drm/amdgpu: restrict the hw sched jobs number to power of two

the module parameter sched_hw_submission is probably from user mode,
and the kernel need to check whether it is legal.

1. align hw sched jobs to power of 2 and set minimum number is 2.
2. use kernel api is_power_of_2() to simplify driver code.
Signed-off-by: Kevin Wang <kevin1.wang@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -1166,6 +1166,16 @@ static int amdgpu_device_check_arguments(struct amdgpu_device *adev)
 		amdgpu_vm_fragment_size = -1;
 	}
 
+	if (amdgpu_sched_hw_submission < 2) {
+		dev_warn(adev->dev, "sched hw submission jobs (%d) must be at least 2\n",
+			 amdgpu_sched_hw_submission);
+		amdgpu_sched_hw_submission = 2;
+	} else if (!is_power_of_2(amdgpu_sched_hw_submission)) {
+		dev_warn(adev->dev, "sched hw submission jobs (%d) must be a power of 2\n",
+			 amdgpu_sched_hw_submission);
+		amdgpu_sched_hw_submission = roundup_pow_of_two(amdgpu_sched_hw_submission);
+	}
+
 	amdgpu_device_check_smu_prv_buffer_size(adev);
 
 	amdgpu_device_check_vm_size(adev);

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

@@ -450,8 +450,7 @@ int amdgpu_fence_driver_init_ring(struct amdgpu_ring *ring,
 	if (!adev)
 		return -EINVAL;
 
-	/* Check that num_hw_submission is a power of two */
-	if ((num_hw_submission & (num_hw_submission - 1)) != 0)
+	if (!is_power_of_2(num_hw_submission))
 		return -EINVAL;
 
 	ring->fence_drv.cpu_addr = NULL;