[PATCH v4 03/30] drm/xe: Move migrate to prefetch to op_lock function

[Zeng, Oak]

> -----Original Message-----
> From: Intel-xe <intel-xe-bounces at lists.freedesktop.org> On Behalf Of Matthew
> Brost
> Sent: Friday, March 8, 2024 12:08 AM
> To: intel-xe at lists.freedesktop.org
> Cc: Brost, Matthew <matthew.brost at intel.com>
> Subject: [PATCH v4 03/30] drm/xe: Move migrate to prefetch to op_lock function
> 
> Migrates need to be done under drm exec to make lockdep happy,


Can you explain more here? By under drm exec, do you mean drm_exec_until_all_locked? I do see xe_vm_prefetch/xe_bo_migrate is called inside drm_exec_until_all_locked, in patch 1 of this series, in function vm_bind_ioctl_ops_execute

 move
> the migrate done for prefetches under the op_lock function.
> 
> Signed-off-by: Matthew Brost <matthew.brost at intel.com>
> ---
>  drivers/gpu/drm/xe/xe_vm.c | 28 +++++++++++++---------------
>  1 file changed, 13 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
> index fb73afcab3b7..70a5ba621e4e 100644
> --- a/drivers/gpu/drm/xe/xe_vm.c
> +++ b/drivers/gpu/drm/xe/xe_vm.c
> @@ -1994,20 +1994,10 @@ static const u32 region_to_mem_type[] = {
> 
>  static struct dma_fence *
>  xe_vm_prefetch(struct xe_vm *vm, struct xe_vma *vma,
> -	       struct xe_exec_queue *q, u32 region,
> -	       struct xe_sync_entry *syncs, u32 num_syncs,
> -	       bool first_op, bool last_op)
> +	       struct xe_exec_queue *q, struct xe_sync_entry *syncs,
> +	       u32 num_syncs, bool first_op, bool last_op)
>  {
>  	struct xe_exec_queue *wait_exec_queue = to_wait_exec_queue(vm,
> q);
> -	int err;
> -
> -	xe_assert(vm->xe, region <= ARRAY_SIZE(region_to_mem_type));
> -
> -	if (!xe_vma_has_no_bo(vma)) {
> -		err = xe_bo_migrate(xe_vma_bo(vma),
> region_to_mem_type[region]);
> -		if (err)
> -			return ERR_PTR(err);
> -	}
> 
>  	if (vma->tile_mask != (vma->tile_present & ~vma->usm.tile_invalidated))
> {
>  		return xe_vm_bind(vm, vma, q, xe_vma_bo(vma), syncs,
> num_syncs,
> @@ -2540,8 +2530,7 @@ static struct dma_fence *op_execute(struct xe_vm
> *vm, struct xe_vma *vma,
>  				     op->flags & XE_VMA_OP_LAST);
>  		break;
>  	case DRM_GPUVA_OP_PREFETCH:
> -		fence = xe_vm_prefetch(vm, vma, op->q, op->prefetch.region,
> -				       op->syncs, op->num_syncs,
> +		fence = xe_vm_prefetch(vm, vma, op->q, op->syncs, op-
> >num_syncs,
>  				       op->flags & XE_VMA_OP_FIRST,
>  				       op->flags & XE_VMA_OP_LAST);
>  		break;
> @@ -2766,8 +2755,17 @@ static int op_lock(struct drm_exec *exec, struct xe_vm
> *vm,
>  		err = vma_lock(exec, gpuva_to_vma(op->base.unmap.va), false);
>  		break;
>  	case DRM_GPUVA_OP_PREFETCH:
> -		err = vma_lock(exec, gpuva_to_vma(op->base.prefetch.va),
> true);
> +	{
> +		struct xe_vma *vma = gpuva_to_vma(op->base.prefetch.va);
> +		u32 region = op->prefetch.region;
> +
> +		xe_assert(vm->xe, region <=
> ARRAY_SIZE(region_to_mem_type));
> +
> +		err = vma_lock(exec, vma, false);
> +		if (!err && !xe_vma_has_no_bo(vma))
> +			err = xe_bo_migrate(xe_vma_bo(vma), region);
>  		break;
> +	}

Understand you have a reason to do this. It does introduce confusion: the function is called op_lock and now you have a migration operation inside.


Oak


>  	default:
>  		drm_warn(&vm->xe->drm, "NOT POSSIBLE");
>  	}
> --
> 2.34.1