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    SubjectRe: [PATCH v6 0/5] efi/firmware/platform-x86: Add EFI embedded fw support
    On Fri, Jun 01, 2018 at 02:53:25PM +0200, Hans de Goede wrote:
    > Hi All,
    >
    > Here is v6 of my patch-set to add support for EFI embedded fw to the kernel.
    >
    > This patch-set applies on top of the "[PATCH v7 00/14] firmware_loader
    > changes for v4.18" series from mcgrof.
    >
    > It now also depends on the series from Andy Lutomirski which allow using the
    > sha256 code in a standalone manner. Andy what is the status of those?
    >
    > Changes since v5:
    > -Rework code to remove casts from if (prefix == mem) comparison
    > -Use SHA256 hashes instead of crc32 sums

    Nice! I see no updates on this progress, but it would seem this
    may then mean this cannot be merged until the release after?

    > -Add new READING_FIRMWARE_EFI_EMBEDDED read_file_id and use it
    > -Call security_kernel_read_file(NULL, READING_FIRMWARE_EFI_EMBEDDED)
    > to check if this is allowed before looking at EFI embedded fw

    There's a discussion over having security_kernel_read_file(NULL,
    READING_WHATEVER) become another LSM hook. So your series would conflict with
    that at the moment.

    So yet another piece of code which this series depends on.

    > -Document why we are not using the PI Firmware Volume protocol
    >
    > For reference I've included the coverletter from v4 (which includes
    > previous covverletters) below.
    >
    > Regards,
    >
    > Hans
    >
    >
    > Previous coverletter:
    >
    > Here is v5 of my patch-set to add support for EFI embedded fw to the kernel.
    >
    > Changes since v4:
    > -Rename the EFI_BOOT_SERVICES flag to EFI_PRESERVE_BS_REGIONS
    >
    > So I think this patch-set is getting close to ready for merging, which
    > brings us to the question of how to merge this, I think that patches 1
    > and 2 should probably both be merged through the same tree. Then an
    > unmutable branch should be created on that tree, merged into the
    > platform/x86 tree and then the last 3 patches can be merged through
    > that tree.
    >
    > Ard has already indicated he is fine with the EFI bits going upstream
    > through another tree, so perhaps patches 1-2 can be merged through the
    > firmware-loader-tree and then do an unmutable branch on the
    > firmware-loader-tree for the platform/x86 tree to merge?
    >
    > I don't think taking all 5 through 1 tree is a good idea because of
    > the file rename under platform/x86.
    >
    >
    > For the record here are the cover letters of the previous versions:
    >
    > Changes since v3:
    > -Drop note in docs about EFI_FIRMWARE_VOLUME_PROTOCOL, it is not part of
    > UEFI proper, so the EFI maintainers don't want us referring people to it
    > -Use new EFI_BOOT_SERVICES flag
    > -Put the new fw_get_efi_embedded_fw() function in its own fallback_efi.c
    > file which only gets built when EFI_EMBEDDED_FIRMWARE is selected
    > -Define an empty stub for fw_get_efi_embedded_fw() in fallback.h hwen
    > EFI_EMBEDDED_FIRMWARE is not selected, to avoid the need for #ifdefs
    > in firmware_loader/main.c
    > -Properly call security_kernel_post_read_file() on the firmware returned
    > by efi_get_embedded_fw() to make sure that we are allowed to use it
    >
    > The 3 most prominent changes in v2 are:
    >
    > 1) Add documentation describing the EFI embedded firmware mechanism to:
    > Documentation/driver-api/firmware/request_firmware.rst
    >
    > 2) Instead of having a single dmi_system_id array with its driver_data
    > members pointing to efi_embedded_fw_desc structs, have the drivers which
    > need EFI embedded-fw support export a dmi_system_id array and register
    > that with the EFI embedded-fw code
    >
    > This series also includes the first driver to use this, in the form of
    > the touchscreen_dmi code (formerly silead_dmi) from drivers/platfrom/x86
    >
    > 3) As discussed during the review of v1 we want to make the firmware_loader
    > code fallback to EFI embedded-fw optional. Rather the adding yet another
    > firmware_request_foo variant for this, with the risk of later also needing
    > firmware_request_foo_nowait, etc. variants I've decided to make the code
    > check if the device has a "efi-embedded-firmware" device-property bool set.
    >
    > This also seemed better because the same driver may want to use the
    > fallback on some systems, but not on others since e.g. not all (x86)
    > systems with a silead touchscreen have their touchscreen firmware embedded
    > in their EFI.
    >
    > Note that (as discussed) when the EFI fallback path is requested, the
    > usermodehelper fallback path is skipped.
    >
    > Here is the full changelog of patch 2/5 which is where most of the changes are:
    >
    > Changes in v2:
    > -Rebased on driver-core/driver-core-next
    > -Add documentation describing the EFI embedded firmware mechanism to:
    > Documentation/driver-api/firmware/request_firmware.rst
    > -Add a new EFI_EMBEDDED_FIRMWARE Kconfig bool and only build the embedded
    > fw support if this is set. This is an invisible option which should be
    > selected by drivers which need this
    > -Remove the efi_embedded_fw_desc and dmi_system_id-s for known devices
    > from the efi-embedded-fw code, instead drivers using this are expected to
    > export a dmi_system_id array, with each entries' driver_data pointing to a
    > efi_embedded_fw_desc struct and register this with the efi-embedded-fw code
    > -Use kmemdup to make a copy instead of efi_mem_reserve()-ing the firmware,
    > this avoids us messing with the EFI memmap and avoids the need to make
    > changes to efi_mem_desc_lookup()
    > -Make the firmware-loader code only fallback to efi_get_embedded_fw() if the
    > passed in device has the "efi-embedded-firmware" device-property bool set
    > -Skip usermodehelper fallback when "efi-embedded-firmware" device-property
    > is set
    >
    > Patches 3-5 are new and implement using the EFI embedded-fw mechanism for
    > Silead gslXXXX and Chipone icn8505 touchscreens on x86 devices.
    >
    >

    --
    Do not panic

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