drm/kfd: Correct pinned buffer handling at kfd restore and validate process

This reverts commit 8a774fe9 ("drm/amdgpu: avoid restore process run into dead loop")
since buffer got pinned is not related whether it needs mapping
And skip buffer validation at kfd driver if the buffer has been pinned.
Signed-off-by: Xiaogang Chen <Xiaogang.Chen@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c

@@ -415,6 +415,10 @@ static int amdgpu_amdkfd_bo_validate(struct amdgpu_bo *bo, uint32_t domain,
 		 "Called with userptr BO"))
 		return -EINVAL;
 
+	/* bo has been pinned, not need validate it */
+	if (bo->tbo.pin_count)
+		return 0;
+
 	amdgpu_bo_placement_from_domain(bo, domain);
 
 	ret = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
@@ -2736,7 +2740,7 @@ static int confirm_valid_user_pages_locked(struct amdkfd_process_info *process_i
 
 		/* keep mem without hmm range at userptr_inval_list */
 		if (!mem->range)
-			 continue;
+			continue;
 
 		/* Only check mem with hmm range associated */
 		valid = amdgpu_ttm_tt_get_user_pages_done(
@@ -2981,9 +2985,6 @@ int amdgpu_amdkfd_gpuvm_restore_process_bos(void *info, struct dma_fence __rcu *
 			if (!attachment->is_mapped)
 				continue;
 
-			if (attachment->bo_va->base.bo->tbo.pin_count)
-				continue;
-
 			kfd_mem_dmaunmap_attachment(mem, attachment);
 			ret = update_gpuvm_pte(mem, attachment, &sync_obj);
 			if (ret) {