);
1259		netif_tx_stop_queue(txq);
1260		if (vnet_tx_dring_avail(dr) < skb_shinfo(skb)->gso_segs)
1261			return NETDEV_TX_BUSY;
1262		netif_tx_wake_queue(txq);
1263	}
1264
1265	maclen = skb_network_header(skb) - skb_mac_header(skb);
1266	skb_pull(skb, maclen);
1267
1268	if (port->tso && gso_size < datalen) {
1269		if (skb_unclone(skb, GFP_ATOMIC))
1270			goto out_dropped;
1271
1272		/* segment to TSO size */
1273		skb_shinfo(skb)->gso_size = datalen;
1274		skb_shinfo(skb)->gso_segs = gso_segs;
1275	}
1276	segs = skb_gso_segment(skb, dev->features & ~NETIF_F_TSO);
1277	if (IS_ERR(segs))
1278		goto out_dropped;
1279
1280	skb_push(skb, maclen);
1281	skb_reset_mac_header(skb);
1282
1283	status = 0;
1284	while (segs) {
1285		struct sk_buff *curr = segs;
1286
1287		segs = segs->next;
1288		curr->next = NULL;
1289		if (port->tso && curr->len > dev->mtu) {
1290			skb_shinfo(curr)->gso_size = gso_size;
1291			skb_shinfo(curr)->gso_type = gso_type;
1292			skb_shinfo(curr)->gso_segs =
1293				DIV_ROUND_UP(curr->len - hlen, gso_size);
1294		} else {
1295			skb_shinfo(curr)->gso_size = 0;
1296		}
1297
1298		skb_push(curr, maclen);
1299		skb_reset_mac_header(curr);
1300		memcpy(skb_mac_header(curr), skb_mac_header(skb),
1301		       maclen);
1302		curr->csum_start = skb_transport_header(curr) - curr->head;
1303		if (ip_hdr(curr)->protocol == IPPROTO_TCP)
1304			curr->csum_offset = offsetof(struct tcphdr, check);
1305		else if (ip_hdr(curr)->protocol == IPPROTO_UDP)
1306			curr->csum_offset = offsetof(struct udphdr, check);
1307
1308		if (!(status & NETDEV_TX_MASK))
1309			status = sunvnet_start_xmit_common(curr, dev,
1310							   vnet_tx_port);
1311		if (status & NETDEV_TX_MASK)
1312			dev_kfree_skb_any(curr);
1313	}
1314
1315	if (!(status & NETDEV_TX_MASK))
1316		dev_kfree_skb_any(skb);
1317	return status;
1318out_dropped:
1319	dev->stats.tx_dropped++;
1320	dev_kfree_skb_any(skb);
1321	return NETDEV_TX_OK;
1322}
1323
1324int sunvnet_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			struct flowi4 fl4;
1356			struct rtable *rt = NULL;
1357
1358			memset(&fl4, 0, sizeof(fl4));
1359			fl4.flowi4_oif = dev->ifindex;
1360			fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos);
1361			fl4.daddr = ip_hdr(skb)->daddr;
1362			fl4.saddr = ip_hdr(skb)->saddr;
1363
1364			rt = ip_route_output_key(dev_net(dev), &fl4);
1365			if (!IS_ERR(rt)) {
1366				skb_dst_set(skb, &rt->dst);
1367				icmp_send(skb, ICMP_DEST_UNREACH,
1368					  ICMP_FRAG_NEEDED,
1369					  htonl(localmtu));
1370			}
1371		}
1372#if IS_ENABLED(CONFIG_IPV6)
1373		else if (skb->protocol == htons(ETH_P_IPV6))
1374			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, localmtu);
1375#endif
1376		goto out_dropped;
1377	}
1378
1379	skb = vnet_skb_shape(skb, 2);
1380
1381	if (unlikely(!skb))
1382		goto out_dropped;
1383
1384	if (skb->ip_summed == CHECKSUM_PARTIAL) {
1385		if (skb->protocol == htons(ETH_P_IP))
1386			vnet_fullcsum_ipv4(skb);
1387#if IS_ENABLED(CONFIG_IPV6)
1388		else if (skb->protocol == htons(ETH_P_IPV6))
1389			vnet_fullcsum_ipv6(skb);
1390#endif
1391	}
1392
