1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35#include <linux/mm.h>
36#include <linux/dma-mapping.h>
37#include <linux/sched/signal.h>
38#include <linux/sched/mm.h>
39#include <linux/export.h>
40#include <linux/hugetlb.h>
41#include <linux/slab.h>
42#include <rdma/ib_umem_odp.h>
43
44#include "uverbs.h"
45
46
47static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty)
48{
49 struct scatterlist *sg;
50 struct page *page;
51 int i;
52
53 if (umem->nmap > 0)
54 ib_dma_unmap_sg(dev, umem->sg_head.sgl,
55 umem->npages,
56 DMA_BIDIRECTIONAL);
57
58 for_each_sg(umem->sg_head.sgl, sg, umem->npages, i) {
59
60 page = sg_page(sg);
61 if (!PageDirty(page) && umem->writable && dirty)
62 set_page_dirty_lock(page);
63 put_page(page);
64 }
65
66 sg_free_table(&umem->sg_head);
67}
68
69
70
71
72
73
74
75
76
77
78
79
80
81struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
82 size_t size, int access, int dmasync)
83{
84 struct ib_umem *umem;
85 struct page **page_list;
86 struct vm_area_struct **vma_list;
87 unsigned long lock_limit;
88 unsigned long new_pinned;
89 unsigned long cur_base;
90 struct mm_struct *mm;
91 unsigned long npages;
92 int ret;
93 int i;
94 unsigned long dma_attrs = 0;
95 struct scatterlist *sg, *sg_list_start;
96 unsigned int gup_flags = FOLL_WRITE;
97
98 if (dmasync)
99 dma_attrs |= DMA_ATTR_WRITE_BARRIER;
100
101
102
103
104
105 if (((addr + size) < addr) ||
106 PAGE_ALIGN(addr + size) < (addr + size))
107 return ERR_PTR(-EINVAL);
108
109 if (!can_do_mlock())
110 return ERR_PTR(-EPERM);
111
112 if (access & IB_ACCESS_ON_DEMAND) {
113 umem = kzalloc(sizeof(struct ib_umem_odp), GFP_KERNEL);
114 if (!umem)
115 return ERR_PTR(-ENOMEM);
116 umem->is_odp = 1;
117 } else {
118 umem = kzalloc(sizeof(*umem), GFP_KERNEL);
119 if (!umem)
120 return ERR_PTR(-ENOMEM);
121 }
122
123 umem->context = context;
124 umem->length = size;
125 umem->address = addr;
126 umem->page_shift = PAGE_SHIFT;
127 umem->writable = ib_access_writable(access);
128 umem->owning_mm = mm = current->mm;
129 mmgrab(mm);
130
131 if (access & IB_ACCESS_ON_DEMAND) {
132 ret = ib_umem_odp_get(to_ib_umem_odp(umem), access);
133 if (ret)
134 goto umem_kfree;
135 return umem;
136 }
137
138
139 umem->hugetlb = 1;
140
141 page_list = (struct page **) __get_free_page(GFP_KERNEL);
142 if (!page_list) {
143 ret = -ENOMEM;
144 goto umem_kfree;
145 }
146
147
148
149
150
151 vma_list = (struct vm_area_struct **) __get_free_page(GFP_KERNEL);
152 if (!vma_list)
153 umem->hugetlb = 0;
154
155 npages = ib_umem_num_pages(umem);
156 if (npages == 0 || npages > UINT_MAX) {
157 ret = -EINVAL;
158 goto out;
159 }
160
161 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
162
163 down_write(&mm->mmap_sem);
164 if (check_add_overflow(mm->pinned_vm, npages, &new_pinned) ||
165 (new_pinned > lock_limit && !capable(CAP_IPC_LOCK))) {
166 up_write(&mm->mmap_sem);
167 ret = -ENOMEM;
168 goto out;
169 }
170 mm->pinned_vm = new_pinned;
171 up_write(&mm->mmap_sem);
172
173 cur_base = addr & PAGE_MASK;
174
175 ret = sg_alloc_table(&umem->sg_head, npages, GFP_KERNEL);
176 if (ret)
177 goto vma;
178
179 if (!umem->writable)
180 gup_flags |= FOLL_FORCE;
181
182 sg_list_start = umem->sg_head.sgl;
183
184 while (npages) {
185 down_read(&mm->mmap_sem);
186 ret = get_user_pages_longterm(cur_base,
187 min_t(unsigned long, npages,
188 PAGE_SIZE / sizeof (struct page *)),
189 gup_flags, page_list, vma_list);
