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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 <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>
hifive-unleashed-5.1
Suzuki K Poulose 2016-02-23 10:31:39 +00:00 committed by Catalin Marinas
parent 2b5fe07a78
commit c4bc34d202
2 changed files with 9 additions and 4 deletions
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8
arch/arm64/include/asm/smp.h
View File

@ -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 */

5
arch/arm64/kernel/cpufeature.c
View File

@ -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();
}
/*