[Intel-gfx] [PATCH] drm/i915: Use memset64() to prefill the GTT page

[Tvrtko Ursulin]

On 26/09/2017 10:53, Chris Wilson wrote:
> Take advantage of optimised memset64() instead of open coding it to
> prefill the GTT pages.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
> Needs backmerge from 4.14-rc1, but it's tantalisingly close.
> ---
>   drivers/gpu/drm/i915/i915_gem_gtt.c | 4 +---
>   1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index 0477949805e1..74062897d331 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -486,10 +486,8 @@ static void fill_page_dma(struct i915_address_space *vm,
>   			  const u64 val)
>   {
>   	u64 * const vaddr = kmap_atomic(p->page);
> -	int i;
>   
> -	for (i = 0; i < 512; i++)
> -		vaddr[i] = val;
> +	memset64(vaddr, val, PAGE_SIZE / sizeof(val));
>   
>   	kunmap_atomic(vaddr);
>   }
> 

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

I wonder if for 32-bit builds (who cares) memset32 would be better in 
fill_page_dma_32 or it makes no difference?

Regards,

Tvrtko