drm: Extract drm_prime.h

Plus a little bit more documentation.

v2: Untangle the missing forward decls to make drm_prime|gem.h
free-standing.

Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170308141257.12119-3-daniel.vetter@ffwll.ch
diff --git a/include/drm/drm_prime.h b/include/drm/drm_prime.h
new file mode 100644
index 0000000..77ceca7
--- /dev/null
+++ b/include/drm/drm_prime.h
@@ -0,0 +1,79 @@
+/*
+ * Copyright © 2012 Red Hat
+ * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
+ * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
+ * Copyright (c) 2009-2010, Code Aurora Forum.
+ *
+ * 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 (including the next
+ * paragraph) 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 AUTHORS OR COPYRIGHT HOLDERS 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.
+ *
+ * Authors:
+ *      Dave Airlie <airlied@redhat.com>
+ *      Rob Clark <rob.clark@linaro.org>
+ *
+ */
+
+#ifndef __DRM_PRIME_H__
+#define __DRM_PRIME_H__
+
+#include <linux/mutex.h>
+#include <linux/rbtree.h>
+
+/**
+ * struct drm_prime_file_private - per-file tracking for PRIME
+ *
+ * This just contains the internal &struct dma_buf and handle caches for each
+ * &struct drm_file used by the PRIME core code.
+ */
+
+struct drm_prime_file_private {
+/* private: */
+	struct mutex lock;
+	struct rb_root dmabufs;
+	struct rb_root handles;
+};
+
+struct dma_buf_export_info;
+struct dma_buf;
+
+struct drm_device;
+struct drm_gem_object;
+struct drm_file;
+
+extern struct dma_buf *drm_gem_prime_export(struct drm_device *dev,
+					    struct drm_gem_object *obj,
+					    int flags);
+extern int drm_gem_prime_handle_to_fd(struct drm_device *dev,
+		struct drm_file *file_priv, uint32_t handle, uint32_t flags,
+		int *prime_fd);
+extern struct drm_gem_object *drm_gem_prime_import(struct drm_device *dev,
+		struct dma_buf *dma_buf);
+extern int drm_gem_prime_fd_to_handle(struct drm_device *dev,
+		struct drm_file *file_priv, int prime_fd, uint32_t *handle);
+struct dma_buf *drm_gem_dmabuf_export(struct drm_device *dev,
+				      struct dma_buf_export_info *exp_info);
+extern void drm_gem_dmabuf_release(struct dma_buf *dma_buf);
+
+extern int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages,
+					    dma_addr_t *addrs, int max_pages);
+extern struct sg_table *drm_prime_pages_to_sg(struct page **pages, unsigned int nr_pages);
+extern void drm_prime_gem_destroy(struct drm_gem_object *obj, struct sg_table *sg);
+
+
+#endif /* __DRM_PRIME_H__ */