diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/i386/kernel/cpu/cpufreq/p4-clockmod.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/i386/kernel/cpu/cpufreq/p4-clockmod.c')
-rw-r--r-- | arch/i386/kernel/cpu/cpufreq/p4-clockmod.c | 337 |
1 files changed, 337 insertions, 0 deletions
diff --git a/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c b/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c new file mode 100644 index 000000000000..aa622d52c6e5 --- /dev/null +++ b/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c | |||
@@ -0,0 +1,337 @@ | |||
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. | ||
17 | * | ||
18 | * Date Errata Description | ||
19 | * 20020525 N44, O17 12.5% or 25% DC causes lockup | ||
20 | * | ||
21 | */ | ||
22 | |||
23 | #include <linux/config.h> | ||
24 | #include <linux/kernel.h> | ||
25 | #include <linux/module.h> | ||
26 | #include <linux/init.h> | ||
27 | #include <linux/smp.h> | ||
28 | #include <linux/cpufreq.h> | ||
29 | #include <linux/slab.h> | ||
30 | #include <linux/cpumask.h> | ||
31 | |||
32 | #include <asm/processor.h> | ||
33 | #include <asm/msr.h> | ||
34 | #include <asm/timex.h> | ||
35 | |||
36 | #include "speedstep-lib.h" | ||
37 | |||
38 | #define PFX "p4-clockmod: " | ||
39 | #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "p4-clockmod", msg) | ||
40 | |||
41 | /* | ||
42 | * Duty Cycle (3bits), note DC_DISABLE is not specified in | ||
43 | * intel docs i just use it to mean disable | ||
44 | */ | ||
45 | enum { | ||
46 | DC_RESV, DC_DFLT, DC_25PT, DC_38PT, DC_50PT, | ||
47 | DC_64PT, DC_75PT, DC_88PT, DC_DISABLE | ||
48 | }; | ||
49 | |||
50 | #define DC_ENTRIES 8 | ||
51 | |||
52 | |||
53 | static int has_N44_O17_errata[NR_CPUS]; | ||
54 | static unsigned int stock_freq; | ||
55 | static struct cpufreq_driver p4clockmod_driver; | ||
56 | static unsigned int cpufreq_p4_get(unsigned int cpu); | ||
57 | |||
58 | static int cpufreq_p4_setdc(unsigned int cpu, unsigned int newstate) | ||
59 | { | ||
60 | u32 l, h; | ||
61 | |||
62 | if (!cpu_online(cpu) || (newstate > DC_DISABLE) || (newstate == DC_RESV)) | ||
63 | return -EINVAL; | ||
64 | |||
65 | rdmsr(MSR_IA32_THERM_STATUS, l, h); | ||
66 | |||
67 | if (l & 0x01) | ||
68 | dprintk("CPU#%d currently thermal throttled\n", cpu); | ||
69 | |||
70 | if (has_N44_O17_errata[cpu] && (newstate == DC_25PT || newstate == DC_DFLT)) | ||
71 | newstate = DC_38PT; | ||
72 | |||
73 | rdmsr(MSR_IA32_THERM_CONTROL, l, h); | ||
74 | if (newstate == DC_DISABLE) { | ||
75 | dprintk("CPU#%d disabling modulation\n", cpu); | ||
76 | wrmsr(MSR_IA32_THERM_CONTROL, l & ~(1<<4), h); | ||
77 | } else { | ||
78 | dprintk("CPU#%d setting duty cycle to %d%%\n", | ||
79 | cpu, ((125 * newstate) / 10)); | ||
80 | /* bits 63 - 5 : reserved | ||
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); | ||
87 | wrmsr(MSR_IA32_THERM_CONTROL, l, h); | ||
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 | |||
108 | static int cpufreq_p4_target(struct cpufreq_policy *policy, | ||
