ACPI: register ACPI Processor as generic thermal cooling device
Register ACPI processor as thermal cooling devices.
A combination of processor T-state and P-state are used for thermal throttling.
the processor will reduce the frequency first and then set the T-state.
we use cpufreq_thermal_reduction_pctg to calculate the cpufreq limit,
and call cpufreq_verify_with_limit to set the cpufreq limit.
if cpufreq driver is loaded, then we have four cooling state for cpufreq control.
cooling state 0: cpufreq limit == max_freq
cooling state 1: cpufreq limit == max_freq * 80%
cooling state 2: cpufreq limit == max_freq * 60%
cooling state 3: cpufreq limit == max_freq * 40%
after the cpufreq limit is set to 40 percentage of the max_freq,
we use T-state for cooling.
eg. a processor has P-state support, and it has 8 T-state (T0-T7),
the max_state of the proceesor is 10:
state cpufreq-limit T-state
0: max_freq T0
1: max_freq * 80% T0
2: max_freq * 60% T0
3: max_freq * 40% T0
4: max_freq * 40% T1
5: max_freq * 40% T2
6: max_freq * 40% T3
7: max_freq * 40% T4
8: max_freq * 40% T5
9: max_freq * 40% T6
10: max_freq * 40% T7
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Thomas Sujith <sujith.thomas@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index 76411b1..0787635 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -4,7 +4,7 @@
#include <linux/kernel.h>
#include <linux/cpu.h>
#include <linux/cpuidle.h>
-
+#include <linux/thermal.h>
#include <asm/acpi.h>
#define ACPI_PROCESSOR_BUSY_METRIC 10
@@ -218,7 +218,7 @@
struct acpi_processor_performance *performance;
struct acpi_processor_throttling throttling;
struct acpi_processor_limit limit;
-
+ struct thermal_cooling_device *cdev;
/* the _PDC objects for this processor, if any */
struct acpi_object_list *pdc;
};
@@ -330,7 +330,7 @@
/* in processor_thermal.c */
int acpi_processor_get_limit_info(struct acpi_processor *pr);
extern struct file_operations acpi_processor_limit_fops;
-
+extern struct thermal_cooling_device_ops processor_cooling_ops;
#ifdef CONFIG_CPU_FREQ
void acpi_thermal_cpufreq_init(void);
void acpi_thermal_cpufreq_exit(void);