[U-Boot] [PATCH 02/27] dm: Add a new uclass driver for VirtIO transport devices

Simon Glass sjg at chromium.org
Thu Sep 27 13:42:04 UTC 2018


Hi Bin,

On 23 September 2018 at 06:42, Bin Meng <bmeng.cn at gmail.com> wrote:
> This adds a new virtio uclass driver for “virtio” [1] family of
> devices that are are found in virtual environments like QEMU,
> yet by design they look like physical devices to the guest.
>
> The uclass driver provides child_pre_probe() and child_post_probe()
> methods to do some common operations for virtio device drivers like
> device and driver supported feature negotiation, etc.
>
> [1] http://docs.oasis-open.org/virtio/virtio/v1.0/virtio-v1.0.pdf

Can you add this link to the header file too? This seems to be lacking
docs.in the source code. Also in a header file, a short statement of
what virtio is for would be good.

>
> Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen at iki.fi>
> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
> ---
>
>  drivers/Kconfig                |   2 +
>  drivers/Makefile               |   1 +
>  drivers/virtio/Kconfig         |  14 +
>  drivers/virtio/Makefile        |   6 +
>  drivers/virtio/virtio-uclass.c | 333 ++++++++++++++++++++
>  include/dm/uclass-id.h         |   1 +
>  include/virtio.h               | 694 +++++++++++++++++++++++++++++++++++++++++
>  include/virtio_types.h         |  24 ++
>  8 files changed, 1075 insertions(+)
>  create mode 100644 drivers/virtio/Kconfig
>  create mode 100644 drivers/virtio/Makefile
>  create mode 100644 drivers/virtio/virtio-uclass.c
>  create mode 100644 include/virtio.h
>  create mode 100644 include/virtio_types.h
>
> diff --git a/drivers/Kconfig b/drivers/Kconfig
> index 56536c4..d40db0d 100644
> --- a/drivers/Kconfig
> +++ b/drivers/Kconfig
> @@ -106,6 +106,8 @@ source "drivers/usb/Kconfig"
>
>  source "drivers/video/Kconfig"
>
> +source "drivers/virtio/Kconfig"
> +
>  source "drivers/watchdog/Kconfig"
>
>  config PHYS_TO_BUS
> diff --git a/drivers/Makefile b/drivers/Makefile
> index 23ea609..f09daae 100644
> --- a/drivers/Makefile
> +++ b/drivers/Makefile
> @@ -14,6 +14,7 @@ obj-$(CONFIG_$(SPL_TPL_)SERIAL_SUPPORT) += serial/
>  obj-$(CONFIG_$(SPL_TPL_)SPI_FLASH_SUPPORT) += mtd/spi/
>  obj-$(CONFIG_$(SPL_TPL_)SPI_SUPPORT) += spi/
>  obj-$(CONFIG_$(SPL_TPL_)TIMER) += timer/
> +obj-$(CONFIG_$(SPL_TPL_)VIRTIO) += virtio/
>  obj-$(CONFIG_$(SPL_)DM_MAILBOX) += mailbox/
>  obj-$(CONFIG_$(SPL_)REMOTEPROC) += remoteproc/
>
> diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
> new file mode 100644
> index 0000000..bdfa96a
> --- /dev/null
> +++ b/drivers/virtio/Kconfig
> @@ -0,0 +1,14 @@
> +# SPDX-License-Identifier: GPL-2.0+
> +#
> +# Copyright (C) 2018, Tuomas Tynkkynen <tuomas.tynkkynen at iki.fi>
> +# Copyright (C) 2018, Bin Meng <bmeng.cn at gmail.com>
> +
> +menu "VirtIO Drivers"
> +
> +config VIRTIO
> +       bool
> +       help
> +         This option is selected by any driver which implements the virtio
> +         bus, such as CONFIG_VIRTIO_MMIO or CONFIG_VIRTIO_PCI.

What is a virtio bus?

