sunvnet.c 49 KB
Newer Older
1
2
/* sunvnet.c: Sun LDOM Virtual Network Driver.
 *
3
 * Copyright (C) 2007, 2008 David S. Miller <davem@davemloft.net>
4
5
 */

6
7
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

8
9
10
11
12
13
14
15
16
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/ethtool.h>
#include <linux/etherdevice.h>
17
#include <linux/mutex.h>
18
#include <linux/highmem.h>
19
#include <linux/if_vlan.h>
20

21
22
23
24
#if IS_ENABLED(CONFIG_IPV6)
#include <linux/icmpv6.h>
#endif

25
#include <net/ip.h>
26
27
28
#include <net/icmp.h>
#include <net/route.h>

29
30
31
32
33
34
35
36
37
#include <asm/vio.h>
#include <asm/ldc.h>

#include "sunvnet.h"

#define DRV_MODULE_NAME		"sunvnet"
#define DRV_MODULE_VERSION	"1.0"
#define DRV_MODULE_RELDATE	"June 25, 2007"

38
static char version[] =
39
40
41
42
43
44
	DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n";
MODULE_AUTHOR("David S. Miller (davem@davemloft.net)");
MODULE_DESCRIPTION("Sun LDOM virtual network driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_MODULE_VERSION);

45
46
#define	VNET_MAX_TXQS		16

47
48
49
50
51
/* Heuristic for the number of times to exponentially backoff and
 * retry sending an LDC trigger when EAGAIN is encountered
 */
#define	VNET_MAX_RETRIES	10

52
53
static int __vnet_tx_trigger(struct vnet_port *port, u32 start);

54
55
/* Ordered from largest major to lowest */
static struct vio_version vnet_versions[] = {
56
57
	{ .major = 1, .minor = 8 },
	{ .major = 1, .minor = 7 },
58
	{ .major = 1, .minor = 6 },
59
60
61
62
63
64
65
66
67
68
69
70
	{ .major = 1, .minor = 0 },
};

static inline u32 vnet_tx_dring_avail(struct vio_dring_state *dr)
{
	return vio_dring_avail(dr, VNET_TX_RING_SIZE);
}

static int vnet_handle_unknown(struct vnet_port *port, void *arg)
{
	struct vio_msg_tag *pkt = arg;

71
	pr_err("Received unknown msg [%02x:%02x:%04x:%08x]\n",
72
	       pkt->type, pkt->stype, pkt->stype_env, pkt->sid);
73
	pr_err("Resetting connection\n");
74
75
76
77
78
79

	ldc_disconnect(port->vio.lp);

	return -ECONNRESET;
}

80
81
static int vnet_port_alloc_tx_ring(struct vnet_port *port);

82
83
84
85
86
static int vnet_send_attr(struct vio_driver_state *vio)
{
	struct vnet_port *port = to_vnet_port(vio);
	struct net_device *dev = port->vp->dev;
	struct vio_net_attr_info pkt;
87
	int framelen = ETH_FRAME_LEN;
88
89
90
91
92
	int i, err;

	err = vnet_port_alloc_tx_ring(to_vnet_port(vio));
	if (err)
		return err;
93
94
95
96
97
98

	memset(&pkt, 0, sizeof(pkt));
	pkt.tag.type = VIO_TYPE_CTRL;
	pkt.tag.stype = VIO_SUBTYPE_INFO;
	pkt.tag.stype_env = VIO_ATTR_INFO;
	pkt.tag.sid = vio_send_sid(vio);
99
100
101
102
	if (vio_version_before(vio, 1, 2))
		pkt.xfer_mode = VIO_DRING_MODE;
	else
		pkt.xfer_mode = VIO_NEW_DRING_MODE;
103
104
105
106
	pkt.addr_type = VNET_ADDR_ETHERMAC;
	pkt.ack_freq = 0;
	for (i = 0; i < 6; i++)
		pkt.addr |= (u64)dev->dev_addr[i] << ((5 - i) * 8);
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
	if (vio_version_after(vio, 1, 3)) {
		if (port->rmtu) {
			port->rmtu = min(VNET_MAXPACKET, port->rmtu);
			pkt.mtu = port->rmtu;
		} else {
			port->rmtu = VNET_MAXPACKET;
			pkt.mtu = port->rmtu;
		}
		if (vio_version_after_eq(vio, 1, 6))
			pkt.options = VIO_TX_DRING;
	} else if (vio_version_before(vio, 1, 3)) {
		pkt.mtu = framelen;
	} else { /* v1.3 */
		pkt.mtu = framelen + VLAN_HLEN;
	}

	pkt.cflags = 0;
David L Stevens's avatar
David L Stevens committed
124
125
126
127
128
129
130
131
	if (vio_version_after_eq(vio, 1, 7) && port->tso) {
		pkt.cflags |= VNET_LSO_IPV4_CAPAB;
		if (!port->tsolen)
			port->tsolen = VNET_MAXTSO;
		pkt.ipv4_lso_maxlen = port->tsolen;
	}

	pkt.plnk_updt = PHYSLINK_UPDATE_NONE;
132
133

	viodbg(HS, "SEND NET ATTR xmode[0x%x] atype[0x%x] addr[%llx] "
134
135
	       "ackfreq[%u] plnk_updt[0x%02x] opts[0x%02x] mtu[%llu] "
	       "cflags[0x%04x] lso_max[%u]\n",
136
	       pkt.xfer_mode, pkt.addr_type,
137
138
139
140
	       (unsigned long long)pkt.addr,
	       pkt.ack_freq, pkt.plnk_updt, pkt.options,
	       (unsigned long long)pkt.mtu, pkt.cflags, pkt.ipv4_lso_maxlen);

141
142
143
144
145
146
147

	return vio_ldc_send(vio, &pkt, sizeof(pkt));
}

static int handle_attr_info(struct vio_driver_state *vio,
			    struct vio_net_attr_info *pkt)
{
148
149
150
151
152
153
154
	struct vnet_port *port = to_vnet_port(vio);
	u64	localmtu;
	u8	xfer_mode;

	viodbg(HS, "GOT NET ATTR xmode[0x%x] atype[0x%x] addr[%llx] "
	       "ackfreq[%u] plnk_updt[0x%02x] opts[0x%02x] mtu[%llu] "
	       " (rmtu[%llu]) cflags[0x%04x] lso_max[%u]\n",
155
	       pkt->xfer_mode, pkt->addr_type,
156
157
158
159
	       (unsigned long long)pkt->addr,
	       pkt->ack_freq, pkt->plnk_updt, pkt->options,
	       (unsigned long long)pkt->mtu, port->rmtu, pkt->cflags,
	       pkt->ipv4_lso_maxlen);
160
161
162

	pkt->tag.sid = vio_send_sid(vio);

163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
	xfer_mode = pkt->xfer_mode;
	/* for version < 1.2, VIO_DRING_MODE = 0x3 and no bitmask */
	if (vio_version_before(vio, 1, 2) && xfer_mode == VIO_DRING_MODE)
		xfer_mode = VIO_NEW_DRING_MODE;

