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net/mlx4_core: Demote simple multicast and broadcast flow steering rules
[deliverable/linux.git] / drivers / net / xen-netfront.c
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 <asm/xen/page.h>
49 #include <xen/xen.h>
50 #include <xen/xenbus.h>
51 #include <xen/events.h>
52 #include <xen/page.h>
53 #include <xen/platform_pci.h>
54 #include <xen/grant_table.h>
55
56 #include <xen/interface/io/netif.h>
57 #include <xen/interface/memory.h>
58 #include <xen/interface/grant_table.h>
59
60 /* Module parameters */
61 static unsigned int xennet_max_queues;
62 module_param_named(max_queues, xennet_max_queues, uint, 0644);
63 MODULE_PARM_DESC(max_queues,
64 "Maximum number of queues per virtual interface");
65
66 static const struct ethtool_ops xennet_ethtool_ops;
67
68 struct netfront_cb {
69 int pull_to;
70 };
71
72 #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
73
74 #define RX_COPY_THRESHOLD 256
75
76 #define GRANT_INVALID_REF 0
77
78 #define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE)
79 #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE)
80
81 /* Minimum number of Rx slots (includes slot for GSO metadata). */
82 #define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1)
83
84 /* Queue name is interface name with "-qNNN" appended */
85 #define QUEUE_NAME_SIZE (IFNAMSIZ + 6)
86
87 /* IRQ name is queue name with "-tx" or "-rx" appended */
88 #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
89
90 struct netfront_stats {
91 u64 packets;
92 u64 bytes;
93 struct u64_stats_sync syncp;
94 };
95
96 struct netfront_info;
97
98 struct netfront_queue {
99 unsigned int id; /* Queue ID, 0-based */
100 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
101 struct netfront_info *info;
102
103 struct napi_struct napi;
104
105 /* Split event channels support, tx_* == rx_* when using
106 * single event channel.
107 */
108 unsigned int tx_evtchn, rx_evtchn;
109 unsigned int tx_irq, rx_irq;
110 /* Only used when split event channels support is enabled */
111 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
112 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
113
114 spinlock_t tx_lock;
115 struct xen_netif_tx_front_ring tx;
116 int tx_ring_ref;
117
118 /*
119 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
120 * are linked from tx_skb_freelist through skb_entry.link.
121 *
122 * NB. Freelist index entries are always going to be less than
123 * PAGE_OFFSET, whereas pointers to skbs will always be equal or
124 * greater than PAGE_OFFSET: we use this property to distinguish
125 * them.
126 */
127 union skb_entry {
128 struct sk_buff *skb;
129 unsigned long link;
130 } tx_skbs[NET_TX_RING_SIZE];
131 grant_ref_t gref_tx_head;
132 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
133 struct page *grant_tx_page[NET_TX_RING_SIZE];
134 unsigned tx_skb_freelist;
135
136 spinlock_t rx_lock ____cacheline_aligned_in_smp;
137 struct xen_netif_rx_front_ring rx;
138 int rx_ring_ref;
139
140 struct timer_list rx_refill_timer;
141
142 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
143 grant_ref_t gref_rx_head;
144 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
145 };
146
147 struct netfront_info {
148 struct list_head list;
149 struct net_device *netdev;
150
151 struct xenbus_device *xbdev;
152
153 /* Multi-queue support */
154 struct netfront_queue *queues;
155
156 /* Statistics */
157 struct netfront_stats __percpu *rx_stats;
158 struct netfront_stats __percpu *tx_stats;
159
160 atomic_t rx_gso_checksum_fixup;
161 };
162
163 struct netfront_rx_info {
164 struct xen_netif_rx_response rx;
165 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
166 };
167
168 static void skb_entry_set_link(union skb_entry *list, unsigned short id)
169 {
170 list->link = id;
171 }
172
173 static int skb_entry_is_link(const union skb_entry *list)
174 {
175 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
176 return (unsigned long)list->skb < PAGE_OFFSET;
177 }
178
179 /*
180 * Access macros for acquiring freeing slots in tx_skbs[].
181 */
182
183 static void add_id_to_freelist(unsigned *head, union skb_entry *list,
184 unsigned short id)
185 {
186 skb_entry_set_link(&list[id], *head);
187 *head = id;
188 }
189
190 static unsigned short get_id_from_freelist(unsigned *head,
191 union skb_entry *list)
192 {
193 unsigned int id = *head;
194 *head = list[id].link;
195 return id;
196 }
197
198 static int xennet_rxidx(RING_IDX idx)
199 {
200 return idx & (NET_RX_RING_SIZE - 1);
201 }
202
203 static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue,
204 RING_IDX ri)
205 {
206 int i = xennet_rxidx(ri);
207 struct sk_buff *skb = queue->rx_skbs[i];
208 queue->rx_skbs[i] = NULL;
209 return skb;
210 }
211
212 static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
213 RING_IDX ri)
214 {
215 int i = xennet_rxidx(ri);
216 grant_ref_t ref = queue->grant_rx_ref[i];
217 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
218 return ref;
219 }
220
221 #ifdef CONFIG_SYSFS
222 static const struct attribute_group xennet_dev_group;
223 #endif
224
225 static bool xennet_can_sg(struct net_device *dev)
226 {
227 return dev->features & NETIF_F_SG;
228 }
229
230
231 static void rx_refill_timeout(unsigned long data)
232 {
233 struct netfront_queue *queue = (struct netfront_queue *)data;
234 napi_schedule(&queue->napi);
235 }
236
237 static int netfront_tx_slot_available(struct netfront_queue *queue)
238 {
239 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
240 (NET_TX_RING_SIZE - MAX_SKB_FRAGS - 2);
241 }
242
243 static void xennet_maybe_wake_tx(struct netfront_queue *queue)
244 {
245 struct net_device *dev = queue->info->netdev;
246 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id);
247
248 if (unlikely(netif_tx_queue_stopped(dev_queue)) &&
249 netfront_tx_slot_available(queue) &&
250 likely(netif_running(dev)))
251 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
252 }
253
254
255 static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue)
256 {
257 struct sk_buff *skb;
258 struct page *page;
259
260 skb = __netdev_alloc_skb(queue->info->netdev,
261 RX_COPY_THRESHOLD + NET_IP_ALIGN,
262 GFP_ATOMIC | __GFP_NOWARN);
263 if (unlikely(!skb))
264 return NULL;
265
266 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
267 if (!page) {
268 kfree_skb(skb);
269 return NULL;
270 }
271 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
272
273 /* Align ip header to a 16 bytes boundary */
274 skb_reserve(skb, NET_IP_ALIGN);
275 skb->dev = queue->info->netdev;
276
277 return skb;
278 }
279
280
281 static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
282 {
283 RING_IDX req_prod = queue->rx.req_prod_pvt;
284 int notify;
285
286 if (unlikely(!netif_carrier_ok(queue->info->netdev)))
287 return;
288
289 for (req_prod = queue->rx.req_prod_pvt;
290 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE;
291 req_prod++) {
292 struct sk_buff *skb;
293 unsigned short id;
294 grant_ref_t ref;
295 unsigned long pfn;
296 struct xen_netif_rx_request *req;
297
298 skb = xennet_alloc_one_rx_buffer(queue);
299 if (!skb)
300 break;
301
302 id = xennet_rxidx(req_prod);
303
304 BUG_ON(queue->rx_skbs[id]);
305 queue->rx_skbs[id] = skb;
306
307 ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
308 BUG_ON((signed short)ref < 0);
309 queue->grant_rx_ref[id] = ref;
310
311 pfn = page_to_pfn(skb_frag_page(&skb_shinfo(skb)->frags[0]));
312
313 req = RING_GET_REQUEST(&queue->rx, req_prod);
314 gnttab_grant_foreign_access_ref(ref,
315 queue->info->xbdev->otherend_id,
316 pfn_to_mfn(pfn),
317 0);
318
319 req->id = id;
320 req->gref = ref;
321 }
322
323 queue->rx.req_prod_pvt = req_prod;
324
325 /* Not enough requests? Try again later. */
326 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN) {
327 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
328 return;
329 }
330
331 wmb(); /* barrier so backend seens requests */
332
333 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
334 if (notify)
335 notify_remote_via_irq(queue->rx_irq);
336 }
337
338 static int xennet_open(struct net_device *dev)
339 {
340 struct netfront_info *np = netdev_priv(dev);
341 unsigned int num_queues = dev->real_num_tx_queues;
342 unsigned int i = 0;
343 struct netfront_queue *queue = NULL;
344
345 for (i = 0; i < num_queues; ++i) {
346 queue = &np->queues[i];
347 napi_enable(&queue->napi);
348
349 spin_lock_bh(&queue->rx_lock);
350 if (netif_carrier_ok(dev)) {
351 xennet_alloc_rx_buffers(queue);
352 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1;
353 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))
354 napi_schedule(&queue->napi);
355 }
356 spin_unlock_bh(&queue->rx_lock);
357 }
358
359 netif_tx_start_all_queues(dev);
360
361 return 0;
362 }
363
364 static void xennet_tx_buf_gc(struct netfront_queue *queue)
365 {
366 RING_IDX cons, prod;
367 unsigned short id;
368 struct sk_buff *skb;
369
370 BUG_ON(!netif_carrier_ok(queue->info->netdev));
371
372 do {
373 prod = queue->tx.sring->rsp_prod;
374 rmb(); /* Ensure we see responses up to 'rp'. */
375
376 for (cons = queue->tx.rsp_cons; cons != prod; cons++) {
377 struct xen_netif_tx_response *txrsp;
378
379 txrsp = RING_GET_RESPONSE(&queue->tx, cons);
380 if (txrsp->status == XEN_NETIF_RSP_NULL)
381 continue;
382
383 id = txrsp->id;
384 skb = queue->tx_skbs[id].skb;
385 if (unlikely(gnttab_query_foreign_access(
386 queue->grant_tx_ref[id]) != 0)) {
387 pr_alert("%s: warning -- grant still in use by backend domain\n",
388 __func__);
389 BUG();
390 }
391 gnttab_end_foreign_access_ref(
392 queue->grant_tx_ref[id], GNTMAP_readonly);
393 gnttab_release_grant_reference(
394 &queue->gref_tx_head, queue->grant_tx_ref[id]);
395 queue->grant_tx_ref[id] = GRANT_INVALID_REF;
396 queue->grant_tx_page[id] = NULL;
397 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id);
398 dev_kfree_skb_irq(skb);
399 }
400
401 queue->tx.rsp_cons = prod;
402
403 /*
404 * Set a new event, then check for race with update of tx_cons.
