@@ -132,7 +132,7 @@ void native_play_dead(void);
void play_dead_common(void);
void wbinvd_on_cpu(int cpu);
int wbinvd_on_all_cpus(void);
-bool wakeup_cpu0(void);
+void wakeup_cpu0_if_needed(void);
void native_smp_send_reschedule(int cpu);
void native_send_call_func_ipi(const struct cpumask *mask);
@@ -1659,7 +1659,7 @@ void play_dead_common(void)
local_irq_disable();
}
-bool wakeup_cpu0(void)
+static bool wakeup_cpu0(void)
{
if (smp_processor_id() == 0 && enable_start_cpu0)
return true;
@@ -1667,6 +1667,13 @@ bool wakeup_cpu0(void)
return false;
}
+void wakeup_cpu0_if_needed(void)
+{
+ if (wakeup_cpu0())
+ start_cpu0();
+}
+EXPORT_SYMBOL_GPL(wakeup_cpu0_if_needed);
+
/*
* We need to flush the caches before going to sleep, lest we have
* dirty data in our caches when we come back up.
@@ -1737,8 +1744,7 @@ static inline void mwait_play_dead(void)
/*
* If NMI wants to wake up CPU0, start CPU0.
*/
- if (wakeup_cpu0())
- start_cpu0();
+ wakeup_cpu0_if_needed();
}
}
@@ -1752,8 +1758,7 @@ void hlt_play_dead(void)
/*
* If NMI wants to wake up CPU0, start CPU0.
*/
- if (wakeup_cpu0())
- start_cpu0();
+ wakeup_cpu0_if_needed();
}
}
@@ -545,8 +545,7 @@ static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
#if defined(CONFIG_X86) && defined(CONFIG_HOTPLUG_CPU)
/* If NMI wants to wake up CPU0, start CPU0. */
- if (wakeup_cpu0())
- start_cpu0();
+ wakeup_cpu0_if_needed();
#endif
}
Commit 8cdddd182bd7 ("ACPI: processor: Fix CPU0 wakeup in acpi_idle_play_dead()") tried to fix CPU0 hotplug breakage by copying wakeup_cpu0() + start_cpu0() logic from hlt_play_dead()//mwait_play_dead() into acpi_idle_play_dead(). The problem is that these functions are not exported to modules so when CONFIG_ACPI_PROCESSOR=m build fails. The issue could've been fixed by exporting both wakeup_cpu0()/start_cpu0() (the later from assembly) but it seems putting the whole pattern into a new function and exporting it instead is better. Reported-by: kernel test robot <lkp@intel.com> Fixes: 8cdddd182bd7 ("CPI: processor: Fix CPU0 wakeup in acpi_idle_play_dead()") Cc: <stable@vger.kernel.org> # 5.10+ Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> --- arch/x86/include/asm/smp.h | 2 +- arch/x86/kernel/smpboot.c | 15 ++++++++++----- drivers/acpi/processor_idle.c | 3 +-- 3 files changed, 12 insertions(+), 8 deletions(-)