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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
34 #include <linux/module.h>
35 #include <linux/kernel.h>
36 #include <linux/netdevice.h>
37 #include <linux/etherdevice.h>
38 #include <linux/skbuff.h>
39 #include <linux/ethtool.h>
40 #include <linux/if_ether.h>
42 #include <linux/udp.h>
43 #include <linux/moduleparam.h>
45 #include <linux/slab.h>
48 #include <asm/xen/page.h>
50 #include <xen/xenbus.h>
51 #include <xen/events.h>
53 #include <xen/platform_pci.h>
54 #include <xen/grant_table.h>
56 #include <xen/interface/io/netif.h>
57 #include <xen/interface/memory.h>
58 #include <xen/interface/grant_table.h>
60 static const struct ethtool_ops xennet_ethtool_ops;
66 #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
68 #define RX_COPY_THRESHOLD 256
70 #define GRANT_INVALID_REF 0
72 #define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE)
73 #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE)
74 #define TX_MAX_TARGET min_t(int, NET_TX_RING_SIZE, 256)
76 struct netfront_stats {
81 struct u64_stats_sync syncp;
84 struct netfront_info {
85 struct list_head list;
86 struct net_device *netdev;
88 struct napi_struct napi;
90 /* Split event channels support, tx_* == rx_* when using
91 * single event channel.
93 unsigned int tx_evtchn, rx_evtchn;
94 unsigned int tx_irq, rx_irq;
95 /* Only used when split event channels support is enabled */
96 char tx_irq_name[IFNAMSIZ+4]; /* DEVNAME-tx */
97 char rx_irq_name[IFNAMSIZ+4]; /* DEVNAME-rx */
99 struct xenbus_device *xbdev;
102 struct xen_netif_tx_front_ring tx;
106 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
107 * are linked from tx_skb_freelist through skb_entry.link.
109 * NB. Freelist index entries are always going to be less than
110 * PAGE_OFFSET, whereas pointers to skbs will always be equal or
111 * greater than PAGE_OFFSET: we use this property to distinguish
117 } tx_skbs[NET_TX_RING_SIZE];
118 grant_ref_t gref_tx_head;
119 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
120 unsigned tx_skb_freelist;
122 spinlock_t rx_lock ____cacheline_aligned_in_smp;
123 struct xen_netif_rx_front_ring rx;
126 /* Receive-ring batched refills. */
127 #define RX_MIN_TARGET 8
128 #define RX_DFL_MIN_TARGET 64
129 #define RX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256)
130 unsigned rx_min_target, rx_max_target, rx_target;
131 struct sk_buff_head rx_batch;
133 struct timer_list rx_refill_timer;
135 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
136 grant_ref_t gref_rx_head;
137 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
139 unsigned long rx_pfn_array[NET_RX_RING_SIZE];
140 struct multicall_entry rx_mcl[NET_RX_RING_SIZE+1];
141 struct mmu_update rx_mmu[NET_RX_RING_SIZE];
144 struct netfront_stats __percpu *stats;
146 unsigned long rx_gso_checksum_fixup;
149 struct netfront_rx_info {
150 struct xen_netif_rx_response rx;
151 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
154 static void skb_entry_set_link(union skb_entry *list, unsigned short id)
159 static int skb_entry_is_link(const union skb_entry *list)
161 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
162 return (unsigned long)list->skb < PAGE_OFFSET;
166 * Access macros for acquiring freeing slots in tx_skbs[].
169 static void add_id_to_freelist(unsigned *head, union skb_entry *list,
172 skb_entry_set_link(&list[id], *head);
176 static unsigned short get_id_from_freelist(unsigned *head,
177 union skb_entry *list)
179 unsigned int id = *head;
180 *head = list[id].link;
184 static int xennet_rxidx(RING_IDX idx)
186 return idx & (NET_RX_RING_SIZE - 1);
189 static struct sk_buff *xennet_get_rx_skb(struct netfront_info *np,
192 int i = xennet_rxidx(ri);
193 struct sk_buff *skb = np->rx_skbs[i];
194 np->rx_skbs[i] = NULL;
198 static grant_ref_t xennet_get_rx_ref(struct netfront_info *np,
201 int i = xennet_rxidx(ri);
202 grant_ref_t ref = np->grant_rx_ref[i];
203 np->grant_rx_ref[i] = GRANT_INVALID_REF;
208 static int xennet_sysfs_addif(struct net_device *netdev);
209 static void xennet_sysfs_delif(struct net_device *netdev);
210 #else /* !CONFIG_SYSFS */
211 #define xennet_sysfs_addif(dev) (0)
212 #define xennet_sysfs_delif(dev) do { } while (0)
215 static bool xennet_can_sg(struct net_device *dev)
217 return dev->features & NETIF_F_SG;
221 static void rx_refill_timeout(unsigned long data)
223 struct net_device *dev = (struct net_device *)data;
224 struct netfront_info *np = netdev_priv(dev);
225 napi_schedule(&np->napi);
228 static int netfront_tx_slot_available(struct netfront_info *np)
230 return (np->tx.req_prod_pvt - np->tx.rsp_cons) <
231 (TX_MAX_TARGET - MAX_SKB_FRAGS - 2);
234 static void xennet_maybe_wake_tx(struct net_device *dev)
236 struct netfront_info *np = netdev_priv(dev);
238 if (unlikely(netif_queue_stopped(dev)) &&
239 netfront_tx_slot_available(np) &&
240 likely(netif_running(dev)))
241 netif_wake_queue(dev);
244 static void xennet_alloc_rx_buffers(struct net_device *dev)
247 struct netfront_info *np = netdev_priv(dev);
250 int i, batch_target, notify;
251 RING_IDX req_prod = np->rx.req_prod_pvt;
255 struct xen_netif_rx_request *req;
257 if (unlikely(!netif_carrier_ok(dev)))
261 * Allocate skbuffs greedily, even though we batch updates to the
262 * receive ring. This creates a less bursty demand on the memory
263 * allocator, so should reduce the chance of failed allocation requests
264 * both for ourself and for other kernel subsystems.