405 * Note that it is essential to schedule a callback, no matter
406 * how few buffers are pending. Even if there is space in the
407 * transmit ring, higher layers may be blocked because too much
408 * data is outstanding: in such cases notification from Xen is
409 * likely to be the only kick that we'll get.
410 */
411 queue->tx.sring->rsp_event =
412 prod + ((queue->tx.sring->req_prod - prod) >> 1) + 1;
413 mb(); /* update shared area */
414 } while ((cons == prod) && (prod != queue->tx.sring->rsp_prod));
415
416 xennet_maybe_wake_tx(queue);
417 }
418
419 static struct xen_netif_tx_request *xennet_make_one_txreq(
420 struct netfront_queue *queue, struct sk_buff *skb,
421 struct page *page, unsigned int offset, unsigned int len)
422 {
423 unsigned int id;
424 struct xen_netif_tx_request *tx;
425 grant_ref_t ref;
426
427 len = min_t(unsigned int, PAGE_SIZE - offset, len);
428
429 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
430 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
431 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
432 BUG_ON((signed short)ref < 0);
433
434 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
435 page_to_mfn(page), GNTMAP_readonly);
436
437 queue->tx_skbs[id].skb = skb;
438 queue->grant_tx_page[id] = page;
439 queue->grant_tx_ref[id] = ref;
440
441 tx->id = id;
442 tx->gref = ref;
443 tx->offset = offset;
444 tx->size = len;
445 tx->flags = 0;
446
447 return tx;
448 }
449
450 static struct xen_netif_tx_request *xennet_make_txreqs(
451 struct netfront_queue *queue, struct xen_netif_tx_request *tx,
452 struct sk_buff *skb, struct page *page,
453 unsigned int offset, unsigned int len)
454 {
455 /* Skip unused frames from start of page */
456 page += offset >> PAGE_SHIFT;
457 offset &= ~PAGE_MASK;
458
459 while (len) {
460 tx->flags |= XEN_NETTXF_more_data;
461 tx = xennet_make_one_txreq(queue, skb_get(skb),
462 page, offset, len);
463 page++;
464 offset = 0;
465 len -= tx->size;
466 }
467
468 return tx;
469 }
470
471 /*
472 * Count how many ring slots are required to send this skb. Each frag
473 * might be a compound page.
474 */
475 static int xennet_count_skb_slots(struct sk_buff *skb)
476 {
477 int i, frags = skb_shinfo(skb)->nr_frags;
478 int pages;
479
480 pages = PFN_UP(offset_in_page(skb->data) + skb_headlen(skb));
481
482 for (i = 0; i < frags; i++) {
483 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
484 unsigned long size = skb_frag_size(frag);
485 unsigned long offset = frag->page_offset;
486
487 /* Skip unused frames from start of page */
488 offset &= ~PAGE_MASK;
489
490 pages += PFN_UP(offset + size);
491 }
492
493 return pages;
494 }
495
496 static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
497 void *accel_priv, select_queue_fallback_t fallback)
498 {
499 unsigned int num_queues = dev->real_num_tx_queues;
500 u32 hash;
501 u16 queue_idx;
502
503 /* First, check if there is only one queue */
504 if (num_queues == 1) {
505 queue_idx = 0;
506 } else {
507 hash = skb_get_hash(skb);
508 queue_idx = hash % num_queues;
509 }
510
511 return queue_idx;
512 }
513
514 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
515 {
516 struct netfront_info *np = netdev_priv(dev);
517 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
518 struct xen_netif_tx_request *tx, *first_tx;
519 unsigned int i;
520 int notify;
521 int slots;
522 struct page *page;
523 unsigned int offset;
524 unsigned int len;
525 unsigned long flags;
526 struct netfront_queue *queue = NULL;
527 unsigned int num_queues = dev->real_num_tx_queues;
528 u16 queue_index;
529
530 /* Drop the packet if no queues are set up */
531 if (num_queues < 1)
532 goto drop;
533 /* Determine which queue to transmit this SKB on */
534 queue_index = skb_get_queue_mapping(skb);
535 queue = &np->queues[queue_index];
536
537 /* If skb->len is too big for wire format, drop skb and alert
538 * user about misconfiguration.
