Initial import

1 files changed, 276 insertions, 0 deletions

diff --git a/drivers/acpi/processor_thermal.c b/drivers/acpi/processor_thermal.c
new file mode 100644
index 000000000..e003663b2
--- /dev/null
+++ b/drivers/acpi/processor_thermal.c
@@ -0,0 +1,276 @@
+/*
+ * processor_thermal.c - Passive cooling submodule of the ACPI processor driver
+ *
+ *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ *  Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
+ *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
+ *  			- Added processor hotplug support
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  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/module.h>
+#include <linux/init.h>
+#include <linux/cpufreq.h>
+#include <linux/acpi.h>
+#include <acpi/processor.h>
+#include <asm/uaccess.h>
+
+#define PREFIX "ACPI: "
+
+#define ACPI_PROCESSOR_CLASS            "processor"
+#define _COMPONENT              ACPI_PROCESSOR_COMPONENT
+ACPI_MODULE_NAME("processor_thermal");
+
+#ifdef CONFIG_CPU_FREQ
+
+/* If a passive cooling situation is detected, primarily CPUfreq is used, as it
+ * offers (in most cases) voltage scaling in addition to frequency scaling, and
+ * thus a cubic (instead of linear) reduction of energy. Also, we allow for
+ * _any_ cpufreq driver and not only the acpi-cpufreq driver.
+ */
+
+#define CPUFREQ_THERMAL_MIN_STEP 0
+#define CPUFREQ_THERMAL_MAX_STEP 3
+
+static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg);
+static unsigned int acpi_thermal_cpufreq_is_init = 0;
+
+#define reduction_pctg(cpu) \
+	per_cpu(cpufreq_thermal_reduction_pctg, phys_package_first_cpu(cpu))
+
+/*
+ * Emulate "per package data" using per cpu data (which should really be
+ * provided elsewhere)
+ *
+ * Note we can lose a CPU on cpu hotunplug, in this case we forget the state
+ * temporarily. Fortunately that's not a big issue here (I hope)
+ */
+static int phys_package_first_cpu(int cpu)
+{
+	int i;
+	int id = topology_physical_package_id(cpu);
+
+	for_each_online_cpu(i)
+		if (topology_physical_package_id(i) == id)
+			return i;
+	return 0;
+}
+
+static int cpu_has_cpufreq(unsigned int cpu)
+{
+	struct cpufreq_policy policy;
+	if (!acpi_thermal_cpufreq_is_init || cpufreq_get_policy(&policy, cpu))
+		return 0;
+	return 1;
+}
+
+static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,
+					 unsigned long event, void *data)
+{
+	struct cpufreq_policy *policy = data;
+	unsigned long max_freq = 0;
+
+	if (event != CPUFREQ_ADJUST)
+		goto out;
+
+	max_freq = (
+	    policy->cpuinfo.max_freq *
+	    (100 - reduction_pctg(policy->cpu) * 20)
+	) / 100;
+
+	cpufreq_verify_within_limits(policy, 0, max_freq);
+
+      out:
+	return 0;
+}
+
+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 reduction_pctg(cpu);
+}
+
+static int cpufreq_set_cur_state(unsigned int cpu, int state)
+{
+	int i;
+
+	if (!cpu_has_cpufreq(cpu))
+		return 0;
+
+	reduction_pctg(cpu) = state;
+
+	/*
+	 * Update all the CPUs in the same package because they all
+	 * contribute to the temperature and often share the same
+	 * frequency.
+	 */
+	for_each_online_cpu(i) {
+		if (topology_physical_package_id(i) ==
+		    topology_physical_package_id(cpu))
+			cpufreq_update_policy(i);
+	}
+	return 0;
+}
+
+void acpi_thermal_cpufreq_init(void)
+{
+	int i;
+
+	i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block,
+				      CPUFREQ_POLICY_NOTIFIER);
+	if (!i)
+		acpi_thermal_cpufreq_is_init = 1;
+}
+
+void acpi_thermal_cpufreq_exit(void)
+{
+	if (acpi_thermal_cpufreq_is_init)
+		cpufreq_unregister_notifier
+		    (&acpi_thermal_cpufreq_notifier_block,
+		     CPUFREQ_POLICY_NOTIFIER);
+
+	acpi_thermal_cpufreq_is_init = 0;
+}
+
+#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;
+}
+
+#endif
+
+/* thermal cooling 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_pctg. 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,
+			unsigned long *state)
+{
+	struct acpi_device *device = cdev->devdata;
+	struct acpi_processor *pr;
+
+	if (!device)
+		return -EINVAL;
+
+	pr = acpi_driver_data(device);
+	if (!pr)
+		return -EINVAL;
+
+	*state = acpi_processor_max_state(pr);
+	return 0;
+}
+
+static int
+processor_get_cur_state(struct thermal_cooling_device *cdev,
+			unsigned long *cur_state)
+{
+	struct acpi_device *device = cdev->devdata;
+	struct acpi_processor *pr;
+
+	if (!device)
+		return -EINVAL;
+
+	pr = acpi_driver_data(device);
+	if (!pr)
+		return -EINVAL;
+
+	*cur_state = cpufreq_get_cur_state(pr->id);
+	if (pr->flags.throttling)
+		*cur_state += pr->throttling.state;
+	return 0;
+}
+
+static int
+processor_set_cur_state(struct thermal_cooling_device *cdev,
+			unsigned long state)
+{
+	struct acpi_device *device = cdev->devdata;
+	struct acpi_processor *pr;
+	int result = 0;
+	int max_pstate;
+
+	if (!device)
+		return -EINVAL;
+
+	pr = acpi_driver_data(device);
+	if (!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, false);
+		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, false);
+	}
+	return result;
+}
+
+const 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,
+};