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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[deliverable/linux.git] / drivers / net / xen-netfront.c
CommitLineData
0d160211
JF		 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#include <linux/module.h>
33#include <linux/kernel.h>
34#include <linux/netdevice.h>
35#include <linux/etherdevice.h>
36#include <linux/skbuff.h>
37#include <linux/ethtool.h>
38#include <linux/if_ether.h>
39#include <linux/tcp.h>
40#include <linux/udp.h>
41#include <linux/moduleparam.h>
42#include <linux/mm.h>
5a0e3ad6 43#include <linux/slab.h>
0d160211
JF		 44#include <net/ip.h>
45
ca981633 46#include <asm/xen/page.h>
1ccbf534 47#include <xen/xen.h>
0d160211
JF		 48#include <xen/xenbus.h>
49#include <xen/events.h>
50#include <xen/page.h>
b9136d20 51#include <xen/platform_pci.h>
0d160211
JF		 52#include <xen/grant_table.h>
53
54#include <xen/interface/io/netif.h>
55#include <xen/interface/memory.h>
56#include <xen/interface/grant_table.h>
57
0fc0b732 58static const struct ethtool_ops xennet_ethtool_ops;
0d160211
JF		 59
60struct netfront_cb {
3683243b 61 int pull_to;
0d160211
JF		 62};
63
64#define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
65
66#define RX_COPY_THRESHOLD 256
67
68#define GRANT_INVALID_REF 0
69
667c78af
JF		 70#define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE)
71#define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE)
40206dd9 72#define TX_MAX_TARGET min_t(int, NET_TX_RING_SIZE, 256)
0d160211 73
e00f85be 74struct netfront_stats {
75 u64 rx_packets;
76 u64 tx_packets;
77 u64 rx_bytes;
78 u64 tx_bytes;
79 struct u64_stats_sync syncp;
80};
81
0d160211
JF		 82struct netfront_info {
83 struct list_head list;
84 struct net_device *netdev;
85
bea3348e 86 struct napi_struct napi;
0d160211 87
0d160211 88 unsigned int evtchn;
84284d3c 89 struct xenbus_device *xbdev;
0d160211 90
84284d3c
JF		 91 spinlock_t tx_lock;
92 struct xen_netif_tx_front_ring tx;
93 int tx_ring_ref;
0d160211
JF		 94
95 /*
96 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
97 * are linked from tx_skb_freelist through skb_entry.link.
98 *
99 * NB. Freelist index entries are always going to be less than
100 * PAGE_OFFSET, whereas pointers to skbs will always be equal or
101 * greater than PAGE_OFFSET: we use this property to distinguish
102 * them.
103 */
104 union skb_entry {
105 struct sk_buff *skb;
1ffb40b8 106 unsigned long link;
0d160211
JF		 107 } tx_skbs[NET_TX_RING_SIZE];
108 grant_ref_t gref_tx_head;
109 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
110 unsigned tx_skb_freelist;
111
84284d3c
JF		 112 spinlock_t rx_lock ____cacheline_aligned_in_smp;
113 struct xen_netif_rx_front_ring rx;
114 int rx_ring_ref;
115
116 /* Receive-ring batched refills. */
117#define RX_MIN_TARGET 8
118#define RX_DFL_MIN_TARGET 64
119#define RX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256)
120 unsigned rx_min_target, rx_max_target, rx_target;
121 struct sk_buff_head rx_batch;
122
123 struct timer_list rx_refill_timer;
124
0d160211
JF		 125 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
126 grant_ref_t gref_rx_head;
127 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
128
0d160211
JF		 129 unsigned long rx_pfn_array[NET_RX_RING_SIZE];
130 struct multicall_entry rx_mcl[NET_RX_RING_SIZE+1];
131 struct mmu_update rx_mmu[NET_RX_RING_SIZE];
e0ce4af9
IC		 132
133 /* Statistics */
e00f85be 134 struct netfront_stats __percpu *stats;
135
e9a799ea 136 unsigned long rx_gso_checksum_fixup;
0d160211
JF		 137};
138
139struct netfront_rx_info {
140 struct xen_netif_rx_response rx;
141 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
142};
143
1ffb40b8
IY		 144static void skb_entry_set_link(union skb_entry *list, unsigned short id)
145{
146 list->link = id;
147}
148
149static int skb_entry_is_link(const union skb_entry *list)
150{
151 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
807540ba 152 return (unsigned long)list->skb < PAGE_OFFSET;
1ffb40b8
IY		 153}
154
0d160211
JF		 155/*
156 * Access macros for acquiring freeing slots in tx_skbs[].
157 */
158
159static void add_id_to_freelist(unsigned *head, union skb_entry *list,
160 unsigned short id)
161{
1ffb40b8 162 skb_entry_set_link(&list[id], *head);
0d160211
JF		 163 *head = id;
164}
165
166static unsigned short get_id_from_freelist(unsigned *head,
167 union skb_entry *list)
168{
169 unsigned int id = *head;
170 *head = list[id].link;
171 return id;
172}
173
174static int xennet_rxidx(RING_IDX idx)
175{
176 return idx & (NET_RX_RING_SIZE - 1);
177}
178
179static struct sk_buff *xennet_get_rx_skb(struct netfront_info *np,
180 RING_IDX ri)
181{
182 int i = xennet_rxidx(ri);
183 struct sk_buff *skb = np->rx_skbs[i];
184 np->rx_skbs[i] = NULL;
185 return skb;
186}
187
188static grant_ref_t xennet_get_rx_ref(struct netfront_info *np,
189 RING_IDX ri)
190{
191 int i = xennet_rxidx(ri);
192 grant_ref_t ref = np->grant_rx_ref[i];
193 np->grant_rx_ref[i] = GRANT_INVALID_REF;
194 return ref;
195}
196
197#ifdef CONFIG_SYSFS
198static int xennet_sysfs_addif(struct net_device *netdev);
199static void xennet_sysfs_delif(struct net_device *netdev);
200#else /* !CONFIG_SYSFS */
201#define xennet_sysfs_addif(dev) (0)
202#define xennet_sysfs_delif(dev) do { } while (0)
203#endif
204
3ad9b358 205static bool xennet_can_sg(struct net_device *dev)
0d160211 206{
3ad9b358 207 return dev->features & NETIF_F_SG;
0d160211
JF		 208}
209
210
211static void rx_refill_timeout(unsigned long data)
212{
213 struct net_device *dev = (struct net_device *)data;
bea3348e 214 struct netfront_info *np = netdev_priv(dev);
288379f0 215 napi_schedule(&np->napi);
0d160211
JF		 216}
217
218static int netfront_tx_slot_available(struct netfront_info *np)
219{
807540ba
ED		 220 return (np->tx.req_prod_pvt - np->tx.rsp_cons) <
221 (TX_MAX_TARGET - MAX_SKB_FRAGS - 2);
0d160211
JF		 222}
223
224static void xennet_maybe_wake_tx(struct net_device *dev)
225{
226 struct netfront_info *np = netdev_priv(dev);
227
228 if (unlikely(netif_queue_stopped(dev)) &&
229 netfront_tx_slot_available(np) &&
230 likely(netif_running(dev)))
231 netif_wake_queue(dev);
232}
233
234static void xennet_alloc_rx_buffers(struct net_device *dev)
235{
236 unsigned short id;
237 struct netfront_info *np = netdev_priv(dev);
238 struct sk_buff *skb;
239 struct page *page;
240 int i, batch_target, notify;
241 RING_IDX req_prod = np->rx.req_prod_pvt;
0d160211
JF		 242 grant_ref_t ref;
243 unsigned long pfn;
244 void *vaddr;
0d160211
JF		 245 struct xen_netif_rx_request *req;
246
247 if (unlikely(!netif_carrier_ok(dev)))
248 return;
249
250 /*
251 * Allocate skbuffs greedily, even though we batch updates to the
252 * receive ring. This creates a less bursty demand on the memory
253 * allocator, so should reduce the chance of failed allocation requests
254 * both for ourself and for other kernel subsystems.
