include/drm/drm_mm.h - linux - Git at Google

 /**************************************************************************
  *
  * Copyright 2006-2008 Tungsten Graphics, Inc., Cedar Park, TX. USA.
  * All Rights Reserved.
  *
  * 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, sub license, 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 NON-INFRINGEMENT. IN NO EVENT SHALL
  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS 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:
  * Thomas Hellstrom <thomas-at-tungstengraphics-dot-com>
  */

 #ifndef _DRM_MM_H_
 #define _DRM_MM_H_

 /*
  * Generic range manager structs
  */
 #include <linux/bug.h>
 #include <linux/rbtree.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
 #ifdef CONFIG_DEBUG_FS
 #include <linux/seq_file.h>
 #endif
 #ifdef CONFIG_DRM_DEBUG_MM
 #include <linux/stackdepot.h>
 #endif

 enum drm_mm_search_flags {
 	DRM_MM_SEARCH_DEFAULT =		0,
 	DRM_MM_SEARCH_BEST =		1 << 0,
 	DRM_MM_SEARCH_BELOW =		1 << 1,
 };

 enum drm_mm_allocator_flags {
 	DRM_MM_CREATE_DEFAULT =		0,
 	DRM_MM_CREATE_TOP =		1 << 0,
 };

 #define DRM_MM_BOTTOMUP DRM_MM_SEARCH_DEFAULT, DRM_MM_CREATE_DEFAULT
 #define DRM_MM_TOPDOWN DRM_MM_SEARCH_BELOW, DRM_MM_CREATE_TOP

 struct drm_mm_node {
 	struct list_head node_list;
 	struct list_head hole_stack;
 	struct rb_node rb;
 	unsigned hole_follows : 1;
 	unsigned scanned_block : 1;
 	unsigned scanned_prev_free : 1;
 	unsigned scanned_next_free : 1;
 	unsigned scanned_preceeds_hole : 1;
 	unsigned allocated : 1;
 	unsigned long color;
 	u64 start;
 	u64 size;
 	u64 __subtree_last;
 	struct drm_mm *mm;
 #ifdef CONFIG_DRM_DEBUG_MM
 	depot_stack_handle_t stack;
 #endif
 };

 struct drm_mm {
 	/* List of all memory nodes that immediately precede a free hole. */
 	struct list_head hole_stack;
 	/* head_node.node_list is the list of all memory nodes, ordered
 	 * according to the (increasing) start address of the memory node. */
 	struct drm_mm_node head_node;
 	/* Keep an interval_tree for fast lookup of drm_mm_nodes by address. */
 	struct rb_root interval_tree;

 	unsigned int scan_check_range : 1;
 	unsigned scan_alignment;
 	unsigned long scan_color;
 	u64 scan_size;
 	u64 scan_hit_start;
 	u64 scan_hit_end;
 	unsigned scanned_blocks;
 	u64 scan_start;
 	u64 scan_end;
 	struct drm_mm_node *prev_scanned_node;

 	void (*color_adjust)(struct drm_mm_node *node, unsigned long color,
 			     u64 *start, u64 *end);
 };

 /**
  * drm_mm_node_allocated - checks whether a node is allocated
  * @node: drm_mm_node to check
  *
  * Drivers should use this helpers for proper encapusulation of drm_mm
  * internals.
  *
  * Returns:
  * True if the @node is allocated.
  */
 static inline bool drm_mm_node_allocated(struct drm_mm_node *node)
 {
 	return node->allocated;
 }

 /**
  * drm_mm_initialized - checks whether an allocator is initialized
  * @mm: drm_mm to check
  *
  * Drivers should use this helpers for proper encapusulation of drm_mm
  * internals.
  *
  * Returns:
  * True if the @mm is initialized.
  */
 static inline bool drm_mm_initialized(struct drm_mm *mm)
 {
 	return mm->hole_stack.next;
 }

 static inline u64 __drm_mm_hole_node_start(struct drm_mm_node *hole_node)
 {
 	return hole_node->start + hole_node->size;
 }

