OpenCloudOS-Kernel/drivers/virtio/virtio_pci_common.c

517 lines
13 KiB
C

/*
* 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;
synchronize_irq(pci_irq_vector(vp_dev->pci_dev, 0));
for (i = 1; 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)
{
struct virtio_pci_device *vp_dev = opaque;
irqreturn_t ret = IRQ_NONE;
struct virtqueue *vq;
list_for_each_entry(vq, &vp_dev->vdev.vqs, list) {
if (vq->callback && vring_interrupt(irq, vq) == IRQ_HANDLED)
ret = IRQ_HANDLED;
}
return ret;
}
/* A small wrapper to also acknowledge the interrupt when it's handled.
* I really need an EIO hook for the vring so I can ack the interrupt once we
* know that we'll be handling the IRQ but before we invoke the callback since
* the callback may notify the host which results in the host attempting to
* raise an interrupt that we would then mask once we acknowledged the
* interrupt. */
static irqreturn_t vp_interrupt(int irq, void *opaque)
{
struct virtio_pci_device *vp_dev = opaque;
u8 isr;
/* reading the ISR has the effect of also clearing it so it's very
* important to save off the value. */
isr = ioread8(vp_dev->isr);
/* It's definitely not us if the ISR was not high */
if (!isr)
return IRQ_NONE;
/* Configuration change? Tell driver if it wants to know. */
if (isr & VIRTIO_PCI_ISR_CONFIG)
vp_config_changed(irq, opaque);
return vp_vring_interrupt(irq, opaque);
}
static void vp_remove_vqs(struct virtio_device *vdev)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
struct virtqueue *vq, *n;
list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
if (vp_dev->msix_vector_map) {
int v = vp_dev->msix_vector_map[vq->index];
if (v != VIRTIO_MSI_NO_VECTOR)
free_irq(pci_irq_vector(vp_dev->pci_dev, v),
vq);
}
vp_dev->del_vq(vq);
}
}
/* the config->del_vqs() implementation */
void vp_del_vqs(struct virtio_device *vdev)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
int i;
if (WARN_ON_ONCE(list_empty_careful(&vdev->vqs)))
return;
vp_remove_vqs(vdev);
if (vp_dev->pci_dev->msix_enabled) {
for (i = 0; i < vp_dev->msix_vectors; i++)
free_cpumask_var(vp_dev->msix_affinity_masks[i]);
/* Disable the vector used for configuration */
vp_dev->config_vector(vp_dev, VIRTIO_MSI_NO_VECTOR);
kfree(vp_dev->msix_affinity_masks);
kfree(vp_dev->msix_names);
kfree(vp_dev->msix_vector_map);
}
free_irq(pci_irq_vector(vp_dev->pci_dev, 0), vp_dev);
pci_free_irq_vectors(vp_dev->pci_dev);
}
static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned nvqs,
struct virtqueue *vqs[], vq_callback_t *callbacks[],
const char * const names[], struct irq_affinity *desc)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
const char *name = dev_name(&vp_dev->vdev.dev);
int i, j, err = -ENOMEM, allocated_vectors, nvectors;
unsigned flags = PCI_IRQ_MSIX;
bool shared = false;
u16 msix_vec;
if (desc) {
flags |= PCI_IRQ_AFFINITY;
desc->pre_vectors++; /* virtio config vector */
}
nvectors = 1;
for (i = 0; i < nvqs; i++)
if (callbacks[i])
nvectors++;
/* Try one vector per queue first. */
err = pci_alloc_irq_vectors_affinity(vp_dev->pci_dev, nvectors,
nvectors, flags, desc);
if (err < 0) {
/* Fallback to one vector for config, one shared for queues. */
shared = true;
err = pci_alloc_irq_vectors(vp_dev->pci_dev, 2, 2,
PCI_IRQ_MSIX);
if (err < 0)
return err;
}
if (err < 0)
return err;
vp_dev->msix_vectors = nvectors;
vp_dev->msix_names = kmalloc_array(nvectors,
sizeof(*vp_dev->msix_names), GFP_KERNEL);
if (!vp_dev->msix_names)
goto out_free_irq_vectors;
vp_dev->msix_affinity_masks = kcalloc(nvectors,
sizeof(*vp_dev->msix_affinity_masks), GFP_KERNEL);
if (!vp_dev->msix_affinity_masks)
goto out_free_msix_names;
for (i = 0; i < nvectors; ++i) {
if (!alloc_cpumask_var(&vp_dev->msix_affinity_masks[i],
