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/*
* cpu.c - Processor handling
*
* Copyright (C) 2000 Andrew Henroid
*
* 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/config.h>
#include <linux/kernel.h>
#include <linux/pm.h>
#include <linux/acpi.h>
#include "acpi.h"
#include "driver.h"
unsigned long acpi_c2_exit_latency = ACPI_INFINITE;
unsigned long acpi_c3_exit_latency = ACPI_INFINITE;
unsigned long acpi_c2_enter_latency = ACPI_INFINITE;
unsigned long acpi_c3_enter_latency = ACPI_INFINITE;
static unsigned long acpi_pblk = ACPI_INVALID;
static int acpi_c2_tested = 0;
static int acpi_c3_tested = 0;
/*
* Clear busmaster activity flag
*/
static inline void
acpi_clear_bm_activity(struct acpi_facp *facp)
{
acpi_write_pm1_status(facp, ACPI_BM);
}
/*
* Returns 1 if there has been busmaster activity
*/
static inline int
acpi_bm_activity(struct acpi_facp *facp)
{
return acpi_read_pm1_status(facp) & ACPI_BM;
}
/*
* Set system to sleep through busmaster requests
*/
static void
acpi_sleep_on_busmaster(struct acpi_facp *facp)
{
u32 pm1_cntr = acpi_read_pm1_control(facp);
if (pm1_cntr & ACPI_BM_RLD) {
pm1_cntr &= ~ACPI_BM_RLD;
acpi_write_pm1_control(facp, pm1_cntr);
}
}
/*
* Set system to wake on busmaster requests
*/
static void
acpi_wake_on_busmaster(struct acpi_facp *facp)
{
u32 pm1_cntr = acpi_read_pm1_control(facp);
if (!(pm1_cntr & ACPI_BM_RLD)) {
pm1_cntr |= ACPI_BM_RLD;
acpi_write_pm1_control(facp, pm1_cntr);
}
acpi_clear_bm_activity(facp);
}
/* The ACPI timer is just the low 24 bits */
#define TIME_BEGIN(tmr) inl(tmr)
#define TIME_END(tmr, begin) ((inl(tmr) - (begin)) & 0x00ffffff)
/*
* Idle loop (uniprocessor only)
*/
static void
acpi_idle(void)
{
static int sleep_level = 1;
struct acpi_facp *facp = &acpi_facp;
if (!facp
|| facp->hdr.signature != ACPI_FACP_SIG
|| !facp->pm_tmr
|| !acpi_pblk)
goto not_initialized;
/*
* start from the previous sleep level..
*/
if (sleep_level == 1)
goto sleep1;
if (sleep_level == 2)
goto sleep2;
sleep3:
sleep_level = 3;
if (!acpi_c3_tested) {
printk(KERN_DEBUG "ACPI C3 works\n");
acpi_c3_tested = 1;
}
acpi_wake_on_busmaster(facp);
if (facp->pm2_cnt)
goto sleep3_with_arbiter;
for (;;) {
unsigned long time;
unsigned int pm_tmr = facp->pm_tmr;
__cli();
if (current->need_resched)
goto out;
if (acpi_bm_activity(facp))
goto sleep2;
time = TIME_BEGIN(pm_tmr);
inb(acpi_pblk + ACPI_P_LVL3);
/* Dummy read, force synchronization with the PMU */
inl(pm_tmr);
time = TIME_END(pm_tmr, time);
__sti();
if (time < acpi_c3_exit_latency)
goto sleep2;
}
sleep3_with_arbiter:
for (;;) {
unsigned long time;
u8 arbiter;
unsigned int pm2_cntr = facp->pm2_cnt;
unsigned int pm_tmr = facp->pm_tmr;
__cli();
if (current->need_resched)
goto out;
if (acpi_bm_activity(facp))
goto sleep2;
time = TIME_BEGIN(pm_tmr);
arbiter = inb(pm2_cntr) & ~ACPI_ARB_DIS;
/* Disable arbiter, park on CPU */
outb(arbiter | ACPI_ARB_DIS, pm2_cntr);
inb(acpi_pblk + ACPI_P_LVL3);
