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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 | ||
bbfebd66 DJ |
61 | if (!cpu_online(cpu) || |
62 | (newstate > DC_DISABLE) || (newstate == DC_RESV)) | |
1da177e4 LT |
63 | return -EINVAL; |
64 | ||
551948bc | 65 | rdmsr_on_cpu(cpu, MSR_IA32_THERM_STATUS, &l, &h); |
1da177e4 LT |
66 | |
67 | if (l & 0x01) | |
2d06d8c4 | 68 | pr_debug("CPU#%d currently thermal throttled\n", cpu); |
1da177e4 | 69 | |
bbfebd66 DJ |
70 | if (has_N44_O17_errata[cpu] && |
71 | (newstate == DC_25PT || newstate == DC_DFLT)) | |
1da177e4 LT |
72 | newstate = DC_38PT; |
73 | ||
551948bc | 74 | rdmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, &l, &h); |
1da177e4 | 75 | if (newstate == DC_DISABLE) { |
2d06d8c4 | 76 | pr_debug("CPU#%d disabling modulation\n", cpu); |
551948bc | 77 | wrmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, l & ~(1<<4), h); |
1da177e4 | 78 | } else { |
2d06d8c4 | 79 | pr_debug("CPU#%d setting duty cycle to %d%%\n", |
1da177e4 | 80 | cpu, ((125 * newstate) / 10)); |
32ee8c3e | 81 | /* bits 63 - 5 : reserved |
1da177e4 LT |
82 | * bit 4 : enable/disable |
83 | * bits 3-1 : duty cycle | |
84 | * bit 0 : reserved | |
85 | */ | |
86 | l = (l & ~14); | |
87 | l = l | (1<<4) | ((newstate & 0x7)<<1); | |
551948bc | 88 | wrmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, l, h); |
1da177e4 LT |
89 | } |
90 | ||
91 | return 0; | |
92 | } | |
93 | ||
94 | ||
95 | static struct cpufreq_frequency_table p4clockmod_table[] = { | |
96 | {DC_RESV, CPUFREQ_ENTRY_INVALID}, | |
97 | {DC_DFLT, 0}, | |
98 | {DC_25PT, 0}, | |
99 | {DC_38PT, 0}, | |
100 | {DC_50PT, 0}, | |
101 | {DC_64PT, 0}, | |
102 | {DC_75PT, 0}, | |
103 | {DC_88PT, 0}, | |
104 | {DC_DISABLE, 0}, | |
105 | {DC_RESV, CPUFREQ_TABLE_END}, | |
106 | }; | |
107 | ||
108 | ||
109 | static int cpufreq_p4_target(struct cpufreq_policy *policy, | |
110 | unsigned int target_freq, | |
111 | unsigned int relation) | |
112 | { | |
113 | unsigned int newstate = DC_RESV; | |
114 | struct cpufreq_freqs freqs; | |
1da177e4 LT |
115 | int i; |
116 | ||
bbfebd66 DJ |
117 | if (cpufreq_frequency_table_target(policy, &p4clockmod_table[0], |
118 | target_freq, relation, &newstate)) | |
1da177e4 LT |
119 | return -EINVAL; |
120 | ||
121 | freqs.old = cpufreq_p4_get(policy->cpu); | |
122 | freqs.new = stock_freq * p4clockmod_table[newstate].index / 8; | |
123 | ||
124 | if (freqs.new == freqs.old) | |
125 | return 0; | |
126 | ||
127 | /* notifiers */ | |
835481d9 | 128 | for_each_cpu(i, policy->cpus) { |
1da177e4 LT |
129 | freqs.cpu = i; |
130 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
131 | } | |
132 | ||
bbfebd66 DJ |
133 | /* run on each logical CPU, |
134 | * see section 13.15.3 of IA32 Intel Architecture Software | |
32ee8c3e | 135 | * Developer's Manual, Volume 3 |
1da177e4 | 136 | */ |
835481d9 | 137 | for_each_cpu(i, policy->cpus) |
1da177e4 | 138 | cpufreq_p4_setdc(i, p4clockmod_table[newstate].index); |
1da177e4 LT |
139 | |
140 | /* notifiers */ | |
835481d9 | 141 | for_each_cpu(i, policy->cpus) { |
1da177e4 LT |
142 | freqs.cpu = i; |
143 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
144 | } | |
145 | ||
146 | return 0; | |
147 | } | |
148 | ||
149 | ||
150 | static int cpufreq_p4_verify(struct cpufreq_policy *policy) | |
151 | { | |
152 | return cpufreq_frequency_table_verify(policy, &p4clockmod_table[0]); | |
153 | } | |
154 | ||