539 */
540 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
541 net_alert_ratelimited(
542 "xennet: skb->len = %u, too big for wire format\n",
543 skb->len);
544 goto drop;
545 }
546
547 slots = xennet_count_skb_slots(skb);
548 if (unlikely(slots > MAX_SKB_FRAGS + 1)) {
549 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
550 slots, skb->len);
551 if (skb_linearize(skb))
552 goto drop;
553 }
554
555 page = virt_to_page(skb->data);
556 offset = offset_in_page(skb->data);
557 len = skb_headlen(skb);
558
559 spin_lock_irqsave(&queue->tx_lock, flags);
560
561 if (unlikely(!netif_carrier_ok(dev) ||
562 (slots > 1 && !xennet_can_sg(dev)) ||
563 netif_needs_gso(skb, netif_skb_features(skb)))) {
564 spin_unlock_irqrestore(&queue->tx_lock, flags);
565 goto drop;
566 }
567
568 /* First request for the linear area. */
569 first_tx = tx = xennet_make_one_txreq(queue, skb,
570 page, offset, len);
571 page++;
572 offset = 0;
573 len -= tx->size;
574
575 if (skb->ip_summed == CHECKSUM_PARTIAL)
576 /* local packet? */
577 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
578 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
579 /* remote but checksummed. */
580 tx->flags |= XEN_NETTXF_data_validated;
581
582 /* Optional extra info after the first request. */
583 if (skb_shinfo(skb)->gso_size) {
584 struct xen_netif_extra_info *gso;
585
586 gso = (struct xen_netif_extra_info *)
587 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
588
589 tx->flags |= XEN_NETTXF_extra_info;
590
591 gso->u.gso.size = skb_shinfo(skb)->gso_size;
592 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
593 XEN_NETIF_GSO_TYPE_TCPV6 :
594 XEN_NETIF_GSO_TYPE_TCPV4;
595 gso->u.gso.pad = 0;
596 gso->u.gso.features = 0;
597
598 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
599 gso->flags = 0;
600 }
601
602 /* Requests for the rest of the linear area. */
603 tx = xennet_make_txreqs(queue, tx, skb, page, offset, len);
604
605 /* Requests for all the frags. */
606 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
607 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
608 tx = xennet_make_txreqs(queue, tx, skb,
609 skb_frag_page(frag), frag->page_offset,
610 skb_frag_size(frag));
611 }
612
613 /* First request has the packet length. */
614 first_tx->size = skb->len;
615
616 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
617 if (notify)
618 notify_remote_via_irq(queue->tx_irq);
619
620 u64_stats_update_begin(&tx_stats->syncp);
621 tx_stats->bytes += skb->len;
622 tx_stats->packets++;
623 u64_stats_update_end(&tx_stats->syncp);
624
625 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
626 xennet_tx_buf_gc(queue);
627
628 if (!netfront_tx_slot_available(queue))
629 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
630
631 spin_unlock_irqrestore(&queue->tx_lock, flags);
632
633 return NETDEV_TX_OK;
634
635 drop:
636 dev->stats.tx_dropped++;
637 dev_kfree_skb_any(skb);
638 return NETDEV_TX_OK;
639 }
640
641 static int xennet_close(struct net_device *dev)
642 {
643 struct netfront_info *np = netdev_priv(dev);
644 unsigned int num_queues = dev->real_num_tx_queues;
645 unsigned int i;
646 struct netfront_queue *queue;
647 netif_tx_stop_all_queues(np->netdev);
648 for (i = 0; i < num_queues; ++i) {
649 queue = &np->queues[i];
650 napi_disable(&queue->napi);
651 }
652 return 0;
653 }
654
655 static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
656 grant_ref_t ref)
657 {
658 int new = xennet_rxidx(queue->rx.req_prod_pvt);
659
660 BUG_ON(queue->rx_skbs[new]);
661 queue->rx_skbs[new] = skb;
662 queue->grant_rx_ref[new] = ref;
663 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new;
664 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref;
665 queue->rx.req_prod_pvt++;
666 }
667
668 static int xennet_get_extras(struct netfront_queue *queue,
669 struct xen_netif_extra_info *extras,
670 RING_IDX rp)
671
672 {
673 struct xen_netif_extra_info *extra;
674 struct device *dev = &queue->info->netdev->dev;
675 RING_IDX cons = queue->rx.rsp_cons;
676 int err = 0;
677
678 do {
679 struct sk_buff *skb;
680 grant_ref_t ref;
681
682 if (unlikely(cons + 1 == rp)) {
683 if (net_ratelimit())
684 dev_warn(dev, "Missing extra info\n");
685 err = -EBADR;
686 break;
687 }
688
689 extra = (struct xen_netif_extra_info *)
690 RING_GET_RESPONSE(&queue->rx, ++cons);
691
692 if (unlikely(!extra->type ||
693 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
694 if (net_ratelimit())
695 dev_warn(dev, "Invalid extra type: %d\n",
696 extra->type);
697 err = -EINVAL;
698 } else {
699 memcpy(&extras[extra->type - 1], extra,
700 sizeof(*extra));
701 }
702
703 skb = xennet_get_rx_skb(queue, cons);
704 ref = xennet_get_rx_ref(queue, cons);
705 xennet_move_rx_slot(queue, skb, ref);
706 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
707
708 queue->rx.rsp_cons = cons;
709 return err;
710 }
711
712 static int xennet_get_responses(struct netfront_queue *queue,
713 struct netfront_rx_info *rinfo, RING_IDX rp,
714 struct sk_buff_head *list)
715 {
716 struct xen_netif_rx_response *rx = &rinfo->rx;
717 struct xen_netif_extra_info *extras = rinfo->extras;
718 struct device *dev = &queue->info->netdev->dev;
719 RING_IDX cons = queue->rx.rsp_cons;
720 struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
721 grant_ref_t ref = xennet_get_rx_ref(queue, cons);
722 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
723 int slots = 1;
724 int err = 0;
725 unsigned long ret;
726
727 if (rx->flags & XEN_NETRXF_extra_info) {
728 err = xennet_get_extras(queue, extras, rp);
729 cons = queue->rx.rsp_cons;
730 }
731
732 for (;;) {
733 if (unlikely(rx->status < 0 ||
734 rx->offset + rx->status > PAGE_SIZE)) {
735 if (net_ratelimit())
736 dev_warn(dev, "rx->offset: %x, size: %u\n",
737 rx->offset, rx->status);
738 xennet_move_rx_slot(queue, skb, ref);
739 err = -EINVAL;
740 goto next;
741 }
742
743 /*
744 * This definitely indicates a bug, either in this driver or in
745 * the backend driver. In future this should flag the bad
746 * situation to the system controller to reboot the backend.
747 */
748 if (ref == GRANT_INVALID_REF) {
749 if (net_ratelimit())
750 dev_warn(dev, "Bad rx response id %d.\n",
751 rx->id);
752 err = -EINVAL;
753 goto next;
754 }
755
756 ret = gnttab_end_foreign_access_ref(ref, 0);
757 BUG_ON(!ret);
758
759 gnttab_release_grant_reference(&queue->gref_rx_head, ref);
760
761 __skb_queue_tail(list, skb);
762
763 next:
764 if (!(rx->flags & XEN_NETRXF_more_data))
765 break;
766
767 if (cons + slots == rp) {
768 if (net_ratelimit())
769 dev_warn(dev, "Need more slots\n");
770 err = -ENOENT;
771 break;
772 }
773
774 rx = RING_GET_RESPONSE(&queue->rx, cons + slots);
775 skb = xennet_get_rx_skb(queue, cons + slots);
776 ref = xennet_get_rx_ref(queue, cons + slots);
777 slots++;
778 }
779
780 if (unlikely(slots > max)) {
781 if (net_ratelimit())
782 dev_warn(dev, "Too many slots\n");
783 err = -E2BIG;
784 }
785
786 if (unlikely(err))
787 queue->rx.rsp_cons = cons + slots;
788
789 return err;
790 }
791
792 static int xennet_set_skb_gso(struct sk_buff *skb,
793 struct xen_netif_extra_info *gso)
794 {
795 if (!gso->u.gso.size) {
796 if (net_ratelimit())
797 pr_warn("GSO size must not be zero\n");
798 return -EINVAL;
799 }
800
801 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
802 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
803 if (net_ratelimit())
804 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
805 return -EINVAL;
806 }
807
808 skb_shinfo(skb)->gso_size = gso->u.gso.size;
809 skb_shinfo(skb)->gso_type =
810 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
811 SKB_GSO_TCPV4 :
812 SKB_GSO_TCPV6;
813
814 /* Header must be checked, and gso_segs computed. */
815 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
816 skb_shinfo(skb)->gso_segs = 0;
817
818 return 0;
819 }
820
821 static RING_IDX xennet_fill_frags(struct netfront_queue *queue,
822 struct sk_buff *skb,
823 struct sk_buff_head *list)
824 {
825 struct skb_shared_info *shinfo = skb_shinfo(skb);
826 RING_IDX cons = queue->rx.rsp_cons;
827 struct sk_buff *nskb;
828
829 while ((nskb = __skb_dequeue(list))) {
830 struct xen_netif_rx_response *rx =
831 RING_GET_RESPONSE(&queue->rx, ++cons);
832 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
833
834 if (shinfo->nr_frags == MAX_SKB_FRAGS) {
835 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
836
837 BUG_ON(pull_to <= skb_headlen(skb));
838 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
839 }
840 BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS);
841
842 skb_add_rx_frag(skb, shinfo->nr_frags, skb_frag_page(nfrag),
843 rx->offset, rx->status, PAGE_SIZE);
844
845 skb_shinfo(nskb)->nr_frags = 0;
846 kfree_skb(nskb);
847 }
848
849 return cons;
850 }
851
852 static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
853 {
854 bool recalculate_partial_csum = false;
855
856 /*
857 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
858 * peers can fail to set NETRXF_csum_blank when sending a GSO
859 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
860 * recalculate the partial checksum.