	/* MTU negotiation:
	 *	< v1.3 - ETH_FRAME_LEN exactly
	 *	> v1.3 - MIN(pkt.mtu, VNET_MAXPACKET, port->rmtu) and change
	 *			pkt->mtu for ACK
	 *	= v1.3 - ETH_FRAME_LEN + VLAN_HLEN exactly
	 */
	if (vio_version_before(vio, 1, 3)) {
		localmtu = ETH_FRAME_LEN;
	} else if (vio_version_after(vio, 1, 3)) {
		localmtu = port->rmtu ? port->rmtu : VNET_MAXPACKET;
		localmtu = min(pkt->mtu, localmtu);
		pkt->mtu = localmtu;
	} else { /* v1.3 */
		localmtu = ETH_FRAME_LEN + VLAN_HLEN;
	}
	port->rmtu = localmtu;

David L Stevens's avatar
David L Stevens committed
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
	/* LSO negotiation */
	if (vio_version_after_eq(vio, 1, 7))
		port->tso &= !!(pkt->cflags & VNET_LSO_IPV4_CAPAB);
	else
		port->tso = false;
	if (port->tso) {
		if (!port->tsolen)
			port->tsolen = VNET_MAXTSO;
		port->tsolen = min(port->tsolen, pkt->ipv4_lso_maxlen);
		if (port->tsolen < VNET_MINTSO) {
			port->tso = false;
			port->tsolen = 0;
			pkt->cflags &= ~VNET_LSO_IPV4_CAPAB;
		}
		pkt->ipv4_lso_maxlen = port->tsolen;
	} else {
		pkt->cflags &= ~VNET_LSO_IPV4_CAPAB;
		pkt->ipv4_lso_maxlen = 0;
	}

205
206
207
208
209
210
211
	/* for version >= 1.6, ACK packet mode we support */
	if (vio_version_after_eq(vio, 1, 6)) {
		pkt->xfer_mode = VIO_NEW_DRING_MODE;
		pkt->options = VIO_TX_DRING;
	}

	if (!(xfer_mode | VIO_NEW_DRING_MODE) ||
212
	    pkt->addr_type != VNET_ADDR_ETHERMAC ||
213
	    pkt->mtu != localmtu) {
214
215
216
217
218
219
220
221
		viodbg(HS, "SEND NET ATTR NACK\n");

		pkt->tag.stype = VIO_SUBTYPE_NACK;

		(void) vio_ldc_send(vio, pkt, sizeof(*pkt));

		return -ECONNRESET;
	} else {
222
223
224
225
226
227
228
229
		viodbg(HS, "SEND NET ATTR ACK xmode[0x%x] atype[0x%x] "
		       "addr[%llx] ackfreq[%u] plnk_updt[0x%02x] opts[0x%02x] "
		       "mtu[%llu] (rmtu[%llu]) cflags[0x%04x] lso_max[%u]\n",
		       pkt->xfer_mode, pkt->addr_type,
		       (unsigned long long)pkt->addr,
		       pkt->ack_freq, pkt->plnk_updt, pkt->options,
		       (unsigned long long)pkt->mtu, port->rmtu, pkt->cflags,
		       pkt->ipv4_lso_maxlen);
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315

		pkt->tag.stype = VIO_SUBTYPE_ACK;

		return vio_ldc_send(vio, pkt, sizeof(*pkt));
	}

}

static int handle_attr_ack(struct vio_driver_state *vio,
			   struct vio_net_attr_info *pkt)
{
	viodbg(HS, "GOT NET ATTR ACK\n");

	return 0;
}

static int handle_attr_nack(struct vio_driver_state *vio,
			    struct vio_net_attr_info *pkt)
{
	viodbg(HS, "GOT NET ATTR NACK\n");

	return -ECONNRESET;
}

static int vnet_handle_attr(struct vio_driver_state *vio, void *arg)
{
	struct vio_net_attr_info *pkt = arg;

	switch (pkt->tag.stype) {
	case VIO_SUBTYPE_INFO:
		return handle_attr_info(vio, pkt);

	case VIO_SUBTYPE_ACK:
		return handle_attr_ack(vio, pkt);

	case VIO_SUBTYPE_NACK:
		return handle_attr_nack(vio, pkt);

	default:
		return -ECONNRESET;
	}
}

static void vnet_handshake_complete(struct vio_driver_state *vio)
{
	struct vio_dring_state *dr;

	dr = &vio->drings[VIO_DRIVER_RX_RING];
	dr->snd_nxt = dr->rcv_nxt = 1;

	dr = &vio->drings[VIO_DRIVER_TX_RING];
	dr->snd_nxt = dr->rcv_nxt = 1;
}

/* The hypervisor interface that implements copying to/from imported
 * memory from another domain requires that copies are done to 8-byte
 * aligned buffers, and that the lengths of such copies are also 8-byte
 * multiples.
 *
 * So we align skb->data to an 8-byte multiple and pad-out the data
 * area so we can round the copy length up to the next multiple of
 * 8 for the copy.
 *
 * The transmitter puts the actual start of the packet 6 bytes into
 * the buffer it sends over, so that the IP headers after the ethernet
 * header are aligned properly.  These 6 bytes are not in the descriptor
 * length, they are simply implied.  This offset is represented using
 * the VNET_PACKET_SKIP macro.
 */
static struct sk_buff *alloc_and_align_skb(struct net_device *dev,
					   unsigned int len)
{
	struct sk_buff *skb = netdev_alloc_skb(dev, len+VNET_PACKET_SKIP+8+8);
	unsigned long addr, off;

	if (unlikely(!skb))
		return NULL;

	addr = (unsigned long) skb->data;
	off = ((addr + 7UL) & ~7UL) - addr;
	if (off)
		skb_reserve(skb, off);

	return skb;
}

316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
static inline void vnet_fullcsum(struct sk_buff *skb)
{
	struct iphdr *iph = ip_hdr(skb);
	int offset = skb_transport_offset(skb);

	if (skb->protocol != htons(ETH_P_IP))
		return;
	if (iph->protocol != IPPROTO_TCP &&
	    iph->protocol != IPPROTO_UDP)
		return;
	skb->ip_summed = CHECKSUM_NONE;
	skb->csum_level = 1;
	skb->csum = 0;
	if (iph->protocol == IPPROTO_TCP) {
		struct tcphdr *ptcp = tcp_hdr(skb);

		ptcp->check = 0;
		skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
		ptcp->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
						skb->len - offset, IPPROTO_TCP,
						skb->csum);
	} else if (iph->protocol == IPPROTO_UDP) {
		struct udphdr *pudp = udp_hdr(skb);

		pudp->check = 0;
		skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
		pudp->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
						skb->len - offset, IPPROTO_UDP,
						skb->csum);
	}
}

static int vnet_rx_one(struct vnet_port *port, struct vio_net_desc *desc)
349
350
{
	struct net_device *dev = port->vp->dev;
351
	unsigned int len = desc->size;
352
353
	unsigned int copy_len;
	struct sk_buff *skb;
354
	int maxlen;
355
356
357
	int err;

	err = -EMSGSIZE;
358
359
360
361
362
	if (port->tso && port->tsolen > port->rmtu)
		maxlen = port->tsolen;
	else
		maxlen = port->rmtu;
	if (unlikely(len < ETH_ZLEN || len > maxlen)) {
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
		dev->stats.rx_length_errors++;
		goto out_dropped;
	}

	skb = alloc_and_align_skb(dev, len);
	err = -ENOMEM;
	if (unlikely(!skb)) {
		dev->stats.rx_missed_errors++;
		goto out_dropped;
	}

	copy_len = (len + VNET_PACKET_SKIP + 7U) & ~7U;
	skb_put(skb, copy_len);
	err = ldc_copy(port->vio.lp, LDC_COPY_IN,
		       skb->data, copy_len, 0,
378
		       desc->cookies, desc->ncookies);
379
380
381
382
383
384
385
386
387
	if (unlikely(err < 0)) {
		dev->stats.rx_frame_errors++;
		goto out_free_skb;
	}

	skb_pull(skb, VNET_PACKET_SKIP);
	skb_trim(skb, len);
	skb->protocol = eth_type_trans(skb, dev);

