diff options
| -rw-r--r-- | arch/arm64/kernel/topology.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c index 3fe1faab0362..b32f13358fbb 100644 --- a/arch/arm64/kernel/topology.c +++ b/arch/arm64/kernel/topology.c @@ -400,16 +400,25 @@ static inline int counters_read_on_cpu(int cpu, smp_call_func_t func, u64 *val) { /* - * Abort call on counterless CPU or when interrupts are - * disabled - can lead to deadlock in smp sync call. + * Abort call on counterless CPU. */ if (!cpu_has_amu_feat(cpu)) return -EOPNOTSUPP; - if (WARN_ON_ONCE(irqs_disabled())) - return -EPERM; - - smp_call_function_single(cpu, func, val, 1); + if (irqs_disabled()) { + /* + * When IRQs are disabled (tick path: sched_tick -> + * topology_scale_freq_tick or cppc_scale_freq_tick), only local + * CPU counter reads are allowed. Remote CPU counter read would + * require smp_call_function_single() which is unsafe with IRQs + * disabled. + */ + if (WARN_ON_ONCE(cpu != smp_processor_id())) + return -EPERM; + func(val); + } else { + smp_call_function_single(cpu, func, val, 1); + } return 0; } |