861 */
862 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
863 struct netfront_info *np = netdev_priv(dev);
864 atomic_inc(&np->rx_gso_checksum_fixup);
865 skb->ip_summed = CHECKSUM_PARTIAL;
866 recalculate_partial_csum = true;
867 }
868
869 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
870 if (skb->ip_summed != CHECKSUM_PARTIAL)
871 return 0;
872
873 return skb_checksum_setup(skb, recalculate_partial_csum);
874 }
875
876 static int handle_incoming_queue(struct netfront_queue *queue,
877 struct sk_buff_head *rxq)
878 {
879 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats);
880 int packets_dropped = 0;
881 struct sk_buff *skb;
882
883 while ((skb = __skb_dequeue(rxq)) != NULL) {
884 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
885
886 if (pull_to > skb_headlen(skb))
887 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
888
889 /* Ethernet work: Delayed to here as it peeks the header. */
890 skb->protocol = eth_type_trans(skb, queue->info->netdev);
891 skb_reset_network_header(skb);
892
893 if (checksum_setup(queue->info->netdev, skb)) {
894 kfree_skb(skb);
895 packets_dropped++;
896 queue->info->netdev->stats.rx_errors++;
897 continue;
898 }
899
900 u64_stats_update_begin(&rx_stats->syncp);
901 rx_stats->packets++;
902 rx_stats->bytes += skb->len;
903 u64_stats_update_end(&rx_stats->syncp);
904
905 /* Pass it up. */
906 napi_gro_receive(&queue->napi, skb);
907 }
908
909 return packets_dropped;
910 }
911
912 static int xennet_poll(struct napi_struct *napi, int budget)
913 {
914 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi);
915 struct net_device *dev = queue->info->netdev;
916 struct sk_buff *skb;
917 struct netfront_rx_info rinfo;
918 struct xen_netif_rx_response *rx = &rinfo.rx;
919 struct xen_netif_extra_info *extras = rinfo.extras;
920 RING_IDX i, rp;
921 int work_done;
922 struct sk_buff_head rxq;
923 struct sk_buff_head errq;
924 struct sk_buff_head tmpq;
925 int err;
926
927 spin_lock(&queue->rx_lock);
928
929 skb_queue_head_init(&rxq);
930 skb_queue_head_init(&errq);
931 skb_queue_head_init(&tmpq);
932
933 rp = queue->rx.sring->rsp_prod;
934 rmb(); /* Ensure we see queued responses up to 'rp'. */
935
936 i = queue->rx.rsp_cons;
937 work_done = 0;
938 while ((i != rp) && (work_done < budget)) {
939 memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx));
940 memset(extras, 0, sizeof(rinfo.extras));
941
942 err = xennet_get_responses(queue, &rinfo, rp, &tmpq);
943
944 if (unlikely(err)) {
945 err:
946 while ((skb = __skb_dequeue(&tmpq)))
947 __skb_queue_tail(&errq, skb);
948 dev->stats.rx_errors++;
949 i = queue->rx.rsp_cons;
950 continue;
951 }
952
953 skb = __skb_dequeue(&tmpq);
954
955 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
956 struct xen_netif_extra_info *gso;
957 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
958
959 if (unlikely(xennet_set_skb_gso(skb, gso))) {
960 __skb_queue_head(&tmpq, skb);
961 queue->rx.rsp_cons += skb_queue_len(&tmpq);
962 goto err;
963 }
964 }
965
966 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
967 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
968 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
969
970 skb_shinfo(skb)->frags[0].page_offset = rx->offset;
971 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
972 skb->data_len = rx->status;
973 skb->len += rx->status;
974
975 i = xennet_fill_frags(queue, skb, &tmpq);
976
977 if (rx->flags & XEN_NETRXF_csum_blank)
978 skb->ip_summed = CHECKSUM_PARTIAL;
979 else if (rx->flags & XEN_NETRXF_data_validated)
980 skb->ip_summed = CHECKSUM_UNNECESSARY;
981
982 __skb_queue_tail(&rxq, skb);
983
984 queue->rx.rsp_cons = ++i;
985 work_done++;
986 }
987
988 __skb_queue_purge(&errq);
989
990 work_done -= handle_incoming_queue(queue, &rxq);
991
992 xennet_alloc_rx_buffers(queue);
993
994 if (work_done < budget) {
995 int more_to_do = 0;
996
997 napi_complete(napi);
998
999 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
1000 if (more_to_do)
1001 napi_schedule(napi);
1002 }
1003
1004 spin_unlock(&queue->rx_lock);
1005
1006 return work_done;
1007 }
1008
1009 static int xennet_change_mtu(struct net_device *dev, int mtu)
1010 {
1011 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN;
1012
1013 if (mtu > max)
1014 return -EINVAL;
1015 dev->mtu = mtu;
1016 return 0;
1017 }
1018
1019 static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
1020 struct rtnl_link_stats64 *tot)
1021 {
1022 struct netfront_info *np = netdev_priv(dev);
1023 int cpu;
1024
1025 for_each_possible_cpu(cpu) {
1026 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu);
1027 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu);
1028 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1029 unsigned int start;
1030
1031 do {
1032 start = u64_stats_fetch_begin_irq(&tx_stats->syncp);
1033 tx_packets = tx_stats->packets;
1034 tx_bytes = tx_stats->bytes;
1035 } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start));
1036
1037 do {
1038 start = u64_stats_fetch_begin_irq(&rx_stats->syncp);
1039 rx_packets = rx_stats->packets;
1040 rx_bytes = rx_stats->bytes;
1041 } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start));
1042
1043 tot->rx_packets += rx_packets;
1044 tot->tx_packets += tx_packets;
1045 tot->rx_bytes += rx_bytes;
1046 tot->tx_bytes += tx_bytes;
1047 }
1048
1049 tot->rx_errors = dev->stats.rx_errors;
1050 tot->tx_dropped = dev->stats.tx_dropped;
1051
1052 return tot;
1053 }
1054
1055 static void xennet_release_tx_bufs(struct netfront_queue *queue)
1056 {
1057 struct sk_buff *skb;
1058 int i;
1059
1060 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1061 /* Skip over entries which are actually freelist references */
1062 if (skb_entry_is_link(&queue->tx_skbs[i]))
1063 continue;
1064
1065 skb = queue->tx_skbs[i].skb;
1066 get_page(queue->grant_tx_page[i]);
1067 gnttab_end_foreign_access(queue->grant_tx_ref[i],
1068 GNTMAP_readonly,
1069 (unsigned long)page_address(queue->grant_tx_page[i]));
1070 queue->grant_tx_page[i] = NULL;
1071 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1072 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i);
1073 dev_kfree_skb_irq(skb);
1074 }
1075 }
1076
1077 static void xennet_release_rx_bufs(struct netfront_queue *queue)
1078 {
1079 int id, ref;
1080
1081 spin_lock_bh(&queue->rx_lock);
1082
1083 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1084 struct sk_buff *skb;
1085 struct page *page;
1086
1087 skb = queue->rx_skbs[id];
1088 if (!skb)
1089 continue;
1090
1091 ref = queue->grant_rx_ref[id];
1092 if (ref == GRANT_INVALID_REF)
1093 continue;
1094
1095 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
1096
1097 /* gnttab_end_foreign_access() needs a page ref until
1098 * foreign access is ended (which may be deferred).
