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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-21 16:29:59 +00:00
![Juergen Gross](/assets/img/avatar_default.png)
Since commit23025393db
("xen/netback: use lateeoi irq binding") xenvif_rx_ring_slots_available() is no longer called only from the rx queue kernel thread, so it needs to access the rx queue with the associated queue held. Reported-by: Igor Druzhinin <igor.druzhinin@citrix.com> Fixes:23025393db
("xen/netback: use lateeoi irq binding") Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: Wei Liu <wl@xen.org> Link: https://lore.kernel.org/r/20210202070938.7863-1-jgross@suse.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
656 lines
16 KiB
C
656 lines
16 KiB
C
/*
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* Copyright (c) 2016 Citrix Systems Inc.
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* Copyright (c) 2002-2005, K A Fraser
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License version 2
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* as published by the Free Software Foundation; or, when distributed
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* separately from the Linux kernel or incorporated into other
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* software packages, subject to the following license:
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this source file (the "Software"), to deal in the Software without
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* restriction, including without limitation the rights to use, copy, modify,
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* merge, publish, distribute, sublicense, and/or sell copies of the Software,
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* and to permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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* IN THE SOFTWARE.
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*/
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#include "common.h"
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#include <linux/kthread.h>
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#include <xen/xen.h>
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#include <xen/events.h>
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static bool xenvif_rx_ring_slots_available(struct xenvif_queue *queue)
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{
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RING_IDX prod, cons;
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struct sk_buff *skb;
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int needed;
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unsigned long flags;
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spin_lock_irqsave(&queue->rx_queue.lock, flags);
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skb = skb_peek(&queue->rx_queue);
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if (!skb) {
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spin_unlock_irqrestore(&queue->rx_queue.lock, flags);
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return false;
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}
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needed = DIV_ROUND_UP(skb->len, XEN_PAGE_SIZE);
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if (skb_is_gso(skb))
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needed++;
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if (skb->sw_hash)
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needed++;
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spin_unlock_irqrestore(&queue->rx_queue.lock, flags);
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do {
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prod = queue->rx.sring->req_prod;
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cons = queue->rx.req_cons;
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if (prod - cons >= needed)
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return true;
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queue->rx.sring->req_event = prod + 1;
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/* Make sure event is visible before we check prod
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* again.
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*/
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mb();
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} while (queue->rx.sring->req_prod != prod);
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return false;
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}
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void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb)
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{
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unsigned long flags;
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spin_lock_irqsave(&queue->rx_queue.lock, flags);
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__skb_queue_tail(&queue->rx_queue, skb);
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queue->rx_queue_len += skb->len;
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if (queue->rx_queue_len > queue->rx_queue_max) {
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struct net_device *dev = queue->vif->dev;
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netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
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}
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spin_unlock_irqrestore(&queue->rx_queue.lock, flags);
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}
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static struct sk_buff *xenvif_rx_dequeue(struct xenvif_queue *queue)
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{
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struct sk_buff *skb;
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spin_lock_irq(&queue->rx_queue.lock);
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skb = __skb_dequeue(&queue->rx_queue);
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if (skb) {
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queue->rx_queue_len -= skb->len;
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if (queue->rx_queue_len < queue->rx_queue_max) {
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struct netdev_queue *txq;
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txq = netdev_get_tx_queue(queue->vif->dev, queue->id);
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netif_tx_wake_queue(txq);
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}
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}
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spin_unlock_irq(&queue->rx_queue.lock);
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return skb;
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}
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static void xenvif_rx_queue_purge(struct xenvif_queue *queue)
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{
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struct sk_buff *skb;
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while ((skb = xenvif_rx_dequeue(queue)) != NULL)
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kfree_skb(skb);
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}
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static void xenvif_rx_queue_drop_expired(struct xenvif_queue *queue)
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{
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struct sk_buff *skb;
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for (;;) {
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skb = skb_peek(&queue->rx_queue);
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if (!skb)
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break;
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if (time_before(jiffies, XENVIF_RX_CB(skb)->expires))
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break;
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xenvif_rx_dequeue(queue);
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kfree_skb(skb);
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}
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}
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static void xenvif_rx_copy_flush(struct xenvif_queue *queue)
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{
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unsigned int i;
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int notify;
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gnttab_batch_copy(queue->rx_copy.op, queue->rx_copy.num);
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for (i = 0; i < queue->rx_copy.num; i++) {
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struct gnttab_copy *op;
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op = &queue->rx_copy.op[i];
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/* If the copy failed, overwrite the status field in
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* the corresponding response.
