summaryrefslogtreecommitdiff
path: root/drivers/media/platform/vsp1/vsp1_dl.c
blob: ad545aff4e35b5585cc5fa6526ecc33b49fd9a15 (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
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
/*
 * vsp1_dl.h  --  R-Car VSP1 Display List
 *
 * Copyright (C) 2015 Renesas Corporation
 *
 * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/workqueue.h>

#include "vsp1.h"
#include "vsp1_dl.h"

#define VSP1_DL_NUM_ENTRIES		256

#define VSP1_DLH_INT_ENABLE		(1 << 1)
#define VSP1_DLH_AUTO_START		(1 << 0)

struct vsp1_dl_header_list {
	u32 num_bytes;
	u32 addr;
} __attribute__((__packed__));

struct vsp1_dl_header {
	u32 num_lists;
	struct vsp1_dl_header_list lists[8];
	u32 next_header;
	u32 flags;
} __attribute__((__packed__));

struct vsp1_dl_entry {
	u32 addr;
	u32 data;
} __attribute__((__packed__));

/**
 * struct vsp1_dl_body - Display list body
 * @list: entry in the display list list of bodies
 * @vsp1: the VSP1 device
 * @entries: array of entries
 * @dma: DMA address of the entries
 * @size: size of the DMA memory in bytes
 * @num_entries: number of stored entries
 */
struct vsp1_dl_body {
	struct list_head list;
	struct vsp1_device *vsp1;

	struct vsp1_dl_entry *entries;
	dma_addr_t dma;
	size_t size;

	unsigned int num_entries;
};

/**
 * struct vsp1_dl_list - Display list
 * @list: entry in the display list manager lists
 * @dlm: the display list manager
 * @header: display list header, NULL for headerless lists
 * @dma: DMA address for the header
 * @body0: first display list body
 * @fragments: list of extra display list bodies
 * @chain: entry in the display list partition chain
 */
struct vsp1_dl_list {
	struct list_head list;
	struct vsp1_dl_manager *dlm;

	struct vsp1_dl_header *header;
	dma_addr_t dma;

	struct vsp1_dl_body body0;
	struct list_head fragments;

	bool has_chain;
	struct list_head chain;
};

enum vsp1_dl_mode {
	VSP1_DL_MODE_HEADER,
	VSP1_DL_MODE_HEADERLESS,
};

/**
 * struct vsp1_dl_manager - Display List manager
 * @index: index of the related WPF
 * @mode: display list operation mode (header or headerless)
 * @vsp1: the VSP1 device
 * @lock: protects the free, active, queued, pending and gc_fragments lists
 * @free: array of all free display lists
 * @active: list currently being processed (loaded) by hardware
 * @queued: list queued to the hardware (written to the DL registers)
 * @pending: list waiting to be queued to the hardware
 * @gc_work: fragments garbage collector work struct
 * @gc_fragments: array of display list fragments waiting to be freed
 */
struct vsp1_dl_manager {
	unsigned int index;
	enum vsp1_dl_mode mode;
	struct vsp1_device *vsp1;

	spinlock_t lock;
	struct list_head free;
	struct vsp1_dl_list *active;
	struct vsp1_dl_list *queued;
	struct vsp1_dl_list *pending;

	struct work_struct gc_work;
	struct list_head gc_fragments;
};

/* -----------------------------------------------------------------------------
 * Display List Body Management
 */

/*
 * Initialize a display list body object and allocate DMA memory for the body
 * data. The display list body object is expected to have been initialized to
 * 0 when allocated.
 */
static int vsp1_dl_body_init(struct vsp1_device *vsp1,
			     struct vsp1_dl_body *dlb, unsigned int num_entries,
			     size_t extra_size)
{
	size_t size = num_entries * sizeof(*dlb->entries) + extra_size;

	dlb->vsp1 = vsp1;
	dlb->size = size;

	dlb->entries = dma_alloc_wc(vsp1->dev, dlb->size, &dlb->dma,
				    GFP_KERNEL);
	if (!dlb->entries)
		return -ENOMEM;

	return 0;
}

/*
 * Cleanup a display list body and free allocated DMA memory allocated.
 */
static void vsp1_dl_body_cleanup(struct vsp1_dl_body *dlb)
{
	dma_free_wc(dlb->vsp1->dev, dlb->size, dlb->entries, dlb->dma);
}

