2 * Virtual network driver for conversing with remote driver backends.
4 * Copyright (c) 2002-2005, K A Fraser
5 * Copyright (c) 2005, XenSource Ltd
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:
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:
20 * The above copyright notice and this permission notice shall be included in
21 * all copies or substantial portions of the Software.
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
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>
40 #include <linux/udp.h>
41 #include <linux/moduleparam.h>
43 #include <linux/slab.h>
46 #include <asm/xen/page.h>
48 #include <xen/xenbus.h>
49 #include <xen/events.h>
51 #include <xen/platform_pci.h>
52 #include <xen/grant_table.h>
54 #include <xen/interface/io/netif.h>
55 #include <xen/interface/memory.h>
56 #include <xen/interface/grant_table.h>
58 static const struct ethtool_ops xennet_ethtool_ops;
64 #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
66 #define RX_COPY_THRESHOLD 256
68 #define GRANT_INVALID_REF 0
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)
72 #define TX_MAX_TARGET min_t(int, NET_TX_RING_SIZE, 256)
74 struct netfront_stats {
79 struct u64_stats_sync syncp;
82 struct netfront_info {
83 struct list_head list;
84 struct net_device *netdev;
86 struct napi_struct napi;
89 struct xenbus_device *xbdev;
92 struct xen_netif_tx_front_ring tx;
96 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
97 * are linked from tx_skb_freelist through skb_entry.link.
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
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;
112 spinlock_t rx_lock ____cacheline_aligned_in_smp;
113 struct xen_netif_rx_front_ring rx;
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;
123 struct timer_list rx_refill_timer;
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];
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];
134 struct netfront_stats __percpu *stats;
136 unsigned long rx_gso_checksum_fixup;
139 struct netfront_rx_info {
140 struct xen_netif_rx_response rx;
141 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
144 static void skb_entry_set_link(union skb_entry *list, unsigned short id)
149 static int skb_entry_is_link(const union skb_entry *list)
151 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
152 return (unsigned long)list->skb < PAGE_OFFSET;
156 * Access macros for acquiring freeing slots in tx_skbs[].
159 static void add_id_to_freelist(unsigned *head, union skb_entry *list,
162 skb_entry_set_link(&list[id], *head);
166 static unsigned short get_id_from_freelist(unsigned *head,
167 union skb_entry *list)
169 unsigned int id = *head;
170 *head = list[id].link;
174 static int xennet_rxidx(RING_IDX idx)
176 return idx & (NET_RX_RING_SIZE - 1);
179 static struct sk_buff *xennet_get_rx_skb(struct netfront_info *np,
182 int i = xennet_rxidx(ri);
183 struct sk_buff *skb = np->rx_skbs[i];
184 np->rx_skbs[i] = NULL;
188 static grant_ref_t xennet_get_rx_ref(struct netfront_info *np,
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;
198 static int xennet_sysfs_addif(struct net_device *netdev);
199 static 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)
205 static bool xennet_can_sg(struct net_device *dev)
207 return dev->features & NETIF_F_SG;
211 static void rx_refill_timeout(unsigned long data)
213 struct net_device *dev = (struct net_device *)data;
214 struct netfront_info *np = netdev_priv(dev);
215 napi_schedule(&np->napi);
218 static int netfront_tx_slot_available(struct netfront_info *np)
220 return (np->tx.req_prod_pvt - np->tx.rsp_cons) <
221 (TX_MAX_TARGET - MAX_SKB_FRAGS - 2);
224 static void xennet_maybe_wake_tx(struct net_device *dev)
226 struct netfront_info *np = netdev_priv(dev);
228 if (unlikely(netif_queue_stopped(dev)) &&
229 netfront_tx_slot_available(np) &&
230 likely(netif_running(dev)))
231 netif_wake_queue(dev);
234 static void xennet_alloc_rx_buffers(struct net_device *dev)
237 struct netfront_info *np = netdev_priv(dev);
240 int i, batch_target, notify;
241 RING_IDX req_prod = np->rx.req_prod_pvt;
245 struct xen_netif_rx_request *req;
247 if (unlikely(!netif_carrier_ok(dev)))
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.
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++) {
258 skb = __netdev_alloc_skb(dev, RX_COPY_THRESHOLD + NET_IP_ALIGN,
259 GFP_ATOMIC | __GFP_NOWARN);
263 /* Align ip header to a 16 bytes boundary */
264 skb_reserve(skb, NET_IP_ALIGN);
266 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
270 /* Any skbuffs queued for refill? Force them out. */
273 /* Could not allocate any skbuffs. Try again later. */
274 mod_timer(&np->rx_refill_timer,
279 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
280 __skb_queue_tail(&np->rx_batch, skb);
283 /* Is the batch large enough to be worthwhile? */
284 if (i < (np->rx_target/2)) {
285 if (req_prod > np->rx.sring->req_prod)
290 /* Adjust our fill target if we risked running out of buffers. */
291 if (((req_prod - np->rx.sring->rsp_prod) < (np->rx_target / 4)) &&
292 ((np->rx_target *= 2) > np->rx_max_target))
293 np->rx_target = np->rx_max_target;
297 skb = __skb_dequeue(&np->rx_batch);
303 id = xennet_rxidx(req_prod + i);
305 BUG_ON(np->rx_skbs[id]);
306 np->rx_skbs[id] = skb;
308 ref = gnttab_claim_grant_reference(&np->gref_rx_head);
309 BUG_ON((signed short)ref < 0);
310 np->grant_rx_ref[id] = ref;
312 pfn = page_to_pfn(skb_frag_page(&skb_shinfo(skb)->frags[0]));
