sound: Move pcm_chnref() and pcm_chnrelease() to pcm/channel.c

Improve code layering. These are channel functions, and so they do not
belong in pcm/sound.c.

While here, assert in chn_ref() that new refcount won't be negative.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Reviewed by:	markj
Differential Revision:	https://reviews.freebsd.org/D44985

5 files changed, 43 insertions, 41 deletions

diff --git a/sys/dev/sound/pcm/channel.c b/sys/dev/sound/pcm/channel.c
index 21a91ff13186..0fea169e3eb7 100644
--- a/sys/dev/sound/pcm/channel.c
+++ b/sys/dev/sound/pcm/channel.c
@@ -1314,6 +1314,34 @@ chn_shutdown(struct pcm_channel *c)
 	c->flags |= CHN_F_DEAD;
 }
 
+/* release a locked channel and unlock it */
+int
+chn_release(struct pcm_channel *c)
+{
+	PCM_BUSYASSERT(c->parentsnddev);
+	CHN_LOCKASSERT(c);
+
+	c->flags &= ~CHN_F_BUSY;
+	c->pid = -1;
+	strlcpy(c->comm, CHN_COMM_UNUSED, sizeof(c->comm));
+	CHN_UNLOCK(c);
+
+	return (0);
+}
+
+int
+chn_ref(struct pcm_channel *c, int ref)
+{
+	PCM_BUSYASSERT(c->parentsnddev);
+	CHN_LOCKASSERT(c);
+	KASSERT((c->refcount + ref) >= 0,
+	    ("%s(): new refcount will be negative", __func__));
+
+	c->refcount += ref;
+
+	return (c->refcount);
+}
+
 int
 chn_setvolume_multi(struct pcm_channel *c, int vc, int left, int right,
     int center)
diff --git a/sys/dev/sound/pcm/channel.h b/sys/dev/sound/pcm/channel.h
index 45381b907fa2..698a1186924f 100644
--- a/sys/dev/sound/pcm/channel.h
+++ b/sys/dev/sound/pcm/channel.h
@@ -262,6 +262,8 @@ int chn_poll(struct pcm_channel *c, int ev, struct thread *td);
 int chn_init(struct pcm_channel *c, void *devinfo, int dir, int direction);
 void chn_kill(struct pcm_channel *c);
 void chn_shutdown(struct pcm_channel *c);
+int chn_release(struct pcm_channel *c);
+int chn_ref(struct pcm_channel *c, int ref);
 int chn_reset(struct pcm_channel *c, u_int32_t fmt, u_int32_t spd);
 int chn_setvolume_multi(struct pcm_channel *c, int vc, int left, int right,
     int center);
diff --git a/sys/dev/sound/pcm/dsp.c b/sys/dev/sound/pcm/dsp.c
index 448ecb183298..9c31fff7e8cd 100644
--- a/sys/dev/sound/pcm/dsp.c
+++ b/sys/dev/sound/pcm/dsp.c
@@ -181,8 +181,8 @@ getchns(struct dsp_cdevpriv *priv, uint32_t prio)
 		pcm_setflags(d->dev, flags);
 		if (ch != NULL) {
 			CHN_LOCK(ch);
-			pcm_chnref(ch, -1);
-			pcm_chnrelease(ch);
+			chn_ref(ch, -1);
+			chn_release(ch);
 		}
 		PCM_RELEASE(d);
 		PCM_UNLOCK(d);
@@ -301,7 +301,7 @@ dsp_close(void *data)
 			wdref--;
 		else {
 			CHN_LOCK(volch);
-			pcm_chnref(volch, -1);
+			chn_ref(volch, -1);
 			CHN_UNLOCK(volch);
 		}
 	}
@@ -332,12 +332,12 @@ dsp_close(void *data)
 				free_unr(pcmsg_unrhdr, sg_ids);
 
 			CHN_LOCK(rdch);
-			pcm_chnref(rdch, rdref);
+			chn_ref(rdch, rdref);
 			chn_abort(rdch); /* won't sleep */
 			rdch->flags &= ~(CHN_F_RUNNING | CHN_F_MMAP |
 			    CHN_F_DEAD | CHN_F_EXCLUSIVE);
 			chn_reset(rdch, 0, 0);
-			pcm_chnrelease(rdch);
+			chn_release(rdch);
 		}
 		if (wrch != NULL) {
 			/*
@@ -350,12 +350,12 @@ dsp_close(void *data)
 				free_unr(pcmsg_unrhdr, sg_ids);
 