 /**
  * drm_mm_hole_node_start - computes the start of the hole following @node
  * @hole_node: drm_mm_node which implicitly tracks the following hole
  *
  * This is useful for driver-sepific debug dumpers. Otherwise drivers should not
  * inspect holes themselves. Drivers must check first whether a hole indeed
  * follows by looking at node->hole_follows.
  *
  * Returns:
  * Start of the subsequent hole.
  */
 static inline u64 drm_mm_hole_node_start(struct drm_mm_node *hole_node)
 {
 	BUG_ON(!hole_node->hole_follows);
 	return __drm_mm_hole_node_start(hole_node);
 }

 static inline u64 __drm_mm_hole_node_end(struct drm_mm_node *hole_node)
 {
 	return list_next_entry(hole_node, node_list)->start;
 }

 /**
  * drm_mm_hole_node_end - computes the end of the hole following @node
  * @hole_node: drm_mm_node which implicitly tracks the following hole
  *
  * This is useful for driver-sepific debug dumpers. Otherwise drivers should not
  * inspect holes themselves. Drivers must check first whether a hole indeed
  * follows by looking at node->hole_follows.
  *
  * Returns:
  * End of the subsequent hole.
  */
 static inline u64 drm_mm_hole_node_end(struct drm_mm_node *hole_node)
 {
 	return __drm_mm_hole_node_end(hole_node);
 }

 /**
  * drm_mm_for_each_node - iterator to walk over all allocated nodes
  * @entry: drm_mm_node structure to assign to in each iteration step
  * @mm: drm_mm allocator to walk
  *
  * This iterator walks over all nodes in the range allocator. It is implemented
  * with list_for_each, so not save against removal of elements.
  */
 #define drm_mm_for_each_node(entry, mm) list_for_each_entry(entry, \
 						&(mm)->head_node.node_list, \
 						node_list)

 #define __drm_mm_for_each_hole(entry, mm, hole_start, hole_end, backwards) \
 	for (entry = list_entry((backwards) ? (mm)->hole_stack.prev : (mm)->hole_stack.next, struct drm_mm_node, hole_stack); \
 	     &entry->hole_stack != &(mm)->hole_stack ? \
 	     hole_start = drm_mm_hole_node_start(entry), \
 	     hole_end = drm_mm_hole_node_end(entry), \
 	     1 : 0; \
 	     entry = list_entry((backwards) ? entry->hole_stack.prev : entry->hole_stack.next, struct drm_mm_node, hole_stack))

 /**
  * drm_mm_for_each_hole - iterator to walk over all holes
  * @entry: drm_mm_node used internally to track progress
  * @mm: drm_mm allocator to walk
  * @hole_start: ulong variable to assign the hole start to on each iteration
  * @hole_end: ulong variable to assign the hole end to on each iteration
  *
  * This iterator walks over all holes in the range allocator. It is implemented
  * with list_for_each, so not save against removal of elements. @entry is used
  * internally and will not reflect a real drm_mm_node for the very first hole.
  * Hence users of this iterator may not access it.
  *
  * Implementation Note:
  * We need to inline list_for_each_entry in order to be able to set hole_start
  * and hole_end on each iteration while keeping the macro sane.
  *
  * The __drm_mm_for_each_hole version is similar, but with added support for
  * going backwards.
  */
 #define drm_mm_for_each_hole(entry, mm, hole_start, hole_end) \
 	__drm_mm_for_each_hole(entry, mm, hole_start, hole_end, 0)

 /*
  * Basic range manager support (drm_mm.c)
  */
 int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node);

