Linux-2.6.12-rc2
[linux-2.6.git] / 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 }