> +
> +endmenu
> diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile
> new file mode 100644
> index 0000000..23e7be7
> --- /dev/null
> +++ b/drivers/virtio/Makefile
> @@ -0,0 +1,6 @@
> +# SPDX-License-Identifier: GPL-2.0+
> +#
> +# Copyright (C) 2018, Tuomas Tynkkynen <tuomas.tynkkynen at iki.fi>
> +# Copyright (C) 2018, Bin Meng <bmeng.cn at gmail.com>
> +
> +obj-y += virtio-uclass.o
> diff --git a/drivers/virtio/virtio-uclass.c b/drivers/virtio/virtio-uclass.c
> new file mode 100644
> index 0000000..1c85856
> --- /dev/null
> +++ b/drivers/virtio/virtio-uclass.c
> @@ -0,0 +1,333 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2018, Tuomas Tynkkynen <tuomas.tynkkynen at iki.fi>
> + * Copyright (C) 2018, Bin Meng <bmeng.cn at gmail.com>
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <virtio.h>
> +#include <dm/device.h>
> +#include <dm/lists.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,
> +};
> +
> +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);
> +       if (!ops->get_config)
> +               return -ENOSYS;

blank line before return (fix globally)

> +       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);
> +       if (!ops->set_config)
> +               return -ENOSYS;
> +       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);
> +       if (!ops->get_status)
> +               return -ENOSYS;
> +       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);
> +       if (!ops->set_status)
> +               return -ENOSYS;
> +       return ops->set_status(vdev->parent, status);
> +}
> +
> +int virtio_reset(struct udevice *vdev)
> +{
> +       struct dm_virtio_ops *ops;
> +
> +       ops = virtio_get_ops(vdev->parent);
> +       if (!ops->reset)
> +               return -ENOSYS;
> +       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);
> +       if (!ops->get_features)
> +               return -ENOSYS;
> +       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);
> +       if (!ops->set_features)
> +               return -ENOSYS;
> +       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);
> +       if (!ops->find_vqs)
> +               return -ENOSYS;
> +       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);
> +       if (!ops->del_vqs)
> +               return -ENOSYS;
> +       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);
> +       if (!ops->notify)
> +               return -ENOSYS;
> +       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 -ENODEV;
> +       }
> +
> +       return 0;
> +}
> +
> +void virtio_driver_features_init(struct virtio_dev_priv *priv,
> +                                u32 *feature, u32 feature_size,
> +                                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;
> +}
> +
> +void virtio_init(void)

Shouldn't this return int if there is an error?

> +{
> +       struct udevice *bus;
> +
> +       /* Enumerate all known virtio devices */
> +       for (uclass_first_device(UCLASS_VIRTIO, &bus);
> +            bus;
> +            uclass_next_device(&bus)) {
> +               ;
> +       }
> +}
> +
> +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;
> +       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;
> +       }
> +
> +       if (!virtio_drv_name[uc_priv->device]) {
> +               debug("(%s): underlying virtio device driver unavailable\n",
> +                     udev->name);
> +               return 0;
> +       }
> +
> +       snprintf(dev_name, sizeof(dev_name), "%s#%d",
> +                virtio_drv_name[uc_priv->device], udev->seq);
> +       str = strdup(dev_name);
> +       if (!str)
> +               return -ENOMEM;

You might consider using log_ret() or log_msg_ret() for your error returns

> +
> +       ret = device_bind_driver(udev, virtio_drv_name[uc_priv->device],
> +                                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);
> +
> +       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);

Not sure this is worth having a new hook?

> +
> +       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;
> +
> +       /*
> +        * 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))
> +                       __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;
> +}
> +
> +UCLASS_DRIVER(virtio) = {
> +       .name   = "virtio",
> +       .id     = UCLASS_VIRTIO,
> +       .flags  = DM_UC_FLAG_SEQ_ALIAS,
> +       .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_alloc_size = sizeof(struct virtio_dev_priv),
> +};
> diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
> index 7027ea0..08b2a8f 100644
> --- a/include/dm/uclass-id.h
> +++ b/include/dm/uclass-id.h
> @@ -93,6 +93,7 @@ enum uclass_id {
>         UCLASS_VIDEO_BRIDGE,    /* Video bridge, e.g. DisplayPort to LVDS */
>         UCLASS_VIDEO_CONSOLE,   /* Text console driver for video device */
>         UCLASS_WDT,             /* Watchdot Timer driver */
> +       UCLASS_VIRTIO,          /* VirtIO transport device */

V before W :-)

>
>         UCLASS_COUNT,
>         UCLASS_INVALID = -1,
> diff --git a/include/virtio.h b/include/virtio.h
> new file mode 100644
> index 0000000..efbedb2
> --- /dev/null
> +++ b/include/virtio.h
> @@ -0,0 +1,694 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * Copyright (C) 2018, Tuomas Tynkkynen <tuomas.tynkkynen at iki.fi>
> + * Copyright (C) 2018, Bin Meng <bmeng.cn at gmail.com>
> + *
> + * This file is largely based on Linux kernel virtio_*.h files
> + */
> +
> +#ifndef __VIRTIO_H__
> +#define __VIRTIO_H__
> +
> +#include <virtio_types.h>
> +#include <dm/device.h>

