u-boot/drivers/virtio/virtio-uclass.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2018, Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
* Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
*
* VirtIO is a virtualization standard for network and disk device drivers
* where just the guest's device driver "knows" it is running in a virtual
* environment, and cooperates with the hypervisor. This enables guests to
* get high performance network and disk operations, and gives most of the
* performance benefits of paravirtualization. In the U-Boot case, the guest
* is U-Boot itself, while the virtual environment are normally QEMU targets
* like ARM, RISC-V and x86.
*
* See http://docs.oasis-open.org/virtio/virtio/v1.0/virtio-v1.0.pdf for
* the VirtIO specification v1.0.
*/
#define LOG_CATEGORY UCLASS_VIRTIO
#include <common.h>
#include <bootdev.h>
#include <dm.h>
#include <log.h>
#include <malloc.h>
#include <virtio_types.h>
#include <virtio.h>
#include <dm/lists.h>
#include <linux/bug.h>
static const char *const virtio_drv_name[VIRTIO_ID_MAX_NUM] = {
[VIRTIO_ID_NET] = VIRTIO_NET_DRV_NAME,
[VIRTIO_ID_BLOCK] = VIRTIO_BLK_DRV_NAME,
[VIRTIO_ID_RNG] = VIRTIO_RNG_DRV_NAME,
};
int virtio_get_config(struct udevice *vdev, unsigned int offset,
void *buf, unsigned int len)
{
struct dm_virtio_ops *ops;
ops = virtio_get_ops(vdev->parent);
return ops->get_config(vdev->parent, offset, buf, len);
}
int virtio_set_config(struct udevice *vdev, unsigned int offset,
void *buf, unsigned int len)
{
struct dm_virtio_ops *ops;
ops = virtio_get_ops(vdev->parent);
return ops->set_config(vdev->parent, offset, buf, len);
}
int virtio_generation(struct udevice *vdev, u32 *counter)
{
struct dm_virtio_ops *ops;
ops = virtio_get_ops(vdev->parent);
if (!ops->generation)
return -ENOSYS;
return ops->generation(vdev->parent, counter);
}
int virtio_get_status(struct udevice *vdev, u8 *status)
{
struct dm_virtio_ops *ops;
ops = virtio_get_ops(vdev->parent);
return ops->get_status(vdev->parent, status);
}
int virtio_set_status(struct udevice *vdev, u8 status)
{
struct dm_virtio_ops *ops;
ops = virtio_get_ops(vdev->parent);
return ops->set_status(vdev->parent, status);
}
int virtio_reset(struct udevice *vdev)
{
struct dm_virtio_ops *ops;
ops = virtio_get_ops(vdev->parent);
return ops->reset(vdev->parent);
}
int virtio_get_features(struct udevice *vdev, u64 *features)
{
struct dm_virtio_ops *ops;
ops = virtio_get_ops(vdev->parent);
return ops->get_features(vdev->parent, features);
}
int virtio_set_features(struct udevice *vdev)
{
struct dm_virtio_ops *ops;
ops = virtio_get_ops(vdev->parent);
return ops->set_features(vdev->parent);
}
int virtio_find_vqs(struct udevice *vdev, unsigned int nvqs,
struct virtqueue *vqs[])
{
struct dm_virtio_ops *ops;
ops = virtio_get_ops(vdev->parent);
return ops->find_vqs(vdev->parent, nvqs, vqs);
}
int virtio_del_vqs(struct udevice *vdev)
{
struct dm_virtio_ops *ops;
ops = virtio_get_ops(vdev->parent);
return ops->del_vqs(vdev->parent);
}
int virtio_notify(struct udevice *vdev, struct virtqueue *vq)
{
struct dm_virtio_ops *ops;
ops = virtio_get_ops(vdev->parent);
return ops->notify(vdev->parent, vq);
}
void virtio_add_status(struct udevice *vdev, u8 status)
{
u8 old;
if (!virtio_get_status(vdev, &old))
virtio_set_status(vdev, old | status);
}
