From 6d011946c556fcea72449f09bb3d95502db6b3b6 Mon Sep 17 00:00:00 2001
From: Kristof Provost <kp@FreeBSD.org>
Date: Sun, 15 Jan 2017 10:21:25 +0000
Subject: [PATCH] arswitch: Ensure the lock is always held when calling
 arswitch_modifyreg()

arswitch_setled() and a number of _global_setup functions did not acquire the
lock before calling arswitch_modifyreg(). With WITNESS enabled this would
instantly panic.

Discovered on a TPLink-3600:
("panic: mutex arswitch not owned at sys/dev/etherswitch/arswitch/arswitch_reg.c:236")

Reviewed by:	adrian, kan
Differential Revision:	https://reviews.freebsd.org/D9187
---
 sys/dev/etherswitch/arswitch/arswitch.c      | 8 +++++++-
 sys/dev/etherswitch/arswitch/arswitch_7240.c | 4 ++++
 sys/dev/etherswitch/arswitch/arswitch_8316.c | 3 +++
 sys/dev/etherswitch/arswitch/arswitch_8327.c | 3 +++
 sys/dev/etherswitch/arswitch/arswitch_9340.c | 4 ++++
 5 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/sys/dev/etherswitch/arswitch/arswitch.c b/sys/dev/etherswitch/arswitch/arswitch.c
index 09055632da0e..f98d84acaafc 100644
--- a/sys/dev/etherswitch/arswitch/arswitch.c
+++ b/sys/dev/etherswitch/arswitch/arswitch.c
@@ -845,6 +845,7 @@ static int
 arswitch_setled(struct arswitch_softc *sc, int phy, int led, int style)
 {
 	int shift;
+	int err;
 
 	if (phy < 0 || phy > sc->numphys)
 		return EINVAL;
@@ -852,10 +853,15 @@ arswitch_setled(struct arswitch_softc *sc, int phy, int led, int style)
 	if (style < 0 || style > ETHERSWITCH_PORT_LED_MAX)
 		return (EINVAL);
 
+	ARSWITCH_LOCK(sc);
+
 	shift = ar8327_led_mapping[phy][led].shift;
-	return (arswitch_modifyreg(sc->sc_dev,
+	err = (arswitch_modifyreg(sc->sc_dev,
 	    ar8327_led_mapping[phy][led].reg,
 	    0x03 << shift, led_pattern_table[style] << shift));
+	ARSWITCH_UNLOCK(sc);
+
+	return (err);
 }
 
 static void
diff --git a/sys/dev/etherswitch/arswitch/arswitch_7240.c b/sys/dev/etherswitch/arswitch/arswitch_7240.c
index 01ea9b3e9c1b..d8f51c2784d1 100644
--- a/sys/dev/etherswitch/arswitch/arswitch_7240.c
+++ b/sys/dev/etherswitch/arswitch/arswitch_7240.c
@@ -81,6 +81,8 @@ static int
 ar7240_hw_global_setup(struct arswitch_softc *sc)
 {
 
+	ARSWITCH_LOCK(sc);
+
 	/* Enable CPU port; disable mirror port */
 	arswitch_writereg(sc->sc_dev, AR8X16_REG_CPU_PORT,
 	    AR8X16_CPU_PORT_EN | AR8X16_CPU_MIRROR_DIS);
@@ -103,6 +105,8 @@ ar7240_hw_global_setup(struct arswitch_softc *sc)
 	arswitch_modifyreg(sc->sc_dev, AR8X16_REG_SERVICE_TAG,
 	    AR8X16_SERVICE_TAG_MASK, 0);
 
+	ARSWITCH_UNLOCK(sc);
+
 	return (0);
 }
 
diff --git a/sys/dev/etherswitch/arswitch/arswitch_8316.c b/sys/dev/etherswitch/arswitch/arswitch_8316.c
index 54d6618bd805..bd46657f8859 100644
--- a/sys/dev/etherswitch/arswitch/arswitch_8316.c
+++ b/sys/dev/etherswitch/arswitch/arswitch_8316.c
@@ -127,6 +127,8 @@ static int
 ar8316_hw_global_setup(struct arswitch_softc *sc)
 {
 
+	ARSWITCH_LOCK(sc);
+
 	arswitch_writereg(sc->sc_dev, 0x38, AR8X16_MAGIC);
 
 	/* Enable CPU port and disable mirror port. */
@@ -156,6 +158,7 @@ ar8316_hw_global_setup(struct arswitch_softc *sc)
 	arswitch_modifyreg(sc->sc_dev, AR8X16_REG_SERVICE_TAG,
 	    AR8X16_SERVICE_TAG_MASK, 0);
 
+	ARSWITCH_UNLOCK(sc);
 	return (0);
 }
 
diff --git a/sys/dev/etherswitch/arswitch/arswitch_8327.c b/sys/dev/etherswitch/arswitch/arswitch_8327.c
index 013688f1cce4..ab26707e300e 100644
--- a/sys/dev/etherswitch/arswitch/arswitch_8327.c
+++ b/sys/dev/etherswitch/arswitch/arswitch_8327.c
@@ -708,6 +708,8 @@ ar8327_hw_global_setup(struct arswitch_softc *sc)
 {
 	uint32_t t;
 
+	ARSWITCH_LOCK(sc);
+
 	/* enable CPU port and disable mirror port */
 	t = AR8327_FWD_CTRL0_CPU_PORT_EN |
 	    AR8327_FWD_CTRL0_MIRROR_PORT;
@@ -741,6 +743,7 @@ ar8327_hw_global_setup(struct arswitch_softc *sc)
 	/* GMAC0 (CPU), GMAC1..5 (PHYs), GMAC6 (CPU) */
 	sc->info.es_nports = 7;
 
+	ARSWITCH_UNLOCK(sc);
 	return (0);
 }
 
diff --git a/sys/dev/etherswitch/arswitch/arswitch_9340.c b/sys/dev/etherswitch/arswitch/arswitch_9340.c
index 89f6caa58c28..fd3ab223843f 100644
--- a/sys/dev/etherswitch/arswitch/arswitch_9340.c
+++ b/sys/dev/etherswitch/arswitch/arswitch_9340.c
@@ -81,6 +81,8 @@ static int
 ar9340_hw_global_setup(struct arswitch_softc *sc)
 {
 
+	ARSWITCH_LOCK(sc);
+
 	/* Enable CPU port; disable mirror port */
 	arswitch_writereg(sc->sc_dev, AR8X16_REG_CPU_PORT,
 	    AR8X16_CPU_PORT_EN | AR8X16_CPU_MIRROR_DIS);
@@ -142,6 +144,7 @@ ar9340_hw_global_setup(struct arswitch_softc *sc)
 	} else {
 		device_printf(sc->sc_dev, "%s: need is_gmii or is_mii set\n",
 		    __func__);
+		ARSWITCH_UNLOCK(sc);
 		return (ENXIO);
 	}
 
@@ -163,6 +166,7 @@ ar9340_hw_global_setup(struct arswitch_softc *sc)
 	/* Settle time */
 	DELAY(1000);
 
+	ARSWITCH_UNLOCK(sc);
 	return (0);
 }