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/mm.h>
35 #include <linux/slab.h>
36 #include <linux/vmalloc.h>
37
38 #include <drm/drm.h>
39 #include <drm/drm_drv.h>
40 #include <drm/drm_print.h>
41
42 #include "drm_legacy.h"
43
44 #define DEBUG_SCATTER 0
45
drm_sg_cleanup(struct drm_sg_mem * entry)46 static void drm_sg_cleanup(struct drm_sg_mem * entry)
47 {
48 struct page *page;
49 int i;
50
51 for (i = 0; i < entry->pages; i++) {
52 page = entry->pagelist[i];
53 if (page)
54 ClearPageReserved(page);
55 }
56
57 vfree(entry->virtual);
58
59 kfree(entry->busaddr);
60 kfree(entry->pagelist);
61 kfree(entry);
62 }
63
drm_legacy_sg_cleanup(struct drm_device * dev)64 void drm_legacy_sg_cleanup(struct drm_device *dev)
65 {
66 if (drm_core_check_feature(dev, DRIVER_SG) && dev->sg &&
67 drm_core_check_feature(dev, DRIVER_LEGACY)) {
68 drm_sg_cleanup(dev->sg);
69 dev->sg = NULL;
70 }
71 }
72 #ifdef _LP64
73 # define ScatterHandle(x) (unsigned int)((x >> 32) + (x & ((1L << 32) - 1)))
74 #else
75 # define ScatterHandle(x) (unsigned int)(x)
76 #endif
77
drm_legacy_sg_alloc(struct drm_device * dev,void * data,struct drm_file * file_priv)78 int drm_legacy_sg_alloc(struct drm_device *dev, void *data,
79 struct drm_file *file_priv)
80 {
81 struct drm_scatter_gather *request = data;
82 struct drm_sg_mem *entry;
83 unsigned long pages, i, j;
84
85 DRM_DEBUG("\n");
86
87 if (!drm_core_check_feature(dev, DRIVER_LEGACY))
88 return -EOPNOTSUPP;
89
90 if (!drm_core_check_feature(dev, DRIVER_SG))
91 return -EOPNOTSUPP;
92
93 if (request->size > SIZE_MAX - PAGE_SIZE)
94 return -EINVAL;
95
96 if (dev->sg)
97 return -EINVAL;
98
99 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
100 if (!entry)
101 return -ENOMEM;
102
103 pages = (request->size + PAGE_SIZE - 1) / PAGE_SIZE;
104 DRM_DEBUG("size=%ld pages=%ld\n", request->size, pages);
105
106 entry->pages = pages;
107 entry->pagelist = kcalloc(pages, sizeof(*entry->pagelist), GFP_KERNEL);
108 if (!entry->pagelist) {
109 kfree(entry);
110 return -ENOMEM;
111 }
112
113 entry->busaddr = kcalloc(pages, sizeof(*entry->busaddr), GFP_KERNEL);
114 if (!entry->busaddr) {
115 kfree(entry->pagelist);
116 kfree(entry);
117 return -ENOMEM;
118 }
119
120 entry->virtual = vmalloc_32(pages << PAGE_SHIFT);
121 if (!entry->virtual) {
122 kfree(entry->busaddr);
123 kfree(entry->pagelist);
124 kfree(entry);
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("handle = %08lx\n", entry->handle);
136 DRM_DEBUG("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 dev->sg = entry;
149
150 #if DEBUG_SCATTER
151 /* Verify that each page points to its virtual address, and vice
152 * versa.
153 */
154 {
155 int error = 0;
156
157 for (i = 0; i < pages; i++) {
158 unsigned long *tmp;
159
160 tmp = page_address(entry->pagelist[i]);
161 for (j = 0;
162 j < PAGE_SIZE / sizeof(unsigned long);
163 j++, tmp++) {
164 *tmp = 0xcafebabe;
165 }
166 tmp = (unsigned long *)((u8 *) entry->virtual +
167 (PAGE_SIZE * i));
168 for (j = 0;
169 j < PAGE_SIZE / sizeof(unsigned long);
170 j++, tmp++) {
171 if (*tmp != 0xcafebabe && error == 0) {
172 error = 1;
173 DRM_ERROR("Scatter allocation error, "
174 "pagelist does not match "
175 "virtual mapping\n");
176 }
177 }
178 tmp = page_address(entry->pagelist[i]);
179 for (j = 0;
180 j < PAGE_SIZE / sizeof(unsigned long);
181 j++, tmp++) {
182 *tmp = 0;
183 }
184 }
185 if (error == 0)
186 DRM_ERROR("Scatter allocation matches pagelist\n");
187 }
188 #endif
189
190 return 0;
191
192 failed:
193 drm_sg_cleanup(entry);
194 return -ENOMEM;
195 }
196
drm_legacy_sg_free(struct drm_device * dev,void * data,struct drm_file * file_priv)197 int drm_legacy_sg_free(struct drm_device *dev, void *data,
198 struct drm_file *file_priv)
199 {
200 struct drm_scatter_gather *request = data;
201 struct drm_sg_mem *entry;
202
203 if (!drm_core_check_feature(dev, DRIVER_LEGACY))
204 return -EOPNOTSUPP;
205
206 if (!drm_core_check_feature(dev, DRIVER_SG))
207 return -EOPNOTSUPP;
208
209 entry = dev->sg;
210 dev->sg = NULL;
211
212 if (!entry || entry->handle != request->handle)
213 return -EINVAL;
214
215 DRM_DEBUG("virtual = %p\n", entry->virtual);
216
217 drm_sg_cleanup(entry);
218
219 return 0;
220 }
221