1099 */
1100 get_page(page);
1101 gnttab_end_foreign_access(ref, 0,
1102 (unsigned long)page_address(page));
1103 queue->grant_rx_ref[id] = GRANT_INVALID_REF;
1104
1105 kfree_skb(skb);
1106 }
1107
1108 spin_unlock_bh(&queue->rx_lock);
1109 }
1110
1111 static netdev_features_t xennet_fix_features(struct net_device *dev,
1112 netdev_features_t features)
1113 {
1114 struct netfront_info *np = netdev_priv(dev);
1115 int val;
1116
1117 if (features & NETIF_F_SG) {
1118 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg",
1119 "%d", &val) < 0)
1120 val = 0;
1121
1122 if (!val)
1123 features &= ~NETIF_F_SG;
1124 }
1125
1126 if (features & NETIF_F_IPV6_CSUM) {
1127 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1128 "feature-ipv6-csum-offload", "%d", &val) < 0)
1129 val = 0;
1130
1131 if (!val)
1132 features &= ~NETIF_F_IPV6_CSUM;
1133 }
1134
1135 if (features & NETIF_F_TSO) {
1136 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1137 "feature-gso-tcpv4", "%d", &val) < 0)
1138 val = 0;
1139
1140 if (!val)
1141 features &= ~NETIF_F_TSO;
1142 }
1143
1144 if (features & NETIF_F_TSO6) {
1145 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1146 "feature-gso-tcpv6", "%d", &val) < 0)
1147 val = 0;
1148
1149 if (!val)
1150 features &= ~NETIF_F_TSO6;
1151 }
1152
1153 return features;
1154 }
1155
1156 static int xennet_set_features(struct net_device *dev,
1157 netdev_features_t features)
1158 {
1159 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1160 netdev_info(dev, "Reducing MTU because no SG offload");
1161 dev->mtu = ETH_DATA_LEN;
1162 }
1163
1164 return 0;
1165 }
1166
1167 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1168 {
1169 struct netfront_queue *queue = dev_id;
1170 unsigned long flags;
1171
1172 spin_lock_irqsave(&queue->tx_lock, flags);
1173 xennet_tx_buf_gc(queue);
1174 spin_unlock_irqrestore(&queue->tx_lock, flags);
1175
1176 return IRQ_HANDLED;
1177 }
1178
1179 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1180 {
1181 struct netfront_queue *queue = dev_id;
1182 struct net_device *dev = queue->info->netdev;
1183
1184 if (likely(netif_carrier_ok(dev) &&
1185 RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)))
1186 napi_schedule(&queue->napi);
1187
1188 return IRQ_HANDLED;
1189 }
1190
1191 static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1192 {
1193 xennet_tx_interrupt(irq, dev_id);
1194 xennet_rx_interrupt(irq, dev_id);
1195 return IRQ_HANDLED;
1196 }
1197
1198 #ifdef CONFIG_NET_POLL_CONTROLLER
1199 static void xennet_poll_controller(struct net_device *dev)
1200 {
1201 /* Poll each queue */
1202 struct netfront_info *info = netdev_priv(dev);
1203 unsigned int num_queues = dev->real_num_tx_queues;
1204 unsigned int i;
1205 for (i = 0; i < num_queues; ++i)
1206 xennet_interrupt(0, &info->queues[i]);
1207 }
1208 #endif
1209
1210 static const struct net_device_ops xennet_netdev_ops = {
1211 .ndo_open = xennet_open,
1212 .ndo_stop = xennet_close,
1213 .ndo_start_xmit = xennet_start_xmit,
1214 .ndo_change_mtu = xennet_change_mtu,
1215 .ndo_get_stats64 = xennet_get_stats64,
1216 .ndo_set_mac_address = eth_mac_addr,
1217 .ndo_validate_addr = eth_validate_addr,
1218 .ndo_fix_features = xennet_fix_features,
1219 .ndo_set_features = xennet_set_features,
1220 .ndo_select_queue = xennet_select_queue,
1221 #ifdef CONFIG_NET_POLL_CONTROLLER
1222 .ndo_poll_controller = xennet_poll_controller,
1223 #endif
1224 };
1225
1226 static void xennet_free_netdev(struct net_device *netdev)
1227 {
1228 struct netfront_info *np = netdev_priv(netdev);
1229
1230 free_percpu(np->rx_stats);
1231 free_percpu(np->tx_stats);
1232 free_netdev(netdev);
1233 }
1234
1235 static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1236 {
1237 int err;
1238 struct net_device *netdev;
1239 struct netfront_info *np;
1240
1241 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues);
1242 if (!netdev)
1243 return ERR_PTR(-ENOMEM);
1244
1245 np = netdev_priv(netdev);
1246 np->xbdev = dev;
1247
1248 /* No need to use rtnl_lock() before the call below as it
1249 * happens before register_netdev().
1250 */
1251 netif_set_real_num_tx_queues(netdev, 0);
1252 np->queues = NULL;
1253
1254 err = -ENOMEM;
1255 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1256 if (np->rx_stats == NULL)
1257 goto exit;
1258 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1259 if (np->tx_stats == NULL)
1260 goto exit;
1261
1262 netdev->netdev_ops = &xennet_netdev_ops;
1263
1264 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1265 NETIF_F_GSO_ROBUST;
1266 netdev->hw_features = NETIF_F_SG |
1267 NETIF_F_IPV6_CSUM |
1268 NETIF_F_TSO | NETIF_F_TSO6;
1269
1270 /*
1271 * Assume that all hw features are available for now. This set
1272 * will be adjusted by the call to netdev_update_features() in
1273 * xennet_connect() which is the earliest point where we can
1274 * negotiate with the backend regarding supported features.
1275 */
1276 netdev->features |= netdev->hw_features;
1277
1278 netdev->ethtool_ops = &xennet_ethtool_ops;
1279 SET_NETDEV_DEV(netdev, &dev->dev);
1280
1281 np->netdev = netdev;
1282
1283 netif_carrier_off(netdev);
1284
1285 return netdev;
1286
1287 exit:
1288 xennet_free_netdev(netdev);
1289 return ERR_PTR(err);
1290 }
1291
1292 /**
1293 * Entry point to this code when a new device is created. Allocate the basic
1294 * structures and the ring buffers for communication with the backend, and
1295 * inform the backend of the appropriate details for those.
1296 */
1297 static int netfront_probe(struct xenbus_device *dev,
1298 const struct xenbus_device_id *id)
1299 {
1300 int err;
1301 struct net_device *netdev;
1302 struct netfront_info *info;
1303
1304 netdev = xennet_create_dev(dev);
1305 if (IS_ERR(netdev)) {
1306 err = PTR_ERR(netdev);
1307 xenbus_dev_fatal(dev, err, "creating netdev");
1308 return err;
1309 }
1310
1311 info = netdev_priv(netdev);
1312 dev_set_drvdata(&dev->dev, info);
1313 #ifdef CONFIG_SYSFS
1314 info->netdev->sysfs_groups[0] = &xennet_dev_group;
1315 #endif
1316 err = register_netdev(info->netdev);
1317 if (err) {
1318 pr_warn("%s: register_netdev err=%d\n", __func__, err);
1319 goto fail;
1320 }
1321
1322 return 0;
1323
1324 fail:
1325 xennet_free_netdev(netdev);
1326 dev_set_drvdata(&dev->dev, NULL);
1327 return err;
1328 }
1329
1330 static void xennet_end_access(int ref, void *page)
1331 {
1332 /* This frees the page as a side-effect */
1333 if (ref != GRANT_INVALID_REF)
1334 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1335 }
1336
1337 static void xennet_disconnect_backend(struct netfront_info *info)
1338 {
1339 unsigned int i = 0;
1340 unsigned int num_queues = info->netdev->real_num_tx_queues;
1341
1342 netif_carrier_off(info->netdev);
1343
1344 for (i = 0; i < num_queues; ++i) {
1345 struct netfront_queue *queue = &info->queues[i];
1346
1347 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
1348 unbind_from_irqhandler(queue->tx_irq, queue);
1349 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
1350 unbind_from_irqhandler(queue->tx_irq, queue);
1351 unbind_from_irqhandler(queue->rx_irq, queue);
1352 }
1353 queue->tx_evtchn = queue->rx_evtchn = 0;
1354 queue->tx_irq = queue->rx_irq = 0;
1355
1356 napi_synchronize(&queue->napi);
1357
1358 xennet_release_tx_bufs(queue);
1359 xennet_release_rx_bufs(queue);
1360 gnttab_free_grant_references(queue->gref_tx_head);
1361 gnttab_free_grant_references(queue->gref_rx_head);
1362
1363 /* End access and free the pages */
1364 xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
1365 xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
1366
1367 queue->tx_ring_ref = GRANT_INVALID_REF;
1368 queue->rx_ring_ref = GRANT_INVALID_REF;
1369 queue->tx.sring = NULL;
1370 queue->rx.sring = NULL;
1371 }
1372 }
1373
1374 /**
1375 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1376 * driver restart. We tear down our netif structure and recreate it, but
1377 * leave the device-layer structures intact so that this is transparent to the
1378 * rest of the kernel.
