[U-Boot] [PATCH 02/27] dm: Add a new uclass driver for VirtIO transport devices
Bin Meng
bmeng.cn at gmail.com
Thu Oct 11 09:08:57 UTC 2018
Hi Simon,
On Thu, Sep 27, 2018 at 9:42 PM Simon Glass <sjg at chromium.org> wrote:
>
> 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.
>
Will add the link and a short statement for VirtIO in virtio.h,
virtio-uclass.c and driver/virtio/Kconfig in v2.
> >
> > 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?
>
Change to transport in v2, as suggested by Tuomas.
> > +
> > +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)
>
Fixed this in v2. However as Tuomas suggested, I added another check
in the uclass' pre_probe method to check these ops once and for all so
most of these checks here are unnecessary in v2.
> > + 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?
>
Changed in v2.
> > +{
> > + 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
>
Keep this for now as currently log_msg_ret() does not build.
> > +
> > + 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 :-)
>
Fixed in v2.
> >
> > 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
>
Fixed in v2.
> > +
> > +#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?
>
These are from Linux header files and I plan to leave them as it is
for now, to keep sync with Linux version.
> > +}
> > +
> > +/**
> > + * __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?
>
In fact this ops can be optional. Will add a comment in v2.
> 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 */
> > --
Regards,
Bin
More information about the U-Boot
mailing list