xref: /freebsd/sys/dev/sound/pcm/feeder.c (revision f0a75d274af375d15b97b830966b99a02b7db911)
1 /*-
2  * Copyright (c) 1999 Cameron Grant <cg@freebsd.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <dev/sound/pcm/sound.h>
28 
29 #include "feeder_if.h"
30 
31 SND_DECLARE_FILE("$FreeBSD$");
32 
33 MALLOC_DEFINE(M_FEEDER, "feeder", "pcm feeder");
34 
35 #define MAXFEEDERS 	256
36 #undef FEEDER_DEBUG
37 
38 int feeder_buffersize = FEEDBUFSZ;
39 TUNABLE_INT("hw.snd.feeder_buffersize", &feeder_buffersize);
40 
41 #ifdef SND_DEBUG
42 static int
43 sysctl_hw_snd_feeder_buffersize(SYSCTL_HANDLER_ARGS)
44 {
45 	int i, err, val;
46 
47 	val = feeder_buffersize;
48 	err = sysctl_handle_int(oidp, &val, sizeof(val), req);
49 
50 	if (err != 0 || req->newptr == NULL)
51 		return err;
52 
53 	if (val < FEEDBUFSZ_MIN || val > FEEDBUFSZ_MAX)
54 		return EINVAL;
55 
56 	i = 0;
57 	while (val >> i)
58 		i++;
59 	i = 1 << i;
60 	if (i > val && (i >> 1) > 0 && (i >> 1) >= ((val * 3) >> 2))
61 		i >>= 1;
62 
63 	feeder_buffersize = i;
64 
65 	return err;
66 }
67 SYSCTL_PROC(_hw_snd, OID_AUTO, feeder_buffersize, CTLTYPE_INT | CTLFLAG_RW,
68 	0, sizeof(int), sysctl_hw_snd_feeder_buffersize, "I",
69 	"feeder buffer size");
70 #else
71 SYSCTL_INT(_hw_snd, OID_AUTO, feeder_buffersize, CTLFLAG_RD,
72 	&feeder_buffersize, FEEDBUFSZ, "feeder buffer size");
73 #endif
74 
75 struct feedertab_entry {
76 	SLIST_ENTRY(feedertab_entry) link;
77 	struct feeder_class *feederclass;
78 	struct pcm_feederdesc *desc;
79 
80 	int idx;
81 };
82 static SLIST_HEAD(, feedertab_entry) feedertab;
83 
84 /*****************************************************************************/
85 
86 void
87 feeder_register(void *p)
88 {
89 	static int feedercnt = 0;
90 
91 	struct feeder_class *fc = p;
92 	struct feedertab_entry *fte;
93 	int i;
94 
95 	if (feedercnt == 0) {
96 		KASSERT(fc->desc == NULL, ("first feeder not root: %s", fc->name));
97 
98 		SLIST_INIT(&feedertab);
99 		fte = malloc(sizeof(*fte), M_FEEDER, M_NOWAIT | M_ZERO);
100 		if (fte == NULL) {
101 			printf("can't allocate memory for root feeder: %s\n",
102 			    fc->name);
103 
104 			return;
105 		}
106 		fte->feederclass = fc;
107 		fte->desc = NULL;
108 		fte->idx = feedercnt;
109 		SLIST_INSERT_HEAD(&feedertab, fte, link);
110 		feedercnt++;
111 
112 		/* initialize global variables */
113 
114 		if (snd_verbose < 0 || snd_verbose > 3)
115 			snd_verbose = 1;
116 
117 		if (snd_unit < 0 || snd_unit > PCMMAXDEV)
118 			snd_unit = 0;
119 
120 		if (snd_maxautovchans < 0 ||
121 		    snd_maxautovchans > SND_MAXVCHANS)
122 			snd_maxautovchans = 0;
123 
124 		if (chn_latency < CHN_LATENCY_MIN ||
125 		    chn_latency > CHN_LATENCY_MAX)
126 			chn_latency = CHN_LATENCY_DEFAULT;
127 
128 		if (chn_latency_profile < CHN_LATENCY_PROFILE_MIN ||
129 		    chn_latency_profile > CHN_LATENCY_PROFILE_MAX)
130 			chn_latency_profile = CHN_LATENCY_PROFILE_DEFAULT;
131 
132 		if (feeder_buffersize < FEEDBUFSZ_MIN ||
133 		    	    feeder_buffersize > FEEDBUFSZ_MAX)
134 			feeder_buffersize = FEEDBUFSZ;
135 
136 		if (feeder_rate_min < FEEDRATE_MIN ||
