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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
40struct 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 */
60void 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 */
80static 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 */
98void 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 */
115void 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_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 */
135void 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 */
178int 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 */
226int 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 */
276static 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 */
304static 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 clear_bit(0, &dev->context_flag);
317
318 return 0;
319}
320
321/*
322 * Reserve contexts.
323 *
324 * \param inode device inode.
325 * \param file_priv DRM file private.
326 * \param cmd command.
327 * \param arg user argument pointing to a drm_ctx_res structure.
328 * \return zero on success or a negative number on failure.
329 */
330int drm_legacy_resctx(struct drm_device *dev, void *data,
331 struct drm_file *file_priv)
332{
333 struct drm_ctx_res *res = data;
334 struct drm_ctx ctx;
335 int i;
336
337 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
338 !drm_core_check_feature(dev, DRIVER_LEGACY))
339 return -EOPNOTSUPP;
340
341 if (res->count >= DRM_RESERVED_CONTEXTS) {
342 memset(&ctx, 0, sizeof(ctx));
343 for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
344 ctx.handle = i;
345 if (copy_to_user(&res->contexts[i], &ctx, sizeof(ctx)))
346 return -EFAULT;
347 }
348 }
349 res->count = DRM_RESERVED_CONTEXTS;
350
351 return 0;
352}
353
354/*
355 * Add context.
356 *
357 * \param inode device inode.
358 * \param file_priv DRM file private.
359 * \param cmd command.
360 * \param arg user argument pointing to a drm_ctx structure.
361 * \return zero on success or a negative number on failure.
362 *
363 * Get a new handle for the context and copy to userspace.
364 */
365int drm_legacy_addctx(struct drm_device *dev, void *data,
366 struct drm_file *file_priv)
367{
368 struct drm_ctx_list *ctx_entry;
369 struct drm_ctx *ctx = data;
370 int tmp_handle;
371
372 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
373 !drm_core_check_feature(dev, DRIVER_LEGACY))
374 return -EOPNOTSUPP;
375
376 tmp_handle = drm_legacy_ctxbitmap_next(dev);
377 if (tmp_handle == DRM_KERNEL_CONTEXT) {
378 /* Skip kernel's context and get a new one. */
379 tmp_handle = drm_legacy_ctxbitmap_next(dev);
380 }
381 DRM_DEBUG("%d\n", tmp_handle);
382 if (tmp_handle < 0) {
383 DRM_DEBUG("Not enough free contexts.\n");
384 /* Should this return -EBUSY instead? */
385 return tmp_handle;
386 }
387
388 ctx->handle = tmp_handle;
389
390 ctx_entry = kmalloc(sizeof(*ctx_entry), GFP_KERNEL);
391 if (!ctx_entry) {
392 DRM_DEBUG("out of memory\n");
393 return -ENOMEM;
394 }
395
396 INIT_LIST_HEAD(&ctx_entry->head);
397 ctx_entry->handle = ctx->handle;
398 ctx_entry->tag = file_priv;
399
400 mutex_lock(&dev->ctxlist_mutex);
401 list_add(&ctx_entry->head, &dev->ctxlist);
402 mutex_unlock(&dev->ctxlist_mutex);
403
404 return 0;
405}
406
407/*
408 * Get context.
409 *
410 * \param inode device inode.
411 * \param file_priv DRM file private.
412 * \param cmd command.
413 * \param arg user argument pointing to a drm_ctx structure.
414 * \return zero on success or a negative number on failure.
415 */
416int drm_legacy_getctx(struct drm_device *dev, void *data,
417 struct drm_file *file_priv)
418{
419 struct drm_ctx *ctx = data;
420
421 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
422 !drm_core_check_feature(dev, DRIVER_LEGACY))
423 return -EOPNOTSUPP;
424
425 /* This is 0, because we don't handle any context flags */
426 ctx->flags = 0;
427
428 return 0;
429}
430
431/*
432 * Switch context.