388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
	if (vio_version_after_eq(&port->vio, 1, 8)) {
		struct vio_net_dext *dext = vio_net_ext(desc);

		if (dext->flags & VNET_PKT_HCK_IPV4_HDRCKSUM) {
			if (skb->protocol == ETH_P_IP) {
				struct iphdr *iph = (struct iphdr *)skb->data;

				iph->check = 0;
				ip_send_check(iph);
			}
		}
		if ((dext->flags & VNET_PKT_HCK_FULLCKSUM) &&
		    skb->ip_summed == CHECKSUM_NONE)
			vnet_fullcsum(skb);
		if (dext->flags & VNET_PKT_HCK_IPV4_HDRCKSUM_OK) {
			skb->ip_summed = CHECKSUM_PARTIAL;
			skb->csum_level = 0;
			if (dext->flags & VNET_PKT_HCK_FULLCKSUM_OK)
				skb->csum_level = 1;
		}
	}

410
411
	skb->ip_summed = port->switch_port ? CHECKSUM_NONE : CHECKSUM_PARTIAL;

412
413
	dev->stats.rx_packets++;
	dev->stats.rx_bytes += len;
Sowmini Varadhan's avatar
Sowmini Varadhan committed
414
	napi_gro_receive(&port->napi, skb);
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
	return 0;

out_free_skb:
	kfree_skb(skb);

out_dropped:
	dev->stats.rx_dropped++;
	return err;
}

static int vnet_send_ack(struct vnet_port *port, struct vio_dring_state *dr,
			 u32 start, u32 end, u8 vio_dring_state)
{
	struct vio_dring_data hdr = {
		.tag = {
			.type		= VIO_TYPE_DATA,
			.stype		= VIO_SUBTYPE_ACK,
			.stype_env	= VIO_DRING_DATA,
			.sid		= vio_send_sid(&port->vio),
		},
		.dring_ident		= dr->ident,
		.start_idx		= start,
		.end_idx		= end,
		.state			= vio_dring_state,
	};
	int err, delay;
441
	int retries = 0;
442
443
444
445
446
447
448
449
450
451
452
453

	hdr.seq = dr->snd_nxt;
	delay = 1;
	do {
		err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
		if (err > 0) {
			dr->snd_nxt++;
			break;
		}
		udelay(delay);
		if ((delay <<= 1) > 128)
			delay = 128;
454
455
456
457
458
		if (retries++ > VNET_MAX_RETRIES) {
			pr_info("ECONNRESET %x:%x:%x:%x:%x:%x\n",
				port->raddr[0], port->raddr[1],
				port->raddr[2], port->raddr[3],
				port->raddr[4], port->raddr[5]);
459
			break;
460
		}
461
462
	} while (err == -EAGAIN);

463
464
465
466
467
468
469
470
	if (err <= 0 && vio_dring_state == VIO_DRING_STOPPED) {
		port->stop_rx_idx = end;
		port->stop_rx = true;
	} else {
		port->stop_rx_idx = 0;
		port->stop_rx = false;
	}

471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
	return err;
}

static struct vio_net_desc *get_rx_desc(struct vnet_port *port,
					struct vio_dring_state *dr,
					u32 index)
{
	struct vio_net_desc *desc = port->vio.desc_buf;
	int err;

	err = ldc_get_dring_entry(port->vio.lp, desc, dr->entry_size,
				  (index * dr->entry_size),
				  dr->cookies, dr->ncookies);
	if (err < 0)
		return ERR_PTR(err);

	return desc;
}

static int put_rx_desc(struct vnet_port *port,
		       struct vio_dring_state *dr,
		       struct vio_net_desc *desc,
		       u32 index)
{
	int err;

	err = ldc_put_dring_entry(port->vio.lp, desc, dr->entry_size,
				  (index * dr->entry_size),
				  dr->cookies, dr->ncookies);
	if (err < 0)
		return err;

	return 0;
}

static int vnet_walk_rx_one(struct vnet_port *port,
			    struct vio_dring_state *dr,
			    u32 index, int *needs_ack)
{
	struct vio_net_desc *desc = get_rx_desc(port, dr, index);
	struct vio_driver_state *vio = &port->vio;
	int err;

Sowmini Varadhan's avatar
Sowmini Varadhan committed
514
	BUG_ON(desc == NULL);
515
516
517
	if (IS_ERR(desc))
		return PTR_ERR(desc);

518
519
520
521
522
	if (desc->hdr.state != VIO_DESC_READY)
		return 1;

	rmb();

523
	viodbg(DATA, "vio_walk_rx_one desc[%02x:%02x:%08x:%08x:%llx:%llx]\n",
524
525
526
527
528
	       desc->hdr.state, desc->hdr.ack,
	       desc->size, desc->ncookies,
	       desc->cookies[0].cookie_addr,
	       desc->cookies[0].cookie_size);

529
	err = vnet_rx_one(port, desc);
530
531
532
533
534
535
536
537
538
539
540
	if (err == -ECONNRESET)
		return err;
	desc->hdr.state = VIO_DESC_DONE;
	err = put_rx_desc(port, dr, desc, index);
	if (err < 0)
		return err;
	*needs_ack = desc->hdr.ack;
	return 0;
}

static int vnet_walk_rx(struct vnet_port *port, struct vio_dring_state *dr,
Sowmini Varadhan's avatar
Sowmini Varadhan committed
541
			u32 start, u32 end, int *npkts, int budget)
542
543
544
{
	struct vio_driver_state *vio = &port->vio;
	int ack_start = -1, ack_end = -1;
Sowmini Varadhan's avatar
Sowmini Varadhan committed
545
	bool send_ack = true;
546

547
548
	end = (end == (u32) -1) ? vio_dring_prev(dr, start)
				: vio_dring_next(dr, end);
549
550
551
552
553
554
555
556
557

	viodbg(DATA, "vnet_walk_rx start[%08x] end[%08x]\n", start, end);

	while (start != end) {
		int ack = 0, err = vnet_walk_rx_one(port, dr, start, &ack);
		if (err == -ECONNRESET)
			return err;
		if (err != 0)
			break;
Sowmini Varadhan's avatar
Sowmini Varadhan committed
558
		(*npkts)++;
559
560
561
		if (ack_start == -1)
			ack_start = start;
		ack_end = start;
562
		start = vio_dring_next(dr, start);
563
564
565
566
567
568
569
		if (ack && start != end) {
			err = vnet_send_ack(port, dr, ack_start, ack_end,
					    VIO_DRING_ACTIVE);
			if (err == -ECONNRESET)
				return err;
			ack_start = -1;
		}
Sowmini Varadhan's avatar
Sowmini Varadhan committed
570
571
572
573
		if ((*npkts) >= budget) {
			send_ack = false;
			break;
		}
574
575
	}
	if (unlikely(ack_start == -1))
576
		ack_start = ack_end = vio_dring_prev(dr, start);
Sowmini Varadhan's avatar
Sowmini Varadhan committed
577
578
579
580
581
582
583
584
585
	if (send_ack) {
		port->napi_resume = false;
		return vnet_send_ack(port, dr, ack_start, ack_end,
				     VIO_DRING_STOPPED);
	} else  {
		port->napi_resume = true;
		port->napi_stop_idx = ack_end;
		return 1;
	}
586
587
}