137 			    feeder_rate_max < FEEDRATE_MIN ||
138 			    feeder_rate_min > FEEDRATE_MAX ||
139 			    feeder_rate_max > FEEDRATE_MAX ||
140 			    !(feeder_rate_min < feeder_rate_max)) {
141 			feeder_rate_min = FEEDRATE_RATEMIN;
142 			feeder_rate_max = FEEDRATE_RATEMAX;
143 		}
144 
145 		if (feeder_rate_round < FEEDRATE_ROUNDHZ_MIN ||
146 		    	    feeder_rate_round > FEEDRATE_ROUNDHZ_MAX)
147 			feeder_rate_round = FEEDRATE_ROUNDHZ;
148 
149 		if (bootverbose)
150 			printf("%s: snd_unit=%d snd_maxautovchans=%d "
151 			    "latency=%d feeder_buffersize=%d "
152 			    "feeder_rate_min=%d feeder_rate_max=%d "
153 			    "feeder_rate_round=%d\n",
154 			    __func__, snd_unit, snd_maxautovchans,
155 			    chn_latency, feeder_buffersize,
156 			    feeder_rate_min, feeder_rate_max,
157 			    feeder_rate_round);
158 
159 		/* we've got our root feeder so don't veto pcm loading anymore */
160 		pcm_veto_load = 0;
161 
162 		return;
163 	}
164 
165 	KASSERT(fc->desc != NULL, ("feeder '%s' has no descriptor", fc->name));
166 
167 	/* beyond this point failure is non-fatal but may result in some translations being unavailable */
168 	i = 0;
169 	while ((feedercnt < MAXFEEDERS) && (fc->desc[i].type > 0)) {
170 		/* printf("adding feeder %s, %x -> %x\n", fc->name, fc->desc[i].in, fc->desc[i].out); */
171 		fte = malloc(sizeof(*fte), M_FEEDER, M_NOWAIT | M_ZERO);
172 		if (fte == NULL) {
173 			printf("can't allocate memory for feeder '%s', %x -> %x\n", fc->name, fc->desc[i].in, fc->desc[i].out);
174 
175 			return;
176 		}
177 		fte->feederclass = fc;
178 		fte->desc = &fc->desc[i];
179 		fte->idx = feedercnt;
180 		fte->desc->idx = feedercnt;
181 		SLIST_INSERT_HEAD(&feedertab, fte, link);
182 		i++;
183 	}
184 	feedercnt++;
185 	if (feedercnt >= MAXFEEDERS)
186 		printf("MAXFEEDERS (%d >= %d) exceeded\n", feedercnt, MAXFEEDERS);
187 }
188 
189 static void
190 feeder_unregisterall(void *p)
191 {
192 	struct feedertab_entry *fte, *next;
193 
194 	next = SLIST_FIRST(&feedertab);
195 	while (next != NULL) {
196 		fte = next;
197 		next = SLIST_NEXT(fte, link);
198 		free(fte, M_FEEDER);
199 	}
200 }
201 
202 static int
203 cmpdesc(struct pcm_feederdesc *n, struct pcm_feederdesc *m)
204 {
205 	return ((n->type == m->type) &&
206 		((n->in == 0) || (n->in == m->in)) &&
207 		((n->out == 0) || (n->out == m->out)) &&
208 		(n->flags == m->flags));
209 }
210 
211 static void
212 feeder_destroy(struct pcm_feeder *f)
213 {
214 	FEEDER_FREE(f);
215 	kobj_delete((kobj_t)f, M_FEEDER);
216 }
217 
218 static struct pcm_feeder *
219 feeder_create(struct feeder_class *fc, struct pcm_feederdesc *desc)
220 {
221 	struct pcm_feeder *f;
222 	int err;
223 
224 	f = (struct pcm_feeder *)kobj_create((kobj_class_t)fc, M_FEEDER, M_NOWAIT | M_ZERO);
225 	if (f == NULL)
226 		return NULL;
227 
228 	f->align = fc->align;
229 	f->data = fc->data;
230 	f->source = NULL;
231 	f->parent = NULL;
232 	f->class = fc;
233 	f->desc = &(f->desc_static);
234 
235 	if (desc) {
236 		*(f->desc) = *desc;
237 	} else {
238 		f->desc->type = FEEDER_ROOT;
239 		f->desc->in = 0;
