[v4,00/12] efi_loader: more tightly integrate UEFI disks to driver model

With this patch set[1] applied, UEFI subsystem maintains a list of its
disk objects dynamically at runtime based on block device's probing.
(See "issues" and "prerequisite" below.)

[1] https://github.com/t-akashi/u-boot/tree/efi/dm_disk

For instance,
=> dm tree
 Class     Index  Probed  Driver                Name
-----------------------------------------------------------
 root          0  [ + ]   root_driver           root_driver
 ...
 pci           0  [ + ]   pci_generic_ecam      |-- pcie@10000000
 ...
 ahci          0  [   ]   ahci_pci              |   |-- ahci_pci
 scsi          0  [   ]   ahci_scsi             |   |   `-- ahci_scsi
 usb           0  [   ]   xhci_pci              |   `-- xhci_pci
 ...
=> efi devices
Missing RNG device for EFI_RNG_PROTOCOL
No EFI system partition
Unable to find TPMv2 device
Device           Device Path
================ ====================
000000013eee88d0 /VenHw(..)
000000013ffeb798 /VenHw(..)/Uart(0,0,D,D)
000000013eeeb810 /VenHw(..)/MAC(525252525252,1)
=> scsi rescan
 ...
=> efi devices
Device           Device Path
================ ====================
000000013eee88d0 /VenHw(..)
000000013ffeb798 /VenHw(..)/Uart(0,0,D,D)
000000013eeeb810 /VenHw(..)/MAC(525252525252,1)
000000013eefb730 /VenHw(..)/Scsi(0,0)
000000013eefb840 /VenHw(..)/Scsi(0,0)/HD(1,GPT,ce86c5a7-b32a-488f-a346-88fe698e0edc,0x22,0x4c2a)
000000013eefbc80 /VenHw(..)/Scsi(0,0)/HD(2,GPT,aa80aab9-33e6-42b6-b5db-def2cb8d7844,0x5000,0x1a800)
=> usb start
 ...
=> efi devices
Device           Device Path
================ ====================
000000013eee88d0 /VenHw(..)
000000013ffeb798 /VenHw(..)/Uart(0,0,D,D)
000000013eeeb810 /VenHw(..)/MAC(525252525252,1)
000000013eefb730 /VenHw(..)/Scsi(0,0)
000000013eefb840 /VenHw(..)/Scsi(0,0)/HD(1,GPT,ce86c5a7-b32a-488f-a346-88fe698e0edc,0x22,0x4c2a)
000000013eefbc80 /VenHw(..)/Scsi(0,0)/HD(2,GPT,aa80aab9-33e6-42b6-b5db-def2cb8d7844,0x5000,0x1a800)
000000013ef01330 /VenHw(..)/UsbClass(0x0,0x0,0x9,0x0,0x3)/UsbClass(0x46f4,0x1,0x0,0x0,0x0)
000000013ef014b0 /VenHw(..)/UsbClass(0x0,0x0,0x9,0x0,0x3)/UsbClass(0x46f4,0x1,0x0,0x0,0x0)/HD(1,GPT,ce86c5a7-b32a-488f-a346-88fe698e0edc,0x22,0x4c2a)
000000013ef018f0 /VenHw(..)/UsbClass(0x0,0x0,0x9,0x0,0x3)/UsbClass(0x46f4,0x1,0x0,0x0,0x0)/HD(2,GPT,aa80aab9-33e6-42b6-b5db-def2cb8d7844,0x5000,0x1a800)
=> dm tree
 ...
 pci           0  [ + ]   pci_generic_ecam      |-- pcie@10000000
 ...
 ahci          0  [ + ]   ahci_pci              |   |-- ahci_pci
 scsi          0  [ + ]   ahci_scsi             |   |   `-- ahci_scsi
 blk           2  [ + ]   scsi_blk              |   |       `-- ahci_scsi.id0lun0
 partition     0  [ + ]   blk_partition         |   |           |-- ahci_scsi.id0lun0:1
 partition     1  [ + ]   blk_partition         |   |           `-- ahci_scsi.id0lun0:2
 usb           0  [ + ]   xhci_pci              |   `-- xhci_pci
 usb_hub       0  [ + ]   usb_hub               |       `-- usb_hub
 usb_mass_s    0  [ + ]   usb_mass_storage      |           |-- usb_mass_storage
 blk           3  [ + ]   usb_storage_blk       |           |   `-- usb_mass_storage.lun0
 partition     2  [ + ]   blk_partition         |           |       |-- usb_mass_storage.lun0:1
 partition     3  [ + ]   blk_partition         |           |       `-- usb_mass_storage.lun0:2
 ...

=> usb stop
stopping USB..
=> efi devices
Device           Device Path
================ ====================
000000013eee88d0 /VenHw(..)
000000013ffeb798 /VenHw(..)/Uart(0,0,D,D)
000000013eeeb810 /VenHw(..)/MAC(525252525252,1)
000000013eefb730 /VenHw(..)/Scsi(0,0)
000000013eefb840 /VenHw(..)/Scsi(0,0)/HD(1,GPT,ce86c5a7-b32a-488f-a346-88fe698e0edc,0x22,0x4c2a)
000000013eefbc80 /VenHw(..)/Scsi(0,0)/HD(2,GPT,aa80aab9-33e6-42b6-b5db-def2cb8d7844,0x5000,0x1a800)


Issues:
=======
* Some (UEFI-unrelated) UT tests still fail for a unknown reason.
  As I reported[2], this might happen due to U-Boot itself or UT framework.

