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/*****************************************************************************
*
* Module Name: prperf.c
* $Revision: 21 $
*
*****************************************************************************/
/*
* Copyright (C) 2000, 2001 Andrew Grover
*
* 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
*/
/*
* TBD: 1. Support ACPI 2.0 processor performance states (not just throttling).
* 2. Fully implement thermal -vs- power management limit control.
*/
#include <acpi.h>
#include <bm.h>
#include "pr.h"
#define _COMPONENT ACPI_PROCESSOR
MODULE_NAME ("prperf")
/****************************************************************************
* Globals
****************************************************************************/
extern fadt_descriptor_rev2 acpi_fadt;
const u32 POWER_OF_2[] = {1,2,4,8,16,32,64,128,256,512};
/****************************************************************************
*
* FUNCTION: pr_perf_get_frequency
*
* PARAMETERS:
*
* RETURN:
*
* DESCRIPTION:
*
****************************************************************************/
acpi_status
pr_perf_get_frequency (
PR_CONTEXT *processor,
u32 *frequency) {
acpi_status status = AE_OK;
FUNCTION_TRACE("pr_perf_get_frequency");
if (!processor || !frequency) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
/* TBD: Generic method to calculate processor frequency. */
return_ACPI_STATUS(status);
}
/****************************************************************************
*
* FUNCTION: pr_perf_get_state
*
* PARAMETERS:
*
* RETURN:
*
* DESCRIPTION:
*
****************************************************************************/
/* TBD: Include support for _real_ performance states (not just throttling). */
acpi_status
pr_perf_get_state (
PR_CONTEXT *processor,
u32 *state)
{
u32 pblk_value = 0;
u32 duty_mask = 0;
u32 duty_cycle = 0;
FUNCTION_TRACE("pr_perf_get_state");
if (!processor || !state) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
if (processor->performance.state_count == 1) {
*state = 0;
return_ACPI_STATUS(AE_OK);
}
acpi_os_read_port(processor->pblk.address, &pblk_value, 32);
/*
* Throttling Enabled?
* -------------------
* If so, calculate the current throttling state, otherwise return
* '100% performance' (state 0).
*/
if (pblk_value & 0x00000010) {
duty_mask = processor->performance.state_count - 1;
duty_mask <<= acpi_fadt.duty_offset;
duty_cycle = pblk_value & duty_mask;
duty_cycle >>= acpi_fadt.duty_offset;
if (duty_cycle == 0) {
*state = 0;
}
else {
*state = processor->performance.state_count -
duty_cycle;
}
}
else {
*state = 0;
}
ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Processor [%02x] is at performance state [%d%%].\n", processor->device_handle, processor->performance.state[*state].performance));
return_ACPI_STATUS(AE_OK);
}
/****************************************************************************
*
* FUNCTION: pr_perf_set_state
*
* PARAMETERS:
*
* RETURN: AE_OK
* AE_BAD_PARAMETER
* AE_BAD_DATA Invalid target throttling state.
*
* DESCRIPTION:
*
****************************************************************************/
/* TBD: Includes support for _real_ performance states (not just throttling). */
acpi_status
pr_perf_set_state (
PR_CONTEXT *processor,
u32 state)
{
u32 pblk_value = 0;
u32 duty_mask = 0;
u32 duty_cycle = 0;
u32 i = 0;
FUNCTION_TRACE ("pr_perf_set_state");
if (!processor) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
if (state > (processor->performance.state_count - 1)) {
return_ACPI_STATUS(AE_BAD_DATA);
}
if ((state == processor->performance.active_state) ||
(processor->performance.state_count == 1)) {
return_ACPI_STATUS(AE_OK);
}
/*
* Calculate Duty Cycle/Mask:
* --------------------------
* Note that we don't support duty_cycle values that span bit 4.
*/
if (state) {
duty_cycle = processor->performance.state_count - state;
duty_cycle <<= acpi_fadt.duty_offset;
}
else {
duty_cycle = 0;
}
duty_mask = ~((u32)(processor->performance.state_count - 1));
for (i=0; i<acpi_fadt.duty_offset; i++) {
duty_mask <<= acpi_fadt.duty_offset;
duty_mask += 1;
}
/*
* Disable Throttling:
* -------------------
* Got to turn it off before you can change the duty_cycle value.
* Throttling is disabled by writing a 0 to bit 4.
*/
acpi_os_read_port(processor->pblk.address, &pblk_value, 32);
if (pblk_value & 0x00000010) {
pblk_value &= 0xFFFFFFEF;
acpi_os_write_port(processor->pblk.address, pblk_value, 32);
}
/*
* Set Duty Cycle:
* ---------------
* Mask off the old duty_cycle value, mask in the new.
*/
pblk_value &= duty_mask;
pblk_value |= duty_cycle;
acpi_os_write_port(processor->pblk.address, pblk_value, 32);
/*
* Enable Throttling:
* ------------------
* But only for non-zero (non-100% performance) states.
