Re: [RFC 07/22] dm: blk: add UCLASS_PARTITION

Simon Glass
2021-10-10T14:17:55Z

Hi Takahiro,

On Thu, 30 Sept 2021 at 23:03, AKASHI Takahiro
<takahiro.akashi@linaro.org> wrote:
>
> UCLASS_PARTITION device will be created as a child node of
> UCLASS_BLK device.
>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> ---
> drivers/block/blk-uclass.c | 111 +++++++++++++++++++++++++++++++++++++
> include/blk.h | 9 +++
> include/dm/uclass-id.h | 1 +
> 3 files changed, 121 insertions(+)
>
> diff --git a/drivers/block/blk-uclass.c b/drivers/block/blk-uclass.c
> index 83682dcc181a..dd7f3c0fe31e 100644
> --- a/drivers/block/blk-uclass.c
> +++ b/drivers/block/blk-uclass.c
> @@ -12,6 +12,7 @@
> #include <log.h>
> #include <malloc.h>
> #include <part.h>
> +#include <string.h>
> #include <dm/device-internal.h>
> #include <dm/lists.h>
> #include <dm/uclass-internal.h>
> @@ -695,6 +696,44 @@ int blk_unbind_all(int if_type)
> return 0;
> }
>
> +int blk_create_partitions(struct udevice *parent)
> +{
> + int part, count;
> + struct blk_desc *desc = dev_get_uclass_plat(parent);
> + struct disk_partition info;
> + struct disk_part *part_data;
> + char devname[32];
> + struct udevice *dev;
> + int ret;
> +
> + if (!CONFIG_IS_ENABLED(PARTITIONS) ||
> + !CONFIG_IS_ENABLED(HAVE_BLOCK_DEVICE))
> + return 0;
> +
> + /* Add devices for each partition */
> + for (count = 0, part = 1; part <= MAX_SEARCH_PARTITIONS; part++) {
> + if (part_get_info(desc, part, &info))
> + continue;
> + snprintf(devname, sizeof(devname), "%s:%d", parent->name,
> + part);
> +
> + ret = device_bind_driver(parent, "blk_partition",
> + strdup(devname), &dev);
> + if (ret)
> + return ret;
> +
> + part_data = dev_get_uclass_plat(dev);
> + part_data->partnum = part;
> + part_data->gpt_part_info = info;
> + count++;
> +
> + device_probe(dev);
> + }
> + debug("%s: %d partitions found in %s\n", __func__, count, parent->name);

log_debug() and drop __func__

> +
> + return 0;
> +}
> +
> static int blk_post_probe(struct udevice *dev)
> {
> if (IS_ENABLED(CONFIG_PARTITIONS) &&
> @@ -713,3 +752,75 @@ UCLASS_DRIVER(blk) = {
> .post_probe = blk_post_probe,
> .per_device_plat_auto = sizeof(struct blk_desc),
> };
> +
> +static ulong blk_part_read(struct udevice *dev, lbaint_t start,
> + lbaint_t blkcnt, void *buffer)
> +{

part_blk_read() so that it is clear that this takes a UCLASS_PARTITION
device, not a UCLASS_BLK

> + struct udevice *parent;
> + struct disk_part *part;
> + const struct blk_ops *ops;
> +
> + parent = dev_get_parent(dev);
> + ops = blk_get_ops(parent);
> + if (!ops->read)
> + return -ENOSYS;
> +
> + part = dev_get_uclass_plat(dev);
> + start += part->gpt_part_info.start;
> +
> + return ops->read(parent, start, blkcnt, buffer);
> +}
> +
> +static ulong blk_part_write(struct udevice *dev, lbaint_t start,
> + lbaint_t blkcnt, const void *buffer)
> +{
> + struct udevice *parent;
> + struct disk_part *part;
> + const struct blk_ops *ops;
> +
> + parent = dev_get_parent(dev);
> + ops = blk_get_ops(parent);
> + if (!ops->write)
> + return -ENOSYS;
> +
> + part = dev_get_uclass_plat(dev);
> + start += part->gpt_part_info.start;
> +
> + return ops->write(parent, start, blkcnt, buffer);
> +}
> +
> +static ulong blk_part_erase(struct udevice *dev, lbaint_t start,
> + lbaint_t blkcnt)
> +{
> + struct udevice *parent;
> + struct disk_part *part;
> + const struct blk_ops *ops;
> +
> + parent = dev_get_parent(dev);
> + ops = blk_get_ops(parent);
> + if (!ops->erase)
> + return -ENOSYS;
> +
> + part = dev_get_uclass_plat(dev);
> + start += part->gpt_part_info.start;
> +
> + return ops->erase(parent, start, blkcnt);
> +}
> +
> +static const struct blk_ops blk_part_ops = {
> + .read = blk_part_read,
> + .write = blk_part_write,
> + .erase = blk_part_erase,
> +};
> +
> +U_BOOT_DRIVER(blk_partition) = {
> + .name = "blk_partition",
> + .id = UCLASS_PARTITION,
> + .ops = &blk_part_ops,
> +};

Can you put this all in a separate part-uclass.c file? This too:

> +
> +UCLASS_DRIVER(partition) = {
> + .id = UCLASS_PARTITION,
> + .per_device_plat_auto = sizeof(struct disk_part),
> + .name = "partition",
> +};
> diff --git a/include/blk.h b/include/blk.h
> index 19bab081c2cd..3d883eb1db64 100644
> --- a/include/blk.h
> +++ b/include/blk.h
> @@ -366,6 +366,15 @@ int blk_create_devicef(struct udevice *parent, const char *drv_name,
> const char *name, int if_type, int devnum, int blksz,
> lbaint_t lba, struct udevice **devp);
>
> +/**
> + * blk_create_partitions - Create block devices for disk partitions
> + *
> + * Create UCLASS_PARTITION udevices for each of disk partitions in @parent
> + *
> + * @parent: Whole disk device

UCLASS_BLK?

It is good to document the device types to avoid people getting confused later.

> + */
> +int blk_create_partitions(struct udevice *parent);
> +
> /**
> * blk_unbind_all() - Unbind all device of the given interface type
> *
> diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
> index e7edd409f307..30892d01ce13 100644
> --- a/include/dm/uclass-id.h
> +++ b/include/dm/uclass-id.h
> @@ -80,6 +80,7 @@ enum uclass_id {
> UCLASS_P2SB, /* (x86) Primary-to-Sideband Bus */
> UCLASS_PANEL, /* Display panel, such as an LCD */
> UCLASS_PANEL_BACKLIGHT, /* Backlight controller for panel */
> + UCLASS_PARTITION, /* Logical disk partition device */
> UCLASS_PCH, /* x86 platform controller hub */
> UCLASS_PCI, /* PCI bus */
> UCLASS_PCI_EP, /* PCI endpoint device */
> --
> 2.33.0
>

This is a new uclass so needs a sandbox test.

Regards,
Simon