[PATCH] amd/amdkfd: Set correct svm range actual loc after spliting

[Chen, Xiaogang]

With a nitpick below, this patch is

Reviewed-by:Xiaogang Chen<Xiaogang.Chen at amd.com>

On 1/8/2024 4:36 PM, Philip Yang wrote:
> After range spliting, set new range and old range actual_loc:
> new range actual_loc is 0 if new->vram_pages is 0.
> old range actual_loc is 0 if old->vram_pages - new->vram_pages == 0.
>
> Signed-off-by: Philip Yang <Philip.Yang at amd.com>
> ---
>   drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 8 +++++---
>   1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> index cc24f30f88fb..cb09e1d3a643 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> @@ -362,7 +362,6 @@ svm_range *svm_range_new(struct svm_range_list *svms, uint64_t start,
>   	INIT_LIST_HEAD(&prange->child_list);
>   	atomic_set(&prange->invalid, 0);
>   	prange->validate_timestamp = 0;
> -	prange->vram_pages = 0;
I think it is better to keep it, also:

+new->actual_loc = 0;

though not necessary as prange is allocated by kzalloc, just keep consistent with previous statements, or remove

atomic_set(&prange->invalid, 0);
prange->validate_timestamp = 0;

too.

Regards
Xiaogang

>   	mutex_init(&prange->migrate_mutex);
>   	mutex_init(&prange->lock);
>   
> @@ -980,8 +979,12 @@ svm_range_split_pages(struct svm_range *new, struct svm_range *old,
>   		if (r)
>   			return r;
>   	}
> -	if (old->actual_loc)
> +	if (old->actual_loc && new->vram_pages) {
>   		old->vram_pages -= new->vram_pages;
> +		new->actual_loc = old->actual_loc;
> +		if (!old->vram_pages)
> +			old->actual_loc = 0;
> +	}
>   
>   	return 0;
>   }
> @@ -1058,7 +1061,6 @@ svm_range_split_adjust(struct svm_range *new, struct svm_range *old,
>   	new->flags = old->flags;
>   	new->preferred_loc = old->preferred_loc;
>   	new->prefetch_loc = old->prefetch_loc;
> -	new->actual_loc = old->actual_loc;
>   	new->granularity = old->granularity;
>   	new->mapped_to_gpu = old->mapped_to_gpu;
>   	bitmap_copy(new->bitmap_access, old->bitmap_access, MAX_GPU_INSTANCE);