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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/acpi/processor_thermal.c | |
download | linux-fsl-qoriq-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/acpi/processor_thermal.c')
-rw-r--r-- | drivers/acpi/processor_thermal.c | 406 |
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 0000000..12bd980 --- /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, +}; + |