240 		f->desc->out = 0;
241 		f->desc->flags = 0;
242 		f->desc->idx = 0;
243 	}
244 
245 	err = FEEDER_INIT(f);
246 	if (err) {
247 		printf("feeder_init(%p) on %s returned %d\n", f, fc->name, err);
248 		feeder_destroy(f);
249 
250 		return NULL;
251 	}
252 
253 	return f;
254 }
255 
256 struct feeder_class *
257 feeder_getclass(struct pcm_feederdesc *desc)
258 {
259 	struct feedertab_entry *fte;
260 
261 	SLIST_FOREACH(fte, &feedertab, link) {
262 		if ((desc == NULL) && (fte->desc == NULL))
263 			return fte->feederclass;
264 		if ((fte->desc != NULL) && (desc != NULL) && cmpdesc(desc, fte->desc))
265 			return fte->feederclass;
266 	}
267 	return NULL;
268 }
269 
270 int
271 chn_addfeeder(struct pcm_channel *c, struct feeder_class *fc, struct pcm_feederdesc *desc)
272 {
273 	struct pcm_feeder *nf;
274 
275 	nf = feeder_create(fc, desc);
276 	if (nf == NULL)
277 		return ENOSPC;
278 
279 	nf->source = c->feeder;
280 
281 	/* XXX we should use the lowest common denominator for align */
282 	if (nf->align > 0)
283 		c->align += nf->align;
284 	else if (nf->align < 0 && c->align < -nf->align)
285 		c->align = -nf->align;
286 	if (c->feeder != NULL)
287 		c->feeder->parent = nf;
288 	c->feeder = nf;
289 
290 	return 0;
291 }
292 
293 int
294 chn_removefeeder(struct pcm_channel *c)
295 {
296 	struct pcm_feeder *f;
297 
298 	if (c->feeder == NULL)
299 		return -1;
300 	f = c->feeder;
301 	c->feeder = c->feeder->source;
302 	feeder_destroy(f);
303 
304 	return 0;
305 }
306 
307 struct pcm_feeder *
308 chn_findfeeder(struct pcm_channel *c, u_int32_t type)
309 {
310 	struct pcm_feeder *f;
311 
312 	f = c->feeder;
313 	while (f != NULL) {
314 		if (f->desc->type == type)
315 			return f;
316 		f = f->source;
317 	}
318 
319 	return NULL;
320 }
321 
322 static int
323 chainok(struct pcm_feeder *test, struct pcm_feeder *stop)
324 {
325 	u_int32_t visited[MAXFEEDERS / 32];
326 	u_int32_t idx, mask;
327 
328 	bzero(visited, sizeof(visited));
329 	while (test && (test != stop)) {
330 		idx = test->desc->idx;
331 		if (idx < 0)
332 			panic("bad idx %d", idx);
333 		if (idx >= MAXFEEDERS)
334 			panic("bad idx %d", idx);
335 		mask = 1 << (idx & 31);
336 		idx >>= 5;
337 		if (visited[idx] & mask)
338 			return 0;
339 		visited[idx] |= mask;
340 		test = test->source;
341 	}
342 
343 	return 1;
344 }
345 
346 /*
347  * See feeder_fmtchain() for the mumbo-jumbo ridiculous explaination
348  * of what the heck is this FMT_Q_*
349  */
350 #define FMT_Q_UP	1
351 #define FMT_Q_DOWN	2
352 #define FMT_Q_EQ	3
353 #define FMT_Q_MULTI	4
354 
355 /*
356  * 14bit format scoring
357  * --------------------
358  *
359  *  13  12  11  10   9   8        2        1   0    offset
360  * +---+---+---+---+---+---+-------------+---+---+
361  * | X | X | X | X | X | X | X X X X X X | X | X |
362  * +---+---+---+---+---+---+-------------+---+---+
363  *   |   |   |   |   |   |        |        |   |
364  *   |   |   |   |   |   |        |        |   +--> signed?
365  *   |   |   |   |   |   |        |        |
366  *   |   |   |   |   |   |        |        +------> bigendian?