433 *
434 * \param inode device inode.
435 * \param file_priv DRM file private.
436 * \param cmd command.
437 * \param arg user argument pointing to a drm_ctx structure.
438 * \return zero on success or a negative number on failure.
439 *
440 * Calls context_switch().
441 */
442int drm_legacy_switchctx(struct drm_device *dev, void *data,
443 struct drm_file *file_priv)
444{
445 struct drm_ctx *ctx = data;
446
447 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
448 !drm_core_check_feature(dev, DRIVER_LEGACY))
449 return -EOPNOTSUPP;
450
451 DRM_DEBUG("%d\n", ctx->handle);
452 return drm_context_switch(dev, dev->last_context, ctx->handle);
453}
454
455/*
456 * New context.
457 *
458 * \param inode device inode.
459 * \param file_priv DRM file private.
460 * \param cmd command.
461 * \param arg user argument pointing to a drm_ctx structure.
462 * \return zero on success or a negative number on failure.
463 *
464 * Calls context_switch_complete().
465 */
466int drm_legacy_newctx(struct drm_device *dev, void *data,
467 struct drm_file *file_priv)
468{
469 struct drm_ctx *ctx = data;
470
471 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
472 !drm_core_check_feature(dev, DRIVER_LEGACY))
473 return -EOPNOTSUPP;
474
475 DRM_DEBUG("%d\n", ctx->handle);
476 drm_context_switch_complete(dev, file_priv, ctx->handle);
477
478 return 0;
479}
480
481/*
482 * Remove context.
483 *
484 * \param inode device inode.
485 * \param file_priv DRM file private.
486 * \param cmd command.
487 * \param arg user argument pointing to a drm_ctx structure.
488 * \return zero on success or a negative number on failure.
489 *
490 * If not the special kernel context, calls ctxbitmap_free() to free the specified context.
491 */
492int drm_legacy_rmctx(struct drm_device *dev, void *data,
493 struct drm_file *file_priv)
494{
495 struct drm_ctx *ctx = data;
496
497 if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
498 !drm_core_check_feature(dev, DRIVER_LEGACY))
499 return -EOPNOTSUPP;
500
501 DRM_DEBUG("%d\n", ctx->handle);
502 if (ctx->handle != DRM_KERNEL_CONTEXT) {
503 if (dev->driver->context_dtor)
504 dev->driver->context_dtor(dev, ctx->handle);
505 drm_legacy_ctxbitmap_free(dev, ctx->handle);
506 }
507
508 mutex_lock(&dev->ctxlist_mutex);
509 if (!list_empty(&dev->ctxlist)) {
510 struct drm_ctx_list *pos, *n;
511
512 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
513 if (pos->handle == ctx->handle) {
514 list_del(&pos->head);
515 kfree(pos);
516 }
517 }
518 }
519 mutex_unlock(&dev->ctxlist_mutex);
520
521 return 0;
522}
523
524/*@}*/
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/*
37 * ChangeLog:
38 * 2001-11-16 Torsten Duwe <duwe@caldera.de>
39 * added context constructor/destructor hooks,
40 * needed by SiS driver's memory management.
41 */
42
43#include <drm/drmP.h>
44
45/******************************************************************/
46/** \name Context bitmap support */
47/*@{*/
48
49/**
50 * Free a handle from the context bitmap.
51 *
52 * \param dev DRM device.
53 * \param ctx_handle context handle.
54 *
55 * Clears the bit specified by \p ctx_handle in drm_device::ctx_bitmap and the entry
56 * in drm_device::ctx_idr, while holding the drm_device::struct_mutex
57 * lock.
58 */
59void drm_ctxbitmap_free(struct drm_device * dev, int ctx_handle)
60{
61 mutex_lock(&dev->struct_mutex);
62 idr_remove(&dev->ctx_idr, ctx_handle);
63 mutex_unlock(&dev->struct_mutex);
64}
65
66/**
67 * Context bitmap allocation.