155 | ||
156 | static unsigned int cpufreq_p4_get_frequency(struct cpuinfo_x86 *c) | |
157 | { | |
4e74663c DB |
158 | if (c->x86 == 0x06) { |
159 | if (cpu_has(c, X86_FEATURE_EST)) | |
853cee26 NC |
160 | printk_once(KERN_WARNING PFX "Warning: EST-capable " |
161 | "CPU detected. The acpi-cpufreq module offers " | |
162 | "voltage scaling in addition to frequency " | |
bbfebd66 DJ |
163 | "scaling. You should use that instead of " |
164 | "p4-clockmod, if possible.\n"); | |
4e74663c DB |
165 | switch (c->x86_model) { |
166 | case 0x0E: /* Core */ | |
167 | case 0x0F: /* Core Duo */ | |
8529154e | 168 | case 0x16: /* Celeron Core */ |
43195037 | 169 | case 0x1C: /* Atom */ |
4e74663c | 170 | p4clockmod_driver.flags |= CPUFREQ_CONST_LOOPS; |
bbfebd66 | 171 | return speedstep_get_frequency(SPEEDSTEP_CPU_PCORE); |
4e74663c DB |
172 | case 0x0D: /* Pentium M (Dothan) */ |
173 | p4clockmod_driver.flags |= CPUFREQ_CONST_LOOPS; | |
174 | /* fall through */ | |
175 | case 0x09: /* Pentium M (Banias) */ | |
bbfebd66 | 176 | return speedstep_get_frequency(SPEEDSTEP_CPU_PM); |
4e74663c | 177 | } |
1da177e4 LT |
178 | } |
179 | ||
9d1f44ee | 180 | if (c->x86 != 0xF) |
1da177e4 | 181 | return 0; |
1da177e4 LT |
182 | |
183 | /* on P-4s, the TSC runs with constant frequency independent whether | |
184 | * throttling is active or not. */ | |
185 | p4clockmod_driver.flags |= CPUFREQ_CONST_LOOPS; | |
186 | ||
bbfebd66 | 187 | if (speedstep_detect_processor() == SPEEDSTEP_CPU_P4M) { |
1da177e4 LT |
188 | printk(KERN_WARNING PFX "Warning: Pentium 4-M detected. " |
189 | "The speedstep-ich or acpi cpufreq modules offer " | |
190 | "voltage scaling in addition of frequency scaling. " | |
191 | "You should use either one instead of p4-clockmod, " | |
192 | "if possible.\n"); | |
bbfebd66 | 193 | return speedstep_get_frequency(SPEEDSTEP_CPU_P4M); |
1da177e4 LT |
194 | } |
195 | ||
bbfebd66 | 196 | return speedstep_get_frequency(SPEEDSTEP_CPU_P4D); |
1da177e4 LT |
197 | } |
198 | ||
32ee8c3e | 199 | |
1da177e4 LT |
200 | |
201 | static int cpufreq_p4_cpu_init(struct cpufreq_policy *policy) | |
202 | { | |
92cb7612 | 203 | struct cpuinfo_x86 *c = &cpu_data(policy->cpu); |
1da177e4 LT |
204 | int cpuid = 0; |
205 | unsigned int i; | |
206 | ||
207 | #ifdef CONFIG_SMP | |
7ad728f9 | 208 | cpumask_copy(policy->cpus, cpu_sibling_mask(policy->cpu)); |
1da177e4 LT |
209 | #endif |
210 | ||
211 | /* Errata workaround */ | |
212 | cpuid = (c->x86 << 8) | (c->x86_model << 4) | c->x86_mask; | |
213 | switch (cpuid) { | |
214 | case 0x0f07: | |
215 | case 0x0f0a: | |
216 | case 0x0f11: | |
217 | case 0x0f12: | |
218 | has_N44_O17_errata[policy->cpu] = 1; | |
2d06d8c4 | 219 | pr_debug("has errata -- disabling low frequencies\n"); |
1da177e4 | 220 | } |
32ee8c3e | 221 | |
199785ea MCO |
222 | if (speedstep_detect_processor() == SPEEDSTEP_CPU_P4D && |
223 | c->x86_model < 2) { | |
224 | /* switch to maximum frequency and measure result */ | |
225 | cpufreq_p4_setdc(policy->cpu, DC_DISABLE); | |
226 | recalibrate_cpu_khz(); | |
227 | } | |
1da177e4 LT |
228 | /* get max frequency */ |
229 | stock_freq = cpufreq_p4_get_frequency(c); | |
230 | if (!stock_freq) | |
231 | return -EINVAL; | |
232 | ||
233 | /* table init */ | |
bbfebd66 DJ |
234 | for (i = 1; (p4clockmod_table[i].frequency != CPUFREQ_TABLE_END); i++) { |
235 | if ((i < 2) && (has_N44_O17_errata[policy->cpu])) | |
1da177e4 LT |
