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.
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:
12 * Redistribution and use in source and binary forms, with or
13 * without modification, are permitted provided that the following
16 * - Redistributions of source code must retain the above
17 * copyright notice, this list of conditions and the following
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.
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
34 * $Id: uverbs_mem.c 2743 2005-06-28 22:27:59Z roland $
38 #include <linux/dma-mapping.h>
39 #include <linux/sched.h>
43 static void __ib_umem_release(struct ib_device
*dev
, struct ib_umem
*umem
, int dirty
)
45 struct ib_umem_chunk
*chunk
, *tmp
;
48 list_for_each_entry_safe(chunk
, tmp
, &umem
->chunk_list
, list
) {
49 ib_dma_unmap_sg(dev
, chunk
->page_list
,
50 chunk
->nents
, DMA_BIDIRECTIONAL
);
51 for (i
= 0; i
< chunk
->nents
; ++i
) {
52 if (umem
->writable
&& dirty
)
53 set_page_dirty_lock(chunk
->page_list
[i
].page
);
54 put_page(chunk
->page_list
[i
].page
);
62 * ib_umem_get - Pin and DMA map userspace memory.
63 * @context: userspace context to pin memory for
64 * @addr: userspace virtual address to start at
65 * @size: length of region to pin
66 * @access: IB_ACCESS_xxx flags for memory being pinned
68 struct ib_umem
*ib_umem_get(struct ib_ucontext
*context
, unsigned long addr
,
69 size_t size
, int access
)
72 struct page
**page_list
;
73 struct ib_umem_chunk
*chunk
;
75 unsigned long lock_limit
;
76 unsigned long cur_base
;
83 return ERR_PTR(-EPERM
);
85 umem
= kmalloc(sizeof *umem
, GFP_KERNEL
);
87 return ERR_PTR(-ENOMEM
);
89 umem
->context
= context
;
91 umem
->offset
= addr
& ~PAGE_MASK
;
92 umem
->page_size
= PAGE_SIZE
;
94 * We ask for writable memory if any access flags other than
95 * "remote read" are set. "Local write" and "remote write"
96 * obviously require write access. "Remote atomic" can do
97 * things like fetch and add, which will modify memory, and
98 * "MW bind" can change permissions by binding a window.
100 umem
->writable
= !!(access
& ~IB_ACCESS_REMOTE_READ
);
102 INIT_LIST_HEAD(&umem
->chunk_list
);
104 page_list
= (struct page
**) __get_free_page(GFP_KERNEL
);
107 return ERR_PTR(-ENOMEM
);
110 npages
= PAGE_ALIGN(size
+ umem
->offset
) >> PAGE_SHIFT
;
112 down_write(¤t
->mm
->mmap_sem
);
114 locked
= npages
+ current
->mm
->locked_vm
;
115 lock_limit
= current
->signal
->rlim
[RLIMIT_MEMLOCK
].rlim_cur
>> PAGE_SHIFT
;
117 if ((locked
> lock_limit
) && !capable(CAP_IPC_LOCK
)) {
122 cur_base
= addr
& PAGE_MASK
;
125 ret
= get_user_pages(current
, current
->mm
, cur_base
,
127 PAGE_SIZE
/ sizeof (struct page
*)),
128 1, !umem
->writable
, page_list
, NULL
);
133 cur_base
+= ret
* PAGE_SIZE
;
139 chunk
= kmalloc(sizeof *chunk
+ sizeof (struct scatterlist
) *
140 min_t(int, ret
, IB_UMEM_MAX_PAGE_CHUNK
),
147 chunk
->nents
= min_t(int, ret
, IB_UMEM_MAX_PAGE_CHUNK
);
148 for (i
= 0; i
< chunk
->nents
; ++i
) {
149 chunk
->page_list
[i
].page
= page_list
[i
+ off
];
150 chunk
->page_list
[i
].offset
= 0;
151 chunk
->page_list
[i
].length
= PAGE_SIZE
;
154 chunk
->nmap
= ib_dma_map_sg(context
->device
,
155 &chunk
->page_list
[0],
158 if (chunk
->nmap
<= 0) {
159 for (i
= 0; i
< chunk
->nents
; ++i
)
160 put_page(chunk
->page_list
[i
].page
);
169 list_add_tail(&chunk
->list
, &umem
->chunk_list
);
177 __ib_umem_release(context
->device
, umem
, 0);
180 current
->mm
->locked_vm
= locked
;
182 up_write(¤t
->mm
->mmap_sem
);
183 free_page((unsigned long) page_list
);
185 return ret
< 0 ? ERR_PTR(ret
) : umem
;
187 EXPORT_SYMBOL(ib_umem_get
);
189 static void ib_umem_account(struct work_struct
*work
)
191 struct ib_umem
*umem
= container_of(work
, struct ib_umem
, work
);
193 down_write(&umem
->mm
->mmap_sem
);
194 umem
->mm
->locked_vm
-= umem
->diff
;
195 up_write(&umem
->mm
->mmap_sem
);
201 * ib_umem_release - release memory pinned with ib_umem_get
202 * @umem: umem struct to release
204 void ib_umem_release(struct ib_umem
*umem
)
206 struct ib_ucontext
*context
= umem
->context
;
207 struct mm_struct
*mm
;
210 __ib_umem_release(umem
->context
->device
, umem
, 1);
212 mm
= get_task_mm(current
);
216 diff
= PAGE_ALIGN(umem
->length
+ umem
->offset
) >> PAGE_SHIFT
;
219 * We may be called with the mm's mmap_sem already held. This
220 * can happen when a userspace munmap() is the call that drops
221 * the last reference to our file and calls our release
222 * method. If there are memory regions to destroy, we'll end
223 * up here and not be able to take the mmap_sem. In that case
224 * we defer the vm_locked accounting to the system workqueue.
226 if (context
->closing
&& !down_write_trylock(&mm
->mmap_sem
)) {
227 INIT_WORK(&umem
->work
, ib_umem_account
);
231 schedule_work(&umem
->work
);
234 down_write(&mm
->mmap_sem
);
236 current
->mm
->locked_vm
-= diff
;
237 up_write(&mm
->mmap_sem
);
241 EXPORT_SYMBOL(ib_umem_release
);
243 int ib_umem_page_count(struct ib_umem
*umem
)
245 struct ib_umem_chunk
*chunk
;
250 shift
= ilog2(umem
->page_size
);
253 list_for_each_entry(chunk
, &umem
->chunk_list
, list
)
254 for (i
= 0; i
< chunk
->nmap
; ++i
)
255 n
+= sg_dma_len(&chunk
->page_list
[i
]) >> shift
;
259 EXPORT_SYMBOL(ib_umem_page_count
);