Sowmini Varadhan's avatar
Sowmini Varadhan committed
588
589
static int vnet_rx(struct vnet_port *port, void *msgbuf, int *npkts,
		   int budget)
590
591
592
593
594
{
	struct vio_dring_data *pkt = msgbuf;
	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_RX_RING];
	struct vio_driver_state *vio = &port->vio;

595
	viodbg(DATA, "vnet_rx stype_env[%04x] seq[%016llx] rcv_nxt[%016llx]\n",
596
597
598
599
600
	       pkt->tag.stype_env, pkt->seq, dr->rcv_nxt);

	if (unlikely(pkt->tag.stype_env != VIO_DRING_DATA))
		return 0;
	if (unlikely(pkt->seq != dr->rcv_nxt)) {
601
602
		pr_err("RX out of sequence seq[0x%llx] rcv_nxt[0x%llx]\n",
		       pkt->seq, dr->rcv_nxt);
603
604
605
		return 0;
	}

Sowmini Varadhan's avatar
Sowmini Varadhan committed
606
607
	if (!port->napi_resume)
		dr->rcv_nxt++;
608
609
610

	/* XXX Validate pkt->start_idx and pkt->end_idx XXX */

Sowmini Varadhan's avatar
Sowmini Varadhan committed
611
612
	return vnet_walk_rx(port, dr, pkt->start_idx, pkt->end_idx,
			    npkts, budget);
613
614
615
616
617
618
619
620
621
622
623
624
}

static int idx_is_pending(struct vio_dring_state *dr, u32 end)
{
	u32 idx = dr->cons;
	int found = 0;

	while (idx != dr->prod) {
		if (idx == end) {
			found = 1;
			break;
		}
625
		idx = vio_dring_next(dr, idx);
626
627
628
629
630
631
632
633
634
635
636
	}
	return found;
}

static int vnet_ack(struct vnet_port *port, void *msgbuf)
{
	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
	struct vio_dring_data *pkt = msgbuf;
	struct net_device *dev;
	struct vnet *vp;
	u32 end;
637
	struct vio_net_desc *desc;
638
639
	struct netdev_queue *txq;

640
641
642
643
	if (unlikely(pkt->tag.stype_env != VIO_DRING_DATA))
		return 0;

	end = pkt->end_idx;
Sowmini Varadhan's avatar
Sowmini Varadhan committed
644
645
	vp = port->vp;
	dev = vp->dev;
646
647
648
649
650
651
	netif_tx_lock(dev);
	if (unlikely(!idx_is_pending(dr, end))) {
		netif_tx_unlock(dev);
		return 0;
	}

652
653
654
	/* sync for race conditions with vnet_start_xmit() and tell xmit it
	 * is time to send a trigger.
	 */
655
	dr->cons = vio_dring_next(dr, end);
656
	desc = vio_dring_entry(dr, dr->cons);
657
	if (desc->hdr.state == VIO_DESC_READY && !port->start_cons) {
658
659
660
661
662
663
664
665
666
667
668
		/* vnet_start_xmit() just populated this dring but missed
		 * sending the "start" LDC message to the consumer.
		 * Send a "start" trigger on its behalf.
		 */
		if (__vnet_tx_trigger(port, dr->cons) > 0)
			port->start_cons = false;
		else
			port->start_cons = true;
	} else {
		port->start_cons = true;
	}
Sowmini Varadhan's avatar
Sowmini Varadhan committed
669
	netif_tx_unlock(dev);
670

671
672
	txq = netdev_get_tx_queue(dev, port->q_index);
	if (unlikely(netif_tx_queue_stopped(txq) &&
673
674
675
676
677
678
679
680
681
682
683
684
		     vnet_tx_dring_avail(dr) >= VNET_TX_WAKEUP_THRESH(dr)))
		return 1;

	return 0;
}

static int vnet_nack(struct vnet_port *port, void *msgbuf)
{
	/* XXX just reset or similar XXX */
	return 0;
}

685
686
687
688
689
static int handle_mcast(struct vnet_port *port, void *msgbuf)
{
	struct vio_net_mcast_info *pkt = msgbuf;

	if (pkt->tag.stype != VIO_SUBTYPE_ACK)
690
		pr_err("%s: Got unexpected MCAST reply [%02x:%02x:%04x:%08x]\n",
691
692
693
694
695
696
697
698
699
		       port->vp->dev->name,
		       pkt->tag.type,
		       pkt->tag.stype,
		       pkt->tag.stype_env,
		       pkt->tag.sid);

	return 0;
}

700
701
702
703
704
/* Got back a STOPPED LDC message on port. If the queue is stopped,
 * wake it up so that we'll send out another START message at the
 * next TX.
 */
static void maybe_tx_wakeup(struct vnet_port *port)
705
{
706
	struct netdev_queue *txq;
707

708
709
710
711
712
713
	txq = netdev_get_tx_queue(port->vp->dev, port->q_index);
	__netif_tx_lock(txq, smp_processor_id());
	if (likely(netif_tx_queue_stopped(txq))) {
		struct vio_dring_state *dr;

		dr = &port->vio.drings[VIO_DRIVER_TX_RING];
714
		netif_tx_wake_queue(txq);
715
	}
716
	__netif_tx_unlock(txq);
717
718
}

Sowmini Varadhan's avatar
Sowmini Varadhan committed
719
720
721
722
723
724
725
726
static inline bool port_is_up(struct vnet_port *vnet)
{
	struct vio_driver_state *vio = &vnet->vio;

	return !!(vio->hs_state & VIO_HS_COMPLETE);
}

static int vnet_event_napi(struct vnet_port *port, int budget)
727
728
729
{
	struct vio_driver_state *vio = &port->vio;
	int tx_wakeup, err;
Sowmini Varadhan's avatar
Sowmini Varadhan committed
730
731
	int npkts = 0;
	int event = (port->rx_event & LDC_EVENT_RESET);
732

Sowmini Varadhan's avatar
Sowmini Varadhan committed
733
ldc_ctrl:
734
735
736
737
	if (unlikely(event == LDC_EVENT_RESET ||
		     event == LDC_EVENT_UP)) {
		vio_link_state_change(vio, event);

738
739
		if (event == LDC_EVENT_RESET) {
			port->rmtu = 0;
David L Stevens's avatar
David L Stevens committed
740
741
			port->tso = true;
			port->tsolen = 0;
742
			vio_port_up(vio);
743
		}
Sowmini Varadhan's avatar
Sowmini Varadhan committed
744
745
		port->rx_event = 0;
		return 0;
746
	}
Sowmini Varadhan's avatar
Sowmini Varadhan committed
747
748
749
750
751
752
753
754
	/* We may have multiple LDC events in rx_event. Unroll send_events() */
	event = (port->rx_event & LDC_EVENT_UP);
	port->rx_event &= ~(LDC_EVENT_RESET|LDC_EVENT_UP);
	if (event == LDC_EVENT_UP)
		goto ldc_ctrl;
	event = port->rx_event;
	if (!(event & LDC_EVENT_DATA_READY))
		return 0;
755