/**
 * vsp1_dl_fragment_alloc - Allocate a display list fragment
 * @vsp1: The VSP1 device
 * @num_entries: The maximum number of entries that the fragment can contain
 *
 * Allocate a display list fragment with enough memory to contain the requested
 * number of entries.
 *
 * Return a pointer to a fragment on success or NULL if memory can't be
 * allocated.
 */
struct vsp1_dl_body *vsp1_dl_fragment_alloc(struct vsp1_device *vsp1,
					    unsigned int num_entries)
{
	struct vsp1_dl_body *dlb;
	int ret;

	dlb = kzalloc(sizeof(*dlb), GFP_KERNEL);
	if (!dlb)
		return NULL;

	ret = vsp1_dl_body_init(vsp1, dlb, num_entries, 0);
	if (ret < 0) {
		kfree(dlb);
		return NULL;
	}

	return dlb;
}

/**
 * vsp1_dl_fragment_free - Free a display list fragment
 * @dlb: The fragment
 *
 * Free the given display list fragment and the associated DMA memory.
 *
 * Fragments must only be freed explicitly if they are not added to a display
 * list, as the display list will take ownership of them and free them
 * otherwise. Manual free typically happens at cleanup time for fragments that
 * have been allocated but not used.
 *
 * Passing a NULL pointer to this function is safe, in that case no operation
 * will be performed.
 */
void vsp1_dl_fragment_free(struct vsp1_dl_body *dlb)
{
	if (!dlb)
		return;

	vsp1_dl_body_cleanup(dlb);
	kfree(dlb);
}

/**
 * vsp1_dl_fragment_write - Write a register to a display list fragment
 * @dlb: The fragment
 * @reg: The register address
 * @data: The register value
 *
 * Write the given register and value to the display list fragment. The maximum
 * number of entries that can be written in a fragment is specified when the
 * fragment is allocated by vsp1_dl_fragment_alloc().
 */
void vsp1_dl_fragment_write(struct vsp1_dl_body *dlb, u32 reg, u32 data)
{
	dlb->entries[dlb->num_entries].addr = reg;
	dlb->entries[dlb->num_entries].data = data;
	dlb->num_entries++;
}

/* -----------------------------------------------------------------------------
 * Display List Transaction Management
 */

static struct vsp1_dl_list *vsp1_dl_list_alloc(struct vsp1_dl_manager *dlm)
{
	struct vsp1_dl_list *dl;
	size_t header_size;
	int ret;

	dl = kzalloc(sizeof(*dl), GFP_KERNEL);
	if (!dl)
		return NULL;

	INIT_LIST_HEAD(&dl->fragments);
	dl->dlm = dlm;

	/* Initialize the display list body and allocate DMA memory for the body
	 * and the optional header. Both are allocated together to avoid memory
	 * fragmentation, with the header located right after the body in
	 * memory.
	 */
	header_size = dlm->mode == VSP1_DL_MODE_HEADER
		    ? ALIGN(sizeof(struct vsp1_dl_header), 8)
		    : 0;

	ret = vsp1_dl_body_init(dlm->vsp1, &dl->body0, VSP1_DL_NUM_ENTRIES,
				header_size);
	if (ret < 0) {
		kfree(dl);
		return NULL;
	}

	if (dlm->mode == VSP1_DL_MODE_HEADER) {
		size_t header_offset = VSP1_DL_NUM_ENTRIES
				     * sizeof(*dl->body0.entries);

		dl->header = ((void *)dl->body0.entries) + header_offset;
		dl->dma = dl->body0.dma + header_offset;

		memset(dl->header, 0, sizeof(*dl->header));
		dl->header->lists[0].addr = dl->body0.dma;
	}

	return dl;
}

static void vsp1_dl_list_free(struct vsp1_dl_list *dl)
{
	vsp1_dl_body_cleanup(&dl->body0);
	list_splice_init(&dl->fragments, &dl->dlm->gc_fragments);
	kfree(dl);
}

/**
 * vsp1_dl_list_get - Get a free display list
 * @dlm: The display list manager
 *
 * Get a display list from the pool of free lists and return it.
 *
 * This function must be called without the display list manager lock held.
 */
struct vsp1_dl_list *vsp1_dl_list_get(struct vsp1_dl_manager *dlm)
{
	struct vsp1_dl_list *dl = NULL;
	unsigned long flags;

	spin_lock_irqsave(&dlm->lock, flags);

	if (!list_empty(&dlm->free)) {
		dl = list_first_entry(&dlm->free, struct vsp1_dl_list, list);
		list_del(&dl->list);

		/*
		 * The display list chain must be initialised to ensure every
		 * display list can assert list_empty() if it is not in a chain.
		 */
		INIT_LIST_HEAD(&dl->chain);
	}

	spin_unlock_irqrestore(&dlm->lock, flags);

	return dl;
}

/* This function must be called with the display list manager lock held.*/
static void __vsp1_dl_list_put(struct vsp1_dl_list *dl)
{
	struct vsp1_dl_list *dl_child;

	if (!dl)
		return;