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*/
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if (unlikely(op->status != GNTST_okay)) {
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struct xen_netif_rx_response *rsp;
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rsp = RING_GET_RESPONSE(&queue->rx,
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queue->rx_copy.idx[i]);
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rsp->status = op->status;
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}
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}
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queue->rx_copy.num = 0;
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/* Push responses for all completed packets. */
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RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&queue->rx, notify);
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if (notify)
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notify_remote_via_irq(queue->rx_irq);
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__skb_queue_purge(queue->rx_copy.completed);
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}
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static void xenvif_rx_copy_add(struct xenvif_queue *queue,
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struct xen_netif_rx_request *req,
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unsigned int offset, void *data, size_t len)
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{
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struct gnttab_copy *op;
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struct page *page;
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struct xen_page_foreign *foreign;
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if (queue->rx_copy.num == COPY_BATCH_SIZE)
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xenvif_rx_copy_flush(queue);
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op = &queue->rx_copy.op[queue->rx_copy.num];
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page = virt_to_page(data);
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op->flags = GNTCOPY_dest_gref;
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foreign = xen_page_foreign(page);
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if (foreign) {
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op->source.domid = foreign->domid;
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op->source.u.ref = foreign->gref;
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op->flags |= GNTCOPY_source_gref;
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} else {
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op->source.u.gmfn = virt_to_gfn(data);
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op->source.domid = DOMID_SELF;
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}
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op->source.offset = xen_offset_in_page(data);
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op->dest.u.ref = req->gref;
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op->dest.domid = queue->vif->domid;
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op->dest.offset = offset;
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op->len = len;
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queue->rx_copy.idx[queue->rx_copy.num] = queue->rx.req_cons;
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queue->rx_copy.num++;
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}
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static unsigned int xenvif_gso_type(struct sk_buff *skb)
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{
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if (skb_is_gso(skb)) {
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if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
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return XEN_NETIF_GSO_TYPE_TCPV4;
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else
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return XEN_NETIF_GSO_TYPE_TCPV6;
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}
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return XEN_NETIF_GSO_TYPE_NONE;
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}
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struct xenvif_pkt_state {
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struct sk_buff *skb;
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size_t remaining_len;
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struct sk_buff *frag_iter;
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int frag; /* frag == -1 => frag_iter->head */
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unsigned int frag_offset;
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struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
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unsigned int extra_count;
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unsigned int slot;
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};
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static void xenvif_rx_next_skb(struct xenvif_queue *queue,
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struct xenvif_pkt_state *pkt)
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{
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struct sk_buff *skb;
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unsigned int gso_type;
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skb = xenvif_rx_dequeue(queue);
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queue->stats.tx_bytes += skb->len;
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queue->stats.tx_packets++;
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/* Reset packet state. */
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memset(pkt, 0, sizeof(struct xenvif_pkt_state));
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pkt->skb = skb;
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pkt->frag_iter = skb;
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pkt->remaining_len = skb->len;
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pkt->frag = -1;
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gso_type = xenvif_gso_type(skb);
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if ((1 << gso_type) & queue->vif->gso_mask) {
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struct xen_netif_extra_info *extra;
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extra = &pkt->extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
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extra->u.gso.type = gso_type;
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extra->u.gso.size = skb_shinfo(skb)->gso_size;
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extra->u.gso.pad = 0;
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extra->u.gso.features = 0;
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extra->type = XEN_NETIF_EXTRA_TYPE_GSO;
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extra->flags = 0;
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pkt->extra_count++;
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}
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if (queue->vif->xdp_headroom) {
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struct xen_netif_extra_info *extra;
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extra = &pkt->extras[XEN_NETIF_EXTRA_TYPE_XDP - 1];
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memset(extra, 0, sizeof(struct xen_netif_extra_info));
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extra->u.xdp.headroom = queue->vif->xdp_headroom;
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extra->type = XEN_NETIF_EXTRA_TYPE_XDP;
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extra->flags = 0;
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pkt->extra_count++;
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}
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if (skb->sw_hash) {
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struct xen_netif_extra_info *extra;
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extra = &pkt->extras[XEN_NETIF_EXTRA_TYPE_HASH - 1];
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extra->u.hash.algorithm =
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XEN_NETIF_CTRL_HASH_ALGORITHM_TOEPLITZ;
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if (skb->l4_hash)
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extra->u.hash.type =
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skb->protocol == htons(ETH_P_IP) ?
