[net-next-2.6.git] / drivers / gpu / drm / drm_mm.c

/**************************************************************************
 *
 * 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>

#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, free_stack);
			list_del(&child->free_stack);
			--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->free_stack, &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->free = 1;
	child->size = size;
	child->start = start;
	child->mm = mm;

	list_add_tail(&child->node_list, &mm->node_list);
	list_add_tail(&child->free_stack, &mm->free_stack);

	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->free_stack);

	child->size = size;
	child->start = parent->start;
	child->mm = parent->mm;

	list_add_tail(&child->node_list, &parent->node_list);
	INIT_LIST_HEAD(&child->free_stack);

	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->free_stack);
		node->free = 0;
	} 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);

struct drm_mm_node *drm_mm_get_block_range_generic(struct drm_mm_node *node,
						unsigned long size,
						unsigned alignment,
						unsigned long start,
						unsigned long end,
						int atomic)
{
	struct drm_mm_node *align_splitoff = NULL;
	unsigned tmp = 0;
	unsigned wasted = 0;

	if (node->start < start)
		wasted += start - node->start;
	if (alignment)
		tmp = ((node->start + wasted) % alignment);

	if (tmp)
		wasted += alignment - tmp;
	if (wasted) {
		align_splitoff = drm_mm_split_at_start(node, wasted, atomic);
		if (unlikely(align_splitoff == NULL))
			return NULL;
	}

	if (node->size == size) {
		list_del_init(&node->free_stack);
		node->free = 0;
	} 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_range_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->node_list;
	struct list_head *root_head = &mm->node_list;
	struct drm_mm_node *prev_node = NULL;
	struct drm_mm_node *next_node;

	int merged = 0;

	BUG_ON(cur->scanned_block || cur->scanned_prev_free
				  || cur->scanned_next_free);

	if (cur_head->prev != root_head) {
		prev_node =
		    list_entry(cur_head->prev, struct drm_mm_node, node_list);
		if (prev_node->free) {
			prev_node->size += cur->size;
			merged = 1;
		}
	}
	if (cur_head->next != root_head) {
		next_node =
		    list_entry(cur_head->next, struct drm_mm_node, node_list);
		if (next_node->free) {
			if (merged) {
				prev_node->size += next_node->size;
				list_del(&next_node->node_list);
				list_del(&next_node->free_stack);
				spin_lock(&mm->unused_lock);
				if (mm->num_unused < MM_UNUSED_TARGET) {
					list_add(&next_node->free_stack,
						 &mm->unused_nodes);
					++mm->num_unused;
				} else
					kfree(next_node);
				spin_unlock(&mm->unused_lock);
			} else {
				next_node->size += cur->size;
				next_node->start = cur->start;
				merged = 1;
			}
		}
	}
	if (!merged) {
		cur->free = 1;
		list_add(&cur->free_stack, &mm->free_stack);
	} else {
		list_del(&cur->node_list);
		spin_lock(&mm->unused_lock);
		if (mm->num_unused < MM_UNUSED_TARGET) {
			list_add(&cur->free_stack, &mm->unused_nodes);
			++mm->num_unused;
		} else
			kfree(cur);
		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->free_stack, free_stack) {
		if (!check_free_hole(entry->start, entry->start + entry->size,
				     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->free_stack, free_stack) {
		unsigned long adj_start = entry->start < start ?
			start : entry->start;
		unsigned long adj_end = entry->start + entry->size > end ?
			end : entry->start + entry->size;

		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);

/**
 * 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;
}
EXPORT_SYMBOL(drm_mm_init_scan);

/**
 * 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 list_head *prev_free, *next_free;
	struct drm_mm_node *prev_node, *next_node;

	mm->scanned_blocks++;

	prev_free = next_free = NULL;

