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ARM: dts: add 'dr_mode' property to hsotg devices for exynos boards
[linux/fpc-iii.git] / drivers / net / xen-netfront.c
blob22bcb4e12e2a1318fc1802fb3c5ff6b2cb4acf92
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 rx_packets;
92 u64 tx_packets;
93 u64 rx_bytes;
94 u64 tx_bytes;
95 struct u64_stats_sync syncp;
96 };
97
98 struct netfront_info;
99
100 struct netfront_queue {
101 unsigned int id; /* Queue ID, 0-based */
102 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
103 struct netfront_info *info;
104
105 struct napi_struct napi;
106
107 /* Split event channels support, tx_* == rx_* when using
108 * single event channel.
109 */
110 unsigned int tx_evtchn, rx_evtchn;
111 unsigned int tx_irq, rx_irq;
112 /* Only used when split event channels support is enabled */
113 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
114 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
115
116 spinlock_t tx_lock;
117 struct xen_netif_tx_front_ring tx;
118 int tx_ring_ref;
119
120 /*
121 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
122 * are linked from tx_skb_freelist through skb_entry.link.
123 *
124 * NB. Freelist index entries are always going to be less than
125 * PAGE_OFFSET, whereas pointers to skbs will always be equal or
126 * greater than PAGE_OFFSET: we use this property to distinguish
127 * them.
128 */
129 union skb_entry {
130 struct sk_buff *skb;
131 unsigned long link;
132 } tx_skbs[NET_TX_RING_SIZE];
133 grant_ref_t gref_tx_head;
134 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
135 struct page *grant_tx_page[NET_TX_RING_SIZE];
136 unsigned tx_skb_freelist;
137
138 spinlock_t rx_lock ____cacheline_aligned_in_smp;
139 struct xen_netif_rx_front_ring rx;
140 int rx_ring_ref;
141
142 struct timer_list rx_refill_timer;
143
144 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
145 grant_ref_t gref_rx_head;
146 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
147
148 unsigned long rx_pfn_array[NET_RX_RING_SIZE];
149 struct multicall_entry rx_mcl[NET_RX_RING_SIZE+1];
150 struct mmu_update rx_mmu[NET_RX_RING_SIZE];
151 };
152
153 struct netfront_info {
154 struct list_head list;
155 struct net_device *netdev;
156
157 struct xenbus_device *xbdev;
158
159 /* Multi-queue support */
160 struct netfront_queue *queues;
161
162 /* Statistics */
163 struct netfront_stats __percpu *stats;
164
165 atomic_t rx_gso_checksum_fixup;
166 };
167
168 struct netfront_rx_info {
169 struct xen_netif_rx_response rx;
170 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
171 };
172
173 static void skb_entry_set_link(union skb_entry *list, unsigned short id)
174 {
175 list->link = id;
176 }
177
178 static int skb_entry_is_link(const union skb_entry *list)
179 {
180 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
181 return (unsigned long)list->skb < PAGE_OFFSET;
182 }
183
184 /*
185 * Access macros for acquiring freeing slots in tx_skbs[].
186 */
187
188 static void add_id_to_freelist(unsigned *head, union skb_entry *list,
189 unsigned short id)
190 {
191 skb_entry_set_link(&list[id], *head);
192 *head = id;
193 }
194
195 static unsigned short get_id_from_freelist(unsigned *head,
196 union skb_entry *list)
197 {
198 unsigned int id = *head;
199 *head = list[id].link;
200 return id;
201 }
202
203 static int xennet_rxidx(RING_IDX idx)
204 {
205 return idx & (NET_RX_RING_SIZE - 1);
206 }
207
208 static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue,
209 RING_IDX ri)
210 {
211 int i = xennet_rxidx(ri);
212 struct sk_buff *skb = queue->rx_skbs[i];
213 queue->rx_skbs[i] = NULL;
214 return skb;
215 }
216
217 static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
218 RING_IDX ri)
219 {
220 int i = xennet_rxidx(ri);
221 grant_ref_t ref = queue->grant_rx_ref[i];
222 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
223 return ref;
224 }
225
226 #ifdef CONFIG_SYSFS
227 static int xennet_sysfs_addif(struct net_device *netdev);
228 static void xennet_sysfs_delif(struct net_device *netdev);
229 #else /* !CONFIG_SYSFS */
230 #define xennet_sysfs_addif(dev) (0)
231 #define xennet_sysfs_delif(dev) do { } while (0)
232 #endif
233
234 static bool xennet_can_sg(struct net_device *dev)
235 {
236 return dev->features & NETIF_F_SG;
237 }
238
239
240 static void rx_refill_timeout(unsigned long data)
241 {
242 struct netfront_queue *queue = (struct netfront_queue *)data;
243 napi_schedule(&queue->napi);
244 }
245
246 static int netfront_tx_slot_available(struct netfront_queue *queue)
247 {
248 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
249 (NET_TX_RING_SIZE - MAX_SKB_FRAGS - 2);
250 }
251
252 static void xennet_maybe_wake_tx(struct netfront_queue *queue)
253 {
254 struct net_device *dev = queue->info->netdev;
255 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id);
256
257 if (unlikely(netif_tx_queue_stopped(dev_queue)) &&
258 netfront_tx_slot_available(queue) &&
259 likely(netif_running(dev)))
260 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
261 }
262
263
264 static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue)
265 {
266 struct sk_buff *skb;
267 struct page *page;
268
269 skb = __netdev_alloc_skb(queue->info->netdev,
270 RX_COPY_THRESHOLD + NET_IP_ALIGN,
271 GFP_ATOMIC | __GFP_NOWARN);
272 if (unlikely(!skb))
273 return NULL;
274
275 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
276 if (!page) {
277 kfree_skb(skb);
278 return NULL;
279 }
280 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
281
282 /* Align ip header to a 16 bytes boundary */
283 skb_reserve(skb, NET_IP_ALIGN);
284 skb->dev = queue->info->netdev;
285
286 return skb;
287 }
288
289
290 static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
291 {
292 RING_IDX req_prod = queue->rx.req_prod_pvt;
293 int notify;
294
295 if (unlikely(!netif_carrier_ok(queue->info->netdev)))
296 return;
297
298 for (req_prod = queue->rx.req_prod_pvt;
299 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE;
300 req_prod++) {
301 struct sk_buff *skb;
302 unsigned short id;
303 grant_ref_t ref;
304 unsigned long pfn;
305 struct xen_netif_rx_request *req;
306
307 skb = xennet_alloc_one_rx_buffer(queue);
308 if (!skb)
309 break;
310
311 id = xennet_rxidx(req_prod);
312
313 BUG_ON(queue->rx_skbs[id]);
314 queue->rx_skbs[id] = skb;
315
316 ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
317 BUG_ON((signed short)ref < 0);
318 queue->grant_rx_ref[id] = ref;
319
320 pfn = page_to_pfn(skb_frag_page(&skb_shinfo(skb)->frags[0]));
321
322 req = RING_GET_REQUEST(&queue->rx, req_prod);
323 gnttab_grant_foreign_access_ref(ref,
324 queue->info->xbdev->otherend_id,
325 pfn_to_mfn(pfn),
326 0);
327
328 req->id = id;
329 req->gref = ref;
330 }
331
332 queue->rx.req_prod_pvt = req_prod;
333
334 /* Not enough requests? Try again later. */
335 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN) {
336 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
337 return;
338 }
339
340 wmb(); /* barrier so backend seens requests */
341
342 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
343 if (notify)
344 notify_remote_via_irq(queue->rx_irq);
345 }
346
347 static int xennet_open(struct net_device *dev)
348 {
349 struct netfront_info *np = netdev_priv(dev);
350 unsigned int num_queues = dev->real_num_tx_queues;
351 unsigned int i = 0;
352 struct netfront_queue *queue = NULL;
353
354 for (i = 0; i < num_queues; ++i) {
355 queue = &np->queues[i];
356 napi_enable(&queue->napi);
357
358 spin_lock_bh(&queue->rx_lock);
359 if (netif_carrier_ok(dev)) {
360 xennet_alloc_rx_buffers(queue);
361 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1;
362 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))
363 napi_schedule(&queue->napi);
364 }
365 spin_unlock_bh(&queue->rx_lock);
366 }
367
368 netif_tx_start_all_queues(dev);
369
370 return 0;
371 }
372
373 static void xennet_tx_buf_gc(struct netfront_queue *queue)
374 {
375 RING_IDX cons, prod;
376 unsigned short id;
377 struct sk_buff *skb;
378
379 BUG_ON(!netif_carrier_ok(queue->info->netdev));
380
381 do {
382 prod = queue->tx.sring->rsp_prod;
383 rmb(); /* Ensure we see responses up to 'rp'. */
384
385 for (cons = queue->tx.rsp_cons; cons != prod; cons++) {
386 struct xen_netif_tx_response *txrsp;
387
388 txrsp = RING_GET_RESPONSE(&queue->tx, cons);
389 if (txrsp->status == XEN_NETIF_RSP_NULL)
390 continue;
391
392 id = txrsp->id;
393 skb = queue->tx_skbs[id].skb;
394 if (unlikely(gnttab_query_foreign_access(
395 queue->grant_tx_ref[id]) != 0)) {
396 pr_alert("%s: warning -- grant still in use by backend domain\n",
397 __func__);
398 BUG();
399 }
400 gnttab_end_foreign_access_ref(
401 queue->grant_tx_ref[id], GNTMAP_readonly);
402 gnttab_release_grant_reference(
403 &queue->gref_tx_head, queue->grant_tx_ref[id]);
404 queue->grant_tx_ref[id] = GRANT_INVALID_REF;
405 queue->grant_tx_page[id] = NULL;
406 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id);
407 dev_kfree_skb_irq(skb);
408 }
409
410 queue->tx.rsp_cons = prod;
411
412 /*
413 * Set a new event, then check for race with update of tx_cons.