367  *   |   |   |   |   |   |        |
368  *   |   |   |   |   |   |        +---------------> total channels
369  *   |   |   |   |   |   |
370  *   |   |   |   |   |   +------------------------> AFMT_A_LAW
371  *   |   |   |   |   |
372  *   |   |   |   |   +----------------------------> AFMT_MU_LAW
373  *   |   |   |   |
374  *   |   |   |   +--------------------------------> AFMT_8BIT
375  *   |   |   |
376  *   |   |   +------------------------------------> AFMT_16BIT
377  *   |   |
378  *   |   +----------------------------------------> AFMT_24BIT
379  *   |
380  *   +--------------------------------------------> AFMT_32BIT
381  */
382 #define score_signeq(s1, s2)	(((s1) & 0x1) == ((s2) & 0x1))
383 #define score_endianeq(s1, s2)	(((s1) & 0x2) == ((s2) & 0x2))
384 #define score_cheq(s1, s2)	(((s1) & 0xfc) == ((s2) & 0xfc))
385 #define score_val(s1)		((s1) & 0x3f00)
386 #define score_cse(s1)		((s1) & 0x7f)
387 
388 u_int32_t
389 chn_fmtscore(u_int32_t fmt)
390 {
391 	u_int32_t ret;
392 
393 	ret = 0;
394 	if (fmt & AFMT_SIGNED)
395 		ret |= 1 << 0;
396 	if (fmt & AFMT_BIGENDIAN)
397 		ret |= 1 << 1;
398 	if (fmt & AFMT_STEREO)
399 		ret |= (2 & 0x3f) << 2;
400 	else
401 		ret |= (1 & 0x3f) << 2;
402 	if (fmt & AFMT_A_LAW)
403 		ret |= 1 << 8;
404 	else if (fmt & AFMT_MU_LAW)
405 		ret |= 1 << 9;
406 	else if (fmt & AFMT_8BIT)
407 		ret |= 1 << 10;
408 	else if (fmt & AFMT_16BIT)
409 		ret |= 1 << 11;
410 	else if (fmt & AFMT_24BIT)
411 		ret |= 1 << 12;
412 	else if (fmt & AFMT_32BIT)
413 		ret |= 1 << 13;
414 
415 	return ret;
416 }
417 
418 static u_int32_t
419 chn_fmtbestfunc(u_int32_t fmt, u_int32_t *fmts, int cheq)
420 {
421 	u_int32_t best, score, score2, oldscore;
422 	int i;
423 
424 	if (fmt == 0 || fmts == NULL || fmts[0] == 0)
425 		return 0;
426 
427 	if (fmtvalid(fmt, fmts))
428 		return fmt;
429 
430 	best = 0;
431 	score = chn_fmtscore(fmt);
432 	oldscore = 0;
433 	for (i = 0; fmts[i] != 0; i++) {
434 		score2 = chn_fmtscore(fmts[i]);
435 		if (cheq && !score_cheq(score, score2))
436 			continue;
437 		if (oldscore == 0 ||
438 			    (score_val(score2) == score_val(score)) ||
439 			    (score_val(score2) == score_val(oldscore)) ||
440 			    (score_val(score2) > score_val(oldscore) &&
441 			    score_val(score2) < score_val(score)) ||
442 			    (score_val(score2) < score_val(oldscore) &&
443 			    score_val(score2) > score_val(score)) ||
444 			    (score_val(oldscore) < score_val(score) &&
445 			    score_val(score2) > score_val(oldscore))) {
446 			if (score_val(oldscore) != score_val(score2) ||
447 				    score_cse(score) == score_cse(score2) ||
448 				    ((score_cse(oldscore) != score_cse(score) &&
449 				    !score_endianeq(score, oldscore) &&
450 				    (score_endianeq(score, score2) ||
451 				    (!score_signeq(score, oldscore) &&
452 				    score_signeq(score, score2)))))) {
453 				best = fmts[i];
454 				oldscore = score2;
455 			}
456 		}
457 	}
458 	return best;
459 }
460 
461 u_int32_t
462 chn_fmtbestbit(u_int32_t fmt, u_int32_t *fmts)
463 {
464 	return chn_fmtbestfunc(fmt, fmts, 0);
465 }
466 
467 u_int32_t
468 chn_fmtbeststereo(u_int32_t fmt, u_int32_t *fmts)
469 {
470 	return chn_fmtbestfunc(fmt, fmts, 1);
471 }
472 
473 u_int32_t
474 chn_fmtbest(u_int32_t fmt, u_int32_t *fmts)
475 {
476 	u_int32_t best1, best2;
477 	u_int32_t score, score1, score2;
478 
479 	if (fmtvalid(fmt, fmts))
480 		return fmt;
481 
482 	best1 = chn_fmtbeststereo(fmt, fmts);
483 	best2 = chn_fmtbestbit(fmt, fmts);
484 
485 	if (best1 != 0 && best2 != 0 && best1 != best2) {
486 		if (fmt & AFMT_STEREO)
487 			return best1;
488 		else {
489 			score = score_val(chn_fmtscore(fmt));
490 			score1 = score_val(chn_fmtscore(best1));
491 			score2 = score_val(chn_fmtscore(best2));
492 			if (score1 == score2 || score1 == score)
493 				return best1;
494 			else if (score2 == score)
495 				return best2;
496 			else if (score1 > score2)
497 				return best1;
498 			return best2;
499 		}
500 	} else if (best2 == 0)
501 		return best1;
502 	else
503 		return best2;
504 }
505 
506 static struct pcm_feeder *
507 feeder_fmtchain(u_int32_t *to, struct pcm_feeder *source, struct pcm_feeder *stop, int maxdepth)
508 {
509 	struct feedertab_entry *fte, *ftebest;
510 	struct pcm_feeder *try, *ret;
511 	uint32_t fl, qout, qsrc, qdst;
512 	int qtype;
513 
514 	if (to == NULL || to[0] == 0)
515 		return NULL;
516 
517 	DEB(printf("trying %s (0x%08x -> 0x%08x)...\n", source->class->name, source->desc->in, source->desc->out));
518 	if (fmtvalid(source->desc->out, to)) {
519 		DEB(printf("got it\n"));
520 		return source;
521 	}
522 
523 	if (maxdepth < 0)
524 		return NULL;
525 
526 	/*
527 	 * WARNING: THIS IS _NOT_ FOR THE FAINT HEART
528 	 * Disclaimer: I don't expect anybody could understand this
529 	 *             without deep logical and mathematical analysis
530 	 *             involving various unnamed probability theorem.