Should be able to avoid this, just put in C file

> +
> +#define VIRTIO_ID_NET          1 /* virtio net */
> +#define VIRTIO_ID_BLOCK                2 /* virtio block */
> +#define VIRTIO_ID_MAX_NUM      3
> +
> +#define VIRTIO_NET_DRV_NAME    "virtio-net"
> +#define VIRTIO_BLK_DRV_NAME    "virtio-blk"
> +
> +/* Status byte for guest to report progress, and synchronize features */
> +
> +/* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */
> +#define VIRTIO_CONFIG_S_ACKNOWLEDGE    1
> +/* We have found a driver for the device */
> +#define VIRTIO_CONFIG_S_DRIVER         2
> +/* Driver has used its parts of the config, and is happy */
> +#define VIRTIO_CONFIG_S_DRIVER_OK      4
> +/* Driver has finished configuring features */
> +#define VIRTIO_CONFIG_S_FEATURES_OK    8
> +/* Device entered invalid state, driver must reset it */
> +#define VIRTIO_CONFIG_S_NEEDS_RESET    0x40
> +/* We've given up on this device */
> +#define VIRTIO_CONFIG_S_FAILED         0x80
> +
> +/*
> + * Virtio feature bits VIRTIO_TRANSPORT_F_START through VIRTIO_TRANSPORT_F_END
> + * are reserved for the transport being used (eg: virtio_ring, virtio_pci etc.),
> + * the rest are per-device feature bits.
> + */
> +#define VIRTIO_TRANSPORT_F_START       28
> +#define VIRTIO_TRANSPORT_F_END         38
> +
> +#ifndef VIRTIO_CONFIG_NO_LEGACY
> +/*
> + * Do we get callbacks when the ring is completely used,
> + * even if we've suppressed them?
> + */
> +#define VIRTIO_F_NOTIFY_ON_EMPTY       24
> +
> +/* Can the device handle any descriptor layout? */
> +#define VIRTIO_F_ANY_LAYOUT            27
> +#endif /* VIRTIO_CONFIG_NO_LEGACY */
> +
> +/* v1.0 compliant */
> +#define VIRTIO_F_VERSION_1             32
> +
> +/*
> + * If clear - device has the IOMMU bypass quirk feature.
> + * If set - use platform tools to detect the IOMMU.
> + *
> + * Note the reverse polarity (compared to most other features),
> + * this is for compatibility with legacy systems.
> + */
> +#define VIRTIO_F_IOMMU_PLATFORM                33
> +
> +/* Does the device support Single Root I/O Virtualization? */
> +#define VIRTIO_F_SR_IOV                        37
> +
> +/**
> + * virtio scatter-gather struct
> + *
> + * @addr:              sg buffer address
> + * @lengh:             sg buffer length
> + */
> +struct virtio_sg {
> +       void *addr;
> +       size_t length;
> +};
> +
> +struct virtqueue;
> +
> +/* virtio bus operations */
> +struct dm_virtio_ops {
> +       /**
> +        * get_config() - read the value of a configuration field
> +        *
> +        * @vdev:       the real virtio device
> +        * @offset:     the offset of the configuration field
> +        * @buf:        the buffer to write the field value into
> +        * @len:        the length of the buffer
> +        * @return 0 if OK, -ve on error
> +        */
> +       int (*get_config)(struct udevice *vdev, unsigned int offset,
> +                         void *buf, unsigned int len);
> +       /**
> +        * set_config() - write the value of a configuration field
> +        *
> +        * @vdev:       the real virtio device
> +        * @offset:     the offset of the configuration field
> +        * @buf:        the buffer to read the field value from
> +        * @len:        the length of the buffer
> +        * @return 0 if OK, -ve on error
> +        */
> +       int (*set_config)(struct udevice *vdev, unsigned int offset,
> +                         const void *buf, unsigned int len);
> +       /**
> +        * generation() - config generation counter
> +        *
> +        * @vdev:       the real virtio device
> +        * @counter:    the returned config generation counter
> +        * @return 0 if OK, -ve on error
> +        */
> +       int (*generation)(struct udevice *vdev, u32 *counter);
> +       /**
> +        * get_status() - read the status byte
> +        *
> +        * @vdev:       the real virtio device
> +        * @status:     the returned status byte
> +        * @return 0 if OK, -ve on error
> +        */
> +       int (*get_status)(struct udevice *vdev, u8 *status);
> +       /**
> +        * set_status() - write the status byte
> +        *
> +        * @vdev:       the real virtio device
> +        * @status:     the new status byte
> +        * @return 0 if OK, -ve on error
> +        */
> +       int (*set_status)(struct udevice *vdev, u8 status);
> +       /**
> +        * reset() - reset the device
> +        *
> +        * @vdev:       the real virtio device
> +        * @return 0 if OK, -ve on error
> +        */
> +       int (*reset)(struct udevice *vdev);
> +       /**
> +        * get_features() - get the array of feature bits for this device
> +        *
> +        * @vdev:       the real virtio device
> +        * @features:   the first 32 feature bits (all we currently need)
> +        * @return 0 if OK, -ve on error
