drivers/char/drm/drm_scatter.c

   1 /**
   2  * \file drm_scatter.c
   3  * IOCTLs to manage scatter/gather memory
   4  *
   5  * \author Gareth Hughes <gareth@valinux.com>
   6  */
   7
   8 /*
   9  * Created: Mon Dec 18 23:20:54 2000 by gareth@valinux.com
  10  *
  11  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
  12  * All Rights Reserved.
  13  *
  14  * Permission is hereby granted, free of charge, to any person obtaining a
  15  * copy of this software and associated documentation files (the "Software"),
  16  * to deal in the Software without restriction, including without limitation
  17  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  18  * and/or sell copies of the Software, and to permit persons to whom the
  19  * Software is furnished to do so, subject to the following conditions:
  20  *
  21  * The above copyright notice and this permission notice (including the next
  22  * paragraph) shall be included in all copies or substantial portions of the
  23  * Software.
  24  *
  25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  26  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  27  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  28  * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  29  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  30  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  31  * DEALINGS IN THE SOFTWARE.
  32  */
  33
  34 #include <linux/vmalloc.h>
  35 #include "drmP.h"
  36
  37 #define DEBUG_SCATTER 0
  38
  39 void drm_sg_cleanup(struct drm_sg_mem * entry)
  40 {
  41         struct page *page;
  42         int i;
  43
  44         for (i = 0; i < entry->pages; i++) {
  45                 page = entry->pagelist[i];
  46                 if (page)
  47                         ClearPageReserved(page);
  48         }
  49
  50         vfree(entry->virtual);
  51
  52         drm_free(entry->busaddr,
  53                  entry->pages * sizeof(*entry->busaddr), DRM_MEM_PAGES);
  54         drm_free(entry->pagelist,
  55                  entry->pages * sizeof(*entry->pagelist), DRM_MEM_PAGES);
  56         drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
  57 }
  58
  59 #ifdef _LP64
  60 # define ScatterHandle(x) (unsigned int)((x >> 32) + (x & ((1L << 32) - 1)))
  61 #else
  62 # define ScatterHandle(x) (unsigned int)(x)
  63 #endif
  64
  65 int drm_sg_alloc(struct inode *inode, struct drm_file *file_priv,
  66                  unsigned int cmd, unsigned long arg)
  67 {
  68         struct drm_device *dev = file_priv->head->dev;
  69         struct drm_scatter_gather __user *argp = (void __user *)arg;
  70         struct drm_scatter_gather request;
  71         struct drm_sg_mem *entry;
  72         unsigned long pages, i, j;
  73
  74         DRM_DEBUG("%s\n", __FUNCTION__);
  75
  76         if (!drm_core_check_feature(dev, DRIVER_SG))
  77                 return -EINVAL;
  78
  79         if (dev->sg)
  80                 return -EINVAL;
  81
  82         if (copy_from_user(&request, argp, sizeof(request)))
  83                 return -EFAULT;
  84
  85         entry = drm_alloc(sizeof(*entry), DRM_MEM_SGLISTS);
  86         if (!entry)
  87                 return -ENOMEM;
  88
  89         memset(entry, 0, sizeof(*entry));
  90
  91         pages = (request.size + PAGE_SIZE - 1) / PAGE_SIZE;
  92         DRM_DEBUG("sg size=%ld pages=%ld\n", request.size, pages);
  93
  94         entry->pages = pages;
  95         entry->pagelist = drm_alloc(pages * sizeof(*entry->pagelist),
  96                                     DRM_MEM_PAGES);
  97         if (!entry->pagelist) {
  98                 drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
  99                 return -ENOMEM;
 100         }
 101
 102         memset(entry->pagelist, 0, pages * sizeof(*entry->pagelist));
 103
 104         entry->busaddr = drm_alloc(pages * sizeof(*entry->busaddr),
 105                                    DRM_MEM_PAGES);
 106         if (!entry->busaddr) {
 107                 drm_free(entry->pagelist,
 108                          entry->pages * sizeof(*entry->pagelist),
 109                          DRM_MEM_PAGES);
 110                 drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
 111                 return -ENOMEM;
 112         }
 113         memset((void *)entry->busaddr, 0, pages * sizeof(*entry->busaddr));
 114
 115         entry->virtual = vmalloc_32(pages << PAGE_SHIFT);
 116         if (!entry->virtual) {
 117                 drm_free(entry->busaddr,
 118                          entry->pages * sizeof(*entry->busaddr), DRM_MEM_PAGES);
 119                 drm_free(entry->pagelist,
 120                          entry->pages * sizeof(*entry->pagelist),
 121                          DRM_MEM_PAGES);
 122                 drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
 123                 return -ENOMEM;
 124         }
 125
 126         /* This also forces the mapping of COW pages, so our page list
 127          * will be valid.  Please don't remove it...
