1 /* $NetBSD: drm_scatter.c,v 1.3 2021/12/18 23:44:57 riastradh Exp $ */
2
3 /*
4 * \file drm_scatter.c
5 * IOCTLs to manage scatter/gather memory
6 *
7 * \author Gareth Hughes <gareth@valinux.com>
8 */
9
10 /*
11 * Created: Mon Dec 18 23:20:54 2000 by gareth@valinux.com
12 *
13 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
14 * All Rights Reserved.
15 *
16 * Permission is hereby granted, free of charge, to any person obtaining a
17 * copy of this software and associated documentation files (the "Software"),
18 * to deal in the Software without restriction, including without limitation
19 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
20 * and/or sell copies of the Software, and to permit persons to whom the
21 * Software is furnished to do so, subject to the following conditions:
22 *
23 * The above copyright notice and this permission notice (including the next
24 * paragraph) shall be included in all copies or substantial portions of the
25 * Software.
26 *
27 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
28 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
29 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
30 * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
31 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
32 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
33 * DEALINGS IN THE SOFTWARE.
34 */
35
36 #include <sys/cdefs.h>
37 __KERNEL_RCSID(0, "$NetBSD: drm_scatter.c,v 1.3 2021/12/18 23:44:57 riastradh Exp $");
38
39 #include <linux/mm.h>
40 #include <linux/slab.h>
41 #include <linux/vmalloc.h>
42
43 #include <drm/drm.h>
44 #include <drm/drm_drv.h>
45 #include <drm/drm_print.h>
46
47 #include "drm_legacy.h"
48
49 #define DEBUG_SCATTER 0
50
drm_vmalloc_dma(unsigned long size)51 static inline void *drm_vmalloc_dma(unsigned long size)
52 {
53 #if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE)
54 return __vmalloc(size, GFP_KERNEL, pgprot_noncached_wc(PAGE_KERNEL));
55 #else
56 return vmalloc_32(size);
57 #endif
58 }
59
drm_sg_cleanup(struct drm_sg_mem * entry)60 static void drm_sg_cleanup(struct drm_sg_mem * entry)
61 {
62 struct page *page;
63 int i;
64
65 for (i = 0; i < entry->pages; i++) {
66 page = entry->pagelist[i];
67 if (page)
68 ClearPageReserved(page);
69 }
70
71 vfree(entry->virtual);
72
73 kfree(entry->busaddr);
74 kfree(entry->pagelist);
75 kfree(entry);
76 }
77
drm_legacy_sg_cleanup(struct drm_device * dev)78 void drm_legacy_sg_cleanup(struct drm_device *dev)
79 {
80 if (drm_core_check_feature(dev, DRIVER_SG) && dev->sg &&
81 drm_core_check_feature(dev, DRIVER_LEGACY)) {
82 drm_sg_cleanup(dev->sg);
83 dev->sg = NULL;
84 }
85 }
86 #ifdef _LP64
87 # define ScatterHandle(x) (unsigned int)((x >> 32) + (x & ((1L << 32) - 1)))
88 #else
89 # define ScatterHandle(x) (unsigned int)(x)
90 #endif
91
drm_legacy_sg_alloc(struct drm_device * dev,void * data,struct drm_file * file_priv)92 int drm_legacy_sg_alloc(struct drm_device *dev, void *data,
93 struct drm_file *file_priv)
94 {
95 struct drm_scatter_gather *request = data;
96 struct drm_sg_mem *entry;
97 unsigned long pages, i, j;
98
99 DRM_DEBUG("\n");
100
101 if (!drm_core_check_feature(dev, DRIVER_LEGACY))
102 return -EOPNOTSUPP;
103
104 if (!drm_core_check_feature(dev, DRIVER_SG))
105 return -EOPNOTSUPP;
106
107 if (dev->sg)
108 return -EINVAL;
109
110 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
111 if (!entry)
112 return -ENOMEM;
113
114 pages = (request->size + PAGE_SIZE - 1) / PAGE_SIZE;
115 DRM_DEBUG("size=%ld pages=%ld\n", request->size, pages);
116
117 entry->pages = pages;
118 entry->pagelist = kcalloc(pages, sizeof(*entry->pagelist), GFP_KERNEL);
119 if (!entry->pagelist) {
120 kfree(entry);
121 return -ENOMEM;
122 }
123
124 entry->busaddr = kcalloc(pages, sizeof(*entry->busaddr), GFP_KERNEL);
125 if (!entry->busaddr) {
126 kfree(entry->pagelist);
127 kfree(entry);
128 return -ENOMEM;
129 }
130
131 entry->virtual = drm_vmalloc_dma(pages << PAGE_SHIFT);
132 if (!entry->virtual) {
133 kfree(entry->busaddr);
134 kfree(entry->pagelist);
135 kfree(entry);
136 return -ENOMEM;
137 }
138
139 /* This also forces the mapping of COW pages, so our page list
140 * will be valid. Please don't remove it...
