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/sched/signal.h>
36 #include <linux/device.h>
37
38 #include "qib.h"
39
__qib_release_user_pages(struct page ** p,size_t num_pages,int dirty)40 static void __qib_release_user_pages(struct page **p, size_t num_pages,
41 int dirty)
42 {
43 size_t i;
44
45 for (i = 0; i < num_pages; i++) {
46 if (dirty)
47 set_page_dirty_lock(p[i]);
48 put_page(p[i]);
49 }
50 }
51
52 /*
53 * Call with current->mm->mmap_sem held.
54 */
__qib_get_user_pages(unsigned long start_page,size_t num_pages,struct page ** p)55 static int __qib_get_user_pages(unsigned long start_page, size_t num_pages,
56 struct page **p)
57 {
58 unsigned long lock_limit;
59 size_t got;
60 int ret;
61
62 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
63
64 if (num_pages > lock_limit && !capable(CAP_IPC_LOCK)) {
65 ret = -ENOMEM;
66 goto bail;
67 }
68
69 for (got = 0; got < num_pages; got += ret) {
70 ret = get_user_pages(start_page + got * PAGE_SIZE,
71 num_pages - got,
72 FOLL_WRITE | FOLL_FORCE,
73 p + got, NULL);
74 if (ret < 0)
75 goto bail_release;
76 }
77
78 current->mm->pinned_vm += num_pages;
79
80 ret = 0;
81 goto bail;
82
83 bail_release:
84 __qib_release_user_pages(p, got, 0);
85 bail:
86 return ret;
87 }
88
89 /**
90 * qib_map_page - a safety wrapper around pci_map_page()
91 *
92 * A dma_addr of all 0's is interpreted by the chip as "disabled".
93 * Unfortunately, it can also be a valid dma_addr returned on some
94 * architectures.
95 *
96 * The powerpc iommu assigns dma_addrs in ascending order, so we don't
97 * have to bother with retries or mapping a dummy page to insure we
98 * don't just get the same mapping again.
99 *
100 * I'm sure we won't be so lucky with other iommu's, so FIXME.
101 */
qib_map_page(struct pci_dev * hwdev,struct page * page,dma_addr_t * daddr)102 int qib_map_page(struct pci_dev *hwdev, struct page *page, dma_addr_t *daddr)
103 {
104 dma_addr_t phys;
105
106 phys = pci_map_page(hwdev, page, 0, PAGE_SIZE, PCI_DMA_FROMDEVICE);
107 if (pci_dma_mapping_error(hwdev, phys))
108 return -ENOMEM;
109
110 if (!phys) {
111 pci_unmap_page(hwdev, phys, PAGE_SIZE, PCI_DMA_FROMDEVICE);
112 phys = pci_map_page(hwdev, page, 0, PAGE_SIZE,
113 PCI_DMA_FROMDEVICE);
114 if (pci_dma_mapping_error(hwdev, phys))
115 return -ENOMEM;
116 /*
117 * FIXME: If we get 0 again, we should keep this page,
118 * map another, then free the 0 page.
119 */
120 }
121 *daddr = phys;
122 return 0;
123 }
124
125 /**
126 * qib_get_user_pages - lock user pages into memory
127 * @start_page: the start page
128 * @num_pages: the number of pages
129 * @p: the output page structures
130 *
131 * This function takes a given start page (page aligned user virtual
132 * address) and pins it and the following specified number of pages. For
133 * now, num_pages is always 1, but that will probably change at some point
134 * (because caller is doing expected sends on a single virtually contiguous
135 * buffer, so we can do all pages at once).
136 */
qib_get_user_pages(unsigned long start_page,size_t num_pages,struct page ** p)137 int qib_get_user_pages(unsigned long start_page, size_t num_pages,
138 struct page **p)
139 {
140 int ret;
141
142 down_write(¤t->mm->mmap_sem);
143
144 ret = __qib_get_user_pages(start_page, num_pages, p);
145
146 up_write(¤t->mm->mmap_sem);
147
148 return ret;
149 }
150
qib_release_user_pages(struct page ** p,size_t num_pages)151 void qib_release_user_pages(struct page **p, size_t num_pages)
152 {
153 if (current->mm) /* during close after signal, mm can be NULL */
154 down_write(¤t->mm->mmap_sem);
155
156 __qib_release_user_pages(p, num_pages, 1);
157
158 if (current->mm) {
159 current->mm->pinned_vm -= num_pages;
160 up_write(¤t->mm->mmap_sem);
161 }
162 }
163