*/
if (state) {
pblk_value |= 0x00000010;
acpi_os_write_port(processor->pblk.address, pblk_value, 32);
}
processor->performance.active_state = state;
ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Processor [%02x] set to performance state [%d%%].\n", processor->device_handle, processor->performance.state[state].performance));
return_ACPI_STATUS(AE_OK);
}
/****************************************************************************
*
* FUNCTION: pr_perf_set_limit
*
* PARAMETERS:
*
* RETURN:
*
* DESCRIPTION:
*
****************************************************************************/
acpi_status
pr_perf_set_limit (
PR_CONTEXT *processor,
u32 limit)
{
acpi_status status = AE_OK;
PR_PERFORMANCE *performance = NULL;
FUNCTION_TRACE ("pr_perf_set_limit");
if (!processor) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
performance = &(processor->performance);
/*
* Set Limit:
* ----------
* TBD: Properly manage thermal and power limits (only set
* performance state iff...).
*/
switch (limit) {
case PR_PERF_DEC:
if (performance->active_state <
(performance->state_count-1)) {
status = pr_perf_set_state(processor,
(performance->active_state+1));
}
break;
case PR_PERF_INC:
if (performance->active_state > 0) {
status = pr_perf_set_state(processor,
(performance->active_state-1));
}
break;
case PR_PERF_MAX:
if (performance->active_state != 0) {
status = pr_perf_set_state(processor, 0);
}
break;
default:
return_ACPI_STATUS(AE_BAD_DATA);
break;
}
if (ACPI_SUCCESS(status)) {
performance->thermal_limit = performance->active_state;
}
ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Processor [%02x] thermal performance limit set to [%d%%].\n", processor->device_handle, processor->performance.state[performance->active_state].performance));
return_ACPI_STATUS(status);
}
/****************************************************************************
* External Functions
****************************************************************************/
/****************************************************************************
*
* FUNCTION: pr_perf_add_device
*
* PARAMETERS: processor Our processor-specific context.
*
* RETURN: AE_OK
* AE_BAD_PARAMETER
*
* DESCRIPTION: Calculates the number of throttling states and the state
* performance/power values.
*
****************************************************************************/
/* TBD: Support duty_cycle values that span bit 4. */
acpi_status
pr_perf_add_device (
PR_CONTEXT *processor)
{
acpi_status status = AE_OK;
u32 i = 0;
u32 performance_step = 0;
u32 percentage = 0;
FUNCTION_TRACE("pr_perf_add_device");
if (!processor) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
/*
* Valid PBLK?
* -----------
* For SMP it is common to have the first (boot) processor have a
* valid PBLK while all others do not -- which implies that
* throttling has system-wide effects (duty_cycle programmed into
* the chipset effects all processors).
*/
if ((processor->pblk.length < 6) || !processor->pblk.address) {
processor->performance.state_count = 1;
}
/*
* Valid Duty Offset/Width?
* ------------------------
* We currently only support duty_cycle values that fall within
* bits 0-3, as things get complicated when this value spans bit 4
* (the throttling enable/disable bit).
*/
else if ((acpi_fadt.duty_offset + acpi_fadt.duty_width) > 4) {
processor->performance.state_count = 1;
}
/*
* Compute State Count:
* --------------------
* The number of throttling states is computed as 2^duty_width,
* but limited by PR_MAX_THROTTLE_STATES. Note that a duty_width
* of zero results is one throttling state (100%).
*/
else {
processor->performance.state_count =
POWER_OF_2[acpi_fadt.duty_width];
}
if (processor->performance.state_count > PR_MAX_THROTTLE_STATES) {
processor->performance.state_count = PR_MAX_THROTTLE_STATES;
}
/*
* Compute State Values:
* ---------------------
* Note that clock throttling displays a linear power/performance
* relationship (at 50% performance the CPU will consume 50% power).
*/
performance_step = (1000 / processor->performance.state_count);
for (i=0; i<processor->performance.state_count; i++) {
percentage = (1000 - (performance_step * i))/10;
processor->performance.state[i].performance = percentage;
processor->performance.state[i].power = percentage;
}
/*
* Get Current State:
* ------------------
*/
status = pr_perf_get_state(processor, &(processor->performance.active_state));
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
/*
* Set to Maximum Performance:
* ---------------------------
* We'll let subsequent policy (e.g. thermal/power) decide to lower
* performance if it so chooses, but for now crank up the speed.
*/
if (0 != processor->performance.active_state) {
status = pr_perf_set_state(processor, 0);
}
return_ACPI_STATUS(status);
}
/****************************************************************************
*
* FUNCTION: pr_perf_remove_device
*
* PARAMETERS:
*
* RETURN:
*
* DESCRIPTION:
*
****************************************************************************/
acpi_status
pr_perf_remove_device (
PR_CONTEXT *processor)
{
acpi_status status = AE_OK;
FUNCTION_TRACE("pr_perf_remove_device");
if (!processor) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
MEMSET(&(processor->performance), 0, sizeof(PR_PERFORMANCE));
return_ACPI_STATUS(status);
}
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