414 * Note that it is essential to schedule a callback, no matter
415 * how few buffers are pending. Even if there is space in the
416 * transmit ring, higher layers may be blocked because too much
417 * data is outstanding: in such cases notification from Xen is
418 * likely to be the only kick that we'll get.
419 */
420 queue->tx.sring->rsp_event =
421 prod + ((queue->tx.sring->req_prod - prod) >> 1) + 1;
422 mb(); /* update shared area */
423 } while ((cons == prod) && (prod != queue->tx.sring->rsp_prod));
424
425 xennet_maybe_wake_tx(queue);
426 }
427
428 static void xennet_make_frags(struct sk_buff *skb, struct netfront_queue *queue,
429 struct xen_netif_tx_request *tx)
430 {
431 char *data = skb->data;
432 unsigned long mfn;
433 RING_IDX prod = queue->tx.req_prod_pvt;
434 int frags = skb_shinfo(skb)->nr_frags;
435 unsigned int offset = offset_in_page(data);
436 unsigned int len = skb_headlen(skb);
437 unsigned int id;
438 grant_ref_t ref;
439 int i;
440
441 /* While the header overlaps a page boundary (including being
442 larger than a page), split it it into page-sized chunks. */
443 while (len > PAGE_SIZE - offset) {
444 tx->size = PAGE_SIZE - offset;
445 tx->flags |= XEN_NETTXF_more_data;
446 len -= tx->size;
447 data += tx->size;
448 offset = 0;
449
450 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
451 queue->tx_skbs[id].skb = skb_get(skb);
452 tx = RING_GET_REQUEST(&queue->tx, prod++);
453 tx->id = id;
454 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
455 BUG_ON((signed short)ref < 0);
456
457 mfn = virt_to_mfn(data);
458 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
459 mfn, GNTMAP_readonly);
460
461 queue->grant_tx_page[id] = virt_to_page(data);
462 tx->gref = queue->grant_tx_ref[id] = ref;
463 tx->offset = offset;
464 tx->size = len;
465 tx->flags = 0;
466 }
467
468 /* Grant backend access to each skb fragment page. */
469 for (i = 0; i < frags; i++) {
470 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
471 struct page *page = skb_frag_page(frag);
472
473 len = skb_frag_size(frag);
474 offset = frag->page_offset;
475
476 /* Skip unused frames from start of page */
477 page += offset >> PAGE_SHIFT;
478 offset &= ~PAGE_MASK;
479
480 while (len > 0) {
481 unsigned long bytes;
482
483 bytes = PAGE_SIZE - offset;
484 if (bytes > len)
485 bytes = len;
486
487 tx->flags |= XEN_NETTXF_more_data;
488
489 id = get_id_from_freelist(&queue->tx_skb_freelist,
490 queue->tx_skbs);
491 queue->tx_skbs[id].skb = skb_get(skb);
492 tx = RING_GET_REQUEST(&queue->tx, prod++);
493 tx->id = id;
494 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
495 BUG_ON((signed short)ref < 0);
496
497 mfn = pfn_to_mfn(page_to_pfn(page));
498 gnttab_grant_foreign_access_ref(ref,
499 queue->info->xbdev->otherend_id,
500 mfn, GNTMAP_readonly);
501
502 queue->grant_tx_page[id] = page;
503 tx->gref = queue->grant_tx_ref[id] = ref;
504 tx->offset = offset;
505 tx->size = bytes;
506 tx->flags = 0;
507
508 offset += bytes;
509 len -= bytes;
510
511 /* Next frame */
512 if (offset == PAGE_SIZE && len) {
513 BUG_ON(!PageCompound(page));
514 page++;
515 offset = 0;
516 }
517 }
518 }
519
520 queue->tx.req_prod_pvt = prod;
521 }
522
523 /*
524 * Count how many ring slots are required to send the frags of this
525 * skb. Each frag might be a compound page.
526 */
527 static int xennet_count_skb_frag_slots(struct sk_buff *skb)
528 {
529 int i, frags = skb_shinfo(skb)->nr_frags;
530 int pages = 0;
531
532 for (i = 0; i < frags; i++) {
533 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
534 unsigned long size = skb_frag_size(frag);
535 unsigned long offset = frag->page_offset;
536
537 /* Skip unused frames from start of page */
538 offset &= ~PAGE_MASK;
539
540 pages += PFN_UP(offset + size);
541 }
542
543 return pages;
544 }
545
546 static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
547 void *accel_priv, select_queue_fallback_t fallback)
548 {
549 unsigned int num_queues = dev->real_num_tx_queues;
550 u32 hash;
551 u16 queue_idx;
552
553 /* First, check if there is only one queue */
554 if (num_queues == 1) {
555 queue_idx = 0;
556 } else {
557 hash = skb_get_hash(skb);
558 queue_idx = hash % num_queues;
559 }
560
561 return queue_idx;
562 }
563
564 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
565 {
566 unsigned short id;
567 struct netfront_info *np = netdev_priv(dev);
568 struct netfront_stats *stats = this_cpu_ptr(np->stats);
569 struct xen_netif_tx_request *tx;
570 char *data = skb->data;
571 RING_IDX i;
572 grant_ref_t ref;
573 unsigned long mfn;
574 int notify;
575 int slots;
576 unsigned int offset = offset_in_page(data);
577 unsigned int len = skb_headlen(skb);
578 unsigned long flags;
579 struct netfront_queue *queue = NULL;
580 unsigned int num_queues = dev->real_num_tx_queues;
581 u16 queue_index;
582
583 /* Drop the packet if no queues are set up */
584 if (num_queues < 1)
585 goto drop;
586 /* Determine which queue to transmit this SKB on */
587 queue_index = skb_get_queue_mapping(skb);
588 queue = &np->queues[queue_index];
589
590 /* If skb->len is too big for wire format, drop skb and alert
591 * user about misconfiguration.