313 vaddr = page_address(skb_frag_page(&skb_shinfo(skb)->frags[0]));
315 req = RING_GET_REQUEST(&np->rx, req_prod + i);
316 gnttab_grant_foreign_access_ref(ref,
317 np->xbdev->otherend_id,
325 wmb(); /* barrier so backend seens requests */
327 /* Above is a suitable barrier to ensure backend will see requests. */
328 np->rx.req_prod_pvt = req_prod + i;
330 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->rx, notify);
332 notify_remote_via_irq(np->netdev->irq);
335 static int xennet_open(struct net_device *dev)
337 struct netfront_info *np = netdev_priv(dev);
339 napi_enable(&np->napi);
341 spin_lock_bh(&np->rx_lock);
342 if (netif_carrier_ok(dev)) {
343 xennet_alloc_rx_buffers(dev);
344 np->rx.sring->rsp_event = np->rx.rsp_cons + 1;
345 if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx))
346 napi_schedule(&np->napi);
348 spin_unlock_bh(&np->rx_lock);
350 netif_start_queue(dev);
355 static void xennet_tx_buf_gc(struct net_device *dev)
359 struct netfront_info *np = netdev_priv(dev);
362 BUG_ON(!netif_carrier_ok(dev));
365 prod = np->tx.sring->rsp_prod;
366 rmb(); /* Ensure we see responses up to 'rp'. */
368 for (cons = np->tx.rsp_cons; cons != prod; cons++) {
369 struct xen_netif_tx_response *txrsp;
371 txrsp = RING_GET_RESPONSE(&np->tx, cons);
372 if (txrsp->status == XEN_NETIF_RSP_NULL)
376 skb = np->tx_skbs[id].skb;
377 if (unlikely(gnttab_query_foreign_access(
378 np->grant_tx_ref[id]) != 0)) {
379 printk(KERN_ALERT "xennet_tx_buf_gc: warning "
380 "-- grant still in use by backend "
384 gnttab_end_foreign_access_ref(
385 np->grant_tx_ref[id], GNTMAP_readonly);
386 gnttab_release_grant_reference(
387 &np->gref_tx_head, np->grant_tx_ref[id]);
388 np->grant_tx_ref[id] = GRANT_INVALID_REF;
389 add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, id);
390 dev_kfree_skb_irq(skb);
393 np->tx.rsp_cons = prod;
396 * Set a new event, then check for race with update of tx_cons.
397 * Note that it is essential to schedule a callback, no matter
398 * how few buffers are pending. Even if there is space in the
399 * transmit ring, higher layers may be blocked because too much
400 * data is outstanding: in such cases notification from Xen is
401 * likely to be the only kick that we'll get.
403 np->tx.sring->rsp_event =
404 prod + ((np->tx.sring->req_prod - prod) >> 1) + 1;
405 mb(); /* update shared area */
406 } while ((cons == prod) && (prod != np->tx.sring->rsp_prod));
408 xennet_maybe_wake_tx(dev);
411 static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev,
412 struct xen_netif_tx_request *tx)
414 struct netfront_info *np = netdev_priv(dev);
415 char *data = skb->data;
417 RING_IDX prod = np->tx.req_prod_pvt;
418 int frags = skb_shinfo(skb)->nr_frags;
419 unsigned int offset = offset_in_page(data);
420 unsigned int len = skb_headlen(skb);
425 /* While the header overlaps a page boundary (including being
426 larger than a page), split it it into page-sized chunks. */
427 while (len > PAGE_SIZE - offset) {
428 tx->size = PAGE_SIZE - offset;
429 tx->flags |= XEN_NETTXF_more_data;
434 id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
435 np->tx_skbs[id].skb = skb_get(skb);
436 tx = RING_GET_REQUEST(&np->tx, prod++);
438 ref = gnttab_claim_grant_reference(&np->gref_tx_head);
439 BUG_ON((signed short)ref < 0);
441 mfn = virt_to_mfn(data);
442 gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id,
443 mfn, GNTMAP_readonly);
445 tx->gref = np->grant_tx_ref[id] = ref;
451 /* Grant backend access to each skb fragment page. */
452 for (i = 0; i < frags; i++) {
453 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
454 struct page *page = skb_frag_page(frag);
456 len = skb_frag_size(frag);
457 offset = frag->page_offset;
459 /* Data must not cross a page boundary. */
460 BUG_ON(len + offset > PAGE_SIZE<<compound_order(page));
462 /* Skip unused frames from start of page */
463 page += offset >> PAGE_SHIFT;
464 offset &= ~PAGE_MASK;
469 BUG_ON(offset >= PAGE_SIZE);
471 bytes = PAGE_SIZE - offset;
475 tx->flags |= XEN_NETTXF_more_data;
477 id = get_id_from_freelist(&np->tx_skb_freelist,
479 np->tx_skbs[id].skb = skb_get(skb);
480 tx = RING_GET_REQUEST(&np->tx, prod++);
482 ref = gnttab_claim_grant_reference(&np->gref_tx_head);
483 BUG_ON((signed short)ref < 0);
485 mfn = pfn_to_mfn(page_to_pfn(page));
486 gnttab_grant_foreign_access_ref(ref,
487 np->xbdev->otherend_id,
488 mfn, GNTMAP_readonly);
490 tx->gref = np->grant_tx_ref[id] = ref;
499 if (offset == PAGE_SIZE && len) {
500 BUG_ON(!PageCompound(page));
507 np->tx.req_prod_pvt = prod;
511 * Count how many ring slots are required to send the frags of this
512 * skb. Each frag might be a compound page.
514 static int xennet_count_skb_frag_slots(struct sk_buff *skb)
516 int i, frags = skb_shinfo(skb)->nr_frags;
519 for (i = 0; i < frags; i++) {
520 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
521 unsigned long size = skb_frag_size(frag);
522 unsigned long offset = frag->page_offset;
524 /* Skip unused frames from start of page */
525 offset &= ~PAGE_MASK;
527 pages += PFN_UP(offset + size);
533 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
536 struct netfront_info *np = netdev_priv(dev);
537 struct netfront_stats *stats = this_cpu_ptr(np->stats);
538 struct xen_netif_tx_request *tx;
539 char *data = skb->data;
545 unsigned int offset = offset_in_page(data);
546 unsigned int len = skb_headlen(skb);
549 /* If skb->len is too big for wire format, drop skb and alert
550 * user about misconfiguration.
