drivers/infiniband/core/uverbs_mem.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  * $Id: uverbs_mem.c 2743 2005-06-28 22:27:59Z roland $
  35  */
  36
  37 #include <linux/mm.h>
  38 #include <linux/dma-mapping.h>
  39
  40 #include "uverbs.h"
  41
  42 struct ib_umem_account_work {
  43         struct work_struct work;
  44         struct mm_struct  *mm;
  45         unsigned long      diff;
  46 };
  47
  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                         if (umem->writable && dirty)
  59                                 set_page_dirty_lock(chunk->page_list[i].page);
  60                         put_page(chunk->page_list[i].page);
  61                 }
  62
  63                 kfree(chunk);
  64         }
  65 }
  66
  67 int ib_umem_get(struct ib_device *dev, struct ib_umem *mem,
  68                 void *addr, size_t size, int write)
  69 {
  70         struct page **page_list;
  71         struct ib_umem_chunk *chunk;
  72         unsigned long locked;
  73         unsigned long lock_limit;
  74         unsigned long cur_base;
  75         unsigned long npages;
  76         int ret = 0;
  77         int off;
  78         int i;
  79
  80         if (!can_do_mlock())
  81                 return -EPERM;
  82
  83         page_list = (struct page **) __get_free_page(GFP_KERNEL);
  84         if (!page_list)
  85                 return -ENOMEM;
  86
  87         mem->user_base = (unsigned long) addr;
  88         mem->length    = size;
  89         mem->offset    = (unsigned long) addr & ~PAGE_MASK;
  90         mem->page_size = PAGE_SIZE;
  91         mem->writable  = write;
  92
  93         INIT_LIST_HEAD(&mem->chunk_list);
  94
  95         npages = PAGE_ALIGN(size + mem->offset) >> PAGE_SHIFT;
  96
  97         down_write(&current->mm->mmap_sem);
  98
  99         locked     = npages + current->mm->locked_vm;
 100         lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur >> PAGE_SHIFT;
 101
 102         if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) {
 103                 ret = -ENOMEM;
 104                 goto out;
 105         }
 106
 107         cur_base = (unsigned long) addr & PAGE_MASK;
 108
 109         while (npages) {
 110                 ret = get_user_pages(current, current->mm, cur_base,
 111                                      min_t(int, npages,
 112                                            PAGE_SIZE / sizeof (struct page *)),
 113                                      1, !write, page_list, NULL);
 114
 115                 if (ret < 0)
 116                         goto out;
 117
 118                 cur_base += ret * PAGE_SIZE;
 119                 npages   -= ret;
 120
 121                 off = 0;
 122
 123                 while (ret) {
 124                         chunk = kmalloc(sizeof *chunk + sizeof (struct scatterlist) *
 125                                         min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK),
 126                                         GFP_KERNEL);
 127                         if (!chunk) {
 128                                 ret = -ENOMEM;
 129                                 goto out;
 130                         }
 131
 132                         chunk->nents = min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK);
 133                         for (i = 0; i < chunk->nents; ++i) {
 134                                 chunk->page_list[i].page   = page_list[i + off];
 135                                 chunk->page_list[i].offset = 0;
 136                                 chunk->page_list[i].length = PAGE_SIZE;
 137                         }
 138
 139                         chunk->nmap = ib_dma_map_sg(dev,
 140                                                     &chunk->page_list[0],
 141                                                     chunk->nents,
 142                                                     DMA_BIDIRECTIONAL);
 143                         if (chunk->nmap <= 0) {
 144                                 for (i = 0; i < chunk->nents; ++i)
 145                                         put_page(chunk->page_list[i].page);
 146                                 kfree(chunk);
 147
 148                                 ret = -ENOMEM;
 149                                 goto out;
 150                         }
 151
 152                         ret -= chunk->nents;
 153                         off += chunk->nents;
 154                         list_add_tail(&chunk->list, &mem->chunk_list);
 155                 }
 156
 157                 ret = 0;
 158         }
 159
 160 out:
 161         if (ret < 0)
 162                 __ib_umem_release(dev, mem, 0);
 163         else
 164                 current->mm->locked_vm = locked;
 165
 166         up_write(&current->mm->mmap_sem);
 167         free_page((unsigned long) page_list);
 168
 169         return ret;
 170 }
 171
 172 void ib_umem_release(struct ib_device *dev, struct ib_umem *umem)
 173 {
 174         __ib_umem_release(dev, umem, 1);
 175
 176         down_write(&current->mm->mmap_sem);
 177         current->mm->locked_vm -=
 178                 PAGE_ALIGN(umem->length + umem->offset) >> PAGE_SHIFT;
 179         up_write(&current->mm->mmap_sem);
 180 }
 181
 182 static void ib_umem_account(struct work_struct *_work)
 183 {
 184         struct ib_umem_account_work *work =
 185                 container_of(_work, struct ib_umem_account_work, work);
 186
 187         down_write(&work->mm->mmap_sem);
 188         work->mm->locked_vm -= work->diff;
 189         up_write(&work->mm->mmap_sem);
 190         mmput(work->mm);
 191         kfree(work);
 192 }
 193
 194 void ib_umem_release_on_close(struct ib_device *dev, struct ib_umem *umem)
 195 {
 196         struct ib_umem_account_work *work;
 197         struct mm_struct *mm;
 198
 199         __ib_umem_release(dev, umem, 1);
 200
 201         mm = get_task_mm(current);
 202         if (!mm)
 203                 return;
 204
 205         /*
 206          * We may be called with the mm's mmap_sem already held.  This
 207          * can happen when a userspace munmap() is the call that drops
 208          * the last reference to our file and calls our release
 209          * method.  If there are memory regions to destroy, we'll end
 210          * up here and not be able to take the mmap_sem.  Therefore we
 211          * defer the vm_locked accounting to the system workqueue.
 212          */
 213
 214         work = kmalloc(sizeof *work, GFP_KERNEL);
 215         if (!work) {
 216                 mmput(mm);
 217                 return;
 218         }
 219
 220         INIT_WORK(&work->work, ib_umem_account);
 221         work->mm   = mm;
 222         work->diff = PAGE_ALIGN(umem->length + umem->offset) >> PAGE_SHIFT;
 223
 224         schedule_work(&work->work);
 225 }