[Intel-gfx] [PATCH v2 2/4] drm/i915/gt: Re-work invalidate_csb_entries

[Tvrtko Ursulin]

On 28/01/2022 22:10, Michael Cheng wrote:
> Re-work invalidate_csb_entries to use drm_clflush_virt_range. This will
> prevent compiler errors when building for non-x86 architectures.
> 
> Signed-off-by: Michael Cheng <michael.cheng at intel.com>
> ---
>   drivers/gpu/drm/i915/gt/intel_execlists_submission.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> index 960a9aaf4f3a..90b5daf9433d 100644
> --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> @@ -1647,8 +1647,8 @@ cancel_port_requests(struct intel_engine_execlists * const execlists,
>   
>   static void invalidate_csb_entries(const u64 *first, const u64 *last)
>   {
> -	clflush((void *)first);
> -	clflush((void *)last);
> +	drm_clflush_virt_range((void *)first, sizeof(*first));
> +	drm_clflush_virt_range((void *)last, sizeof(*last));

How about dropping the helper and from the single call site do:

drm_clflush_virt_range(&buf[0], num_entries * sizeof(buf[0]));

One less function call and CSB is a single cacheline before Gen11 ayway, 
two afterwards, so overall better conversion I think. How does that sound?

Regards,

Tvrtko

>   }
>   
>   /*
>