	BUG_ON(node->free);
	node->scanned_block = 1;
	node->free = 1;

	if (node->node_list.prev != &mm->node_list) {
		prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
				       node_list);

		if (prev_node->free) {
			list_del(&prev_node->node_list);

			node->start = prev_node->start;
			node->size += prev_node->size;

			prev_node->scanned_prev_free = 1;

			prev_free = &prev_node->free_stack;
		}
	}

	if (node->node_list.next != &mm->node_list) {
		next_node = list_entry(node->node_list.next, struct drm_mm_node,
				       node_list);

		if (next_node->free) {
			list_del(&next_node->node_list);

			node->size += next_node->size;

			next_node->scanned_next_free = 1;

			next_free = &next_node->free_stack;
		}
	}

	/* The free_stack list is not used for allocated objects, so these two
	 * pointers can be abused (as long as no allocations in this memory
	 * manager happens). */
	node->free_stack.prev = prev_free;
	node->free_stack.next = next_free;

	if (check_free_hole(node->start, node->start + node->size,
			    mm->scan_size, mm->scan_alignment)) {
		mm->scan_hit_start = node->start;
		mm->scan_hit_size = node->size;

		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
 * immediatly 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, *next_node;

	mm->scanned_blocks--;

	BUG_ON(!node->scanned_block);
	node->scanned_block = 0;
	node->free = 0;

	prev_node = list_entry(node->free_stack.prev, struct drm_mm_node,
			       free_stack);
	next_node = list_entry(node->free_stack.next, struct drm_mm_node,
			       free_stack);

	if (prev_node) {
		BUG_ON(!prev_node->scanned_prev_free);
		prev_node->scanned_prev_free = 0;

		list_add_tail(&prev_node->node_list, &node->node_list);

		node->start = prev_node->start + prev_node->size;
		node->size -= prev_node->size;
	}

	if (next_node) {
		BUG_ON(!next_node->scanned_next_free);
		next_node->scanned_next_free = 0;

		list_add(&next_node->node_list, &node->node_list);

		node->size -= next_node->size;
	}

	INIT_LIST_HEAD(&node->free_stack);

	/* 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->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->node_list);
	INIT_LIST_HEAD(&mm->free_stack);
	INIT_LIST_HEAD(&mm->unused_nodes);
	mm->num_unused = 0;
	mm->scanned_blocks = 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->free_stack.next;
	struct drm_mm_node *entry;
	struct drm_mm_node *next;

	entry = list_entry(bnode, struct drm_mm_node, free_stack);

	if (entry->node_list.next != &mm->node_list ||
	    entry->free_stack.next != &mm->free_stack) {
		DRM_ERROR("Memory manager not clean. Delaying takedown\n");
		return;
	}

	list_del(&entry->free_stack);
	list_del(&entry->node_list);
	kfree(entry);

	spin_lock(&mm->unused_lock);
	list_for_each_entry_safe(entry, next, &mm->unused_nodes, free_stack) {
		list_del(&entry->free_stack);
		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;
	int total_used = 0, total_free = 0, total = 0;

	list_for_each_entry(entry, &mm->node_list, node_list) {
		printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8ld: %s\n",
			prefix, entry->start, entry->start + entry->size,
			entry->size, entry->free ? "free" : "used");
		total += entry->size;
		if (entry->free)
			total_free += entry->size;
		else
			total_used += entry->size;
	}
	printk(KERN_DEBUG "%s total: %d, used %d free %d\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;
	int total_used = 0, total_free = 0, total = 0;