68 *
69 * \param dev DRM device.
70 * \return (non-negative) context handle on success or a negative number on failure.
71 *
72 * Allocate a new idr from drm_device::ctx_idr while holding the
73 * drm_device::struct_mutex lock.
74 */
75static int drm_ctxbitmap_next(struct drm_device * dev)
76{
77 int ret;
78
79 mutex_lock(&dev->struct_mutex);
80 ret = idr_alloc(&dev->ctx_idr, NULL, DRM_RESERVED_CONTEXTS, 0,
81 GFP_KERNEL);
82 mutex_unlock(&dev->struct_mutex);
83 return ret;
84}
85
86/**
87 * Context bitmap initialization.
88 *
89 * \param dev DRM device.
90 *
91 * Initialise the drm_device::ctx_idr
92 */
93int drm_ctxbitmap_init(struct drm_device * dev)
94{
95 idr_init(&dev->ctx_idr);
96 return 0;
97}
98
99/**
100 * Context bitmap cleanup.
101 *
102 * \param dev DRM device.
103 *
104 * Free all idr members using drm_ctx_sarea_free helper function
105 * while holding the drm_device::struct_mutex lock.
106 */
107void drm_ctxbitmap_cleanup(struct drm_device * dev)
108{
109 mutex_lock(&dev->struct_mutex);
110 idr_destroy(&dev->ctx_idr);
111 mutex_unlock(&dev->struct_mutex);
112}
113
114/*@}*/
115
116/******************************************************************/
117/** \name Per Context SAREA Support */
118/*@{*/
119
120/**
121 * Get per-context SAREA.
122 *
123 * \param inode device inode.
124 * \param file_priv DRM file private.
125 * \param cmd command.
126 * \param arg user argument pointing to a drm_ctx_priv_map structure.
127 * \return zero on success or a negative number on failure.
128 *
129 * Gets the map from drm_device::ctx_idr with the handle specified and
130 * returns its handle.
131 */
132int drm_getsareactx(struct drm_device *dev, void *data,
133 struct drm_file *file_priv)
134{
135 struct drm_ctx_priv_map *request = data;
136 struct drm_local_map *map;
137 struct drm_map_list *_entry;
138
139 mutex_lock(&dev->struct_mutex);
140
141 map = idr_find(&dev->ctx_idr, request->ctx_id);
142 if (!map) {
143 mutex_unlock(&dev->struct_mutex);
144 return -EINVAL;
145 }
146
147 request->handle = NULL;
148 list_for_each_entry(_entry, &dev->maplist, head) {
149 if (_entry->map == map) {
150 request->handle =
151 (void *)(unsigned long)_entry->user_token;
152 break;
153 }
154 }
155
156 mutex_unlock(&dev->struct_mutex);
157
158 if (request->handle == NULL)
159 return -EINVAL;
160
161 return 0;
162}
163
164/**
165 * Set per-context SAREA.
166 *
167 * \param inode device inode.
168 * \param file_priv DRM file private.
169 * \param cmd command.
170 * \param arg user argument pointing to a drm_ctx_priv_map structure.
171 * \return zero on success or a negative number on failure.
172 *
173 * Searches the mapping specified in \p arg and update the entry in
174 * drm_device::ctx_idr with it.