int virtio_finalize_features(struct udevice *vdev)
{
struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(vdev->parent);
u8 status;
int ret;
ret = virtio_set_features(vdev);
if (ret)
return ret;
if (uc_priv->legacy)
return 0;
virtio_add_status(vdev, VIRTIO_CONFIG_S_FEATURES_OK);
ret = virtio_get_status(vdev, &status);
if (ret)
return ret;
if (!(status & VIRTIO_CONFIG_S_FEATURES_OK)) {
debug("(%s): device refuses features %x\n", vdev->name, status);
return -EINVAL;
}
return 0;
}
void virtio_driver_features_init(struct virtio_dev_priv *priv,
const u32 *feature,
u32 feature_size,
const u32 *feature_legacy,
u32 feature_legacy_size)
{
priv->feature_table = feature;
priv->feature_table_size = feature_size;
priv->feature_table_legacy = feature_legacy;
priv->feature_table_size_legacy = feature_legacy_size;
}
int virtio_init(void)
{
/* Enumerate all known virtio devices */
return uclass_probe_all(UCLASS_VIRTIO);
}
static int virtio_uclass_pre_probe(struct udevice *udev)
{
struct dm_virtio_ops *ops;
ops = (struct dm_virtio_ops *)(udev->driver->ops);
/*
* Check virtio transport driver ops here so that we don't need
* check these ops each time when the virtio_xxx APIs are called.
*
* Only generation op is optional. All other ops are must-have.
*/
if (!ops->get_config || !ops->set_config ||
!ops->get_status || !ops->set_status ||
!ops->get_features || !ops->set_features ||
!ops->find_vqs || !ops->del_vqs ||
!ops->reset || !ops->notify)
return -ENOENT;
return 0;
}
static int virtio_uclass_post_probe(struct udevice *udev)
{
struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(udev);
char dev_name[30], *str;
struct udevice *vdev;
const char *name;
int ret;
if (uc_priv->device >= VIRTIO_ID_MAX_NUM) {
debug("(%s): virtio device ID %d exceeds maximum num\n",
udev->name, uc_priv->device);
return 0;
}
name = virtio_drv_name[uc_priv->device];
if (!name) {
debug("(%s): underlying virtio device driver unavailable\n",
udev->name);
return 0;
}
snprintf(dev_name, sizeof(dev_name), "%s#%d", name, dev_seq(udev));
str = strdup(dev_name);
if (!str)
return -ENOMEM;
ret = device_bind_driver(udev, name, str, &vdev);
if (ret == -ENOENT) {
debug("(%s): no driver configured\n", udev->name);
return 0;
}
if (ret) {
free(str);
return ret;
}
device_set_name_alloced(vdev);
if (uc_priv->device == VIRTIO_ID_BLOCK && !IS_ENABLED(CONFIG_SANDBOX)) {
ret = bootdev_setup_sibling_blk(vdev, "virtio_bootdev");
if (ret)
return log_msg_ret("bootdev", ret);
}
INIT_LIST_HEAD(&uc_priv->vqs);
return 0;
}
static int virtio_uclass_child_post_bind(struct udevice *vdev)
{
/* Acknowledge that we've seen the device */
virtio_add_status(vdev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
return 0;
}
static int virtio_uclass_child_pre_probe(struct udevice *vdev)
{
struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(vdev->parent);
u64 device_features;
u64 driver_features;
u64 driver_features_legacy;
int i;
int ret;
/* bootdevs are not virtio devices */
if (device_get_uclass_id(vdev) == UCLASS_BOOTDEV)
return 0;
/*
* Save the real virtio device (eg: virtio-net, virtio-blk) to
* the transport (parent) device's uclass priv for future use.
*/
uc_priv->vdev = vdev;
/*
* We always start by resetting the device, in case a previous driver
* messed it up. This also tests that code path a little.
