drivers/char/drm/drm_scatter.c

   1 /**
   2  * \file drm_scatter.h
   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/config.h>
  35 #include <linux/vmalloc.h>
  36 #include "drmP.h"
  37
  38 #define DEBUG_SCATTER 0
  39
  40 void drm_sg_cleanup( drm_sg_mem_t *entry )
  41 {
  42         struct page *page;
  43         int i;
  44
  45         for ( i = 0 ; i < entry->pages ; i++ ) {
  46                 page = entry->pagelist[i];
  47                 if ( page )
  48                         ClearPageReserved( page );
  49         }
  50
  51         vfree( entry->virtual );
  52
  53         drm_free( entry->busaddr,
  54                    entry->pages * sizeof(*entry->busaddr),
  55                    DRM_MEM_PAGES );
  56         drm_free( entry->pagelist,
  57                    entry->pages * sizeof(*entry->pagelist),
  58                    DRM_MEM_PAGES );
  59         drm_free( entry,
  60                    sizeof(*entry),
  61                    DRM_MEM_SGLISTS );
  62 }
  63
  64 #ifdef _LP64
  65 # define ScatterHandle(x) (unsigned int)((x >> 32) + (x & ((1L << 32) - 1)))
  66 #else
  67 # define ScatterHandle(x) (unsigned int)(x)
  68 #endif
  69
  70 int drm_sg_alloc( struct inode *inode, struct file *filp,
  71                    unsigned int cmd, unsigned long arg )
  72 {
  73         drm_file_t *priv = filp->private_data;
  74         drm_device_t *dev = priv->head->dev;
  75         drm_scatter_gather_t __user *argp = (void __user *)arg;
  76         drm_scatter_gather_t request;
  77         drm_sg_mem_t *entry;
  78         unsigned long pages, i, j;
  79
  80         DRM_DEBUG( "%s\n", __FUNCTION__ );
  81
  82         if (!drm_core_check_feature(dev, DRIVER_SG))
  83                 return -EINVAL;
  84
  85         if ( dev->sg )
  86                 return -EINVAL;
  87
  88         if ( copy_from_user( &request, argp, sizeof(request) ) )
  89                 return -EFAULT;
  90
  91         entry = drm_alloc( sizeof(*entry), DRM_MEM_SGLISTS );
  92         if ( !entry )
  93                 return -ENOMEM;
  94
  95         memset( entry, 0, sizeof(*entry) );
  96
  97         pages = (request.size + PAGE_SIZE - 1) / PAGE_SIZE;
  98         DRM_DEBUG( "sg size=%ld pages=%ld\n", request.size, pages );
  99
 100         entry->pages = pages;
 101         entry->pagelist = drm_alloc( pages * sizeof(*entry->pagelist),
 102                                      DRM_MEM_PAGES );
 103         if ( !entry->pagelist ) {
 104                 drm_free( entry, sizeof(*entry), DRM_MEM_SGLISTS );
 105                 return -ENOMEM;
 106         }
 107
 108         memset(entry->pagelist, 0, pages * sizeof(*entry->pagelist));
 109
 110         entry->busaddr = drm_alloc( pages * sizeof(*entry->busaddr),
 111                                      DRM_MEM_PAGES );
 112         if ( !entry->busaddr ) {
 113                 drm_free( entry->pagelist,
 114                            entry->pages * sizeof(*entry->pagelist),
 115                            DRM_MEM_PAGES );
 116                 drm_free( entry,
 117                            sizeof(*entry),
 118                            DRM_MEM_SGLISTS );
 119                 return -ENOMEM;
 120         }
 121         memset( (void *)entry->busaddr, 0, pages * sizeof(*entry->busaddr) );
 122
 123         entry->virtual = vmalloc_32( pages << PAGE_SHIFT );
 124         if ( !entry->virtual ) {
 125                 drm_free( entry->busaddr,
 126                            entry->pages * sizeof(*entry->busaddr),
 127                            DRM_MEM_PAGES );
 128                 drm_free( entry->pagelist,
 129                            entry->pages * sizeof(*entry->pagelist),
 130                            DRM_MEM_PAGES );
 131                 drm_free( entry,
 132                            sizeof(*entry),
 133                            DRM_MEM_SGLISTS );
 134                 return -ENOMEM;
 135         }
 136
 137         /* This also forces the mapping of COW pages, so our page list
 138          * will be valid.  Please don't remove it...
