Merge branches 'topic/slob/cleanups', 'topic/slob/fixes', 'topic/slub/core', 'topic...
[linux-block.git] / arch / x86 / kernel / cpu / cpufreq / p4-clockmod.c
CommitLineData
1da177e4
LT
1/*
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.
32ee8c3e 17 *
1da177e4
LT
18 * Date Errata Description
19 * 20020525 N44, O17 12.5% or 25% DC causes lockup
20 *
21 */
22
1da177e4 23#include <linux/kernel.h>
32ee8c3e 24#include <linux/module.h>
1da177e4
LT
25#include <linux/init.h>
26#include <linux/smp.h>
27#include <linux/cpufreq.h>
28#include <linux/slab.h>
29#include <linux/cpumask.h>
30
32ee8c3e 31#include <asm/processor.h>
1da177e4
LT
32#include <asm/msr.h>
33#include <asm/timex.h>
34
35#include "speedstep-lib.h"
36
37#define PFX "p4-clockmod: "
38#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "p4-clockmod", msg)
39
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
61 if (!cpu_online(cpu) || (newstate > DC_DISABLE) || (newstate == DC_RESV))
62 return -EINVAL;
63
551948bc 64 rdmsr_on_cpu(cpu, MSR_IA32_THERM_STATUS, &l, &h);
1da177e4
LT
65
66 if (l & 0x01)
67 dprintk("CPU#%d currently thermal throttled\n", cpu);
68
69 if (has_N44_O17_errata[cpu] && (newstate == DC_25PT || newstate == DC_DFLT))
70 newstate = DC_38PT;
71
551948bc 72 rdmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, &l, &h);
1da177e4
LT
73 if (newstate == DC_DISABLE) {
74 dprintk("CPU#%d disabling modulation\n", cpu);
551948bc 75 wrmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, l & ~(1<<4), h);
1da177e4
LT
76 } else {
77 dprintk("CPU#%d setting duty cycle to %d%%\n",
78 cpu, ((125 * newstate) / 10));
32ee8c3e 79 /* bits 63 - 5 : reserved
1da177e4
LT
80 * bit 4 : enable/disable
81 * bits 3-1 : duty cycle
82 * bit 0 : reserved
83 */
84 l = (l & ~14);
85 l = l | (1<<4) | ((newstate & 0x7)<<1);
551948bc 86 wrmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, l, h);
1da177e4
LT
87 }
88
89 return 0;
90}
91
92
93static struct cpufreq_frequency_table p4clockmod_table[] = {
94 {DC_RESV, CPUFREQ_ENTRY_INVALID},
95 {DC_DFLT, 0},
96 {DC_25PT, 0},
97 {DC_38PT, 0},
98 {DC_50PT, 0},
99 {DC_64PT, 0},
100 {DC_75PT, 0},
101 {DC_88PT, 0},
102 {DC_DISABLE, 0},
103 {DC_RESV, CPUFREQ_TABLE_END},
104};
105
106
107static int cpufreq_p4_target(struct cpufreq_policy *policy,
108 unsigned int target_freq,
109 unsigned int relation)
110{
111 unsigned int newstate = DC_RESV;
112 struct cpufreq_freqs freqs;
1da177e4
LT
113 int i;
114
115 if (cpufreq_frequency_table_target(policy, &p4clockmod_table[0], target_freq, relation, &newstate))
116 return -EINVAL;
117
118 freqs.old = cpufreq_p4_get(policy->cpu);
119 freqs.new = stock_freq * p4clockmod_table[newstate].index / 8;
120
121 if (freqs.new == freqs.old)
122 return 0;
123
124 /* notifiers */
835481d9 125 for_each_cpu(i, policy->cpus) {
1da177e4
LT
126 freqs.cpu = i;
127 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
128 }
