[PATCH v7 06/20] coresight: etm4x: Hook CPU PM callbacks

[Leo Yan]

Hook the CPU save and restore callbacks when the self-hosted state is
enabled (pm_save_enable == PARAM_PM_SAVE_SELF_HOSTED) so they can be
invoked by the core layer.

The CPU PM notifier in the ETMv4 driver is no longer needed, remove it
along with its registration and unregistration code.

Reviewed-by: James Clark <james.clark at linaro.org>
Tested-by: James Clark <james.clark at linaro.org>
Reviewed-by: Yeoreum Yun <yeoreum.yun at arm.com>
Signed-off-by: Leo Yan <leo.yan at arm.com>
---
 drivers/hwtracing/coresight/coresight-etm4x-core.c | 57 +++++-----------------
 1 file changed, 11 insertions(+), 46 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 66a8058098376264d3f8c5815763a75ebffb352e..6ed0ee95c78c24bcb6c636d9ebf2ae463c748b22 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -1200,7 +1200,7 @@ static const struct coresight_ops_source etm4_source_ops = {
 	.pause_perf	= etm4_pause_perf,
 };
 
-static const struct coresight_ops etm4_cs_ops = {
+static struct coresight_ops etm4_cs_ops = {
 	.trace_id	= coresight_etm_get_trace_id,
 	.source_ops	= &etm4_source_ops,
 };
@@ -2000,8 +2000,9 @@ static int __etm4_cpu_save(struct etmv4_drvdata *drvdata)
 	return ret;
 }
 
-static int etm4_cpu_save(struct etmv4_drvdata *drvdata)
+static int etm4_cpu_save(struct coresight_device *csdev)
 {
+	struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
 	int ret = 0;
 
 	if (pm_save_enable != PARAM_PM_SAVE_SELF_HOSTED)
@@ -2117,8 +2118,10 @@ static void __etm4_cpu_restore(struct etmv4_drvdata *drvdata)
 	etm4_cs_lock(drvdata, csa);
 }
 
-static void etm4_cpu_restore(struct etmv4_drvdata *drvdata)
+static void etm4_cpu_restore(struct coresight_device *csdev)
 {
+	struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
 	if (pm_save_enable != PARAM_PM_SAVE_SELF_HOSTED)
 		return;
 
@@ -2126,55 +2129,17 @@ static void etm4_cpu_restore(struct etmv4_drvdata *drvdata)
 		__etm4_cpu_restore(drvdata);
 }
 
-static int etm4_cpu_pm_notify(struct notifier_block *nb, unsigned long cmd,
-			      void *v)
-{
-	struct etmv4_drvdata *drvdata;
-	unsigned int cpu = smp_processor_id();
-
-	if (!etmdrvdata[cpu])
-		return NOTIFY_OK;
-
-	drvdata = etmdrvdata[cpu];
-
-	if (WARN_ON_ONCE(drvdata->cpu != cpu))
-		return NOTIFY_BAD;
-
-	switch (cmd) {
-	case CPU_PM_ENTER:
-		if (etm4_cpu_save(drvdata))
-			return NOTIFY_BAD;
-		break;
-	case CPU_PM_EXIT:
-	case CPU_PM_ENTER_FAILED:
-		etm4_cpu_restore(drvdata);
-		break;
-	default:
-		return NOTIFY_DONE;
-	}
-
-	return NOTIFY_OK;
-}
-
-static struct notifier_block etm4_cpu_pm_nb = {
-	.notifier_call = etm4_cpu_pm_notify,
-};
-
 /* Setup PM. Deals with error conditions and counts */
 static int __init etm4_pm_setup(void)
 {
 	int ret;
 
-	ret = cpu_pm_register_notifier(&etm4_cpu_pm_nb);
-	if (ret)
-		return ret;
-
 	ret = cpuhp_setup_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING,
 					"arm/coresight4:starting",
 					etm4_starting_cpu, etm4_dying_cpu);
 
 	if (ret)
-		goto unregister_notifier;
+		return ret;
 
 	ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
 					"arm/coresight4:online",
@@ -2188,15 +2153,11 @@ static int __init etm4_pm_setup(void)
 
 	/* failed dyn state - remove others */
 	cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING);
-
-unregister_notifier:
-	cpu_pm_unregister_notifier(&etm4_cpu_pm_nb);
 	return ret;
 }
 
 static void etm4_pm_clear(void)
 {
-	cpu_pm_unregister_notifier(&etm4_cpu_pm_nb);
 	cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING);
 	if (hp_online) {
 		cpuhp_remove_state_nocalls(hp_online);
@@ -2308,6 +2269,10 @@ static int etm4_probe(struct device *dev)
 				sizeof(struct etmv4_save_state), GFP_KERNEL);
 		if (!drvdata->save_state)
 			return -ENOMEM;
+
+		/* Setup CPU PM callbacks */
+		etm4_cs_ops.pm_save_disable = etm4_cpu_save;
+		etm4_cs_ops.pm_restore_enable = etm4_cpu_restore;
 	}
 
 	raw_spin_lock_init(&drvdata->spinlock);

-- 
2.34.1