266 batch_target = np->rx_target - (req_prod - np->rx.rsp_cons);
267 for (i = skb_queue_len(&np->rx_batch); i < batch_target; i++) {
268 skb = __netdev_alloc_skb(dev, RX_COPY_THRESHOLD + NET_IP_ALIGN,
269 GFP_ATOMIC | __GFP_NOWARN);
273 /* Align ip header to a 16 bytes boundary */
274 skb_reserve(skb, NET_IP_ALIGN);
276 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
280 /* Any skbuffs queued for refill? Force them out. */
283 /* Could not allocate any skbuffs. Try again later. */
284 mod_timer(&np->rx_refill_timer,
289 __skb_fill_page_desc(skb, 0, page, 0, 0);
290 skb_shinfo(skb)->nr_frags = 1;
291 __skb_queue_tail(&np->rx_batch, skb);
294 /* Is the batch large enough to be worthwhile? */
295 if (i < (np->rx_target/2)) {
296 if (req_prod > np->rx.sring->req_prod)
301 /* Adjust our fill target if we risked running out of buffers. */
302 if (((req_prod - np->rx.sring->rsp_prod) < (np->rx_target / 4)) &&
303 ((np->rx_target *= 2) > np->rx_max_target))
304 np->rx_target = np->rx_max_target;
308 skb = __skb_dequeue(&np->rx_batch);
314 id = xennet_rxidx(req_prod + i);
316 BUG_ON(np->rx_skbs[id]);
317 np->rx_skbs[id] = skb;
319 ref = gnttab_claim_grant_reference(&np->gref_rx_head);
320 BUG_ON((signed short)ref < 0);
321 np->grant_rx_ref[id] = ref;
323 pfn = page_to_pfn(skb_frag_page(&skb_shinfo(skb)->frags[0]));
324 vaddr = page_address(skb_frag_page(&skb_shinfo(skb)->frags[0]));
326 req = RING_GET_REQUEST(&np->rx, req_prod + i);
327 gnttab_grant_foreign_access_ref(ref,
328 np->xbdev->otherend_id,
336 wmb(); /* barrier so backend seens requests */
338 /* Above is a suitable barrier to ensure backend will see requests. */
339 np->rx.req_prod_pvt = req_prod + i;
341 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->rx, notify);
343 notify_remote_via_irq(np->rx_irq);
346 static int xennet_open(struct net_device *dev)
348 struct netfront_info *np = netdev_priv(dev);
350 napi_enable(&np->napi);
352 spin_lock_bh(&np->rx_lock);
353 if (netif_carrier_ok(dev)) {
354 xennet_alloc_rx_buffers(dev);
355 np->rx.sring->rsp_event = np->rx.rsp_cons + 1;
356 if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx))
357 napi_schedule(&np->napi);
359 spin_unlock_bh(&np->rx_lock);
361 netif_start_queue(dev);
366 static void xennet_tx_buf_gc(struct net_device *dev)
370 struct netfront_info *np = netdev_priv(dev);
373 BUG_ON(!netif_carrier_ok(dev));
376 prod = np->tx.sring->rsp_prod;
377 rmb(); /* Ensure we see responses up to 'rp'. */
379 for (cons = np->tx.rsp_cons; cons != prod; cons++) {
380 struct xen_netif_tx_response *txrsp;
382 txrsp = RING_GET_RESPONSE(&np->tx, cons);
383 if (txrsp->status == XEN_NETIF_RSP_NULL)
387 skb = np->tx_skbs[id].skb;
388 if (unlikely(gnttab_query_foreign_access(
389 np->grant_tx_ref[id]) != 0)) {
390 pr_alert("%s: warning -- grant still in use by backend domain\n",
394 gnttab_end_foreign_access_ref(
395 np->grant_tx_ref[id], GNTMAP_readonly);
396 gnttab_release_grant_reference(
397 &np->gref_tx_head, np->grant_tx_ref[id]);
398 np->grant_tx_ref[id] = GRANT_INVALID_REF;
399 add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, id);
400 dev_kfree_skb_irq(skb);
403 np->tx.rsp_cons = prod;
406 * Set a new event, then check for race with update of tx_cons.
407 * Note that it is essential to schedule a callback, no matter
408 * how few buffers are pending. Even if there is space in the
409 * transmit ring, higher layers may be blocked because too much
410 * data is outstanding: in such cases notification from Xen is
411 * likely to be the only kick that we'll get.
413 np->tx.sring->rsp_event =
414 prod + ((np->tx.sring->req_prod - prod) >> 1) + 1;
415 mb(); /* update shared area */
416 } while ((cons == prod) && (prod != np->tx.sring->rsp_prod));
418 xennet_maybe_wake_tx(dev);
421 static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev,
422 struct xen_netif_tx_request *tx)
424 struct netfront_info *np = netdev_priv(dev);
425 char *data = skb->data;
427 RING_IDX prod = np->tx.req_prod_pvt;
428 int frags = skb_shinfo(skb)->nr_frags;
429 unsigned int offset = offset_in_page(data);
430 unsigned int len = skb_headlen(skb);
435 /* While the header overlaps a page boundary (including being
436 larger than a page), split it it into page-sized chunks. */
437 while (len > PAGE_SIZE - offset) {
438 tx->size = PAGE_SIZE - offset;
439 tx->flags |= XEN_NETTXF_more_data;
444 id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
445 np->tx_skbs[id].skb = skb_get(skb);
446 tx = RING_GET_REQUEST(&np->tx, prod++);
448 ref = gnttab_claim_grant_reference(&np->gref_tx_head);
449 BUG_ON((signed short)ref < 0);
451 mfn = virt_to_mfn(data);
452 gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id,
453 mfn, GNTMAP_readonly);
455 tx->gref = np->grant_tx_ref[id] = ref;
461 /* Grant backend access to each skb fragment page. */
462 for (i = 0; i < frags; i++) {
463 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
464 struct page *page = skb_frag_page(frag);
466 len = skb_frag_size(frag);
467 offset = frag->page_offset;
469 /* Data must not cross a page boundary. */
470 BUG_ON(len + offset > PAGE_SIZE<<compound_order(page));
472 /* Skip unused frames from start of page */
473 page += offset >> PAGE_SHIFT;
474 offset &= ~PAGE_MASK;
479 BUG_ON(offset >= PAGE_SIZE);
481 bytes = PAGE_SIZE - offset;
485 tx->flags |= XEN_NETTXF_more_data;
487 id = get_id_from_freelist(&np->tx_skb_freelist,
489 np->tx_skbs[id].skb = skb_get(skb);
490 tx = RING_GET_REQUEST(&np->tx, prod++);
492 ref = gnttab_claim_grant_reference(&np->gref_tx_head);
493 BUG_ON((signed short)ref < 0);
495 mfn = pfn_to_mfn(page_to_pfn(page));
496 gnttab_grant_foreign_access_ref(ref,
497 np->xbdev->otherend_id,
498 mfn, GNTMAP_readonly);
500 tx->gref = np->grant_tx_ref[id] = ref;
509 if (offset == PAGE_SIZE && len) {
510 BUG_ON(!PageCompound(page));
517 np->tx.req_prod_pvt = prod;
521 * Count how many ring slots are required to send the frags of this
522 * skb. Each frag might be a compound page.
