?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
tcp: tsq: add shortcut in tcp_tasklet_func()
[linux-2.6/btrfs-unstable.git] / drivers / net / xen-netfront.c
blobe085c8c31cfe0d21f5ad4c2c9fe94f0514c10a98
1 /*
2 * Virtual network driver for conversing with remote driver backends.
3 *
4 * Copyright (c) 2002-2005, K A Fraser
5 * Copyright (c) 2005, XenSource Ltd
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version 2
9 * as published by the Free Software Foundation; or, when distributed
10 * separately from the Linux kernel or incorporated into other
11 * software packages, subject to the following license:
12 *
13 * Permission is hereby granted, free of charge, to any person obtaining a copy
14 * of this source file (the "Software"), to deal in the Software without
15 * restriction, including without limitation the rights to use, copy, modify,
16 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
17 * and to permit persons to whom the Software is furnished to do so, subject to
18 * the following conditions:
19 *
20 * The above copyright notice and this permission notice shall be included in
21 * all copies or substantial portions of the Software.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
24 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
25 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
26 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
27 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
28 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
29 * IN THE SOFTWARE.
30 */
31
32 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
33
34 #include <linux/module.h>
35 #include <linux/kernel.h>
36 #include <linux/netdevice.h>
37 #include <linux/etherdevice.h>
38 #include <linux/skbuff.h>
39 #include <linux/ethtool.h>
40 #include <linux/if_ether.h>
41 #include <net/tcp.h>
42 #include <linux/udp.h>
43 #include <linux/moduleparam.h>
44 #include <linux/mm.h>
45 #include <linux/slab.h>
46 #include <net/ip.h>
47
48 #include <xen/xen.h>
49 #include <xen/xenbus.h>
50 #include <xen/events.h>
51 #include <xen/page.h>
52 #include <xen/platform_pci.h>
53 #include <xen/grant_table.h>
54
55 #include <xen/interface/io/netif.h>
56 #include <xen/interface/memory.h>
57 #include <xen/interface/grant_table.h>
58
59 /* Module parameters */
60 static unsigned int xennet_max_queues;
61 module_param_named(max_queues, xennet_max_queues, uint, 0644);
62 MODULE_PARM_DESC(max_queues,
63 "Maximum number of queues per virtual interface");
64
65 static const struct ethtool_ops xennet_ethtool_ops;
66
67 struct netfront_cb {
68 int pull_to;
69 };
70
71 #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
72
73 #define RX_COPY_THRESHOLD 256
74
75 #define GRANT_INVALID_REF 0
76
77 #define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE)
78 #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE)
79
80 /* Minimum number of Rx slots (includes slot for GSO metadata). */
81 #define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1)
82
83 /* Queue name is interface name with "-qNNN" appended */
84 #define QUEUE_NAME_SIZE (IFNAMSIZ + 6)
85
86 /* IRQ name is queue name with "-tx" or "-rx" appended */
87 #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
88
89 struct netfront_stats {
90 u64 packets;
91 u64 bytes;
92 struct u64_stats_sync syncp;
93 };
94
95 struct netfront_info;
96
97 struct netfront_queue {
98 unsigned int id; /* Queue ID, 0-based */
99 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
100 struct netfront_info *info;
101
102 struct napi_struct napi;
103
104 /* Split event channels support, tx_* == rx_* when using
105 * single event channel.
106 */
107 unsigned int tx_evtchn, rx_evtchn;
108 unsigned int tx_irq, rx_irq;
109 /* Only used when split event channels support is enabled */
110 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
111 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
112
113 spinlock_t tx_lock;
114 struct xen_netif_tx_front_ring tx;
115 int tx_ring_ref;
116
117 /*
118 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
119 * are linked from tx_skb_freelist through skb_entry.link.
120 *
121 * NB. Freelist index entries are always going to be less than
122 * PAGE_OFFSET, whereas pointers to skbs will always be equal or
123 * greater than PAGE_OFFSET: we use this property to distinguish
124 * them.
125 */
126 union skb_entry {
127 struct sk_buff *skb;
128 unsigned long link;
129 } tx_skbs[NET_TX_RING_SIZE];
130 grant_ref_t gref_tx_head;
131 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
132 struct page *grant_tx_page[NET_TX_RING_SIZE];
133 unsigned tx_skb_freelist;
134
135 spinlock_t rx_lock ____cacheline_aligned_in_smp;
136 struct xen_netif_rx_front_ring rx;
137 int rx_ring_ref;
138
139 struct timer_list rx_refill_timer;
140
141 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
142 grant_ref_t gref_rx_head;
143 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
144 };
145
146 struct netfront_info {
147 struct list_head list;
148 struct net_device *netdev;
149
150 struct xenbus_device *xbdev;
151
152 /* Multi-queue support */
153 struct netfront_queue *queues;
154
155 /* Statistics */
156 struct netfront_stats __percpu *rx_stats;
157 struct netfront_stats __percpu *tx_stats;
158
159 atomic_t rx_gso_checksum_fixup;
160 };
161
162 struct netfront_rx_info {
163 struct xen_netif_rx_response rx;
164 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
165 };
166
167 static void skb_entry_set_link(union skb_entry *list, unsigned short id)
168 {
169 list->link = id;
170 }
171
172 static int skb_entry_is_link(const union skb_entry *list)
173 {
174 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
175 return (unsigned long)list->skb < PAGE_OFFSET;
176 }
177
178 /*
179 * Access macros for acquiring freeing slots in tx_skbs[].
180 */
181
182 static void add_id_to_freelist(unsigned *head, union skb_entry *list,
183 unsigned short id)
184 {
185 skb_entry_set_link(&list[id], *head);
186 *head = id;
187 }
188
189 static unsigned short get_id_from_freelist(unsigned *head,
190 union skb_entry *list)
191 {
192 unsigned int id = *head;
193 *head = list[id].link;
194 return id;
195 }
196
197 static int xennet_rxidx(RING_IDX idx)
198 {
199 return idx & (NET_RX_RING_SIZE - 1);
200 }
201
202 static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue,
203 RING_IDX ri)
204 {
205 int i = xennet_rxidx(ri);
206 struct sk_buff *skb = queue->rx_skbs[i];
207 queue->rx_skbs[i] = NULL;
208 return skb;
209 }
210
211 static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
212 RING_IDX ri)
213 {
214 int i = xennet_rxidx(ri);
215 grant_ref_t ref = queue->grant_rx_ref[i];
216 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
217 return ref;
218 }
219
220 #ifdef CONFIG_SYSFS
221 static const struct attribute_group xennet_dev_group;
222 #endif
223
224 static bool xennet_can_sg(struct net_device *dev)
225 {
226 return dev->features & NETIF_F_SG;
227 }
228
229
230 static void rx_refill_timeout(unsigned long data)
231 {
232 struct netfront_queue *queue = (struct netfront_queue *)data;
233 napi_schedule(&queue->napi);
234 }
235
236 static int netfront_tx_slot_available(struct netfront_queue *queue)
237 {
238 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
239 (NET_TX_RING_SIZE - MAX_SKB_FRAGS - 2);
240 }
241
242 static void xennet_maybe_wake_tx(struct netfront_queue *queue)
243 {
244 struct net_device *dev = queue->info->netdev;
245 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id);
246
247 if (unlikely(netif_tx_queue_stopped(dev_queue)) &&
248 netfront_tx_slot_available(queue) &&
249 likely(netif_running(dev)))
250 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
251 }
252
253
254 static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue)
255 {
256 struct sk_buff *skb;
257 struct page *page;
258
259 skb = __netdev_alloc_skb(queue->info->netdev,
260 RX_COPY_THRESHOLD + NET_IP_ALIGN,
261 GFP_ATOMIC | __GFP_NOWARN);
262 if (unlikely(!skb))
263 return NULL;
264
265 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
266 if (!page) {
267 kfree_skb(skb);
268 return NULL;
269 }
270 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
271
272 /* Align ip header to a 16 bytes boundary */