1393	dr = &port->vio.drings[VIO_DRIVER_TX_RING];
1394	i = skb_get_queue_mapping(skb);
1395	txq = netdev_get_tx_queue(dev, i);
1396	if (unlikely(vnet_tx_dring_avail(dr) < 1)) {
1397		if (!netif_tx_queue_stopped(txq)) {
1398			netif_tx_stop_queue(txq);
1399
1400			/* This is a hard error, log it. */
1401			netdev_err(dev, "BUG! Tx Ring full when queue awake!\n");
1402			dev->stats.tx_errors++;
1403		}
1404		rcu_read_unlock();
1405		return NETDEV_TX_BUSY;
1406	}
1407
1408	d = vio_dring_cur(dr);
1409
1410	txi = dr->prod;
1411
1412	freeskbs = vnet_clean_tx_ring(port, &pending);
1413
1414	BUG_ON(port->tx_bufs[txi].skb);
1415
1416	len = skb->len;
1417	if (len < ETH_ZLEN)
1418		len = ETH_ZLEN;
1419
1420	err = vnet_skb_map(port->vio.lp, skb, port->tx_bufs[txi].cookies, 2,
1421			   (LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_RW));
1422	if (err < 0) {
1423		netdev_info(dev, "tx buffer map error %d\n", err);
1424		goto out_dropped;
1425	}
1426
1427	port->tx_bufs[txi].skb = skb;
1428	skb = NULL;
1429	port->tx_bufs[txi].ncookies = err;
1430
1431	/* We don't rely on the ACKs to free the skb in vnet_start_xmit(),
1432	 * thus it is safe to not set VIO_ACK_ENABLE for each transmission:
1433	 * the protocol itself does not require it as long as the peer
1434	 * sends a VIO_SUBTYPE_ACK for VIO_DRING_STOPPED.
1435	 *
1436	 * An ACK for every packet in the ring is expensive as the
1437	 * sending of LDC messages is slow and affects performance.
1438	 */
1439	d->hdr.ack = VIO_ACK_DISABLE;
1440	d->size = len;
1441	d->ncookies = port->tx_bufs[txi].ncookies;
1442	for (i = 0; i < d->ncookies; i++)
1443		d->cookies[i] = port->tx_bufs[txi].cookies[i];
1444	if (vio_version_after_eq(&port->vio, 1, 7)) {
1445		struct vio_net_dext *dext = vio_net_ext(d);
1446
1447		memset(dext, 0, sizeof(*dext));
1448		if (skb_is_gso(port->tx_bufs[txi].skb)) {
1449			dext->ipv4_lso_mss = skb_shinfo(port->tx_bufs[txi].skb)
1450					     ->gso_size;
1451			dext->flags |= VNET_PKT_IPV4_LSO;
1452		}
1453		if (vio_version_after_eq(&port->vio, 1, 8) &&
1454		    !port->switch_port) {
1455			dext->flags |= VNET_PKT_HCK_IPV4_HDRCKSUM_OK;
1456			dext->flags |= VNET_PKT_HCK_FULLCKSUM_OK;
1457		}
1458	}
1459
1460	/* This has to be a non-SMP write barrier because we are writing
1461	 * to memory which is shared with the peer LDOM.
1462	 */
1463	dma_wmb();
1464
1465	d->hdr.state = VIO_DESC_READY;
1466
1467	/* Exactly one ldc "start" trigger (for dr->cons) needs to be sent
1468	 * to notify the consumer that some descriptors are READY.
1469	 * After that "start" trigger, no additional triggers are needed until
1470	 * a DRING_STOPPED is received from the consumer. The dr->cons field
1471	 * (set up by vnet_ack()) has the value of the next dring index
1472	 * that has not yet been ack-ed. We send a "start" trigger here
1473	 * if, and only if, start_cons is true (reset it afterward). Conversely,
1474	 * vnet_ack() should check if the dring corresponding to cons
1475	 * is marked READY, but start_cons was false.
1476	 * If so, vnet_ack() should send out the missed "start" trigger.