552 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
553 net_alert_ratelimited(
554 "xennet: skb->len = %u, too big for wire format\n",
559 slots = DIV_ROUND_UP(offset + len, PAGE_SIZE) +
560 xennet_count_skb_frag_slots(skb);
561 if (unlikely(slots > MAX_SKB_FRAGS + 1)) {
562 net_alert_ratelimited(
563 "xennet: skb rides the rocket: %d slots\n", slots);
567 spin_lock_irqsave(&np->tx_lock, flags);
569 if (unlikely(!netif_carrier_ok(dev) ||
570 (slots > 1 && !xennet_can_sg(dev)) ||
571 netif_needs_gso(skb, netif_skb_features(skb)))) {
572 spin_unlock_irqrestore(&np->tx_lock, flags);
576 i = np->tx.req_prod_pvt;
578 id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
579 np->tx_skbs[id].skb = skb;
581 tx = RING_GET_REQUEST(&np->tx, i);
584 ref = gnttab_claim_grant_reference(&np->gref_tx_head);
585 BUG_ON((signed short)ref < 0);
586 mfn = virt_to_mfn(data);
587 gnttab_grant_foreign_access_ref(
588 ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly);
589 tx->gref = np->grant_tx_ref[id] = ref;
594 if (skb->ip_summed == CHECKSUM_PARTIAL)
596 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
597 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
598 /* remote but checksummed. */
599 tx->flags |= XEN_NETTXF_data_validated;
601 if (skb_shinfo(skb)->gso_size) {
602 struct xen_netif_extra_info *gso;
604 gso = (struct xen_netif_extra_info *)
605 RING_GET_REQUEST(&np->tx, ++i);
607 tx->flags |= XEN_NETTXF_extra_info;
609 gso->u.gso.size = skb_shinfo(skb)->gso_size;
610 gso->u.gso.type = XEN_NETIF_GSO_TYPE_TCPV4;
612 gso->u.gso.features = 0;
614 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
618 np->tx.req_prod_pvt = i + 1;
620 xennet_make_frags(skb, dev, tx);
623 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->tx, notify);
625 notify_remote_via_irq(np->netdev->irq);
627 u64_stats_update_begin(&stats->syncp);
628 stats->tx_bytes += skb->len;
630 u64_stats_update_end(&stats->syncp);
632 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
633 xennet_tx_buf_gc(dev);
635 if (!netfront_tx_slot_available(np))
636 netif_stop_queue(dev);
638 spin_unlock_irqrestore(&np->tx_lock, flags);
643 dev->stats.tx_dropped++;
648 static int xennet_close(struct net_device *dev)
650 struct netfront_info *np = netdev_priv(dev);
651 netif_stop_queue(np->netdev);
652 napi_disable(&np->napi);
656 static void xennet_move_rx_slot(struct netfront_info *np, struct sk_buff *skb,
659 int new = xennet_rxidx(np->rx.req_prod_pvt);
661 BUG_ON(np->rx_skbs[new]);
662 np->rx_skbs[new] = skb;
663 np->grant_rx_ref[new] = ref;
664 RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->id = new;
665 RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->gref = ref;
666 np->rx.req_prod_pvt++;
669 static int xennet_get_extras(struct netfront_info *np,
670 struct xen_netif_extra_info *extras,
674 struct xen_netif_extra_info *extra;
675 struct device *dev = &np->netdev->dev;
676 RING_IDX cons = np->rx.rsp_cons;
683 if (unlikely(cons + 1 == rp)) {
685 dev_warn(dev, "Missing extra info\n");
690 extra = (struct xen_netif_extra_info *)
691 RING_GET_RESPONSE(&np->rx, ++cons);
693 if (unlikely(!extra->type ||
694 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
696 dev_warn(dev, "Invalid extra type: %d\n",
700 memcpy(&extras[extra->type - 1], extra,
704 skb = xennet_get_rx_skb(np, cons);
705 ref = xennet_get_rx_ref(np, cons);
706 xennet_move_rx_slot(np, skb, ref);
707 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
709 np->rx.rsp_cons = cons;
713 static int xennet_get_responses(struct netfront_info *np,
714 struct netfront_rx_info *rinfo, RING_IDX rp,
715 struct sk_buff_head *list)
717 struct xen_netif_rx_response *rx = &rinfo->rx;
718 struct xen_netif_extra_info *extras = rinfo->extras;
719 struct device *dev = &np->netdev->dev;
720 RING_IDX cons = np->rx.rsp_cons;
721 struct sk_buff *skb = xennet_get_rx_skb(np, cons);
722 grant_ref_t ref = xennet_get_rx_ref(np, cons);
723 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
728 if (rx->flags & XEN_NETRXF_extra_info) {
729 err = xennet_get_extras(np, extras, rp);
730 cons = np->rx.rsp_cons;
734 if (unlikely(rx->status < 0 ||
735 rx->offset + rx->status > PAGE_SIZE)) {
737 dev_warn(dev, "rx->offset: %x, size: %u\n",
738 rx->offset, rx->status);
739 xennet_move_rx_slot(np, skb, ref);
745 * This definitely indicates a bug, either in this driver or in
746 * the backend driver. In future this should flag the bad
747 * situation to the system controller to reboot the backend.
