summaryrefslogtreecommitdiffstats
path: root/drivers/char/drm/drm_context.c
blob: bd958d69a2ac2aeccb166739c83de1cb674fa4cc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
/**
 * \file drm_context.c
 * IOCTLs for generic contexts
 *
 * \author Rickard E. (Rik) Faith <faith@valinux.com>
 * \author Gareth Hughes <gareth@valinux.com>
 */

/*
 * Created: Fri Nov 24 18:31:37 2000 by gareth@valinux.com
 *
 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

/*
 * ChangeLog:
 *  2001-11-16	Torsten Duwe <duwe@caldera.de>
 *		added context constructor/destructor hooks,
 *		needed by SiS driver's memory management.
 */

#include "drmP.h"

/******************************************************************/
/** \name Context bitmap support */
/*@{*/

/**
 * Free a handle from the context bitmap.
 *
 * \param dev DRM device.
 * \param ctx_handle context handle.
 *
 * Clears the bit specified by \p ctx_handle in drm_device::ctx_bitmap and the entry
 * in drm_device::context_sareas, while holding the drm_device::struct_sem
 * lock.
 */
void drm_ctxbitmap_free(drm_device_t * dev, int ctx_handle)
{
	if (ctx_handle < 0)
		goto failed;
	if (!dev->ctx_bitmap)
		goto failed;

	if (ctx_handle < DRM_MAX_CTXBITMAP) {
		down(&dev->struct_sem);
		clear_bit(ctx_handle, dev->ctx_bitmap);
		dev->context_sareas[ctx_handle] = NULL;
		up(&dev->struct_sem);
		return;
	}
      failed:
	DRM_ERROR("Attempt to free invalid context handle: %d\n", ctx_handle);
	return;
}

/**
 * Context bitmap allocation.
 *
 * \param dev DRM device.
 * \return (non-negative) context handle on success or a negative number on failure.
 *
 * Find the first zero bit in drm_device::ctx_bitmap and (re)allocates
 * drm_device::context_sareas to accommodate the new entry while holding the
 * drm_device::struct_sem lock.
 */
static int drm_ctxbitmap_next(drm_device_t * dev)
{
	int bit;

	if (!dev->ctx_bitmap)
		return -1;

	down(&dev->struct_sem);
	bit = find_first_zero_bit(dev->ctx_bitmap, DRM_MAX_CTXBITMAP);
	if (bit < DRM_MAX_CTXBITMAP) {
		set_bit(bit, dev->ctx_bitmap);
		DRM_DEBUG("drm_ctxbitmap_next bit : %d\n", bit);
		if ((bit + 1) > dev->max_context) {
			dev->max_context = (bit + 1);
			if (dev->context_sareas) {
				drm_map_t **ctx_sareas;

				ctx_sareas = drm_realloc(dev->context_sareas,
							 (dev->max_context -
							  1) *
							 sizeof(*dev->
								context_sareas),
							 dev->max_context *
							 sizeof(*dev->
								context_sareas),
							 DRM_MEM_MAPS);
				if (!ctx_sareas) {
					clear_bit(bit, dev->ctx_bitmap);
					up(&dev->struct_sem);
					return -1;
				}
				dev->context_sareas = ctx_sareas;
				dev->context_sareas[bit] = NULL;
			} else {
				/* max_context == 1 at this point */
				dev->context_sareas =
				    drm_alloc(dev->max_context *
					      sizeof(*dev->context_sareas),
					      DRM_MEM_MAPS);
				if (!dev->context_sareas) {
					clear_bit(bit, dev->ctx_bitmap);
					up(&dev->struct_sem);
					return -1;
				}
				dev->context_sareas[bit] = NULL;
			}
		}
		up(&dev->struct_sem);
		return bit;
	}
	up(&dev->struct_sem);
	return -1;
}

