/**************************************************************************
*
* Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND., 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.
*
*
**************************************************************************/
/*
* Generic simple memory manager implementation. Intended to be used as a base
* class implementation for more advanced memory managers.
*
* Note that the algorithm used is quite simple and there might be substantial
* performance gains if a smarter free list is implemented. Currently it is just an
* unordered stack of free regions. This could easily be improved if an RB-tree
* is used instead. At least if we expect heavy fragmentation.
*
* Aligned allocations can also see improvement.
*
* Authors:
* Thomas Hellström <thomas-at-tungstengraphics-dot-com>
*/
#include "drmP.h"
#include "drm_mm.h"
//#include <linux/slab.h>
#define MM_UNUSED_TARGET 4
unsigned long drm_mm_tail_space(struct drm_mm *mm)
{
struct list_head *tail_node;
struct drm_mm_node *entry;
tail_node = mm->ml_entry.prev;
entry = list_entry(tail_node, struct drm_mm_node, ml_entry);
return 0;
return entry->size;
}
int drm_mm_remove_space_from_tail(struct drm_mm *mm, unsigned long size)
{
struct list_head *tail_node;
struct drm_mm_node *entry;
tail_node = mm->ml_entry.prev;
entry = list_entry(tail_node, struct drm_mm_node, ml_entry);
return -ENOMEM;
if (entry->size <= size)
return -ENOMEM;
entry->size -= size;
return 0;
}
static struct drm_mm_node *drm_mm_kmalloc(struct drm_mm *mm, int atomic)
{
struct drm_mm_node *child;
child
= malloc(sizeof(*child
));
if (unlikely(child == NULL)) {
spin_lock(&mm->unused_lock);
if (list_empty(&mm->unused_nodes))
child = NULL;
else {
child =
list_entry(mm->unused_nodes.next,
struct drm_mm_node, fl_entry);
list_del(&child->fl_entry);
--mm->num_unused;
}
spin_unlock(&mm->unused_lock);
}
return child;
}
int drm_mm_pre_get(struct drm_mm *mm)
{
struct drm_mm_node *node;
spin_lock(&mm->unused_lock);
while (mm->num_unused < MM_UNUSED_TARGET) {
spin_unlock(&mm->unused_lock);
node = kmalloc(sizeof(*node), GFP_KERNEL);
spin_lock(&mm->unused_lock);
if (unlikely(node == NULL)) {
int ret = (mm->num_unused < 2) ? -ENOMEM : 0;
spin_unlock(&mm->unused_lock);
return ret;
}
++mm->num_unused;
list_add_tail(&node->fl_entry, &mm->unused_nodes);
}
spin_unlock(&mm->unused_lock);
return 0;
}
EXPORT_SYMBOL(drm_mm_pre_get);
static int drm_mm_create_tail_node(struct drm_mm *mm,
unsigned long start,
unsigned long size, int atomic)
{
struct drm_mm_node *child;
child = drm_mm_kmalloc(mm, atomic);
if (unlikely(child == NULL))
return -ENOMEM;
child->size = size;
child->start = start;
child->mm = mm;
list_add_tail(&child->ml_entry, &mm->ml_entry);
list_add_tail(&child->fl_entry, &mm->fl_entry);
return 0;
}
int drm_mm_add_space_to_tail(struct drm_mm *mm, unsigned long size, int atomic)
{
struct list_head *tail_node;
struct drm_mm_node *entry;
tail_node = mm->ml_entry.prev;
entry = list_entry(tail_node, struct drm_mm_node, ml_entry);
return drm_mm_create_tail_node(mm, entry->start + entry->size,
size, atomic);
}
entry->size += size;
return 0;
}
static struct drm_mm_node *drm_mm_split_at_start(struct drm_mm_node *parent,
unsigned long size,
int atomic)
{
struct drm_mm_node *child;
child = drm_mm_kmalloc(parent->mm, atomic);
if (unlikely(child == NULL))
return NULL;
INIT_LIST_HEAD(&child->fl_entry);
child->size = size;
child->start = parent->start;
child->mm = parent->mm;
list_add_tail(&child->ml_entry, &parent->ml_entry);
INIT_LIST_HEAD(&child->fl_entry);
parent->size -= size;
parent->start += size;
return child;
}
struct drm_mm_node *drm_mm_get_block_generic(struct drm_mm_node *node,
unsigned long size,
unsigned alignment,
int atomic)
{
struct drm_mm_node *align_splitoff = NULL;
unsigned tmp = 0;
if (alignment)
tmp = node->start % alignment;
if (tmp) {
align_splitoff =
drm_mm_split_at_start(node, alignment - tmp, atomic);
if (unlikely(align_splitoff == NULL))
return NULL;
}
if (node->size == size) {
list_del_init(&node->fl_entry);
} else {
node = drm_mm_split_at_start(node, size, atomic);
}
if (align_splitoff)
drm_mm_put_block(align_splitoff);
return node;
}
EXPORT_SYMBOL(drm_mm_get_block_generic);
/*
* Put a block. Merge with the previous and / or next block if they are free.
