intel_rapl: abstract RAPL common code

Split intel_rapl.c to intel_rapl_common.c and intel_rapl_msr.c, where
intel_rapl_common.c contains the common code that can be used by both MSR
and MMIO interface.
intel_rapl_msr.c contains the implementation of RAPL MSR interface.
Reviewed-by: Pandruvada, Srinivas <srinivas.pandruvada@intel.com>
Tested-by: Pandruvada, Srinivas <srinivas.pandruvada@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/powercap/Kconfig

@@ -16,14 +16,17 @@ menuconfig POWERCAP
 
 if POWERCAP
 # Client driver configurations go here.
+config INTEL_RAPL_CORE
+	tristate
+
 config INTEL_RAPL
-	tristate "Intel RAPL Support"
+	tristate "Intel RAPL Support via MSR Interface"
 	depends on X86 && IOSF_MBI
-	default n
+	select INTEL_RAPL_CORE
 	---help---
 	  This enables support for the Intel Running Average Power Limit (RAPL)
-	  technology which allows power limits to be enforced and monitored on
-	  modern Intel processors (Sandy Bridge and later).
+	  technology via MSR interface, which allows power limits to be enforced
+	  and monitored on modern Intel processors (Sandy Bridge and later).
 
 	  In RAPL, the platform level settings are divided into domains for
 	  fine grained control. These domains include processor package, DRAM

drivers/powercap/Makefile

 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_POWERCAP)	+= powercap_sys.o
-obj-$(CONFIG_INTEL_RAPL) += intel_rapl.o
+obj-$(CONFIG_INTEL_RAPL_CORE) += intel_rapl_common.o
+obj-$(CONFIG_INTEL_RAPL) += intel_rapl_msr.o
 obj-$(CONFIG_IDLE_INJECT) += idle_inject.o

