freebsd-skq/sys/dev/acpica/acpi_processor.c
msmith a69e8faa90 Initial FreeBSD OSPM (operating system power management) modules for
ACPICA.  Most of these are still works in progress.  Support exists for:

 - Fixed feature and control method power, lid and sleep buttons.
 - Detection of ISA PnP devices using ACPI namespace.
 - Detection of PCI root busses using ACPI namespace.
 - CPU throttling and sleep states (incomplete)
 - Thermal monitoring and cooling control (incomplete)
 - Interface to platform embedded controllers (mostly complete)
 - ACPI timer (incomplete)
 - Simple userland control of sleep states.
 - Shutdown and poweroff.
2000-10-28 06:59:48 +00:00

641 lines
22 KiB
C

/*-
* Copyright (c) 2000 Michael Smith
* Copyright (c) 2000 BSDi
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
/******************************************************************************
*
* 1. Copyright Notice
*
* Some or all of this work - Copyright (c) 1999, Intel Corp. All rights
* reserved.
*
* 2. License
*
* 2.1. This is your license from Intel Corp. under its intellectual property
* rights. You may have additional license terms from the party that provided
* you this software, covering your right to use that party's intellectual
* property rights.
*
* 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a
* copy of the source code appearing in this file ("Covered Code") an
* irrevocable, perpetual, worldwide license under Intel's copyrights in the
* base code distributed originally by Intel ("Original Intel Code") to copy,
* make derivatives, distribute, use and display any portion of the Covered
* Code in any form, with the right to sublicense such rights; and
*
* 2.3. Intel grants Licensee a non-exclusive and non-transferable patent
* license (with the right to sublicense), under only those claims of Intel
* patents that are infringed by the Original Intel Code, to make, use, sell,
* offer to sell, and import the Covered Code and derivative works thereof
* solely to the minimum extent necessary to exercise the above copyright
* license, and in no event shall the patent license extend to any additions
* to or modifications of the Original Intel Code. No other license or right
* is granted directly or by implication, estoppel or otherwise;
*
* The above copyright and patent license is granted only if the following
* conditions are met:
*
* 3. Conditions
*
* 3.1. Redistribution of Source with Rights to Further Distribute Source.
* Redistribution of source code of any substantial portion of the Covered
* Code or modification with rights to further distribute source must include
* the above Copyright Notice, the above License, this list of Conditions,
* and the following Disclaimer and Export Compliance provision. In addition,
* Licensee must cause all Covered Code to which Licensee contributes to
* contain a file documenting the changes Licensee made to create that Covered
* Code and the date of any change. Licensee must include in that file the
* documentation of any changes made by any predecessor Licensee. Licensee
* must include a prominent statement that the modification is derived,
* directly or indirectly, from Original Intel Code.
*
* 3.2. Redistribution of Source with no Rights to Further Distribute Source.
* Redistribution of source code of any substantial portion of the Covered
* Code or modification without rights to further distribute source must
* include the following Disclaimer and Export Compliance provision in the
* documentation and/or other materials provided with distribution. In
* addition, Licensee may not authorize further sublicense of source of any
* portion of the Covered Code, and must include terms to the effect that the
* license from Licensee to its licensee is limited to the intellectual
* property embodied in the software Licensee provides to its licensee, and
* not to intellectual property embodied in modifications its licensee may
* make.
*
* 3.3. Redistribution of Executable. Redistribution in executable form of any
* substantial portion of the Covered Code or modification must reproduce the
* above Copyright Notice, and the following Disclaimer and Export Compliance
* provision in the documentation and/or other materials provided with the
* distribution.
*
* 3.4. Intel retains all right, title, and interest in and to the Original
* Intel Code.
*
* 3.5. Neither the name Intel nor any other trademark owned or controlled by
* Intel shall be used in advertising or otherwise to promote the sale, use or
* other dealings in products derived from or relating to the Covered Code
* without prior written authorization from Intel.
