[PATCH v2 02/14] arm: add initjmp()

[Jerome Forissier]

On 2/28/25 14:28, Heinrich Schuchardt wrote:
> On 28.02.25 14:21, Jerome Forissier wrote:
>>
>>
>> On 2/28/25 14:05, Heinrich Schuchardt wrote:
>>> On 25.02.25 17:34, Jerome Forissier wrote:
>>>> Implement initjmp() for Arm.
>>>>
>>>> Signed-off-by: Jerome Forissier <jerome.forissier at linaro.org>
>>>> ---
>>>>    arch/Kconfig                  |  1 +
>>>>    arch/arm/include/asm/setjmp.h |  1 +
>>>>    arch/arm/lib/setjmp.S         | 11 +++++++++++
>>>>    arch/arm/lib/setjmp_aarch64.S |  9 +++++++++
>>>>    4 files changed, 22 insertions(+)
>>>>
>>>> diff --git a/arch/Kconfig b/arch/Kconfig
>>>> index 8d5b54031b3..57695fada8d 100644
>>>> --- a/arch/Kconfig
>>>> +++ b/arch/Kconfig
>>>> @@ -94,6 +94,7 @@ config ARC
>>>>    config ARM
>>>>        bool "ARM architecture"
>>>>        select HAVE_SETJMP
>>>> +    select HAVE_INITJMP
>>>>        select ARCH_SUPPORTS_LTO
>>>>        select CREATE_ARCH_SYMLINK
>>>>        select HAVE_PRIVATE_LIBGCC if !ARM64
>>>> diff --git a/arch/arm/include/asm/setjmp.h b/arch/arm/include/asm/setjmp.h
>>>> index 662bec86321..1ad5b500f2a 100644
>>>> --- a/arch/arm/include/asm/setjmp.h
>>>> +++ b/arch/arm/include/asm/setjmp.h
>>>> @@ -23,5 +23,6 @@ typedef struct jmp_buf_data jmp_buf[1];
>>>>
>>>>    int setjmp(jmp_buf jmp);
>>>>    void longjmp(jmp_buf jmp, int ret);
>>>> +int initjmp(jmp_buf jmp, void __noreturn (*func)(void), void *stack_top);
>>>
>>> As this is not a standard function we cannot expect developers to know
>>> what it does and how to use it.
>>>
>>> Please, provide Sphinx style documentation with the necessary information.
>>
>> I agree on principle, but if I add documentation here then I should add the
>> same for all architectures. That being said the prototypes are already
>> duplicated so maybe consolidation is a question for another time.  I will
>> add Shpinx style doc to all 3 commits "{arm,riscv,sandbox}: add initjmp()".
> 
> Yes, this was not designed correctly:
> 
> We should move setjmp.h to include/asm-generic and include an
> architecture specific setjmp_bits.h from there.
> 
> setjmp_bits.h would provide the struct jmp_buf_data definition.

Makes sense. I'll rework in v3.

> 
>>
>> As for usage, I think the best documentation is test/lib/initjmp.c added
>> by "test: lib: add initjmp() test".
> 
> Example code is valuable but does not replace documentation.

Should I provide a stripped-down example in the Sphinx doc? Or do you have
another location in mind? (doc/develop/initjmp.rst?).

Thanks,
-- 
Jerome

> 
> Best regards
> 
> Heinrich