	list_for_each_entry(entry, &mm->node_list, node_list) {
		seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: %s\n", entry->start, entry->start + entry->size, entry->size, entry->free ? "free" : "used");
		total += entry->size;
		if (entry->free)
			total_free += entry->size;
		else
			total_used += entry->size;
	}
	seq_printf(m, "total: %d, used %d free %d\n", total, total_used, total_free);
	return 0;
}
EXPORT_SYMBOL(drm_mm_dump_table);
#endif
Commit	Line	Data
3a1bd924 TH	1	/**************************************************************************
	2	*
	3	* Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND., USA.
	4	* All Rights Reserved.
	5	*
	6	* Permission is hereby granted, free of charge, to any person obtaining a
	7	* copy of this software and associated documentation files (the
	8	* "Software"), to deal in the Software without restriction, including
	9	* without limitation the rights to use, copy, modify, merge, publish,
	10	* distribute, sub license, and/or sell copies of the Software, and to
	11	* permit persons to whom the Software is furnished to do so, subject to
	12	* the following conditions:
	13	*
	14	* The above copyright notice and this permission notice (including the
	15	* next paragraph) shall be included in all copies or substantial portions
	16	* of the Software.
	17	*
	18	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	19	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	20	* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
	21	* THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
	22	* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
	23	* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
	24	* USE OR OTHER DEALINGS IN THE SOFTWARE.
	25	*
	26	*
	27	**************************************************************************/
	28
	29	/*
	30	* Generic simple memory manager implementation. Intended to be used as a base
	31	* class implementation for more advanced memory managers.
	32	*
	33	* Note that the algorithm used is quite simple and there might be substantial
	34	* performance gains if a smarter free list is implemented. Currently it is just an
	35	* unordered stack of free regions. This could easily be improved if an RB-tree
	36	* is used instead. At least if we expect heavy fragmentation.
	37	*
	38	* Aligned allocations can also see improvement.
	39	*
	40	* Authors:
96de0e25	41	* Thomas Hellström <thomas-at-tungstengraphics-dot-com>
3a1bd924 TH	42	*/
	43
	44	#include "drmP.h"
249d6048	45	#include "drm_mm.h"
1d58420b	46	#include <linux/slab.h>
fa8a1238	47	#include <linux/seq_file.h>
1d58420b	48
249d6048 JG	49	#define MM_UNUSED_TARGET 4
249d6048 JG	50
249d6048 JG	51	static struct drm_mm_node drm_mm_kmalloc(struct drm_mm mm, int atomic)
	52	{
	53	struct drm_mm_node *child;
	54
	55	if (atomic)
709ea971	56	child = kzalloc(sizeof(*child), GFP_ATOMIC);
249d6048	57	else
709ea971	58	child = kzalloc(sizeof(*child), GFP_KERNEL);
249d6048 JG	59
	60	if (unlikely(child == NULL)) {
	61	spin_lock(&mm->unused_lock);
	62	if (list_empty(&mm->unused_nodes))
	63	child = NULL;
	64	else {
	65	child =
	66	list_entry(mm->unused_nodes.next,
d1024ce9 DV	67	struct drm_mm_node, free_stack);
d1024ce9 DV	68	list_del(&child->free_stack);
249d6048 JG	69	--mm->num_unused;
	70	}
	71	spin_unlock(&mm->unused_lock);
	72	}
	73	return child;
	74	}
	75
