drivers/virtio/virtio-uclass.c - platform/external/u-boot - Gitiles

 // 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): %s driver not configured\n", udev->name, 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_for_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;

 	if (IS_ENABLED(CONFIG_PCI)) {
 		ret = uclass_probe_all(UCLASS_PCI);
 		if (ret && ret != -ENOENT)
 			return log_msg_ret("pci", 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),
 };
	// 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): %s driver not configured\n", udev->name, 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_for_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;

	if (IS_ENABLED(CONFIG_PCI)) {
	ret = uclass_probe_all(UCLASS_PCI);
	if (ret && ret != -ENOENT)
	return log_msg_ret("pci", 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),
	};