236 | p4clockmod_table[i].frequency = CPUFREQ_ENTRY_INVALID; |
237 | else | |
238 | p4clockmod_table[i].frequency = (stock_freq * i)/8; | |
239 | } | |
240 | cpufreq_frequency_table_get_attr(p4clockmod_table, policy->cpu); | |
32ee8c3e | 241 | |
1da177e4 | 242 | /* cpuinfo and default policy values */ |
36e8abf3 DJ |
243 | |
244 | /* the transition latency is set to be 1 higher than the maximum | |
245 | * transition latency of the ondemand governor */ | |
246 | policy->cpuinfo.transition_latency = 10000001; | |
1da177e4 LT |
247 | policy->cur = stock_freq; |
248 | ||
249 | return cpufreq_frequency_table_cpuinfo(policy, &p4clockmod_table[0]); | |
250 | } | |
251 | ||
252 | ||
253 | static int cpufreq_p4_cpu_exit(struct cpufreq_policy *policy) | |
254 | { | |
32ee8c3e | 255 | cpufreq_frequency_table_put_attr(policy->cpu); |
1da177e4 LT |
256 | return 0; |
257 | } | |
258 | ||
259 | static unsigned int cpufreq_p4_get(unsigned int cpu) | |
260 | { | |
1da177e4 LT |
261 | u32 l, h; |
262 | ||
551948bc | 263 | rdmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, &l, &h); |
1da177e4 LT |
264 | |
265 | if (l & 0x10) { | |
266 | l = l >> 1; | |
267 | l &= 0x7; | |
268 | } else | |
269 | l = DC_DISABLE; | |
270 | ||
271 | if (l != DC_DISABLE) | |
bbfebd66 | 272 | return stock_freq * l / 8; |
1da177e4 LT |
273 | |
274 | return stock_freq; | |
275 | } | |
276 | ||
bbfebd66 | 277 | static struct freq_attr *p4clockmod_attr[] = { |
1da177e4 LT |
278 | &cpufreq_freq_attr_scaling_available_freqs, |
279 | NULL, | |
280 | }; | |
281 | ||
282 | static struct cpufreq_driver p4clockmod_driver = { | |
32ee8c3e | 283 | .verify = cpufreq_p4_verify, |
1da177e4 LT |
284 | .target = cpufreq_p4_target, |
285 | .init = cpufreq_p4_cpu_init, | |
286 | .exit = cpufreq_p4_cpu_exit, | |
287 | .get = cpufreq_p4_get, | |
288 | .name = "p4-clockmod", | |
289 | .owner = THIS_MODULE, | |
290 | .attr = p4clockmod_attr, | |
291 | }; | |
292 | ||
fa8031ae AK |
293 | static const struct x86_cpu_id cpufreq_p4_id[] = { |
294 | { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, X86_FEATURE_ACC }, | |
295 | {} | |
296 | }; | |
297 | ||
298 | /* | |
299 | * Intentionally no MODULE_DEVICE_TABLE here: this driver should not | |
300 | * be auto loaded. Please don't add one. | |
301 | */ | |
1da177e4 LT |
302 | |
303 | static int __init cpufreq_p4_init(void) | |
32ee8c3e | 304 | { |
1da177e4 LT |
305 | int ret; |
306 | ||
307 | /* | |
32ee8c3e | 308 | * THERM_CONTROL is architectural for IA32 now, so |
1da177e4 LT |
309 | * we can rely on the capability checks |
310 | */ | |
fa8031ae | 311 | if (!x86_match_cpu(cpufreq_p4_id) || !boot_cpu_has(X86_FEATURE_ACPI)) |
1da177e4 LT |
312 | return -ENODEV; |
313 | ||
314 | ret = cpufreq_register_driver(&p4clockmod_driver); | |
315 | if (!ret) | |
bbfebd66 DJ |
316 | printk(KERN_INFO PFX "P4/Xeon(TM) CPU On-Demand Clock " |
317 | "Modulation available\n"); | |
1da177e4 | 318 | |
bbfebd66 | 319 | return ret; |
1da177e4 LT |
320 | } |
321 | ||
322 | ||
323 | static void __exit cpufreq_p4_exit(void) | |
324 | { | |
325 | cpufreq_unregister_driver(&p4clockmod_driver); | |
326 | } | |
327 | ||
328 | ||
bbfebd66 DJ |
329 | MODULE_AUTHOR("Zwane Mwaikambo <zwane@commfireservices.com>"); |
330 | MODULE_DESCRIPTION("cpufreq driver for Pentium(TM) 4/Xeon(TM)"); | |
331 | MODULE_LICENSE("GPL"); | |
1da177e4 LT |
332 | |
333 | late_initcall(cpufreq_p4_init); | |
334 | module_exit(cpufreq_p4_exit); |