129
130 /* run on each logical CPU, see section 13.15.3 of IA32 Intel Architecture Software
32ee8c3e 131 * Developer's Manual, Volume 3
1da177e4 132 */
835481d9 133 for_each_cpu(i, policy->cpus)
1da177e4 134 cpufreq_p4_setdc(i, p4clockmod_table[newstate].index);
1da177e4
LT
135
136 /* notifiers */
835481d9 137 for_each_cpu(i, policy->cpus) {
1da177e4
LT
138 freqs.cpu = i;
139 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
140 }
141
142 return 0;
143}
144
145
146static int cpufreq_p4_verify(struct cpufreq_policy *policy)
147{
148 return cpufreq_frequency_table_verify(policy, &p4clockmod_table[0]);
149}
150
151
152static unsigned int cpufreq_p4_get_frequency(struct cpuinfo_x86 *c)
153{
4e74663c
DB
154 if (c->x86 == 0x06) {
155 if (cpu_has(c, X86_FEATURE_EST))
156 printk(KERN_WARNING PFX "Warning: EST-capable CPU detected. "
157 "The acpi-cpufreq module offers voltage scaling"
158 " in addition of frequency scaling. You should use "
159 "that instead of p4-clockmod, if possible.\n");
160 switch (c->x86_model) {
161 case 0x0E: /* Core */
162 case 0x0F: /* Core Duo */
8529154e 163 case 0x16: /* Celeron Core */
4e74663c
DB
164 p4clockmod_driver.flags |= CPUFREQ_CONST_LOOPS;
165 return speedstep_get_processor_frequency(SPEEDSTEP_PROCESSOR_PCORE);
166 case 0x0D: /* Pentium M (Dothan) */
167 p4clockmod_driver.flags |= CPUFREQ_CONST_LOOPS;
168 /* fall through */
169 case 0x09: /* Pentium M (Banias) */
170 return speedstep_get_processor_frequency(SPEEDSTEP_PROCESSOR_PM);
171 }
1da177e4
LT
172 }
173
174 if (c->x86 != 0xF) {
10db2e5c
DB
175 if (!cpu_has(c, X86_FEATURE_EST))
176 printk(KERN_WARNING PFX "Unknown p4-clockmod-capable CPU. "
177 "Please send an e-mail to <cpufreq@vger.kernel.org>\n");
1da177e4
LT
178 return 0;
179 }
180
181 /* on P-4s, the TSC runs with constant frequency independent whether
182 * throttling is active or not. */
183 p4clockmod_driver.flags |= CPUFREQ_CONST_LOOPS;
184
185 if (speedstep_detect_processor() == SPEEDSTEP_PROCESSOR_P4M) {
186 printk(KERN_WARNING PFX "Warning: Pentium 4-M detected. "
187 "The speedstep-ich or acpi cpufreq modules offer "
188 "voltage scaling in addition of frequency scaling. "
189 "You should use either one instead of p4-clockmod, "
190 "if possible.\n");
191 return speedstep_get_processor_frequency(SPEEDSTEP_PROCESSOR_P4M);
192 }
193
194 return speedstep_get_processor_frequency(SPEEDSTEP_PROCESSOR_P4D);
195}
196
32ee8c3e 197
1da177e4
LT
198
199static int cpufreq_p4_cpu_init(struct cpufreq_policy *policy)
200{
92cb7612 201 struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
1da177e4
LT
202 int cpuid = 0;
203 unsigned int i;
204
205#ifdef CONFIG_SMP
835481d9 206 cpumask_copy(policy->cpus, &per_cpu(cpu_sibling_map, policy->cpu));
1da177e4
LT
207#endif
208
209 /* Errata workaround */
210 cpuid = (c->x86 << 8) | (c->x86_model << 4) | c->x86_mask;
211 switch (cpuid) {
212 case 0x0f07:
