1 /*
2 * Copyright (c) 2006, 2007, 2008, 2009 QLogic Corporation. All rights reserved.
3 * Copyright (c) 2003, 2004, 2005, 2006 PathScale, Inc. All rights reserved.
4 *
5 * This software is available to you under a choice of one of two
6 * licenses. You may choose to be licensed under the terms of the GNU
7 * General Public License (GPL) Version 2, available from the file
8 * COPYING in the main directory of this source tree, or the
9 * OpenIB.org BSD license below:
10 *
11 * Redistribution and use in source and binary forms, with or
12 * without modification, are permitted provided that the following
13 * conditions are met:
14 *
15 * - Redistributions of source code must retain the above
16 * copyright notice, this list of conditions and the following
17 * disclaimer.
18 *
19 * - Redistributions in binary form must reproduce the above
20 * copyright notice, this list of conditions and the following
21 * disclaimer in the documentation and/or other materials
22 * provided with the distribution.
23 *
24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31 * SOFTWARE.
32 */
33
34 #include <linux/mm.h>
35 #include <linux/device.h>
36
37 #include "qib.h"
38
__qib_release_user_pages(struct page ** p,size_t num_pages,int dirty)39 static void __qib_release_user_pages(struct page **p, size_t num_pages,
40 int dirty)
41 {
42 size_t i;
43
44 for (i = 0; i < num_pages; i++) {
45 if (dirty)
46 set_page_dirty_lock(p[i]);
47 put_page(p[i]);
48 }
49 }
50
51 /*
52 * Call with current->mm->mmap_sem held.
53 */
__qib_get_user_pages(unsigned long start_page,size_t num_pages,struct page ** p,struct vm_area_struct ** vma)54 static int __qib_get_user_pages(unsigned long start_page, size_t num_pages,
55 struct page **p, struct vm_area_struct **vma)
56 {
57 unsigned long lock_limit;
58 size_t got;
59 int ret;
60
61 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
62
63 if (num_pages > lock_limit && !capable(CAP_IPC_LOCK)) {
64 ret = -ENOMEM;
65 goto bail;
66 }
67
68 for (got = 0; got < num_pages; got += ret) {
69 ret = get_user_pages(current, current->mm,
70 start_page + got * PAGE_SIZE,
71 num_pages - got, 1, 1,
72 p + got, vma);
73 if (ret < 0)
74 goto bail_release;
75 }
76
77 current->mm->pinned_vm += num_pages;
78
79 ret = 0;
80 goto bail;
81
82 bail_release:
83 __qib_release_user_pages(p, got, 0);
84 bail:
85 return ret;
86 }
87
88 /**
89 * qib_map_page - a safety wrapper around pci_map_page()
90 *
91 * A dma_addr of all 0's is interpreted by the chip as "disabled".
92 * Unfortunately, it can also be a valid dma_addr returned on some
93 * architectures.
94 *
95 * The powerpc iommu assigns dma_addrs in ascending order, so we don't
96 * have to bother with retries or mapping a dummy page to insure we
97 * don't just get the same mapping again.
98 *
99 * I'm sure we won't be so lucky with other iommu's, so FIXME.
100 */
qib_map_page(struct pci_dev * hwdev,struct page * page,unsigned long offset,size_t size,int direction)101 dma_addr_t qib_map_page(struct pci_dev *hwdev, struct page *page,
102 unsigned long offset, size_t size, int direction)
103 {
104 dma_addr_t phys;
105
106 phys = pci_map_page(hwdev, page, offset, size, direction);
107
108 if (phys == 0) {
109 pci_unmap_page(hwdev, phys, size, direction);
110 phys = pci_map_page(hwdev, page, offset, size, direction);
111 /*
112 * FIXME: If we get 0 again, we should keep this page,
113 * map another, then free the 0 page.
114 */
115 }
116
117 return phys;
118 }
119
120 /**
121 * qib_get_user_pages - lock user pages into memory
122 * @start_page: the start page
123 * @num_pages: the number of pages
124 * @p: the output page structures
125 *
126 * This function takes a given start page (page aligned user virtual
127 * address) and pins it and the following specified number of pages. For
128 * now, num_pages is always 1, but that will probably change at some point
129 * (because caller is doing expected sends on a single virtually contiguous
130 * buffer, so we can do all pages at once).
131 */
qib_get_user_pages(unsigned long start_page,size_t num_pages,struct page ** p)132 int qib_get_user_pages(unsigned long start_page, size_t num_pages,
133 struct page **p)
134 {
135 int ret;
136
137 down_write(¤t->mm->mmap_sem);
138
139 ret = __qib_get_user_pages(start_page, num_pages, p, NULL);
140
141 up_write(¤t->mm->mmap_sem);
142
143 return ret;
144 }
145
qib_release_user_pages(struct page ** p,size_t num_pages)146 void qib_release_user_pages(struct page **p, size_t num_pages)
147 {
148 if (current->mm) /* during close after signal, mm can be NULL */
149 down_write(¤t->mm->mmap_sem);
150
151 __qib_release_user_pages(p, num_pages, 1);
152
153 if (current->mm) {
154 current->mm->pinned_vm -= num_pages;
155 up_write(¤t->mm->mmap_sem);
156 }
157 }
158