Commit | Line | Data |
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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> | |
1da177e4 | 28 | #include <linux/cpumask.h> |
bbfebd66 | 29 | #include <linux/timex.h> |
1da177e4 | 30 | |
32ee8c3e | 31 | #include <asm/processor.h> |
1da177e4 | 32 | #include <asm/msr.h> |
199785ea | 33 | #include <asm/timer.h> |
fa8031ae | 34 | #include <asm/cpu_device_id.h> |
1da177e4 LT |
35 | |
36 | #include "speedstep-lib.h" | |
37 | ||
38 | #define PFX "p4-clockmod: " | |
1da177e4 LT |
39 | |
40 | /* | |
41 | * Duty Cycle (3bits), note DC_DISABLE is not specified in | |
42 | * intel docs i just use it to mean disable | |
43 | */ | |
44 | enum { | |
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 | ||
52 | static int has_N44_O17_errata[NR_CPUS]; | |
53 | static unsigned int stock_freq; | |
54 | static struct cpufreq_driver p4clockmod_driver; | |
55 | static unsigned int cpufreq_p4_get(unsigned int cpu); | |
56 | ||
57 | static int cpufreq_p4_setdc(unsigned int cpu, unsigned int newstate) | |
58 | { | |
59 | u32 l, h; | |
60 | ||
e9f51837 | 61 | if ((newstate > DC_DISABLE) || (newstate == DC_RESV)) |
1da177e4 LT |
62 | return -EINVAL; |
63 | ||
551948bc | 64 | rdmsr_on_cpu(cpu, MSR_IA32_THERM_STATUS, &l, &h); |
1da177e4 LT |
65 | |
66 | if (l & 0x01) | |
2d06d8c4 | 67 | pr_debug("CPU#%d currently thermal throttled\n", cpu); |
1da177e4 | 68 | |
bbfebd66 DJ |
69 | if (has_N44_O17_errata[cpu] && |
70 | (newstate == DC_25PT || newstate == DC_DFLT)) | |
1da177e4 LT |
71 | newstate = DC_38PT; |
72 | ||
551948bc | 73 | rdmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, &l, &h); |
1da177e4 | 74 | if (newstate == DC_DISABLE) { |
2d06d8c4 | 75 | pr_debug("CPU#%d disabling modulation\n", cpu); |
551948bc | 76 | wrmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, l & ~(1<<4), h); |
1da177e4 | 77 | } else { |
2d06d8c4 | 78 | pr_debug("CPU#%d setting duty cycle to %d%%\n", |
1da177e4 | 79 | cpu, ((125 * newstate) / 10)); |
32ee8c3e | 80 | /* bits 63 - 5 : reserved |
1da177e4 LT |
81 | * 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); | |
551948bc | 87 | wrmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, l, h); |
1da177e4 LT |
88 | } |
89 | ||
90 | return 0; | |
91 | } | |
92 | ||
93 | ||
94 | static struct cpufreq_frequency_table p4clockmod_table[] = { | |
95 | {DC_RESV, CPUFREQ_ENTRY_INVALID}, | |
96 | {DC_DFLT, 0}, | |
97 | {DC_25PT, 0}, | |
98 | {DC_38PT, 0}, | |
99 | {DC_50PT, 0}, | |
100 | {DC_64PT, 0}, | |
101 | {DC_75PT, 0}, | |
102 | {DC_88PT, 0}, | |
103 | {DC_DISABLE, 0}, | |
104 | {DC_RESV, CPUFREQ_TABLE_END}, | |
105 | }; | |
106 | ||
107 | ||
9c0ebcf7 | 108 | static int cpufreq_p4_target(struct cpufreq_policy *policy, unsigned int index) |
1da177e4 | 109 | { |
1da177e4 LT |
110 | int i; |
111 | ||
bbfebd66 DJ |
112 | /* run on each logical CPU, |
113 | * see section 13.15.3 of IA32 Intel Architecture Software | |