/**
 * Context bitmap initialization.
 *
 * \param dev DRM device.
 *
 * Allocates and initialize drm_device::ctx_bitmap and drm_device::context_sareas, while holding
 * the drm_device::struct_sem lock.
 */
int drm_ctxbitmap_init(drm_device_t * dev)
{
	int i;
	int temp;

	down(&dev->struct_sem);
	dev->ctx_bitmap = (unsigned long *)drm_alloc(PAGE_SIZE,
						     DRM_MEM_CTXBITMAP);
	if (dev->ctx_bitmap == NULL) {
		up(&dev->struct_sem);
		return -ENOMEM;
	}
	memset((void *)dev->ctx_bitmap, 0, PAGE_SIZE);
	dev->context_sareas = NULL;
	dev->max_context = -1;
	up(&dev->struct_sem);

	for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
		temp = drm_ctxbitmap_next(dev);
		DRM_DEBUG("drm_ctxbitmap_init : %d\n", temp);
	}

	return 0;
}

/**
 * Context bitmap cleanup.
 *
 * \param dev DRM device.
 *
 * Frees drm_device::ctx_bitmap and drm_device::context_sareas, while holding
 * the drm_device::struct_sem lock.
 */
void drm_ctxbitmap_cleanup(drm_device_t * dev)
{
	down(&dev->struct_sem);
	if (dev->context_sareas)
		drm_free(dev->context_sareas,
			 sizeof(*dev->context_sareas) *
			 dev->max_context, DRM_MEM_MAPS);
	drm_free((void *)dev->ctx_bitmap, PAGE_SIZE, DRM_MEM_CTXBITMAP);
	up(&dev->struct_sem);
}

/*@}*/

/******************************************************************/
/** \name Per Context SAREA Support */
/*@{*/

/**
 * Get per-context SAREA.
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg user argument pointing to a drm_ctx_priv_map structure.
 * \return zero on success or a negative number on failure.
 *
 * Gets the map from drm_device::context_sareas with the handle specified and
 * returns its handle.
 */
int drm_getsareactx(struct inode *inode, struct file *filp,
		    unsigned int cmd, unsigned long arg)
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	drm_ctx_priv_map_t __user *argp = (void __user *)arg;
	drm_ctx_priv_map_t request;
	drm_map_t *map;
	drm_map_list_t *_entry;

	if (copy_from_user(&request, argp, sizeof(request)))
		return -EFAULT;

	down(&dev->struct_sem);
	if (dev->max_context < 0
	    || request.ctx_id >= (unsigned)dev->max_context) {
		up(&dev->struct_sem);
		return -EINVAL;
	}

	map = dev->context_sareas[request.ctx_id];
	up(&dev->struct_sem);

	request.handle = NULL;
	list_for_each_entry(_entry, &dev->maplist->head, head) {
		if (_entry->map == map) {
			request.handle =
			    (void *)(unsigned long)_entry->user_token;
			break;
		}
	}
	if (request.handle == NULL)
		return -EINVAL;

	if (copy_to_user(argp, &request, sizeof(request)))
		return -EFAULT;
	return 0;
}

/**
 * Set per-context SAREA.
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg user argument pointing to a drm_ctx_priv_map structure.
 * \return zero on success or a negative number on failure.
 *
 * Searches the mapping specified in \p arg and update the entry in
 * drm_device::context_sareas with it.
 */
int drm_setsareactx(struct inode *inode, struct file *filp,
		    unsigned int cmd, unsigned long arg)
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	drm_ctx_priv_map_t request;
	drm_map_t *map = NULL;
	drm_map_list_t *r_list = NULL;
	struct list_head *list;

	if (copy_from_user(&request,
			   (drm_ctx_priv_map_t __user *) arg, sizeof(request)))
		return -EFAULT;

	down(&dev->struct_sem);
	list_for_each(list, &dev->maplist->head) {
		r_list = list_entry(list, drm_map_list_t, head);
		if (r_list->map
		    && r_list->user_token == (unsigned long)request.handle)
			goto found;
	}
      bad:
	up(&dev->struct_sem);
	return -EINVAL;

      found:
	map = r_list->map;
	if (!map)
		goto bad;
	if (dev->max_context < 0)
		goto bad;
	if (request.ctx_id >= (unsigned)dev->max_context)
		goto bad;
	dev->context_sareas[request.ctx_id] = map;
	up(&dev->struct_sem);
	return 0;
}