190 if (ret < 0) {
191 up_read(&mm->mmap_sem);
192 goto umem_release;
193 }
194
195 umem->npages += ret;
196 cur_base += ret * PAGE_SIZE;
197 npages -= ret;
198
199
200
201
202 for_each_sg(sg_list_start, sg, ret, i) {
203 if (vma_list && !is_vm_hugetlb_page(vma_list[i]))
204 umem->hugetlb = 0;
205
206 sg_set_page(sg, page_list[i], PAGE_SIZE, 0);
207 }
208 up_read(&mm->mmap_sem);
209
210
211 sg_list_start = sg;
212 }
213
214 umem->nmap = ib_dma_map_sg_attrs(context->device,
215 umem->sg_head.sgl,
216 umem->npages,
217 DMA_BIDIRECTIONAL,
218 dma_attrs);
219
220 if (!umem->nmap) {
221 ret = -ENOMEM;
222 goto umem_release;
223 }
224
225 ret = 0;
226 goto out;
227
228umem_release:
229 __ib_umem_release(context->device, umem, 0);
230vma:
231 down_write(&mm->mmap_sem);
232 mm->pinned_vm -= ib_umem_num_pages(umem);
233 up_write(&mm->mmap_sem);
234out:
235 if (vma_list)
236 free_page((unsigned long) vma_list);
237 free_page((unsigned long) page_list);
238umem_kfree:
239 if (ret) {
240 mmdrop(umem->owning_mm);
241 kfree(umem);
242 }
243 return ret ? ERR_PTR(ret) : umem;
244}
245EXPORT_SYMBOL(ib_umem_get);
246
247static void __ib_umem_release_tail(struct ib_umem *umem)
248{
249 mmdrop(umem->owning_mm);
250 if (umem->is_odp)
251 kfree(to_ib_umem_odp(umem));
252 else
253 kfree(umem);
254}
255
256static void ib_umem_release_defer(struct work_struct *work)
257{
258 struct ib_umem *umem = container_of(work, struct ib_umem, work);
259
260 down_write(&umem->owning_mm->mmap_sem);
261 umem->owning_mm->pinned_vm -= ib_umem_num_pages(umem);
262 up_write(&umem->owning_mm->mmap_sem);
263
264 __ib_umem_release_tail(umem);
265}
266
267
268
269
270
271void ib_umem_release(struct ib_umem *umem)
272{
273 struct ib_ucontext *context = umem->context;
274
275 if (umem->is_odp) {
276 ib_umem_odp_release(to_ib_umem_odp(umem));
277 __ib_umem_release_tail(umem);
278 return;
279 }
280
281 __ib_umem_release(umem->context->device, umem, 1);
282
283
284
285
286
287
288
289
290
291 if (context->closing) {
292 if (!down_write_trylock(&umem->owning_mm->mmap_sem)) {
293 INIT_WORK(&umem->work, ib_umem_release_defer);
294 queue_work(ib_wq, &umem->work);
295 return;
296 }
297 } else {
298 down_write(&umem->owning_mm->mmap_sem);
299 }
300 umem->owning_mm->pinned_vm -= ib_umem_num_pages(umem);
301 up_write(&umem->owning_mm->mmap_sem);
302
303 __ib_umem_release_tail(umem);
304}
305EXPORT_SYMBOL(ib_umem_release);
306
307int ib_umem_page_count(struct ib_umem *umem)
308{
309 int i;
310 int n;
311 struct scatterlist *sg;
312
313 if (umem->is_odp)
314 return ib_umem_num_pages(umem);
315
316 n = 0;
317 for_each_sg(umem->sg_head.sgl, sg, umem->nmap, i)
318 n += sg_dma_len(sg) >> umem->page_shift;
319
320 return n;
321}
322EXPORT_SYMBOL(ib_umem_page_count);
323
324
325
326
327
328
329
330
331
332
333
334int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
335 size_t length)
336{
337 size_t end = offset + length;
338 int ret;
339
340 if (offset > umem->length || length > umem->length - offset) {
341 pr_err("ib_umem_copy_from not in range. offset: %zd umem length: %zd end: %zd\n",
342 offset, umem->length, end);
343 return -EINVAL;
344 }
345
346 ret = sg_pcopy_to_buffer(umem->sg_head.sgl, umem->npages, dst, length,
347 offset + ib_umem_offset(umem));
348
349 if (ret < 0)
350 return ret;
351 else if (ret != length)
352 return -EINVAL;
353 else
354 return 0;
355}
356EXPORT_SYMBOL(ib_umem_copy_from);
357