Re: [v2 PATCH 1/5] efi: Move arm-stub to a common file

From: Heinrich Schuchardt <xypron.glpk@gmx.de>
To: Palmer Dabbelt <palmer@dabbelt.com>,
	Atish Patra <Atish.Patra@wdc.com>,
	will@kernel.org
Cc: linux-efi@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
	Greg KH <gregkh@linuxfoundation.org>,
	masahiroy@kernel.org, linux-kernel@vger.kernel.org,
	mingo@kernel.org, catalin.marinas@arm.com, linux@armlinux.org.uk,
	linux-riscv@lists.infradead.org, ardb@kernel.org,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [v2 PATCH 1/5] efi: Move arm-stub to a common file
Date: Sat, 25 Apr 2020 11:47:49 +0200	[thread overview]
Message-ID: <8bf726ff-2f25-e8ba-17c7-2abf450b7c72@gmx.de> (raw)
In-Reply-To: <mhng-b521aadc-a209-48d6-886c-957c87f97367@palmerdabbelt-glaptop1>

On 4/21/20 9:19 PM, Palmer Dabbelt wrote:
> On Mon, 13 Apr 2020 14:29:03 PDT (-0700), Atish Patra wrote:
>> Most of the arm-stub code is written in an architecture independent
>> manner.
>> As a result, RISC-V can reuse most of the arm-stub code.
>>
>> Rename the arm-stub.c to efi-stub.c so that ARM, ARM64 and RISC-V can
>> use it.
>> This patch doesn't introduce any functional changes.
>>
>> Signed-off-by: Atish Patra <atish.patra@wdc.com>

The code being moved has some problems:

The ARM stub ignores the return value of efi_setup_gop().

drivers/firmware/efi/libstub/arm-stub.c and
drivers/firmware/efi/libstub/x86-stub.c both call LocateHandle() before
calling efi_setup_gop(). I think this should be moved to efi_setup_gop().

I guess the issues can be addressed in some follow up patch.

