drm/ttm: revert "Export ttm_bo_get_unless_zero()"

This reverts commit 24dc64c1ba.

Shouldn't be needed by drivers any more.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Simona Vetter <simona.vetter@ffwll.ch>
Link: https://lore.kernel.org/r/20240723121750.2086-6-christian.koenig@amd.com

drivers/gpu/drm/ttm/ttm_bo.c

@@ -46,6 +46,7 @@
 #include <linux/dma-resv.h>
 
 #include "ttm_module.h"
+#include "ttm_bo_internal.h"
 
 static void ttm_bo_mem_space_debug(struct ttm_buffer_object *bo,
 					struct ttm_placement *placement)

drivers/gpu/drm/ttm/ttm_bo_internal.h

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2018 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ *
+ */
+
+#ifndef _TTM_BO_INTERNAL_H_
+#define _TTM_BO_INTERNAL_H_
+
+#include <drm/ttm/ttm_bo.h>
+
+/**
+ * ttm_bo_get_unless_zero - reference a struct ttm_buffer_object unless
+ * its refcount has already reached zero.
+ * @bo: The buffer object.
+ *
+ * Used to reference a TTM buffer object in lookups where the object is removed
+ * from the lookup structure during the destructor and for RCU lookups.
+ *
+ * Returns: @bo if the referencing was successful, NULL otherwise.
+ */
+static inline __must_check struct ttm_buffer_object *
+ttm_bo_get_unless_zero(struct ttm_buffer_object *bo)
+{
+	if (!kref_get_unless_zero(&bo->kref))
+		return NULL;
+	return bo;
+}
+
+#endif

drivers/gpu/drm/ttm/ttm_bo_util.c

@@ -37,6 +37,8 @@
 
 #include <drm/drm_cache.h>
 
+#include "ttm_bo_internal.h"
+
 struct ttm_transfer_obj {
 	struct ttm_buffer_object base;
 	struct ttm_buffer_object *bo;

drivers/gpu/drm/ttm/ttm_device.c

@@ -36,6 +36,7 @@
 #include <drm/ttm/ttm_placement.h>
 
 #include "ttm_module.h"
+#include "ttm_bo_internal.h"
 
 /*
  * ttm_global_mutex - protecting the global state

include/drm/ttm/ttm_bo.h

@@ -254,24 +254,6 @@ static inline void ttm_bo_get(struct ttm_buffer_object *bo)
 	kref_get(&bo->kref);
 }
 
-/**
- * ttm_bo_get_unless_zero - reference a struct ttm_buffer_object unless
- * its refcount has already reached zero.
- * @bo: The buffer object.
- *
- * Used to reference a TTM buffer object in lookups where the object is removed
- * from the lookup structure during the destructor and for RCU lookups.
- *
- * Returns: @bo if the referencing was successful, NULL otherwise.
- */
-static inline __must_check struct ttm_buffer_object *
-ttm_bo_get_unless_zero(struct ttm_buffer_object *bo)
-{
-	if (!kref_get_unless_zero(&bo->kref))
-		return NULL;
-	return bo;
-}
-
 /**
  * ttm_bo_reserve:
  *