/**************************************************************************
*
* 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>
#include <linux/seq_file.h>
#include <linux/export.h>
#define MM_UNUSED_TARGET 4
static struct drm_mm_node *drm_mm_kmalloc(struct drm_mm *mm, int atomic)
{
struct drm_mm_node *child;
if (atomic)
child = kzalloc(sizeof(*child), GFP_ATOMIC);
else
child = kzalloc(sizeof(*child), GFP_KERNEL);
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, node_list);
list_del(&child->node_list);
--mm->num_unused;
}
spin_unlock(&mm->unused_lock);
}
return child;
}
/* drm_mm_pre_get() - pre allocate drm_mm_node structure
* drm_mm: memory manager struct we are pre-allocating for
*
* Returns 0 on success or -ENOMEM if allocation fails.
*/
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 = kzalloc(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->node_list, &mm->unused_nodes);
}
spin_unlock(&mm->unused_lock);
return 0;
}
EXPORT_SYMBOL(drm_mm_pre_get);
static inline unsigned long drm_mm_hole_node_start(struct drm_mm_node *hole_node)
{
return hole_node->start + hole_node->size;
}
static inline unsigned long drm_mm_hole_node_end(struct drm_mm_node *hole_node)
{
struct drm_mm_node *next_node =
list_entry(hole_node->node_list.next, struct drm_mm_node,
node_list);
return next_node->start;
}
static void drm_mm_insert_helper(struct drm_mm_node *hole_node,
struct drm_mm_node *node,
unsigned long size, unsigned alignment)
{
struct drm_mm *mm = hole_node->mm;
unsigned long tmp = 0, wasted = 0;
unsigned long hole_start = drm_mm_hole_node_start(hole_node);
unsigned long hole_end = drm_mm_hole_node_end(hole_node);
BUG_ON(!hole_node->hole_follows || node->allocated);
if (alignment)
tmp = hole_start % alignment;
if (!tmp) {
hole_node->hole_follows = 0;
list_del_init(&hole_node->hole_stack);
} else
wasted = alignment - tmp;
node->start = hole_start + wasted;
node->size = size;
node->mm = mm;
node->allocated = 1;
INIT_LIST_HEAD(&node->hole_stack);
list_add(&node->node_list, &hole_node->node_list);
BUG_ON(node->start + node->size > hole_end);
if (node->start + node->size < hole_end) {
list_add(&node->hole_stack, &mm->hole_stack);
node->hole_follows = 1;
} else {
node->hole_follows = 0;
}
}
struct drm_mm_node *drm_mm_get_block_generic(struct drm_mm_node *hole_node,
unsigned long size,
unsigned alignment,
int atomic)
{
struct drm_mm_node *node;
node = drm_mm_kmalloc(hole_node->mm, atomic);
if (unlikely(node == NULL))
return NULL;
drm_mm_insert_helper(hole_node, node, size, alignment);
return node;
}
EXPORT_SYMBOL(drm_mm_get_block_generic);
/**
* Search for free space and insert a preallocated memory node. Returns
* -ENOSPC if no suitable free area is available. The preallocated memory node
* must be cleared.
*/
int drm_mm_insert_node(struct drm_mm *mm, struct drm_mm_node *node,
unsigned long size, unsigned alignment)
{
struct drm_mm_node *hole_node;
hole_node = drm_mm_search_free(mm, size, alignment, 0);
if (!hole_node)
return -ENOSPC;
drm_mm_insert_helper(hole_node, node, size, alignment);
return 0;
}
EXPORT_SYMBOL(drm_mm_insert_node);
static void drm_mm_insert_helper_range(struct drm_mm_node *hole_node,
struct drm_mm_node *node,
unsigned long size, unsigned alignment,
unsigned long start, unsigned long end)
{
struct drm_mm *mm = hole_node->mm;
unsigned long tmp = 0, wasted = 0;
unsigned long hole_start = drm_mm_hole_node_start(hole_node);
unsigned long hole_end = drm_mm_hole_node_end(hole_node);
BUG_ON(!hole_node->hole_follows || node->allocated);
if (hole_start < start)
wasted += start - hole_start;
if (alignment)
tmp = (hole_start + wasted) % alignment;
if (tmp)
wasted += alignment - tmp;
if (!wasted) {
hole_node->hole_follows = 0;
list_del_init(&hole_node->hole_stack);
}
node->start = hole_start + wasted;
node->size = size;
node->mm = mm;
node->allocated = 1;
INIT_LIST_HEAD(&node->hole_stack);
list_add(&node->node_list, &hole_node->node_list);
BUG_ON(node->start + node->size > hole_end);
BUG_ON(node->start + node->size > end);
if (node->start + node->size < hole_end) {
list_add(&node->hole_stack, &mm->hole_stack);
node->hole_follows = 1;
} else {
node->hole_follows = 0;
}
}
struct drm_mm_node *drm_mm_get_block_range_generic(struct drm_mm_node *hole_node,
unsigned long size,
unsigned alignment,
unsigned long start,
unsigned long end,
int atomic)
{
struct drm_mm_node *node;
node = drm_mm_kmalloc(hole_node->mm, atomic);
if (unlikely(node == NULL))
return NULL;
drm_mm_insert_helper_range(hole_node, node, size, alignment,
start, end);
return node;
}
EXPORT_SYMBOL(drm_mm_get_block_range_generic);
/**
* Search for free space and insert a preallocated memory node. Returns
* -ENOSPC if no suitable free area is available. This is for range
* restricted allocations. The preallocated memory node must be cleared.
