1 /**
2 * \file drm_context.c
3 * IOCTLs for generic contexts
4 *
5 * \author Rickard E. (Rik) Faith <faith@valinux.com>
6 * \author Gareth Hughes <gareth@valinux.com>
7 */
8
9 /*
10 * Created: Fri Nov 24 18:31:37 2000 by gareth@valinux.com
11 *
12 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
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 * VA LINUX SYSTEMS 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
33 * OTHER DEALINGS IN THE SOFTWARE.
34 */
35
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38
39 /*
40 * ChangeLog:
41 * 2001-11-16 Torsten Duwe <duwe@caldera.de>
42 * added context constructor/destructor hooks,
43 * needed by SiS driver's memory management.
44 */
45
46 #include <dev/drm2/drmP.h>
47
48 /******************************************************************/
49 /** \name Context bitmap support */
50 /*@{*/
51
52 /**
53 * Free a handle from the context bitmap.
54 *
55 * \param dev DRM device.
56 * \param ctx_handle context handle.
57 *
58 * Clears the bit specified by \p ctx_handle in drm_device::ctx_bitmap and the entry
59 * in drm_device::ctx_idr, while holding the drm_device::struct_mutex
60 * lock.
61 */
62 void drm_ctxbitmap_free(struct drm_device * dev, int ctx_handle)
63 {
64 if (ctx_handle < 0 || ctx_handle >= DRM_MAX_CTXBITMAP ||
65 dev->ctx_bitmap == NULL) {
66 DRM_ERROR("Attempt to free invalid context handle: %d\n",
67 ctx_handle);
68 return;
69 }
70
71 DRM_LOCK(dev);
72 clear_bit(ctx_handle, dev->ctx_bitmap);
73 dev->context_sareas[ctx_handle] = NULL;
74 DRM_UNLOCK(dev);
75 }
76
77 /**
78 * Context bitmap allocation.
79 *
80 * \param dev DRM device.
81 * \return (non-negative) context handle on success or a negative number on failure.
82 *
83 * Allocate a new idr from drm_device::ctx_idr while holding the
84 * drm_device::struct_mutex lock.
85 */
86 static int drm_ctxbitmap_next(struct drm_device * dev)
87 {
88 int bit;
89
90 if (dev->ctx_bitmap == NULL)
91 return -1;
92
93 DRM_LOCK(dev);
94 bit = find_first_zero_bit(dev->ctx_bitmap, DRM_MAX_CTXBITMAP);
95 if (bit >= DRM_MAX_CTXBITMAP) {
96 DRM_UNLOCK(dev);
97 return -1;
98 }
99
100 set_bit(bit, dev->ctx_bitmap);
101 DRM_DEBUG("bit : %d\n", bit);
102 if ((bit+1) > dev->max_context) {
103 struct drm_local_map **ctx_sareas;
104 int max_ctx = (bit+1);
105
106 ctx_sareas = realloc(dev->context_sareas,
107 max_ctx * sizeof(*dev->context_sareas),
108 DRM_MEM_SAREA, M_NOWAIT);
109 if (ctx_sareas == NULL) {
110 clear_bit(bit, dev->ctx_bitmap);
111 DRM_DEBUG("failed to allocate bit : %d\n", bit);
112 DRM_UNLOCK(dev);
113 return -1;
114 }
115 dev->max_context = max_ctx;
116 dev->context_sareas = ctx_sareas;
117 dev->context_sareas[bit] = NULL;
118 }
119 DRM_UNLOCK(dev);
120 return bit;
121 }
122
123 /**
124 * Context bitmap initialization.
125 *
126 * \param dev DRM device.
127 *
128 * Initialise the drm_device::ctx_idr
129 */
130 int drm_ctxbitmap_init(struct drm_device * dev)
131 {
132 int i;
133 int temp;
134
135 DRM_LOCK(dev);
136 dev->ctx_bitmap = malloc(PAGE_SIZE, DRM_MEM_CTXBITMAP,
137 M_NOWAIT | M_ZERO);
138 if (dev->ctx_bitmap == NULL) {
139 DRM_UNLOCK(dev);
140 return ENOMEM;
141 }
142 dev->context_sareas = NULL;
143 dev->max_context = -1;
144 DRM_UNLOCK(dev);
145
146 for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
147 temp = drm_ctxbitmap_next(dev);
148 DRM_DEBUG("drm_ctxbitmap_init : %d\n", temp);
149 }
150
151 return 0;
152 }
153
154 /**
155 * Context bitmap cleanup.
156 *
157 * \param dev DRM device.
158 *
159 * Free all idr members using drm_ctx_sarea_free helper function
160 * while holding the drm_device::struct_mutex lock.
161 */
162 void drm_ctxbitmap_cleanup(struct drm_device * dev)
163 {
164 DRM_LOCK(dev);
165 if (dev->context_sareas != NULL)
166 free(dev->context_sareas, DRM_MEM_SAREA);
167 free(dev->ctx_bitmap, DRM_MEM_CTXBITMAP);
168 DRM_UNLOCK(dev);
169 }
170
171 /*@}*/
172
173 /******************************************************************/
174 /** \name Per Context SAREA Support */
175 /*@{*/
176
177 /**
178 * Get per-context SAREA.