749 if (ref == GRANT_INVALID_REF) {
751 dev_warn(dev, "Bad rx response id %d.\n",
757 ret = gnttab_end_foreign_access_ref(ref, 0);
760 gnttab_release_grant_reference(&np->gref_rx_head, ref);
762 __skb_queue_tail(list, skb);
765 if (!(rx->flags & XEN_NETRXF_more_data))
768 if (cons + slots == rp) {
770 dev_warn(dev, "Need more slots\n");
775 rx = RING_GET_RESPONSE(&np->rx, cons + slots);
776 skb = xennet_get_rx_skb(np, cons + slots);
777 ref = xennet_get_rx_ref(np, cons + slots);
781 if (unlikely(slots > max)) {
783 dev_warn(dev, "Too many slots\n");
788 np->rx.rsp_cons = cons + slots;
793 static int xennet_set_skb_gso(struct sk_buff *skb,
794 struct xen_netif_extra_info *gso)
796 if (!gso->u.gso.size) {
798 printk(KERN_WARNING "GSO size must not be zero.\n");
802 /* Currently only TCPv4 S.O. is supported. */
803 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4) {
805 printk(KERN_WARNING "Bad GSO type %d.\n", gso->u.gso.type);
809 skb_shinfo(skb)->gso_size = gso->u.gso.size;
810 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
812 /* Header must be checked, and gso_segs computed. */
813 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
814 skb_shinfo(skb)->gso_segs = 0;
819 static RING_IDX xennet_fill_frags(struct netfront_info *np,
821 struct sk_buff_head *list)
823 struct skb_shared_info *shinfo = skb_shinfo(skb);
824 RING_IDX cons = np->rx.rsp_cons;
825 struct sk_buff *nskb;
827 while ((nskb = __skb_dequeue(list))) {
828 struct xen_netif_rx_response *rx =
829 RING_GET_RESPONSE(&np->rx, ++cons);
830 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
832 if (shinfo->nr_frags == MAX_SKB_FRAGS) {
833 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
835 BUG_ON(pull_to <= skb_headlen(skb));
836 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
838 BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS);
840 skb_add_rx_frag(skb, shinfo->nr_frags, skb_frag_page(nfrag),
841 rx->offset, rx->status, PAGE_SIZE);
843 skb_shinfo(nskb)->nr_frags = 0;
850 static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
855 int recalculate_partial_csum = 0;
858 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
859 * peers can fail to set NETRXF_csum_blank when sending a GSO
860 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
861 * recalculate the partial checksum.
863 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
864 struct netfront_info *np = netdev_priv(dev);
865 np->rx_gso_checksum_fixup++;
866 skb->ip_summed = CHECKSUM_PARTIAL;
867 recalculate_partial_csum = 1;
870 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
871 if (skb->ip_summed != CHECKSUM_PARTIAL)
874 if (skb->protocol != htons(ETH_P_IP))
877 iph = (void *)skb->data;
878 th = skb->data + 4 * iph->ihl;
879 if (th >= skb_tail_pointer(skb))
882 skb->csum_start = th - skb->head;
883 switch (iph->protocol) {
885 skb->csum_offset = offsetof(struct tcphdr, check);
887 if (recalculate_partial_csum) {
888 struct tcphdr *tcph = (struct tcphdr *)th;
889 tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
890 skb->len - iph->ihl*4,
895 skb->csum_offset = offsetof(struct udphdr, check);
897 if (recalculate_partial_csum) {
898 struct udphdr *udph = (struct udphdr *)th;
899 udph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
900 skb->len - iph->ihl*4,
906 printk(KERN_ERR "Attempting to checksum a non-"
907 "TCP/UDP packet, dropping a protocol"
908 " %d packet", iph->protocol);
912 if ((th + skb->csum_offset + 2) > skb_tail_pointer(skb))
921 static int handle_incoming_queue(struct net_device *dev,
922 struct sk_buff_head *rxq)
924 struct netfront_info *np = netdev_priv(dev);
925 struct netfront_stats *stats = this_cpu_ptr(np->stats);
926 int packets_dropped = 0;
929 while ((skb = __skb_dequeue(rxq)) != NULL) {
930 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
932 if (pull_to > skb_headlen(skb))
933 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
935 /* Ethernet work: Delayed to here as it peeks the header. */
936 skb->protocol = eth_type_trans(skb, dev);
938 if (checksum_setup(dev, skb)) {
941 dev->stats.rx_errors++;
945 u64_stats_update_begin(&stats->syncp);
947 stats->rx_bytes += skb->len;
948 u64_stats_update_end(&stats->syncp);
951 netif_receive_skb(skb);
954 return packets_dropped;
957 static int xennet_poll(struct napi_struct *napi, int budget)
959 struct netfront_info *np = container_of(napi, struct netfront_info, napi);
960 struct net_device *dev = np->netdev;
962 struct netfront_rx_info rinfo;
963 struct xen_netif_rx_response *rx = &rinfo.rx;
964 struct xen_netif_extra_info *extras = rinfo.extras;
967 struct sk_buff_head rxq;
968 struct sk_buff_head errq;
969 struct sk_buff_head tmpq;
973 spin_lock(&np->rx_lock);
975 skb_queue_head_init(&rxq);
976 skb_queue_head_init(&errq);
977 skb_queue_head_init(&tmpq);
979 rp = np->rx.sring->rsp_prod;
980 rmb(); /* Ensure we see queued responses up to 'rp'. */
984 while ((i != rp) && (work_done < budget)) {
985 memcpy(rx, RING_GET_RESPONSE(&np->rx, i), sizeof(*rx));
986 memset(extras, 0, sizeof(rinfo.extras));
988 err = xennet_get_responses(np, &rinfo, rp, &tmpq);
992 while ((skb = __skb_dequeue(&tmpq)))
993 __skb_queue_tail(&errq, skb);
994 dev->stats.rx_errors++;
999 skb = __skb_dequeue(&tmpq);
1001 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1002 struct xen_netif_extra_info *gso;
1003 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1005 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1006 __skb_queue_head(&tmpq, skb);
1007 np->rx.rsp_cons += skb_queue_len(&tmpq);
1012 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1013 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1014 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1016 skb_shinfo(skb)->frags[0].page_offset = rx->offset;
1017 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1018 skb->data_len = rx->status;
1019 skb->len += rx->status;
1021 i = xennet_fill_frags(np, skb, &tmpq);
1023 if (rx->flags & XEN_NETRXF_csum_blank)
1024 skb->ip_summed = CHECKSUM_PARTIAL;
1025 else if (rx->flags & XEN_NETRXF_data_validated)
1026 skb->ip_summed = CHECKSUM_UNNECESSARY;
1028 __skb_queue_tail(&rxq, skb);
1030 np->rx.rsp_cons = ++i;
1034 __skb_queue_purge(&errq);
1036 work_done -= handle_incoming_queue(dev, &rxq);
1038 /* If we get a callback with very few responses, reduce fill target. */
1039 /* NB. Note exponential increase, linear decrease. */
1040 if (((np->rx.req_prod_pvt - np->rx.sring->rsp_prod) >
1041 ((3*np->rx_target) / 4)) &&
1042 (--np->rx_target < np->rx_min_target))
1043 np->rx_target = np->rx_min_target;
1045 xennet_alloc_rx_buffers(dev);
1047 if (work_done < budget) {
1050 local_irq_save(flags);
1052 RING_FINAL_CHECK_FOR_RESPONSES(&np->rx, more_to_do);
1054 __napi_complete(napi);
1056 local_irq_restore(flags);
1059 spin_unlock(&np->rx_lock);
1064 static int xennet_change_mtu(struct net_device *dev, int mtu)
1066 int max = xennet_can_sg(dev) ?
