linux-imx

/*

 * Network-device interface management.

 *

 * Copyright (c) 2004-2005, Keir Fraser

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License version 2

 * as published by the Free Software Foundation; or, when distributed

 * separately from the Linux kernel or incorporated into other

 * software packages, subject to the following license:

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this source file (the "Software"), to deal in the Software without

 * restriction, including without limitation the rights to use, copy, modify,

 * merge, publish, distribute, sublicense, and/or sell copies of the Software,

 * and to permit persons to whom the Software is furnished to do so, subject to

 * the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS

 * IN THE SOFTWARE.

 */

​

#include "common.h"

​

#include <linux/kthread.h>

#include <linux/sched/task.h>

#include <linux/ethtool.h>

#include <linux/rtnetlink.h>

#include <linux/if_vlan.h>

#include <linux/vmalloc.h>

​

#include <xen/events.h>

#include <asm/xen/hypercall.h>

#include <xen/balloon.h>

​

#define XENVIF_QUEUE_LENGTH 32

#define XENVIF_NAPI_WEIGHT  64

​

/* Number of bytes allowed on the internal guest Rx queue. */

#define XENVIF_RX_QUEUE_BYTES (XEN_NETIF_RX_RING_SIZE/2 * PAGE_SIZE)

​

/* This function is used to set SKBTX_DEV_ZEROCOPY as well as

 * increasing the inflight counter. We need to increase the inflight

 * counter because core driver calls into xenvif_zerocopy_callback

 * which calls xenvif_skb_zerocopy_complete.

 */

void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue,

                 struct sk_buff *skb)

{

    skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;

    atomic_inc(&queue->inflight_packets);

}

​

void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue)

{

    atomic_dec(&queue->inflight_packets);

​

    /* Wake the dealloc thread _after_ decrementing inflight_packets so

     * that if kthread_stop() has already been called, the dealloc thread

     * does not wait forever with nothing to wake it.

     */

    wake_up(&queue->dealloc_wq);

}

​

int xenvif_schedulable(struct xenvif *vif)

{

    return netif_running(vif->dev) &&

        test_bit(VIF_STATUS_CONNECTED, &vif->status) &&

        !vif->disabled;

}

​

static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id)

{

    struct xenvif_queue *queue = dev_id;

​

    if (RING_HAS_UNCONSUMED_REQUESTS(&queue->tx))

        napi_schedule(&queue->napi);

​

    return IRQ_HANDLED;

}

​

static int xenvif_poll(struct napi_struct *napi, int budget)

{

    struct xenvif_queue *queue =