* [PATCH v3] ACPI: processor: Fix build when CONFIG_ACPI_PROCESSOR=m
@ 2021-04-06 15:56 Vitaly Kuznetsov
2021-04-07 17:06 ` Rafael J. Wysocki
0 siblings, 1 reply; 2+ messages in thread
From: Vitaly Kuznetsov @ 2021-04-06 15:56 UTC (permalink / raw)
To: linux-acpi, Rafael J. Wysocki
Cc: x86, Len Brown, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
H. Peter Anvin, stable, kernel test robot, linux-kernel
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>
---
Changes since v2:
- Use proper kerneldoc format [Rafael J. Wysocki]
---
arch/x86/include/asm/smp.h | 2 +-
arch/x86/kernel/smpboot.c | 26 ++++++++++++--------------
drivers/acpi/processor_idle.c | 4 +---
3 files changed, 14 insertions(+), 18 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();
}
}
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 768a6b4d2368..4e2d76b8b697 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -544,9 +544,7 @@ static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
return -ENODEV;
#if defined(CONFIG_X86) && defined(CONFIG_HOTPLUG_CPU)
- /* If NMI wants to wake up CPU0, start CPU0. */
- if (wakeup_cpu0())
- start_cpu0();
+ cond_wakeup_cpu0();
#endif
}
--
2.30.2
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v3] ACPI: processor: Fix build when CONFIG_ACPI_PROCESSOR=m
2021-04-06 15:56 [PATCH v3] ACPI: processor: Fix build when CONFIG_ACPI_PROCESSOR=m Vitaly Kuznetsov
@ 2021-04-07 17:06 ` Rafael J. Wysocki
0 siblings, 0 replies; 2+ messages in thread
From: Rafael J. Wysocki @ 2021-04-07 17:06 UTC (permalink / raw)
To: Vitaly Kuznetsov
Cc: ACPI Devel Maling List, Rafael J. Wysocki,
the arch/x86 maintainers, Len Brown, Thomas Gleixner,
Ingo Molnar, Borislav Petkov, H. Peter Anvin, Stable,
kernel test robot, Linux Kernel Mailing List
On Tue, Apr 6, 2021 at 5:56 PM Vitaly Kuznetsov <vkuznets@redhat.com> wrote:
>
> 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>
Applied as 5.12-rc material, thanks!
> ---
> Changes since v2:
> - Use proper kerneldoc format [Rafael J. Wysocki]
> ---
> arch/x86/include/asm/smp.h | 2 +-
> arch/x86/kernel/smpboot.c | 26 ++++++++++++--------------
> drivers/acpi/processor_idle.c | 4 +---
> 3 files changed, 14 insertions(+), 18 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();
> }
> }
>
> diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
> index 768a6b4d2368..4e2d76b8b697 100644
> --- a/drivers/acpi/processor_idle.c
> +++ b/drivers/acpi/processor_idle.c
> @@ -544,9 +544,7 @@ static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
> return -ENODEV;
>
> #if defined(CONFIG_X86) && defined(CONFIG_HOTPLUG_CPU)
> - /* If NMI wants to wake up CPU0, start CPU0. */
> - if (wakeup_cpu0())
> - start_cpu0();
> + cond_wakeup_cpu0();
> #endif
> }
>
> --
> 2.30.2
>
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