273 skb_reserve(skb, NET_IP_ALIGN);
274 skb->dev = queue->info->netdev;
275
276 return skb;
277 }
278
279
280 static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
281 {
282 RING_IDX req_prod = queue->rx.req_prod_pvt;
283 int notify;
284
285 if (unlikely(!netif_carrier_ok(queue->info->netdev)))
286 return;
287
288 for (req_prod = queue->rx.req_prod_pvt;
289 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE;
290 req_prod++) {
291 struct sk_buff *skb;
292 unsigned short id;
293 grant_ref_t ref;
294 struct page *page;
295 struct xen_netif_rx_request *req;
296
297 skb = xennet_alloc_one_rx_buffer(queue);
298 if (!skb)
299 break;
300
301 id = xennet_rxidx(req_prod);
302
303 BUG_ON(queue->rx_skbs[id]);
304 queue->rx_skbs[id] = skb;
305
306 ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
307 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
308 queue->grant_rx_ref[id] = ref;
309
310 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
311
312 req = RING_GET_REQUEST(&queue->rx, req_prod);
313 gnttab_page_grant_foreign_access_ref_one(ref,
314 queue->info->xbdev->otherend_id,
315 page,
316 0);
317 req->id = id;
318 req->gref = ref;
319 }
320
321 queue->rx.req_prod_pvt = req_prod;
322
323 /* Not enough requests? Try again later. */
324 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN) {
325 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
326 return;
327 }
328
329 wmb(); /* barrier so backend seens requests */
330
331 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
332 if (notify)
333 notify_remote_via_irq(queue->rx_irq);
334 }
335
336 static int xennet_open(struct net_device *dev)
337 {
338 struct netfront_info *np = netdev_priv(dev);
339 unsigned int num_queues = dev->real_num_tx_queues;
340 unsigned int i = 0;
341 struct netfront_queue *queue = NULL;
342
343 for (i = 0; i < num_queues; ++i) {
344 queue = &np->queues[i];
345 napi_enable(&queue->napi);
346
347 spin_lock_bh(&queue->rx_lock);
348 if (netif_carrier_ok(dev)) {
349 xennet_alloc_rx_buffers(queue);
350 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1;
351 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))
352 napi_schedule(&queue->napi);
353 }
354 spin_unlock_bh(&queue->rx_lock);
355 }
356
357 netif_tx_start_all_queues(dev);
358
359 return 0;
360 }
361
362 static void xennet_tx_buf_gc(struct netfront_queue *queue)
363 {
364 RING_IDX cons, prod;
365 unsigned short id;
366 struct sk_buff *skb;
367 bool more_to_do;
368
369 BUG_ON(!netif_carrier_ok(queue->info->netdev));
370
371 do {
372 prod = queue->tx.sring->rsp_prod;
373 rmb(); /* Ensure we see responses up to 'rp'. */
374
375 for (cons = queue->tx.rsp_cons; cons != prod; cons++) {
376 struct xen_netif_tx_response *txrsp;
377
378 txrsp = RING_GET_RESPONSE(&queue->tx, cons);
379 if (txrsp->status == XEN_NETIF_RSP_NULL)
380 continue;
381
382 id = txrsp->id;
383 skb = queue->tx_skbs[id].skb;
384 if (unlikely(gnttab_query_foreign_access(
385 queue->grant_tx_ref[id]) != 0)) {
386 pr_alert("%s: warning -- grant still in use by backend domain\n",
387 __func__);
388 BUG();
389 }
390 gnttab_end_foreign_access_ref(
391 queue->grant_tx_ref[id], GNTMAP_readonly);
392 gnttab_release_grant_reference(
393 &queue->gref_tx_head, queue->grant_tx_ref[id]);
394 queue->grant_tx_ref[id] = GRANT_INVALID_REF;
395 queue->grant_tx_page[id] = NULL;
396 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id);
397 dev_kfree_skb_irq(skb);
398 }
399
400 queue->tx.rsp_cons = prod;
401
402 RING_FINAL_CHECK_FOR_RESPONSES(&queue->tx, more_to_do);
403 } while (more_to_do);
404
405 xennet_maybe_wake_tx(queue);
406 }
407
408 struct xennet_gnttab_make_txreq {
409 struct netfront_queue *queue;
410 struct sk_buff *skb;
411 struct page *page;
412 struct xen_netif_tx_request *tx; /* Last request */
413 unsigned int size;
414 };
415
416 static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset,
417 unsigned int len, void *data)
418 {
419 struct xennet_gnttab_make_txreq *info = data;
420 unsigned int id;
421 struct xen_netif_tx_request *tx;
422 grant_ref_t ref;
423 /* convenient aliases */
424 struct page *page = info->page;
425 struct netfront_queue *queue = info->queue;
426 struct sk_buff *skb = info->skb;
427
428 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
429 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
430 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
431 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
432
433 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
434 gfn, GNTMAP_readonly);
435
436 queue->tx_skbs[id].skb = skb;
437 queue->grant_tx_page[id] = page;
438 queue->grant_tx_ref[id] = ref;
439
440 tx->id = id;
441 tx->gref = ref;
442 tx->offset = offset;
443 tx->size = len;
444 tx->flags = 0;
445
446 info->tx = tx;
447 info->size += tx->size;
448 }
449
450 static struct xen_netif_tx_request *xennet_make_first_txreq(
451 struct netfront_queue *queue, struct sk_buff *skb,
452 struct page *page, unsigned int offset, unsigned int len)
453 {
454 struct xennet_gnttab_make_txreq info = {
455 .queue = queue,
456 .skb = skb,
457 .page = page,
458 .size = 0,
459 };
460
461 gnttab_for_one_grant(page, offset, len, xennet_tx_setup_grant, &info);
462
463 return info.tx;
464 }
465
466 static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset,
467 unsigned int len, void *data)
468 {
469 struct xennet_gnttab_make_txreq *info = data;
470
471 info->tx->flags |= XEN_NETTXF_more_data;
472 skb_get(info->skb);
473 xennet_tx_setup_grant(gfn, offset, len, data);
474 }
475
476 static struct xen_netif_tx_request *xennet_make_txreqs(
477 struct netfront_queue *queue, struct xen_netif_tx_request *tx,
478 struct sk_buff *skb, struct page *page,
479 unsigned int offset, unsigned int len)
480 {
481 struct xennet_gnttab_make_txreq info = {
482 .queue = queue,
483 .skb = skb,
484 .tx = tx,
485 };
486
487 /* Skip unused frames from start of page */
488 page += offset >> PAGE_SHIFT;
489 offset &= ~PAGE_MASK;
490
491 while (len) {
492 info.page = page;
493 info.size = 0;
494
495 gnttab_foreach_grant_in_range(page, offset, len,
496 xennet_make_one_txreq,
497 &info);
498
499 page++;
500 offset = 0;
501 len -= info.size;
502 }
503
504 return info.tx;
505 }
506
507 /*
508 * Count how many ring slots are required to send this skb. Each frag
509 * might be a compound page.
510 */
511 static int xennet_count_skb_slots(struct sk_buff *skb)
512 {
513 int i, frags = skb_shinfo(skb)->nr_frags;
514 int slots;
515
516 slots = gnttab_count_grant(offset_in_page(skb->data),
517 skb_headlen(skb));
518
519 for (i = 0; i < frags; i++) {
520 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
521 unsigned long size = skb_frag_size(frag);
522 unsigned long offset = frag->page_offset;
523
524 /* Skip unused frames from start of page */
525 offset &= ~PAGE_MASK;
526
527 slots += gnttab_count_grant(offset, size);
528 }
529
530 return slots;
531 }
532
533 static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
534 void *accel_priv, select_queue_fallback_t fallback)
535 {
536 unsigned int num_queues = dev->real_num_tx_queues;
537 u32 hash;
538 u16 queue_idx;
539
540 /* First, check if there is only one queue */
541 if (num_queues == 1) {
542 queue_idx = 0;
543 } else {
544 hash = skb_get_hash(skb);
545 queue_idx = hash % num_queues;
546 }
547
548 return queue_idx;
549 }
550
551 #define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1)
552
553 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
554 {
555 struct netfront_info *np = netdev_priv(dev);
556 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
557 struct xen_netif_tx_request *tx, *first_tx;
558 unsigned int i;
559 int notify;
560 int slots;
561 struct page *page;
562 unsigned int offset;
563 unsigned int len;
564 unsigned long flags;
565 struct netfront_queue *queue = NULL;
566 unsigned int num_queues = dev->real_num_tx_queues;
567 u16 queue_index;
568 struct sk_buff *nskb;
569
570 /* Drop the packet if no queues are set up */
571 if (num_queues < 1)
572 goto drop;
573 /* Determine which queue to transmit this SKB on */
574 queue_index = skb_get_queue_mapping(skb);
575 queue = &np->queues[queue_index];
576
577 /* If skb->len is too big for wire format, drop skb and alert
578 * user about misconfiguration.
