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authorVitaly Kuznetsov <vkuznets@redhat.com>2021-04-06 17:56:40 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2021-04-07 19:02:43 +0200
commitfa26d0c778b432d3d9814ea82552e813b33eeb5c (patch)
tree39348f87174de17b37f636b285fc208dd5100516 /arch
parente49d033bddf5b565044e2abe4241353959bc9120 (diff)
ACPI: processor: Fix build when CONFIG_ACPI_PROCESSOR=m
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> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/include/asm/smp.h2
-rw-r--r--arch/x86/kernel/smpboot.c26
2 files changed, 13 insertions, 15 deletions
diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
index 57ef2094af93..630ff08532be 100644
--- a/arch/x86/include/asm/smp.h
+++ b/arch/x86/include/asm/smp.h
@@ -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 cond_wakeup_cpu0(void);
void native_smp_send_reschedule(int cpu);
void native_send_call_func_ipi(const struct cpumask *mask);
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index f877150a91da..16703c35a944 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1659,13 +1659,17 @@ void play_dead_common(void)
local_irq_disable();
}
-bool wakeup_cpu0(void)
+/**
+ * cond_wakeup_cpu0 - Wake up CPU0 if needed.
+ *
+ * If NMI wants to wake up CPU0, start CPU0.
+ */
+void cond_wakeup_cpu0(void)
{
if (smp_processor_id() == 0 && enable_start_cpu0)
- return true;
-
- return false;
+ start_cpu0();
}
+EXPORT_SYMBOL_GPL(cond_wakeup_cpu0);
/*
* We need to flush the caches before going to sleep, lest we have
@@ -1734,11 +1738,8 @@ static inline void mwait_play_dead(void)
__monitor(mwait_ptr, 0, 0);
mb();
__mwait(eax, 0);
- /*
- * If NMI wants to wake up CPU0, start CPU0.
- */
- if (wakeup_cpu0())
- start_cpu0();
+
+ cond_wakeup_cpu0();
}
}
@@ -1749,11 +1750,8 @@ void hlt_play_dead(void)
while (1) {
native_halt();
- /*
- * If NMI wants to wake up CPU0, start CPU0.
- */
- if (wakeup_cpu0())
- start_cpu0();
+
+ cond_wakeup_cpu0();
}
}