Messages in this thread Patch in this message |  | | From | Viresh Kumar <> | Subject | [PATCH] arm64: topology: Don't support AMU without cpufreq | Date | Thu, 9 Jul 2020 12:22:45 +0530 |
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The commit cd0ed03a8903 ("arm64: use activity monitors for frequency invariance"), mentions that:
"if CONFIG_CPU_FREQ is not enabled, the use of counters is enabled on all CPUs only if all possible CPUs correctly support the necessary counters"
But that's not really true as validate_cpu_freq_invariance_counters() fails if max_freq_hz is returned as 0 (in case there is no policy for the CPU). And the AMUs won't be supported in that case.
Make the code reflect this reality.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- arch/arm64/kernel/topology.c | 19 +++---------------- 1 file changed, 3 insertions(+), 16 deletions(-)
diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c index 0801a0f3c156..b7da372819fc 100644 --- a/arch/arm64/kernel/topology.c +++ b/arch/arm64/kernel/topology.c @@ -187,14 +187,13 @@ static int validate_cpu_freq_invariance_counters(int cpu) return 0; } -static inline bool -enable_policy_freq_counters(int cpu, cpumask_var_t valid_cpus) +static inline void update_amu_fie_cpus(int cpu, cpumask_var_t valid_cpus) { struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); if (!policy) { pr_debug("CPU%d: No cpufreq policy found.\n", cpu); - return false; + return; } if (cpumask_subset(policy->related_cpus, valid_cpus)) @@ -202,8 +201,6 @@ enable_policy_freq_counters(int cpu, cpumask_var_t valid_cpus) amu_fie_cpus); cpufreq_cpu_put(policy); - - return true; } static DEFINE_STATIC_KEY_FALSE(amu_fie_key); @@ -212,7 +209,6 @@ static DEFINE_STATIC_KEY_FALSE(amu_fie_key); static int __init init_amu_fie(void) { cpumask_var_t valid_cpus; - bool have_policy = false; int ret = 0; int cpu; @@ -228,18 +224,9 @@ static int __init init_amu_fie(void) if (validate_cpu_freq_invariance_counters(cpu)) continue; cpumask_set_cpu(cpu, valid_cpus); - have_policy |= enable_policy_freq_counters(cpu, valid_cpus); + update_amu_fie_cpus(cpu, valid_cpus); } - /* - * If we are not restricted by cpufreq policies, we only enable - * the use of the AMU feature for FIE if all CPUs support AMU. - * Otherwise, enable_policy_freq_counters has already enabled - * policy cpus. - */ - if (!have_policy && cpumask_equal(valid_cpus, cpu_present_mask)) - cpumask_or(amu_fie_cpus, amu_fie_cpus, valid_cpus); - if (!cpumask_empty(amu_fie_cpus)) { pr_info("CPUs[%*pbl]: counters will be used for FIE.", cpumask_pr_args(amu_fie_cpus)); -- 2.25.0.rc1.19.g042ed3e048af
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