1 /* $NetBSD: drm_agp_hook.c,v 1.7 2022/07/19 22:24:34 riastradh Exp $ */
2
3 /*-
4 * Copyright (c) 2018 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Taylor R. Campbell.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: drm_agp_hook.c,v 1.7 2022/07/19 22:24:34 riastradh Exp $");
34
35 #include <sys/types.h>
36 #include <sys/condvar.h>
37 #include <sys/errno.h>
38 #include <sys/mutex.h>
39 #include <sys/once.h>
40
41 #include <drm/drm_agpsupport.h>
42 #include <drm/drm_drv.h>
43 #include "../dist/drm/drm_internal.h"
44
45 static struct {
46 kmutex_t lock;
47 kcondvar_t cv;
48 unsigned refcnt; /* at most one per device */
49 const struct drm_agp_hooks *hooks;
50 } agp_hooks __cacheline_aligned;
51
52 void
drm_agp_hooks_init(void)53 drm_agp_hooks_init(void)
54 {
55
56 mutex_init(&agp_hooks.lock, MUTEX_DEFAULT, IPL_NONE);
57 cv_init(&agp_hooks.cv, "agphooks");
58 agp_hooks.refcnt = 0;
59 agp_hooks.hooks = NULL;
60 }
61
62 void
drm_agp_hooks_fini(void)63 drm_agp_hooks_fini(void)
64 {
65
66 KASSERT(agp_hooks.hooks == NULL);
67 KASSERT(agp_hooks.refcnt == 0);
68 cv_destroy(&agp_hooks.cv);
69 mutex_destroy(&agp_hooks.lock);
70 }
71
72 int
drm_agp_register(const struct drm_agp_hooks * hooks)73 drm_agp_register(const struct drm_agp_hooks *hooks)
74 {
75 int error = 0;
76
77 mutex_enter(&agp_hooks.lock);
78 if (agp_hooks.refcnt) {
79 KASSERT(agp_hooks.hooks);
80 error = EBUSY;
81 } else {
82 agp_hooks.refcnt++;
83 agp_hooks.hooks = hooks;
84 }
85 mutex_exit(&agp_hooks.lock);
86
87 return error;
88 }
89
90 int
drm_agp_deregister(const struct drm_agp_hooks * hooks)91 drm_agp_deregister(const struct drm_agp_hooks *hooks)
92 {
93 int error = 0;
94
95 mutex_enter(&agp_hooks.lock);
96 KASSERT(agp_hooks.hooks == hooks);
97 if (agp_hooks.refcnt > 1) {
98 error = EBUSY;
99 } else {
100 agp_hooks.refcnt = 0;
101 agp_hooks.hooks = NULL;
102 }
103 mutex_exit(&agp_hooks.lock);
104
105 return error;
106 }
107
108 static const struct drm_agp_hooks *
drm_agp_hooks_acquire(void)109 drm_agp_hooks_acquire(void)
110 {
111 const struct drm_agp_hooks *hooks;
112
113 mutex_enter(&agp_hooks.lock);
114 if (agp_hooks.refcnt == 0) {
115 hooks = NULL;
116 } else {
117 KASSERT(agp_hooks.refcnt < UINT_MAX);
118 agp_hooks.refcnt++;
119 hooks = agp_hooks.hooks;
120 }
121 mutex_exit(&agp_hooks.lock);
122
123 return hooks;
124 }
125
126 static void
drm_agp_hooks_release(const struct drm_agp_hooks * hooks)127 drm_agp_hooks_release(const struct drm_agp_hooks *hooks)
128 {
129
130 mutex_enter(&agp_hooks.lock);
131 KASSERT(agp_hooks.hooks == hooks);
132 KASSERT(agp_hooks.refcnt);
133 if (--agp_hooks.refcnt == 0)
134 cv_broadcast(&agp_hooks.cv);
135 mutex_exit(&agp_hooks.lock);
136 }
137
138 struct drm_agp_head *
drm_agp_init(struct drm_device * dev)139 drm_agp_init(struct drm_device *dev)
140 {
141 const struct drm_agp_hooks *hooks;
142 struct drm_agp_head *agp;
143
144 if ((hooks = drm_agp_hooks_acquire()) == NULL)
145 return NULL;
146 agp = hooks->agph_init(dev);
147 if (agp == NULL)
148 drm_agp_hooks_release(hooks);
149 else
150 agp->hooks = hooks;
151
152 return agp;
153 }
154
155 void
drm_agp_fini(struct drm_device * dev)156 drm_agp_fini(struct drm_device *dev)
157 {
158
159 if (dev->agp == NULL)
160 return;
161 dev->agp->hooks->agph_clear(dev);
162 drm_agp_hooks_release(dev->agp->hooks);
