[net-next-2.6.git] / drivers / char / drm / drm_hashtab.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.
 *
 *
 **************************************************************************/
/*
 * Simple open hash tab implementation.
 *
 * Authors:
 * Thomas Hellström <thomas-at-tungstengraphics-dot-com>
 */

#include "drmP.h"
#include "drm_hashtab.h"
#include <linux/hash.h>

int drm_ht_create(struct drm_open_hash *ht, unsigned int order)
{
	unsigned int i;

	ht->size = 1 << order;
	ht->order = order;
	ht->fill = 0;
	ht->table = NULL;
	ht->use_vmalloc = ((ht->size * sizeof(*ht->table)) > PAGE_SIZE);
	if (!ht->use_vmalloc) {
		ht->table = drm_calloc(ht->size, sizeof(*ht->table),
				       DRM_MEM_HASHTAB);
	}
	if (!ht->table) {
		ht->use_vmalloc = 1;
		ht->table = vmalloc(ht->size*sizeof(*ht->table));
	}
	if (!ht->table) {
		DRM_ERROR("Out of memory for hash table\n");
		return -ENOMEM;
	}
	for (i=0; i< ht->size; ++i) {
		INIT_HLIST_HEAD(&ht->table[i]);
	}
	return 0;
}

void drm_ht_verbose_list(struct drm_open_hash *ht, unsigned long key)
{
	struct drm_hash_item *entry;
	struct hlist_head *h_list;
	struct hlist_node *list;
	unsigned int hashed_key;
	int count = 0;

	hashed_key = hash_long(key, ht->order);
	DRM_DEBUG("Key is 0x%08lx, Hashed key is 0x%08x\n", key, hashed_key);
	h_list = &ht->table[hashed_key];
	hlist_for_each(list, h_list) {
		entry = hlist_entry(list, struct drm_hash_item, head);
		DRM_DEBUG("count %d, key: 0x%08lx\n", count++, entry->key);
	}
}

static struct hlist_node *drm_ht_find_key(struct drm_open_hash *ht, 
					  unsigned long key)
{
	struct drm_hash_item *entry;
	struct hlist_head *h_list;
	struct hlist_node *list;
	unsigned int hashed_key;

	hashed_key = hash_long(key, ht->order);
	h_list = &ht->table[hashed_key];
	hlist_for_each(list, h_list) {
		entry = hlist_entry(list, struct drm_hash_item, head);
		if (entry->key == key)
			return list;
		if (entry->key > key)
			break;
	}
	return NULL;
}


int drm_ht_insert_item(struct drm_open_hash *ht, struct drm_hash_item *item)
{
	struct drm_hash_item *entry;
	struct hlist_head *h_list;
	struct hlist_node *list, *parent;
	unsigned int hashed_key;
	unsigned long key = item->key;

	hashed_key = hash_long(key, ht->order);
	h_list = &ht->table[hashed_key];
	parent = NULL;
	hlist_for_each(list, h_list) {
		entry = hlist_entry(list, struct drm_hash_item, head);
		if (entry->key == key)
			return -EINVAL;
		if (entry->key > key)
			break;
		parent = list;
	}
	if (parent) {
		hlist_add_after(parent, &item->head);
	} else {
		hlist_add_head(&item->head, h_list);
	}
	return 0;
}

/*
 * Just insert an item and return any "bits" bit key that hasn't been 
 * used before.
 */
int drm_ht_just_insert_please(struct drm_open_hash *ht, struct drm_hash_item *item,
			      unsigned long seed, int bits, int shift,
			      unsigned long add)
{
	int ret;
	unsigned long mask = (1 << bits) - 1;
	unsigned long first, unshifted_key;

	unshifted_key = hash_long(seed, bits);
	first = unshifted_key;
	do {
		item->key = (unshifted_key << shift) + add;
		ret = drm_ht_insert_item(ht, item);
		if (ret)
			unshifted_key = (unshifted_key + 1) & mask;
	} while(ret && (unshifted_key != first));

	if (ret) {
		DRM_ERROR("Available key bit space exhausted\n");
		return -EINVAL;
	}
	return 0;
}

int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key,
		     struct drm_hash_item **item)
{
	struct hlist_node *list;

	list = drm_ht_find_key(ht, key);
	if (!list)
		return -EINVAL;