179 *
180 * \param inode device inode.
181 * \param file_priv DRM file private.
182 * \param cmd command.
183 * \param arg user argument pointing to a drm_ctx_priv_map structure.
184 * \return zero on success or a negative number on failure.
185 *
186 * Gets the map from drm_device::ctx_idr with the handle specified and
187 * returns its handle.
188 */
189 int drm_getsareactx(struct drm_device *dev, void *data,
190 struct drm_file *file_priv)
191 {
192 struct drm_ctx_priv_map *request = data;
193 struct drm_local_map *map;
194
195 DRM_LOCK(dev);
196 if (dev->max_context < 0 ||
197 request->ctx_id >= (unsigned) dev->max_context) {
198 DRM_UNLOCK(dev);
199 return EINVAL;
200 }
201
202 map = dev->context_sareas[request->ctx_id];
203 DRM_UNLOCK(dev);
204
205 request->handle = (void *)map->handle;
206
207 return 0;
208 }
209
210 /**
211 * Set per-context SAREA.
212 *
213 * \param inode device inode.
214 * \param file_priv DRM file private.
215 * \param cmd command.
216 * \param arg user argument pointing to a drm_ctx_priv_map structure.
217 * \return zero on success or a negative number on failure.
218 *
219 * Searches the mapping specified in \p arg and update the entry in
220 * drm_device::ctx_idr with it.
221 */
222 int drm_setsareactx(struct drm_device *dev, void *data,
223 struct drm_file *file_priv)
224 {
225 struct drm_ctx_priv_map *request = data;
226 struct drm_local_map *map = NULL;
227 struct drm_map_list *r_list = NULL;
228
229 DRM_LOCK(dev);
230 list_for_each_entry(r_list, &dev->maplist, head) {
231 if (r_list->map
232 && r_list->user_token == (unsigned long) request->handle) {
233 if (dev->max_context < 0)
234 goto bad;
235 if (request->ctx_id >= (unsigned) dev->max_context)
236 goto bad;
237 dev->context_sareas[request->ctx_id] = map;
238 DRM_UNLOCK(dev);
239 return 0;
240 }
241 }
242
243 bad:
244 DRM_UNLOCK(dev);
245 return EINVAL;
246 }
247
248 /*@}*/
249
250 /******************************************************************/
251 /** \name The actual DRM context handling routines */
252 /*@{*/
253
254 /**
255 * Switch context.
256 *
257 * \param dev DRM device.
258 * \param old old context handle.
259 * \param new new context handle.
260 * \return zero on success or a negative number on failure.
261 *
262 * Attempt to set drm_device::context_flag.
263 */
264 static int drm_context_switch(struct drm_device * dev, int old, int new)
265 {
266 if (test_and_set_bit(0, &dev->context_flag)) {
267 DRM_ERROR("Reentering -- FIXME\n");
268 return -EBUSY;
269 }
270
271 DRM_DEBUG("Context switch from %d to %d\n", old, new);
272
273 if (new == dev->last_context) {
274 clear_bit(0, &dev->context_flag);
275 return 0;
276 }
277
278 return 0;
279 }
280
281 /**
282 * Complete context switch.
283 *
284 * \param dev DRM device.
285 * \param new new context handle.
286 * \return zero on success or a negative number on failure.
287 *
288 * Updates drm_device::last_context and drm_device::last_switch. Verifies the
289 * hardware lock is held, clears the drm_device::context_flag and wakes up
290 * drm_device::context_wait.
291 */
292 static int drm_context_switch_complete(struct drm_device *dev,
293 struct drm_file *file_priv, int new)
294 {
295 dev->last_context = new; /* PRE/POST: This is the _only_ writer. */
296 dev->last_switch = jiffies;
297
298 if (!_DRM_LOCK_IS_HELD(file_priv->master->lock.hw_lock->lock)) {
299 DRM_ERROR("Lock isn't held after context switch\n");
300 }
301
302 /* If a context switch is ever initiated
303 when the kernel holds the lock, release
304 that lock here. */
305 clear_bit(0, &dev->context_flag);
306 wakeup(&dev->context_wait);
307
308 return 0;
309 }
310
311 /**
312 * Reserve contexts.
313 *
314 * \param inode device inode.
315 * \param file_priv DRM file private.
316 * \param cmd command.
317 * \param arg user argument pointing to a drm_ctx_res structure.
318 * \return zero on success or a negative number on failure.
319 */
320 int drm_resctx(struct drm_device *dev, void *data,
321 struct drm_file *file_priv)
322 {
323 struct drm_ctx_res *res = data;
324 struct drm_ctx ctx;
325 int i;
326
327 if (res->count >= DRM_RESERVED_CONTEXTS) {
328 memset(&ctx, 0, sizeof(ctx));
329 for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
330 ctx.handle = i;
331 if (copy_to_user(&res->contexts[i], &ctx, sizeof(ctx)))
332 return -EFAULT;
333 }
334 }
335 res->count = DRM_RESERVED_CONTEXTS;
336
337 return 0;
338 }
339
340 /**
341 * Add context.
