processor_pdc.c
/*
* Copyright (C) 2005 Intel Corporation
* Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
*
* Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
* - Added _PDC for platforms with Intel CPUs
*/
#define pr_fmt(fmt) "ACPI: " fmt
#include <linux/dmi.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <acpi/processor.h>
#include "internal.h"
#define _COMPONENT ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME("processor_pdc");
static bool __init processor_physically_present(acpi_handle handle)
{
int cpuid, type;
u32 acpi_id;
acpi_status status;
acpi_object_type acpi_type;
unsigned long long tmp;
union acpi_object object = { 0 };
struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
status = acpi_get_type(handle, &acpi_type);
if (ACPI_FAILURE(status))
return false;
switch (acpi_type) {
case ACPI_TYPE_PROCESSOR:
status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
if (ACPI_FAILURE(status))
return false;
acpi_id = object.processor.proc_id;
break;
case ACPI_TYPE_DEVICE:
status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
if (ACPI_FAILURE(status))
return false;
acpi_id = tmp;
break;
default:
return false;
}
type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
cpuid = acpi_get_cpuid(handle, type, acpi_id);
if (cpuid == -1)
return false;
return true;
}
static void acpi_set_pdc_bits(u32 *buf)
{
buf[0] = ACPI_PDC_REVISION_ID;
buf[1] = 1;
/* Enable coordination with firmware's _TSD info */
buf[2] = ACPI_PDC_SMP_T_SWCOORD;
/* Twiddle arch-specific bits needed for _PDC */
arch_acpi_set_pdc_bits(buf);
}
static struct acpi_object_list *acpi_processor_alloc_pdc(void)
{
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)
goto out;
obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
if (!obj) {
kfree(obj_list);
goto out;
}
buf = kmalloc(12, GFP_KERNEL);
if (!buf) {
kfree(obj);
kfree(obj_list);
goto out;
}
acpi_set_pdc_bits(buf);
obj->type = ACPI_TYPE_BUFFER;
obj->buffer.length = 12;
obj->buffer.pointer = (u8 *) buf;
obj_list->count = 1;
obj_list->pointer = obj;
return obj_list;
out:
pr_err("Memory allocation error\n");
return NULL;
}
/*
* _PDC is required for a BIOS-OS handshake for most of the newer
* ACPI processor features.
*/
static acpi_status
acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in)
{
acpi_status status = AE_OK;
if (boot_option_idle_override == IDLE_NOMWAIT) {
/*
* If mwait is disabled for CPU C-states, the C2C3_FFH access
* mode will be disabled in the parameter of _PDC object.
* Of course C1_FFH access mode will also be disabled.
*/
union acpi_object *obj;
u32 *buffer = NULL;
obj = pdc_in->pointer;
buffer = (u32 *)(obj->buffer.pointer);
buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH);
}
status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL);
if (ACPI_FAILURE(status))
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Could not evaluate _PDC, using legacy perf. control.\n"));
return status;
}
void acpi_processor_set_pdc(acpi_handle handle)
{
struct acpi_object_list *obj_list;
if (arch_has_acpi_pdc() == false)
return;
obj_list = acpi_processor_alloc_pdc();
if (!obj_list)
return;
acpi_processor_eval_pdc(handle, obj_list);
kfree(obj_list->pointer->buffer.pointer);
kfree(obj_list->pointer);
kfree(obj_list);
}
static acpi_status __init
early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)
{
if (processor_physically_present(handle) == false)
return AE_OK;
acpi_processor_set_pdc(handle);
return AE_OK;
}
static int __init set_no_mwait(const struct dmi_system_id *id)
{
pr_notice("%s detected - disabling mwait for CPU C-states\n",
id->ident);
boot_option_idle_override = IDLE_NOMWAIT;
return 0;
}
static struct dmi_system_id processor_idle_dmi_table[] __initdata = {
{
set_no_mwait, "Extensa 5220", {
DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
DMI_MATCH(DMI_PRODUCT_VERSION, "0100"),
DMI_MATCH(DMI_BOARD_NAME, "Columbia") }, NULL},
{},
};
static void __init processor_dmi_check(void)
{
/*
* Check whether the system is DMI table. If yes, OSPM
* should not use mwait for CPU-states.
*/
dmi_check_system(processor_idle_dmi_table);
}
void __init acpi_early_processor_set_pdc(void)
{
processor_dmi_check();
acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
ACPI_UINT32_MAX,
early_init_pdc, NULL, NULL, NULL);
acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, early_init_pdc, NULL, NULL);
}