[PATCH -next v7 2/7] arm64: entry: Refactor the entry and exit for exceptions from EL1

[Ada Couprie Diaz]

On 06/08/2025 03:49, Jinjie Ruan wrote:

> On 2025/8/5 23:06, Ada Couprie Diaz wrote:
>> Hi,
>>
>> On 29/07/2025 02:54, Jinjie Ruan wrote:
>>
>>> [...]
>>> diff --git a/arch/arm64/kernel/entry-common.c
>>> b/arch/arm64/kernel/entry-common.c
>>> index 8e798f46ad28..97e0741abde1 100644
>>> --- a/arch/arm64/kernel/entry-common.c
>>> +++ b/arch/arm64/kernel/entry-common.c
>>> [...]
>>> @@ -475,73 +497,81 @@ UNHANDLED(el1t, 64, error)
>>>    static void noinstr el1_abort(struct pt_regs *regs, unsigned long esr)
>>>    {
>>>        unsigned long far = read_sysreg(far_el1);
>>> +    arm64_irqentry_state_t state;
>>>    -    enter_from_kernel_mode(regs);
>>> +    state = enter_from_kernel_mode(regs);
>> Nit: There is some inconsistencies with some functions splitting state's
>> definition
>> and declaration (like el1_abort here), while some others do it on the
>> same line
>> (el1_undef() below for example).
>> In some cases it is welcome as the entry function is called after some
>> other work,
>> but here for example it doesn't seem to be beneficial ?
> Both methods can keep the modifications to `enter_from_kernel_mode()` on
> the same line as the original code, which will facilitate code review.
>
> I think it is also fine to do it on the same line here, which can reduce
> one line code, which method is better may be a matter of personal opinion.
Fair point !
Then, as mentioned previously, I'm happy to leave my Reviewed-By.
>>>        local_daif_inherit(regs);
>>>        do_mem_abort(far, esr, regs);
>>>        local_daif_mask();
>>> -    exit_to_kernel_mode(regs);
>>> +    exit_to_kernel_mode(regs, state);
>>>    }
>>>      static void noinstr el1_pc(struct pt_regs *regs, unsigned long esr)
>>>    {
>>>        unsigned long far = read_sysreg(far_el1);
>>> +    arm64_irqentry_state_t state;
>>>    -    enter_from_kernel_mode(regs);
>>> +    state = enter_from_kernel_mode(regs);
>>>        local_daif_inherit(regs);
>>>        do_sp_pc_abort(far, esr, regs);
>>>        local_daif_mask();
>>> -    exit_to_kernel_mode(regs);
>>> +    exit_to_kernel_mode(regs, state);
>>>    }
>>>      static void noinstr el1_undef(struct pt_regs *regs, unsigned long
>>> esr)
>>>    {
>>> -    enter_from_kernel_mode(regs);
>>> +    arm64_irqentry_state_t state = enter_from_kernel_mode(regs);
>>> +
>>>        local_daif_inherit(regs);
>>>        do_el1_undef(regs, esr);
>>>        local_daif_mask();
>>> -    exit_to_kernel_mode(regs);
>>> +    exit_to_kernel_mode(regs, state);
>>>    }
>>>
>>> [...]
>> Other than the small nit:
>> Reviewed-by: Ada Couprie Diaz <ada.coupriediaz at arm.com>