/*
   * Intel Running Average Power Limit (RAPL) Driver
   * Copyright (c) 2013, Intel Corporation.
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms and conditions of the GNU General Public License,
   * version 2, as published by the Free Software Foundation.
   *
   * This program is distributed in the hope it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
   * more details.
   *
   * You should have received a copy of the GNU General Public License along with
   * this program; if not, write to the Free Software Foundation, Inc.
   *
   */
  #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 <asm/processor.h>
  #include <asm/cpu_device_id.h>
  
  /* bitmasks for RAPL MSRs, used by primitive access functions */
  #define ENERGY_STATUS_MASK      0xffffffff
  
  #define POWER_LIMIT1_MASK       0x7FFF
  #define POWER_LIMIT1_ENABLE     BIT(15)
  #define POWER_LIMIT1_CLAMP      BIT(16)
  
  #define POWER_LIMIT2_MASK       (0x7FFFULL<<32)
  #define POWER_LIMIT2_ENABLE     BIT_ULL(47)
  #define POWER_LIMIT2_CLAMP      BIT_ULL(48)
  #define POWER_PACKAGE_LOCK      BIT_ULL(63)
  #define POWER_PP_LOCK           BIT(31)
  
  #define TIME_WINDOW1_MASK       (0x7FULL<<17)
  #define TIME_WINDOW2_MASK       (0x7FULL<<49)
  
  #define POWER_UNIT_OFFSET	0
  #define POWER_UNIT_MASK		0x0F
  
  #define ENERGY_UNIT_OFFSET	0x08
  #define ENERGY_UNIT_MASK	0x1F00
  
  #define TIME_UNIT_OFFSET	0x10
  #define TIME_UNIT_MASK		0xF0000
  
  #define POWER_INFO_MAX_MASK     (0x7fffULL<<32)
  #define POWER_INFO_MIN_MASK     (0x7fffULL<<16)
  #define POWER_INFO_MAX_TIME_WIN_MASK     (0x3fULL<<48)
  #define POWER_INFO_THERMAL_SPEC_MASK     0x7fff
  
  #define PERF_STATUS_THROTTLE_TIME_MASK 0xffffffff
  #define PP_POLICY_MASK         0x1F
  
  /* Non HW constants */
  #define RAPL_PRIMITIVE_DERIVED       BIT(1) /* not from raw data */
  #define RAPL_PRIMITIVE_DUMMY         BIT(2)
  
  /* scale RAPL units to avoid floating point math inside kernel */
  #define POWER_UNIT_SCALE     (1000000)
  #define ENERGY_UNIT_SCALE    (1000000)
  #define TIME_UNIT_SCALE      (1000000)
  
  #define TIME_WINDOW_MAX_MSEC 40000
  #define TIME_WINDOW_MIN_MSEC 250
  
  enum unit_type {
  	ARBITRARY_UNIT, /* no translation */
  	POWER_UNIT,
  	ENERGY_UNIT,
  	TIME_UNIT,
  };
  
  enum rapl_domain_type {
  	RAPL_DOMAIN_PACKAGE, /* entire package/socket */
  	RAPL_DOMAIN_PP0, /* core power plane */
  	RAPL_DOMAIN_PP1, /* graphics uncore */
  	RAPL_DOMAIN_DRAM,/* DRAM control_type */
  	RAPL_DOMAIN_MAX,
  };
  
  enum rapl_domain_msr_id {
  	RAPL_DOMAIN_MSR_LIMIT,
  	RAPL_DOMAIN_MSR_STATUS,
  	RAPL_DOMAIN_MSR_PERF,
  	RAPL_DOMAIN_MSR_POLICY,
  	RAPL_DOMAIN_MSR_INFO,
  	RAPL_DOMAIN_MSR_MAX,
  };
  
  /* per domain data, some are optional */
  enum rapl_primitives {
  	ENERGY_COUNTER,
  	POWER_LIMIT1,
  	POWER_LIMIT2,
  	FW_LOCK,
  
  	PL1_ENABLE,  /* power limit 1, aka long term */
  	PL1_CLAMP,   /* allow frequency to go below OS request */
  	PL2_ENABLE,  /* power limit 2, aka short term, instantaneous */
  	PL2_CLAMP,
  
  	TIME_WINDOW1, /* long term */
  	TIME_WINDOW2, /* short term */
  	THERMAL_SPEC_POWER,
  	MAX_POWER,
  
  	MIN_POWER,
  	MAX_TIME_WINDOW,
  	THROTTLED_TIME,
  	PRIORITY_LEVEL,
  
  	/* below are not raw primitive data */
  	AVERAGE_POWER,
  	NR_RAPL_PRIMITIVES,
  };
  
  #define NR_RAW_PRIMITIVES (NR_RAPL_PRIMITIVES - 2)
  
  /* Can be expanded to include events, etc.*/
  struct rapl_domain_data {
  	u64 primitives[NR_RAPL_PRIMITIVES];
  	unsigned long timestamp;
  };
  
  
  #define	DOMAIN_STATE_INACTIVE           BIT(0)
  #define	DOMAIN_STATE_POWER_LIMIT_SET    BIT(1)
  #define DOMAIN_STATE_BIOS_LOCKED        BIT(2)
  
  #define NR_POWER_LIMITS (2)
  struct rapl_power_limit {
  	struct powercap_zone_constraint *constraint;
  	int prim_id; /* primitive ID used to enable */
  	struct rapl_domain *domain;
  	const char *name;
  };
  
  static const char pl1_name[] = "long_term";
  static const char pl2_name[] = "short_term";
  
  struct rapl_domain {
  	const char *name;
  	enum rapl_domain_type id;
  	int msrs[RAPL_DOMAIN_MSR_MAX];
  	struct powercap_zone power_zone;
  	struct rapl_domain_data rdd;
  	struct rapl_power_limit rpl[NR_POWER_LIMITS];
  	u64 attr_map; /* track capabilities */
  	unsigned int state;
  	int package_id;
  };
  #define power_zone_to_rapl_domain(_zone) \
  	container_of(_zone, struct rapl_domain, power_zone)
  
