@@ -237,6 +237,80 @@ static int amd_set_hfi_ipcc_score(struct amd_hfi_cpuinfo *hfi_cpuinfo, int cpu)
return 0;
}
+static int amd_hfi_set_state(unsigned int cpu, bool state)
+{
+ int ret;
+
+ ret = wrmsrl_on_cpu(cpu, AMD_WORKLOAD_CLASS_CONFIG, state);
+ if (ret)
+ return ret;
+
+ return wrmsrl_on_cpu(cpu, AMD_WORKLOAD_HRST, 0x1);
+}
+
+/**
+ * amd_hfi_online() - Enable workload classification on @cpu
+ * @cpu: CPU in which the workload classification will be enabled
+ *
+ * Return: 0 on success, negative error code on failure
+ */
+static int amd_hfi_online(unsigned int cpu)
+{
+ struct amd_hfi_cpuinfo *hfi_info = per_cpu_ptr(&amd_hfi_cpuinfo, cpu);
+ struct amd_hfi_classes *hfi_classes;
+ int ret;
+
+ if (WARN_ON_ONCE(!hfi_info))
+ return -EINVAL;
+
+ /*
+ * Check if @cpu as an associated, initialized and ranking data must be filled
+ */
+ hfi_classes = hfi_info->amd_hfi_classes;
+ if (!hfi_classes)
+ return -EINVAL;
+
+ guard(mutex)(&hfi_cpuinfo_lock);
+
+ if (!zalloc_cpumask_var(&hfi_info->cpus, GFP_KERNEL))
+ return -ENOMEM;
+
+ cpumask_set_cpu(cpu, hfi_info->cpus);
+
+ ret = amd_hfi_set_state(cpu, true);
+ if (ret)
+ pr_err("WCT enable failed for CPU %d\n", cpu);
+
+ return ret;
+}
+
+/**
+ * amd_hfi_offline() - Disable workload classification on @cpu
+ * @cpu: CPU in which the workload classification will be disabled
+ *
+ * Remove @cpu from those covered by its HFI instance.
+ *
+ * Return: 0 on success, negative error code on failure
+ */
+static int amd_hfi_offline(unsigned int cpu)
+{
+ struct amd_hfi_cpuinfo *hfi_info = &per_cpu(amd_hfi_cpuinfo, cpu);
+ int ret;
+
+ if (WARN_ON_ONCE(!hfi_info))
+ return -EINVAL;
+
+ guard(mutex)(&hfi_cpuinfo_lock);
+
+ ret = amd_hfi_set_state(cpu, false);
+ if (ret)
+ pr_err("WCT disable failed for CPU %d\n", cpu);
+
+ free_cpumask_var(hfi_info->cpus);
+
+ return ret;
+}
+
static int update_hfi_ipcc_scores(void)
{
int cpu;
@@ -342,6 +416,11 @@ static int amd_hfi_probe(struct platform_device *pdev)
if (ret)
return ret;
+ ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/amd_hfi:online",
+ amd_hfi_online, amd_hfi_offline);
+ if (ret < 0)
+ return ret;
+
return 0;
}