Re: [PATCH v2 15/39] efi: Add EFI uclass for media

[Heinrich Schuchardt <xypron.glpk@gmx.de>]

On 9/25/21 02:30, Simon Glass wrote:
> At present UCLASS_EFI is used to represent an EFI filesystem among other

UCLASS_EFI is for UEFI drivers that provide the driver binding protocol.

Your new UCLASS seems to be for U-Boot drivers consuming the
EFI_BLOCK_IO_PROTOCOL.

I agree that lib/efi_driver/efi_block_device.c is to much intertwined
with the UEFI subsystem to easily merge it with your requirement. But it
at least can serve as a template.

> things. The description of this uclass is "EFI managed devices" which is
> pretty vague. The only driver that uses this uclass is in fact not a real
> U-Boot driver, since its operations do not include a struct udevice.
>
> Rather than mess with this, create a new UCLASS_EFI_MEDIA uclass to handle
> EFI media such as disks. Make this the uclass to use for EFI media so that

In UEFI speak MEDIA relates to:

* block devices
* firmware files
* Bluetooth
* REST services
* etc

Do you only mean block devices?
Why can't you use UCLASS_BLK for your new driver?

Best regards

Heinrich

> it can be used with 'part list', for example.
>
> The existing implementation using UCLASS_EFI remains as is, for
> discussion.
>
> Signed-off-by: Simon Glass <sjg@chromium.org>
> ---
>
> Changes in v2:
> - Add MAINTAINERS entry
> - Show the correct interface type with 'part list'
> - Update the commit message to explain things better
>
>   MAINTAINERS                      |  3 +++
>   arch/sandbox/dts/test.dts        |  4 ++++
>   disk/part.c                      |  5 ++++-
>   drivers/block/Kconfig            | 23 +++++++++++++++++++++++
>   drivers/block/Makefile           |  3 +++
>   drivers/block/blk-uclass.c       |  2 +-
>   drivers/block/efi-media-uclass.c | 15 +++++++++++++++
>   drivers/block/sb_efi_media.c     | 20 ++++++++++++++++++++
>   include/dm/uclass-id.h           |  1 +
>   test/dm/Makefile                 |  1 +
>   test/dm/efi_media.c              | 24 ++++++++++++++++++++++++
>   11 files changed, 99 insertions(+), 2 deletions(-)
>   create mode 100644 drivers/block/efi-media-uclass.c
>   create mode 100644 drivers/block/sb_efi_media.c
>   create mode 100644 test/dm/efi_media.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index a254b705e73..0c1cbff7d01 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -708,8 +708,11 @@ W:	https://u-boot.readthedocs.io/en/latest/develop/uefi/u-boot_on_efi.html
>   F:	board/efi/efi-x86_app
>   F:	configs/efi-x86_app*
>   F:	doc/develop/uefi/u-boot_on_efi.rst
> +F:	drivers/block/efi-media-uclass.c
> +F:	drivers/block/sb_efi_media.c
>   F:	lib/efi/efi_app.c
>   F:	scripts/build-efi.sh
> +F:	test/dm/efi_media.c
>
>   EFI PAYLOAD
>   M:	Heinrich Schuchardt <xypron.glpk@gmx.de>
> diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
> index b36447c4a79..23b8435a92a 100644
> --- a/arch/sandbox/dts/test.dts
> +++ b/arch/sandbox/dts/test.dts
> @@ -495,6 +495,10 @@
>   		compatible = "sandbox,clk-ccf";
>   	};
>
> +	efi-media {
> +		compatible = "sandbox,efi-media";
> +	};
> +
>   	eth@10002000 {
>   		compatible = "sandbox,eth";
>   		reg = <0x10002000 0x1000>;
> diff --git a/disk/part.c b/disk/part.c
> index a6a8f7052bd..2560f6a50bc 100644
> --- a/disk/part.c
> +++ b/disk/part.c
> @@ -296,8 +296,11 @@ static void print_part_header(const char *type, struct blk_desc *dev_desc)
>   	case IF_TYPE_VIRTIO:
>   		puts("VirtIO");
>   		break;
> +	case IF_TYPE_EFI:
> +		puts("EFI");
> +		break;
>   	default:
> -		puts ("UNKNOWN");
> +		puts("UNKNOWN");
>   		break;
>   	}
>   	printf (" device %d  --   Partition Type: %s\n\n",
> diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
> index 56a4eec05ac..755fdccb574 100644
> --- a/drivers/block/Kconfig
> +++ b/drivers/block/Kconfig
> @@ -61,6 +61,29 @@ config TPL_BLOCK_CACHE
>   	help
>   	  This option enables the disk-block cache in TPL
>
> +config EFI_MEDIA
> +	bool "Support EFI media drivers"
> +	default y if EFI || SANDBOX
> +	help
> +	  Enable this to support media devices on top of UEFI. This enables
> +	  just the uclass so you also need a specific driver to make this do
> +	  anything.
> +
> +	  For sandbox there is a test driver.
> +
> +if EFI_MEDIA
> +
> +config EFI_MEDIA_SANDBOX
> +	bool "Sandbox EFI media driver"
> +	depends on SANDBOX
> +	default y
> +	help
> +	  Enables a simple sandbox media driver, used for testing just the
> +	  EFI_MEDIA uclass. It does not do anything useful, since sandbox does
> +	  not actually support running on top of UEFI.
> +
> +endif  # EFI_MEDIA
> +
>   config IDE
>   	bool "Support IDE controllers"
>   	select HAVE_BLOCK_DEVICE
> diff --git a/drivers/block/Makefile b/drivers/block/Makefile
> index 94ab5c6f906..3778633da1d 100644
> --- a/drivers/block/Makefile
> +++ b/drivers/block/Makefile
> @@ -14,3 +14,6 @@ obj-$(CONFIG_IDE) += ide.o
>   endif
>   obj-$(CONFIG_SANDBOX) += sandbox.o
>   obj-$(CONFIG_$(SPL_TPL_)BLOCK_CACHE) += blkcache.o
> +
> +obj-$(CONFIG_EFI_MEDIA) += efi-media-uclass.o
> +obj-$(CONFIG_EFI_MEDIA_SANDBOX) += sb_efi_media.o
> diff --git a/drivers/block/blk-uclass.c b/drivers/block/blk-uclass.c
> index 83682dcc181..2db7ce5de20 100644
> --- a/drivers/block/blk-uclass.c
> +++ b/drivers/block/blk-uclass.c
> @@ -44,7 +44,7 @@ static enum uclass_id if_type_uclass_id[IF_TYPE_COUNT] = {
>   	[IF_TYPE_SATA]		= UCLASS_AHCI,
>   	[IF_TYPE_HOST]		= UCLASS_ROOT,
>   	[IF_TYPE_NVME]		= UCLASS_NVME,
> -	[IF_TYPE_EFI]		= UCLASS_EFI,