579 */
580 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
581 net_alert_ratelimited(
582 "xennet: skb->len = %u, too big for wire format\n",
583 skb->len);
584 goto drop;
585 }
586
587 slots = xennet_count_skb_slots(skb);
588 if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) {
589 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
590 slots, skb->len);
591 if (skb_linearize(skb))
592 goto drop;
593 }
594
595 page = virt_to_page(skb->data);
596 offset = offset_in_page(skb->data);
597
598 /* The first req should be at least ETH_HLEN size or the packet will be
599 * dropped by netback.
600 */
601 if (unlikely(PAGE_SIZE - offset < ETH_HLEN)) {
602 nskb = skb_copy(skb, GFP_ATOMIC);
603 if (!nskb)
604 goto drop;
605 dev_kfree_skb_any(skb);
606 skb = nskb;
607 page = virt_to_page(skb->data);
608 offset = offset_in_page(skb->data);
609 }
610
611 len = skb_headlen(skb);
612
613 spin_lock_irqsave(&queue->tx_lock, flags);
614
615 if (unlikely(!netif_carrier_ok(dev) ||
616 (slots > 1 && !xennet_can_sg(dev)) ||
617 netif_needs_gso(skb, netif_skb_features(skb)))) {
618 spin_unlock_irqrestore(&queue->tx_lock, flags);
619 goto drop;
620 }
621
622 /* First request for the linear area. */
623 first_tx = tx = xennet_make_first_txreq(queue, skb,
624 page, offset, len);
625 offset += tx->size;
626 if (offset == PAGE_SIZE) {
627 page++;
628 offset = 0;
629 }
630 len -= tx->size;
631
632 if (skb->ip_summed == CHECKSUM_PARTIAL)
633 /* local packet? */
634 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
635 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
636 /* remote but checksummed. */
637 tx->flags |= XEN_NETTXF_data_validated;
638
639 /* Optional extra info after the first request. */
640 if (skb_shinfo(skb)->gso_size) {
641 struct xen_netif_extra_info *gso;
642
643 gso = (struct xen_netif_extra_info *)
644 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
645
646 tx->flags |= XEN_NETTXF_extra_info;
647
648 gso->u.gso.size = skb_shinfo(skb)->gso_size;
649 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
650 XEN_NETIF_GSO_TYPE_TCPV6 :
651 XEN_NETIF_GSO_TYPE_TCPV4;
652 gso->u.gso.pad = 0;
653 gso->u.gso.features = 0;
654
655 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
656 gso->flags = 0;
657 }
658
659 /* Requests for the rest of the linear area. */
660 tx = xennet_make_txreqs(queue, tx, skb, page, offset, len);
661
662 /* Requests for all the frags. */
663 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
664 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
665 tx = xennet_make_txreqs(queue, tx, skb,
666 skb_frag_page(frag), frag->page_offset,
667 skb_frag_size(frag));
668 }
669
670 /* First request has the packet length. */
671 first_tx->size = skb->len;
672
673 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
674 if (notify)
675 notify_remote_via_irq(queue->tx_irq);
676
677 u64_stats_update_begin(&tx_stats->syncp);
678 tx_stats->bytes += skb->len;
679 tx_stats->packets++;
680 u64_stats_update_end(&tx_stats->syncp);
681
682 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
683 xennet_tx_buf_gc(queue);
684
685 if (!netfront_tx_slot_available(queue))
686 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
687
688 spin_unlock_irqrestore(&queue->tx_lock, flags);
689
690 return NETDEV_TX_OK;
691
692 drop:
693 dev->stats.tx_dropped++;
694 dev_kfree_skb_any(skb);
695 return NETDEV_TX_OK;
696 }
697
698 static int xennet_close(struct net_device *dev)
699 {
700 struct netfront_info *np = netdev_priv(dev);
701 unsigned int num_queues = dev->real_num_tx_queues;
702 unsigned int i;
703 struct netfront_queue *queue;
704 netif_tx_stop_all_queues(np->netdev);
705 for (i = 0; i < num_queues; ++i) {
706 queue = &np->queues[i];
707 napi_disable(&queue->napi);
708 }
709 return 0;
710 }
711
712 static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
713 grant_ref_t ref)
714 {
715 int new = xennet_rxidx(queue->rx.req_prod_pvt);
716
717 BUG_ON(queue->rx_skbs[new]);
718 queue->rx_skbs[new] = skb;
719 queue->grant_rx_ref[new] = ref;
720 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new;
721 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref;
722 queue->rx.req_prod_pvt++;
723 }
724
725 static int xennet_get_extras(struct netfront_queue *queue,
726 struct xen_netif_extra_info *extras,
727 RING_IDX rp)
728
729 {
730 struct xen_netif_extra_info *extra;
731 struct device *dev = &queue->info->netdev->dev;
732 RING_IDX cons = queue->rx.rsp_cons;
733 int err = 0;
734
735 do {
736 struct sk_buff *skb;
737 grant_ref_t ref;
738
739 if (unlikely(cons + 1 == rp)) {
740 if (net_ratelimit())
741 dev_warn(dev, "Missing extra info\n");
742 err = -EBADR;
743 break;
744 }
745
746 extra = (struct xen_netif_extra_info *)
747 RING_GET_RESPONSE(&queue->rx, ++cons);
748
749 if (unlikely(!extra->type ||
750 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
751 if (net_ratelimit())
752 dev_warn(dev, "Invalid extra type: %d\n",
753 extra->type);
754 err = -EINVAL;
755 } else {
756 memcpy(&extras[extra->type - 1], extra,
757 sizeof(*extra));
758 }
759
760 skb = xennet_get_rx_skb(queue, cons);
761 ref = xennet_get_rx_ref(queue, cons);
762 xennet_move_rx_slot(queue, skb, ref);
763 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
764
765 queue->rx.rsp_cons = cons;
766 return err;
767 }
768
769 static int xennet_get_responses(struct netfront_queue *queue,
770 struct netfront_rx_info *rinfo, RING_IDX rp,
771 struct sk_buff_head *list)
772 {
773 struct xen_netif_rx_response *rx = &rinfo->rx;
774 struct xen_netif_extra_info *extras = rinfo->extras;
775 struct device *dev = &queue->info->netdev->dev;
776 RING_IDX cons = queue->rx.rsp_cons;
777 struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
778 grant_ref_t ref = xennet_get_rx_ref(queue, cons);
779 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
780 int slots = 1;
781 int err = 0;
782 unsigned long ret;
783
784 if (rx->flags & XEN_NETRXF_extra_info) {
785 err = xennet_get_extras(queue, extras, rp);
786 cons = queue->rx.rsp_cons;
787 }
788
789 for (;;) {
790 if (unlikely(rx->status < 0 ||
791 rx->offset + rx->status > XEN_PAGE_SIZE)) {
792 if (net_ratelimit())
793 dev_warn(dev, "rx->offset: %u, size: %d\n",
794 rx->offset, rx->status);
795 xennet_move_rx_slot(queue, skb, ref);
796 err = -EINVAL;
797 goto next;
798 }
799
800 /*
801 * This definitely indicates a bug, either in this driver or in
802 * the backend driver. In future this should flag the bad
803 * situation to the system controller to reboot the backend.