a698cf34 JG	76	/* drm_mm_pre_get() - pre allocate drm_mm_node structure
	77	* drm_mm: memory manager struct we are pre-allocating for
	78	*
	79	* Returns 0 on success or -ENOMEM if allocation fails.
	80	*/
249d6048 JG	81	int drm_mm_pre_get(struct drm_mm *mm)
	82	{
	83	struct drm_mm_node *node;
	84
	85	spin_lock(&mm->unused_lock);
	86	while (mm->num_unused < MM_UNUSED_TARGET) {
	87	spin_unlock(&mm->unused_lock);
709ea971	88	node = kzalloc(sizeof(*node), GFP_KERNEL);
249d6048 JG	89	spin_lock(&mm->unused_lock);
	90
	91	if (unlikely(node == NULL)) {
	92	int ret = (mm->num_unused < 2) ? -ENOMEM : 0;
	93	spin_unlock(&mm->unused_lock);
	94	return ret;
	95	}
	96	++mm->num_unused;
d1024ce9	97	list_add_tail(&node->free_stack, &mm->unused_nodes);
249d6048 JG	98	}
	99	spin_unlock(&mm->unused_lock);
	100	return 0;
	101	}
	102	EXPORT_SYMBOL(drm_mm_pre_get);
1d58420b	103
55910517	104	static int drm_mm_create_tail_node(struct drm_mm *mm,
249d6048 JG	105	unsigned long start,
249d6048 JG	106	unsigned long size, int atomic)
1d58420b	107	{
55910517	108	struct drm_mm_node *child;
1d58420b	109
249d6048 JG	110	child = drm_mm_kmalloc(mm, atomic);
249d6048 JG	111	if (unlikely(child == NULL))
1d58420b TH	112	return -ENOMEM;
	113
	114	child->free = 1;
	115	child->size = size;
	116	child->start = start;
	117	child->mm = mm;
	118
d1024ce9 DV	119	list_add_tail(&child->node_list, &mm->node_list);
d1024ce9 DV	120	list_add_tail(&child->free_stack, &mm->free_stack);
1d58420b TH	121
	122	return 0;
	123	}
	124
55910517	125	static struct drm_mm_node drm_mm_split_at_start(struct drm_mm_node parent,
249d6048 JG	126	unsigned long size,
249d6048 JG	127	int atomic)
1d58420b	128	{
55910517	129	struct drm_mm_node *child;
1d58420b	130
249d6048 JG	131	child = drm_mm_kmalloc(parent->mm, atomic);
249d6048 JG	132	if (unlikely(child == NULL))
1d58420b TH	133	return NULL;
1d58420b TH	134
d1024ce9	135	INIT_LIST_HEAD(&child->free_stack);
1d58420b	136
1d58420b TH	137	child->size = size;
	138	child->start = parent->start;
	139	child->mm = parent->mm;
	140
d1024ce9 DV	141	list_add_tail(&child->node_list, &parent->node_list);
d1024ce9 DV	142	INIT_LIST_HEAD(&child->free_stack);
1d58420b TH	143
	144	parent->size -= size;
	145	parent->start += size;
	146	return child;
	147	}
	148
	149
89579f77 TH	150	struct drm_mm_node drm_mm_get_block_generic(struct drm_mm_node node,
	151	unsigned long size,
	152	unsigned alignment,
	153	int atomic)
3a1bd924 TH	154	{
3a1bd924 TH	155
55910517	156	struct drm_mm_node *align_splitoff = NULL;
1d58420b	157	unsigned tmp = 0;
3a1bd924 TH	158
3a1bd924 TH	159	if (alignment)
e6c03c5b	160	tmp = node->start % alignment;
1d58420b TH	161
1d58420b TH	162	if (tmp) {
249d6048	163	align_splitoff =
89579f77	164	drm_mm_split_at_start(node, alignment - tmp, atomic);
249d6048	165	if (unlikely(align_splitoff == NULL))
1d58420b TH	166	return NULL;
1d58420b TH	167	}
3a1bd924	168
e6c03c5b	169	if (node->size == size) {
d1024ce9	170	list_del_init(&node->free_stack);
e6c03c5b	171	node->free = 0;
3a1bd924	172	} else {
89579f77	173	node = drm_mm_split_at_start(node, size, atomic);
1d58420b	174	}
3a1bd924	175
1d58420b TH	176	if (align_splitoff)
1d58420b TH	177	drm_mm_put_block(align_splitoff);
3a1bd924	178
e6c03c5b	179	return node;
3a1bd924	180	}
89579f77	181	EXPORT_SYMBOL(drm_mm_get_block_generic);
249d6048	182
a2e68e92 JG	183	struct drm_mm_node drm_mm_get_block_range_generic(struct drm_mm_node node,