524 static int xennet_count_skb_frag_slots(struct sk_buff *skb)
526 int i, frags = skb_shinfo(skb)->nr_frags;
529 for (i = 0; i < frags; i++) {
530 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
531 unsigned long size = skb_frag_size(frag);
532 unsigned long offset = frag->page_offset;
534 /* Skip unused frames from start of page */
535 offset &= ~PAGE_MASK;
537 pages += PFN_UP(offset + size);
543 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
546 struct netfront_info *np = netdev_priv(dev);
547 struct netfront_stats *stats = this_cpu_ptr(np->stats);
548 struct xen_netif_tx_request *tx;
549 char *data = skb->data;
555 unsigned int offset = offset_in_page(data);
556 unsigned int len = skb_headlen(skb);
559 /* If skb->len is too big for wire format, drop skb and alert
560 * user about misconfiguration.
562 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
563 net_alert_ratelimited(
564 "xennet: skb->len = %u, too big for wire format\n",
569 slots = DIV_ROUND_UP(offset + len, PAGE_SIZE) +
570 xennet_count_skb_frag_slots(skb);
571 if (unlikely(slots > MAX_SKB_FRAGS + 1)) {
572 net_alert_ratelimited(
573 "xennet: skb rides the rocket: %d slots\n", slots);
577 spin_lock_irqsave(&np->tx_lock, flags);
579 if (unlikely(!netif_carrier_ok(dev) ||
580 (slots > 1 && !xennet_can_sg(dev)) ||
581 netif_needs_gso(skb, netif_skb_features(skb)))) {
582 spin_unlock_irqrestore(&np->tx_lock, flags);
586 i = np->tx.req_prod_pvt;
588 id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
589 np->tx_skbs[id].skb = skb;
591 tx = RING_GET_REQUEST(&np->tx, i);
594 ref = gnttab_claim_grant_reference(&np->gref_tx_head);
595 BUG_ON((signed short)ref < 0);
596 mfn = virt_to_mfn(data);
597 gnttab_grant_foreign_access_ref(
598 ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly);
599 tx->gref = np->grant_tx_ref[id] = ref;
604 if (skb->ip_summed == CHECKSUM_PARTIAL)
606 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
607 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
608 /* remote but checksummed. */
609 tx->flags |= XEN_NETTXF_data_validated;
611 if (skb_shinfo(skb)->gso_size) {
612 struct xen_netif_extra_info *gso;
614 gso = (struct xen_netif_extra_info *)
615 RING_GET_REQUEST(&np->tx, ++i);
617 tx->flags |= XEN_NETTXF_extra_info;
619 gso->u.gso.size = skb_shinfo(skb)->gso_size;
620 gso->u.gso.type = XEN_NETIF_GSO_TYPE_TCPV4;
622 gso->u.gso.features = 0;
624 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
628 np->tx.req_prod_pvt = i + 1;
630 xennet_make_frags(skb, dev, tx);
633 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->tx, notify);
635 notify_remote_via_irq(np->tx_irq);
637 u64_stats_update_begin(&stats->syncp);
638 stats->tx_bytes += skb->len;
640 u64_stats_update_end(&stats->syncp);
642 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
643 xennet_tx_buf_gc(dev);
645 if (!netfront_tx_slot_available(np))
646 netif_stop_queue(dev);
648 spin_unlock_irqrestore(&np->tx_lock, flags);
653 dev->stats.tx_dropped++;
658 static int xennet_close(struct net_device *dev)
660 struct netfront_info *np = netdev_priv(dev);
661 netif_stop_queue(np->netdev);
662 napi_disable(&np->napi);
666 static void xennet_move_rx_slot(struct netfront_info *np, struct sk_buff *skb,
669 int new = xennet_rxidx(np->rx.req_prod_pvt);
671 BUG_ON(np->rx_skbs[new]);
672 np->rx_skbs[new] = skb;
673 np->grant_rx_ref[new] = ref;
674 RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->id = new;
675 RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->gref = ref;
676 np->rx.req_prod_pvt++;
679 static int xennet_get_extras(struct netfront_info *np,
680 struct xen_netif_extra_info *extras,
684 struct xen_netif_extra_info *extra;
685 struct device *dev = &np->netdev->dev;
686 RING_IDX cons = np->rx.rsp_cons;
693 if (unlikely(cons + 1 == rp)) {
695 dev_warn(dev, "Missing extra info\n");
700 extra = (struct xen_netif_extra_info *)
701 RING_GET_RESPONSE(&np->rx, ++cons);
703 if (unlikely(!extra->type ||
704 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
706 dev_warn(dev, "Invalid extra type: %d\n",
710 memcpy(&extras[extra->type - 1], extra,
714 skb = xennet_get_rx_skb(np, cons);
715 ref = xennet_get_rx_ref(np, cons);
716 xennet_move_rx_slot(np, skb, ref);
717 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
719 np->rx.rsp_cons = cons;
723 static int xennet_get_responses(struct netfront_info *np,
724 struct netfront_rx_info *rinfo, RING_IDX rp,
725 struct sk_buff_head *list)
727 struct xen_netif_rx_response *rx = &rinfo->rx;
728 struct xen_netif_extra_info *extras = rinfo->extras;
729 struct device *dev = &np->netdev->dev;
730 RING_IDX cons = np->rx.rsp_cons;
731 struct sk_buff *skb = xennet_get_rx_skb(np, cons);
732 grant_ref_t ref = xennet_get_rx_ref(np, cons);
733 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
738 if (rx->flags & XEN_NETRXF_extra_info) {
739 err = xennet_get_extras(np, extras, rp);
740 cons = np->rx.rsp_cons;
744 if (unlikely(rx->status < 0 ||
745 rx->offset + rx->status > PAGE_SIZE)) {
747 dev_warn(dev, "rx->offset: %x, size: %u\n",
748 rx->offset, rx->status);
749 xennet_move_rx_slot(np, skb, ref);
755 * This definitely indicates a bug, either in this driver or in
756 * the backend driver. In future this should flag the bad
757 * situation to the system controller to reboot the backend.
759 if (ref == GRANT_INVALID_REF) {
761 dev_warn(dev, "Bad rx response id %d.\n",
767 ret = gnttab_end_foreign_access_ref(ref, 0);
770 gnttab_release_grant_reference(&np->gref_rx_head, ref);
772 __skb_queue_tail(list, skb);
775 if (!(rx->flags & XEN_NETRXF_more_data))
778 if (cons + slots == rp) {
780 dev_warn(dev, "Need more slots\n");
785 rx = RING_GET_RESPONSE(&np->rx, cons + slots);
786 skb = xennet_get_rx_skb(np, cons + slots);
787 ref = xennet_get_rx_ref(np, cons + slots);
791 if (unlikely(slots > max)) {
793 dev_warn(dev, "Too many slots\n");
798 np->rx.rsp_cons = cons + slots;
803 static int xennet_set_skb_gso(struct sk_buff *skb,
804 struct xen_netif_extra_info *gso)
806 if (!gso->u.gso.size) {
808 pr_warn("GSO size must not be zero\n");
812 /* Currently only TCPv4 S.O. is supported. */
813 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4) {
815 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
819 skb_shinfo(skb)->gso_size = gso->u.gso.size;
820 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
822 /* Header must be checked, and gso_segs computed. */
823 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
824 skb_shinfo(skb)->gso_segs = 0;
829 static RING_IDX xennet_fill_frags(struct netfront_info *np,
831 struct sk_buff_head *list)
833 struct skb_shared_info *shinfo = skb_shinfo(skb);
834 int nr_frags = shinfo->nr_frags;
835 RING_IDX cons = np->rx.rsp_cons;
836 struct sk_buff *nskb;
838 while ((nskb = __skb_dequeue(list))) {
839 struct xen_netif_rx_response *rx =
840 RING_GET_RESPONSE(&np->rx, ++cons);
841 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
843 __skb_fill_page_desc(skb, nr_frags,
844 skb_frag_page(nfrag),
845 rx->offset, rx->status);
847 skb->data_len += rx->status;
849 skb_shinfo(nskb)->nr_frags = 0;
855 shinfo->nr_frags = nr_frags;
859 static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
863 int recalculate_partial_csum = 0;
866 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
867 * peers can fail to set NETRXF_csum_blank when sending a GSO
868 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
869 * recalculate the partial checksum.