804 */
805 if (ref == GRANT_INVALID_REF) {
806 if (net_ratelimit())
807 dev_warn(dev, "Bad rx response id %d.\n",
808 rx->id);
809 err = -EINVAL;
810 goto next;
811 }
812
813 ret = gnttab_end_foreign_access_ref(ref, 0);
814 BUG_ON(!ret);
815
816 gnttab_release_grant_reference(&queue->gref_rx_head, ref);
817
818 __skb_queue_tail(list, skb);
819
820 next:
821 if (!(rx->flags & XEN_NETRXF_more_data))
822 break;
823
824 if (cons + slots == rp) {
825 if (net_ratelimit())
826 dev_warn(dev, "Need more slots\n");
827 err = -ENOENT;
828 break;
829 }
830
831 rx = RING_GET_RESPONSE(&queue->rx, cons + slots);
832 skb = xennet_get_rx_skb(queue, cons + slots);
833 ref = xennet_get_rx_ref(queue, cons + slots);
834 slots++;
835 }
836
837 if (unlikely(slots > max)) {
838 if (net_ratelimit())
839 dev_warn(dev, "Too many slots\n");
840 err = -E2BIG;
841 }
842
843 if (unlikely(err))
844 queue->rx.rsp_cons = cons + slots;
845
846 return err;
847 }
848
849 static int xennet_set_skb_gso(struct sk_buff *skb,
850 struct xen_netif_extra_info *gso)
851 {
852 if (!gso->u.gso.size) {
853 if (net_ratelimit())
854 pr_warn("GSO size must not be zero\n");
855 return -EINVAL;
856 }
857
858 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
859 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
860 if (net_ratelimit())
861 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
862 return -EINVAL;
863 }
864
865 skb_shinfo(skb)->gso_size = gso->u.gso.size;
866 skb_shinfo(skb)->gso_type =
867 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
868 SKB_GSO_TCPV4 :
869 SKB_GSO_TCPV6;
870
871 /* Header must be checked, and gso_segs computed. */
872 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
873 skb_shinfo(skb)->gso_segs = 0;
874
875 return 0;
876 }
877
878 static RING_IDX xennet_fill_frags(struct netfront_queue *queue,
879 struct sk_buff *skb,
880 struct sk_buff_head *list)
881 {
882 struct skb_shared_info *shinfo = skb_shinfo(skb);
883 RING_IDX cons = queue->rx.rsp_cons;
884 struct sk_buff *nskb;
885
886 while ((nskb = __skb_dequeue(list))) {
887 struct xen_netif_rx_response *rx =
888 RING_GET_RESPONSE(&queue->rx, ++cons);
889 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
890
891 if (shinfo->nr_frags == MAX_SKB_FRAGS) {
892 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
893
894 BUG_ON(pull_to <= skb_headlen(skb));
895 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
896 }
897 BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS);
898
899 skb_add_rx_frag(skb, shinfo->nr_frags, skb_frag_page(nfrag),
900 rx->offset, rx->status, PAGE_SIZE);
901
902 skb_shinfo(nskb)->nr_frags = 0;
903 kfree_skb(nskb);
904 }
905
906 return cons;
907 }
908
909 static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
910 {
911 bool recalculate_partial_csum = false;
912
913 /*
914 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
915 * peers can fail to set NETRXF_csum_blank when sending a GSO
916 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
917 * recalculate the partial checksum.
918 */
919 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
920 struct netfront_info *np = netdev_priv(dev);
921 atomic_inc(&np->rx_gso_checksum_fixup);
922 skb->ip_summed = CHECKSUM_PARTIAL;
923 recalculate_partial_csum = true;
924 }
925
926 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
927 if (skb->ip_summed != CHECKSUM_PARTIAL)
928 return 0;
929
930 return skb_checksum_setup(skb, recalculate_partial_csum);
931 }
932
933 static int handle_incoming_queue(struct netfront_queue *queue,
934 struct sk_buff_head *rxq)
935 {
936 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats);
937 int packets_dropped = 0;
938 struct sk_buff *skb;
939
940 while ((skb = __skb_dequeue(rxq)) != NULL) {
941 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
942
943 if (pull_to > skb_headlen(skb))
944 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
945
946 /* Ethernet work: Delayed to here as it peeks the header. */
947 skb->protocol = eth_type_trans(skb, queue->info->netdev);
948 skb_reset_network_header(skb);
949
950 if (checksum_setup(queue->info->netdev, skb)) {
951 kfree_skb(skb);
952 packets_dropped++;
953 queue->info->netdev->stats.rx_errors++;
954 continue;
955 }
956
957 u64_stats_update_begin(&rx_stats->syncp);
958 rx_stats->packets++;
959 rx_stats->bytes += skb->len;
960 u64_stats_update_end(&rx_stats->syncp);
961
962 /* Pass it up. */
963 napi_gro_receive(&queue->napi, skb);
964 }
965
966 return packets_dropped;
967 }
968
969 static int xennet_poll(struct napi_struct *napi, int budget)
970 {
971 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi);
972 struct net_device *dev = queue->info->netdev;
973 struct sk_buff *skb;
974 struct netfront_rx_info rinfo;
975 struct xen_netif_rx_response *rx = &rinfo.rx;
976 struct xen_netif_extra_info *extras = rinfo.extras;
977 RING_IDX i, rp;
978 int work_done;
979 struct sk_buff_head rxq;
980 struct sk_buff_head errq;
981 struct sk_buff_head tmpq;
982 int err;
983
984 spin_lock(&queue->rx_lock);
985
986 skb_queue_head_init(&rxq);
987 skb_queue_head_init(&errq);
988 skb_queue_head_init(&tmpq);
989
990 rp = queue->rx.sring->rsp_prod;
991 rmb(); /* Ensure we see queued responses up to 'rp'. */
992
993 i = queue->rx.rsp_cons;
994 work_done = 0;
995 while ((i != rp) && (work_done < budget)) {
996 memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx));
997 memset(extras, 0, sizeof(rinfo.extras));
998
999 err = xennet_get_responses(queue, &rinfo, rp, &tmpq);
1000
1001 if (unlikely(err)) {
1002 err:
1003 while ((skb = __skb_dequeue(&tmpq)))
1004 __skb_queue_tail(&errq, skb);
1005 dev->stats.rx_errors++;
1006 i = queue->rx.rsp_cons;
1007 continue;
1008 }
1009
1010 skb = __skb_dequeue(&tmpq);
1011
1012 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1013 struct xen_netif_extra_info *gso;
1014 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1015
1016 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1017 __skb_queue_head(&tmpq, skb);
1018 queue->rx.rsp_cons += skb_queue_len(&tmpq);
1019 goto err;
1020 }
1021 }
1022
1023 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1024 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1025 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1026
1027 skb_shinfo(skb)->frags[0].page_offset = rx->offset;
1028 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1029 skb->data_len = rx->status;
1030 skb->len += rx->status;
1031
1032 i = xennet_fill_frags(queue, skb, &tmpq);
1033
1034 if (rx->flags & XEN_NETRXF_csum_blank)
1035 skb->ip_summed = CHECKSUM_PARTIAL;
1036 else if (rx->flags & XEN_NETRXF_data_validated)
1037 skb->ip_summed = CHECKSUM_UNNECESSARY;
1038
1039 __skb_queue_tail(&rxq, skb);
1040
1041 queue->rx.rsp_cons = ++i;
1042 work_done++;
1043 }
1044
1045 __skb_queue_purge(&errq);
1046
1047 work_done -= handle_incoming_queue(queue, &rxq);
1048
1049 xennet_alloc_rx_buffers(queue);
1050
1051 if (work_done < budget) {
1052 int more_to_do = 0;
1053
1054 napi_complete(napi);
1055
1056 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
1057 if (more_to_do)
1058 napi_schedule(napi);
1059 }
1060
1061 spin_unlock(&queue->rx_lock);
1062
1063 return work_done;
1064 }
1065
1066 static int xennet_change_mtu(struct net_device *dev, int mtu)
1067 {
1068 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN;
1069
1070 if (mtu > max)
1071 return -EINVAL;
1072 dev->mtu = mtu;
1073 return 0;
1074 }
1075
1076 static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
1077 struct rtnl_link_stats64 *tot)
1078 {
1079 struct netfront_info *np = netdev_priv(dev);
1080 int cpu;
1081
1082 for_each_possible_cpu(cpu) {
1083 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu);
1084 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu);
1085 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1086 unsigned int start;
1087
1088 do {
1089 start = u64_stats_fetch_begin_irq(&tx_stats->syncp);
1090 tx_packets = tx_stats->packets;
1091 tx_bytes = tx_stats->bytes;
1092 } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start));
1093
1094 do {
1095 start = u64_stats_fetch_begin_irq(&rx_stats->syncp);
1096 rx_packets = rx_stats->packets;
1097 rx_bytes = rx_stats->bytes;
1098 } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start));
1099
1100 tot->rx_packets += rx_packets;
1101 tot->tx_packets += tx_packets;
1102 tot->rx_bytes += rx_bytes;
1103 tot->tx_bytes += tx_bytes;
1104 }
1105
1106 tot->rx_errors = dev->stats.rx_errors;
1107 tot->tx_dropped = dev->stats.tx_dropped;
1108
1109 return tot;
1110 }
1111
1112 static void xennet_release_tx_bufs(struct netfront_queue *queue)
1113 {
1114 struct sk_buff *skb;
1115 int i;
1116
1117 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1118 /* Skip over entries which are actually freelist references */
1119 if (skb_entry_is_link(&queue->tx_skbs[i]))
1120 continue;
1121
1122 skb = queue->tx_skbs[i].skb;
1123 get_page(queue->grant_tx_page[i]);
1124 gnttab_end_foreign_access(queue->grant_tx_ref[i],
1125 GNTMAP_readonly,
1126 (unsigned long)page_address(queue->grant_tx_page[i]));
1127 queue->grant_tx_page[i] = NULL;
1128 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1129 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i);
1130 dev_kfree_skb_irq(skb);
1131 }
1132 }
1133
1134 static void xennet_release_rx_bufs(struct netfront_queue *queue)
1135 {
1136 int id, ref;
1137
1138 spin_lock_bh(&queue->rx_lock);
1139
1140 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1141 struct sk_buff *skb;
1142 struct page *page;
1143
1144 skb = queue->rx_skbs[id];
1145 if (!skb)
1146 continue;
1147
1148 ref = queue->grant_rx_ref[id];
1149 if (ref == GRANT_INVALID_REF)
1150 continue;
1151
1152 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
1153
1154 /* gnttab_end_foreign_access() needs a page ref until
1155 * foreign access is ended (which may be deferred).
