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 <drm/drmP.h>
32 #include "drm_legacy.h"
33
34 struct drm_ctx_list {
35 struct list_head head;
36 drm_context_t handle;
37 struct drm_file *tag;
38 };
39
40 /******************************************************************/
41 /** \name Context bitmap support */
42 /*@{*/
43
44 /**
45 * Free a handle from the context bitmap.
46 *
47 * \param dev DRM device.
48 * \param ctx_handle context handle.
49 *
50 * Clears the bit specified by \p ctx_handle in drm_device::ctx_bitmap and the entry
51 * in drm_device::ctx_idr, while holding the drm_device::struct_mutex
52 * lock.
53 */
drm_legacy_ctxbitmap_free(struct drm_device * dev,int ctx_handle)54 void drm_legacy_ctxbitmap_free(struct drm_device * dev, int ctx_handle)
55 {
56 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
57 !drm_core_check_feature(dev, DRIVER_LEGACY))
58 return;
59
60 mutex_lock(&dev->struct_mutex);
61 idr_remove(&dev->ctx_idr, ctx_handle);
62 mutex_unlock(&dev->struct_mutex);
63 }
64
65 /**
66 * Context bitmap allocation.
67 *
68 * \param dev DRM device.
69 * \return (non-negative) context handle on success or a negative number on failure.
70 *
71 * Allocate a new idr from drm_device::ctx_idr while holding the
72 * drm_device::struct_mutex lock.
73 */
drm_legacy_ctxbitmap_next(struct drm_device * dev)74 static int drm_legacy_ctxbitmap_next(struct drm_device * dev)
75 {
76 int ret;
77
78 mutex_lock(&dev->struct_mutex);
79 ret = idr_alloc(&dev->ctx_idr, NULL, DRM_RESERVED_CONTEXTS, 0,
80 GFP_KERNEL);
81 mutex_unlock(&dev->struct_mutex);
82 return ret;
83 }
84
85 /**
86 * Context bitmap initialization.
87 *
88 * \param dev DRM device.
89 *
90 * Initialise the drm_device::ctx_idr
91 */
drm_legacy_ctxbitmap_init(struct drm_device * dev)92 void drm_legacy_ctxbitmap_init(struct drm_device * dev)
93 {
94 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
95 !drm_core_check_feature(dev, DRIVER_LEGACY))
96 return;
97
98 idr_init(&dev->ctx_idr);
99 }
100
101 /**
102 * Context bitmap cleanup.
103 *
104 * \param dev DRM device.
105 *
106 * Free all idr members using drm_ctx_sarea_free helper function
107 * while holding the drm_device::struct_mutex lock.
108 */
drm_legacy_ctxbitmap_cleanup(struct drm_device * dev)109 void drm_legacy_ctxbitmap_cleanup(struct drm_device * dev)
110 {
111 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
112 !drm_core_check_feature(dev, DRIVER_LEGACY))
113 return;
114
115 mutex_lock(&dev->struct_mutex);
116 idr_destroy(&dev->ctx_idr);
117 mutex_unlock(&dev->struct_mutex);
118 }
119
120 /**
121 * drm_ctxbitmap_flush() - Flush all contexts owned by a file
122 * @dev: DRM device to operate on
123 * @file: Open file to flush contexts for
124 *
125 * This iterates over all contexts on @dev and drops them if they're owned by
126 * @file. Note that after this call returns, new contexts might be added if
127 * the file is still alive.
