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authorWill Deacon <will@kernel.org>2021-02-12 18:15:53 +0300
committerWill Deacon <will@kernel.org>2021-02-12 18:15:53 +0300
commitdcabe10d97f51d0ceca4ef54e607de85d665546f (patch)
tree0ea0f644d8539a58e4482f4680134370f68c4eda /arch/arm64
parentd23fa87cde1dcdcc892d385a7bb5eb6f0420b917 (diff)
parenta5f1b187cd24f7da35eb7a48fc50839c554d52a2 (diff)
downloadlinux-dcabe10d97f51d0ceca4ef54e607de85d665546f.tar.xz
Merge branch 'for-next/topology' into for-next/core
Cleanup to the AMU support code and initialisation rework to support cpufreq drivers built as modules. * for-next/topology: arm64: topology: Make AMUs work with modular cpufreq drivers arm64: topology: Reorder init_amu_fie() a bit arm64: topology: Avoid the have_policy check
Diffstat (limited to 'arch/arm64')
-rw-r--r--arch/arm64/kernel/topology.c115
1 files changed, 56 insertions, 59 deletions
diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c
index f6faa697e83e..e08a4126453a 100644
--- a/arch/arm64/kernel/topology.c
+++ b/arch/arm64/kernel/topology.c
@@ -199,76 +199,38 @@ static int freq_inv_set_max_ratio(int cpu, u64 max_rate, u64 ref_rate)
return 0;
}
-static inline bool
-enable_policy_freq_counters(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;
- }
-
- if (cpumask_subset(policy->related_cpus, valid_cpus))
- cpumask_or(amu_fie_cpus, policy->related_cpus,
- amu_fie_cpus);
-
- cpufreq_cpu_put(policy);
-
- return true;
-}
-
static DEFINE_STATIC_KEY_FALSE(amu_fie_key);
#define amu_freq_invariant() static_branch_unlikely(&amu_fie_key)
-static int __init init_amu_fie(void)
+static void amu_fie_setup(const struct cpumask *cpus)
{
- bool invariance_status = topology_scale_freq_invariant();
- cpumask_var_t valid_cpus;
- bool have_policy = false;
- int ret = 0;
+ bool invariant;
int cpu;
- if (!zalloc_cpumask_var(&valid_cpus, GFP_KERNEL))
- return -ENOMEM;
-
- if (!zalloc_cpumask_var(&amu_fie_cpus, GFP_KERNEL)) {
- ret = -ENOMEM;
- goto free_valid_mask;
- }
+ /* We are already set since the last insmod of cpufreq driver */
+ if (unlikely(cpumask_subset(cpus, amu_fie_cpus)))
+ return;
- for_each_present_cpu(cpu) {
+ for_each_cpu(cpu, cpus) {
if (!freq_counters_valid(cpu) ||
freq_inv_set_max_ratio(cpu,
cpufreq_get_hw_max_freq(cpu) * 1000,
arch_timer_get_rate()))
- continue;
-
- cpumask_set_cpu(cpu, valid_cpus);
- have_policy |= enable_policy_freq_counters(cpu, valid_cpus);
+ return;
}
- /*
- * 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);
+ cpumask_or(amu_fie_cpus, amu_fie_cpus, cpus);
- if (!cpumask_empty(amu_fie_cpus)) {
- pr_info("CPUs[%*pbl]: counters will be used for FIE.",
- cpumask_pr_args(amu_fie_cpus));
- static_branch_enable(&amu_fie_key);
- }
+ invariant = topology_scale_freq_invariant();
- /*
- * If the system is not fully invariant after AMU init, disable
- * partial use of counters for frequency invariance.
- */
- if (!topology_scale_freq_invariant())
- static_branch_disable(&amu_fie_key);
+ /* We aren't fully invariant yet */
+ if (!invariant && !cpumask_equal(amu_fie_cpus, cpu_present_mask))
+ return;
+
+ static_branch_enable(&amu_fie_key);
+
+ pr_debug("CPUs[%*pbl]: counters will be used for FIE.",
+ cpumask_pr_args(cpus));
/*
* Task scheduler behavior depends on frequency invariance support,
@@ -276,15 +238,50 @@ static int __init init_amu_fie(void)
* a result of counter initialisation and use, retrigger the build of
* scheduling domains to ensure the information is propagated properly.
*/
- if (invariance_status != topology_scale_freq_invariant())
+ if (!invariant)
rebuild_sched_domains_energy();
+}
+
+static int init_amu_fie_callback(struct notifier_block *nb, unsigned long val,
+ void *data)
+{
+ struct cpufreq_policy *policy = data;
+
+ if (val == CPUFREQ_CREATE_POLICY)
+ amu_fie_setup(policy->related_cpus);
+
+ /*
+ * We don't need to handle CPUFREQ_REMOVE_POLICY event as the AMU
+ * counters don't have any dependency on cpufreq driver once we have
+ * initialized AMU support and enabled invariance. The AMU counters will
+ * keep on working just fine in the absence of the cpufreq driver, and
+ * for the CPUs for which there are no counters available, the last set
+ * value of freq_scale will remain valid as that is the frequency those
+ * CPUs are running at.
+ */
+
+ return 0;
+}
+
+static struct notifier_block init_amu_fie_notifier = {
+ .notifier_call = init_amu_fie_callback,
+};
+
+static int __init init_amu_fie(void)
+{
+ int ret;
+
+ if (!zalloc_cpumask_var(&amu_fie_cpus, GFP_KERNEL))
+ return -ENOMEM;
-free_valid_mask:
- free_cpumask_var(valid_cpus);
+ ret = cpufreq_register_notifier(&init_amu_fie_notifier,
+ CPUFREQ_POLICY_NOTIFIER);
+ if (ret)
+ free_cpumask_var(amu_fie_cpus);
return ret;
}
-late_initcall_sync(init_amu_fie);
+core_initcall(init_amu_fie);
bool arch_freq_counters_available(const struct cpumask *cpus)
{