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7f510b46 | 1 | /* |
759d5768 | 2 | * Copyright (c) 2006 QLogic, Inc. All rights reserved. |
7f510b46 BS |
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 "ipath_kernel.h" | |
38 | ||
39 | static void __ipath_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 | ipath_cdbg(MM, "%lu/%lu put_page %p\n", (unsigned long) i, | |
46 | (unsigned long) num_pages, p[i]); | |
47 | if (dirty) | |
48 | set_page_dirty_lock(p[i]); | |
49 | put_page(p[i]); | |
50 | } | |
51 | } | |
52 | ||
53 | /* call with current->mm->mmap_sem held */ | |
54 | static int __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 | ||
7f510b46 BS |
61 | lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur >> |
62 | PAGE_SHIFT; | |
63 | ||
64 | if (num_pages > lock_limit) { | |
65 | ret = -ENOMEM; | |
66 | goto bail; | |
67 | } | |
68 | ||
69 | ipath_cdbg(VERBOSE, "pin %lx pages from vaddr %lx\n", | |
70 | (unsigned long) num_pages, start_page); | |
71 | ||
72 | for (got = 0; got < num_pages; got += ret) { | |
73 | ret = get_user_pages(current, current->mm, | |
74 | start_page + got * PAGE_SIZE, | |
75 | num_pages - got, 1, 1, | |
76 | p + got, vma); | |
77 | if (ret < 0) | |
78 | goto bail_release; | |
79 | } | |
80 | ||
81 | current->mm->locked_vm += num_pages; | |
82 | ||
83 | ret = 0; | |
84 | goto bail; | |
85 | ||
86 | bail_release: | |
87 | __ipath_release_user_pages(p, got, 0); | |
88 | bail: | |
89 | return ret; | |
90 | } | |
91 | ||
1fd3b40f BS |
92 | /** |
93 | * ipath_map_page - a safety wrapper around pci_map_page() | |
94 | * | |
95 | * A dma_addr of all 0's is interpreted by the chip as "disabled". | |
96 | * Unfortunately, it can also be a valid dma_addr returned on some | |
97 | * architectures. | |
98 | * | |
99 | * The powerpc iommu assigns dma_addrs in ascending order, so we don't | |
100 | * have to bother with retries or mapping a dummy page to insure we | |
101 | * don't just get the same mapping again. | |
102 | * | |
103 | * I'm sure we won't be so lucky with other iommu's, so FIXME. | |
104 | */ | |
105 | dma_addr_t ipath_map_page(struct pci_dev *hwdev, struct page *page, | |
106 | unsigned long offset, size_t size, int direction) | |
107 | { | |
108 | dma_addr_t phys; | |
109 | ||
110 | phys = pci_map_page(hwdev, page, offset, size, direction); | |
111 | ||
112 | if (phys == 0) { | |
113 | pci_unmap_page(hwdev, phys, size, direction); | |
114 | phys = pci_map_page(hwdev, page, offset, size, direction); | |
115 | /* | |
116 | * FIXME: If we get 0 again, we should keep this page, | |
117 | * map another, then free the 0 page. | |
118 | */ | |
119 | } | |
120 | ||
121 | return phys; | |
122 | } | |
123 | ||
124 | /** | |
125 | * ipath_map_single - a safety wrapper around pci_map_single() | |
126 | * | |
127 | * Same idea as ipath_map_page(). | |
128 | */ | |
129 | dma_addr_t ipath_map_single(struct pci_dev *hwdev, void *ptr, size_t size, | |
130 | int direction) | |
131 | { | |
132 | dma_addr_t phys; | |
133 | ||
134 | phys = pci_map_single(hwdev, ptr, size, direction); | |
135 | ||
136 | if (phys == 0) { | |
137 | pci_unmap_single(hwdev, phys, size, direction); | |
138 | phys = pci_map_single(hwdev, ptr, size, direction); | |
139 | /* | |
140 | * FIXME: If we get 0 again, we should keep this page, | |
141 | * map another, then free the 0 page. | |
142 | */ | |
143 | } | |
144 | ||
145 | return phys; | |
146 | } | |
147 | ||
7f510b46 BS |
148 | /** |