*/
int drm_mm_insert_node_in_range(struct drm_mm *mm, struct drm_mm_node *node,
unsigned long size, unsigned alignment,
unsigned long start, unsigned long end)
{
struct drm_mm_node *hole_node;
hole_node = drm_mm_search_free_in_range(mm, size, alignment,
start, end, 0);
if (!hole_node)
return -ENOSPC;
drm_mm_insert_helper_range(hole_node, node, size, alignment,
start, end);
return 0;
}
EXPORT_SYMBOL(drm_mm_insert_node_in_range);
/**
* Remove a memory node from the allocator.
*/
void drm_mm_remove_node(struct drm_mm_node *node)
{
struct drm_mm *mm = node->mm;
struct drm_mm_node *prev_node;
BUG_ON(node->scanned_block || node->scanned_prev_free
|| node->scanned_next_free);
prev_node =
list_entry(node->node_list.prev, struct drm_mm_node, node_list);
if (node->hole_follows) {
BUG_ON(drm_mm_hole_node_start(node)
== drm_mm_hole_node_end(node));
list_del(&node->hole_stack);
} else
BUG_ON(drm_mm_hole_node_start(node)
!= drm_mm_hole_node_end(node));
if (!prev_node->hole_follows) {
prev_node->hole_follows = 1;
list_add(&prev_node->hole_stack, &mm->hole_stack);
} else
list_move(&prev_node->hole_stack, &mm->hole_stack);
list_del(&node->node_list);
node->allocated = 0;
}
EXPORT_SYMBOL(drm_mm_remove_node);
/*
* Remove a memory node from the allocator and free the allocated struct
* drm_mm_node. Only to be used on a struct drm_mm_node obtained by one of the
* drm_mm_get_block functions.
*/
void drm_mm_put_block(struct drm_mm_node *node)
{
struct drm_mm *mm = node->mm;
drm_mm_remove_node(node);
spin_lock(&mm->unused_lock);
if (mm->num_unused < MM_UNUSED_TARGET) {
list_add(&node->node_list, &mm->unused_nodes);
++mm->num_unused;
} else
kfree(node);
spin_unlock(&mm->unused_lock);
}
EXPORT_SYMBOL(drm_mm_put_block);
static int check_free_hole(unsigned long start, unsigned long end,
unsigned long size, unsigned alignment)
{
unsigned wasted = 0;
if (end - start < size)
return 0;
if (alignment) {
unsigned tmp = start % alignment;
if (tmp)
wasted = alignment - tmp;
}
if (end >= start + size + wasted) {
return 1;
}
return 0;
}
struct drm_mm_node *drm_mm_search_free(const struct drm_mm *mm,
unsigned long size,
unsigned alignment, int best_match)
{
struct drm_mm_node *entry;
struct drm_mm_node *best;
unsigned long best_size;
BUG_ON(mm->scanned_blocks);
best = NULL;
best_size = ~0UL;
list_for_each_entry(entry, &mm->hole_stack, hole_stack) {
BUG_ON(!entry->hole_follows);
if (!check_free_hole(drm_mm_hole_node_start(entry),
drm_mm_hole_node_end(entry),
size, alignment))
continue;
if (!best_match)
return entry;
if (entry->size < best_size) {
best = entry;
best_size = entry->size;
}
}
return best;
}
EXPORT_SYMBOL(drm_mm_search_free);
struct drm_mm_node *drm_mm_search_free_in_range(const struct drm_mm *mm,
unsigned long size,
unsigned alignment,
unsigned long start,
unsigned long end,
int best_match)
{
struct drm_mm_node *entry;
struct drm_mm_node *best;
unsigned long best_size;
BUG_ON(mm->scanned_blocks);
best = NULL;
best_size = ~0UL;
list_for_each_entry(entry, &mm->hole_stack, hole_stack) {
unsigned long adj_start = drm_mm_hole_node_start(entry) < start ?