592 */
593 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
594 net_alert_ratelimited(
595 "xennet: skb->len = %u, too big for wire format\n",
596 skb->len);
597 goto drop;
598 }
599
600 slots = DIV_ROUND_UP(offset + len, PAGE_SIZE) +
601 xennet_count_skb_frag_slots(skb);
602 if (unlikely(slots > MAX_SKB_FRAGS + 1)) {
603 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
604 slots, skb->len);
605 if (skb_linearize(skb))
606 goto drop;
607 data = skb->data;
608 offset = offset_in_page(data);
609 len = skb_headlen(skb);
610 }
611
612 spin_lock_irqsave(&queue->tx_lock, flags);
613
614 if (unlikely(!netif_carrier_ok(dev) ||
615 (slots > 1 && !xennet_can_sg(dev)) ||
616 netif_needs_gso(dev, skb, netif_skb_features(skb)))) {
617 spin_unlock_irqrestore(&queue->tx_lock, flags);
618 goto drop;
619 }
620
621 i = queue->tx.req_prod_pvt;
622
623 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
624 queue->tx_skbs[id].skb = skb;
625
626 tx = RING_GET_REQUEST(&queue->tx, i);
627
628 tx->id = id;
629 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
630 BUG_ON((signed short)ref < 0);
631 mfn = virt_to_mfn(data);
632 gnttab_grant_foreign_access_ref(
633 ref, queue->info->xbdev->otherend_id, mfn, GNTMAP_readonly);
634 queue->grant_tx_page[id] = virt_to_page(data);
635 tx->gref = queue->grant_tx_ref[id] = ref;
636 tx->offset = offset;
637 tx->size = len;
638
639 tx->flags = 0;
640 if (skb->ip_summed == CHECKSUM_PARTIAL)
641 /* local packet? */
642 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
643 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
644 /* remote but checksummed. */
645 tx->flags |= XEN_NETTXF_data_validated;
646
647 if (skb_shinfo(skb)->gso_size) {
648 struct xen_netif_extra_info *gso;
649
650 gso = (struct xen_netif_extra_info *)
651 RING_GET_REQUEST(&queue->tx, ++i);
652
653 tx->flags |= XEN_NETTXF_extra_info;
654
655 gso->u.gso.size = skb_shinfo(skb)->gso_size;
656 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
657 XEN_NETIF_GSO_TYPE_TCPV6 :
658 XEN_NETIF_GSO_TYPE_TCPV4;
659 gso->u.gso.pad = 0;
660 gso->u.gso.features = 0;
661
662 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
663 gso->flags = 0;
664 }
665
666 queue->tx.req_prod_pvt = i + 1;
667
668 xennet_make_frags(skb, queue, tx);
669 tx->size = skb->len;
670
671 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
672 if (notify)
673 notify_remote_via_irq(queue->tx_irq);
674
675 u64_stats_update_begin(&stats->syncp);
676 stats->tx_bytes += skb->len;
677 stats->tx_packets++;
678 u64_stats_update_end(&stats->syncp);
679
680 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
681 xennet_tx_buf_gc(queue);
682
683 if (!netfront_tx_slot_available(queue))
684 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
685
686 spin_unlock_irqrestore(&queue->tx_lock, flags);
687
688 return NETDEV_TX_OK;
689
690 drop:
691 dev->stats.tx_dropped++;
692 dev_kfree_skb_any(skb);
693 return NETDEV_TX_OK;
694 }
695
696 static int xennet_close(struct net_device *dev)
697 {
698 struct netfront_info *np = netdev_priv(dev);
699 unsigned int num_queues = dev->real_num_tx_queues;
700 unsigned int i;
701 struct netfront_queue *queue;
702 netif_tx_stop_all_queues(np->netdev);
703 for (i = 0; i < num_queues; ++i) {
704 queue = &np->queues[i];
705 napi_disable(&queue->napi);
706 }
707 return 0;
708 }
709
710 static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
711 grant_ref_t ref)
712 {
713 int new = xennet_rxidx(queue->rx.req_prod_pvt);
714
715 BUG_ON(queue->rx_skbs[new]);
716 queue->rx_skbs[new] = skb;
717 queue->grant_rx_ref[new] = ref;
718 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new;
719 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref;
720 queue->rx.req_prod_pvt++;
721 }
722
723 static int xennet_get_extras(struct netfront_queue *queue,
724 struct xen_netif_extra_info *extras,
725 RING_IDX rp)
726
727 {
728 struct xen_netif_extra_info *extra;
729 struct device *dev = &queue->info->netdev->dev;
730 RING_IDX cons = queue->rx.rsp_cons;
731 int err = 0;
732
733 do {
734 struct sk_buff *skb;
735 grant_ref_t ref;
736
737 if (unlikely(cons + 1 == rp)) {
738 if (net_ratelimit())
739 dev_warn(dev, "Missing extra info\n");
740 err = -EBADR;
741 break;
742 }
743
744 extra = (struct xen_netif_extra_info *)
745 RING_GET_RESPONSE(&queue->rx, ++cons);
746
747 if (unlikely(!extra->type ||
748 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
749 if (net_ratelimit())
750 dev_warn(dev, "Invalid extra type: %d\n",
751 extra->type);
752 err = -EINVAL;
753 } else {
754 memcpy(&extras[extra->type - 1], extra,
755 sizeof(*extra));
756 }
757
758 skb = xennet_get_rx_skb(queue, cons);
759 ref = xennet_get_rx_ref(queue, cons);
760 xennet_move_rx_slot(queue, skb, ref);
761 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
762
763 queue->rx.rsp_cons = cons;
764 return err;
765 }
766
767 static int xennet_get_responses(struct netfront_queue *queue,
768 struct netfront_rx_info *rinfo, RING_IDX rp,
769 struct sk_buff_head *list)
770 {
771 struct xen_netif_rx_response *rx = &rinfo->rx;
772 struct xen_netif_extra_info *extras = rinfo->extras;
773 struct device *dev = &queue->info->netdev->dev;
774 RING_IDX cons = queue->rx.rsp_cons;
775 struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
776 grant_ref_t ref = xennet_get_rx_ref(queue, cons);
777 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
778 int slots = 1;
779 int err = 0;
780 unsigned long ret;
781
782 if (rx->flags & XEN_NETRXF_extra_info) {
783 err = xennet_get_extras(queue, extras, rp);
784 cons = queue->rx.rsp_cons;
785 }
786
787 for (;;) {
788 if (unlikely(rx->status < 0 ||
789 rx->offset + rx->status > PAGE_SIZE)) {
790 if (net_ratelimit())
791 dev_warn(dev, "rx->offset: %x, size: %u\n",
792 rx->offset, rx->status);
793 xennet_move_rx_slot(queue, skb, ref);
794 err = -EINVAL;
795 goto next;
796 }
797
798 /*
799 * This definitely indicates a bug, either in this driver or in
800 * the backend driver. In future this should flag the bad
801 * situation to the system controller to reboot the backend.
802 */
803 if (ref == GRANT_INVALID_REF) {
804 if (net_ratelimit())
805 dev_warn(dev, "Bad rx response id %d.\n",
806 rx->id);
807 err = -EINVAL;
808 goto next;
809 }
810
811 ret = gnttab_end_foreign_access_ref(ref, 0);
812 BUG_ON(!ret);
813
814 gnttab_release_grant_reference(&queue->gref_rx_head, ref);
815
816 __skb_queue_tail(list, skb);
817
818 next:
819 if (!(rx->flags & XEN_NETRXF_more_data))
820 break;
821
822 if (cons + slots == rp) {
823 if (net_ratelimit())
824 dev_warn(dev, "Need more slots\n");
825 err = -ENOENT;
826 break;
827 }
828
829 rx = RING_GET_RESPONSE(&queue->rx, cons + slots);
830 skb = xennet_get_rx_skb(queue, cons + slots);
831 ref = xennet_get_rx_ref(queue, cons + slots);
832 slots++;
833 }
834
835 if (unlikely(slots > max)) {
836 if (net_ratelimit())
837 dev_warn(dev, "Too many slots\n");
838 err = -E2BIG;
839 }
840
841 if (unlikely(err))
842 queue->rx.rsp_cons = cons + slots;
843
844 return err;
845 }
846
847 static int xennet_set_skb_gso(struct sk_buff *skb,
848 struct xen_netif_extra_info *gso)
849 {
850 if (!gso->u.gso.size) {
851 if (net_ratelimit())
852 pr_warn("GSO size must not be zero\n");
853 return -EINVAL;
854 }
855
856 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
857 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
858 if (net_ratelimit())
859 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
860 return -EINVAL;
861 }
862
863 skb_shinfo(skb)->gso_size = gso->u.gso.size;
864 skb_shinfo(skb)->gso_type =
865 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
866 SKB_GSO_TCPV4 :
867 SKB_GSO_TCPV6;
868
869 /* Header must be checked, and gso_segs computed. */
870 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
871 skb_shinfo(skb)->gso_segs = 0;
872
873 return 0;
874 }
875
876 static RING_IDX xennet_fill_frags(struct netfront_queue *queue,
877 struct sk_buff *skb,
878 struct sk_buff_head *list)
879 {
880 struct skb_shared_info *shinfo = skb_shinfo(skb);
881 RING_IDX cons = queue->rx.rsp_cons;
882 struct sk_buff *nskb;
883
884 while ((nskb = __skb_dequeue(list))) {
885 struct xen_netif_rx_response *rx =
886 RING_GET_RESPONSE(&queue->rx, ++cons);
887 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
888
889 if (shinfo->nr_frags == MAX_SKB_FRAGS) {
890 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
891
892 BUG_ON(pull_to <= skb_headlen(skb));
893 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
894 }
895 BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS);
896
897 skb_add_rx_frag(skb, shinfo->nr_frags, skb_frag_page(nfrag),
898 rx->offset, rx->status, PAGE_SIZE);
899
900 skb_shinfo(nskb)->nr_frags = 0;
901 kfree_skb(nskb);
902 }
903
904 return cons;
905 }
906
907 static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
908 {
909 bool recalculate_partial_csum = false;
910
911 /*
912 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
913 * peers can fail to set NETRXF_csum_blank when sending a GSO
914 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
915 * recalculate the partial checksum.