* Otherwise add to the free stack.
*/
void drm_mm_put_block(struct drm_mm_node *cur)
{
struct drm_mm *mm = cur->mm;
struct list_head *cur_head = &cur->ml_entry;
struct list_head *root_head = &mm->ml_entry;
struct drm_mm_node *prev_node = NULL;
struct drm_mm_node *next_node;
int merged = 0;
if (cur_head->prev != root_head) {
prev_node =
list_entry(cur_head->prev, struct drm_mm_node, ml_entry);
prev_node->size += cur->size;
merged = 1;
}
}
if (cur_head->next != root_head) {
next_node =
list_entry(cur_head->next, struct drm_mm_node, ml_entry);
if (merged) {
prev_node->size += next_node->size;
list_del(&next_node->ml_entry);
list_del(&next_node->fl_entry);
if (mm->num_unused < MM_UNUSED_TARGET) {
list_add(&next_node->fl_entry,
&mm->unused_nodes);
++mm->num_unused;
} else
kfree(next_node);
} else {
next_node->size += cur->size;
next_node->start = cur->start;
merged = 1;
}
}
}
if (!merged) {
list_add(&cur->fl_entry, &mm->fl_entry);
} else {
list_del(&cur->ml_entry);
if (mm->num_unused < MM_UNUSED_TARGET) {
list_add(&cur->fl_entry, &mm->unused_nodes);
++mm->num_unused;
} else
kfree(cur);
}
}
EXPORT_SYMBOL(drm_mm_put_block);
struct drm_mm_node *drm_mm_search_free(const struct drm_mm *mm,
unsigned long size,
unsigned alignment, int best_match)
{
struct list_head *list;
const struct list_head *free_stack = &mm->fl_entry;
struct drm_mm_node *entry;
struct drm_mm_node *best;
unsigned long best_size;
unsigned wasted;
best = NULL;
best_size = ~0UL;
list_for_each(list, free_stack) {
entry = list_entry(list, struct drm_mm_node, fl_entry);
wasted = 0;
if (entry->size < size)
continue;
if (alignment) {
register unsigned tmp = entry->start % alignment;
if (tmp)
wasted += alignment - tmp;
}
if (entry->size >= size + wasted) {
if (!best_match)
return entry;
if (size < best_size) {
best = entry;
best_size = entry->size;
}
}
}
return best;
}
EXPORT_SYMBOL(drm_mm_search_free);
int drm_mm_clean(struct drm_mm * mm)
{
struct list_head *head = &mm->ml_entry;
return (head->next->next == head);
}
EXPORT_SYMBOL(drm_mm_clean);
int drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size)
{
INIT_LIST_HEAD(&mm->ml_entry);
INIT_LIST_HEAD(&mm->fl_entry);
INIT_LIST_HEAD(&mm->unused_nodes);
mm->num_unused = 0;
spin_lock_init(&mm->unused_lock);
return drm_mm_create_tail_node(mm, start, size, 0);
}
EXPORT_SYMBOL(drm_mm_init);
void drm_mm_takedown(struct drm_mm * mm)
{
struct list_head *bnode = mm->fl_entry.next;
struct drm_mm_node *entry;
struct drm_mm_node *next;
entry = list_entry(bnode, struct drm_mm_node, fl_entry);
if (entry->ml_entry.next != &mm->ml_entry ||
entry->fl_entry.next != &mm->fl_entry) {
DRM_ERROR("Memory manager not clean. Delaying takedown\n");
return;
}
list_del(&entry->fl_entry);
list_del(&entry->ml_entry);
kfree(entry);
spin_lock(&mm->unused_lock);
list_for_each_entry_safe(entry, next, &mm->unused_nodes, fl_entry) {
list_del(&entry->fl_entry);
kfree(entry);
--mm->num_unused;
}
spin_unlock(&mm->unused_lock);
BUG_ON(mm->num_unused != 0);
}
EXPORT_SYMBOL(drm_mm_takedown);