> +        */
> +       int (*get_features)(struct udevice *vdev, u64 *features);
> +       /**
> +        * set_features() - confirm what device features we'll be using
> +        *
> +        * @vdev:       the real virtio device
> +        * @return 0 if OK, -ve on error
> +        */
> +       int (*set_features)(struct udevice *vdev);
> +       /**
> +        * find_vqs() - find virtqueues and instantiate them
> +        *
> +        * @vdev:       the real virtio device
> +        * @nvqs:       the number of virtqueues to find
> +        * @vqs:        on success, includes new virtqueues
> +        * @return 0 if OK, -ve on error
> +        */
> +       int (*find_vqs)(struct udevice *vdev, unsigned int nvqs,
> +                       struct virtqueue *vqs[]);
> +       /**
> +        * del_vqs() - free virtqueues found by find_vqs()
> +        *
> +        * @vdev:       the real virtio device
> +        * @return 0 if OK, -ve on error
> +        */
> +       int (*del_vqs)(struct udevice *vdev);
> +       /**
> +        * notify() - notify the device to process the queue
> +        *
> +        * @vdev:       the real virtio device
> +        * @vq:         virtqueue to process
> +        * @return 0 if OK, -ve on error
> +        */
> +       int (*notify)(struct udevice *vdev, struct virtqueue *vq);
> +};
> +
> +/* Get access to a virtio bus' operations */
> +#define virtio_get_ops(dev)    ((struct dm_virtio_ops *)(dev)->driver->ops)
> +
> +/**
> + * virtio uclass per device private data
> + *
> + * @vqs:                       virtualqueue for the virtio device
> + * @vdev:                      the real virtio device underneath
> + * @legacy:                    is it a legacy device?
> + * @device:                    virtio device ID
> + * @vendor:                    virtio vendor ID
> + * @features:                  negotiated supported features
> + * @feature_table:             an array of feature supported by the driver
> + * @feature_table_size:                number of entries in the feature table array
> + * @feature_table_legacy:      same as feature_table but working in legacy mode
> + * @feature_table_size_legacy: number of entries in feature table legacy array
> + */
> +struct virtio_dev_priv {
> +       struct list_head vqs;
> +       struct udevice *vdev;
> +       bool legacy;
> +       u32 device;
> +       u32 vendor;
> +       u64 features;
> +       u32 *feature_table;
> +       u32 feature_table_size;
> +       u32 *feature_table_legacy;
> +       u32 feature_table_size_legacy;
> +};
> +
> +/**
> + * virtio_get_config() - read the value of a configuration field
> + *
> + * @vdev:      the real virtio device
> + * @offset:    the offset of the configuration field
> + * @buf:       the buffer to write the field value into
> + * @len:       the length of the buffer
> + * @return 0 if OK, -ve on error
> + */
> +int virtio_get_config(struct udevice *vdev, unsigned int offset,
> +                     void *buf, unsigned int len);
> +
> +/**
> + * virtio_set_config() - write the value of a configuration field
> + *
> + * @vdev:      the real virtio device
> + * @offset:    the offset of the configuration field
> + * @buf:       the buffer to read the field value from
> + * @len:       the length of the buffer
> + * @return 0 if OK, -ve on error
> + */
> +int virtio_set_config(struct udevice *vdev, unsigned int offset,
> +                     void *buf, unsigned int len);
> +
> +/**
> + * virtio_generation() - config generation counter
> + *
> + * @vdev:      the real virtio device
> + * @counter:   the returned config generation counter
> + * @return 0 if OK, -ve on error
> + */
> +int virtio_generation(struct udevice *vdev, u32 *counter);
> +
> +/**
> + * virtio_get_status() - read the status byte
> + *
> + * @vdev:      the real virtio device
> + * @status:    the returned status byte
> + * @return 0 if OK, -ve on error
> + */
> +int virtio_get_status(struct udevice *vdev, u8 *status);
> +
> +/**
> + * virtio_set_status() - write the status byte
> + *
> + * @vdev:      the real virtio device
> + * @status:    the new status byte
> + * @return 0 if OK, -ve on error
> + */
> +int virtio_set_status(struct udevice *vdev, u8 status);
> +
> +/**
> + * virtio_reset() - reset the device
> + *
> + * @vdev:      the real virtio device
> + * @return 0 if OK, -ve on error
> + */
> +int virtio_reset(struct udevice *vdev);
> +
> +/**
> + * virtio_get_features() - get the array of feature bits for this device
> + *
> + * @vdev:      the real virtio device
> + * @features:  the first 32 feature bits (all we currently need)
> + * @return 0 if OK, -ve on error
> + */
> +int virtio_get_features(struct udevice *vdev, u64 *features);
> +
> +/**
> + * virtio_set_features() - confirm what device features we'll be using
> + *
