[PATCH v2 12/14] torture: Replace cpu_up/down with device_online/offline

[Qais Yousef]

The core device API performs extra housekeeping bits that are missing
from directly calling cpu_up/down.

See commit a6717c01ddc2 ("powerpc/rtas: use device model APIs and
serialization during LPM") for an example description of what might go
wrong.

This also prepares to make cpu_up/down a private interface for anything
but the cpu subsystem.

Signed-off-by: Qais Yousef <qais.yousef@xxxxxxx>
CC: Davidlohr Bueso <dave@xxxxxxxxxxxx>
CC: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
CC: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
CC: linux-kernel@xxxxxxxxxxxxxxx
---
 kernel/torture.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/kernel/torture.c b/kernel/torture.c
index 7c13f5558b71..12115024feb2 100644
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -97,7 +97,9 @@ bool torture_offline(int cpu, long *n_offl_attempts, long *n_offl_successes,
 			 torture_type, cpu);
 	starttime = jiffies;
 	(*n_offl_attempts)++;
-	ret = cpu_down(cpu);
+	lock_device_hotplug();
+	ret = device_offline(get_cpu_device(cpu));
+	unlock_device_hotplug();
 	if (ret) {
 		if (verbose)
 			pr_alert("%s" TORTURE_FLAG
@@ -148,7 +150,9 @@ bool torture_online(int cpu, long *n_onl_attempts, long *n_onl_successes,
 			 torture_type, cpu);
 	starttime = jiffies;
 	(*n_onl_attempts)++;
-	ret = cpu_up(cpu);
+	lock_device_hotplug();
+	ret = device_online(get_cpu_device(cpu));
+	unlock_device_hotplug();
 	if (ret) {
 		if (verbose)
 			pr_alert("%s" TORTURE_FLAG
@@ -192,17 +196,20 @@ torture_onoff(void *arg)
 	for_each_online_cpu(cpu)
 		maxcpu = cpu;
 	WARN_ON(maxcpu < 0);
-	if (!IS_MODULE(CONFIG_TORTURE_TEST))
+	if (!IS_MODULE(CONFIG_TORTURE_TEST)) {
+		lock_device_hotplug();
 		for_each_possible_cpu(cpu) {
 			if (cpu_online(cpu))
 				continue;
-			ret = cpu_up(cpu);
+			ret = device_online(get_cpu_device(cpu));
 			if (ret && verbose) {
 				pr_alert("%s" TORTURE_FLAG
 					 "%s: Initial online %d: errno %d\n",
 					 __func__, torture_type, cpu, ret);
 			}
 		}
+		unlock_device_hotplug();
+	}
 
 	if (maxcpu == 0) {
 		VERBOSE_TOROUT_STRING("Only one CPU, so CPU-hotplug testing is disabled");
-- 
2.17.1