	184	unsigned long size,
	185	unsigned alignment,
	186	unsigned long start,
	187	unsigned long end,
	188	int atomic)
	189	{
	190	struct drm_mm_node *align_splitoff = NULL;
	191	unsigned tmp = 0;
	192	unsigned wasted = 0;
	193
	194	if (node->start < start)
	195	wasted += start - node->start;
	196	if (alignment)
	197	tmp = ((node->start + wasted) % alignment);
	198
	199	if (tmp)
	200	wasted += alignment - tmp;
	201	if (wasted) {
	202	align_splitoff = drm_mm_split_at_start(node, wasted, atomic);
	203	if (unlikely(align_splitoff == NULL))
	204	return NULL;
	205	}
	206
	207	if (node->size == size) {
d1024ce9	208	list_del_init(&node->free_stack);
a2e68e92 JG	209	node->free = 0;
	210	} else {
	211	node = drm_mm_split_at_start(node, size, atomic);
	212	}
	213
	214	if (align_splitoff)
	215	drm_mm_put_block(align_splitoff);
	216
	217	return node;
	218	}
	219	EXPORT_SYMBOL(drm_mm_get_block_range_generic);
	220
3a1bd924 TH	221	/*
	222	* Put a block. Merge with the previous and / or next block if they are free.
	223	* Otherwise add to the free stack.
	224	*/
	225
249d6048	226	void drm_mm_put_block(struct drm_mm_node *cur)
3a1bd924 TH	227	{
3a1bd924 TH	228
55910517	229	struct drm_mm *mm = cur->mm;
d1024ce9 DV	230	struct list_head *cur_head = &cur->node_list;
d1024ce9 DV	231	struct list_head *root_head = &mm->node_list;
55910517 DA	232	struct drm_mm_node *prev_node = NULL;
55910517 DA	233	struct drm_mm_node *next_node;
3a1bd924	234
a1d0fcf5	235	int merged = 0;
3a1bd924	236
709ea971 DV	237	BUG_ON(cur->scanned_block \|\| cur->scanned_prev_free
	238	\|\| cur->scanned_next_free);
	239
3a1bd924	240	if (cur_head->prev != root_head) {
249d6048	241	prev_node =
d1024ce9	242	list_entry(cur_head->prev, struct drm_mm_node, node_list);
3a1bd924 TH	243	if (prev_node->free) {
3a1bd924 TH	244	prev_node->size += cur->size;
a1d0fcf5	245	merged = 1;
3a1bd924 TH	246	}
	247	}
	248	if (cur_head->next != root_head) {
249d6048	249	next_node =
d1024ce9	250	list_entry(cur_head->next, struct drm_mm_node, node_list);
3a1bd924 TH	251	if (next_node->free) {
	252	if (merged) {
	253	prev_node->size += next_node->size;
d1024ce9 DV	254	list_del(&next_node->node_list);
d1024ce9 DV	255	list_del(&next_node->free_stack);
a698cf34	256	spin_lock(&mm->unused_lock);
249d6048	257	if (mm->num_unused < MM_UNUSED_TARGET) {
d1024ce9	258	list_add(&next_node->free_stack,
249d6048 JG	259	&mm->unused_nodes);
	260	++mm->num_unused;
	261	} else
	262	kfree(next_node);
a698cf34	263	spin_unlock(&mm->unused_lock);
3a1bd924 TH	264	} else {
	265	next_node->size += cur->size;
	266	next_node->start = cur->start;
a1d0fcf5	267	merged = 1;
3a1bd924 TH	268	}
	269	}
	270	}
	271	if (!merged) {
a1d0fcf5	272	cur->free = 1;
d1024ce9	273	list_add(&cur->free_stack, &mm->free_stack);
3a1bd924	274	} else {
d1024ce9	275	list_del(&cur->node_list);
a698cf34	276	spin_lock(&mm->unused_lock);
249d6048	277	if (mm->num_unused < MM_UNUSED_TARGET) {
d1024ce9	278	list_add(&cur->free_stack, &mm->unused_nodes);
249d6048 JG	279	++mm->num_unused;
	280	} else
	281	kfree(cur);
a698cf34	282	spin_unlock(&mm->unused_lock);
3a1bd924 TH	283	}
3a1bd924 TH	284	}
249d6048	285
673a394b	286	EXPORT_SYMBOL(drm_mm_put_block);
3a1bd924	287
75214733 DV	288	static int check_free_hole(unsigned long start, unsigned long end,
75214733 DV	289	unsigned long size, unsigned alignment)
7a6b2896 DV	290	{
	291	unsigned wasted = 0;
	292
