From: Suzuki K Poulose suzuki.poulose@arm.com
Commit c4bc34d20273db698c51951a1951dba0a722e162 upstream.
Adds a routine which can be used to park CPUs (spinning in kernel) when they can't be killed.
Cc: Mark Rutland mark.rutland@arm.com Acked-by: Will Deacon will.deacon@arm.com Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- arch/arm64/include/asm/smp.h | 8 ++++++++ arch/arm64/kernel/cpufeature.c | 5 +---- 2 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/include/asm/smp.h b/arch/arm64/include/asm/smp.h index d9c3d6a6100a..53b53a9b3e5a 100644 --- a/arch/arm64/include/asm/smp.h +++ b/arch/arm64/include/asm/smp.h @@ -69,4 +69,12 @@ extern int __cpu_disable(void); extern void __cpu_die(unsigned int cpu); extern void cpu_die(void);
+static inline void cpu_park_loop(void) +{ + for (;;) { + wfe(); + wfi(); + } +} + #endif /* ifndef __ASM_SMP_H */ diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index b7f01bf47988..4adf18307568 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -868,10 +868,7 @@ void cpu_die_early(void) /* Check if we can park ourselves */ if (cpu_ops[cpu] && cpu_ops[cpu]->cpu_die) cpu_ops[cpu]->cpu_die(cpu); - asm( - "1: wfe\n" - " wfi\n" - " b 1b"); + cpu_park_loop(); }
/*