342 *
343 * \param inode device inode.
344 * \param file_priv DRM file private.
345 * \param cmd command.
346 * \param arg user argument pointing to a drm_ctx structure.
347 * \return zero on success or a negative number on failure.
348 *
349 * Get a new handle for the context and copy to userspace.
350 */
351 int drm_addctx(struct drm_device *dev, void *data,
352 struct drm_file *file_priv)
353 {
354 struct drm_ctx_list *ctx_entry;
355 struct drm_ctx *ctx = data;
356
357 ctx->handle = drm_ctxbitmap_next(dev);
358 if (ctx->handle == DRM_KERNEL_CONTEXT) {
359 /* Skip kernel's context and get a new one. */
360 ctx->handle = drm_ctxbitmap_next(dev);
361 }
362 DRM_DEBUG("%d\n", ctx->handle);
363 if (ctx->handle == -1) {
364 DRM_DEBUG("Not enough free contexts.\n");
365 /* Should this return -EBUSY instead? */
366 return -ENOMEM;
367 }
368
369 ctx_entry = malloc(sizeof(*ctx_entry), DRM_MEM_CTXBITMAP, M_NOWAIT);
370 if (!ctx_entry) {
371 DRM_DEBUG("out of memory\n");
372 return -ENOMEM;
373 }
374
375 INIT_LIST_HEAD(&ctx_entry->head);
376 ctx_entry->handle = ctx->handle;
377 ctx_entry->tag = file_priv;
378
379 DRM_LOCK(dev);
380 list_add(&ctx_entry->head, &dev->ctxlist);
381 ++dev->ctx_count;
382 DRM_UNLOCK(dev);
383
384 return 0;
385 }
386
387 int drm_modctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
388 {
389 /* This does nothing */
390 return 0;
391 }
392
393 /**
394 * Get context.
395 *
396 * \param inode device inode.
397 * \param file_priv DRM file private.
398 * \param cmd command.
399 * \param arg user argument pointing to a drm_ctx structure.
400 * \return zero on success or a negative number on failure.
401 */
402 int drm_getctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
403 {
404 struct drm_ctx *ctx = data;
405
406 /* This is 0, because we don't handle any context flags */
407 ctx->flags = 0;
408
409 return 0;
410 }
411
412 /**
413 * Switch context.
414 *
415 * \param inode device inode.
416 * \param file_priv DRM file private.
417 * \param cmd command.
418 * \param arg user argument pointing to a drm_ctx structure.
419 * \return zero on success or a negative number on failure.
420 *
421 * Calls context_switch().
422 */
423 int drm_switchctx(struct drm_device *dev, void *data,
424 struct drm_file *file_priv)
425 {
426 struct drm_ctx *ctx = data;
427
428 DRM_DEBUG("%d\n", ctx->handle);
429 return drm_context_switch(dev, dev->last_context, ctx->handle);
430 }
431
432 /**
433 * New context.
434 *
435 * \param inode device inode.
436 * \param file_priv DRM file private.
437 * \param cmd command.
438 * \param arg user argument pointing to a drm_ctx structure.
439 * \return zero on success or a negative number on failure.
440 *
441 * Calls context_switch_complete().
442 */
443 int drm_newctx(struct drm_device *dev, void *data,
444 struct drm_file *file_priv)
445 {
446 struct drm_ctx *ctx = data;
447
448 DRM_DEBUG("%d\n", ctx->handle);
449 drm_context_switch_complete(dev, file_priv, ctx->handle);
450
451 return 0;
452 }
453
454 /**
455 * Remove context.
456 *
457 * \param inode device inode.
458 * \param file_priv DRM file private.
459 * \param cmd command.
460 * \param arg user argument pointing to a drm_ctx structure.
461 * \return zero on success or a negative number on failure.
462 *
463 * If not the special kernel context, calls ctxbitmap_free() to free the specified context.
464 */
465 int drm_rmctx(struct drm_device *dev, void *data,
466 struct drm_file *file_priv)
467 {
468 struct drm_ctx *ctx = data;
469
470 DRM_DEBUG("%d\n", ctx->handle);
471 if (ctx->handle != DRM_KERNEL_CONTEXT) {
472 if (dev->driver->context_dtor)
473 dev->driver->context_dtor(dev, ctx->handle);
474 drm_ctxbitmap_free(dev, ctx->handle);
475 }
476
477 DRM_LOCK(dev);
478 if (!list_empty(&dev->ctxlist)) {
479 struct drm_ctx_list *pos, *n;
480
481 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
482 if (pos->handle == ctx->handle) {
483 list_del(&pos->head);
484 free(pos, DRM_MEM_CTXBITMAP);
485 --dev->ctx_count;
486 }
487 }
488 }
489 DRM_UNLOCK(dev);
490
491 return 0;
492 }
493
494 /*@}*/
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