p4tcc.c revision 134199 
1168211Syar/*	$OpenBSD: p4tcc.c,v 1.1 2003/12/20 18:23:18 tedu Exp $ */
2168211Syar/*
3168211Syar * 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 134199 2004-08-23 09:47:56Z 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;
57static u_int			p4tcc_performance;
58static struct sysctl_ctx_list	p4tcc_sysctl_ctx;
59static struct sysctl_oid	*p4tcc_sysctl_tree;
60
61static struct {
62	u_short level;
63	u_short rlevel;
64	u_short reg;
65} tcc[] = {
66	{ 88, 100, 0 },
67	{ 75, 88,  7 },
68	{ 63, 75,  6 },
69	{ 50, 63,  5 },
70	{ 38, 50,  4 },
71	{ 25, 38,  3 },
72	{ 13, 25,  2 },
73	{ 0,  13,  1 }
74};
75
76#define TCC_LEVELS	sizeof(tcc) / sizeof(tcc[0])
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[0].rlevel)
101		percentage = tcc[0].rlevel;
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[0].rlevel)
179		arg = tcc[0].rlevel;
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	int nsteps, i;
195        static char p4tcc_levels[(3 * TCC_LEVELS) + 1];
196        char buf[4 + 1];
197
198	if ((cpu_feature & (CPUID_ACPI | CPUID_TM)) !=
199	    (CPUID_ACPI | CPUID_TM))
200		return;
201
202	nsteps = TCC_LEVELS;
203	switch (cpu_id & 0xf) {
204	case 0x22:	/* errata O50 P44 and Z21 */
205	case 0x24:
206	case 0x25:
207	case 0x27:
208	case 0x29:
209		/* hang with 12.5 */
210		tcc[TCC_LEVELS - 1] = tcc[TCC_LEVELS - 2];
211		nsteps -= 1;
212		break;
213	case 0x07:	/* errata N44 and P18 */
214	case 0x0a:
215	case 0x12:
216	case 0x13:
217		/* hang at 12.5 and 25 */
218		tcc[TCC_LEVELS - 1] = tcc[TCC_LEVELS - 2] = tcc[TCC_LEVELS - 3];
219		nsteps -= 2;
220		break;
221	default:
222		break;
223	}
224
225	p4tcc_levels[0] = '\0';
226	for (i = nsteps; i > 0; i--) {
227	    sprintf(buf, "%d%s", tcc[i - 1].rlevel, (i != 1) ? " " : "");
228	    strcat(p4tcc_levels, buf);
229	}
230
231	p4tcc_economy = tcc[TCC_LEVELS - 1].rlevel;
232	p4tcc_performance = tcc[0].rlevel;
233
234	p4tcc_percentage = p4tcc_getperf();
235	printf("Pentium 4 TCC support enabled, %d steps from 100%% to %d%%, "
236	    "current performance %u%%\n", nsteps, p4tcc_economy,
237	    p4tcc_percentage);
238
239	sysctl_ctx_init(&p4tcc_sysctl_ctx);
240	p4tcc_sysctl_tree = SYSCTL_ADD_NODE(&p4tcc_sysctl_ctx,
241	    SYSCTL_STATIC_CHILDREN(_hw), OID_AUTO, "p4tcc", CTLFLAG_RD, 0,
242	    "Pentium 4 Thermal Control Circuitry support");
243	SYSCTL_ADD_PROC(&p4tcc_sysctl_ctx,
244	    SYSCTL_CHILDREN(p4tcc_sysctl_tree), OID_AUTO,
245	    "cpuperf", CTLTYPE_INT | CTLFLAG_RW,
246	    &p4tcc_percentage, 0, p4tcc_perf_sysctl, "I",
247	    "CPU performance in % of maximum");
248	SYSCTL_ADD_PROC(&p4tcc_sysctl_ctx,
249	    SYSCTL_CHILDREN(p4tcc_sysctl_tree), OID_AUTO,
250	    "cpuperf_performance", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_RW,
251	    &p4tcc_performance, 0, p4tcc_profile_sysctl, "I",
252	    "CPU performance in % of maximum in Performance mode");
253	SYSCTL_ADD_PROC(&p4tcc_sysctl_ctx,
254	    SYSCTL_CHILDREN(p4tcc_sysctl_tree), OID_AUTO,
255	    "cpuperf_economy", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_RW,
256	    &p4tcc_economy, 0, p4tcc_profile_sysctl, "I",
257	    "CPU performance in % of maximum in Economy mode");
258	SYSCTL_ADD_STRING(&p4tcc_sysctl_ctx,
259	    SYSCTL_CHILDREN(p4tcc_sysctl_tree), OID_AUTO,
260	    "cpuperf_levels", CTLFLAG_RD, p4tcc_levels, 0,
261	    "Perormance levels supported by the Pentium 4 Thermal Control "
262	    "Circuitry");
263
264	/* register performance profile change handler */
265	EVENTHANDLER_REGISTER(power_profile_change, p4tcc_power_profile, NULL, 0);
266}
267SYSINIT(setup_p4tcc, SI_SUB_CPU, SI_ORDER_ANY, setup_p4tcc, NULL);
268