linux/include/drm/drm_mm.h
Chris Wilson 202b52b7fb drm: Track drm_mm nodes with an interval tree
In addition to the last-in/first-out stack for accessing drm_mm nodes,
we occasionally and in the future often want to find a drm_mm_node by an
address. To do so efficiently we need to track the nodes in an interval
tree - lookups for a particular address will then be O(lg(N)), where N
is the number of nodes in the range manager as opposed to O(N).
Insertion however gains an extra O(lg(N)) step for all nodes
irrespective of whether the interval tree is in use. For future i915
patches, eliminating the linear walk is a significant improvement.

v2: Use generic interval-tree template for u64 and faster insertion.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1470236651-678-1-git-send-email-chris@chris-wilson.co.uk
2016-08-08 10:05:16 +02:00

329 lines
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C

/**************************************************************************
*
* 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
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;
};
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);
struct drm_mm_node *
drm_mm_interval_next(struct drm_mm_node *node, u64 start, u64 last);
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