255 */
256 batch_target = np->rx_target - (req_prod - np->rx.rsp_cons);
257 for (i = skb_queue_len(&np->rx_batch); i < batch_target; i++) {
617a20bb 258 skb = __netdev_alloc_skb(dev, RX_COPY_THRESHOLD + NET_IP_ALIGN,
0d160211
JF		 259 GFP_ATOMIC | __GFP_NOWARN);
260 if (unlikely(!skb))
261 goto no_skb;
262
617a20bb
IY		 263 /* Align ip header to a 16 bytes boundary */
264 skb_reserve(skb, NET_IP_ALIGN);
265
0d160211
JF		 266 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
267 if (!page) {
268 kfree_skb(skb);
269no_skb:
270 /* Any skbuffs queued for refill? Force them out. */
271 if (i != 0)
272 goto refill;
273 /* Could not allocate any skbuffs. Try again later. */
274 mod_timer(&np->rx_refill_timer,
275 jiffies + (HZ/10));
276 break;
277 }
278
01c68026 279 __skb_fill_page_desc(skb, 0, page, 0, 0);
0d160211
JF		 280 skb_shinfo(skb)->nr_frags = 1;
281 __skb_queue_tail(&np->rx_batch, skb);
282 }
283
284 /* Is the batch large enough to be worthwhile? */
285 if (i < (np->rx_target/2)) {
286 if (req_prod > np->rx.sring->req_prod)
287 goto push;
288 return;
289 }
290
291 /* Adjust our fill target if we risked running out of buffers. */
292 if (((req_prod - np->rx.sring->rsp_prod) < (np->rx_target / 4)) &&
293 ((np->rx_target *= 2) > np->rx_max_target))
294 np->rx_target = np->rx_max_target;
295
296 refill:
5dcddfae 297 for (i = 0; ; i++) {
0d160211
JF		 298 skb = __skb_dequeue(&np->rx_batch);
299 if (skb == NULL)
300 break;
301
302 skb->dev = dev;
303
304 id = xennet_rxidx(req_prod + i);
305
306 BUG_ON(np->rx_skbs[id]);
307 np->rx_skbs[id] = skb;
308
309 ref = gnttab_claim_grant_reference(&np->gref_rx_head);
310 BUG_ON((signed short)ref < 0);
311 np->grant_rx_ref[id] = ref;
312
01c68026
IC		 313 pfn = page_to_pfn(skb_frag_page(&skb_shinfo(skb)->frags[0]));
314 vaddr = page_address(skb_frag_page(&skb_shinfo(skb)->frags[0]));
0d160211
JF		 315
316 req = RING_GET_REQUEST(&np->rx, req_prod + i);
317 gnttab_grant_foreign_access_ref(ref,
318 np->xbdev->otherend_id,
319 pfn_to_mfn(pfn),
320 0);
321
322 req->id = id;
323 req->gref = ref;
324 }
325
5dcddfae 326 wmb(); /* barrier so backend seens requests */
0d160211
JF		 327
328 /* Above is a suitable barrier to ensure backend will see requests. */
329 np->rx.req_prod_pvt = req_prod + i;
330 push:
331 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->rx, notify);
332 if (notify)
333 notify_remote_via_irq(np->netdev->irq);
334}
335
336static int xennet_open(struct net_device *dev)
337{
338 struct netfront_info *np = netdev_priv(dev);
339
bea3348e
SH		 340 napi_enable(&np->napi);
341
0d160211
JF		 342 spin_lock_bh(&np->rx_lock);
343 if (netif_carrier_ok(dev)) {
344 xennet_alloc_rx_buffers(dev);
345 np->rx.sring->rsp_event = np->rx.rsp_cons + 1;
346 if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx))
288379f0 347 napi_schedule(&np->napi);
0d160211
JF		 348 }
349 spin_unlock_bh(&np->rx_lock);
350
0b1ab1b8 351 netif_start_queue(dev);
0d160211
JF		 352
353 return 0;
354}
355
356static void xennet_tx_buf_gc(struct net_device *dev)
357{
358 RING_IDX cons, prod;
359 unsigned short id;
360 struct netfront_info *np = netdev_priv(dev);
361 struct sk_buff *skb;
362
363 BUG_ON(!netif_carrier_ok(dev));
364
365 do {
366 prod = np->tx.sring->rsp_prod;
367 rmb(); /* Ensure we see responses up to 'rp'. */
368
369 for (cons = np->tx.rsp_cons; cons != prod; cons++) {
370 struct xen_netif_tx_response *txrsp;
371
372 txrsp = RING_GET_RESPONSE(&np->tx, cons);
f942dc25 373 if (txrsp->status == XEN_NETIF_RSP_NULL)
0d160211
JF		 374 continue;
375
376 id = txrsp->id;
377 skb = np->tx_skbs[id].skb;
378 if (unlikely(gnttab_query_foreign_access(
379 np->grant_tx_ref[id]) != 0)) {
380 printk(KERN_ALERT "xennet_tx_buf_gc: warning "
381 "-- grant still in use by backend "
382 "domain.\n");
383 BUG();
384 }
385 gnttab_end_foreign_access_ref(
386 np->grant_tx_ref[id], GNTMAP_readonly);
387 gnttab_release_grant_reference(
388 &np->gref_tx_head, np->grant_tx_ref[id]);
389 np->grant_tx_ref[id] = GRANT_INVALID_REF;
390 add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, id);
391 dev_kfree_skb_irq(skb);
392 }
393
394 np->tx.rsp_cons = prod;
395
396 /*
397 * Set a new event, then check for race with update of tx_cons.
398 * Note that it is essential to schedule a callback, no matter
399 * how few buffers are pending. Even if there is space in the
400 * transmit ring, higher layers may be blocked because too much
401 * data is outstanding: in such cases notification from Xen is
402 * likely to be the only kick that we'll get.
403 */
404 np->tx.sring->rsp_event =
405 prod + ((np->tx.sring->req_prod - prod) >> 1) + 1;
406 mb(); /* update shared area */
407 } while ((cons == prod) && (prod != np->tx.sring->rsp_prod));
408
409 xennet_maybe_wake_tx(dev);
410}
411
412static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev,
413 struct xen_netif_tx_request *tx)
414{
415 struct netfront_info *np = netdev_priv(dev);
416 char *data = skb->data;
417 unsigned long mfn;
418 RING_IDX prod = np->tx.req_prod_pvt;
419 int frags = skb_shinfo(skb)->nr_frags;
420 unsigned int offset = offset_in_page(data);
421 unsigned int len = skb_headlen(skb);
422 unsigned int id;
423 grant_ref_t ref;
424 int i;
425
426 /* While the header overlaps a page boundary (including being
427 larger than a page), split it it into page-sized chunks. */
428 while (len > PAGE_SIZE - offset) {
429 tx->size = PAGE_SIZE - offset;
f942dc25 430 tx->flags |= XEN_NETTXF_more_data;
0d160211
JF		 431 len -= tx->size;
432 data += tx->size;
433 offset = 0;
434
435 id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
436 np->tx_skbs[id].skb = skb_get(skb);
437 tx = RING_GET_REQUEST(&np->tx, prod++);
438 tx->id = id;
439 ref = gnttab_claim_grant_reference(&np->gref_tx_head);
440 BUG_ON((signed short)ref < 0);
441
442 mfn = virt_to_mfn(data);
443 gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id,
444 mfn, GNTMAP_readonly);
445
446 tx->gref = np->grant_tx_ref[id] = ref;
447 tx->offset = offset;
448 tx->size = len;
449 tx->flags = 0;
450 }
451
452 /* Grant backend access to each skb fragment page. */
453 for (i = 0; i < frags; i++) {
454 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
f36c3747 455 struct page *page = skb_frag_page(frag);
0d160211 456
f36c3747
IC		 457 len = skb_frag_size(frag);
458 offset = frag->page_offset;
0d160211 459
f36c3747
IC		 460 /* Data must not cross a page boundary. */
461 BUG_ON(len + offset > PAGE_SIZE<<compound_order(page));
0d160211 462
f36c3747
IC		 463 /* Skip unused frames from start of page */
464 page += offset >> PAGE_SHIFT;
465 offset &= ~PAGE_MASK;
0d160211 466
f36c3747
IC		 467 while (len > 0) {
468 unsigned long bytes;
469
470 BUG_ON(offset >= PAGE_SIZE);
471
472 bytes = PAGE_SIZE - offset;
473 if (bytes > len)
474 bytes = len;
475
476 tx->flags |= XEN_NETTXF_more_data;
477
478 id = get_id_from_freelist(&np->tx_skb_freelist,
479 np->tx_skbs);
480 np->tx_skbs[id].skb = skb_get(skb);
481 tx = RING_GET_REQUEST(&np->tx, prod++);
482 tx->id = id;
483 ref = gnttab_claim_grant_reference(&np->gref_tx_head);
484 BUG_ON((signed short)ref < 0);
485
486 mfn = pfn_to_mfn(page_to_pfn(page));
487 gnttab_grant_foreign_access_ref(ref,
488 np->xbdev->otherend_id,
489 mfn, GNTMAP_readonly);
490
491 tx->gref = np->grant_tx_ref[id] = ref;
492 tx->offset = offset;
493 tx->size = bytes;
494 tx->flags = 0;
495
496 offset += bytes;
497 len -= bytes;
498
499 /* Next frame */
500 if (offset == PAGE_SIZE && len) {
501 BUG_ON(!PageCompound(page));
502 page++;
503 offset = 0;
504 }
505 }
0d160211
JF		 506 }
507
508 np->tx.req_prod_pvt = prod;
509}
510
f36c3747
IC		 511/*
512 * Count how many ring slots are required to send the frags of this
513 * skb. Each frag might be a compound page.
