seq_oss_writeq.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * OSS compatible sequencer driver
  4 *
  5 * seq_oss_writeq.c - write queue and sync
  6 *
  7 * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
  8 */
  9
 10#include "seq_oss_writeq.h"
 11#include "seq_oss_event.h"
 12#include "seq_oss_timer.h"
 13#include <sound/seq_oss_legacy.h>
 14#include "../seq_lock.h"
 15#include "../seq_clientmgr.h"
 16#include <linux/wait.h>
 17#include <linux/slab.h>
 18#include <linux/sched/signal.h>
 19
 20
 21/*
 22 * create a write queue record
 23 */
 24struct seq_oss_writeq *
 25snd_seq_oss_writeq_new(struct seq_oss_devinfo *dp, int maxlen)
 26{
 27	struct seq_oss_writeq *q;
 28	struct snd_seq_client_pool pool;
 29
 30	q = kzalloc(sizeof(*q), GFP_KERNEL);
 31	if (!q)
 32		return NULL;
 33	q->dp = dp;
 34	q->maxlen = maxlen;
 35	spin_lock_init(&q->sync_lock);
 36	q->sync_event_put = 0;
 37	q->sync_time = 0;
 38	init_waitqueue_head(&q->sync_sleep);
 39
 40	memset(&pool, 0, sizeof(pool));
 41	pool.client = dp->cseq;
 42	pool.output_pool = maxlen;
 43	pool.output_room = maxlen / 2;
 44
 45	snd_seq_oss_control(dp, SNDRV_SEQ_IOCTL_SET_CLIENT_POOL, &pool);
 46
 47	return q;
 48}
 49
 50/*
 51 * delete the write queue
 52 */
 53void
 54snd_seq_oss_writeq_delete(struct seq_oss_writeq *q)
 55{
 56	if (q) {
 57		snd_seq_oss_writeq_clear(q);	/* to be sure */
 58		kfree(q);
 59	}
 60}
 61
 62
 63/*
 64 * reset the write queue
 65 */
 66void
 67snd_seq_oss_writeq_clear(struct seq_oss_writeq *q)
 68{
 69	struct snd_seq_remove_events reset;
 70
 71	memset(&reset, 0, sizeof(reset));
 72	reset.remove_mode = SNDRV_SEQ_REMOVE_OUTPUT; /* remove all */
 73	snd_seq_oss_control(q->dp, SNDRV_SEQ_IOCTL_REMOVE_EVENTS, &reset);
 74
 75	/* wake up sleepers if any */
 76	snd_seq_oss_writeq_wakeup(q, 0);
 77}
 78
 79/*
 80 * wait until the write buffer has enough room
 81 */
 82int
 83snd_seq_oss_writeq_sync(struct seq_oss_writeq *q)
 84{
 85	struct seq_oss_devinfo *dp = q->dp;
 86	abstime_t time;
 87
 88	time = snd_seq_oss_timer_cur_tick(dp->timer);
 89	if (q->sync_time >= time)
 90		return 0; /* already finished */
 91
 92	if (! q->sync_event_put) {
 93		struct snd_seq_event ev;
 94		union evrec *rec;
 95
 96		/* put echoback event */
 97		memset(&ev, 0, sizeof(ev));
 98		ev.flags = 0;
 99		ev.type = SNDRV_SEQ_EVENT_ECHO;
100		ev.time.tick = time;
101		/* echo back to itself */
102		snd_seq_oss_fill_addr(dp, &ev, dp->addr.client, dp->addr.port);
103		rec = (union evrec *)&ev.data;
104		rec->t.code = SEQ_SYNCTIMER;
105		rec->t.time = time;
106		q->sync_event_put = 1;
107		snd_seq_kernel_client_enqueue(dp->cseq, &ev, NULL, true);
108	}
109
110	wait_event_interruptible_timeout(q->sync_sleep, ! q->sync_event_put, HZ);
111	if (signal_pending(current))
112		/* interrupted - return 0 to finish sync */
113		q->sync_event_put = 0;
114	if (! q->sync_event_put || q->sync_time >= time)
115		return 0;
116	return 1;
117}
118
119/*
120 * wake up sync - echo event was catched
121 */
122void
123snd_seq_oss_writeq_wakeup(struct seq_oss_writeq *q, abstime_t time)
124{
125	guard(spinlock_irqsave)(&q->sync_lock);
126	q->sync_time = time;
127	q->sync_event_put = 0;
128	wake_up(&q->sync_sleep);
129}
130
131
132/*
133 * return the unused pool size
134 */
135int
136snd_seq_oss_writeq_get_free_size(struct seq_oss_writeq *q)
137{
138	struct snd_seq_client_pool pool;
139	pool.client = q->dp->cseq;
140	snd_seq_oss_control(q->dp, SNDRV_SEQ_IOCTL_GET_CLIENT_POOL, &pool);
141	return pool.output_free;
142}
143
144
145/*
146 * set output threshold size from ioctl
147 */
148void
149snd_seq_oss_writeq_set_output(struct seq_oss_writeq *q, int val)
150{
151	struct snd_seq_client_pool pool;
152	pool.client = q->dp->cseq;
153	snd_seq_oss_control(q->dp, SNDRV_SEQ_IOCTL_GET_CLIENT_POOL, &pool);
154	pool.output_room = val;
155	snd_seq_oss_control(q->dp, SNDRV_SEQ_IOCTL_SET_CLIENT_POOL, &pool);
156}
157