871 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
872 struct netfront_info *np = netdev_priv(dev);
873 np->rx_gso_checksum_fixup++;
874 skb->ip_summed = CHECKSUM_PARTIAL;
875 recalculate_partial_csum = 1;
878 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
879 if (skb->ip_summed != CHECKSUM_PARTIAL)
882 if (skb->protocol != htons(ETH_P_IP))
885 iph = (void *)skb->data;
887 switch (iph->protocol) {
889 if (!skb_partial_csum_set(skb, 4 * iph->ihl,
890 offsetof(struct tcphdr, check)))
893 if (recalculate_partial_csum) {
894 struct tcphdr *tcph = tcp_hdr(skb);
895 tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
896 skb->len - iph->ihl*4,
901 if (!skb_partial_csum_set(skb, 4 * iph->ihl,
902 offsetof(struct udphdr, check)))
905 if (recalculate_partial_csum) {
906 struct udphdr *udph = udp_hdr(skb);
907 udph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
908 skb->len - iph->ihl*4,
914 pr_err("Attempting to checksum a non-TCP/UDP packet, dropping a protocol %d packet\n",
925 static int handle_incoming_queue(struct net_device *dev,
926 struct sk_buff_head *rxq)
928 struct netfront_info *np = netdev_priv(dev);
929 struct netfront_stats *stats = this_cpu_ptr(np->stats);
930 int packets_dropped = 0;
933 while ((skb = __skb_dequeue(rxq)) != NULL) {
934 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
936 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
938 /* Ethernet work: Delayed to here as it peeks the header. */
939 skb->protocol = eth_type_trans(skb, dev);
941 if (checksum_setup(dev, skb)) {
944 dev->stats.rx_errors++;
948 u64_stats_update_begin(&stats->syncp);
950 stats->rx_bytes += skb->len;
951 u64_stats_update_end(&stats->syncp);
954 netif_receive_skb(skb);
957 return packets_dropped;
960 static int xennet_poll(struct napi_struct *napi, int budget)
962 struct netfront_info *np = container_of(napi, struct netfront_info, napi);
963 struct net_device *dev = np->netdev;
965 struct netfront_rx_info rinfo;
966 struct xen_netif_rx_response *rx = &rinfo.rx;
967 struct xen_netif_extra_info *extras = rinfo.extras;
970 struct sk_buff_head rxq;
971 struct sk_buff_head errq;
972 struct sk_buff_head tmpq;
976 spin_lock(&np->rx_lock);
978 skb_queue_head_init(&rxq);
979 skb_queue_head_init(&errq);
980 skb_queue_head_init(&tmpq);
982 rp = np->rx.sring->rsp_prod;
983 rmb(); /* Ensure we see queued responses up to 'rp'. */
987 while ((i != rp) && (work_done < budget)) {
988 memcpy(rx, RING_GET_RESPONSE(&np->rx, i), sizeof(*rx));
989 memset(extras, 0, sizeof(rinfo.extras));
991 err = xennet_get_responses(np, &rinfo, rp, &tmpq);
995 while ((skb = __skb_dequeue(&tmpq)))
996 __skb_queue_tail(&errq, skb);
997 dev->stats.rx_errors++;
1002 skb = __skb_dequeue(&tmpq);
1004 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1005 struct xen_netif_extra_info *gso;
1006 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1008 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1009 __skb_queue_head(&tmpq, skb);
1010 np->rx.rsp_cons += skb_queue_len(&tmpq);
1015 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1016 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1017 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1019 skb_shinfo(skb)->frags[0].page_offset = rx->offset;
1020 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1021 skb->data_len = rx->status;
1023 i = xennet_fill_frags(np, skb, &tmpq);
1026 * Truesize is the actual allocation size, even if the
1027 * allocation is only partially used.
1029 skb->truesize += PAGE_SIZE * skb_shinfo(skb)->nr_frags;
1030 skb->len += skb->data_len;
1032 if (rx->flags & XEN_NETRXF_csum_blank)
1033 skb->ip_summed = CHECKSUM_PARTIAL;
1034 else if (rx->flags & XEN_NETRXF_data_validated)
1035 skb->ip_summed = CHECKSUM_UNNECESSARY;
1037 __skb_queue_tail(&rxq, skb);
1039 np->rx.rsp_cons = ++i;
1043 __skb_queue_purge(&errq);
1045 work_done -= handle_incoming_queue(dev, &rxq);
1047 /* If we get a callback with very few responses, reduce fill target. */
1048 /* NB. Note exponential increase, linear decrease. */
1049 if (((np->rx.req_prod_pvt - np->rx.sring->rsp_prod) >
1050 ((3*np->rx_target) / 4)) &&
1051 (--np->rx_target < np->rx_min_target))
1052 np->rx_target = np->rx_min_target;
1054 xennet_alloc_rx_buffers(dev);
1056 if (work_done < budget) {
1059 local_irq_save(flags);
1061 RING_FINAL_CHECK_FOR_RESPONSES(&np->rx, more_to_do);
1063 __napi_complete(napi);
1065 local_irq_restore(flags);
1068 spin_unlock(&np->rx_lock);
1073 static int xennet_change_mtu(struct net_device *dev, int mtu)
1075 int max = xennet_can_sg(dev) ?
