xref: /freebsd-12.1/sys/dev/drm/drm_context.c (revision dfd1ff19) 
1 /* drm_context.h -- IOCTLs for generic contexts -*- linux-c -*-
2  * Created: Fri Nov 24 18:31:37 2000 by [email protected]
3  */
4 /*-
5  * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
6  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
7  * All Rights Reserved.
8  *
9  * Permission is hereby granted, free of charge, to any person obtaining a
10  * copy of this software and associated documentation files (the "Software"),
11  * to deal in the Software without restriction, including without limitation
12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
13  * and/or sell copies of the Software, and to permit persons to whom the
14  * Software is furnished to do so, subject to the following conditions:
15  *
16  * The above copyright notice and this permission notice (including the next
17  * paragraph) shall be included in all copies or substantial portions of the
18  * Software.
19  *
20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
23  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
24  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
25  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
26  * OTHER DEALINGS IN THE SOFTWARE.
27  *
28  * Authors:
29  *    Rickard E. (Rik) Faith <[email protected]>
30  *    Gareth Hughes <[email protected]>
31  *
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include "dev/drm/drmP.h"
38 
39 /* ================================================================
40  * Context bitmap support
41  */
42 
43 void drm_ctxbitmap_free(drm_device_t *dev, int ctx_handle)
44 {
45 	if (ctx_handle < 0 || ctx_handle >= DRM_MAX_CTXBITMAP ||
46 	    dev->ctx_bitmap == NULL) {
47 		DRM_ERROR("Attempt to free invalid context handle: %d\n",
48 		   ctx_handle);
49 		return;
50 	}
51 
52 	DRM_LOCK();
53 	clear_bit(ctx_handle, dev->ctx_bitmap);
54 	dev->context_sareas[ctx_handle] = NULL;
55 	DRM_UNLOCK();
56 	return;
57 }
58 
59 int drm_ctxbitmap_next(drm_device_t *dev)
60 {
61 	int bit;
62 
63 	if (dev->ctx_bitmap == NULL)
64 		return -1;
65 
66 	DRM_LOCK();
67 	bit = find_first_zero_bit( dev->ctx_bitmap, DRM_MAX_CTXBITMAP );
68 	if (bit >= DRM_MAX_CTXBITMAP) {
69 		DRM_UNLOCK();
70 		return -1;
71 	}
72 
73 	set_bit(bit, dev->ctx_bitmap);
74 	DRM_DEBUG("drm_ctxbitmap_next bit : %d\n", bit);
75 	if ((bit+1) > dev->max_context) {
76 		dev->max_context = (bit+1);
77 		if (dev->context_sareas != NULL) {
78 			drm_local_map_t **ctx_sareas;
79 
80 			ctx_sareas = realloc(dev->context_sareas,
81 			    dev->max_context * sizeof(*dev->context_sareas),
82 			    M_DRM, M_NOWAIT);
83 			if (ctx_sareas == NULL) {
84 				clear_bit(bit, dev->ctx_bitmap);
85 				DRM_UNLOCK();
86 				return -1;
87 			}
88 			dev->context_sareas = ctx_sareas;
89 			dev->context_sareas[bit] = NULL;
90 		} else {
91 			/* max_context == 1 at this point */
92 			dev->context_sareas = malloc(dev->max_context *
93 			    sizeof(*dev->context_sareas), M_DRM, M_NOWAIT);
94 			if (dev->context_sareas == NULL) {
95 				clear_bit(bit, dev->ctx_bitmap);
96 				DRM_UNLOCK();
97 				return -1;
98 			}
99 			dev->context_sareas[bit] = NULL;
