[PATCH] arm64: Get rid of ARM64_HAS_NO_HW_PREFETCH

[Catalin Marinas]

On Wed, Nov 22, 2023 at 01:37:54PM +0000, Marc Zyngier wrote:
> Back in 2016, it was argued that implementations lacking a HW
> prefetcher could be helped by sprinkling a number of PRFM
> instructions in strategic locations.
> 
> In 2023, the one platform that presumably needed this hack is no
> longer in active use (let alone maintained), and an quick
> experiment shows dropping this hack only leads to a 0.4% drop
> on a full kernel compilation (tested on a MT30-GS0 48 CPU system).
> 
> Given that this is pretty much in the noise department and that
> it may give odd ideas to other implementers, drop the hack for
> good.
> 
> Suggested-by: Will Deacon <will at kernel.org>
> Suggested-by: Mark Rutland <mark.rutland at arm.com>
> Signed-off-by: Marc Zyngier <maz at kernel.org>

Acked-by: Catalin Marinas <catalin.marinas at arm.com>