*
* 4. Disclaimer and Export Compliance
*
* 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED
* HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE
* IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE,
* INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY
* UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY
* IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
* PARTICULAR PURPOSE.
*
* 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
* OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
* COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
* SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
* CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
* HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS
* SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
* LIMITED REMEDY.
*
* 4.3. Licensee shall not export, either directly or indirectly, any of this
* software or system incorporating such software without first obtaining any
* required license or other approval from the U. S. Department of Commerce or
* any other agency or department of the United States Government. In the
* event Licensee exports any such software from the United States or
* re-exports any such software from a foreign destination, Licensee shall
* ensure that the distribution and export/re-export of the software is in
* compliance with all laws, regulations, orders, or other restrictions of the
* U.S. Export Administration Regulations. Licensee agrees that neither it nor
* any of its subsidiaries will export/re-export any technical data, process,
* software, or service, directly or indirectly, to any country for which the
* United States government or any agency thereof requires an export license,
* other governmental approval, or letter of assurance, without first obtaining
* such license, approval or letter.
*
*****************************************************************************/
/*
* Processor driver.
*
* XXX Note that the power state code here is almost certainly suboptimal.
* We should go raid the Linux code for their ideas and experience.
*
* Code style here is a hairy mix of BSD-like and Intel-like. Should be
* sanitised at some point.
*/
#include "opt_acpi.h"
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include "acpi.h"
#include <dev/acpica/acpivar.h>
#define PR_MAX_POWER_STATES 4
#define PR_MAX_PERFORMANCE_STATES 8
#define PR_MAX_THROTTLING_STATES 8
/*
* Processor Commands:
* -------------------
*/
#define PR_COMMAND_GET_INFO ((BM_COMMAND) 0x80)
#define PR_COMMAND_SET_CX_STATE_INFO ((BM_COMMAND) 0x81)
#define PR_COMMAND_GET_THROTTLING_STATE ((BM_COMMAND) 0x82)
#define PR_COMMAND_SET_THROTTLING_STATE ((BM_COMMAND) 0x83)
#define PR_COMMAND_GET_PERF_STATE ((BM_COMMAND) 0x84)
#define PR_COMMAND_SET_PERF_STATE ((BM_COMMAND) 0x85)
#define PR_COMMAND_GET_CURRENT_FREQ ((BM_COMMAND) 0x86)
/*
* PR_POWER_STATE:
* ---------------
*/
typedef u_int32_t PR_POWER_STATE;
#define PR_POWER_STATE_UNKNOWN ((PR_POWER_STATE) 0xFFFFFFFF)
#define PR_POWER_STATE_C0 ((PR_POWER_STATE) 0x00000000)
#define PR_POWER_STATE_C1 ((PR_POWER_STATE) 0x00000001)
#define PR_POWER_STATE_C2 ((PR_POWER_STATE) 0x00000002)
#define PR_POWER_STATE_C3 ((PR_POWER_STATE) 0x00000003)
/*
* Processor Notifications:
* ------------------------
*/
#define PR_NOTIFY_PERF_STATES_CHANGE ((BM_NOTIFY) 0x80)
#define PR_NOTIFY_POWER_STATES_CHANGE ((BM_NOTIFY) 0x81)
typedef struct
{
u_int32_t TimeThreshold;
u_int32_t CountThreshold;
u_int32_t Count;
PR_POWER_STATE TargetState;
} PR_POLICY_VALUES;
