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 | */ |
60 | void drm_legacy_ctxbitmap_free(struct drm_device * dev, int ctx_handle) |
61 | { |
62 | if (!drm_core_check_feature(dev, feature: DRIVER_LEGACY)) |
63 | return; |
64 | |
65 | mutex_lock(&dev->struct_mutex); |
66 | idr_remove(&dev->ctx_idr, id: ctx_handle); |
67 | mutex_unlock(lock: &dev->struct_mutex); |
68 | } |
69 | |
70 | /* |
71 | * Context bitmap allocation. |
72 | * |
73 | * \param dev DRM device. |
74 | * \return (non-negative) context handle on success or a negative number on failure. |
75 | * |
76 | * Allocate a new idr from drm_device::ctx_idr while holding the |
77 | * drm_device::struct_mutex lock. |
78 | */ |
79 | static int drm_legacy_ctxbitmap_next(struct drm_device * dev) |
80 | { |
81 | int ret; |
82 | |
83 | mutex_lock(&dev->struct_mutex); |
84 | ret = idr_alloc(&dev->ctx_idr, NULL, DRM_RESERVED_CONTEXTS, end: 0, |
85 | GFP_KERNEL); |
86 | mutex_unlock(lock: &dev->struct_mutex); |
87 | return ret; |
88 | } |
89 | |
90 | /* |
91 | * Context bitmap initialization. |
92 | * |
93 | * \param dev DRM device. |
94 | * |
95 | * Initialise the drm_device::ctx_idr |
96 | */ |
97 | void drm_legacy_ctxbitmap_init(struct drm_device * dev) |
98 | { |
99 | if (!drm_core_check_feature(dev, feature: DRIVER_LEGACY)) |
100 | return; |
101 | |
102 | idr_init(idr: &dev->ctx_idr); |
103 | } |
104 | |
105 | /* |
106 | * Context bitmap cleanup. |
107 | * |
108 | * \param dev DRM device. |
109 | * |
110 | * Free all idr members using drm_ctx_sarea_free helper function |
111 | * while holding the drm_device::struct_mutex lock. |
112 | */ |
113 | void drm_legacy_ctxbitmap_cleanup(struct drm_device * dev) |
114 | { |
115 | if (!drm_core_check_feature(dev, feature: DRIVER_LEGACY)) |
116 | return; |
117 | |
118 | mutex_lock(&dev->struct_mutex); |
119 | idr_destroy(&dev->ctx_idr); |
120 | mutex_unlock(lock: &dev->struct_mutex); |
121 | } |
122 | |
123 | /** |
124 | * drm_legacy_ctxbitmap_flush() - Flush all contexts owned by a file |
125 | * @dev: DRM device to operate on |
126 | * @file: Open file to flush contexts for |
127 | * |
128 | * This iterates over all contexts on @dev and drops them if they're owned by |
129 | * @file. Note that after this call returns, new contexts might be added if |
130 | * the file is still alive. |
131 | */ |
132 | void drm_legacy_ctxbitmap_flush(struct drm_device *dev, struct drm_file *file) |
133 | { |
134 | struct drm_ctx_list *pos, *tmp; |
135 | |
136 | if (!drm_core_check_feature(dev, feature: DRIVER_LEGACY)) |
137 | return; |
138 | |
139 | mutex_lock(&dev->ctxlist_mutex); |
140 | |
141 | list_for_each_entry_safe(pos, tmp, &dev->ctxlist, head) { |
142 | if (pos->tag == file && |
143 | pos->handle != DRM_KERNEL_CONTEXT) { |
144 | if (dev->driver->context_dtor) |
145 | dev->driver->context_dtor(dev, pos->handle); |
146 | |
147 | drm_legacy_ctxbitmap_free(dev, ctx_handle: pos->handle); |
148 | list_del(entry: &pos->head); |
149 | kfree(objp: pos); |
150 | } |
151 | } |
152 | |
153 | mutex_unlock(lock: &dev->ctxlist_mutex); |
154 | } |
155 | |
156 | /*@}*/ |
157 | |
158 | /******************************************************************/ |
159 | /** \name Per Context SAREA Support */ |
160 | /*@{*/ |
161 | |
162 | /* |
163 | * Get per-context SAREA. |
164 | * |
165 | * \param inode device inode. |
166 | * \param file_priv DRM file private. |
167 | * \param cmd command. |
168 | * \param arg user argument pointing to a drm_ctx_priv_map structure. |
169 | * \return zero on success or a negative number on failure. |
170 | * |
171 | * Gets the map from drm_device::ctx_idr with the handle specified and |
