[PATCH 11/12] smp: Create a new function to bringup nonboot cpus online

Qais Yousef
2019-10-30T15:42:43Z

This is the last direct user of cpu_up() before we can hide it now as
internal implementation detail of the cpu subsystem.

Signed-off-by: Qais Yousef <qais.yousef@arm.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Josh Poimboeuf <jpoimboe@redhat.com>
CC: "Peter Zijlstra (Intel)" <peterz@infradead.org>
CC: Jiri Kosina <jkosina@suse.cz>
CC: Nicholas Piggin <npiggin@gmail.com>
CC: Daniel Lezcano <daniel.lezcano@linaro.org>
CC: Ingo Molnar <mingo@kernel.org>
CC: Eiichi Tsukata <devel@etsukata.com>
CC: Zhenzhong Duan <zhenzhong.duan@oracle.com>
CC: Nadav Amit <namit@vmware.com>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
CC: linux-kernel@vger.kernel.org
---
include/linux/cpu.h | 1 +
kernel/cpu.c | 13 +++++++++++++
kernel/smp.c | 9 +--------
3 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index 3b1fbe192989..b1c7b788b8e9 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -88,6 +88,7 @@ void notify_cpu_starting(unsigned int cpu);
extern void cpu_maps_update_begin(void);
extern void cpu_maps_update_done(void);
extern int hibernation_bringup_sleep_cpu(unsigned int sleep_cpu);
+extern void smp_bringup_nonboot_cpus(unsigned int setup_max_cpus);

#else /* CONFIG_SMP */
#define cpuhp_tasks_frozen 0
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 219f9033f438..e16695b841de 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -1211,6 +1211,19 @@ int hibernation_bringup_sleep_cpu(unsigned int sleep_cpu)
}
}

+void smp_bringup_nonboot_cpus(unsigned int setup_max_cpus)
+{
+ unsigned int cpu;
+
+ /* FIXME: This should be done in userspace --RR */
+ for_each_present_cpu(cpu) {
+ if (num_online_cpus() >= setup_max_cpus)
+ break;
+ if (!cpu_online(cpu))
+ cpu_up(cpu);
+ }
+}
+
#ifdef CONFIG_PM_SLEEP_SMP
static cpumask_var_t frozen_cpus;

diff --git a/kernel/smp.c b/kernel/smp.c
index 7dbcb402c2fc..74134272b5aa 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -578,20 +578,13 @@ void __init setup_nr_cpu_ids(void)
void __init smp_init(void)
{
int num_nodes, num_cpus;
- unsigned int cpu;

idle_threads_init();
cpuhp_threads_init();

pr_info("Bringing up secondary CPUs ...\n");

- /* FIXME: This should be done in userspace --RR */
- for_each_present_cpu(cpu) {
- if (num_online_cpus() >= setup_max_cpus)
- break;
- if (!cpu_online(cpu))
- cpu_up(cpu);
- }
+ smp_bringup_nonboot_cpus(setup_max_cpus);

num_nodes = num_online_nodes();
num_cpus = num_online_cpus();
--
2.17.1