1 /*
2 * Legacy: Generic DRM Contexts
3 *
4 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
5 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
6 * All Rights Reserved.
7 *
8 * Author: Rickard E. (Rik) Faith <faith@valinux.com>
9 * Author: Gareth Hughes <gareth@valinux.com>
10 *
11 * Permission is hereby granted, free of charge, to any person obtaining a
12 * copy of this software and associated documentation files (the "Software"),
13 * to deal in the Software without restriction, including without limitation
14 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
15 * and/or sell copies of the Software, and to permit persons to whom the
16 * Software is furnished to do so, subject to the following conditions:
17 *
18 * The above copyright notice and this permission notice (including the next
19 * paragraph) shall be included in all copies or substantial portions of the
20 * Software.
21 *
22 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
23 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
24 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
25 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
26 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
27 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
28 * OTHER DEALINGS IN THE SOFTWARE.
29 */
30
31 #include <linux/slab.h>
32 #include <linux/uaccess.h>
33
34 #include <drm/drm_drv.h>
35 #include <drm/drm_file.h>
36 #include <drm/drm_print.h>
37
38 #include "drm_legacy.h"
39
40 struct drm_ctx_list {
41 struct list_head head;
42 drm_context_t handle;
43 struct drm_file *tag;
44 };
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_legacy_ctxbitmap_free(struct drm_device * dev,int ctx_handle)60 void drm_legacy_ctxbitmap_free(struct drm_device * dev, int ctx_handle)
61 {
62 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
63 !drm_core_check_feature(dev, DRIVER_LEGACY))
64 return;
65
66 mutex_lock(&dev->struct_mutex);
67 idr_remove(&dev->ctx_idr, ctx_handle);
68 mutex_unlock(&dev->struct_mutex);
69 }
70
71 /*
72 * Context bitmap allocation.
73 *
74 * \param dev DRM device.
75 * \return (non-negative) context handle on success or a negative number on failure.
76 *
77 * Allocate a new idr from drm_device::ctx_idr while holding the
78 * drm_device::struct_mutex lock.
79 */
drm_legacy_ctxbitmap_next(struct drm_device * dev)80 static int drm_legacy_ctxbitmap_next(struct drm_device * dev)
81 {
82 int ret;
83
84 mutex_lock(&dev->struct_mutex);
85 ret = idr_alloc(&dev->ctx_idr, NULL, DRM_RESERVED_CONTEXTS, 0,
86 GFP_KERNEL);
87 mutex_unlock(&dev->struct_mutex);
88 return ret;
89 }
90
91 /*
92 * Context bitmap initialization.
93 *
94 * \param dev DRM device.
95 *
96 * Initialise the drm_device::ctx_idr
97 */
drm_legacy_ctxbitmap_init(struct drm_device * dev)98 void drm_legacy_ctxbitmap_init(struct drm_device * dev)
99 {
100 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
101 !drm_core_check_feature(dev, DRIVER_LEGACY))
102 return;
103
104 idr_init(&dev->ctx_idr);
105 }
106
107 /*
108 * Context bitmap cleanup.
109 *
110 * \param dev DRM device.
111 *
112 * Free all idr members using drm_ctx_sarea_free helper function
113 * while holding the drm_device::struct_mutex lock.
114 */
drm_legacy_ctxbitmap_cleanup(struct drm_device * dev)115 void drm_legacy_ctxbitmap_cleanup(struct drm_device * dev)
116 {
117 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
118 !drm_core_check_feature(dev, DRIVER_LEGACY))
119 return;
120
121 mutex_lock(&dev->struct_mutex);
122 idr_destroy(&dev->ctx_idr);
123 mutex_unlock(&dev->struct_mutex);
124 }
125
126 /**
127 * drm_legacy_ctxbitmap_flush() - Flush all contexts owned by a file
128 * @dev: DRM device to operate on
129 * @file: Open file to flush contexts for
130 *
131 * This iterates over all contexts on @dev and drops them if they're owned by
132 * @file. Note that after this call returns, new contexts might be added if
133 * the file is still alive.