75214733	293	if (end - start < size)
7a6b2896 DV	294	return 0;
	295
	296	if (alignment) {
75214733	297	unsigned tmp = start % alignment;
7a6b2896 DV	298	if (tmp)
	299	wasted = alignment - tmp;
	300	}
	301
75214733	302	if (end >= start + size + wasted) {
7a6b2896 DV	303	return 1;
	304	}
	305
	306	return 0;
	307	}
	308
249d6048 JG	309	struct drm_mm_node drm_mm_search_free(const struct drm_mm mm,
	310	unsigned long size,
	311	unsigned alignment, int best_match)
3a1bd924	312	{
55910517 DA	313	struct drm_mm_node *entry;
55910517 DA	314	struct drm_mm_node *best;
3a1bd924 TH	315	unsigned long best_size;
3a1bd924 TH	316
709ea971 DV	317	BUG_ON(mm->scanned_blocks);
709ea971 DV	318
3a1bd924 TH	319	best = NULL;
	320	best_size = ~0UL;
	321
d1024ce9	322	list_for_each_entry(entry, &mm->free_stack, free_stack) {
75214733 DV	323	if (!check_free_hole(entry->start, entry->start + entry->size,
75214733 DV	324	size, alignment))
1d58420b TH	325	continue;
1d58420b TH	326
7a6b2896 DV	327	if (!best_match)
7a6b2896 DV	328	return entry;
1d58420b	329
7a6b2896 DV	330	if (entry->size < best_size) {
	331	best = entry;
	332	best_size = entry->size;
3a1bd924 TH	333	}
	334	}
	335
	336	return best;
	337	}
249d6048	338	EXPORT_SYMBOL(drm_mm_search_free);
3a1bd924	339
a2e68e92 JG	340	struct drm_mm_node drm_mm_search_free_in_range(const struct drm_mm mm,
	341	unsigned long size,
	342	unsigned alignment,
	343	unsigned long start,
	344	unsigned long end,
	345	int best_match)
	346	{
a2e68e92 JG	347	struct drm_mm_node *entry;
	348	struct drm_mm_node *best;
	349	unsigned long best_size;
a2e68e92	350
709ea971 DV	351	BUG_ON(mm->scanned_blocks);
709ea971 DV	352
a2e68e92 JG	353	best = NULL;
	354	best_size = ~0UL;
	355
d1024ce9	356	list_for_each_entry(entry, &mm->free_stack, free_stack) {
75214733 DV	357	unsigned long adj_start = entry->start < start ?
	358	start : entry->start;
	359	unsigned long adj_end = entry->start + entry->size > end ?
	360	end : entry->start + entry->size;
a2e68e92	361
75214733	362	if (!check_free_hole(adj_start, adj_end, size, alignment))
a2e68e92 JG	363	continue;
a2e68e92 JG	364
7a6b2896 DV	365	if (!best_match)
7a6b2896 DV	366	return entry;
a2e68e92	367
7a6b2896 DV	368	if (entry->size < best_size) {
	369	best = entry;
	370	best_size = entry->size;
a2e68e92 JG	371	}
	372	}
	373
	374	return best;
	375	}
	376	EXPORT_SYMBOL(drm_mm_search_free_in_range);
	377
709ea971 DV	378	/**
	379	* Initializa lru scanning.
	380	*
	381	* This simply sets up the scanning routines with the parameters for the desired
	382	* hole.
	383	*
	384	* Warning: As long as the scan list is non-empty, no other operations than
	385	* adding/removing nodes to/from the scan list are allowed.
	386	*/
	387	void drm_mm_init_scan(struct drm_mm *mm, unsigned long size,
	388	unsigned alignment)
	389	{
	390	mm->scan_alignment = alignment;
	391	mm->scan_size = size;
	392	mm->scanned_blocks = 0;
	393	mm->scan_hit_start = 0;
	394	mm->scan_hit_size = 0;
	395	}
	396	EXPORT_SYMBOL(drm_mm_init_scan);
	397
	398	/**
	399	* Add a node to the scan list that might be freed to make space for the desired
	400	* hole.
	401	*
	402	* Returns non-zero, if a hole has been found, zero otherwise.
	403	*/
	404	int drm_mm_scan_add_block(struct drm_mm_node *node)
	405	{
	406	struct drm_mm *mm = node->mm;
	407	struct list_head prev_free, next_free;
	408	struct drm_mm_node prev_node, next_node;
	409
