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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Virtio PCI driver - legacy device support
*
* 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>
*/
#include "linux/virtio_pci_legacy.h"
#include "virtio_pci_common.h"
/* virtio config->get_features() implementation */
static u64 vp_get_features(struct virtio_device *vdev)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
/* When someone needs more than 32 feature bits, we'll need to
* steal a bit to indicate that the rest are somewhere else. */
return vp_legacy_get_features(&vp_dev->ldev);
}
/* virtio config->finalize_features() implementation */
static int vp_finalize_features(struct virtio_device *vdev)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
/* Give virtio_ring a chance to accept features. */
vring_transport_features(vdev);
/* Make sure we don't have any features > 32 bits! */
BUG_ON((u32)vdev->features != vdev->features);
/* We only support 32 feature bits. */
vp_legacy_set_features(&vp_dev->ldev, vdev->features);
return 0;
}
/* virtio config->get() implementation */
static void vp_get(struct virtio_device *vdev, unsigned offset,
void *buf, unsigned len)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
void __iomem *ioaddr = vp_dev->ldev.ioaddr +
VIRTIO_PCI_CONFIG_OFF(vp_dev->msix_enabled) +
offset;
u8 *ptr = buf;
int i;
for (i = 0; i < len; i++)
ptr[i] = ioread8(ioaddr + i);
}
/* the config->set() implementation. it's symmetric to the config->get()
* implementation */
static void vp_set(struct virtio_device *vdev, unsigned offset,
const void *buf, unsigned len)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
void __iomem *ioaddr = vp_dev->ldev.ioaddr +
VIRTIO_PCI_CONFIG_OFF(vp_dev->msix_enabled) +
offset;
const u8 *ptr = buf;
int i;
for (i = 0; i < len; i++)
iowrite8(ptr[i], ioaddr + i);
}
/* config->{get,set}_status() implementations */
static u8 vp_get_status(struct virtio_device *vdev)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
return vp_legacy_get_status(&vp_dev->ldev);
}
static void vp_set_status(struct virtio_device *vdev, u8 status)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
/* We should never be setting status to 0. */
BUG_ON(status == 0);
vp_legacy_set_status(&vp_dev->ldev, status);
}
static void vp_reset(struct virtio_device *vdev)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
/* 0 status means a reset. */
vp_legacy_set_status(&vp_dev->ldev, 0);
/* Flush out the status write, and flush in device writes,
* including MSi-X interrupts, if any. */
vp_legacy_get_status(&vp_dev->ldev);
/* Flush pending VQ/configuration callbacks. */
vp_synchronize_vectors(vdev);
}
static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
{
return vp_legacy_config_vector(&vp_dev->ldev, vector);
}
static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
struct virtio_pci_vq_info *info,
unsigned index,
void (*callback)(struct virtqueue *vq),
const char *name,
bool ctx,
u16 msix_vec)
{
struct virtqueue *vq;
u16 num;
int err;
u64 q_pfn;
/* Check if queue is either not available or already active. */
num = vp_legacy_get_queue_size(&vp_dev->ldev, index);
if (!num || vp_legacy_get_queue_enable(&vp_dev->ldev, index))
return ERR_PTR(-ENOENT);
info->msix_vector = msix_vec;
/* create the vring */
vq = vring_create_virtqueue(index, num,
VIRTIO_PCI_VRING_ALIGN, &vp_dev->vdev,
true, false, ctx,
vp_notify, callback, name);
if (!vq)
return ERR_PTR(-ENOMEM);
q_pfn = virtqueue_get_desc_addr(vq) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT;
if (q_pfn >> 32) {
dev_err(&vp_dev->pci_dev->dev,
"platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n",
0x1ULL << (32 + PAGE_SHIFT - 30));
err = -E2BIG;
goto out_del_vq;
}
/* activate the queue */
vp_legacy_set_queue_address(&vp_dev->ldev, index, q_pfn);
vq->priv = (void __force *)vp_dev->ldev.ioaddr + VIRTIO_PCI_QUEUE_NOTIFY;
if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
msix_vec = vp_legacy_queue_vector(&vp_dev->ldev, index, msix_vec);
if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
err = -EBUSY;
goto out_deactivate;
}
}
return vq;
out_deactivate:
vp_legacy_set_queue_address(&vp_dev->ldev, index, 0);
out_del_vq:
vring_del_virtqueue(vq);
return ERR_PTR(err);
}
static void del_vq(struct virtio_pci_vq_info *info)
{
struct virtqueue *vq = info->vq;
struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
if (vp_dev->msix_enabled) {
vp_legacy_queue_vector(&vp_dev->ldev, vq->index,
VIRTIO_MSI_NO_VECTOR);
/* Flush the write out to device */
ioread8(vp_dev->ldev.ioaddr + VIRTIO_PCI_ISR);
}
/* Select and deactivate the queue */
vp_legacy_set_queue_address(&vp_dev->ldev, vq->index, 0);
vring_del_virtqueue(vq);
}
static const struct virtio_config_ops virtio_pci_config_ops = {
.get = vp_get,
.set = vp_set,
.get_status = vp_get_status,
.set_status = vp_set_status,
.reset = vp_reset,
.find_vqs = vp_find_vqs,
.del_vqs = vp_del_vqs,
.get_features = vp_get_features,
.finalize_features = vp_finalize_features,
.bus_name = vp_bus_name,
.set_vq_affinity = vp_set_vq_affinity,
.get_vq_affinity = vp_get_vq_affinity,
};
/* the PCI probing function */
int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
{
struct virtio_pci_legacy_device *ldev = &vp_dev->ldev;
struct pci_dev *pci_dev = vp_dev->pci_dev;
int rc;
ldev->pci_dev = pci_dev;
rc = vp_legacy_probe(ldev);
if (rc)
return rc;
vp_dev->isr = ldev->isr;
vp_dev->vdev.id = ldev->id;
vp_dev->vdev.config = &virtio_pci_config_ops;
vp_dev->config_vector = vp_config_vector;
vp_dev->setup_vq = setup_vq;
vp_dev->del_vq = del_vq;
return 0;
}
void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
{
struct virtio_pci_legacy_device *ldev = &vp_dev->ldev;
vp_legacy_remove(ldev);
}
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