514 */
515static int xennet_count_skb_frag_slots(struct sk_buff *skb)
516{
517 int i, frags = skb_shinfo(skb)->nr_frags;
518 int pages = 0;
519
520 for (i = 0; i < frags; i++) {
521 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
522 unsigned long size = skb_frag_size(frag);
523 unsigned long offset = frag->page_offset;
524
525 /* Skip unused frames from start of page */
526 offset &= ~PAGE_MASK;
527
528 pages += PFN_UP(offset + size);
529 }
530
531 return pages;
532}
533
0d160211
JF		 534static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
535{
536 unsigned short id;
537 struct netfront_info *np = netdev_priv(dev);
e00f85be 538 struct netfront_stats *stats = this_cpu_ptr(np->stats);
0d160211
JF		 539 struct xen_netif_tx_request *tx;
540 struct xen_netif_extra_info *extra;
541 char *data = skb->data;
542 RING_IDX i;
543 grant_ref_t ref;
544 unsigned long mfn;
545 int notify;
f36c3747 546 int slots;
0d160211
JF		 547 unsigned int offset = offset_in_page(data);
548 unsigned int len = skb_headlen(skb);
cf66f9d4 549 unsigned long flags;
0d160211 550
f36c3747
IC		 551 slots = DIV_ROUND_UP(offset + len, PAGE_SIZE) +
552 xennet_count_skb_frag_slots(skb);
553 if (unlikely(slots > MAX_SKB_FRAGS + 1)) {
554 net_alert_ratelimited(
555 "xennet: skb rides the rocket: %d slots\n", slots);
0d160211
JF		 556 goto drop;
557 }
558
cf66f9d4 559 spin_lock_irqsave(&np->tx_lock, flags);
0d160211
JF		 560
561 if (unlikely(!netif_carrier_ok(dev) ||
f36c3747 562 (slots > 1 && !xennet_can_sg(dev)) ||
fc741216 563 netif_needs_gso(skb, netif_skb_features(skb)))) {
cf66f9d4 564 spin_unlock_irqrestore(&np->tx_lock, flags);
0d160211
JF		 565 goto drop;
566 }
567
568 i = np->tx.req_prod_pvt;
569
570 id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
571 np->tx_skbs[id].skb = skb;
572
573 tx = RING_GET_REQUEST(&np->tx, i);
574
575 tx->id = id;
576 ref = gnttab_claim_grant_reference(&np->gref_tx_head);
577 BUG_ON((signed short)ref < 0);
578 mfn = virt_to_mfn(data);
579 gnttab_grant_foreign_access_ref(
580 ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly);
581 tx->gref = np->grant_tx_ref[id] = ref;
582 tx->offset = offset;
583 tx->size = len;
584 extra = NULL;
585
586 tx->flags = 0;
587 if (skb->ip_summed == CHECKSUM_PARTIAL)
588 /* local packet? */
f942dc25 589 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
0d160211
JF		 590 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
591 /* remote but checksummed. */
f942dc25 592 tx->flags |= XEN_NETTXF_data_validated;
0d160211
JF		 593
594 if (skb_shinfo(skb)->gso_size) {
595 struct xen_netif_extra_info *gso;
596
597 gso = (struct xen_netif_extra_info *)
598 RING_GET_REQUEST(&np->tx, ++i);
599
600 if (extra)
601 extra->flags |= XEN_NETIF_EXTRA_FLAG_MORE;
602 else
f942dc25 603 tx->flags |= XEN_NETTXF_extra_info;
0d160211
JF		 604
605 gso->u.gso.size = skb_shinfo(skb)->gso_size;
606 gso->u.gso.type = XEN_NETIF_GSO_TYPE_TCPV4;
607 gso->u.gso.pad = 0;
608 gso->u.gso.features = 0;
609
610 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
611 gso->flags = 0;
612 extra = gso;
613 }
614
615 np->tx.req_prod_pvt = i + 1;
616
617 xennet_make_frags(skb, dev, tx);
618 tx->size = skb->len;
619
620 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->tx, notify);
621 if (notify)
622 notify_remote_via_irq(np->netdev->irq);
623
e00f85be 624 u64_stats_update_begin(&stats->syncp);
625 stats->tx_bytes += skb->len;
626 stats->tx_packets++;
627 u64_stats_update_end(&stats->syncp);
10a273a6
JF		 628
629 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
0d160211
JF		 630 xennet_tx_buf_gc(dev);
631
632 if (!netfront_tx_slot_available(np))
633 netif_stop_queue(dev);
634
cf66f9d4 635 spin_unlock_irqrestore(&np->tx_lock, flags);
0d160211 636
6ed10654 637 return NETDEV_TX_OK;
0d160211
JF		 638
639 drop:
09f75cd7 640 dev->stats.tx_dropped++;
0d160211 641 dev_kfree_skb(skb);
6ed10654 642 return NETDEV_TX_OK;
0d160211
JF		 643}
644
645static int xennet_close(struct net_device *dev)
646{
647 struct netfront_info *np = netdev_priv(dev);
648 netif_stop_queue(np->netdev);
bea3348e 649 napi_disable(&np->napi);
0d160211
JF		 650 return 0;
651}
652
0d160211
JF		 653static void xennet_move_rx_slot(struct netfront_info *np, struct sk_buff *skb,
654 grant_ref_t ref)
655{
656 int new = xennet_rxidx(np->rx.req_prod_pvt);
657
658 BUG_ON(np->rx_skbs[new]);
659 np->rx_skbs[new] = skb;
660 np->grant_rx_ref[new] = ref;
661 RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->id = new;
662 RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->gref = ref;
663 np->rx.req_prod_pvt++;
664}
665
666static int xennet_get_extras(struct netfront_info *np,
667 struct xen_netif_extra_info *extras,
668 RING_IDX rp)
669
670{
671 struct xen_netif_extra_info *extra;
672 struct device *dev = &np->netdev->dev;
673 RING_IDX cons = np->rx.rsp_cons;
674 int err = 0;
675
676 do {
677 struct sk_buff *skb;
678 grant_ref_t ref;
679
680 if (unlikely(cons + 1 == rp)) {
681 if (net_ratelimit())
682 dev_warn(dev, "Missing extra info\n");
683 err = -EBADR;
684 break;
685 }
686
687 extra = (struct xen_netif_extra_info *)
688 RING_GET_RESPONSE(&np->rx, ++cons);
689
690 if (unlikely(!extra->type ||
691 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
692 if (net_ratelimit())
693 dev_warn(dev, "Invalid extra type: %d\n",
694 extra->type);
695 err = -EINVAL;
696 } else {
697 memcpy(&extras[extra->type - 1], extra,
698 sizeof(*extra));
699 }
700
701 skb = xennet_get_rx_skb(np, cons);
702 ref = xennet_get_rx_ref(np, cons);
703 xennet_move_rx_slot(np, skb, ref);
704 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
705
706 np->rx.rsp_cons = cons;
707 return err;
708}
709
710static int xennet_get_responses(struct netfront_info *np,
711 struct netfront_rx_info *rinfo, RING_IDX rp,
712 struct sk_buff_head *list)
713{
714 struct xen_netif_rx_response *rx = &rinfo->rx;
715 struct xen_netif_extra_info *extras = rinfo->extras;
716 struct device *dev = &np->netdev->dev;
717 RING_IDX cons = np->rx.rsp_cons;
718 struct sk_buff *skb = xennet_get_rx_skb(np, cons);
719 grant_ref_t ref = xennet_get_rx_ref(np, cons);
720 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
721 int frags = 1;
722 int err = 0;
723 unsigned long ret;
724
f942dc25 725 if (rx->flags & XEN_NETRXF_extra_info) {
0d160211
JF		 726 err = xennet_get_extras(np, extras, rp);
727 cons = np->rx.rsp_cons;
728 }
729
730 for (;;) {
731 if (unlikely(rx->status < 0 ||
732 rx->offset + rx->status > PAGE_SIZE)) {
733 if (net_ratelimit())
734 dev_warn(dev, "rx->offset: %x, size: %u\n",
735 rx->offset, rx->status);
736 xennet_move_rx_slot(np, skb, ref);
737 err = -EINVAL;
738 goto next;
739 }
740
741 /*
742 * This definitely indicates a bug, either in this driver or in
743 * the backend driver. In future this should flag the bad
744 * situation to the system controller to reboot the backed.
