![Jan Engelhardt](/assets/img/avatar_default.png)
Signed-off-by: Jan Engelhardt <jengelh@gmx.de> Signed-off-by: Len Brown <len.brown@intel.com>
339 lines
8.4 KiB
C
339 lines
8.4 KiB
C
/*
|
|
* processor_throttling.c - Throttling 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/io.h>
|
|
#include <asm/uaccess.h>
|
|
|
|
#include <acpi/acpi_bus.h>
|
|
#include <acpi/processor.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")
|
|
|
|
/* --------------------------------------------------------------------------
|
|
Throttling Control
|
|
-------------------------------------------------------------------------- */
|
|
static int acpi_processor_get_throttling(struct acpi_processor *pr)
|
|
{
|
|
int state = 0;
|
|
u32 value = 0;
|
|
u32 duty_mask = 0;
|
|
u32 duty_value = 0;
|
|
|
|
|
|
if (!pr)
|
|
return -EINVAL;
|
|
|
|
if (!pr->flags.throttling)
|
|
return -ENODEV;
|
|
|
|
pr->throttling.state = 0;
|
|
|
|
duty_mask = pr->throttling.state_count - 1;
|
|
|
|
duty_mask <<= pr->throttling.duty_offset;
|
|
|
|
local_irq_disable();
|
|
|
|
value = inl(pr->throttling.address);
|
|
|
|
/*
|
|
* Compute the current throttling state when throttling is enabled
|
|
* (bit 4 is on).
|
|
*/
|
|
if (value & 0x10) {
|
|
duty_value = value & duty_mask;
|
|
duty_value >>= pr->throttling.duty_offset;
|
|
|
|
if (duty_value)
|
|
state = pr->throttling.state_count - duty_value;
|
|
}
|
|
|
|
pr->throttling.state = state;
|
|
|
|
local_irq_enable();
|
|
|
|
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
|
|
"Throttling state is T%d (%d%% throttling applied)\n",
|
|
state, pr->throttling.states[state].performance));
|
|
|
|
return 0;
|
|
}
|
|
|
|
int acpi_processor_set_throttling(struct acpi_processor *pr, int state)
|
|
{
|
|
u32 value = 0;
|
|
u32 duty_mask = 0;
|
|
u32 duty_value = 0;
|
|
|
|
|
|
if (!pr)
|
|
return -EINVAL;
|
|
|
|
if ((state < 0) || (state > (pr->throttling.state_count - 1)))
|
|
return -EINVAL;
|
|
|
|
if (!pr->flags.throttling)
|
|
return -ENODEV;
|
|
|
|
if (state == pr->throttling.state)
|
|
return 0;
|
|
|
|
/*
|
|
* Calculate the duty_value and duty_mask.
|
|
*/
|
|
if (state) {
|
|
duty_value = pr->throttling.state_count - state;
|
|
|
|
duty_value <<= pr->throttling.duty_offset;
|
|
|
|
/* Used to clear all duty_value bits */
|
|
duty_mask = pr->throttling.state_count - 1;
|
|
|
|
duty_mask <<= acpi_fadt.duty_offset;
|
|
duty_mask = ~duty_mask;
|
|
}
|
|
|
|
local_irq_disable();
|
|
|
|
/*
|
|
* Disable throttling by writing a 0 to bit 4. Note that we must
|
|
* turn it off before you can change the duty_value.
|
|
*/
|
|
value = inl(pr->throttling.address);
|
|
if (value & 0x10) {
|
|
value &= 0xFFFFFFEF;
|
|
outl(value, pr->throttling.address);
|
|
}
|
|
|
|
/*
|
|
* Write the new duty_value and then enable throttling. Note
|
|
* that a state value of 0 leaves throttling disabled.
|
|
*/
|
|
if (state) {
|
|
value &= duty_mask;
|
|
value |= duty_value;
|
|
outl(value, pr->throttling.address);
|
|
|
|
value |= 0x00000010;
|
|
outl(value, pr->throttling.address);
|
|
}
|
|
|
|
pr->throttling.state = state;
|
|
|
|
local_irq_enable();
|
|
|
|
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
|
|
"Throttling state set to T%d (%d%%)\n", state,
|
|
(pr->throttling.states[state].performance ? pr->
|
|
throttling.states[state].performance / 10 : 0)));
|
|
|
|
return 0;
|
|
}
|
|
|
|
int acpi_processor_get_throttling_info(struct acpi_processor *pr)
|
|
{
|
|
int result = 0;
|
|
int step = 0;
|
|
int i = 0;
|
|
|
|
|
|
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
|
|
"pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
|
|
pr->throttling.address,
|
|
pr->throttling.duty_offset,
|
|
pr->throttling.duty_width));
|
|
|
|
if (!pr)
|
|
return -EINVAL;
|
|
|
|
/* TBD: Support ACPI 2.0 objects */
|
|
|
|
if (!pr->throttling.address) {
|
|
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
|
|
return 0;
|
|
} else if (!pr->throttling.duty_width) {
|
|
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
|
|
return 0;
|
|
}
|
|
/* TBD: Support duty_cycle values that span bit 4. */
|
|
else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
|
|
printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* PIIX4 Errata: We don't support throttling on the original PIIX4.