 int drm_mm_insert_node_generic(struct drm_mm *mm,
 			       struct drm_mm_node *node,
 			       u64 size,
 			       unsigned alignment,
 			       unsigned long color,
 			       enum drm_mm_search_flags sflags,
 			       enum drm_mm_allocator_flags aflags);
 /**
  * drm_mm_insert_node - search for space and insert @node
  * @mm: drm_mm to allocate from
  * @node: preallocate node to insert
  * @size: size of the allocation
  * @alignment: alignment of the allocation
  * @flags: flags to fine-tune the allocation
  *
  * This is a simplified version of drm_mm_insert_node_generic() with @color set
  * to 0.
  *
  * The preallocated node must be cleared to 0.
  *
  * Returns:
  * 0 on success, -ENOSPC if there's no suitable hole.
  */
 static inline int drm_mm_insert_node(struct drm_mm *mm,
 				     struct drm_mm_node *node,
 				     u64 size,
 				     unsigned alignment,
 				     enum drm_mm_search_flags flags)
 {
 	return drm_mm_insert_node_generic(mm, node, size, alignment, 0, flags,
 					  DRM_MM_CREATE_DEFAULT);
 }

 int drm_mm_insert_node_in_range_generic(struct drm_mm *mm,
 					struct drm_mm_node *node,
 					u64 size,
 					unsigned alignment,
 					unsigned long color,
 					u64 start,
 					u64 end,
 					enum drm_mm_search_flags sflags,
 					enum drm_mm_allocator_flags aflags);
 /**
  * drm_mm_insert_node_in_range - ranged search for space and insert @node
  * @mm: drm_mm to allocate from
  * @node: preallocate node to insert
  * @size: size of the allocation
  * @alignment: alignment of the allocation
  * @start: start of the allowed range for this node
  * @end: end of the allowed range for this node
  * @flags: flags to fine-tune the allocation
  *
  * This is a simplified version of drm_mm_insert_node_in_range_generic() with
  * @color set to 0.
  *
  * The preallocated node must be cleared to 0.
  *
  * Returns:
  * 0 on success, -ENOSPC if there's no suitable hole.
  */
 static inline int drm_mm_insert_node_in_range(struct drm_mm *mm,
 					      struct drm_mm_node *node,
 					      u64 size,
 					      unsigned alignment,
 					      u64 start,
 					      u64 end,
 					      enum drm_mm_search_flags flags)
 {
 	return drm_mm_insert_node_in_range_generic(mm, node, size, alignment,
 						   0, start, end, flags,
 						   DRM_MM_CREATE_DEFAULT);
 }

 void drm_mm_remove_node(struct drm_mm_node *node);
 void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new);
 void drm_mm_init(struct drm_mm *mm,
 		 u64 start,
 		 u64 size);
 void drm_mm_takedown(struct drm_mm *mm);
 bool drm_mm_clean(struct drm_mm *mm);

 struct drm_mm_node *
 __drm_mm_interval_first(struct drm_mm *mm, u64 start, u64 last);

 /**
  * drm_mm_for_each_node_in_range - iterator to walk over a range of
  * allocated nodes
  * @node__: drm_mm_node structure to assign to in each iteration step
  * @mm__: drm_mm allocator to walk
  * @start__: starting offset, the first node will overlap this
  * @end__: ending offset, the last node will start before this (but may overlap)
  *
  * This iterator walks over all nodes in the range allocator that lie
  * between @start and @end. It is implemented similarly to list_for_each(),
  * but using the internal interval tree to accelerate the search for the
  * starting node, and so not safe against removal of elements. It assumes
  * that @end is within (or is the upper limit of) the drm_mm allocator.
  */
 #define drm_mm_for_each_node_in_range(node__, mm__, start__, end__)	\
 	for (node__ = __drm_mm_interval_first((mm__), (start__), (end__)-1); \
 	     node__ && node__->start < (end__);				\
 	     node__ = list_next_entry(node__, node_list))

 void drm_mm_init_scan(struct drm_mm *mm,
 		      u64 size,
 		      unsigned alignment,
 		      unsigned long color);
 void drm_mm_init_scan_with_range(struct drm_mm *mm,
 				 u64 size,
 				 unsigned alignment,
 				 unsigned long color,
 				 u64 start,
 				 u64 end);
 bool drm_mm_scan_add_block(struct drm_mm_node *node);
 bool drm_mm_scan_remove_block(struct drm_mm_node *node);

 void drm_mm_debug_table(struct drm_mm *mm, const char *prefix);
 #ifdef CONFIG_DEBUG_FS
 int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm);
 #endif

