From c4bc34d20273db698c51951a1951dba0a722e162 Mon Sep 17 00:00:00 2001 From: Suzuki K Poulose Date: Tue, 23 Feb 2016 10:31:39 +0000 Subject: [PATCH] arm64: Add a helper for parking CPUs in a loop Adds a routine which can be used to park CPUs (spinning in kernel) when they can't be killed. Cc: Mark Rutland Acked-by: Will Deacon Signed-off-by: Suzuki K Poulose Signed-off-by: Catalin Marinas --- 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 2013a4dc5124..b93eb3303131 100644 --- a/arch/arm64/include/asm/smp.h +++ b/arch/arm64/include/asm/smp.h @@ -78,4 +78,12 @@ 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 7566cad9fa1d..99f0c5ce5758 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -890,10 +890,7 @@ static void fail_incapable_cpu(char *cap_type, /* 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(); } /* -- 2.20.1