1 /*
2 *
3 * This file is provided under a dual BSD/GPLv2 license. When using or
4 * redistributing this file, you may do so under either license.
5 *
6 * GPL LICENSE SUMMARY
7 *
8 * Copyright(c) 2015 Intel Corporation.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of version 2 of the GNU General Public License as
12 * published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
18 *
19 * BSD LICENSE
20 *
21 * Copyright(c) 2015 Intel Corporation.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 *
27 * - Redistributions of source code must retain the above copyright
28 * notice, this list of conditions and the following disclaimer.
29 * - Redistributions in binary form must reproduce the above copyright
30 * notice, this list of conditions and the following disclaimer in
31 * the documentation and/or other materials provided with the
32 * distribution.
33 * - Neither the name of Intel Corporation nor the names of its
34 * contributors may be used to endorse or promote products derived
35 * from this software without specific prior written permission.
36 *
37 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
38 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
39 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
40 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
41 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
42 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
43 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
44 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
45 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
46 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
47 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
48 *
49 */
50
51 #include <linux/mm.h>
52 #include <linux/device.h>
53
54 #include "hfi.h"
55
__hfi1_release_user_pages(struct page ** p,size_t num_pages,int dirty)56 static void __hfi1_release_user_pages(struct page **p, size_t num_pages,
57 int dirty)
58 {
59 size_t i;
60
61 for (i = 0; i < num_pages; i++) {
62 if (dirty)
63 set_page_dirty_lock(p[i]);
64 put_page(p[i]);
65 }
66 }
67
68 /*
69 * Call with current->mm->mmap_sem held.
70 */
__hfi1_get_user_pages(unsigned long start_page,size_t num_pages,struct page ** p)71 static int __hfi1_get_user_pages(unsigned long start_page, size_t num_pages,
72 struct page **p)
73 {
74 unsigned long lock_limit;
75 size_t got;
76 int ret;
77
78 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
79
80 if (num_pages > lock_limit && !capable(CAP_IPC_LOCK)) {
81 ret = -ENOMEM;
82 goto bail;
83 }
84
85 for (got = 0; got < num_pages; got += ret) {
86 ret = get_user_pages(current, current->mm,
87 start_page + got * PAGE_SIZE,
88 num_pages - got, FOLL_WRITE | FOLL_FORCE,
89 p + got, NULL);
90 if (ret < 0)
91 goto bail_release;
92 }
93
94 current->mm->pinned_vm += num_pages;
95
96 ret = 0;
97 goto bail;
98
99 bail_release:
100 __hfi1_release_user_pages(p, got, 0);
101 bail:
102 return ret;
103 }
104
105 /**
106 * hfi1_map_page - a safety wrapper around pci_map_page()
107 *
108 */
hfi1_map_page(struct pci_dev * hwdev,struct page * page,unsigned long offset,size_t size,int direction)109 dma_addr_t hfi1_map_page(struct pci_dev *hwdev, struct page *page,
110 unsigned long offset, size_t size, int direction)
111 {
112 dma_addr_t phys;
113
114 phys = pci_map_page(hwdev, page, offset, size, direction);
115
116 return phys;
117 }
118
119 /**
120 * hfi1_get_user_pages - lock user pages into memory
121 * @start_page: the start page
122 * @num_pages: the number of pages
123 * @p: the output page structures
124 *
125 * This function takes a given start page (page aligned user virtual
126 * address) and pins it and the following specified number of pages. For
127 * now, num_pages is always 1, but that will probably change at some point
128 * (because caller is doing expected sends on a single virtually contiguous
129 * buffer, so we can do all pages at once).
130 */
hfi1_get_user_pages(unsigned long start_page,size_t num_pages,struct page ** p)131 int hfi1_get_user_pages(unsigned long start_page, size_t num_pages,
132 struct page **p)
133 {
134 int ret;
135
136 down_write(¤t->mm->mmap_sem);
137
138 ret = __hfi1_get_user_pages(start_page, num_pages, p);
139
140 up_write(¤t->mm->mmap_sem);
141
142 return ret;
143 }
144
hfi1_release_user_pages(struct page ** p,size_t num_pages)145 void hfi1_release_user_pages(struct page **p, size_t num_pages)
146 {
147 if (current->mm) /* during close after signal, mm can be NULL */
148 down_write(¤t->mm->mmap_sem);
149
150 __hfi1_release_user_pages(p, num_pages, 1);
151
152 if (current->mm) {
153 current->mm->pinned_vm -= num_pages;
154 up_write(¤t->mm->mmap_sem);
155 }
156 }
157