  
  /* Each physical package contains multiple domains, these are the common
   * data across RAPL domains within a package.
   */
  struct rapl_package {
  	unsigned int id; /* physical package/socket id */
  	unsigned int nr_domains;
  	unsigned long domain_map; /* bit map of active domains */
  	unsigned int power_unit_divisor;
  	unsigned int energy_unit_divisor;
  	unsigned int time_unit_divisor;
  	struct rapl_domain *domains; /* array of domains, sized at runtime */
  	struct powercap_zone *power_zone; /* keep track of parent zone */
  	int nr_cpus; /* active cpus on the package, topology info is lost during
  		      * cpu hotplug. so we have to track ourselves.
  		      */
  	unsigned long power_limit_irq; /* keep track of package power limit
  					* notify interrupt enable status.
  					*/
  	struct list_head plist;
  };
  #define PACKAGE_PLN_INT_SAVED   BIT(0)
  #define MAX_PRIM_NAME (32)
  
  /* per domain data. used to describe individual knobs such that access function
   * can be consolidated into one instead of many inline functions.
   */
  struct rapl_primitive_info {
  	const char *name;
  	u64 mask;
  	int shift;
  	enum rapl_domain_msr_id id;
  	enum unit_type unit;
  	u32 flag;
  };
  
  #define PRIMITIVE_INFO_INIT(p, m, s, i, u, f) {	\
  		.name = #p,			\
  		.mask = m,			\
  		.shift = s,			\
  		.id = i,			\
  		.unit = u,			\
  		.flag = f			\
  	}
  
  static void rapl_init_domains(struct rapl_package *rp);
  static int rapl_read_data_raw(struct rapl_domain *rd,
  			enum rapl_primitives prim,
  			bool xlate, u64 *data);
  static int rapl_write_data_raw(struct rapl_domain *rd,
  			enum rapl_primitives prim,
  			unsigned long long value);
  static u64 rapl_unit_xlate(int package, enum unit_type type, u64 value,
  			int to_raw);
  static void package_power_limit_irq_save(int package_id);
  
  static LIST_HEAD(rapl_packages); /* guarded by CPU hotplug lock */
  
  static const char * const rapl_domain_names[] = {
  	"package",
  	"core",
  	"uncore",
  	"dram",
  };
  
  static struct powercap_control_type *control_type; /* PowerCap Controller */
  
  /* caller to ensure CPU hotplug lock is held */
  static struct rapl_package *find_package_by_id(int id)
  {
  	struct rapl_package *rp;
  
  	list_for_each_entry(rp, &rapl_packages, plist) {
  		if (rp->id == id)
  			return rp;
  	}
  
  	return NULL;
  }
  
  /* caller to ensure CPU hotplug lock is held */
  static int find_active_cpu_on_package(int package_id)
  {
  	int i;
  
  	for_each_online_cpu(i) {
  		if (topology_physical_package_id(i) == package_id)
  			return i;
  	}
  	/* all CPUs on this package are offline */
  
  	return -ENODEV;
  }
  
  /* caller must hold cpu hotplug lock */
  static void rapl_cleanup_data(void)
  {
  	struct rapl_package *p, *tmp;
  
  	list_for_each_entry_safe(p, tmp, &rapl_packages, plist) {
  		kfree(p->domains);
  		list_del(&p->plist);
  		kfree(p);
  	}
  }
  
  static int get_energy_counter(struct powercap_zone *power_zone, u64 *energy_raw)
  {
  	struct rapl_domain *rd;
  	u64 energy_now;
  
  	/* prevent CPU hotplug, make sure the RAPL domain does not go
  	 * away while reading the counter.
  	 */
  	get_online_cpus();
  	rd = power_zone_to_rapl_domain(power_zone);
  
  	if (!rapl_read_data_raw(rd, ENERGY_COUNTER, true, &energy_now)) {
  		*energy_raw = energy_now;
  		put_online_cpus();
  
  		return 0;
  	}
  	put_online_cpus();
  
  	return -EIO;
  }
  
  static int get_max_energy_counter(struct powercap_zone *pcd_dev, u64 *energy)
  {
  	*energy = rapl_unit_xlate(0, ENERGY_UNIT, ENERGY_STATUS_MASK, 0);
  	return 0;
  }
  
  static int release_zone(struct powercap_zone *power_zone)
  {
  	struct rapl_domain *rd = power_zone_to_rapl_domain(power_zone);
  	struct rapl_package *rp;
  
  	/* package zone is the last zone of a package, we can free
  	 * memory here since all children has been unregistered.
  	 */
  	if (rd->id == RAPL_DOMAIN_PACKAGE) {
  		rp = find_package_by_id(rd->package_id);
  		if (!rp) {
  			dev_warn(&power_zone->dev, "no package id %s
  ",
  				rd->name);
  			return -ENODEV;
  		}
  		kfree(rd);
  		rp->domains = NULL;
  	}
  
  	return 0;
  
  }
  
  static int find_nr_power_limit(struct rapl_domain *rd)
  {
  	int i;
  
  	for (i = 0; i < NR_POWER_LIMITS; i++) {
  		if (rd->rpl[i].name == NULL)
  			break;
  	}
  
  	return i;
  }
  
  static int set_domain_enable(struct powercap_zone *power_zone, bool mode)
  {
  	struct rapl_domain *rd = power_zone_to_rapl_domain(power_zone);
  	int nr_powerlimit;
  
  	if (rd->state & DOMAIN_STATE_BIOS_LOCKED)
  		return -EACCES;
  	get_online_cpus();
  	nr_powerlimit = find_nr_power_limit(rd);
  	/* here we activate/deactivate the hardware for power limiting */
  	rapl_write_data_raw(rd, PL1_ENABLE, mode);
  	/* always enable clamp such that p-state can go below OS requested
  	 * range. power capping priority over guranteed frequency.
  	 */
  	rapl_write_data_raw(rd, PL1_CLAMP, mode);
  	/* some domains have pl2 */
  	if (nr_powerlimit > 1) {
  		rapl_write_data_raw(rd, PL2_ENABLE, mode);
  		rapl_write_data_raw(rd, PL2_CLAMP, mode);
  	}
  	put_online_cpus();
  
  	return 0;
  }
  
  static int get_domain_enable(struct powercap_zone *power_zone, bool *mode)
  {
  	struct rapl_domain *rd = power_zone_to_rapl_domain(power_zone);
  	u64 val;
  
  	if (rd->state & DOMAIN_STATE_BIOS_LOCKED) {
  		*mode = false;
  		return 0;
  	}
  	get_online_cpus();
  	if (rapl_read_data_raw(rd, PL1_ENABLE, true, &val)) {
  		put_online_cpus();
  		return -EIO;
  	}
  	*mode = val;
  	put_online_cpus();
  
