include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit...
[linux-3.10.git] / drivers / infiniband / core / umem.c
1 /*
2  * Copyright (c) 2005 Topspin Communications.  All rights reserved.
3  * Copyright (c) 2005 Cisco Systems.  All rights reserved.
4  * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
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
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 #include <linux/slab.h>
41
42 #include "uverbs.h"
43
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
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) {
55                 ib_dma_unmap_sg(dev, chunk->page_list,
56                                 chunk->nents, DMA_BIDIRECTIONAL);
57                 for (i = 0; i < chunk->nents; ++i) {
58                         struct page *page = sg_page(&chunk->page_list[i]);
59
60                         if (umem->writable && dirty)
61                                 set_page_dirty_lock(page);
62                         put_page(page);
63                 }
64
65                 kfree(chunk);
66         }
67 }
68
69 /**
70  * ib_umem_get - Pin and DMA map userspace memory.
71  * @context: userspace context to pin memory for
72  * @addr: userspace virtual address to start at
73  * @size: length of region to pin
74  * @access: IB_ACCESS_xxx flags for memory being pinned
75  * @dmasync: flush in-flight DMA when the memory region is written
76  */
77 struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
78                             size_t size, int access, int dmasync)
79 {
80         struct ib_umem *umem;
81         struct page **page_list;
82         struct vm_area_struct **vma_list;
83         struct ib_umem_chunk *chunk;
84         unsigned long locked;
85         unsigned long lock_limit;
86         unsigned long cur_base;
87         unsigned long npages;
88         int ret;
89         int off;
90         int i;
91         DEFINE_DMA_ATTRS(attrs);
92
93         if (dmasync)
94                 dma_set_attr(DMA_ATTR_WRITE_BARRIER, &attrs);
95
96         if (!can_do_mlock())
97                 return ERR_PTR(-EPERM);
98
99         umem = kmalloc(sizeof *umem, GFP_KERNEL);
100         if (!umem)
101                 return ERR_PTR(-ENOMEM);
102
103         umem->context   = context;
104         umem->length    = size;
105         umem->offset    = addr & ~PAGE_MASK;
106         umem->page_size = PAGE_SIZE;
107         /*
108          * We ask for writable memory if any access flags other than
109          * "remote read" are set.  "Local write" and "remote write"
110          * obviously require write access.  "Remote atomic" can do
111          * things like fetch and add, which will modify memory, and
112          * "MW bind" can change permissions by binding a window.
113          */
114         umem->writable  = !!(access & ~IB_ACCESS_REMOTE_READ);
115
116         /* We assume the memory is from hugetlb until proved otherwise */
117         umem->hugetlb   = 1;
118
119         INIT_LIST_HEAD(&umem->chunk_list);
120
121         page_list = (struct page **) __get_free_page(GFP_KERNEL);
122         if (!page_list) {
123                 kfree(umem);
124                 return ERR_PTR(-ENOMEM);
125         }
126
127         /*
128          * if we can't alloc the vma_list, it's not so bad;
129          * just assume the memory is not hugetlb memory
130          */
131         vma_list = (struct vm_area_struct **) __get_free_page(GFP_KERNEL);
132         if (!vma_list)
133                 umem->hugetlb = 0;
134
135         npages = PAGE_ALIGN(size + umem->offset) >> PAGE_SHIFT;
136
137         down_write(&current->mm->mmap_sem);
138
139         locked     = npages + current->mm->locked_vm;
140         lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
141
142         if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) {
143                 ret = -ENOMEM;
144                 goto out;
145         }
146
147         cur_base = addr & PAGE_MASK;
148
149         ret = 0;
150         while (npages) {
151                 ret = get_user_pages(current, current->mm, cur_base,
152                                      min_t(unsigned long, npages,
153                                            PAGE_SIZE / sizeof (struct page *)),
154                                      1, !umem->writable, page_list, vma_list);
155
156                 if (ret < 0)
157                         goto out;
158
159                 cur_base += ret * PAGE_SIZE;
160                 npages   -= ret;
161
162                 off = 0;
163
164                 while (ret) {
165                         chunk = kmalloc(sizeof *chunk + sizeof (struct scatterlist) *
166                                         min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK),