149 | * ipath_get_user_pages - lock user pages into memory | |
150 | * @start_page: the start page | |
151 | * @num_pages: the number of pages | |
152 | * @p: the output page structures | |
153 | * | |
154 | * This function takes a given start page (page aligned user virtual | |
155 | * address) and pins it and the following specified number of pages. For | |
156 | * now, num_pages is always 1, but that will probably change at some point | |
157 | * (because caller is doing expected sends on a single virtually contiguous | |
158 | * buffer, so we can do all pages at once). | |
159 | */ | |
160 | int ipath_get_user_pages(unsigned long start_page, size_t num_pages, | |
161 | struct page **p) | |
162 | { | |
163 | int ret; | |
164 | ||
165 | down_write(¤t->mm->mmap_sem); | |
166 | ||
167 | ret = __get_user_pages(start_page, num_pages, p, NULL); | |
168 | ||
169 | up_write(¤t->mm->mmap_sem); | |
170 | ||
171 | return ret; | |
172 | } | |
173 | ||
174 | /** | |
175 | * ipath_get_user_pages_nocopy - lock a single page for I/O and mark shared | |
176 | * @start_page: the page to lock | |
177 | * @p: the output page structure | |
178 | * | |
179 | * This is similar to ipath_get_user_pages, but it's always one page, and we | |
180 | * mark the page as locked for I/O, and shared. This is used for the user | |
181 | * process page that contains the destination address for the rcvhdrq tail | |
182 | * update, so we need to have the vma. If we don't do this, the page can be | |
183 | * taken away from us on fork, even if the child never touches it, and then | |
184 | * the user process never sees the tail register updates. | |
185 | */ | |
186 | int ipath_get_user_pages_nocopy(unsigned long page, struct page **p) | |
187 | { | |
188 | struct vm_area_struct *vma; | |
189 | int ret; | |
190 | ||
191 | down_write(¤t->mm->mmap_sem); | |
192 | ||
193 | ret = __get_user_pages(page, 1, p, &vma); | |
194 | ||
195 | up_write(¤t->mm->mmap_sem); | |
196 | ||
197 | return ret; | |
198 | } | |
199 | ||
200 | void ipath_release_user_pages(struct page **p, size_t num_pages) | |
201 | { | |
202 | down_write(¤t->mm->mmap_sem); | |
203 | ||
204 | __ipath_release_user_pages(p, num_pages, 1); | |
205 | ||
206 | current->mm->locked_vm -= num_pages; | |
207 | ||
208 | up_write(¤t->mm->mmap_sem); | |
209 | } | |
210 | ||
211 | struct ipath_user_pages_work { | |
212 | struct work_struct work; | |
213 | struct mm_struct *mm; | |
214 | unsigned long num_pages; | |
215 | }; | |
216 | ||
217 | static void user_pages_account(void *ptr) | |
218 | { | |
219 | struct ipath_user_pages_work *work = ptr; | |
220 | ||
221 | down_write(&work->mm->mmap_sem); | |
222 | work->mm->locked_vm -= work->num_pages; | |
223 | up_write(&work->mm->mmap_sem); | |
224 | mmput(work->mm); | |
225 | kfree(work); | |
226 | } | |
227 | ||
228 | void ipath_release_user_pages_on_close(struct page **p, size_t num_pages) | |
229 | { | |
230 | struct ipath_user_pages_work *work; | |
231 | struct mm_struct *mm; | |
232 | ||
233 | __ipath_release_user_pages(p, num_pages, 1); | |
234 | ||
235 | mm = get_task_mm(current); | |
236 | if (!mm) | |
237 | goto bail; | |
238 | ||
239 | work = kmalloc(sizeof(*work), GFP_KERNEL); | |
240 | if (!work) | |
241 | goto bail_mm; | |
242 | ||
243 | goto bail; | |
244 | ||
245 | INIT_WORK(&work->work, user_pages_account, work); | |
246 | work->mm = mm; | |
247 | work->num_pages = num_pages; | |
248 | ||
249 | bail_mm: | |
250 | mmput(mm); | |
251 | bail: | |
252 | return; | |
253 | } |