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eb8ffbfe RD |
1 | /* |
2 | * Copyright (c) 2005 Topspin Communications. All rights reserved. | |
3 | * Copyright (c) 2005 Cisco Systems. All rights reserved. | |
2a1d9b7f | 4 | * Copyright (c) 2005 Mellanox Technologies. All rights reserved. |
eb8ffbfe RD |
5 | * |
6 | * This software is available to you under a choice of one of two | |
7 | * licenses. You may choose to be licensed under the terms of the GNU | |
8 | * General Public License (GPL) Version 2, available from the file | |
9 | * COPYING in the main directory of this source tree, or the | |
10 | * OpenIB.org BSD license below: | |
11 | * | |
12 | * Redistribution and use in source and binary forms, with or | |
13 | * without modification, are permitted provided that the following | |
14 | * conditions are met: | |
15 | * | |
16 | * - Redistributions of source code must retain the above | |
17 | * copyright notice, this list of conditions and the following | |
18 | * disclaimer. | |
19 | * | |
20 | * - Redistributions in binary form must reproduce the above | |
21 | * copyright notice, this list of conditions and the following | |
22 | * disclaimer in the documentation and/or other materials | |
23 | * provided with the distribution. | |
24 | * | |
25 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, | |
26 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF | |
27 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND | |
28 | * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS | |
29 | * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN | |
30 | * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN | |
31 | * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE | |
32 | * SOFTWARE. | |
33 | * | |
34 | * $Id: uverbs_mem.c 2743 2005-06-28 22:27:59Z roland $ | |
35 | */ | |
36 | ||
37 | #include <linux/mm.h> | |
38 | #include <linux/dma-mapping.h> | |
e8edc6e0 | 39 | #include <linux/sched.h> |
c8d8beea | 40 | #include <linux/hugetlb.h> |
eb8ffbfe RD |
41 | |
42 | #include "uverbs.h" | |
43 | ||
92ddc447 DB |
44 | #define IB_UMEM_MAX_PAGE_CHUNK \ |
45 | ((PAGE_SIZE - offsetof(struct ib_umem_chunk, page_list)) / \ | |
46 | ((void *) &((struct ib_umem_chunk *) 0)->page_list[1] - \ | |
47 | (void *) &((struct ib_umem_chunk *) 0)->page_list[0])) | |
48 | ||
eb8ffbfe RD |
49 | static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty) |
50 | { | |
51 | struct ib_umem_chunk *chunk, *tmp; | |
52 | int i; | |
53 | ||
54 | list_for_each_entry_safe(chunk, tmp, &umem->chunk_list, list) { | |
1527106f RC |
55 | ib_dma_unmap_sg(dev, chunk->page_list, |
56 | chunk->nents, DMA_BIDIRECTIONAL); | |
eb8ffbfe RD |
57 | for (i = 0; i < chunk->nents; ++i) { |
58 | if (umem->writable && dirty) | |
59 | set_page_dirty_lock(chunk->page_list[i].page); | |
60 | put_page(chunk->page_list[i].page); | |
61 | } | |
62 | ||
63 | kfree(chunk); | |
64 | } | |
65 | } | |
66 | ||
f7c6a7b5 RD |
67 | /** |
68 | * ib_umem_get - Pin and DMA map userspace memory. | |
69 | * @context: userspace context to pin memory for | |
70 | * @addr: userspace virtual address to start at | |
71 | * @size: length of region to pin | |
72 | * @access: IB_ACCESS_xxx flags for memory being pinned | |
73 | */ | |
74 | struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr, | |
75 | size_t size, int access) | |
eb8ffbfe | 76 | { |
f7c6a7b5 | 77 | struct ib_umem *umem; |
eb8ffbfe | 78 | struct page **page_list; |
c8d8beea | 79 | struct vm_area_struct **vma_list; |
eb8ffbfe RD |
80 | struct ib_umem_chunk *chunk; |
81 | unsigned long locked; | |
