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 int drm_sg_alloc( struct inode *inode, struct file *filp,
  65                    unsigned int cmd, unsigned long arg )
  66 {
  67         drm_file_t *priv = filp->private_data;
  68         drm_device_t *dev = priv->head->dev;
  69         drm_scatter_gather_t __user *argp = (void __user *)arg;
  70         drm_scatter_gather_t request;
  71         drm_sg_mem_t *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,
 111                            sizeof(*entry),
 112                            DRM_MEM_SGLISTS );
 113                 return -ENOMEM;
 114         }
 115         memset( (void *)entry->busaddr, 0, pages * sizeof(*entry->busaddr) );
 116
 117         entry->virtual = vmalloc_32( pages << PAGE_SHIFT );
 118         if ( !entry->virtual ) {
 119                 drm_free( entry->busaddr,
 120                            entry->pages * sizeof(*entry->busaddr),
 121                            DRM_MEM_PAGES );
 122                 drm_free( entry->pagelist,
 123                            entry->pages * sizeof(*entry->pagelist),
 124                            DRM_MEM_PAGES );
 125                 drm_free( entry,
 126                            sizeof(*entry),
 127                            DRM_MEM_SGLISTS );
 128                 return -ENOMEM;
 129         }
 130
 131         /* This also forces the mapping of COW pages, so our page list
 132          * will be valid.  Please don't remove it...
 133          */
 134         memset( entry->virtual, 0, pages << PAGE_SHIFT );
 135
 136         entry->handle = (unsigned long)entry->virtual;
 137
 138         DRM_DEBUG( "sg alloc handle  = %08lx\n", entry->handle );
 139         DRM_DEBUG( "sg alloc virtual = %p\n", entry->virtual );
 140
 141         for ( i = entry->handle, j = 0 ; j < pages ; i += PAGE_SIZE, j++ ) {
 142                 entry->pagelist[j] = vmalloc_to_page((void *)i);
 143                 if (!entry->pagelist[j])
 144                         goto failed;
 145                 SetPageReserved(entry->pagelist[j]);
 146         }
 147
 148         request.handle = entry->handle;
 149
 150         if ( copy_to_user( argp, &request, sizeof(request) ) ) {
 151                 drm_sg_cleanup( entry );
 152                 return -EFAULT;
 153         }
 154
 155         dev->sg = entry;
 156
 157 #if DEBUG_SCATTER
 158         /* Verify that each page points to its virtual address, and vice
 159          * versa.
 160          */
 161         {
 162         int error = 0;
 163
 164         for ( i = 0 ; i < pages ; i++ ) {
 165                 unsigned long *tmp;
 166
 167                 tmp = page_address( entry->pagelist[i] );
 168                 for ( j = 0 ;
 169                       j < PAGE_SIZE / sizeof(unsigned long) ;
 170                       j++, tmp++ ) {
 171                         *tmp = 0xcafebabe;
 172                 }
 173                 tmp = (unsigned long *)((u8 *)entry->virtual +
 174                                         (PAGE_SIZE * i));
 175                 for( j = 0 ;
 176                      j < PAGE_SIZE / sizeof(unsigned long) ;
 177                      j++, tmp++ ) {
 178                         if ( *tmp != 0xcafebabe && error == 0 ) {
 179                                 error = 1;
 180                                 DRM_ERROR( "Scatter allocation error, "
 181                                            "pagelist does not match "
 182                                            "virtual mapping\n" );
 183                         }
 184                 }
 185                 tmp = page_address( entry->pagelist[i] );
 186                 for(j = 0 ;
 187                     j < PAGE_SIZE / sizeof(unsigned long) ;
 188                     j++, tmp++) {
 189                         *tmp = 0;
 190                 }
 191         }
 192         if (error == 0)
 193                 DRM_ERROR( "Scatter allocation matches pagelist\n" );
 194         }
 195 #endif
 196
 197         return 0;
 198
 199  failed:
 200         drm_sg_cleanup( entry );
 201         return -ENOMEM;
 202 }
 203
 204 int drm_sg_free( struct inode *inode, struct file *filp,
 205                  unsigned int cmd, unsigned long arg )
 206 {
 207         drm_file_t *priv = filp->private_data;
 208         drm_device_t *dev = priv->head->dev;
 209         drm_scatter_gather_t request;
 210         drm_sg_mem_t *entry;
 211
 212         if (!drm_core_check_feature(dev, DRIVER_SG))
 213                 return -EINVAL;
 214
 215         if ( copy_from_user( &request,
 216                              (drm_scatter_gather_t __user *)arg,
 217                              sizeof(request) ) )
 218                 return -EFAULT;
 219
 220         entry = dev->sg;
 221         dev->sg = NULL;
 222
 223         if ( !entry || entry->handle != request.handle )
 224                 return -EINVAL;
 225
 226         DRM_DEBUG( "sg free virtual  = %p\n", entry->virtual );
 227
 228         drm_sg_cleanup( entry );
 229
 230         return 0;
 231 }