213 case 0x0f0a:
214 case 0x0f11:
215 case 0x0f12:
216 has_N44_O17_errata[policy->cpu] = 1;
217 dprintk("has errata -- disabling low frequencies\n");
218 }
32ee8c3e 219
1da177e4
LT
220 /* get max frequency */
221 stock_freq = cpufreq_p4_get_frequency(c);
222 if (!stock_freq)
223 return -EINVAL;
224
225 /* table init */
226 for (i=1; (p4clockmod_table[i].frequency != CPUFREQ_TABLE_END); i++) {
227 if ((i<2) && (has_N44_O17_errata[policy->cpu]))
228 p4clockmod_table[i].frequency = CPUFREQ_ENTRY_INVALID;
229 else
230 p4clockmod_table[i].frequency = (stock_freq * i)/8;
231 }
232 cpufreq_frequency_table_get_attr(p4clockmod_table, policy->cpu);
32ee8c3e 233
1da177e4 234 /* cpuinfo and default policy values */
1da177e4
LT
235 policy->cpuinfo.transition_latency = 1000000; /* assumed */
236 policy->cur = stock_freq;
237
238 return cpufreq_frequency_table_cpuinfo(policy, &p4clockmod_table[0]);
239}
240
241
242static int cpufreq_p4_cpu_exit(struct cpufreq_policy *policy)
243{
32ee8c3e 244 cpufreq_frequency_table_put_attr(policy->cpu);
1da177e4
LT
245 return 0;
246}
247
248static unsigned int cpufreq_p4_get(unsigned int cpu)
249{
1da177e4
LT
250 u32 l, h;
251
551948bc 252 rdmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, &l, &h);
1da177e4
LT
253
254 if (l & 0x10) {
255 l = l >> 1;
256 l &= 0x7;
257 } else
258 l = DC_DISABLE;
259
260 if (l != DC_DISABLE)
261 return (stock_freq * l / 8);
262
263 return stock_freq;
264}
265
266static struct freq_attr* p4clockmod_attr[] = {
267 &cpufreq_freq_attr_scaling_available_freqs,
268 NULL,
269};
270
271static struct cpufreq_driver p4clockmod_driver = {
32ee8c3e 272 .verify = cpufreq_p4_verify,
1da177e4
LT
273 .target = cpufreq_p4_target,
274 .init = cpufreq_p4_cpu_init,
275 .exit = cpufreq_p4_cpu_exit,
276 .get = cpufreq_p4_get,
277 .name = "p4-clockmod",
278 .owner = THIS_MODULE,
279 .attr = p4clockmod_attr,
280};
281
282
283static int __init cpufreq_p4_init(void)
32ee8c3e 284{
92cb7612 285 struct cpuinfo_x86 *c = &cpu_data(0);
1da177e4
LT
286 int ret;
287
288 /*
32ee8c3e 289 * THERM_CONTROL is architectural for IA32 now, so
1da177e4
LT
290 * we can rely on the capability checks
291 */
292 if (c->x86_vendor != X86_VENDOR_INTEL)
293 return -ENODEV;
294
8ce116e5
IM
295 if (!test_cpu_cap(c, X86_FEATURE_ACPI) ||
296 !test_cpu_cap(c, X86_FEATURE_ACC))
1da177e4
LT
297 return -ENODEV;
298
299 ret = cpufreq_register_driver(&p4clockmod_driver);
300 if (!ret)
301 printk(KERN_INFO PFX "P4/Xeon(TM) CPU On-Demand Clock Modulation available\n");
302
303 return (ret);
304}
305
306
307static void __exit cpufreq_p4_exit(void)
308{
309 cpufreq_unregister_driver(&p4clockmod_driver);
310}
311
312
313MODULE_AUTHOR ("Zwane Mwaikambo <zwane@commfireservices.com>");
314MODULE_DESCRIPTION ("cpufreq driver for Pentium(TM) 4/Xeon(TM)");
315MODULE_LICENSE ("GPL");
316
317late_initcall(cpufreq_p4_init);
318module_exit(cpufreq_p4_exit);