	410	mm->scanned_blocks++;
	411
	412	prev_free = next_free = NULL;
	413
	414	BUG_ON(node->free);
	415	node->scanned_block = 1;
	416	node->free = 1;
	417
	418	if (node->node_list.prev != &mm->node_list) {
	419	prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
	420	node_list);
	421
	422	if (prev_node->free) {
	423	list_del(&prev_node->node_list);
	424
	425	node->start = prev_node->start;
	426	node->size += prev_node->size;
	427
	428	prev_node->scanned_prev_free = 1;
	429
	430	prev_free = &prev_node->free_stack;
	431	}
	432	}
	433
	434	if (node->node_list.next != &mm->node_list) {
	435	next_node = list_entry(node->node_list.next, struct drm_mm_node,
	436	node_list);
	437
	438	if (next_node->free) {
	439	list_del(&next_node->node_list);
	440
	441	node->size += next_node->size;
442
443	next_node->scanned_next_free = 1;
444
445	next_free = &next_node->free_stack;
446	}
447	}
448
449	/* The free_stack list is not used for allocated objects, so these two
450	* pointers can be abused (as long as no allocations in this memory
451	* manager happens). */
452	node->free_stack.prev = prev_free;
453	node->free_stack.next = next_free;
454
75214733 DV	455	if (check_free_hole(node->start, node->start + node->size,
75214733 DV	456	mm->scan_size, mm->scan_alignment)) {
709ea971 DV	457	mm->scan_hit_start = node->start;
	458	mm->scan_hit_size = node->size;
	459
	460	return 1;
	461	}
	462
	463	return 0;
	464	}
	465	EXPORT_SYMBOL(drm_mm_scan_add_block);
	466
	467	/**
	468	* Remove a node from the scan list.
	469	*
	470	* Nodes _must_ be removed in the exact same order from the scan list as they
	471	* have been added, otherwise the internal state of the memory manager will be
	472	* corrupted.
	473	*
	474	* When the scan list is empty, the selected memory nodes can be freed. An
	475	* immediatly following drm_mm_search_free with best_match = 0 will then return
	476	* the just freed block (because its at the top of the free_stack list).
	477	*
	478	* Returns one if this block should be evicted, zero otherwise. Will always
	479	* return zero when no hole has been found.
	480	*/
	481	int drm_mm_scan_remove_block(struct drm_mm_node *node)
	482	{
	483	struct drm_mm *mm = node->mm;
	484	struct drm_mm_node prev_node, next_node;
	485
	486	mm->scanned_blocks--;
	487
	488	BUG_ON(!node->scanned_block);
	489	node->scanned_block = 0;
	490	node->free = 0;
	491
	492	prev_node = list_entry(node->free_stack.prev, struct drm_mm_node,
	493	free_stack);
	494	next_node = list_entry(node->free_stack.next, struct drm_mm_node,
	495	free_stack);
	496
	497	if (prev_node) {
	498	BUG_ON(!prev_node->scanned_prev_free);
	499	prev_node->scanned_prev_free = 0;
	500
	501	list_add_tail(&prev_node->node_list, &node->node_list);
	502
	503	node->start = prev_node->start + prev_node->size;
	504	node->size -= prev_node->size;
	505	}
	506
	507	if (next_node) {
	508	BUG_ON(!next_node->scanned_next_free);
	509	next_node->scanned_next_free = 0;
	510
	511	list_add(&next_node->node_list, &node->node_list);
	512
	513	node->size -= next_node->size;
	514	}
	515
	516	INIT_LIST_HEAD(&node->free_stack);
	517
	518	/* Only need to check for containement because start&size for the
	519	* complete resulting free block (not just the desired part) is
	520	* stored. */
521	if (node->start >= mm->scan_hit_start &&
522	node->start + node->size
523	<= mm->scan_hit_start + mm->scan_hit_size) {