916 */
917 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
918 struct netfront_info *np = netdev_priv(dev);
919 atomic_inc(&np->rx_gso_checksum_fixup);
920 skb->ip_summed = CHECKSUM_PARTIAL;
921 recalculate_partial_csum = true;
922 }
923
924 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
925 if (skb->ip_summed != CHECKSUM_PARTIAL)
926 return 0;
927
928 return skb_checksum_setup(skb, recalculate_partial_csum);
929 }
930
931 static int handle_incoming_queue(struct netfront_queue *queue,
932 struct sk_buff_head *rxq)
933 {
934 struct netfront_stats *stats = this_cpu_ptr(queue->info->stats);
935 int packets_dropped = 0;
936 struct sk_buff *skb;
937
938 while ((skb = __skb_dequeue(rxq)) != NULL) {
939 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
940
941 if (pull_to > skb_headlen(skb))
942 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
943
944 /* Ethernet work: Delayed to here as it peeks the header. */
945 skb->protocol = eth_type_trans(skb, queue->info->netdev);
946 skb_reset_network_header(skb);
947
948 if (checksum_setup(queue->info->netdev, skb)) {
949 kfree_skb(skb);
950 packets_dropped++;
951 queue->info->netdev->stats.rx_errors++;
952 continue;
953 }
954
955 u64_stats_update_begin(&stats->syncp);
956 stats->rx_packets++;
957 stats->rx_bytes += skb->len;
958 u64_stats_update_end(&stats->syncp);
959
960 /* Pass it up. */
961 napi_gro_receive(&queue->napi, skb);
962 }
963
964 return packets_dropped;
965 }
966
967 static int xennet_poll(struct napi_struct *napi, int budget)
968 {
969 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi);
970 struct net_device *dev = queue->info->netdev;
971 struct sk_buff *skb;
972 struct netfront_rx_info rinfo;
973 struct xen_netif_rx_response *rx = &rinfo.rx;
974 struct xen_netif_extra_info *extras = rinfo.extras;
975 RING_IDX i, rp;
976 int work_done;
977 struct sk_buff_head rxq;
978 struct sk_buff_head errq;
979 struct sk_buff_head tmpq;
980 int err;
981
982 spin_lock(&queue->rx_lock);
983
984 skb_queue_head_init(&rxq);
985 skb_queue_head_init(&errq);
986 skb_queue_head_init(&tmpq);
987
988 rp = queue->rx.sring->rsp_prod;
989 rmb(); /* Ensure we see queued responses up to 'rp'. */
990
991 i = queue->rx.rsp_cons;
992 work_done = 0;
993 while ((i != rp) && (work_done < budget)) {
994 memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx));
995 memset(extras, 0, sizeof(rinfo.extras));
996
997 err = xennet_get_responses(queue, &rinfo, rp, &tmpq);
998
999 if (unlikely(err)) {
1000 err:
1001 while ((skb = __skb_dequeue(&tmpq)))
1002 __skb_queue_tail(&errq, skb);
1003 dev->stats.rx_errors++;
1004 i = queue->rx.rsp_cons;
1005 continue;
1006 }
1007
1008 skb = __skb_dequeue(&tmpq);
1009
1010 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1011 struct xen_netif_extra_info *gso;
1012 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1013
1014 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1015 __skb_queue_head(&tmpq, skb);
1016 queue->rx.rsp_cons += skb_queue_len(&tmpq);
1017 goto err;
1018 }
1019 }
1020
1021 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1022 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1023 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1024
1025 skb_shinfo(skb)->frags[0].page_offset = rx->offset;
1026 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1027 skb->data_len = rx->status;
1028 skb->len += rx->status;
1029
1030 i = xennet_fill_frags(queue, skb, &tmpq);
1031
1032 if (rx->flags & XEN_NETRXF_csum_blank)
1033 skb->ip_summed = CHECKSUM_PARTIAL;
1034 else if (rx->flags & XEN_NETRXF_data_validated)
1035 skb->ip_summed = CHECKSUM_UNNECESSARY;
1036
1037 __skb_queue_tail(&rxq, skb);
1038
1039 queue->rx.rsp_cons = ++i;
1040 work_done++;
1041 }
1042
1043 __skb_queue_purge(&errq);
1044
1045 work_done -= handle_incoming_queue(queue, &rxq);
1046
1047 xennet_alloc_rx_buffers(queue);
1048
1049 if (work_done < budget) {
1050 int more_to_do = 0;
1051
1052 napi_complete(napi);
1053
1054 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
1055 if (more_to_do)
1056 napi_schedule(napi);
1057 }
1058
1059 spin_unlock(&queue->rx_lock);
1060
1061 return work_done;
1062 }
1063
1064 static int xennet_change_mtu(struct net_device *dev, int mtu)
1065 {
1066 int max = xennet_can_sg(dev) ?
1067 XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER : ETH_DATA_LEN;
1068
1069 if (mtu > max)
1070 return -EINVAL;
1071 dev->mtu = mtu;
1072 return 0;
1073 }
1074
1075 static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
1076 struct rtnl_link_stats64 *tot)
1077 {
1078 struct netfront_info *np = netdev_priv(dev);
1079 int cpu;
1080
1081 for_each_possible_cpu(cpu) {
1082 struct netfront_stats *stats = per_cpu_ptr(np->stats, cpu);
1083 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1084 unsigned int start;
1085
1086 do {
1087 start = u64_stats_fetch_begin_irq(&stats->syncp);
1088
1089 rx_packets = stats->rx_packets;
1090 tx_packets = stats->tx_packets;
1091 rx_bytes = stats->rx_bytes;
1092 tx_bytes = stats->tx_bytes;
1093 } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1094
1095 tot->rx_packets += rx_packets;
1096 tot->tx_packets += tx_packets;
1097 tot->rx_bytes += rx_bytes;
1098 tot->tx_bytes += tx_bytes;
1099 }
1100
1101 tot->rx_errors = dev->stats.rx_errors;
1102 tot->tx_dropped = dev->stats.tx_dropped;
1103
1104 return tot;
1105 }
1106
1107 static void xennet_release_tx_bufs(struct netfront_queue *queue)
1108 {
1109 struct sk_buff *skb;
1110 int i;
1111
1112 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1113 /* Skip over entries which are actually freelist references */
1114 if (skb_entry_is_link(&queue->tx_skbs[i]))
1115 continue;
1116
1117 skb = queue->tx_skbs[i].skb;
1118 get_page(queue->grant_tx_page[i]);
1119 gnttab_end_foreign_access(queue->grant_tx_ref[i],
1120 GNTMAP_readonly,
1121 (unsigned long)page_address(queue->grant_tx_page[i]));
1122 queue->grant_tx_page[i] = NULL;
1123 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1124 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i);
1125 dev_kfree_skb_irq(skb);
1126 }
1127 }
1128
1129 static void xennet_release_rx_bufs(struct netfront_queue *queue)
1130 {
1131 int id, ref;
1132
1133 spin_lock_bh(&queue->rx_lock);
1134
1135 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1136 struct sk_buff *skb;
1137 struct page *page;
1138
1139 skb = queue->rx_skbs[id];
1140 if (!skb)
1141 continue;
1142
1143 ref = queue->grant_rx_ref[id];
1144 if (ref == GRANT_INVALID_REF)
1145 continue;
1146
1147 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
1148
1149 /* gnttab_end_foreign_access() needs a page ref until
1150 * foreign access is ended (which may be deferred).
