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