1 /*
2 * Copyright (c) 2006, 2007 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 #include <linux/slab.h>
37 #include <linux/sched.h>
38
39 #include "ipath_kernel.h"
40
__ipath_release_user_pages(struct page ** p,size_t num_pages,int dirty)41 static void __ipath_release_user_pages(struct page **p, size_t num_pages,
42 int dirty)
43 {
44 size_t i;
45
46 for (i = 0; i < num_pages; i++) {
47 ipath_cdbg(MM, "%lu/%lu put_page %p\n", (unsigned long) i,
48 (unsigned long) num_pages, p[i]);
49 if (dirty)
50 set_page_dirty_lock(p[i]);
51 put_page(p[i]);
52 }
53 }
54
55 /* call with current->mm->mmap_sem held */
__ipath_get_user_pages(unsigned long start_page,size_t num_pages,struct page ** p)56 static int __ipath_get_user_pages(unsigned long start_page, size_t num_pages,
57 struct page **p)
58 {
59 unsigned long lock_limit;
60 size_t got;
61 int ret;
62
63 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
64
65 if (num_pages > lock_limit) {
66 ret = -ENOMEM;
67 goto bail;
68 }
69
70 ipath_cdbg(VERBOSE, "pin %lx pages from vaddr %lx\n",
71 (unsigned long) num_pages, start_page);
72
73 for (got = 0; got < num_pages; got += ret) {
74 ret = get_user_pages(current, current->mm,
75 start_page + got * PAGE_SIZE,
76 num_pages - got, 1, 1,
77 p + got, NULL);
78 if (ret < 0)
79 goto bail_release;
80 }
81
82 current->mm->pinned_vm += num_pages;
83
84 ret = 0;
85 goto bail;
86
87 bail_release:
88 __ipath_release_user_pages(p, got, 0);
89 bail:
90 return ret;
91 }
92
93 /**
94 * ipath_map_page - a safety wrapper around pci_map_page()
95 *
96 * A dma_addr of all 0's is interpreted by the chip as "disabled".
97 * Unfortunately, it can also be a valid dma_addr returned on some
98 * architectures.
99 *
100 * The powerpc iommu assigns dma_addrs in ascending order, so we don't
101 * have to bother with retries or mapping a dummy page to insure we
102 * don't just get the same mapping again.
103 *
104 * I'm sure we won't be so lucky with other iommu's, so FIXME.
105 */
ipath_map_page(struct pci_dev * hwdev,struct page * page,unsigned long offset,size_t size,int direction)106 dma_addr_t ipath_map_page(struct pci_dev *hwdev, struct page *page,
107 unsigned long offset, size_t size, int direction)
108 {
109 dma_addr_t phys;
110
111 phys = pci_map_page(hwdev, page, offset, size, direction);
112
113 if (phys == 0) {
114 pci_unmap_page(hwdev, phys, size, direction);
115 phys = pci_map_page(hwdev, page, offset, size, direction);
116 /*
117 * FIXME: If we get 0 again, we should keep this page,
118 * map another, then free the 0 page.
119 */
120 }
121
122 return phys;
123 }
124
125 /**
126 * ipath_map_single - a safety wrapper around pci_map_single()
127 *
128 * Same idea as ipath_map_page().
129 */
ipath_map_single(struct pci_dev * hwdev,void * ptr,size_t size,int direction)130 dma_addr_t ipath_map_single(struct pci_dev *hwdev, void *ptr, size_t size,
131 int direction)
132 {
133 dma_addr_t phys;
134
135 phys = pci_map_single(hwdev, ptr, size, direction);
136
137 if (phys == 0) {
138 pci_unmap_single(hwdev, phys, size, direction);
139 phys = pci_map_single(hwdev, ptr, size, direction);
140 /*
141 * FIXME: If we get 0 again, we should keep this page,
142 * map another, then free the 0 page.
143 */
144 }
145
146 return phys;
147 }
148
149 /**
150 * ipath_get_user_pages - lock user pages into memory
151 * @start_page: the start page
152 * @num_pages: the number of pages
153 * @p: the output page structures
154 *
155 * This function takes a given start page (page aligned user virtual
156 * address) and pins it and the following specified number of pages. For
157 * now, num_pages is always 1, but that will probably change at some point
158 * (because caller is doing expected sends on a single virtually contiguous
159 * buffer, so we can do all pages at once).
160 */
ipath_get_user_pages(unsigned long start_page,size_t num_pages,struct page ** p)161 int ipath_get_user_pages(unsigned long start_page, size_t num_pages,
162 struct page **p)
163 {
164 int ret;
165
166 down_write(¤t->mm->mmap_sem);
167
168 ret = __ipath_get_user_pages(start_page, num_pages, p);
169
170 up_write(¤t->mm->mmap_sem);
171
172 return ret;
173 }
174
ipath_release_user_pages(struct page ** p,size_t num_pages)175 void ipath_release_user_pages(struct page **p, size_t num_pages)
176 {
177 down_write(¤t->mm->mmap_sem);
178
179 __ipath_release_user_pages(p, num_pages, 1);
180
181 current->mm->pinned_vm -= num_pages;
182
183 up_write(¤t->mm->mmap_sem);
184 }
185
186 struct ipath_user_pages_work {
187 struct work_struct work;
188 struct mm_struct *mm;
189 unsigned long num_pages;
190 };
191
user_pages_account(struct work_struct * _work)192 static void user_pages_account(struct work_struct *_work)
193 {
194 struct ipath_user_pages_work *work =
195 container_of(_work, struct ipath_user_pages_work, work);
196
197 down_write(&work->mm->mmap_sem);
198 work->mm->pinned_vm -= work->num_pages;
199 up_write(&work->mm->mmap_sem);
200 mmput(work->mm);
201 kfree(work);
202 }
203
ipath_release_user_pages_on_close(struct page ** p,size_t num_pages)204 void ipath_release_user_pages_on_close(struct page **p, size_t num_pages)
205 {
206 struct ipath_user_pages_work *work;
207 struct mm_struct *mm;
208
209 __ipath_release_user_pages(p, num_pages, 1);
210
211 mm = get_task_mm(current);
212 if (!mm)
213 return;
214
215 work = kmalloc(sizeof(*work), GFP_KERNEL);
216 if (!work)
217 goto bail_mm;
218
219 INIT_WORK(&work->work, user_pages_account);
220 work->mm = mm;
221 work->num_pages = num_pages;
222
223 queue_work(ib_wq, &work->work);
224 return;
225
226 bail_mm:
227 mmput(mm);
228 return;
229 }
230