 			CHN_LOCK(wrch);
-			pcm_chnref(wrch, wdref);
+			chn_ref(wrch, wdref);
 			chn_flush(wrch); /* may sleep */
 			wrch->flags &= ~(CHN_F_RUNNING | CHN_F_MMAP |
 			    CHN_F_DEAD | CHN_F_EXCLUSIVE);
 			chn_reset(wrch, 0, 0);
-			pcm_chnrelease(wrch);
+			chn_release(wrch);
 		}
 		PCM_LOCK(d);
 	}
@@ -451,7 +451,7 @@ dsp_open(struct cdev *i_dev, int flags, int mode, struct thread *td)
 
 		if (rderror != 0) {
 			if (rdch != NULL)
-				pcm_chnrelease(rdch);
+				chn_release(rdch);
 			if (!DSP_F_DUPLEX(flags)) {
 				PCM_RELEASE_QUICK(d);
 				PCM_GIANT_EXIT(d);
@@ -463,7 +463,7 @@ dsp_open(struct cdev *i_dev, int flags, int mode, struct thread *td)
 				rdch->flags |= CHN_F_NBIO;
 			if (flags & O_EXCL)
 				rdch->flags |= CHN_F_EXCLUSIVE;
-			pcm_chnref(rdch, 1);
+			chn_ref(rdch, 1);
 			chn_vpc_reset(rdch, SND_VOL_C_PCM, 0);
 		 	CHN_UNLOCK(rdch);
 		}
@@ -479,7 +479,7 @@ dsp_open(struct cdev *i_dev, int flags, int mode, struct thread *td)
 
 		if (wrerror != 0) {
 			if (wrch != NULL)
-				pcm_chnrelease(wrch);
+				chn_release(wrch);
 			if (!DSP_F_DUPLEX(flags)) {
 				if (rdch != NULL) {
 					/*
@@ -487,8 +487,8 @@ dsp_open(struct cdev *i_dev, int flags, int mode, struct thread *td)
 					 * created record channel
 					 */
 					CHN_LOCK(rdch);
-					pcm_chnref(rdch, -1);
-					pcm_chnrelease(rdch);
+					chn_ref(rdch, -1);
+					chn_release(rdch);
 				}
 				PCM_RELEASE_QUICK(d);
 				PCM_GIANT_EXIT(d);
@@ -500,7 +500,7 @@ dsp_open(struct cdev *i_dev, int flags, int mode, struct thread *td)
 				wrch->flags |= CHN_F_NBIO;
 			if (flags & O_EXCL)
 				wrch->flags |= CHN_F_EXCLUSIVE;
-			pcm_chnref(wrch, 1);
+			chn_ref(wrch, 1);
 			chn_vpc_reset(wrch, SND_VOL_C_PCM, 0);
 			CHN_UNLOCK(wrch);
 		}
diff --git a/sys/dev/sound/pcm/sound.c b/sys/dev/sound/pcm/sound.c
index b44a7344121c..029326dfc05a 100644
--- a/sys/dev/sound/pcm/sound.c
+++ b/sys/dev/sound/pcm/sound.c
@@ -306,32 +306,6 @@ vchan_alloc:
 	return (err);
 }
 
-/* release a locked channel and unlock it */
-int
-pcm_chnrelease(struct pcm_channel *c)
-{
-	PCM_BUSYASSERT(c->parentsnddev);
-	CHN_LOCKASSERT(c);
-
-	c->flags &= ~CHN_F_BUSY;
-	c->pid = -1;
-	strlcpy(c->comm, CHN_COMM_UNUSED, sizeof(c->comm));
-	CHN_UNLOCK(c);
-
-	return (0);
-}
-
-int
-pcm_chnref(struct pcm_channel *c, int ref)
-{
-	PCM_BUSYASSERT(c->parentsnddev);
-	CHN_LOCKASSERT(c);
-
-	c->refcount += ref;
-
-	return (c->refcount);
-}
-
 static void
 pcm_setmaxautovchans(struct snddev_info *d, int num)
 {
diff --git a/sys/dev/sound/pcm/sound.h b/sys/dev/sound/pcm/sound.h
index 70addf32bddd..08aa56cc96f7 100644
--- a/sys/dev/sound/pcm/sound.h
+++ b/sys/dev/sound/pcm/sound.h
@@ -296,8 +296,6 @@ SYSCTL_DECL(_hw_snd);
 int pcm_setvchans(struct snddev_info *d, int direction, int newcnt, int num);
 int pcm_chnalloc(struct snddev_info *d, struct pcm_channel **ch, int direction,
     pid_t pid, char *comm);
-int pcm_chnrelease(struct pcm_channel *c);
-int pcm_chnref(struct pcm_channel *c, int ref);
 
 struct pcm_channel *pcm_chn_create(struct snddev_info *d, struct pcm_channel *parent, kobj_class_t cls, int dir, int num, void *devinfo);
 int pcm_chn_add(struct snddev_info *d, struct pcm_channel *ch);