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-rw-r--r--kernel/cpu.c20
1 files changed, 18 insertions, 2 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 025f419d16f6..6754f3ecfd94 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -564,6 +564,20 @@ static void undo_cpu_up(unsigned int cpu, struct cpuhp_cpu_state *st)
564 cpuhp_invoke_callback(cpu, st->state, false, NULL, NULL); 564 cpuhp_invoke_callback(cpu, st->state, false, NULL, NULL);
565} 565}
566 566
567static inline bool can_rollback_cpu(struct cpuhp_cpu_state *st)
568{
569 if (IS_ENABLED(CONFIG_HOTPLUG_CPU))
570 return true;
571 /*
572 * When CPU hotplug is disabled, then taking the CPU down is not
573 * possible because takedown_cpu() and the architecture and
574 * subsystem specific mechanisms are not available. So the CPU
575 * which would be completely unplugged again needs to stay around
576 * in the current state.
577 */
578 return st->state <= CPUHP_BRINGUP_CPU;
579}
580
567static int cpuhp_up_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st, 581static int cpuhp_up_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st,
568 enum cpuhp_state target) 582 enum cpuhp_state target)
569{ 583{
@@ -574,8 +588,10 @@ static int cpuhp_up_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st,
574 st->state++; 588 st->state++;
575 ret = cpuhp_invoke_callback(cpu, st->state, true, NULL, NULL); 589 ret = cpuhp_invoke_callback(cpu, st->state, true, NULL, NULL);
576 if (ret) { 590 if (ret) {
577 st->target = prev_state; 591 if (can_rollback_cpu(st)) {
578 undo_cpu_up(cpu, st); 592 st->target = prev_state;
593 undo_cpu_up(cpu, st);
594 }
579 break; 595 break;
580 } 596 }
581 } 597 }