1156 */
1157 get_page(page);
1158 gnttab_end_foreign_access(ref, 0,
1159 (unsigned long)page_address(page));
1160 queue->grant_rx_ref[id] = GRANT_INVALID_REF;
1161
1162 kfree_skb(skb);
1163 }
1164
1165 spin_unlock_bh(&queue->rx_lock);
1166 }
1167
1168 static netdev_features_t xennet_fix_features(struct net_device *dev,
1169 netdev_features_t features)
1170 {
1171 struct netfront_info *np = netdev_priv(dev);
1172 int val;
1173
1174 if (features & NETIF_F_SG) {
1175 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg",
1176 "%d", &val) < 0)
1177 val = 0;
1178
1179 if (!val)
1180 features &= ~NETIF_F_SG;
1181 }
1182
1183 if (features & NETIF_F_IPV6_CSUM) {
1184 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1185 "feature-ipv6-csum-offload", "%d", &val) < 0)
1186 val = 0;
1187
1188 if (!val)
1189 features &= ~NETIF_F_IPV6_CSUM;
1190 }
1191
1192 if (features & NETIF_F_TSO) {
1193 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1194 "feature-gso-tcpv4", "%d", &val) < 0)
1195 val = 0;
1196
1197 if (!val)
1198 features &= ~NETIF_F_TSO;
1199 }
1200
1201 if (features & NETIF_F_TSO6) {
1202 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1203 "feature-gso-tcpv6", "%d", &val) < 0)
1204 val = 0;
1205
1206 if (!val)
1207 features &= ~NETIF_F_TSO6;
1208 }
1209
1210 return features;
1211 }
1212
1213 static int xennet_set_features(struct net_device *dev,
1214 netdev_features_t features)
1215 {
1216 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1217 netdev_info(dev, "Reducing MTU because no SG offload");
1218 dev->mtu = ETH_DATA_LEN;
1219 }
1220
1221 return 0;
1222 }
1223
1224 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1225 {
1226 struct netfront_queue *queue = dev_id;
1227 unsigned long flags;
1228
1229 spin_lock_irqsave(&queue->tx_lock, flags);
1230 xennet_tx_buf_gc(queue);
1231 spin_unlock_irqrestore(&queue->tx_lock, flags);
1232
1233 return IRQ_HANDLED;
1234 }
1235
1236 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1237 {
1238 struct netfront_queue *queue = dev_id;
1239 struct net_device *dev = queue->info->netdev;
1240
1241 if (likely(netif_carrier_ok(dev) &&
1242 RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)))
1243 napi_schedule(&queue->napi);
1244
1245 return IRQ_HANDLED;
1246 }
1247
1248 static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1249 {
1250 xennet_tx_interrupt(irq, dev_id);
1251 xennet_rx_interrupt(irq, dev_id);
1252 return IRQ_HANDLED;
1253 }
1254
1255 #ifdef CONFIG_NET_POLL_CONTROLLER
1256 static void xennet_poll_controller(struct net_device *dev)
1257 {
1258 /* Poll each queue */
1259 struct netfront_info *info = netdev_priv(dev);
1260 unsigned int num_queues = dev->real_num_tx_queues;
1261 unsigned int i;
1262 for (i = 0; i < num_queues; ++i)
1263 xennet_interrupt(0, &info->queues[i]);
1264 }
1265 #endif
1266
1267 static const struct net_device_ops xennet_netdev_ops = {
1268 .ndo_open = xennet_open,
1269 .ndo_stop = xennet_close,
1270 .ndo_start_xmit = xennet_start_xmit,
1271 .ndo_change_mtu = xennet_change_mtu,
1272 .ndo_get_stats64 = xennet_get_stats64,
1273 .ndo_set_mac_address = eth_mac_addr,
1274 .ndo_validate_addr = eth_validate_addr,
1275 .ndo_fix_features = xennet_fix_features,
1276 .ndo_set_features = xennet_set_features,
1277 .ndo_select_queue = xennet_select_queue,
1278 #ifdef CONFIG_NET_POLL_CONTROLLER
1279 .ndo_poll_controller = xennet_poll_controller,
1280 #endif
1281 };
1282
1283 static void xennet_free_netdev(struct net_device *netdev)
1284 {
1285 struct netfront_info *np = netdev_priv(netdev);
1286
1287 free_percpu(np->rx_stats);
1288 free_percpu(np->tx_stats);
1289 free_netdev(netdev);
1290 }
1291
1292 static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1293 {
1294 int err;
1295 struct net_device *netdev;
1296 struct netfront_info *np;
1297
1298 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues);
1299 if (!netdev)
1300 return ERR_PTR(-ENOMEM);
1301
1302 np = netdev_priv(netdev);
1303 np->xbdev = dev;
1304
1305 np->queues = NULL;
1306
1307 err = -ENOMEM;
1308 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1309 if (np->rx_stats == NULL)
1310 goto exit;
1311 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1312 if (np->tx_stats == NULL)
1313 goto exit;
1314
1315 netdev->netdev_ops = &xennet_netdev_ops;
1316
1317 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1318 NETIF_F_GSO_ROBUST;
1319 netdev->hw_features = NETIF_F_SG |
1320 NETIF_F_IPV6_CSUM |
1321 NETIF_F_TSO | NETIF_F_TSO6;
1322
1323 /*
1324 * Assume that all hw features are available for now. This set
1325 * will be adjusted by the call to netdev_update_features() in
1326 * xennet_connect() which is the earliest point where we can
1327 * negotiate with the backend regarding supported features.
1328 */
1329 netdev->features |= netdev->hw_features;
1330
1331 netdev->ethtool_ops = &xennet_ethtool_ops;
1332 netdev->min_mtu = 0;
1333 netdev->max_mtu = XEN_NETIF_MAX_TX_SIZE;
1334 SET_NETDEV_DEV(netdev, &dev->dev);
1335
1336 np->netdev = netdev;
1337
1338 netif_carrier_off(netdev);
1339
1340 return netdev;
1341
1342 exit:
1343 xennet_free_netdev(netdev);
1344 return ERR_PTR(err);
1345 }
1346
1347 /**
1348 * Entry point to this code when a new device is created. Allocate the basic
1349 * structures and the ring buffers for communication with the backend, and
1350 * inform the backend of the appropriate details for those.