1477	 *
1478	 * Note that the dma_wmb() above makes sure the cookies et al. are
1479	 * not globally visible before the VIO_DESC_READY, and that the
1480	 * stores are ordered correctly by the compiler. The consumer will
1481	 * not proceed until the VIO_DESC_READY is visible assuring that
1482	 * the consumer does not observe anything related to descriptors
1483	 * out of order. The HV trap from the LDC start trigger is the
1484	 * producer to consumer announcement that work is available to the
1485	 * consumer
1486	 */
1487	if (!port->start_cons) { /* previous trigger suffices */
1488		trace_vnet_skip_tx_trigger(port->vio._local_sid,
1489					   port->vio._peer_sid, dr->cons);
1490		goto ldc_start_done;
1491	}
1492
1493	err = __vnet_tx_trigger(port, dr->cons);
1494	if (unlikely(err < 0)) {
1495		netdev_info(dev, "TX trigger error %d\n", err);
1496		d->hdr.state = VIO_DESC_FREE;
1497		skb = port->tx_bufs[txi].skb;
1498		port->tx_bufs[txi].skb = NULL;
1499		dev->stats.tx_carrier_errors++;
1500		goto out_dropped;
1501	}
1502
1503ldc_start_done:
1504	port->start_cons = false;
1505
1506	dev->stats.tx_packets++;
1507	dev->stats.tx_bytes += port->tx_bufs[txi].skb->len;
1508	port->stats.tx_packets++;
1509	port->stats.tx_bytes += port->tx_bufs[txi].skb->len;
1510
1511	dr->prod = (dr->prod + 1) & (VNET_TX_RING_SIZE - 1);
1512	if (unlikely(vnet_tx_dring_avail(dr) < 1)) {
1513		netif_tx_stop_queue(txq);
1514		smp_rmb();
1515		if (vnet_tx_dring_avail(dr) > VNET_TX_WAKEUP_THRESH(dr))
1516			netif_tx_wake_queue(txq);
1517	}
1518
1519	(void)mod_timer(&port->clean_timer, jiffies + VNET_CLEAN_TIMEOUT);
1520	rcu_read_unlock();
1521
1522	vnet_free_skbs(freeskbs);
1523
1524	return NETDEV_TX_OK;
1525
1526out_dropped:
1527	if (pending)
1528		(void)mod_timer(&port->clean_timer,
1529				jiffies + VNET_CLEAN_TIMEOUT);
1530	else if (port)
1531		del_timer(&port->clean_timer);
1532	rcu_read_unlock();
1533	if (skb)
1534		dev_kfree_skb(skb);
1535	vnet_free_skbs(freeskbs);
1536	dev->stats.tx_dropped++;
1537	return NETDEV_TX_OK;
1538}
1539EXPORT_SYMBOL_GPL(sunvnet_start_xmit_common);
1540
1541void sunvnet_tx_timeout_common(struct net_device *dev)
1542{
1543	/* XXX Implement me XXX */
1544}
1545EXPORT_SYMBOL_GPL(sunvnet_tx_timeout_common);
1546
1547int sunvnet_open_common(struct net_device *dev)
1548{
1549	netif_carrier_on(dev);
1550	netif_tx_start_all_queues(dev);
1551
1552	return 0;
1553}
1554EXPORT_SYMBOL_GPL(sunvnet_open_common);
1555
1556int sunvnet_close_common(struct net_device *dev)
1557{
1558	netif_tx_stop_all_queues(dev);
1559	netif_carrier_off(dev);
1560
1561	return 0;
1562}
1563EXPORT_SYMBOL_GPL(sunvnet_close_common);
1564
1565static struct vnet_mcast_entry *__vnet_mc_find(struct vnet *vp, u8 *addr)
1566{
1567	struct vnet_mcast_entry *m;
1568
1569	for (m = vp->mcast_list; m; m = m->next) {
1570		if (ether_addr_equal(m->addr, addr))
1571			return m;
1572	}
1573	return NULL;
1574}
1575
1576static void __update_mc_list(struct vnet *vp, struct net_device *dev)
1577{
1578	struct netdev_hw_addr *ha;
1579
1580	netdev_for_each_mc_addr(ha, dev) {
1581		struct vnet_mcast_entry *m;
1582
1583		m = __vnet_mc_find(vp, ha->addr);
