From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: linux-acpi@vger.kernel.org, "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: x86@kernel.org, Len Brown <lenb@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"H. Peter Anvin" <hpa@zytor.com>,
stable@vger.kernel.org, kernel test robot <lkp@intel.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH] ACPI: processor: Fix build when CONFIG_ACPI_PROCESSOR=m
Date: Tue, 6 Apr 2021 14:50:47 +0200 [thread overview]
Message-ID: <20210406125047.547501-1-vkuznets@redhat.com> (raw)
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(-)
diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
index 57ef2094af93..6f79deb1f970 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 wakeup_cpu0_if_needed(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..9547d870ee27 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -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();
}
}
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 768a6b4d2368..de15116b754a 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -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
}
--
2.30.2
next reply other threads:[~2021-04-06 12:50 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-06 12:50 Vitaly Kuznetsov [this message]
2021-04-06 13:22 ` [PATCH] ACPI: processor: Fix build when CONFIG_ACPI_PROCESSOR=m Rafael J. Wysocki
2021-04-06 13:37 ` Vitaly Kuznetsov
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