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

Simon Glass
2021-10-10T14:16:22Z

Hi Takahiro,

On Thu, 30 Sept 2021 at 23:04, AKASHI Takahiro
<takahiro.akashi@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@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