linux-imx

/*

 * Virtio PCI driver - common functionality for all device versions

 *

 * This module allows virtio devices to be used over a virtual PCI device.

 * This can be used with QEMU based VMMs like KVM or Xen.

 *

 * Copyright IBM Corp. 2007

 * Copyright Red Hat, Inc. 2014

 *

 * Authors:

 *  Anthony Liguori  <aliguori@us.ibm.com>

 *  Rusty Russell <rusty@rustcorp.com.au>

 *  Michael S. Tsirkin <mst@redhat.com>

 *

 * This work is licensed under the terms of the GNU GPL, version 2 or later.

 * See the COPYING file in the top-level directory.

 *

 */

​

#include "virtio_pci_common.h"

​

static bool force_legacy = false;

​

#if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)

module_param(force_legacy, bool, 0444);

MODULE_PARM_DESC(force_legacy,

         "Force legacy mode for transitional virtio 1 devices");

#endif

​

/* wait for pending irq handlers */

void vp_synchronize_vectors(struct virtio_device *vdev)

{

    struct virtio_pci_device *vp_dev = to_vp_device(vdev);

    int i;

​

    if (vp_dev->intx_enabled)

        synchronize_irq(vp_dev->pci_dev->irq);

​

    for (i = 0; i < vp_dev->msix_vectors; ++i)

        synchronize_irq(pci_irq_vector(vp_dev->pci_dev, i));

}

​

/* the notify function used when creating a virt queue */

bool vp_notify(struct virtqueue *vq)

{

    /* we write the queue's selector into the notification register to

     * signal the other end */

    iowrite16(vq->index, (void __iomem *)vq->priv);

    return true;

}

​

/* Handle a configuration change: Tell driver if it wants to know. */

static irqreturn_t vp_config_changed(int irq, void *opaque)

{

    struct virtio_pci_device *vp_dev = opaque;

​

    virtio_config_changed(&vp_dev->vdev);

    return IRQ_HANDLED;

}

​

/* Notify all virtqueues on an interrupt. */

static irqreturn_t vp_vring_interrupt(int irq, void *opaque)

{