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

[Catalin Marinas <catalin.marinas@arm.com>]

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.

> +/*
> + * 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).

-- 
Catalin