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35#include <linux/mm.h>
36#include <linux/dma-mapping.h>
37#include <linux/sched.h>
38#include <linux/hugetlb.h>
39#include <linux/dma-attrs.h>
40
41#include "uverbs.h"
42
43#define IB_UMEM_MAX_PAGE_CHUNK \
44 ((PAGE_SIZE - offsetof(struct ib_umem_chunk, page_list)) / \
45 ((void *) &((struct ib_umem_chunk *) 0)->page_list[1] - \
46 (void *) &((struct ib_umem_chunk *) 0)->page_list[0]))
47
48static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty)
49{
50 struct ib_umem_chunk *chunk, *tmp;
51 int i;
52
53 list_for_each_entry_safe(chunk, tmp, &umem->chunk_list, list) {
54 ib_dma_unmap_sg(dev, chunk->page_list,
55 chunk->nents, DMA_BIDIRECTIONAL);
56 for (i = 0; i < chunk->nents; ++i) {
57 struct page *page = sg_page(&chunk->page_list[i]);
58
59 if (umem->writable && dirty)
60 set_page_dirty_lock(page);
61 put_page(page);
62 }
63
64 kfree(chunk);
65 }
66}
67
68
69
70
71
72
73
74
75
76struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
77 size_t size, int access, int dmasync)
78{
79 struct ib_umem *umem;
80 struct page **page_list;
81 struct vm_area_struct **vma_list;
82 struct ib_umem_chunk *chunk;
83 unsigned long locked;
84 unsigned long lock_limit;
85 unsigned long cur_base;
86 unsigned long npages;
87 int ret;
88 int off;
89 int i;
90 DEFINE_DMA_ATTRS(attrs);
91
92 if (dmasync)
93 dma_set_attr(DMA_ATTR_WRITE_BARRIER, &attrs);
94
95 if (!can_do_mlock())
96 return ERR_PTR(-EPERM);
97
98 umem = kmalloc(sizeof *umem, GFP_KERNEL);
99 if (!umem)
100 return ERR_PTR(-ENOMEM);
101
102 umem->context = context;
103 umem->length = size;
104 umem->offset = addr & ~PAGE_MASK;
105 umem->page_size = PAGE_SIZE;
106
107
108
109
110
111
112
113 umem->writable = !!(access & ~IB_ACCESS_REMOTE_READ);
114
115
116 umem->hugetlb = 1;
117
118 INIT_LIST_HEAD(&umem->chunk_list);
119
120 page_list = (struct page **) __get_free_page(GFP_KERNEL);
121 if (!page_list) {
122 kfree(umem);
123 return ERR_PTR(-ENOMEM);
124 }
125
126
127
128
129
130 vma_list = (struct vm_area_struct **) __get_free_page(GFP_KERNEL);
131 if (!vma_list)
132 umem->hugetlb = 0;
133
134 npages = PAGE_ALIGN(size + umem->offset) >> PAGE_SHIFT;
135
136 down_write(¤t->mm->mmap_sem);
137
138 locked = npages + current->mm->locked_vm;
139 lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur >> PAGE_SHIFT;
140
141 if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) {
142 ret = -ENOMEM;
143 goto out;
144 }
145
146 cur_base = addr & PAGE_MASK;
147
148 ret = 0;
149 while (npages) {
150 ret = get_user_pages(current, current->mm, cur_base,
151 min_t(unsigned long, npages,
152 PAGE_SIZE / sizeof (struct page *)),
153 1, !umem->writable, page_list, vma_list);
154
155 if (ret < 0)
156 goto out;
157
158 cur_base += ret * PAGE_SIZE;
159 npages -= ret;
160
161 off = 0;
162
163 while (ret) {
164 chunk = kmalloc(sizeof *chunk + sizeof (struct scatterlist) *
165 min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK),
166 GFP_KERNEL);
167 if (!chunk) {
168 ret = -ENOMEM;
169 goto out;
170 }
171
172 chunk->nents = min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK);
173 sg_init_table(chunk->page_list, chunk->nents);
174 for (i = 0; i < chunk->nents; ++i) {
175 if (vma_list &&
176 !is_vm_hugetlb_page(vma_list[i + off]))
177 umem->hugetlb = 0;
178 sg_set_page(&chunk->page_list[i], page_list[i + off], PAGE_SIZE, 0);
179 }
180
181 chunk->nmap = ib_dma_map_sg_attrs(context->device,
182 &chunk->page_list[0],
183 chunk->nents,
184 DMA_BIDIRECTIONAL,
185 &attrs);
186 if (chunk->nmap <= 0) {
187 for (i = 0; i < chunk->nents; ++i)
188 put_page(sg_page(&chunk->page_list[i]));
189 kfree(chunk);
190
191 ret = -ENOMEM;
192 goto out;
193 }
194
195 ret -= chunk->nents;
196 off += chunk->nents;
197 list_add_tail(&chunk->list, &umem->chunk_list);
198 }
199
200 ret = 0;
201 }
202
203out:
204 if (ret < 0) {
205 __ib_umem_release(context->device, umem, 0);
206 kfree(umem);
207 } else
208 current->mm->locked_vm = locked;
209
210 up_write(¤t->mm->mmap_sem);
211 if (vma_list)
212 free_page((unsigned long) vma_list);
213 free_page((unsigned long) page_list);
214
215 return ret < 0 ? ERR_PTR(ret) : umem;
216}
217EXPORT_SYMBOL(ib_umem_get);
218
219static void ib_umem_account(struct work_struct *work)
220{
221 struct ib_umem *umem = container_of(work, struct ib_umem, work);
222
223 down_write(&umem->mm->mmap_sem);
224 umem->mm->locked_vm -= umem->diff;
225 up_write(&umem->mm->mmap_sem);
226 mmput(umem->mm);
227 kfree(umem);
228}
229
230
231
232
233
234void ib_umem_release(struct ib_umem *umem)
235{
236 struct ib_ucontext *context = umem->context;
237 struct mm_struct *mm;
238 unsigned long diff;
239
240 __ib_umem_release(umem->context->device, umem, 1);
241
242 mm = get_task_mm(current);
243 if (!mm) {
244 kfree(umem);
245 return;
246 }
247
248 diff = PAGE_ALIGN(umem->length + umem->offset) >> PAGE_SHIFT;
249
250
251
252
253
254
255
256
257
258 if (context->closing) {
259 if (!down_write_trylock(&mm->mmap_sem)) {
260 INIT_WORK(&umem->work, ib_umem_account);
261 umem->mm = mm;
262 umem->diff = diff;
263
264 schedule_work(&umem->work);
265 return;
266 }
267 } else
268 down_write(&mm->mmap_sem);
269
270 current->mm->locked_vm -= diff;
271 up_write(&mm->mmap_sem);
272 mmput(mm);
273 kfree(umem);
274}
275EXPORT_SYMBOL(ib_umem_release);
276
277int ib_umem_page_count(struct ib_umem *umem)
278{
279 struct ib_umem_chunk *chunk;
280 int shift;
281 int i;
282 int n;
283
284 shift = ilog2(umem->page_size);
285
286 n = 0;
287 list_for_each_entry(chunk, &umem->chunk_list, list)
288 for (i = 0; i < chunk->nmap; ++i)
289 n += sg_dma_len(&chunk->page_list[i]) >> shift;
290
291 return n;
292}
293EXPORT_SYMBOL(ib_umem_page_count);
294