175 */
176int drm_setsareactx(struct drm_device *dev, void *data,
177 struct drm_file *file_priv)
178{
179 struct drm_ctx_priv_map *request = data;
180 struct drm_local_map *map = NULL;
181 struct drm_map_list *r_list = NULL;
182
183 mutex_lock(&dev->struct_mutex);
184 list_for_each_entry(r_list, &dev->maplist, head) {
185 if (r_list->map
186 && r_list->user_token == (unsigned long) request->handle)
187 goto found;
188 }
189 bad:
190 mutex_unlock(&dev->struct_mutex);
191 return -EINVAL;
192
193 found:
194 map = r_list->map;
195 if (!map)
196 goto bad;
197
198 if (IS_ERR(idr_replace(&dev->ctx_idr, map, request->ctx_id)))
199 goto bad;
200
201 mutex_unlock(&dev->struct_mutex);
202
203 return 0;
204}
205
206/*@}*/
207
208/******************************************************************/
209/** \name The actual DRM context handling routines */
210/*@{*/
211
212/**
213 * Switch context.
214 *
215 * \param dev DRM device.
216 * \param old old context handle.
217 * \param new new context handle.
218 * \return zero on success or a negative number on failure.
219 *
220 * Attempt to set drm_device::context_flag.
221 */
222static int drm_context_switch(struct drm_device * dev, int old, int new)
223{
224 if (test_and_set_bit(0, &dev->context_flag)) {
225 DRM_ERROR("Reentering -- FIXME\n");
226 return -EBUSY;
227 }
228
229 DRM_DEBUG("Context switch from %d to %d\n", old, new);
230
231 if (new == dev->last_context) {
232 clear_bit(0, &dev->context_flag);
233 return 0;
234 }
235
236 return 0;
237}
238
239/**
240 * Complete context switch.
241 *
242 * \param dev DRM device.
243 * \param new new context handle.
244 * \return zero on success or a negative number on failure.
245 *
246 * Updates drm_device::last_context and drm_device::last_switch. Verifies the
247 * hardware lock is held, clears the drm_device::context_flag and wakes up
248 * drm_device::context_wait.
249 */
250static int drm_context_switch_complete(struct drm_device *dev,
251 struct drm_file *file_priv, int new)
252{
253 dev->last_context = new; /* PRE/POST: This is the _only_ writer. */
254
255 if (!_DRM_LOCK_IS_HELD(file_priv->master->lock.hw_lock->lock)) {
256 DRM_ERROR("Lock isn't held after context switch\n");
257 }
258
259 /* If a context switch is ever initiated
260 when the kernel holds the lock, release
261 that lock here. */
262 clear_bit(0, &dev->context_flag);
263
264 return 0;
265}
266
267/**
268 * Reserve contexts.
269 *
270 * \param inode device inode.
271 * \param file_priv DRM file private.
272 * \param cmd command.
273 * \param arg user argument pointing to a drm_ctx_res structure.
274 * \return zero on success or a negative number on failure.
275 */
276int drm_resctx(struct drm_device *dev, void *data,
277 struct drm_file *file_priv)
278{
279 struct drm_ctx_res *res = data;
280 struct drm_ctx ctx;
281 int i;
282
283 if (res->count >= DRM_RESERVED_CONTEXTS) {
284 memset(&ctx, 0, sizeof(ctx));
285 for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
286 ctx.handle = i;
287 if (copy_to_user(&res->contexts[i], &ctx, sizeof(ctx)))
288 return -EFAULT;
289 }
290 }
291 res->count = DRM_RESERVED_CONTEXTS;
292
293 return 0;
294}
295
296/**
297 * Add context.
298 *
299 * \param inode device inode.
300 * \param file_priv DRM file private.
301 * \param cmd command.
302 * \param arg user argument pointing to a drm_ctx structure.
303 * \return zero on success or a negative number on failure.
304 *
305 * Get a new handle for the context and copy to userspace.