1076 XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER : ETH_DATA_LEN;
1084 static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
1085 struct rtnl_link_stats64 *tot)
1087 struct netfront_info *np = netdev_priv(dev);
1090 for_each_possible_cpu(cpu) {
1091 struct netfront_stats *stats = per_cpu_ptr(np->stats, cpu);
1092 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1096 start = u64_stats_fetch_begin_bh(&stats->syncp);
1098 rx_packets = stats->rx_packets;
1099 tx_packets = stats->tx_packets;
1100 rx_bytes = stats->rx_bytes;
1101 tx_bytes = stats->tx_bytes;
1102 } while (u64_stats_fetch_retry_bh(&stats->syncp, start));
1104 tot->rx_packets += rx_packets;
1105 tot->tx_packets += tx_packets;
1106 tot->rx_bytes += rx_bytes;
1107 tot->tx_bytes += tx_bytes;
1110 tot->rx_errors = dev->stats.rx_errors;
1111 tot->tx_dropped = dev->stats.tx_dropped;
1116 static void xennet_release_tx_bufs(struct netfront_info *np)
1118 struct sk_buff *skb;
1121 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1122 /* Skip over entries which are actually freelist references */
1123 if (skb_entry_is_link(&np->tx_skbs[i]))
1126 skb = np->tx_skbs[i].skb;
1127 gnttab_end_foreign_access_ref(np->grant_tx_ref[i],
1129 gnttab_release_grant_reference(&np->gref_tx_head,
1130 np->grant_tx_ref[i]);
1131 np->grant_tx_ref[i] = GRANT_INVALID_REF;
1132 add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, i);
1133 dev_kfree_skb_irq(skb);
1137 static void xennet_release_rx_bufs(struct netfront_info *np)
1139 struct mmu_update *mmu = np->rx_mmu;
1140 struct multicall_entry *mcl = np->rx_mcl;
1141 struct sk_buff_head free_list;
1142 struct sk_buff *skb;
1144 int xfer = 0, noxfer = 0, unused = 0;
1147 dev_warn(&np->netdev->dev, "%s: fix me for copying receiver.\n",
1151 skb_queue_head_init(&free_list);
1153 spin_lock_bh(&np->rx_lock);
1155 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1156 ref = np->grant_rx_ref[id];
1157 if (ref == GRANT_INVALID_REF) {
1162 skb = np->rx_skbs[id];
1163 mfn = gnttab_end_foreign_transfer_ref(ref);
1164 gnttab_release_grant_reference(&np->gref_rx_head, ref);
1165 np->grant_rx_ref[id] = GRANT_INVALID_REF;
1168 skb_shinfo(skb)->nr_frags = 0;
1174 if (!xen_feature(XENFEAT_auto_translated_physmap)) {
1175 /* Remap the page. */
1176 const struct page *page =
1177 skb_frag_page(&skb_shinfo(skb)->frags[0]);
1178 unsigned long pfn = page_to_pfn(page);
1179 void *vaddr = page_address(page);
1181 MULTI_update_va_mapping(mcl, (unsigned long)vaddr,
1182 mfn_pte(mfn, PAGE_KERNEL),
1185 mmu->ptr = ((u64)mfn << PAGE_SHIFT)
1186 | MMU_MACHPHYS_UPDATE;
1190 set_phys_to_machine(pfn, mfn);
1192 __skb_queue_tail(&free_list, skb);
1196 dev_info(&np->netdev->dev, "%s: %d xfer, %d noxfer, %d unused\n",
1197 __func__, xfer, noxfer, unused);
1200 if (!xen_feature(XENFEAT_auto_translated_physmap)) {
1201 /* Do all the remapping work and M2P updates. */
1202 MULTI_mmu_update(mcl, np->rx_mmu, mmu - np->rx_mmu,
1205 HYPERVISOR_multicall(np->rx_mcl, mcl - np->rx_mcl);
1209 __skb_queue_purge(&free_list);
1211 spin_unlock_bh(&np->rx_lock);
1214 static void xennet_uninit(struct net_device *dev)
1216 struct netfront_info *np = netdev_priv(dev);
1217 xennet_release_tx_bufs(np);
1218 xennet_release_rx_bufs(np);
1219 gnttab_free_grant_references(np->gref_tx_head);
1220 gnttab_free_grant_references(np->gref_rx_head);
1223 static netdev_features_t xennet_fix_features(struct net_device *dev,
1224 netdev_features_t features)
1226 struct netfront_info *np = netdev_priv(dev);
1229 if (features & NETIF_F_SG) {
1230 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg",
1235 features &= ~NETIF_F_SG;
1238 if (features & NETIF_F_TSO) {
1239 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1240 "feature-gso-tcpv4", "%d", &val) < 0)
1244 features &= ~NETIF_F_TSO;
1250 static int xennet_set_features(struct net_device *dev,
1251 netdev_features_t features)
1253 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1254 netdev_info(dev, "Reducing MTU because no SG offload");
1255 dev->mtu = ETH_DATA_LEN;
1261 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1263 struct netfront_info *np = dev_id;
1264 struct net_device *dev = np->netdev;
1265 unsigned long flags;
1267 spin_lock_irqsave(&np->tx_lock, flags);
1268 xennet_tx_buf_gc(dev);
1269 spin_unlock_irqrestore(&np->tx_lock, flags);
1274 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1276 struct netfront_info *np = dev_id;
1277 struct net_device *dev = np->netdev;
1279 if (likely(netif_carrier_ok(dev) &&
1280 RING_HAS_UNCONSUMED_RESPONSES(&np->rx)))
1281 napi_schedule(&np->napi);
1286 static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1288 xennet_tx_interrupt(irq, dev_id);
1289 xennet_rx_interrupt(irq, dev_id);
1293 #ifdef CONFIG_NET_POLL_CONTROLLER
1294 static void xennet_poll_controller(struct net_device *dev)
1296 xennet_interrupt(0, dev);
1300 static const struct net_device_ops xennet_netdev_ops = {
1301 .ndo_open = xennet_open,
1302 .ndo_uninit = xennet_uninit,
1303 .ndo_stop = xennet_close,
1304 .ndo_start_xmit = xennet_start_xmit,
1305 .ndo_change_mtu = xennet_change_mtu,
1306 .ndo_get_stats64 = xennet_get_stats64,
1307 .ndo_set_mac_address = eth_mac_addr,
1308 .ndo_validate_addr = eth_validate_addr,
1309 .ndo_fix_features = xennet_fix_features,
1310 .ndo_set_features = xennet_set_features,
1311 #ifdef CONFIG_NET_POLL_CONTROLLER
1312 .ndo_poll_controller = xennet_poll_controller,
1316 static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1319 struct net_device *netdev;
1320 struct netfront_info *np;
1322 netdev = alloc_etherdev(sizeof(struct netfront_info));
1324 return ERR_PTR(-ENOMEM);
1326 np = netdev_priv(netdev);
1329 spin_lock_init(&np->tx_lock);
1330 spin_lock_init(&np->rx_lock);
1332 skb_queue_head_init(&np->rx_batch);
1333 np->rx_target = RX_DFL_MIN_TARGET;
1334 np->rx_min_target = RX_DFL_MIN_TARGET;
1335 np->rx_max_target = RX_MAX_TARGET;
1337 init_timer(&np->rx_refill_timer);
1338 np->rx_refill_timer.data = (unsigned long)netdev;
1339 np->rx_refill_timer.function = rx_refill_timeout;
1342 np->stats = alloc_percpu(struct netfront_stats);
1343 if (np->stats == NULL)
1346 /* Initialise tx_skbs as a free chain containing every entry. */
1347 np->tx_skb_freelist = 0;
1348 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1349 skb_entry_set_link(&np->tx_skbs[i], i+1);
1350 np->grant_tx_ref[i] = GRANT_INVALID_REF;
1353 /* Clear out rx_skbs */
1354 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1355 np->rx_skbs[i] = NULL;
1356 np->grant_rx_ref[i] = GRANT_INVALID_REF;
1359 /* A grant for every tx ring slot */
1360 if (gnttab_alloc_grant_references(TX_MAX_TARGET,
1361 &np->gref_tx_head) < 0) {
1362 pr_alert("can't alloc tx grant refs\n");
1364 goto exit_free_stats;
1366 /* A grant for every rx ring slot */
1367 if (gnttab_alloc_grant_references(RX_MAX_TARGET,
1368 &np->gref_rx_head) < 0) {
1369 pr_alert("can't alloc rx grant refs\n");
1374 netdev->netdev_ops = &xennet_netdev_ops;
1376 netif_napi_add(netdev, &np->napi, xennet_poll, 64);
1377 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1379 netdev->hw_features = NETIF_F_IP_CSUM | NETIF_F_SG | NETIF_F_TSO;
1382 * Assume that all hw features are available for now. This set
1383 * will be adjusted by the call to netdev_update_features() in
1384 * xennet_connect() which is the earliest point where we can
1385 * negotiate with the backend regarding supported features.