32ee8c3e | 114 | * Developer's Manual, Volume 3 |
1da177e4 | 115 | */ |
835481d9 | 116 | for_each_cpu(i, policy->cpus) |
9c0ebcf7 | 117 | cpufreq_p4_setdc(i, p4clockmod_table[index].driver_data); |
1da177e4 | 118 | |
1da177e4 LT |
119 | return 0; |
120 | } | |
121 | ||
122 | ||
1da177e4 LT |
123 | static unsigned int cpufreq_p4_get_frequency(struct cpuinfo_x86 *c) |
124 | { | |
4e74663c DB |
125 | if (c->x86 == 0x06) { |
126 | if (cpu_has(c, X86_FEATURE_EST)) | |
853cee26 NC |
127 | printk_once(KERN_WARNING PFX "Warning: EST-capable " |
128 | "CPU detected. The acpi-cpufreq module offers " | |
129 | "voltage scaling in addition to frequency " | |
bbfebd66 DJ |
130 | "scaling. You should use that instead of " |
131 | "p4-clockmod, if possible.\n"); | |
4e74663c DB |
132 | switch (c->x86_model) { |
133 | case 0x0E: /* Core */ | |
134 | case 0x0F: /* Core Duo */ | |
8529154e | 135 | case 0x16: /* Celeron Core */ |
43195037 | 136 | case 0x1C: /* Atom */ |
4e74663c | 137 | p4clockmod_driver.flags |= CPUFREQ_CONST_LOOPS; |
bbfebd66 | 138 | return speedstep_get_frequency(SPEEDSTEP_CPU_PCORE); |
4e74663c DB |
139 | case 0x0D: /* Pentium M (Dothan) */ |
140 | p4clockmod_driver.flags |= CPUFREQ_CONST_LOOPS; | |
141 | /* fall through */ | |
142 | case 0x09: /* Pentium M (Banias) */ | |
bbfebd66 | 143 | return speedstep_get_frequency(SPEEDSTEP_CPU_PM); |
4e74663c | 144 | } |
1da177e4 LT |
145 | } |
146 | ||
9d1f44ee | 147 | if (c->x86 != 0xF) |
1da177e4 | 148 | return 0; |
1da177e4 LT |
149 | |
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 | ||
bbfebd66 | 154 | if (speedstep_detect_processor() == SPEEDSTEP_CPU_P4M) { |
1da177e4 LT |
155 | 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"); | |
bbfebd66 | 160 | return speedstep_get_frequency(SPEEDSTEP_CPU_P4M); |
1da177e4 LT |
161 | } |
162 | ||
bbfebd66 | 163 | return speedstep_get_frequency(SPEEDSTEP_CPU_P4D); |
1da177e4 LT |
164 | } |
165 | ||
32ee8c3e | 166 | |
1da177e4 LT |
167 | |
168 | static int cpufreq_p4_cpu_init(struct cpufreq_policy *policy) | |
169 | { | |
92cb7612 | 170 | struct cpuinfo_x86 *c = &cpu_data(policy->cpu); |
1da177e4 LT |
171 | int cpuid = 0; |
172 | unsigned int i; | |
173 | ||
174 | #ifdef CONFIG_SMP | |
7ad728f9 | 175 | cpumask_copy(policy->cpus, cpu_sibling_mask(policy->cpu)); |
1da177e4 LT |
176 | #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; | |
2d06d8c4 | 186 | pr_debug("has errata -- disabling low frequencies\n"); |
1da177e4 | 187 | } |
32ee8c3e | 188 | |
199785ea MCO |
189 | 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 | } | |
1da177e4 LT |
195 | /* get max frequency */ |
196 | stock_freq = cpufreq_p4_get_frequency(c); | |
197 | if (!stock_freq) | |
198 | return -EINVAL; | |
199 | ||
200 | /* table init */ | |
bbfebd66 DJ |
201 | for (i = 1; (p4clockmod_table[i].frequency != CPUFREQ_TABLE_END); i++) { |
202 | if ((i < 2) && (has_N44_O17_errata[policy->cpu])) | |