306 */
307int drm_addctx(struct drm_device *dev, void *data,
308 struct drm_file *file_priv)
309{
310 struct drm_ctx_list *ctx_entry;
311 struct drm_ctx *ctx = data;
312
313 ctx->handle = drm_ctxbitmap_next(dev);
314 if (ctx->handle == DRM_KERNEL_CONTEXT) {
315 /* Skip kernel's context and get a new one. */
316 ctx->handle = drm_ctxbitmap_next(dev);
317 }
318 DRM_DEBUG("%d\n", ctx->handle);
319 if (ctx->handle == -1) {
320 DRM_DEBUG("Not enough free contexts.\n");
321 /* Should this return -EBUSY instead? */
322 return -ENOMEM;
323 }
324
325 ctx_entry = kmalloc(sizeof(*ctx_entry), GFP_KERNEL);
326 if (!ctx_entry) {
327 DRM_DEBUG("out of memory\n");
328 return -ENOMEM;
329 }
330
331 INIT_LIST_HEAD(&ctx_entry->head);
332 ctx_entry->handle = ctx->handle;
333 ctx_entry->tag = file_priv;
334
335 mutex_lock(&dev->ctxlist_mutex);
336 list_add(&ctx_entry->head, &dev->ctxlist);
337 mutex_unlock(&dev->ctxlist_mutex);
338
339 return 0;
340}
341
342/**
343 * Get context.
344 *
345 * \param inode device inode.
346 * \param file_priv DRM file private.
347 * \param cmd command.
348 * \param arg user argument pointing to a drm_ctx structure.
349 * \return zero on success or a negative number on failure.
350 */
351int drm_getctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
352{
353 struct drm_ctx *ctx = data;
354
355 /* This is 0, because we don't handle any context flags */
356 ctx->flags = 0;
357
358 return 0;
359}
360
361/**
362 * Switch context.
363 *
364 * \param inode device inode.
365 * \param file_priv DRM file private.
366 * \param cmd command.
367 * \param arg user argument pointing to a drm_ctx structure.
368 * \return zero on success or a negative number on failure.
369 *
370 * Calls context_switch().
371 */
372int drm_switchctx(struct drm_device *dev, void *data,
373 struct drm_file *file_priv)
374{
375 struct drm_ctx *ctx = data;
376
377 DRM_DEBUG("%d\n", ctx->handle);
378 return drm_context_switch(dev, dev->last_context, ctx->handle);
379}
380
381/**
382 * New context.
383 *
384 * \param inode device inode.
385 * \param file_priv DRM file private.
386 * \param cmd command.
387 * \param arg user argument pointing to a drm_ctx structure.
388 * \return zero on success or a negative number on failure.
389 *
390 * Calls context_switch_complete().
391 */
392int drm_newctx(struct drm_device *dev, void *data,
393 struct drm_file *file_priv)
394{
395 struct drm_ctx *ctx = data;
396
397 DRM_DEBUG("%d\n", ctx->handle);
398 drm_context_switch_complete(dev, file_priv, ctx->handle);
399
400 return 0;
401}
402
403/**
404 * Remove context.
405 *
406 * \param inode device inode.
407 * \param file_priv DRM file private.
408 * \param cmd command.
409 * \param arg user argument pointing to a drm_ctx structure.
410 * \return zero on success or a negative number on failure.
411 *
412 * If not the special kernel context, calls ctxbitmap_free() to free the specified context.
413 */
414int drm_rmctx(struct drm_device *dev, void *data,
415 struct drm_file *file_priv)
416{
417 struct drm_ctx *ctx = data;
418
419 DRM_DEBUG("%d\n", ctx->handle);
420 if (ctx->handle != DRM_KERNEL_CONTEXT) {
421 if (dev->driver->context_dtor)
422 dev->driver->context_dtor(dev, ctx->handle);
423 drm_ctxbitmap_free(dev, ctx->handle);
424 }
425
426 mutex_lock(&dev->ctxlist_mutex);
427 if (!list_empty(&dev->ctxlist)) {
428 struct drm_ctx_list *pos, *n;
429
430 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
431 if (pos->handle == ctx->handle) {
432 list_del(&pos->head);
433 kfree(pos);
434 }
435 }
436 }
437 mutex_unlock(&dev->ctxlist_mutex);
438
439 return 0;
440}
441
442/*@}*/