1387 netdev->features |= netdev->hw_features;
1389 SET_ETHTOOL_OPS(netdev, &xennet_ethtool_ops);
1390 SET_NETDEV_DEV(netdev, &dev->dev);
1392 netif_set_gso_max_size(netdev, XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER);
1394 np->netdev = netdev;
1396 netif_carrier_off(netdev);
1401 gnttab_free_grant_references(np->gref_tx_head);
1403 free_percpu(np->stats);
1405 free_netdev(netdev);
1406 return ERR_PTR(err);
1410 * Entry point to this code when a new device is created. Allocate the basic
1411 * structures and the ring buffers for communication with the backend, and
1412 * inform the backend of the appropriate details for those.
1414 static int netfront_probe(struct xenbus_device *dev,
1415 const struct xenbus_device_id *id)
1418 struct net_device *netdev;
1419 struct netfront_info *info;
1421 netdev = xennet_create_dev(dev);
1422 if (IS_ERR(netdev)) {
1423 err = PTR_ERR(netdev);
1424 xenbus_dev_fatal(dev, err, "creating netdev");
1428 info = netdev_priv(netdev);
1429 dev_set_drvdata(&dev->dev, info);
1431 err = register_netdev(info->netdev);
1433 pr_warn("%s: register_netdev err=%d\n", __func__, err);
1437 err = xennet_sysfs_addif(info->netdev);
1439 unregister_netdev(info->netdev);
1440 pr_warn("%s: add sysfs failed err=%d\n", __func__, err);
1447 free_netdev(netdev);
1448 dev_set_drvdata(&dev->dev, NULL);
1452 static void xennet_end_access(int ref, void *page)
1454 /* This frees the page as a side-effect */
1455 if (ref != GRANT_INVALID_REF)
1456 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1459 static void xennet_disconnect_backend(struct netfront_info *info)
1461 /* Stop old i/f to prevent errors whilst we rebuild the state. */
1462 spin_lock_bh(&info->rx_lock);
1463 spin_lock_irq(&info->tx_lock);
1464 netif_carrier_off(info->netdev);
1465 spin_unlock_irq(&info->tx_lock);
1466 spin_unlock_bh(&info->rx_lock);
1468 if (info->tx_irq && (info->tx_irq == info->rx_irq))
1469 unbind_from_irqhandler(info->tx_irq, info);
1470 if (info->tx_irq && (info->tx_irq != info->rx_irq)) {
1471 unbind_from_irqhandler(info->tx_irq, info);
1472 unbind_from_irqhandler(info->rx_irq, info);
1474 info->tx_evtchn = info->rx_evtchn = 0;
1475 info->tx_irq = info->rx_irq = 0;
1477 /* End access and free the pages */
1478 xennet_end_access(info->tx_ring_ref, info->tx.sring);
1479 xennet_end_access(info->rx_ring_ref, info->rx.sring);
1481 info->tx_ring_ref = GRANT_INVALID_REF;
1482 info->rx_ring_ref = GRANT_INVALID_REF;
1483 info->tx.sring = NULL;
1484 info->rx.sring = NULL;
1488 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1489 * driver restart. We tear down our netif structure and recreate it, but
1490 * leave the device-layer structures intact so that this is transparent to the
1491 * rest of the kernel.