109 | unsigned int target_freq, | ||
110 | unsigned int relation) | ||
111 | { | ||
112 | unsigned int newstate = DC_RESV; | ||
113 | struct cpufreq_freqs freqs; | ||
114 | cpumask_t cpus_allowed; | ||
115 | int i; | ||
116 | |||
117 | if (cpufreq_frequency_table_target(policy, &p4clockmod_table[0], target_freq, relation, &newstate)) | ||
118 | return -EINVAL; | ||
119 | |||
120 | freqs.old = cpufreq_p4_get(policy->cpu); | ||
121 | freqs.new = stock_freq * p4clockmod_table[newstate].index / 8; | ||
122 | |||
123 | if (freqs.new == freqs.old) | ||
124 | return 0; | ||
125 | |||
126 | /* notifiers */ | ||
127 | for_each_cpu_mask(i, policy->cpus) { | ||
128 | freqs.cpu = i; | ||
129 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | ||
130 | } | ||
131 | |||
132 | /* run on each logical CPU, see section 13.15.3 of IA32 Intel Architecture Software | ||
133 | * Developer's Manual, Volume 3 | ||
134 | */ | ||
135 | cpus_allowed = current->cpus_allowed; | ||
136 | |||
137 | for_each_cpu_mask(i, policy->cpus) { | ||
138 | cpumask_t this_cpu = cpumask_of_cpu(i); | ||
139 | |||
140 | set_cpus_allowed(current, this_cpu); | ||
141 | BUG_ON(smp_processor_id() != i); | ||
142 | |||
143 | cpufreq_p4_setdc(i, p4clockmod_table[newstate].index); | ||
144 | } | ||
145 | set_cpus_allowed(current, cpus_allowed); | ||
146 | |||
147 | /* notifiers */ | ||
148 | for_each_cpu_mask(i, policy->cpus) { | ||
149 | freqs.cpu = i; | ||
150 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | ||
151 | } | ||
152 | |||
153 | return 0; | ||
154 | } | ||
155 | |||
156 | |||
157 | static int cpufreq_p4_verify(struct cpufreq_policy *policy) | ||
158 | { | ||
159 | return cpufreq_frequency_table_verify(policy, &p4clockmod_table[0]); | ||
160 | } | ||
161 | |||
162 | |||
163 | static unsigned int cpufreq_p4_get_frequency(struct cpuinfo_x86 *c) | ||
164 | { | ||
165 | if ((c->x86 == 0x06) && (c->x86_model == 0x09)) { | ||
166 | /* Pentium M (Banias) */ | ||
167 | printk(KERN_WARNING PFX "Warning: Pentium M detected. " | ||
168 | "The speedstep_centrino module offers voltage scaling" | ||
169 | " in addition of frequency scaling. You should use " | ||
170 | "that instead of p4-clockmod, if possible.\n"); | ||
171 | return speedstep_get_processor_frequency(SPEEDSTEP_PROCESSOR_PM); | ||
172 | } | ||
173 | |||
174 | if ((c->x86 == 0x06) && (c->x86_model == 0x0D)) { | ||
175 | /* Pentium M (Dothan) */ | ||
176 | printk(KERN_WARNING PFX "Warning: Pentium M detected. " | ||
177 | "The speedstep_centrino module offers voltage scaling" | ||
178 | " in addition of frequency scaling. You should use " | ||
179 | "that instead of p4-clockmod, if possible.\n"); | ||
180 | /* on P-4s, the TSC runs with constant frequency independent whether | ||
181 | * throttling is active or not. */ | ||
182 | p4clockmod_driver.flags |= CPUFREQ_CONST_LOOPS; | ||
183 | return speedstep_get_processor_frequency(SPEEDSTEP_PROCESSOR_PM); | ||
184 | } | ||
185 | |||
186 | if (c->x86 != 0xF) { | ||
