--- /dev/null
+/*
+ * 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/proc_fs.h>
+#include <linux/seq_file.h>
+
+#include <asm/uaccess.h>
+
+#include <acpi/acpi_bus.h>
+#include <acpi/processor.h>
+#include <acpi/acpi_drivers.h>
+
+#define ACPI_PROCESSOR_COMPONENT 0x01000000
+#define ACPI_PROCESSOR_CLASS "processor"
+#define ACPI_PROCESSOR_DRIVER_NAME "ACPI Processor Driver"
+#define _COMPONENT ACPI_PROCESSOR_COMPONENT
+ACPI_MODULE_NAME ("acpi_processor")
+
+
+/* --------------------------------------------------------------------------
+ Limit Interface
+ -------------------------------------------------------------------------- */
+
+static int
+acpi_processor_apply_limit (
+ struct acpi_processor* pr)
+{
+ int result = 0;
+ u16 px = 0;
+ u16 tx = 0;
+
+ ACPI_FUNCTION_TRACE("acpi_processor_apply_limit");
+
+ if (!pr)
+ return_VALUE(-EINVAL);
+
+ if (!pr->flags.limit)
+ return_VALUE(-ENODEV);
+
+ if (pr->flags.throttling) {
+ if (pr->limit.user.tx > tx)
+ tx = pr->limit.user.tx;
+ if (pr->limit.thermal.tx > tx)
+ tx = pr->limit.thermal.tx;
+
+ result = acpi_processor_set_throttling(pr, tx);
+ if (result)
+ goto end;
+ }
+
+ pr->limit.state.px = px;
+ pr->limit.state.tx = tx;
+
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d] limit set to (P%d:T%d)\n",
+ pr->id,
+ pr->limit.state.px,
+ pr->limit.state.tx));
+
+end:
+ if (result)
+ ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to set limit\n"));
+
+ return_VALUE(result);
+}
+
+
+#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.
+ */
+
+static unsigned int cpufreq_thermal_reduction_pctg[NR_CPUS];
+static unsigned int acpi_thermal_cpufreq_is_init = 0;
+
+
+static int cpu_has_cpufreq(unsigned int cpu)
+{
+ struct cpufreq_policy policy;
+ if (!acpi_thermal_cpufreq_is_init)
+ return -ENODEV;
+ if (!cpufreq_get_policy(&policy, cpu))
+ return -ENODEV;
+ return 0;
+}
+
+
+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;
+ cpufreq_update_policy(cpu);
+ return 0;
+ }
+
+ return -ERANGE;
+}
+
+
+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;
+ cpufreq_update_policy(cpu);
+ return 0;
+ }
+
+ return -ERANGE;
+}
+
+
+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 - cpufreq_thermal_reduction_pctg[policy->cpu])) / 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,
+};
+
+
+void acpi_thermal_cpufreq_init(void) {
+ int i;
+
+ for (i=0; i<NR_CPUS; i++)
+ cpufreq_thermal_reduction_pctg[i] = 0;
+
+ 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 acpi_thermal_cpufreq_increase(unsigned int cpu) { return -ENODEV; }
+static int acpi_thermal_cpufreq_decrease(unsigned int cpu) { return -ENODEV; }
+
+
+#endif
+
+
+int
+acpi_processor_set_thermal_limit (
+ acpi_handle handle,
+ int type)
+{
+ int result = 0;
+ struct acpi_processor *pr = NULL;
+ struct acpi_device *device = NULL;
+ int tx = 0;
+
+ ACPI_FUNCTION_TRACE("acpi_processor_set_thermal_limit");
+
+ if ((type < ACPI_PROCESSOR_LIMIT_NONE)
+ || (type > ACPI_PROCESSOR_LIMIT_DECREMENT))
+ return_VALUE(-EINVAL);
+
+ result = acpi_bus_get_device(handle, &device);
+ if (result)
+ return_VALUE(result);
+
+ pr = (struct acpi_processor *) acpi_driver_data(device);
+ if (!pr)
+ return_VALUE(-ENODEV);
+
+ /* Thermal limits are always relative to the current Px/Tx state. */
+ if (pr->flags.throttling)
+ pr->limit.thermal.tx = pr->throttling.state;
+
+ /*
+ * Our default policy is to only use throttling at the lowest
+ * performance state.