128 */
drm_legacy_ctxbitmap_flush(struct drm_device * dev,struct drm_file * file)129 void drm_legacy_ctxbitmap_flush(struct drm_device *dev, struct drm_file *file)
130 {
131 struct drm_ctx_list *pos, *tmp;
132
133 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
134 !drm_core_check_feature(dev, DRIVER_LEGACY))
135 return;
136
137 mutex_lock(&dev->ctxlist_mutex);
138
139 list_for_each_entry_safe(pos, tmp, &dev->ctxlist, head) {
140 if (pos->tag == file &&
141 pos->handle != DRM_KERNEL_CONTEXT) {
142 if (dev->driver->context_dtor)
143 dev->driver->context_dtor(dev, pos->handle);
144
145 drm_legacy_ctxbitmap_free(dev, pos->handle);
146 list_del(&pos->head);
147 kfree(pos);
148 }
149 }
150
151 mutex_unlock(&dev->ctxlist_mutex);
152 }
153
154 /*@}*/
155
156 /******************************************************************/
157 /** \name Per Context SAREA Support */
158 /*@{*/
159
160 /**
161 * Get per-context SAREA.
162 *
163 * \param inode device inode.
164 * \param file_priv DRM file private.
165 * \param cmd command.
166 * \param arg user argument pointing to a drm_ctx_priv_map structure.
167 * \return zero on success or a negative number on failure.
168 *
169 * Gets the map from drm_device::ctx_idr with the handle specified and
170 * returns its handle.
171 */
drm_legacy_getsareactx(struct drm_device * dev,void * data,struct drm_file * file_priv)172 int drm_legacy_getsareactx(struct drm_device *dev, void *data,
173 struct drm_file *file_priv)
174 {
175 struct drm_ctx_priv_map *request = data;
176 struct drm_local_map *map;
177 struct drm_map_list *_entry;
178
179 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
180 !drm_core_check_feature(dev, DRIVER_LEGACY))
181 return -EINVAL;
182
183 mutex_lock(&dev->struct_mutex);
184
185 map = idr_find(&dev->ctx_idr, request->ctx_id);
186 if (!map) {
187 mutex_unlock(&dev->struct_mutex);
188 return -EINVAL;
189 }
190
191 request->handle = NULL;
192 list_for_each_entry(_entry, &dev->maplist, head) {
193 if (_entry->map == map) {
194 request->handle =
195 (void *)(unsigned long)_entry->user_token;
196 break;
197 }
198 }
199
200 mutex_unlock(&dev->struct_mutex);
201
202 if (request->handle == NULL)
203 return -EINVAL;
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_legacy_setsareactx(struct drm_device * dev,void * data,struct drm_file * file_priv)220 int drm_legacy_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 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
228 !drm_core_check_feature(dev, DRIVER_LEGACY))
229 return -EINVAL;
230
231 mutex_lock(&dev->struct_mutex);
232 list_for_each_entry(r_list, &dev->maplist, head) {
233 if (r_list->map
234 && r_list->user_token == (unsigned long) request->handle)
235 goto found;
236 }
237 bad:
238 mutex_unlock(&dev->struct_mutex);
239 return -EINVAL;
240
241 found:
242 map = r_list->map;
243 if (!map)
244 goto bad;
245
246 if (IS_ERR(idr_replace(&dev->ctx_idr, map, request->ctx_id)))
247 goto bad;
248
249 mutex_unlock(&dev->struct_mutex);
250
251 return 0;
252 }
253
254 /*@}*/
255
256 /******************************************************************/
257 /** \name The actual DRM context handling routines */
258 /*@{*/
259
260 /**
261 * Switch context.
262 *
263 * \param dev DRM device.
264 * \param old old context handle.
265 * \param new new context handle.
266 * \return zero on success or a negative number on failure.
267 *
268 * Attempt to set drm_device::context_flag.
269 */
drm_context_switch(struct drm_device * dev,int old,int new)270 static int drm_context_switch(struct drm_device * dev, int old, int new)
271 {
272 if (test_and_set_bit(0, &dev->context_flag)) {
273 DRM_ERROR("Reentering -- FIXME\n");
274 return -EBUSY;
275 }
276
277 DRM_DEBUG("Context switch from %d to %d\n", old, new);
278
279 if (new == dev->last_context) {
280 clear_bit(0, &dev->context_flag);
281 return 0;
282 }
283
284 return 0;
285 }
286
287 /**
288 * Complete context switch.
289 *
290 * \param dev DRM device.
291 * \param new new context handle.