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_XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP :
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_XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP;
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else
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extra->u.hash.type =
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skb->protocol == htons(ETH_P_IP) ?
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_XEN_NETIF_CTRL_HASH_TYPE_IPV4 :
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_XEN_NETIF_CTRL_HASH_TYPE_IPV6;
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*(uint32_t *)extra->u.hash.value = skb_get_hash_raw(skb);
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extra->type = XEN_NETIF_EXTRA_TYPE_HASH;
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extra->flags = 0;
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pkt->extra_count++;
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}
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}
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static void xenvif_rx_complete(struct xenvif_queue *queue,
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struct xenvif_pkt_state *pkt)
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{
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/* All responses are ready to be pushed. */
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queue->rx.rsp_prod_pvt = queue->rx.req_cons;
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__skb_queue_tail(queue->rx_copy.completed, pkt->skb);
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}
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static void xenvif_rx_next_frag(struct xenvif_pkt_state *pkt)
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{
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struct sk_buff *frag_iter = pkt->frag_iter;
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unsigned int nr_frags = skb_shinfo(frag_iter)->nr_frags;
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pkt->frag++;
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pkt->frag_offset = 0;
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if (pkt->frag >= nr_frags) {
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if (frag_iter == pkt->skb)
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pkt->frag_iter = skb_shinfo(frag_iter)->frag_list;
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else
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pkt->frag_iter = frag_iter->next;
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pkt->frag = -1;
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}
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}
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static void xenvif_rx_next_chunk(struct xenvif_queue *queue,
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struct xenvif_pkt_state *pkt,
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unsigned int offset, void **data,
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size_t *len)
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{
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struct sk_buff *frag_iter = pkt->frag_iter;
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void *frag_data;
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size_t frag_len, chunk_len;
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BUG_ON(!frag_iter);
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if (pkt->frag == -1) {
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frag_data = frag_iter->data;
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frag_len = skb_headlen(frag_iter);
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} else {
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skb_frag_t *frag = &skb_shinfo(frag_iter)->frags[pkt->frag];
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frag_data = skb_frag_address(frag);
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frag_len = skb_frag_size(frag);
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}
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frag_data += pkt->frag_offset;
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frag_len -= pkt->frag_offset;
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chunk_len = min_t(size_t, frag_len, XEN_PAGE_SIZE - offset);
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chunk_len = min_t(size_t, chunk_len, XEN_PAGE_SIZE -
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xen_offset_in_page(frag_data));
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pkt->frag_offset += chunk_len;
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/* Advance to next frag? */
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if (frag_len == chunk_len)
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xenvif_rx_next_frag(pkt);
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*data = frag_data;
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*len = chunk_len;
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}
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static void xenvif_rx_data_slot(struct xenvif_queue *queue,
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struct xenvif_pkt_state *pkt,
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struct xen_netif_rx_request *req,
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struct xen_netif_rx_response *rsp)
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{
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unsigned int offset = queue->vif->xdp_headroom;
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unsigned int flags;
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do {
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size_t len;
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void *data;
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xenvif_rx_next_chunk(queue, pkt, offset, &data, &len);
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xenvif_rx_copy_add(queue, req, offset, data, len);
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offset += len;
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pkt->remaining_len -= len;
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} while (offset < XEN_PAGE_SIZE && pkt->remaining_len > 0);
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if (pkt->remaining_len > 0)
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flags = XEN_NETRXF_more_data;
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else
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flags = 0;
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if (pkt->slot == 0) {
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struct sk_buff *skb = pkt->skb;
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if (skb->ip_summed == CHECKSUM_PARTIAL)
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flags |= XEN_NETRXF_csum_blank |
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XEN_NETRXF_data_validated;
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else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
