Skip site navigation (1)Skip section navigation (2) 
Date:      Mon, 10 Jun 2019 03:16:55 +0000 (UTC)
From:      Justin Hibbits <jhibbits@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r348844 - head/sys/powerpc/powernv
Message-ID:  <201906100316.x5A3Gtj4005247@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help 
Author: jhibbits
Date: Mon Jun 10 03:16:55 2019
New Revision: 348844
URL: https://svnweb.freebsd.org/changeset/base/348844

Log:
  powerpc/powernv: Reduce the scope of the sensor guarding mutex
  
  vmem_xalloc() cannot be called while holding a nonblocking mutex, warned
  by WITNESS.  The lock may not be necessary in general, but it avoids
  superfluous concurrent OPAL calls for the same sensor.
  
  Reported by:	pkubaj

Modified:
  head/sys/powerpc/powernv/opal_sensor.c

Modified: head/sys/powerpc/powernv/opal_sensor.c
==============================================================================
--- head/sys/powerpc/powernv/opal_sensor.c	Mon Jun 10 03:07:10 2019	(r348843)
+++ head/sys/powerpc/powernv/opal_sensor.c	Mon Jun 10 03:16:55 2019	(r348844)
@@ -92,13 +92,14 @@ const char *opal_sensor_types[] = {
  * Retrieve the raw value from OPAL.  This will be cooked by the sysctl handler.
  */
 static int
-opal_sensor_get_val(uint32_t key, uint64_t *val)
+opal_sensor_get_val(struct opal_sensor_softc *sc, uint32_t key, uint64_t *val)
 {
 	struct opal_msg msg;
 	uint32_t val32;
 	int rv, token;
 
 	token = opal_alloc_async_token();
+	SENSOR_LOCK(sc);
 	rv = opal_call(OPAL_SENSOR_READ, key, token, vtophys(&val32));
 
 	if (rv == OPAL_ASYNC_COMPLETION) {
@@ -110,6 +111,7 @@ opal_sensor_get_val(uint32_t key, uint64_t *val)
 		if (rv == OPAL_SUCCESS)
 			val32 = msg.params[0];
 	}
+	SENSOR_UNLOCK(sc);
 
 	if (rv == OPAL_SUCCESS)
 		*val = val32;
@@ -131,9 +133,7 @@ opal_sensor_sysctl(SYSCTL_HANDLER_ARGS)
 	sc = arg1;
 	sensor = arg2;
 
-	SENSOR_LOCK(sc);
-	error = opal_sensor_get_val(sensor, &sensval);
-	SENSOR_UNLOCK(sc);
+	error = opal_sensor_get_val(sc, sensor, &sensval);
 
 	if (error)
 		return (error);

Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201906100316.x5A3Gtj4005247>