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-rw-r--r--drivers/powercap/Kconfig13
-rw-r--r--drivers/powercap/Makefile1
-rw-r--r--drivers/powercap/intel_rapl.c1395
3 files changed, 1409 insertions, 0 deletions
diff --git a/drivers/powercap/Kconfig b/drivers/powercap/Kconfig
index a37055e..a7c81b5 100644
--- a/drivers/powercap/Kconfig
+++ b/drivers/powercap/Kconfig
@@ -15,5 +15,18 @@ menuconfig POWERCAP
if POWERCAP
# Client driver configurations go here.
+config INTEL_RAPL
+ tristate "Intel RAPL Support"
+ depends on X86
+ default n
+ ---help---
+ This enables support for the Intel Running Average Power Limit (RAPL)
+ technology which allows power limits to be enforced and monitored on
+ modern Intel processors (Sandy Bridge and later).
+
+ In RAPL, the platform level settings are divided into domains for
+ fine grained control. These domains include processor package, DRAM
+ controller, CPU core (Power Plance 0), graphics uncore (Power Plane
+ 1), etc.
endif
diff --git a/drivers/powercap/Makefile b/drivers/powercap/Makefile
index 6defbc8..0a21ef3 100644
--- a/drivers/powercap/Makefile
+++ b/drivers/powercap/Makefile
@@ -1 +1,2 @@
obj-$(CONFIG_POWERCAP) += powercap_sys.o
+obj-$(CONFIG_INTEL_RAPL) += intel_rapl.o
diff --git a/drivers/powercap/intel_rapl.c b/drivers/powercap/intel_rapl.c
new file mode 100644
index 0000000..2a786c5
--- /dev/null
+++ b/drivers/powercap/intel_rapl.c
@@ -0,0 +1,1395 @@
+/*
+ * 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\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);
+ 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\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;
+ 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\n", 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\n", 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\n", msr, cpu);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+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.\n",
+ 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;
+ 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\n",
+ 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, 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\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 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\n", 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\n",
+ 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\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_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_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\n",
+ 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");
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