+ */
+
+ tx = pr->limit.thermal.tx;
+
+ switch (type) {
+
+ case ACPI_PROCESSOR_LIMIT_NONE:
+ do {
+ result = acpi_thermal_cpufreq_decrease(pr->id);
+ } while (!result);
+ tx = 0;
+ break;
+
+ case ACPI_PROCESSOR_LIMIT_INCREMENT:
+ /* if going up: P-states first, T-states later */
+
+ result = acpi_thermal_cpufreq_increase(pr->id);
+ if (!result)
+ goto end;
+ else if (result == -ERANGE)
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+ "At maximum performance state\n"));
+
+ if (pr->flags.throttling) {
+ if (tx == (pr->throttling.state_count - 1))
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+ "At maximum throttling state\n"));
+ else
+ tx++;
+ }
+ break;
+
+ case ACPI_PROCESSOR_LIMIT_DECREMENT:
+ /* if going down: T-states first, P-states later */
+
+ if (pr->flags.throttling) {
+ if (tx == 0)
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+ "At minimum throttling state\n"));
+ else {
+ tx--;
+ goto end;
+ }
+ }
+
+ result = acpi_thermal_cpufreq_decrease(pr->id);
+ if (result == -ERANGE)
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+ "At minimum performance state\n"));
+
+ break;
+ }
+
+end:
+ if (pr->flags.throttling) {
+ pr->limit.thermal.px = 0;
+ pr->limit.thermal.tx = tx;
+
+ result = acpi_processor_apply_limit(pr);
+ if (result)
+ ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+ "Unable to set thermal limit\n"));
+
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Thermal limit now (P%d:T%d)\n",
+ pr->limit.thermal.px,
+ pr->limit.thermal.tx));
+ } else
+ result = 0;
+
+ return_VALUE(result);
+}
+
+
+int
+acpi_processor_get_limit_info (
+ struct acpi_processor *pr)
+{
+ ACPI_FUNCTION_TRACE("acpi_processor_get_limit_info");
+
+ if (!pr)
+ return_VALUE(-EINVAL);
+
+ if (pr->flags.throttling)
+ pr->flags.limit = 1;
+
+ return_VALUE(0);
+}
+
+
+/* /proc interface */
+
+static int acpi_processor_limit_seq_show(struct seq_file *seq, void *offset)
+{
+ struct acpi_processor *pr = (struct acpi_processor *)seq->private;
+
+ ACPI_FUNCTION_TRACE("acpi_processor_limit_seq_show");
+
+ if (!pr)
+ goto end;
+
+ if (!pr->flags.limit) {
+ seq_puts(seq, "<not supported>\n");
+ goto end;
+ }
+
+ seq_printf(seq, "active limit: P%d:T%d\n"
+ "user limit: P%d:T%d\n"
+ "thermal limit: P%d:T%d\n",
+ pr->limit.state.px, pr->limit.state.tx,
+ pr->limit.user.px, pr->limit.user.tx,
+ pr->limit.thermal.px, pr->limit.thermal.tx);
+
+end:
+ return_VALUE(0);
+}
+
+int acpi_processor_limit_open_fs(struct inode *inode, struct file *file)
+{
+ return single_open(file, acpi_processor_limit_seq_show,
+ PDE(inode)->data);
+}
+
+ssize_t acpi_processor_write_limit (
+ struct file *file,
+ const char __user *buffer,
+ size_t count,
+ loff_t *data)
+{
+ int result = 0;
+ struct seq_file *m = (struct seq_file *)file->private_data;
+ struct acpi_processor *pr = (struct acpi_processor *)m->private;
+ char limit_string[25] = {'\0'};
+ int px = 0;
+ int tx = 0;
+
+ ACPI_FUNCTION_TRACE("acpi_processor_write_limit");
+
+ if (!pr || (count > sizeof(limit_string) - 1)) {
+ ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid argument\n"));
+ return_VALUE(-EINVAL);
+ }
+
+ if (copy_from_user(limit_string, buffer, count)) {
+ ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid data\n"));
+ return_VALUE(-EFAULT);
+ }
+
+ limit_string[count] = '\0';
+
+ if (sscanf(limit_string, "%d:%d", &px, &tx) != 2) {
+ ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid data format\n"));
+ return_VALUE(-EINVAL);
+ }
+
+ if (pr->flags.throttling) {
+ if ((tx < 0) || (tx > (pr->throttling.state_count - 1))) {
+ ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid tx\n"));
+ return_VALUE(-EINVAL);
+ }
+ pr->limit.user.tx = tx;
+ }
+
+ result = acpi_processor_apply_limit(pr);
+
+ return_VALUE(count);
+}
+
+
+struct file_operations acpi_processor_limit_fops = {
+ .open = acpi_processor_limit_open_fs,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
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