163 kfree(dev->agp);
164 dev->agp = NULL;
165 }
166
167 void
drm_legacy_agp_clear(struct drm_device * dev)168 drm_legacy_agp_clear(struct drm_device *dev)
169 {
170
171 if (dev->agp == NULL)
172 return;
173 dev->agp->hooks->agph_clear(dev);
174 }
175
176 int
drm_agp_acquire(struct drm_device * dev)177 drm_agp_acquire(struct drm_device *dev)
178 {
179
180 if (dev->agp == NULL)
181 return -ENODEV;
182 return dev->agp->hooks->agph_acquire(dev);
183 }
184
185 int
drm_agp_release(struct drm_device * dev)186 drm_agp_release(struct drm_device *dev)
187 {
188
189 if (dev->agp == NULL)
190 return -EINVAL;
191 return dev->agp->hooks->agph_release(dev);
192 }
193
194 int
drm_agp_enable(struct drm_device * dev,struct drm_agp_mode mode)195 drm_agp_enable(struct drm_device *dev, struct drm_agp_mode mode)
196 {
197
198 if (dev->agp == NULL)
199 return -EINVAL;
200 return dev->agp->hooks->agph_enable(dev, mode);
201 }
202
203 int
drm_agp_info(struct drm_device * dev,struct drm_agp_info * info)204 drm_agp_info(struct drm_device *dev, struct drm_agp_info *info)
205 {
206
207 if (dev->agp == NULL)
208 return -EINVAL;
209 return dev->agp->hooks->agph_info(dev, info);
210 }
211
212 int
drm_agp_alloc(struct drm_device * dev,struct drm_agp_buffer * request)213 drm_agp_alloc(struct drm_device *dev, struct drm_agp_buffer *request)
214 {
215
216 if (dev->agp == NULL)
217 return -EINVAL;
218 return dev->agp->hooks->agph_alloc(dev, request);
219 }
220
221 int
drm_agp_free(struct drm_device * dev,struct drm_agp_buffer * request)222 drm_agp_free(struct drm_device *dev, struct drm_agp_buffer *request)
223 {
224
225 if (dev->agp == NULL)
226 return -EINVAL;
227 return dev->agp->hooks->agph_free(dev, request);
228 }
229
230 int
drm_agp_bind(struct drm_device * dev,struct drm_agp_binding * request)231 drm_agp_bind(struct drm_device *dev, struct drm_agp_binding *request)
232 {
233
234 if (dev->agp == NULL)
235 return -EINVAL;
236 return dev->agp->hooks->agph_bind(dev, request);
237 }
238
239 int
drm_agp_unbind(struct drm_device * dev,struct drm_agp_binding * request)240 drm_agp_unbind(struct drm_device *dev, struct drm_agp_binding *request)
241 {
242
243 if (dev->agp == NULL)
244 return -EINVAL;
245 return dev->agp->hooks->agph_unbind(dev, request);
246 }
247
248 #define DEFINE_AGP_HOOK_IOCTL(NAME, FIELD) \
249 int \
250 NAME(struct drm_device *dev, void *data, struct drm_file *file) \
251 { \
252 \
253 if (dev->agp == NULL) \
254 return -ENODEV; \
255 return dev->agp->hooks->FIELD(dev, data, file); \
256 }
257
DEFINE_AGP_HOOK_IOCTL(drm_agp_acquire_ioctl,agph_acquire_ioctl)258 DEFINE_AGP_HOOK_IOCTL(drm_agp_acquire_ioctl, agph_acquire_ioctl)
259 DEFINE_AGP_HOOK_IOCTL(drm_agp_release_ioctl, agph_release_ioctl)
260 DEFINE_AGP_HOOK_IOCTL(drm_agp_enable_ioctl, agph_enable_ioctl)
261 DEFINE_AGP_HOOK_IOCTL(drm_agp_info_ioctl, agph_info_ioctl)
262 DEFINE_AGP_HOOK_IOCTL(drm_agp_alloc_ioctl, agph_alloc_ioctl)
263 DEFINE_AGP_HOOK_IOCTL(drm_agp_free_ioctl, agph_free_ioctl)
264 DEFINE_AGP_HOOK_IOCTL(drm_agp_bind_ioctl, agph_bind_ioctl)
265 DEFINE_AGP_HOOK_IOCTL(drm_agp_unbind_ioctl, agph_unbind_ioctl)
266
267 void
268 drm_agp_flush(void)
269 {
270 const struct drm_agp_hooks *hooks;
271
272 if ((hooks = drm_agp_hooks_acquire()) == NULL)
273 return;
274 hooks->agph_flush();
275 drm_agp_hooks_release(hooks);
276 }
277