 139          */
 140         memset( entry->virtual, 0, pages << PAGE_SHIFT );
 141
 142         entry->handle = ScatterHandle((unsigned long)entry->virtual);
 143
 144         DRM_DEBUG( "sg alloc handle  = %08lx\n", entry->handle );
 145         DRM_DEBUG( "sg alloc virtual = %p\n", entry->virtual );
 146
 147         for (i = (unsigned long)entry->virtual, j = 0; j < pages;
 148                 i += PAGE_SIZE, j++) {
 149                 entry->pagelist[j] = vmalloc_to_page((void *)i);
 150                 if (!entry->pagelist[j])
 151                         goto failed;
 152                 SetPageReserved(entry->pagelist[j]);
 153         }
 154
 155         request.handle = entry->handle;
 156
 157         if ( copy_to_user( argp, &request, sizeof(request) ) ) {
 158                 drm_sg_cleanup( entry );
 159                 return -EFAULT;
 160         }
 161
 162         dev->sg = entry;
 163
 164 #if DEBUG_SCATTER
 165         /* Verify that each page points to its virtual address, and vice
 166          * versa.
 167          */
 168         {
 169         int error = 0;
 170
 171         for ( i = 0 ; i < pages ; i++ ) {
 172                 unsigned long *tmp;
 173
 174                 tmp = page_address( entry->pagelist[i] );
 175                 for ( j = 0 ;
 176                       j < PAGE_SIZE / sizeof(unsigned long) ;
 177                       j++, tmp++ ) {
 178                         *tmp = 0xcafebabe;
 179                 }
 180                 tmp = (unsigned long *)((u8 *)entry->virtual +
 181                                         (PAGE_SIZE * i));
 182                 for( j = 0 ;
 183                      j < PAGE_SIZE / sizeof(unsigned long) ;
 184                      j++, tmp++ ) {
 185                         if ( *tmp != 0xcafebabe && error == 0 ) {
 186                                 error = 1;
 187                                 DRM_ERROR( "Scatter allocation error, "
 188                                            "pagelist does not match "
 189                                            "virtual mapping\n" );
 190                         }
 191                 }
 192                 tmp = page_address( entry->pagelist[i] );
 193                 for(j = 0 ;
 194                     j < PAGE_SIZE / sizeof(unsigned long) ;
 195                     j++, tmp++) {
 196                         *tmp = 0;
 197                 }
 198         }
 199         if (error == 0)
 200                 DRM_ERROR( "Scatter allocation matches pagelist\n" );
 201         }
 202 #endif
 203
 204         return 0;
 205
 206  failed:
 207         drm_sg_cleanup( entry );
 208         return -ENOMEM;
 209 }
 210
 211 int drm_sg_free( struct inode *inode, struct file *filp,
 212                  unsigned int cmd, unsigned long arg )
 213 {
 214         drm_file_t *priv = filp->private_data;
 215         drm_device_t *dev = priv->head->dev;
 216         drm_scatter_gather_t request;
 217         drm_sg_mem_t *entry;
 218
 219         if (!drm_core_check_feature(dev, DRIVER_SG))
 220                 return -EINVAL;
 221
 222         if ( copy_from_user( &request,
 223                              (drm_scatter_gather_t __user *)arg,
 224                              sizeof(request) ) )
 225                 return -EFAULT;
 226
 227         entry = dev->sg;
 228         dev->sg = NULL;
 229
 230         if ( !entry || entry->handle != request.handle )
 231                 return -EINVAL;
 232
 233         DRM_DEBUG( "sg free virtual  = %p\n", entry->virtual );
 234
 235         drm_sg_cleanup( entry );
 236
 237         return 0;
 238 }