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/**************************************************************************
*
* Copyright 2006-2008 Tungsten Graphics, Inc., Cedar Park, TX. USA.
* Copyright 2016 Intel Corporation
* 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/mm_types.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#ifdef CONFIG_DRM_DEBUG_MM
#include <linux/stackdepot.h>
#endif
#include <drm/drm_print.h>
#ifdef CONFIG_DRM_DEBUG_MM
#define DRM_MM_BUG_ON(expr) BUG_ON(expr)
#else
#define DRM_MM_BUG_ON(expr) BUILD_BUG_ON_INVALID(expr)
#endif
/**
* enum drm_mm_insert_mode - control search and allocation behaviour
*
* The &struct drm_mm range manager supports finding a suitable modes using
* a number of search trees. These trees are oranised by size, by address and
* in most recent eviction order. This allows the user to find either the
* smallest hole to reuse, the lowest or highest address to reuse, or simply
* reuse the most recent eviction that fits. When allocating the &drm_mm_node
* from within the hole, the &drm_mm_insert_mode also dictate whether to
* allocate the lowest matching address or the highest.
*/
enum drm_mm_insert_mode {
/**
* @DRM_MM_INSERT_BEST:
*
* Search for the smallest hole (within the search range) that fits
* the desired node.
*
* Allocates the node from the bottom of the found hole.
*/
DRM_MM_INSERT_BEST = 0,
/**
* @DRM_MM_INSERT_LOW:
*
* Search for the lowest hole (address closest to 0, within the search
* range) that fits the desired node.
*
* Allocates the node from the bottom of the found hole.
*/
DRM_MM_INSERT_LOW,
/**
* @DRM_MM_INSERT_HIGH:
*
* Search for the highest hole (address closest to U64_MAX, within the
* search range) that fits the desired node.
*
* Allocates the node from the *top* of the found hole. The specified
* alignment for the node is applied to the base of the node
* (&drm_mm_node.start).
*/
DRM_MM_INSERT_HIGH,
/**
* @DRM_MM_INSERT_EVICT:
*
* Search for the most recently evicted hole (within the search range)
* that fits the desired node. This is appropriate for use immediately
* after performing an eviction scan (see drm_mm_scan_init()) and
* removing the selected nodes to form a hole.
*
* Allocates the node from the bottom of the found hole.
*/
DRM_MM_INSERT_EVICT,
/**
* @DRM_MM_INSERT_ONCE:
*
* Only check the first hole for suitablity and report -ENOSPC
* immediately otherwise, rather than check every hole until a
* suitable one is found. Can only be used in conjunction with another
* search method such as DRM_MM_INSERT_HIGH or DRM_MM_INSERT_LOW.
*/
DRM_MM_INSERT_ONCE = BIT(31),
/**
* @DRM_MM_INSERT_HIGHEST:
*
* Only check the highest hole (the hole with the largest address) and
* insert the node at the top of the hole or report -ENOSPC if
* unsuitable.
*
* Does not search all holes.
*/
DRM_MM_INSERT_HIGHEST = DRM_MM_INSERT_HIGH | DRM_MM_INSERT_ONCE,
/**
* @DRM_MM_INSERT_LOWEST:
*
* Only check the lowest hole (the hole with the smallest address) and
* insert the node at the bottom of the hole or report -ENOSPC if
* unsuitable.
*
* Does not search all holes.
*/
DRM_MM_INSERT_LOWEST = DRM_MM_INSERT_LOW | DRM_MM_INSERT_ONCE,
};
/**
* struct drm_mm_node - allocated block in the DRM allocator
*
* This represents an allocated block in a &drm_mm allocator. Except for
* pre-reserved nodes inserted using drm_mm_reserve_node() the structure is
* entirely opaque and should only be accessed through the provided funcions.
* Since allocation of these nodes is entirely handled by the driver they can be
* embedded.
*/
struct drm_mm_node {
/** @color: Opaque driver-private tag. */
unsigned long color;
/** @start: Start address of the allocated block. */
u64 start;
/** @size: Size of the allocated block. */
u64 size;
/* private: */
struct drm_mm *mm;
struct list_head node_list;
struct list_head hole_stack;
struct rb_node rb;
struct rb_node rb_hole_size;
struct rb_node rb_hole_addr;
u64 __subtree_last;
u64 hole_size;
u64 subtree_max_hole;
unsigned long flags;
#define DRM_MM_NODE_ALLOCATED_BIT 0
#define DRM_MM_NODE_SCANNED_BIT 1
#ifdef CONFIG_DRM_DEBUG_MM
depot_stack_handle_t stack;
#endif
};
/**
* struct drm_mm - DRM allocator
*
* DRM range allocator with a few special functions and features geared towards
* managing GPU memory. Except for the @color_adjust callback the structure is
* entirely opaque and should only be accessed through the provided functions
* and macros. This structure can be embedded into larger driver structures.