745 */
746 if (ref == GRANT_INVALID_REF) {
747 if (net_ratelimit())
748 dev_warn(dev, "Bad rx response id %d.\n",
749 rx->id);
750 err = -EINVAL;
751 goto next;
752 }
753
754 ret = gnttab_end_foreign_access_ref(ref, 0);
755 BUG_ON(!ret);
756
757 gnttab_release_grant_reference(&np->gref_rx_head, ref);
758
759 __skb_queue_tail(list, skb);
760
761next:
f942dc25 762 if (!(rx->flags & XEN_NETRXF_more_data))
0d160211
JF		 763 break;
764
765 if (cons + frags == rp) {
766 if (net_ratelimit())
767 dev_warn(dev, "Need more frags\n");
768 err = -ENOENT;
769 break;
770 }
771
772 rx = RING_GET_RESPONSE(&np->rx, cons + frags);
773 skb = xennet_get_rx_skb(np, cons + frags);
774 ref = xennet_get_rx_ref(np, cons + frags);
775 frags++;
776 }
777
778 if (unlikely(frags > max)) {
779 if (net_ratelimit())
780 dev_warn(dev, "Too many frags\n");
781 err = -E2BIG;
782 }
783
784 if (unlikely(err))
785 np->rx.rsp_cons = cons + frags;
786
787 return err;
788}
789
790static int xennet_set_skb_gso(struct sk_buff *skb,
791 struct xen_netif_extra_info *gso)
792{
793 if (!gso->u.gso.size) {
794 if (net_ratelimit())
795 printk(KERN_WARNING "GSO size must not be zero.\n");
796 return -EINVAL;
797 }
798
799 /* Currently only TCPv4 S.O. is supported. */
800 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4) {
801 if (net_ratelimit())
802 printk(KERN_WARNING "Bad GSO type %d.\n", gso->u.gso.type);
803 return -EINVAL;
804 }
805
806 skb_shinfo(skb)->gso_size = gso->u.gso.size;
807 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
808
809 /* Header must be checked, and gso_segs computed. */
810 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
811 skb_shinfo(skb)->gso_segs = 0;
812
813 return 0;
814}
815
816static RING_IDX xennet_fill_frags(struct netfront_info *np,
817 struct sk_buff *skb,
818 struct sk_buff_head *list)
819{
820 struct skb_shared_info *shinfo = skb_shinfo(skb);
821 int nr_frags = shinfo->nr_frags;
822 RING_IDX cons = np->rx.rsp_cons;
0d160211
JF		 823 struct sk_buff *nskb;
824
825 while ((nskb = __skb_dequeue(list))) {
826 struct xen_netif_rx_response *rx =
827 RING_GET_RESPONSE(&np->rx, ++cons);
01c68026 828 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
0d160211 829
01c68026
IC		 830 __skb_fill_page_desc(skb, nr_frags,
831 skb_frag_page(nfrag),
832 rx->offset, rx->status);
0d160211
JF		 833
834 skb->data_len += rx->status;
835
836 skb_shinfo(nskb)->nr_frags = 0;
837 kfree_skb(nskb);
838
0d160211
JF		 839 nr_frags++;
840 }
841
842 shinfo->nr_frags = nr_frags;
843 return cons;
844}
845
e0ce4af9 846static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
0d160211
JF		 847{
848 struct iphdr *iph;
849 unsigned char *th;
850 int err = -EPROTO;
e0ce4af9
IC		 851 int recalculate_partial_csum = 0;
852
853 /*
854 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
855 * peers can fail to set NETRXF_csum_blank when sending a GSO
856 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
857 * recalculate the partial checksum.
858 */
859 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
860 struct netfront_info *np = netdev_priv(dev);
861 np->rx_gso_checksum_fixup++;
862 skb->ip_summed = CHECKSUM_PARTIAL;
863 recalculate_partial_csum = 1;
864 }
865
866 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
867 if (skb->ip_summed != CHECKSUM_PARTIAL)
868 return 0;
0d160211
JF		 869
870 if (skb->protocol != htons(ETH_P_IP))
871 goto out;
872
873 iph = (void *)skb->data;
874 th = skb->data + 4 * iph->ihl;
875 if (th >= skb_tail_pointer(skb))
876 goto out;
877
878 skb->csum_start = th - skb->head;
879 switch (iph->protocol) {
880 case IPPROTO_TCP:
881 skb->csum_offset = offsetof(struct tcphdr, check);
e0ce4af9
IC		 882
883 if (recalculate_partial_csum) {
884 struct tcphdr *tcph = (struct tcphdr *)th;
885 tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
886 skb->len - iph->ihl*4,
887 IPPROTO_TCP, 0);
888 }
0d160211
JF		 889 break;
890 case IPPROTO_UDP:
891 skb->csum_offset = offsetof(struct udphdr, check);
e0ce4af9
IC		 892
893 if (recalculate_partial_csum) {
894 struct udphdr *udph = (struct udphdr *)th;
895 udph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
896 skb->len - iph->ihl*4,
897 IPPROTO_UDP, 0);
898 }
0d160211
JF		 899 break;
900 default:
901 if (net_ratelimit())
902 printk(KERN_ERR "Attempting to checksum a non-"
903 "TCP/UDP packet, dropping a protocol"
904 " %d packet", iph->protocol);
905 goto out;
906 }
907
908 if ((th + skb->csum_offset + 2) > skb_tail_pointer(skb))
909 goto out;
910
911 err = 0;
912
913out:
914 return err;
915}
916
917static int handle_incoming_queue(struct net_device *dev,
09f75cd7 918 struct sk_buff_head *rxq)
0d160211 919{
e00f85be 920 struct netfront_info *np = netdev_priv(dev);
921 struct netfront_stats *stats = this_cpu_ptr(np->stats);
0d160211
JF		 922 int packets_dropped = 0;
923 struct sk_buff *skb;
924
925 while ((skb = __skb_dequeue(rxq)) != NULL) {
3683243b 926 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
0d160211 927
3683243b 928 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
0d160211
JF		 929
930 /* Ethernet work: Delayed to here as it peeks the header. */
931 skb->protocol = eth_type_trans(skb, dev);
932
e0ce4af9
IC		 933 if (checksum_setup(dev, skb)) {
934 kfree_skb(skb);
935 packets_dropped++;
936 dev->stats.rx_errors++;
937 continue;
0d160211
JF		 938 }
939
e00f85be 940 u64_stats_update_begin(&stats->syncp);
941 stats->rx_packets++;
942 stats->rx_bytes += skb->len;
943 u64_stats_update_end(&stats->syncp);
0d160211
JF		 944
945 /* Pass it up. */
946 netif_receive_skb(skb);
0d160211
JF		 947 }
948
949 return packets_dropped;
950}
951
bea3348e 952static int xennet_poll(struct napi_struct *napi, int budget)
0d160211 953{
bea3348e
SH		 954 struct netfront_info *np = container_of(napi, struct netfront_info, napi);
955 struct net_device *dev = np->netdev;
0d160211
JF		 956 struct sk_buff *skb;
957 struct netfront_rx_info rinfo;
958 struct xen_netif_rx_response *rx = &rinfo.rx;
959 struct xen_netif_extra_info *extras = rinfo.extras;
960 RING_IDX i, rp;
bea3348e 961 int work_done;
0d160211
JF		 962 struct sk_buff_head rxq;
963 struct sk_buff_head errq;
964 struct sk_buff_head tmpq;
965 unsigned long flags;
0d160211
JF		 966 int err;
967
968 spin_lock(&np->rx_lock);
969
0d160211
JF		 970 skb_queue_head_init(&rxq);
971 skb_queue_head_init(&errq);
972 skb_queue_head_init(&tmpq);
973
0d160211
JF		 974 rp = np->rx.sring->rsp_prod;
975 rmb(); /* Ensure we see queued responses up to 'rp'. */
976
977 i = np->rx.rsp_cons;
978 work_done = 0;
979 while ((i != rp) && (work_done < budget)) {
980 memcpy(rx, RING_GET_RESPONSE(&np->rx, i), sizeof(*rx));
981 memset(extras, 0, sizeof(rinfo.extras));
982
983 err = xennet_get_responses(np, &rinfo, rp, &tmpq);
984
985 if (unlikely(err)) {
986err:
987 while ((skb = __skb_dequeue(&tmpq)))
988 __skb_queue_tail(&errq, skb);
09f75cd7 989 dev->stats.rx_errors++;
0d160211
JF		 990 i = np->rx.rsp_cons;
991 continue;
992 }
993
994 skb = __skb_dequeue(&tmpq);
995
996 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
997 struct xen_netif_extra_info *gso;
998 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
999
1000 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1001 __skb_queue_head(&tmpq, skb);
1002 np->rx.rsp_cons += skb_queue_len(&tmpq);
1003 goto err;
1004 }
1005 }
1006
3683243b
IC		 1007 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1008 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1009 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
0d160211 1010
3683243b
IC		 1011 skb_shinfo(skb)->frags[0].page_offset = rx->offset;
1012 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1013 skb->data_len = rx->status;
0d160211
JF		 1014
1015 i = xennet_fill_frags(np, skb, &tmpq);
1016
1017 /*
1018 * Truesize approximates the size of true data plus
1019 * any supervisor overheads. Adding hypervisor
1020 * overheads has been shown to significantly reduce
1021 * achievable bandwidth with the default receive
1022 * buffer size. It is therefore not wise to account
1023 * for it here.
1024 *
1025 * After alloc_skb(RX_COPY_THRESHOLD), truesize is set
1026 * to RX_COPY_THRESHOLD + the supervisor
1027 * overheads. Here, we add the size of the data pulled
1028 * in xennet_fill_frags().
