[PATCH] drm/amdgpu: Fix build errors with HMM disabled

[Kuehling, Felix]

Looks like Arnd Bergmann already fixed it with a different patch. That's 
fine with me too. Feel free to ignore this.

On 2019-07-08 12:05 p.m., Kuehling, Felix wrote:
> Only define struct amdgpu_mn if HMM_MIRROR is enabled. Add back a
> forward declaration for the case that it isn't.
>
> Fixes: 6f1c3e61d2d8 ("drm/amdgpu: Prepare for hmm_range_register API change")
> Signed-off-by: Felix Kuehling <Felix.Kuehling at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h
> index 281fd9fef662..33ca6214db90 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h
> @@ -35,6 +35,8 @@ enum amdgpu_mn_type {
>   	AMDGPU_MN_TYPE_HSA,
>   };
>   
> +#if defined(CONFIG_HMM_MIRROR)
> +
>   /**
>    * struct amdgpu_mn
>    *
> @@ -69,7 +71,6 @@ struct amdgpu_mn {
>   	struct hmm_mirror	mirror;
>   };
>   
> -#if defined(CONFIG_HMM_MIRROR)
>   void amdgpu_mn_lock(struct amdgpu_mn *mn);
>   void amdgpu_mn_unlock(struct amdgpu_mn *mn);
>   struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,
> @@ -78,6 +79,9 @@ int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr);
>   void amdgpu_mn_unregister(struct amdgpu_bo *bo);
>   void amdgpu_hmm_init_range(struct hmm_range *range);
>   #else
> +
> +struct amdgpu_mn;
> +
>   static inline void amdgpu_mn_lock(struct amdgpu_mn *mn) {}
>   static inline void amdgpu_mn_unlock(struct amdgpu_mn *mn) {}
>   static inline struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,