1067 XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER : ETH_DATA_LEN;
1075 static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
1076 struct rtnl_link_stats64 *tot)
1078 struct netfront_info *np = netdev_priv(dev);
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;
1087 start = u64_stats_fetch_begin_bh(&stats->syncp);
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_bh(&stats->syncp, start));
1095 tot->rx_packets += rx_packets;
1096 tot->tx_packets += tx_packets;
1097 tot->rx_bytes += rx_bytes;
1098 tot->tx_bytes += tx_bytes;
1101 tot->rx_errors = dev->stats.rx_errors;
1102 tot->tx_dropped = dev->stats.tx_dropped;
1107 static void xennet_release_tx_bufs(struct netfront_info *np)
1109 struct sk_buff *skb;
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(&np->tx_skbs[i]))
1117 skb = np->tx_skbs[i].skb;
1118 gnttab_end_foreign_access_ref(np->grant_tx_ref[i],
1120 gnttab_release_grant_reference(&np->gref_tx_head,
1121 np->grant_tx_ref[i]);
1122 np->grant_tx_ref[i] = GRANT_INVALID_REF;
1123 add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, i);
1124 dev_kfree_skb_irq(skb);
1128 static void xennet_release_rx_bufs(struct netfront_info *np)
1130 struct mmu_update *mmu = np->rx_mmu;
1131 struct multicall_entry *mcl = np->rx_mcl;
1132 struct sk_buff_head free_list;
1133 struct sk_buff *skb;
1135 int xfer = 0, noxfer = 0, unused = 0;
1138 dev_warn(&np->netdev->dev, "%s: fix me for copying receiver.\n",
1142 skb_queue_head_init(&free_list);
1144 spin_lock_bh(&np->rx_lock);
1146 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1147 ref = np->grant_rx_ref[id];
1148 if (ref == GRANT_INVALID_REF) {
1153 skb = np->rx_skbs[id];
1154 mfn = gnttab_end_foreign_transfer_ref(ref);
1155 gnttab_release_grant_reference(&np->gref_rx_head, ref);
1156 np->grant_rx_ref[id] = GRANT_INVALID_REF;
1159 skb_shinfo(skb)->nr_frags = 0;
1165 if (!xen_feature(XENFEAT_auto_translated_physmap)) {
1166 /* Remap the page. */
1167 const struct page *page =
1168 skb_frag_page(&skb_shinfo(skb)->frags[0]);
1169 unsigned long pfn = page_to_pfn(page);
1170 void *vaddr = page_address(page);
1172 MULTI_update_va_mapping(mcl, (unsigned long)vaddr,
1173 mfn_pte(mfn, PAGE_KERNEL),
1176 mmu->ptr = ((u64)mfn << PAGE_SHIFT)
1177 | MMU_MACHPHYS_UPDATE;
1181 set_phys_to_machine(pfn, mfn);
1183 __skb_queue_tail(&free_list, skb);
1187 dev_info(&np->netdev->dev, "%s: %d xfer, %d noxfer, %d unused\n",
1188 __func__, xfer, noxfer, unused);
1191 if (!xen_feature(XENFEAT_auto_translated_physmap)) {
1192 /* Do all the remapping work and M2P updates. */
1193 MULTI_mmu_update(mcl, np->rx_mmu, mmu - np->rx_mmu,
1196 HYPERVISOR_multicall(np->rx_mcl, mcl - np->rx_mcl);
1200 __skb_queue_purge(&free_list);
1202 spin_unlock_bh(&np->rx_lock);
1205 static void xennet_uninit(struct net_device *dev)
1207 struct netfront_info *np = netdev_priv(dev);
1208 xennet_release_tx_bufs(np);
1209 xennet_release_rx_bufs(np);
1210 gnttab_free_grant_references(np->gref_tx_head);
1211 gnttab_free_grant_references(np->gref_rx_head);
1214 static netdev_features_t xennet_fix_features(struct net_device *dev,
1215 netdev_features_t features)
1217 struct netfront_info *np = netdev_priv(dev);
1220 if (features & NETIF_F_SG) {
1221 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg",
1226 features &= ~NETIF_F_SG;
1229 if (features & NETIF_F_TSO) {
1230 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1231 "feature-gso-tcpv4", "%d", &val) < 0)
1235 features &= ~NETIF_F_TSO;
1241 static int xennet_set_features(struct net_device *dev,
1242 netdev_features_t features)
1244 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1245 netdev_info(dev, "Reducing MTU because no SG offload");
1246 dev->mtu = ETH_DATA_LEN;
1252 static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1254 struct net_device *dev = dev_id;
1255 struct netfront_info *np = netdev_priv(dev);
1256 unsigned long flags;
1258 spin_lock_irqsave(&np->tx_lock, flags);
1260 if (likely(netif_carrier_ok(dev))) {
1261 xennet_tx_buf_gc(dev);
1262 /* Under tx_lock: protects access to rx shared-ring indexes. */
1263 if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx))
1264 napi_schedule(&np->napi);
1267 spin_unlock_irqrestore(&np->tx_lock, flags);
1272 #ifdef CONFIG_NET_POLL_CONTROLLER
1273 static void xennet_poll_controller(struct net_device *dev)
1275 xennet_interrupt(0, dev);
1279 static const struct net_device_ops xennet_netdev_ops = {
1280 .ndo_open = xennet_open,
1281 .ndo_uninit = xennet_uninit,
1282 .ndo_stop = xennet_close,
1283 .ndo_start_xmit = xennet_start_xmit,
1284 .ndo_change_mtu = xennet_change_mtu,
1285 .ndo_get_stats64 = xennet_get_stats64,
1286 .ndo_set_mac_address = eth_mac_addr,
1287 .ndo_validate_addr = eth_validate_addr,
