xref: /freebsd/sys/dev/drm2/drm_context.c (revision 4fd0d10e0fe684211328bc148edf89a792425b39)
1 /*-
2  * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
3  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
4  * All Rights Reserved.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the "Software"),
8  * to deal in the Software without restriction, including without limitation
9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10  * and/or sell copies of the Software, and to permit persons to whom the
11  * Software is furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice (including the next
14  * paragraph) shall be included in all copies or substantial portions of the
15  * Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
20  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
21  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
22  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
23  * OTHER DEALINGS IN THE SOFTWARE.
24  *
25  * Authors:
26  *    Rickard E. (Rik) Faith <faith@valinux.com>
27  *    Gareth Hughes <gareth@valinux.com>
28  *
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 /** @file drm_context.c
35  * Implementation of the context management ioctls.
36  */
37 
38 #include <dev/drm2/drmP.h>
39 
40 /* ================================================================
41  * Context bitmap support
42  */
43 
44 void drm_ctxbitmap_free(struct drm_device *dev, int ctx_handle)
45 {
46 	if (ctx_handle < 0 || ctx_handle >= DRM_MAX_CTXBITMAP ||
47 	    dev->ctx_bitmap == NULL) {
48 		DRM_ERROR("Attempt to free invalid context handle: %d\n",
49 		   ctx_handle);
50 		return;
51 	}
52 
53 	DRM_LOCK(dev);
54 	clear_bit(ctx_handle, dev->ctx_bitmap);
55 	dev->context_sareas[ctx_handle] = NULL;
56 	DRM_UNLOCK(dev);
57 	return;
58 }
59 
60 int drm_ctxbitmap_next(struct drm_device *dev)
61 {
62 	int bit;
63 
64 	if (dev->ctx_bitmap == NULL)
65 		return -1;
66 
67 	DRM_LOCK(dev);
68 	bit = find_first_zero_bit(dev->ctx_bitmap, DRM_MAX_CTXBITMAP);
69 	if (bit >= DRM_MAX_CTXBITMAP) {
70 		DRM_UNLOCK(dev);
71 		return -1;
72 	}
73 
74 	set_bit(bit, dev->ctx_bitmap);
75 	DRM_DEBUG("bit : %d\n", bit);
76 	if ((bit+1) > dev->max_context) {
77 		drm_local_map_t **ctx_sareas;
78 		int max_ctx = (bit+1);
79 
80 		ctx_sareas = realloc(dev->context_sareas,
81 		    max_ctx * sizeof(*dev->context_sareas),
82 		    DRM_MEM_SAREA, M_NOWAIT);
83 		if (ctx_sareas == NULL) {
84 			clear_bit(bit, dev->ctx_bitmap);
85 			DRM_DEBUG("failed to allocate bit : %d\n", bit);
86 			DRM_UNLOCK(dev);
87 			return -1;
88 		}
89 		dev->max_context = max_ctx;
90 		dev->context_sareas = ctx_sareas;
91 		dev->context_sareas[bit] = NULL;
92 	}
93 	DRM_UNLOCK(dev);
94 	return bit;
95 }
96 
97 int drm_ctxbitmap_init(struct drm_device *dev)
98 {
99 	int i;
100    	int temp;
101 
102 	DRM_LOCK(dev);
103 	dev->ctx_bitmap = malloc(PAGE_SIZE, DRM_MEM_CTXBITMAP,
104 	    M_NOWAIT | M_ZERO);
105 	if (dev->ctx_bitmap == NULL) {
106 		DRM_UNLOCK(dev);
107 		return ENOMEM;
108 	}
109 	dev->context_sareas = NULL;
110 	dev->max_context = -1;
111 	DRM_UNLOCK(dev);
112 
113 	for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
114 		temp = drm_ctxbitmap_next(dev);
115 		DRM_DEBUG("drm_ctxbitmap_init : %d\n", temp);
116 	}
117 
118 	return 0;
119 }
120 
121 void drm_ctxbitmap_cleanup(struct drm_device *dev)
122 {
123 	DRM_LOCK(dev);
124 	if (dev->context_sareas != NULL)
125 		free(dev->context_sareas, DRM_MEM_SAREA);
126 	free(dev->ctx_bitmap, DRM_MEM_CTXBITMAP);
127 	DRM_UNLOCK(dev);
128 }
129 
130 /* ================================================================
131  * Per Context SAREA Support
132  */
133 
134 int drm_getsareactx(struct drm_device *dev, void *data,
135 		    struct drm_file *file_priv)
136 {
137 	struct drm_ctx_priv_map *request = data;
138 	drm_local_map_t *map;
139 
140 	DRM_LOCK(dev);
141 	if (dev->max_context < 0 ||
142 	    request->ctx_id >= (unsigned) dev->max_context) {
143 		DRM_UNLOCK(dev);
144 		return EINVAL;
145 	}
146 
147 	map = dev->context_sareas[request->ctx_id];
148 	DRM_UNLOCK(dev);
149 
150 	request->handle = (void *)map->handle;
151 
