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authorZhang Rui <rui.zhang@intel.com>2008-01-17 15:51:23 +0800
committerLen Brown <len.brown@intel.com>2008-02-01 23:18:19 -0500
commitd9460fd227ed2ce52941b6a12ad4de05c195f6aa (patch)
tree1fb877cf41c8599e0fc9c1fbf902b88baba60708 /drivers/acpi/processor_thermal.c
parent05a83d972293f39a66bc2aa409a5e7996bba585d (diff)
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>
Diffstat (limited to 'drivers/acpi/processor_thermal.c')
-rw-r--r--drivers/acpi/processor_thermal.c134
1 files changed, 129 insertions, 5 deletions
diff --git a/drivers/acpi/processor_thermal.c b/drivers/acpi/processor_thermal.c
index 06e6f3fb8825..9cb43f52f7b6 100644
--- a/drivers/acpi/processor_thermal.c
+++ b/drivers/acpi/processor_thermal.c
@@ -32,6 +32,7 @@
#include <linux/cpufreq.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
+#include <linux/sysdev.h>
#include <asm/uaccess.h>
@@ -93,6 +94,9 @@ static int acpi_processor_apply_limit(struct acpi_processor *pr)
* _any_ cpufreq driver and not only the acpi-cpufreq driver.
*/
+#define CPUFREQ_THERMAL_MIN_STEP 0
+#define CPUFREQ_THERMAL_MAX_STEP 3
+
static unsigned int cpufreq_thermal_reduction_pctg[NR_CPUS];
static unsigned int acpi_thermal_cpufreq_is_init = 0;
@@ -109,8 +113,9 @@ static int acpi_thermal_cpufreq_increase(unsigned int cpu)
if (!cpu_has_cpufreq(cpu))
return -ENODEV;
- if (cpufreq_thermal_reduction_pctg[cpu] < 60) {
- cpufreq_thermal_reduction_pctg[cpu] += 20;
+ if (cpufreq_thermal_reduction_pctg[cpu] <
+ CPUFREQ_THERMAL_MAX_STEP) {
+ cpufreq_thermal_reduction_pctg[cpu]++;
cpufreq_update_policy(cpu);
return 0;
}
@@ -123,8 +128,9 @@ static int acpi_thermal_cpufreq_decrease(unsigned int cpu)
if (!cpu_has_cpufreq(cpu))
return -ENODEV;
- if (cpufreq_thermal_reduction_pctg[cpu] > 20)
- cpufreq_thermal_reduction_pctg[cpu] -= 20;
+ if (cpufreq_thermal_reduction_pctg[cpu] >
+ (CPUFREQ_THERMAL_MIN_STEP + 1))
+ cpufreq_thermal_reduction_pctg[cpu]--;
else
cpufreq_thermal_reduction_pctg[cpu] = 0;
cpufreq_update_policy(cpu);
@@ -143,7 +149,7 @@ static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,
max_freq =
(policy->cpuinfo.max_freq *
- (100 - cpufreq_thermal_reduction_pctg[policy->cpu])) / 100;
+ (100 - cpufreq_thermal_reduction_pctg[policy->cpu] * 20)) / 100;
cpufreq_verify_within_limits(policy, 0, max_freq);
@@ -155,6 +161,32 @@ static struct notifier_block acpi_thermal_cpufreq_notifier_block = {
.notifier_call = acpi_thermal_cpufreq_notifier,
};
+static int cpufreq_get_max_state(unsigned int cpu)
+{
+ if (!cpu_has_cpufreq(cpu))
+ return 0;
+
+ return CPUFREQ_THERMAL_MAX_STEP;
+}
+
+static int cpufreq_get_cur_state(unsigned int cpu)
+{
+ if (!cpu_has_cpufreq(cpu))
+ return 0;
+
+ return cpufreq_thermal_reduction_pctg[cpu];
+}
+
+static int cpufreq_set_cur_state(unsigned int cpu, int state)
+{
+ if (!cpu_has_cpufreq(cpu))
+ return 0;
+
+ cpufreq_thermal_reduction_pctg[cpu] = state;
+ cpufreq_update_policy(cpu);
+ return 0;
+}
+
void acpi_thermal_cpufreq_init(void)
{
int i;
@@ -179,6 +211,20 @@ void acpi_thermal_cpufreq_exit(void)
}
#else /* ! CONFIG_CPU_FREQ */
+static int cpufreq_get_max_state(unsigned int cpu)
+{
+ return 0;
+}
+
+static int cpufreq_get_cur_state(unsigned int cpu)
+{
+ return 0;
+}
+
+static int cpufreq_set_cur_state(unsigned int cpu, int state)
+{
+ return 0;
+}
static int acpi_thermal_cpufreq_increase(unsigned int cpu)
{
@@ -310,6 +356,84 @@ int acpi_processor_get_limit_info(struct acpi_processor *pr)
return 0;
}
+/* thermal coolign device callbacks */
+static int acpi_processor_max_state(struct acpi_processor *pr)
+{
+ int max_state = 0;
+
+ /*
+ * There exists four states according to
+ * cpufreq_thermal_reduction_ptg. 0, 1, 2, 3
+ */
+ max_state += cpufreq_get_max_state(pr->id);
+ if (pr->flags.throttling)
+ max_state += (pr->throttling.state_count -1);
+
+ return max_state;
+}
+static int
+processor_get_max_state(struct thermal_cooling_device *cdev, char *buf)
+{
+ struct acpi_device *device = cdev->devdata;
+ struct acpi_processor *pr = acpi_driver_data(device);
+
+ if (!device || !pr)
+ return -EINVAL;
+
+ return sprintf(buf, "%d\n", acpi_processor_max_state(pr));
+}
+
+static int
+processor_get_cur_state(struct thermal_cooling_device *cdev, char *buf)
+{
+ struct acpi_device *device = cdev->devdata;
+ struct acpi_processor *pr = acpi_driver_data(device);
+ int cur_state;
+
+ if (!device || !pr)
+ return -EINVAL;
+
+ cur_state = cpufreq_get_cur_state(pr->id);
+ if (pr->flags.throttling)
+ cur_state += pr->throttling.state;
+
+ return sprintf(buf, "%d\n", cur_state);
+}
+
+static int
+processor_set_cur_state(struct thermal_cooling_device *cdev, unsigned int state)
+{
+ struct acpi_device *device = cdev->devdata;
+ struct acpi_processor *pr = acpi_driver_data(device);
+ int result = 0;
+ int max_pstate;
+
+ if (!device || !pr)
+ return -EINVAL;
+
+ max_pstate = cpufreq_get_max_state(pr->id);
+
+ if (state > acpi_processor_max_state(pr))
+ return -EINVAL;
+
+ if (state <= max_pstate) {
+ if (pr->flags.throttling && pr->throttling.state)
+ result = acpi_processor_set_throttling(pr, 0);
+ cpufreq_set_cur_state(pr->id, state);
+ } else {
+ cpufreq_set_cur_state(pr->id, max_pstate);
+ result = acpi_processor_set_throttling(pr,
+ state - max_pstate);
+ }
+ return result;
+}
+
+struct thermal_cooling_device_ops processor_cooling_ops = {
+ .get_max_state = processor_get_max_state,
+ .get_cur_state = processor_get_cur_state,
+ .set_cur_state = processor_set_cur_state,
+};
+
/* /proc interface */
static int acpi_processor_limit_seq_show(struct seq_file *seq, void *offset)