	*item = hlist_entry(list, struct drm_hash_item, head);
	return 0;
}

int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key)
{
	struct hlist_node *list;

	list = drm_ht_find_key(ht, key);
	if (list) {
		hlist_del_init(list);
		ht->fill--;
		return 0;
	}
	return -EINVAL;
}

int drm_ht_remove_item(struct drm_open_hash *ht, struct drm_hash_item *item)
{
	hlist_del_init(&item->head);
	ht->fill--;
	return 0;
}

void drm_ht_remove(struct drm_open_hash *ht)
{
	if (ht->table) {
		if (ht->use_vmalloc)
			vfree(ht->table);
		else
			drm_free(ht->table, ht->size * sizeof(*ht->table),
				 DRM_MEM_HASHTAB);
		ht->table = NULL;
	}
}
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	* Simple open hash tab implementation.
	30	*
	31	* Authors:
96de0e25	32	* Thomas Hellström <thomas-at-tungstengraphics-dot-com>
3a1bd924 TH	33	*/
	34
	35	#include "drmP.h"
	36	#include "drm_hashtab.h"
	37	#include <linux/hash.h>
	38
e0be428e	39	int drm_ht_create(struct drm_open_hash *ht, unsigned int order)
3a1bd924 TH	40	{
	41	unsigned int i;
	42
	43	ht->size = 1 << order;
	44	ht->order = order;
	45	ht->fill = 0;
c1185ccd	46	ht->table = NULL;
cd839d00 DA	47	ht->use_vmalloc = ((ht->size * sizeof(*ht->table)) > PAGE_SIZE);
	48	if (!ht->use_vmalloc) {
	49	ht->table = drm_calloc(ht->size, sizeof(*ht->table),
	50	DRM_MEM_HASHTAB);
	51	}
	52	if (!ht->table) {
	53	ht->use_vmalloc = 1;
	54	ht->table = vmalloc(ht->sizesizeof(ht->table));
	55	}
3a1bd924 TH	56	if (!ht->table) {
	57	DRM_ERROR("Out of memory for hash table\n");
	58	return -ENOMEM;
	59	}
	60	for (i=0; i< ht->size; ++i) {
	61	INIT_HLIST_HEAD(&ht->table[i]);
	62	}
	63	return 0;
	64	}
	65
e0be428e	66	void drm_ht_verbose_list(struct drm_open_hash *ht, unsigned long key)
3a1bd924	67	{
e0be428e	68	struct drm_hash_item *entry;
3a1bd924 TH	69	struct hlist_head *h_list;
	70	struct hlist_node *list;
	71	unsigned int hashed_key;
	72	int count = 0;
	73
	74	hashed_key = hash_long(key, ht->order);
	75	DRM_DEBUG("Key is 0x%08lx, Hashed key is 0x%08x\n", key, hashed_key);
	76	h_list = &ht->table[hashed_key];
	77	hlist_for_each(list, h_list) {
e0be428e	78	entry = hlist_entry(list, struct drm_hash_item, head);
3a1bd924 TH	79	DRM_DEBUG("count %d, key: 0x%08lx\n", count++, entry->key);
	80	}
	81	}
	82
e0be428e	83	static struct hlist_node drm_ht_find_key(struct drm_open_hash ht,
3a1bd924 TH	84	unsigned long key)
3a1bd924 TH	85	{
e0be428e	86	struct drm_hash_item *entry;
3a1bd924 TH	87	struct hlist_head *h_list;
	88	struct hlist_node *list;
	89	unsigned int hashed_key;
	90
	91	hashed_key = hash_long(key, ht->order);
	92	h_list = &ht->table[hashed_key];
	93	hlist_for_each(list, h_list) {
e0be428e	94	entry = hlist_entry(list, struct drm_hash_item, head);
3a1bd924 TH	95	if (entry->key == key)
	96	return list;
	97	if (entry->key > key)
	98	break;
	99	}