	/*
	 * Release any linked display-lists which were chained for a single
	 * hardware operation.
	 */
	if (dl->has_chain) {
		list_for_each_entry(dl_child, &dl->chain, chain)
			__vsp1_dl_list_put(dl_child);
	}

	dl->has_chain = false;

	/*
	 * We can't free fragments here as DMA memory can only be freed in
	 * interruptible context. Move all fragments to the display list
	 * manager's list of fragments to be freed, they will be
	 * garbage-collected by the work queue.
	 */
	if (!list_empty(&dl->fragments)) {
		list_splice_init(&dl->fragments, &dl->dlm->gc_fragments);
		schedule_work(&dl->dlm->gc_work);
	}

	dl->body0.num_entries = 0;

	list_add_tail(&dl->list, &dl->dlm->free);
}

/**
 * vsp1_dl_list_put - Release a display list
 * @dl: The display list
 *
 * Release the display list and return it to the pool of free lists.
 *
 * Passing a NULL pointer to this function is safe, in that case no operation
 * will be performed.
 */
void vsp1_dl_list_put(struct vsp1_dl_list *dl)
{
	unsigned long flags;

	if (!dl)
		return;

	spin_lock_irqsave(&dl->dlm->lock, flags);
	__vsp1_dl_list_put(dl);
	spin_unlock_irqrestore(&dl->dlm->lock, flags);
}

/**
 * vsp1_dl_list_write - Write a register to the display list
 * @dl: The display list
 * @reg: The register address
 * @data: The register value
 *
 * Write the given register and value to the display list. Up to 256 registers
 * can be written per display list.
 */
void vsp1_dl_list_write(struct vsp1_dl_list *dl, u32 reg, u32 data)
{
	vsp1_dl_fragment_write(&dl->body0, reg, data);
}

/**
 * vsp1_dl_list_add_fragment - Add a fragment to the display list
 * @dl: The display list
 * @dlb: The fragment
 *
 * Add a display list body as a fragment to a display list. Registers contained
 * in fragments are processed after registers contained in the main display
 * list, in the order in which fragments are added.
 *
 * Adding a fragment to a display list passes ownership of the fragment to the
 * list. The caller must not touch the fragment after this call, and must not
 * free it explicitly with vsp1_dl_fragment_free().
 *
 * Fragments are only usable for display lists in header mode. Attempt to
 * add a fragment to a header-less display list will return an error.
 */
int vsp1_dl_list_add_fragment(struct vsp1_dl_list *dl,
			      struct vsp1_dl_body *dlb)
{
	/* Multi-body lists are only available in header mode. */
	if (dl->dlm->mode != VSP1_DL_MODE_HEADER)
		return -EINVAL;

	list_add_tail(&dlb->list, &dl->fragments);
	return 0;
}

/**
 * vsp1_dl_list_add_chain - Add a display list to a chain
 * @head: The head display list
 * @dl: The new display list
 *
 * Add a display list to an existing display list chain. The chained lists
 * will be automatically processed by the hardware without intervention from
 * the CPU. A display list end interrupt will only complete after the last
 * display list in the chain has completed processing.
 *
 * Adding a display list to a chain passes ownership of the display list to
 * the head display list item. The chain is released when the head dl item is
 * put back with __vsp1_dl_list_put().
 *
 * Chained display lists are only usable in header mode. Attempts to add a
 * display list to a chain in header-less mode will return an error.
 */
int vsp1_dl_list_add_chain(struct vsp1_dl_list *head,
			   struct vsp1_dl_list *dl)
{
	/* Chained lists are only available in header mode. */
	if (head->dlm->mode != VSP1_DL_MODE_HEADER)
		return -EINVAL;

	head->has_chain = true;
	list_add_tail(&dl->chain, &head->chain);
	return 0;
}

static void vsp1_dl_list_fill_header(struct vsp1_dl_list *dl, bool is_last)
{
	struct vsp1_dl_header_list *hdr = dl->header->lists;
	struct vsp1_dl_body *dlb;
	unsigned int num_lists = 0;

	/*
	 * Fill the header with the display list bodies addresses and sizes. The
	 * address of the first body has already been filled when the display
	 * list was allocated.
	 */

	hdr->num_bytes = dl->body0.num_entries
		       * sizeof(*dl->header->lists);

	list_for_each_entry(dlb, &dl->fragments, list) {
		num_lists++;
		hdr++;

		hdr->addr = dlb->dma;
		hdr->num_bytes = dlb->num_entries
			       * sizeof(*dl->header->lists);
	}

	dl->header->num_lists = num_lists;