1493 static int netfront_resume(struct xenbus_device *dev)
1495 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1497 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1499 xennet_disconnect_backend(info);
1503 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1505 char *s, *e, *macstr;
1508 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1510 return PTR_ERR(macstr);
1512 for (i = 0; i < ETH_ALEN; i++) {
1513 mac[i] = simple_strtoul(s, &e, 16);
1514 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1525 static int setup_netfront_single(struct netfront_info *info)
1529 err = xenbus_alloc_evtchn(info->xbdev, &info->tx_evtchn);
1533 err = bind_evtchn_to_irqhandler(info->tx_evtchn,
1535 0, info->netdev->name, info);
1538 info->rx_evtchn = info->tx_evtchn;
1539 info->rx_irq = info->tx_irq = err;
1544 xenbus_free_evtchn(info->xbdev, info->tx_evtchn);
1545 info->tx_evtchn = 0;
1550 static int setup_netfront_split(struct netfront_info *info)
1554 err = xenbus_alloc_evtchn(info->xbdev, &info->tx_evtchn);
1557 err = xenbus_alloc_evtchn(info->xbdev, &info->rx_evtchn);
1559 goto alloc_rx_evtchn_fail;
1561 snprintf(info->tx_irq_name, sizeof(info->tx_irq_name),
1562 "%s-tx", info->netdev->name);
1563 err = bind_evtchn_to_irqhandler(info->tx_evtchn,
1564 xennet_tx_interrupt,
1565 0, info->tx_irq_name, info);
1570 snprintf(info->rx_irq_name, sizeof(info->rx_irq_name),
1571 "%s-rx", info->netdev->name);
1572 err = bind_evtchn_to_irqhandler(info->rx_evtchn,
1573 xennet_rx_interrupt,
1574 0, info->rx_irq_name, info);
1582 unbind_from_irqhandler(info->tx_irq, info);
1585 xenbus_free_evtchn(info->xbdev, info->rx_evtchn);
1586 info->rx_evtchn = 0;
1587 alloc_rx_evtchn_fail:
1588 xenbus_free_evtchn(info->xbdev, info->tx_evtchn);
1589 info->tx_evtchn = 0;
1594 static int setup_netfront(struct xenbus_device *dev, struct netfront_info *info)
1596 struct xen_netif_tx_sring *txs;
1597 struct xen_netif_rx_sring *rxs;
1599 struct net_device *netdev = info->netdev;
1600 unsigned int feature_split_evtchn;
1602 info->tx_ring_ref = GRANT_INVALID_REF;
1603 info->rx_ring_ref = GRANT_INVALID_REF;
1604 info->rx.sring = NULL;
1605 info->tx.sring = NULL;
1608 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
1609 "feature-split-event-channels", "%u",
1610 &feature_split_evtchn);
1612 feature_split_evtchn = 0;
1614 err = xen_net_read_mac(dev, netdev->dev_addr);
1616 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1620 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1623 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1626 SHARED_RING_INIT(txs);
1627 FRONT_RING_INIT(&info->tx, txs, PAGE_SIZE);
1629 err = xenbus_grant_ring(dev, virt_to_mfn(txs));
1631 goto grant_tx_ring_fail;
1633 info->tx_ring_ref = err;
1634 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1637 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1638 goto alloc_rx_ring_fail;
1640 SHARED_RING_INIT(rxs);
1641 FRONT_RING_INIT(&info->rx, rxs, PAGE_SIZE);
1643 err = xenbus_grant_ring(dev, virt_to_mfn(rxs));
1645 goto grant_rx_ring_fail;
1646 info->rx_ring_ref = err;
1648 if (feature_split_evtchn)
1649 err = setup_netfront_split(info);
1650 /* setup single event channel if
1651 * a) feature-split-event-channels == 0
1652 * b) feature-split-event-channels == 1 but failed to setup
1654 if (!feature_split_evtchn || (feature_split_evtchn && err))
1655 err = setup_netfront_single(info);
1658 goto alloc_evtchn_fail;
1662 /* If we fail to setup netfront, it is safe to just revoke access to
1663 * granted pages because backend is not accessing it at this point.
1666 gnttab_end_foreign_access_ref(info->rx_ring_ref, 0);
1668 free_page((unsigned long)rxs);
1670 gnttab_end_foreign_access_ref(info->tx_ring_ref, 0);
1672 free_page((unsigned long)txs);
1677 /* Common code used when first setting up, and when resuming. */
1678 static int talk_to_netback(struct xenbus_device *dev,
1679 struct netfront_info *info)
1681 const char *message;
1682 struct xenbus_transaction xbt;
1685 /* Create shared ring, alloc event channel. */
1686 err = setup_netfront(dev, info);
1691 err = xenbus_transaction_start(&xbt);
1693 xenbus_dev_fatal(dev, err, "starting transaction");
1697 err = xenbus_printf(xbt, dev->nodename, "tx-ring-ref", "%u",
1700 message = "writing tx ring-ref";
1701 goto abort_transaction;
1703 err = xenbus_printf(xbt, dev->nodename, "rx-ring-ref", "%u",
1706 message = "writing rx ring-ref";
1707 goto abort_transaction;
1710 if (info->tx_evtchn == info->rx_evtchn) {
1711 err = xenbus_printf(xbt, dev->nodename,
1712 "event-channel", "%u", info->tx_evtchn);
1714 message = "writing event-channel";
1715 goto abort_transaction;
1718 err = xenbus_printf(xbt, dev->nodename,
1719 "event-channel-tx", "%u", info->tx_evtchn);
1721 message = "writing event-channel-tx";
1722 goto abort_transaction;
1724 err = xenbus_printf(xbt, dev->nodename,
1725 "event-channel-rx", "%u", info->rx_evtchn);
1727 message = "writing event-channel-rx";
1728 goto abort_transaction;
1732 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
1735 message = "writing request-rx-copy";
1736 goto abort_transaction;
1739 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
1741 message = "writing feature-rx-notify";
1742 goto abort_transaction;
1745 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
1747 message = "writing feature-sg";
1748 goto abort_transaction;
1751 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
1753 message = "writing feature-gso-tcpv4";
1754 goto abort_transaction;
1757 err = xenbus_transaction_end(xbt, 0);
1761 xenbus_dev_fatal(dev, err, "completing transaction");
1768 xenbus_transaction_end(xbt, 1);
1769 xenbus_dev_fatal(dev, err, "%s", message);
1771 xennet_disconnect_backend(info);
1776 static int xennet_connect(struct net_device *dev)
1778 struct netfront_info *np = netdev_priv(dev);
1779 int i, requeue_idx, err;
1780 struct sk_buff *skb;
1782 struct xen_netif_rx_request *req;
1783 unsigned int feature_rx_copy;
1785 err = xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1786 "feature-rx-copy", "%u", &feature_rx_copy);
1788 feature_rx_copy = 0;
1790 if (!feature_rx_copy) {
1792 "backend does not support copying receive path\n");
1796 err = talk_to_netback(np->xbdev, np);
1801 netdev_update_features(dev);
1804 spin_lock_bh(&np->rx_lock);
1805 spin_lock_irq(&np->tx_lock);
1807 /* Step 1: Discard all pending TX packet fragments. */
1808 xennet_release_tx_bufs(np);
1810 /* Step 2: Rebuild the RX buffer freelist and the RX ring itself. */
1811 for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) {
1813 const struct page *page;
1814 if (!np->rx_skbs[i])
1817 skb = np->rx_skbs[requeue_idx] = xennet_get_rx_skb(np, i);
1818 ref = np->grant_rx_ref[requeue_idx] = xennet_get_rx_ref(np, i);
1819 req = RING_GET_REQUEST(&np->rx, requeue_idx);
1821 frag = &skb_shinfo(skb)->frags[0];
1822 page = skb_frag_page(frag);
1823 gnttab_grant_foreign_access_ref(
1824 ref, np->xbdev->otherend_id,
1825 pfn_to_mfn(page_to_pfn(page)),
1828 req->id = requeue_idx;
1833 np->rx.req_prod_pvt = requeue_idx;
1836 * Step 3: All public and private state should now be sane. Get
1837 * ready to start sending and receiving packets and give the driver
1838 * domain a kick because we've probably just requeued some
1841 netif_carrier_on(np->netdev);
1842 notify_remote_via_irq(np->tx_irq);
1843 if (np->tx_irq != np->rx_irq)
1844 notify_remote_via_irq(np->rx_irq);
1845 xennet_tx_buf_gc(dev);
1846 xennet_alloc_rx_buffers(dev);
1848 spin_unlock_irq(&np->tx_lock);
1849 spin_unlock_bh(&np->rx_lock);
1855 * Callback received when the backend's state changes.