/*@}*/

/******************************************************************/
/** \name The actual DRM context handling routines */
/*@{*/

/**
 * Switch context.
 *
 * \param dev DRM device.
 * \param old old context handle.
 * \param new new context handle.
 * \return zero on success or a negative number on failure.
 *
 * Attempt to set drm_device::context_flag.
 */
static int drm_context_switch(drm_device_t * dev, int old, int new)
{
	if (test_and_set_bit(0, &dev->context_flag)) {
		DRM_ERROR("Reentering -- FIXME\n");
		return -EBUSY;
	}

	DRM_DEBUG("Context switch from %d to %d\n", old, new);

	if (new == dev->last_context) {
		clear_bit(0, &dev->context_flag);
		return 0;
	}

	return 0;
}

/**
 * Complete context switch.
 *
 * \param dev DRM device.
 * \param new new context handle.
 * \return zero on success or a negative number on failure.
 *
 * Updates drm_device::last_context and drm_device::last_switch. Verifies the
 * hardware lock is held, clears the drm_device::context_flag and wakes up
 * drm_device::context_wait.
 */
static int drm_context_switch_complete(drm_device_t * dev, int new)
{
	dev->last_context = new;	/* PRE/POST: This is the _only_ writer. */
	dev->last_switch = jiffies;

	if (!_DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock)) {
		DRM_ERROR("Lock isn't held after context switch\n");
	}

	/* If a context switch is ever initiated
	   when the kernel holds the lock, release
	   that lock here. */
	clear_bit(0, &dev->context_flag);
	wake_up(&dev->context_wait);

	return 0;
}

/**
 * Reserve contexts.
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg user argument pointing to a drm_ctx_res structure.
 * \return zero on success or a negative number on failure.
 */
int drm_resctx(struct inode *inode, struct file *filp,
	       unsigned int cmd, unsigned long arg)
{
	drm_ctx_res_t res;
	drm_ctx_t __user *argp = (void __user *)arg;
	drm_ctx_t ctx;
	int i;

	if (copy_from_user(&res, argp, sizeof(res)))
		return -EFAULT;

	if (res.count >= DRM_RESERVED_CONTEXTS) {
		memset(&ctx, 0, sizeof(ctx));
		for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
			ctx.handle = i;
			if (copy_to_user(&res.contexts[i], &ctx, sizeof(ctx)))
				return -EFAULT;
		}
	}
	res.count = DRM_RESERVED_CONTEXTS;

	if (copy_to_user(argp, &res, sizeof(res)))
		return -EFAULT;
	return 0;
}

/**
 * Add context.
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg user argument pointing to a drm_ctx structure.
 * \return zero on success or a negative number on failure.
 *
 * Get a new handle for the context and copy to userspace.
 */
int drm_addctx(struct inode *inode, struct file *filp,
	       unsigned int cmd, unsigned long arg)
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	drm_ctx_list_t *ctx_entry;
	drm_ctx_t __user *argp = (void __user *)arg;
	drm_ctx_t ctx;

	if (copy_from_user(&ctx, argp, sizeof(ctx)))
		return -EFAULT;

	ctx.handle = drm_ctxbitmap_next(dev);
	if (ctx.handle == DRM_KERNEL_CONTEXT) {
		/* Skip kernel's context and get a new one. */
		ctx.handle = drm_ctxbitmap_next(dev);
	}
	DRM_DEBUG("%d\n", ctx.handle);
	if (ctx.handle == -1) {
		DRM_DEBUG("Not enough free contexts.\n");
		/* Should this return -EBUSY instead? */
		return -ENOMEM;
	}

	if (ctx.handle != DRM_KERNEL_CONTEXT) {
		if (dev->driver->context_ctor)
			if (!dev->driver->context_ctor(dev, ctx.handle)) {
				DRM_DEBUG( "Running out of ctxs or memory.\n");
				return -ENOMEM;
			}
	}

	ctx_entry = drm_alloc(sizeof(*ctx_entry), DRM_MEM_CTXLIST);
	if (!ctx_entry) {
		DRM_DEBUG("out of memory\n");
		return -ENOMEM;
	}