172 | * returns its handle. |
173 | */ |
174 | int drm_legacy_getsareactx(struct drm_device *dev, void *data, |
175 | struct drm_file *file_priv) |
176 | { |
177 | struct drm_ctx_priv_map *request = data; |
178 | struct drm_local_map *map; |
179 | struct drm_map_list *_entry; |
180 | |
181 | if (!drm_core_check_feature(dev, feature: DRIVER_LEGACY)) |
182 | return -EOPNOTSUPP; |
183 | |
184 | mutex_lock(&dev->struct_mutex); |
185 | |
186 | map = idr_find(&dev->ctx_idr, id: request->ctx_id); |
187 | if (!map) { |
188 | mutex_unlock(lock: &dev->struct_mutex); |
189 | return -EINVAL; |
190 | } |
191 | |
192 | request->handle = NULL; |
193 | list_for_each_entry(_entry, &dev->maplist, head) { |
194 | if (_entry->map == map) { |
195 | request->handle = |
196 | (void *)(unsigned long)_entry->user_token; |
197 | break; |
198 | } |
199 | } |
200 | |
201 | mutex_unlock(lock: &dev->struct_mutex); |
202 | |
203 | if (request->handle == NULL) |
204 | return -EINVAL; |
205 | |
206 | return 0; |
207 | } |
208 | |
209 | /* |
210 | * Set per-context SAREA. |
211 | * |
212 | * \param inode device inode. |
213 | * \param file_priv DRM file private. |
214 | * \param cmd command. |
215 | * \param arg user argument pointing to a drm_ctx_priv_map structure. |
216 | * \return zero on success or a negative number on failure. |
217 | * |
218 | * Searches the mapping specified in \p arg and update the entry in |
219 | * drm_device::ctx_idr with it. |
220 | */ |
221 | int drm_legacy_setsareactx(struct drm_device *dev, void *data, |
222 | struct drm_file *file_priv) |
223 | { |
224 | struct drm_ctx_priv_map *request = data; |
225 | struct drm_local_map *map = NULL; |
226 | struct drm_map_list *r_list = NULL; |
227 | |
228 | if (!drm_core_check_feature(dev, feature: DRIVER_LEGACY)) |
229 | return -EOPNOTSUPP; |
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(lock: &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(ptr: idr_replace(&dev->ctx_idr, map, id: request->ctx_id))) |
247 | goto bad; |
248 | |
249 | mutex_unlock(lock: &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 | */ |
270 | static int drm_context_switch(struct drm_device * dev, int old, int new) |
271 | { |
272 | if (test_and_set_bit(nr: 0, addr: &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(nr: 0, addr: &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 | */ |
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 | */ |
311 | clear_bit(nr: 0, addr: &dev->context_flag); |
312 | |
313 | return 0; |
314 | } |
315 | |
316 | /* |
317 | * Reserve contexts. |
318 | * |
319 | * \param inode device inode. |
320 | * \param file_priv DRM file private. |
321 | * \param cmd command. |
322 | * \param arg user argument pointing to a drm_ctx_res structure. |
323 | * \return zero on success or a negative number on failure. |
324 | */ |
325 | int drm_legacy_resctx(struct drm_device *dev, void *data, |
326 | struct drm_file *file_priv) |
327 | { |
328 | struct drm_ctx_res *res = data; |
329 | struct drm_ctx ctx; |
330 | int i; |
331 | |
332 | if (!drm_core_check_feature(dev, feature: DRIVER_LEGACY)) |
333 | return -EOPNOTSUPP; |
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(to: &res->contexts[i], from: &ctx, n: 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 | */ |
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 | int tmp_handle; |
365 | |
366 | if (!drm_core_check_feature(dev, feature: DRIVER_LEGACY)) |
367 | return -EOPNOTSUPP; |
368 | |
369 | tmp_handle = drm_legacy_ctxbitmap_next(dev); |
370 | if (tmp_handle == DRM_KERNEL_CONTEXT) { |
371 | /* Skip kernel's context and get a new one. */ |
372 | tmp_handle = drm_legacy_ctxbitmap_next(dev); |
373 | } |