1584		if (m) {
1585			m->hit = 1;
1586			continue;
1587		}
1588
1589		if (!m) {
1590			m = kzalloc(sizeof(*m), GFP_ATOMIC);
1591			if (!m)
1592				continue;
1593			memcpy(m->addr, ha->addr, ETH_ALEN);
1594			m->hit = 1;
1595
1596			m->next = vp->mcast_list;
1597			vp->mcast_list = m;
1598		}
1599	}
1600}
1601
1602static void __send_mc_list(struct vnet *vp, struct vnet_port *port)
1603{
1604	struct vio_net_mcast_info info;
1605	struct vnet_mcast_entry *m, **pp;
1606	int n_addrs;
1607
1608	memset(&info, 0, sizeof(info));
1609
1610	info.tag.type = VIO_TYPE_CTRL;
1611	info.tag.stype = VIO_SUBTYPE_INFO;
1612	info.tag.stype_env = VNET_MCAST_INFO;
1613	info.tag.sid = vio_send_sid(&port->vio);
1614	info.set = 1;
1615
1616	n_addrs = 0;
1617	for (m = vp->mcast_list; m; m = m->next) {
1618		if (m->sent)
1619			continue;
1620		m->sent = 1;
1621		memcpy(&info.mcast_addr[n_addrs * ETH_ALEN],
1622		       m->addr, ETH_ALEN);
1623		if (++n_addrs == VNET_NUM_MCAST) {
1624			info.count = n_addrs;
1625
1626			(void)vio_ldc_send(&port->vio, &info,
1627					   sizeof(info));
1628			n_addrs = 0;
1629		}
1630	}
1631	if (n_addrs) {
1632		info.count = n_addrs;
1633		(void)vio_ldc_send(&port->vio, &info, sizeof(info));
1634	}
1635
1636	info.set = 0;
1637
1638	n_addrs = 0;
1639	pp = &vp->mcast_list;
1640	while ((m = *pp) != NULL) {
1641		if (m->hit) {
1642			m->hit = 0;
1643			pp = &m->next;
1644			continue;
1645		}
1646
1647		memcpy(&info.mcast_addr[n_addrs * ETH_ALEN],
1648		       m->addr, ETH_ALEN);
1649		if (++n_addrs == VNET_NUM_MCAST) {
1650			info.count = n_addrs;
1651			(void)vio_ldc_send(&port->vio, &info,
1652					   sizeof(info));
1653			n_addrs = 0;
1654		}
1655
1656		*pp = m->next;
1657		kfree(m);
1658	}
1659	if (n_addrs) {
1660		info.count = n_addrs;
1661		(void)vio_ldc_send(&port->vio, &info, sizeof(info));
1662	}
1663}
1664
1665void sunvnet_set_rx_mode_common(struct net_device *dev, struct vnet *vp)
1666{
1667	struct vnet_port *port;
1668
1669	rcu_read_lock();
1670	list_for_each_entry_rcu(port, &vp->port_list, list) {
1671		if (port->switch_port) {
1672			__update_mc_list(vp, dev);
1673			__send_mc_list(vp, port);
1674			break;
1675		}
1676	}
1677	rcu_read_unlock();
1678}
1679EXPORT_SYMBOL_GPL(sunvnet_set_rx_mode_common);
1680
1681int sunvnet_set_mac_addr_common(struct net_device *dev, void *p)
1682{
1683	return -EINVAL;
1684}
1685EXPORT_SYMBOL_GPL(sunvnet_set_mac_addr_common);
1686
1687void sunvnet_port_free_tx_bufs_common(struct vnet_port *port)
1688{
1689	struct vio_dring_state *dr;
1690	int i;
1691
1692	dr = &port->vio.drings[VIO_DRIVER_TX_RING];
1693
1694	if (!dr->base)
1695		return;
1696
1697	for (i = 0; i < VNET_TX_RING_SIZE; i++) {
1698		struct vio_net_desc *d;
1699		void *skb = port->tx_bufs[i].skb;
1700
1701		if (!skb)
1702			continue;
1703
1704		d = vio_dring_entry(dr, i);
1705
1706		ldc_unmap(port->vio.lp,
1707			  port->tx_bufs[i].cookies,
1708			  port->tx_bufs[i].ncookies);
1709		dev_kfree_skb(skb);
1710		port->tx_bufs[i].skb = NULL;
1711		d->hdr.state = VIO_DESC_FREE;
1712	}
1713	ldc_free_exp_dring(port->vio.lp, dr->base,
1714			   (dr->entry_size * dr->num_entries),