/*
* PR_CX_STATE_INFO:
* -----------------
*/
typedef struct
{
u_int32_t Latency;
u_int64_t Utilization;
PR_POLICY_VALUES PromotionPolicy;
PR_POLICY_VALUES DemotionPolicy;
} PR_CX_STATE_INFO;
/*
* PR_POWER_INFO:
* --------------
*/
typedef struct
{
u_int32_t Count;
PR_POWER_STATE ActiveState;
PR_CX_STATE_INFO Info[PR_MAX_POWER_STATES];
} PR_POWER_INFO;
/*
* PR_PERFORMANCE_INFO:
* --------------------
*/
typedef struct
{
u_int32_t Count;
/* TODO... */
} PR_PERFORMANCE_INFO;
/*
* PR_THROTTLING_INFO:
* -------------------
*/
typedef struct
{
u_int32_t Count;
u_int32_t Percentage[PR_MAX_THROTTLING_STATES];
} PR_THROTTLING_INFO;
struct acpi_pr_softc {
device_t pr_dev;
ACPI_HANDLE pr_handle;
PR_POWER_INFO pr_PowerStates;
PR_PERFORMANCE_INFO pr_PerformanceStates;
PR_THROTTLING_INFO pr_ThrottlingStates;
eventhandler_tag pr_idleevent;
/* local APIC data */
PROCESSOR_APIC pr_lapic;
};
#define PR_MAGIC 0x20555043 /* "CPU " */
static void acpi_pr_identify(driver_t *driver, device_t bus);
static ACPI_STATUS acpi_pr_identify_cpu(ACPI_HANDLE handle, UINT32 level, void *context, void **status);
static int acpi_pr_probe(device_t dev);
static int acpi_pr_attach(device_t dev);
static void acpi_pr_FindLapic(device_t dev, ACPI_HANDLE handle, PROCESSOR_APIC *lapic);
static ACPI_STATUS acpi_pr_CalculatePowerStates(struct acpi_pr_softc *sc);
static ACPI_STATUS acpi_pr_CalculatePerformanceStates(struct acpi_pr_softc *sc);
static ACPI_STATUS acpi_pr_CalculateThrottlingStates(struct acpi_pr_softc *sc);
static void acpi_pr_IdleHandler(void *arg, int count);
static ACPI_STATUS acpi_pr_PolicyInitialize(struct acpi_pr_softc *sc);
static device_method_t acpi_pr_methods[] = {
/* Device interface */
DEVMETHOD(device_identify, acpi_pr_identify),
DEVMETHOD(device_probe, acpi_pr_probe),
DEVMETHOD(device_attach, acpi_pr_attach),
{0, 0}
};
static driver_t acpi_pr_driver = {
"acpi_pr",
acpi_pr_methods,
sizeof(struct acpi_pr_softc),
};
devclass_t acpi_pr_devclass;
DRIVER_MODULE(acpi_pr, acpi, acpi_pr_driver, acpi_pr_devclass, 0, 0);
/*
* Scan the \_PR_ scope for processor objects, and attach them accordingly.
*
* XXX note that we should find the local APIC address and obtain a resource
* that we can hand to child devices for access to it...
*/
static void
acpi_pr_identify(driver_t *driver, device_t bus)
{
ACPI_HANDLE handle;
if (AcpiGetHandle(ACPI_ROOT_OBJECT, "\\_PR_", &handle) == AE_OK)
AcpiWalkNamespace(ACPI_TYPE_PROCESSOR, handle, 2, acpi_pr_identify_cpu, bus, NULL);
}
/*
* Create a child device for CPUs
*/
static ACPI_STATUS
acpi_pr_identify_cpu(ACPI_HANDLE handle, UINT32 level, void *context, void **status)
{
device_t bus = (device_t)context;
device_t child;
PROCESSOR_APIC lapic;
acpi_pr_FindLapic(bus, handle, &lapic);
if (lapic.ProcessorEnabled) {
if ((child = BUS_ADD_CHILD(bus, 0, "acpi_pr", -1)) == NULL) {
device_printf(bus, "could not create CPU device\n");
return(AE_OK);
}
acpi_set_handle(child, handle);
acpi_set_magic(child, PR_MAGIC);
device_set_desc(child, "processor device");
}
return(AE_OK);
}
static int
acpi_pr_probe(device_t dev)
{
if (acpi_get_magic(dev) == PR_MAGIC)
return(0);
return(ENXIO);
}
static int
acpi_pr_attach(device_t dev)
{
struct acpi_pr_softc *sc;
sc = device_get_softc(dev);
sc->pr_dev = dev;
sc->pr_handle = acpi_get_handle(dev);
acpi_pr_FindLapic(dev, sc->pr_handle, &sc->pr_lapic);
/*
* If the APIC information is valid, print it
*/
if (sc->pr_lapic.LocalApicId != (UINT8)0xff)
device_printf(dev, "local APIC ID %d\n", sc->pr_lapic.LocalApicId);
/*
* Fetch operational parameters.