167                                         GFP_KERNEL);
168                         if (!chunk) {
169                                 ret = -ENOMEM;
170                                 goto out;
171                         }
172
173                         chunk->nents = min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK);
174                         sg_init_table(chunk->page_list, chunk->nents);
175                         for (i = 0; i < chunk->nents; ++i) {
176                                 if (vma_list &&
177                                     !is_vm_hugetlb_page(vma_list[i + off]))
178                                         umem->hugetlb = 0;
179                                 sg_set_page(&chunk->page_list[i], page_list[i + off], PAGE_SIZE, 0);
180                         }
181
182                         chunk->nmap = ib_dma_map_sg_attrs(context->device,
183                                                           &chunk->page_list[0],
184                                                           chunk->nents,
185                                                           DMA_BIDIRECTIONAL,
186                                                           &attrs);
187                         if (chunk->nmap <= 0) {
188                                 for (i = 0; i < chunk->nents; ++i)
189                                         put_page(sg_page(&chunk->page_list[i]));
190                                 kfree(chunk);
191
192                                 ret = -ENOMEM;
193                                 goto out;
194                         }
195
196                         ret -= chunk->nents;
197                         off += chunk->nents;
198                         list_add_tail(&chunk->list, &umem->chunk_list);
199                 }
200
201                 ret = 0;
202         }
203
204 out:
205         if (ret < 0) {
206                 __ib_umem_release(context->device, umem, 0);
207                 kfree(umem);
208         } else
209                 current->mm->locked_vm = locked;
210
211         up_write(&current->mm->mmap_sem);
212         if (vma_list)
213                 free_page((unsigned long) vma_list);
214         free_page((unsigned long) page_list);
215
216         return ret < 0 ? ERR_PTR(ret) : umem;
217 }
218 EXPORT_SYMBOL(ib_umem_get);
219
220 static void ib_umem_account(struct work_struct *work)
221 {
222         struct ib_umem *umem = container_of(work, struct ib_umem, work);
223
224         down_write(&umem->mm->mmap_sem);
225         umem->mm->locked_vm -= umem->diff;
226         up_write(&umem->mm->mmap_sem);
227         mmput(umem->mm);
228         kfree(umem);
229 }
230
231 /**
232  * ib_umem_release - release memory pinned with ib_umem_get
233  * @umem: umem struct to release
234  */
235 void ib_umem_release(struct ib_umem *umem)
236 {
237         struct ib_ucontext *context = umem->context;
238         struct mm_struct *mm;
239         unsigned long diff;
240
241         __ib_umem_release(umem->context->device, umem, 1);
242
243         mm = get_task_mm(current);
244         if (!mm) {
245                 kfree(umem);
246                 return;
247         }
248
249         diff = PAGE_ALIGN(umem->length + umem->offset) >> PAGE_SHIFT;
250
251         /*
252          * We may be called with the mm's mmap_sem already held.  This
253          * can happen when a userspace munmap() is the call that drops
254          * the last reference to our file and calls our release
255          * method.  If there are memory regions to destroy, we'll end
256          * up here and not be able to take the mmap_sem.  In that case
257          * we defer the vm_locked accounting to the system workqueue.
258          */
259         if (context->closing) {
260                 if (!down_write_trylock(&mm->mmap_sem)) {
261                         INIT_WORK(&umem->work, ib_umem_account);
262                         umem->mm   = mm;
263                         umem->diff = diff;
264
265                         schedule_work(&umem->work);
266                         return;
267                 }
268         } else
269                 down_write(&mm->mmap_sem);
270
271         current->mm->locked_vm -= diff;
272         up_write(&mm->mmap_sem);
273         mmput(mm);
274         kfree(umem);
275 }
276 EXPORT_SYMBOL(ib_umem_release);
277
278 int ib_umem_page_count(struct ib_umem *umem)
279 {
280         struct ib_umem_chunk *chunk;
281         int shift;
282         int i;
283         int n;
284
285         shift = ilog2(umem->page_size);
286
287         n = 0;
288         list_for_each_entry(chunk, &umem->chunk_list, list)
289                 for (i = 0; i < chunk->nmap; ++i)
290                         n += sg_dma_len(&chunk->page_list[i]) >> shift;
291
292         return n;
293 }
294 EXPORT_SYMBOL(ib_umem_page_count);