1857 static void netback_changed(struct xenbus_device *dev,
1858 enum xenbus_state backend_state)
1860 struct netfront_info *np = dev_get_drvdata(&dev->dev);
1861 struct net_device *netdev = np->netdev;
1863 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
1865 switch (backend_state) {
1866 case XenbusStateInitialising:
1867 case XenbusStateInitialised:
1868 case XenbusStateReconfiguring:
1869 case XenbusStateReconfigured:
1870 case XenbusStateUnknown:
1871 case XenbusStateClosed:
1874 case XenbusStateInitWait:
1875 if (dev->state != XenbusStateInitialising)
1877 if (xennet_connect(netdev) != 0)
1879 xenbus_switch_state(dev, XenbusStateConnected);
1882 case XenbusStateConnected:
1883 netdev_notify_peers(netdev);
1886 case XenbusStateClosing:
1887 xenbus_frontend_closed(dev);
1892 static const struct xennet_stat {
1893 char name[ETH_GSTRING_LEN];
1895 } xennet_stats[] = {
1897 "rx_gso_checksum_fixup",
1898 offsetof(struct netfront_info, rx_gso_checksum_fixup)
1902 static int xennet_get_sset_count(struct net_device *dev, int string_set)
1904 switch (string_set) {
1906 return ARRAY_SIZE(xennet_stats);
1912 static void xennet_get_ethtool_stats(struct net_device *dev,
1913 struct ethtool_stats *stats, u64 * data)
1915 void *np = netdev_priv(dev);
1918 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
1919 data[i] = *(unsigned long *)(np + xennet_stats[i].offset);
1922 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
1926 switch (stringset) {
1928 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
1929 memcpy(data + i * ETH_GSTRING_LEN,
1930 xennet_stats[i].name, ETH_GSTRING_LEN);
1935 static const struct ethtool_ops xennet_ethtool_ops =
1937 .get_link = ethtool_op_get_link,
1939 .get_sset_count = xennet_get_sset_count,
1940 .get_ethtool_stats = xennet_get_ethtool_stats,
1941 .get_strings = xennet_get_strings,
1945 static ssize_t show_rxbuf_min(struct device *dev,
1946 struct device_attribute *attr, char *buf)
1948 struct net_device *netdev = to_net_dev(dev);
1949 struct netfront_info *info = netdev_priv(netdev);
1951 return sprintf(buf, "%u\n", info->rx_min_target);
1954 static ssize_t store_rxbuf_min(struct device *dev,
1955 struct device_attribute *attr,
1956 const char *buf, size_t len)
1958 struct net_device *netdev = to_net_dev(dev);
1959 struct netfront_info *np = netdev_priv(netdev);
1961 unsigned long target;
1963 if (!capable(CAP_NET_ADMIN))
1966 target = simple_strtoul(buf, &endp, 0);
1970 if (target < RX_MIN_TARGET)
1971 target = RX_MIN_TARGET;
1972 if (target > RX_MAX_TARGET)
1973 target = RX_MAX_TARGET;
1975 spin_lock_bh(&np->rx_lock);
1976 if (target > np->rx_max_target)
1977 np->rx_max_target = target;
1978 np->rx_min_target = target;
1979 if (target > np->rx_target)
1980 np->rx_target = target;
1982 xennet_alloc_rx_buffers(netdev);
1984 spin_unlock_bh(&np->rx_lock);
1988 static ssize_t show_rxbuf_max(struct device *dev,
1989 struct device_attribute *attr, char *buf)
1991 struct net_device *netdev = to_net_dev(dev);
1992 struct netfront_info *info = netdev_priv(netdev);
1994 return sprintf(buf, "%u\n", info->rx_max_target);
1997 static ssize_t store_rxbuf_max(struct device *dev,
1998 struct device_attribute *attr,
1999 const char *buf, size_t len)
2001 struct net_device *netdev = to_net_dev(dev);
2002 struct netfront_info *np = netdev_priv(netdev);
2004 unsigned long target;
2006 if (!capable(CAP_NET_ADMIN))
2009 target = simple_strtoul(buf, &endp, 0);
2013 if (target < RX_MIN_TARGET)
2014 target = RX_MIN_TARGET;
2015 if (target > RX_MAX_TARGET)
2016 target = RX_MAX_TARGET;
2018 spin_lock_bh(&np->rx_lock);
2019 if (target < np->rx_min_target)
2020 np->rx_min_target = target;
2021 np->rx_max_target = target;
2022 if (target < np->rx_target)
2023 np->rx_target = target;
2025 xennet_alloc_rx_buffers(netdev);
2027 spin_unlock_bh(&np->rx_lock);
2031 static ssize_t show_rxbuf_cur(struct device *dev,
2032 struct device_attribute *attr, char *buf)
2034 struct net_device *netdev = to_net_dev(dev);
2035 struct netfront_info *info = netdev_priv(netdev);
2037 return sprintf(buf, "%u\n", info->rx_target);
2040 static struct device_attribute xennet_attrs[] = {
2041 __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf_min, store_rxbuf_min),
2042 __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf_max, store_rxbuf_max),
2043 __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf_cur, NULL),
2046 static int xennet_sysfs_addif(struct net_device *netdev)
2051 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) {
2052 err = device_create_file(&netdev->dev,
2061 device_remove_file(&netdev->dev, &xennet_attrs[i]);
2065 static void xennet_sysfs_delif(struct net_device *netdev)
2069 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++)
2070 device_remove_file(&netdev->dev, &xennet_attrs[i]);
2073 #endif /* CONFIG_SYSFS */
2075 static const struct xenbus_device_id netfront_ids[] = {
2081 static int xennet_remove(struct xenbus_device *dev)
2083 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2085 dev_dbg(&dev->dev, "%s\n", dev->nodename);
2087 xennet_disconnect_backend(info);
2089 xennet_sysfs_delif(info->netdev);
2091 unregister_netdev(info->netdev);
2093 del_timer_sync(&info->rx_refill_timer);
2095 free_percpu(info->stats);
2097 free_netdev(info->netdev);
2102 static DEFINE_XENBUS_DRIVER(netfront, ,
2103 .probe = netfront_probe,
2104 .remove = xennet_remove,
2105 .resume = netfront_resume,
2106 .otherend_changed = netback_changed,
2109 static int __init netif_init(void)
2114 if (xen_hvm_domain() && !xen_platform_pci_unplug)
2117 pr_info("Initialising Xen virtual ethernet driver\n");
2119 return xenbus_register_frontend(&netfront_driver);
2121 module_init(netif_init);
2124 static void __exit netif_exit(void)
2126 xenbus_unregister_driver(&netfront_driver);
2128 module_exit(netif_exit);
2130 MODULE_DESCRIPTION("Xen virtual network device frontend");
2131 MODULE_LICENSE("GPL");
2132 MODULE_ALIAS("xen:vif");
2133 MODULE_ALIAS("xennet");