by Fenghua Yu

[permalink] [raw]

Subject: [tip:x86/hwmon] x86, hwmon: Package Level Thermal/Power: power limit

Commit-ID: 0199114c31798af5b83841b21759b64171060d9b
Gitweb: http://git.kernel.org/tip/0199114c31798af5b83841b21759b64171060d9b
Author: Fenghua Yu <[email protected]>
AuthorDate: Thu, 29 Jul 2010 17:13:45 -0700
Committer: H. Peter Anvin <[email protected]>
CommitDate: Tue, 3 Aug 2010 15:58:56 -0700

x86, hwmon: Package Level Thermal/Power: power limit

Power limit notification feature is published in Intel 64 and IA-32
Architectures SDMV Vol 3A 14.5.6 Power Limit Notification.

It is implemented first on Intel Sandy Bridge platform.

The patch handles notification interrupt. Interrupt handler dumps power limit
information in log_buf, logs the event in mce log, and increases the event
counters (core_power_limit and package_power_limit). Upper level applications
could use the data to detect system health or diagnose functionality/performance
issues.

In the future, the event could be handled in a more fancy way.

Signed-off-by: Fenghua Yu <[email protected]>
LKML-Reference: <[email protected]>
Reviewed-by: Len Brown <[email protected]>
Signed-off-by: H. Peter Anvin <[email protected]>
---
arch/x86/kernel/cpu/mcheck/therm_throt.c | 183 +++++++++++++++++++++---------
1 files changed, 129 insertions(+), 54 deletions(-)

diff --git a/arch/x86/kernel/cpu/mcheck/therm_throt.c b/arch/x86/kernel/cpu/mcheck/therm_throt.c
index d307f9f..c2a8b26 100644
--- a/arch/x86/kernel/cpu/mcheck/therm_throt.c
+++ b/arch/x86/kernel/cpu/mcheck/therm_throt.c
@@ -34,20 +34,25 @@
/* How long to wait between reporting thermal events */
#define CHECK_INTERVAL (300 * HZ)

+#define THERMAL_THROTTLING_EVENT 0
+#define POWER_LIMIT_EVENT 1
+
/*
- * Current thermal throttling state:
+ * Current thermal event state:
*/
struct _thermal_state {
- bool is_throttled;
-
+ bool new_event;
+ int event;
u64 next_check;
- unsigned long throttle_count;
- unsigned long last_throttle_count;
+ unsigned long count;
+ unsigned long last_count;
};

struct thermal_state {
- struct _thermal_state core;
- struct _thermal_state package;
+ struct _thermal_state core_throttle;
+ struct _thermal_state core_power_limit;
+ struct _thermal_state package_throttle;
+ struct _thermal_state package_power_limit;
};

static DEFINE_PER_CPU(struct thermal_state, thermal_state);
@@ -62,9 +67,9 @@ static u32 lvtthmr_init __read_mostly;
therm_throt_sysdev_show_##_name, \
NULL) \

-#define define_therm_throt_sysdev_show_func(level, name) \
+#define define_therm_throt_sysdev_show_func(event, name) \
\
-static ssize_t therm_throt_sysdev_show_##level##_##name( \
+static ssize_t therm_throt_sysdev_show_##event##_##name( \
struct sys_device *dev, \
struct sysdev_attribute *attr, \
char *buf) \
@@ -75,7 +80,7 @@ static ssize_t therm_throt_sysdev_show_##level##_##name( \
preempt_disable(); /* CPU hotplug */ \
if (cpu_online(cpu)) { \
ret = sprintf(buf, "%lu\n", \
- per_cpu(thermal_state, cpu).level.name); \
+ per_cpu(thermal_state, cpu).event.name); \
} else \
ret = 0; \
preempt_enable(); \
@@ -83,23 +88,32 @@ static ssize_t therm_throt_sysdev_show_##level##_##name( \
return ret; \
}

-define_therm_throt_sysdev_show_func(core, throttle_count);
+define_therm_throt_sysdev_show_func(core_throttle, count);
define_therm_throt_sysdev_one_ro(core_throttle_count);

-define_therm_throt_sysdev_show_func(package, throttle_count);
+define_therm_throt_sysdev_show_func(core_power_limit, count);
+define_therm_throt_sysdev_one_ro(core_power_limit_count);
+
+define_therm_throt_sysdev_show_func(package_throttle, count);
define_therm_throt_sysdev_one_ro(package_throttle_count);