292 * \return zero on success or a negative number on failure.
293 *
294 * Updates drm_device::last_context and drm_device::last_switch. Verifies the
295 * hardware lock is held, clears the drm_device::context_flag and wakes up
296 * drm_device::context_wait.
297 */
drm_context_switch_complete(struct drm_device * dev,struct drm_file * file_priv,int new)298 static int drm_context_switch_complete(struct drm_device *dev,
299 struct drm_file *file_priv, int new)
300 {
301 dev->last_context = new; /* PRE/POST: This is the _only_ writer. */
302
303 if (!_DRM_LOCK_IS_HELD(file_priv->master->lock.hw_lock->lock)) {
304 DRM_ERROR("Lock isn't held after context switch\n");
305 }
306
307 /* If a context switch is ever initiated
308 when the kernel holds the lock, release
309 that lock here. */
310 clear_bit(0, &dev->context_flag);
311
312 return 0;
313 }
314
315 /**
316 * Reserve contexts.
317 *
318 * \param inode device inode.
319 * \param file_priv DRM file private.
320 * \param cmd command.
321 * \param arg user argument pointing to a drm_ctx_res structure.
322 * \return zero on success or a negative number on failure.
323 */
drm_legacy_resctx(struct drm_device * dev,void * data,struct drm_file * file_priv)324 int drm_legacy_resctx(struct drm_device *dev, void *data,
325 struct drm_file *file_priv)
326 {
327 struct drm_ctx_res *res = data;
328 struct drm_ctx ctx;
329 int i;
330
331 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
332 !drm_core_check_feature(dev, DRIVER_LEGACY))
333 return -EINVAL;
334
335 if (res->count >= DRM_RESERVED_CONTEXTS) {
336 memset(&ctx, 0, sizeof(ctx));
337 for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
338 ctx.handle = i;
339 if (copy_to_user(&res->contexts[i], &ctx, sizeof(ctx)))
340 return -EFAULT;
341 }
342 }
343 res->count = DRM_RESERVED_CONTEXTS;
344
345 return 0;
346 }
347
348 /**
349 * Add context.
350 *
351 * \param inode device inode.
352 * \param file_priv DRM file private.
353 * \param cmd command.
354 * \param arg user argument pointing to a drm_ctx structure.
355 * \return zero on success or a negative number on failure.
356 *
357 * Get a new handle for the context and copy to userspace.
358 */
drm_legacy_addctx(struct drm_device * dev,void * data,struct drm_file * file_priv)359 int drm_legacy_addctx(struct drm_device *dev, void *data,
360 struct drm_file *file_priv)
361 {
362 struct drm_ctx_list *ctx_entry;
363 struct drm_ctx *ctx = data;
364
365 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
366 !drm_core_check_feature(dev, DRIVER_LEGACY))
367 return -EINVAL;
368
369 ctx->handle = drm_legacy_ctxbitmap_next(dev);
370 if (ctx->handle == DRM_KERNEL_CONTEXT) {
371 /* Skip kernel's context and get a new one. */
372 ctx->handle = drm_legacy_ctxbitmap_next(dev);
373 }
374 DRM_DEBUG("%d\n", ctx->handle);
375 if (ctx->handle < 0) {
376 DRM_DEBUG("Not enough free contexts.\n");
377 /* Should this return -EBUSY instead? */
378 return -ENOMEM;
379 }
380
381 ctx_entry = kmalloc(sizeof(*ctx_entry), GFP_KERNEL);
382 if (!ctx_entry) {
383 DRM_DEBUG("out of memory\n");
384 return -ENOMEM;
385 }
386
387 INIT_LIST_HEAD(&ctx_entry->head);
388 ctx_entry->handle = ctx->handle;
389 ctx_entry->tag = file_priv;
390
391 mutex_lock(&dev->ctxlist_mutex);
392 list_add(&ctx_entry->head, &dev->ctxlist);
393 mutex_unlock(&dev->ctxlist_mutex);
394
395 return 0;
396 }
397
398 /**
399 * Get context.
