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[linux-2.6-omap-h63xx.git] / 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/vmalloc.h>
35 #include "drmP.h"
36
37 #define DEBUG_SCATTER 0
38
39 void drm_sg_cleanup(struct drm_sg_mem * entry)
40 {
41         struct page *page;
42         int i;
43
44         for (i = 0; i < entry->pages; i++) {
45                 page = entry->pagelist[i];
46                 if (page)
47                         ClearPageReserved(page);
48         }
49
50         vfree(entry->virtual);
51
52         drm_free(entry->busaddr,
53                  entry->pages * sizeof(*entry->busaddr), DRM_MEM_PAGES);
54         drm_free(entry->pagelist,
55                  entry->pages * sizeof(*entry->pagelist), DRM_MEM_PAGES);
56         drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
57 }
58
59 #ifdef _LP64
60 # define ScatterHandle(x) (unsigned int)((x >> 32) + (x & ((1L << 32) - 1)))
61 #else
62 # define ScatterHandle(x) (unsigned int)(x)
63 #endif
64
65 int drm_sg_alloc(struct drm_device *dev, struct drm_scatter_gather * request)
66 {
67         struct drm_sg_mem *entry;
68         unsigned long pages, i, j;
69
70         DRM_DEBUG("\n");
71
72         if (!drm_core_check_feature(dev, DRIVER_SG))
73                 return -EINVAL;
74
75         if (dev->sg)
76                 return -EINVAL;
77
78         entry = drm_alloc(sizeof(*entry), DRM_MEM_SGLISTS);
79         if (!entry)
80                 return -ENOMEM;
81
82         memset(entry, 0, sizeof(*entry));
83         pages = (request->size + PAGE_SIZE - 1) / PAGE_SIZE;
84         DRM_DEBUG("size=%ld pages=%ld\n", request->size, pages);
85
86         entry->pages = pages;
87         entry->pagelist = drm_alloc(pages * sizeof(*entry->pagelist),
88                                     DRM_MEM_PAGES);
89         if (!entry->pagelist) {
90                 drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
91                 return -ENOMEM;
92         }
93
94         memset(entry->pagelist, 0, pages * sizeof(*entry->pagelist));
95
96         entry->busaddr = drm_alloc(pages * sizeof(*entry->busaddr),
97                                    DRM_MEM_PAGES);
98         if (!entry->busaddr) {
99                 drm_free(entry->pagelist,
100                          entry->pages * sizeof(*entry->pagelist),
101                          DRM_MEM_PAGES);
102                 drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
103                 return -ENOMEM;
104         }
105         memset((void *)entry->busaddr, 0, pages * sizeof(*entry->busaddr));
106
107         entry->virtual = vmalloc_32(pages << PAGE_SHIFT);
108         if (!entry->virtual) {
109                 drm_free(entry->busaddr,
110                          entry->pages * sizeof(*entry->busaddr), DRM_MEM_PAGES);
111                 drm_free(entry->pagelist,
112                          entry->pages * sizeof(*entry->pagelist),
113                          DRM_MEM_PAGES);
114                 drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
115                 return -ENOMEM;
116         }
117
118         /* This also forces the mapping of COW pages, so our page list
119          * will be valid.  Please don't remove it...
120          */
121         memset(entry->virtual, 0, pages << PAGE_SHIFT);
122
123         entry->handle = ScatterHandle((unsigned long)entry->virtual);
124
125         DRM_DEBUG("handle  = %08lx\n", entry->handle);
126         DRM_DEBUG("virtual = %p\n", entry->virtual);
127
128         for (i = (unsigned long)entry->virtual, j = 0; j < pages;
129              i += PAGE_SIZE, j++) {
130                 entry->pagelist[j] = vmalloc_to_page((void *)i);
131                 if (!entry->pagelist[j])
132                         goto failed;
133                 SetPageReserved(entry->pagelist[j]);
134         }
135
136         request->handle = entry->handle;
137
138         dev->sg = entry;
139
140 #if DEBUG_SCATTER
141         /* Verify that each page points to its virtual address, and vice
142          * versa.
143          */
144         {
145                 int error = 0;
146
147                 for (i = 0; i < pages; i++) {
148                         unsigned long *tmp;
149
150                         tmp = page_address(entry->pagelist[i]);
151                         for (j = 0;
152                              j < PAGE_SIZE / sizeof(unsigned long);
153                              j++, tmp++) {
154                                 *tmp = 0xcafebabe;
155                         }
156                         tmp = (unsigned long *)((u8 *) entry->virtual +
157                                                 (PAGE_SIZE * i));
158                         for (j = 0;
159                              j < PAGE_SIZE / sizeof(unsigned long);
160                              j++, tmp++) {
161                                 if (*tmp != 0xcafebabe && error == 0) {
162                                         error = 1;
163                                         DRM_ERROR("Scatter allocation error, "
164                                                   "pagelist does not match "
165                                                   "virtual mapping\n");
166                                 }
167                         }
168                         tmp = page_address(entry->pagelist[i]);
169                         for (j = 0;
170                              j < PAGE_SIZE / sizeof(unsigned long);
171                              j++, tmp++) {
172                                 *tmp = 0;
173                         }
174                 }
175                 if (error == 0)
176                         DRM_ERROR("Scatter allocation matches pagelist\n");
177         }
178 #endif
179
180         return 0;
181
182       failed:
183         drm_sg_cleanup(entry);
184         return -ENOMEM;
185 }
186 EXPORT_SYMBOL(drm_sg_alloc);
187
188
189 int drm_sg_alloc_ioctl(struct drm_device *dev, void *data,
190                        struct drm_file *file_priv)
191 {
192         struct drm_scatter_gather *request = data;
193
194         return drm_sg_alloc(dev, request);
195
196 }
197
198 int drm_sg_free(struct drm_device *dev, void *data,
199                 struct drm_file *file_priv)
200 {
201         struct drm_scatter_gather *request = data;
202         struct drm_sg_mem *entry;
203
204         if (!drm_core_check_feature(dev, DRIVER_SG))
205                 return -EINVAL;
206
207         entry = dev->sg;
208         dev->sg = NULL;
209
210         if (!entry || entry->handle != request->handle)
211                 return -EINVAL;
212
213         DRM_DEBUG("virtual  = %p\n", entry->virtual);
214
215         drm_sg_cleanup(entry);
216
217         return 0;
218 }