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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 <drm/drmP.h>
32#include "drm_legacy.h"
33
34struct 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 */
54void 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_MODESET))
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 */
74static 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 */
92void 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_MODESET))
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 */
109void 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_MODESET))
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 */
129void 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_MODESET))
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 */
172int 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_MODESET))
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 */
220int 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_MODESET))
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 */
270static 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 */
298static 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 */
324int 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_MODESET))
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 */
359int 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_MODESET))
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 == -1) {
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 */
407int 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_MODESET))
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 */
433int 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_MODESET))
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 */
457int 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_MODESET))
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 */
483int 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_MODESET))
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/*@}*/
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 "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 new_id;
78 int ret;
79
80again:
81 if (idr_pre_get(&dev->ctx_idr, GFP_KERNEL) == 0) {
82 DRM_ERROR("Out of memory expanding drawable idr\n");
83 return -ENOMEM;
84 }
85 mutex_lock(&dev->struct_mutex);
86 ret = idr_get_new_above(&dev->ctx_idr, NULL,
87 DRM_RESERVED_CONTEXTS, &new_id);
88 mutex_unlock(&dev->struct_mutex);
89 if (ret == -EAGAIN)
90 goto again;
91 else if (ret)
92 return ret;
93
94 return new_id;
95}
96
97/**
98 * Context bitmap initialization.
99 *
100 * \param dev DRM device.
101 *
102 * Initialise the drm_device::ctx_idr
103 */
104int drm_ctxbitmap_init(struct drm_device * dev)
105{
106 idr_init(&dev->ctx_idr);
107 return 0;
108}
109
110/**
111 * Context bitmap cleanup.
112 *
113 * \param dev DRM device.
114 *
115 * Free all idr members using drm_ctx_sarea_free helper function
116 * while holding the drm_device::struct_mutex lock.
117 */
118void drm_ctxbitmap_cleanup(struct drm_device * dev)
119{
120 mutex_lock(&dev->struct_mutex);
121 idr_remove_all(&dev->ctx_idr);
122 mutex_unlock(&dev->struct_mutex);
123}
124
125/*@}*/
126
127/******************************************************************/
128/** \name Per Context SAREA Support */
129/*@{*/
130
131/**
132 * Get per-context SAREA.
133 *
134 * \param inode device inode.
135 * \param file_priv DRM file private.
136 * \param cmd command.
137 * \param arg user argument pointing to a drm_ctx_priv_map structure.
138 * \return zero on success or a negative number on failure.
139 *
140 * Gets the map from drm_device::ctx_idr with the handle specified and
141 * returns its handle.
142 */
143int drm_getsareactx(struct drm_device *dev, void *data,
144 struct drm_file *file_priv)
145{
146 struct drm_ctx_priv_map *request = data;
147 struct drm_local_map *map;
148 struct drm_map_list *_entry;
149
150 mutex_lock(&dev->struct_mutex);
151
152 map = idr_find(&dev->ctx_idr, request->ctx_id);
153 if (!map) {
154 mutex_unlock(&dev->struct_mutex);
155 return -EINVAL;
156 }
157
158 request->handle = NULL;
159 list_for_each_entry(_entry, &dev->maplist, head) {
160 if (_entry->map == map) {
161 request->handle =
162 (void *)(unsigned long)_entry->user_token;
163 break;
164 }
165 }
166
167 mutex_unlock(&dev->struct_mutex);
168
169 if (request->handle == NULL)
170 return -EINVAL;
171
172 return 0;
173}
174
175/**
176 * Set 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 * Searches the mapping specified in \p arg and update the entry in
185 * drm_device::ctx_idr with it.
186 */
187int drm_setsareactx(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 = NULL;
192 struct drm_map_list *r_list = NULL;
193
194 mutex_lock(&dev->struct_mutex);
195 list_for_each_entry(r_list, &dev->maplist, head) {
196 if (r_list->map
197 && r_list->user_token == (unsigned long) request->handle)
198 goto found;
199 }
200 bad:
201 mutex_unlock(&dev->struct_mutex);
202 return -EINVAL;
203
204 found:
205 map = r_list->map;
206 if (!map)
207 goto bad;
208
209 if (IS_ERR(idr_replace(&dev->ctx_idr, map, request->ctx_id)))
210 goto bad;
211
212 mutex_unlock(&dev->struct_mutex);
213
214 return 0;
215}
216
217/*@}*/
218
219/******************************************************************/
220/** \name The actual DRM context handling routines */
221/*@{*/
222
223/**
224 * Switch context.
225 *
226 * \param dev DRM device.
227 * \param old old context handle.
228 * \param new new context handle.
229 * \return zero on success or a negative number on failure.
230 *
231 * Attempt to set drm_device::context_flag.
232 */
233static int drm_context_switch(struct drm_device * dev, int old, int new)
234{
235 if (test_and_set_bit(0, &dev->context_flag)) {
236 DRM_ERROR("Reentering -- FIXME\n");
237 return -EBUSY;
238 }
239
240 DRM_DEBUG("Context switch from %d to %d\n", old, new);
241
242 if (new == dev->last_context) {
243 clear_bit(0, &dev->context_flag);
244 return 0;
245 }
246
247 return 0;
248}
249
250/**
251 * Complete context switch.
252 *
253 * \param dev DRM device.
254 * \param new new context handle.
255 * \return zero on success or a negative number on failure.
256 *
257 * Updates drm_device::last_context and drm_device::last_switch. Verifies the
258 * hardware lock is held, clears the drm_device::context_flag and wakes up
259 * drm_device::context_wait.
