Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull SMP hotplug updates from Ingo Molnar:
 "Simplify the CPU hot-plug state machine"

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpu/hotplug: Fix unused function warning
  cpu/hotplug: Merge cpuhp_bp_states and cpuhp_ap_states

1 files changed, 24 insertions, 36 deletions

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 53f7dc65f9a3..0db8938fbb23 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -124,24 +124,11 @@ struct cpuhp_step {
 };
 
 static DEFINE_MUTEX(cpuhp_state_mutex);
-static struct cpuhp_step cpuhp_bp_states[];
-static struct cpuhp_step cpuhp_ap_states[];
-
-static bool cpuhp_is_ap_state(enum cpuhp_state state)
-{
-        /*
-         * The extra check for CPUHP_TEARDOWN_CPU is only for documentation
-         * purposes as that state is handled explicitly in cpu_down.
-         */
-        return state > CPUHP_BRINGUP_CPU && state != CPUHP_TEARDOWN_CPU;
-}
+static struct cpuhp_step cpuhp_hp_states[];
 
 static struct cpuhp_step *cpuhp_get_step(enum cpuhp_state state)
 {
-        struct cpuhp_step *sp;
-
-        sp = cpuhp_is_ap_state(state) ? cpuhp_ap_states : cpuhp_bp_states;
-        return sp + state;
+        return cpuhp_hp_states + state;
 }
 
 /**
@@ -239,6 +226,15 @@ err:
 }
 
 #ifdef CONFIG_SMP
+static bool cpuhp_is_ap_state(enum cpuhp_state state)
+{
+        /*
+         * The extra check for CPUHP_TEARDOWN_CPU is only for documentation
+         * purposes as that state is handled explicitly in cpu_down.
+         */
+        return state > CPUHP_BRINGUP_CPU && state != CPUHP_TEARDOWN_CPU;
+}
+
 static inline void wait_for_ap_thread(struct cpuhp_cpu_state *st, bool bringup)
 {
         struct completion *done = bringup ? &st->done_up : &st->done_down;
@@ -1224,7 +1220,7 @@ int __boot_cpu_id;
 #endif /* CONFIG_SMP */
 
 /* Boot processor state steps */
-static struct cpuhp_step cpuhp_bp_states[] = {
+static struct cpuhp_step cpuhp_hp_states[] = {
         [CPUHP_OFFLINE] = {
                 .name                   = "offline",
                 .startup.single         = NULL,
@@ -1289,24 +1285,6 @@ static struct cpuhp_step cpuhp_bp_states[] = {
                 .teardown.single        = NULL,
                 .cant_stop              = true,
         },
-        /*
-         * Handled on controll processor until the plugged processor manages
-         * this itself.
-         */
-        [CPUHP_TEARDOWN_CPU] = {
-                .name                   = "cpu:teardown",
-                .startup.single         = NULL,
-                .teardown.single        = takedown_cpu,
-                .cant_stop              = true,
-        },
-#else
-        [CPUHP_BRINGUP_CPU] = { },
-#endif
-};
-
-/* Application processor state steps */
-static struct cpuhp_step cpuhp_ap_states[] = {
-#ifdef CONFIG_SMP
         /* Final state before CPU kills itself */
         [CPUHP_AP_IDLE_DEAD] = {
                 .name                   = "idle:dead",
@@ -1340,6 +1318,16 @@ static struct cpuhp_step cpuhp_ap_states[] = {
         [CPUHP_AP_ONLINE] = {
                 .name                   = "ap:online",
         },
+        /*
+         * Handled on controll processor until the plugged processor manages
+         * this itself.
+         */
+        [CPUHP_TEARDOWN_CPU] = {
+                .name                   = "cpu:teardown",
+                .startup.single         = NULL,
+                .teardown.single        = takedown_cpu,
+                .cant_stop              = true,
+        },
         /* Handle smpboot threads park/unpark */
         [CPUHP_AP_SMPBOOT_THREADS] = {
                 .name                   = "smpboot/threads:online",
@@ -1408,11 +1396,11 @@ static int cpuhp_reserve_state(enum cpuhp_state state)
 
         switch (state) {
         case CPUHP_AP_ONLINE_DYN:
-                step = cpuhp_ap_states + CPUHP_AP_ONLINE_DYN;
+                step = cpuhp_hp_states + CPUHP_AP_ONLINE_DYN;
                 end = CPUHP_AP_ONLINE_DYN_END;
                 break;
         case CPUHP_BP_PREPARE_DYN:
-                step = cpuhp_bp_states + CPUHP_BP_PREPARE_DYN;
+                step = cpuhp_hp_states + CPUHP_BP_PREPARE_DYN;
                 end = CPUHP_BP_PREPARE_DYN_END;
                 break;
         default: