diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2024-02-29 15:23:36 +0100 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2024-03-01 21:04:27 +0100 |
| commit | 2be2a197ff6c3a659ab9285e1d88cbdc609ac6de (patch) | |
| tree | e742ba7b20801029543c26db8d259147194b0c9a /include/linux/cpu.h | |
| parent | 44c76825d6eefee9eb7ce06c38e1a6632ac7eb7d (diff) | |
sched/idle: Conditionally handle tick broadcast in default_idle_call()
The x86 architecture has an idle routine for AMD CPUs which are affected
by erratum 400. On the affected CPUs the local APIC timer stops in the
C1E halt state.
It therefore requires tick broadcasting. The invocation of
tick_broadcast_enter()/exit() from this function violates the RCU
constraints because it can end up in lockdep or tracing, which
rightfully triggers a warning.
tick_broadcast_enter()/exit() must be invoked before ct_cpuidle_enter()
and after ct_cpuidle_exit() in default_idle_call().
Add a static branch conditional invocation of tick_broadcast_enter()/exit()
into this function to allow X86 to replace the AMD specific idle code. It's
guarded by a config switch which will be selected by x86. Otherwise it's
a NOOP.
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240229142248.266708822@linutronix.de
Diffstat (limited to 'include/linux/cpu.h')
| -rw-r--r-- | include/linux/cpu.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/cpu.h b/include/linux/cpu.h index dcb89c987164..715017d4432b 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -196,6 +196,8 @@ void arch_cpu_idle(void); void arch_cpu_idle_prepare(void); void arch_cpu_idle_enter(void); void arch_cpu_idle_exit(void); +void arch_tick_broadcast_enter(void); +void arch_tick_broadcast_exit(void); void __noreturn arch_cpu_idle_dead(void); #ifdef CONFIG_ARCH_HAS_CPU_FINALIZE_INIT |