100 		}
101 	}
102 	DRM_UNLOCK();
103 	return bit;
104 }
105 
106 int drm_ctxbitmap_init(drm_device_t *dev)
107 {
108 	int i;
109    	int temp;
110 
111 	DRM_LOCK();
112 	dev->ctx_bitmap = malloc(PAGE_SIZE, M_DRM, M_NOWAIT | M_ZERO);
113 	if ( dev->ctx_bitmap == NULL ) {
114 		DRM_UNLOCK();
115 		return DRM_ERR(ENOMEM);
116 	}
117 	dev->context_sareas = NULL;
118 	dev->max_context = -1;
119 	DRM_UNLOCK();
120 
121 	for ( i = 0 ; i < DRM_RESERVED_CONTEXTS ; i++ ) {
122 		temp = drm_ctxbitmap_next(dev);
123 	   	DRM_DEBUG( "drm_ctxbitmap_init : %d\n", temp );
124 	}
125 
126 	return 0;
127 }
128 
129 void drm_ctxbitmap_cleanup(drm_device_t *dev)
130 {
131 	DRM_LOCK();
132 	if (dev->context_sareas != NULL)
133 		free(dev->context_sareas, M_DRM);
134 	free(dev->ctx_bitmap, M_DRM);
135 	DRM_UNLOCK();
136 }
137 
138 /* ================================================================
139  * Per Context SAREA Support
140  */
141 
142 int drm_getsareactx( DRM_IOCTL_ARGS )
143 {
144 	DRM_DEVICE;
145 	drm_ctx_priv_map_t request;
146 	drm_local_map_t *map;
147 
148 	DRM_COPY_FROM_USER_IOCTL( request, (drm_ctx_priv_map_t *)data,
149 			   sizeof(request) );
150 
151 	DRM_LOCK();
152 	if (dev->max_context < 0 || request.ctx_id >= (unsigned) dev->max_context) {
153 		DRM_UNLOCK();
154 		return DRM_ERR(EINVAL);
155 	}
156 
157 	map = dev->context_sareas[request.ctx_id];
158 	DRM_UNLOCK();
159 
160 	request.handle = map->handle;
161 
162 	DRM_COPY_TO_USER_IOCTL( (drm_ctx_priv_map_t *)data, request, sizeof(request) );
163 
164 	return 0;
165 }
166 
167 int drm_setsareactx( DRM_IOCTL_ARGS )
168 {
169 	DRM_DEVICE;
170 	drm_ctx_priv_map_t request;
171 	drm_local_map_t *map = NULL;
172 
173 	DRM_COPY_FROM_USER_IOCTL( request, (drm_ctx_priv_map_t *)data,
174 			   sizeof(request) );
175 
176 	DRM_LOCK();
177 	TAILQ_FOREACH(map, &dev->maplist, link) {
178 		if (map->handle == request.handle) {
179 			if (dev->max_context < 0)
180 				goto bad;
181 			if (request.ctx_id >= (unsigned) dev->max_context)
182 				goto bad;
183 			dev->context_sareas[request.ctx_id] = map;
184 			DRM_UNLOCK();
185 			return 0;
186 		}
187 	}
188 
189 bad:
190 	DRM_UNLOCK();
191 	return DRM_ERR(EINVAL);
192 }
193 
194 /* ================================================================
195  * The actual DRM context handling routines
196  */
197 
198 int drm_context_switch(drm_device_t *dev, int old, int new)
199 {
200         if ( test_and_set_bit( 0, &dev->context_flag ) ) {
201                 DRM_ERROR( "Reentering -- FIXME\n" );
202                 return DRM_ERR(EBUSY);
203         }
204 
205         DRM_DEBUG( "Context switch from %d to %d\n", old, new );
206 
207         if ( new == dev->last_context ) {
208                 clear_bit( 0, &dev->context_flag );
209                 return 0;
210         }
211 
212         return 0;
213 }
214 
215 int drm_context_switch_complete(drm_device_t *dev, int new)
216 {
217         dev->last_context = new;  /* PRE/POST: This is the _only_ writer. */
218 
219         if ( !_DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock) ) {
220                 DRM_ERROR( "Lock isn't held after context switch\n" );
221         }