	/*
	 * If this display list's chain is not empty, we are on a list, where
	 * the next item in the list is the display list entity which should be
	 * automatically queued by the hardware.
	 */
	if (!list_empty(&dl->chain) && !is_last) {
		struct vsp1_dl_list *next = list_next_entry(dl, chain);

		dl->header->next_header = next->dma;
		dl->header->flags = VSP1_DLH_AUTO_START;
	} else {
		dl->header->flags = VSP1_DLH_INT_ENABLE;
	}
}

void vsp1_dl_list_commit(struct vsp1_dl_list *dl)
{
	struct vsp1_dl_manager *dlm = dl->dlm;
	struct vsp1_device *vsp1 = dlm->vsp1;
	unsigned long flags;
	bool update;

	spin_lock_irqsave(&dlm->lock, flags);

	if (dl->dlm->mode == VSP1_DL_MODE_HEADER) {
		struct vsp1_dl_list *dl_child;

		/*
		 * In header mode the caller guarantees that the hardware is
		 * idle at this point.
		 */

		/* Fill the header for the head and chained display lists. */
		vsp1_dl_list_fill_header(dl, list_empty(&dl->chain));

		list_for_each_entry(dl_child, &dl->chain, chain) {
			bool last = list_is_last(&dl_child->chain, &dl->chain);

			vsp1_dl_list_fill_header(dl_child, last);
		}

		/*
		 * Commit the head display list to hardware. Chained headers
		 * will auto-start.
		 */
		vsp1_write(vsp1, VI6_DL_HDR_ADDR(dlm->index), dl->dma);

		dlm->active = dl;
		goto done;
	}

	/* Once the UPD bit has been set the hardware can start processing the
	 * display list at any time and we can't touch the address and size
	 * registers. In that case mark the update as pending, it will be
	 * queued up to the hardware by the frame end interrupt handler.
	 */
	update = !!(vsp1_read(vsp1, VI6_DL_BODY_SIZE) & VI6_DL_BODY_SIZE_UPD);
	if (update) {
		__vsp1_dl_list_put(dlm->pending);
		dlm->pending = dl;
		goto done;
	}

	/* Program the hardware with the display list body address and size.
	 * The UPD bit will be cleared by the device when the display list is
	 * processed.
	 */
	vsp1_write(vsp1, VI6_DL_HDR_ADDR(0), dl->body0.dma);
	vsp1_write(vsp1, VI6_DL_BODY_SIZE, VI6_DL_BODY_SIZE_UPD |
		   (dl->body0.num_entries * sizeof(*dl->header->lists)));

	__vsp1_dl_list_put(dlm->queued);
	dlm->queued = dl;

done:
	spin_unlock_irqrestore(&dlm->lock, flags);
}

/* -----------------------------------------------------------------------------
 * Display List Manager
 */

/* Interrupt Handling */
void vsp1_dlm_irq_display_start(struct vsp1_dl_manager *dlm)
{
	spin_lock(&dlm->lock);

	/* The display start interrupt signals the end of the display list
	 * processing by the device. The active display list, if any, won't be
	 * accessed anymore and can be reused.
	 */
	__vsp1_dl_list_put(dlm->active);
	dlm->active = NULL;

	spin_unlock(&dlm->lock);
}

void vsp1_dlm_irq_frame_end(struct vsp1_dl_manager *dlm)
{
	struct vsp1_device *vsp1 = dlm->vsp1;

	spin_lock(&dlm->lock);

	__vsp1_dl_list_put(dlm->active);
	dlm->active = NULL;

	/* Header mode is used for mem-to-mem pipelines only. We don't need to
	 * perform any operation as there can't be any new display list queued
	 * in that case.
	 */
	if (dlm->mode == VSP1_DL_MODE_HEADER)
		goto done;

	/* The UPD bit set indicates that the commit operation raced with the
	 * interrupt and occurred after the frame end event and UPD clear but
	 * before interrupt processing. The hardware hasn't taken the update
	 * into account yet, we'll thus skip one frame and retry.
	 */
	if (vsp1_read(vsp1, VI6_DL_BODY_SIZE) & VI6_DL_BODY_SIZE_UPD)
		goto done;

	/* The device starts processing the queued display list right after the
	 * frame end interrupt. The display list thus becomes active.
	 */
	if (dlm->queued) {
		dlm->active = dlm->queued;
		dlm->queued = NULL;
	}

