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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. | |
eb8ffbfe RD |
33 | */ |
34 | ||
35 | #include <linux/mm.h> | |
36 | #include <linux/dma-mapping.h> | |
e8edc6e0 | 37 | #include <linux/sched.h> |
b108d976 | 38 | #include <linux/export.h> |
c8d8beea | 39 | #include <linux/hugetlb.h> |
cb9fbc5c | 40 | #include <linux/dma-attrs.h> |
5a0e3ad6 | 41 | #include <linux/slab.h> |
8ada2c1c | 42 | #include <rdma/ib_umem_odp.h> |
eb8ffbfe RD |
43 | |
44 | #include "uverbs.h" | |
45 | ||
92ddc447 | 46 | |
eb8ffbfe RD |
47 | static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty) |
48 | { | |
eeb8461e YH |
49 | struct scatterlist *sg; |
50 | struct page *page; | |
eb8ffbfe RD |
51 | int i; |
52 | ||
eeb8461e YH |
53 | if (umem->nmap > 0) |
54 | ib_dma_unmap_sg(dev, umem->sg_head.sgl, | |
55 | umem->nmap, | |
56 | DMA_BIDIRECTIONAL); | |
45711f1a | 57 | |
eeb8461e | 58 | for_each_sg(umem->sg_head.sgl, sg, umem->npages, i) { |
eb8ffbfe | 59 | |
eeb8461e YH |
60 | page = sg_page(sg); |
61 | if (umem->writable && dirty) | |
62 | set_page_dirty_lock(page); | |
63 | put_page(page); | |
eb8ffbfe | 64 | } |
eeb8461e YH |
65 | |
66 | sg_free_table(&umem->sg_head); | |
67 | return; | |
68 | ||
eb8ffbfe RD |
69 | } |
70 | ||
f7c6a7b5 RD |
71 | /** |
72 | * ib_umem_get - Pin and DMA map userspace memory. | |
8ada2c1c SR |
73 | * |
74 | * If access flags indicate ODP memory, avoid pinning. Instead, stores | |
882214e2 | 75 | * the mm for future page fault handling in conjunction with MMU notifiers. |
8ada2c1c | 76 | * |
f7c6a7b5 RD |
77 | * @context: userspace context to pin memory for |
78 | * @addr: userspace virtual address to start at | |
79 | * @size: length of region to pin | |
80 | * @access: IB_ACCESS_xxx flags for memory being pinned | |
cb9fbc5c | 81 | * @dmasync: flush in-flight DMA when the memory region is written |
f7c6a7b5 RD |
82 | */ |
83 | struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr, | |
cb9fbc5c | 84 | size_t size, int access, int dmasync) |
eb8ffbfe | 85 | { |
f7c6a7b5 | 86 | struct ib_umem *umem; |
eb8ffbfe | 87 | struct page **page_list; |
c8d8beea | 88 | struct vm_area_struct **vma_list; |
eb8ffbfe RD |
89 | unsigned long locked; |
90 | unsigned long lock_limit; | |
91 | unsigned long cur_base; | |
92 | unsigned long npages; | |
f7c6a7b5 | 93 | int ret; |
eb8ffbfe | 94 | int i; |
cb9fbc5c | 95 | DEFINE_DMA_ATTRS(attrs); |
eeb8461e YH |
96 | struct scatterlist *sg, *sg_list_start; |
97 | int need_release = 0; | |
cb9fbc5c AK |
98 | |
99 | if (dmasync) | |
100 | dma_set_attr(DMA_ATTR_WRITE_BARRIER, &attrs); | |
eb8ffbfe RD |
101 | |
102 | if (!can_do_mlock()) | |
f7c6a7b5 | 103 | return ERR_PTR(-EPERM); |
eb8ffbfe | 104 | |
eeb8461e | 105 | umem = kzalloc(sizeof *umem, GFP_KERNEL); |
f7c6a7b5 RD |
106 | if (!umem) |
