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279 lines
7.8 KiB
279 lines
7.8 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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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 <[email protected]> |
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* Rusty Russell <[email protected]> |
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* Michael S. Tsirkin <[email protected]> |
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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_OFF(vp_dev->msix_enabled) + |
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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_OFF(vp_dev->msix_enabled) + |
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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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