[PATCH 04/10] drm/amdgpu: get owner ref in validate and map

[Felix Kuehling]

On 2021-06-21 12:04 p.m., Alex Sierra wrote:
> Get the proper owner reference for amdgpu_hmm_range_get_pages function.
> This is useful for partial migrations. To avoid migrating back to
> system memory, VRAM pages, that are accessible by all devices in the
> same memory domain.
> Ex. multiple devices in the same hive.
>
> Signed-off-by: Alex Sierra <alex.sierra at amd.com>

Reviewed-by: Felix Kuehling <Felix.Kuehling at amd.com>


> ---
>   drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 25 ++++++++++++++++++++++++-
>   1 file changed, 24 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> index 54f47b09b14a..2b4318646a75 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> @@ -1313,6 +1313,17 @@ static void svm_range_unreserve_bos(struct svm_validate_context *ctx)
>   	ttm_eu_backoff_reservation(&ctx->ticket, &ctx->validate_list);
>   }
>   
> +static void *kfd_svm_page_owner(struct kfd_process *p, int32_t gpuidx)
> +{
> +	struct kfd_process_device *pdd;
> +	struct amdgpu_device *adev;
> +
> +	pdd = kfd_process_device_from_gpuidx(p, gpuidx);
> +	adev = (struct amdgpu_device *)pdd->dev->kgd;
> +
> +	return SVM_ADEV_PGMAP_OWNER(adev);
> +}
> +
>   /*
>    * Validation+GPU mapping with concurrent invalidation (MMU notifiers)
>    *
> @@ -1343,6 +1354,9 @@ static int svm_range_validate_and_map(struct mm_struct *mm,
>   {
>   	struct svm_validate_context ctx;
>   	struct hmm_range *hmm_range;
> +	struct kfd_process *p;
> +	void *owner;
> +	int32_t idx;
>   	int r = 0;
>   
>   	ctx.process = container_of(prange->svms, struct kfd_process, svms);
> @@ -1389,10 +1403,19 @@ static int svm_range_validate_and_map(struct mm_struct *mm,
>   	svm_range_reserve_bos(&ctx);
>   
>   	if (!prange->actual_loc) {
> +		p = container_of(prange->svms, struct kfd_process, svms);
> +		owner = kfd_svm_page_owner(p, find_first_bit(ctx.bitmap,
> +							MAX_GPU_INSTANCE));
> +		for_each_set_bit(idx, ctx.bitmap, MAX_GPU_INSTANCE) {
> +			if (kfd_svm_page_owner(p, idx) != owner) {
> +				owner = NULL;
> +				break;
> +			}
> +		}
>   		r = amdgpu_hmm_range_get_pages(&prange->notifier, mm, NULL,
>   					       prange->start << PAGE_SHIFT,
>   					       prange->npages, &hmm_range,
> -					       false, true, NULL);
> +					       false, true, owner);
>   		if (r) {
>   			pr_debug("failed %d to get svm range pages\n", r);
>   			goto unreserve_out;