1da177e4 LT |
203 | p4clockmod_table[i].frequency = CPUFREQ_ENTRY_INVALID; |
204 | else | |
205 | p4clockmod_table[i].frequency = (stock_freq * i)/8; | |
206 | } | |
32ee8c3e | 207 | |
1da177e4 | 208 | /* cpuinfo and default policy values */ |
36e8abf3 DJ |
209 | |
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; | |
1da177e4 | 213 | |
719ffe49 | 214 | return cpufreq_table_validate_and_show(policy, &p4clockmod_table[0]); |
1da177e4 LT |
215 | } |
216 | ||
217 | ||
1da177e4 LT |
218 | static unsigned int cpufreq_p4_get(unsigned int cpu) |
219 | { | |
1da177e4 LT |
220 | u32 l, h; |
221 | ||
551948bc | 222 | rdmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, &l, &h); |
1da177e4 LT |
223 | |
224 | if (l & 0x10) { | |
225 | l = l >> 1; | |
226 | l &= 0x7; | |
227 | } else | |
228 | l = DC_DISABLE; | |
229 | ||
230 | if (l != DC_DISABLE) | |
bbfebd66 | 231 | return stock_freq * l / 8; |
1da177e4 LT |
232 | |
233 | return stock_freq; | |
234 | } | |
235 | ||
1da177e4 | 236 | static struct cpufreq_driver p4clockmod_driver = { |
522f70ce | 237 | .verify = cpufreq_generic_frequency_table_verify, |
9c0ebcf7 | 238 | .target_index = cpufreq_p4_target, |
1da177e4 | 239 | .init = cpufreq_p4_cpu_init, |
522f70ce | 240 | .exit = cpufreq_generic_exit, |
1da177e4 LT |
241 | .get = cpufreq_p4_get, |
242 | .name = "p4-clockmod", | |
522f70ce | 243 | .attr = cpufreq_generic_attr, |
1da177e4 LT |
244 | }; |
245 | ||
fa8031ae AK |
246 | static const struct x86_cpu_id cpufreq_p4_id[] = { |
247 | { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, X86_FEATURE_ACC }, | |
248 | {} | |
249 | }; | |
250 | ||
251 | /* | |
252 | * Intentionally no MODULE_DEVICE_TABLE here: this driver should not | |
253 | * be auto loaded. Please don't add one. | |
254 | */ | |
1da177e4 LT |
255 | |
256 | static int __init cpufreq_p4_init(void) | |
32ee8c3e | 257 | { |
1da177e4 LT |
258 | int ret; |
259 | ||
260 | /* | |
32ee8c3e | 261 | * THERM_CONTROL is architectural for IA32 now, so |
1da177e4 LT |
262 | * we can rely on the capability checks |
263 | */ | |
fa8031ae | 264 | if (!x86_match_cpu(cpufreq_p4_id) || !boot_cpu_has(X86_FEATURE_ACPI)) |
1da177e4 LT |
265 | return -ENODEV; |
266 | ||
267 | ret = cpufreq_register_driver(&p4clockmod_driver); | |
268 | if (!ret) | |
bbfebd66 DJ |
269 | printk(KERN_INFO PFX "P4/Xeon(TM) CPU On-Demand Clock " |
270 | "Modulation available\n"); | |
1da177e4 | 271 | |
bbfebd66 | 272 | return ret; |
1da177e4 LT |
273 | } |
274 | ||
275 | ||
276 | static void __exit cpufreq_p4_exit(void) | |
277 | { | |
278 | cpufreq_unregister_driver(&p4clockmod_driver); | |
279 | } | |
280 | ||
281 | ||
bbfebd66 DJ |
282 | MODULE_AUTHOR("Zwane Mwaikambo <zwane@commfireservices.com>"); |
283 | MODULE_DESCRIPTION("cpufreq driver for Pentium(TM) 4/Xeon(TM)"); | |
284 | MODULE_LICENSE("GPL"); | |
1da177e4 LT |
285 | |
286 | late_initcall(cpufreq_p4_init); | |
287 | module_exit(cpufreq_p4_exit); |