141 */
142 memset(entry->virtual, 0, pages << PAGE_SHIFT);
143
144 entry->handle = ScatterHandle((unsigned long)entry->virtual);
145
146 DRM_DEBUG("handle = %08lx\n", entry->handle);
147 DRM_DEBUG("virtual = %p\n", entry->virtual);
148
149 for (i = (unsigned long)entry->virtual, j = 0; j < pages;
150 i += PAGE_SIZE, j++) {
151 entry->pagelist[j] = vmalloc_to_page((void *)i);
152 if (!entry->pagelist[j])
153 goto failed;
154 SetPageReserved(entry->pagelist[j]);
155 }
156
157 request->handle = entry->handle;
158
159 dev->sg = entry;
160
161 #if DEBUG_SCATTER
162 /* Verify that each page points to its virtual address, and vice
163 * versa.
164 */
165 {
166 int error = 0;
167
168 for (i = 0; i < pages; i++) {
169 unsigned long *tmp;
170
171 tmp = page_address(entry->pagelist[i]);
172 for (j = 0;
173 j < PAGE_SIZE / sizeof(unsigned long);
174 j++, tmp++) {
175 *tmp = 0xcafebabe;
176 }
177 tmp = (unsigned long *)((u8 *) entry->virtual +
178 (PAGE_SIZE * i));
179 for (j = 0;
180 j < PAGE_SIZE / sizeof(unsigned long);
181 j++, tmp++) {
182 if (*tmp != 0xcafebabe && error == 0) {
183 error = 1;
184 DRM_ERROR("Scatter allocation error, "
185 "pagelist does not match "
186 "virtual mapping\n");
187 }
188 }
189 tmp = page_address(entry->pagelist[i]);
190 for (j = 0;
191 j < PAGE_SIZE / sizeof(unsigned long);
192 j++, tmp++) {
193 *tmp = 0;
194 }
195 }
196 if (error == 0)
197 DRM_ERROR("Scatter allocation matches pagelist\n");
198 }
199 #endif
200
201 return 0;
202
203 failed:
204 drm_sg_cleanup(entry);
205 return -ENOMEM;
206 }
207
drm_legacy_sg_free(struct drm_device * dev,void * data,struct drm_file * file_priv)208 int drm_legacy_sg_free(struct drm_device *dev, void *data,
209 struct drm_file *file_priv)
210 {
211 struct drm_scatter_gather *request = data;
212 struct drm_sg_mem *entry;
213
214 if (!drm_core_check_feature(dev, DRIVER_LEGACY))
215 return -EOPNOTSUPP;
216
217 if (!drm_core_check_feature(dev, DRIVER_SG))
218 return -EOPNOTSUPP;
219
220 entry = dev->sg;
221 dev->sg = NULL;
222
223 if (!entry || entry->handle != request->handle)
224 return -EINVAL;
225
226 DRM_DEBUG("virtual = %p\n", entry->virtual);
227
228 drm_sg_cleanup(entry);
229
230 return 0;
231 }
232