ed267d49bc6aa9c4dee72c006a41a61f9991e35b
[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 #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 }