*/
struct drm_mm {
/**
* @color_adjust:
*
* Optional driver callback to further apply restrictions on a hole. The
* node argument points at the node containing the hole from which the
* block would be allocated (see drm_mm_hole_follows() and friends). The
* other arguments are the size of the block to be allocated. The driver
* can adjust the start and end as needed to e.g. insert guard pages.
*/
void (*color_adjust)(const struct drm_mm_node *node,
unsigned long color,
u64 *start, u64 *end);
/* private: */
/* 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_cached interval_tree;
struct rb_root_cached holes_size;
struct rb_root holes_addr;
unsigned long scan_active;
};
/**
* struct drm_mm_scan - DRM allocator eviction roaster data
*
* This structure tracks data needed for the eviction roaster set up using
* drm_mm_scan_init(), and used with drm_mm_scan_add_block() and
* drm_mm_scan_remove_block(). The structure is entirely opaque and should only
* be accessed through the provided functions and macros. It is meant to be
* allocated temporarily by the driver on the stack.
*/
struct drm_mm_scan {
/* private: */
struct drm_mm *mm;
u64 size;
u64 alignment;
u64 remainder_mask;
u64 range_start;
u64 range_end;
u64 hit_start;
u64 hit_end;
unsigned long color;
enum drm_mm_insert_mode mode;
};
/**
* drm_mm_node_allocated - checks whether a node is allocated
* @node: drm_mm_node to check
*
* Drivers are required to clear a node prior to using it with the
* drm_mm range manager.
*
* Drivers should use this helper for proper encapsulation of drm_mm
* internals.
*
* Returns:
* True if the @node is allocated.
*/
static inline bool drm_mm_node_allocated(const struct drm_mm_node *node)
{
return test_bit(DRM_MM_NODE_ALLOCATED_BIT, &node->flags);
}
/**
* drm_mm_initialized - checks whether an allocator is initialized
* @mm: drm_mm to check
*
* Drivers should clear the struct drm_mm prior to initialisation if they
* want to use this function.
*
* Drivers should use this helper for proper encapsulation of drm_mm
* internals.
*
* Returns:
* True if the @mm is initialized.
*/
static inline bool drm_mm_initialized(const struct drm_mm *mm)
{
return READ_ONCE(mm->hole_stack.next);
}
/**
* drm_mm_hole_follows - checks whether a hole follows this node
* @node: drm_mm_node to check
*
* Holes are embedded into the drm_mm using the tail of a drm_mm_node.
* If you wish to know whether a hole follows this particular node,
* query this function. See also drm_mm_hole_node_start() and
* drm_mm_hole_node_end().
*
* Returns:
* True if a hole follows the @node.
*/
static inline bool drm_mm_hole_follows(const struct drm_mm_node *node)
{
return node->hole_size;
}
static inline u64 __drm_mm_hole_node_start(const 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-specific debug dumpers. Otherwise drivers should
* not inspect holes themselves. Drivers must check first whether a hole indeed
* follows by looking at drm_mm_hole_follows()
*
* Returns:
* Start of the subsequent hole.
*/
static inline u64 drm_mm_hole_node_start(const struct drm_mm_node *hole_node)
{
DRM_MM_BUG_ON(!drm_mm_hole_follows(hole_node));
return __drm_mm_hole_node_start(hole_node);
}
static inline u64 __drm_mm_hole_node_end(const 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-specific debug dumpers. Otherwise drivers should
* not inspect holes themselves. Drivers must check first whether a hole indeed
* follows by looking at drm_mm_hole_follows().
*
* Returns:
* End of the subsequent hole.
*/
static inline u64 drm_mm_hole_node_end(const struct drm_mm_node *hole_node)
{
return __drm_mm_hole_node_end(hole_node);
}
/**
* drm_mm_nodes - list of nodes under the drm_mm range manager
* @mm: the struct drm_mm range manager
*
* As the drm_mm range manager hides its node_list deep with its
* structure, extracting it looks painful and repetitive. This is
* not expected to be used outside of the drm_mm_for_each_node()
* macros and similar internal functions.
*
* Returns:
* The node list, may be empty.