drivers/powercap/intel_rapl_msr.c

+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Intel Running Average Power Limit (RAPL) Driver via MSR interface
+ * Copyright (c) 2019, Intel Corporation.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/log2.h>
+#include <linux/bitmap.h>
+#include <linux/delay.h>
+#include <linux/sysfs.h>
+#include <linux/cpu.h>
+#include <linux/powercap.h>
+#include <linux/suspend.h>
+#include <linux/intel_rapl.h>
+#include <linux/processor.h>
+
+#include <asm/iosf_mbi.h>
+#include <asm/cpu_device_id.h>
+#include <asm/intel-family.h>
+
+/* Local defines */
+#define MSR_PLATFORM_POWER_LIMIT	0x0000065C
+
+/* private data for RAPL MSR Interface */
+static struct rapl_if_priv rapl_msr_priv = {
+	.reg_unit = MSR_RAPL_POWER_UNIT,
+	.regs[RAPL_DOMAIN_PACKAGE] = {
+		MSR_PKG_POWER_LIMIT, MSR_PKG_ENERGY_STATUS, MSR_PKG_PERF_STATUS, 0, MSR_PKG_POWER_INFO },
+	.regs[RAPL_DOMAIN_PP0] = {
+		MSR_PP0_POWER_LIMIT, MSR_PP0_ENERGY_STATUS, 0, MSR_PP0_POLICY, 0 },
+	.regs[RAPL_DOMAIN_PP1] = {
+		MSR_PP1_POWER_LIMIT, MSR_PP1_ENERGY_STATUS, 0, MSR_PP1_POLICY, 0 },
+	.regs[RAPL_DOMAIN_DRAM] = {
+		MSR_DRAM_POWER_LIMIT, MSR_DRAM_ENERGY_STATUS, MSR_DRAM_PERF_STATUS, 0, MSR_DRAM_POWER_INFO },
+	.regs[RAPL_DOMAIN_PLATFORM] = {
+		MSR_PLATFORM_POWER_LIMIT, MSR_PLATFORM_ENERGY_STATUS, 0, 0, 0},
+};
+
+/* Handles CPU hotplug on multi-socket systems.
+ * If a CPU goes online as the first CPU of the physical package
+ * we add the RAPL package to the system. Similarly, when the last
+ * CPU of the package is removed, we remove the RAPL package and its
+ * associated domains. Cooling devices are handled accordingly at
+ * per-domain level.
+ */
+static int rapl_cpu_online(unsigned int cpu)
+{
+	struct rapl_package *rp;
+
+	rp = rapl_find_package_domain(cpu, &rapl_msr_priv);
+	if (!rp) {
+		rp = rapl_add_package(cpu, &rapl_msr_priv);
+		if (IS_ERR(rp))
+			return PTR_ERR(rp);
+	}
+	cpumask_set_cpu(cpu, &rp->cpumask);
+	return 0;
+}
+
+static int rapl_cpu_down_prep(unsigned int cpu)
+{
+	struct rapl_package *rp;
+	int lead_cpu;
+
+	rp = rapl_find_package_domain(cpu, &rapl_msr_priv);
+	if (!rp)
+		return 0;
+
+	cpumask_clear_cpu(cpu, &rp->cpumask);
+	lead_cpu = cpumask_first(&rp->cpumask);
+	if (lead_cpu >= nr_cpu_ids)
+		rapl_remove_package(rp);
+	else if (rp->lead_cpu == cpu)
+		rp->lead_cpu = lead_cpu;
+	return 0;
+}
+
+static int rapl_msr_read_raw(int cpu, struct reg_action *ra)
+{
+	if (rdmsrl_safe_on_cpu(cpu, ra->reg, &ra->value)) {
+		pr_debug("failed to read msr 0x%x on cpu %d\n", ra->reg, cpu);
+		return -EIO;
+	}
+	ra->value &= ra->mask;
+	return 0;
+}
+
+static void rapl_msr_update_func(void *info)
+{
+	struct reg_action *ra = info;
+	u64 val;
+
+	ra->err = rdmsrl_safe(ra->reg, &val);
+	if (ra->err)
+		return;
+
+	val &= ~ra->mask;
+	val |= ra->value;
+
+	ra->err = wrmsrl_safe(ra->reg, val);
+}
+
+static int rapl_msr_write_raw(int cpu, struct reg_action *ra)
+{
+	int ret;
+
+	ret = smp_call_function_single(cpu, rapl_msr_update_func, ra, 1);
+	if (WARN_ON_ONCE(ret))
+		return ret;
+
+	return ra->err;
+}
+
+static int __init rapl_msr_init(void)
+{
+	int ret;
+
+	rapl_msr_priv.read_raw = rapl_msr_read_raw;
+	rapl_msr_priv.write_raw = rapl_msr_write_raw;
+
+	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;
+
+	/* Don't bail out if PSys is not supported */
+	rapl_add_platform_domain(&rapl_msr_priv);
+
+	return 0;
+
+out:
+	if (ret)
+		powercap_unregister_control_type(rapl_msr_priv.control_type);
+	return ret;
+}
+
+static void __exit rapl_msr_exit(void)
+{
+	cpuhp_remove_state(rapl_msr_priv.pcap_rapl_online);
+	rapl_remove_platform_domain(&rapl_msr_priv);
+	powercap_unregister_control_type(rapl_msr_priv.control_type);
+}
+
+module_init(rapl_msr_init);
+module_exit(rapl_msr_exit);
+
+MODULE_DESCRIPTION("Driver for Intel RAPL (Running Average Power Limit) control via MSR interface");
+MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>");
+MODULE_LICENSE("GPL v2");

include/linux/intel_rapl.h

@@ -142,4 +142,11 @@ struct rapl_package {
 	struct rapl_if_priv *priv;
 };
 
+struct rapl_package *rapl_find_package_domain(int cpu, struct rapl_if_priv *priv);
+struct rapl_package *rapl_add_package(int cpu, struct rapl_if_priv *priv);
+void rapl_remove_package(struct rapl_package *rp);
+
+int rapl_add_platform_domain(struct rapl_if_priv *priv);
+void rapl_remove_platform_domain(struct rapl_if_priv *priv);
+
 #endif /* __INTEL_RAPL_H__ */