281 lines
7.9 KiB
C
281 lines
7.9 KiB
C
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/*
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* Virtio PCI driver - legacy device support
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*
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* This module allows virtio devices to be used over a virtual PCI device.
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* This can be used with QEMU based VMMs like KVM or Xen.
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*
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* Copyright IBM Corp. 2007
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* Copyright Red Hat, Inc. 2014
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*
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* Authors:
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* Anthony Liguori <aliguori@us.ibm.com>
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* Rusty Russell <rusty@rustcorp.com.au>
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* Michael S. Tsirkin <mst@redhat.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or later.
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* See the COPYING file in the top-level directory.
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*
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*/
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#include "virtio_pci_common.h"
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/* virtio config->get_features() implementation */
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static u64 vp_get_features(struct virtio_device *vdev)
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{
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struct virtio_pci_device *vp_dev = to_vp_device(vdev);
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/* When someone needs more than 32 feature bits, we'll need to
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* steal a bit to indicate that the rest are somewhere else. */
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return ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
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}
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/* virtio config->finalize_features() implementation */
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static int vp_finalize_features(struct virtio_device *vdev)
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{
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struct virtio_pci_device *vp_dev = to_vp_device(vdev);
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/* Give virtio_ring a chance to accept features. */
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vring_transport_features(vdev);
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/* Make sure we don't have any features > 32 bits! */
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BUG_ON((u32)vdev->features != vdev->features);
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/* We only support 32 feature bits. */
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iowrite32(vdev->features, vp_dev->ioaddr + VIRTIO_PCI_GUEST_FEATURES);
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return 0;
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}
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/* virtio config->get() implementation */
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static void vp_get(struct virtio_device *vdev, unsigned offset,
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void *buf, unsigned len)
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{
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struct virtio_pci_device *vp_dev = to_vp_device(vdev);
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void __iomem *ioaddr = vp_dev->ioaddr +
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VIRTIO_PCI_CONFIG(vp_dev) + offset;
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u8 *ptr = buf;
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int i;
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for (i = 0; i < len; i++)
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ptr[i] = ioread8(ioaddr + i);
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}
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/* the config->set() implementation. it's symmetric to the config->get()
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* implementation */
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static void vp_set(struct virtio_device *vdev, unsigned offset,
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const void *buf, unsigned len)
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{
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struct virtio_pci_device *vp_dev = to_vp_device(vdev);
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void __iomem *ioaddr = vp_dev->ioaddr +
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VIRTIO_PCI_CONFIG(vp_dev) + offset;
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const u8 *ptr = buf;
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int i;
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for (i = 0; i < len; i++)
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iowrite8(ptr[i], ioaddr + i);
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}
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/* config->{get,set}_status() implementations */
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static u8 vp_get_status(struct virtio_device *vdev)
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{
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struct virtio_pci_device *vp_dev = to_vp_device(vdev);
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return ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
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}
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static void vp_set_status(struct virtio_device *vdev, u8 status)
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{
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struct virtio_pci_device *vp_dev = to_vp_device(vdev);
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/* We should never be setting status to 0. */
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BUG_ON(status == 0);
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iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
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}
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static void vp_reset(struct virtio_device *vdev)
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{
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struct virtio_pci_device *vp_dev = to_vp_device(vdev);
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/* 0 status means a reset. */
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iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
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/* Flush out the status write, and flush in device writes,
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* including MSi-X interrupts, if any. */
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ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
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/* Flush pending VQ/configuration callbacks. */
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vp_synchronize_vectors(vdev);
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}
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static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
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{
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/* Setup the vector used for configuration events */
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iowrite16(vector, vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
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/* Verify we had enough resources to assign the vector */
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/* Will also flush the write out to device */
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return ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
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}
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static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
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struct virtio_pci_vq_info *info,
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unsigned index,
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void (*callback)(struct virtqueue *vq),
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const char *name,
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bool ctx,
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u16 msix_vec)
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{
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struct virtqueue *vq;
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u16 num;
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int err;
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u64 q_pfn;
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/* Select the queue we're interested in */
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iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
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/* Check if queue is either not available or already active. */
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num = ioread16(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NUM);
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if (!num || ioread32(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN))
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return ERR_PTR(-ENOENT);
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info->msix_vector = msix_vec;
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/* create the vring */