  	return 0;
  }
  
  /* per RAPL domain ops, in the order of rapl_domain_type */
  static struct powercap_zone_ops zone_ops[] = {
  	/* RAPL_DOMAIN_PACKAGE */
  	{
  		.get_energy_uj = get_energy_counter,
  		.get_max_energy_range_uj = get_max_energy_counter,
  		.release = release_zone,
  		.set_enable = set_domain_enable,
  		.get_enable = get_domain_enable,
  	},
  	/* RAPL_DOMAIN_PP0 */
  	{
  		.get_energy_uj = get_energy_counter,
  		.get_max_energy_range_uj = get_max_energy_counter,
  		.release = release_zone,
  		.set_enable = set_domain_enable,
  		.get_enable = get_domain_enable,
  	},
  	/* RAPL_DOMAIN_PP1 */
  	{
  		.get_energy_uj = get_energy_counter,
  		.get_max_energy_range_uj = get_max_energy_counter,
  		.release = release_zone,
  		.set_enable = set_domain_enable,
  		.get_enable = get_domain_enable,
  	},
  	/* RAPL_DOMAIN_DRAM */
  	{
  		.get_energy_uj = get_energy_counter,
  		.get_max_energy_range_uj = get_max_energy_counter,
  		.release = release_zone,
  		.set_enable = set_domain_enable,
  		.get_enable = get_domain_enable,
  	},
  };
  
  static int set_power_limit(struct powercap_zone *power_zone, int id,
  			u64 power_limit)
  {
  	struct rapl_domain *rd;
  	struct rapl_package *rp;
  	int ret = 0;
  
  	get_online_cpus();
  	rd = power_zone_to_rapl_domain(power_zone);
  	rp = find_package_by_id(rd->package_id);
  	if (!rp) {
  		ret = -ENODEV;
  		goto set_exit;
  	}
  
  	if (rd->state & DOMAIN_STATE_BIOS_LOCKED) {
  		dev_warn(&power_zone->dev, "%s locked by BIOS, monitoring only
  ",
  			rd->name);
  		ret = -EACCES;
  		goto set_exit;
  	}
  
  	switch (rd->rpl[id].prim_id) {
  	case PL1_ENABLE:
  		rapl_write_data_raw(rd, POWER_LIMIT1, power_limit);
  		break;
  	case PL2_ENABLE:
  		rapl_write_data_raw(rd, POWER_LIMIT2, power_limit);
  		break;
  	default:
  		ret = -EINVAL;
  	}
  	if (!ret)
  		package_power_limit_irq_save(rd->package_id);
  set_exit:
  	put_online_cpus();
  	return ret;
  }
  
  static int get_current_power_limit(struct powercap_zone *power_zone, int id,
  					u64 *data)
  {
  	struct rapl_domain *rd;
  	u64 val;
  	int prim;
  	int ret = 0;
  
  	get_online_cpus();
  	rd = power_zone_to_rapl_domain(power_zone);
  	switch (rd->rpl[id].prim_id) {
  	case PL1_ENABLE:
  		prim = POWER_LIMIT1;
  		break;
  	case PL2_ENABLE:
  		prim = POWER_LIMIT2;
  		break;
  	default:
  		put_online_cpus();
  		return -EINVAL;
  	}
  	if (rapl_read_data_raw(rd, prim, true, &val))
  		ret = -EIO;
  	else
  		*data = val;
  
  	put_online_cpus();
  
  	return ret;
  }
  
  static int set_time_window(struct powercap_zone *power_zone, int id,
  								u64 window)
  {
  	struct rapl_domain *rd;
  	int ret = 0;
  
  	get_online_cpus();
  	rd = power_zone_to_rapl_domain(power_zone);
  	switch (rd->rpl[id].prim_id) {
  	case PL1_ENABLE:
  		rapl_write_data_raw(rd, TIME_WINDOW1, window);
  		break;
  	case PL2_ENABLE:
  		rapl_write_data_raw(rd, TIME_WINDOW2, window);
  		break;
  	default:
  		ret = -EINVAL;
  	}
  	put_online_cpus();
  	return ret;
  }
  
  static int get_time_window(struct powercap_zone *power_zone, int id, u64 *data)
  {
  	struct rapl_domain *rd;
  	u64 val;
  	int ret = 0;
  
  	get_online_cpus();
  	rd = power_zone_to_rapl_domain(power_zone);
  	switch (rd->rpl[id].prim_id) {
  	case PL1_ENABLE:
  		ret = rapl_read_data_raw(rd, TIME_WINDOW1, true, &val);
  		break;
  	case PL2_ENABLE:
  		ret = rapl_read_data_raw(rd, TIME_WINDOW2, true, &val);
  		break;
  	default:
  		put_online_cpus();
  		return -EINVAL;
  	}
  	if (!ret)
  		*data = val;
  	put_online_cpus();
  
  	return ret;
  }
  
  static const char *get_constraint_name(struct powercap_zone *power_zone, int id)
  {
  	struct rapl_power_limit *rpl;
  	struct rapl_domain *rd;
  
  	rd = power_zone_to_rapl_domain(power_zone);
  	rpl = (struct rapl_power_limit *) &rd->rpl[id];
  
  	return rpl->name;
  }
  
  
  static int get_max_power(struct powercap_zone *power_zone, int id,
  					u64 *data)
  {
  	struct rapl_domain *rd;
  	u64 val;
  	int prim;
  	int ret = 0;
  
  	get_online_cpus();
  	rd = power_zone_to_rapl_domain(power_zone);
  	switch (rd->rpl[id].prim_id) {
  	case PL1_ENABLE:
  		prim = THERMAL_SPEC_POWER;
  		break;
  	case PL2_ENABLE:
  		prim = MAX_POWER;
  		break;
  	default:
  		put_online_cpus();
  		return -EINVAL;
  	}
  	if (rapl_read_data_raw(rd, prim, true, &val))
  		ret = -EIO;
  	else
  		*data = val;
  
  	put_online_cpus();
  
  	return ret;
  }
  
  static struct powercap_zone_constraint_ops constraint_ops = {
  	.set_power_limit_uw = set_power_limit,
  	.get_power_limit_uw = get_current_power_limit,
  	.set_time_window_us = set_time_window,
  	.get_time_window_us = get_time_window,
  	.get_max_power_uw = get_max_power,
  	.get_name = get_constraint_name,
  };
  