1288 .ndo_fix_features = xennet_fix_features,
1289 .ndo_set_features = xennet_set_features,
1290 #ifdef CONFIG_NET_POLL_CONTROLLER
1291 .ndo_poll_controller = xennet_poll_controller,
1295 static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1298 struct net_device *netdev;
1299 struct netfront_info *np;
1301 netdev = alloc_etherdev(sizeof(struct netfront_info));
1303 return ERR_PTR(-ENOMEM);
1305 np = netdev_priv(netdev);
1308 spin_lock_init(&np->tx_lock);
1309 spin_lock_init(&np->rx_lock);
1311 skb_queue_head_init(&np->rx_batch);
1312 np->rx_target = RX_DFL_MIN_TARGET;
1313 np->rx_min_target = RX_DFL_MIN_TARGET;
1314 np->rx_max_target = RX_MAX_TARGET;
1316 init_timer(&np->rx_refill_timer);
1317 np->rx_refill_timer.data = (unsigned long)netdev;
1318 np->rx_refill_timer.function = rx_refill_timeout;
1321 np->stats = alloc_percpu(struct netfront_stats);
1322 if (np->stats == NULL)
1325 /* Initialise tx_skbs as a free chain containing every entry. */
1326 np->tx_skb_freelist = 0;
1327 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1328 skb_entry_set_link(&np->tx_skbs[i], i+1);
1329 np->grant_tx_ref[i] = GRANT_INVALID_REF;
1332 /* Clear out rx_skbs */
1333 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1334 np->rx_skbs[i] = NULL;
1335 np->grant_rx_ref[i] = GRANT_INVALID_REF;
1338 /* A grant for every tx ring slot */
1339 if (gnttab_alloc_grant_references(TX_MAX_TARGET,
1340 &np->gref_tx_head) < 0) {
1341 printk(KERN_ALERT "#### netfront can't alloc tx grant refs\n");
1343 goto exit_free_stats;
1345 /* A grant for every rx ring slot */
1346 if (gnttab_alloc_grant_references(RX_MAX_TARGET,
1347 &np->gref_rx_head) < 0) {
1348 printk(KERN_ALERT "#### netfront can't alloc rx grant refs\n");
1353 netdev->netdev_ops = &xennet_netdev_ops;
1355 netif_napi_add(netdev, &np->napi, xennet_poll, 64);
1356 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1358 netdev->hw_features = NETIF_F_IP_CSUM | NETIF_F_SG | NETIF_F_TSO;
1361 * Assume that all hw features are available for now. This set
1362 * will be adjusted by the call to netdev_update_features() in
1363 * xennet_connect() which is the earliest point where we can
1364 * negotiate with the backend regarding supported features.
1366 netdev->features |= netdev->hw_features;
1368 SET_ETHTOOL_OPS(netdev, &xennet_ethtool_ops);
1369 SET_NETDEV_DEV(netdev, &dev->dev);
1371 netif_set_gso_max_size(netdev, XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER);
1373 np->netdev = netdev;
1375 netif_carrier_off(netdev);
1380 gnttab_free_grant_references(np->gref_tx_head);
1382 free_percpu(np->stats);
1384 free_netdev(netdev);
1385 return ERR_PTR(err);
1389 * Entry point to this code when a new device is created. Allocate the basic
1390 * structures and the ring buffers for communication with the backend, and
1391 * inform the backend of the appropriate details for those.
1393 static int netfront_probe(struct xenbus_device *dev,
1394 const struct xenbus_device_id *id)
1397 struct net_device *netdev;
1398 struct netfront_info *info;
1400 netdev = xennet_create_dev(dev);
1401 if (IS_ERR(netdev)) {
1402 err = PTR_ERR(netdev);
1403 xenbus_dev_fatal(dev, err, "creating netdev");
1407 info = netdev_priv(netdev);
1408 dev_set_drvdata(&dev->dev, info);
1410 err = register_netdev(info->netdev);
1412 printk(KERN_WARNING "%s: register_netdev err=%d\n",
1417 err = xennet_sysfs_addif(info->netdev);
1419 unregister_netdev(info->netdev);
1420 printk(KERN_WARNING "%s: add sysfs failed err=%d\n",
1428 free_netdev(netdev);
1429 dev_set_drvdata(&dev->dev, NULL);
1433 static void xennet_end_access(int ref, void *page)
1435 /* This frees the page as a side-effect */
1436 if (ref != GRANT_INVALID_REF)
1437 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1440 static void xennet_disconnect_backend(struct netfront_info *info)
1442 /* Stop old i/f to prevent errors whilst we rebuild the state. */
1443 spin_lock_bh(&info->rx_lock);
1444 spin_lock_irq(&info->tx_lock);
1445 netif_carrier_off(info->netdev);
1446 spin_unlock_irq(&info->tx_lock);
1447 spin_unlock_bh(&info->rx_lock);
1449 if (info->netdev->irq)
1450 unbind_from_irqhandler(info->netdev->irq, info->netdev);
1451 info->evtchn = info->netdev->irq = 0;
1453 /* End access and free the pages */
1454 xennet_end_access(info->tx_ring_ref, info->tx.sring);
1455 xennet_end_access(info->rx_ring_ref, info->rx.sring);
1457 info->tx_ring_ref = GRANT_INVALID_REF;
1458 info->rx_ring_ref = GRANT_INVALID_REF;
1459 info->tx.sring = NULL;
1460 info->rx.sring = NULL;
1464 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1465 * driver restart. We tear down our netif structure and recreate it, but
1466 * leave the device-layer structures intact so that this is transparent to the
1467 * rest of the kernel.