Best regards

Heinrich

>
> We'll need a bunch of Acked-bys for these, but I'm happy to take this in my
> tree.
>
>> ---
>>  arch/arm/Kconfig                                     |  2 +-
>>  arch/arm64/Kconfig                                   |  2 +-
>>  drivers/firmware/efi/Kconfig                         |  4 ++--
>>  drivers/firmware/efi/libstub/Makefile                | 12 ++++++------
>>  .../firmware/efi/libstub/{arm-stub.c => efi-stub.c}  |  0
>>  5 files changed, 10 insertions(+), 10 deletions(-)
>>  rename drivers/firmware/efi/libstub/{arm-stub.c => efi-stub.c} (100%)
>>
>> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
>> index 66a04f6f4775..165987aa5bcd 100644
>> --- a/arch/arm/Kconfig
>> +++ b/arch/arm/Kconfig
>> @@ -1954,7 +1954,7 @@ config EFI
>>      select UCS2_STRING
>>      select EFI_PARAMS_FROM_FDT
>>      select EFI_STUB
>> -    select EFI_ARMSTUB
>> +    select EFI_GENERIC_STUB
>>      select EFI_RUNTIME_WRAPPERS
>>      ---help---
>>        This option provides support for runtime services provided
>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
>> index 40fb05d96c60..32d818c5ccda 100644
>> --- a/arch/arm64/Kconfig
>> +++ b/arch/arm64/Kconfig
>> @@ -1785,7 +1785,7 @@ config EFI
>>      select EFI_PARAMS_FROM_FDT
>>      select EFI_RUNTIME_WRAPPERS
>>      select EFI_STUB
>> -    select EFI_ARMSTUB
>> +    select EFI_GENERIC_STUB
>>      default y
>>      help
>>        This option provides support for runtime services provided
>> diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig
>> index 613828d3f106..2a2b2b96a1dc 100644
>> --- a/drivers/firmware/efi/Kconfig
>> +++ b/drivers/firmware/efi/Kconfig
>> @@ -106,12 +106,12 @@ config EFI_PARAMS_FROM_FDT
>>  config EFI_RUNTIME_WRAPPERS
>>      bool
>>
>> -config EFI_ARMSTUB
>> +config EFI_GENERIC_STUB
>>      bool
>>
>>  config EFI_ARMSTUB_DTB_LOADER
>>      bool "Enable the DTB loader"
>> -    depends on EFI_ARMSTUB
>> +    depends on EFI_GENERIC_STUB
>>      default y
>>      help
>>        Select this config option to add support for the dtb= command
>> diff --git a/drivers/firmware/efi/libstub/Makefile
>> b/drivers/firmware/efi/libstub/Makefile
>> index 094eabdecfe6..d590504541f6 100644
>> --- a/drivers/firmware/efi/libstub/Makefile
>> +++ b/drivers/firmware/efi/libstub/Makefile
>> @@ -23,7 +23,7 @@ cflags-$(CONFIG_ARM)        := $(subst
>> $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \
>>                     -fno-builtin -fpic \
>>                     $(call cc-option,-mno-single-pic-base)
>>
>> -cflags-$(CONFIG_EFI_ARMSTUB)    += -I$(srctree)/scripts/dtc/libfdt
>> +cflags-$(CONFIG_EFI_GENERIC_STUB)    += -I$(srctree)/scripts/dtc/libfdt
>>
>>  KBUILD_CFLAGS            := $(cflags-y) -DDISABLE_BRANCH_PROFILING \
>>                     -include
>> $(srctree)/drivers/firmware/efi/libstub/hidden.h \
>> @@ -45,13 +45,13 @@ lib-y                := efi-stub-helper.o gop.o
>> secureboot.o tpm.o \
>>                     skip_spaces.o lib-cmdline.o lib-ctype.o
>>
>>  # include the stub's generic dependencies from lib/ when building for
>> ARM/arm64
>> -arm-deps-y := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c
>> fdt_sw.c
>> +efi-deps-y := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c
>> fdt_sw.c
>>
>>  $(obj)/lib-%.o: $(srctree)/lib/%.c FORCE
>>      $(call if_changed_rule,cc_o_c)
>>
>> -lib-$(CONFIG_EFI_ARMSTUB)    += arm-stub.o fdt.o string.o \
>> -                   $(patsubst %.c,lib-%.o,$(arm-deps-y))
>> +lib-$(CONFIG_EFI_GENERIC_STUB)        += efi-stub.o fdt.o string.o \
>> +                   $(patsubst %.c,lib-%.o,$(efi-deps-y))
>>
>>  lib-$(CONFIG_ARM)        += arm32-stub.o
>>  lib-$(CONFIG_ARM64)        += arm64-stub.o
>> @@ -73,8 +73,8 @@ CFLAGS_arm64-stub.o        :=
>> -DTEXT_OFFSET=$(TEXT_OFFSET)
>>  # a verification pass to see if any absolute relocations exist in any
>> of the
>>  # object files.
>>  #
>> -extra-$(CONFIG_EFI_ARMSTUB)    := $(lib-y)
>> -lib-$(CONFIG_EFI_ARMSTUB)    := $(patsubst %.o,%.stub.o,$(lib-y))
>> +extra-$(CONFIG_EFI_GENERIC_STUB)    := $(lib-y)
>> +lib-$(CONFIG_EFI_GENERIC_STUB)    := $(patsubst %.o,%.stub.o,$(lib-y))
>>
>>  STUBCOPY_FLAGS-$(CONFIG_ARM64)    += --prefix-alloc-sections=.init \
>>                     --prefix-symbols=__efistub_
>> diff --git a/drivers/firmware/efi/libstub/arm-stub.c
>> b/drivers/firmware/efi/libstub/efi-stub.c
>> similarity index 100%
>> rename from drivers/firmware/efi/libstub/arm-stub.c
>> rename to drivers/firmware/efi/libstub/efi-stub.c
>
> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
>
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