+define_therm_throt_sysdev_show_func(package_power_limit, count);
+define_therm_throt_sysdev_one_ro(package_power_limit_count);
+
static struct attribute *thermal_throttle_attrs[] = {
&attr_core_throttle_count.attr,
NULL
};

-static struct attribute_group thermal_throttle_attr_group = {
+static struct attribute_group thermal_attr_group = {
.attrs = thermal_throttle_attrs,
.name = "thermal_throttle"
};
#endif /* CONFIG_SYSFS */

+#define CORE_LEVEL 0
+#define PACKAGE_LEVEL 1
+
/***
* therm_throt_process - Process thermal throttling event from interrupt
* @curr: Whether the condition is current or not (boolean), since the
@@ -116,49 +130,70 @@ static struct attribute_group thermal_throttle_attr_group = {
* 1 : Event should be logged further, and a message has been
* printed to the syslog.
*/
-#define CORE_LEVEL 0
-#define PACKAGE_LEVEL 1
-static int therm_throt_process(bool is_throttled, int level)
+static int therm_throt_process(bool new_event, int event, int level)
{
struct _thermal_state *state;
- unsigned int this_cpu;
- bool was_throttled;
+ unsigned int this_cpu = smp_processor_id();
+ bool old_event;
u64 now;
+ struct thermal_state *pstate = &per_cpu(thermal_state, this_cpu);

- this_cpu = smp_processor_id();
now = get_jiffies_64();
- if (level == CORE_LEVEL)
- state = &per_cpu(thermal_state, this_cpu).core;
- else
- state = &per_cpu(thermal_state, this_cpu).package;
+ if (level == CORE_LEVEL) {
+ if (event == THERMAL_THROTTLING_EVENT)
+ state = &pstate->core_throttle;
+ else if (event == POWER_LIMIT_EVENT)
+ state = &pstate->core_power_limit;
+ else
+ return 0;
+ } else if (level == PACKAGE_LEVEL) {
+ if (event == THERMAL_THROTTLING_EVENT)
+ state = &pstate->package_throttle;
+ else if (event == POWER_LIMIT_EVENT)
+ state = &pstate->package_power_limit;
+ else
+ return 0;
+ } else
+ return 0;

- was_throttled = state->is_throttled;
- state->is_throttled = is_throttled;
+ old_event = state->new_event;
+ state->new_event = new_event;

- if (is_throttled)
- state->throttle_count++;
+ if (new_event)
+ state->count++;

if (time_before64(now, state->next_check) &&
- state->throttle_count != state->last_throttle_count)
+ state->count != state->last_count)
return 0;

state->next_check = now + CHECK_INTERVAL;
- state->last_throttle_count = state->throttle_count;
+ state->last_count = state->count;

/* if we just entered the thermal event */
- if (is_throttled) {
- printk(KERN_CRIT "CPU%d: %s temperature above threshold, cpu clock throttled (total events = %lu)\n",
- this_cpu,
- level == CORE_LEVEL ? "Core" : "Package",
- state->throttle_count);
+ if (new_event) {
+ if (event == THERMAL_THROTTLING_EVENT)
+ printk(KERN_CRIT "CPU%d: %s temperature above threshold, cpu clock throttled (total events = %lu)\n",
+ this_cpu,
+ level == CORE_LEVEL ? "Core" : "Package",
+ state->count);
+ else
+ printk(KERN_CRIT "CPU%d: %s power limit notification (total events = %lu)\n",
+ this_cpu,
+ level == CORE_LEVEL ? "Core" : "Package",
+ state->count);

add_taint(TAINT_MACHINE_CHECK);
return 1;
}
- if (was_throttled) {
- printk(KERN_INFO "CPU%d: %s temperature/speed normal\n",
- this_cpu,
- level == CORE_LEVEL ? "Core" : "Package");
+ if (old_event) {
+ if (event == THERMAL_THROTTLING_EVENT)
+ printk(KERN_INFO "CPU%d: %s temperature/speed normal\n",
+ this_cpu,
+ level == CORE_LEVEL ? "Core" : "Package");
+ else
+ printk(KERN_INFO "CPU%d: %s power limit normal\n",
+ this_cpu,
+ level == CORE_LEVEL ? "Core" : "Package");
return 1;
}

