/*
* 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>
*
* 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"
/* 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 ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
}
/* 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. */
iowrite32(vdev->features, vp_dev->ioaddr + VIRTIO_PCI_GUEST_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->ioaddr +
VIRTIO_PCI_CONFIG(vp_dev) + 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->ioaddr +
VIRTIO_PCI_CONFIG(vp_dev) + 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 ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
}
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);
iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
}
static void vp_reset(struct virtio_device *vdev)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
/* 0 status means a reset. */
iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
/* Flush out the status write, and flush in device writes,
* including MSi-X interrupts, if any. */
ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
/* Flush pending VQ/configuration callbacks. */
vp_synchronize_vectors(vdev);
}
static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
{
/* Setup the vector used for configuration events */
iowrite16(vector, vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
/* Verify we had enough resources to assign the vector */
/* Will also flush the write out to device */
return ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
}
static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
unsigned index,
void (*callback)(struct virtqueue *vq),
const char *name,
u16 msix_vec)
{
struct virtqueue *vq;
u16 num;
int err;
/* Select the queue we're interested in */
iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
/* Check if queue is either not available or already active. */
num = ioread16(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NUM);
if (!num || ioread32(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN))
return ERR_PTR(-ENOENT);
/* create the vring */
vq = vring_create_virtqueue(index, num,
VIRTIO_PCI_VRING_ALIGN, &vp_dev->vdev,
true, false, vp_notify, callback, name);
if (!vq)
return ERR_PTR(-ENOMEM);
/* activate the queue */
iowrite32(virtqueue_get_desc_addr(vq) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT,
vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
vq->priv = (void __force *)vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY;
if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
iowrite16(msix_vec, vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
msix_vec = ioread16(vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
err = -EBUSY;
goto out_deactivate;
}
}
return vq;
out_deactivate:
iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
vring_del_virtqueue(vq);
return ERR_PTR(err);
}
static void del_vq(struct virtqueue *vq)
{
struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
iowrite16(vq->index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
if (vp_dev->pci_dev->msix_enabled) {
iowrite16(VIRTIO_MSI_NO_VECTOR,
vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
/* Flush the write out to device */
ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
}
/* Select and deactivate the queue */
iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
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 pci_dev *pci_dev = vp_dev->pci_dev;
int rc;
/* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
return -ENODEV;
if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) {
printk(KERN_ERR "virtio_pci: expected ABI version %d, got %d\n",
VIRTIO_PCI_ABI_VERSION, pci_dev->revision);
return -ENODEV;
}
rc = dma_set_mask(&pci_dev->dev, DMA_BIT_MASK(64));
if (rc) {
rc = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(32));
} else {
/*
* The virtio ring base address is expressed as a 32-bit PFN,
* with a page size of 1 << VIRTIO_PCI_QUEUE_ADDR_SHIFT.
*/
dma_set_coherent_mask(&pci_dev->dev,
DMA_BIT_MASK(32 + VIRTIO_PCI_QUEUE_ADDR_SHIFT));
}
if (rc)
dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
rc = pci_request_region(pci_dev, 0, "virtio-pci-legacy");
if (rc)
return rc;
rc = -ENOMEM;
vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
if (!vp_dev->ioaddr)
goto err_iomap;
vp_dev->isr = vp_dev->ioaddr + VIRTIO_PCI_ISR;
/* we use the subsystem vendor/device id as the virtio vendor/device
* id. this allows us to use the same PCI vendor/device id for all
* virtio devices and to identify the particular virtio driver by
* the subsystem ids */
vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
vp_dev->vdev.id.device = pci_dev->subsystem_device;
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;
err_iomap:
pci_release_region(pci_dev, 0);
return rc;
}
void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
{
struct pci_dev *pci_dev = vp_dev->pci_dev;
pci_iounmap(pci_dev, vp_dev->ioaddr);
pci_release_region(pci_dev, 0);
}