107 | return ERR_PTR(-ENOMEM); | |
eb8ffbfe | 108 | |
f7c6a7b5 RD |
109 | umem->context = context; |
110 | umem->length = size; | |
406f9e5f | 111 | umem->address = addr; |
f7c6a7b5 | 112 | umem->page_size = PAGE_SIZE; |
87773dd5 | 113 | umem->pid = get_task_pid(current, PIDTYPE_PID); |
f7c6a7b5 | 114 | /* |
860f10a7 SG |
115 | * We ask for writable memory if any of the following |
116 | * access flags are set. "Local write" and "remote write" | |
f7c6a7b5 RD |
117 | * obviously require write access. "Remote atomic" can do |
118 | * things like fetch and add, which will modify memory, and | |
119 | * "MW bind" can change permissions by binding a window. | |
120 | */ | |
860f10a7 SG |
121 | umem->writable = !!(access & |
122 | (IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_WRITE | | |
123 | IB_ACCESS_REMOTE_ATOMIC | IB_ACCESS_MW_BIND)); | |
eb8ffbfe | 124 | |
8ada2c1c SR |
125 | if (access & IB_ACCESS_ON_DEMAND) { |
126 | ret = ib_umem_odp_get(context, umem); | |
127 | if (ret) { | |
128 | kfree(umem); | |
129 | return ERR_PTR(ret); | |
130 | } | |
131 | return umem; | |
132 | } | |
133 | ||
134 | umem->odp_data = NULL; | |
135 | ||
c8d8beea JF |
136 | /* We assume the memory is from hugetlb until proved otherwise */ |
137 | umem->hugetlb = 1; | |
138 | ||
f7c6a7b5 RD |
139 | page_list = (struct page **) __get_free_page(GFP_KERNEL); |
140 | if (!page_list) { | |
141 | kfree(umem); | |
142 | return ERR_PTR(-ENOMEM); | |
143 | } | |
eb8ffbfe | 144 | |
c8d8beea JF |
145 | /* |
146 | * if we can't alloc the vma_list, it's not so bad; | |
147 | * just assume the memory is not hugetlb memory | |
148 | */ | |
149 | vma_list = (struct vm_area_struct **) __get_free_page(GFP_KERNEL); | |
150 | if (!vma_list) | |
151 | umem->hugetlb = 0; | |
152 | ||
406f9e5f | 153 | npages = ib_umem_num_pages(umem); |
eb8ffbfe RD |
154 | |
155 | down_write(¤t->mm->mmap_sem); | |
156 | ||
bc3e53f6 | 157 | locked = npages + current->mm->pinned_vm; |
ccbe9f0b | 158 | lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; |
eb8ffbfe RD |
159 | |
160 | if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) { | |
161 | ret = -ENOMEM; | |
162 | goto out; | |
163 | } | |
164 | ||
f7c6a7b5 | 165 | cur_base = addr & PAGE_MASK; |
eb8ffbfe | 166 | |
eeb8461e YH |
167 | if (npages == 0) { |
168 | ret = -EINVAL; | |
169 | goto out; | |
170 | } | |
171 | ||
172 | ret = sg_alloc_table(&umem->sg_head, npages, GFP_KERNEL); | |
173 | if (ret) | |
174 | goto out; | |
175 | ||
176 | need_release = 1; | |
177 | sg_list_start = umem->sg_head.sgl; | |
178 | ||
eb8ffbfe RD |
179 | while (npages) { |
180 | ret = get_user_pages(current, current->mm, cur_base, | |
8079ffa0 | 181 | min_t(unsigned long, npages, |
eb8ffbfe | 182 | PAGE_SIZE / sizeof (struct page *)), |
c8d8beea | 183 | 1, !umem->writable, page_list, vma_list); |
eb8ffbfe RD |
184 | |
185 | if (ret < 0) | |