start : drm_mm_hole_node_start(entry);
unsigned long adj_end = drm_mm_hole_node_end(entry) > end ?
end : drm_mm_hole_node_end(entry);
BUG_ON(!entry->hole_follows);
if (!check_free_hole(adj_start, adj_end, size, alignment))
continue;
if (!best_match)
return entry;
if (entry->size < best_size) {
best = entry;
best_size = entry->size;
}
}
return best;
}
EXPORT_SYMBOL(drm_mm_search_free_in_range);
/**
* Moves an allocation. To be used with embedded struct drm_mm_node.
*/
void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new)
{
list_replace(&old->node_list, &new->node_list);
list_replace(&old->hole_stack, &new->hole_stack);
new->hole_follows = old->hole_follows;
new->mm = old->mm;
new->start = old->start;
new->size = old->size;
old->allocated = 0;
new->allocated = 1;
}
EXPORT_SYMBOL(drm_mm_replace_node);
/**
* Initializa lru scanning.
*
* 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.
*/
void drm_mm_init_scan(struct drm_mm *mm, unsigned long size,
unsigned alignment)
{
mm->scan_alignment = alignment;
mm->scan_size = size;
mm->scanned_blocks = 0;
mm->scan_hit_start = 0;
mm->scan_hit_size = 0;
mm->scan_check_range = 0;
mm->prev_scanned_node = NULL;
}
EXPORT_SYMBOL(drm_mm_init_scan);
/**
* Initializa lru scanning.
*
* This simply sets up the scanning routines with the parameters for the desired
* hole. This version is for range-restricted scans.
*
* Warning: As long as the scan list is non-empty, no other operations than
* adding/removing nodes to/from the scan list are allowed.
*/
void drm_mm_init_scan_with_range(struct drm_mm *mm, unsigned long size,
unsigned alignment,
unsigned long start,
unsigned long end)
{
mm->scan_alignment = alignment;
mm->scan_size = size;
mm->scanned_blocks = 0;
mm->scan_hit_start = 0;
mm->scan_hit_size = 0;
mm->scan_start = start;
mm->scan_end = end;
mm->scan_check_range = 1;
mm->prev_scanned_node = NULL;
}
EXPORT_SYMBOL(drm_mm_init_scan_with_range);
/**
* Add a node to the scan list that might be freed to make space for the desired
* hole.
*
* Returns non-zero, if a hole has been found, zero otherwise.
*/
int drm_mm_scan_add_block(struct drm_mm_node *node)
{
struct drm_mm *mm = node->mm;
struct drm_mm_node *prev_node;
unsigned long hole_start, hole_end;
unsigned long adj_start;
unsigned long adj_end;
mm->scanned_blocks++;
BUG_ON(node->scanned_block);
node->scanned_block = 1;
prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
node_list);
node->scanned_preceeds_hole = prev_node->hole_follows;
prev_node->hole_follows = 1;
list_del(&node->node_list);
node->node_list.prev = &prev_node->node_list;
node->node_list.next = &mm->prev_scanned_node->node_list;
mm->prev_scanned_node = node;
hole_start = drm_mm_hole_node_start(prev_node);
hole_end = drm_mm_hole_node_end(prev_node);
if (mm->scan_check_range) {
adj_start = hole_start < mm->scan_start ?
mm->scan_start : hole_start;
adj_end = hole_end > mm->scan_end ?
mm->scan_end : hole_end;
} else {
adj_start = hole_start;
adj_end = hole_end;
}
if (check_free_hole(adj_start , adj_end,
mm->scan_size, mm->scan_alignment)) {
mm->scan_hit_start = hole_start;
mm->scan_hit_size = hole_end;
return 1;
}
return 0;
}
EXPORT_SYMBOL(drm_mm_scan_add_block);
/**
* Remove a node from the scan list.
*
* Nodes _must_ be removed in the exact same order from the scan list as they
* have been added, otherwise the internal state of the memory manager will be
* corrupted.
*
* When the scan list is empty, the selected memory nodes can be freed. An
* immediately following drm_mm_search_free with best_match = 0 will then return
* the just freed block (because its at the top of the free_stack list).
*
* Returns one if this block should be evicted, zero otherwise. Will always
* return zero when no hole has been found.
