release/src-rt-6.x.4708/linux/linux-2.6.36/drivers/infiniband/hw/ipath/ipath_user_pages.c

   1 /*
   2  * Copyright (c) 2006, 2007 QLogic Corporation. All rights reserved.
   3  * Copyright (c) 2003, 2004, 2005, 2006 PathScale, Inc. 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
  34 #include <linux/mm.h>
  35 #include <linux/device.h>
  36 #include <linux/slab.h>
  37 #include <linux/sched.h>
  38
  39 #include "ipath_kernel.h"
  40
  41 static void __ipath_release_user_pages(struct page **p, size_t num_pages,
  42                                    int dirty)
  43 {
  44         size_t i;
  45
  46         for (i = 0; i < num_pages; i++) {
  47                 ipath_cdbg(MM, "%lu/%lu put_page %p\n", (unsigned long) i,
  48                            (unsigned long) num_pages, p[i]);
  49                 if (dirty)
  50                         set_page_dirty_lock(p[i]);
  51                 put_page(p[i]);
  52         }
  53 }
  54
  55 /* call with current->mm->mmap_sem held */
  56 static int __get_user_pages(unsigned long start_page, size_t num_pages,
  57                         struct page **p, struct vm_area_struct **vma)
  58 {
  59         unsigned long lock_limit;
  60         size_t got;
  61         int ret;
  62
  63         lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
  64
  65         if (num_pages > lock_limit) {
  66                 ret = -ENOMEM;
  67                 goto bail;
  68         }
  69
  70         ipath_cdbg(VERBOSE, "pin %lx pages from vaddr %lx\n",
  71                    (unsigned long) num_pages, start_page);
  72
  73         for (got = 0; got < num_pages; got += ret) {
  74                 ret = get_user_pages(current, current->mm,
  75                                      start_page + got * PAGE_SIZE,
  76                                      num_pages - got, 1, 1,
  77                                      p + got, vma);
  78                 if (ret < 0)
  79                         goto bail_release;
  80         }
  81
  82         current->mm->locked_vm += num_pages;
  83
  84         ret = 0;
  85         goto bail;
  86
  87 bail_release:
  88         __ipath_release_user_pages(p, got, 0);
  89 bail:
  90         return ret;
  91 }
  92
  93 dma_addr_t ipath_map_page(struct pci_dev *hwdev, struct page *page,
  94         unsigned long offset, size_t size, int direction)
  95 {
  96         dma_addr_t phys;
  97
  98         phys = pci_map_page(hwdev, page, offset, size, direction);
  99
 100         if (phys == 0) {
 101                 pci_unmap_page(hwdev, phys, size, direction);
 102                 phys = pci_map_page(hwdev, page, offset, size, direction);
 103         }
 104
 105         return phys;
 106 }
 107
 108 /**
 109  * ipath_map_single - a safety wrapper around pci_map_single()
 110  *
 111  * Same idea as ipath_map_page().
 112  */
 113 dma_addr_t ipath_map_single(struct pci_dev *hwdev, void *ptr, size_t size,
 114         int direction)
 115 {
 116         dma_addr_t phys;
 117
 118         phys = pci_map_single(hwdev, ptr, size, direction);
 119
 120         if (phys == 0) {
 121                 pci_unmap_single(hwdev, phys, size, direction);
 122                 phys = pci_map_single(hwdev, ptr, size, direction);
 123         }
 124
 125         return phys;
 126 }
 127
 128 /**
 129  * ipath_get_user_pages - lock user pages into memory
 130  * @start_page: the start page
 131  * @num_pages: the number of pages
 132  * @p: the output page structures
 133  *
 134  * This function takes a given start page (page aligned user virtual
 135  * address) and pins it and the following specified number of pages.  For
 136  * now, num_pages is always 1, but that will probably change at some point
 137  * (because caller is doing expected sends on a single virtually contiguous
 138  * buffer, so we can do all pages at once).
 139  */
 140 int ipath_get_user_pages(unsigned long start_page, size_t num_pages,
 141                          struct page **p)
 142 {
 143         int ret;
 144
 145         down_write(&current->mm->mmap_sem);
 146
 147         ret = __get_user_pages(start_page, num_pages, p, NULL);
 148
 149         up_write(&current->mm->mmap_sem);
 150
 151         return ret;
 152 }
 153
 154 void ipath_release_user_pages(struct page **p, size_t num_pages)
 155 {
 156         down_write(&current->mm->mmap_sem);
 157
 158         __ipath_release_user_pages(p, num_pages, 1);
 159
 160         current->mm->locked_vm -= num_pages;
 161
 162         up_write(&current->mm->mmap_sem);
 163 }
 164
 165 struct ipath_user_pages_work {
 166         struct work_struct work;
 167         struct mm_struct *mm;
 168         unsigned long num_pages;
 169 };
 170
 171 static void user_pages_account(struct work_struct *_work)
 172 {
 173         struct ipath_user_pages_work *work =
 174                 container_of(_work, struct ipath_user_pages_work, work);
 175
 176         down_write(&work->mm->mmap_sem);
 177         work->mm->locked_vm -= work->num_pages;
 178         up_write(&work->mm->mmap_sem);
 179         mmput(work->mm);
 180         kfree(work);
 181 }
 182
 183 void ipath_release_user_pages_on_close(struct page **p, size_t num_pages)
 184 {
 185         struct ipath_user_pages_work *work;
 186         struct mm_struct *mm;
 187
 188         __ipath_release_user_pages(p, num_pages, 1);
 189
 190         mm = get_task_mm(current);
 191         if (!mm)
 192                 return;
 193
 194         work = kmalloc(sizeof(*work), GFP_KERNEL);
 195         if (!work)
 196                 goto bail_mm;
 197
 198         INIT_WORK(&work->work, user_pages_account);
 199         work->mm = mm;
 200         work->num_pages = num_pages;
 201
 202         schedule_work(&work->work);
 203         return;
 204
 205 bail_mm:
 206         mmput(mm);
 207         return;
 208 }