1151 */
1152 get_page(page);
1153 gnttab_end_foreign_access(ref, 0,
1154 (unsigned long)page_address(page));
1155 queue->grant_rx_ref[id] = GRANT_INVALID_REF;
1156
1157 kfree_skb(skb);
1158 }
1159
1160 spin_unlock_bh(&queue->rx_lock);
1161 }
1162
1163 static netdev_features_t xennet_fix_features(struct net_device *dev,
1164 netdev_features_t features)
1165 {
1166 struct netfront_info *np = netdev_priv(dev);
1167 int val;
1168
1169 if (features & NETIF_F_SG) {
1170 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg",
1171 "%d", &val) < 0)
1172 val = 0;
1173
1174 if (!val)
1175 features &= ~NETIF_F_SG;
1176 }
1177
1178 if (features & NETIF_F_IPV6_CSUM) {
1179 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1180 "feature-ipv6-csum-offload", "%d", &val) < 0)
1181 val = 0;
1182
1183 if (!val)
1184 features &= ~NETIF_F_IPV6_CSUM;
1185 }
1186
1187 if (features & NETIF_F_TSO) {
1188 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1189 "feature-gso-tcpv4", "%d", &val) < 0)
1190 val = 0;
1191
1192 if (!val)
1193 features &= ~NETIF_F_TSO;
1194 }
1195
1196 if (features & NETIF_F_TSO6) {
1197 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1198 "feature-gso-tcpv6", "%d", &val) < 0)
1199 val = 0;
1200
1201 if (!val)
1202 features &= ~NETIF_F_TSO6;
1203 }
1204
1205 return features;
1206 }
1207
1208 static int xennet_set_features(struct net_device *dev,
1209 netdev_features_t features)
1210 {
1211 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1212 netdev_info(dev, "Reducing MTU because no SG offload");
1213 dev->mtu = ETH_DATA_LEN;
1214 }
1215
1216 return 0;
1217 }
1218
1219 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1220 {
1221 struct netfront_queue *queue = dev_id;
1222 unsigned long flags;
1223
1224 spin_lock_irqsave(&queue->tx_lock, flags);
1225 xennet_tx_buf_gc(queue);
1226 spin_unlock_irqrestore(&queue->tx_lock, flags);
1227
1228 return IRQ_HANDLED;
1229 }
1230
1231 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1232 {
1233 struct netfront_queue *queue = dev_id;
1234 struct net_device *dev = queue->info->netdev;
1235
1236 if (likely(netif_carrier_ok(dev) &&
1237 RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)))
1238 napi_schedule(&queue->napi);
1239
1240 return IRQ_HANDLED;
1241 }
1242
1243 static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1244 {
1245 xennet_tx_interrupt(irq, dev_id);
1246 xennet_rx_interrupt(irq, dev_id);
1247 return IRQ_HANDLED;
1248 }
1249
1250 #ifdef CONFIG_NET_POLL_CONTROLLER
1251 static void xennet_poll_controller(struct net_device *dev)
1252 {
1253 /* Poll each queue */
1254 struct netfront_info *info = netdev_priv(dev);
1255 unsigned int num_queues = dev->real_num_tx_queues;
1256 unsigned int i;
1257 for (i = 0; i < num_queues; ++i)
1258 xennet_interrupt(0, &info->queues[i]);
1259 }
1260 #endif
1261
1262 static const struct net_device_ops xennet_netdev_ops = {
1263 .ndo_open = xennet_open,
1264 .ndo_stop = xennet_close,
1265 .ndo_start_xmit = xennet_start_xmit,
1266 .ndo_change_mtu = xennet_change_mtu,
1267 .ndo_get_stats64 = xennet_get_stats64,
1268 .ndo_set_mac_address = eth_mac_addr,
1269 .ndo_validate_addr = eth_validate_addr,
1270 .ndo_fix_features = xennet_fix_features,
1271 .ndo_set_features = xennet_set_features,
1272 .ndo_select_queue = xennet_select_queue,
1273 #ifdef CONFIG_NET_POLL_CONTROLLER
1274 .ndo_poll_controller = xennet_poll_controller,
1275 #endif
1276 };
1277
1278 static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1279 {
1280 int err;
1281 struct net_device *netdev;
1282 struct netfront_info *np;
1283
1284 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues);
1285 if (!netdev)
1286 return ERR_PTR(-ENOMEM);
1287
1288 np = netdev_priv(netdev);
1289 np->xbdev = dev;
1290
1291 /* No need to use rtnl_lock() before the call below as it
1292 * happens before register_netdev().
1293 */
1294 netif_set_real_num_tx_queues(netdev, 0);
1295 np->queues = NULL;
1296
1297 err = -ENOMEM;
1298 np->stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1299 if (np->stats == NULL)
1300 goto exit;
1301
1302 netdev->netdev_ops = &xennet_netdev_ops;
1303
1304 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1305 NETIF_F_GSO_ROBUST;
1306 netdev->hw_features = NETIF_F_SG |
1307 NETIF_F_IPV6_CSUM |
1308 NETIF_F_TSO | NETIF_F_TSO6;
1309
1310 /*
1311 * Assume that all hw features are available for now. This set
1312 * will be adjusted by the call to netdev_update_features() in
1313 * xennet_connect() which is the earliest point where we can
1314 * negotiate with the backend regarding supported features.
1315 */
1316 netdev->features |= netdev->hw_features;
1317
1318 netdev->ethtool_ops = &xennet_ethtool_ops;
1319 SET_NETDEV_DEV(netdev, &dev->dev);
1320
1321 netif_set_gso_max_size(netdev, XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER);
1322
1323 np->netdev = netdev;
1324
1325 netif_carrier_off(netdev);
1326
1327 return netdev;
1328
1329 exit:
1330 free_netdev(netdev);
1331 return ERR_PTR(err);
1332 }
1333
1334 /**
1335 * Entry point to this code when a new device is created. Allocate the basic
1336 * structures and the ring buffers for communication with the backend, and
1337 * inform the backend of the appropriate details for those.
1338 */
1339 static int netfront_probe(struct xenbus_device *dev,
1340 const struct xenbus_device_id *id)
1341 {
1342 int err;
1343 struct net_device *netdev;
1344 struct netfront_info *info;
1345
1346 netdev = xennet_create_dev(dev);
1347 if (IS_ERR(netdev)) {
1348 err = PTR_ERR(netdev);
1349 xenbus_dev_fatal(dev, err, "creating netdev");
1350 return err;
1351 }
1352
1353 info = netdev_priv(netdev);
1354 dev_set_drvdata(&dev->dev, info);
1355
1356 err = register_netdev(info->netdev);
1357 if (err) {
1358 pr_warn("%s: register_netdev err=%d\n", __func__, err);
1359 goto fail;
1360 }
1361
1362 err = xennet_sysfs_addif(info->netdev);
1363 if (err) {
1364 unregister_netdev(info->netdev);
1365 pr_warn("%s: add sysfs failed err=%d\n", __func__, err);
1366 goto fail;
1367 }
1368
1369 return 0;
1370
1371 fail:
1372 free_netdev(netdev);
1373 dev_set_drvdata(&dev->dev, NULL);
1374 return err;
1375 }
1376
1377 static void xennet_end_access(int ref, void *page)
1378 {
1379 /* This frees the page as a side-effect */
1380 if (ref != GRANT_INVALID_REF)
1381 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1382 }
1383
1384 static void xennet_disconnect_backend(struct netfront_info *info)
1385 {
1386 unsigned int i = 0;
1387 unsigned int num_queues = info->netdev->real_num_tx_queues;
1388
1389 netif_carrier_off(info->netdev);
1390
1391 for (i = 0; i < num_queues; ++i) {
1392 struct netfront_queue *queue = &info->queues[i];
1393
1394 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
1395 unbind_from_irqhandler(queue->tx_irq, queue);
1396 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
1397 unbind_from_irqhandler(queue->tx_irq, queue);
1398 unbind_from_irqhandler(queue->rx_irq, queue);
1399 }
1400 queue->tx_evtchn = queue->rx_evtchn = 0;
1401 queue->tx_irq = queue->rx_irq = 0;
1402
1403 napi_synchronize(&queue->napi);
1404
1405 xennet_release_tx_bufs(queue);
1406 xennet_release_rx_bufs(queue);
1407 gnttab_free_grant_references(queue->gref_tx_head);
1408 gnttab_free_grant_references(queue->gref_rx_head);
1409
1410 /* End access and free the pages */
1411 xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
1412 xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
1413
1414 queue->tx_ring_ref = GRANT_INVALID_REF;
1415 queue->rx_ring_ref = GRANT_INVALID_REF;
1416 queue->tx.sring = NULL;
1417 queue->rx.sring = NULL;
1418 }
1419 }
1420
1421 /**
1422 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1423 * driver restart. We tear down our netif structure and recreate it, but
1424 * leave the device-layer structures intact so that this is transparent to the
1425 * rest of the kernel.
