| Message ID | 20170524081547.983493849@linutronix.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, May 24, 2017 at 10:15:23AM +0200, Thomas Gleixner wrote: > From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> > > etm_probe4() 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@linutronix.de> > Signed-off-by: Thomas Gleixner <tglx@linutronix.de> > Cc: Mathieu Poirier <mathieu.poirier@linaro.org> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Steven Rostedt <rostedt@goodmis.org> > Cc: linux-arm-kernel@lists.infradead.org Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org> > > --- > drivers/hwtracing/coresight/coresight-etm4x.c | 20 ++++++++++---------- > 1 file changed, 10 insertions(+), 10 deletions(-) > > --- a/drivers/hwtracing/coresight/coresight-etm4x.c > +++ b/drivers/hwtracing/coresight/coresight-etm4x.c > @@ -371,7 +371,7 @@ static void etm4_disable_sysfs(struct co > * 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); > > /* > @@ -381,7 +381,7 @@ static void etm4_disable_sysfs(struct co > smp_call_function_single(drvdata->cpu, etm4_disable_hw, drvdata, 1); > > spin_unlock(&drvdata->spinlock); > - put_online_cpus(); > + cpus_read_unlock(); > > dev_info(drvdata->dev, "ETM tracing disabled\n"); > } > @@ -982,7 +982,7 @@ static int etm4_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, > @@ -990,18 +990,18 @@ static int etm4_probe(struct amba_device > dev_err(dev, "ETM arch init failed\n"); > > if (!etm4_count++) { > - cpuhp_setup_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING, > - "arm/coresight4:starting", > - etm4_starting_cpu, etm4_dying_cpu); > - ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, > - "arm/coresight4:online", > - etm4_online_cpu, NULL); > + cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ARM_CORESIGHT_STARTING, > + "arm/coresight4:starting", > + etm4_starting_cpu, etm4_dying_cpu); > + ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN, > + "arm/coresight4:online", > + etm4_online_cpu, NULL); > if (ret < 0) > goto err_arch_supported; > hp_online = ret; > } > > - put_online_cpus(); > + cpus_read_unlock(); > > if (etm4_arch_supported(drvdata->arch) == false) { > ret = -EINVAL; > >
--- a/drivers/hwtracing/coresight/coresight-etm4x.c +++ b/drivers/hwtracing/coresight/coresight-etm4x.c @@ -371,7 +371,7 @@ static void etm4_disable_sysfs(struct co * 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); /* @@ -381,7 +381,7 @@ static void etm4_disable_sysfs(struct co smp_call_function_single(drvdata->cpu, etm4_disable_hw, drvdata, 1); spin_unlock(&drvdata->spinlock); - put_online_cpus(); + cpus_read_unlock(); dev_info(drvdata->dev, "ETM tracing disabled\n"); } @@ -982,7 +982,7 @@ static int etm4_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, @@ -990,18 +990,18 @@ static int etm4_probe(struct amba_device dev_err(dev, "ETM arch init failed\n"); if (!etm4_count++) { - cpuhp_setup_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING, - "arm/coresight4:starting", - etm4_starting_cpu, etm4_dying_cpu); - ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, - "arm/coresight4:online", - etm4_online_cpu, NULL); + cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ARM_CORESIGHT_STARTING, + "arm/coresight4:starting", + etm4_starting_cpu, etm4_dying_cpu); + ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN, + "arm/coresight4:online", + etm4_online_cpu, NULL); if (ret < 0) goto err_arch_supported; hp_online = ret; } - put_online_cpus(); + cpus_read_unlock(); if (etm4_arch_supported(drvdata->arch) == false) { ret = -EINVAL;