134 */
drm_legacy_ctxbitmap_flush(struct drm_device * dev,struct drm_file * file)135 void drm_legacy_ctxbitmap_flush(struct drm_device *dev, struct drm_file *file)
136 {
137 struct drm_ctx_list *pos, *tmp;
138
139 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
140 !drm_core_check_feature(dev, DRIVER_LEGACY))
141 return;
142
143 mutex_lock(&dev->ctxlist_mutex);
144
145 list_for_each_entry_safe(pos, tmp, &dev->ctxlist, head) {
146 if (pos->tag == file &&
147 pos->handle != DRM_KERNEL_CONTEXT) {
148 if (dev->driver->context_dtor)
149 dev->driver->context_dtor(dev, pos->handle);
150
151 drm_legacy_ctxbitmap_free(dev, pos->handle);
152 list_del(&pos->head);
153 kfree(pos);
154 }
155 }
156
157 mutex_unlock(&dev->ctxlist_mutex);
158 }
159
160 /*@}*/
161
162 /******************************************************************/
163 /** \name Per Context SAREA Support */
164 /*@{*/
165
166 /*
167 * Get per-context SAREA.
168 *
169 * \param inode device inode.
170 * \param file_priv DRM file private.
171 * \param cmd command.
172 * \param arg user argument pointing to a drm_ctx_priv_map structure.
173 * \return zero on success or a negative number on failure.
174 *
175 * Gets the map from drm_device::ctx_idr with the handle specified and
176 * returns its handle.
177 */
drm_legacy_getsareactx(struct drm_device * dev,void * data,struct drm_file * file_priv)178 int drm_legacy_getsareactx(struct drm_device *dev, void *data,
179 struct drm_file *file_priv)
180 {
181 struct drm_ctx_priv_map *request = data;
182 struct drm_local_map *map;
183 struct drm_map_list *_entry;
184
185 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
186 !drm_core_check_feature(dev, DRIVER_LEGACY))
187 return -EOPNOTSUPP;
188
189 mutex_lock(&dev->struct_mutex);
190
191 map = idr_find(&dev->ctx_idr, request->ctx_id);
192 if (!map) {
193 mutex_unlock(&dev->struct_mutex);
194 return -EINVAL;
195 }
196
197 request->handle = NULL;
198 list_for_each_entry(_entry, &dev->maplist, head) {
199 if (_entry->map == map) {
200 request->handle =
201 (void *)(unsigned long)_entry->user_token;
202 break;
203 }
204 }
205
206 mutex_unlock(&dev->struct_mutex);
207
208 if (request->handle == NULL)
209 return -EINVAL;
210
211 return 0;
212 }
213
214 /*
215 * Set per-context SAREA.
216 *
217 * \param inode device inode.
218 * \param file_priv DRM file private.
219 * \param cmd command.
220 * \param arg user argument pointing to a drm_ctx_priv_map structure.
221 * \return zero on success or a negative number on failure.
222 *
223 * Searches the mapping specified in \p arg and update the entry in
224 * drm_device::ctx_idr with it.
225 */
drm_legacy_setsareactx(struct drm_device * dev,void * data,struct drm_file * file_priv)226 int drm_legacy_setsareactx(struct drm_device *dev, void *data,
227 struct drm_file *file_priv)
228 {
229 struct drm_ctx_priv_map *request = data;
230 struct drm_local_map *map = NULL;
231 struct drm_map_list *r_list = NULL;
232
233 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
234 !drm_core_check_feature(dev, DRIVER_LEGACY))
235 return -EOPNOTSUPP;
236
237 mutex_lock(&dev->struct_mutex);
238 list_for_each_entry(r_list, &dev->maplist, head) {
239 if (r_list->map
240 && r_list->user_token == (unsigned long) request->handle)
241 goto found;
242 }
243 bad:
244 mutex_unlock(&dev->struct_mutex);
245 return -EINVAL;
246
247 found:
248 map = r_list->map;
249 if (!map)
250 goto bad;
251
252 if (IS_ERR(idr_replace(&dev->ctx_idr, map, request->ctx_id)))
253 goto bad;
254
255 mutex_unlock(&dev->struct_mutex);
256
257 return 0;
258 }
259
260 /*@}*/
261
262 /******************************************************************/
263 /** \name The actual DRM context handling routines */
264 /*@{*/
265
266 /*
267 * Switch context.
268 *
269 * \param dev DRM device.
270 * \param old old context handle.
271 * \param new new context handle.
272 * \return zero on success or a negative number on failure.