1029 *
1030 * We also adjust for any unused space in the main
1031 * data area by subtracting (RX_COPY_THRESHOLD -
1032 * len). This is especially important with drivers
1033 * which split incoming packets into header and data,
1034 * using only 66 bytes of the main data area (see the
1035 * e1000 driver for example.) On such systems,
1036 * without this last adjustement, our achievable
1037 * receive throughout using the standard receive
1038 * buffer size was cut by 25%(!!!).
1039 */
3683243b 1040 skb->truesize += skb->data_len - RX_COPY_THRESHOLD;
0d160211
JF		 1041 skb->len += skb->data_len;
1042
f942dc25 1043 if (rx->flags & XEN_NETRXF_csum_blank)
0d160211 1044 skb->ip_summed = CHECKSUM_PARTIAL;
f942dc25 1045 else if (rx->flags & XEN_NETRXF_data_validated)
0d160211
JF		 1046 skb->ip_summed = CHECKSUM_UNNECESSARY;
1047
1048 __skb_queue_tail(&rxq, skb);
1049
1050 np->rx.rsp_cons = ++i;
1051 work_done++;
1052 }
1053
56cfe5d0 1054 __skb_queue_purge(&errq);
0d160211
JF		 1055
1056 work_done -= handle_incoming_queue(dev, &rxq);
1057
1058 /* If we get a callback with very few responses, reduce fill target. */
1059 /* NB. Note exponential increase, linear decrease. */
1060 if (((np->rx.req_prod_pvt - np->rx.sring->rsp_prod) >
1061 ((3*np->rx_target) / 4)) &&
1062 (--np->rx_target < np->rx_min_target))
1063 np->rx_target = np->rx_min_target;
1064
1065 xennet_alloc_rx_buffers(dev);
1066
0d160211 1067 if (work_done < budget) {
bea3348e
SH		 1068 int more_to_do = 0;
1069
0d160211
JF		 1070 local_irq_save(flags);
1071
1072 RING_FINAL_CHECK_FOR_RESPONSES(&np->rx, more_to_do);
1073 if (!more_to_do)
288379f0 1074 __napi_complete(napi);
0d160211
JF		 1075
1076 local_irq_restore(flags);
1077 }
1078
1079 spin_unlock(&np->rx_lock);
1080
bea3348e 1081 return work_done;
0d160211
JF		 1082}
1083
1084static int xennet_change_mtu(struct net_device *dev, int mtu)
1085{
1086 int max = xennet_can_sg(dev) ? 65535 - ETH_HLEN : ETH_DATA_LEN;
1087
1088 if (mtu > max)
1089 return -EINVAL;
1090 dev->mtu = mtu;
1091 return 0;
1092}
1093
e00f85be 1094static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
1095 struct rtnl_link_stats64 *tot)
1096{
1097 struct netfront_info *np = netdev_priv(dev);
1098 int cpu;
1099
1100 for_each_possible_cpu(cpu) {
1101 struct netfront_stats *stats = per_cpu_ptr(np->stats, cpu);
1102 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1103 unsigned int start;
1104
1105 do {
1106 start = u64_stats_fetch_begin_bh(&stats->syncp);
1107
1108 rx_packets = stats->rx_packets;
1109 tx_packets = stats->tx_packets;
1110 rx_bytes = stats->rx_bytes;
1111 tx_bytes = stats->tx_bytes;
1112 } while (u64_stats_fetch_retry_bh(&stats->syncp, start));
1113
1114 tot->rx_packets += rx_packets;
1115 tot->tx_packets += tx_packets;
1116 tot->rx_bytes += rx_bytes;
1117 tot->tx_bytes += tx_bytes;
1118 }
1119
1120 tot->rx_errors = dev->stats.rx_errors;
1121 tot->tx_dropped = dev->stats.tx_dropped;
1122
1123 return tot;
1124}
1125
0d160211
JF		 1126static void xennet_release_tx_bufs(struct netfront_info *np)
1127{
1128 struct sk_buff *skb;
1129 int i;
1130
1131 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1132 /* Skip over entries which are actually freelist references */
1ffb40b8 1133 if (skb_entry_is_link(&np->tx_skbs[i]))
0d160211
JF		 1134 continue;
1135
1136 skb = np->tx_skbs[i].skb;
1137 gnttab_end_foreign_access_ref(np->grant_tx_ref[i],
1138 GNTMAP_readonly);
1139 gnttab_release_grant_reference(&np->gref_tx_head,
1140 np->grant_tx_ref[i]);
1141 np->grant_tx_ref[i] = GRANT_INVALID_REF;
1142 add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, i);
1143 dev_kfree_skb_irq(skb);
1144 }
1145}
1146
1147static void xennet_release_rx_bufs(struct netfront_info *np)
1148{
1149 struct mmu_update *mmu = np->rx_mmu;
1150 struct multicall_entry *mcl = np->rx_mcl;
1151 struct sk_buff_head free_list;
1152 struct sk_buff *skb;
1153 unsigned long mfn;
1154 int xfer = 0, noxfer = 0, unused = 0;
1155 int id, ref;
1156
1157 dev_warn(&np->netdev->dev, "%s: fix me for copying receiver.\n",
1158 __func__);
1159 return;
1160
1161 skb_queue_head_init(&free_list);
1162
1163 spin_lock_bh(&np->rx_lock);
1164
1165 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1166 ref = np->grant_rx_ref[id];
1167 if (ref == GRANT_INVALID_REF) {
1168 unused++;
1169 continue;
1170 }
1171
1172 skb = np->rx_skbs[id];
1173 mfn = gnttab_end_foreign_transfer_ref(ref);
1174 gnttab_release_grant_reference(&np->gref_rx_head, ref);
1175 np->grant_rx_ref[id] = GRANT_INVALID_REF;
1176
1177 if (0 == mfn) {
1178 skb_shinfo(skb)->nr_frags = 0;
1179 dev_kfree_skb(skb);
1180 noxfer++;
1181 continue;
1182 }
1183
1184 if (!xen_feature(XENFEAT_auto_translated_physmap)) {
1185 /* Remap the page. */
01c68026
IC		 1186 const struct page *page =
1187 skb_frag_page(&skb_shinfo(skb)->frags[0]);
0d160211
JF		 1188 unsigned long pfn = page_to_pfn(page);
1189 void *vaddr = page_address(page);
1190
1191 MULTI_update_va_mapping(mcl, (unsigned long)vaddr,
1192 mfn_pte(mfn, PAGE_KERNEL),
1193 0);
1194 mcl++;
1195 mmu->ptr = ((u64)mfn << PAGE_SHIFT)
1196 | MMU_MACHPHYS_UPDATE;
1197 mmu->val = pfn;
1198 mmu++;
1199
1200 set_phys_to_machine(pfn, mfn);
1201 }
1202 __skb_queue_tail(&free_list, skb);
1203 xfer++;
1204 }
1205
1206 dev_info(&np->netdev->dev, "%s: %d xfer, %d noxfer, %d unused\n",
1207 __func__, xfer, noxfer, unused);
1208
1209 if (xfer) {
1210 if (!xen_feature(XENFEAT_auto_translated_physmap)) {
1211 /* Do all the remapping work and M2P updates. */
1212 MULTI_mmu_update(mcl, np->rx_mmu, mmu - np->rx_mmu,
79ea13ce 1213 NULL, DOMID_SELF);
0d160211
JF		 1214 mcl++;
1215 HYPERVISOR_multicall(np->rx_mcl, mcl - np->rx_mcl);
1216 }
1217 }
1218
56cfe5d0 1219 __skb_queue_purge(&free_list);
0d160211
JF		 1220
1221 spin_unlock_bh(&np->rx_lock);
1222}
1223
1224static void xennet_uninit(struct net_device *dev)
1225{
1226 struct netfront_info *np = netdev_priv(dev);
1227 xennet_release_tx_bufs(np);
1228 xennet_release_rx_bufs(np);
1229 gnttab_free_grant_references(np->gref_tx_head);
1230 gnttab_free_grant_references(np->gref_rx_head);
1231}
1232
c8f44aff
MM		 1233static netdev_features_t xennet_fix_features(struct net_device *dev,
1234 netdev_features_t features)
8f7b01a1
ED		 1235{
1236 struct netfront_info *np = netdev_priv(dev);
1237 int val;
1238
1239 if (features & NETIF_F_SG) {
1240 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg",
1241 "%d", &val) < 0)
1242 val = 0;
1243
1244 if (!val)
1245 features &= ~NETIF_F_SG;
1246 }
1247
1248 if (features & NETIF_F_TSO) {
1249 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1250 "feature-gso-tcpv4", "%d", &val) < 0)
1251 val = 0;
1252
1253 if (!val)
1254 features &= ~NETIF_F_TSO;
1255 }
1256
1257 return features;
1258}
1259
c8f44aff
MM		 1260static int xennet_set_features(struct net_device *dev,
1261 netdev_features_t features)
8f7b01a1
ED		 1262{
1263 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1264 netdev_info(dev, "Reducing MTU because no SG offload");