1469 static int netfront_resume(struct xenbus_device *dev)
1471 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1473 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1475 xennet_disconnect_backend(info);
1479 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1481 char *s, *e, *macstr;
1484 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1486 return PTR_ERR(macstr);
1488 for (i = 0; i < ETH_ALEN; i++) {
1489 mac[i] = simple_strtoul(s, &e, 16);
1490 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1501 static int setup_netfront(struct xenbus_device *dev, struct netfront_info *info)
1503 struct xen_netif_tx_sring *txs;
1504 struct xen_netif_rx_sring *rxs;
1506 struct net_device *netdev = info->netdev;
1508 info->tx_ring_ref = GRANT_INVALID_REF;
1509 info->rx_ring_ref = GRANT_INVALID_REF;
1510 info->rx.sring = NULL;
1511 info->tx.sring = NULL;
1514 err = xen_net_read_mac(dev, netdev->dev_addr);
1516 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1520 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1523 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1526 SHARED_RING_INIT(txs);
1527 FRONT_RING_INIT(&info->tx, txs, PAGE_SIZE);
1529 err = xenbus_grant_ring(dev, virt_to_mfn(txs));
1531 free_page((unsigned long)txs);
1535 info->tx_ring_ref = err;
1536 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1539 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1542 SHARED_RING_INIT(rxs);
1543 FRONT_RING_INIT(&info->rx, rxs, PAGE_SIZE);
1545 err = xenbus_grant_ring(dev, virt_to_mfn(rxs));
1547 free_page((unsigned long)rxs);
1550 info->rx_ring_ref = err;
1552 err = xenbus_alloc_evtchn(dev, &info->evtchn);
1556 err = bind_evtchn_to_irqhandler(info->evtchn, xennet_interrupt,
1557 0, netdev->name, netdev);
1567 /* Common code used when first setting up, and when resuming. */
1568 static int talk_to_netback(struct xenbus_device *dev,
1569 struct netfront_info *info)
1571 const char *message;
1572 struct xenbus_transaction xbt;
1575 /* Create shared ring, alloc event channel. */
1576 err = setup_netfront(dev, info);
1581 err = xenbus_transaction_start(&xbt);
1583 xenbus_dev_fatal(dev, err, "starting transaction");
1587 err = xenbus_printf(xbt, dev->nodename, "tx-ring-ref", "%u",
1590 message = "writing tx ring-ref";
1591 goto abort_transaction;
1593 err = xenbus_printf(xbt, dev->nodename, "rx-ring-ref", "%u",
1596 message = "writing rx ring-ref";
1597 goto abort_transaction;
1599 err = xenbus_printf(xbt, dev->nodename,
1600 "event-channel", "%u", info->evtchn);
1602 message = "writing event-channel";
1603 goto abort_transaction;
1606 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
1609 message = "writing request-rx-copy";
1610 goto abort_transaction;
1613 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
1615 message = "writing feature-rx-notify";
1616 goto abort_transaction;
1619 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
1621 message = "writing feature-sg";
1622 goto abort_transaction;
1625 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
1627 message = "writing feature-gso-tcpv4";
1628 goto abort_transaction;
1631 err = xenbus_transaction_end(xbt, 0);
1635 xenbus_dev_fatal(dev, err, "completing transaction");
1642 xenbus_transaction_end(xbt, 1);
1643 xenbus_dev_fatal(dev, err, "%s", message);
1645 xennet_disconnect_backend(info);
1650 static int xennet_connect(struct net_device *dev)
1652 struct netfront_info *np = netdev_priv(dev);
1653 int i, requeue_idx, err;
1654 struct sk_buff *skb;
1656 struct xen_netif_rx_request *req;
1657 unsigned int feature_rx_copy;
1659 err = xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1660 "feature-rx-copy", "%u", &feature_rx_copy);
1662 feature_rx_copy = 0;
1664 if (!feature_rx_copy) {
1666 "backend does not support copying receive path\n");
1670 err = talk_to_netback(np->xbdev, np);
1675 netdev_update_features(dev);
1678 spin_lock_bh(&np->rx_lock);
1679 spin_lock_irq(&np->tx_lock);
1681 /* Step 1: Discard all pending TX packet fragments. */
1682 xennet_release_tx_bufs(np);
1684 /* Step 2: Rebuild the RX buffer freelist and the RX ring itself. */
1685 for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) {
1687 const struct page *page;
1688 if (!np->rx_skbs[i])
1691 skb = np->rx_skbs[requeue_idx] = xennet_get_rx_skb(np, i);
1692 ref = np->grant_rx_ref[requeue_idx] = xennet_get_rx_ref(np, i);
1693 req = RING_GET_REQUEST(&np->rx, requeue_idx);
1695 frag = &skb_shinfo(skb)->frags[0];
1696 page = skb_frag_page(frag);
1697 gnttab_grant_foreign_access_ref(
1698 ref, np->xbdev->otherend_id,
1699 pfn_to_mfn(page_to_pfn(page)),
1702 req->id = requeue_idx;
1707 np->rx.req_prod_pvt = requeue_idx;
1710 * Step 3: All public and private state should now be sane. Get
1711 * ready to start sending and receiving packets and give the driver
1712 * domain a kick because we've probably just requeued some
1715 netif_carrier_on(np->netdev);
1716 notify_remote_via_irq(np->netdev->irq);
1717 xennet_tx_buf_gc(dev);
1718 xennet_alloc_rx_buffers(dev);
1720 spin_unlock_irq(&np->tx_lock);
1721 spin_unlock_bh(&np->rx_lock);
1727 * Callback received when the backend's state changes.