*/
#define drm_mm_nodes(mm) (&(mm)->head_node.node_list)
/**
* drm_mm_for_each_node - iterator to walk over all allocated nodes
* @entry: &struct drm_mm_node 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, drm_mm_nodes(mm), node_list)
/**
* drm_mm_for_each_node_safe - iterator to walk over all allocated nodes
* @entry: &struct drm_mm_node to assign to in each iteration step
* @next: &struct drm_mm_node to store the next step
* @mm: &drm_mm allocator to walk
*
* This iterator walks over all nodes in the range allocator. It is implemented
* with list_for_each_safe(), so save against removal of elements.
*/
#define drm_mm_for_each_node_safe(entry, next, mm) \
list_for_each_entry_safe(entry, next, drm_mm_nodes(mm), node_list)
/**
* drm_mm_for_each_hole - iterator to walk over all holes
* @pos: &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.
*/
#define drm_mm_for_each_hole(pos, mm, hole_start, hole_end) \
for (pos = list_first_entry(&(mm)->hole_stack, \
typeof(*pos), hole_stack); \
&pos->hole_stack != &(mm)->hole_stack ? \
hole_start = drm_mm_hole_node_start(pos), \
hole_end = hole_start + pos->hole_size, \
1 : 0; \
pos = list_next_entry(pos, hole_stack))
/*
* 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_in_range(struct drm_mm *mm,
struct drm_mm_node *node,
u64 size,
u64 alignment,
unsigned long color,
u64 start,
u64 end,
enum drm_mm_insert_mode mode);
/**
* drm_mm_insert_node_generic - 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
* @color: opaque tag value to use for this node
* @mode: fine-tune the allocation search and placement
*
* This is a simplified version of drm_mm_insert_node_in_range() with no
* range restrictions applied.
*
* 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_generic(struct drm_mm *mm, struct drm_mm_node *node,
u64 size, u64 alignment,
unsigned long color,
enum drm_mm_insert_mode mode)
{
return drm_mm_insert_node_in_range(mm, node,
size, alignment, color,
0, U64_MAX, mode);
}
/**
* 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
*
* 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)
{
return drm_mm_insert_node_generic(mm, node, size, 0, 0, 0);
}
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);
/**
* drm_mm_clean - checks whether an allocator is clean
* @mm: drm_mm allocator to check
*
* Returns:
* True if the allocator is completely free, false if there's still a node
* allocated in it.
*/
static inline bool drm_mm_clean(const struct drm_mm *mm)
{
return list_empty(drm_mm_nodes(mm));
}
struct drm_mm_node *
__drm_mm_interval_first(const 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.
* If [@start, @end] are beyond the range of the drm_mm, the iterator may walk
* over the special _unallocated_ &drm_mm.head_node, and may even continue
* indefinitely.
*/
#define drm_mm_for_each_node_in_range(node__, mm__, start__, end__) \
for (node__ = __drm_mm_interval_first((mm__), (start__), (end__)-1); \
node__->start < (end__); \
node__ = list_next_entry(node__, node_list))
void drm_mm_scan_init_with_range(struct drm_mm_scan *scan,
struct drm_mm *mm,
u64 size, u64 alignment, unsigned long color,
u64 start, u64 end,
enum drm_mm_insert_mode mode);
/**
* drm_mm_scan_init - initialize lru scanning
* @scan: scan state
* @mm: drm_mm to scan
* @size: size of the allocation
* @alignment: alignment of the allocation
* @color: opaque tag value to use for the allocation
* @mode: fine-tune the allocation search and placement
*
* This is a simplified version of drm_mm_scan_init_with_range() with no range
* restrictions applied.
*
* This simply sets up the scanning routines with the parameters for the desired
* hole.
*
* Warning:
* As long as the scan list is non-empty, no other operations than
* adding/removing nodes to/from the scan list are allowed.
*/
static inline void drm_mm_scan_init(struct drm_mm_scan *scan,
struct drm_mm *mm,
u64 size,
u64 alignment,
unsigned long color,
enum drm_mm_insert_mode mode)
{
drm_mm_scan_init_with_range(scan, mm,
size, alignment, color,
0, U64_MAX, mode);
}
bool drm_mm_scan_add_block(struct drm_mm_scan *scan,
struct drm_mm_node *node);
bool drm_mm_scan_remove_block(struct drm_mm_scan *scan,
struct drm_mm_node *node);
struct drm_mm_node *drm_mm_scan_color_evict(struct drm_mm_scan *scan);
void drm_mm_print(const struct drm_mm *mm, struct drm_printer *p);
#endif
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