1715			   dr->cookies, dr->ncookies);
1716	dr->base = NULL;
1717	dr->entry_size = 0;
1718	dr->num_entries = 0;
1719	dr->pending = 0;
1720	dr->ncookies = 0;
1721}
1722EXPORT_SYMBOL_GPL(sunvnet_port_free_tx_bufs_common);
1723
1724void vnet_port_reset(struct vnet_port *port)
1725{
1726	del_timer(&port->clean_timer);
1727	sunvnet_port_free_tx_bufs_common(port);
1728	port->rmtu = 0;
1729	port->tso = (port->vsw == 0);  /* no tso in vsw, misbehaves in bridge */
1730	port->tsolen = 0;
1731}
1732EXPORT_SYMBOL_GPL(vnet_port_reset);
1733
1734static int vnet_port_alloc_tx_ring(struct vnet_port *port)
1735{
1736	struct vio_dring_state *dr;
1737	unsigned long len, elen;
1738	int i, err, ncookies;
1739	void *dring;
1740
1741	dr = &port->vio.drings[VIO_DRIVER_TX_RING];
1742
1743	elen = sizeof(struct vio_net_desc) +
1744	       sizeof(struct ldc_trans_cookie) * 2;
1745	if (vio_version_after_eq(&port->vio, 1, 7))
1746		elen += sizeof(struct vio_net_dext);
1747	len = VNET_TX_RING_SIZE * elen;
1748
1749	ncookies = VIO_MAX_RING_COOKIES;
1750	dring = ldc_alloc_exp_dring(port->vio.lp, len,
1751				    dr->cookies, &ncookies,
1752				    (LDC_MAP_SHADOW |
1753				     LDC_MAP_DIRECT |
1754				     LDC_MAP_RW));
1755	if (IS_ERR(dring)) {
1756		err = PTR_ERR(dring);
1757		goto err_out;
1758	}
1759
1760	dr->base = dring;
1761	dr->entry_size = elen;
1762	dr->num_entries = VNET_TX_RING_SIZE;
1763	dr->prod = 0;
1764	dr->cons = 0;
1765	port->start_cons  = true; /* need an initial trigger */
1766	dr->pending = VNET_TX_RING_SIZE;
1767	dr->ncookies = ncookies;
1768
1769	for (i = 0; i < VNET_TX_RING_SIZE; ++i) {
1770		struct vio_net_desc *d;
1771
1772		d = vio_dring_entry(dr, i);
1773		d->hdr.state = VIO_DESC_FREE;
1774	}
1775	return 0;
1776
1777err_out:
1778	sunvnet_port_free_tx_bufs_common(port);
1779
1780	return err;
1781}
1782
1783#ifdef CONFIG_NET_POLL_CONTROLLER
1784void sunvnet_poll_controller_common(struct net_device *dev, struct vnet *vp)
1785{
1786	struct vnet_port *port;
1787	unsigned long flags;
1788
1789	spin_lock_irqsave(&vp->lock, flags);
1790	if (!list_empty(&vp->port_list)) {
1791		port = list_entry(vp->port_list.next, struct vnet_port, list);
1792		napi_schedule(&port->napi);
1793	}
1794	spin_unlock_irqrestore(&vp->lock, flags);
1795}
1796EXPORT_SYMBOL_GPL(sunvnet_poll_controller_common);
1797#endif
1798
1799void sunvnet_port_add_txq_common(struct vnet_port *port)
1800{
1801	struct vnet *vp = port->vp;
1802	int smallest = 0;
1803	int i;
1804
1805	/* find the first least-used q
1806	 * When there are more ldoms than q's, we start to
1807	 * double up on ports per queue.
1808	 */
1809	for (i = 0; i < VNET_MAX_TXQS; i++) {
1810		if (vp->q_used[i] == 0) {
1811			smallest = i;
1812			break;
1813		}
1814		if (vp->q_used[i] < vp->q_used[smallest])
1815			smallest = i;
1816	}
1817
1818	vp->nports++;
1819	vp->q_used[smallest]++;
1820	port->q_index = smallest;
1821}
1822EXPORT_SYMBOL_GPL(sunvnet_port_add_txq_common);
1823
1824void sunvnet_port_rm_txq_common(struct vnet_port *port)
1825{
1826	port->vp->nports--;
1827	port->vp->q_used[port->q_index]--;
1828	port->q_index = 0;
1829}
1830EXPORT_SYMBOL_GPL(sunvnet_port_rm_txq_common);