1351 */
1352 static int netfront_probe(struct xenbus_device *dev,
1353 const struct xenbus_device_id *id)
1354 {
1355 int err;
1356 struct net_device *netdev;
1357 struct netfront_info *info;
1358
1359 netdev = xennet_create_dev(dev);
1360 if (IS_ERR(netdev)) {
1361 err = PTR_ERR(netdev);
1362 xenbus_dev_fatal(dev, err, "creating netdev");
1363 return err;
1364 }
1365
1366 info = netdev_priv(netdev);
1367 dev_set_drvdata(&dev->dev, info);
1368 #ifdef CONFIG_SYSFS
1369 info->netdev->sysfs_groups[0] = &xennet_dev_group;
1370 #endif
1371 err = register_netdev(info->netdev);
1372 if (err) {
1373 pr_warn("%s: register_netdev err=%d\n", __func__, err);
1374 goto fail;
1375 }
1376
1377 return 0;
1378
1379 fail:
1380 xennet_free_netdev(netdev);
1381 dev_set_drvdata(&dev->dev, NULL);
1382 return err;
1383 }
1384
1385 static void xennet_end_access(int ref, void *page)
1386 {
1387 /* This frees the page as a side-effect */
1388 if (ref != GRANT_INVALID_REF)
1389 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1390 }
1391
1392 static void xennet_disconnect_backend(struct netfront_info *info)
1393 {
1394 unsigned int i = 0;
1395 unsigned int num_queues = info->netdev->real_num_tx_queues;
1396
1397 netif_carrier_off(info->netdev);
1398
1399 for (i = 0; i < num_queues && info->queues; ++i) {
1400 struct netfront_queue *queue = &info->queues[i];
1401
1402 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
1403 unbind_from_irqhandler(queue->tx_irq, queue);
1404 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
1405 unbind_from_irqhandler(queue->tx_irq, queue);
1406 unbind_from_irqhandler(queue->rx_irq, queue);
1407 }
1408 queue->tx_evtchn = queue->rx_evtchn = 0;
1409 queue->tx_irq = queue->rx_irq = 0;
1410
1411 if (netif_running(info->netdev))
1412 napi_synchronize(&queue->napi);
1413
1414 xennet_release_tx_bufs(queue);
1415 xennet_release_rx_bufs(queue);
1416 gnttab_free_grant_references(queue->gref_tx_head);
1417 gnttab_free_grant_references(queue->gref_rx_head);
1418
1419 /* End access and free the pages */
1420 xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
1421 xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
1422
1423 queue->tx_ring_ref = GRANT_INVALID_REF;
1424 queue->rx_ring_ref = GRANT_INVALID_REF;
1425 queue->tx.sring = NULL;
1426 queue->rx.sring = NULL;
1427 }
1428 }
1429
1430 /**
1431 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1432 * driver restart. We tear down our netif structure and recreate it, but
1433 * leave the device-layer structures intact so that this is transparent to the
1434 * rest of the kernel.
1435 */
1436 static int netfront_resume(struct xenbus_device *dev)
1437 {
1438 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1439
1440 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1441
1442 xennet_disconnect_backend(info);
1443 return 0;
1444 }
1445
1446 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1447 {
1448 char *s, *e, *macstr;
1449 int i;
1450
1451 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1452 if (IS_ERR(macstr))
1453 return PTR_ERR(macstr);
1454
1455 for (i = 0; i < ETH_ALEN; i++) {
1456 mac[i] = simple_strtoul(s, &e, 16);
1457 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1458 kfree(macstr);
1459 return -ENOENT;
1460 }
1461 s = e+1;
1462 }
1463
1464 kfree(macstr);
1465 return 0;
1466 }
1467
1468 static int setup_netfront_single(struct netfront_queue *queue)
1469 {
1470 int err;
1471
1472 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1473 if (err < 0)
1474 goto fail;
1475
1476 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1477 xennet_interrupt,
1478 0, queue->info->netdev->name, queue);
1479 if (err < 0)
1480 goto bind_fail;
1481 queue->rx_evtchn = queue->tx_evtchn;
1482 queue->rx_irq = queue->tx_irq = err;
1483
1484 return 0;
1485
1486 bind_fail:
1487 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1488 queue->tx_evtchn = 0;
1489 fail:
1490 return err;
1491 }
1492
1493 static int setup_netfront_split(struct netfront_queue *queue)
1494 {
1495 int err;
1496
1497 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1498 if (err < 0)
1499 goto fail;
1500 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn);
1501 if (err < 0)
1502 goto alloc_rx_evtchn_fail;
1503
1504 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
1505 "%s-tx", queue->name);
1506 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1507 xennet_tx_interrupt,
1508 0, queue->tx_irq_name, queue);
1509 if (err < 0)
1510 goto bind_tx_fail;
1511 queue->tx_irq = err;
1512
1513 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
1514 "%s-rx", queue->name);
1515 err = bind_evtchn_to_irqhandler(queue->rx_evtchn,
1516 xennet_rx_interrupt,
1517 0, queue->rx_irq_name, queue);
1518 if (err < 0)
1519 goto bind_rx_fail;
1520 queue->rx_irq = err;
1521
1522 return 0;
1523
1524 bind_rx_fail:
1525 unbind_from_irqhandler(queue->tx_irq, queue);
1526 queue->tx_irq = 0;
1527 bind_tx_fail:
1528 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn);
1529 queue->rx_evtchn = 0;
1530 alloc_rx_evtchn_fail:
1531 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1532 queue->tx_evtchn = 0;
1533 fail:
1534 return err;
1535 }
1536
1537 static int setup_netfront(struct xenbus_device *dev,
1538 struct netfront_queue *queue, unsigned int feature_split_evtchn)
1539 {
1540 struct xen_netif_tx_sring *txs;
1541 struct xen_netif_rx_sring *rxs;
1542 grant_ref_t gref;
1543 int err;
1544
1545 queue->tx_ring_ref = GRANT_INVALID_REF;
1546 queue->rx_ring_ref = GRANT_INVALID_REF;
1547 queue->rx.sring = NULL;
1548 queue->tx.sring = NULL;
1549
1550 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1551 if (!txs) {
1552 err = -ENOMEM;
1553 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1554 goto fail;
1555 }
1556 SHARED_RING_INIT(txs);
1557 FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);
1558
1559 err = xenbus_grant_ring(dev, txs, 1, &gref);
1560 if (err < 0)
1561 goto grant_tx_ring_fail;
1562 queue->tx_ring_ref = gref;
1563
1564 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1565 if (!rxs) {
1566 err = -ENOMEM;
1567 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1568 goto alloc_rx_ring_fail;
1569 }
1570 SHARED_RING_INIT(rxs);
1571 FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);
1572
1573 err = xenbus_grant_ring(dev, rxs, 1, &gref);
1574 if (err < 0)
1575 goto grant_rx_ring_fail;
1576 queue->rx_ring_ref = gref;
1577
1578 if (feature_split_evtchn)
1579 err = setup_netfront_split(queue);
1580 /* setup single event channel if
1581 * a) feature-split-event-channels == 0
1582 * b) feature-split-event-channels == 1 but failed to setup
1583 */
1584 if (!feature_split_evtchn || (feature_split_evtchn && err))
1585 err = setup_netfront_single(queue);
1586
1587 if (err)
1588 goto alloc_evtchn_fail;
1589
1590 return 0;
1591
1592 /* If we fail to setup netfront, it is safe to just revoke access to
1593 * granted pages because backend is not accessing it at this point.
1594 */
1595 alloc_evtchn_fail:
1596 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0);
1597 grant_rx_ring_fail:
1598 free_page((unsigned long)rxs);
1599 alloc_rx_ring_fail:
1600 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0);
1601 grant_tx_ring_fail:
1602 free_page((unsigned long)txs);
1603 fail:
1604 return err;
1605 }
1606
1607 /* Queue-specific initialisation
1608 * This used to be done in xennet_create_dev() but must now
1609 * be run per-queue.
1610 */
1611 static int xennet_init_queue(struct netfront_queue *queue)
1612 {
1613 unsigned short i;
1614 int err = 0;
1615
1616 spin_lock_init(&queue->tx_lock);
1617 spin_lock_init(&queue->rx_lock);
1618
1619 setup_timer(&queue->rx_refill_timer, rx_refill_timeout,
1620 (unsigned long)queue);
1621
1622 snprintf(queue->name, sizeof(queue->name), "%s-q%u",
1623 queue->info->netdev->name, queue->id);
1624
1625 /* Initialise tx_skbs as a free chain containing every entry. */
1626 queue->tx_skb_freelist = 0;
1627 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1628 skb_entry_set_link(&queue->tx_skbs[i], i+1);
1629 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1630 queue->grant_tx_page[i] = NULL;
1631 }
1632
1633 /* Clear out rx_skbs */
1634 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1635 queue->rx_skbs[i] = NULL;
1636 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
1637 }
1638
1639 /* A grant for every tx ring slot */
1640 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
1641 &queue->gref_tx_head) < 0) {
1642 pr_alert("can't alloc tx grant refs\n");
1643 err = -ENOMEM;
1644 goto exit;
1645 }
1646
1647 /* A grant for every rx ring slot */
1648 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
1649 &queue->gref_rx_head) < 0) {
1650 pr_alert("can't alloc rx grant refs\n");
1651 err = -ENOMEM;
1652 goto exit_free_tx;
1653 }
1654
1655 return 0;
1656
1657 exit_free_tx:
1658 gnttab_free_grant_references(queue->gref_tx_head);
1659 exit:
1660 return err;
1661 }
1662
1663 static int write_queue_xenstore_keys(struct netfront_queue *queue,
1664 struct xenbus_transaction *xbt, int write_hierarchical)
1665 {
1666 /* Write the queue-specific keys into XenStore in the traditional
1667 * way for a single queue, or in a queue subkeys for multiple
1668 * queues.