	100	return NULL;
	101	}
	102
	103
e0be428e	104	int drm_ht_insert_item(struct drm_open_hash ht, struct drm_hash_item item)
3a1bd924	105	{
e0be428e	106	struct drm_hash_item *entry;
3a1bd924 TH	107	struct hlist_head *h_list;
	108	struct hlist_node list, parent;
	109	unsigned int hashed_key;
	110	unsigned long key = item->key;
	111
	112	hashed_key = hash_long(key, ht->order);
	113	h_list = &ht->table[hashed_key];
	114	parent = NULL;
	115	hlist_for_each(list, h_list) {
e0be428e	116	entry = hlist_entry(list, struct drm_hash_item, head);
3a1bd924	117	if (entry->key == key)
47cc1409	118	return -EINVAL;
3a1bd924 TH	119	if (entry->key > key)
	120	break;
	121	parent = list;
	122	}
	123	if (parent) {
	124	hlist_add_after(parent, &item->head);
	125	} else {
	126	hlist_add_head(&item->head, h_list);
	127	}
	128	return 0;
	129	}
	130
	131	/*
	132	* Just insert an item and return any "bits" bit key that hasn't been
	133	* used before.
	134	*/
e0be428e	135	int drm_ht_just_insert_please(struct drm_open_hash ht, struct drm_hash_item item,
3a1bd924 TH	136	unsigned long seed, int bits, int shift,
	137	unsigned long add)
	138	{
	139	int ret;
	140	unsigned long mask = (1 << bits) - 1;
	141	unsigned long first, unshifted_key;
	142
	143	unshifted_key = hash_long(seed, bits);
	144	first = unshifted_key;
	145	do {
	146	item->key = (unshifted_key << shift) + add;
	147	ret = drm_ht_insert_item(ht, item);
	148	if (ret)
	149	unshifted_key = (unshifted_key + 1) & mask;
	150	} while(ret && (unshifted_key != first));
	151
	152	if (ret) {
	153	DRM_ERROR("Available key bit space exhausted\n");
	154	return -EINVAL;
	155	}
	156	return 0;
	157	}
	158
e0be428e DA	159	int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key,
e0be428e DA	160	struct drm_hash_item **item)
3a1bd924 TH	161	{
	162	struct hlist_node *list;
	163
	164	list = drm_ht_find_key(ht, key);
	165	if (!list)
47cc1409	166	return -EINVAL;
3a1bd924	167
e0be428e	168	*item = hlist_entry(list, struct drm_hash_item, head);
3a1bd924 TH	169	return 0;
	170	}
	171
e0be428e	172	int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key)
3a1bd924 TH	173	{
	174	struct hlist_node *list;
	175
	176	list = drm_ht_find_key(ht, key);
	177	if (list) {
	178	hlist_del_init(list);
	179	ht->fill--;
	180	return 0;
	181	}
47cc1409	182	return -EINVAL;
3a1bd924 TH	183	}
3a1bd924 TH	184
e0be428e	185	int drm_ht_remove_item(struct drm_open_hash ht, struct drm_hash_item item)
3a1bd924 TH	186	{
	187	hlist_del_init(&item->head);
	188	ht->fill--;
	189	return 0;
	190	}
	191
e0be428e	192	void drm_ht_remove(struct drm_open_hash *ht)
3a1bd924 TH	193	{
3a1bd924 TH	194	if (ht->table) {
cd839d00 DA	195	if (ht->use_vmalloc)
	196	vfree(ht->table);
	197	else
	198	drm_free(ht->table, ht->size * sizeof(*ht->table),
	199	DRM_MEM_HASHTAB);
3a1bd924 TH	200	ht->table = NULL;
	201	}
	202	}
	203