|
|
* This shouldn't be an issue as few (if any) mobile systems ever
|
|
* used this part.
|
|
*/
|
|
if (errata.piix4.throttle) {
|
|
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
|
|
"Throttling not supported on PIIX4 A- or B-step\n"));
|
|
return 0;
|
|
}
|
|
|
|
pr->throttling.state_count = 1 << acpi_fadt.duty_width;
|
|
|
|
/*
|
|
* Compute state values. Note that throttling displays a linear power/
|
|
* performance relationship (at 50% performance the CPU will consume
|
|
* 50% power). Values are in 1/10th of a percent to preserve accuracy.
|
|
*/
|
|
|
|
step = (1000 / pr->throttling.state_count);
|
|
|
|
for (i = 0; i < pr->throttling.state_count; i++) {
|
|
pr->throttling.states[i].performance = step * i;
|
|
pr->throttling.states[i].power = step * i;
|
|
}
|
|
|
|
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
|
|
pr->throttling.state_count));
|
|
|
|
pr->flags.throttling = 1;
|
|
|
|
/*
|
|
* Disable throttling (if enabled). We'll let subsequent policy (e.g.
|
|
* thermal) decide to lower performance if it so chooses, but for now
|
|
* we'll crank up the speed.
|
|
*/
|
|
|
|
result = acpi_processor_get_throttling(pr);
|
|
if (result)
|
|
goto end;
|
|
|
|
if (pr->throttling.state) {
|
|
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
|
|
"Disabling throttling (was T%d)\n",
|
|
pr->throttling.state));
|
|
result = acpi_processor_set_throttling(pr, 0);
|
|
if (result)
|
|
goto end;
|
|
}
|
|
|
|
end:
|
|
if (result)
|
|
pr->flags.throttling = 0;
|
|
|
|
return result;
|
|
}
|
|
|
|
/* proc interface */
|
|
|
|
static int acpi_processor_throttling_seq_show(struct seq_file *seq,
|
|
void *offset)
|
|
{
|
|
struct acpi_processor *pr = seq->private;
|
|
int i = 0;
|
|
int result = 0;
|
|
|
|
|
|
if (!pr)
|
|
goto end;
|
|
|
|
if (!(pr->throttling.state_count > 0)) {
|
|
seq_puts(seq, "<not supported>\n");
|
|
goto end;
|
|
}
|
|
|
|
result = acpi_processor_get_throttling(pr);
|
|
|
|
if (result) {
|
|
seq_puts(seq,
|
|
"Could not determine current throttling state.\n");
|
|
goto end;
|
|
}
|
|
|
|
seq_printf(seq, "state count: %d\n"
|
|
"active state: T%d\n",
|
|
pr->throttling.state_count, pr->throttling.state);
|
|
|
|
seq_puts(seq, "states:\n");
|
|
for (i = 0; i < pr->throttling.state_count; i++)
|
|
seq_printf(seq, " %cT%d: %02d%%\n",
|
|
(i == pr->throttling.state ? '*' : ' '), i,
|
|
(pr->throttling.states[i].performance ? pr->
|
|
throttling.states[i].performance / 10 : 0));
|
|
|
|
end:
|
|
return 0;
|
|
}
|
|
|
|
static int acpi_processor_throttling_open_fs(struct inode *inode,
|
|
struct file *file)
|
|
{
|
|
return single_open(file, acpi_processor_throttling_seq_show,
|
|
PDE(inode)->data);
|
|
}
|
|
|
|
static ssize_t acpi_processor_write_throttling(struct file * file,
|
|
const char __user * buffer,
|
|
size_t count, loff_t * data)
|
|
{
|
|
int result = 0;
|
|
struct seq_file *m = file->private_data;
|
|
struct acpi_processor *pr = m->private;
|
|
char state_string[12] = { '\0' };
|
|
|
|
|
|
if (!pr || (count > sizeof(state_string) - 1))
|
|
return -EINVAL;
|
|
|
|
if (copy_from_user(state_string, buffer, count))
|
|
return -EFAULT;
|
|
|
|
state_string[count] = '\0';
|
|
|
|
result = acpi_processor_set_throttling(pr,
|
|
simple_strtoul(state_string,
|
|
NULL, 0));
|
|
if (result)
|
|
return result;
|
|
|
|
return count;
|
|
}
|
|
|
|
struct file_operations acpi_processor_throttling_fops = {
|
|
.open = acpi_processor_throttling_open_fs,
|
|
.read = seq_read,
|
|
.write = acpi_processor_write_throttling,
|
|
.llseek = seq_lseek,
|
|
.release = single_release,
|
|
};
|