GFP_KERNEL))
goto out_free_msix_affinity_masks;
}
/* Set the vector used for configuration */
snprintf(vp_dev->msix_names[0], sizeof(*vp_dev->msix_names),
"%s-config", name);
err = request_irq(pci_irq_vector(vp_dev->pci_dev, 0), vp_config_changed,
0, vp_dev->msix_names[0], vp_dev);
if (err)
goto out_free_msix_affinity_masks;
/* Verify we had enough resources to assign the vector */
if (vp_dev->config_vector(vp_dev, 0) == VIRTIO_MSI_NO_VECTOR) {
err = -EBUSY;
goto out_free_config_irq;
}
vp_dev->msix_vector_map = kmalloc_array(nvqs,
sizeof(*vp_dev->msix_vector_map), GFP_KERNEL);
if (!vp_dev->msix_vector_map)
goto out_disable_config_irq;
allocated_vectors = j = 1; /* vector 0 is the config interrupt */
for (i = 0; i < nvqs; ++i) {
if (!names[i]) {
vqs[i] = NULL;
continue;
}
if (callbacks[i])
msix_vec = allocated_vectors;
else
msix_vec = VIRTIO_MSI_NO_VECTOR;
vqs[i] = vp_dev->setup_vq(vp_dev, i, callbacks[i], names[i],
msix_vec);
if (IS_ERR(vqs[i])) {
err = PTR_ERR(vqs[i]);
goto out_remove_vqs;
}
if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
vp_dev->msix_vector_map[i] = VIRTIO_MSI_NO_VECTOR;
continue;
}
snprintf(vp_dev->msix_names[j],
sizeof(*vp_dev->msix_names), "%s-%s",
dev_name(&vp_dev->vdev.dev), names[i]);
err = request_irq(pci_irq_vector(vp_dev->pci_dev, msix_vec),
vring_interrupt, IRQF_SHARED,
vp_dev->msix_names[j], vqs[i]);
if (err) {
/* don't free this irq on error */
vp_dev->msix_vector_map[i] = VIRTIO_MSI_NO_VECTOR;
goto out_remove_vqs;
}
vp_dev->msix_vector_map[i] = msix_vec;
j++;
/*
* Use a different vector for each queue if they are available,
* else share the same vector for all VQs.
*/
if (!shared)
allocated_vectors++;
}
return 0;
out_remove_vqs:
vp_remove_vqs(vdev);
kfree(vp_dev->msix_vector_map);
out_disable_config_irq:
vp_dev->config_vector(vp_dev, VIRTIO_MSI_NO_VECTOR);
out_free_config_irq:
free_irq(pci_irq_vector(vp_dev->pci_dev, 0), vp_dev);
out_free_msix_affinity_masks:
for (i = 0; i < nvectors; i++) {
if (vp_dev->msix_affinity_masks[i])
free_cpumask_var(vp_dev->msix_affinity_masks[i]);
}
kfree(vp_dev->msix_affinity_masks);
out_free_msix_names:
kfree(vp_dev->msix_names);
out_free_irq_vectors:
pci_free_irq_vectors(vp_dev->pci_dev);
return err;
}
static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned nvqs,
struct virtqueue *vqs[], vq_callback_t *callbacks[],
const char * const names[])
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
int i, err;
err = request_irq(vp_dev->pci_dev->irq, vp_interrupt, IRQF_SHARED,
dev_name(&vdev->dev), vp_dev);
if (err)
return err;
for (i = 0; i < nvqs; ++i) {
if (!names[i]) {
vqs[i] = NULL;
continue;
}
vqs[i] = vp_dev->setup_vq(vp_dev, i, callbacks[i], names[i],
VIRTIO_MSI_NO_VECTOR);
if (IS_ERR(vqs[i])) {
err = PTR_ERR(vqs[i]);
goto out_remove_vqs;
}
}
return 0;
out_remove_vqs:
vp_remove_vqs(vdev);
free_irq(pci_irq_vector(vp_dev->pci_dev, 0), vp_dev);
return err;
}
/* the config->find_vqs() implementation */
int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
struct virtqueue *vqs[], vq_callback_t *callbacks[],
const char * const names[], struct irq_affinity *desc)
{
int err;
err = vp_find_vqs_msix(vdev, nvqs, vqs, callbacks, names, desc);
if (!err)
return 0;
return vp_find_vqs_intx(vdev, nvqs, vqs, callbacks, names);
}
const char *vp_bus_name(struct virtio_device *vdev)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
return pci_name(vp_dev->pci_dev);
}
/* Setup the affinity for a virtqueue:
* - force the affinity for per vq vector
* - OR over all affinities for shared MSI
* - ignore the affinity request if we're using INTX
*/
int vp_set_vq_affinity(struct virtqueue *vq, int cpu)
{
struct virtio_device *vdev = vq->vdev;