@@ -172,21 +207,29 @@ static __cpuinit int thermal_throttle_add_dev(struct sys_device *sys_dev)
int err;
struct cpuinfo_x86 *c = &cpu_data(smp_processor_id());

- err = sysfs_create_group(&sys_dev->kobj, &thermal_throttle_attr_group);
+ err = sysfs_create_group(&sys_dev->kobj, &thermal_attr_group);
if (err)
return err;

+ if (cpu_has(c, X86_FEATURE_PLN))
+ err = sysfs_add_file_to_group(&sys_dev->kobj,
+ &attr_core_power_limit_count.attr,
+ thermal_attr_group.name);
if (cpu_has(c, X86_FEATURE_PTS))
err = sysfs_add_file_to_group(&sys_dev->kobj,
&attr_package_throttle_count.attr,
- thermal_throttle_attr_group.name);
+ thermal_attr_group.name);
+ if (cpu_has(c, X86_FEATURE_PLN))
+ err = sysfs_add_file_to_group(&sys_dev->kobj,
+ &attr_package_power_limit_count.attr,
+ thermal_attr_group.name);

return err;
}

static __cpuinit void thermal_throttle_remove_dev(struct sys_device *sys_dev)
{
- sysfs_remove_group(&sys_dev->kobj, &thermal_throttle_attr_group);
+ sysfs_remove_group(&sys_dev->kobj, &thermal_attr_group);
}

/* Mutex protecting device creation against CPU hotplug: */
@@ -257,6 +300,17 @@ device_initcall(thermal_throttle_init_device);

#endif /* CONFIG_SYSFS */

+/*
+ * Set up the most two significant bit to notify mce log that this thermal
+ * event type.
+ * This is a temp solution. May be changed in the future with mce log
+ * infrasture.
+ */
+#define CORE_THROTTLED (0)
+#define CORE_POWER_LIMIT ((__u64)1 << 62)
+#define PACKAGE_THROTTLED ((__u64)2 << 62)
+#define PACKAGE_POWER_LIMIT ((__u64)3 << 62)
+
/* Thermal transition interrupt handler */
static void intel_thermal_interrupt(void)
{
@@ -264,21 +318,31 @@ static void intel_thermal_interrupt(void)
struct cpuinfo_x86 *c = &cpu_data(smp_processor_id());

rdmsrl(MSR_IA32_THERM_STATUS, msr_val);
+
if (therm_throt_process(msr_val & THERM_STATUS_PROCHOT,
+ THERMAL_THROTTLING_EVENT,
CORE_LEVEL) != 0)
- mce_log_therm_throt_event(msr_val);
+ mce_log_therm_throt_event(CORE_THROTTLED | msr_val);
+
+ if (cpu_has(c, X86_FEATURE_PLN))
+ if (therm_throt_process(msr_val & THERM_STATUS_POWER_LIMIT,
+ POWER_LIMIT_EVENT,
+ CORE_LEVEL) != 0)
+ mce_log_therm_throt_event(CORE_POWER_LIMIT | msr_val);

if (cpu_has(c, X86_FEATURE_PTS)) {
rdmsrl(MSR_IA32_PACKAGE_THERM_STATUS, msr_val);
if (therm_throt_process(msr_val & PACKAGE_THERM_STATUS_PROCHOT,
+ THERMAL_THROTTLING_EVENT,
PACKAGE_LEVEL) != 0)
- /*
- * Set up the most significant bit to notify mce log
- * that this thermal event is a package level event.
- * This is a temp solution. May be changed in the future
- * with mce log infrasture.
- */
- mce_log_therm_throt_event(((__u64)1 << 63) | msr_val);
+ mce_log_therm_throt_event(PACKAGE_THROTTLED | msr_val);
+ if (cpu_has(c, X86_FEATURE_PLN))
+ if (therm_throt_process(msr_val &
+ PACKAGE_THERM_STATUS_POWER_LIMIT,
+ POWER_LIMIT_EVENT,
+ PACKAGE_LEVEL) != 0)
+ mce_log_therm_throt_event(PACKAGE_POWER_LIMIT
+ | msr_val);
}
}