> + * @vdev:      the real virtio device
> + * @return 0 if OK, -ve on error
> + */
> +int virtio_set_features(struct udevice *vdev);
> +
> +/**
> + * virtio_find_vqs() - find virtqueues and instantiate them
> + *
> + * @vdev:      the real virtio device
> + * @nvqs:      the number of virtqueues to find
> + * @vqs:       on success, includes new virtqueues
> + * @return 0 if OK, -ve on error
> + */
> +int virtio_find_vqs(struct udevice *vdev, unsigned int nvqs,
> +                   struct virtqueue *vqs[]);
> +
> +/**
> + * virtio_del_vqs() - free virtqueues found by find_vqs()
> + *
> + * @vdev:      the real virtio device
> + * @return 0 if OK, -ve on error
> + */
> +int virtio_del_vqs(struct udevice *vdev);
> +
> +/**
> + * virtio_notify() - notify the device to process the queue
> + *
> + * @vdev:      the real virtio device
> + * @vq:                virtqueue to process
> + * @return 0 if OK, -ve on error
> + */
> +int virtio_notify(struct udevice *vdev, struct virtqueue *vq);
> +
> +/**
> + * virtio_add_status() - helper to set a new status code to the device
> + *
> + * @vdev:      the real virtio device
> + * @status:    new status code to be added
> + */
> +void virtio_add_status(struct udevice *vdev, u8 status);
> +
> +/**
> + * virtio_finalize_features() - helper to finalize features
> + *
> + * @vdev:      the real virtio device
> + * @return 0 if OK, -ve on error
> + */
> +int virtio_finalize_features(struct udevice *vdev);
> +
> +/**
> + * virtio_driver_features_init() - initialize driver supported features
> + *
> + * This fills in the virtio device parent per child private data with the given
> + * information, which contains driver supported features and legacy features.
> + *
> + * This API should be called in the virtio device driver's bind method, so that
> + * later virtio transport uclass driver can utilize the driver supplied features
> + * to negotiate with the device on the final supported features.
> + *
> + * @priv:              virtio uclass per device private data
> + * @feature:           an array of feature supported by the driver
> + * @feature_size:      number of entries in the feature table array
> + * @feature_legacy:    same as feature_table but working in legacy mode
> + * @feature_legacy_size:number of entries in feature table legacy array
> + */
> +void virtio_driver_features_init(struct virtio_dev_priv *priv,
> +                                u32 *feature, u32 feature_size,
> +                                u32 *feature_legacy, u32 feature_legacy_size);
> +
> +/**
> + * virtio_init() - helper to enumerate all known virtio devices
> + */
> +void virtio_init(void);
> +
> +static inline u16 __virtio16_to_cpu(bool little_endian, __virtio16 val)
> +{
> +       if (little_endian)
> +               return le16_to_cpu((__force __le16)val);
> +       else
> +               return be16_to_cpu((__force __be16)val);
> +}
> +
> +static inline __virtio16 __cpu_to_virtio16(bool little_endian, u16 val)
> +{
> +       if (little_endian)
> +               return (__force __virtio16)cpu_to_le16(val);
> +       else
> +               return (__force __virtio16)cpu_to_be16(val);
> +}
> +
> +static inline u32 __virtio32_to_cpu(bool little_endian, __virtio32 val)
> +{
> +       if (little_endian)
> +               return le32_to_cpu((__force __le32)val);
> +       else
> +               return be32_to_cpu((__force __be32)val);
> +}
> +
> +static inline __virtio32 __cpu_to_virtio32(bool little_endian, u32 val)
> +{
> +       if (little_endian)
> +               return (__force __virtio32)cpu_to_le32(val);
> +       else
> +               return (__force __virtio32)cpu_to_be32(val);
> +}
> +
> +static inline u64 __virtio64_to_cpu(bool little_endian, __virtio64 val)
> +{
> +       if (little_endian)
> +               return le64_to_cpu((__force __le64)val);
> +       else
> +               return be64_to_cpu((__force __be64)val);
> +}
> +
> +static inline __virtio64 __cpu_to_virtio64(bool little_endian, u64 val)
> +{
> +       if (little_endian)
> +               return (__force __virtio64)cpu_to_le64(val);
> +       else
> +               return (__force __virtio64)cpu_to_be64(val);
> +}
> +
> +/**
> + * __virtio_test_bit - helper to test feature bits
> + *
> + * For use by transports. Devices should normally use virtio_has_feature,
> + * which includes more checks.
> + *
> + * @udev: the transport device
> + * @fbit: the feature bit
> + */
> +static inline bool __virtio_test_bit(struct udevice *udev, unsigned int fbit)
> +{
> +       struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(udev);
> +
> +       /* Did you forget to fix assumptions on max features? */
> +       if (__builtin_constant_p(fbit))
> +               BUILD_BUG_ON(fbit >= 64);
> +       else
> +               WARN_ON(fbit >= 64);
> +
> +       return uc_priv->features & BIT_ULL(fbit);