273 *
274 * Attempt to set drm_device::context_flag.
275 */
drm_context_switch(struct drm_device * dev,int old,int new)276 static int drm_context_switch(struct drm_device * dev, int old, int new)
277 {
278 if (test_and_set_bit(0, &dev->context_flag)) {
279 DRM_ERROR("Reentering -- FIXME\n");
280 return -EBUSY;
281 }
282
283 DRM_DEBUG("Context switch from %d to %d\n", old, new);
284
285 if (new == dev->last_context) {
286 clear_bit(0, &dev->context_flag);
287 return 0;
288 }
289
290 return 0;
291 }
292
293 /*
294 * Complete context switch.
295 *
296 * \param dev DRM device.
297 * \param new new context handle.
298 * \return zero on success or a negative number on failure.
299 *
300 * Updates drm_device::last_context and drm_device::last_switch. Verifies the
301 * hardware lock is held, clears the drm_device::context_flag and wakes up
302 * drm_device::context_wait.
303 */
drm_context_switch_complete(struct drm_device * dev,struct drm_file * file_priv,int new)304 static int drm_context_switch_complete(struct drm_device *dev,
305 struct drm_file *file_priv, int new)
306 {
307 dev->last_context = new; /* PRE/POST: This is the _only_ writer. */
308
309 if (!_DRM_LOCK_IS_HELD(file_priv->master->lock.hw_lock->lock)) {
310 DRM_ERROR("Lock isn't held after context switch\n");
311 }
312
313 /* If a context switch is ever initiated
314 when the kernel holds the lock, release
315 that lock here.
316 */
317 clear_bit(0, &dev->context_flag);
318
319 return 0;
320 }
321
322 /*
323 * Reserve contexts.
324 *
325 * \param inode device inode.
326 * \param file_priv DRM file private.
327 * \param cmd command.
328 * \param arg user argument pointing to a drm_ctx_res structure.
329 * \return zero on success or a negative number on failure.
330 */
drm_legacy_resctx(struct drm_device * dev,void * data,struct drm_file * file_priv)331 int drm_legacy_resctx(struct drm_device *dev, void *data,
332 struct drm_file *file_priv)
333 {
334 struct drm_ctx_res *res = data;
335 struct drm_ctx ctx;
336 int i;
337
338 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
339 !drm_core_check_feature(dev, DRIVER_LEGACY))
340 return -EOPNOTSUPP;
341
342 if (res->count >= DRM_RESERVED_CONTEXTS) {
343 memset(&ctx, 0, sizeof(ctx));
344 for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
345 ctx.handle = i;
346 if (copy_to_user(&res->contexts[i], &ctx, sizeof(ctx)))
347 return -EFAULT;
348 }
349 }
350 res->count = DRM_RESERVED_CONTEXTS;
351
352 return 0;
353 }
354
355 /*
356 * Add context.
357 *
358 * \param inode device inode.
359 * \param file_priv DRM file private.
360 * \param cmd command.
361 * \param arg user argument pointing to a drm_ctx structure.
362 * \return zero on success or a negative number on failure.
363 *
364 * Get a new handle for the context and copy to userspace.
365 */
drm_legacy_addctx(struct drm_device * dev,void * data,struct drm_file * file_priv)366 int drm_legacy_addctx(struct drm_device *dev, void *data,
367 struct drm_file *file_priv)
368 {
369 struct drm_ctx_list *ctx_entry;
370 struct drm_ctx *ctx = data;
371 int tmp_handle;
372
373 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
374 !drm_core_check_feature(dev, DRIVER_LEGACY))
375 return -EOPNOTSUPP;
376
377 tmp_handle = drm_legacy_ctxbitmap_next(dev);
378 if (tmp_handle == DRM_KERNEL_CONTEXT) {
379 /* Skip kernel's context and get a new one. */
380 tmp_handle = drm_legacy_ctxbitmap_next(dev);
381 }
382 DRM_DEBUG("%d\n", tmp_handle);
383 if (tmp_handle < 0) {
384 DRM_DEBUG("Not enough free contexts.\n");
385 /* Should this return -EBUSY instead? */
386 return tmp_handle;
387 }
388
389 ctx->handle = tmp_handle;
390
391 ctx_entry = kmalloc(sizeof(*ctx_entry), GFP_KERNEL);
392 if (!ctx_entry) {
393 DRM_DEBUG("out of memory\n");
394 return -ENOMEM;
395 }
396
397 INIT_LIST_HEAD(&ctx_entry->head);
398 ctx_entry->handle = ctx->handle;
399 ctx_entry->tag = file_priv;
400
401 mutex_lock(&dev->ctxlist_mutex);
402 list_add(&ctx_entry->head, &dev->ctxlist);
403 mutex_unlock(&dev->ctxlist_mutex);
404
405 return 0;
406 }
407
408 /*
409 * Get context.
