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/drivers/infiniband/core/umem.c

https://bitbucket.org/ndreys/linux-sunxi
C | 294 lines | 182 code | 47 blank | 65 comment | 24 complexity | ba23705b45d9d9bfdfdee8b81aa9219c MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
  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
 49static 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 */
 77struct 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
204out:
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}
218EXPORT_SYMBOL(ib_umem_get);
219
220static 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 */
235void 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			queue_work(ib_wq, &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}
276EXPORT_SYMBOL(ib_umem_release);
277
278int 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}
294EXPORT_SYMBOL(ib_umem_page_count);