 #endif
	/**************************************************************************
	*
	* Copyright 2006-2008 Tungsten Graphics, Inc., Cedar Park, TX. USA.
	* All Rights Reserved.
	*
	* 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, sub license, 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 NON-INFRINGEMENT. IN NO EVENT SHALL
	* THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS 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:
	* Thomas Hellstrom <thomas-at-tungstengraphics-dot-com>
	*/

	#ifndef _DRM_MM_H_
	#define _DRM_MM_H_

	/*
	* Generic range manager structs
	*/
	#include <linux/bug.h>
	#include <linux/rbtree.h>
	#include <linux/kernel.h>
	#include <linux/list.h>
	#include <linux/spinlock.h>
	#ifdef CONFIG_DEBUG_FS
	#include <linux/seq_file.h>
	#endif
	#ifdef CONFIG_DRM_DEBUG_MM
	#include <linux/stackdepot.h>
	#endif

	enum drm_mm_search_flags {
	DRM_MM_SEARCH_DEFAULT = 0,
	DRM_MM_SEARCH_BEST = 1 << 0,
	DRM_MM_SEARCH_BELOW = 1 << 1,
	};

	enum drm_mm_allocator_flags {
	DRM_MM_CREATE_DEFAULT = 0,
	DRM_MM_CREATE_TOP = 1 << 0,
	};

	#define DRM_MM_BOTTOMUP DRM_MM_SEARCH_DEFAULT, DRM_MM_CREATE_DEFAULT
	#define DRM_MM_TOPDOWN DRM_MM_SEARCH_BELOW, DRM_MM_CREATE_TOP

	struct drm_mm_node {
	struct list_head node_list;
	struct list_head hole_stack;
	struct rb_node rb;
	unsigned hole_follows : 1;
	unsigned scanned_block : 1;
	unsigned scanned_prev_free : 1;
	unsigned scanned_next_free : 1;
	unsigned scanned_preceeds_hole : 1;
	unsigned allocated : 1;
	unsigned long color;
	u64 start;
	u64 size;
	u64 __subtree_last;
	struct drm_mm *mm;
	#ifdef CONFIG_DRM_DEBUG_MM
	depot_stack_handle_t stack;
	#endif
	};

	struct drm_mm {
	/* List of all memory nodes that immediately precede a free hole. */
	struct list_head hole_stack;
	/* head_node.node_list is the list of all memory nodes, ordered
	* according to the (increasing) start address of the memory node. */
	struct drm_mm_node head_node;
	/* Keep an interval_tree for fast lookup of drm_mm_nodes by address. */
	struct rb_root interval_tree;

	unsigned int scan_check_range : 1;
	unsigned scan_alignment;
	unsigned long scan_color;
	u64 scan_size;
	u64 scan_hit_start;
	u64 scan_hit_end;
	unsigned scanned_blocks;
	u64 scan_start;
	u64 scan_end;
	struct drm_mm_node *prev_scanned_node;

	void (color_adjust)(struct drm_mm_node node, unsigned long color,
	u64 start, u64 end);
	};

	/**
	* drm_mm_node_allocated - checks whether a node is allocated
	* @node: drm_mm_node to check
	*
	* Drivers should use this helpers for proper encapusulation of drm_mm
	* internals.
	*
	* Returns:
	* True if the @node is allocated.
	*/
	static inline bool drm_mm_node_allocated(struct drm_mm_node *node)
	{
	return node->allocated;
	}

	/**
	* drm_mm_initialized - checks whether an allocator is initialized
	* @mm: drm_mm to check
	*
	* Drivers should use this helpers for proper encapusulation of drm_mm
	* internals.
	*
	* Returns:
	* True if the @mm is initialized.
	*/
	static inline bool drm_mm_initialized(struct drm_mm *mm)
	{
	return mm->hole_stack.next;
	}

	static inline u64 __drm_mm_hole_node_start(struct drm_mm_node *hole_node)
	{
	return hole_node->start + hole_node->size;
	}