/* Dummy read, force synchronization with the PMU */
inl(pm_tmr);
time = TIME_END(pm_tmr, time);
/* Enable arbiter again.. */
outb(arbiter, pm2_cntr);
__sti();
if (time < acpi_c3_exit_latency)
goto sleep2;
}
sleep2:
sleep_level = 2;
if (!acpi_c2_tested) {
printk(KERN_DEBUG "ACPI C2 works\n");
acpi_c2_tested = 1;
}
acpi_wake_on_busmaster(facp); /* Required to track BM activity.. */
for (;;) {
unsigned long time;
unsigned int pm_tmr = facp->pm_tmr;
__cli();
if (current->need_resched)
goto out;
time = TIME_BEGIN(pm_tmr);
inb(acpi_pblk + ACPI_P_LVL2);
/* Dummy read, force synchronization with the PMU */
inl(pm_tmr);
time = TIME_END(pm_tmr, time);
__sti();
if (time < acpi_c2_exit_latency)
goto sleep1;
if (acpi_bm_activity(facp)) {
acpi_clear_bm_activity(facp);
continue;
}
if (time > acpi_c3_enter_latency)
goto sleep3;
}
sleep1:
sleep_level = 1;
acpi_sleep_on_busmaster(facp);
for (;;) {
unsigned long time;
unsigned int pm_tmr = facp->pm_tmr;
__cli();
if (current->need_resched)
goto out;
time = TIME_BEGIN(pm_tmr);
safe_halt();
time = TIME_END(pm_tmr, time);
if (time > acpi_c2_enter_latency)
goto sleep2;
}
not_initialized:
for (;;) {
__cli();
if (current->need_resched)
goto out;
safe_halt();
}
out:
__sti();
}
/*
* Get processor information
*/
static ACPI_STATUS
acpi_find_cpu(ACPI_HANDLE handle, u32 level, void *ctx, void **value)
{
ACPI_OBJECT obj;
ACPI_CX_STATE lat[4];
ACPI_CPU_THROTTLING_STATE throttle[ACPI_MAX_THROTTLE];
ACPI_BUFFER buf;
int i, count;
buf.length = sizeof(obj);
buf.pointer = &obj;
if (!ACPI_SUCCESS(acpi_evaluate_object(handle, NULL, NULL, &buf)))
return AE_OK;
printk(KERN_INFO "ACPI: PBLK %d @ 0x%04x:%d\n",
obj.processor.proc_id,
obj.processor.pblk_address,
obj.processor.pblk_length);
if (acpi_pblk != ACPI_INVALID
|| !obj.processor.pblk_address
|| obj.processor.pblk_length != 6)
return AE_OK;
acpi_pblk = obj.processor.pblk_address;
buf.length = sizeof(lat);
buf.pointer = lat;
if (!ACPI_SUCCESS(acpi_get_processor_cx_info(handle, &buf)))
return AE_OK;
if (lat[2].latency < MAX_CX_STATE_LATENCY) {
printk(KERN_INFO "ACPI: C2 supported\n");
acpi_c2_exit_latency = lat[2].latency;
}
if (lat[3].latency < MAX_CX_STATE_LATENCY) {
printk(KERN_INFO "ACPI: C3 supported\n");
acpi_c3_exit_latency = lat[3].latency;
}
memset(throttle, 0, sizeof(throttle));
buf.length = sizeof(throttle);
buf.pointer = throttle;
if (!ACPI_SUCCESS(acpi_get_processor_throttling_info(handle, &buf)))
return AE_OK;
for (i = 0, count = 0; i < ACPI_MAX_THROTTLE; i++) {
if (throttle[i].percent_of_clock)
count++;
}
count--;
if (count > 0)
printk(KERN_INFO "ACPI: %d throttling states\n", count);
return AE_OK;
}
int
acpi_cpu_init(void)
{
acpi_walk_namespace(ACPI_TYPE_PROCESSOR,
ACPI_ROOT_OBJECT,
ACPI_INT32_MAX,
acpi_find_cpu,
NULL,
NULL);
#ifdef CONFIG_SMP
if (smp_num_cpus == 1)
pm_idle = acpi_idle;
#else
pm_idle = acpi_idle;
#endif
return 0;
}
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