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Commit 89666c50 authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Thomas Gleixner
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x86/oprofile/nmi: Convert to hotplug state machine 



Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.

Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Robert Richter <rric@kernel.org>
Cc: oprofile-list@lists.sf.net
Cc: rt@linuxtronix.de
Link: http://lkml.kernel.org/r/20161117183541.8588-20-bigeasy@linutronix.de


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 08ed487c

arch/x86/oprofile/nmi_int.c

+18 −43
Original line number Diff line number Diff line
@@ -339,10 +339,11 @@ static int allocate_msrs(void) 
	return 0;

}



static void nmi_cpu_setup(void *dummy)

static void nmi_cpu_setup(void)

{

	int cpu = smp_processor_id();

	struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);



	nmi_cpu_save_registers(msrs);

	raw_spin_lock(&oprofilefs_lock);

	model->setup_ctrs(model, msrs);
@@ -369,7 +370,7 @@ static void nmi_cpu_restore_registers(struct op_msrs *msrs) 
	}

}



static void nmi_cpu_shutdown(void *dummy)

static void nmi_cpu_shutdown(void)

{

	unsigned int v;

	int cpu = smp_processor_id();
@@ -387,24 +388,26 @@ static void nmi_cpu_shutdown(void *dummy) 
	nmi_cpu_restore_registers(msrs);

}



static void nmi_cpu_up(void)

static int nmi_cpu_online(unsigned int cpu)

{

	local_irq_disable();

	if (nmi_enabled)

		nmi_cpu_setup(NULL);

		nmi_cpu_setup();

	if (ctr_running)

		nmi_cpu_start(NULL);

	local_irq_enable();

	return 0;

}



static void nmi_cpu_down(void)

static int nmi_cpu_down_prep(unsigned int cpu)

{

	local_irq_disable();

	if (ctr_running)

		nmi_cpu_stop(NULL);

	if (nmi_enabled)

		nmi_cpu_shutdown(NULL);

		nmi_cpu_shutdown();

	local_irq_enable();

	return 0;

}



static int nmi_create_files(struct dentry *root)
@@ -437,24 +440,7 @@ static int nmi_create_files(struct dentry *root) 
	return 0;

}



static int oprofile_cpu_notifier(struct notifier_block *b, unsigned long action,

				 void *data)

{

	switch (action & ~CPU_TASKS_FROZEN) {

	case CPU_DOWN_FAILED:

	case CPU_ONLINE:

		nmi_cpu_up();

		break;

	case CPU_DOWN_PREPARE:

		nmi_cpu_down();

		break;

	}

	return NOTIFY_DONE;

}



static struct notifier_block oprofile_cpu_nb = {

	.notifier_call = oprofile_cpu_notifier

};

static enum cpuhp_state cpuhp_nmi_online;



static int nmi_setup(void)

{
@@ -497,20 +483,17 @@ static int nmi_setup(void) 
	if (err)

		goto fail;



	cpu_notifier_register_begin();



	/* Use get/put_online_cpus() to protect 'nmi_enabled' */

	get_online_cpus();

	nmi_enabled = 1;

	/* make nmi_enabled visible to the nmi handler: */

	smp_mb();

	on_each_cpu(nmi_cpu_setup, NULL, 1);

	__register_cpu_notifier(&oprofile_cpu_nb);

	put_online_cpus();



	cpu_notifier_register_done();



	err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/oprofile:online",

				nmi_cpu_online, nmi_cpu_down_prep);

	if (err < 0)

		goto fail_nmi;

	cpuhp_nmi_online = err;

	return 0;

fail_nmi:

	unregister_nmi_handler(NMI_LOCAL, "oprofile");

fail:

	free_msrs();

	return err;
@@ -520,17 +503,9 @@ static void nmi_shutdown(void) 
{

	struct op_msrs *msrs;



	cpu_notifier_register_begin();



	/* Use get/put_online_cpus() to protect 'nmi_enabled' & 'ctr_running' */

	get_online_cpus();

	on_each_cpu(nmi_cpu_shutdown, NULL, 1);

	cpuhp_remove_state(cpuhp_nmi_online);

	nmi_enabled = 0;

	ctr_running = 0;

	__unregister_cpu_notifier(&oprofile_cpu_nb);

	put_online_cpus();



	cpu_notifier_register_done();



	/* make variables visible to the nmi handler: */

	smp_mb();