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