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
36 #include <linux/dma-mapping.h>
37 #include <linux/sched.h>
38 #include <linux/export.h>
39 #include <linux/hugetlb.h>
40 #include <linux/dma-attrs.h>
41 #include <linux/slab.h>
46 static void __ib_umem_release(struct ib_device
*dev
, struct ib_umem
*umem
, int dirty
)
48 struct scatterlist
*sg
;
53 ib_dma_unmap_sg(dev
, umem
->sg_head
.sgl
,
57 for_each_sg(umem
->sg_head
.sgl
, sg
, umem
->npages
, i
) {
60 if (umem
->writable
&& dirty
)
61 set_page_dirty_lock(page
);
65 sg_free_table(&umem
->sg_head
);
71 * ib_umem_get - Pin and DMA map userspace memory.
72 * @context: userspace context to pin memory for
73 * @addr: userspace virtual address to start at
74 * @size: length of region to pin
75 * @access: IB_ACCESS_xxx flags for memory being pinned
76 * @dmasync: flush in-flight DMA when the memory region is written
78 struct ib_umem
*ib_umem_get(struct ib_ucontext
*context
, unsigned long addr
,
79 size_t size
, int access
, int dmasync
)
82 struct page
**page_list
;
83 struct vm_area_struct
**vma_list
;
85 unsigned long lock_limit
;
86 unsigned long cur_base
;
90 DEFINE_DMA_ATTRS(attrs
);
91 struct scatterlist
*sg
, *sg_list_start
;
95 dma_set_attr(DMA_ATTR_WRITE_BARRIER
, &attrs
);
98 return ERR_PTR(-EPERM
);
100 umem
= kzalloc(sizeof *umem
, GFP_KERNEL
);
102 return ERR_PTR(-ENOMEM
);
104 umem
->context
= context
;
106 umem
->address
= addr
;
107 umem
->page_size
= PAGE_SIZE
;
108 umem
->pid
= get_task_pid(current
, PIDTYPE_PID
);
110 * We ask for writable memory if any of the following
111 * access flags are set. "Local write" and "remote write"
112 * obviously require write access. "Remote atomic" can do
113 * things like fetch and add, which will modify memory, and
114 * "MW bind" can change permissions by binding a window.
116 umem
->writable
= !!(access
&
117 (IB_ACCESS_LOCAL_WRITE
| IB_ACCESS_REMOTE_WRITE
|
118 IB_ACCESS_REMOTE_ATOMIC
| IB_ACCESS_MW_BIND
));
120 /* We assume the memory is from hugetlb until proved otherwise */
123 page_list
= (struct page
**) __get_free_page(GFP_KERNEL
);
126 return ERR_PTR(-ENOMEM
);
130 * if we can't alloc the vma_list, it's not so bad;
131 * just assume the memory is not hugetlb memory
133 vma_list
= (struct vm_area_struct
**) __get_free_page(GFP_KERNEL
);
137 npages
= ib_umem_num_pages(umem
);
139 down_write(¤t
->mm
->mmap_sem
);
141 locked
= npages
+ current
->mm
->pinned_vm
;
142 lock_limit
= rlimit(RLIMIT_MEMLOCK
) >> PAGE_SHIFT
;
144 if ((locked
> lock_limit
) && !capable(CAP_IPC_LOCK
)) {
149 cur_base
= addr
& PAGE_MASK
;
156 ret
= sg_alloc_table(&umem
->sg_head
, npages
, GFP_KERNEL
);
161 sg_list_start
= umem
->sg_head
.sgl
;
164 ret
= get_user_pages(current
, current
->mm
, cur_base
,
165 min_t(unsigned long, npages
,
166 PAGE_SIZE
/ sizeof (struct page
*)),
167 1, !umem
->writable
, page_list
, vma_list
);
173 cur_base
+= ret
* PAGE_SIZE
;
176 for_each_sg(sg_list_start
, sg
, ret
, i
) {
177 if (vma_list
&& !is_vm_hugetlb_page(vma_list
[i
]))
180 sg_set_page(sg
, page_list
[i
], PAGE_SIZE
, 0);
183 /* preparing for next loop */
187 umem
->nmap
= ib_dma_map_sg_attrs(context
->device
,
193 if (umem
->nmap
<= 0) {
203 __ib_umem_release(context
->device
, umem
, 0);
207 current
->mm
->pinned_vm
= locked
;
209 up_write(¤t
->mm
->mmap_sem
);
211 free_page((unsigned long) vma_list
);
212 free_page((unsigned long) page_list
);
214 return ret
< 0 ? ERR_PTR(ret
) : umem
;
216 EXPORT_SYMBOL(ib_umem_get
);
218 static void ib_umem_account(struct work_struct
*work
)
220 struct ib_umem
*umem
= container_of(work
, struct ib_umem
, work
);
222 down_write(&umem
->mm
->mmap_sem
);
223 umem
->mm
->pinned_vm
-= umem
->diff
;
224 up_write(&umem
->mm
->mmap_sem
);
230 * ib_umem_release - release memory pinned with ib_umem_get
231 * @umem: umem struct to release
233 void ib_umem_release(struct ib_umem
*umem
)
235 struct ib_ucontext
*context
= umem
->context
;
236 struct mm_struct
*mm
;
237 struct task_struct
*task
;
240 __ib_umem_release(umem
->context
->device
, umem
, 1);
242 task
= get_pid_task(umem
->pid
, PIDTYPE_PID
);
246 mm
= get_task_mm(task
);
247 put_task_struct(task
);
251 diff
= ib_umem_num_pages(umem
);
254 * We may be called with the mm's mmap_sem already held. This
255 * can happen when a userspace munmap() is the call that drops
256 * the last reference to our file and calls our release
257 * method. If there are memory regions to destroy, we'll end
258 * up here and not be able to take the mmap_sem. In that case
259 * we defer the vm_locked accounting to the system workqueue.
261 if (context
->closing
) {
262 if (!down_write_trylock(&mm
->mmap_sem
)) {
263 INIT_WORK(&umem
->work
, ib_umem_account
);
267 queue_work(ib_wq
, &umem
->work
);
271 down_write(&mm
->mmap_sem
);
273 mm
->pinned_vm
-= diff
;
274 up_write(&mm
->mmap_sem
);
279 EXPORT_SYMBOL(ib_umem_release
);
281 int ib_umem_page_count(struct ib_umem
*umem
)
286 struct scatterlist
*sg
;
288 shift
= ilog2(umem
->page_size
);
291 for_each_sg(umem
->sg_head
.sgl
, sg
, umem
->nmap
, i
)
292 n
+= sg_dma_len(sg
) >> shift
;
296 EXPORT_SYMBOL(ib_umem_page_count
);
299 * Copy from the given ib_umem's pages to the given buffer.
301 * umem - the umem to copy from
302 * offset - offset to start copying from
303 * dst - destination buffer
304 * length - buffer length
306 * Returns 0 on success, or an error code.
308 int ib_umem_copy_from(void *dst
, struct ib_umem
*umem
, size_t offset
,
311 size_t end
= offset
+ length
;
314 if (offset
> umem
->length
|| length
> umem
->length
- offset
) {
315 pr_err("ib_umem_copy_from not in range. offset: %zd umem length: %zd end: %zd\n",
316 offset
, umem
->length
, end
);
320 ret
= sg_pcopy_to_buffer(umem
->sg_head
.sgl
, umem
->nmap
, dst
, length
,
321 offset
+ ib_umem_offset(umem
));
325 else if (ret
!= length
)
330 EXPORT_SYMBOL(ib_umem_copy_from
);
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