static int rapl_msr_probe()

in intel_rapl_msr.c [146:191]

• 40 lines of code
• 8 McCabe index (conditional complexity)

static int rapl_msr_probe(struct platform_device *pdev)
{
	const struct x86_cpu_id *id = x86_match_cpu(pl4_support_ids);
	int ret;

	switch (boot_cpu_data.x86_vendor) {
	case X86_VENDOR_INTEL:
		rapl_msr_priv = &rapl_msr_priv_intel;
		break;
	case X86_VENDOR_HYGON:
	case X86_VENDOR_AMD:
		rapl_msr_priv = &rapl_msr_priv_amd;
		break;
	default:
		pr_err("intel-rapl does not support CPU vendor %d\n", boot_cpu_data.x86_vendor);
		return -ENODEV;
	}
	rapl_msr_priv->read_raw = rapl_msr_read_raw;
	rapl_msr_priv->write_raw = rapl_msr_write_raw;

	if (id) {
		rapl_msr_priv->limits[RAPL_DOMAIN_PACKAGE] = 3;
		rapl_msr_priv->regs[RAPL_DOMAIN_PACKAGE][RAPL_DOMAIN_REG_PL4] =
			MSR_VR_CURRENT_CONFIG;
		pr_info("PL4 support detected.\n");
	}

	rapl_msr_priv->control_type = powercap_register_control_type(NULL, "intel-rapl", NULL);
	if (IS_ERR(rapl_msr_priv->control_type)) {
		pr_debug("failed to register powercap control_type.\n");
		return PTR_ERR(rapl_msr_priv->control_type);
	}

	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "powercap/rapl:online",
				rapl_cpu_online, rapl_cpu_down_prep);
	if (ret < 0)
		goto out;
	rapl_msr_priv->pcap_rapl_online = ret;

	return 0;

out:
	if (ret)
		powercap_unregister_control_type(rapl_msr_priv->control_type);
	return ret;
}