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>
45 #define IB_UMEM_MAX_PAGE_CHUNK \
46 ((PAGE_SIZE - offsetof(struct ib_umem_chunk, page_list)) / \
47 ((void *) &((struct ib_umem_chunk *) 0)->page_list[1] - \
48 (void *) &((struct ib_umem_chunk *) 0)->page_list[0]))
50 static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty)
52 struct ib_umem_chunk *chunk, *tmp;
55 list_for_each_entry_safe(chunk, tmp, &umem->chunk_list, list) {
56 ib_dma_unmap_sg(dev, chunk->page_list,
57 chunk->nents, DMA_BIDIRECTIONAL);
58 for (i = 0; i < chunk->nents; ++i) {
59 struct page *page = sg_page(&chunk->page_list[i]);
61 if (umem->writable && dirty)
62 set_page_dirty_lock(page);
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;
84 struct ib_umem_chunk *chunk;
86 unsigned long lock_limit;
87 unsigned long cur_base;
92 DEFINE_DMA_ATTRS(attrs);
95 dma_set_attr(DMA_ATTR_WRITE_BARRIER, &attrs);
98 return ERR_PTR(-EINVAL);
101 * If the combination of the addr and size requested for this memory
102 * region causes an integer overflow, return error.
104 if (((addr + size) < addr) ||
105 PAGE_ALIGN(addr + size) < (addr + size))
106 return ERR_PTR(-EINVAL);
109 return ERR_PTR(-EPERM);
111 umem = kmalloc(sizeof *umem, GFP_KERNEL);
113 return ERR_PTR(-ENOMEM);
115 umem->context = context;
117 umem->offset = addr & ~PAGE_MASK;
118 umem->page_size = PAGE_SIZE;
120 * We ask for writable memory if any access flags other than
121 * "remote read" are set. "Local write" and "remote write"
122 * obviously require write access. "Remote atomic" can do
123 * things like fetch and add, which will modify memory, and
124 * "MW bind" can change permissions by binding a window.
126 umem->writable = !!(access & ~IB_ACCESS_REMOTE_READ);
128 /* We assume the memory is from hugetlb until proved otherwise */
131 INIT_LIST_HEAD(&umem->chunk_list);
133 page_list = (struct page **) __get_free_page(GFP_KERNEL);
136 return ERR_PTR(-ENOMEM);
140 * if we can't alloc the vma_list, it's not so bad;
141 * just assume the memory is not hugetlb memory
143 vma_list = (struct vm_area_struct **) __get_free_page(GFP_KERNEL);
147 npages = PAGE_ALIGN(size + umem->offset) >> PAGE_SHIFT;
149 down_write(¤t->mm->mmap_sem);
151 locked = npages + current->mm->pinned_vm;
152 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
154 if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) {
159 cur_base = addr & PAGE_MASK;
163 ret = get_user_pages(current, current->mm, cur_base,
164 min_t(unsigned long, npages,
165 PAGE_SIZE / sizeof (struct page *)),
166 1, !umem->writable, page_list, vma_list);
171 cur_base += ret * PAGE_SIZE;
177 chunk = kmalloc(sizeof *chunk + sizeof (struct scatterlist) *
178 min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK),
185 chunk->nents = min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK);
186 sg_init_table(chunk->page_list, chunk->nents);
187 for (i = 0; i < chunk->nents; ++i) {
189 !is_vm_hugetlb_page(vma_list[i + off]))
191 sg_set_page(&chunk->page_list[i], page_list[i + off], PAGE_SIZE, 0);
194 chunk->nmap = ib_dma_map_sg_attrs(context->device,
195 &chunk->page_list[0],
199 if (chunk->nmap <= 0) {
200 for (i = 0; i < chunk->nents; ++i)
201 put_page(sg_page(&chunk->page_list[i]));
210 list_add_tail(&chunk->list, &umem->chunk_list);
218 __ib_umem_release(context->device, umem, 0);
221 current->mm->pinned_vm = locked;
223 up_write(¤t->mm->mmap_sem);
225 free_page((unsigned long) vma_list);
226 free_page((unsigned long) page_list);
228 return ret < 0 ? ERR_PTR(ret) : umem;
230 EXPORT_SYMBOL(ib_umem_get);
232 static void ib_umem_account(struct work_struct *work)
234 struct ib_umem *umem = container_of(work, struct ib_umem, work);
236 down_write(&umem->mm->mmap_sem);
237 umem->mm->pinned_vm -= umem->diff;
238 up_write(&umem->mm->mmap_sem);
244 * ib_umem_release - release memory pinned with ib_umem_get
245 * @umem: umem struct to release
247 void ib_umem_release(struct ib_umem *umem)
249 struct ib_ucontext *context = umem->context;
250 struct mm_struct *mm;
253 __ib_umem_release(umem->context->device, umem, 1);
255 mm = get_task_mm(current);
261 diff = PAGE_ALIGN(umem->length + umem->offset) >> PAGE_SHIFT;
264 * We may be called with the mm's mmap_sem already held. This
265 * can happen when a userspace munmap() is the call that drops
266 * the last reference to our file and calls our release
267 * method. If there are memory regions to destroy, we'll end
268 * up here and not be able to take the mmap_sem. In that case
269 * we defer the vm_locked accounting to the system workqueue.
271 if (context->closing) {
272 if (!down_write_trylock(&mm->mmap_sem)) {
273 INIT_WORK(&umem->work, ib_umem_account);
277 queue_work(ib_wq, &umem->work);
281 down_write(&mm->mmap_sem);
283 current->mm->pinned_vm -= diff;
284 up_write(&mm->mmap_sem);
288 EXPORT_SYMBOL(ib_umem_release);
290 int ib_umem_page_count(struct ib_umem *umem)
292 struct ib_umem_chunk *chunk;
297 shift = ilog2(umem->page_size);
300 list_for_each_entry(chunk, &umem->chunk_list, list)
301 for (i = 0; i < chunk->nmap; ++i)
302 n += sg_dma_len(&chunk->page_list[i]) >> shift;
306 EXPORT_SYMBOL(ib_umem_page_count);