[patch V3 11/32] hwtracing/coresight-etm3x: Use cpuhp_setup_state_nocalls_cpuslocked()
Thomas Gleixner
tglx at linutronix.de
Wed May 24 01:15:22 PDT 2017
From: Sebastian Andrzej Siewior <bigeasy at linutronix.de>
etm_probe() holds get_online_cpus() while invoking
cpuhp_setup_state_nocalls().
cpuhp_setup_state_nocalls() invokes get_online_cpus() as well. This is
correct, but prevents the conversion of the hotplug locking to a percpu
rwsem.
Use cpuhp_setup_state_nocalls_cpuslocked() to avoid the nested
call. Convert *_online_cpus() to the new interfaces while at it.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy at linutronix.de>
Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
Cc: Mathieu Poirier <mathieu.poirier at linaro.org>
Cc: Peter Zijlstra <peterz at infradead.org>
Cc: Steven Rostedt <rostedt at goodmis.org>
Cc: linux-arm-kernel at lists.infradead.org
---
drivers/hwtracing/coresight/coresight-etm3x.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
--- a/drivers/hwtracing/coresight/coresight-etm3x.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x.c
@@ -587,7 +587,7 @@ static void etm_disable_sysfs(struct cor
* after cpu online mask indicates the cpu is offline but before the
* DYING hotplug callback is serviced by the ETM driver.
*/
- get_online_cpus();
+ cpus_read_lock();
spin_lock(&drvdata->spinlock);
/*
@@ -597,7 +597,7 @@ static void etm_disable_sysfs(struct cor
smp_call_function_single(drvdata->cpu, etm_disable_hw, drvdata, 1);
spin_unlock(&drvdata->spinlock);
- put_online_cpus();
+ cpus_read_unlock();
dev_info(drvdata->dev, "ETM tracing disabled\n");
}
@@ -795,7 +795,7 @@ static int etm_probe(struct amba_device
drvdata->cpu = pdata ? pdata->cpu : 0;
- get_online_cpus();
+ cpus_read_lock();
etmdrvdata[drvdata->cpu] = drvdata;
if (smp_call_function_single(drvdata->cpu,
@@ -803,17 +803,17 @@ static int etm_probe(struct amba_device
dev_err(dev, "ETM arch init failed\n");
if (!etm_count++) {
- cpuhp_setup_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING,
- "arm/coresight:starting",
- etm_starting_cpu, etm_dying_cpu);
- ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
- "arm/coresight:online",
- etm_online_cpu, NULL);
+ cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ARM_CORESIGHT_STARTING,
+ "arm/coresight:starting",
+ etm_starting_cpu, etm_dying_cpu);
+ ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN,
+ "arm/coresight:online",
+ etm_online_cpu, NULL);
if (ret < 0)
goto err_arch_supported;
hp_online = ret;
}
- put_online_cpus();
+ cpus_read_unlock();
if (etm_arch_supported(drvdata->arch) == false) {
ret = -EINVAL;
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