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  *
   5  * This software is available to you under a choice of one of two
   6  * licenses.  You may choose to be licensed under the terms of the GNU
   7  * General Public License (GPL) Version 2, available from the file
   8  * COPYING in the main directory of this source tree, or the
   9  * OpenIB.org BSD license below:
  10  *
  11  *     Redistribution and use in source and binary forms, with or
  12  *     without modification, are permitted provided that the following
  13  *     conditions are met:
  14  *
  15  *      - Redistributions of source code must retain the above
  16  *        copyright notice, this list of conditions and the following
  17  *        disclaimer.
  18  *
  19  *      - Redistributions in binary form must reproduce the above
  20  *        copyright notice, this list of conditions and the following
  21  *        disclaimer in the documentation and/or other materials
  22  *        provided with the distribution.
  23  *
  24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  31  * SOFTWARE.
  32  *
  33  * $Id: uverbs_mem.c 2743 2005-06-28 22:27:59Z roland $
  34  */
  35
  36 #include <linux/mm.h>
  37 #include <linux/dma-mapping.h>
  38
  39 #include "uverbs.h"
  40
  41 struct ib_umem_account_work {
  42         struct work_struct work;
  43         struct mm_struct  *mm;
  44         unsigned long      diff;
  45 };
  46
  47
  48 static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty)
  49 {
  50         struct ib_umem_chunk *chunk, *tmp;
  51         int i;
  52
  53         list_for_each_entry_safe(chunk, tmp, &umem->chunk_list, list) {
  54                 dma_unmap_sg(dev->dma_device, chunk->page_list,
  55                              chunk->nents, DMA_BIDIRECTIONAL);
  56                 for (i = 0; i < chunk->nents; ++i) {
  57                         if (umem->writable && dirty)
  58                                 set_page_dirty_lock(chunk->page_list[i].page);
  59                         put_page(chunk->page_list[i].page);
  60                 }
  61
  62                 kfree(chunk);
  63         }
  64 }
  65
  66 int ib_umem_get(struct ib_device *dev, struct ib_umem *mem,
  67                 void *addr, size_t size, int write)
  68 {
  69         struct page **page_list;
  70         struct ib_umem_chunk *chunk;
  71         unsigned long locked;
  72         unsigned long lock_limit;
  73         unsigned long cur_base;
  74         unsigned long npages;
  75         int ret = 0;
  76         int off;
  77         int i;
  78
  79         if (!can_do_mlock())
  80                 return -EPERM;
  81
  82         page_list = (struct page **) __get_free_page(GFP_KERNEL);
  83         if (!page_list)
  84                 return -ENOMEM;
  85
  86         mem->user_base = (unsigned long) addr;
  87         mem->length    = size;
  88         mem->offset    = (unsigned long) addr & ~PAGE_MASK;
  89         mem->page_size = PAGE_SIZE;
  90         mem->writable  = write;
  91
  92         INIT_LIST_HEAD(&mem->chunk_list);
  93
  94         npages = PAGE_ALIGN(size + mem->offset) >> PAGE_SHIFT;
  95
  96         down_write(&current->mm->mmap_sem);
  97
  98         locked     = npages + current->mm->locked_vm;
  99         lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur >> PAGE_SHIFT;
 100
 101         if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) {
 102                 ret = -ENOMEM;
 103                 goto out;
 104         }
 105
 106         cur_base = (unsigned long) addr & PAGE_MASK;
 107
 108         while (npages) {
 109                 ret = get_user_pages(current, current->mm, cur_base,
 110                                      min_t(int, npages,
 111                                            PAGE_SIZE / sizeof (struct page *)),
 112                                      1, !write, page_list, NULL);
 113
 114                 if (ret < 0)
 115                         goto out;
 116
 117                 cur_base += ret * PAGE_SIZE;
 118                 npages   -= ret;
 119
 120                 off = 0;
 121
 122                 while (ret) {
 123                         chunk = kmalloc(sizeof *chunk + sizeof (struct scatterlist) *
 124                                         min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK),
 125                                         GFP_KERNEL);
 126                         if (!chunk) {
 127                                 ret = -ENOMEM;
 128                                 goto out;
 129                         }
 130
 131                         chunk->nents = min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK);
 132                         for (i = 0; i < chunk->nents; ++i) {
 133                                 chunk->page_list[i].page   = page_list[i + off];
 134                                 chunk->page_list[i].offset = 0;
 135                                 chunk->page_list[i].length = PAGE_SIZE;
 136                         }
 137
 138                         chunk->nmap = dma_map_sg(dev->dma_device,
 139                                                  &chunk->page_list[0],
 140                                                  chunk->nents,
 141                                                  DMA_BIDIRECTIONAL);
 142                         if (chunk->nmap <= 0) {
 143                                 for (i = 0; i < chunk->nents; ++i)
 144                                         put_page(chunk->page_list[i].page);
 145                                 kfree(chunk);
 146
 147                                 ret = -ENOMEM;
 148                                 goto out;
 149                         }
 150
 151                         ret -= chunk->nents;
 152                         off += chunk->nents;
 153                         list_add_tail(&chunk->list, &mem->chunk_list);
 154                 }
 155
 156                 ret = 0;
 157         }
 158
 159 out:
 160         if (ret < 0)
 161                 __ib_umem_release(dev, mem, 0);
 162         else
 163                 current->mm->locked_vm = locked;
 164
 165         up_write(&current->mm->mmap_sem);
 166         free_page((unsigned long) page_list);
 167
 168         return ret;
 169 }
 170
 171 void ib_umem_release(struct ib_device *dev, struct ib_umem *umem)
 172 {
 173         __ib_umem_release(dev, umem, 1);
 174
 175         down_write(&current->mm->mmap_sem);
 176         current->mm->locked_vm -=
 177                 PAGE_ALIGN(umem->length + umem->offset) >> PAGE_SHIFT;
 178         up_write(&current->mm->mmap_sem);
 179 }
 180
 181 static void ib_umem_account(void *work_ptr)
 182 {
 183         struct ib_umem_account_work *work = work_ptr;
 184
 185         down_write(&work->mm->mmap_sem);
 186         work->mm->locked_vm -= work->diff;
 187         up_write(&work->mm->mmap_sem);
 188         mmput(work->mm);
 189         kfree(work);
 190 }
 191
 192 void ib_umem_release_on_close(struct ib_device *dev, struct ib_umem *umem)
 193 {
 194         struct ib_umem_account_work *work;
 195         struct mm_struct *mm;
 196
 197         __ib_umem_release(dev, umem, 1);
 198
 199         mm = get_task_mm(current);
 200         if (!mm)
 201                 return;
 202
 203         /*
 204          * We may be called with the mm's mmap_sem already held.  This
 205          * can happen when a userspace munmap() is the call that drops
 206          * the last reference to our file and calls our release
 207          * method.  If there are memory regions to destroy, we'll end
 208          * up here and not be able to take the mmap_sem.  Therefore we
 209          * defer the vm_locked accounting to the system workqueue.
 210          */
 211
 212         work = kmalloc(sizeof *work, GFP_KERNEL);
 213         if (!work)
 214                 return;
 215
 216         INIT_WORK(&work->work, ib_umem_account, work);
 217         work->mm   = mm;
 218         work->diff = PAGE_ALIGN(umem->length + umem->offset) >> PAGE_SHIFT;
 219
 220         schedule_work(&work->work);
 221 }