*/
if (acpi_pr_CalculatePowerStates(sc) == AE_OK) {
acpi_pr_PolicyInitialize(sc);
}
acpi_pr_CalculatePerformanceStates(sc);
acpi_pr_CalculateThrottlingStates(sc);
/* XXX call MD cpu-identification here? */
return(0);
}
/*
* Find the Local Apic information for this CPU
*/
static void
acpi_pr_FindLapic(device_t dev, ACPI_HANDLE handle, PROCESSOR_APIC *lapic)
{
ACPI_BUFFER buf;
ACPI_STATUS status;
APIC_HEADER *hdr;
APIC_TABLE *tbl;
PROCESSOR_APIC *pap;
int len, cpuno;
/*
* Assume that we're not going to suceed in finding/parsing the APIC table.
* In this case, CPU 0 is valid, and any other CPU is invalid.
*/
lapic->LocalApicId = 0xff;
lapic->ProcessorEnabled = 0;
if ((status = AcpiGetProcessorId(handle, &cpuno)) != AE_OK) {
device_printf(dev, "error fetching CPU device ID - %s\n", acpi_strerror(status));
return;
}
lapic->ProcessorEnabled = (cpuno == 0);
/*
* Perform the tedious double-get to fetch the actual APIC table, and suck it in.
*/
buf.Length = 0;
buf.Pointer = NULL;
if ((status = AcpiGetTable(ACPI_TABLE_APIC, 1, &buf)) != AE_BUFFER_OVERFLOW) {
if (status != AE_NOT_EXIST)
device_printf(dev, "error sizing APIC table - %s\n", acpi_strerror(status));
return;
}
if ((buf.Pointer = AcpiOsAllocate(buf.Length)) == NULL)
return;
if ((status = AcpiGetTable(ACPI_TABLE_APIC, 1, &buf)) != AE_OK) {
device_printf(dev, "error fetching APIC table - %s\n", acpi_strerror(status));
return;
}
/*
* Scan the tables looking for this CPU index.
*/
tbl = (APIC_TABLE *)buf.Pointer;
len = tbl->header.Length - sizeof(APIC_TABLE);
hdr = (APIC_HEADER *)((char *)buf.Pointer + sizeof(APIC_TABLE));
while(len > 0) {
if (hdr->Length > len) {
device_printf(dev, "APIC header corrupt (claims %d bytes where only %d left in structure)\n",
hdr->Length, len);
break;
}
/*
* If we have found a processor APIC definition with
* matching CPU index, copy it out and return.
*/
if (hdr->Type == APIC_PROC) {
pap = (PROCESSOR_APIC *)hdr;
if (pap->ProcessorApicId == cpuno) {
bcopy(pap, lapic, sizeof(*pap));
break;
}
}
len -= hdr->Length;
hdr = (APIC_HEADER *)((char *)hdr + hdr->Length);
}
AcpiOsFree(buf.Pointer);
}
static ACPI_STATUS
acpi_pr_CalculatePowerStates(struct acpi_pr_softc *sc)
{
ACPI_STATUS Status = AE_OK;
ACPI_BUFFER Buffer;
ACPI_CX_STATE *State = NULL;
u_int32_t StateCount = 0;
u_int32_t i = 0;
/*
* Set Latency Defaults:
* ---------------------
* Default state latency to ACPI_UINT32_MAX -- meaning that this state
* should not be used by policy. This value is overriden by states
* that are present and have usable latencies (e.g. <= 1000us for C3).