1426 */
1427 static int netfront_resume(struct xenbus_device *dev)
1428 {
1429 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1430
1431 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1432
1433 xennet_disconnect_backend(info);
1434 return 0;
1435 }
1436
1437 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1438 {
1439 char *s, *e, *macstr;
1440 int i;
1441
1442 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1443 if (IS_ERR(macstr))
1444 return PTR_ERR(macstr);
1445
1446 for (i = 0; i < ETH_ALEN; i++) {
1447 mac[i] = simple_strtoul(s, &e, 16);
1448 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1449 kfree(macstr);
1450 return -ENOENT;
1451 }
1452 s = e+1;
1453 }
1454
1455 kfree(macstr);
1456 return 0;
1457 }
1458
1459 static int setup_netfront_single(struct netfront_queue *queue)
1460 {
1461 int err;
1462
1463 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1464 if (err < 0)
1465 goto fail;
1466
1467 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1468 xennet_interrupt,
1469 0, queue->info->netdev->name, queue);
1470 if (err < 0)
1471 goto bind_fail;
1472 queue->rx_evtchn = queue->tx_evtchn;
1473 queue->rx_irq = queue->tx_irq = err;
1474
1475 return 0;
1476
1477 bind_fail:
1478 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1479 queue->tx_evtchn = 0;
1480 fail:
1481 return err;
1482 }
1483
1484 static int setup_netfront_split(struct netfront_queue *queue)
1485 {
1486 int err;
1487
1488 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1489 if (err < 0)
1490 goto fail;
1491 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn);
1492 if (err < 0)
1493 goto alloc_rx_evtchn_fail;
1494
1495 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
1496 "%s-tx", queue->name);
1497 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1498 xennet_tx_interrupt,
1499 0, queue->tx_irq_name, queue);
1500 if (err < 0)
1501 goto bind_tx_fail;
1502 queue->tx_irq = err;
1503
1504 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
1505 "%s-rx", queue->name);
1506 err = bind_evtchn_to_irqhandler(queue->rx_evtchn,
1507 xennet_rx_interrupt,
1508 0, queue->rx_irq_name, queue);
1509 if (err < 0)
1510 goto bind_rx_fail;
1511 queue->rx_irq = err;
1512
1513 return 0;
1514
1515 bind_rx_fail:
1516 unbind_from_irqhandler(queue->tx_irq, queue);
1517 queue->tx_irq = 0;
1518 bind_tx_fail:
1519 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn);
1520 queue->rx_evtchn = 0;
1521 alloc_rx_evtchn_fail:
1522 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1523 queue->tx_evtchn = 0;
1524 fail:
1525 return err;
1526 }
1527
1528 static int setup_netfront(struct xenbus_device *dev,
1529 struct netfront_queue *queue, unsigned int feature_split_evtchn)
1530 {
1531 struct xen_netif_tx_sring *txs;
1532 struct xen_netif_rx_sring *rxs;
1533 int err;
1534
1535 queue->tx_ring_ref = GRANT_INVALID_REF;
1536 queue->rx_ring_ref = GRANT_INVALID_REF;
1537 queue->rx.sring = NULL;
1538 queue->tx.sring = NULL;
1539
1540 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1541 if (!txs) {
1542 err = -ENOMEM;
1543 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1544 goto fail;
1545 }
1546 SHARED_RING_INIT(txs);
1547 FRONT_RING_INIT(&queue->tx, txs, PAGE_SIZE);
1548
1549 err = xenbus_grant_ring(dev, virt_to_mfn(txs));
1550 if (err < 0)
1551 goto grant_tx_ring_fail;
1552 queue->tx_ring_ref = err;
1553
1554 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1555 if (!rxs) {
1556 err = -ENOMEM;
1557 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1558 goto alloc_rx_ring_fail;
1559 }
1560 SHARED_RING_INIT(rxs);
1561 FRONT_RING_INIT(&queue->rx, rxs, PAGE_SIZE);
1562
1563 err = xenbus_grant_ring(dev, virt_to_mfn(rxs));
1564 if (err < 0)
1565 goto grant_rx_ring_fail;
1566 queue->rx_ring_ref = err;
1567
1568 if (feature_split_evtchn)
1569 err = setup_netfront_split(queue);
1570 /* setup single event channel if
1571 * a) feature-split-event-channels == 0
1572 * b) feature-split-event-channels == 1 but failed to setup
1573 */
1574 if (!feature_split_evtchn || (feature_split_evtchn && err))
1575 err = setup_netfront_single(queue);
1576
1577 if (err)
1578 goto alloc_evtchn_fail;
1579
1580 return 0;
1581
1582 /* If we fail to setup netfront, it is safe to just revoke access to
1583 * granted pages because backend is not accessing it at this point.
1584 */
1585 alloc_evtchn_fail:
1586 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0);
1587 grant_rx_ring_fail:
1588 free_page((unsigned long)rxs);
1589 alloc_rx_ring_fail:
1590 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0);
1591 grant_tx_ring_fail:
1592 free_page((unsigned long)txs);
1593 fail:
1594 return err;
1595 }
1596
1597 /* Queue-specific initialisation
1598 * This used to be done in xennet_create_dev() but must now
1599 * be run per-queue.
1600 */
1601 static int xennet_init_queue(struct netfront_queue *queue)
1602 {
1603 unsigned short i;
1604 int err = 0;
1605
1606 spin_lock_init(&queue->tx_lock);
1607 spin_lock_init(&queue->rx_lock);
1608
1609 init_timer(&queue->rx_refill_timer);
1610 queue->rx_refill_timer.data = (unsigned long)queue;
1611 queue->rx_refill_timer.function = rx_refill_timeout;
1612
1613 snprintf(queue->name, sizeof(queue->name), "%s-q%u",
1614 queue->info->netdev->name, queue->id);
1615
1616 /* Initialise tx_skbs as a free chain containing every entry. */
1617 queue->tx_skb_freelist = 0;
1618 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1619 skb_entry_set_link(&queue->tx_skbs[i], i+1);
1620 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1621 queue->grant_tx_page[i] = NULL;
1622 }
1623
1624 /* Clear out rx_skbs */
1625 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1626 queue->rx_skbs[i] = NULL;
1627 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
1628 }
1629
1630 /* A grant for every tx ring slot */
1631 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
1632 &queue->gref_tx_head) < 0) {
1633 pr_alert("can't alloc tx grant refs\n");
1634 err = -ENOMEM;
1635 goto exit;
1636 }
1637
1638 /* A grant for every rx ring slot */
1639 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
1640 &queue->gref_rx_head) < 0) {
1641 pr_alert("can't alloc rx grant refs\n");
1642 err = -ENOMEM;
1643 goto exit_free_tx;
1644 }
1645
1646 return 0;
1647
1648 exit_free_tx:
1649 gnttab_free_grant_references(queue->gref_tx_head);
1650 exit:
1651 return err;
1652 }
1653
1654 static int write_queue_xenstore_keys(struct netfront_queue *queue,
1655 struct xenbus_transaction *xbt, int write_hierarchical)
1656 {
1657 /* Write the queue-specific keys into XenStore in the traditional
1658 * way for a single queue, or in a queue subkeys for multiple
1659 * queues.
1660 */
1661 struct xenbus_device *dev = queue->info->xbdev;
1662 int err;
1663 const char *message;
1664 char *path;
1665 size_t pathsize;
1666
1667 /* Choose the correct place to write the keys */
1668 if (write_hierarchical) {
1669 pathsize = strlen(dev->nodename) + 10;
1670 path = kzalloc(pathsize, GFP_KERNEL);
1671 if (!path) {
1672 err = -ENOMEM;
1673 message = "out of memory while writing ring references";
1674 goto error;
1675 }
1676 snprintf(path, pathsize, "%s/queue-%u",
1677 dev->nodename, queue->id);
1678 } else {
1679 path = (char *)dev->nodename;
1680 }
1681
1682 /* Write ring references */
1683 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u",
1684 queue->tx_ring_ref);
1685 if (err) {
1686 message = "writing tx-ring-ref";
1687 goto error;
1688 }
1689
1690 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u",
1691 queue->rx_ring_ref);
1692 if (err) {
1693 message = "writing rx-ring-ref";
1694 goto error;
1695 }
1696
1697 /* Write event channels; taking into account both shared
1698 * and split event channel scenarios.
