[PATCH resend 02/15] arm64: add abstractions for FPSIMD state manipulation

[Ard Biesheuvel]

On 6 May 2014 16:43, Catalin Marinas <catalin.marinas at arm.com> wrote:
> On Thu, May 01, 2014 at 04:49:34PM +0100, Ard Biesheuvel wrote:
>> diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
>> index 4aef42a04bdc..86ac6a9bc86a 100644
>> --- a/arch/arm64/kernel/fpsimd.c
>> +++ b/arch/arm64/kernel/fpsimd.c
>> @@ -87,6 +87,39 @@ void fpsimd_flush_thread(void)
>>       preempt_enable();
>>  }
>>
>> +/*
>> + * Save the userland FPSIMD state of 'current' to memory
>> + */
>> +void fpsimd_preserve_current_state(void)
>> +{
>> +     fpsimd_save_state(&current->thread.fpsimd_state);
>> +}
>> +
>> +/*
>> + * Load the userland FPSIMD state of 'current' from memory
>> + */
>> +void fpsimd_restore_current_state(void)
>> +{
>> +     fpsimd_load_state(&current->thread.fpsimd_state);
>> +}
>> +
>> +/*
>> + * Load an updated userland FPSIMD state for 'current' from memory
>> + */
>> +void fpsimd_update_current_state(struct fpsimd_state *state)
>> +{
>> +     preempt_disable();
>> +     fpsimd_load_state(state);
>> +     preempt_enable();
>> +}
>
> Minor - please update the comment above the functions to state that
> preemption needs to be disabled by the caller.
>

Do you mean in all three cases? And, by implication, that the
preempt_disable()/enable() pair should be moved to the call site for
fpsimd_update_current_state() ?


>> +/*
>> + * Invalidate live CPU copies of task t's FPSIMD state
>> + */
>> +void fpsimd_flush_task_state(struct task_struct *t)
>> +{
>> +}
>
> I guess this will be added in a subsequent patch. You could either move
> it there or add a comment in the commit log that it is a dummy function
> for now (I prefer the former).
>

OK

-- 
Ard.