82 | unsigned long lock_limit; | |
83 | unsigned long cur_base; | |
84 | unsigned long npages; | |
f7c6a7b5 | 85 | int ret; |
eb8ffbfe RD |
86 | int off; |
87 | int i; | |
88 | ||
89 | if (!can_do_mlock()) | |
f7c6a7b5 | 90 | return ERR_PTR(-EPERM); |
eb8ffbfe | 91 | |
f7c6a7b5 RD |
92 | umem = kmalloc(sizeof *umem, GFP_KERNEL); |
93 | if (!umem) | |
94 | return ERR_PTR(-ENOMEM); | |
eb8ffbfe | 95 | |
f7c6a7b5 RD |
96 | umem->context = context; |
97 | umem->length = size; | |
98 | umem->offset = addr & ~PAGE_MASK; | |
99 | umem->page_size = PAGE_SIZE; | |
100 | /* | |
101 | * We ask for writable memory if any access flags other than | |
102 | * "remote read" are set. "Local write" and "remote write" | |
103 | * obviously require write access. "Remote atomic" can do | |
104 | * things like fetch and add, which will modify memory, and | |
105 | * "MW bind" can change permissions by binding a window. | |
106 | */ | |
107 | umem->writable = !!(access & ~IB_ACCESS_REMOTE_READ); | |
eb8ffbfe | 108 | |
c8d8beea JF |
109 | /* We assume the memory is from hugetlb until proved otherwise */ |
110 | umem->hugetlb = 1; | |
111 | ||
f7c6a7b5 RD |
112 | INIT_LIST_HEAD(&umem->chunk_list); |
113 | ||
114 | page_list = (struct page **) __get_free_page(GFP_KERNEL); | |
115 | if (!page_list) { | |
116 | kfree(umem); | |
117 | return ERR_PTR(-ENOMEM); | |
118 | } | |
eb8ffbfe | 119 | |
c8d8beea JF |
120 | /* |
121 | * if we can't alloc the vma_list, it's not so bad; | |
122 | * just assume the memory is not hugetlb memory | |
123 | */ | |
124 | vma_list = (struct vm_area_struct **) __get_free_page(GFP_KERNEL); | |
125 | if (!vma_list) | |
126 | umem->hugetlb = 0; | |
127 | ||
f7c6a7b5 | 128 | npages = PAGE_ALIGN(size + umem->offset) >> PAGE_SHIFT; |
eb8ffbfe RD |
129 | |
130 | down_write(¤t->mm->mmap_sem); | |
131 | ||
132 | locked = npages + current->mm->locked_vm; | |
133 | lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur >> PAGE_SHIFT; | |
134 | ||
135 | if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) { | |
136 | ret = -ENOMEM; | |
137 | goto out; | |
138 | } | |
139 | ||
f7c6a7b5 | 140 | cur_base = addr & PAGE_MASK; |
eb8ffbfe | 141 | |
1d3f4b90 | 142 | ret = 0; |
eb8ffbfe RD |
143 | while (npages) { |
144 | ret = get_user_pages(current, current->mm, cur_base, | |
145 | min_t(int, npages, | |
146 | PAGE_SIZE / sizeof (struct page *)), | |
c8d8beea | 147 | 1, !umem->writable, page_list, vma_list); |
eb8ffbfe RD |
148 | |
149 | if (ret < 0) | |
150 | goto out; | |
151 | ||
152 | cur_base += ret * PAGE_SIZE; | |
153 | npages -= ret; | |
154 | ||
155 | off = 0; | |
156 | ||
157 | while (ret) { | |
158 | chunk = kmalloc(sizeof *chunk + sizeof (struct scatterlist) * | |
159 | min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK), | |
160 | GFP_KERNEL); | |
161 | if (!chunk) { | |
162 | ret = -ENOMEM; | |
163 | goto out; | |
164 | } | |
165 | ||
166 | chunk->nents = min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK); | |
167 | for (i = 0; i < chunk->nents; ++i) { | |
c8d8beea JF |
168 | if (vma_list && |
169 | !is_vm_hugetlb_page(vma_list[i + off])) | |
170 | umem->hugetlb = 0; | |
eb8ffbfe RD |
171 | chunk->page_list[i].page = page_list[i + off]; |
172 | chunk->page_list[i].offset = 0; | |
173 | chunk->page_list[i].length = PAGE_SIZE; | |
174 | } | |
175 | ||
f7c6a7b5 | 176 | chunk->nmap = ib_dma_map_sg(context->device, |
1527106f RC |
177 | &chunk->page_list[0], |
178 | chunk->nents, | |
179 | DMA_BIDIRECTIONAL); | |
eb8ffbfe RD |
180 | if (chunk->nmap <= 0) { |
181 | for (i = 0; i < chunk->nents; ++i) | |
182 | put_page(chunk->page_list[i].page); | |