374 | DRM_DEBUG("%d\n" , tmp_handle); |
375 | if (tmp_handle < 0) { |
376 | DRM_DEBUG("Not enough free contexts.\n" ); |
377 | /* Should this return -EBUSY instead? */ |
378 | return tmp_handle; |
379 | } |
380 | |
381 | ctx->handle = tmp_handle; |
382 | |
383 | ctx_entry = kmalloc(size: sizeof(*ctx_entry), GFP_KERNEL); |
384 | if (!ctx_entry) { |
385 | DRM_DEBUG("out of memory\n" ); |
386 | return -ENOMEM; |
387 | } |
388 | |
389 | INIT_LIST_HEAD(list: &ctx_entry->head); |
390 | ctx_entry->handle = ctx->handle; |
391 | ctx_entry->tag = file_priv; |
392 | |
393 | mutex_lock(&dev->ctxlist_mutex); |
394 | list_add(new: &ctx_entry->head, head: &dev->ctxlist); |
395 | mutex_unlock(lock: &dev->ctxlist_mutex); |
396 | |
397 | return 0; |
398 | } |
399 | |
400 | /* |
401 | * Get context. |
402 | * |
403 | * \param inode device inode. |
404 | * \param file_priv DRM file private. |
405 | * \param cmd command. |
406 | * \param arg user argument pointing to a drm_ctx structure. |
407 | * \return zero on success or a negative number on failure. |
408 | */ |
409 | int drm_legacy_getctx(struct drm_device *dev, void *data, |
410 | struct drm_file *file_priv) |
411 | { |
412 | struct drm_ctx *ctx = data; |
413 | |
414 | if (!drm_core_check_feature(dev, feature: DRIVER_LEGACY)) |
415 | return -EOPNOTSUPP; |
416 | |
417 | /* This is 0, because we don't handle any context flags */ |
418 | ctx->flags = 0; |
419 | |
420 | return 0; |
421 | } |
422 | |
423 | /* |
424 | * Switch 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 | * Calls context_switch(). |
433 | */ |
434 | int drm_legacy_switchctx(struct drm_device *dev, void *data, |
435 | struct drm_file *file_priv) |
436 | { |
437 | struct drm_ctx *ctx = data; |
438 | |
439 | if (!drm_core_check_feature(dev, feature: DRIVER_LEGACY)) |
440 | return -EOPNOTSUPP; |
441 | |
442 | DRM_DEBUG("%d\n" , ctx->handle); |
443 | return drm_context_switch(dev, old: dev->last_context, new: 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 | */ |
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, feature: DRIVER_LEGACY)) |
463 | return -EOPNOTSUPP; |
464 | |
465 | DRM_DEBUG("%d\n" , ctx->handle); |
466 | drm_context_switch_complete(dev, file_priv, new: ctx->handle); |
467 | |
468 | return 0; |
469 | } |
470 | |
471 | /* |
472 | * Remove context. |
473 | * |
474 | * \param inode device inode. |
475 | * \param file_priv DRM file private. |
476 | * \param cmd command. |
477 | * \param arg user argument pointing to a drm_ctx structure. |
478 | * \return zero on success or a negative number on failure. |
479 | * |
480 | * If not the special kernel context, calls ctxbitmap_free() to free the specified context. |
481 | */ |
482 | int drm_legacy_rmctx(struct drm_device *dev, void *data, |
483 | struct drm_file *file_priv) |
484 | { |
485 | struct drm_ctx *ctx = data; |
486 | |
487 | if (!drm_core_check_feature(dev, feature: DRIVER_LEGACY)) |
488 | return -EOPNOTSUPP; |
489 | |
490 | DRM_DEBUG("%d\n" , ctx->handle); |
491 | if (ctx->handle != DRM_KERNEL_CONTEXT) { |
492 | if (dev->driver->context_dtor) |
493 | dev->driver->context_dtor(dev, ctx->handle); |
494 | drm_legacy_ctxbitmap_free(dev, ctx_handle: ctx->handle); |
495 | } |
496 | |
497 | mutex_lock(&dev->ctxlist_mutex); |
498 | if (!list_empty(head: &dev->ctxlist)) { |
499 | struct drm_ctx_list *pos, *n; |
500 | |
501 | list_for_each_entry_safe(pos, n, &dev->ctxlist, head) { |
502 | if (pos->handle == ctx->handle) { |
503 | list_del(entry: &pos->head); |
504 | kfree(objp: pos); |
505 | } |
506 | } |
507 | } |
508 | mutex_unlock(lock: &dev->ctxlist_mutex); |
509 | |
510 | return 0; |
511 | } |
512 | |
513 | /*@}*/ |
514 | |