1699 */
1700 if (queue->tx_evtchn == queue->rx_evtchn) {
1701 /* Shared event channel */
1702 err = xenbus_printf(*xbt, path,
1703 "event-channel", "%u", queue->tx_evtchn);
1704 if (err) {
1705 message = "writing event-channel";
1706 goto error;
1707 }
1708 } else {
1709 /* Split event channels */
1710 err = xenbus_printf(*xbt, path,
1711 "event-channel-tx", "%u", queue->tx_evtchn);
1712 if (err) {
1713 message = "writing event-channel-tx";
1714 goto error;
1715 }
1716
1717 err = xenbus_printf(*xbt, path,
1718 "event-channel-rx", "%u", queue->rx_evtchn);
1719 if (err) {
1720 message = "writing event-channel-rx";
1721 goto error;
1722 }
1723 }
1724
1725 if (write_hierarchical)
1726 kfree(path);
1727 return 0;
1728
1729 error:
1730 if (write_hierarchical)
1731 kfree(path);
1732 xenbus_dev_fatal(dev, err, "%s", message);
1733 return err;
1734 }
1735
1736 static void xennet_destroy_queues(struct netfront_info *info)
1737 {
1738 unsigned int i;
1739
1740 rtnl_lock();
1741
1742 for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
1743 struct netfront_queue *queue = &info->queues[i];
1744
1745 if (netif_running(info->netdev))
1746 napi_disable(&queue->napi);
1747 netif_napi_del(&queue->napi);
1748 }
1749
1750 rtnl_unlock();
1751
1752 kfree(info->queues);
1753 info->queues = NULL;
1754 }
1755
1756 static int xennet_create_queues(struct netfront_info *info,
1757 unsigned int num_queues)
1758 {
1759 unsigned int i;
1760 int ret;
1761
1762 info->queues = kcalloc(num_queues, sizeof(struct netfront_queue),
1763 GFP_KERNEL);
1764 if (!info->queues)
1765 return -ENOMEM;
1766
1767 rtnl_lock();
1768
1769 for (i = 0; i < num_queues; i++) {
1770 struct netfront_queue *queue = &info->queues[i];
1771
1772 queue->id = i;
1773 queue->info = info;
1774
1775 ret = xennet_init_queue(queue);
1776 if (ret < 0) {
1777 dev_warn(&info->netdev->dev,
1778 "only created %d queues\n", i);
1779 num_queues = i;
1780 break;
1781 }
1782
1783 netif_napi_add(queue->info->netdev, &queue->napi,
1784 xennet_poll, 64);
1785 if (netif_running(info->netdev))
1786 napi_enable(&queue->napi);
1787 }
1788
1789 netif_set_real_num_tx_queues(info->netdev, num_queues);
1790
1791 rtnl_unlock();
1792
1793 if (num_queues == 0) {
1794 dev_err(&info->netdev->dev, "no queues\n");
1795 return -EINVAL;
1796 }
1797 return 0;
1798 }
1799
1800 /* Common code used when first setting up, and when resuming. */
1801 static int talk_to_netback(struct xenbus_device *dev,
1802 struct netfront_info *info)
1803 {
1804 const char *message;
1805 struct xenbus_transaction xbt;
1806 int err;
1807 unsigned int feature_split_evtchn;
1808 unsigned int i = 0;
1809 unsigned int max_queues = 0;
1810 struct netfront_queue *queue = NULL;
1811 unsigned int num_queues = 1;
1812
1813 info->netdev->irq = 0;
1814
1815 /* Check if backend supports multiple queues */
1816 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
1817 "multi-queue-max-queues", "%u", &max_queues);
1818 if (err < 0)
1819 max_queues = 1;
1820 num_queues = min(max_queues, xennet_max_queues);
1821
1822 /* Check feature-split-event-channels */
1823 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
1824 "feature-split-event-channels", "%u",
1825 &feature_split_evtchn);
1826 if (err < 0)
1827 feature_split_evtchn = 0;
1828
1829 /* Read mac addr. */
1830 err = xen_net_read_mac(dev, info->netdev->dev_addr);
1831 if (err) {
1832 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1833 goto out;
1834 }
1835
1836 if (info->queues)
1837 xennet_destroy_queues(info);
1838
1839 err = xennet_create_queues(info, num_queues);
1840 if (err < 0)
1841 goto destroy_ring;
1842
1843 /* Create shared ring, alloc event channel -- for each queue */
1844 for (i = 0; i < num_queues; ++i) {
1845 queue = &info->queues[i];
1846 err = setup_netfront(dev, queue, feature_split_evtchn);
1847 if (err) {
1848 /* setup_netfront() will tidy up the current
1849 * queue on error, but we need to clean up
1850 * those already allocated.
1851 */
1852 if (i > 0) {
1853 rtnl_lock();
1854 netif_set_real_num_tx_queues(info->netdev, i);
1855 rtnl_unlock();
1856 goto destroy_ring;
1857 } else {
1858 goto out;
1859 }
1860 }
1861 }
1862
1863 again:
1864 err = xenbus_transaction_start(&xbt);
1865 if (err) {
1866 xenbus_dev_fatal(dev, err, "starting transaction");
1867 goto destroy_ring;
1868 }
1869
1870 if (num_queues == 1) {
1871 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */
1872 if (err)
1873 goto abort_transaction_no_dev_fatal;
1874 } else {
1875 /* Write the number of queues */
1876 err = xenbus_printf(xbt, dev->nodename, "multi-queue-num-queues",
1877 "%u", num_queues);
1878 if (err) {
1879 message = "writing multi-queue-num-queues";
1880 goto abort_transaction_no_dev_fatal;
1881 }
1882
1883 /* Write the keys for each queue */
1884 for (i = 0; i < num_queues; ++i) {
1885 queue = &info->queues[i];
1886 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */
1887 if (err)
1888 goto abort_transaction_no_dev_fatal;
1889 }
1890 }
1891
1892 /* The remaining keys are not queue-specific */
1893 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
1894 1);
1895 if (err) {
1896 message = "writing request-rx-copy";
1897 goto abort_transaction;
1898 }
1899
1900 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
1901 if (err) {
1902 message = "writing feature-rx-notify";
1903 goto abort_transaction;
1904 }
1905
1906 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
1907 if (err) {
1908 message = "writing feature-sg";
1909 goto abort_transaction;
1910 }
1911
1912 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
1913 if (err) {
1914 message = "writing feature-gso-tcpv4";
1915 goto abort_transaction;
1916 }
1917
1918 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1");
1919 if (err) {
1920 message = "writing feature-gso-tcpv6";
1921 goto abort_transaction;
1922 }
1923
1924 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload",
1925 "1");
1926 if (err) {
1927 message = "writing feature-ipv6-csum-offload";
1928 goto abort_transaction;
1929 }
1930
1931 err = xenbus_transaction_end(xbt, 0);
1932 if (err) {
1933 if (err == -EAGAIN)
1934 goto again;
1935 xenbus_dev_fatal(dev, err, "completing transaction");
1936 goto destroy_ring;
1937 }
1938
1939 return 0;
1940
1941 abort_transaction:
1942 xenbus_dev_fatal(dev, err, "%s", message);
1943 abort_transaction_no_dev_fatal:
1944 xenbus_transaction_end(xbt, 1);
1945 destroy_ring:
1946 xennet_disconnect_backend(info);
1947 kfree(info->queues);
1948 info->queues = NULL;
1949 rtnl_lock();
1950 netif_set_real_num_tx_queues(info->netdev, 0);
1951 rtnl_unlock();
1952 out:
1953 return err;
1954 }
1955
1956 static int xennet_connect(struct net_device *dev)
1957 {
1958 struct netfront_info *np = netdev_priv(dev);
1959 unsigned int num_queues = 0;
1960 int err;
1961 unsigned int feature_rx_copy;
1962 unsigned int j = 0;
1963 struct netfront_queue *queue = NULL;
1964
1965 err = xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1966 "feature-rx-copy", "%u", &feature_rx_copy);
1967 if (err != 1)
1968 feature_rx_copy = 0;
1969
1970 if (!feature_rx_copy) {
1971 dev_info(&dev->dev,
1972 "backend does not support copying receive path\n");
1973 return -ENODEV;
1974 }
1975
1976 err = talk_to_netback(np->xbdev, np);
1977 if (err)
1978 return err;
1979
1980 /* talk_to_netback() sets the correct number of queues */
1981 num_queues = dev->real_num_tx_queues;
1982
1983 rtnl_lock();
1984 netdev_update_features(dev);
1985 rtnl_unlock();
1986
1987 /*
1988 * All public and private state should now be sane. Get
1989 * ready to start sending and receiving packets and give the driver
1990 * domain a kick because we've probably just requeued some
1991 * packets.
