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Subject[PATCH 2/3] introduce intel_rapl driver
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Introduce Intel RAPL driver.

RAPL (running average power limit) is a new feature which provides mechanisms
to enforce power consumption limit, on some new processors.

RAPL provides MSRs reporting the total amount of energy consumed
by the package/core/uncore/dram.
Further more, by using RAPL, OS can set a power bugdet in a certain time window,
and let Hardware to throttle the processor P/T-state to meet this enery limitation.

Currently, we don't have the plan to support the RAPL power control,
but we do want to export the package/core/uncore/dram power consumption
information via perf tool first.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
---
drivers/platform/x86/Kconfig | 8
drivers/platform/x86/Makefile | 1
drivers/platform/x86/intel_rapl.c | 368 ++++++++++++++++++++++++++++++++++++++
include/linux/perf_event.h | 4
4 files changed, 381 insertions(+)

Index: linux-2.6/drivers/platform/x86/Kconfig
===================================================================
--- linux-2.6.orig/drivers/platform/x86/Kconfig
+++ linux-2.6/drivers/platform/x86/Kconfig
@@ -753,4 +753,12 @@ config SAMSUNG_LAPTOP
To compile this driver as a module, choose M here: the module
will be called samsung-laptop.

+config INTEL_RAPL
+ tristate "Intel RAPL Support"
+ depends on X86
+ default y
+ ---help---
+ RAPL, AKA, Running Average Power Limit provides mechanisms to enforce
+ power consumption limit.
+
endif # X86_PLATFORM_DEVICES
Index: linux-2.6/drivers/platform/x86/Makefile
===================================================================
--- linux-2.6.orig/drivers/platform/x86/Makefile
+++ linux-2.6/drivers/platform/x86/Makefile
@@ -42,3 +42,4 @@ obj-$(CONFIG_XO15_EBOOK) += xo15-ebook.o
obj-$(CONFIG_IBM_RTL) += ibm_rtl.o
obj-$(CONFIG_SAMSUNG_LAPTOP) += samsung-laptop.o
obj-$(CONFIG_INTEL_MFLD_THERMAL) += intel_mid_thermal.o
+obj-$(CONFIG_INTEL_RAPL) += intel_rapl.o
Index: linux-2.6/include/linux/perf_event.h
===================================================================
--- linux-2.6.orig/include/linux/perf_event.h
+++ linux-2.6/include/linux/perf_event.h
@@ -107,6 +107,10 @@ enum perf_sw_ids {
PERF_COUNT_SW_PAGE_FAULTS_MAJ = 6,
PERF_COUNT_SW_ALIGNMENT_FAULTS = 7,
PERF_COUNT_SW_EMULATION_FAULTS = 8,
+ PERF_COUNT_SW_PKG_ENERGY = 9,
+ PERF_COUNT_SW_CORE_ENERGY = 10,
+ PERF_COUNT_SW_UNCORE_ENERGY = 11,
+ PERF_COUNT_SW_DRAM_ENERGY = 12,