152 	return 0;
153 }
154 
155 int drm_setsareactx(struct drm_device *dev, void *data,
156 		    struct drm_file *file_priv)
157 {
158 	struct drm_ctx_priv_map *request = data;
159 	drm_local_map_t *map = NULL;
160 
161 	DRM_LOCK(dev);
162 	TAILQ_FOREACH(map, &dev->maplist, link) {
163 		if (map->handle == request->handle) {
164 			if (dev->max_context < 0)
165 				goto bad;
166 			if (request->ctx_id >= (unsigned) dev->max_context)
167 				goto bad;
168 			dev->context_sareas[request->ctx_id] = map;
169 			DRM_UNLOCK(dev);
170 			return 0;
171 		}
172 	}
173 
174 bad:
175 	DRM_UNLOCK(dev);
176 	return EINVAL;
177 }
178 
179 /* ================================================================
180  * The actual DRM context handling routines
181  */
182 
183 int drm_context_switch(struct drm_device *dev, int old, int new)
184 {
185 	if (atomic_xchg(&dev->context_flag, 1) != 0) {
186 		DRM_ERROR("Reentering -- FIXME\n");
187 		return EBUSY;
188 	}
189 
190 	DRM_DEBUG("Context switch from %d to %d\n", old, new);
191 
192 	if (new == dev->last_context) {
193 		atomic_xchg(&dev->context_flag, 0);
194 		return 0;
195 	}
196 
197 	return 0;
198 }
199 
200 int drm_context_switch_complete(struct drm_device *dev, int new)
201 {
202 	dev->last_context = new;  /* PRE/POST: This is the _only_ writer. */
203 
204 	if (!_DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock)) {
205 		DRM_ERROR("Lock isn't held after context switch\n");
206 	}
207 
208 	/* If a context switch is ever initiated
209 	   when the kernel holds the lock, release
210 	   that lock here. */
211 	atomic_xchg(&dev->context_flag, 0);
212 
213 	return 0;
214 }
215 
216 int drm_resctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
217 {
218 	struct drm_ctx_res *res = data;
219 	struct drm_ctx ctx;
220 	int i;
221 
222 	if (res->count >= DRM_RESERVED_CONTEXTS) {
223 		bzero(&ctx, sizeof(ctx));
224 		for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
225 			ctx.handle = i;
226 			if (DRM_COPY_TO_USER(&res->contexts[i],
227 			    &ctx, sizeof(ctx)))
228 				return EFAULT;
229 		}
230 	}
231 	res->count = DRM_RESERVED_CONTEXTS;
232 
233 	return 0;
234 }
235 
236 int drm_addctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
237 {
238 	struct drm_ctx *ctx = data;
239 
240 	ctx->handle = drm_ctxbitmap_next(dev);
241 	if (ctx->handle == DRM_KERNEL_CONTEXT) {
242 		/* Skip kernel's context and get a new one. */
243 		ctx->handle = drm_ctxbitmap_next(dev);
244 	}
245 	DRM_DEBUG("%d\n", ctx->handle);
246 	if (ctx->handle == -1) {
247 		DRM_DEBUG("Not enough free contexts.\n");
248 		/* Should this return -EBUSY instead? */
249 		return ENOMEM;
250 	}
251 
252 	if (dev->driver->context_ctor && ctx->handle != DRM_KERNEL_CONTEXT) {
253 		DRM_LOCK(dev);
254 		dev->driver->context_ctor(dev, ctx->handle);
255 		DRM_UNLOCK(dev);
256 	}
257 
258 	return 0;
259 }
260 
261 int drm_modctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
262 {
263 	/* This does nothing */
264 	return 0;
265 }
266 
267 int drm_getctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
268 {
269 	struct drm_ctx *ctx = data;
270 
271 	/* This is 0, because we don't handle any context flags */
272 	ctx->flags = 0;
273 
274 	return 0;
275 }
276 
277 int drm_switchctx(struct drm_device *dev, void *data,
278 		  struct drm_file *file_priv)
279 {
280 	struct drm_ctx *ctx = data;
281 
282 	DRM_DEBUG("%d\n", ctx->handle);
283 	return drm_context_switch(dev, dev->last_context, ctx->handle);
284 }
285 
286 int drm_newctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
287 {
288 	struct drm_ctx *ctx = data;
289 
290 	DRM_DEBUG("%d\n", ctx->handle);
291 	drm_context_switch_complete(dev, ctx->handle);
292 
293 	return 0;
294 }
295 
296 int drm_rmctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
297 {
298 	struct drm_ctx *ctx = data;
299 
300 	DRM_DEBUG("%d\n", ctx->handle);
301 	if (ctx->handle != DRM_KERNEL_CONTEXT) {
302 		if (dev->driver->context_dtor) {
303 			DRM_LOCK(dev);
304 			dev->driver->context_dtor(dev, ctx->handle);
305 			DRM_UNLOCK(dev);
306 		}
307 
308 		drm_ctxbitmap_free(dev, ctx->handle);
309 	}
310 
311 	return 0;
312 }
313