p4tcc.c revision 124684 
1/*	$OpenBSD: p4tcc.c,v 1.1 2003/12/20 18:23:18 tedu Exp $ */
2/*
3 * Copyright (c) 2003 Ted Unangst
4 * Copyright (c) 2004 Maxim Sobolev <sobomax@FreeBSD.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28/*
29 * Restrict power consumption by using thermal control circuit.
30 * This operates independently of speedstep.
31 * Found on Pentium 4 and later models (feature TM).
32 *
33 * References:
34 * Intel Developer's manual v.3 #245472-012
35 *
36 * On some models, the cpu can hang if it's running at a slow speed.
37 * Workarounds included below.
38 */
39
40#include <sys/cdefs.h>
41__FBSDID("$FreeBSD: head/sys/i386/cpufreq/p4tcc.c 124684 2004-01-18 21:06:56Z sobomax $");
42
43#include "opt_cpu.h"
44#include <sys/param.h>
45#include <sys/systm.h>
46#include <sys/kernel.h>
47#include <sys/conf.h>
48#include <sys/power.h>
49#include <sys/sysctl.h>
50#include <sys/types.h>
51
52#include <machine/md_var.h>
53#include <machine/specialreg.h>
54
55static u_int			p4tcc_percentage;
56static u_int			p4tcc_economy = 13;
57static u_int			p4tcc_performance = 100;
58static struct sysctl_ctx_list	p4tcc_sysctl_ctx;
59
60static struct {
61	u_short level;
62	u_short rlevel;
63	u_short reg;
64} tcc[] = {
65	{ 88, 100, 0 },
66	{ 75, 88,  7 },
67	{ 63, 75,  6 },
68	{ 50, 63,  5 },
69	{ 38, 50,  4 },
70	{ 25, 38,  3 },
71	{ 13, 25,  2 },
72	{ 0,  13,  1 }
73};
74
75#define TCC_LEVELS	sizeof(tcc) / sizeof(tcc[0])
76#define	TCC_MAXPERF	100
77
78static u_short
79p4tcc_getperf(void)
80{
81	u_int64_t msreg;
82	int i;
83
84	msreg = rdmsr(MSR_THERM_CONTROL);
85	msreg = (msreg >> 1) & 0x07;
86	for (i = 0; i < TCC_LEVELS; i++) {
87		if (msreg == tcc[i].reg)
88			break;
89	}
90
91	return (tcc[i].rlevel);
92}
93
94static void
95p4tcc_setperf(u_int percentage)
96{
97	int i;
98	u_int64_t msreg;
99
100	if (percentage > TCC_MAXPERF)
101		percentage = TCC_MAXPERF;
102	for (i = 0; i < TCC_LEVELS - 1; i++) {
103		if (percentage > tcc[i].level)
104			break;
105	}
106
107	msreg = rdmsr(MSR_THERM_CONTROL);
108	msreg &= ~0x1e;	/* bit 0 reserved */
109	if (tcc[i].reg != 0)
110		msreg |= tcc[i].reg << 1 | 1 << 4;
111	wrmsr(MSR_THERM_CONTROL, msreg);
112}
113
114static int
115p4tcc_perf_sysctl(SYSCTL_HANDLER_ARGS)
116{
117	u_int percentage;
118	int error;
119
120	p4tcc_percentage = p4tcc_getperf();
121	percentage = p4tcc_percentage;
122	error = sysctl_handle_int(oidp, &percentage, 0, req);
123	if (error || !req->newptr) {
124		return (error);
125	}
126	if (p4tcc_percentage != percentage) {
127		p4tcc_setperf(percentage);
128	}
129
130	return (error);
131}
132
133static void
134p4tcc_power_profile(void *arg)
135{
136	int state;
137	u_int new;
138
139	state = power_profile_get_state();
140	if (state != POWER_PROFILE_PERFORMANCE &&
141	    state != POWER_PROFILE_ECONOMY) {
142		return;
143	}
144
145	switch (state) {
146	case POWER_PROFILE_PERFORMANCE:
147		new = p4tcc_performance;
148		break;
149	case POWER_PROFILE_ECONOMY:
150		new = p4tcc_economy;
151		break;
152	default:
153		new = p4tcc_getperf();
154		break;
155	}
156
157	if (p4tcc_getperf() != new) {
158		p4tcc_setperf(new);
159	}
160}
161
162static int
163p4tcc_profile_sysctl(SYSCTL_HANDLER_ARGS)
164{
165	u_int32_t *argp;
166	u_int32_t arg;
167	int error;
168
169	argp = (u_int32_t *)oidp->oid_arg1;
170	arg = *argp;
171	error = sysctl_handle_int(oidp, &arg, 0, req);
172
173	/* error or no new value */
174	if ((error != 0) || (req->newptr == NULL))
175		return (error);
176
177	/* range check */
178	if (arg > TCC_MAXPERF)
179		arg = TCC_MAXPERF;
180
181	/* set new value and possibly switch */
182	*argp = arg;
183
184	p4tcc_power_profile(NULL);
185
186	*argp = p4tcc_getperf();
187
188	return (0);
189}
190
191static void
192setup_p4tcc(void *dummy __unused)
193{
194
195	if ((cpu_feature & (CPUID_ACPI | CPUID_TM)) !=
196	    (CPUID_ACPI | CPUID_TM))
197		return;
198
199	switch (cpu_id & 0xf) {
200	case 0x22:	/* errata O50 P44 and Z21 */
201	case 0x24:
202	case 0x25:
203	case 0x27:
204	case 0x29:
205		/* hang with 12.5 */
206		tcc[TCC_LEVELS - 1].reg = 2;
207		break;
208	case 0x07:	/* errata N44 and P18 */
209	case 0x0a:
210	case 0x12:
211	case 0x13:
212		/* hang at 12.5 and 25 */
213		tcc[TCC_LEVELS - 1].reg = 3;
214		tcc[TCC_LEVELS - 2].reg = 3;
215		break;
216	default:
217		break;
218	}
219
220	p4tcc_percentage = p4tcc_getperf();
221	printf("Pentium 4 TCC support enabled, current performance %u%%\n",
222	    p4tcc_percentage);
223
224	sysctl_ctx_init(&p4tcc_sysctl_ctx);
225	SYSCTL_ADD_PROC(&p4tcc_sysctl_ctx,
226	    SYSCTL_STATIC_CHILDREN(_machdep), OID_AUTO,
227	    "cpuperf", CTLTYPE_INT | CTLFLAG_RW,
228	    &p4tcc_percentage, 0, p4tcc_perf_sysctl, "I",
229	    "CPU performance in % of maximum");
230	SYSCTL_ADD_PROC(&p4tcc_sysctl_ctx,
231	    SYSCTL_STATIC_CHILDREN(_machdep), OID_AUTO,
232	    "cpuperf_performance", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_RW,
233	    &p4tcc_performance, 0, p4tcc_profile_sysctl, "I",
234	    "CPU performance in % of maximum in Performance mode");
235	SYSCTL_ADD_PROC(&p4tcc_sysctl_ctx,
236	    SYSCTL_STATIC_CHILDREN(_machdep), OID_AUTO,
237	    "cpuperf_economy", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_RW,
238	    &p4tcc_economy, 0, p4tcc_profile_sysctl, "I",
239	    "CPU performance in % of maximum in Economy mode");
240
241	/* register performance profile change handler */
242	EVENTHANDLER_REGISTER(power_profile_change, p4tcc_power_profile, NULL, 0);
243}
244SYSINIT(setup_p4tcc, SI_SUB_CPU, SI_ORDER_ANY, setup_p4tcc, NULL);
245