[RFC 14/22] dm: blk: call efi's device-probe hook

[Simon Glass]

Hi Takahiro,

On Thu, 30 Sept 2021 at 23:04, AKASHI Takahiro
<takahiro.akashi at linaro.org> wrote:
>
> Adding this callback function, efi_disk_create() in block devices's
> post_probe hook will allows for automatically creating efi_disk objects
> per block device.
>
> This will end up not only eliminating efi_disk_register() called in UEFI
> initialization, but also enabling detections of new block devices even
> after the initialization.
>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
> ---
>  drivers/block/blk-uclass.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)

This is where events come in. We need a way to notify things when
devices go through different stages, etc.

I am thinking of:

enum dm_event_t {
   DMEVT_PROBE,
   DMEVT_POST_PROBE,
...
};

struct dm_event {
    enum dm_event_t type;
    union {
        // add data for different event types in here
    } data;
}

int (*dm_handler_t)(void *ctx, struct dm_event *event);

int dm_register(enum dm_event_t evtype, dm_handler_t func, void *ctx)

int dm_notify(struct udevice *dev, enum dm_event_t type, void *data);

Then the code below becomes:

dm_notify(struct udevice *dev, DMEVT_POST_PROBE, NULL);

the implementation of which will call the handler.

If you like I could create an impl of the above as a separate patch
for discussion.

>
> diff --git a/drivers/block/blk-uclass.c b/drivers/block/blk-uclass.c
> index 8fbec8779e1e..ce45cf0a8768 100644
> --- a/drivers/block/blk-uclass.c
> +++ b/drivers/block/blk-uclass.c
> @@ -9,6 +9,7 @@
>  #include <common.h>
>  #include <blk.h>
>  #include <dm.h>
> +#include <efi_loader.h>
>  #include <log.h>
>  #include <malloc.h>
>  #include <part.h>
> @@ -827,6 +828,11 @@ int blk_create_partitions(struct udevice *parent)
>
>  static int blk_post_probe(struct udevice *dev)
>  {
> +       if (CONFIG_IS_ENABLED(EFI_LOADER)) {
> +               if (efi_disk_create(dev))
> +                       debug("*** efi_post_probe_device failed\n");
> +       }
> +
>         if (IS_ENABLED(CONFIG_PARTITIONS) &&
>             IS_ENABLED(CONFIG_HAVE_BLOCK_DEVICE)) {
>                 struct blk_desc *desc = dev_get_uclass_plat(dev);
> @@ -843,6 +849,10 @@ static int blk_post_probe(struct udevice *dev)
>
>  static int blk_part_post_probe(struct udevice *dev)
>  {
> +       if (CONFIG_IS_ENABLED(EFI_LOADER)) {
> +               if (efi_disk_create(dev))
> +                       debug("*** efi_post_probe_device failed\n");
> +       }
>         /*
>          * TODO:
>          * If we call blk_creat_partitions() here, it would allow for
> --
> 2.33.0
>

Regards,
Simon