	/* Now that the UPD bit has been cleared we can queue the next display
	 * list to the hardware if one has been prepared.
	 */
	if (dlm->pending) {
		struct vsp1_dl_list *dl = dlm->pending;

		vsp1_write(vsp1, VI6_DL_HDR_ADDR(0), dl->body0.dma);
		vsp1_write(vsp1, VI6_DL_BODY_SIZE, VI6_DL_BODY_SIZE_UPD |
			   (dl->body0.num_entries *
			    sizeof(*dl->header->lists)));

		dlm->queued = dl;
		dlm->pending = NULL;
	}

done:
	spin_unlock(&dlm->lock);
}

/* Hardware Setup */
void vsp1_dlm_setup(struct vsp1_device *vsp1)
{
	u32 ctrl = (256 << VI6_DL_CTRL_AR_WAIT_SHIFT)
		 | VI6_DL_CTRL_DC2 | VI6_DL_CTRL_DC1 | VI6_DL_CTRL_DC0
		 | VI6_DL_CTRL_DLE;

	/* The DRM pipeline operates with display lists in Continuous Frame
	 * Mode, all other pipelines use manual start.
	 */
	if (vsp1->drm)
		ctrl |= VI6_DL_CTRL_CFM0 | VI6_DL_CTRL_NH0;

	vsp1_write(vsp1, VI6_DL_CTRL, ctrl);
	vsp1_write(vsp1, VI6_DL_SWAP, VI6_DL_SWAP_LWS);
}

void vsp1_dlm_reset(struct vsp1_dl_manager *dlm)
{
	unsigned long flags;

	spin_lock_irqsave(&dlm->lock, flags);

	__vsp1_dl_list_put(dlm->active);
	__vsp1_dl_list_put(dlm->queued);
	__vsp1_dl_list_put(dlm->pending);

	spin_unlock_irqrestore(&dlm->lock, flags);

	dlm->active = NULL;
	dlm->queued = NULL;
	dlm->pending = NULL;
}

/*
 * Free all fragments awaiting to be garbage-collected.
 *
 * This function must be called without the display list manager lock held.
 */
static void vsp1_dlm_fragments_free(struct vsp1_dl_manager *dlm)
{
	unsigned long flags;

	spin_lock_irqsave(&dlm->lock, flags);

	while (!list_empty(&dlm->gc_fragments)) {
		struct vsp1_dl_body *dlb;

		dlb = list_first_entry(&dlm->gc_fragments, struct vsp1_dl_body,
				       list);
		list_del(&dlb->list);

		spin_unlock_irqrestore(&dlm->lock, flags);
		vsp1_dl_fragment_free(dlb);
		spin_lock_irqsave(&dlm->lock, flags);
	}

	spin_unlock_irqrestore(&dlm->lock, flags);
}

static void vsp1_dlm_garbage_collect(struct work_struct *work)
{
	struct vsp1_dl_manager *dlm =
		container_of(work, struct vsp1_dl_manager, gc_work);

	vsp1_dlm_fragments_free(dlm);
}

struct vsp1_dl_manager *vsp1_dlm_create(struct vsp1_device *vsp1,
					unsigned int index,
					unsigned int prealloc)
{
	struct vsp1_dl_manager *dlm;
	unsigned int i;

	dlm = devm_kzalloc(vsp1->dev, sizeof(*dlm), GFP_KERNEL);
	if (!dlm)
		return NULL;

	dlm->index = index;
	dlm->mode = index == 0 && !vsp1->info->uapi
		  ? VSP1_DL_MODE_HEADERLESS : VSP1_DL_MODE_HEADER;
	dlm->vsp1 = vsp1;

	spin_lock_init(&dlm->lock);
	INIT_LIST_HEAD(&dlm->free);
	INIT_LIST_HEAD(&dlm->gc_fragments);
	INIT_WORK(&dlm->gc_work, vsp1_dlm_garbage_collect);

	for (i = 0; i < prealloc; ++i) {
		struct vsp1_dl_list *dl;

		dl = vsp1_dl_list_alloc(dlm);
		if (!dl)
			return NULL;

		list_add_tail(&dl->list, &dlm->free);
	}

	return dlm;
}

void vsp1_dlm_destroy(struct vsp1_dl_manager *dlm)
{
	struct vsp1_dl_list *dl, *next;

	if (!dlm)
		return;

	cancel_work_sync(&dlm->gc_work);

	list_for_each_entry_safe(dl, next, &dlm->free, list) {
		list_del(&dl->list);
		vsp1_dl_list_free(dl);
	}

	vsp1_dlm_fragments_free(dlm);
}