drivers/staging/rdma/hfi1/user_pages.c

   1 /*
   2  *
   3  * This file is provided under a dual BSD/GPLv2 license.  When using or
   4  * redistributing this file, you may do so under either license.
   5  *
   6  * GPL LICENSE SUMMARY
   7  *
   8  * Copyright(c) 2015 Intel Corporation.
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of version 2 of the GNU General Public License as
  12  * published by the Free Software Foundation.
  13  *
  14  * This program is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * General Public License for more details.
  18  *
  19  * BSD LICENSE
  20  *
  21  * Copyright(c) 2015 Intel Corporation.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  *
  27  *  - Redistributions of source code must retain the above copyright
  28  *    notice, this list of conditions and the following disclaimer.
  29  *  - Redistributions in binary form must reproduce the above copyright
  30  *    notice, this list of conditions and the following disclaimer in
  31  *    the documentation and/or other materials provided with the
  32  *    distribution.
  33  *  - Neither the name of Intel Corporation nor the names of its
  34  *    contributors may be used to endorse or promote products derived
  35  *    from this software without specific prior written permission.
  36  *
  37  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  38  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  39  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  40  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  41  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  42  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  43  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  44  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  45  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  46  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  47  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  48  *
  49  */
  50
  51 #include <linux/mm.h>
  52 #include <linux/sched.h>
  53 #include <linux/device.h>
  54
  55 #include "hfi.h"
  56
  57 /**
  58  * hfi1_map_page - a safety wrapper around pci_map_page()
  59  *
  60  */
  61 dma_addr_t hfi1_map_page(struct pci_dev *hwdev, struct page *page,
  62                          unsigned long offset, size_t size, int direction)
  63 {
  64         dma_addr_t phys;
  65
  66         phys = pci_map_page(hwdev, page, offset, size, direction);
  67
  68         return phys;
  69 }
  70
  71 int hfi1_acquire_user_pages(unsigned long vaddr, size_t npages, bool writable,
  72                             struct page **pages)
  73 {
  74         unsigned long pinned, lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
  75         bool can_lock = capable(CAP_IPC_LOCK);
  76         int ret;
  77
  78         down_read(&current->mm->mmap_sem);
  79         pinned = current->mm->pinned_vm;
  80         up_read(&current->mm->mmap_sem);
  81
  82         if (pinned + npages > lock_limit && !can_lock)
  83                 return -ENOMEM;
  84
  85         ret = get_user_pages_fast(vaddr, npages, writable, pages);
  86         if (ret < 0)
  87                 return ret;
  88
  89         down_write(&current->mm->mmap_sem);
  90         current->mm->pinned_vm += ret;
  91         up_write(&current->mm->mmap_sem);
  92
  93         return ret;
  94 }
  95
  96 void hfi1_release_user_pages(struct page **p, size_t npages, bool dirty)
  97 {
  98         size_t i;
  99
 100         for (i = 0; i < npages; i++) {
 101                 if (dirty)
 102                         set_page_dirty_lock(p[i]);
 103                 put_page(p[i]);
 104         }
 105
 106         if (current->mm) { /* during close after signal, mm can be NULL */
 107                 down_write(&current->mm->mmap_sem);
 108                 current->mm->pinned_vm -= npages;
 109                 up_write(&current->mm->mmap_sem);
 110         }
 111 }