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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Pentium 4/Xeon CPU on demand clock modulation/speed scaling
3 * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
4 * (C) 2002 Zwane Mwaikambo <zwane@commfireservices.com>
5 * (C) 2002 Arjan van de Ven <arjanv@redhat.com>
6 * (C) 2002 Tora T. Engstad
7 * All Rights Reserved
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
13 *
14 * The author(s) of this software shall not be held liable for damages
15 * of any nature resulting due to the use of this software. This
16 * software is provided AS-IS with no warranties.
Dave Jones32ee8c32006-02-28 00:43:23 -050017 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070018 * Date Errata Description
19 * 20020525 N44, O17 12.5% or 25% DC causes lockup
20 *
21 */
22
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <linux/kernel.h>
Dave Jones32ee8c32006-02-28 00:43:23 -050024#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <linux/init.h>
26#include <linux/smp.h>
27#include <linux/cpufreq.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <linux/cpumask.h>
Dave Jonesbbfebd62009-01-17 23:55:22 -050029#include <linux/timex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030
Dave Jones32ee8c32006-02-28 00:43:23 -050031#include <asm/processor.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#include <asm/msr.h>
Matthias-Christian Ott199785e2009-02-20 20:52:17 -050033#include <asm/timer.h>
Andi Kleenfa8031a2012-01-26 00:09:12 +010034#include <asm/cpu_device_id.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035
36#include "speedstep-lib.h"
37
38#define PFX "p4-clockmod: "
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
40/*
41 * Duty Cycle (3bits), note DC_DISABLE is not specified in
42 * intel docs i just use it to mean disable
43 */
44enum {
45 DC_RESV, DC_DFLT, DC_25PT, DC_38PT, DC_50PT,
46 DC_64PT, DC_75PT, DC_88PT, DC_DISABLE
47};
48
49#define DC_ENTRIES 8
50
51
52static int has_N44_O17_errata[NR_CPUS];
53static unsigned int stock_freq;
54static struct cpufreq_driver p4clockmod_driver;
55static unsigned int cpufreq_p4_get(unsigned int cpu);
56
57static int cpufreq_p4_setdc(unsigned int cpu, unsigned int newstate)
58{
59 u32 l, h;
60
Viresh Kumare9f51832013-04-01 12:57:46 +000061 if ((newstate > DC_DISABLE) || (newstate == DC_RESV))
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 return -EINVAL;
63
Alexey Dobriyan551948b2007-03-19 19:17:00 +030064 rdmsr_on_cpu(cpu, MSR_IA32_THERM_STATUS, &l, &h);
Linus Torvalds1da177e2005-04-16 15:20:36 -070065
66 if (l & 0x01)
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +020067 pr_debug("CPU#%d currently thermal throttled\n", cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
Dave Jonesbbfebd62009-01-17 23:55:22 -050069 if (has_N44_O17_errata[cpu] &&
70 (newstate == DC_25PT || newstate == DC_DFLT))
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 newstate = DC_38PT;
72
Alexey Dobriyan551948b2007-03-19 19:17:00 +030073 rdmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, &l, &h);
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 if (newstate == DC_DISABLE) {
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +020075 pr_debug("CPU#%d disabling modulation\n", cpu);
Alexey Dobriyan551948b2007-03-19 19:17:00 +030076 wrmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, l & ~(1<<4), h);
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 } else {
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +020078 pr_debug("CPU#%d setting duty cycle to %d%%\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 cpu, ((125 * newstate) / 10));
Dave Jones32ee8c32006-02-28 00:43:23 -050080 /* bits 63 - 5 : reserved
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 * bit 4 : enable/disable
82 * bits 3-1 : duty cycle
83 * bit 0 : reserved
84 */
85 l = (l & ~14);
86 l = l | (1<<4) | ((newstate & 0x7)<<1);
Alexey Dobriyan551948b2007-03-19 19:17:00 +030087 wrmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, l, h);
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 }
89
90 return 0;
91}
92
93
94static struct cpufreq_frequency_table p4clockmod_table[] = {
Viresh Kumar7f4b0462014-03-28 19:11:47 +053095 {0, DC_RESV, CPUFREQ_ENTRY_INVALID},
96 {0, DC_DFLT, 0},
97 {0, DC_25PT, 0},
98 {0, DC_38PT, 0},
99 {0, DC_50PT, 0},
100 {0, DC_64PT, 0},
101 {0, DC_75PT, 0},