*/
ret = virtio_reset(vdev);
if (ret)
goto err;
/* We have a driver! */
virtio_add_status(vdev, VIRTIO_CONFIG_S_DRIVER);
/* Figure out what features the device supports */
virtio_get_features(vdev, &device_features);
debug("(%s) plain device features supported %016llx\n",
vdev->name, device_features);
if (!(device_features & (1ULL << VIRTIO_F_VERSION_1)))
uc_priv->legacy = true;
/* Figure out what features the driver supports */
driver_features = 0;
for (i = 0; i < uc_priv->feature_table_size; i++) {
unsigned int f = uc_priv->feature_table[i];
WARN_ON(f >= 64);
driver_features |= (1ULL << f);
}
/* Some drivers have a separate feature table for virtio v1.0 */
if (uc_priv->feature_table_legacy) {
driver_features_legacy = 0;
for (i = 0; i < uc_priv->feature_table_size_legacy; i++) {
unsigned int f = uc_priv->feature_table_legacy[i];
WARN_ON(f >= 64);
driver_features_legacy |= (1ULL << f);
}
} else {
driver_features_legacy = driver_features;
}
if (uc_priv->legacy) {
debug("(%s): legacy virtio device\n", vdev->name);
uc_priv->features = driver_features_legacy & device_features;
} else {
debug("(%s): v1.0 complaint virtio device\n", vdev->name);
uc_priv->features = driver_features & device_features;
}
/* Transport features always preserved to pass to finalize_features */
for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++)
if ((device_features & (1ULL << i)) &&
(i == VIRTIO_F_VERSION_1 || i == VIRTIO_F_IOMMU_PLATFORM))
__virtio_set_bit(vdev->parent, i);
debug("(%s) final negotiated features supported %016llx\n",
vdev->name, uc_priv->features);
ret = virtio_finalize_features(vdev);
if (ret)
goto err;
return 0;
err:
virtio_add_status(vdev, VIRTIO_CONFIG_S_FAILED);
return ret;
}
static int virtio_uclass_child_post_probe(struct udevice *vdev)
{
/* Indicates that the driver is set up and ready to drive the device */
virtio_add_status(vdev, VIRTIO_CONFIG_S_DRIVER_OK);
return 0;
}
static int virtio_bootdev_bind(struct udevice *dev)
{
struct bootdev_uc_plat *ucp = dev_get_uclass_plat(dev);
ucp->prio = BOOTDEVP_4_SCAN_FAST;
return 0;
}
static int virtio_bootdev_hunt(struct bootdev_hunter *info, bool show)
{
int ret;
ret = uclass_probe_all(UCLASS_VIRTIO);
if (ret && ret != -ENOENT)
return log_msg_ret("vir", ret);
return 0;
}
UCLASS_DRIVER(virtio) = {
.name = "virtio",
.id = UCLASS_VIRTIO,
.flags = DM_UC_FLAG_SEQ_ALIAS,
.pre_probe = virtio_uclass_pre_probe,
.post_probe = virtio_uclass_post_probe,
.child_post_bind = virtio_uclass_child_post_bind,
.child_pre_probe = virtio_uclass_child_pre_probe,
.child_post_probe = virtio_uclass_child_post_probe,
.per_device_auto = sizeof(struct virtio_dev_priv),
};
struct bootdev_ops virtio_bootdev_ops = {
};
static const struct udevice_id virtio_bootdev_ids[] = {
{ .compatible = "u-boot,bootdev-virtio" },
{ }
};
U_BOOT_DRIVER(virtio_bootdev) = {
.name = "virtio_bootdev",
.id = UCLASS_BOOTDEV,
.ops = &virtio_bootdev_ops,
.bind = virtio_bootdev_bind,
.of_match = virtio_bootdev_ids,
};
BOOTDEV_HUNTER(virtio_bootdev_hunter) = {
.prio = BOOTDEVP_4_SCAN_FAST,
.uclass = UCLASS_VIRTIO,
.hunt = virtio_bootdev_hunt,
.drv = DM_DRIVER_REF(virtio_bootdev),
};