UCLASS_EFI_MEDIA is only relevant for the EFI app and should not be
compiled into normal U-Boot. This change is bound to break the UEFI
sub-system.

Why don't you define a new if_type for your use case?

blk_get_devnum_by_typename() uses if_type to check if the corresponding
uclass exists. Why is this check needed? If we remove it, we can drop
if_type_uclass_id[] completely. This would be my preferred solution.

Best regards

Heinrich

> +	[IF_TYPE_EFI]		= UCLASS_EFI_MEDIA,
>   	[IF_TYPE_VIRTIO]	= UCLASS_VIRTIO,
>   	[IF_TYPE_PVBLOCK]	= UCLASS_PVBLOCK,
>   };
> diff --git a/drivers/block/efi-media-uclass.c b/drivers/block/efi-media-uclass.c
> new file mode 100644
> index 00000000000..e012f6f2f4c
> --- /dev/null
> +++ b/drivers/block/efi-media-uclass.c
> @@ -0,0 +1,15 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Uclass for EFI media devices
> + *
> + * Copyright 2021 Google LLC
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +
> +UCLASS_DRIVER(efi_media) = {
> +	.id		= UCLASS_EFI_MEDIA,
> +	.name		= "efi_media",
> +	.flags		= DM_UC_FLAG_SEQ_ALIAS,
> +};
> diff --git a/drivers/block/sb_efi_media.c b/drivers/block/sb_efi_media.c
> new file mode 100644
> index 00000000000..52af155a600
> --- /dev/null
> +++ b/drivers/block/sb_efi_media.c
> @@ -0,0 +1,20 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * EFI_MEDIA driver for sandbox
> + *
> + * Copyright 2021 Google LLC
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +
> +static const struct udevice_id sandbox_efi_media_ids[] = {
> +	{ .compatible = "sandbox,efi-media" },
> +	{ }
> +};
> +
> +U_BOOT_DRIVER(sandbox_efi_media) = {
> +	.name		= "sandbox_efi_media",
> +	.id		= UCLASS_EFI_MEDIA,
> +	.of_match	= sandbox_efi_media_ids,
> +};
> diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
> index 3768432b680..34f5e6689d3 100644
> --- a/include/dm/uclass-id.h
> +++ b/include/dm/uclass-id.h
> @@ -49,6 +49,7 @@ enum uclass_id {
>   	UCLASS_DSA,		/* Distributed (Ethernet) Switch Architecture */
>   	UCLASS_ECDSA,		/* Elliptic curve cryptographic device */
>   	UCLASS_EFI,		/* EFI managed devices */
> +	UCLASS_EFI_MEDIA,	/* EFI media (e.g. a disk) */
>   	UCLASS_ETH,		/* Ethernet device */
>   	UCLASS_ETH_PHY,		/* Ethernet PHY device */
>   	UCLASS_FIRMWARE,	/* Firmware */
> diff --git a/test/dm/Makefile b/test/dm/Makefile
> index 55162e9499d..e24679eb640 100644
> --- a/test/dm/Makefile
> +++ b/test/dm/Makefile
> @@ -37,6 +37,7 @@ obj-$(CONFIG_DMA) += dma.o
>   obj-$(CONFIG_VIDEO_MIPI_DSI) += dsi_host.o
>   obj-$(CONFIG_DM_DSA) += dsa.o
>   obj-$(CONFIG_ECDSA_VERIFY) += ecdsa.o
> +obj-$(CONFIG_EFI_MEDIA_SANDBOX) += efi_media.o
>   obj-$(CONFIG_DM_ETH) += eth.o
>   ifneq ($(CONFIG_EFI_PARTITION),)
>   obj-$(CONFIG_FASTBOOT_FLASH_MMC) += fastboot.o
> diff --git a/test/dm/efi_media.c b/test/dm/efi_media.c
> new file mode 100644
> index 00000000000..e343a0e9c85
> --- /dev/null
> +++ b/test/dm/efi_media.c
> @@ -0,0 +1,24 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Test for EFI_MEDIA uclass
> + *
> + * Copyright 2021 Google LLC
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <asm/test.h>
> +#include <dm/test.h>
> +#include <test/test.h>
> +#include <test/ut.h>
> +
> +/* Test that we can use the EFI_MEDIA uclass */
> +static int dm_test_efi_media(struct unit_test_state *uts)
> +{
> +	struct udevice *dev;
> +
> +	ut_assertok(uclass_first_device_err(UCLASS_EFI_MEDIA, &dev));
> +
> +	return 0;
> +}
> +DM_TEST(dm_test_efi_media, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);
>