1265 dev->mtu = ETH_DATA_LEN;
1266 }
1267
1268 return 0;
1269}
1270
cf66f9d4
KRW		 1271static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1272{
1273 struct net_device *dev = dev_id;
1274 struct netfront_info *np = netdev_priv(dev);
1275 unsigned long flags;
1276
1277 spin_lock_irqsave(&np->tx_lock, flags);
1278
1279 if (likely(netif_carrier_ok(dev))) {
1280 xennet_tx_buf_gc(dev);
1281 /* Under tx_lock: protects access to rx shared-ring indexes. */
1282 if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx))
1283 napi_schedule(&np->napi);
1284 }
1285
1286 spin_unlock_irqrestore(&np->tx_lock, flags);
1287
1288 return IRQ_HANDLED;
1289}
1290
1291#ifdef CONFIG_NET_POLL_CONTROLLER
1292static void xennet_poll_controller(struct net_device *dev)
1293{
1294 xennet_interrupt(0, dev);
1295}
1296#endif
1297
0a0b9d2e
SH		 1298static const struct net_device_ops xennet_netdev_ops = {
1299 .ndo_open = xennet_open,
1300 .ndo_uninit = xennet_uninit,
1301 .ndo_stop = xennet_close,
1302 .ndo_start_xmit = xennet_start_xmit,
1303 .ndo_change_mtu = xennet_change_mtu,
e00f85be 1304 .ndo_get_stats64 = xennet_get_stats64,
0a0b9d2e
SH		 1305 .ndo_set_mac_address = eth_mac_addr,
1306 .ndo_validate_addr = eth_validate_addr,
fb507934
MM		 1307 .ndo_fix_features = xennet_fix_features,
1308 .ndo_set_features = xennet_set_features,
cf66f9d4
KRW		 1309#ifdef CONFIG_NET_POLL_CONTROLLER
1310 .ndo_poll_controller = xennet_poll_controller,
1311#endif
0a0b9d2e
SH		 1312};
1313
0d160211
JF		 1314static struct net_device * __devinit xennet_create_dev(struct xenbus_device *dev)
1315{
1316 int i, err;
1317 struct net_device *netdev;
1318 struct netfront_info *np;
1319
1320 netdev = alloc_etherdev(sizeof(struct netfront_info));
41de8d4c 1321 if (!netdev)
0d160211 1322 return ERR_PTR(-ENOMEM);
0d160211
JF		 1323
1324 np = netdev_priv(netdev);
1325 np->xbdev = dev;
1326
1327 spin_lock_init(&np->tx_lock);
1328 spin_lock_init(&np->rx_lock);
1329
1330 skb_queue_head_init(&np->rx_batch);
1331 np->rx_target = RX_DFL_MIN_TARGET;
1332 np->rx_min_target = RX_DFL_MIN_TARGET;
1333 np->rx_max_target = RX_MAX_TARGET;
1334
1335 init_timer(&np->rx_refill_timer);
1336 np->rx_refill_timer.data = (unsigned long)netdev;
1337 np->rx_refill_timer.function = rx_refill_timeout;
1338
e00f85be 1339 err = -ENOMEM;
1340 np->stats = alloc_percpu(struct netfront_stats);
1341 if (np->stats == NULL)
1342 goto exit;
1343
0d160211
JF		 1344 /* Initialise tx_skbs as a free chain containing every entry. */
1345 np->tx_skb_freelist = 0;
1346 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1ffb40b8 1347 skb_entry_set_link(&np->tx_skbs[i], i+1);
0d160211
JF		 1348 np->grant_tx_ref[i] = GRANT_INVALID_REF;
1349 }
1350
1351 /* Clear out rx_skbs */
1352 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1353 np->rx_skbs[i] = NULL;
1354 np->grant_rx_ref[i] = GRANT_INVALID_REF;
1355 }
1356
1357 /* A grant for every tx ring slot */
1358 if (gnttab_alloc_grant_references(TX_MAX_TARGET,
1359 &np->gref_tx_head) < 0) {
1360 printk(KERN_ALERT "#### netfront can't alloc tx grant refs\n");
1361 err = -ENOMEM;
e00f85be 1362 goto exit_free_stats;
0d160211
JF		 1363 }
1364 /* A grant for every rx ring slot */
1365 if (gnttab_alloc_grant_references(RX_MAX_TARGET,
1366 &np->gref_rx_head) < 0) {
1367 printk(KERN_ALERT "#### netfront can't alloc rx grant refs\n");
1368 err = -ENOMEM;
1369 goto exit_free_tx;
1370 }
1371
0a0b9d2e
SH		 1372 netdev->netdev_ops = &xennet_netdev_ops;
1373
bea3348e 1374 netif_napi_add(netdev, &np->napi, xennet_poll, 64);
fb507934
MM		 1375 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1376 NETIF_F_GSO_ROBUST;
1377 netdev->hw_features = NETIF_F_IP_CSUM | NETIF_F_SG | NETIF_F_TSO;
0d160211 1378
fc3e5941
IC		 1379 /*
1380 * Assume that all hw features are available for now. This set
1381 * will be adjusted by the call to netdev_update_features() in
1382 * xennet_connect() which is the earliest point where we can
1383 * negotiate with the backend regarding supported features.
1384 */
1385 netdev->features |= netdev->hw_features;
1386
0d160211 1387 SET_ETHTOOL_OPS(netdev, &xennet_ethtool_ops);
0d160211
JF		 1388 SET_NETDEV_DEV(netdev, &dev->dev);
1389
1390 np->netdev = netdev;
1391
1392 netif_carrier_off(netdev);
1393
1394 return netdev;
1395
1396 exit_free_tx:
1397 gnttab_free_grant_references(np->gref_tx_head);
e00f85be 1398 exit_free_stats:
1399 free_percpu(np->stats);
0d160211
JF		 1400 exit:
1401 free_netdev(netdev);
1402 return ERR_PTR(err);
1403}
1404
1405/**
1406 * Entry point to this code when a new device is created. Allocate the basic
1407 * structures and the ring buffers for communication with the backend, and
1408 * inform the backend of the appropriate details for those.
1409 */
1410static int __devinit netfront_probe(struct xenbus_device *dev,
1411 const struct xenbus_device_id *id)
1412{
1413 int err;
1414 struct net_device *netdev;
1415 struct netfront_info *info;
1416
1417 netdev = xennet_create_dev(dev);
1418 if (IS_ERR(netdev)) {
1419 err = PTR_ERR(netdev);
1420 xenbus_dev_fatal(dev, err, "creating netdev");
1421 return err;
1422 }
1423
1424 info = netdev_priv(netdev);
1b713e00 1425 dev_set_drvdata(&dev->dev, info);
0d160211
JF		 1426
1427 err = register_netdev(info->netdev);
1428 if (err) {
1429 printk(KERN_WARNING "%s: register_netdev err=%d\n",
1430 __func__, err);
1431 goto fail;
1432 }
1433
1434 err = xennet_sysfs_addif(info->netdev);
1435 if (err) {
1436 unregister_netdev(info->netdev);
1437 printk(KERN_WARNING "%s: add sysfs failed err=%d\n",
1438 __func__, err);
1439 goto fail;
1440 }
1441
1442 return 0;
1443
1444 fail:
1445 free_netdev(netdev);
1b713e00 1446 dev_set_drvdata(&dev->dev, NULL);
0d160211
JF		 1447 return err;
1448}
1449
1450static void xennet_end_access(int ref, void *page)
1451{
1452 /* This frees the page as a side-effect */
1453 if (ref != GRANT_INVALID_REF)
1454 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1455}
1456
1457static void xennet_disconnect_backend(struct netfront_info *info)
1458{
1459 /* Stop old i/f to prevent errors whilst we rebuild the state. */
1460 spin_lock_bh(&info->rx_lock);
1461 spin_lock_irq(&info->tx_lock);
1462 netif_carrier_off(info->netdev);
1463 spin_unlock_irq(&info->tx_lock);
1464 spin_unlock_bh(&info->rx_lock);
1465
1466 if (info->netdev->irq)
1467 unbind_from_irqhandler(info->netdev->irq, info->netdev);
1468 info->evtchn = info->netdev->irq = 0;
1469
1470 /* End access and free the pages */
1471 xennet_end_access(info->tx_ring_ref, info->tx.sring);
1472 xennet_end_access(info->rx_ring_ref, info->rx.sring);
1473
1474 info->tx_ring_ref = GRANT_INVALID_REF;
1475 info->rx_ring_ref = GRANT_INVALID_REF;
1476 info->tx.sring = NULL;
1477 info->rx.sring = NULL;
1478}
1479
1480/**
1481 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1482 * driver restart. We tear down our netif structure and recreate it, but
1483 * leave the device-layer structures intact so that this is transparent to the
1484 * rest of the kernel.