186 | goto out; | |
187 | ||
eeb8461e | 188 | umem->npages += ret; |
eb8ffbfe RD |
189 | cur_base += ret * PAGE_SIZE; |
190 | npages -= ret; | |
191 | ||
eeb8461e YH |
192 | for_each_sg(sg_list_start, sg, ret, i) { |
193 | if (vma_list && !is_vm_hugetlb_page(vma_list[i])) | |
194 | umem->hugetlb = 0; | |
195 | ||
196 | sg_set_page(sg, page_list[i], PAGE_SIZE, 0); | |
eb8ffbfe RD |
197 | } |
198 | ||
eeb8461e YH |
199 | /* preparing for next loop */ |
200 | sg_list_start = sg; | |
eb8ffbfe RD |
201 | } |
202 | ||
eeb8461e YH |
203 | umem->nmap = ib_dma_map_sg_attrs(context->device, |
204 | umem->sg_head.sgl, | |
205 | umem->npages, | |
206 | DMA_BIDIRECTIONAL, | |
207 | &attrs); | |
208 | ||
209 | if (umem->nmap <= 0) { | |
210 | ret = -ENOMEM; | |
211 | goto out; | |
212 | } | |
213 | ||
214 | ret = 0; | |
215 | ||
eb8ffbfe | 216 | out: |
f7c6a7b5 | 217 | if (ret < 0) { |
eeb8461e YH |
218 | if (need_release) |
219 | __ib_umem_release(context->device, umem, 0); | |
87773dd5 | 220 | put_pid(umem->pid); |
f7c6a7b5 RD |
221 | kfree(umem); |
222 | } else | |
bc3e53f6 | 223 | current->mm->pinned_vm = locked; |
eb8ffbfe RD |
224 | |
225 | up_write(¤t->mm->mmap_sem); | |
c8d8beea JF |
226 | if (vma_list) |
227 | free_page((unsigned long) vma_list); | |
eb8ffbfe RD |
228 | free_page((unsigned long) page_list); |
229 | ||
f7c6a7b5 | 230 | return ret < 0 ? ERR_PTR(ret) : umem; |
eb8ffbfe | 231 | } |
f7c6a7b5 | 232 | EXPORT_SYMBOL(ib_umem_get); |
eb8ffbfe | 233 | |
1bf66a30 | 234 | static void ib_umem_account(struct work_struct *work) |
eb8ffbfe | 235 | { |
1bf66a30 RD |
236 | struct ib_umem *umem = container_of(work, struct ib_umem, work); |
237 | ||
238 | down_write(&umem->mm->mmap_sem); | |
bc3e53f6 | 239 | umem->mm->pinned_vm -= umem->diff; |
1bf66a30 RD |
240 | up_write(&umem->mm->mmap_sem); |
241 | mmput(umem->mm); | |
242 | kfree(umem); | |
eb8ffbfe RD |
243 | } |
244 | ||
f7c6a7b5 RD |
245 | /** |
246 | * ib_umem_release - release memory pinned with ib_umem_get | |
247 | * @umem: umem struct to release | |
248 | */ | |
249 | void ib_umem_release(struct ib_umem *umem) | |
eb8ffbfe | 250 | { |
f7c6a7b5 | 251 | struct ib_ucontext *context = umem->context; |
eb8ffbfe | 252 | struct mm_struct *mm; |
87773dd5 | 253 | struct task_struct *task; |
f7c6a7b5 | 254 | unsigned long diff; |
eb8ffbfe | 255 | |
8ada2c1c SR |
256 | if (umem->odp_data) { |
257 | ib_umem_odp_release(umem); | |
258 | return; | |
259 | } | |
260 | ||
f7c6a7b5 | 261 | __ib_umem_release(umem->context->device, umem, 1); |
eb8ffbfe | 262 | |
87773dd5 SB |
263 | task = get_pid_task(umem->pid, PIDTYPE_PID); |
264 | put_pid(umem->pid); | |
265 | if (!task) | |
266 | goto out; | |
267 | mm = get_task_mm(task); | |
268 | put_task_struct(task); | |
269 | if (!mm) | |
270 | goto out; | |
eb8ffbfe | 271 | |
406f9e5f | 272 | diff = ib_umem_num_pages(umem); |