Why is this (and the ones below) inline? I worry this might bloat the
code for no purpose?

> +}
> +
> +/**
> + * __virtio_set_bit - helper to set feature bits
> + *
> + * For use by transports.
> + *
> + * @udev: the transport device
> + * @fbit: the feature bit
> + */
> +static inline void __virtio_set_bit(struct udevice *udev, unsigned int fbit)
> +{
> +       struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(udev);
> +
> +       /* Did you forget to fix assumptions on max features? */
> +       if (__builtin_constant_p(fbit))
> +               BUILD_BUG_ON(fbit >= 64);
> +       else
> +               WARN_ON(fbit >= 64);
> +
> +       uc_priv->features |= BIT_ULL(fbit);
> +}
> +
> +/**
> + * __virtio_clear_bit - helper to clear feature bits
> + *
> + * For use by transports.
> + *
> + * @vdev: the transport device
> + * @fbit: the feature bit
> + */
> +static inline void __virtio_clear_bit(struct udevice *udev, unsigned int fbit)
> +{
> +       struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(udev);
> +
> +       /* Did you forget to fix assumptions on max features? */
> +       if (__builtin_constant_p(fbit))
> +               BUILD_BUG_ON(fbit >= 64);
> +       else
> +               WARN_ON(fbit >= 64);
> +
> +       uc_priv->features &= ~BIT_ULL(fbit);
> +}
> +
> +/**
> + * virtio_has_feature - helper to determine if this device has this feature
> + *
> + * Note this API is only usable after the virtio device driver's bind phase,
> + * as the feature has been negotiated between the device and the driver.
> + *
> + * @vdev: the virtio device
> + * @fbit: the feature bit
> + */
> +static inline bool virtio_has_feature(struct udevice *vdev, unsigned int fbit)
> +{
> +       if (!(vdev->flags & DM_FLAG_BOUND))
> +               WARN_ON(true);
> +
> +       return __virtio_test_bit(vdev->parent, fbit);
> +}
> +
> +static inline bool virtio_legacy_is_little_endian(void)
> +{
> +#ifdef __LITTLE_ENDIAN
> +       return true;
> +#else
> +       return false;
> +#endif
> +}
> +
> +static inline bool virtio_is_little_endian(struct udevice *vdev)
> +{
> +       struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(vdev->parent);
> +
> +       return !uc_priv->legacy || virtio_legacy_is_little_endian();
> +}
> +
> +/* Memory accessors */
> +static inline u16 virtio16_to_cpu(struct udevice *vdev, __virtio16 val)
> +{
> +       return __virtio16_to_cpu(virtio_is_little_endian(vdev), val);
> +}
> +
> +static inline __virtio16 cpu_to_virtio16(struct udevice *vdev, u16 val)
> +{
> +       return __cpu_to_virtio16(virtio_is_little_endian(vdev), val);
> +}
> +
> +static inline u32 virtio32_to_cpu(struct udevice *vdev, __virtio32 val)
> +{
> +       return __virtio32_to_cpu(virtio_is_little_endian(vdev), val);
> +}
> +
> +static inline __virtio32 cpu_to_virtio32(struct udevice *vdev, u32 val)
> +{
> +       return __cpu_to_virtio32(virtio_is_little_endian(vdev), val);
> +}
> +
> +static inline u64 virtio64_to_cpu(struct udevice *vdev, __virtio64 val)
> +{
> +       return __virtio64_to_cpu(virtio_is_little_endian(vdev), val);
> +}
> +
> +static inline __virtio64 cpu_to_virtio64(struct udevice *vdev, u64 val)
> +{
> +       return __cpu_to_virtio64(virtio_is_little_endian(vdev), val);
> +}
> +
> +/* Read @count fields, @bytes each */
> +static inline void __virtio_cread_many(struct udevice *vdev,
> +                                      unsigned int offset,
> +                                      void *buf, size_t count, size_t bytes)
> +{
> +       u32 old, gen;
> +       int i;
> +
> +       virtio_generation(vdev, &gen);