  /* called after domain detection and package level data are set */
  static void rapl_init_domains(struct rapl_package *rp)
  {
  	int i;
  	struct rapl_domain *rd = rp->domains;
  
  	for (i = 0; i < RAPL_DOMAIN_MAX; i++) {
  		unsigned int mask = rp->domain_map & (1 << i);
  		switch (mask) {
  		case BIT(RAPL_DOMAIN_PACKAGE):
  			rd->name = rapl_domain_names[RAPL_DOMAIN_PACKAGE];
  			rd->id = RAPL_DOMAIN_PACKAGE;
  			rd->msrs[0] = MSR_PKG_POWER_LIMIT;
  			rd->msrs[1] = MSR_PKG_ENERGY_STATUS;
  			rd->msrs[2] = MSR_PKG_PERF_STATUS;
  			rd->msrs[3] = 0;
  			rd->msrs[4] = MSR_PKG_POWER_INFO;
  			rd->rpl[0].prim_id = PL1_ENABLE;
  			rd->rpl[0].name = pl1_name;
  			rd->rpl[1].prim_id = PL2_ENABLE;
  			rd->rpl[1].name = pl2_name;
  			break;
  		case BIT(RAPL_DOMAIN_PP0):
  			rd->name = rapl_domain_names[RAPL_DOMAIN_PP0];
  			rd->id = RAPL_DOMAIN_PP0;
  			rd->msrs[0] = MSR_PP0_POWER_LIMIT;
  			rd->msrs[1] = MSR_PP0_ENERGY_STATUS;
  			rd->msrs[2] = 0;
  			rd->msrs[3] = MSR_PP0_POLICY;
  			rd->msrs[4] = 0;
  			rd->rpl[0].prim_id = PL1_ENABLE;
  			rd->rpl[0].name = pl1_name;
  			break;
  		case BIT(RAPL_DOMAIN_PP1):
  			rd->name = rapl_domain_names[RAPL_DOMAIN_PP1];
  			rd->id = RAPL_DOMAIN_PP1;
  			rd->msrs[0] = MSR_PP1_POWER_LIMIT;
  			rd->msrs[1] = MSR_PP1_ENERGY_STATUS;
  			rd->msrs[2] = 0;
  			rd->msrs[3] = MSR_PP1_POLICY;
  			rd->msrs[4] = 0;
  			rd->rpl[0].prim_id = PL1_ENABLE;
  			rd->rpl[0].name = pl1_name;
  			break;
  		case BIT(RAPL_DOMAIN_DRAM):
  			rd->name = rapl_domain_names[RAPL_DOMAIN_DRAM];
  			rd->id = RAPL_DOMAIN_DRAM;
  			rd->msrs[0] = MSR_DRAM_POWER_LIMIT;
  			rd->msrs[1] = MSR_DRAM_ENERGY_STATUS;
  			rd->msrs[2] = MSR_DRAM_PERF_STATUS;
  			rd->msrs[3] = 0;
  			rd->msrs[4] = MSR_DRAM_POWER_INFO;
  			rd->rpl[0].prim_id = PL1_ENABLE;
  			rd->rpl[0].name = pl1_name;
  			break;
  		}
  		if (mask) {
  			rd->package_id = rp->id;
  			rd++;
  		}
  	}
  }
  
  static u64 rapl_unit_xlate(int package, enum unit_type type, u64 value,
  			int to_raw)
  {
  	u64 divisor = 1;
  	int scale = 1; /* scale to user friendly data without floating point */
  	u64 f, y; /* fraction and exp. used for time unit */
  	struct rapl_package *rp;
  
  	rp = find_package_by_id(package);
  	if (!rp)
  		return value;
  
  	switch (type) {
  	case POWER_UNIT:
  		divisor = rp->power_unit_divisor;
  		scale = POWER_UNIT_SCALE;
  		break;
  	case ENERGY_UNIT:
  		scale = ENERGY_UNIT_SCALE;
  		divisor = rp->energy_unit_divisor;
  		break;
  	case TIME_UNIT:
  		divisor = rp->time_unit_divisor;
  		scale = TIME_UNIT_SCALE;
  		/* special processing based on 2^Y*(1+F)/4 = val/divisor, refer
  		 * to Intel Software Developer's manual Vol. 3a, CH 14.7.4.
  		 */
  		if (!to_raw) {
  			f = (value & 0x60) >> 5;
  			y = value & 0x1f;
  			value = (1 << y) * (4 + f) * scale / 4;
  			return div64_u64(value, divisor);
  		} else {
  			do_div(value, scale);
  			value *= divisor;
  			y = ilog2(value);
  			f = div64_u64(4 * (value - (1 << y)), 1 << y);
  			value = (y & 0x1f) | ((f & 0x3) << 5);
  			return value;
  		}
  		break;
  	case ARBITRARY_UNIT:
  	default:
  		return value;
  	};
  
  	if (to_raw)
  		return div64_u64(value * divisor, scale);
  	else
  		return div64_u64(value * scale, divisor);
  }
  