1669 */
1670 struct xenbus_device *dev = queue->info->xbdev;
1671 int err;
1672 const char *message;
1673 char *path;
1674 size_t pathsize;
1675
1676 /* Choose the correct place to write the keys */
1677 if (write_hierarchical) {
1678 pathsize = strlen(dev->nodename) + 10;
1679 path = kzalloc(pathsize, GFP_KERNEL);
1680 if (!path) {
1681 err = -ENOMEM;
1682 message = "out of memory while writing ring references";
1683 goto error;
1684 }
1685 snprintf(path, pathsize, "%s/queue-%u",
1686 dev->nodename, queue->id);
1687 } else {
1688 path = (char *)dev->nodename;
1689 }
1690
1691 /* Write ring references */
1692 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u",
1693 queue->tx_ring_ref);
1694 if (err) {
1695 message = "writing tx-ring-ref";
1696 goto error;
1697 }
1698
1699 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u",
1700 queue->rx_ring_ref);
1701 if (err) {
1702 message = "writing rx-ring-ref";
1703 goto error;
1704 }
1705
1706 /* Write event channels; taking into account both shared
1707 * and split event channel scenarios.
1708 */
1709 if (queue->tx_evtchn == queue->rx_evtchn) {
1710 /* Shared event channel */
1711 err = xenbus_printf(*xbt, path,
1712 "event-channel", "%u", queue->tx_evtchn);
1713 if (err) {
1714 message = "writing event-channel";
1715 goto error;
1716 }
1717 } else {
1718 /* Split event channels */
1719 err = xenbus_printf(*xbt, path,
1720 "event-channel-tx", "%u", queue->tx_evtchn);
1721 if (err) {
1722 message = "writing event-channel-tx";
1723 goto error;
1724 }
1725
1726 err = xenbus_printf(*xbt, path,
1727 "event-channel-rx", "%u", queue->rx_evtchn);
1728 if (err) {
1729 message = "writing event-channel-rx";
1730 goto error;
1731 }
1732 }
1733
1734 if (write_hierarchical)
1735 kfree(path);
1736 return 0;
1737
1738 error:
1739 if (write_hierarchical)
1740 kfree(path);
1741 xenbus_dev_fatal(dev, err, "%s", message);
1742 return err;
1743 }
1744
1745 static void xennet_destroy_queues(struct netfront_info *info)
1746 {
1747 unsigned int i;
1748
1749 rtnl_lock();
1750
1751 for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
1752 struct netfront_queue *queue = &info->queues[i];
1753
1754 if (netif_running(info->netdev))
1755 napi_disable(&queue->napi);
1756 del_timer_sync(&queue->rx_refill_timer);
1757 netif_napi_del(&queue->napi);
1758 }
1759
1760 rtnl_unlock();
1761
1762 kfree(info->queues);
1763 info->queues = NULL;
1764 }
1765
1766 static int xennet_create_queues(struct netfront_info *info,
1767 unsigned int *num_queues)
1768 {
1769 unsigned int i;
1770 int ret;
1771
1772 info->queues = kcalloc(*num_queues, sizeof(struct netfront_queue),
1773 GFP_KERNEL);
1774 if (!info->queues)
1775 return -ENOMEM;
1776
1777 rtnl_lock();
1778
1779 for (i = 0; i < *num_queues; i++) {
1780 struct netfront_queue *queue = &info->queues[i];
1781
1782 queue->id = i;
1783 queue->info = info;
1784
1785 ret = xennet_init_queue(queue);
1786 if (ret < 0) {
1787 dev_warn(&info->netdev->dev,
1788 "only created %d queues\n", i);
1789 *num_queues = i;
1790 break;
1791 }
1792
1793 netif_napi_add(queue->info->netdev, &queue->napi,
1794 xennet_poll, 64);
1795 if (netif_running(info->netdev))
1796 napi_enable(&queue->napi);
1797 }
1798
1799 netif_set_real_num_tx_queues(info->netdev, *num_queues);
1800
1801 rtnl_unlock();
1802
1803 if (*num_queues == 0) {
1804 dev_err(&info->netdev->dev, "no queues\n");
1805 return -EINVAL;
1806 }
1807 return 0;
1808 }
1809
1810 /* Common code used when first setting up, and when resuming. */
1811 static int talk_to_netback(struct xenbus_device *dev,
1812 struct netfront_info *info)
1813 {
1814 const char *message;
1815 struct xenbus_transaction xbt;
1816 int err;
1817 unsigned int feature_split_evtchn;
1818 unsigned int i = 0;
1819 unsigned int max_queues = 0;
1820 struct netfront_queue *queue = NULL;
1821 unsigned int num_queues = 1;
1822
1823 info->netdev->irq = 0;
1824
1825 /* Check if backend supports multiple queues */
1826 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
1827 "multi-queue-max-queues", "%u", &max_queues);
1828 if (err < 0)
1829 max_queues = 1;
1830 num_queues = min(max_queues, xennet_max_queues);
1831
1832 /* Check feature-split-event-channels */
1833 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
1834 "feature-split-event-channels", "%u",
1835 &feature_split_evtchn);
1836 if (err < 0)
1837 feature_split_evtchn = 0;
1838
1839 /* Read mac addr. */
1840 err = xen_net_read_mac(dev, info->netdev->dev_addr);
1841 if (err) {
1842 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1843 goto out;
1844 }
1845
1846 if (info->queues)
1847 xennet_destroy_queues(info);
1848
1849 err = xennet_create_queues(info, &num_queues);
1850 if (err < 0)
1851 goto destroy_ring;
1852
1853 /* Create shared ring, alloc event channel -- for each queue */
1854 for (i = 0; i < num_queues; ++i) {
1855 queue = &info->queues[i];
1856 err = setup_netfront(dev, queue, feature_split_evtchn);
1857 if (err) {
1858 /* setup_netfront() will tidy up the current
1859 * queue on error, but we need to clean up
1860 * those already allocated.
1861 */
1862 if (i > 0) {
1863 rtnl_lock();
1864 netif_set_real_num_tx_queues(info->netdev, i);
1865 rtnl_unlock();
1866 goto destroy_ring;
1867 } else {
1868 goto out;
1869 }
1870 }
1871 }
1872
1873 again:
1874 err = xenbus_transaction_start(&xbt);
1875 if (err) {
1876 xenbus_dev_fatal(dev, err, "starting transaction");
1877 goto destroy_ring;
1878 }
1879
1880 if (xenbus_exists(XBT_NIL,
1881 info->xbdev->otherend, "multi-queue-max-queues")) {
1882 /* Write the number of queues */
1883 err = xenbus_printf(xbt, dev->nodename,
1884 "multi-queue-num-queues", "%u", num_queues);
1885 if (err) {
1886 message = "writing multi-queue-num-queues";
1887 goto abort_transaction_no_dev_fatal;
1888 }
1889 }
1890
1891 if (num_queues == 1) {
1892 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */
1893 if (err)
1894 goto abort_transaction_no_dev_fatal;
1895 } else {
1896 /* Write the keys for each queue */
1897 for (i = 0; i < num_queues; ++i) {
1898 queue = &info->queues[i];
1899 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */
1900 if (err)
1901 goto abort_transaction_no_dev_fatal;
1902 }
1903 }
1904
1905 /* The remaining keys are not queue-specific */
1906 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
1907 1);
1908 if (err) {
1909 message = "writing request-rx-copy";
1910 goto abort_transaction;
1911 }
1912
1913 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
1914 if (err) {
1915 message = "writing feature-rx-notify";
1916 goto abort_transaction;
1917 }
1918
1919 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
1920 if (err) {
1921 message = "writing feature-sg";
1922 goto abort_transaction;
1923 }
1924
1925 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
1926 if (err) {
1927 message = "writing feature-gso-tcpv4";
1928 goto abort_transaction;
1929 }
1930
1931 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1");
1932 if (err) {
1933 message = "writing feature-gso-tcpv6";
1934 goto abort_transaction;
1935 }
1936
1937 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload",
1938 "1");
1939 if (err) {
1940 message = "writing feature-ipv6-csum-offload";
1941 goto abort_transaction;
1942 }
1943
1944 err = xenbus_transaction_end(xbt, 0);
1945 if (err) {
1946 if (err == -EAGAIN)
1947 goto again;
1948 xenbus_dev_fatal(dev, err, "completing transaction");
1949 goto destroy_ring;
1950 }
1951
1952 return 0;
1953
1954 abort_transaction:
1955 xenbus_dev_fatal(dev, err, "%s", message);
1956 abort_transaction_no_dev_fatal:
1957 xenbus_transaction_end(xbt, 1);
1958 destroy_ring:
1959 xennet_disconnect_backend(info);
1960 kfree(info->queues);
1961 info->queues = NULL;
1962 out:
1963 return err;
1964 }
1965
1966 static int xennet_connect(struct net_device *dev)
1967 {
1968 struct netfront_info *np = netdev_priv(dev);
1969 unsigned int num_queues = 0;
1970 int err;
1971 unsigned int feature_rx_copy;
1972 unsigned int j = 0;
1973 struct netfront_queue *queue = NULL;
1974
1975 err = xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1976 "feature-rx-copy", "%u", &feature_rx_copy);
1977 if (err != 1)
1978 feature_rx_copy = 0;
1979
1980 if (!feature_rx_copy) {
1981 dev_info(&dev->dev,
1982 "backend does not support copying receive path\n");
1983 return -ENODEV;
1984 }
1985
1986 err = talk_to_netback(np->xbdev, np);
1987 if (err)
1988 return err;
1989
1990 /* talk_to_netback() sets the correct number of queues */
1991 num_queues = dev->real_num_tx_queues;
1992
1993 rtnl_lock();
1994 netdev_update_features(dev);
1995 rtnl_unlock();
1996
1997 /*
1998 * All public and private state should now be sane. Get
1999 * ready to start sending and receiving packets and give the driver
2000 * domain a kick because we've probably just requeued some
2001 * packets.
