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DragonFly kernel List (threaded) for 2004-01
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Something to do


From: David Rhodus <drhodus@xxxxxxxxxxx>
Date: Mon, 19 Jan 2004 23:23:10 -0500

If someone is still wanting something to do, make this
compile and then send in a patch for this..
This is all that is needed for the Thermal Control Circuitry
that is found in some P4 chips to work. This allows us restrict
the power consumption of the chip.

-DR

/* $OpenBSD: p4tcc.c,v 1.1 2003/12/20 18:23:18 tedu Exp $ */
/*
* Copyright (c) 2003 Ted Unangst
* Copyright (c) 2004 Maxim Sobolev <sobomax@xxxxxxxxxxx>
* 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 ``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 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.
*/
/*
* Restrict power consumption by using thermal control circuit.
* This operates independently of speedstep.
* Found on Pentium 4 and later models (feature TM).
*
* References:
* Intel Developer's manual v.3 #245472-012
*
* On some models, the cpu can hang if it's running at a slow speed.
* Workarounds included below.
*/


#include <sys/cdefs.h>
__FBSDID("$FreeBSD: /repoman/r/ncvs/src/sys/i386/i386/p4tcc.c,v 1.1 2004/01/18 21:06:56 sobomax Exp $");


#include "opt_cpu.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/conf.h>
#include <sys/power.h>
#include <sys/sysctl.h>
#include <sys/types.h>

#include <machine/md_var.h>
#include <machine/specialreg.h>

static u_int			p4tcc_percentage;
static u_int			p4tcc_economy = 13;
static u_int			p4tcc_performance = 100;
static struct sysctl_ctx_list	p4tcc_sysctl_ctx;

static struct {
	u_short level;
	u_short rlevel;
	u_short reg;
} tcc[] = {
	{ 88, 100, 0 },
	{ 75, 88,  7 },
	{ 63, 75,  6 },
	{ 50, 63,  5 },
	{ 38, 50,  4 },
	{ 25, 38,  3 },
	{ 13, 25,  2 },
	{ 0,  13,  1 }
};

#define TCC_LEVELS	sizeof(tcc) / sizeof(tcc[0])
#define	TCC_MAXPERF	100

static u_short
p4tcc_getperf(void)
{
	u_int64_t msreg;
	int i;

	msreg = rdmsr(MSR_THERM_CONTROL);
	msreg = (msreg >> 1) & 0x07;
	for (i = 0; i < TCC_LEVELS; i++) {
		if (msreg == tcc[i].reg)
			break;
	}

	return (tcc[i].rlevel);
}

static void
p4tcc_setperf(u_int percentage)
{
	int i;
	u_int64_t msreg;

	if (percentage > TCC_MAXPERF)
		percentage = TCC_MAXPERF;
	for (i = 0; i < TCC_LEVELS - 1; i++) {
		if (percentage > tcc[i].level)
			break;
	}

	msreg = rdmsr(MSR_THERM_CONTROL);
	msreg &= ~0x1e;	/* bit 0 reserved */
	if (tcc[i].reg != 0)
		msreg |= tcc[i].reg << 1 | 1 << 4;
	wrmsr(MSR_THERM_CONTROL, msreg);
}

static int
p4tcc_perf_sysctl(SYSCTL_HANDLER_ARGS)
{
	u_int percentage;
	int error;

	p4tcc_percentage = p4tcc_getperf();
	percentage = p4tcc_percentage;
	error = sysctl_handle_int(oidp, &percentage, 0, req);
	if (error || !req->newptr) {
		return (error);
	}
	if (p4tcc_percentage != percentage) {
		p4tcc_setperf(percentage);
	}

	return (error);
}

static void
p4tcc_power_profile(void *arg)
{
	int state;
	u_int new;

	state = power_profile_get_state();
	if (state != POWER_PROFILE_PERFORMANCE &&
	    state != POWER_PROFILE_ECONOMY) {
		return;
	}

	switch (state) {
	case POWER_PROFILE_PERFORMANCE:
		new = p4tcc_performance;
		break;
	case POWER_PROFILE_ECONOMY:
		new = p4tcc_economy;
		break;
	default:
		new = p4tcc_getperf();
		break;
	}

	if (p4tcc_getperf() != new) {
		p4tcc_setperf(new);
	}
}

static int
p4tcc_profile_sysctl(SYSCTL_HANDLER_ARGS)
{
	u_int32_t *argp;
	u_int32_t arg;
	int error;

	argp = (u_int32_t *)oidp->oid_arg1;
	arg = *argp;
	error = sysctl_handle_int(oidp, &arg, 0, req);

	/* error or no new value */
	if ((error != 0) || (req->newptr == NULL))
		return (error);

	/* range check */
	if (arg > TCC_MAXPERF)
		arg = TCC_MAXPERF;

	/* set new value and possibly switch */
	*argp = arg;

p4tcc_power_profile(NULL);

*argp = p4tcc_getperf();

	return (0);
}

static void
setup_p4tcc(void *dummy __unused)
{

	if ((cpu_feature & (CPUID_ACPI | CPUID_TM)) !=
	    (CPUID_ACPI | CPUID_TM))
		return;

	switch (cpu_id & 0xf) {
	case 0x22:	/* errata O50 P44 and Z21 */
	case 0x24:
	case 0x25:
	case 0x27:
	case 0x29:
		/* hang with 12.5 */
		tcc[TCC_LEVELS - 1].reg = 2;
		break;
	case 0x07:	/* errata N44 and P18 */
	case 0x0a:
	case 0x12:
	case 0x13:
		/* hang at 12.5 and 25 */
		tcc[TCC_LEVELS - 1].reg = 3;
		tcc[TCC_LEVELS - 2].reg = 3;
		break;
	default:
		break;
	}

	p4tcc_percentage = p4tcc_getperf();
	printf("Pentium 4 TCC support enabled, current performance %u%%\n",
	    p4tcc_percentage);

	sysctl_ctx_init(&p4tcc_sysctl_ctx);
	SYSCTL_ADD_PROC(&p4tcc_sysctl_ctx,
	    SYSCTL_STATIC_CHILDREN(_machdep), OID_AUTO,
	    "cpuperf", CTLTYPE_INT | CTLFLAG_RW,
	    &p4tcc_percentage, 0, p4tcc_perf_sysctl, "I",
	    "CPU performance in % of maximum");
	SYSCTL_ADD_PROC(&p4tcc_sysctl_ctx,
	    SYSCTL_STATIC_CHILDREN(_machdep), OID_AUTO,
	    "cpuperf_performance", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_RW,
	    &p4tcc_performance, 0, p4tcc_profile_sysctl, "I",
	    "CPU performance in % of maximum in Performance mode");
	SYSCTL_ADD_PROC(&p4tcc_sysctl_ctx,
	    SYSCTL_STATIC_CHILDREN(_machdep), OID_AUTO,
	    "cpuperf_economy", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_RW,
	    &p4tcc_economy, 0, p4tcc_profile_sysctl, "I",
	    "CPU performance in % of maximum in Economy mode");

/* register performance profile change handler */
EVENTHANDLER_REGISTER(power_profile_change, p4tcc_power_profile, NULL, 0);
}
SYSINIT(setup_p4tcc, SI_SUB_CPU, SI_ORDER_ANY, setup_p4tcc, NULL);





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