f7c6a7b5 | 273 | |
eb8ffbfe RD |
274 | /* |
275 | * We may be called with the mm's mmap_sem already held. This | |
276 | * can happen when a userspace munmap() is the call that drops | |
277 | * the last reference to our file and calls our release | |
278 | * method. If there are memory regions to destroy, we'll end | |
f7c6a7b5 RD |
279 | * up here and not be able to take the mmap_sem. In that case |
280 | * we defer the vm_locked accounting to the system workqueue. | |
eb8ffbfe | 281 | */ |
24bce508 RD |
282 | if (context->closing) { |
283 | if (!down_write_trylock(&mm->mmap_sem)) { | |
284 | INIT_WORK(&umem->work, ib_umem_account); | |
285 | umem->mm = mm; | |
286 | umem->diff = diff; | |
287 | ||
f0626710 | 288 | queue_work(ib_wq, &umem->work); |
24bce508 RD |
289 | return; |
290 | } | |
f7c6a7b5 RD |
291 | } else |
292 | down_write(&mm->mmap_sem); | |
293 | ||
87773dd5 | 294 | mm->pinned_vm -= diff; |
f7c6a7b5 RD |
295 | up_write(&mm->mmap_sem); |
296 | mmput(mm); | |
87773dd5 | 297 | out: |
1bf66a30 | 298 | kfree(umem); |
f7c6a7b5 RD |
299 | } |
300 | EXPORT_SYMBOL(ib_umem_release); | |
301 | ||
302 | int ib_umem_page_count(struct ib_umem *umem) | |
303 | { | |
f7c6a7b5 RD |
304 | int shift; |
305 | int i; | |
306 | int n; | |
eeb8461e | 307 | struct scatterlist *sg; |
f7c6a7b5 | 308 | |
8ada2c1c SR |
309 | if (umem->odp_data) |
310 | return ib_umem_num_pages(umem); | |
311 | ||
f7c6a7b5 | 312 | shift = ilog2(umem->page_size); |
eb8ffbfe | 313 | |
f7c6a7b5 | 314 | n = 0; |
eeb8461e YH |
315 | for_each_sg(umem->sg_head.sgl, sg, umem->nmap, i) |
316 | n += sg_dma_len(sg) >> shift; | |
eb8ffbfe | 317 | |
f7c6a7b5 | 318 | return n; |
eb8ffbfe | 319 | } |
f7c6a7b5 | 320 | EXPORT_SYMBOL(ib_umem_page_count); |
c5d76f13 HE |
321 | |
322 | /* | |
323 | * Copy from the given ib_umem's pages to the given buffer. | |
324 | * | |
325 | * umem - the umem to copy from | |
326 | * offset - offset to start copying from | |
327 | * dst - destination buffer | |
328 | * length - buffer length | |
329 | * | |
330 | * Returns 0 on success, or an error code. | |
331 | */ | |
332 | int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset, | |
333 | size_t length) | |
334 | { | |
335 | size_t end = offset + length; | |
336 | int ret; | |
337 | ||
338 | if (offset > umem->length || length > umem->length - offset) { | |
339 | pr_err("ib_umem_copy_from not in range. offset: %zd umem length: %zd end: %zd\n", | |
340 | offset, umem->length, end); | |
341 | return -EINVAL; | |
342 | } | |
343 | ||
344 | ret = sg_pcopy_to_buffer(umem->sg_head.sgl, umem->nmap, dst, length, | |
345 | offset + ib_umem_offset(umem)); | |
346 | ||
347 | if (ret < 0) | |
348 | return ret; | |
349 | else if (ret != length) | |
350 | return -EINVAL; | |
351 | else | |
352 | return 0; | |
353 | } | |
354 | EXPORT_SYMBOL(ib_umem_copy_from); |