  /* in the order of enum rapl_primitives */
  static struct rapl_primitive_info rpi[] = {
  	/* name, mask, shift, msr index, unit divisor */
  	PRIMITIVE_INFO_INIT(ENERGY_COUNTER, ENERGY_STATUS_MASK, 0,
  				RAPL_DOMAIN_MSR_STATUS, ENERGY_UNIT, 0),
  	PRIMITIVE_INFO_INIT(POWER_LIMIT1, POWER_LIMIT1_MASK, 0,
  				RAPL_DOMAIN_MSR_LIMIT, POWER_UNIT, 0),
  	PRIMITIVE_INFO_INIT(POWER_LIMIT2, POWER_LIMIT2_MASK, 32,
  				RAPL_DOMAIN_MSR_LIMIT, POWER_UNIT, 0),
  	PRIMITIVE_INFO_INIT(FW_LOCK, POWER_PP_LOCK, 31,
  				RAPL_DOMAIN_MSR_LIMIT, ARBITRARY_UNIT, 0),
  	PRIMITIVE_INFO_INIT(PL1_ENABLE, POWER_LIMIT1_ENABLE, 15,
  				RAPL_DOMAIN_MSR_LIMIT, ARBITRARY_UNIT, 0),
  	PRIMITIVE_INFO_INIT(PL1_CLAMP, POWER_LIMIT1_CLAMP, 16,
  				RAPL_DOMAIN_MSR_LIMIT, ARBITRARY_UNIT, 0),
  	PRIMITIVE_INFO_INIT(PL2_ENABLE, POWER_LIMIT2_ENABLE, 47,
  				RAPL_DOMAIN_MSR_LIMIT, ARBITRARY_UNIT, 0),
  	PRIMITIVE_INFO_INIT(PL2_CLAMP, POWER_LIMIT2_CLAMP, 48,
  				RAPL_DOMAIN_MSR_LIMIT, ARBITRARY_UNIT, 0),
  	PRIMITIVE_INFO_INIT(TIME_WINDOW1, TIME_WINDOW1_MASK, 17,
  				RAPL_DOMAIN_MSR_LIMIT, TIME_UNIT, 0),
  	PRIMITIVE_INFO_INIT(TIME_WINDOW2, TIME_WINDOW2_MASK, 49,
  				RAPL_DOMAIN_MSR_LIMIT, TIME_UNIT, 0),
  	PRIMITIVE_INFO_INIT(THERMAL_SPEC_POWER, POWER_INFO_THERMAL_SPEC_MASK,
  				0, RAPL_DOMAIN_MSR_INFO, POWER_UNIT, 0),
  	PRIMITIVE_INFO_INIT(MAX_POWER, POWER_INFO_MAX_MASK, 32,
  				RAPL_DOMAIN_MSR_INFO, POWER_UNIT, 0),
  	PRIMITIVE_INFO_INIT(MIN_POWER, POWER_INFO_MIN_MASK, 16,
  				RAPL_DOMAIN_MSR_INFO, POWER_UNIT, 0),
  	PRIMITIVE_INFO_INIT(MAX_TIME_WINDOW, POWER_INFO_MAX_TIME_WIN_MASK, 48,
  				RAPL_DOMAIN_MSR_INFO, TIME_UNIT, 0),
  	PRIMITIVE_INFO_INIT(THROTTLED_TIME, PERF_STATUS_THROTTLE_TIME_MASK, 0,
  				RAPL_DOMAIN_MSR_PERF, TIME_UNIT, 0),
  	PRIMITIVE_INFO_INIT(PRIORITY_LEVEL, PP_POLICY_MASK, 0,
  				RAPL_DOMAIN_MSR_POLICY, ARBITRARY_UNIT, 0),
  	/* non-hardware */
  	PRIMITIVE_INFO_INIT(AVERAGE_POWER, 0, 0, 0, POWER_UNIT,
  				RAPL_PRIMITIVE_DERIVED),
  	{NULL, 0, 0, 0},
  };
  
  /* Read primitive data based on its related struct rapl_primitive_info.
   * if xlate flag is set, return translated data based on data units, i.e.
   * time, energy, and power.
   * RAPL MSRs are non-architectual and are laid out not consistently across
   * domains. Here we use primitive info to allow writing consolidated access
   * functions.
   * For a given primitive, it is processed by MSR mask and shift. Unit conversion
   * is pre-assigned based on RAPL unit MSRs read at init time.
   * 63-------------------------- 31--------------------------- 0
   * |                           xxxxx (mask)                   |
   * |                                |<- shift ----------------|
   * 63-------------------------- 31--------------------------- 0
   */
  static int rapl_read_data_raw(struct rapl_domain *rd,
  			enum rapl_primitives prim,
  			bool xlate, u64 *data)
  {
  	u64 value, final;
  	u32 msr;
  	struct rapl_primitive_info *rp = &rpi[prim];
  	int cpu;
  
  	if (!rp->name || rp->flag & RAPL_PRIMITIVE_DUMMY)
  		return -EINVAL;
  
  	msr = rd->msrs[rp->id];
  	if (!msr)
  		return -EINVAL;
  	/* use physical package id to look up active cpus */
  	cpu = find_active_cpu_on_package(rd->package_id);
  	if (cpu < 0)
  		return cpu;
  
  	/* special-case package domain, which uses a different bit*/
  	if (prim == FW_LOCK && rd->id == RAPL_DOMAIN_PACKAGE) {
  		rp->mask = POWER_PACKAGE_LOCK;
  		rp->shift = 63;
  	}
  	/* non-hardware data are collected by the polling thread */
  	if (rp->flag & RAPL_PRIMITIVE_DERIVED) {
  		*data = rd->rdd.primitives[prim];
  		return 0;
  	}
  
  	if (rdmsrl_safe_on_cpu(cpu, msr, &value)) {
  		pr_debug("failed to read msr 0x%x on cpu %d
  ", msr, cpu);
  		return -EIO;
  	}
  
  	final = value & rp->mask;
  	final = final >> rp->shift;
  	if (xlate)
  		*data = rapl_unit_xlate(rd->package_id, rp->unit, final, 0);
  	else
  		*data = final;
  
  	return 0;
  }
  
  /* Similar use of primitive info in the read counterpart */
  static int rapl_write_data_raw(struct rapl_domain *rd,
  			enum rapl_primitives prim,
  			unsigned long long value)
  {
  	u64 msr_val;
  	u32 msr;
  	struct rapl_primitive_info *rp = &rpi[prim];
  	int cpu;
  
  	cpu = find_active_cpu_on_package(rd->package_id);
  	if (cpu < 0)
  		return cpu;
  	msr = rd->msrs[rp->id];
  	if (rdmsrl_safe_on_cpu(cpu, msr, &msr_val)) {
  		dev_dbg(&rd->power_zone.dev,
  			"failed to read msr 0x%x on cpu %d
  ", msr, cpu);
  		return -EIO;
  	}
  	value = rapl_unit_xlate(rd->package_id, rp->unit, value, 1);
  	msr_val &= ~rp->mask;
  	msr_val |= value << rp->shift;
  	if (wrmsrl_safe_on_cpu(cpu, msr, msr_val)) {
  		dev_dbg(&rd->power_zone.dev,
  			"failed to write msr 0x%x on cpu %d
  ", msr, cpu);
  		return -EIO;
  	}
  
  	return 0;
  }
  
  static const struct x86_cpu_id energy_unit_quirk_ids[] = {
  	{ X86_VENDOR_INTEL, 6, 0x37},/* VLV */
  	{}
  };
  
  static int rapl_check_unit(struct rapl_package *rp, int cpu)
  {
  	u64 msr_val;
  	u32 value;
  
  	if (rdmsrl_safe_on_cpu(cpu, MSR_RAPL_POWER_UNIT, &msr_val)) {
  		pr_err("Failed to read power unit MSR 0x%x on CPU %d, exit.
  ",
  			MSR_RAPL_POWER_UNIT, cpu);
  		return -ENODEV;
  	}
  
