Commit 715c3211 authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Thomas Gleixner
Browse files

ia64/palinfo: Convert to hotplug state machine 



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

The removal of the files happens now in the prepare down stage as there is
no reason to keep them around until the cpu has actually died.

Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-ia64@vger.kernel.org
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20161103145021.28528-16-bigeasy@linutronix.de


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 12223144

arch/ia64/kernel/palinfo.c

+16 −44
Original line number Diff line number Diff line
@@ -932,8 +932,7 @@ static const struct file_operations proc_palinfo_fops = { 
	.release	= single_release,

};



static void

create_palinfo_proc_entries(unsigned int cpu)

static int palinfo_add_proc(unsigned int cpu)

{

	pal_func_cpu_u_t f;

	struct proc_dir_entry *cpu_dir;
@@ -943,7 +942,7 @@ create_palinfo_proc_entries(unsigned int cpu) 


	cpu_dir = proc_mkdir(cpustr, palinfo_dir);

	if (!cpu_dir)

		return;

		return -EINVAL;



	f.req_cpu = cpu;
@@ -952,42 +951,21 @@ create_palinfo_proc_entries(unsigned int cpu) 
		proc_create_data(palinfo_entries[j].name, 0, cpu_dir,

				 &proc_palinfo_fops, (void *)f.value);

	}

	return 0;

}



static void

remove_palinfo_proc_entries(unsigned int hcpu)

static int palinfo_del_proc(unsigned int hcpu)

{

	char cpustr[3+4+1];	/* cpu numbers are up to 4095 on itanic */



	sprintf(cpustr, "cpu%d", hcpu);

	remove_proc_subtree(cpustr, palinfo_dir);

	return 0;

}



static int palinfo_cpu_callback(struct notifier_block *nfb,

					unsigned long action, void *hcpu)

{

	unsigned int hotcpu = (unsigned long)hcpu;



	switch (action) {

	case CPU_ONLINE:

	case CPU_ONLINE_FROZEN:

		create_palinfo_proc_entries(hotcpu);

		break;

	case CPU_DEAD:

	case CPU_DEAD_FROZEN:

		remove_palinfo_proc_entries(hotcpu);

		break;

	}

	return NOTIFY_OK;

}



static struct notifier_block __refdata palinfo_cpu_notifier =

{

	.notifier_call = palinfo_cpu_callback,

	.priority = 0,

};

static enum cpuhp_state hp_online;



static int __init

palinfo_init(void)

static int __init palinfo_init(void)

{

	int i = 0;
@@ -996,25 +974,19 @@ palinfo_init(void) 
	if (!palinfo_dir)

		return -ENOMEM;



	cpu_notifier_register_begin();



	/* Create palinfo dirs in /proc for all online cpus */

	for_each_online_cpu(i) {

		create_palinfo_proc_entries(i);

	i = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "ia64/palinfo:online",

			      palinfo_add_proc, palinfo_del_proc);

	if (i < 0) {

		remove_proc_subtree("pal", NULL);

		return i;

	}



	/* Register for future delivery via notify registration */

	__register_hotcpu_notifier(&palinfo_cpu_notifier);



	cpu_notifier_register_done();



	hp_online = i;

	return 0;

}



static void __exit

palinfo_exit(void)

static void __exit palinfo_exit(void)

{

	unregister_hotcpu_notifier(&palinfo_cpu_notifier);

	cpuhp_remove_state(hp_online);

	remove_proc_subtree("pal", NULL);

}

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