*/
for (i = 0; i < PR_MAX_POWER_STATES; i++)
sc->pr_PowerStates.Info[i].Latency = ACPI_UINT32_MAX;
/*
* Get Power State Latencies:
* --------------------------
*
* XXX Note that ACPICA will never give us back C2 if it costs more than 100us,
* or C3 if it costs more than 1000us, so some of this code is redundant.
*/
Status = acpi_GetIntoBuffer(sc->pr_handle, AcpiGetProcessorCxInfo, &Buffer);
if (Status != AE_OK) {
device_printf(sc->pr_dev, "could not fetch ProcessorCxInfo - %s\n", acpi_strerror(Status));
return(Status);
}
State = (ACPI_CX_STATE*)(Buffer.Pointer);
if (State != NULL) {
device_printf(sc->pr_dev, "supported power states:");
StateCount = Buffer.Length / sizeof(ACPI_CX_STATE);
for (i = 0; i < StateCount; i++) {
/* XXX C3 isn't supportable in MP configurations, how to best handle this? */
if ((State[i].StateNumber < PR_MAX_POWER_STATES) && (State[i].Latency <= 1000)) {
printf(" C%d (%dus)", i, State[i].Latency);
sc->pr_PowerStates.Info[State[i].StateNumber].Latency = State[i].Latency;
}
}
printf("\n");
}
sc->pr_PowerStates.Count = PR_MAX_POWER_STATES;
sc->pr_PowerStates.ActiveState = PR_POWER_STATE_C1;
AcpiOsFree(Buffer.Pointer);
return(Status);
}
static ACPI_STATUS
acpi_pr_CalculatePerformanceStates(struct acpi_pr_softc *sc)
{
ACPI_STATUS Status = AE_OK;
/* TODO... */
return(Status);
}
static ACPI_STATUS
acpi_pr_CalculateThrottlingStates(struct acpi_pr_softc *sc)
{
ACPI_STATUS Status = AE_OK;
ACPI_BUFFER Buffer;
ACPI_CPU_THROTTLING_STATE *State = NULL;
u_int32_t StateCount = 0;
u_int32_t i = 0;
/*
* Get Throttling States:
* ----------------------
*/
Status = acpi_GetIntoBuffer(sc->pr_handle, AcpiGetProcessorThrottlingInfo, &Buffer);
if (Status != AE_OK) {
device_printf(sc->pr_dev, "could not fetch ThrottlingInfo - %s\n", acpi_strerror(Status));
return(Status);
}
State = (ACPI_CPU_THROTTLING_STATE*)(Buffer.Pointer);
if (State != NULL) {
StateCount = Buffer.Length / sizeof(ACPI_CPU_THROTTLING_STATE);
device_printf(sc->pr_dev, "supported throttling states:");
for (i = 0; i < StateCount; i++) {
if (State[i].StateNumber < PR_MAX_THROTTLING_STATES) {
/* TODO: Verify that state is *really* supported by this chipset/processor (e.g. errata). */
sc->pr_ThrottlingStates.Percentage[State[i].StateNumber] = State[i].PercentOfClock;
sc->pr_ThrottlingStates.Count++;
printf(" %d%%", State[i].PercentOfClock);
}
}
printf("\n");
}
AcpiOsFree(Buffer.Pointer);
return(Status);
}
static ACPI_STATUS
acpi_pr_PolicyInitialize(struct acpi_pr_softc *sc)
{
ACPI_STATUS status;
if ((status = AcpiSetProcessorSleepState(sc->pr_handle, sc->pr_PowerStates.ActiveState)) != AE_OK) {
device_printf(sc->pr_dev, "could not set Active sleep state - %s\n", acpi_strerror(status));
return(status);
}
/* XXX need to hook ourselves to be called when things go idle */
/* sc->pr_idleevent = EVENTHANDLER_FAST_REGISTER(idle_event, acpi_pr_IdleHandler, sc, IDLE_PRI_FIRST); */
return(AE_OK);
}
static void