	INIT_LIST_HEAD(&ctx_entry->head);
	ctx_entry->handle = ctx.handle;
	ctx_entry->tag = priv;

	down(&dev->ctxlist_sem);
	list_add(&ctx_entry->head, &dev->ctxlist->head);
	++dev->ctx_count;
	up(&dev->ctxlist_sem);

	if (copy_to_user(argp, &ctx, sizeof(ctx)))
		return -EFAULT;
	return 0;
}

int drm_modctx(struct inode *inode, struct file *filp,
	       unsigned int cmd, unsigned long arg)
{
	/* This does nothing */
	return 0;
}

/**
 * Get context.
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg user argument pointing to a drm_ctx structure.
 * \return zero on success or a negative number on failure.
 */
int drm_getctx(struct inode *inode, struct file *filp,
	       unsigned int cmd, unsigned long arg)
{
	drm_ctx_t __user *argp = (void __user *)arg;
	drm_ctx_t ctx;

	if (copy_from_user(&ctx, argp, sizeof(ctx)))
		return -EFAULT;

	/* This is 0, because we don't handle any context flags */
	ctx.flags = 0;

	if (copy_to_user(argp, &ctx, sizeof(ctx)))
		return -EFAULT;
	return 0;
}

/**
 * Switch context.
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg user argument pointing to a drm_ctx structure.
 * \return zero on success or a negative number on failure.
 *
 * Calls context_switch().
 */
int drm_switchctx(struct inode *inode, struct file *filp,
		  unsigned int cmd, unsigned long arg)
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	drm_ctx_t ctx;

	if (copy_from_user(&ctx, (drm_ctx_t __user *) arg, sizeof(ctx)))
		return -EFAULT;

	DRM_DEBUG("%d\n", ctx.handle);
	return drm_context_switch(dev, dev->last_context, ctx.handle);
}

/**
 * New context.
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg user argument pointing to a drm_ctx structure.
 * \return zero on success or a negative number on failure.
 *
 * Calls context_switch_complete().
 */
int drm_newctx(struct inode *inode, struct file *filp,
	       unsigned int cmd, unsigned long arg)
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	drm_ctx_t ctx;

	if (copy_from_user(&ctx, (drm_ctx_t __user *) arg, sizeof(ctx)))
		return -EFAULT;

	DRM_DEBUG("%d\n", ctx.handle);
	drm_context_switch_complete(dev, ctx.handle);

	return 0;
}

/**
 * Remove context.
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg user argument pointing to a drm_ctx structure.
 * \return zero on success or a negative number on failure.
 *
 * If not the special kernel context, calls ctxbitmap_free() to free the specified context.
 */
int drm_rmctx(struct inode *inode, struct file *filp,
	      unsigned int cmd, unsigned long arg)
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	drm_ctx_t ctx;

	if (copy_from_user(&ctx, (drm_ctx_t __user *) arg, sizeof(ctx)))
		return -EFAULT;

	DRM_DEBUG("%d\n", ctx.handle);
	if (ctx.handle == DRM_KERNEL_CONTEXT + 1) {
		priv->remove_auth_on_close = 1;
	}
	if (ctx.handle != DRM_KERNEL_CONTEXT) {
		if (dev->driver->context_dtor)
			dev->driver->context_dtor(dev, ctx.handle);
		drm_ctxbitmap_free(dev, ctx.handle);
	}

	down(&dev->ctxlist_sem);
	if (!list_empty(&dev->ctxlist->head)) {
		drm_ctx_list_t *pos, *n;

		list_for_each_entry_safe(pos, n, &dev->ctxlist->head, head) {
			if (pos->handle == ctx.handle) {
				list_del(&pos->head);
				drm_free(pos, sizeof(*pos), DRM_MEM_CTXLIST);
				--dev->ctx_count;
			}
		}
	}
	up(&dev->ctxlist_sem);

	return 0;
}

/*@}*/