Error check?

Should be in the uclass C file I think

> +       do {
> +               old = gen;
> +
> +               for (i = 0; i < count; i++)
> +                       virtio_get_config(vdev, offset + bytes * i,
> +                                         buf + i * bytes, bytes);
> +
> +               virtio_generation(vdev, &gen);
> +       } while (gen != old);
> +}
> +
> +static inline void virtio_cread_bytes(struct udevice *vdev,
> +                                     unsigned int offset,
> +                                     void *buf, size_t len)
> +{
> +       __virtio_cread_many(vdev, offset, buf, len, 1);
> +}
> +
> +static inline u8 virtio_cread8(struct udevice *vdev, unsigned int offset)
> +{
> +       u8 ret;
> +
> +       virtio_get_config(vdev, offset, &ret, sizeof(ret));
> +       return ret;
> +}
> +
> +static inline void virtio_cwrite8(struct udevice *vdev,
> +                                 unsigned int offset, u8 val)
> +{
> +       virtio_set_config(vdev, offset, &val, sizeof(val));
> +}
> +
> +static inline u16 virtio_cread16(struct udevice *vdev,
> +                                unsigned int offset)
> +{
> +       u16 ret;
> +
> +       virtio_get_config(vdev, offset, &ret, sizeof(ret));
> +       return virtio16_to_cpu(vdev, (__force __virtio16)ret);
> +}
> +
> +static inline void virtio_cwrite16(struct udevice *vdev,
> +                                  unsigned int offset, u16 val)
> +{
> +       val = (__force u16)cpu_to_virtio16(vdev, val);
> +       virtio_set_config(vdev, offset, &val, sizeof(val));
> +}
> +
> +static inline u32 virtio_cread32(struct udevice *vdev,
> +                                unsigned int offset)
> +{
> +       u32 ret;
> +
> +       virtio_get_config(vdev, offset, &ret, sizeof(ret));
> +       return virtio32_to_cpu(vdev, (__force __virtio32)ret);
> +}
> +
> +static inline void virtio_cwrite32(struct udevice *vdev,
> +                                  unsigned int offset, u32 val)
> +{
> +       val = (__force u32)cpu_to_virtio32(vdev, val);
> +       virtio_set_config(vdev, offset, &val, sizeof(val));
> +}
> +
> +static inline u64 virtio_cread64(struct udevice *vdev,
> +                                unsigned int offset)
> +{
> +       u64 ret;
> +
> +       __virtio_cread_many(vdev, offset, &ret, 1, sizeof(ret));
> +       return virtio64_to_cpu(vdev, (__force __virtio64)ret);
> +}
> +
> +static inline void virtio_cwrite64(struct udevice *vdev,
> +                                  unsigned int offset, u64 val)
> +{
> +       val = (__force u64)cpu_to_virtio64(vdev, val);
> +       virtio_set_config(vdev, offset, &val, sizeof(val));
> +}
> +
> +/* Config space read accessor */
> +#define virtio_cread(vdev, structname, member, ptr)                    \
> +       do {                                                            \
> +               /* Must match the member's type, and be integer */      \
> +               if (!typecheck(typeof((((structname *)0)->member)), *(ptr))) \
> +                       (*ptr) = 1;                                     \
> +                                                                       \
> +               switch (sizeof(*ptr)) {                                 \
> +               case 1:                                                 \
> +                       *(ptr) = virtio_cread8(vdev,                    \
> +                                              offsetof(structname, member)); \
> +                       break;                                          \
> +               case 2:                                                 \
> +                       *(ptr) = virtio_cread16(vdev,                   \
> +                                               offsetof(structname, member)); \
> +                       break;                                          \
> +               case 4:                                                 \
> +                       *(ptr) = virtio_cread32(vdev,                   \
> +                                               offsetof(structname, member)); \
> +                       break;                                          \
> +               case 8:                                                 \
> +                       *(ptr) = virtio_cread64(vdev,                   \
> +                                               offsetof(structname, member)); \