PERF_COUNT_SW_MAX, /* non-ABI */
};
Index: linux-2.6/drivers/platform/x86/intel_rapl.c
===================================================================
--- /dev/null
+++ linux-2.6/drivers/platform/x86/intel_rapl.c
@@ -0,0 +1,368 @@
+/*
+ * Intel RAPL interface driver
+ *
+ * Copyright (C) 2010-2011 Zhang Rui <rui.zhang@intel.com>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that 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.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/list.h>
+#include <asm/processor.h>
+#include <linux/perf_event.h>
+
+MODULE_AUTHOR("Zhang Rui");
+MODULE_DESCRIPTION("Intel RAPL interface Driver");
+MODULE_LICENSE("GPL");
+
+#define PREFIX "Intel: RAPL: "
+
+#define MSR_RAPL_POWER_UNIT 0x606
+
+/*
+ * Platform specific RAPL Domains.
+ * Note that PP1 RAPL Domain is supported on 062A only
+ * And DRAM RAPL Domain is supported on 062D only
+ */
+/* Package RAPL Domain */
+#define MSR_PKG_RAPL_POWER_LIMIT 0x610
+#define MSR_PKG_ENERGY_STATUS 0x611
+#define MSR_PKG_PERF_STATUS 0x613
+#define MSR_PKG_POWER_INFO 0x614
+
+/* PP0 RAPL Domain */
+#define MSR_PP0_POWER_LIMIT 0x638
+#define MSR_PP0_ENERGY_STATUS 0x639
+#define MSR_PP0_POLICY 0x63A
+#define MSR_PP0_PERF_STATUS 0x63B
+
+/* PP1 RAPL Domain, may reflect to uncore devices */
+#define MSR_PP1_POWER_LIMIT 0x640
+#define MSR_PP1_ENERGY_STATUS 0x641
+#define MSR_PP1_POLICY 0x642
+
+/* DRAM RAPL Domain */
+#define MSR_DRAM_POWER_LIMIT 0x618
+#define MSR_DRAM_ENERGY_STATUS 0x619
+#define MSR_DRAM_PERF_STATUS 0x61B
+#define MSR_DRAM_POWER_INFO 0x61C
+
+/* RAPL UNIT BITMASK */
+#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 0xF000
+
+static int rapl_pmu_pkg_event_init(struct perf_event *event);
+static int rapl_pmu_core_event_init(struct perf_event *event);
+static int rapl_pmu_uncore_event_init(struct perf_event *event);
+static int rapl_pmu_dram_event_init(struct perf_event *event);
+static void rapl_event_start(struct perf_event *event, int flags);
+static void rapl_event_stop(struct perf_event *event, int flags);
+static int rapl_event_add(struct perf_event *event, int flags);
+static void rapl_event_del(struct perf_event *event, int flags);
+static void rapl_event_read(struct perf_event *event);
+
+enum rapl_domain_id {
+ RAPL_DOMAIN_PKG,
+ RAPL_DOMAIN_PP0,
+ RAPL_DOMAIN_PP1,
+ RAPL_DOMAIN_DRAM,
+ RAPL_DOMAIN_MAX
+};
+
+struct rapl_domain_msr {
+ int limit;
+ int status;
+};
+
+struct rapl_domain {
+ enum rapl_domain_id domain_id;
+ struct rapl_domain_msr msrs;
+ struct pmu pmu;
+ enum perf_sw_ids event_id;
+ int valid;
+};
+
+#define to_rapl_domain(p) container_of(p, struct rapl_domain, pmu);
+
+static struct rapl_domain rapl_domains[] = {
+ [RAPL_DOMAIN_PKG] = {
+ .domain_id = RAPL_DOMAIN_PKG,
+ .msrs = {
+ .limit = MSR_PKG_RAPL_POWER_LIMIT,
+ .status = MSR_PKG_ENERGY_STATUS,
+ },
+ .pmu = {
+ .name = "rapl_pkg_energy_meter",
+ .event_init = rapl_pmu_pkg_event_init,
+ .add = rapl_event_add,
+ .del = rapl_event_del,
+ .start = rapl_event_start,
+ .stop = rapl_event_stop,
+ .read = rapl_event_read,
+ },
+ .event_id = PERF_COUNT_SW_PKG_ENERGY,
+ .valid = 1,
+ },
+ [RAPL_DOMAIN_PP0] = {
+ .domain_id = RAPL_DOMAIN_PP0,
+ .msrs = {
+ .limit = MSR_PP0_POWER_LIMIT,
+ .status = MSR_PP0_ENERGY_STATUS,
+ },
+ .pmu = {
+ .name = "rapl_core_energy_meter",
+ .event_init = rapl_pmu_core_event_init,
+ .add = rapl_event_add,
+ .del = rapl_event_del,
+ .start = rapl_event_start,
+ .stop = rapl_event_stop,
+ .read = rapl_event_read,
+ },
+ .event_id = PERF_COUNT_SW_CORE_ENERGY,
+ .valid = 1,
+ },
+ [RAPL_DOMAIN_PP1] = {
+ .domain_id = RAPL_DOMAIN_PP1,
+ .msrs = {
+ .limit = MSR_PP1_POWER_LIMIT,
+ .status = MSR_PP1_ENERGY_STATUS,
+ },
+ .pmu = {
+ .name = "rapl_uncore_energy_meter",
+ .event_init = rapl_pmu_uncore_event_init,
+ .add = rapl_event_add,
+ .del = rapl_event_del,
+ .start = rapl_event_start,
+ .stop = rapl_event_stop,
+ .read = rapl_event_read,
+ },
+ .event_id = PERF_COUNT_SW_UNCORE_ENERGY,
+ },
+ [RAPL_DOMAIN_DRAM] = {
+ .domain_id = RAPL_DOMAIN_DRAM,
+ .msrs = {
+ .limit = MSR_DRAM_POWER_LIMIT,
+ .status = MSR_DRAM_ENERGY_STATUS,
+ },
+ .pmu = {
+ .name = "rapl_dram_energy_meter",
+ .event_init = rapl_pmu_dram_event_init,
+ .add = rapl_event_add,
+ .del = rapl_event_del,
+ .start = rapl_event_start,
+ .stop = rapl_event_stop,
+ .read = rapl_event_read,
+ },
+ .event_id = PERF_COUNT_SW_DRAM_ENERGY,