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
if (!vq->callback)
return -EINVAL;
if (vp_dev->pci_dev->msix_enabled) {
int vec = vp_dev->msix_vector_map[vq->index];
struct cpumask *mask = vp_dev->msix_affinity_masks[vec];
unsigned int irq = pci_irq_vector(vp_dev->pci_dev, vec);
if (cpu == -1)
irq_set_affinity_hint(irq, NULL);
else {
cpumask_clear(mask);
cpumask_set_cpu(cpu, mask);
irq_set_affinity_hint(irq, mask);
}
}
return 0;
}
const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
unsigned int *map = vp_dev->msix_vector_map;
if (!map || map[index] == VIRTIO_MSI_NO_VECTOR)
return NULL;
return pci_irq_get_affinity(vp_dev->pci_dev, map[index]);
}
#ifdef CONFIG_PM_SLEEP
static int virtio_pci_freeze(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
int ret;
ret = virtio_device_freeze(&vp_dev->vdev);
if (!ret)
pci_disable_device(pci_dev);
return ret;
}
static int virtio_pci_restore(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
int ret;
ret = pci_enable_device(pci_dev);
if (ret)
return ret;
pci_set_master(pci_dev);
return virtio_device_restore(&vp_dev->vdev);
}
static const struct dev_pm_ops virtio_pci_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(virtio_pci_freeze, virtio_pci_restore)
};
#endif
/* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
static const struct pci_device_id virtio_pci_id_table[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_REDHAT_QUMRANET, PCI_ANY_ID) },
{ 0 }
};
MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
static void virtio_pci_release_dev(struct device *_d)
{
struct virtio_device *vdev = dev_to_virtio(_d);
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
/* As struct device is a kobject, it's not safe to
* free the memory (including the reference counter itself)
* until it's release callback. */
kfree(vp_dev);
}
static int virtio_pci_probe(struct pci_dev *pci_dev,
const struct pci_device_id *id)
{
struct virtio_pci_device *vp_dev;
int rc;
/* allocate our structure and fill it out */
vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
if (!vp_dev)
return -ENOMEM;
pci_set_drvdata(pci_dev, vp_dev);
vp_dev->vdev.dev.parent = &pci_dev->dev;
vp_dev->vdev.dev.release = virtio_pci_release_dev;
vp_dev->pci_dev = pci_dev;
/* enable the device */
rc = pci_enable_device(pci_dev);
if (rc)
goto err_enable_device;
if (force_legacy) {
rc = virtio_pci_legacy_probe(vp_dev);
/* Also try modern mode if we can't map BAR0 (no IO space). */
if (rc == -ENODEV || rc == -ENOMEM)
rc = virtio_pci_modern_probe(vp_dev);
if (rc)
goto err_probe;
} else {
rc = virtio_pci_modern_probe(vp_dev);
if (rc == -ENODEV)
rc = virtio_pci_legacy_probe(vp_dev);
if (rc)
goto err_probe;
}
pci_set_master(pci_dev);
rc = register_virtio_device(&vp_dev->vdev);
if (rc)
goto err_register;
return 0;
err_register:
if (vp_dev->ioaddr)
virtio_pci_legacy_remove(vp_dev);
else
virtio_pci_modern_remove(vp_dev);
err_probe:
pci_disable_device(pci_dev);
err_enable_device:
kfree(vp_dev);
return rc;
}
static void virtio_pci_remove(struct pci_dev *pci_dev)
{
struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
struct device *dev = get_device(&vp_dev->vdev.dev);
unregister_virtio_device(&vp_dev->vdev);
if (vp_dev->ioaddr)
virtio_pci_legacy_remove(vp_dev);
else
virtio_pci_modern_remove(vp_dev);
pci_disable_device(pci_dev);
put_device(dev);
}
static struct pci_driver virtio_pci_driver = {
.name = "virtio-pci",
.id_table = virtio_pci_id_table,
.probe = virtio_pci_probe,
.remove = virtio_pci_remove,
#ifdef CONFIG_PM_SLEEP
.driver.pm = &virtio_pci_pm_ops,
#endif
};
module_pci_driver(virtio_pci_driver);
MODULE_AUTHOR("Anthony Liguori <aliguori@us.ibm.com>");
MODULE_DESCRIPTION("virtio-pci");
MODULE_LICENSE("GPL");
MODULE_VERSION("1");