  	/* Raw RAPL data stored in MSRs are in certain scales. We need to
  	 * convert them into standard units based on the divisors reported in
  	 * the RAPL unit MSRs.
  	 * i.e.
  	 * energy unit: 1/enery_unit_divisor Joules
  	 * power unit: 1/power_unit_divisor Watts
  	 * time unit: 1/time_unit_divisor Seconds
  	 */
  	value = (msr_val & ENERGY_UNIT_MASK) >> ENERGY_UNIT_OFFSET;
  	/* some CPUs have different way to calculate energy unit */
  	if (x86_match_cpu(energy_unit_quirk_ids))
  		rp->energy_unit_divisor = 1000000 / (1 << value);
  	else
  		rp->energy_unit_divisor = 1 << value;
  
  	value = (msr_val & POWER_UNIT_MASK) >> POWER_UNIT_OFFSET;
  	rp->power_unit_divisor = 1 << value;
  
  	value = (msr_val & TIME_UNIT_MASK) >> TIME_UNIT_OFFSET;
  	rp->time_unit_divisor = 1 << value;
  
  	pr_debug("Physical package %d units: energy=%d, time=%d, power=%d
  ",
  		rp->id,
  		rp->energy_unit_divisor,
  		rp->time_unit_divisor,
  		rp->power_unit_divisor);
  
  	return 0;
  }
  
  /* REVISIT:
   * When package power limit is set artificially low by RAPL, LVT
   * thermal interrupt for package power limit should be ignored
   * since we are not really exceeding the real limit. The intention
   * is to avoid excessive interrupts while we are trying to save power.
   * A useful feature might be routing the package_power_limit interrupt
   * to userspace via eventfd. once we have a usecase, this is simple
   * to do by adding an atomic notifier.
   */
  
  static void package_power_limit_irq_save(int package_id)
  {
  	u32 l, h = 0;
  	int cpu;
  	struct rapl_package *rp;
  
  	rp = find_package_by_id(package_id);
  	if (!rp)
  		return;
  
  	if (!boot_cpu_has(X86_FEATURE_PTS) || !boot_cpu_has(X86_FEATURE_PLN))
  		return;
  
  	cpu = find_active_cpu_on_package(package_id);
  	if (cpu < 0)
  		return;
  	/* save the state of PLN irq mask bit before disabling it */
  	rdmsr_safe_on_cpu(cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT, &l, &h);
  	if (!(rp->power_limit_irq & PACKAGE_PLN_INT_SAVED)) {
  		rp->power_limit_irq = l & PACKAGE_THERM_INT_PLN_ENABLE;
  		rp->power_limit_irq |= PACKAGE_PLN_INT_SAVED;
  	}
  	l &= ~PACKAGE_THERM_INT_PLN_ENABLE;
  	wrmsr_on_cpu(cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
  }
  
  /* restore per package power limit interrupt enable state */
  static void package_power_limit_irq_restore(int package_id)
  {
  	u32 l, h;
  	int cpu;
  	struct rapl_package *rp;
  
  	rp = find_package_by_id(package_id);
  	if (!rp)
  		return;
  
  	if (!boot_cpu_has(X86_FEATURE_PTS) || !boot_cpu_has(X86_FEATURE_PLN))
  		return;
  
  	cpu = find_active_cpu_on_package(package_id);
  	if (cpu < 0)
  		return;
  
  	/* irq enable state not saved, nothing to restore */
  	if (!(rp->power_limit_irq & PACKAGE_PLN_INT_SAVED))
  		return;
  	rdmsr_safe_on_cpu(cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT, &l, &h);
  
  	if (rp->power_limit_irq & PACKAGE_THERM_INT_PLN_ENABLE)
  		l |= PACKAGE_THERM_INT_PLN_ENABLE;
  	else
  		l &= ~PACKAGE_THERM_INT_PLN_ENABLE;
  
  	wrmsr_on_cpu(cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
  }
  
  static const struct x86_cpu_id rapl_ids[] = {
  	{ X86_VENDOR_INTEL, 6, 0x2a},/* SNB */
  	{ X86_VENDOR_INTEL, 6, 0x2d},/* SNB EP */
  	{ X86_VENDOR_INTEL, 6, 0x37},/* VLV */
  	{ X86_VENDOR_INTEL, 6, 0x3a},/* IVB */
  	{ X86_VENDOR_INTEL, 6, 0x45},/* HSW */
  	/* TODO: Add more CPU IDs after testing */
  	{}
  };
  MODULE_DEVICE_TABLE(x86cpu, rapl_ids);
  
  /* read once for all raw primitive data for all packages, domains */
  static void rapl_update_domain_data(void)
  {
  	int dmn, prim;
  	u64 val;
  	struct rapl_package *rp;
  
  	list_for_each_entry(rp, &rapl_packages, plist) {
  		for (dmn = 0; dmn < rp->nr_domains; dmn++) {
  			pr_debug("update package %d domain %s data
  ", rp->id,
  				rp->domains[dmn].name);
  			/* exclude non-raw primitives */
  			for (prim = 0; prim < NR_RAW_PRIMITIVES; prim++)
  				if (!rapl_read_data_raw(&rp->domains[dmn], prim,
  								rpi[prim].unit,
  								&val))
  					rp->domains[dmn].rdd.primitives[prim] =
  									val;
  		}
  	}
  
  }
  
  static int rapl_unregister_powercap(void)
  {
  	struct rapl_package *rp;
  	struct rapl_domain *rd, *rd_package = NULL;
  
  	/* unregister all active rapl packages from the powercap layer,
  	 * hotplug lock held
  	 */
  	list_for_each_entry(rp, &rapl_packages, plist) {
  		package_power_limit_irq_restore(rp->id);
  
  		for (rd = rp->domains; rd < rp->domains + rp->nr_domains;
  		     rd++) {
  			pr_debug("remove package, undo power limit on %d: %s
  ",
  				rp->id, rd->name);
  			rapl_write_data_raw(rd, PL1_ENABLE, 0);
  			rapl_write_data_raw(rd, PL2_ENABLE, 0);
  			rapl_write_data_raw(rd, PL1_CLAMP, 0);
  			rapl_write_data_raw(rd, PL2_CLAMP, 0);
  			if (rd->id == RAPL_DOMAIN_PACKAGE) {
  				rd_package = rd;
  				continue;
  			}
  			powercap_unregister_zone(control_type, &rd->power_zone);
  		}
  		/* do the package zone last */
  		if (rd_package)
  			powercap_unregister_zone(control_type,
  						&rd_package->power_zone);
  	}
  	powercap_unregister_control_type(control_type);
  
  	return 0;
  }
  
  static int rapl_package_register_powercap(struct rapl_package *rp)
  {
  	struct rapl_domain *rd;
  	int ret = 0;
  	char dev_name[17]; /* max domain name = 7 + 1 + 8 for int + 1 for null*/
  	struct powercap_zone *power_zone = NULL;
  	int nr_pl;
  