183 | kfree(chunk); | |
184 | ||
185 | ret = -ENOMEM; | |
186 | goto out; | |
187 | } | |
188 | ||
189 | ret -= chunk->nents; | |
190 | off += chunk->nents; | |
f7c6a7b5 | 191 | list_add_tail(&chunk->list, &umem->chunk_list); |
eb8ffbfe RD |
192 | } |
193 | ||
194 | ret = 0; | |
195 | } | |
196 | ||
197 | out: | |
f7c6a7b5 RD |
198 | if (ret < 0) { |
199 | __ib_umem_release(context->device, umem, 0); | |
200 | kfree(umem); | |
201 | } else | |
eb8ffbfe RD |
202 | current->mm->locked_vm = locked; |
203 | ||
204 | up_write(¤t->mm->mmap_sem); | |
c8d8beea JF |
205 | if (vma_list) |
206 | free_page((unsigned long) vma_list); | |
eb8ffbfe RD |
207 | free_page((unsigned long) page_list); |
208 | ||
f7c6a7b5 | 209 | return ret < 0 ? ERR_PTR(ret) : umem; |
eb8ffbfe | 210 | } |
f7c6a7b5 | 211 | EXPORT_SYMBOL(ib_umem_get); |
eb8ffbfe | 212 | |
1bf66a30 | 213 | static void ib_umem_account(struct work_struct *work) |
eb8ffbfe | 214 | { |
1bf66a30 RD |
215 | struct ib_umem *umem = container_of(work, struct ib_umem, work); |
216 | ||
217 | down_write(&umem->mm->mmap_sem); | |
218 | umem->mm->locked_vm -= umem->diff; | |
219 | up_write(&umem->mm->mmap_sem); | |
220 | mmput(umem->mm); | |
221 | kfree(umem); | |
eb8ffbfe RD |
222 | } |
223 | ||
f7c6a7b5 RD |
224 | /** |
225 | * ib_umem_release - release memory pinned with ib_umem_get | |
226 | * @umem: umem struct to release | |
227 | */ | |
228 | void ib_umem_release(struct ib_umem *umem) | |
eb8ffbfe | 229 | { |
f7c6a7b5 | 230 | struct ib_ucontext *context = umem->context; |
eb8ffbfe | 231 | struct mm_struct *mm; |
f7c6a7b5 | 232 | unsigned long diff; |
eb8ffbfe | 233 | |
f7c6a7b5 | 234 | __ib_umem_release(umem->context->device, umem, 1); |
eb8ffbfe RD |
235 | |
236 | mm = get_task_mm(current); | |
7b82cd8e EC |
237 | if (!mm) { |
238 | kfree(umem); | |
eb8ffbfe | 239 | return; |
7b82cd8e | 240 | } |
eb8ffbfe | 241 | |
f7c6a7b5 | 242 | diff = PAGE_ALIGN(umem->length + umem->offset) >> PAGE_SHIFT; |
f7c6a7b5 | 243 | |
eb8ffbfe RD |
244 | /* |
245 | * We may be called with the mm's mmap_sem already held. This | |
246 | * can happen when a userspace munmap() is the call that drops | |
247 | * the last reference to our file and calls our release | |
248 | * method. If there are memory regions to destroy, we'll end | |
f7c6a7b5 RD |
249 | * up here and not be able to take the mmap_sem. In that case |
250 | * we defer the vm_locked accounting to the system workqueue. | |
eb8ffbfe | 251 | */ |
24bce508 RD |
252 | if (context->closing) { |
253 | if (!down_write_trylock(&mm->mmap_sem)) { | |
254 | INIT_WORK(&umem->work, ib_umem_account); | |
255 | umem->mm = mm; | |
256 | umem->diff = diff; | |
257 | ||
258 | schedule_work(&umem->work); | |
259 | return; | |
260 | } | |
f7c6a7b5 RD |
261 | } else |
262 | down_write(&mm->mmap_sem); | |
263 | ||
264 | current->mm->locked_vm -= diff; | |
265 | up_write(&mm->mmap_sem); | |
266 | mmput(mm); | |
1bf66a30 | 267 | kfree(umem); |
f7c6a7b5 RD |
268 | } |
269 | EXPORT_SYMBOL(ib_umem_release); | |
270 | ||
271 | int ib_umem_page_count(struct ib_umem *umem) | |
272 | { | |
273 | struct ib_umem_chunk *chunk; | |
274 | int shift; | |
275 | int i; | |
276 | int n; | |
277 | ||
278 | shift = ilog2(umem->page_size); | |
eb8ffbfe | 279 | |
f7c6a7b5 RD |
280 | n = 0; |
281 | list_for_each_entry(chunk, &umem->chunk_list, list) | |
282 | for (i = 0; i < chunk->nmap; ++i) | |
283 | n += sg_dma_len(&chunk->page_list[i]) >> shift; | |
eb8ffbfe | 284 | |
f7c6a7b5 | 285 | return n; |
eb8ffbfe | 286 | } |
f7c6a7b5 | 287 | EXPORT_SYMBOL(ib_umem_page_count); |