260 */
261static int drm_context_switch_complete(struct drm_device *dev,
262 struct drm_file *file_priv, int new)
263{
264 dev->last_context = new; /* PRE/POST: This is the _only_ writer. */
265 dev->last_switch = jiffies;
266
267 if (!_DRM_LOCK_IS_HELD(file_priv->master->lock.hw_lock->lock)) {
268 DRM_ERROR("Lock isn't held after context switch\n");
269 }
270
271 /* If a context switch is ever initiated
272 when the kernel holds the lock, release
273 that lock here. */
274 clear_bit(0, &dev->context_flag);
275 wake_up(&dev->context_wait);
276
277 return 0;
278}
279
280/**
281 * Reserve contexts.
282 *
283 * \param inode device inode.
284 * \param file_priv DRM file private.
285 * \param cmd command.
286 * \param arg user argument pointing to a drm_ctx_res structure.
287 * \return zero on success or a negative number on failure.
288 */
289int drm_resctx(struct drm_device *dev, void *data,
290 struct drm_file *file_priv)
291{
292 struct drm_ctx_res *res = data;
293 struct drm_ctx ctx;
294 int i;
295
296 if (res->count >= DRM_RESERVED_CONTEXTS) {
297 memset(&ctx, 0, sizeof(ctx));
298 for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
299 ctx.handle = i;
300 if (copy_to_user(&res->contexts[i], &ctx, sizeof(ctx)))
301 return -EFAULT;
302 }
303 }
304 res->count = DRM_RESERVED_CONTEXTS;
305
306 return 0;
307}
308
309/**
310 * Add context.
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 structure.
316 * \return zero on success or a negative number on failure.
317 *
318 * Get a new handle for the context and copy to userspace.
319 */
320int drm_addctx(struct drm_device *dev, void *data,
321 struct drm_file *file_priv)
322{
323 struct drm_ctx_list *ctx_entry;
324 struct drm_ctx *ctx = data;
325
326 ctx->handle = drm_ctxbitmap_next(dev);
327 if (ctx->handle == DRM_KERNEL_CONTEXT) {
328 /* Skip kernel's context and get a new one. */
329 ctx->handle = drm_ctxbitmap_next(dev);
330 }
331 DRM_DEBUG("%d\n", ctx->handle);
332 if (ctx->handle == -1) {
333 DRM_DEBUG("Not enough free contexts.\n");
334 /* Should this return -EBUSY instead? */
335 return -ENOMEM;
336 }
337
338 ctx_entry = kmalloc(sizeof(*ctx_entry), GFP_KERNEL);
339 if (!ctx_entry) {
340 DRM_DEBUG("out of memory\n");
341 return -ENOMEM;
342 }
343
344 INIT_LIST_HEAD(&ctx_entry->head);
345 ctx_entry->handle = ctx->handle;
346 ctx_entry->tag = file_priv;
347
348 mutex_lock(&dev->ctxlist_mutex);
349 list_add(&ctx_entry->head, &dev->ctxlist);
350 ++dev->ctx_count;
351 mutex_unlock(&dev->ctxlist_mutex);
352
353 return 0;
354}
355
356int drm_modctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
357{
358 /* This does nothing */
359 return 0;
360}
361
362/**
363 * Get context.
364 *
365 * \param inode device inode.
366 * \param file_priv DRM file private.
367 * \param cmd command.
368 * \param arg user argument pointing to a drm_ctx structure.
369 * \return zero on success or a negative number on failure.
370 */
371int drm_getctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
372{
373 struct drm_ctx *ctx = data;
374
375 /* This is 0, because we don't handle any context flags */
376 ctx->flags = 0;
377
378 return 0;
379}
380
381/**
382 * Switch 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().
391 */
392int drm_switchctx(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 return drm_context_switch(dev, dev->last_context, ctx->handle);
399}
400
401/**
402 * New context.
403 *
404 * \param inode device inode.
405 * \param file_priv DRM file private.
406 * \param cmd command.
407 * \param arg user argument pointing to a drm_ctx structure.
408 * \return zero on success or a negative number on failure.
409 *
410 * Calls context_switch_complete().
411 */
412int drm_newctx(struct drm_device *dev, void *data,
413 struct drm_file *file_priv)
414{
415 struct drm_ctx *ctx = data;
416
417 DRM_DEBUG("%d\n", ctx->handle);
418 drm_context_switch_complete(dev, file_priv, ctx->handle);
419
420 return 0;
421}
422
423/**
424 * Remove context.
425 *
426 * \param inode device inode.
427 * \param file_priv DRM file private.
428 * \param cmd command.
429 * \param arg user argument pointing to a drm_ctx structure.
430 * \return zero on success or a negative number on failure.
431 *
432 * If not the special kernel context, calls ctxbitmap_free() to free the specified context.
433 */
434int drm_rmctx(struct drm_device *dev, void *data,
435 struct drm_file *file_priv)
436{
437 struct drm_ctx *ctx = data;
438
439 DRM_DEBUG("%d\n", ctx->handle);
440 if (ctx->handle != DRM_KERNEL_CONTEXT) {
441 if (dev->driver->context_dtor)
442 dev->driver->context_dtor(dev, ctx->handle);
443 drm_ctxbitmap_free(dev, ctx->handle);
444 }
445
446 mutex_lock(&dev->ctxlist_mutex);
447 if (!list_empty(&dev->ctxlist)) {
448 struct drm_ctx_list *pos, *n;
449
450 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
451 if (pos->handle == ctx->handle) {
452 list_del(&pos->head);
453 kfree(pos);
454 --dev->ctx_count;
455 }
456 }
457 }
458 mutex_unlock(&dev->ctxlist_mutex);
459
460 return 0;
461}
462
463/*@}*/