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vq = vring_create_virtqueue(index, num,
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VIRTIO_PCI_VRING_ALIGN, &vp_dev->vdev,
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true, false, ctx,
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vp_notify, callback, name);
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if (!vq)
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return ERR_PTR(-ENOMEM);
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q_pfn = virtqueue_get_desc_addr(vq) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT;
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if (q_pfn >> 32) {
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dev_err(&vp_dev->pci_dev->dev,
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"platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n",
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0x1ULL << (32 + PAGE_SHIFT - 30));
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err = -E2BIG;
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goto out_del_vq;
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}
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/* activate the queue */
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iowrite32(q_pfn, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
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vq->priv = (void __force *)vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY;
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if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
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iowrite16(msix_vec, vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
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msix_vec = ioread16(vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
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if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
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err = -EBUSY;
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goto out_deactivate;
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}
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}
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return vq;
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out_deactivate:
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iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
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out_del_vq:
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vring_del_virtqueue(vq);
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return ERR_PTR(err);
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}
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static void del_vq(struct virtio_pci_vq_info *info)
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{
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struct virtqueue *vq = info->vq;
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struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
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iowrite16(vq->index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
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if (vp_dev->msix_enabled) {
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iowrite16(VIRTIO_MSI_NO_VECTOR,
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vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
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/* Flush the write out to device */
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ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
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}
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/* Select and deactivate the queue */
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iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
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vring_del_virtqueue(vq);
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}
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static const struct virtio_config_ops virtio_pci_config_ops = {
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.get = vp_get,
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.set = vp_set,
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.get_status = vp_get_status,
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.set_status = vp_set_status,
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.reset = vp_reset,
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.find_vqs = vp_find_vqs,
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.del_vqs = vp_del_vqs,
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.get_features = vp_get_features,
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.finalize_features = vp_finalize_features,
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.bus_name = vp_bus_name,
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.set_vq_affinity = vp_set_vq_affinity,
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.get_vq_affinity = vp_get_vq_affinity,
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};
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/* the PCI probing function */
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int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
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{
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struct pci_dev *pci_dev = vp_dev->pci_dev;
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int rc;
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/* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
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if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
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return -ENODEV;
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if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) {
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printk(KERN_ERR "virtio_pci: expected ABI version %d, got %d\n",
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VIRTIO_PCI_ABI_VERSION, pci_dev->revision);
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return -ENODEV;
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}
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rc = dma_set_mask(&pci_dev->dev, DMA_BIT_MASK(64));
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if (rc) {
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rc = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(32));
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} else {
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/*
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* The virtio ring base address is expressed as a 32-bit PFN,
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* with a page size of 1 << VIRTIO_PCI_QUEUE_ADDR_SHIFT.
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*/
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dma_set_coherent_mask(&pci_dev->dev,
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DMA_BIT_MASK(32 + VIRTIO_PCI_QUEUE_ADDR_SHIFT));
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}
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if (rc)
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dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
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rc = pci_request_region(pci_dev, 0, "virtio-pci-legacy");
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if (rc)
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return rc;
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rc = -ENOMEM;
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vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
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if (!vp_dev->ioaddr)
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goto err_iomap;
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vp_dev->isr = vp_dev->ioaddr + VIRTIO_PCI_ISR;
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/* we use the subsystem vendor/device id as the virtio vendor/device
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* id. this allows us to use the same PCI vendor/device id for all
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* virtio devices and to identify the particular virtio driver by
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* the subsystem ids */
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vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
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vp_dev->vdev.id.device = pci_dev->subsystem_device;
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vp_dev->vdev.config = &virtio_pci_config_ops;
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vp_dev->config_vector = vp_config_vector;
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vp_dev->setup_vq = setup_vq;
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vp_dev->del_vq = del_vq;
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return 0;
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err_iomap:
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pci_release_region(pci_dev, 0);
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return rc;
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}
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void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
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{
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struct pci_dev *pci_dev = vp_dev->pci_dev;
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pci_iounmap(pci_dev, vp_dev->ioaddr);
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pci_release_region(pci_dev, 0);
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}
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