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flags |= XEN_NETRXF_data_validated;
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if (pkt->extra_count != 0)
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flags |= XEN_NETRXF_extra_info;
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}
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rsp->offset = 0;
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rsp->flags = flags;
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rsp->id = req->id;
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rsp->status = (s16)offset;
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}
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static void xenvif_rx_extra_slot(struct xenvif_queue *queue,
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struct xenvif_pkt_state *pkt,
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struct xen_netif_rx_request *req,
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struct xen_netif_rx_response *rsp)
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{
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struct xen_netif_extra_info *extra = (void *)rsp;
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unsigned int i;
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pkt->extra_count--;
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for (i = 0; i < ARRAY_SIZE(pkt->extras); i++) {
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if (pkt->extras[i].type) {
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*extra = pkt->extras[i];
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if (pkt->extra_count != 0)
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extra->flags |= XEN_NETIF_EXTRA_FLAG_MORE;
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pkt->extras[i].type = 0;
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return;
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}
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}
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BUG();
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}
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static void xenvif_rx_skb(struct xenvif_queue *queue)
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{
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struct xenvif_pkt_state pkt;
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xenvif_rx_next_skb(queue, &pkt);
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queue->last_rx_time = jiffies;
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do {
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struct xen_netif_rx_request *req;
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struct xen_netif_rx_response *rsp;
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req = RING_GET_REQUEST(&queue->rx, queue->rx.req_cons);
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rsp = RING_GET_RESPONSE(&queue->rx, queue->rx.req_cons);
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/* Extras must go after the first data slot */
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if (pkt.slot != 0 && pkt.extra_count != 0)
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xenvif_rx_extra_slot(queue, &pkt, req, rsp);
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else
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xenvif_rx_data_slot(queue, &pkt, req, rsp);
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queue->rx.req_cons++;
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pkt.slot++;
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} while (pkt.remaining_len > 0 || pkt.extra_count != 0);
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xenvif_rx_complete(queue, &pkt);
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}
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#define RX_BATCH_SIZE 64
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void xenvif_rx_action(struct xenvif_queue *queue)
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{
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struct sk_buff_head completed_skbs;
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unsigned int work_done = 0;
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__skb_queue_head_init(&completed_skbs);
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queue->rx_copy.completed = &completed_skbs;
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while (xenvif_rx_ring_slots_available(queue) &&
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work_done < RX_BATCH_SIZE) {
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xenvif_rx_skb(queue);
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work_done++;
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}
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/* Flush any pending copies and complete all skbs. */
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xenvif_rx_copy_flush(queue);
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}
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static bool xenvif_rx_queue_stalled(struct xenvif_queue *queue)
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{
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RING_IDX prod, cons;
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prod = queue->rx.sring->req_prod;
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cons = queue->rx.req_cons;
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return !queue->stalled &&
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prod - cons < 1 &&
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time_after(jiffies,
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queue->last_rx_time + queue->vif->stall_timeout);
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|
}
|
|
|
|
static bool xenvif_rx_queue_ready(struct xenvif_queue *queue)
|
|
{
|
|
RING_IDX prod, cons;
|
|
|
|
prod = queue->rx.sring->req_prod;
|
|
cons = queue->rx.req_cons;
|
|
|
|
return queue->stalled && prod - cons >= 1;
|
|
}
|
|
|
|
bool xenvif_have_rx_work(struct xenvif_queue *queue, bool test_kthread)
|
|
{
|
|
return xenvif_rx_ring_slots_available(queue) ||
|
|
(queue->vif->stall_timeout &&
|
|
(xenvif_rx_queue_stalled(queue) ||
|
|
xenvif_rx_queue_ready(queue))) ||
|
|
(test_kthread && kthread_should_stop()) ||
|
|
queue->vif->disabled;
|
|
}
|
|
|
|
static long xenvif_rx_queue_timeout(struct xenvif_queue *queue)
|
|
{
|
|
struct sk_buff *skb;
|
|
long timeout;
|
|
|
|
skb = skb_peek(&queue->rx_queue);
|
|
if (!skb)
|
|
return MAX_SCHEDULE_TIMEOUT;
|
|
|
|
timeout = XENVIF_RX_CB(skb)->expires - jiffies;
|
|
return timeout < 0 ? 0 : timeout;
|
|
}
|
|
|
|
/* Wait until the guest Rx thread has work.
|
|
*
|
|
* The timeout needs to be adjusted based on the current head of the
|
|
* queue (and not just the head at the beginning). In particular, if
|
|
* the queue is initially empty an infinite timeout is used and this
|
|
* needs to be reduced when a skb is queued.
|
|
*
|
|
* This cannot be done with wait_event_timeout() because it only
|
|
* calculates the timeout once.