  	/* first we register package domain as the parent zone*/
  	for (rd = rp->domains; rd < rp->domains + rp->nr_domains; rd++) {
  		if (rd->id == RAPL_DOMAIN_PACKAGE) {
  			nr_pl = find_nr_power_limit(rd);
  			pr_debug("register socket %d package domain %s
  ",
  				rp->id, rd->name);
  			memset(dev_name, 0, sizeof(dev_name));
  			snprintf(dev_name, sizeof(dev_name), "%s-%d",
  				rd->name, rp->id);
  			power_zone = powercap_register_zone(&rd->power_zone,
  							control_type,
  							dev_name, NULL,
  							&zone_ops[rd->id],
  							nr_pl,
  							&constraint_ops);
  			if (IS_ERR(power_zone)) {
  				pr_debug("failed to register package, %d
  ",
  					rp->id);
  				ret = PTR_ERR(power_zone);
  				goto exit_package;
  			}
  			/* track parent zone in per package/socket data */
  			rp->power_zone = power_zone;
  			/* done, only one package domain per socket */
  			break;
  		}
  	}
  	if (!power_zone) {
  		pr_err("no package domain found, unknown topology!
  ");
  		ret = -ENODEV;
  		goto exit_package;
  	}
  	/* now register domains as children of the socket/package*/
  	for (rd = rp->domains; rd < rp->domains + rp->nr_domains; rd++) {
  		if (rd->id == RAPL_DOMAIN_PACKAGE)
  			continue;
  		/* number of power limits per domain varies */
  		nr_pl = find_nr_power_limit(rd);
  		power_zone = powercap_register_zone(&rd->power_zone,
  						control_type, rd->name,
  						rp->power_zone,
  						&zone_ops[rd->id], nr_pl,
  						&constraint_ops);
  
  		if (IS_ERR(power_zone)) {
  			pr_debug("failed to register power_zone, %d:%s:%s
  ",
  				rp->id, rd->name, dev_name);
  			ret = PTR_ERR(power_zone);
  			goto err_cleanup;
  		}
  	}
  
  exit_package:
  	return ret;
  err_cleanup:
  	/* clean up previously initialized domains within the package if we
  	 * failed after the first domain setup.
  	 */
  	while (--rd >= rp->domains) {
  		pr_debug("unregister package %d domain %s
  ", rp->id, rd->name);
  		powercap_unregister_zone(control_type, &rd->power_zone);
  	}
  
  	return ret;
  }
  
  static int rapl_register_powercap(void)
  {
  	struct rapl_domain *rd;
  	struct rapl_package *rp;
  	int ret = 0;
  
  	control_type = powercap_register_control_type(NULL, "intel-rapl", NULL);
  	if (IS_ERR(control_type)) {
  		pr_debug("failed to register powercap control_type.
  ");
  		return PTR_ERR(control_type);
  	}
  	/* read the initial data */
  	rapl_update_domain_data();
  	list_for_each_entry(rp, &rapl_packages, plist)
  		if (rapl_package_register_powercap(rp))
  			goto err_cleanup_package;
  	return ret;
  
  err_cleanup_package:
  	/* clean up previously initialized packages */
  	list_for_each_entry_continue_reverse(rp, &rapl_packages, plist) {
  		for (rd = rp->domains; rd < rp->domains + rp->nr_domains;
  		     rd++) {
  			pr_debug("unregister zone/package %d, %s domain
  ",
  				rp->id, rd->name);
  			powercap_unregister_zone(control_type, &rd->power_zone);
  		}
  	}
  
  	return ret;
  }
  
  static int rapl_check_domain(int cpu, int domain)
  {
  	unsigned msr;
  	u64 val1, val2 = 0;
  	int retry = 0;
  
  	switch (domain) {
  	case RAPL_DOMAIN_PACKAGE:
  		msr = MSR_PKG_ENERGY_STATUS;
  		break;
  	case RAPL_DOMAIN_PP0:
  		msr = MSR_PP0_ENERGY_STATUS;
  		break;
  	case RAPL_DOMAIN_PP1:
  		msr = MSR_PP1_ENERGY_STATUS;
  		break;
  	case RAPL_DOMAIN_DRAM:
  		msr = MSR_DRAM_ENERGY_STATUS;
  		break;
  	default:
  		pr_err("invalid domain id %d
  ", domain);
  		return -EINVAL;
  	}
  	if (rdmsrl_safe_on_cpu(cpu, msr, &val1))
  		return -ENODEV;
  
  	/* energy counters roll slowly on some domains */
  	while (++retry < 10) {
  		usleep_range(10000, 15000);
  		rdmsrl_safe_on_cpu(cpu, msr, &val2);
  		if ((val1 & ENERGY_STATUS_MASK) != (val2 & ENERGY_STATUS_MASK))
  			return 0;
  	}
  	/* if energy counter does not change, report as bad domain */
  	pr_info("domain %s energy ctr %llu:%llu not working, skip
  ",
  		rapl_domain_names[domain], val1, val2);
  
  	return -ENODEV;
  }
  
  /* Detect active and valid domains for the given CPU, caller must
   * ensure the CPU belongs to the targeted package and CPU hotlug is disabled.
   */
  static int rapl_detect_domains(struct rapl_package *rp, int cpu)
  {
  	int i;
  	int ret = 0;
  	struct rapl_domain *rd;
  	u64 locked;
  
  	for (i = 0; i < RAPL_DOMAIN_MAX; i++) {
  		/* use physical package id to read counters */
  		if (!rapl_check_domain(cpu, i))
  			rp->domain_map |= 1 << i;
  	}
  	rp->nr_domains = bitmap_weight(&rp->domain_map,	RAPL_DOMAIN_MAX);
  	if (!rp->nr_domains) {
  		pr_err("no valid rapl domains found in package %d
  ", rp->id);
  		ret = -ENODEV;
  		goto done;
  	}
  	pr_debug("found %d domains on package %d
  ", rp->nr_domains, rp->id);
  
  	rp->domains = kcalloc(rp->nr_domains + 1, sizeof(struct rapl_domain),
  			GFP_KERNEL);
  	if (!rp->domains) {
  		ret = -ENOMEM;
  		goto done;
  	}
  	rapl_init_domains(rp);
  
  	for (rd = rp->domains; rd < rp->domains + rp->nr_domains; rd++) {
  		/* check if the domain is locked by BIOS */
  		if (rapl_read_data_raw(rd, FW_LOCK, false, &locked)) {
  			pr_info("RAPL package %d domain %s locked by BIOS
  ",
  				rp->id, rd->name);
  				rd->state |= DOMAIN_STATE_BIOS_LOCKED;
  		}
  	}
  
  
  done:
  	return ret;
  }
  
  static bool is_package_new(int package)
  {
  	struct rapl_package *rp;
  