@@ -381,14 +445,25 @@ void intel_init_thermal(struct cpuinfo_x86 *c)
apic_write(APIC_LVTTHMR, h);

rdmsr(MSR_IA32_THERM_INTERRUPT, l, h);
- wrmsr(MSR_IA32_THERM_INTERRUPT,
- l | (THERM_INT_LOW_ENABLE | THERM_INT_HIGH_ENABLE), h);
+ if (cpu_has(c, X86_FEATURE_PLN))
+ wrmsr(MSR_IA32_THERM_INTERRUPT,
+ l | (THERM_INT_LOW_ENABLE
+ | THERM_INT_HIGH_ENABLE | THERM_INT_PLN_ENABLE), h);
+ else
+ wrmsr(MSR_IA32_THERM_INTERRUPT,
+ l | (THERM_INT_LOW_ENABLE | THERM_INT_HIGH_ENABLE), h);

if (cpu_has(c, X86_FEATURE_PTS)) {
rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
- wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
- l | (PACKAGE_THERM_INT_LOW_ENABLE
- | PACKAGE_THERM_INT_HIGH_ENABLE), h);
+ if (cpu_has(c, X86_FEATURE_PLN))
+ wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
+ l | (PACKAGE_THERM_INT_LOW_ENABLE
+ | PACKAGE_THERM_INT_HIGH_ENABLE
+ | PACKAGE_THERM_INT_PLN_ENABLE), h);
+ else
+ wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
+ l | (PACKAGE_THERM_INT_LOW_ENABLE
+ | PACKAGE_THERM_INT_HIGH_ENABLE), h);
}

smp_thermal_vector = intel_thermal_interrupt;

2010-08-04 00:02:10

by Fenghua Yu

[permalink] [raw]

Subject: [tip:x86/hwmon] x86, hwmon: Package Level Thermal/Power: pkgtemp documentation

Commit-ID: a3159864f2978bf2ace9cc787d73d315c98bbf9a
Gitweb: http://git.kernel.org/tip/a3159864f2978bf2ace9cc787d73d315c98bbf9a
Author: Fenghua Yu <[email protected]>
AuthorDate: Thu, 29 Jul 2010 17:13:46 -0700
Committer: H. Peter Anvin <[email protected]>
CommitDate: Tue, 3 Aug 2010 15:58:56 -0700

x86, hwmon: Package Level Thermal/Power: pkgtemp documentation

Document for package level thermal hwmon driver.

Signed-off-by: Fenghua Yu <[email protected]>
LKML-Reference: <[email protected]>
Reviewed-by: Len Brown <[email protected]>
Signed-off-by: H. Peter Anvin <[email protected]>
---
Documentation/hwmon/pkgtemp | 36 ++++++++++++++++++++++++++++++++++++
1 files changed, 36 insertions(+), 0 deletions(-)

diff --git a/Documentation/hwmon/pkgtemp b/Documentation/hwmon/pkgtemp
new file mode 100644
index 0000000..c8e1fb0
--- /dev/null
+++ b/Documentation/hwmon/pkgtemp
@@ -0,0 +1,36 @@
+Kernel driver pkgtemp
+======================
+
+Supported chips:
+ * Intel family
+ Prefix: 'pkgtemp'
+ CPUID:
+ Datasheet: Intel 64 and IA-32 Architectures Software Developer's Manual
+ Volume 3A: System Programming Guide
+
+Author: Fenghua Yu
+
+Description
+-----------
+
+This driver permits reading package level temperature sensor embedded inside
+Intel CPU package. The sensors can be in core, uncore, memory controller, or
+other components in a package. The feature is first implemented in Intel Sandy
+Bridge platform.
+
+Temperature is measured in degrees Celsius and measurement resolution is
+1 degree C. Valid temperatures are from 0 to TjMax degrees C, because the actual
+value of temperature register is in fact a delta from TjMax.
+
+Temperature known as TjMax is the maximum junction temperature of package.
+We get this from MSR_IA32_TEMPERATURE_TARGET. If the MSR is not accessible,
+we define TjMax as 100 degrees Celsius. At this temperature, protection
+mechanism will perform actions to forcibly cool down the package. Alarm
+may be raised, if the temperature grows enough (more than TjMax) to trigger
+the Out-Of-Spec bit. Following table summarizes the exported sysfs files:
+
+temp1_input - Package temperature (in millidegrees Celsius).
+temp1_max - All cooling devices should be turned on.
+temp1_crit - Maximum junction temperature (in millidegrees Celsius).
+temp1_crit_alarm - Set when Out-of-spec bit is set, never clears.
+ Correct CPU operation is no longer guaranteed.