Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / powercap / intel_rapl.c
diff --git a/kernel/drivers/powercap/intel_rapl.c b/kernel/drivers/powercap/intel_rapl.c
new file mode 100644 (file)
index 0000000..fd24323
--- /dev/null
@@ -0,0 +1,1523 @@
+/*
+ * 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/iosf_mbi.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)
+
+#define TIME_WINDOW_MAX_MSEC 40000
+#define TIME_WINDOW_MIN_MSEC 250
+#define ENERGY_UNIT_SCALE    1000 /* scale from driver unit to powercap unit */
+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;
+       unsigned int domain_energy_unit;
+       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;
+       unsigned int energy_unit;
+       unsigned int time_unit;
+       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;
+};
+
+struct rapl_defaults {
+       int (*check_unit)(struct rapl_package *rp, int cpu);
+       void (*set_floor_freq)(struct rapl_domain *rd, bool mode);
+       u64 (*compute_time_window)(struct rapl_package *rp, u64 val,
+                               bool to_raw);
+       unsigned int dram_domain_energy_unit;
+};
+static struct rapl_defaults *rapl_defaults;
+
+/* Sideband MBI registers */
+#define IOSF_CPU_POWER_BUDGET_CTL (0x2)
+
+#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(struct rapl_domain *rd, 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)
+{
+       struct rapl_domain *rd = power_zone_to_rapl_domain(pcd_dev);
+
+       *energy = rapl_unit_xlate(rd, 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\n",
+                               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);
+
+       if (rd->state & DOMAIN_STATE_BIOS_LOCKED)
+               return -EACCES;
+
+       get_online_cpus();
+       rapl_write_data_raw(rd, PL1_ENABLE, mode);
+       rapl_defaults->set_floor_freq(rd, 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\n",
+                       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;
+                       rd->domain_energy_unit =
+                               rapl_defaults->dram_domain_energy_unit;
+                       if (rd->domain_energy_unit)
+                               pr_info("DRAM domain energy unit %dpj\n",
+                                       rd->domain_energy_unit);
+                       break;
+               }
+               if (mask) {
+                       rd->package_id = rp->id;
+                       rd++;
+               }
+       }
+}
+
+static u64 rapl_unit_xlate(struct rapl_domain *rd, int package,
+                       enum unit_type type, u64 value,
+                       int to_raw)
+{
+       u64 units = 1;
+       struct rapl_package *rp;
+       u64 scale = 1;
+
+       rp = find_package_by_id(package);
+       if (!rp)
+               return value;
+
+       switch (type) {
+       case POWER_UNIT:
+               units = rp->power_unit;
+               break;
+       case ENERGY_UNIT:
+               scale = ENERGY_UNIT_SCALE;
+               /* per domain unit takes precedence */
+               if (rd && rd->domain_energy_unit)
+                       units = rd->domain_energy_unit;
+               else
+                       units = rp->energy_unit;
+               break;
+       case TIME_UNIT:
+               return rapl_defaults->compute_time_window(rp, value, to_raw);
+       case ARBITRARY_UNIT:
+       default:
+               return value;
+       };
+
+       if (to_raw)
+               return div64_u64(value, units) * scale;
+
+       value *= units;
+
+       return div64_u64(value, scale);
+}
+
+/* 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\n", msr, cpu);
+               return -EIO;
+       }
+
+       final = value & rp->mask;
+       final = final >> rp->shift;
+       if (xlate)
+               *data = rapl_unit_xlate(rd, 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\n", msr, cpu);
+               return -EIO;
+       }
+       value = rapl_unit_xlate(rd, 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\n", msr, cpu);
+               return -EIO;
+       }
+
+       return 0;
+}
+
+/*
+ * Raw RAPL data stored in MSRs are in certain scales. We need to
+ * convert them into standard units based on the units reported in
+ * the RAPL unit MSRs. This is specific to CPUs as the method to
+ * calculate units differ on different CPUs.
+ * We convert the units to below format based on CPUs.
+ * i.e.
