1/*
2 * Copyright (c) 2005 Topspin Communications.  All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses.  You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
9 *
10 *     Redistribution and use in source and binary forms, with or
11 *     without modification, are permitted provided that the following
12 *     conditions are met:
13 *
14 *      - Redistributions of source code must retain the above
15 *        copyright notice, this list of conditions and the following
16 *        disclaimer.
17 *
18 *      - Redistributions in binary form must reproduce the above
19 *        copyright notice, this list of conditions and the following
20 *        disclaimer in the documentation and/or other materials
21 *        provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 */
32
33#if HAVE_CONFIG_H
34#  include <config.h>
35#endif /* HAVE_CONFIG_H */
36
37#include <stdlib.h>
38#include <netinet/in.h>
39#include <pthread.h>
40#include <string.h>
41
42#include "mlx4.h"
43
44struct mlx4_db_page {
45	struct mlx4_db_page	       *prev, *next;
46	struct mlx4_buf			buf;
47	int				num_db;
48	int				use_cnt;
49	unsigned long			free[0];
50};
51
52static const int db_size[] = {
53	[MLX4_DB_TYPE_CQ] = 8,
54	[MLX4_DB_TYPE_RQ] = 4,
55};
56
57static struct mlx4_db_page *__add_page(struct mlx4_context *context,
58				       enum mlx4_db_type type)
59{
60	struct mlx4_db_page *page;
61	int ps = to_mdev(context->ibv_ctx.device)->page_size;
62	int pp;
63	int i;
64
65	pp = ps / db_size[type];
66
67	page = malloc(sizeof *page + pp / 8);
68	if (!page)
69		return NULL;
70
71	if (mlx4_alloc_buf(&page->buf, ps, ps)) {
72		free(page);
73		return NULL;
74	}
75
76	page->num_db  = pp;
77	page->use_cnt = 0;
78	for (i = 0; i < pp / (sizeof (long) * 8); ++i)
79		page->free[i] = ~0;
80
81	page->prev = NULL;
82	page->next = context->db_list[type];
83	context->db_list[type] = page;
84	if (page->next)
85		page->next->prev = page;
86
87	return page;
88}
89
90uint32_t *mlx4_alloc_db(struct mlx4_context *context, enum mlx4_db_type type)
91{
92	struct mlx4_db_page *page;
93	uint32_t *db = NULL;
94	int i, j;
95
96	pthread_mutex_lock(&context->db_list_mutex);
97
98	for (page = context->db_list[type]; page; page = page->next)
99		if (page->use_cnt < page->num_db)
100			goto found;
101
102	page = __add_page(context, type);
103	if (!page)
104		goto out;
105
106found:
107	++page->use_cnt;
108
109	for (i = 0; !page->free[i]; ++i)
110		/* nothing */;
111
112	j = ffsl(page->free[i]);
113	page->free[i] &= ~(1UL << (j - 1));
114	db = page->buf.buf + (i * 8 * sizeof (long) + (j - 1)) * db_size[type];
115
116out:
117	pthread_mutex_unlock(&context->db_list_mutex);
118
119	return db;
120}
121
122void mlx4_free_db(struct mlx4_context *context, enum mlx4_db_type type, uint32_t *db)
123{
124	struct mlx4_db_page *page;
125	uintptr_t ps = to_mdev(context->ibv_ctx.device)->page_size;
126	int i;
127
128	pthread_mutex_lock(&context->db_list_mutex);
129
130	for (page = context->db_list[type]; page; page = page->next)
131		if (((uintptr_t) db & ~(ps - 1)) == (uintptr_t) page->buf.buf)
132			break;
133
134	if (!page)
135		goto out;
136
137	i = ((void *) db - page->buf.buf) / db_size[type];
138	page->free[i / (8 * sizeof (long))] |= 1UL << (i % (8 * sizeof (long)));
139
140	if (!--page->use_cnt) {
141		if (page->prev)
142			page->prev->next = page->next;
143		else
144			context->db_list[type] = page->next;
145		if (page->next)
146			page->next->prev = page->prev;
147
148		mlx4_free_buf(&page->buf);
149		free(page);
150	}
151
152out:
153	pthread_mutex_unlock(&context->db_list_mutex);
154}
155