222 
223 				/* If a context switch is ever initiated
224                                    when the kernel holds the lock, release
225                                    that lock here. */
226         clear_bit( 0, &dev->context_flag );
227 
228         return 0;
229 }
230 
231 int drm_resctx(DRM_IOCTL_ARGS)
232 {
233 	drm_ctx_res_t res;
234 	drm_ctx_t ctx;
235 	int i;
236 
237 	DRM_COPY_FROM_USER_IOCTL( res, (drm_ctx_res_t *)data, sizeof(res) );
238 
239 	if ( res.count >= DRM_RESERVED_CONTEXTS ) {
240 		bzero(&ctx, sizeof(ctx));
241 		for ( i = 0 ; i < DRM_RESERVED_CONTEXTS ; i++ ) {
242 			ctx.handle = i;
243 			if ( DRM_COPY_TO_USER( &res.contexts[i],
244 					   &ctx, sizeof(ctx) ) )
245 				return DRM_ERR(EFAULT);
246 		}
247 	}
248 	res.count = DRM_RESERVED_CONTEXTS;
249 
250 	DRM_COPY_TO_USER_IOCTL( (drm_ctx_res_t *)data, res, sizeof(res) );
251 
252 	return 0;
253 }
254 
255 int drm_addctx(DRM_IOCTL_ARGS)
256 {
257 	DRM_DEVICE;
258 	drm_ctx_t ctx;
259 
260 	DRM_COPY_FROM_USER_IOCTL( ctx, (drm_ctx_t *)data, sizeof(ctx) );
261 
262 	ctx.handle = drm_ctxbitmap_next(dev);
263 	if ( ctx.handle == DRM_KERNEL_CONTEXT ) {
264 				/* Skip kernel's context and get a new one. */
265 		ctx.handle = drm_ctxbitmap_next(dev);
266 	}
267 	DRM_DEBUG( "%d\n", ctx.handle );
268 	if ( ctx.handle == -1 ) {
269 		DRM_DEBUG( "Not enough free contexts.\n" );
270 				/* Should this return -EBUSY instead? */
271 		return DRM_ERR(ENOMEM);
272 	}
273 
274 	if (dev->driver.context_ctor && ctx.handle != DRM_KERNEL_CONTEXT) {
275 		DRM_LOCK();
276 		dev->driver.context_ctor(dev, ctx.handle);
277 		DRM_UNLOCK();
278 	}
279 
280 	DRM_COPY_TO_USER_IOCTL( (drm_ctx_t *)data, ctx, sizeof(ctx) );
281 
282 	return 0;
283 }
284 
285 int drm_modctx(DRM_IOCTL_ARGS)
286 {
287 	/* This does nothing */
288 	return 0;
289 }
290 
291 int drm_getctx(DRM_IOCTL_ARGS)
292 {
293 	drm_ctx_t ctx;
294 
295 	DRM_COPY_FROM_USER_IOCTL( ctx, (drm_ctx_t *)data, sizeof(ctx) );
296 
297 	/* This is 0, because we don't handle any context flags */
298 	ctx.flags = 0;
299 
300 	DRM_COPY_TO_USER_IOCTL( (drm_ctx_t *)data, ctx, sizeof(ctx) );
301 
302 	return 0;
303 }
304 
305 int drm_switchctx(DRM_IOCTL_ARGS)
306 {
307 	DRM_DEVICE;
308 	drm_ctx_t ctx;
309 
310 	DRM_COPY_FROM_USER_IOCTL( ctx, (drm_ctx_t *)data, sizeof(ctx) );
311 
312 	DRM_DEBUG( "%d\n", ctx.handle );
313 	return drm_context_switch(dev, dev->last_context, ctx.handle);
314 }
315 
316 int drm_newctx(DRM_IOCTL_ARGS)
317 {
318 	DRM_DEVICE;
319 	drm_ctx_t ctx;
320 
321 	DRM_COPY_FROM_USER_IOCTL( ctx, (drm_ctx_t *)data, sizeof(ctx) );
322 
323 	DRM_DEBUG( "%d\n", ctx.handle );
324 	drm_context_switch_complete(dev, ctx.handle);
325 
326 	return 0;
327 }
328 
329 int drm_rmctx(DRM_IOCTL_ARGS)
330 {
331 	DRM_DEVICE;
332 	drm_ctx_t ctx;
333 
334 	DRM_COPY_FROM_USER_IOCTL( ctx, (drm_ctx_t *)data, sizeof(ctx) );
335 
336 	DRM_DEBUG( "%d\n", ctx.handle );
337 	if ( ctx.handle != DRM_KERNEL_CONTEXT ) {
338 		if (dev->driver.context_dtor) {
339 			DRM_LOCK();
340 			dev->driver.context_dtor(dev, ctx.handle);
341 			DRM_UNLOCK();
342 		}
343 
344 		drm_ctxbitmap_free(dev, ctx.handle);
345 	}
346 
347 	return 0;
348 }
349