+ * energy unit: picoJoules  : Represented in picoJoules by default
+ * power unit : microWatts  : Represented in milliWatts by default
+ * time unit  : microseconds: Represented in seconds by default
+ */
+static int rapl_check_unit_core(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.\n",
+                       MSR_RAPL_POWER_UNIT, cpu);
+               return -ENODEV;
+       }
+
+       value = (msr_val & ENERGY_UNIT_MASK) >> ENERGY_UNIT_OFFSET;
+       rp->energy_unit = ENERGY_UNIT_SCALE * 1000000 / (1 << value);
+
+       value = (msr_val & POWER_UNIT_MASK) >> POWER_UNIT_OFFSET;
+       rp->power_unit = 1000000 / (1 << value);
+
+       value = (msr_val & TIME_UNIT_MASK) >> TIME_UNIT_OFFSET;
+       rp->time_unit = 1000000 / (1 << value);
+
+       pr_debug("Core CPU package %d energy=%dpJ, time=%dus, power=%duW\n",
+               rp->id, rp->energy_unit, rp->time_unit, rp->power_unit);
+
+       return 0;
+}
+
+static int rapl_check_unit_atom(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.\n",
+                       MSR_RAPL_POWER_UNIT, cpu);
+               return -ENODEV;
+       }
+       value = (msr_val & ENERGY_UNIT_MASK) >> ENERGY_UNIT_OFFSET;
+       rp->energy_unit = ENERGY_UNIT_SCALE * 1 << value;
+
+       value = (msr_val & POWER_UNIT_MASK) >> POWER_UNIT_OFFSET;
+       rp->power_unit = (1 << value) * 1000;
+
+       value = (msr_val & TIME_UNIT_MASK) >> TIME_UNIT_OFFSET;
+       rp->time_unit = 1000000 / (1 << value);
+
+       pr_debug("Atom package %d energy=%dpJ, time=%dus, power=%duW\n",
+               rp->id, rp->energy_unit, rp->time_unit, rp->power_unit);
+
+       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 void set_floor_freq_default(struct rapl_domain *rd, bool mode)
+{
+       int nr_powerlimit = find_nr_power_limit(rd);
+
+       /* 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);
+       }
+}
+
+static void set_floor_freq_atom(struct rapl_domain *rd, bool enable)
+{
+       static u32 power_ctrl_orig_val;
+       u32 mdata;
+
+       if (!power_ctrl_orig_val)
+               iosf_mbi_read(BT_MBI_UNIT_PMC, BT_MBI_PMC_READ,
+                       IOSF_CPU_POWER_BUDGET_CTL, &power_ctrl_orig_val);
+       mdata = power_ctrl_orig_val;
+       if (enable) {
+               mdata &= ~(0x7f << 8);
+               mdata |= 1 << 8;
+       }
+       iosf_mbi_write(BT_MBI_UNIT_PMC, BT_MBI_PMC_WRITE,
+               IOSF_CPU_POWER_BUDGET_CTL, mdata);
+}
+
+static u64 rapl_compute_time_window_core(struct rapl_package *rp, u64 value,
+                                       bool to_raw)
+{
+       u64 f, y; /* fraction and exp. used for time unit */
+
+       /*
+        * Special processing based on 2^Y*(1+F/4), refer
+        * to Intel Software Developer's manual Vol.3B: CH 14.9.3.
+        */
+       if (!to_raw) {
+               f = (value & 0x60) >> 5;
+               y = value & 0x1f;
+               value = (1 << y) * (4 + f) * rp->time_unit / 4;
+       } else {
+               do_div(value, rp->time_unit);
+               y = ilog2(value);
+               f = div64_u64(4 * (value - (1 << y)), 1 << y);
+               value = (y & 0x1f) | ((f & 0x3) << 5);
+       }
+       return value;
+}
+
+static u64 rapl_compute_time_window_atom(struct rapl_package *rp, u64 value,
+                                       bool to_raw)
+{
+       /*
+        * Atom time unit encoding is straight forward val * time_unit,
+        * where time_unit is default to 1 sec. Never 0.