1485 */
1486static int netfront_resume(struct xenbus_device *dev)
1487{
1b713e00 1488 struct netfront_info *info = dev_get_drvdata(&dev->dev);
0d160211
JF		 1489
1490 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1491
1492 xennet_disconnect_backend(info);
1493 return 0;
1494}
1495
1496static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1497{
1498 char *s, *e, *macstr;
1499 int i;
1500
1501 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1502 if (IS_ERR(macstr))
1503 return PTR_ERR(macstr);
1504
1505 for (i = 0; i < ETH_ALEN; i++) {
1506 mac[i] = simple_strtoul(s, &e, 16);
1507 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1508 kfree(macstr);
1509 return -ENOENT;
1510 }
1511 s = e+1;
1512 }
1513
1514 kfree(macstr);
1515 return 0;
1516}
1517
0d160211
JF		 1518static int setup_netfront(struct xenbus_device *dev, struct netfront_info *info)
1519{
1520 struct xen_netif_tx_sring *txs;
1521 struct xen_netif_rx_sring *rxs;
1522 int err;
1523 struct net_device *netdev = info->netdev;
1524
1525 info->tx_ring_ref = GRANT_INVALID_REF;
1526 info->rx_ring_ref = GRANT_INVALID_REF;
1527 info->rx.sring = NULL;
1528 info->tx.sring = NULL;
1529 netdev->irq = 0;
1530
1531 err = xen_net_read_mac(dev, netdev->dev_addr);
1532 if (err) {
1533 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1534 goto fail;
1535 }
1536
a144ff09 1537 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
0d160211
JF		 1538 if (!txs) {
1539 err = -ENOMEM;
1540 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1541 goto fail;
1542 }
1543 SHARED_RING_INIT(txs);
1544 FRONT_RING_INIT(&info->tx, txs, PAGE_SIZE);
1545
1546 err = xenbus_grant_ring(dev, virt_to_mfn(txs));
1547 if (err < 0) {
1548 free_page((unsigned long)txs);
1549 goto fail;
1550 }
1551
1552 info->tx_ring_ref = err;
a144ff09 1553 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
0d160211
JF		 1554 if (!rxs) {
1555 err = -ENOMEM;
1556 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1557 goto fail;
1558 }
1559 SHARED_RING_INIT(rxs);
1560 FRONT_RING_INIT(&info->rx, rxs, PAGE_SIZE);
1561
1562 err = xenbus_grant_ring(dev, virt_to_mfn(rxs));
1563 if (err < 0) {
1564 free_page((unsigned long)rxs);
1565 goto fail;
1566 }
1567 info->rx_ring_ref = err;
1568
1569 err = xenbus_alloc_evtchn(dev, &info->evtchn);
1570 if (err)
1571 goto fail;
1572
1573 err = bind_evtchn_to_irqhandler(info->evtchn, xennet_interrupt,
ab392d2d 1574 0, netdev->name, netdev);
0d160211
JF		 1575 if (err < 0)
1576 goto fail;
1577 netdev->irq = err;
1578 return 0;
1579
1580 fail:
1581 return err;
1582}
1583
1584/* Common code used when first setting up, and when resuming. */
f502bf2b 1585static int talk_to_netback(struct xenbus_device *dev,
0d160211
JF		 1586 struct netfront_info *info)
1587{
1588 const char *message;
1589 struct xenbus_transaction xbt;
1590 int err;
1591
1592 /* Create shared ring, alloc event channel. */
1593 err = setup_netfront(dev, info);
1594 if (err)
1595 goto out;
1596
1597again:
1598 err = xenbus_transaction_start(&xbt);
1599 if (err) {
1600 xenbus_dev_fatal(dev, err, "starting transaction");
1601 goto destroy_ring;
1602 }
1603
1604 err = xenbus_printf(xbt, dev->nodename, "tx-ring-ref", "%u",
1605 info->tx_ring_ref);
1606 if (err) {
1607 message = "writing tx ring-ref";
1608 goto abort_transaction;
1609 }
1610 err = xenbus_printf(xbt, dev->nodename, "rx-ring-ref", "%u",
1611 info->rx_ring_ref);
1612 if (err) {
1613 message = "writing rx ring-ref";
1614 goto abort_transaction;
1615 }
1616 err = xenbus_printf(xbt, dev->nodename,
1617 "event-channel", "%u", info->evtchn);
1618 if (err) {
1619 message = "writing event-channel";
1620 goto abort_transaction;
1621 }
1622
1623 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
1624 1);
1625 if (err) {
1626 message = "writing request-rx-copy";
1627 goto abort_transaction;
1628 }
1629
1630 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
1631 if (err) {
1632 message = "writing feature-rx-notify";
1633 goto abort_transaction;
1634 }
1635
1636 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
1637 if (err) {
1638 message = "writing feature-sg";
1639 goto abort_transaction;
1640 }
1641
1642 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
1643 if (err) {
1644 message = "writing feature-gso-tcpv4";
1645 goto abort_transaction;
1646 }
1647
1648 err = xenbus_transaction_end(xbt, 0);
1649 if (err) {
1650 if (err == -EAGAIN)
1651 goto again;
1652 xenbus_dev_fatal(dev, err, "completing transaction");
1653 goto destroy_ring;
1654 }
1655
1656 return 0;
1657
1658 abort_transaction:
1659 xenbus_transaction_end(xbt, 1);
1660 xenbus_dev_fatal(dev, err, "%s", message);
1661 destroy_ring:
1662 xennet_disconnect_backend(info);
1663 out:
1664 return err;
1665}
1666
0d160211
JF		 1667static int xennet_connect(struct net_device *dev)
1668{
1669 struct netfront_info *np = netdev_priv(dev);
1670 int i, requeue_idx, err;
1671 struct sk_buff *skb;
1672 grant_ref_t ref;
1673 struct xen_netif_rx_request *req;
1674 unsigned int feature_rx_copy;
1675
1676 err = xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1677 "feature-rx-copy", "%u", &feature_rx_copy);
1678 if (err != 1)
1679 feature_rx_copy = 0;
1680
1681 if (!feature_rx_copy) {
1682 dev_info(&dev->dev,
898eb71c 1683 "backend does not support copying receive path\n");
0d160211
JF		 1684 return -ENODEV;
1685 }
1686
f502bf2b 1687 err = talk_to_netback(np->xbdev, np);
0d160211
JF		 1688 if (err)
1689 return err;
1690
1ba37c51 1691 rtnl_lock();
fb507934 1692 netdev_update_features(dev);
1ba37c51 1693 rtnl_unlock();
0d160211
JF		 1694
1695 spin_lock_bh(&np->rx_lock);
1696 spin_lock_irq(&np->tx_lock);
1697
1698 /* Step 1: Discard all pending TX packet fragments. */
1699 xennet_release_tx_bufs(np);
1700
1701 /* Step 2: Rebuild the RX buffer freelist and the RX ring itself. */
1702 for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) {
01c68026
IC		 1703 skb_frag_t *frag;
1704 const struct page *page;
0d160211
JF		 1705 if (!np->rx_skbs[i])
1706 continue;
1707
1708 skb = np->rx_skbs[requeue_idx] = xennet_get_rx_skb(np, i);
1709 ref = np->grant_rx_ref[requeue_idx] = xennet_get_rx_ref(np, i);
1710 req = RING_GET_REQUEST(&np->rx, requeue_idx);
1711
01c68026
IC		 1712 frag = &skb_shinfo(skb)->frags[0];
1713 page = skb_frag_page(frag);
0d160211
JF		 1714 gnttab_grant_foreign_access_ref(
1715 ref, np->xbdev->otherend_id,
01c68026 1716 pfn_to_mfn(page_to_pfn(page)),
0d160211
JF		 1717 0);
1718 req->gref = ref;
1719 req->id = requeue_idx;
1720
1721 requeue_idx++;
1722 }
1723
1724 np->rx.req_prod_pvt = requeue_idx;
1725
1726 /*
1727 * Step 3: All public and private state should now be sane. Get
1728 * ready to start sending and receiving packets and give the driver
1729 * domain a kick because we've probably just requeued some
1730 * packets.
1731 */
1732 netif_carrier_on(np->netdev);
1733 notify_remote_via_irq(np->netdev->irq);
1734 xennet_tx_buf_gc(dev);
1735 xennet_alloc_rx_buffers(dev);
1736
1737 spin_unlock_irq(&np->tx_lock);
1738 spin_unlock_bh(&np->rx_lock);
1739
1740 return 0;
1741}
1742
1743/**
1744 * Callback received when the backend's state changes.
