[RFC v2 PATCH 4/7] arm64: tlbflush.h: add __tlbi() macro

[Will Deacon]

On Mon, Sep 05, 2016 at 05:31:34PM +0100, Punit Agrawal wrote:
> From: Mark Rutland <mark.rutland at arm.com>
> 
> As with dsb() and isb(), add a __tlbi() helper so that we can avoid
> distracting asm boilerplate every time we want a TLBI. As some TLBI
> operations take an argument while others do not, some pre-processor is
> used to handle these two cases with different assembly blocks.
> 
> The existing tlbflush.h code is moved over to use the helper.
> 
> Signed-off-by: Mark Rutland <mark.rutland at arm.com>
> Cc: Catalin Marinas <catalin.marinas at arm.com>
> Cc: Marc Zyngier <marc.zyngier at arm.com>
> Cc: Will Deacon <will.deacon at arm.com>
> [ rename helper to __tlbi, update commit log ]
> Signed-off-by: Punit Agrawal <punit.agrawal at arm.com>
> ---
>  arch/arm64/include/asm/tlbflush.h | 31 +++++++++++++++++++++++--------
>  1 file changed, 23 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
> index b460ae2..e9e42a7 100644
> --- a/arch/arm64/include/asm/tlbflush.h
> +++ b/arch/arm64/include/asm/tlbflush.h
> @@ -25,6 +25,21 @@
>  #include <asm/cputype.h>
>  
>  /*
> + * Raw TLBI operations. Drivers and most kernel code should use the TLB
> + * management routines below in preference to these. Where necessary, these can
> + * be used to avoid asm() boilerplate.
> + *
> + * Can be used as __tlbi(op) or __tlbi(op, arg), depending on whether a
> + * particular TLBI op takes an argument or not. The macros below handle invoking
> + * the asm with or without the register argument as appropriate.
> + */
> +#define __TLBI_0(op, arg)		asm ("tlbi " #op)
> +#define __TLBI_1(op, arg)		asm ("tlbi " #op ", %0" : : "r" (arg))
> +#define __TLBI_N(op, arg, n, ...)	__TLBI_##n(op, arg)
> +
> +#define __tlbi(op, ...)		__TLBI_N(op, ##__VA_ARGS__, 1, 0)

This looks ok to me now. With Christoffer's comments address:

Reviewed-by: Will Deacon <will.deacon at arm.com>

Will