[PATCH 10/12] torture: Replace cpu_up/down with device_online/offline

Qais Yousef
2019-10-30T15:42:39Z

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@arm.com>
CC: Davidlohr Bueso <dave@stgolabs.net>
CC: "Paul E. McKenney" <paulmck@kernel.org>
CC: Josh Triplett <josh@joshtriplett.org>
CC: linux-kernel@vger.kernel.org
---
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