*/
int drm_mm_scan_remove_block(struct drm_mm_node *node)
{
struct drm_mm *mm = node->mm;
struct drm_mm_node *prev_node;
mm->scanned_blocks--;
BUG_ON(!node->scanned_block);
node->scanned_block = 0;
prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
node_list);
prev_node->hole_follows = node->scanned_preceeds_hole;
INIT_LIST_HEAD(&node->node_list);
list_add(&node->node_list, &prev_node->node_list);
/* Only need to check for containement because start&size for the
* complete resulting free block (not just the desired part) is
* stored. */
if (node->start >= mm->scan_hit_start &&
node->start + node->size
<= mm->scan_hit_start + mm->scan_hit_size) {
return 1;
}
return 0;
}
EXPORT_SYMBOL(drm_mm_scan_remove_block);
int drm_mm_clean(struct drm_mm * mm)
{
struct list_head *head = &mm->head_node.node_list;
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->hole_stack);
INIT_LIST_HEAD(&mm->unused_nodes);
mm->num_unused = 0;
mm->scanned_blocks = 0;
spin_lock_init(&mm->unused_lock);
/* Clever trick to avoid a special case in the free hole tracking. */
INIT_LIST_HEAD(&mm->head_node.node_list);
INIT_LIST_HEAD(&mm->head_node.hole_stack);
mm->head_node.hole_follows = 1;
mm->head_node.scanned_block = 0;
mm->head_node.scanned_prev_free = 0;
mm->head_node.scanned_next_free = 0;
mm->head_node.mm = mm;
mm->head_node.start = start + size;
mm->head_node.size = start - mm->head_node.start;
list_add_tail(&mm->head_node.hole_stack, &mm->hole_stack);
return 0;
}
EXPORT_SYMBOL(drm_mm_init);
void drm_mm_takedown(struct drm_mm * mm)
{
struct drm_mm_node *entry, *next;
if (!list_empty(&mm->head_node.node_list)) {
DRM_ERROR("Memory manager not clean. Delaying takedown\n");
return;
}
spin_lock(&mm->unused_lock);
list_for_each_entry_safe(entry, next, &mm->unused_nodes, node_list) {
list_del(&entry->node_list);
kfree(entry);
--mm->num_unused;
}
spin_unlock(&mm->unused_lock);
BUG_ON(mm->num_unused != 0);
}
EXPORT_SYMBOL(drm_mm_takedown);
void drm_mm_debug_table(struct drm_mm *mm, const char *prefix)
{
struct drm_mm_node *entry;
unsigned long total_used = 0, total_free = 0, total = 0;
unsigned long hole_start, hole_end, hole_size;
hole_start = drm_mm_hole_node_start(&mm->head_node);
hole_end = drm_mm_hole_node_end(&mm->head_node);
hole_size = hole_end - hole_start;
if (hole_size)
printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: free\n",
prefix, hole_start, hole_end,
hole_size);
total_free += hole_size;
drm_mm_for_each_node(entry, mm) {
printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: used\n",
prefix, entry->start, entry->start + entry->size,
entry->size);
total_used += entry->size;
if (entry->hole_follows) {
hole_start = drm_mm_hole_node_start(entry);
hole_end = drm_mm_hole_node_end(entry);
hole_size = hole_end - hole_start;
printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: free\n",
prefix, hole_start, hole_end,
hole_size);
total_free += hole_size;
}
}
total = total_free + total_used;
printk(KERN_DEBUG "%s total: %lu, used %lu free %lu\n", prefix, total,
total_used, total_free);
}
EXPORT_SYMBOL(drm_mm_debug_table);
#if defined(CONFIG_DEBUG_FS)
int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm)
{
struct drm_mm_node *entry;
unsigned long total_used = 0, total_free = 0, total = 0;
unsigned long hole_start, hole_end, hole_size;
hole_start = drm_mm_hole_node_start(&mm->head_node);
hole_end = drm_mm_hole_node_end(&mm->head_node);
hole_size = hole_end - hole_start;
if (hole_size)
seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: free\n",
hole_start, hole_end, hole_size);
total_free += hole_size;
drm_mm_for_each_node(entry, mm) {
seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: used\n",
entry->start, entry->start + entry->size,
entry->size);
total_used += entry->size;
if (entry->hole_follows) {
hole_start = drm_mm_hole_node_start(entry);
hole_end = drm_mm_hole_node_end(entry);
hole_size = hole_end - hole_start;
seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: free\n",
hole_start, hole_end, hole_size);
total_free += hole_size;
}
}
total = total_free + total_used;
seq_printf(m, "total: %lu, used %lu free %lu\n", total, total_used, total_free);
return 0;
}
EXPORT_SYMBOL(drm_mm_dump_table);
#endif