1729 static void netback_changed(struct xenbus_device *dev,
1730 enum xenbus_state backend_state)
1732 struct netfront_info *np = dev_get_drvdata(&dev->dev);
1733 struct net_device *netdev = np->netdev;
1735 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
1737 switch (backend_state) {
1738 case XenbusStateInitialising:
1739 case XenbusStateInitialised:
1740 case XenbusStateReconfiguring:
1741 case XenbusStateReconfigured:
1742 case XenbusStateUnknown:
1743 case XenbusStateClosed:
1746 case XenbusStateInitWait:
1747 if (dev->state != XenbusStateInitialising)
1749 if (xennet_connect(netdev) != 0)
1751 xenbus_switch_state(dev, XenbusStateConnected);
1754 case XenbusStateConnected:
1755 netdev_notify_peers(netdev);
1758 case XenbusStateClosing:
1759 xenbus_frontend_closed(dev);
1764 static const struct xennet_stat {
1765 char name[ETH_GSTRING_LEN];
1767 } xennet_stats[] = {
1769 "rx_gso_checksum_fixup",
1770 offsetof(struct netfront_info, rx_gso_checksum_fixup)
1774 static int xennet_get_sset_count(struct net_device *dev, int string_set)
1776 switch (string_set) {
1778 return ARRAY_SIZE(xennet_stats);
1784 static void xennet_get_ethtool_stats(struct net_device *dev,
1785 struct ethtool_stats *stats, u64 * data)
1787 void *np = netdev_priv(dev);
1790 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
1791 data[i] = *(unsigned long *)(np + xennet_stats[i].offset);
1794 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
1798 switch (stringset) {
1800 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
1801 memcpy(data + i * ETH_GSTRING_LEN,
1802 xennet_stats[i].name, ETH_GSTRING_LEN);
1807 static const struct ethtool_ops xennet_ethtool_ops =
1809 .get_link = ethtool_op_get_link,
1811 .get_sset_count = xennet_get_sset_count,
1812 .get_ethtool_stats = xennet_get_ethtool_stats,
1813 .get_strings = xennet_get_strings,
1817 static ssize_t show_rxbuf_min(struct device *dev,
1818 struct device_attribute *attr, char *buf)
1820 struct net_device *netdev = to_net_dev(dev);
1821 struct netfront_info *info = netdev_priv(netdev);
1823 return sprintf(buf, "%u\n", info->rx_min_target);
1826 static ssize_t store_rxbuf_min(struct device *dev,
1827 struct device_attribute *attr,
1828 const char *buf, size_t len)
1830 struct net_device *netdev = to_net_dev(dev);
1831 struct netfront_info *np = netdev_priv(netdev);
1833 unsigned long target;
1835 if (!capable(CAP_NET_ADMIN))
1838 target = simple_strtoul(buf, &endp, 0);
1842 if (target < RX_MIN_TARGET)
1843 target = RX_MIN_TARGET;
1844 if (target > RX_MAX_TARGET)
1845 target = RX_MAX_TARGET;
1847 spin_lock_bh(&np->rx_lock);
1848 if (target > np->rx_max_target)
1849 np->rx_max_target = target;
1850 np->rx_min_target = target;
1851 if (target > np->rx_target)
1852 np->rx_target = target;
1854 xennet_alloc_rx_buffers(netdev);
1856 spin_unlock_bh(&np->rx_lock);
1860 static ssize_t show_rxbuf_max(struct device *dev,
1861 struct device_attribute *attr, char *buf)
1863 struct net_device *netdev = to_net_dev(dev);
1864 struct netfront_info *info = netdev_priv(netdev);
1866 return sprintf(buf, "%u\n", info->rx_max_target);
1869 static ssize_t store_rxbuf_max(struct device *dev,
1870 struct device_attribute *attr,
1871 const char *buf, size_t len)
1873 struct net_device *netdev = to_net_dev(dev);
1874 struct netfront_info *np = netdev_priv(netdev);
1876 unsigned long target;
1878 if (!capable(CAP_NET_ADMIN))
1881 target = simple_strtoul(buf, &endp, 0);
1885 if (target < RX_MIN_TARGET)
1886 target = RX_MIN_TARGET;
1887 if (target > RX_MAX_TARGET)
1888 target = RX_MAX_TARGET;
1890 spin_lock_bh(&np->rx_lock);
1891 if (target < np->rx_min_target)
1892 np->rx_min_target = target;
1893 np->rx_max_target = target;
1894 if (target < np->rx_target)
1895 np->rx_target = target;
1897 xennet_alloc_rx_buffers(netdev);
1899 spin_unlock_bh(&np->rx_lock);
1903 static ssize_t show_rxbuf_cur(struct device *dev,
1904 struct device_attribute *attr, char *buf)
1906 struct net_device *netdev = to_net_dev(dev);
1907 struct netfront_info *info = netdev_priv(netdev);
1909 return sprintf(buf, "%u\n", info->rx_target);
1912 static struct device_attribute xennet_attrs[] = {
1913 __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf_min, store_rxbuf_min),
1914 __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf_max, store_rxbuf_max),
1915 __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf_cur, NULL),
1918 static int xennet_sysfs_addif(struct net_device *netdev)
1923 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) {
1924 err = device_create_file(&netdev->dev,
1933 device_remove_file(&netdev->dev, &xennet_attrs[i]);
1937 static void xennet_sysfs_delif(struct net_device *netdev)
1941 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++)
1942 device_remove_file(&netdev->dev, &xennet_attrs[i]);
1945 #endif /* CONFIG_SYSFS */
1947 static const struct xenbus_device_id netfront_ids[] = {
1953 static int xennet_remove(struct xenbus_device *dev)
1955 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1957 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1959 xennet_disconnect_backend(info);
1961 xennet_sysfs_delif(info->netdev);
1963 unregister_netdev(info->netdev);
1965 del_timer_sync(&info->rx_refill_timer);
1967 free_percpu(info->stats);
1969 free_netdev(info->netdev);
1974 static DEFINE_XENBUS_DRIVER(netfront, ,
1975 .probe = netfront_probe,
1976 .remove = xennet_remove,
1977 .resume = netfront_resume,
1978 .otherend_changed = netback_changed,
1981 static int __init netif_init(void)
1986 if (xen_hvm_domain() && !xen_platform_pci_unplug)
1989 printk(KERN_INFO "Initialising Xen virtual ethernet driver.\n");
1991 return xenbus_register_frontend(&netfront_driver);
1993 module_init(netif_init);
1996 static void __exit netif_exit(void)
1998 xenbus_unregister_driver(&netfront_driver);
2000 module_exit(netif_exit);
2002 MODULE_DESCRIPTION("Xen virtual network device frontend");
2003 MODULE_LICENSE("GPL");
2004 MODULE_ALIAS("xen:vif");
2005 MODULE_ALIAS("xennet");