1379 */
1380 static int netfront_resume(struct xenbus_device *dev)
1381 {
1382 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1383
1384 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1385
1386 xennet_disconnect_backend(info);
1387 return 0;
1388 }
1389
1390 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1391 {
1392 char *s, *e, *macstr;
1393 int i;
1394
1395 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1396 if (IS_ERR(macstr))
1397 return PTR_ERR(macstr);
1398
1399 for (i = 0; i < ETH_ALEN; i++) {
1400 mac[i] = simple_strtoul(s, &e, 16);
1401 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1402 kfree(macstr);
1403 return -ENOENT;
1404 }
1405 s = e+1;
1406 }
1407
1408 kfree(macstr);
1409 return 0;
1410 }
1411
1412 static int setup_netfront_single(struct netfront_queue *queue)
1413 {
1414 int err;
1415
1416 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1417 if (err < 0)
1418 goto fail;
1419
1420 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1421 xennet_interrupt,
1422 0, queue->info->netdev->name, queue);
1423 if (err < 0)
1424 goto bind_fail;
1425 queue->rx_evtchn = queue->tx_evtchn;
1426 queue->rx_irq = queue->tx_irq = err;
1427
1428 return 0;
1429
1430 bind_fail:
1431 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1432 queue->tx_evtchn = 0;
1433 fail:
1434 return err;
1435 }
1436
1437 static int setup_netfront_split(struct netfront_queue *queue)
1438 {
1439 int err;
1440
1441 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1442 if (err < 0)
1443 goto fail;
1444 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn);
1445 if (err < 0)
1446 goto alloc_rx_evtchn_fail;
1447
1448 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
1449 "%s-tx", queue->name);
1450 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1451 xennet_tx_interrupt,
1452 0, queue->tx_irq_name, queue);
1453 if (err < 0)
1454 goto bind_tx_fail;
1455 queue->tx_irq = err;
1456
1457 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
1458 "%s-rx", queue->name);
1459 err = bind_evtchn_to_irqhandler(queue->rx_evtchn,
1460 xennet_rx_interrupt,
1461 0, queue->rx_irq_name, queue);
1462 if (err < 0)
1463 goto bind_rx_fail;
1464 queue->rx_irq = err;
1465
1466 return 0;
1467
1468 bind_rx_fail:
1469 unbind_from_irqhandler(queue->tx_irq, queue);
1470 queue->tx_irq = 0;
1471 bind_tx_fail:
1472 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn);
1473 queue->rx_evtchn = 0;
1474 alloc_rx_evtchn_fail:
1475 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1476 queue->tx_evtchn = 0;
1477 fail:
1478 return err;
1479 }
1480
1481 static int setup_netfront(struct xenbus_device *dev,
1482 struct netfront_queue *queue, unsigned int feature_split_evtchn)
1483 {
1484 struct xen_netif_tx_sring *txs;
1485 struct xen_netif_rx_sring *rxs;
1486 grant_ref_t gref;
1487 int err;
1488
1489 queue->tx_ring_ref = GRANT_INVALID_REF;
1490 queue->rx_ring_ref = GRANT_INVALID_REF;
1491 queue->rx.sring = NULL;
1492 queue->tx.sring = NULL;
1493
1494 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1495 if (!txs) {
1496 err = -ENOMEM;
1497 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1498 goto fail;
1499 }
1500 SHARED_RING_INIT(txs);
1501 FRONT_RING_INIT(&queue->tx, txs, PAGE_SIZE);
1502
1503 err = xenbus_grant_ring(dev, txs, 1, &gref);
1504 if (err < 0)
1505 goto grant_tx_ring_fail;
1506 queue->tx_ring_ref = gref;
1507
1508 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1509 if (!rxs) {
1510 err = -ENOMEM;
1511 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1512 goto alloc_rx_ring_fail;
1513 }
1514 SHARED_RING_INIT(rxs);
1515 FRONT_RING_INIT(&queue->rx, rxs, PAGE_SIZE);
1516
1517 err = xenbus_grant_ring(dev, rxs, 1, &gref);
1518 if (err < 0)
1519 goto grant_rx_ring_fail;
1520 queue->rx_ring_ref = gref;
1521
1522 if (feature_split_evtchn)
1523 err = setup_netfront_split(queue);
1524 /* setup single event channel if
1525 * a) feature-split-event-channels == 0
1526 * b) feature-split-event-channels == 1 but failed to setup
1527 */
1528 if (!feature_split_evtchn || (feature_split_evtchn && err))
1529 err = setup_netfront_single(queue);
1530
1531 if (err)
1532 goto alloc_evtchn_fail;
1533
1534 return 0;
1535
1536 /* If we fail to setup netfront, it is safe to just revoke access to
1537 * granted pages because backend is not accessing it at this point.
1538 */
1539 alloc_evtchn_fail:
1540 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0);
1541 grant_rx_ring_fail:
1542 free_page((unsigned long)rxs);
1543 alloc_rx_ring_fail:
1544 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0);
1545 grant_tx_ring_fail:
1546 free_page((unsigned long)txs);
1547 fail:
1548 return err;
1549 }
1550
1551 /* Queue-specific initialisation
1552 * This used to be done in xennet_create_dev() but must now
1553 * be run per-queue.
1554 */
1555 static int xennet_init_queue(struct netfront_queue *queue)
1556 {
1557 unsigned short i;
1558 int err = 0;
1559
1560 spin_lock_init(&queue->tx_lock);
1561 spin_lock_init(&queue->rx_lock);
1562
1563 init_timer(&queue->rx_refill_timer);
1564 queue->rx_refill_timer.data = (unsigned long)queue;
1565 queue->rx_refill_timer.function = rx_refill_timeout;
1566
1567 snprintf(queue->name, sizeof(queue->name), "%s-q%u",
1568 queue->info->netdev->name, queue->id);
1569
1570 /* Initialise tx_skbs as a free chain containing every entry. */
1571 queue->tx_skb_freelist = 0;
1572 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1573 skb_entry_set_link(&queue->tx_skbs[i], i+1);
1574 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1575 queue->grant_tx_page[i] = NULL;
1576 }
1577
1578 /* Clear out rx_skbs */
1579 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1580 queue->rx_skbs[i] = NULL;
1581 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
1582 }
1583
1584 /* A grant for every tx ring slot */
1585 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
1586 &queue->gref_tx_head) < 0) {
1587 pr_alert("can't alloc tx grant refs\n");
1588 err = -ENOMEM;
1589 goto exit;
1590 }
1591
1592 /* A grant for every rx ring slot */
1593 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
1594 &queue->gref_rx_head) < 0) {
1595 pr_alert("can't alloc rx grant refs\n");
1596 err = -ENOMEM;
1597 goto exit_free_tx;
1598 }
1599
1600 return 0;
1601
1602 exit_free_tx:
1603 gnttab_free_grant_references(queue->gref_tx_head);
1604 exit:
1605 return err;
1606 }
1607
1608 static int write_queue_xenstore_keys(struct netfront_queue *queue,
1609 struct xenbus_transaction *xbt, int write_hierarchical)
1610 {
1611 /* Write the queue-specific keys into XenStore in the traditional
1612 * way for a single queue, or in a queue subkeys for multiple
1613 * queues.
1614 */
1615 struct xenbus_device *dev = queue->info->xbdev;
1616 int err;
1617 const char *message;
1618 char *path;
1619 size_t pathsize;
1620
1621 /* Choose the correct place to write the keys */
1622 if (write_hierarchical) {
1623 pathsize = strlen(dev->nodename) + 10;
1624 path = kzalloc(pathsize, GFP_KERNEL);
1625 if (!path) {
1626 err = -ENOMEM;
1627 message = "out of memory while writing ring references";
1628 goto error;
1629 }
1630 snprintf(path, pathsize, "%s/queue-%u",
1631 dev->nodename, queue->id);
1632 } else {
1633 path = (char *)dev->nodename;
1634 }
1635
1636 /* Write ring references */
1637 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u",
1638 queue->tx_ring_ref);
1639 if (err) {
1640 message = "writing tx-ring-ref";
1641 goto error;
1642 }
1643
1644 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u",
1645 queue->rx_ring_ref);
1646 if (err) {
1647 message = "writing rx-ring-ref";
1648 goto error;
1649 }
1650
1651 /* Write event channels; taking into account both shared
1652 * and split event channel scenarios.