 128          */
 129         memset(entry->virtual, 0, pages << PAGE_SHIFT);
 130
 131         entry->handle = ScatterHandle((unsigned long)entry->virtual);
 132
 133         DRM_DEBUG("sg alloc handle  = %08lx\n", entry->handle);
 134         DRM_DEBUG("sg alloc virtual = %p\n", entry->virtual);
 135
 136         for (i = (unsigned long)entry->virtual, j = 0; j < pages;
 137              i += PAGE_SIZE, j++) {
 138                 entry->pagelist[j] = vmalloc_to_page((void *)i);
 139                 if (!entry->pagelist[j])
 140                         goto failed;
 141                 SetPageReserved(entry->pagelist[j]);
 142         }
 143
 144         request.handle = entry->handle;
 145
 146         if (copy_to_user(argp, &request, sizeof(request))) {
 147                 drm_sg_cleanup(entry);
 148                 return -EFAULT;
 149         }
 150
 151         dev->sg = entry;
 152
 153 #if DEBUG_SCATTER
 154         /* Verify that each page points to its virtual address, and vice
 155          * versa.
 156          */
 157         {
 158                 int error = 0;
 159
 160                 for (i = 0; i < pages; i++) {
 161                         unsigned long *tmp;
 162
 163                         tmp = page_address(entry->pagelist[i]);
 164                         for (j = 0;
 165                              j < PAGE_SIZE / sizeof(unsigned long);
 166                              j++, tmp++) {
 167                                 *tmp = 0xcafebabe;
 168                         }
 169                         tmp = (unsigned long *)((u8 *) entry->virtual +
 170                                                 (PAGE_SIZE * i));
 171                         for (j = 0;
 172                              j < PAGE_SIZE / sizeof(unsigned long);
 173                              j++, tmp++) {
 174                                 if (*tmp != 0xcafebabe && error == 0) {
 175                                         error = 1;
 176                                         DRM_ERROR("Scatter allocation error, "
 177                                                   "pagelist does not match "
 178                                                   "virtual mapping\n");
 179                                 }
 180                         }
 181                         tmp = page_address(entry->pagelist[i]);
 182                         for (j = 0;
 183                              j < PAGE_SIZE / sizeof(unsigned long);
 184                              j++, tmp++) {
 185                                 *tmp = 0;
 186                         }
 187                 }
 188                 if (error == 0)
 189                         DRM_ERROR("Scatter allocation matches pagelist\n");
 190         }
 191 #endif
 192
 193         return 0;
 194
 195       failed:
 196         drm_sg_cleanup(entry);
 197         return -ENOMEM;
 198 }
 199
 200 int drm_sg_free(struct inode *inode, struct drm_file *file_priv,
 201                 unsigned int cmd, unsigned long arg)
 202 {
 203         struct drm_device *dev = file_priv->head->dev;
 204         struct drm_scatter_gather request;
 205         struct drm_sg_mem *entry;
 206
 207         if (!drm_core_check_feature(dev, DRIVER_SG))
 208                 return -EINVAL;
 209
 210         if (copy_from_user(&request,
 211                            (struct drm_scatter_gather __user *) arg,
 212                            sizeof(request)))
 213                 return -EFAULT;
 214
 215         entry = dev->sg;
 216         dev->sg = NULL;
 217
 218         if (!entry || entry->handle != request.handle)
 219                 return -EINVAL;
 220
 221         DRM_DEBUG("sg free virtual  = %p\n", entry->virtual);
 222
 223         drm_sg_cleanup(entry);
 224
 225         return 0;
 226 }