531 	 *
532 	 * This "Best Fit Random Chain Selection" (BLEHBLEHWHATEVER) algorithm
533 	 * is **extremely** difficult to digest especially when applied to
534 	 * large sets / numbers of random chains (feeders), each with
535 	 * unique characteristic providing different sets of in/out format.
536 	 *
537 	 * Basically, our FEEDER_FMT (see feeder_fmt.c) chains characteristic:
538 	 * 1) Format chains
539 	 *    1.1 "8bit to any, not to 8bit"
540 	 *      1.1.1 sign can remain consistent, e.g: u8 -> u16[le|be]
541 	 *      1.1.2 sign can be changed, e.g: u8 -> s16[le|be]
542 	 *      1.1.3 endian can be changed, e.g: u8 -> u16[le|be]
543 	 *      1.1.4 both can be changed, e.g: u8 -> [u|s]16[le|be]
544 	 *    1.2 "Any to 8bit, not from 8bit"
545 	 *      1.2.1 sign can remain consistent, e.g: s16le -> s8
546 	 *      1.2.2 sign can be changed, e.g: s16le -> u8
547 	 *      1.2.3 source endian can be anything e.g: s16[le|be] -> s8
548 	 *      1.2.4 source endian / sign can be anything e.g: [u|s]16[le|be] -> u8
549 	 *    1.3 "Any to any where BOTH input and output either 8bit or non-8bit"
550 	 *      1.3.1 endian MUST remain consistent
551 	 *      1.3.2 sign CAN be changed
552 	 *    1.4 "Long jump" is allowed, e.g: from 16bit to 32bit, excluding
553 	 *        16bit to 24bit .
554 	 * 2) Channel chains (mono <-> stereo)
555 	 *    2.1 Both endian and sign MUST remain consistent
556 	 * 3) Endian chains (big endian <-> little endian)
557 	 *    3.1 Channels and sign MUST remain consistent
558 	 * 4) Sign chains (signed <-> unsigned)
559 	 *    4.1 Channels and endian MUST remain consistent
560 	 *
561 	 * .. and the mother of all chaining rules:
562 	 *
563 	 * Rules 0: Source and destination MUST not contain multiple selections.
564 	 *          (qtype != FMT_Q_MULTI)
565 	 *
566 	 * First of all, our caller ( chn_fmtchain() ) will reduce the possible
567 	 * multiple from/to formats to a single best format using chn_fmtbest().
568 	 * Then, using chn_fmtscore(), we determine the chaining characteristic.
569 	 * Our main goal is to narrow it down until it reach FMT_Q_EQ chaining
570 	 * type while still adhering above chaining rules.
571 	 *
572 	 * The need for this complicated chaining procedures is inevitable,
573 	 * since currently we have more than 200 different types of FEEDER_FMT
574 	 * doing various unique format conversion. Without this (the old way),
575 	 * it is possible to generate broken chain since it doesn't do any
576 	 * sanity checking to ensure that the output format is "properly aligned"
577 	 * with the direction of conversion (quality up/down/equal).
578 	 *
579 	 *   Conversion: s24le to s32le
580 	 *   Possible chain: 1) s24le -> s32le (correct, optimized)
581 	 *                   2) s24le -> s16le -> s32le
582 	 *                      (since we have feeder_24to16 and feeder_16to32)
583 	 *                      +-- obviously broken!