1653 */
1654 if (queue->tx_evtchn == queue->rx_evtchn) {
1655 /* Shared event channel */
1656 err = xenbus_printf(*xbt, path,
1657 "event-channel", "%u", queue->tx_evtchn);
1658 if (err) {
1659 message = "writing event-channel";
1660 goto error;
1661 }
1662 } else {
1663 /* Split event channels */
1664 err = xenbus_printf(*xbt, path,
1665 "event-channel-tx", "%u", queue->tx_evtchn);
1666 if (err) {
1667 message = "writing event-channel-tx";
1668 goto error;
1669 }
1670
1671 err = xenbus_printf(*xbt, path,
1672 "event-channel-rx", "%u", queue->rx_evtchn);
1673 if (err) {
1674 message = "writing event-channel-rx";
1675 goto error;
1676 }
1677 }
1678
1679 if (write_hierarchical)
1680 kfree(path);
1681 return 0;
1682
1683 error:
1684 if (write_hierarchical)
1685 kfree(path);
1686 xenbus_dev_fatal(dev, err, "%s", message);
1687 return err;
1688 }
1689
1690 static void xennet_destroy_queues(struct netfront_info *info)
1691 {
1692 unsigned int i;
1693
1694 rtnl_lock();
1695
1696 for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
1697 struct netfront_queue *queue = &info->queues[i];
1698
1699 if (netif_running(info->netdev))
1700 napi_disable(&queue->napi);
1701 netif_napi_del(&queue->napi);
1702 }
1703
1704 rtnl_unlock();
1705
1706 kfree(info->queues);
1707 info->queues = NULL;
1708 }
1709
1710 static int xennet_create_queues(struct netfront_info *info,
1711 unsigned int num_queues)
1712 {
1713 unsigned int i;
1714 int ret;
1715
1716 info->queues = kcalloc(num_queues, sizeof(struct netfront_queue),
1717 GFP_KERNEL);
1718 if (!info->queues)
1719 return -ENOMEM;
1720
1721 rtnl_lock();
1722
1723 for (i = 0; i < num_queues; i++) {
1724 struct netfront_queue *queue = &info->queues[i];
1725
1726 queue->id = i;
1727 queue->info = info;
1728
1729 ret = xennet_init_queue(queue);
1730 if (ret < 0) {
1731 dev_warn(&info->netdev->dev,
1732 "only created %d queues\n", i);
1733 num_queues = i;
1734 break;
1735 }
1736
1737 netif_napi_add(queue->info->netdev, &queue->napi,
1738 xennet_poll, 64);
1739 if (netif_running(info->netdev))
1740 napi_enable(&queue->napi);
1741 }
1742
1743 netif_set_real_num_tx_queues(info->netdev, num_queues);
1744
1745 rtnl_unlock();
1746
1747 if (num_queues == 0) {
1748 dev_err(&info->netdev->dev, "no queues\n");
1749 return -EINVAL;
1750 }
1751 return 0;
1752 }
1753
1754 /* Common code used when first setting up, and when resuming. */
1755 static int talk_to_netback(struct xenbus_device *dev,
1756 struct netfront_info *info)
1757 {
1758 const char *message;
1759 struct xenbus_transaction xbt;
1760 int err;
1761 unsigned int feature_split_evtchn;
1762 unsigned int i = 0;
1763 unsigned int max_queues = 0;
1764 struct netfront_queue *queue = NULL;
1765 unsigned int num_queues = 1;
1766
1767 info->netdev->irq = 0;
1768
1769 /* Check if backend supports multiple queues */
1770 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
1771 "multi-queue-max-queues", "%u", &max_queues);
1772 if (err < 0)
1773 max_queues = 1;
1774 num_queues = min(max_queues, xennet_max_queues);
1775
1776 /* Check feature-split-event-channels */
1777 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
1778 "feature-split-event-channels", "%u",
1779 &feature_split_evtchn);
1780 if (err < 0)
1781 feature_split_evtchn = 0;
1782
1783 /* Read mac addr. */
1784 err = xen_net_read_mac(dev, info->netdev->dev_addr);
1785 if (err) {
1786 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1787 goto out;
1788 }
1789
1790 if (info->queues)
1791 xennet_destroy_queues(info);
1792
1793 err = xennet_create_queues(info, num_queues);
1794 if (err < 0)
1795 goto destroy_ring;
1796
1797 /* Create shared ring, alloc event channel -- for each queue */
1798 for (i = 0; i < num_queues; ++i) {
1799 queue = &info->queues[i];
1800 err = setup_netfront(dev, queue, feature_split_evtchn);
1801 if (err) {
1802 /* setup_netfront() will tidy up the current
1803 * queue on error, but we need to clean up
1804 * those already allocated.
1805 */
1806 if (i > 0) {
1807 rtnl_lock();
1808 netif_set_real_num_tx_queues(info->netdev, i);
1809 rtnl_unlock();
1810 goto destroy_ring;
1811 } else {
1812 goto out;
1813 }
1814 }
1815 }
1816
1817 again:
1818 err = xenbus_transaction_start(&xbt);
1819 if (err) {
1820 xenbus_dev_fatal(dev, err, "starting transaction");
1821 goto destroy_ring;
1822 }
1823
1824 if (num_queues == 1) {
1825 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */
1826 if (err)
1827 goto abort_transaction_no_dev_fatal;
1828 } else {
1829 /* Write the number of queues */
1830 err = xenbus_printf(xbt, dev->nodename, "multi-queue-num-queues",
1831 "%u", num_queues);
1832 if (err) {
1833 message = "writing multi-queue-num-queues";
1834 goto abort_transaction_no_dev_fatal;
1835 }
1836
1837 /* Write the keys for each queue */
1838 for (i = 0; i < num_queues; ++i) {
1839 queue = &info->queues[i];
1840 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */
1841 if (err)
1842 goto abort_transaction_no_dev_fatal;
1843 }
1844 }
1845
1846 /* The remaining keys are not queue-specific */
1847 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
1848 1);
1849 if (err) {
1850 message = "writing request-rx-copy";
1851 goto abort_transaction;
1852 }
1853
1854 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
1855 if (err) {
1856 message = "writing feature-rx-notify";
1857 goto abort_transaction;
1858 }
1859
1860 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
1861 if (err) {
1862 message = "writing feature-sg";
1863 goto abort_transaction;
1864 }
1865
1866 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
1867 if (err) {
1868 message = "writing feature-gso-tcpv4";
1869 goto abort_transaction;
1870 }
1871
1872 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1");
1873 if (err) {
1874 message = "writing feature-gso-tcpv6";
1875 goto abort_transaction;
1876 }
1877
1878 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload",
1879 "1");
1880 if (err) {
1881 message = "writing feature-ipv6-csum-offload";
1882 goto abort_transaction;
1883 }
1884
1885 err = xenbus_transaction_end(xbt, 0);
1886 if (err) {
1887 if (err == -EAGAIN)
1888 goto again;
1889 xenbus_dev_fatal(dev, err, "completing transaction");
1890 goto destroy_ring;
1891 }
1892
1893 return 0;
1894
1895 abort_transaction:
1896 xenbus_dev_fatal(dev, err, "%s", message);
1897 abort_transaction_no_dev_fatal:
1898 xenbus_transaction_end(xbt, 1);
1899 destroy_ring:
1900 xennet_disconnect_backend(info);
1901 kfree(info->queues);
1902 info->queues = NULL;
1903 rtnl_lock();
1904 netif_set_real_num_tx_queues(info->netdev, 0);
1905 rtnl_unlock();
1906 out:
1907 return err;
1908 }
1909
1910 static int xennet_connect(struct net_device *dev)
1911 {
1912 struct netfront_info *np = netdev_priv(dev);
1913 unsigned int num_queues = 0;
1914 int err;
1915 unsigned int feature_rx_copy;
1916 unsigned int j = 0;
1917 struct netfront_queue *queue = NULL;
1918
1919 err = xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1920 "feature-rx-copy", "%u", &feature_rx_copy);
1921 if (err != 1)
1922 feature_rx_copy = 0;
1923
1924 if (!feature_rx_copy) {
1925 dev_info(&dev->dev,
1926 "backend does not support copying receive path\n");
1927 return -ENODEV;
1928 }
1929
1930 err = talk_to_netback(np->xbdev, np);
1931 if (err)
1932 return err;
1933
1934 /* talk_to_netback() sets the correct number of queues */
1935 num_queues = dev->real_num_tx_queues;
1936
1937 rtnl_lock();
1938 netdev_update_features(dev);
1939 rtnl_unlock();
1940
1941 /*
1942 * All public and private state should now be sane. Get
1943 * ready to start sending and receiving packets and give the driver
1944 * domain a kick because we've probably just requeued some
1945 * packets.
