linux-stable-rt/arch/i386/kernel/acpi/cstate.c

104 lines
2.4 KiB
C

/*
* arch/i386/kernel/acpi/cstate.c
*
* Copyright (C) 2005 Intel Corporation
* Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
* - Added _PDC for SMP C-states on Intel CPUs
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/acpi.h>
#include <acpi/processor.h>
#include <asm/acpi.h>
static void acpi_processor_power_init_intel_pdc(struct acpi_processor_power
*pow)
{
struct acpi_object_list *obj_list;
union acpi_object *obj;
u32 *buf;
/* allocate and initialize pdc. It will be used later. */
obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL);
if (!obj_list) {
printk(KERN_ERR "Memory allocation error\n");
return;
}
obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
if (!obj) {
printk(KERN_ERR "Memory allocation error\n");
kfree(obj_list);
return;
}
buf = kmalloc(12, GFP_KERNEL);
if (!buf) {
printk(KERN_ERR "Memory allocation error\n");
kfree(obj);
kfree(obj_list);
return;
}
buf[0] = ACPI_PDC_REVISION_ID;
buf[1] = 1;
buf[2] = ACPI_PDC_C_CAPABILITY_SMP;
obj->type = ACPI_TYPE_BUFFER;
obj->buffer.length = 12;
obj->buffer.pointer = (u8 *) buf;
obj_list->count = 1;
obj_list->pointer = obj;
pow->pdc = obj_list;
return;
}
/* Initialize _PDC data based on the CPU vendor */
void acpi_processor_power_init_pdc(struct acpi_processor_power *pow,
unsigned int cpu)
{
struct cpuinfo_x86 *c = cpu_data + cpu;
pow->pdc = NULL;
if (c->x86_vendor == X86_VENDOR_INTEL)
acpi_processor_power_init_intel_pdc(pow);
return;
}
EXPORT_SYMBOL(acpi_processor_power_init_pdc);
/*
* Initialize bm_flags based on the CPU cache properties
* On SMP it depends on cache configuration
* - When cache is not shared among all CPUs, we flush cache
* before entering C3.
* - When cache is shared among all CPUs, we use bm_check
* mechanism as in UP case
*
* This routine is called only after all the CPUs are online
*/
void acpi_processor_power_init_bm_check(struct acpi_processor_flags *flags,
unsigned int cpu)
{
struct cpuinfo_x86 *c = cpu_data + cpu;
flags->bm_check = 0;
if (num_online_cpus() == 1)
flags->bm_check = 1;
else if (c->x86_vendor == X86_VENDOR_INTEL) {
/*
* Today all CPUs that support C3 share cache.
* TBD: This needs to look at cache shared map, once
* multi-core detection patch makes to the base.
*/
flags->bm_check = 1;
}
}
EXPORT_SYMBOL(acpi_processor_power_init_bm_check);