584 	 *
585 	 * Using scoring mechanisme, this will ensure that the chaining
586 	 * process do the right thing, or at least, give the best chain
587 	 * possible without causing quality (the 'Q') degradation.
588 	 */
589 
590 	qdst = chn_fmtscore(to[0]);
591 	qsrc = chn_fmtscore(source->desc->out);
592 
593 #define score_q(s1)			score_val(s1)
594 #define score_8bit(s1)			((s1) & 0x700)
595 #define score_non8bit(s1)		(!score_8bit(s1))
596 #define score_across8bit(s1, s2)	((score_8bit(s1) && score_non8bit(s2)) || \
597 					(score_8bit(s2) && score_non8bit(s1)))
598 
599 #define FMT_CHAIN_Q_UP(s1, s2)		(score_q(s1) < score_q(s2))
600 #define FMT_CHAIN_Q_DOWN(s1, s2)	(score_q(s1) > score_q(s2))
601 #define FMT_CHAIN_Q_EQ(s1, s2)		(score_q(s1) == score_q(s2))
602 #define FMT_Q_DOWN_FLAGS(s1, s2)	(0x1 | (score_across8bit(s1, s2) ? \
603 						0x2 : 0x0))
604 #define FMT_Q_UP_FLAGS(s1, s2)		FMT_Q_DOWN_FLAGS(s1, s2)
605 #define FMT_Q_EQ_FLAGS(s1, s2)		(0x3ffc | \
606 					((score_cheq(s1, s2) && \
607 						score_endianeq(s1, s2)) ? \
608 						0x1 : 0x0) | \
609 					((score_cheq(s1, s2) && \
610 						score_signeq(s1, s2)) ? \
611 						0x2 : 0x0))
612 
613 	/* Determine chaining direction and set matching flag */
614 	fl = 0x3fff;
615 	if (to[1] != 0) {
616 		qtype = FMT_Q_MULTI;
617 		printf("%s: WARNING: FMT_Q_MULTI chaining. Expect the unexpected.\n", __func__);
618 	} else if (FMT_CHAIN_Q_DOWN(qsrc, qdst)) {
619 		qtype = FMT_Q_DOWN;
620 		fl = FMT_Q_DOWN_FLAGS(qsrc, qdst);
621 	} else if (FMT_CHAIN_Q_UP(qsrc, qdst)) {
622 		qtype = FMT_Q_UP;
623 		fl = FMT_Q_UP_FLAGS(qsrc, qdst);
624 	} else {
625 		qtype = FMT_Q_EQ;
626 		fl = FMT_Q_EQ_FLAGS(qsrc, qdst);
627 	}
628 
629 	ftebest = NULL;
630 
631 	SLIST_FOREACH(fte, &feedertab, link) {
632 		if (fte->desc == NULL)
633 			continue;
634 		if (fte->desc->type != FEEDER_FMT)
635 			continue;
636 		qout = chn_fmtscore(fte->desc->out);
637 #define FMT_Q_MULTI_VALIDATE(qt)		((qt) == FMT_Q_MULTI)
638 #define FMT_Q_FL_MATCH(qfl, s1, s2)		(((s1) & (qfl)) == ((s2) & (qfl)))
639 #define FMT_Q_UP_VALIDATE(qt, s1, s2, s3)	((qt) == FMT_Q_UP && \
640 						score_q(s3) >= score_q(s1) && \
641 						score_q(s3) <= score_q(s2))
642 #define FMT_Q_DOWN_VALIDATE(qt, s1, s2, s3)	((qt) == FMT_Q_DOWN && \
643 						score_q(s3) <= score_q(s1) && \
644 						score_q(s3) >= score_q(s2))
645 #define FMT_Q_EQ_VALIDATE(qt, s1, s2)		((qt) == FMT_Q_EQ && \
646 						score_q(s1) == score_q(s2))
647 		if (fte->desc->in == source->desc->out &&
648 			    (FMT_Q_MULTI_VALIDATE(qtype) ||
649 			    (FMT_Q_FL_MATCH(fl, qout, qdst) &&
650 			    (FMT_Q_UP_VALIDATE(qtype, qsrc, qdst, qout) ||
651 			    FMT_Q_DOWN_VALIDATE(qtype, qsrc, qdst, qout) ||
652 			    FMT_Q_EQ_VALIDATE(qtype, qdst, qout))))) {
653 			try = feeder_create(fte->feederclass, fte->desc);
654 			if (try) {
655 				try->source = source;
656 				ret = chainok(try, stop) ? feeder_fmtchain(to, try, stop, maxdepth - 1) : NULL;
657 				if (ret != NULL)
658 					return ret;
659 				feeder_destroy(try);
660 			}
661 		} else if (fte->desc->in == source->desc->out) {
662 			/* XXX quality must be considered! */
663 			if (ftebest == NULL)
664 				ftebest = fte;
665 		}
666 	}
667 
668 	if (ftebest != NULL) {
669 		try = feeder_create(ftebest->feederclass, ftebest->desc);
