Merge branch 'master' of /home/tglx/work/mtd/git/linux-2.6.git/
[linux-2.6] / 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/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), DRM_MEM_PAGES);
55         drm_free(entry->pagelist,
56                  entry->pages * sizeof(*entry->pagelist), DRM_MEM_PAGES);
57         drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
58 }
59
60 #ifdef _LP64
61 # define ScatterHandle(x) (unsigned int)((x >> 32) + (x & ((1L << 32) - 1)))
62 #else
63 # define ScatterHandle(x) (unsigned int)(x)
64 #endif
65
66 int drm_sg_alloc(struct inode *inode, struct file *filp,
67                  unsigned int cmd, unsigned long arg)
68 {
69         drm_file_t *priv = filp->private_data;
70         drm_device_t *dev = priv->head->dev;
71         drm_scatter_gather_t __user *argp = (void __user *)arg;
72         drm_scatter_gather_t request;
73         drm_sg_mem_t *entry;
74         unsigned long pages, i, j;
75
76         DRM_DEBUG("%s\n", __FUNCTION__);
77
78         if (!drm_core_check_feature(dev, DRIVER_SG))
79                 return -EINVAL;
80
81         if (dev->sg)
82                 return -EINVAL;
83
84         if (copy_from_user(&request, argp, sizeof(request)))
85                 return -EFAULT;
86
87         entry = drm_alloc(sizeof(*entry), DRM_MEM_SGLISTS);
88         if (!entry)
89                 return -ENOMEM;
90
91         memset(entry, 0, sizeof(*entry));
92
93         pages = (request.size + PAGE_SIZE - 1) / PAGE_SIZE;
94         DRM_DEBUG("sg size=%ld pages=%ld\n", request.size, pages);
95
96         entry->pages = pages;
97         entry->pagelist = drm_alloc(pages * sizeof(*entry->pagelist),
98                                     DRM_MEM_PAGES);
99         if (!entry->pagelist) {
100                 drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
101                 return -ENOMEM;
102         }
103
104         memset(entry->pagelist, 0, pages * sizeof(*entry->pagelist));
105
106         entry->busaddr = drm_alloc(pages * sizeof(*entry->busaddr),
107                                    DRM_MEM_PAGES);
108         if (!entry->busaddr) {
109                 drm_free(entry->pagelist,
110                          entry->pages * sizeof(*entry->pagelist),
111                          DRM_MEM_PAGES);
112                 drm_free(entry, sizeof(*entry), 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), DRM_MEM_PAGES);
121                 drm_free(entry->pagelist,
122                          entry->pages * sizeof(*entry->pagelist),
123                          DRM_MEM_PAGES);
124                 drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
125                 return -ENOMEM;
126         }
127
128         /* This also forces the mapping of COW pages, so our page list
129          * will be valid.  Please don't remove it...
130          */
131         memset(entry->virtual, 0, pages << PAGE_SHIFT);
132
133         entry->handle = ScatterHandle((unsigned long)entry->virtual);
134
135         DRM_DEBUG("sg alloc handle  = %08lx\n", entry->handle);
136         DRM_DEBUG("sg alloc virtual = %p\n", entry->virtual);
137
138         for (i = (unsigned long)entry->virtual, j = 0; j < pages;
139              i += PAGE_SIZE, j++) {
140                 entry->pagelist[j] = vmalloc_to_page((void *)i);
141                 if (!entry->pagelist[j])
142                         goto failed;
143                 SetPageReserved(entry->pagelist[j]);
144         }
145
146         request.handle = entry->handle;
147
148         if (copy_to_user(argp, &request, sizeof(request))) {
149                 drm_sg_cleanup(entry);
150                 return -EFAULT;
151         }
152
153         dev->sg = entry;
154
155 #if DEBUG_SCATTER
156         /* Verify that each page points to its virtual address, and vice
157          * versa.
158          */
159         {
160                 int error = 0;
161
162                 for (i = 0; i < pages; i++) {
163                         unsigned long *tmp;
164
165                         tmp = page_address(entry->pagelist[i]);
166                         for (j = 0;
167                              j < PAGE_SIZE / sizeof(unsigned long);
168                              j++, tmp++) {
169                                 *tmp = 0xcafebabe;
170                         }
171                         tmp = (unsigned long *)((u8 *) entry->virtual +
172                                                 (PAGE_SIZE * i));
173                         for (j = 0;
174                              j < PAGE_SIZE / sizeof(unsigned long);
175                              j++, tmp++) {
176                                 if (*tmp != 0xcafebabe && error == 0) {
177                                         error = 1;
178                                         DRM_ERROR("Scatter allocation error, "
179                                                   "pagelist does not match "
180                                                   "virtual mapping\n");
181                                 }
182                         }
183                         tmp = page_address(entry->pagelist[i]);
184                         for (j = 0;
185                              j < PAGE_SIZE / sizeof(unsigned long);
186                              j++, tmp++) {
187                                 *tmp = 0;
188                         }
189                 }
190                 if (error == 0)
191                         DRM_ERROR("Scatter allocation matches pagelist\n");
192         }
193 #endif
194
195         return 0;
196
197       failed:
198         drm_sg_cleanup(entry);
199         return -ENOMEM;
200 }
201
202 int drm_sg_free(struct inode *inode, struct file *filp,
203                 unsigned int cmd, unsigned long arg)
204 {
205         drm_file_t *priv = filp->private_data;
206         drm_device_t *dev = priv->head->dev;
207         drm_scatter_gather_t request;
208         drm_sg_mem_t *entry;
209
210         if (!drm_core_check_feature(dev, DRIVER_SG))
211                 return -EINVAL;
212
213         if (copy_from_user(&request,
214                            (drm_scatter_gather_t __user *) arg,
215                            sizeof(request)))
216                 return -EFAULT;
217
218         entry = dev->sg;
219         dev->sg = NULL;
220
221         if (!entry || entry->handle != request.handle)
222                 return -EINVAL;
223
224         DRM_DEBUG("sg free virtual  = %p\n", entry->virtual);
225
226         drm_sg_cleanup(entry);
227
228         return 0;
229 }