* For removal case, we may need more consideration since removing handles
  unconditionally may end up breaking integrity of handles
  (as some may still be held and referenced to by a UEFI app).

[2] https://lists.denx.de/pipermail/u-boot/2022-April/481405.html


Prerequisite:
=============
* my patch, "disk: don't compile in partition support for spl/tpl if not
  really necessary"[3]

[3] https://lists.denx.de/pipermail/u-boot/2022-April/481531.html


Patchs:
=======
For easy understandings, patches may be categorized into separate groups
of changes.

Patch#1-#3: DM: add a new feature (DM tag)
Patch#4-#10: UEFI: dynamically create/remove efi_disk's for a raw disk
  and its partitions
Patch#11-#12: UEFI: use udevice read/write interfaces


Change history:
===============
v4 (Apr, 15, 2022)
* rebased on pre-2022.07-rc1
* removed already-merged patches
* added patch#1 (for better error code)
* merged v3's patch#19 to patch#7 to make bisect work
* split v3's patch#13 into patch#8(create) and patch#10(delete)
* move a function prototype out of "#ifdef CONFIG_PARTITIONS" (patch#4)
* move function prototypes out of "#ifdef CONFIG_PARTITIONS" (patch#11)

v3 (Mar 8, 2022)
* rebased on 2022.04-rc3
* rebased on v2 of Simon's event patch
  (hence removed his patch from this patch set)
* fix a spl-build error in mmc_blk_probe() (patch#3)
* fix a build warning in fsl_ata_probe()/sil_pci_probe() (patch#5)
* remove a problematic log message in efi_disk_probe() (patch#14)

v2 (Feb 10, 2022)
* add/revise an error message if device_probe() fails (patch#3,#5)
* fix a build error in sandbox_spl_defconfig (patch#8)
* fix warnings in 'make htmldocs' (patch#8,#9,#18)
* new commit: split efi_init_obj_list() (patch#14)
* new commit: simplify efi_capsule pytest (patch#21)

v1 (Feb 2, 2022)
* rebased on 2022.04-rc1
* drop patches that have already been merged
* modify a tag-range check with "tag >= DM_TAG_COUNT" (patch#9)
* move dmtag_list to GD (global data) (patch#9)
* add function descriptions and a document about DM tag feature (patch#9,10)
* add tests for DM tag support (patch#11)
* change 'depends on EVENT' to 'select EVENT' for EFI_LOADER (patch#14)
* migrate IF_TYPE_EFI to IF_TYPE_EFI_LOADER (patch#18)

RFCv2 (Dec 10, 2021)
* rebased on 2022-rc3
* re-order and merge some related commits into ones
* call device_probe() in MMC (not bind, but) probe hook (patch#5)
* fix a wrong name of variable (patch#7)
* add patch#9
* invoke device_probe() for virtio devices (patch#10)
* add DM event notification (from Simon) (patch#11)
* add DM tag support (patch#12)
* move UCLASS_PARTITION driver under disk/ (patch#13)
* create partition's dp using its parent's. This change is necessary
  in particular for 'efi_blk' efi_disk (patch#13)
* modify the code so that we will use new features like tags and
  event notification (patch#13,15,16,20)
* rename new functions from blk_read/write() to dev_read/write()
  (patch#17,18)
* isolate changes in efi_driver from the rest (in efi_loader) (patch#19)
* drop the previous patch#22 ("efi_selftest: block device: adjust dp
  for a test") due to the fix in patch#13

RFC (Nov 16, 2021)
* initial RFC

AKASHI Takahiro (12):
  dm: tag: change ENOSPC to ENOMEM
  dm: tag: add some document
  test: dm: add tests for tag support
  dm: disk: add UCLASS_PARTITION
  dm: blk: add a device-probe hook for scanning disk partitions
  efi_loader: split efi_init_obj_list() into two stages
  efi_loader: disk: a helper function to create efi_disk objects from
    udevice
  efi_loader: disk: not create BLK device for BLK(IF_TYPE_EFI_LOADER)
    devices
  efi_loader: disk: a helper function to delete efi_disk objects
  efi_loader: disk: not delete BLK device for BLK(IF_TYPE_EFI_LOADER)
    devices
  dm: disk: add read/write interfaces with udevice
  efi_loader: disk: use udevice instead of blk_desc

 common/board_r.c                    |   2 +-
 common/main.c                       |   7 +-
 disk/Makefile                       |   3 +
 disk/disk-uclass.c                  | 247 ++++++++++++++++++++++
 doc/develop/driver-model/design.rst |  20 ++
 drivers/block/blk-uclass.c          |   4 +
 drivers/core/tag.c                  |   4 +-
 include/dm/uclass-id.h              |   1 +
 include/efi_loader.h                |   6 +-
 include/part.h                      |  17 ++
 lib/efi_driver/efi_block_device.c   |  34 +--
 lib/efi_loader/Kconfig              |   3 +
 lib/efi_loader/efi_disk.c           | 314 +++++++++++++++++++++-------
 lib/efi_loader/efi_setup.c          |  62 ++++--
 test/dm/Makefile                    |   1 +
 test/dm/tag.c                       |  84 ++++++++
 16 files changed, 685 insertions(+), 124 deletions(-)
 create mode 100644 disk/disk-uclass.c
 create mode 100644 test/dm/tag.c