	/**
	* drm_mm_hole_node_start - computes the start of the hole following @node
	* @hole_node: drm_mm_node which implicitly tracks the following hole
	*
	* This is useful for driver-sepific debug dumpers. Otherwise drivers should not
	* inspect holes themselves. Drivers must check first whether a hole indeed
	* follows by looking at node->hole_follows.
	*
	* Returns:
	* Start of the subsequent hole.
	*/
	static inline u64 drm_mm_hole_node_start(struct drm_mm_node *hole_node)
	{
	BUG_ON(!hole_node->hole_follows);
	return __drm_mm_hole_node_start(hole_node);
	}

	static inline u64 __drm_mm_hole_node_end(struct drm_mm_node *hole_node)
	{
	return list_next_entry(hole_node, node_list)->start;
	}

	/**
	* drm_mm_hole_node_end - computes the end of the hole following @node
	* @hole_node: drm_mm_node which implicitly tracks the following hole
	*
	* This is useful for driver-sepific debug dumpers. Otherwise drivers should not
	* inspect holes themselves. Drivers must check first whether a hole indeed
	* follows by looking at node->hole_follows.
	*
	* Returns:
	* End of the subsequent hole.
	*/
	static inline u64 drm_mm_hole_node_end(struct drm_mm_node *hole_node)
	{
	return __drm_mm_hole_node_end(hole_node);
	}

	/**
	* drm_mm_for_each_node - iterator to walk over all allocated nodes
	* @entry: drm_mm_node structure to assign to in each iteration step
	* @mm: drm_mm allocator to walk
	*
	* This iterator walks over all nodes in the range allocator. It is implemented
	* with list_for_each, so not save against removal of elements.
	*/
	#define drm_mm_for_each_node(entry, mm) list_for_each_entry(entry, \
	&(mm)->head_node.node_list, \
	node_list)

	#define __drm_mm_for_each_hole(entry, mm, hole_start, hole_end, backwards) \
	for (entry = list_entry((backwards) ? (mm)->hole_stack.prev : (mm)->hole_stack.next, struct drm_mm_node, hole_stack); \
	&entry->hole_stack != &(mm)->hole_stack ? \
	hole_start = drm_mm_hole_node_start(entry), \
	hole_end = drm_mm_hole_node_end(entry), \
	1 : 0; \
	entry = list_entry((backwards) ? entry->hole_stack.prev : entry->hole_stack.next, struct drm_mm_node, hole_stack))

	/**
	* drm_mm_for_each_hole - iterator to walk over all holes
	* @entry: drm_mm_node used internally to track progress
	* @mm: drm_mm allocator to walk
	* @hole_start: ulong variable to assign the hole start to on each iteration
	* @hole_end: ulong variable to assign the hole end to on each iteration
	*
	* This iterator walks over all holes in the range allocator. It is implemented
	* with list_for_each, so not save against removal of elements. @entry is used
	* internally and will not reflect a real drm_mm_node for the very first hole.
	* Hence users of this iterator may not access it.
	*
	* Implementation Note:
	* We need to inline list_for_each_entry in order to be able to set hole_start
	* and hole_end on each iteration while keeping the macro sane.
	*
	* The __drm_mm_for_each_hole version is similar, but with added support for
	* going backwards.
	*/
	#define drm_mm_for_each_hole(entry, mm, hole_start, hole_end) \
	__drm_mm_for_each_hole(entry, mm, hole_start, hole_end, 0)

	/*
	* Basic range manager support (drm_mm.c)
	*/
	int drm_mm_reserve_node(struct drm_mm mm, struct drm_mm_node node);