670 		if (try) {
671 			try->source = source;
672 			ret = chainok(try, stop) ? feeder_fmtchain(to, try, stop, maxdepth - 1) : NULL;
673 			if (ret != NULL)
674 				return ret;
675 			feeder_destroy(try);
676 		}
677 	}
678 
679 	/* printf("giving up %s...\n", source->class->name); */
680 
681 	return NULL;
682 }
683 
684 u_int32_t
685 chn_fmtchain(struct pcm_channel *c, u_int32_t *to)
686 {
687 	struct pcm_feeder *try, *del, *stop;
688 	u_int32_t tmpfrom[2], tmpto[2], best, *from;
689 	int i, max, bestmax;
690 
691 	KASSERT(c != NULL, ("c == NULL"));
692 	KASSERT(c->feeder != NULL, ("c->feeder == NULL"));
693 	KASSERT(to != NULL, ("to == NULL"));
694 	KASSERT(to[0] != 0, ("to[0] == 0"));
695 
696 	if (c == NULL || c->feeder == NULL || to == NULL || to[0] == 0)
697 		return 0;
698 
699 	stop = c->feeder;
700 	best = 0;
701 
702 	if (c->direction == PCMDIR_REC && c->feeder->desc->type == FEEDER_ROOT) {
703 		from = chn_getcaps(c)->fmtlist;
704 		if (from[1] != 0) {
705 			best = chn_fmtbest(to[0], from);
706 			if (best != 0) {
707 				tmpfrom[0] = best;
708 				tmpfrom[1] = 0;
709 				from = tmpfrom;
710 			}
711 		}
712 	} else {
713 		tmpfrom[0] = c->feeder->desc->out;
714 		tmpfrom[1] = 0;
715 		from = tmpfrom;
716 		if (to[1] != 0) {
717 			best = chn_fmtbest(from[0], to);
718 			if (best != 0) {
719 				tmpto[0] = best;
720 				tmpto[1] = 0;
721 				to = tmpto;
722 			}
723 		}
724 	}
725 
726 #define FEEDER_FMTCHAIN_MAXDEPTH	8
727 
728 	try = NULL;
729 
730 	if (to[0] != 0 && from[0] != 0 &&
731 		    to[1] == 0 && from[1] == 0) {
732 		max = 0;
733 		best = from[0];
734 		c->feeder->desc->out = best;
735 		do {
736 			try = feeder_fmtchain(to, c->feeder, stop, max);
737 			DEB(if (try != NULL) {
738 				printf("%s: 0x%08x -> 0x%08x (maxdepth: %d)\n",
739 					__func__, from[0], to[0], max);
740 			});
741 		} while (try == NULL && max++ < FEEDER_FMTCHAIN_MAXDEPTH);
742 	} else {
743 		printf("%s: Using the old-way format chaining!\n", __func__);
744 		i = 0;
745 		best = 0;
746 		bestmax = 100;
747 		while (from[i] != 0) {
748 			c->feeder->desc->out = from[i];
749 			try = NULL;
750 			max = 0;
751 			do {
752 				try = feeder_fmtchain(to, c->feeder, stop, max);
753 			} while (try == NULL && max++ < FEEDER_FMTCHAIN_MAXDEPTH);
754 			if (try != NULL && max < bestmax) {
755 				bestmax = max;
756 				best = from[i];
757 			}
758 			while (try != NULL && try != stop) {
759 				del = try;
760 				try = try->source;
761 				feeder_destroy(del);
762 			}
763 			i++;
764 		}
765 		if (best == 0)
766 			return 0;
767 
768 		c->feeder->desc->out = best;
769 		try = feeder_fmtchain(to, c->feeder, stop, bestmax);
770 	}
771 	if (try == NULL)
772 		return 0;
773 
774 	c->feeder = try;
775 	c->align = 0;
776 #ifdef FEEDER_DEBUG
777 	printf("\n\nchain: ");
778 #endif
779 	while (try && (try != stop)) {
780 #ifdef FEEDER_DEBUG
781 		printf("%s [%d]", try->class->name, try->desc->idx);
782 		if (try->source)
783 			printf(" -> ");
784 #endif
785 		if (try->source)
786 			try->source->parent = try;
787 		if (try->align > 0)
788 			c->align += try->align;
789 		else if (try->align < 0 && c->align < -try->align)
790 			c->align = -try->align;
791 		try = try->source;
792 	}
793 #ifdef FEEDER_DEBUG
794 	printf("%s [%d]\n", try->class->name, try->desc->idx);