400 *
401 * \param inode device inode.
402 * \param file_priv DRM file private.
403 * \param cmd command.
404 * \param arg user argument pointing to a drm_ctx structure.
405 * \return zero on success or a negative number on failure.
406 */
drm_legacy_getctx(struct drm_device * dev,void * data,struct drm_file * file_priv)407 int drm_legacy_getctx(struct drm_device *dev, void *data,
408 struct drm_file *file_priv)
409 {
410 struct drm_ctx *ctx = data;
411
412 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
413 !drm_core_check_feature(dev, DRIVER_LEGACY))
414 return -EINVAL;
415
416 /* This is 0, because we don't handle any context flags */
417 ctx->flags = 0;
418
419 return 0;
420 }
421
422 /**
423 * Switch context.
424 *
425 * \param inode device inode.
426 * \param file_priv DRM file private.
427 * \param cmd command.
428 * \param arg user argument pointing to a drm_ctx structure.
429 * \return zero on success or a negative number on failure.
430 *
431 * Calls context_switch().
432 */
drm_legacy_switchctx(struct drm_device * dev,void * data,struct drm_file * file_priv)433 int drm_legacy_switchctx(struct drm_device *dev, void *data,
434 struct drm_file *file_priv)
435 {
436 struct drm_ctx *ctx = data;
437
438 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
439 !drm_core_check_feature(dev, DRIVER_LEGACY))
440 return -EINVAL;
441
442 DRM_DEBUG("%d\n", ctx->handle);
443 return drm_context_switch(dev, dev->last_context, ctx->handle);
444 }
445
446 /**
447 * New context.
448 *
449 * \param inode device inode.
450 * \param file_priv DRM file private.
451 * \param cmd command.
452 * \param arg user argument pointing to a drm_ctx structure.
453 * \return zero on success or a negative number on failure.
454 *
455 * Calls context_switch_complete().
456 */
drm_legacy_newctx(struct drm_device * dev,void * data,struct drm_file * file_priv)457 int drm_legacy_newctx(struct drm_device *dev, void *data,
458 struct drm_file *file_priv)
459 {
460 struct drm_ctx *ctx = data;
461
462 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
463 !drm_core_check_feature(dev, DRIVER_LEGACY))
464 return -EINVAL;
465
466 DRM_DEBUG("%d\n", ctx->handle);
467 drm_context_switch_complete(dev, file_priv, ctx->handle);
468
469 return 0;
470 }
471
472 /**
473 * Remove context.
474 *
475 * \param inode device inode.
476 * \param file_priv DRM file private.
477 * \param cmd command.
478 * \param arg user argument pointing to a drm_ctx structure.
479 * \return zero on success or a negative number on failure.
480 *
481 * If not the special kernel context, calls ctxbitmap_free() to free the specified context.
482 */
drm_legacy_rmctx(struct drm_device * dev,void * data,struct drm_file * file_priv)483 int drm_legacy_rmctx(struct drm_device *dev, void *data,
484 struct drm_file *file_priv)
485 {
486 struct drm_ctx *ctx = data;
487
488 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
489 !drm_core_check_feature(dev, DRIVER_LEGACY))
490 return -EINVAL;
491
492 DRM_DEBUG("%d\n", ctx->handle);
493 if (ctx->handle != DRM_KERNEL_CONTEXT) {
494 if (dev->driver->context_dtor)
495 dev->driver->context_dtor(dev, ctx->handle);
496 drm_legacy_ctxbitmap_free(dev, ctx->handle);
497 }
498
499 mutex_lock(&dev->ctxlist_mutex);
500 if (!list_empty(&dev->ctxlist)) {
501 struct drm_ctx_list *pos, *n;
502
503 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
504 if (pos->handle == ctx->handle) {
505 list_del(&pos->head);
506 kfree(pos);
507 }
508 }
509 }
510 mutex_unlock(&dev->ctxlist_mutex);
511
512 return 0;
513 }
514
515 /*@}*/
516