acpi_pr_IdleHandler(void *arg, int count)
{
struct acpi_pr_softc *sc = (struct acpi_pr_softc *)arg;
ACPI_STATUS Status = AE_OK;
PR_CX_STATE_INFO *CxState = NULL;
PR_POWER_STATE ActiveState = PR_POWER_STATE_UNKNOWN;
PR_POWER_STATE NextState = PR_POWER_STATE_UNKNOWN;
u_int32_t PmTimerTicks = 0;
ActiveState = NextState = sc->pr_PowerStates.ActiveState;
CxState = &(sc->pr_PowerStates.Info[ActiveState]);
CxState->Utilization++;
/*
* Invoke Cx State:
* ----------------
*/
if ((Status = AcpiProcessorSleep(sc->pr_handle, &PmTimerTicks)) != AE_OK) {
device_printf(sc->pr_dev, "AcpiProcessorSleep() failed - %s\n", acpi_strerror(Status));
/*
* Something went wrong with the sleep attempt, so give up on trying to do this.
*/
/* EVENTHANDLER_FAST_DEREGISTER(idle_event, sc->pr_idleevent);*/
device_printf(sc->pr_dev, "disabling CPU power saving\n");
return;
}
/*
* Check For State Promotion:
* --------------------------
* Only need to check for promotion on C1 and C2, and then only
* when the state has a non-zero count threshold and target state.
*/
if (CxState->PromotionPolicy.CountThreshold && CxState->PromotionPolicy.TargetState &&
((ActiveState == PR_POWER_STATE_C1) || (ActiveState == PR_POWER_STATE_C2))) {
/*
* Check the amount of time we spent in the Cx state against our
* promotion policy. If successful (asleep longer than our threshold)
* increment our count and see if a promotion is in order.
*/
if (PmTimerTicks > (CxState->PromotionPolicy.TimeThreshold)) {
CxState->PromotionPolicy.Count++;
CxState->DemotionPolicy.Count = 0;
if (CxState->PromotionPolicy.Count >= CxState->PromotionPolicy.CountThreshold)
NextState = CxState->PromotionPolicy.TargetState;
}
}
/*
* Check For State Demotion:
* -------------------------
* Only need to check for demotion on C2 and C3, and then only
* when the state has a non-zero count threshold and target state.
*/
if (CxState->DemotionPolicy.CountThreshold && CxState->DemotionPolicy.TargetState &&
((ActiveState == PR_POWER_STATE_C2) || (ActiveState == PR_POWER_STATE_C3))) {
/*
* Check the amount of time we spent in the Cx state against our
* demotion policy. If unsuccessful (asleep shorter than our threshold)
* increment our count and see if a demotion is in order.
*/
if (PmTimerTicks < (CxState->DemotionPolicy.TimeThreshold)) {
CxState->DemotionPolicy.Count++;
CxState->PromotionPolicy.Count = 0;
if (CxState->DemotionPolicy.Count >= CxState->DemotionPolicy.CountThreshold)
NextState = CxState->DemotionPolicy.TargetState;
}
}
/*
* New Cx State?
* -------------
* If so, clean up from the previous Cx state (if necessary).
*/
if (NextState != sc->pr_PowerStates.ActiveState) {
if ((Status = AcpiSetProcessorSleepState(sc->pr_handle, NextState)) != AE_OK) {
device_printf(sc->pr_dev, "AcpiSetProcessorSleepState() returned error [0x%08X]\n", Status);
} else {
CxState->PromotionPolicy.Count = 0;
CxState->DemotionPolicy.Count = 0;
sc->pr_PowerStates.ActiveState = NextState;
}
}
}