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 #define _GNU_SOURCE
33 #include <config.h>
34
35 #include <stdlib.h>
36 #include <pthread.h>
37 #include <string.h>
38
39 #include "mlx4.h"
40
41 struct mlx4_db_page {
42 struct mlx4_db_page *prev, *next;
43 struct mlx4_buf buf;
44 int num_db;
45 int use_cnt;
46 unsigned long free[0];
47 };
48
49 static const int db_size[] = {
50 [MLX4_DB_TYPE_CQ] = 8,
51 [MLX4_DB_TYPE_RQ] = 4,
52 };
53
__add_page(struct mlx4_context * context,enum mlx4_db_type type)54 static struct mlx4_db_page *__add_page(struct mlx4_context *context,
55 enum mlx4_db_type type)
56 {
57 struct mlx4_db_page *page;
58 int ps = to_mdev(context->ibv_ctx.device)->page_size;
59 int pp;
60 int i;
61
62 pp = ps / db_size[type];
63
64 page = malloc(sizeof *page + pp / 8);
65 if (!page)
66 return NULL;
67
68 if (mlx4_alloc_buf(&page->buf, ps, ps)) {
69 free(page);
70 return NULL;
71 }
72
73 page->num_db = pp;
74 page->use_cnt = 0;
75 for (i = 0; i < pp / (sizeof (long) * 8); ++i)
76 page->free[i] = ~0;
77
78 page->prev = NULL;
79 page->next = context->db_list[type];
80 context->db_list[type] = page;
81 if (page->next)
82 page->next->prev = page;
83
84 return page;
85 }
86
mlx4_alloc_db(struct mlx4_context * context,enum mlx4_db_type type)87 uint32_t *mlx4_alloc_db(struct mlx4_context *context, enum mlx4_db_type type)
88 {
89 struct mlx4_db_page *page;
90 uint32_t *db = NULL;
91 int i, j;
92
93 pthread_mutex_lock(&context->db_list_mutex);
94
95 for (page = context->db_list[type]; page; page = page->next)
96 if (page->use_cnt < page->num_db)
97 goto found;
98
99 page = __add_page(context, type);
100 if (!page)
101 goto out;
102
103 found:
104 ++page->use_cnt;
105
106 for (i = 0; !page->free[i]; ++i)
107 /* nothing */;
108
109 j = ffsl(page->free[i]);
110 page->free[i] &= ~(1UL << (j - 1));
111 db = page->buf.buf + (i * 8 * sizeof (long) + (j - 1)) * db_size[type];
112
113 out:
114 pthread_mutex_unlock(&context->db_list_mutex);
115
116 return db;
117 }
118
mlx4_free_db(struct mlx4_context * context,enum mlx4_db_type type,uint32_t * db)119 void mlx4_free_db(struct mlx4_context *context, enum mlx4_db_type type, uint32_t *db)
120 {
121 struct mlx4_db_page *page;
122 uintptr_t ps = to_mdev(context->ibv_ctx.device)->page_size;
123 int i;
124
125 pthread_mutex_lock(&context->db_list_mutex);
126
127 for (page = context->db_list[type]; page; page = page->next)
128 if (((uintptr_t) db & ~(ps - 1)) == (uintptr_t) page->buf.buf)
129 break;
130
131 if (!page)
132 goto out;
133
134 i = ((void *) db - page->buf.buf) / db_size[type];
135 page->free[i / (8 * sizeof (long))] |= 1UL << (i % (8 * sizeof (long)));
136
137 if (!--page->use_cnt) {
138 if (page->prev)
139 page->prev->next = page->next;
140 else
141 context->db_list[type] = page->next;
142 if (page->next)
143 page->next->prev = page->prev;
144
145 mlx4_free_buf(&page->buf);
146 free(page);
147 }
148
149 out:
150 pthread_mutex_unlock(&context->db_list_mutex);
151 }
152