+ },
+};
+
+static unsigned int power_unit_divisor;
+static unsigned int energy_unit_divisor;
+static unsigned int time_unit_divisor;
+
+enum unit_type {
+ POWER_UNIT,
+ ENERGY_UNIT,
+ TIME_UNIT
+};
+static u64 rapl_unit_xlate(enum unit_type type, u64 value, int action)
+{
+ u64 divisor;
+
+ switch (type) {
+ case POWER_UNIT:
+ divisor = power_unit_divisor;
+ break;
+ case ENERGY_UNIT:
+ divisor = energy_unit_divisor;
+ break;
+ case TIME_UNIT:
+ divisor = time_unit_divisor;
+ break;
+ default:
+ return 0;
+ };
+
+ if (action)
+ return value * divisor; /* value is from users */
+ else
+ return div64_u64(value, divisor); /* value is from MSR */
+}
+
+/* show the energy status, in Jelous */
+static int rapl_read_energy(struct rapl_domain *domain)
+{
+ u64 value;
+ u32 msr = domain->msrs.status;
+
+ rdmsrl(msr, value);
+ return rapl_unit_xlate(ENERGY_UNIT, value, 0);
+}
+
+static void rapl_event_update(struct perf_event *event)
+{
+ s64 prev;
+ u64 now;
+ struct rapl_domain *domain = to_rapl_domain(event->pmu);
+
+ now = rapl_read_energy(domain);
+ prev = local64_xchg(&event->hw.prev_count, now);
+ local64_add(now - prev, &event->count);
+}
+
+static void rapl_event_start(struct perf_event *event, int flags)
+{
+ struct rapl_domain *domain = to_rapl_domain(event->pmu);
+
+ local64_set(&event->hw.prev_count, rapl_read_energy(domain));
+ perf_swevent_start_hrtimer(event);
+}
+
+static void rapl_event_stop(struct perf_event *event, int flags)
+{
+ perf_swevent_cancel_hrtimer(event);
+ rapl_event_update(event);
+}
+
+static int rapl_event_add(struct perf_event *event, int flags)
+{
+ if (flags & PERF_EF_START)
+ rapl_event_start(event, flags);
+ return 0;
+}
+static void rapl_event_del(struct perf_event *event, int flags)
+{
+ rapl_event_stop(event, flags);
+}
+
+static void rapl_event_read(struct perf_event *event)
+{
+ rapl_event_update(event);
+}
+
+static int rapl_pmu_event_init(struct perf_event *event,
+ enum rapl_domain_id id)
+{
+ struct rapl_domain *domain = &(rapl_domains[id]);
+
+ if (event->attr.type != PERF_TYPE_SOFTWARE)
+ return -ENOENT;
+
+ if (event->attr.config != domain->event_id)
+ return -ENOENT;
+
+ /* Do periodecal update every second */
+ event->attr.freq = 1;
+ event->attr.sample_period = 1;
+
+ perf_swevent_init_hrtimer(event);
+
+ return 0;
+}
+
+static int rapl_pmu_pkg_event_init(struct perf_event *event)
+{
+ return rapl_pmu_event_init(event, RAPL_DOMAIN_PKG);
+}
+
+static int rapl_pmu_core_event_init(struct perf_event *event)
+{
+ return rapl_pmu_event_init(event, RAPL_DOMAIN_PP0);
+}
+
+static int rapl_pmu_uncore_event_init(struct perf_event *event)
+{
+ return rapl_pmu_event_init(event, RAPL_DOMAIN_PP1);
+}
+
+static int rapl_pmu_dram_event_init(struct perf_event *event)
+{
+ return rapl_pmu_event_init(event, RAPL_DOMAIN_DRAM);
+}
+
+static int rapl_check_unit(void)
+{
+ u64 output;
+ u32 value;
+
+ rdmsrl(MSR_RAPL_POWER_UNIT, output);
+
+ /* energy unit: 1/enery_unit_divisor Joules */
+ value = (output & ENERGY_UNIT_MASK) >> ENERGY_UNIT_OFFSET;
+ energy_unit_divisor = 1 << value;
+
+ /* power unit: 1/power_unit_divisor Watts */
+ value = (output & POWER_UNIT_MASK) >> POWER_UNIT_OFFSET;
+ power_unit_divisor = 1 << value;
+
+ /* time unit: 1/time_unit_divisor Seconds */
+ value =(output & TIME_UNIT_MASK) >> TIME_UNIT_OFFSET;
+ time_unit_divisor = 1 << value;
+
+ return 0;
+}
+
+static int __init intel_rapl_init(void)
+{
+ enum rapl_domain_id id;
+
+ /*
+ * RAPL features are only supported on processors have a CPUID
+ * signature with DisplayFamily_DisplayModel of 06_2AH, 06_2DH
+ */
+ if (boot_cpu_data.x86 != 0x06)
+ return -ENODEV;
+
+ if (boot_cpu_data.x86_model == 0x2A)
+ rapl_domains[RAPL_DOMAIN_PP1].valid = 1;
+ else if (boot_cpu_data.x86_model == 0x2D)
+ rapl_domains[RAPL_DOMAIN_DRAM].valid = 1;
+ else
+ return -ENODEV;
+
+ if (rapl_check_unit())
+ return -ENODEV;
+
+ for(id = 0; id < RAPL_DOMAIN_MAX; id++)
+ if (rapl_domains[id].valid)
+ perf_pmu_register(&(rapl_domains[id].pmu), rapl_domains[id].pmu.name, PERF_TYPE_SOFTWARE);
+ return 0;
+}
+
+static void __exit intel_rapl_exit(void)
+{
+ enum rapl_domain_id id;
+
+ for(id = 0; id < RAPL_DOMAIN_MAX; id++)
+ if (rapl_domains[id].valid)
+ perf_pmu_unregister(&(rapl_domains[id].pmu));
+}
+
+module_init(intel_rapl_init);
+module_exit(intel_rapl_exit);



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