[tip: smp/core] cpu/hotplug: Make HOTPLUG_PARALLEL independent of HOTPLUG_SMT

[tip-bot2 for Jiaxun Yang]

The following commit has been merged into the smp/core branch of tip:

Commit-ID:     c0e81a455e23f77683178b8ae32651df5841f065
Gitweb:        https://git.kernel.org/tip/c0e81a455e23f77683178b8ae32651df5841f065
Author:        Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
AuthorDate:    Tue, 16 Jul 2024 22:14:58 +08:00
Committer:     Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Fri, 02 Aug 2024 16:06:36 +02:00

cpu/hotplug: Make HOTPLUG_PARALLEL independent of HOTPLUG_SMT

Provide stub functions for SMT related parallel bring up functions so that
HOTPLUG_PARALLEL can work without HOTPLUG_SMT.

Signed-off-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/all/20240716-loongarch-hotplug-v3-1-af59b3bb35c8@xxxxxxxxxxx

---
 kernel/cpu.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 1209dda..c89e0e9 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -1808,6 +1808,7 @@ static int __init parallel_bringup_parse_param(char *arg)
 }
 early_param("cpuhp.parallel", parallel_bringup_parse_param);
 
+#ifdef CONFIG_HOTPLUG_SMT
 static inline bool cpuhp_smt_aware(void)
 {
 	return cpu_smt_max_threads > 1;
@@ -1817,6 +1818,16 @@ static inline const struct cpumask *cpuhp_get_primary_thread_mask(void)
 {
 	return cpu_primary_thread_mask;
 }
+#else
+static inline bool cpuhp_smt_aware(void)
+{
+	return false;
+}
+static inline const struct cpumask *cpuhp_get_primary_thread_mask(void)
+{
+	return cpu_none_mask;
+}
+#endif
 
 /*
  * On architectures which have enabled parallel bringup this invokes all BP