Sowmini Varadhan's avatar
Sowmini Varadhan committed
756
757
	/* we dont expect any other bits than RESET, UP, DATA_READY */
	BUG_ON(event != LDC_EVENT_DATA_READY);
758
759
760
761
762
763
764
765

	tx_wakeup = err = 0;
	while (1) {
		union {
			struct vio_msg_tag tag;
			u64 raw[8];
		} msgbuf;

Sowmini Varadhan's avatar
Sowmini Varadhan committed
766
767
768
769
770
771
772
773
774
775
		if (port->napi_resume) {
			struct vio_dring_data *pkt =
				(struct vio_dring_data *)&msgbuf;
			struct vio_dring_state *dr =
				&port->vio.drings[VIO_DRIVER_RX_RING];

			pkt->tag.type = VIO_TYPE_DATA;
			pkt->tag.stype = VIO_SUBTYPE_INFO;
			pkt->tag.stype_env = VIO_DRING_DATA;
			pkt->seq = dr->rcv_nxt;
776
			pkt->start_idx = vio_dring_next(dr, port->napi_stop_idx);
Sowmini Varadhan's avatar
Sowmini Varadhan committed
777
778
779
			pkt->end_idx = -1;
			goto napi_resume;
		}
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
		err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf));
		if (unlikely(err < 0)) {
			if (err == -ECONNRESET)
				vio_conn_reset(vio);
			break;
		}
		if (err == 0)
			break;
		viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n",
		       msgbuf.tag.type,
		       msgbuf.tag.stype,
		       msgbuf.tag.stype_env,
		       msgbuf.tag.sid);
		err = vio_validate_sid(vio, &msgbuf.tag);
		if (err < 0)
			break;
Sowmini Varadhan's avatar
Sowmini Varadhan committed
796
napi_resume:
797
798
		if (likely(msgbuf.tag.type == VIO_TYPE_DATA)) {
			if (msgbuf.tag.stype == VIO_SUBTYPE_INFO) {
Sowmini Varadhan's avatar
Sowmini Varadhan committed
799
800
801
802
803
804
805
806
807
808
809
				if (!port_is_up(port)) {
					/* failures like handshake_failure()
					 * may have cleaned up dring, but
					 * NAPI polling may bring us here.
					 */
					err = -ECONNRESET;
					break;
				}
				err = vnet_rx(port, &msgbuf, &npkts, budget);
				if (npkts >= budget)
					break;
810
811
				if (npkts == 0)
					break;
812
813
814
815
816
817
818
819
			} else if (msgbuf.tag.stype == VIO_SUBTYPE_ACK) {
				err = vnet_ack(port, &msgbuf);
				if (err > 0)
					tx_wakeup |= err;
			} else if (msgbuf.tag.stype == VIO_SUBTYPE_NACK) {
				err = vnet_nack(port, &msgbuf);
			}
		} else if (msgbuf.tag.type == VIO_TYPE_CTRL) {
820
821
822
823
			if (msgbuf.tag.stype_env == VNET_MCAST_INFO)
				err = handle_mcast(port, &msgbuf);
			else
				err = vio_control_pkt_engine(vio, &msgbuf);
824
825
826
827
828
829
830
831
832
			if (err)
				break;
		} else {
			err = vnet_handle_unknown(port, &msgbuf);
		}
		if (err == -ECONNRESET)
			break;
	}
	if (unlikely(tx_wakeup && err != -ECONNRESET))
833
		maybe_tx_wakeup(port);
Sowmini Varadhan's avatar
Sowmini Varadhan committed
834
835
836
837
838
839
840
841
842
843
844
	return npkts;
}

static int vnet_poll(struct napi_struct *napi, int budget)
{
	struct vnet_port *port = container_of(napi, struct vnet_port, napi);
	struct vio_driver_state *vio = &port->vio;
	int processed = vnet_event_napi(port, budget);

	if (processed < budget) {
		napi_complete(napi);
845
		port->rx_event &= ~LDC_EVENT_DATA_READY;
Sowmini Varadhan's avatar
Sowmini Varadhan committed
846
847
848
849
850
851
852
853
854
855
856
857
858
		vio_set_intr(vio->vdev->rx_ino, HV_INTR_ENABLED);
	}
	return processed;
}

static void vnet_event(void *arg, int event)
{
	struct vnet_port *port = arg;
	struct vio_driver_state *vio = &port->vio;

	port->rx_event |= event;
	vio_set_intr(vio->vdev->rx_ino, HV_INTR_DISABLED);
	napi_schedule(&port->napi);
859

860
861
}

862
static int __vnet_tx_trigger(struct vnet_port *port, u32 start)
863
864
865
866
867
868
869
870
871
872
{
	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
	struct vio_dring_data hdr = {
		.tag = {
			.type		= VIO_TYPE_DATA,
			.stype		= VIO_SUBTYPE_INFO,
			.stype_env	= VIO_DRING_DATA,
			.sid		= vio_send_sid(&port->vio),
		},
		.dring_ident		= dr->ident,
873
		.start_idx		= start,
874
875
876
		.end_idx		= (u32) -1,
	};
	int err, delay;
877
	int retries = 0;
878

879
880
881
882
883
884
885
886
887
	if (port->stop_rx) {
		err = vnet_send_ack(port,
				    &port->vio.drings[VIO_DRIVER_RX_RING],
				    port->stop_rx_idx, -1,
				    VIO_DRING_STOPPED);
		if (err <= 0)
			return err;
	}

888
889
890
891
892
893
894
895
896
897
898
	hdr.seq = dr->snd_nxt;
	delay = 1;
	do {
		err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
		if (err > 0) {
			dr->snd_nxt++;
			break;
		}
		udelay(delay);
		if ((delay <<= 1) > 128)
			delay = 128;
899
900
		if (retries++ > VNET_MAX_RETRIES)
			break;
901
902
903
904
905
906
907
908
909
910
911
	} while (err == -EAGAIN);

	return err;
}

struct vnet_port *__tx_port_find(struct vnet *vp, struct sk_buff *skb)
{
	unsigned int hash = vnet_hashfn(skb->data);
	struct hlist_head *hp = &vp->port_hash[hash];
	struct vnet_port *port;

912
	hlist_for_each_entry_rcu(port, hp, hash) {
913
914
		if (!port_is_up(port))
			continue;
915
		if (ether_addr_equal(port->raddr, skb->data))
916
917
			return port;
	}
918
	list_for_each_entry_rcu(port, &vp->port_list, list) {
919
920
921
922
923
924
925
		if (!port->switch_port)
			continue;
		if (!port_is_up(port))
			continue;
		return port;
	}
	return NULL;
926
927
}

928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
static struct sk_buff *vnet_clean_tx_ring(struct vnet_port *port,
					  unsigned *pending)
{
	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
	struct sk_buff *skb = NULL;
	int i, txi;