> +                       break;                                          \
> +               default:                                                \
> +                       WARN_ON(true);                                  \
> +               }                                                       \
> +       } while (0)
> +
> +/* Config space write accessor */
> +#define virtio_cwrite(vdev, structname, member, ptr)                   \
> +       do {                                                            \
> +               /* Must match the member's type, and be integer */      \
> +               if (!typecheck(typeof((((structname *)0)->member)), *(ptr))) \
> +                       WARN_ON((*ptr) == 1);                           \
> +                                                                       \
> +               switch (sizeof(*ptr)) {                                 \
> +               case 1:                                                 \
> +                       virtio_cwrite8(vdev,                            \
> +                                      offsetof(structname, member),    \
> +                                      *(ptr));                         \
> +                       break;                                          \
> +               case 2:                                                 \
> +                       virtio_cwrite16(vdev,                           \
> +                                       offsetof(structname, member),   \
> +                                       *(ptr));                        \
> +                       break;                                          \
> +               case 4:                                                 \
> +                       virtio_cwrite32(vdev,                           \
> +                                       offsetof(structname, member),   \
> +                                       *(ptr));                        \
> +                       break;                                          \
> +               case 8:                                                 \
> +                       virtio_cwrite64(vdev,                           \
> +                                       offsetof(structname, member),   \
> +                                       *(ptr));                        \
> +                       break;                                          \
> +               default:                                                \
> +                       WARN_ON(true);                                  \
> +               }                                                       \
> +       } while (0)
> +
> +/* Conditional config space accessors */
> +#define virtio_cread_feature(vdev, fbit, structname, member, ptr)      \
> +       ({                                                              \
> +               int _r = 0;                                             \
> +               if (!virtio_has_feature(vdev, fbit))                    \
> +                       _r = -ENOENT;                                   \
> +               else                                                    \
> +                       virtio_cread(vdev, structname, member, ptr);    \
> +               _r;                                                     \
> +       })
> +
> +#endif /* __VIRTIO_H__ */
> diff --git a/include/virtio_types.h b/include/virtio_types.h
> new file mode 100644
> index 0000000..d700d19
> --- /dev/null
> +++ b/include/virtio_types.h
> @@ -0,0 +1,24 @@
> +/* SPDX-License-Identifier: BSD-3-Clause */
> +/*
> + * Copyright (C) 2018, Tuomas Tynkkynen <tuomas.tynkkynen at iki.fi>
> + * Copyright (C) 2018, Bin Meng <bmeng.cn at gmail.com>
> + *
> + * From Linux kernel include/uapi/linux/virtio_types.h
> + */
> +
> +#ifndef _LINUX_VIRTIO_TYPES_H
> +#define _LINUX_VIRTIO_TYPES_H
> +
> +#include <linux/types.h>
> +
> +/*
> + * __virtio{16,32,64} have the following meaning:
> + * - __u{16,32,64} for virtio devices in legacy mode, accessed in native endian
> + * - __le{16,32,64} for standard-compliant virtio devices
> + */
> +
> +typedef __u16 __bitwise __virtio16;
> +typedef __u32 __bitwise __virtio32;
> +typedef __u64 __bitwise __virtio64;
> +
> +#endif /* _LINUX_VIRTIO_TYPES_H */
> --
> 2.7.4
>

Regards,
Simon


More information about the U-Boot mailing list