102 {0, DC_88PT, 0},
103 {0, DC_DISABLE, 0},
104 {0, DC_RESV, CPUFREQ_TABLE_END},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105};
106
107
Viresh Kumar9c0ebcf2013-10-25 19:45:48 +0530108static int cpufreq_p4_target(struct cpufreq_policy *policy, unsigned int index)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110 int i;
111
Dave Jonesbbfebd62009-01-17 23:55:22 -0500112 /* run on each logical CPU,
113 * see section 13.15.3 of IA32 Intel Architecture Software
Dave Jones32ee8c32006-02-28 00:43:23 -0500114 * Developer's Manual, Volume 3
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 */
Rusty Russell835481d2009-01-04 05:18:06 -0800116 for_each_cpu(i, policy->cpus)
Viresh Kumar9c0ebcf2013-10-25 19:45:48 +0530117 cpufreq_p4_setdc(i, p4clockmod_table[index].driver_data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 return 0;
120}
121
122
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123static unsigned int cpufreq_p4_get_frequency(struct cpuinfo_x86 *c)
124{
Dominik Brodowski4e746632006-10-31 12:44:08 -0500125 if (c->x86 == 0x06) {
126 if (cpu_has(c, X86_FEATURE_EST))
Naga Chumbalkar853cee22011-02-15 17:44:11 +0000127 printk_once(KERN_WARNING PFX "Warning: EST-capable "
128 "CPU detected. The acpi-cpufreq module offers "
129 "voltage scaling in addition to frequency "
Dave Jonesbbfebd62009-01-17 23:55:22 -0500130 "scaling. You should use that instead of "
131 "p4-clockmod, if possible.\n");
Dominik Brodowski4e746632006-10-31 12:44:08 -0500132 switch (c->x86_model) {
133 case 0x0E: /* Core */
134 case 0x0F: /* Core Duo */
Herton Ronaldo Krzesinski85291542008-11-15 17:02:46 -0200135 case 0x16: /* Celeron Core */
Jarod Wilson43195032009-03-06 20:24:57 +0000136 case 0x1C: /* Atom */
Dominik Brodowski4e746632006-10-31 12:44:08 -0500137 p4clockmod_driver.flags |= CPUFREQ_CONST_LOOPS;
Dave Jonesbbfebd62009-01-17 23:55:22 -0500138 return speedstep_get_frequency(SPEEDSTEP_CPU_PCORE);
Dominik Brodowski4e746632006-10-31 12:44:08 -0500139 case 0x0D: /* Pentium M (Dothan) */
140 p4clockmod_driver.flags |= CPUFREQ_CONST_LOOPS;
141 /* fall through */
142 case 0x09: /* Pentium M (Banias) */
Dave Jonesbbfebd62009-01-17 23:55:22 -0500143 return speedstep_get_frequency(SPEEDSTEP_CPU_PM);
Dominik Brodowski4e746632006-10-31 12:44:08 -0500144 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 }
146
Dave Jones9d1f44e2010-08-03 13:47:30 -0400147 if (c->x86 != 0xF)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149
150 /* on P-4s, the TSC runs with constant frequency independent whether
151 * throttling is active or not. */
152 p4clockmod_driver.flags |= CPUFREQ_CONST_LOOPS;
153
Dave Jonesbbfebd62009-01-17 23:55:22 -0500154 if (speedstep_detect_processor() == SPEEDSTEP_CPU_P4M) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 printk(KERN_WARNING PFX "Warning: Pentium 4-M detected. "
156 "The speedstep-ich or acpi cpufreq modules offer "
157 "voltage scaling in addition of frequency scaling. "
158 "You should use either one instead of p4-clockmod, "
159 "if possible.\n");
Dave Jonesbbfebd62009-01-17 23:55:22 -0500160 return speedstep_get_frequency(SPEEDSTEP_CPU_P4M);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161 }
162
Dave Jonesbbfebd62009-01-17 23:55:22 -0500163 return speedstep_get_frequency(SPEEDSTEP_CPU_P4D);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164}
165
Dave Jones32ee8c32006-02-28 00:43:23 -0500166
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167
168static int cpufreq_p4_cpu_init(struct cpufreq_policy *policy)
169{
Mike Travis92cb7612007-10-19 20:35:04 +0200170 struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 int cpuid = 0;
172 unsigned int i;
173
174#ifdef CONFIG_SMP
Rusty Russell7ad728f2009-03-13 14:49:50 +1030175 cpumask_copy(policy->cpus, cpu_sibling_mask(policy->cpu));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176#endif
177
178 /* Errata workaround */
179 cpuid = (c->x86 << 8) | (c->x86_model << 4) | c->x86_mask;
180 switch (cpuid) {
181 case 0x0f07:
182 case 0x0f0a:
183 case 0x0f11:
184 case 0x0f12:
185 has_N44_O17_errata[policy->cpu] = 1;
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200186 pr_debug("has errata -- disabling low frequencies\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 }
Dave Jones32ee8c32006-02-28 00:43:23 -0500188
Matthias-Christian Ott199785e2009-02-20 20:52:17 -0500189 if (speedstep_detect_processor() == SPEEDSTEP_CPU_P4D &&