|
|
*/
|
|
static void xenvif_wait_for_rx_work(struct xenvif_queue *queue)
|
|
{
|
|
DEFINE_WAIT(wait);
|
|
|
|
if (xenvif_have_rx_work(queue, true))
|
|
return;
|
|
|
|
for (;;) {
|
|
long ret;
|
|
|
|
prepare_to_wait(&queue->wq, &wait, TASK_INTERRUPTIBLE);
|
|
if (xenvif_have_rx_work(queue, true))
|
|
break;
|
|
if (atomic_fetch_andnot(NETBK_RX_EOI | NETBK_COMMON_EOI,
|
|
&queue->eoi_pending) &
|
|
(NETBK_RX_EOI | NETBK_COMMON_EOI))
|
|
xen_irq_lateeoi(queue->rx_irq, 0);
|
|
|
|
ret = schedule_timeout(xenvif_rx_queue_timeout(queue));
|
|
if (!ret)
|
|
break;
|
|
}
|
|
finish_wait(&queue->wq, &wait);
|
|
}
|
|
|
|
static void xenvif_queue_carrier_off(struct xenvif_queue *queue)
|
|
{
|
|
struct xenvif *vif = queue->vif;
|
|
|
|
queue->stalled = true;
|
|
|
|
/* At least one queue has stalled? Disable the carrier. */
|
|
spin_lock(&vif->lock);
|
|
if (vif->stalled_queues++ == 0) {
|
|
netdev_info(vif->dev, "Guest Rx stalled");
|
|
netif_carrier_off(vif->dev);
|
|
}
|
|
spin_unlock(&vif->lock);
|
|
}
|
|
|
|
static void xenvif_queue_carrier_on(struct xenvif_queue *queue)
|
|
{
|
|
struct xenvif *vif = queue->vif;
|
|
|
|
queue->last_rx_time = jiffies; /* Reset Rx stall detection. */
|
|
queue->stalled = false;
|
|
|
|
/* All queues are ready? Enable the carrier. */
|
|
spin_lock(&vif->lock);
|
|
if (--vif->stalled_queues == 0) {
|
|
netdev_info(vif->dev, "Guest Rx ready");
|
|
netif_carrier_on(vif->dev);
|
|
}
|
|
spin_unlock(&vif->lock);
|
|
}
|
|
|
|
int xenvif_kthread_guest_rx(void *data)
|
|
{
|
|
struct xenvif_queue *queue = data;
|
|
struct xenvif *vif = queue->vif;
|
|
|
|
if (!vif->stall_timeout)
|
|
xenvif_queue_carrier_on(queue);
|
|
|
|
for (;;) {
|
|
xenvif_wait_for_rx_work(queue);
|
|
|
|
if (kthread_should_stop())
|
|
break;
|
|
|
|
/* This frontend is found to be rogue, disable it in
|
|
* kthread context. Currently this is only set when
|
|
* netback finds out frontend sends malformed packet,
|
|
* but we cannot disable the interface in softirq
|
|
* context so we defer it here, if this thread is
|
|
* associated with queue 0.
|
|
*/
|
|
if (unlikely(vif->disabled && queue->id == 0)) {
|
|
xenvif_carrier_off(vif);
|
|
break;
|
|
}
|
|
|
|
if (!skb_queue_empty(&queue->rx_queue))
|
|
xenvif_rx_action(queue);
|
|
|
|
/* If the guest hasn't provided any Rx slots for a
|
|
* while it's probably not responsive, drop the
|
|
* carrier so packets are dropped earlier.
|
|
*/
|
|
if (vif->stall_timeout) {
|
|
if (xenvif_rx_queue_stalled(queue))
|
|
xenvif_queue_carrier_off(queue);
|
|
else if (xenvif_rx_queue_ready(queue))
|
|
xenvif_queue_carrier_on(queue);
|
|
}
|
|
|
|
/* Queued packets may have foreign pages from other
|
|
* domains. These cannot be queued indefinitely as
|
|
* this would starve guests of grant refs and transmit
|
|
* slots.
|
|
*/
|
|
xenvif_rx_queue_drop_expired(queue);
|
|
|
|
cond_resched();
|
|
}
|
|
|
|
/* Bin any remaining skbs */
|
|
xenvif_rx_queue_purge(queue);
|
|
|
|
return 0;
|
|
}
|