1 /* 2 * Copyright (c) 2012 Mellanox Technologies, Inc. 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 "mlx5.h" 40 41 struct mlx5_db_page { 42 struct mlx5_db_page *prev, *next; 43 struct mlx5_buf buf; 44 int num_db; 45 int use_cnt; 46 unsigned long free[0]; 47 }; 48 49 static struct mlx5_db_page *__add_page(struct mlx5_context *context) 50 { 51 struct mlx5_db_page *page; 52 int ps = to_mdev(context->ibv_ctx.device)->page_size; 53 int pp; 54 int i; 55 int nlong; 56 57 pp = ps / context->cache_line_size; 58 nlong = (pp + 8 * sizeof(long) - 1) / (8 * sizeof(long)); 59 60 page = malloc(sizeof *page + nlong * sizeof(long)); 61 if (!page) 62 return NULL; 63 64 if (mlx5_alloc_buf(&page->buf, ps, ps)) { 65 free(page); 66 return NULL; 67 } 68 69 page->num_db = pp; 70 page->use_cnt = 0; 71 for (i = 0; i < nlong; ++i) 72 page->free[i] = ~0; 73 74 page->prev = NULL; 75 page->next = context->db_list; 76 context->db_list = page; 77 if (page->next) 78 page->next->prev = page; 79 80 return page; 81 } 82 83 uint32_t *mlx5_alloc_dbrec(struct mlx5_context *context) 84 { 85 struct mlx5_db_page *page; 86 uint32_t *db = NULL; 87 int i, j; 88 89 pthread_mutex_lock(&context->db_list_mutex); 90 91 for (page = context->db_list; page; page = page->next) 92 if (page->use_cnt < page->num_db) 93 goto found; 94 95 page = __add_page(context); 96 if (!page) 97 goto out; 98 99 found: 100 ++page->use_cnt; 101 102 for (i = 0; !page->free[i]; ++i) 103 /* nothing */; 104 105 j = ffsl(page->free[i]); 106 --j; 107 page->free[i] &= ~(1UL << j); 108 db = page->buf.buf + (i * 8 * sizeof(long) + j) * context->cache_line_size; 109 110 out: 111 pthread_mutex_unlock(&context->db_list_mutex); 112 113 return db; 114 } 115 116 void mlx5_free_db(struct mlx5_context *context, uint32_t *db) 117 { 118 struct mlx5_db_page *page; 119 uintptr_t ps = to_mdev(context->ibv_ctx.device)->page_size; 120 int i; 121 122 pthread_mutex_lock(&context->db_list_mutex); 123 124 for (page = context->db_list; page; page = page->next) 125 if (((uintptr_t) db & ~(ps - 1)) == (uintptr_t) page->buf.buf) 126 break; 127 128 if (!page) 129 goto out; 130 131 i = ((void *) db - page->buf.buf) / context->cache_line_size; 132 page->free[i / (8 * sizeof(long))] |= 1UL << (i % (8 * sizeof(long))); 133 134 if (!--page->use_cnt) { 135 if (page->prev) 136 page->prev->next = page->next; 137 else 138 context->db_list = page->next; 139 if (page->next) 140 page->next->prev = page->prev; 141 142 mlx5_free_buf(&page->buf); 143 free(page); 144 } 145 146 out: 147 pthread_mutex_unlock(&context->db_list_mutex); 148 } 149