1 /*-
2 * Copyright (c) 2013-2015, Mellanox Technologies, Ltd. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS `AS IS' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 *
25 * $FreeBSD$
26 */
27
28 #include "opt_rss.h"
29 #include "opt_ratelimit.h"
30
31 #include <linux/kref.h>
32 #include <linux/slab.h>
33 #include <rdma/ib_umem.h>
34
35 #include <dev/mlx5/mlx5_ib/mlx5_ib.h>
36
37 struct mlx5_ib_user_db_page {
38 struct list_head list;
39 struct ib_umem *umem;
40 unsigned long user_virt;
41 int refcnt;
42 };
43
44 int mlx5_ib_db_map_user(struct mlx5_ib_ucontext *context, unsigned long virt,
45 struct mlx5_db *db)
46 {
47 struct mlx5_ib_user_db_page *page;
48 int err = 0;
49
50 mutex_lock(&context->db_page_mutex);
51
52 list_for_each_entry(page, &context->db_page_list, list)
53 if (page->user_virt == (virt & PAGE_MASK))
54 goto found;
55
56 page = kmalloc(sizeof(*page), GFP_KERNEL);
57 if (!page) {
58 err = -ENOMEM;
59 goto out;
60 }
61
62 page->user_virt = (virt & PAGE_MASK);
63 page->refcnt = 0;
64 page->umem = ib_umem_get(&context->ibucontext, virt & PAGE_MASK,
65 PAGE_SIZE, 0, 0);
66 if (IS_ERR(page->umem)) {
67 err = PTR_ERR(page->umem);
68 kfree(page);
69 goto out;
70 }
71
72 list_add(&page->list, &context->db_page_list);
73
74 found:
75 db->dma = sg_dma_address(page->umem->sg_head.sgl) + (virt & ~PAGE_MASK);
76 db->u.user_page = page;
77 ++page->refcnt;
78
79 out:
80 mutex_unlock(&context->db_page_mutex);
81
82 return err;
83 }
84
85 void mlx5_ib_db_unmap_user(struct mlx5_ib_ucontext *context, struct mlx5_db *db)
86 {
87 mutex_lock(&context->db_page_mutex);
88
89 if (!--db->u.user_page->refcnt) {
90 list_del(&db->u.user_page->list);
91 ib_umem_release(db->u.user_page->umem);
92 kfree(db->u.user_page);
93 }
94
95 mutex_unlock(&context->db_page_mutex);
96 }
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