Re: [RFC 14/22] efi_loader: disk: a helper function to create efi_disk objects from udevice

Simon Glass
2021-10-12T14:08:37Z

Hi Akashi,

On Mon, 11 Oct 2021 at 19:09, AKASHI Takahiro
<takahiro.akashi@linaro.org> wrote:
>
> Simon,
>
> On Mon, Oct 11, 2021 at 08:54:06AM -0600, Simon Glass wrote:
> > Hi Takahiro,
> >
> > On Mon, 11 Oct 2021 at 00:52, AKASHI Takahiro
> > <takahiro.akashi@linaro.org> wrote:
> > >
> > > On Sun, Oct 10, 2021 at 08:14:21AM -0600, Simon Glass wrote:
> > > > On Thu, 30 Sept 2021 at 23:04, AKASHI Takahiro
> > > > <takahiro.akashi@linaro.org> wrote:
> > > > >
> > > > > Add efi_disk_create() function.
> > > > >
> > > > > Any UEFI handle created by efi_disk_create() can be treated as a efi_disk
> > > > > object, the udevice is either a UCLASS_BLK (a whole raw disk) or
> > > > > UCLASS_PARTITION (a disk partition).
> > > > >
> > > > > So this function is expected to be called every time such an udevice
> > > > > is detected and activated through a device model's "probe" interface.
> > > > >
> > > > > Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> > > > > ---
> > > > > include/efi_loader.h | 2 +
> > > > > lib/efi_loader/efi_disk.c | 92 +++++++++++++++++++++++++++++++++++++++
> > > > > 2 files changed, 94 insertions(+)
> > > > >
> > > >
> > > > Reviewed-by: Simon Glass <sjg@chromium.org>
> > > >
> > > > But some nits below.
> > > >
> > > > Don't worry about !CONFIG_BLK - that code should be removed.
> > >
> > > Yes. I added a tentative patch to remove !CONFIG_BLK code in efi_disk
> > > in patch#13.
> > >
> > >
> > > > > diff --git a/include/efi_loader.h b/include/efi_loader.h
> > > > > index c440962fe522..751fde7fb153 100644
> > > > > --- a/include/efi_loader.h
> > > > > +++ b/include/efi_loader.h
> > > > > @@ -517,6 +517,8 @@ efi_status_t EFIAPI efi_convert_pointer(efi_uintn_t debug_disposition,
> > > > > void efi_carve_out_dt_rsv(void *fdt);
> > > > > /* Called by bootefi to make console interface available */
> > > > > efi_status_t efi_console_register(void);
> > > > > +/* Called when a block devices has been probed */
> > > > > +int efi_disk_create(struct udevice *dev);
> > > >
> > > > Please buck the trend in this file and add a full function comment. In
> > > > this case it needs to cover @dev and the return value and also explain
> > > > what the function does.
> > >
> > > OK.
> > >
> > > > > /* Called by bootefi to make all disk storage accessible as EFI objects */
> > > > > efi_status_t efi_disk_register(void);
> > > > > /* Called by efi_init_obj_list() to install EFI_RNG_PROTOCOL */
> > > > > diff --git a/lib/efi_loader/efi_disk.c b/lib/efi_loader/efi_disk.c
> > > > > index cd5528046251..3fae40e034fb 100644
> > > > > --- a/lib/efi_loader/efi_disk.c
> > > > > +++ b/lib/efi_loader/efi_disk.c
> > > > > @@ -10,6 +10,7 @@
> > > > > #include <common.h>
> > > > > #include <blk.h>
> > > > > #include <dm.h>
> > > > > +#include <dm/device-internal.h>
> > > > > #include <efi_loader.h>
> > > > > #include <fs.h>
> > > > > #include <log.h>
> > > > > @@ -484,6 +485,7 @@ error:
> > > > > return ret;
> > > > > }
> > > > >
> > > > > +#ifndef CONFIG_BLK
> > > > > /**
> > > > > * efi_disk_create_partitions() - create handles and protocols for partitions
> > > > > *
> > > > > @@ -531,6 +533,96 @@ int efi_disk_create_partitions(efi_handle_t parent, struct blk_desc *desc,
> > > > >
> > > > > return disks;
> > > > > }
> > > > > +#endif /* CONFIG_BLK */
> > > > > +
> > > > > +/*
> > > > > + * Create a handle for a whole raw disk
> > > > > + *
> > > > > + * @dev uclass device
> > > >
> > > > ?? what type of device?
> > >
> > > (Will fix: UCLASS_BLK)
> > >
> > >
> > > > > + * @return 0 on success, -1 otherwise
> > > > > + */
> > > > > +static int efi_disk_create_raw(struct udevice *dev)
> > > > > +{
> > > > > + struct efi_disk_obj *disk;
> > > > > + struct blk_desc *desc;
> > > > > + const char *if_typename;
> > > > > + int diskid;
> > > > > + efi_status_t ret;
> > > > > +
> > > > > + desc = dev_get_uclass_plat(dev);
> > > > > + if_typename = blk_get_if_type_name(desc->if_type);
> > > > > + diskid = desc->devnum;
> > > > > +
> > > > > + ret = efi_disk_add_dev(NULL, NULL, if_typename, desc,
> > > > > + diskid, NULL, 0, &disk);
> > > > > + if (ret != EFI_SUCCESS) {
> > > >
> > > > if (ret)
> > > >
> > > > is much shorter and easier to read
> > >
> > > Yeah, but I don't want to assume EFI_SUCCESS is *zero*.
> >
> > It is defined as 0 in 'Appendix D - Status Code' and cannot change, as
> > I understand it. This is one of the things I don't like about the EFI
> > code in U-Boot. Presumably the people who wrote the spec defined it as
> > 0 to make use of C constructs.
>
> Yeah, I confirmed that, but still want to keep the code
> as "ret != EFI_SUCCESS" is used everywhere in UEFI code :)

OK that can be a clean-up for another day, along with the overly long
types and naming in general.

At least we managed to avoid all the capital letters and camel case...

Regards,
Simon