410 *
411 * \param inode device inode.
412 * \param file_priv DRM file private.
413 * \param cmd command.
414 * \param arg user argument pointing to a drm_ctx structure.
415 * \return zero on success or a negative number on failure.
416 */
drm_legacy_getctx(struct drm_device * dev,void * data,struct drm_file * file_priv)417 int drm_legacy_getctx(struct drm_device *dev, void *data,
418 struct drm_file *file_priv)
419 {
420 struct drm_ctx *ctx = data;
421
422 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
423 !drm_core_check_feature(dev, DRIVER_LEGACY))
424 return -EOPNOTSUPP;
425
426 /* This is 0, because we don't handle any context flags */
427 ctx->flags = 0;
428
429 return 0;
430 }
431
432 /*
433 * Switch 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().
442 */
drm_legacy_switchctx(struct drm_device * dev,void * data,struct drm_file * file_priv)443 int drm_legacy_switchctx(struct drm_device *dev, void *data,
444 struct drm_file *file_priv)
445 {
446 struct drm_ctx *ctx = data;
447
448 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
449 !drm_core_check_feature(dev, DRIVER_LEGACY))
450 return -EOPNOTSUPP;
451
452 DRM_DEBUG("%d\n", ctx->handle);
453 return drm_context_switch(dev, dev->last_context, ctx->handle);
454 }
455
456 /*
457 * New context.
458 *
459 * \param inode device inode.
460 * \param file_priv DRM file private.
461 * \param cmd command.
462 * \param arg user argument pointing to a drm_ctx structure.
463 * \return zero on success or a negative number on failure.
464 *
465 * Calls context_switch_complete().
466 */
drm_legacy_newctx(struct drm_device * dev,void * data,struct drm_file * file_priv)467 int drm_legacy_newctx(struct drm_device *dev, void *data,
468 struct drm_file *file_priv)
469 {
470 struct drm_ctx *ctx = data;
471
472 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
473 !drm_core_check_feature(dev, DRIVER_LEGACY))
474 return -EOPNOTSUPP;
475
476 DRM_DEBUG("%d\n", ctx->handle);
477 drm_context_switch_complete(dev, file_priv, ctx->handle);
478
479 return 0;
480 }
481
482 /*
483 * Remove context.
484 *
485 * \param inode device inode.
486 * \param file_priv DRM file private.
487 * \param cmd command.
488 * \param arg user argument pointing to a drm_ctx structure.
489 * \return zero on success or a negative number on failure.
490 *
491 * If not the special kernel context, calls ctxbitmap_free() to free the specified context.
492 */
drm_legacy_rmctx(struct drm_device * dev,void * data,struct drm_file * file_priv)493 int drm_legacy_rmctx(struct drm_device *dev, void *data,
494 struct drm_file *file_priv)
495 {
496 struct drm_ctx *ctx = data;
497
498 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
499 !drm_core_check_feature(dev, DRIVER_LEGACY))
500 return -EOPNOTSUPP;
501
502 DRM_DEBUG("%d\n", ctx->handle);
503 if (ctx->handle != DRM_KERNEL_CONTEXT) {
504 if (dev->driver->context_dtor)
505 dev->driver->context_dtor(dev, ctx->handle);
506 drm_legacy_ctxbitmap_free(dev, ctx->handle);
507 }
508
509 mutex_lock(&dev->ctxlist_mutex);
510 if (!list_empty(&dev->ctxlist)) {
511 struct drm_ctx_list *pos, *n;
512
513 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
514 if (pos->handle == ctx->handle) {
515 list_del(&pos->head);
516 kfree(pos);
517 }
518 }
519 }
520 mutex_unlock(&dev->ctxlist_mutex);
521
522 return 0;
523 }
524
525 /*@}*/
526