  	/* caller prevents cpu hotplug, there will be no new packages added
  	 * or deleted while traversing the package list, no need for locking.
  	 */
  	list_for_each_entry(rp, &rapl_packages, plist)
  		if (package == rp->id)
  			return false;
  
  	return true;
  }
  
  /* RAPL interface can be made of a two-level hierarchy: package level and domain
   * level. We first detect the number of packages then domains of each package.
   * We have to consider the possiblity of CPU online/offline due to hotplug and
   * other scenarios.
   */
  static int rapl_detect_topology(void)
  {
  	int i;
  	int phy_package_id;
  	struct rapl_package *new_package, *rp;
  
  	for_each_online_cpu(i) {
  		phy_package_id = topology_physical_package_id(i);
  		if (is_package_new(phy_package_id)) {
  			new_package = kzalloc(sizeof(*rp), GFP_KERNEL);
  			if (!new_package) {
  				rapl_cleanup_data();
  				return -ENOMEM;
  			}
  			/* add the new package to the list */
  			new_package->id = phy_package_id;
  			new_package->nr_cpus = 1;
  
  			/* check if the package contains valid domains */
  			if (rapl_detect_domains(new_package, i) ||
  				rapl_check_unit(new_package, i)) {
  				kfree(new_package->domains);
  				kfree(new_package);
  				/* free up the packages already initialized */
  				rapl_cleanup_data();
  				return -ENODEV;
  			}
  			INIT_LIST_HEAD(&new_package->plist);
  			list_add(&new_package->plist, &rapl_packages);
  		} else {
  			rp = find_package_by_id(phy_package_id);
  			if (rp)
  				++rp->nr_cpus;
  		}
  	}
  
  	return 0;
  }
  
  /* called from CPU hotplug notifier, hotplug lock held */
  static void rapl_remove_package(struct rapl_package *rp)
  {
  	struct rapl_domain *rd, *rd_package = NULL;
  
  	for (rd = rp->domains; rd < rp->domains + rp->nr_domains; rd++) {
  		if (rd->id == RAPL_DOMAIN_PACKAGE) {
  			rd_package = rd;
  			continue;
  		}
  		pr_debug("remove package %d, %s domain
  ", rp->id, rd->name);
  		powercap_unregister_zone(control_type, &rd->power_zone);
  	}
  	/* do parent zone last */
  	powercap_unregister_zone(control_type, &rd_package->power_zone);
  	list_del(&rp->plist);
  	kfree(rp);
  }
  
  /* called from CPU hotplug notifier, hotplug lock held */
  static int rapl_add_package(int cpu)
  {
  	int ret = 0;
  	int phy_package_id;
  	struct rapl_package *rp;
  
  	phy_package_id = topology_physical_package_id(cpu);
  	rp = kzalloc(sizeof(struct rapl_package), GFP_KERNEL);
  	if (!rp)
  		return -ENOMEM;
  
  	/* add the new package to the list */
  	rp->id = phy_package_id;
  	rp->nr_cpus = 1;
  	/* check if the package contains valid domains */
  	if (rapl_detect_domains(rp, cpu) ||
  		rapl_check_unit(rp, cpu)) {
  		ret = -ENODEV;
  		goto err_free_package;
  	}
  	if (!rapl_package_register_powercap(rp)) {
  		INIT_LIST_HEAD(&rp->plist);
  		list_add(&rp->plist, &rapl_packages);
  		return ret;
  	}
  
  err_free_package:
  	kfree(rp->domains);
  	kfree(rp);
  
  	return ret;
  }
  
  /* 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_callback(struct notifier_block *nfb,
  				unsigned long action, void *hcpu)
  {
  	unsigned long cpu = (unsigned long)hcpu;
  	int phy_package_id;
  	struct rapl_package *rp;
  
  	phy_package_id = topology_physical_package_id(cpu);
  	switch (action) {
  	case CPU_ONLINE:
  	case CPU_ONLINE_FROZEN:
  	case CPU_DOWN_FAILED:
  	case CPU_DOWN_FAILED_FROZEN:
  		rp = find_package_by_id(phy_package_id);
  		if (rp)
  			++rp->nr_cpus;
  		else
  			rapl_add_package(cpu);
  		break;
  	case CPU_DOWN_PREPARE:
  	case CPU_DOWN_PREPARE_FROZEN:
  		rp = find_package_by_id(phy_package_id);
  		if (!rp)
  			break;
  		if (--rp->nr_cpus == 0)
  			rapl_remove_package(rp);
  	}
  
  	return NOTIFY_OK;
  }
  
  static struct notifier_block rapl_cpu_notifier = {
  	.notifier_call = rapl_cpu_callback,
  };
  
  static int __init rapl_init(void)
  {
  	int ret = 0;
  
  	if (!x86_match_cpu(rapl_ids)) {
  		pr_err("driver does not support CPU family %d model %d
  ",
  			boot_cpu_data.x86, boot_cpu_data.x86_model);
  
  		return -ENODEV;
  	}
  	/* prevent CPU hotplug during detection */
  	get_online_cpus();
  	ret = rapl_detect_topology();
  	if (ret)
  		goto done;
  
  	if (rapl_register_powercap()) {
  		rapl_cleanup_data();
  		ret = -ENODEV;
  		goto done;
  	}
  	register_hotcpu_notifier(&rapl_cpu_notifier);
  done:
  	put_online_cpus();
  
  	return ret;
  }
  
  static void __exit rapl_exit(void)
  {
  	get_online_cpus();
  	unregister_hotcpu_notifier(&rapl_cpu_notifier);
  	rapl_unregister_powercap();
  	rapl_cleanup_data();
  	put_online_cpus();
  }
  
  module_init(rapl_init);
  module_exit(rapl_exit);
  
  MODULE_DESCRIPTION("Driver for Intel RAPL (Running Average Power Limit)");
  MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@intel.com>");
  MODULE_LICENSE("GPL v2");