	int drm_mm_insert_node_generic(struct drm_mm *mm,
	struct drm_mm_node *node,
	u64 size,
	unsigned alignment,
	unsigned long color,
	enum drm_mm_search_flags sflags,
	enum drm_mm_allocator_flags aflags);
	/**
	* drm_mm_insert_node - search for space and insert @node
	* @mm: drm_mm to allocate from
	* @node: preallocate node to insert
	* @size: size of the allocation
	* @alignment: alignment of the allocation
	* @flags: flags to fine-tune the allocation
	*
	* This is a simplified version of drm_mm_insert_node_generic() with @color set
	* to 0.
	*
	* The preallocated node must be cleared to 0.
	*
	* Returns:
	* 0 on success, -ENOSPC if there's no suitable hole.
	*/
	static inline int drm_mm_insert_node(struct drm_mm *mm,
	struct drm_mm_node *node,
	u64 size,
	unsigned alignment,
	enum drm_mm_search_flags flags)
	{
	return drm_mm_insert_node_generic(mm, node, size, alignment, 0, flags,
	DRM_MM_CREATE_DEFAULT);
	}

	int drm_mm_insert_node_in_range_generic(struct drm_mm *mm,
	struct drm_mm_node *node,
	u64 size,
	unsigned alignment,
	unsigned long color,
	u64 start,
	u64 end,
	enum drm_mm_search_flags sflags,
	enum drm_mm_allocator_flags aflags);
	/**
	* drm_mm_insert_node_in_range - ranged search for space and insert @node
	* @mm: drm_mm to allocate from
	* @node: preallocate node to insert
	* @size: size of the allocation
	* @alignment: alignment of the allocation
	* @start: start of the allowed range for this node
	* @end: end of the allowed range for this node
	* @flags: flags to fine-tune the allocation
	*
	* This is a simplified version of drm_mm_insert_node_in_range_generic() with
	* @color set to 0.
	*
	* The preallocated node must be cleared to 0.
	*
	* Returns:
	* 0 on success, -ENOSPC if there's no suitable hole.
	*/
	static inline int drm_mm_insert_node_in_range(struct drm_mm *mm,
	struct drm_mm_node *node,
	u64 size,
	unsigned alignment,
	u64 start,
	u64 end,
	enum drm_mm_search_flags flags)
	{
	return drm_mm_insert_node_in_range_generic(mm, node, size, alignment,
	0, start, end, flags,
	DRM_MM_CREATE_DEFAULT);
	}

	void drm_mm_remove_node(struct drm_mm_node *node);
	void drm_mm_replace_node(struct drm_mm_node old, struct drm_mm_node new);
	void drm_mm_init(struct drm_mm *mm,
	u64 start,
	u64 size);
	void drm_mm_takedown(struct drm_mm *mm);
	bool drm_mm_clean(struct drm_mm *mm);

	struct drm_mm_node *
	__drm_mm_interval_first(struct drm_mm *mm, u64 start, u64 last);

	/**
	* drm_mm_for_each_node_in_range - iterator to walk over a range of
	* allocated nodes
	* @node__: drm_mm_node structure to assign to in each iteration step
	* @mm__: drm_mm allocator to walk
	* @start__: starting offset, the first node will overlap this
	* @end__: ending offset, the last node will start before this (but may overlap)
	*
	* This iterator walks over all nodes in the range allocator that lie
	* between @start and @end. It is implemented similarly to list_for_each(),
	* but using the internal interval tree to accelerate the search for the
	* starting node, and so not safe against removal of elements. It assumes
	* that @end is within (or is the upper limit of) the drm_mm allocator.
	*/
	#define drm_mm_for_each_node_in_range(node__, mm__, start__, end__) \
	for (node__ = __drm_mm_interval_first((mm__), (start__), (end__)-1); \
	node__ && node__->start < (end__); \
	node__ = list_next_entry(node__, node_list))

	void drm_mm_init_scan(struct drm_mm *mm,
	u64 size,
	unsigned alignment,
	unsigned long color);
	void drm_mm_init_scan_with_range(struct drm_mm *mm,
	u64 size,
	unsigned alignment,
	unsigned long color,
	u64 start,
	u64 end);
	bool drm_mm_scan_add_block(struct drm_mm_node *node);
	bool drm_mm_scan_remove_block(struct drm_mm_node *node);

	void drm_mm_debug_table(struct drm_mm mm, const char prefix);
	#ifdef CONFIG_DEBUG_FS
	int drm_mm_dump_table(struct seq_file m, struct drm_mm mm);
	#endif

	#endif