Remove duplicate definitions from arm64/riscv, add unified
implementation in smp.h.

Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>
---
 arch/arm64/kernel/smp.c | 11 -----------
 arch/riscv/kernel/smp.c | 11 -----------
 include/linux/smp.h     | 11 +++++++++++
 3 files changed, 11 insertions(+), 22 deletions(-)

diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 68cea3a4a35ca..2d1e7839dc9b0 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -1171,17 +1171,6 @@ void tick_broadcast(const struct cpumask *mask)
 }
 #endif
 
-/*
- * The number of CPUs online, not counting this CPU (which may not be
- * fully online and so not counted in num_online_cpus()).
- */
-static inline unsigned int num_other_online_cpus(void)
-{
-	unsigned int this_cpu_online = cpu_online(smp_processor_id());
-
-	return num_online_cpus() - this_cpu_online;
-}
-
 void smp_send_stop(void)
 {
 	static unsigned long stop_in_progress;
diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c
index 9dbcb9a06a96d..669325e68a21a 100644
--- a/arch/riscv/kernel/smp.c
+++ b/arch/riscv/kernel/smp.c
@@ -272,17 +272,6 @@ void smp_send_stop(void)
 }
 
 #ifdef CONFIG_KEXEC_CORE
-/*
- * The number of CPUs online, not counting this CPU (which may not be
- * fully online and so not counted in num_online_cpus()).
- */
-static inline unsigned int num_other_online_cpus(void)
-{
-	unsigned int this_cpu_online = cpu_online(smp_processor_id());
-
-	return num_online_cpus() - this_cpu_online;
-}
-
 void crash_smp_send_stop(void)
 {
 	static int cpus_stopped;
diff --git a/include/linux/smp.h b/include/linux/smp.h
index 18e9c918325e5..5300c5c14232b 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -275,6 +275,17 @@ static inline int get_boot_cpu_id(void)
 #define get_cpu()		({ preempt_disable(); __smp_processor_id(); })
 #define put_cpu()		preempt_enable()
 
+/*
+ * The number of CPUs online, not counting this CPU (which may not be
+ * fully online and so not counted in num_online_cpus()).
+ */
+static inline unsigned int num_other_online_cpus(void)
+{
+	unsigned int this_cpu_online = cpu_online(smp_processor_id());
+
+	return num_online_cpus() - this_cpu_online;
+}
+
 /*
  * Callback to arch code if there's nosmp or maxcpus=0 on the
  * boot command line:
-- 
2.39.5