2002 */
2003 netif_carrier_on(np->netdev);
2004 for (j = 0; j < num_queues; ++j) {
2005 queue = &np->queues[j];
2006
2007 notify_remote_via_irq(queue->tx_irq);
2008 if (queue->tx_irq != queue->rx_irq)
2009 notify_remote_via_irq(queue->rx_irq);
2010
2011 spin_lock_irq(&queue->tx_lock);
2012 xennet_tx_buf_gc(queue);
2013 spin_unlock_irq(&queue->tx_lock);
2014
2015 spin_lock_bh(&queue->rx_lock);
2016 xennet_alloc_rx_buffers(queue);
2017 spin_unlock_bh(&queue->rx_lock);
2018 }
2019
2020 return 0;
2021 }
2022
2023 /**
2024 * Callback received when the backend's state changes.
2025 */
2026 static void netback_changed(struct xenbus_device *dev,
2027 enum xenbus_state backend_state)
2028 {
2029 struct netfront_info *np = dev_get_drvdata(&dev->dev);
2030 struct net_device *netdev = np->netdev;
2031
2032 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
2033
2034 switch (backend_state) {
2035 case XenbusStateInitialising:
2036 case XenbusStateInitialised:
2037 case XenbusStateReconfiguring:
2038 case XenbusStateReconfigured:
2039 case XenbusStateUnknown:
2040 break;
2041
2042 case XenbusStateInitWait:
2043 if (dev->state != XenbusStateInitialising)
2044 break;
2045 if (xennet_connect(netdev) != 0)
2046 break;
2047 xenbus_switch_state(dev, XenbusStateConnected);
2048 break;
2049
2050 case XenbusStateConnected:
2051 netdev_notify_peers(netdev);
2052 break;
2053
2054 case XenbusStateClosed:
2055 if (dev->state == XenbusStateClosed)
2056 break;
2057 /* Missed the backend's CLOSING state -- fallthrough */
2058 case XenbusStateClosing:
2059 xenbus_frontend_closed(dev);
2060 break;
2061 }
2062 }
2063
2064 static const struct xennet_stat {
2065 char name[ETH_GSTRING_LEN];
2066 u16 offset;
2067 } xennet_stats[] = {
2068 {
2069 "rx_gso_checksum_fixup",
2070 offsetof(struct netfront_info, rx_gso_checksum_fixup)
2071 },
2072 };
2073
2074 static int xennet_get_sset_count(struct net_device *dev, int string_set)
2075 {
2076 switch (string_set) {
2077 case ETH_SS_STATS:
2078 return ARRAY_SIZE(xennet_stats);
2079 default:
2080 return -EINVAL;
2081 }
2082 }
2083
2084 static void xennet_get_ethtool_stats(struct net_device *dev,
2085 struct ethtool_stats *stats, u64 * data)
2086 {
2087 void *np = netdev_priv(dev);
2088 int i;
2089
2090 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2091 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset));
2092 }
2093
2094 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
2095 {
2096 int i;
2097
2098 switch (stringset) {
2099 case ETH_SS_STATS:
2100 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2101 memcpy(data + i * ETH_GSTRING_LEN,
2102 xennet_stats[i].name, ETH_GSTRING_LEN);
2103 break;
2104 }
2105 }
2106
2107 static const struct ethtool_ops xennet_ethtool_ops =
2108 {
2109 .get_link = ethtool_op_get_link,
2110
2111 .get_sset_count = xennet_get_sset_count,
2112 .get_ethtool_stats = xennet_get_ethtool_stats,
2113 .get_strings = xennet_get_strings,
2114 };
2115
2116 #ifdef CONFIG_SYSFS
2117 static ssize_t show_rxbuf(struct device *dev,
2118 struct device_attribute *attr, char *buf)
2119 {
2120 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE);
2121 }
2122
2123 static ssize_t store_rxbuf(struct device *dev,
2124 struct device_attribute *attr,
2125 const char *buf, size_t len)
2126 {
2127 char *endp;
2128 unsigned long target;
2129
2130 if (!capable(CAP_NET_ADMIN))
2131 return -EPERM;
2132
2133 target = simple_strtoul(buf, &endp, 0);
2134 if (endp == buf)
2135 return -EBADMSG;
2136
2137 /* rxbuf_min and rxbuf_max are no longer configurable. */
2138
2139 return len;
2140 }
2141
2142 static DEVICE_ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
2143 static DEVICE_ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
2144 static DEVICE_ATTR(rxbuf_cur, S_IRUGO, show_rxbuf, NULL);
2145
2146 static struct attribute *xennet_dev_attrs[] = {
2147 &dev_attr_rxbuf_min.attr,
2148 &dev_attr_rxbuf_max.attr,
2149 &dev_attr_rxbuf_cur.attr,
2150 NULL
2151 };
2152
2153 static const struct attribute_group xennet_dev_group = {
2154 .attrs = xennet_dev_attrs
2155 };
2156 #endif /* CONFIG_SYSFS */
2157
2158 static int xennet_remove(struct xenbus_device *dev)
2159 {
2160 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2161
2162 dev_dbg(&dev->dev, "%s\n", dev->nodename);
2163
2164 xennet_disconnect_backend(info);
2165
2166 unregister_netdev(info->netdev);
2167
2168 if (info->queues)
2169 xennet_destroy_queues(info);
2170 xennet_free_netdev(info->netdev);
2171
2172 return 0;
2173 }
2174
2175 static const struct xenbus_device_id netfront_ids[] = {
2176 { "vif" },
2177 { "" }
2178 };
2179
2180 static struct xenbus_driver netfront_driver = {
2181 .ids = netfront_ids,
2182 .probe = netfront_probe,
2183 .remove = xennet_remove,
2184 .resume = netfront_resume,
2185 .otherend_changed = netback_changed,
2186 };
2187
2188 static int __init netif_init(void)
2189 {
2190 if (!xen_domain())
2191 return -ENODEV;
2192
2193 if (!xen_has_pv_nic_devices())
2194 return -ENODEV;
2195
2196 pr_info("Initialising Xen virtual ethernet driver\n");
2197
2198 /* Allow as many queues as there are CPUs if user has not
2199 * specified a value.
2200 */
2201 if (xennet_max_queues == 0)
2202 xennet_max_queues = num_online_cpus();
2203
2204 return xenbus_register_frontend(&netfront_driver);
2205 }
2206 module_init(netif_init);
2207
2208
2209 static void __exit netif_exit(void)
2210 {
2211 xenbus_unregister_driver(&netfront_driver);
2212 }
2213 module_exit(netif_exit);
2214
2215 MODULE_DESCRIPTION("Xen virtual network device frontend");
2216 MODULE_LICENSE("GPL");
2217 MODULE_ALIAS("xen:vif");
2218 MODULE_ALIAS("xennet");
(deprecated) Btrfs devel tree