	*pending = 0;

	txi = dr->prod-1;
	if (txi < 0)
		txi = VNET_TX_RING_SIZE-1;

	for (i = 0; i < VNET_TX_RING_SIZE; ++i) {
		struct vio_net_desc *d;

		d = vio_dring_entry(dr, txi);

		if (d->hdr.state == VIO_DESC_DONE) {
			if (port->tx_bufs[txi].skb) {
				BUG_ON(port->tx_bufs[txi].skb->next);

				port->tx_bufs[txi].skb->next = skb;
				skb = port->tx_bufs[txi].skb;
				port->tx_bufs[txi].skb = NULL;

				ldc_unmap(port->vio.lp,
					  port->tx_bufs[txi].cookies,
					  port->tx_bufs[txi].ncookies);
			}
			d->hdr.state = VIO_DESC_FREE;
		} else if (d->hdr.state == VIO_DESC_READY) {
			(*pending)++;
		} else if (d->hdr.state == VIO_DESC_FREE) {
			break;
		}
		--txi;
		if (txi < 0)
			txi = VNET_TX_RING_SIZE-1;
	}
	return skb;
}

static inline void vnet_free_skbs(struct sk_buff *skb)
{
	struct sk_buff *next;

	while (skb) {
		next = skb->next;
		skb->next = NULL;
		dev_kfree_skb(skb);
		skb = next;
	}
}

static void vnet_clean_timer_expire(unsigned long port0)
{
	struct vnet_port *port = (struct vnet_port *)port0;
	struct sk_buff *freeskbs;
	unsigned pending;

989
	netif_tx_lock(port->vp->dev);
990
	freeskbs = vnet_clean_tx_ring(port, &pending);
991
	netif_tx_unlock(port->vp->dev);
992
993
994
995
996
997
998
999
1000
1001

	vnet_free_skbs(freeskbs);

	if (pending)
		(void)mod_timer(&port->clean_timer,
				jiffies + VNET_CLEAN_TIMEOUT);
	 else
		del_timer(&port->clean_timer);
}

1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
static inline int vnet_skb_map(struct ldc_channel *lp, struct sk_buff *skb,
			       struct ldc_trans_cookie *cookies, int ncookies,
			       unsigned int map_perm)
{
	int i, nc, err, blen;

	/* header */
	blen = skb_headlen(skb);
	if (blen < ETH_ZLEN)
		blen = ETH_ZLEN;
	blen += VNET_PACKET_SKIP;
	blen += 8 - (blen & 7);

	err = ldc_map_single(lp, skb->data-VNET_PACKET_SKIP, blen, cookies,
			     ncookies, map_perm);
	if (err < 0)
		return err;
	nc = err;

	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
		skb_frag_t *f = &skb_shinfo(skb)->frags[i];
		u8 *vaddr;

		if (nc < ncookies) {
			vaddr = kmap_atomic(skb_frag_page(f));
			blen = skb_frag_size(f);
			blen += 8 - (blen & 7);
			err = ldc_map_single(lp, vaddr + f->page_offset,
					     blen, cookies + nc, ncookies - nc,
					     map_perm);
			kunmap_atomic(vaddr);
		} else {
			err = -EMSGSIZE;
		}

		if (err < 0) {
			ldc_unmap(lp, cookies, nc);
			return err;
		}
		nc += err;
	}
	return nc;
}

static inline struct sk_buff *vnet_skb_shape(struct sk_buff *skb, int ncookies)
1047
1048
{
	struct sk_buff *nskb;
1049
	int i, len, pad, docopy;
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059

	len = skb->len;
	pad = 0;
	if (len < ETH_ZLEN) {
		pad += ETH_ZLEN - skb->len;
		len += pad;
	}
	len += VNET_PACKET_SKIP;
	pad += 8 - (len & 7);

1060
1061
1062
1063
1064
1065
1066
	/* make sure we have enough cookies and alignment in every frag */
	docopy = skb_shinfo(skb)->nr_frags >= ncookies;
	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
		skb_frag_t *f = &skb_shinfo(skb)->frags[i];

		docopy |= f->page_offset & 7;
	}
1067
1068
	if (((unsigned long)skb->data & 7) != VNET_PACKET_SKIP ||
	    skb_tailroom(skb) < pad ||
1069
	    skb_headroom(skb) < VNET_PACKET_SKIP || docopy) {
1070
1071
		int start = 0, offset;
		__wsum csum;
1072

1073
1074
1075
1076
1077
1078
		len = skb->len > ETH_ZLEN ? skb->len : ETH_ZLEN;
		nskb = alloc_and_align_skb(skb->dev, len);
		if (nskb == NULL) {
			dev_kfree_skb(skb);
			return NULL;
		}
1079
		skb_reserve(nskb, VNET_PACKET_SKIP);
1080
1081
1082
1083
1084
1085
1086
1087
1088

		nskb->protocol = skb->protocol;
		offset = skb_mac_header(skb) - skb->data;
		skb_set_mac_header(nskb, offset);
		offset = skb_network_header(skb) - skb->data;
		skb_set_network_header(nskb, offset);
		offset = skb_transport_header(skb) - skb->data;
		skb_set_transport_header(nskb, offset);

1089
		offset = 0;
1090
1091
1092
		nskb->csum_offset = skb->csum_offset;
		nskb->ip_summed = skb->ip_summed;

1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
		if (skb->ip_summed == CHECKSUM_PARTIAL)
			start = skb_checksum_start_offset(skb);
		if (start) {
			struct iphdr *iph = ip_hdr(nskb);
			int offset = start + nskb->csum_offset;

			if (skb_copy_bits(skb, 0, nskb->data, start)) {
				dev_kfree_skb(nskb);
				dev_kfree_skb(skb);
				return NULL;
			}
			*(__sum16 *)(skb->data + offset) = 0;
			csum = skb_copy_and_csum_bits(skb, start,
						      nskb->data + start,
						      skb->len - start, 0);
			if (iph->protocol == IPPROTO_TCP ||
			    iph->protocol == IPPROTO_UDP) {
				csum = csum_tcpudp_magic(iph->saddr, iph->daddr,
							 skb->len - start,
							 iph->protocol, csum);
			}
			*(__sum16 *)(nskb->data + offset) = csum;

			nskb->ip_summed = CHECKSUM_NONE;
		} else if (skb_copy_bits(skb, 0, nskb->data, skb->len)) {
1118
1119
1120
1121
1122
			dev_kfree_skb(nskb);
			dev_kfree_skb(skb);
			return NULL;
		}
		(void)skb_put(nskb, skb->len);
David L Stevens's avatar
David L Stevens committed
1123
1124
1125
1126
		if (skb_is_gso(skb)) {
			skb_shinfo(nskb)->gso_size = skb_shinfo(skb)->gso_size;
			skb_shinfo(nskb)->gso_type = skb_shinfo(skb)->gso_type;
		}
1127
1128
1129
1130
1131
1132
		dev_kfree_skb(skb);
		skb = nskb;
	}
	return skb;
}

1133
1134
1135
1136
1137
1138
1139
static u16
vnet_select_queue(struct net_device *dev, struct sk_buff *skb,
		  void *accel_priv, select_queue_fallback_t fallback)
{
	struct vnet *vp = netdev_priv(dev);
	struct vnet_port *port = __tx_port_find(vp, skb);