1946 */
1947 netif_carrier_on(np->netdev);
1948 for (j = 0; j < num_queues; ++j) {
1949 queue = &np->queues[j];
1950
1951 notify_remote_via_irq(queue->tx_irq);
1952 if (queue->tx_irq != queue->rx_irq)
1953 notify_remote_via_irq(queue->rx_irq);
1954
1955 spin_lock_irq(&queue->tx_lock);
1956 xennet_tx_buf_gc(queue);
1957 spin_unlock_irq(&queue->tx_lock);
1958
1959 spin_lock_bh(&queue->rx_lock);
1960 xennet_alloc_rx_buffers(queue);
1961 spin_unlock_bh(&queue->rx_lock);
1962 }
1963
1964 return 0;
1965 }
1966
1967 /**
1968 * Callback received when the backend's state changes.
1969 */
1970 static void netback_changed(struct xenbus_device *dev,
1971 enum xenbus_state backend_state)
1972 {
1973 struct netfront_info *np = dev_get_drvdata(&dev->dev);
1974 struct net_device *netdev = np->netdev;
1975
1976 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
1977
1978 switch (backend_state) {
1979 case XenbusStateInitialising:
1980 case XenbusStateInitialised:
1981 case XenbusStateReconfiguring:
1982 case XenbusStateReconfigured:
1983 case XenbusStateUnknown:
1984 break;
1985
1986 case XenbusStateInitWait:
1987 if (dev->state != XenbusStateInitialising)
1988 break;
1989 if (xennet_connect(netdev) != 0)
1990 break;
1991 xenbus_switch_state(dev, XenbusStateConnected);
1992 break;
1993
1994 case XenbusStateConnected:
1995 netdev_notify_peers(netdev);
1996 break;
1997
1998 case XenbusStateClosed:
1999 if (dev->state == XenbusStateClosed)
2000 break;
2001 /* Missed the backend's CLOSING state -- fallthrough */
2002 case XenbusStateClosing:
2003 xenbus_frontend_closed(dev);
2004 break;
2005 }
2006 }
2007
2008 static const struct xennet_stat {
2009 char name[ETH_GSTRING_LEN];
2010 u16 offset;
2011 } xennet_stats[] = {
2012 {
2013 "rx_gso_checksum_fixup",
2014 offsetof(struct netfront_info, rx_gso_checksum_fixup)
2015 },
2016 };
2017
2018 static int xennet_get_sset_count(struct net_device *dev, int string_set)
2019 {
2020 switch (string_set) {
2021 case ETH_SS_STATS:
2022 return ARRAY_SIZE(xennet_stats);
2023 default:
2024 return -EINVAL;
2025 }
2026 }
2027
2028 static void xennet_get_ethtool_stats(struct net_device *dev,
2029 struct ethtool_stats *stats, u64 * data)
2030 {
2031 void *np = netdev_priv(dev);
2032 int i;
2033
2034 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2035 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset));
2036 }
2037
2038 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
2039 {
2040 int i;
2041
2042 switch (stringset) {
2043 case ETH_SS_STATS:
2044 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2045 memcpy(data + i * ETH_GSTRING_LEN,
2046 xennet_stats[i].name, ETH_GSTRING_LEN);
2047 break;
2048 }
2049 }
2050
2051 static const struct ethtool_ops xennet_ethtool_ops =
2052 {
2053 .get_link = ethtool_op_get_link,
2054
2055 .get_sset_count = xennet_get_sset_count,
2056 .get_ethtool_stats = xennet_get_ethtool_stats,
2057 .get_strings = xennet_get_strings,
2058 };
2059
2060 #ifdef CONFIG_SYSFS
2061 static ssize_t show_rxbuf(struct device *dev,
2062 struct device_attribute *attr, char *buf)
2063 {
2064 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE);
2065 }
2066
2067 static ssize_t store_rxbuf(struct device *dev,
2068 struct device_attribute *attr,
2069 const char *buf, size_t len)
2070 {
2071 char *endp;
2072 unsigned long target;
2073
2074 if (!capable(CAP_NET_ADMIN))
2075 return -EPERM;
2076
2077 target = simple_strtoul(buf, &endp, 0);
2078 if (endp == buf)
2079 return -EBADMSG;
2080
2081 /* rxbuf_min and rxbuf_max are no longer configurable. */
2082
2083 return len;
2084 }
2085
2086 static DEVICE_ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
2087 static DEVICE_ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
2088 static DEVICE_ATTR(rxbuf_cur, S_IRUGO, show_rxbuf, NULL);
2089
2090 static struct attribute *xennet_dev_attrs[] = {
2091 &dev_attr_rxbuf_min.attr,
2092 &dev_attr_rxbuf_max.attr,
2093 &dev_attr_rxbuf_cur.attr,
2094 NULL
2095 };
2096
2097 static const struct attribute_group xennet_dev_group = {
2098 .attrs = xennet_dev_attrs
2099 };
2100 #endif /* CONFIG_SYSFS */
2101
2102 static int xennet_remove(struct xenbus_device *dev)
2103 {
2104 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2105 unsigned int num_queues = info->netdev->real_num_tx_queues;
2106 struct netfront_queue *queue = NULL;
2107 unsigned int i = 0;
2108
2109 dev_dbg(&dev->dev, "%s\n", dev->nodename);
2110
2111 xennet_disconnect_backend(info);
2112
2113 unregister_netdev(info->netdev);
2114
2115 for (i = 0; i < num_queues; ++i) {
2116 queue = &info->queues[i];
2117 del_timer_sync(&queue->rx_refill_timer);
2118 }
2119
2120 if (num_queues) {
2121 kfree(info->queues);
2122 info->queues = NULL;
2123 }
2124
2125 xennet_free_netdev(info->netdev);
2126
2127 return 0;
2128 }
2129
2130 static const struct xenbus_device_id netfront_ids[] = {
2131 { "vif" },
2132 { "" }
2133 };
2134
2135 static struct xenbus_driver netfront_driver = {
2136 .ids = netfront_ids,
2137 .probe = netfront_probe,
2138 .remove = xennet_remove,
2139 .resume = netfront_resume,
2140 .otherend_changed = netback_changed,
2141 };
2142
2143 static int __init netif_init(void)
2144 {
2145 if (!xen_domain())
2146 return -ENODEV;
2147
2148 if (!xen_has_pv_nic_devices())
2149 return -ENODEV;
2150
2151 pr_info("Initialising Xen virtual ethernet driver\n");
2152
2153 /* Allow as many queues as there are CPUs, by default */
2154 xennet_max_queues = num_online_cpus();
2155
2156 return xenbus_register_frontend(&netfront_driver);
2157 }
2158 module_init(netif_init);
2159
2160
2161 static void __exit netif_exit(void)
2162 {
2163 xenbus_unregister_driver(&netfront_driver);
2164 }
2165 module_exit(netif_exit);
2166
2167 MODULE_DESCRIPTION("Xen virtual network device frontend");
2168 MODULE_LICENSE("GPL");
2169 MODULE_ALIAS("xen:vif");
2170 MODULE_ALIAS("xennet");
Linux kernel - Deliverables
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