1992 */
1993 netif_carrier_on(np->netdev);
1994 for (j = 0; j < num_queues; ++j) {
1995 queue = &np->queues[j];
1996
1997 notify_remote_via_irq(queue->tx_irq);
1998 if (queue->tx_irq != queue->rx_irq)
1999 notify_remote_via_irq(queue->rx_irq);
2000
2001 spin_lock_irq(&queue->tx_lock);
2002 xennet_tx_buf_gc(queue);
2003 spin_unlock_irq(&queue->tx_lock);
2004
2005 spin_lock_bh(&queue->rx_lock);
2006 xennet_alloc_rx_buffers(queue);
2007 spin_unlock_bh(&queue->rx_lock);
2008 }
2009
2010 return 0;
2011 }
2012
2013 /**
2014 * Callback received when the backend's state changes.
2015 */
2016 static void netback_changed(struct xenbus_device *dev,
2017 enum xenbus_state backend_state)
2018 {
2019 struct netfront_info *np = dev_get_drvdata(&dev->dev);
2020 struct net_device *netdev = np->netdev;
2021
2022 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
2023
2024 switch (backend_state) {
2025 case XenbusStateInitialising:
2026 case XenbusStateInitialised:
2027 case XenbusStateReconfiguring:
2028 case XenbusStateReconfigured:
2029 case XenbusStateUnknown:
2030 break;
2031
2032 case XenbusStateInitWait:
2033 if (dev->state != XenbusStateInitialising)
2034 break;
2035 if (xennet_connect(netdev) != 0)
2036 break;
2037 xenbus_switch_state(dev, XenbusStateConnected);
2038 break;
2039
2040 case XenbusStateConnected:
2041 netdev_notify_peers(netdev);
2042 break;
2043
2044 case XenbusStateClosed:
2045 if (dev->state == XenbusStateClosed)
2046 break;
2047 /* Missed the backend's CLOSING state -- fallthrough */
2048 case XenbusStateClosing:
2049 xenbus_frontend_closed(dev);
2050 break;
2051 }
2052 }
2053
2054 static const struct xennet_stat {
2055 char name[ETH_GSTRING_LEN];
2056 u16 offset;
2057 } xennet_stats[] = {
2058 {
2059 "rx_gso_checksum_fixup",
2060 offsetof(struct netfront_info, rx_gso_checksum_fixup)
2061 },
2062 };
2063
2064 static int xennet_get_sset_count(struct net_device *dev, int string_set)
2065 {
2066 switch (string_set) {
2067 case ETH_SS_STATS:
2068 return ARRAY_SIZE(xennet_stats);
2069 default:
2070 return -EINVAL;
2071 }
2072 }
2073
2074 static void xennet_get_ethtool_stats(struct net_device *dev,
2075 struct ethtool_stats *stats, u64 * data)
2076 {
2077 void *np = netdev_priv(dev);
2078 int i;
2079
2080 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2081 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset));
2082 }
2083
2084 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
2085 {
2086 int i;
2087
2088 switch (stringset) {
2089 case ETH_SS_STATS:
2090 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2091 memcpy(data + i * ETH_GSTRING_LEN,
2092 xennet_stats[i].name, ETH_GSTRING_LEN);
2093 break;
2094 }
2095 }
2096
2097 static const struct ethtool_ops xennet_ethtool_ops =
2098 {
2099 .get_link = ethtool_op_get_link,
2100
2101 .get_sset_count = xennet_get_sset_count,
2102 .get_ethtool_stats = xennet_get_ethtool_stats,
2103 .get_strings = xennet_get_strings,
2104 };
2105
2106 #ifdef CONFIG_SYSFS
2107 static ssize_t show_rxbuf(struct device *dev,
2108 struct device_attribute *attr, char *buf)
2109 {
2110 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE);
2111 }
2112
2113 static ssize_t store_rxbuf(struct device *dev,
2114 struct device_attribute *attr,
2115 const char *buf, size_t len)
2116 {
2117 char *endp;
2118 unsigned long target;
2119
2120 if (!capable(CAP_NET_ADMIN))
2121 return -EPERM;
2122
2123 target = simple_strtoul(buf, &endp, 0);
2124 if (endp == buf)
2125 return -EBADMSG;
2126
2127 /* rxbuf_min and rxbuf_max are no longer configurable. */
2128
2129 return len;
2130 }
2131
2132 static struct device_attribute xennet_attrs[] = {
2133 __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf),
2134 __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf),
2135 __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf, NULL),
2136 };
2137
2138 static int xennet_sysfs_addif(struct net_device *netdev)
2139 {
2140 int i;
2141 int err;
2142
2143 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) {
2144 err = device_create_file(&netdev->dev,
2145 &xennet_attrs[i]);
2146 if (err)
2147 goto fail;
2148 }
2149 return 0;
2150
2151 fail:
2152 while (--i >= 0)
2153 device_remove_file(&netdev->dev, &xennet_attrs[i]);
2154 return err;
2155 }
2156
2157 static void xennet_sysfs_delif(struct net_device *netdev)
2158 {
2159 int i;
2160
2161 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++)
2162 device_remove_file(&netdev->dev, &xennet_attrs[i]);
2163 }
2164
2165 #endif /* CONFIG_SYSFS */
2166
2167 static int xennet_remove(struct xenbus_device *dev)
2168 {
2169 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2170 unsigned int num_queues = info->netdev->real_num_tx_queues;
2171 struct netfront_queue *queue = NULL;
2172 unsigned int i = 0;
2173
2174 dev_dbg(&dev->dev, "%s\n", dev->nodename);
2175
2176 xennet_disconnect_backend(info);
2177
2178 xennet_sysfs_delif(info->netdev);
2179
2180 unregister_netdev(info->netdev);
2181
2182 for (i = 0; i < num_queues; ++i) {
2183 queue = &info->queues[i];
2184 del_timer_sync(&queue->rx_refill_timer);
2185 }
2186
2187 if (num_queues) {
2188 kfree(info->queues);
2189 info->queues = NULL;
2190 }
2191
2192 free_percpu(info->stats);
2193
2194 free_netdev(info->netdev);
2195
2196 return 0;
2197 }
2198
2199 static const struct xenbus_device_id netfront_ids[] = {
2200 { "vif" },
2201 { "" }
2202 };
2203
2204 static struct xenbus_driver netfront_driver = {
2205 .ids = netfront_ids,
2206 .probe = netfront_probe,
2207 .remove = xennet_remove,
2208 .resume = netfront_resume,
2209 .otherend_changed = netback_changed,
2210 };
2211
2212 static int __init netif_init(void)
2213 {
2214 if (!xen_domain())
2215 return -ENODEV;
2216
2217 if (!xen_has_pv_nic_devices())
2218 return -ENODEV;
2219
2220 pr_info("Initialising Xen virtual ethernet driver\n");
2221
2222 /* Allow as many queues as there are CPUs, by default */
2223 xennet_max_queues = num_online_cpus();
2224
2225 return xenbus_register_frontend(&netfront_driver);
2226 }
2227 module_init(netif_init);
2228
2229
2230 static void __exit netif_exit(void)
2231 {
2232 xenbus_unregister_driver(&netfront_driver);
2233 }
2234 module_exit(netif_exit);
2235
2236 MODULE_DESCRIPTION("Xen virtual network device frontend");
2237 MODULE_LICENSE("GPL");
2238 MODULE_ALIAS("xen:vif");
2239 MODULE_ALIAS("xennet");
Linux with added FPC-III support