1140
1141
	if (port == NULL)
		return 0;
1142
1143
1144
	return port->q_index;
}

David L Stevens's avatar
David L Stevens committed
1145
1146
1147
1148
1149
1150
1151
static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev);

static int vnet_handle_offloads(struct vnet_port *port, struct sk_buff *skb)
{
	struct net_device *dev = port->vp->dev;
	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
	struct sk_buff *segs;
David L Stevens's avatar
David L Stevens committed
1152
	int maclen, datalen;
David L Stevens's avatar
David L Stevens committed
1153
	int status;
David L Stevens's avatar
David L Stevens committed
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
	int gso_size, gso_type, gso_segs;
	int hlen = skb_transport_header(skb) - skb_mac_header(skb);
	int proto = IPPROTO_IP;

	if (skb->protocol == htons(ETH_P_IP))
		proto = ip_hdr(skb)->protocol;
	else if (skb->protocol == htons(ETH_P_IPV6))
		proto = ipv6_hdr(skb)->nexthdr;

	if (proto == IPPROTO_TCP)
		hlen += tcp_hdr(skb)->doff * 4;
	else if (proto == IPPROTO_UDP)
		hlen += sizeof(struct udphdr);
	else {
		pr_err("vnet_handle_offloads GSO with unknown transport "
		       "protocol %d tproto %d\n", skb->protocol, proto);
		hlen = 128; /* XXX */
	}
	datalen = port->tsolen - hlen;

	gso_size = skb_shinfo(skb)->gso_size;
	gso_type = skb_shinfo(skb)->gso_type;
	gso_segs = skb_shinfo(skb)->gso_segs;

	if (port->tso && gso_size < datalen)
		gso_segs = DIV_ROUND_UP(skb->len - hlen, datalen);
David L Stevens's avatar
David L Stevens committed
1180

David L Stevens's avatar
David L Stevens committed
1181
	if (unlikely(vnet_tx_dring_avail(dr) < gso_segs)) {
David L Stevens's avatar
David L Stevens committed
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
		struct netdev_queue *txq;

		txq  = netdev_get_tx_queue(dev, port->q_index);
		netif_tx_stop_queue(txq);
		if (vnet_tx_dring_avail(dr) < skb_shinfo(skb)->gso_segs)
			return NETDEV_TX_BUSY;
		netif_tx_wake_queue(txq);
	}

	maclen = skb_network_header(skb) - skb_mac_header(skb);
	skb_pull(skb, maclen);

David L Stevens's avatar
David L Stevens committed
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
	if (port->tso && gso_size < datalen) {
		/* segment to TSO size */
		skb_shinfo(skb)->gso_size = datalen;
		skb_shinfo(skb)->gso_segs = gso_segs;

		segs = skb_gso_segment(skb, dev->features & ~NETIF_F_TSO);

		/* restore gso_size & gso_segs */
		skb_shinfo(skb)->gso_size = gso_size;
		skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len - hlen,
							 gso_size);
	} else
		segs = skb_gso_segment(skb, dev->features & ~NETIF_F_TSO);
David L Stevens's avatar
David L Stevens committed
1207
1208
	if (IS_ERR(segs)) {
		dev->stats.tx_dropped++;
1209
		dev_kfree_skb_any(skb);
David L Stevens's avatar
David L Stevens committed
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
		return NETDEV_TX_OK;
	}

	skb_push(skb, maclen);
	skb_reset_mac_header(skb);

	status = 0;
	while (segs) {
		struct sk_buff *curr = segs;

		segs = segs->next;
		curr->next = NULL;
David L Stevens's avatar
David L Stevens committed
1222
1223
1224
1225
1226
1227
1228
		if (port->tso && curr->len > dev->mtu) {
			skb_shinfo(curr)->gso_size = gso_size;
			skb_shinfo(curr)->gso_type = gso_type;
			skb_shinfo(curr)->gso_segs =
				DIV_ROUND_UP(curr->len - hlen, gso_size);
		} else
			skb_shinfo(curr)->gso_size = 0;
David L Stevens's avatar
David L Stevens committed
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250

		skb_push(curr, maclen);
		skb_reset_mac_header(curr);
		memcpy(skb_mac_header(curr), skb_mac_header(skb),
		       maclen);
		curr->csum_start = skb_transport_header(curr) - curr->head;
		if (ip_hdr(curr)->protocol == IPPROTO_TCP)
			curr->csum_offset = offsetof(struct tcphdr, check);
		else if (ip_hdr(curr)->protocol == IPPROTO_UDP)
			curr->csum_offset = offsetof(struct udphdr, check);

		if (!(status & NETDEV_TX_MASK))
			status = vnet_start_xmit(curr, dev);
		if (status & NETDEV_TX_MASK)
			dev_kfree_skb_any(curr);
	}

	if (!(status & NETDEV_TX_MASK))
		dev_kfree_skb_any(skb);
	return status;
}

1251
1252
1253
static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct vnet *vp = netdev_priv(dev);
1254
	struct vnet_port *port = NULL;
1255
1256
1257
	struct vio_dring_state *dr;
	struct vio_net_desc *d;
	unsigned int len;
1258
1259
1260
	struct sk_buff *freeskbs = NULL;
	int i, err, txi;
	unsigned pending = 0;
1261
	struct netdev_queue *txq;
1262

1263
	rcu_read_lock();
1264
	port = __tx_port_find(vp, skb);
1265
1266
	if (unlikely(!port)) {
		rcu_read_unlock();
1267
		goto out_dropped;
1268
	}
1269

David L Stevens's avatar
David L Stevens committed
1270
	if (skb_is_gso(skb) && skb->len > port->tsolen) {
David L Stevens's avatar
David L Stevens committed
1271
1272
1273
1274
1275
		err = vnet_handle_offloads(port, skb);
		rcu_read_unlock();
		return err;
	}

David L Stevens's avatar
David L Stevens committed
1276
	if (!skb_is_gso(skb) && skb->len > port->rmtu) {
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
		unsigned long localmtu = port->rmtu - ETH_HLEN;

		if (vio_version_after_eq(&port->vio, 1, 3))
			localmtu -= VLAN_HLEN;

		if (skb->protocol == htons(ETH_P_IP)) {
			struct flowi4 fl4;
			struct rtable *rt = NULL;

			memset(&fl4, 0, sizeof(fl4));
			fl4.flowi4_oif = dev->ifindex;
			fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos);
			fl4.daddr = ip_hdr(skb)->daddr;
			fl4.saddr = ip_hdr(skb)->saddr;

			rt = ip_route_output_key(dev_net(dev), &fl4);
1293
			rcu_read_unlock();
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
			if (!IS_ERR(rt)) {
				skb_dst_set(skb, &rt->dst);
				icmp_send(skb, ICMP_DEST_UNREACH,
					  ICMP_FRAG_NEEDED,
					  htonl(localmtu));
			}
		}
#if IS_ENABLED(CONFIG_IPV6)
		else if (skb->protocol == htons(ETH_P_IPV6))
			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, localmtu);
#endif
1305
		goto out_dropped;
1306
	}
1307

1308
1309
	skb = vnet_skb_shape(skb, 2);

1310
	if (unlikely(!skb))
1311
1312
		goto out_dropped;

1313
1314
1315
	if (skb->ip_summed == CHECKSUM_PARTIAL)
		vnet_fullcsum(skb);