+        */
+       if (!to_raw)
+               return (value) ? value *= rp->time_unit : rp->time_unit;
+       else
+               value = div64_u64(value, rp->time_unit);
+
+       return value;
+}
+
+static const struct rapl_defaults rapl_defaults_core = {
+       .check_unit = rapl_check_unit_core,
+       .set_floor_freq = set_floor_freq_default,
+       .compute_time_window = rapl_compute_time_window_core,
+};
+
+static const struct rapl_defaults rapl_defaults_hsw_server = {
+       .check_unit = rapl_check_unit_core,
+       .set_floor_freq = set_floor_freq_default,
+       .compute_time_window = rapl_compute_time_window_core,
+       .dram_domain_energy_unit = 15300,
+};
+
+static const struct rapl_defaults rapl_defaults_atom = {
+       .check_unit = rapl_check_unit_atom,
+       .set_floor_freq = set_floor_freq_atom,
+       .compute_time_window = rapl_compute_time_window_atom,
+};
+
+#define RAPL_CPU(_model, _ops) {                       \
+               .vendor = X86_VENDOR_INTEL,             \
+               .family = 6,                            \
+               .model = _model,                        \
+               .driver_data = (kernel_ulong_t)&_ops,   \
+               }
+
+static const struct x86_cpu_id rapl_ids[] __initconst = {
+       RAPL_CPU(0x2a, rapl_defaults_core),/* Sandy Bridge */
+       RAPL_CPU(0x2d, rapl_defaults_core),/* Sandy Bridge EP */
+       RAPL_CPU(0x37, rapl_defaults_atom),/* Valleyview */
+       RAPL_CPU(0x3a, rapl_defaults_core),/* Ivy Bridge */
+       RAPL_CPU(0x3c, rapl_defaults_core),/* Haswell */
+       RAPL_CPU(0x3d, rapl_defaults_core),/* Broadwell */
+       RAPL_CPU(0x3f, rapl_defaults_hsw_server),/* Haswell servers */
+       RAPL_CPU(0x4f, rapl_defaults_hsw_server),/* Broadwell servers */
+       RAPL_CPU(0x45, rapl_defaults_core),/* Haswell ULT */
+       RAPL_CPU(0x4E, rapl_defaults_core),/* Skylake */
+       RAPL_CPU(0x4C, rapl_defaults_atom),/* Braswell */
+       RAPL_CPU(0x4A, rapl_defaults_atom),/* Tangier */
+       RAPL_CPU(0x56, rapl_defaults_core),/* Future Xeon */
+       RAPL_CPU(0x5A, rapl_defaults_atom),/* Annidale */
+       {}
+};
+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\n", 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\n",
+                               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\n",
+                               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\n",
+                                       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!\n");
+               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\n",
+                               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\n", 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.\n");
+               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\n",
+                               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 val = 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\n", domain);
+               return -EINVAL;
+       }
+       /* make sure domain counters are available and contains non-zero
+        * values, otherwise skip it.
+        */
+       if (rdmsrl_safe_on_cpu(cpu, msr, &val) || !val)
+               return -ENODEV;
+
+       return 0;
+}
+
+/* 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;
+                       pr_info("Found RAPL domain %s\n", rapl_domain_names[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\n", rp->id);
+               ret = -ENODEV;
+               goto done;
+       }
+       pr_debug("found %d domains on package %d\n", 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\n",
+                               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_defaults->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\n", 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_defaults->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;
+       const struct x86_cpu_id *id;
+
+       id = x86_match_cpu(rapl_ids);
+       if (!id) {
+               pr_err("driver does not support CPU family %d model %d\n",
+                       boot_cpu_data.x86, boot_cpu_data.x86_model);
+
+               return -ENODEV;
+       }
+
+       rapl_defaults = (struct rapl_defaults *)id->driver_data;
+
+       cpu_notifier_register_begin();
+
+       /* 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();
+       cpu_notifier_register_done();
+
+       return ret;
+}
+
+static void __exit rapl_exit(void)
+{
+       cpu_notifier_register_begin();
+       get_online_cpus();
+       __unregister_hotcpu_notifier(&rapl_cpu_notifier);
+       rapl_unregister_powercap();
+       rapl_cleanup_data();
+       put_online_cpus();
+       cpu_notifier_register_done();
+}
+
+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");