190 c->x86_model < 2) {
191 /* switch to maximum frequency and measure result */
192 cpufreq_p4_setdc(policy->cpu, DC_DISABLE);
193 recalibrate_cpu_khz();
194 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 /* get max frequency */
196 stock_freq = cpufreq_p4_get_frequency(c);
197 if (!stock_freq)
198 return -EINVAL;
199
200 /* table init */
Dave Jonesbbfebd62009-01-17 23:55:22 -0500201 for (i = 1; (p4clockmod_table[i].frequency != CPUFREQ_TABLE_END); i++) {
202 if ((i < 2) && (has_N44_O17_errata[policy->cpu]))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 p4clockmod_table[i].frequency = CPUFREQ_ENTRY_INVALID;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 else
205 p4clockmod_table[i].frequency = (stock_freq * i)/8;
206 }
Dave Jones32ee8c32006-02-28 00:43:23 -0500207
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 /* cpuinfo and default policy values */
Dave Jones36e8abf2009-03-05 00:16:26 -0500209
210 /* the transition latency is set to be 1 higher than the maximum
211 * transition latency of the ondemand governor */
212 policy->cpuinfo.transition_latency = 10000001;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213
Viresh Kumar719ffe42013-09-16 18:56:24 +0530214 return cpufreq_table_validate_and_show(policy, &p4clockmod_table[0]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215}
216
217
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218static unsigned int cpufreq_p4_get(unsigned int cpu)
219{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 u32 l, h;
221
Alexey Dobriyan551948b2007-03-19 19:17:00 +0300222 rdmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, &l, &h);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223
224 if (l & 0x10) {
225 l = l >> 1;
226 l &= 0x7;
227 } else
228 l = DC_DISABLE;
229
230 if (l != DC_DISABLE)
Dave Jonesbbfebd62009-01-17 23:55:22 -0500231 return stock_freq * l / 8;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232
233 return stock_freq;
234}
235
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236static struct cpufreq_driver p4clockmod_driver = {
Viresh Kumar522f70c2013-10-03 20:28:14 +0530237 .verify = cpufreq_generic_frequency_table_verify,
Viresh Kumar9c0ebcf2013-10-25 19:45:48 +0530238 .target_index = cpufreq_p4_target,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239 .init = cpufreq_p4_cpu_init,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 .get = cpufreq_p4_get,
241 .name = "p4-clockmod",
Viresh Kumar522f70c2013-10-03 20:28:14 +0530242 .attr = cpufreq_generic_attr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243};
244
Andi Kleenfa8031a2012-01-26 00:09:12 +0100245static const struct x86_cpu_id cpufreq_p4_id[] = {
246 { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, X86_FEATURE_ACC },
247 {}
248};
249
250/*
251 * Intentionally no MODULE_DEVICE_TABLE here: this driver should not
252 * be auto loaded. Please don't add one.
253 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254
255static int __init cpufreq_p4_init(void)
Dave Jones32ee8c32006-02-28 00:43:23 -0500256{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 int ret;
258
259 /*
Dave Jones32ee8c32006-02-28 00:43:23 -0500260 * THERM_CONTROL is architectural for IA32 now, so
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261 * we can rely on the capability checks
262 */
Andi Kleenfa8031a2012-01-26 00:09:12 +0100263 if (!x86_match_cpu(cpufreq_p4_id) || !boot_cpu_has(X86_FEATURE_ACPI))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 return -ENODEV;
265
266 ret = cpufreq_register_driver(&p4clockmod_driver);
267 if (!ret)
Dave Jonesbbfebd62009-01-17 23:55:22 -0500268 printk(KERN_INFO PFX "P4/Xeon(TM) CPU On-Demand Clock "
269 "Modulation available\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270
Dave Jonesbbfebd62009-01-17 23:55:22 -0500271 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272}
273
274
275static void __exit cpufreq_p4_exit(void)
276{
277 cpufreq_unregister_driver(&p4clockmod_driver);
278}
279
280
Dave Jonesbbfebd62009-01-17 23:55:22 -0500281MODULE_AUTHOR("Zwane Mwaikambo <zwane@commfireservices.com>");
282MODULE_DESCRIPTION("cpufreq driver for Pentium(TM) 4/Xeon(TM)");
283MODULE_LICENSE("GPL");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284
285late_initcall(cpufreq_p4_init);
286module_exit(cpufreq_p4_exit);