1316
	dr = &port->vio.drings[VIO_DRIVER_TX_RING];
1317
1318
	i = skb_get_queue_mapping(skb);
	txq = netdev_get_tx_queue(dev, i);
1319
	if (unlikely(vnet_tx_dring_avail(dr) < 1)) {
1320
1321
		if (!netif_tx_queue_stopped(txq)) {
			netif_tx_stop_queue(txq);
1322
1323

			/* This is a hard error, log it. */
1324
			netdev_err(dev, "BUG! Tx Ring full when queue awake!\n");
1325
1326
			dev->stats.tx_errors++;
		}
1327
		rcu_read_unlock();
1328
1329
1330
1331
1332
		return NETDEV_TX_BUSY;
	}

	d = vio_dring_cur(dr);

1333
1334
1335
1336
1337
	txi = dr->prod;

	freeskbs = vnet_clean_tx_ring(port, &pending);

	BUG_ON(port->tx_bufs[txi].skb);
1338
1339

	len = skb->len;
1340
	if (len < ETH_ZLEN)
1341
		len = ETH_ZLEN;
1342

1343
1344
	err = vnet_skb_map(port->vio.lp, skb, port->tx_bufs[txi].cookies, 2,
			   (LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_RW));
1345
1346
	if (err < 0) {
		netdev_info(dev, "tx buffer map error %d\n", err);
1347
		goto out_dropped;
1348
	}
1349
1350
1351

	port->tx_bufs[txi].skb = skb;
	skb = NULL;
1352
	port->tx_bufs[txi].ncookies = err;
1353

1354
1355
1356
1357
1358
1359
1360
1361
1362
	/* We don't rely on the ACKs to free the skb in vnet_start_xmit(),
	 * thus it is safe to not set VIO_ACK_ENABLE for each transmission:
	 * the protocol itself does not require it as long as the peer
	 * sends a VIO_SUBTYPE_ACK for VIO_DRING_STOPPED.
	 *
	 * An ACK for every packet in the ring is expensive as the
	 * sending of LDC messages is slow and affects performance.
	 */
	d->hdr.ack = VIO_ACK_DISABLE;
1363
	d->size = len;
1364
	d->ncookies = port->tx_bufs[txi].ncookies;
1365
	for (i = 0; i < d->ncookies; i++)
1366
		d->cookies[i] = port->tx_bufs[txi].cookies[i];
1367
1368
1369
1370
	if (vio_version_after_eq(&port->vio, 1, 7)) {
		struct vio_net_dext *dext = vio_net_ext(d);

		memset(dext, 0, sizeof(*dext));
David L Stevens's avatar
David L Stevens committed
1371
1372
1373
1374
1375
		if (skb_is_gso(port->tx_bufs[txi].skb)) {
			dext->ipv4_lso_mss = skb_shinfo(port->tx_bufs[txi].skb)
					     ->gso_size;
			dext->flags |= VNET_PKT_IPV4_LSO;
		}
1376
1377
1378
1379
1380
1381
		if (vio_version_after_eq(&port->vio, 1, 8) &&
		    !port->switch_port) {
			dext->flags |= VNET_PKT_HCK_IPV4_HDRCKSUM_OK;
			dext->flags |= VNET_PKT_HCK_FULLCKSUM_OK;
		}
	}
1382
1383
1384
1385
1386
1387
1388
1389

	/* This has to be a non-SMP write barrier because we are writing
	 * to memory which is shared with the peer LDOM.
	 */
	wmb();

	d->hdr.state = VIO_DESC_READY;

1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
	/* Exactly one ldc "start" trigger (for dr->cons) needs to be sent
	 * to notify the consumer that some descriptors are READY.
	 * After that "start" trigger, no additional triggers are needed until
	 * a DRING_STOPPED is received from the consumer. The dr->cons field
	 * (set up by vnet_ack()) has the value of the next dring index
	 * that has not yet been ack-ed. We send a "start" trigger here
	 * if, and only if, start_cons is true (reset it afterward). Conversely,
	 * vnet_ack() should check if the dring corresponding to cons
	 * is marked READY, but start_cons was false.
	 * If so, vnet_ack() should send out the missed "start" trigger.
	 *
	 * Note that the wmb() above makes sure the cookies et al. are
	 * not globally visible before the VIO_DESC_READY, and that the
	 * stores are ordered correctly by the compiler. The consumer will
	 * not proceed until the VIO_DESC_READY is visible assuring that
	 * the consumer does not observe anything related to descriptors
	 * out of order. The HV trap from the LDC start trigger is the
	 * producer to consumer announcement that work is available to the
	 * consumer
	 */
	if (!port->start_cons)
		goto ldc_start_done; /* previous trigger suffices */

	err = __vnet_tx_trigger(port, dr->cons);
1414
	if (unlikely(err < 0)) {
1415
		netdev_info(dev, "TX trigger error %d\n", err);
1416
1417
		d->hdr.state = VIO_DESC_FREE;
		dev->stats.tx_carrier_errors++;
1418
		goto out_dropped;
1419
1420
	}

1421
1422
1423
ldc_start_done:
	port->start_cons = false;

1424
	dev->stats.tx_packets++;
1425
	dev->stats.tx_bytes += port->tx_bufs[txi].skb->len;
1426
1427

	dr->prod = (dr->prod + 1) & (VNET_TX_RING_SIZE - 1);
1428
	if (unlikely(vnet_tx_dring_avail(dr) < 1)) {
1429
		netif_tx_stop_queue(txq);
1430
		if (vnet_tx_dring_avail(dr) > VNET_TX_WAKEUP_THRESH(dr))
1431
			netif_tx_wake_queue(txq);
1432
1433
	}

1434
1435
	(void)mod_timer(&port->clean_timer, jiffies + VNET_CLEAN_TIMEOUT);
	rcu_read_unlock();
1436

1437
1438
	vnet_free_skbs(freeskbs);

1439
1440
1441
	return NETDEV_TX_OK;

out_dropped:
1442
1443
1444
	if (pending)
		(void)mod_timer(&port->clean_timer,
				jiffies + VNET_CLEAN_TIMEOUT);
1445
	else if (port)
1446
		del_timer(&port->clean_timer);
1447
1448
1449
1450
1451
	if (port)
		rcu_read_unlock();
	if (skb)
		dev_kfree_skb(skb);
	vnet_free_skbs(freeskbs);
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
	dev->stats.tx_dropped++;
	return NETDEV_TX_OK;
}

static void vnet_tx_timeout(struct net_device *dev)
{
	/* XXX Implement me XXX */
}

static int vnet_open(struct net_device *dev)
{
	netif_carrier_on(dev);
1464
	netif_tx_start_all_queues(dev);
1465
1466
1467
1468
1469
1470

	return 0;
}

static int vnet_close(struct net_device *dev)
{
1471
	netif_tx_stop_all_queues(dev);
1472
1473
1474
1475
1476
	netif_carrier_off(dev);

	return 0;
}

1477
1478
1479
1480
1481
static struct vnet_mcast_entry *__vnet_mc_find(struct vnet *vp, u8 *addr)
{
	struct vnet_mcast_entry *m;

	for (m = vp->mcast_list; m; m = m->next) {
1482
		if (ether_addr_equal(m->addr, addr))
1483
1484
1485