1745 */
f502bf2b 1746static void netback_changed(struct xenbus_device *dev,
0d160211
JF		 1747 enum xenbus_state backend_state)
1748{
1b713e00 1749 struct netfront_info *np = dev_get_drvdata(&dev->dev);
0d160211
JF		 1750 struct net_device *netdev = np->netdev;
1751
1752 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
1753
1754 switch (backend_state) {
1755 case XenbusStateInitialising:
1756 case XenbusStateInitialised:
b78c9512
NI		 1757 case XenbusStateReconfiguring:
1758 case XenbusStateReconfigured:
0d160211
JF		 1759 case XenbusStateUnknown:
1760 case XenbusStateClosed:
1761 break;
1762
1763 case XenbusStateInitWait:
1764 if (dev->state != XenbusStateInitialising)
1765 break;
1766 if (xennet_connect(netdev) != 0)
1767 break;
1768 xenbus_switch_state(dev, XenbusStateConnected);
08e34eb1
LE		 1769 break;
1770
1771 case XenbusStateConnected:
ee89bab1 1772 netdev_notify_peers(netdev);
0d160211
JF		 1773 break;
1774
1775 case XenbusStateClosing:
1776 xenbus_frontend_closed(dev);
1777 break;
1778 }
1779}
1780
e0ce4af9
IC		 1781static const struct xennet_stat {
1782 char name[ETH_GSTRING_LEN];
1783 u16 offset;
1784} xennet_stats[] = {
1785 {
1786 "rx_gso_checksum_fixup",
1787 offsetof(struct netfront_info, rx_gso_checksum_fixup)
1788 },
1789};
1790
1791static int xennet_get_sset_count(struct net_device *dev, int string_set)
1792{
1793 switch (string_set) {
1794 case ETH_SS_STATS:
1795 return ARRAY_SIZE(xennet_stats);
1796 default:
1797 return -EINVAL;
1798 }
1799}
1800
1801static void xennet_get_ethtool_stats(struct net_device *dev,
1802 struct ethtool_stats *stats, u64 * data)
1803{
1804 void *np = netdev_priv(dev);
1805 int i;
1806
1807 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
48f26d51 1808 data[i] = *(unsigned long *)(np + xennet_stats[i].offset);
e0ce4af9
IC		 1809}
1810
1811static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
1812{
1813 int i;
1814
1815 switch (stringset) {
1816 case ETH_SS_STATS:
1817 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
1818 memcpy(data + i * ETH_GSTRING_LEN,
1819 xennet_stats[i].name, ETH_GSTRING_LEN);
1820 break;
1821 }
1822}
1823
0fc0b732 1824static const struct ethtool_ops xennet_ethtool_ops =
0d160211 1825{
0d160211 1826 .get_link = ethtool_op_get_link,
e0ce4af9
IC		 1827
1828 .get_sset_count = xennet_get_sset_count,
1829 .get_ethtool_stats = xennet_get_ethtool_stats,
1830 .get_strings = xennet_get_strings,
0d160211
JF		 1831};
1832
1833#ifdef CONFIG_SYSFS
1834static ssize_t show_rxbuf_min(struct device *dev,
1835 struct device_attribute *attr, char *buf)
1836{
1837 struct net_device *netdev = to_net_dev(dev);
1838 struct netfront_info *info = netdev_priv(netdev);
1839
1840 return sprintf(buf, "%u\n", info->rx_min_target);
1841}
1842
1843static ssize_t store_rxbuf_min(struct device *dev,
1844 struct device_attribute *attr,
1845 const char *buf, size_t len)
1846{
1847 struct net_device *netdev = to_net_dev(dev);
1848 struct netfront_info *np = netdev_priv(netdev);
1849 char *endp;
1850 unsigned long target;
1851
1852 if (!capable(CAP_NET_ADMIN))
1853 return -EPERM;
1854
1855 target = simple_strtoul(buf, &endp, 0);
1856 if (endp == buf)
1857 return -EBADMSG;
1858
1859 if (target < RX_MIN_TARGET)
1860 target = RX_MIN_TARGET;
1861 if (target > RX_MAX_TARGET)
1862 target = RX_MAX_TARGET;
1863
1864 spin_lock_bh(&np->rx_lock);
1865 if (target > np->rx_max_target)
1866 np->rx_max_target = target;
1867 np->rx_min_target = target;
1868 if (target > np->rx_target)
1869 np->rx_target = target;
1870
1871 xennet_alloc_rx_buffers(netdev);
1872
1873 spin_unlock_bh(&np->rx_lock);
1874 return len;
1875}
1876
1877static ssize_t show_rxbuf_max(struct device *dev,
1878 struct device_attribute *attr, char *buf)
1879{
1880 struct net_device *netdev = to_net_dev(dev);
1881 struct netfront_info *info = netdev_priv(netdev);
1882
1883 return sprintf(buf, "%u\n", info->rx_max_target);
1884}
1885
1886static ssize_t store_rxbuf_max(struct device *dev,
1887 struct device_attribute *attr,
1888 const char *buf, size_t len)
1889{
1890 struct net_device *netdev = to_net_dev(dev);
1891 struct netfront_info *np = netdev_priv(netdev);
1892 char *endp;
1893 unsigned long target;
1894
1895 if (!capable(CAP_NET_ADMIN))
1896 return -EPERM;
1897
1898 target = simple_strtoul(buf, &endp, 0);
1899 if (endp == buf)
1900 return -EBADMSG;
1901
1902 if (target < RX_MIN_TARGET)
1903 target = RX_MIN_TARGET;
1904 if (target > RX_MAX_TARGET)
1905 target = RX_MAX_TARGET;
1906
1907 spin_lock_bh(&np->rx_lock);
1908 if (target < np->rx_min_target)
1909 np->rx_min_target = target;
1910 np->rx_max_target = target;
1911 if (target < np->rx_target)
1912 np->rx_target = target;
1913
1914 xennet_alloc_rx_buffers(netdev);
1915
1916 spin_unlock_bh(&np->rx_lock);
1917 return len;
1918}
1919
1920static ssize_t show_rxbuf_cur(struct device *dev,
1921 struct device_attribute *attr, char *buf)
1922{
1923 struct net_device *netdev = to_net_dev(dev);
1924 struct netfront_info *info = netdev_priv(netdev);
1925
1926 return sprintf(buf, "%u\n", info->rx_target);
1927}
1928
1929static struct device_attribute xennet_attrs[] = {
1930 __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf_min, store_rxbuf_min),
1931 __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf_max, store_rxbuf_max),
1932 __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf_cur, NULL),
1933};
1934
1935static int xennet_sysfs_addif(struct net_device *netdev)
1936{
1937 int i;
1938 int err;
1939
1940 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) {
1941 err = device_create_file(&netdev->dev,
1942 &xennet_attrs[i]);
1943 if (err)
1944 goto fail;
1945 }
1946 return 0;
1947
1948 fail:
1949 while (--i >= 0)
1950 device_remove_file(&netdev->dev, &xennet_attrs[i]);
1951 return err;
1952}
1953
1954static void xennet_sysfs_delif(struct net_device *netdev)
1955{
1956 int i;
1957
1958 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++)
1959 device_remove_file(&netdev->dev, &xennet_attrs[i]);
1960}
1961
1962#endif /* CONFIG_SYSFS */
1963
73db144b 1964static const struct xenbus_device_id netfront_ids[] = {
0d160211
JF		 1965 { "vif" },
1966 { "" }
1967};
1968
1969
1970static int __devexit xennet_remove(struct xenbus_device *dev)
1971{
1b713e00 1972 struct netfront_info *info = dev_get_drvdata(&dev->dev);
0d160211
JF		 1973
1974 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1975
0d160211
JF		 1976 xennet_disconnect_backend(info);
1977
0d160211
JF		 1978 xennet_sysfs_delif(info->netdev);
1979
6bc96d04
IC		 1980 unregister_netdev(info->netdev);
1981
1982 del_timer_sync(&info->rx_refill_timer);
1983
e00f85be 1984 free_percpu(info->stats);
1985
0d160211
JF		 1986 free_netdev(info->netdev);
1987
1988 return 0;
1989}
1990
73db144b 1991static DEFINE_XENBUS_DRIVER(netfront, ,
0d160211
JF		 1992 .probe = netfront_probe,
1993 .remove = __devexit_p(xennet_remove),
1994 .resume = netfront_resume,
f502bf2b 1995 .otherend_changed = netback_changed,
73db144b 1996);
0d160211
JF		 1997
1998static int __init netif_init(void)
1999{
6e833587 2000 if (!xen_domain())
0d160211
JF		 2001 return -ENODEV;
2002
e95ae5a4 2003 if (xen_hvm_domain() && !xen_platform_pci_unplug)
b9136d20
IM		 2004 return -ENODEV;
2005
0d160211
JF		 2006 printk(KERN_INFO "Initialising Xen virtual ethernet driver.\n");
2007
ffb78a26 2008 return xenbus_register_frontend(&netfront_driver);
0d160211
JF		 2009}
2010module_init(netif_init);
2011
2012
2013static void __exit netif_exit(void)
2014{
ffb78a26 2015 xenbus_unregister_driver(&netfront_driver);
0d160211
JF		 2016}
2017module_exit(netif_exit);
2018
2019MODULE_DESCRIPTION("Xen virtual network device frontend");
2020MODULE_LICENSE("GPL");
d2f0c52b 2021MODULE_ALIAS("xen:vif");
4f93f09b 2022MODULE_ALIAS("xennet");
Linux kernel - Deliverables
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