1 files changed, 406 insertions, 0 deletions

diff --git a/drivers/acpi/processor_thermal.c b/drivers/acpi/processor_thermal.c
new file mode 100644
index 000000000000..12bd980a12e9
--- /dev/null
+++ b/drivers/acpi/processor_thermal.c
@@ -0,0 +1,406 @@
+/*
+ * 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);
+}
+
+static 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,
+};
+