524	return 1;
525	}
526
527	return 0;
528	}
529	EXPORT_SYMBOL(drm_mm_scan_remove_block);
530
55910517	531	int drm_mm_clean(struct drm_mm * mm)
3a1bd924	532	{
d1024ce9	533	struct list_head *head = &mm->node_list;
3a1bd924	534
1d58420b TH	535	return (head->next->next == head);
1d58420b TH	536	}
249d6048	537	EXPORT_SYMBOL(drm_mm_clean);
3a1bd924	538
55910517	539	int drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size)
1d58420b	540	{
d1024ce9 DV	541	INIT_LIST_HEAD(&mm->node_list);
d1024ce9 DV	542	INIT_LIST_HEAD(&mm->free_stack);
249d6048 JG	543	INIT_LIST_HEAD(&mm->unused_nodes);
249d6048 JG	544	mm->num_unused = 0;
709ea971	545	mm->scanned_blocks = 0;
249d6048	546	spin_lock_init(&mm->unused_lock);
3a1bd924	547
249d6048	548	return drm_mm_create_tail_node(mm, start, size, 0);
3a1bd924	549	}
673a394b	550	EXPORT_SYMBOL(drm_mm_init);
3a1bd924	551
55910517	552	void drm_mm_takedown(struct drm_mm * mm)
3a1bd924	553	{
d1024ce9	554	struct list_head *bnode = mm->free_stack.next;
55910517	555	struct drm_mm_node *entry;
249d6048	556	struct drm_mm_node *next;
3a1bd924	557
d1024ce9	558	entry = list_entry(bnode, struct drm_mm_node, free_stack);
3a1bd924	559
d1024ce9 DV	560	if (entry->node_list.next != &mm->node_list \|\|
d1024ce9 DV	561	entry->free_stack.next != &mm->free_stack) {
3a1bd924 TH	562	DRM_ERROR("Memory manager not clean. Delaying takedown\n");
	563	return;
	564	}
	565
d1024ce9 DV	566	list_del(&entry->free_stack);
d1024ce9 DV	567	list_del(&entry->node_list);
249d6048 JG	568	kfree(entry);
	569
	570	spin_lock(&mm->unused_lock);
d1024ce9 DV	571	list_for_each_entry_safe(entry, next, &mm->unused_nodes, free_stack) {
d1024ce9 DV	572	list_del(&entry->free_stack);
249d6048 JG	573	kfree(entry);
	574	--mm->num_unused;
	575	}
	576	spin_unlock(&mm->unused_lock);
3a1bd924	577
249d6048	578	BUG_ON(mm->num_unused != 0);
3a1bd924	579	}
f453ba04	580	EXPORT_SYMBOL(drm_mm_takedown);
fa8a1238	581
99d7e48e JG	582	void drm_mm_debug_table(struct drm_mm mm, const char prefix)
	583	{
	584	struct drm_mm_node *entry;
	585	int total_used = 0, total_free = 0, total = 0;
	586
d1024ce9	587	list_for_each_entry(entry, &mm->node_list, node_list) {
99d7e48e JG	588	printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8ld: %s\n",
	589	prefix, entry->start, entry->start + entry->size,
	590	entry->size, entry->free ? "free" : "used");
	591	total += entry->size;
	592	if (entry->free)
	593	total_free += entry->size;
	594	else
	595	total_used += entry->size;
	596	}
	597	printk(KERN_DEBUG "%s total: %d, used %d free %d\n", prefix, total,
	598	total_used, total_free);
	599	}
	600	EXPORT_SYMBOL(drm_mm_debug_table);
	601
fa8a1238 DA	602	#if defined(CONFIG_DEBUG_FS)
	603	int drm_mm_dump_table(struct seq_file m, struct drm_mm mm)
	604	{
	605	struct drm_mm_node *entry;
	606	int total_used = 0, total_free = 0, total = 0;
	607
d1024ce9	608	list_for_each_entry(entry, &mm->node_list, node_list) {
fa8a1238 DA	609	seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: %s\n", entry->start, entry->start + entry->size, entry->size, entry->free ? "free" : "used");
	610	total += entry->size;
	611	if (entry->free)
	612	total_free += entry->size;
	613	else
	614	total_used += entry->size;
	615	}
01d01ba9	616	seq_printf(m, "total: %d, used %d free %d\n", total, total_used, total_free);
fa8a1238 DA	617	return 0;
	618	}
	619	EXPORT_SYMBOL(drm_mm_dump_table);
	620	#endif