795 #endif
796 
797 	if (c->direction == PCMDIR_REC) {
798 		try = c->feeder;
799 		while (try != NULL) {
800 			if (try->desc->type == FEEDER_ROOT)
801 				return try->desc->out;
802 			try = try->source;
803 		}
804 		return best;
805 	} else
806 		return c->feeder->desc->out;
807 }
808 
809 void
810 feeder_printchain(struct pcm_feeder *head)
811 {
812 	struct pcm_feeder *f;
813 
814 	printf("feeder chain (head @%p)\n", head);
815 	f = head;
816 	while (f != NULL) {
817 		printf("%s/%d @ %p\n", f->class->name, f->desc->idx, f);
818 		f = f->source;
819 	}
820 	printf("[end]\n\n");
821 }
822 
823 /*****************************************************************************/
824 
825 static int
826 feed_root(struct pcm_feeder *feeder, struct pcm_channel *ch, u_int8_t *buffer, u_int32_t count, void *source)
827 {
828 	struct snd_dbuf *src = source;
829 	int l, offset;
830 
831 	KASSERT(count > 0, ("feed_root: count == 0"));
832 	/* count &= ~((1 << ch->align) - 1); */
833 	KASSERT(count > 0, ("feed_root: aligned count == 0 (align = %d)", ch->align));
834 
835 	if (++ch->feedcount == 0)
836 		ch->feedcount = 2;
837 
838 	l = min(count, sndbuf_getready(src));
839 
840 	/* When recording only return as much data as available */
841 	if (ch->direction == PCMDIR_REC) {
842 		sndbuf_dispose(src, buffer, l);
843 		return l;
844 	}
845 
846 
847 	offset = count - l;
848 
849 	if (offset > 0) {
850 		if (snd_verbose > 3)
851 			printf("%s: (%s) %spending %d bytes "
852 			    "(count=%d l=%d feed=%d)\n",
853 			    __func__,
854 			    (ch->flags & CHN_F_VIRTUAL) ? "virtual" : "hardware",
855 			    (ch->feedcount == 1) ? "pre" : "ap",
856 			    offset, count, l, ch->feedcount);
857 
858 		if (ch->feedcount == 1) {
859 			memset(buffer,
860 			    sndbuf_zerodata(sndbuf_getfmt(src)),
861 			    offset);
862 			if (l > 0)
863 				sndbuf_dispose(src, buffer + offset, l);
864 			else
865 				ch->feedcount--;
866 		} else {
867 			if (l > 0)
868 				sndbuf_dispose(src, buffer, l);
869 #if 1
870 			memset(buffer + l,
871 			    sndbuf_zerodata(sndbuf_getfmt(src)),
872 			    offset);
873 			if (!(ch->flags & CHN_F_CLOSING))
874 				ch->xruns++;
875 #else
876 			if (l < 1 || (ch->flags & CHN_F_CLOSING)) {
877 				memset(buffer + l,
878 				    sndbuf_zerodata(sndbuf_getfmt(src)),
879 				    offset);
880 				if (!(ch->flags & CHN_F_CLOSING))
881 					ch->xruns++;
882 			} else {
883 				int cp, tgt;
884 
885 				tgt = l;
886 				while (offset > 0) {
887 					cp = min(l, offset);
888 					memcpy(buffer + tgt, buffer, cp);
889 					offset -= cp;
890 					tgt += cp;
891 				}
892 				ch->xruns++;
893 			}
894 #endif
895 		}
896 	} else if (l > 0)
897 		sndbuf_dispose(src, buffer, l);
898 
899 	return count;
900 }
901 
902 static kobj_method_t feeder_root_methods[] = {
903     	KOBJMETHOD(feeder_feed,		feed_root),
904 	{ 0, 0 }
905 };
906 static struct feeder_class feeder_root_class = {
907 	.name =		"feeder_root",
908 	.methods =	feeder_root_methods,
909 	.size =		sizeof(struct pcm_feeder),
910 	.align =	0,
911 	.desc =		NULL,
912 	.data =		NULL,
913 };
914 SYSINIT(feeder_root, SI_SUB_DRIVERS, SI_ORDER_FIRST, feeder_register, &feeder_root_class);
915 SYSUNINIT(feeder_root, SI_SUB_DRIVERS, SI_ORDER_FIRST, feeder_unregisterall, NULL);
916