Re: [Intel-xe] [PATCH v2 25/30] drm/xe: Invalidate TLB on all affected GTs during GGTT updates

["Das, Nirmoy" <nirmoy.das@linux.intel.com>]

On 5/20/2023 1:18 AM, Matt Roper wrote:
> The GGTT is part of the tile and is shared by the primary and media GTs
> on platforms with a standalone media architecture.  However each of
> these GTs has its own TLBs caching the page table lookups, and each
> needs to be invalidated separately.
>
> Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
> ---
>   drivers/gpu/drm/xe/xe_ggtt.c | 16 ++++++++++------
>   1 file changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_ggtt.c b/drivers/gpu/drm/xe/xe_ggtt.c
> index 7c87623ef5c5..31f958613c2f 100644
> --- a/drivers/gpu/drm/xe/xe_ggtt.c
> +++ b/drivers/gpu/drm/xe/xe_ggtt.c
> @@ -188,13 +188,10 @@ int xe_ggtt_init(struct xe_ggtt *ggtt)
>   #define PVC_GUC_TLB_INV_DESC1			XE_REG(0xcf80)
>   #define   PVC_GUC_TLB_INV_DESC1_INVALIDATE	REG_BIT(6)
>   
> -void xe_ggtt_invalidate(struct xe_ggtt *ggtt)
> +static void ggtt_invalidate_gt_tlb(struct xe_gt *gt)
>   {
> -	/*
> -	 * TODO: Loop over each GT in tile once media GT support is
> -	 * re-added
> -	 */
> -	struct xe_gt *gt = ggtt->tile->primary_gt;
> +	if (!gt)
> +		return;
>   
>   	/* TODO: vfunc for GuC vs. non-GuC */
>   
> @@ -219,6 +216,13 @@ void xe_ggtt_invalidate(struct xe_ggtt *ggtt)
>   	}
>   }
>   
> +void xe_ggtt_invalidate(struct xe_ggtt *ggtt)
> +{
> +	/* Each GT in a tile has its own TLB to cache GGTT lookups */
> +	ggtt_invalidate_gt_tlb(ggtt->tile->primary_gt);
> +	ggtt_invalidate_gt_tlb(ggtt->tile->media_gt);
> +}
> +
>   void xe_ggtt_printk(struct xe_ggtt *ggtt, const char *prefix)
>   {
>   	u64 addr, scratch_pte;