[tip:x86/hwmon] x86, hwmon: Add core threshold notification to therm_throt.c

From: tip-bot for R, Durgadoss
Date: Tue Jan 04 2011 - 03:22:21 EST


Commit-ID: 9e76a97efd31a08cb19d0ba12013b8fb4ad3e474
Gitweb: http://git.kernel.org/tip/9e76a97efd31a08cb19d0ba12013b8fb4ad3e474
Author: R, Durgadoss <durgadoss.r@xxxxxxxxx>
AuthorDate: Mon, 3 Jan 2011 17:22:04 +0530
Committer: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
CommitDate: Mon, 3 Jan 2011 08:30:30 -0800

x86, hwmon: Add core threshold notification to therm_throt.c

This patch adds code to therm_throt.c to notify core thermal threshold
events. These thresholds are supported by the IA32_THERM_INTERRUPT register.
The status/log for the same is monitored using the IA32_THERM_STATUS register.
The necessary #defines are in msr-index.h. A call back is added to mce.h, to
further notify the thermal stack, about the threshold events.

Signed-off-by: Durgadoss R <durgadoss.r@xxxxxxxxx>
LKML-Reference: <D6D887BA8C9DFF48B5233887EF04654105C1251710@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
---
arch/x86/include/asm/mce.h | 3 ++
arch/x86/include/asm/msr-index.h | 12 +++++++++
arch/x86/kernel/cpu/mcheck/therm_throt.c | 40 ++++++++++++++++++++++++++++++
3 files changed, 55 insertions(+), 0 deletions(-)

diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index c62c13c..eb16e94 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -223,6 +223,9 @@ void intel_init_thermal(struct cpuinfo_x86 *c);

void mce_log_therm_throt_event(__u64 status);

+/* Interrupt Handler for core thermal thresholds */
+extern int (*platform_thermal_notify)(__u64 msr_val);
+
#ifdef CONFIG_X86_THERMAL_VECTOR
extern void mcheck_intel_therm_init(void);
#else
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 6b89f5e..622c80b 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -253,6 +253,18 @@
#define PACKAGE_THERM_INT_LOW_ENABLE (1 << 1)
#define PACKAGE_THERM_INT_PLN_ENABLE (1 << 24)

+/* Thermal Thresholds Support */
+#define THERM_INT_THRESHOLD0_ENABLE (1 << 15)
+#define THERM_SHIFT_THRESHOLD0 8
+#define THERM_MASK_THRESHOLD0 (0x7f << THERM_SHIFT_THRESHOLD0)
+#define THERM_INT_THRESHOLD1_ENABLE (1 << 23)
+#define THERM_SHIFT_THRESHOLD1 16
+#define THERM_MASK_THRESHOLD1 (0x7f << THERM_SHIFT_THRESHOLD1)
+#define THERM_STATUS_THRESHOLD0 (1 << 6)
+#define THERM_LOG_THRESHOLD0 (1 << 7)
+#define THERM_STATUS_THRESHOLD1 (1 << 8)
+#define THERM_LOG_THRESHOLD1 (1 << 9)
+
/* MISC_ENABLE bits: architectural */
#define MSR_IA32_MISC_ENABLE_FAST_STRING (1ULL << 0)
#define MSR_IA32_MISC_ENABLE_TCC (1ULL << 1)
diff --git a/arch/x86/kernel/cpu/mcheck/therm_throt.c b/arch/x86/kernel/cpu/mcheck/therm_throt.c
index 4b68326..e12246f 100644
--- a/arch/x86/kernel/cpu/mcheck/therm_throt.c
+++ b/arch/x86/kernel/cpu/mcheck/therm_throt.c
@@ -53,8 +53,13 @@ struct thermal_state {
struct _thermal_state core_power_limit;
struct _thermal_state package_throttle;
struct _thermal_state package_power_limit;
+ struct _thermal_state core_thresh0;
+ struct _thermal_state core_thresh1;
};

+/* Callback to handle core threshold interrupts */
+int (*platform_thermal_notify)(__u64 msr_val);
+
static DEFINE_PER_CPU(struct thermal_state, thermal_state);

static atomic_t therm_throt_en = ATOMIC_INIT(0);
@@ -200,6 +205,22 @@ static int therm_throt_process(bool new_event, int event, int level)
return 0;
}

+static int thresh_event_valid(int event)
+{
+ struct _thermal_state *state;
+ unsigned int this_cpu = smp_processor_id();
+ struct thermal_state *pstate = &per_cpu(thermal_state, this_cpu);
+ u64 now = get_jiffies_64();
+
+ state = (event == 0) ? &pstate->core_thresh0 : &pstate->core_thresh1;
+
+ if (time_before64(now, state->next_check))
+ return 0;
+
+ state->next_check = now + CHECK_INTERVAL;
+ return 1;
+}
+
#ifdef CONFIG_SYSFS
/* Add/Remove thermal_throttle interface for CPU device: */
static __cpuinit int thermal_throttle_add_dev(struct sys_device *sys_dev,
@@ -313,6 +334,22 @@ device_initcall(thermal_throttle_init_device);
#define PACKAGE_THROTTLED ((__u64)2 << 62)
#define PACKAGE_POWER_LIMIT ((__u64)3 << 62)

+static void notify_thresholds(__u64 msr_val)
+{
+ /* check whether the interrupt handler is defined;
+ * otherwise simply return
+ */
+ if (!platform_thermal_notify)
+ return;
+
+ /* lower threshold reached */
+ if ((msr_val & THERM_LOG_THRESHOLD0) && thresh_event_valid(0))
+ platform_thermal_notify(msr_val);
+ /* higher threshold reached */
+ if ((msr_val & THERM_LOG_THRESHOLD1) && thresh_event_valid(1))
+ platform_thermal_notify(msr_val);
+}
+
/* Thermal transition interrupt handler */
static void intel_thermal_interrupt(void)
{
@@ -321,6 +358,9 @@ static void intel_thermal_interrupt(void)

rdmsrl(MSR_IA32_THERM_STATUS, msr_val);

+ /* Check for violation of core thermal thresholds*/
+ notify_thresholds(msr_val);
+
if (therm_throt_process(msr_val & THERM_STATUS_PROCHOT,
THERMAL_THROTTLING_EVENT,
CORE_LEVEL) != 0)
--
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