187 | printk(KERN_WARNING PFX "Unknown p4-clockmod-capable CPU. Please send an e-mail to <linux@brodo.de>\n"); | ||
188 | return 0; | ||
189 | } | ||
190 | |||
191 | /* on P-4s, the TSC runs with constant frequency independent whether | ||
192 | * throttling is active or not. */ | ||
193 | p4clockmod_driver.flags |= CPUFREQ_CONST_LOOPS; | ||
194 | |||
195 | if (speedstep_detect_processor() == SPEEDSTEP_PROCESSOR_P4M) { | ||
196 | printk(KERN_WARNING PFX "Warning: Pentium 4-M detected. " | ||
197 | "The speedstep-ich or acpi cpufreq modules offer " | ||
198 | "voltage scaling in addition of frequency scaling. " | ||
199 | "You should use either one instead of p4-clockmod, " | ||
200 | "if possible.\n"); | ||
201 | return speedstep_get_processor_frequency(SPEEDSTEP_PROCESSOR_P4M); | ||
202 | } | ||
203 | |||
204 | return speedstep_get_processor_frequency(SPEEDSTEP_PROCESSOR_P4D); | ||
205 | } | ||
206 | |||
207 | |||
208 | |||
209 | static int cpufreq_p4_cpu_init(struct cpufreq_policy *policy) | ||
210 | { | ||
211 | struct cpuinfo_x86 *c = &cpu_data[policy->cpu]; | ||
212 | int cpuid = 0; | ||
213 | unsigned int i; | ||
214 | |||
215 | #ifdef CONFIG_SMP | ||
216 | policy->cpus = cpu_sibling_map[policy->cpu]; | ||
217 | #endif | ||
218 | |||
219 | /* Errata workaround */ | ||
220 | cpuid = (c->x86 << 8) | (c->x86_model << 4) | c->x86_mask; | ||
221 | switch (cpuid) { | ||
222 | case 0x0f07: | ||
223 | case 0x0f0a: | ||
224 | case 0x0f11: | ||
225 | case 0x0f12: | ||
226 | has_N44_O17_errata[policy->cpu] = 1; | ||
227 | dprintk("has errata -- disabling low frequencies\n"); | ||
228 | } | ||
229 | |||
230 | /* get max frequency */ | ||
231 | stock_freq = cpufreq_p4_get_frequency(c); | ||
232 | if (!stock_freq) | ||
233 | return -EINVAL; | ||
234 | |||
235 | /* table init */ | ||
236 | for (i=1; (p4clockmod_table[i].frequency != CPUFREQ_TABLE_END); i++) { | ||
237 | if ((i<2) && (has_N44_O17_errata[policy->cpu])) | ||
238 | p4clockmod_table[i].frequency = CPUFREQ_ENTRY_INVALID; | ||
239 | else | ||
240 | p4clockmod_table[i].frequency = (stock_freq * i)/8; | ||
241 | } | ||
242 | cpufreq_frequency_table_get_attr(p4clockmod_table, policy->cpu); | ||
243 | |||
244 | /* cpuinfo and default policy values */ | ||
245 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | ||
246 | policy->cpuinfo.transition_latency = 1000000; /* assumed */ | ||
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 | { | ||
255 | cpufreq_frequency_table_put_attr(policy->cpu); | ||
256 | return 0; | ||
257 | } | ||
258 | |||
259 | static unsigned int cpufreq_p4_get(unsigned int cpu) | ||
260 | { | ||
261 | cpumask_t cpus_allowed; | ||
262 | u32 l, h; | ||
263 | |||
264 | cpus_allowed = current->cpus_allowed; | ||
265 | |||
266 | set_cpus_allowed(current, cpumask_of_cpu(cpu)); | ||
267 | BUG_ON(smp_processor_id() != cpu); | ||
268 | |||
269 | rdmsr(MSR_IA32_THERM_CONTROL, l, h); | ||
270 | |||
271 | set_cpus_allowed(current, cpus_allowed); | ||
272 | |||
273 | if (l & 0x10) { | ||
274 | l = l >> 1; | ||
275 | l &= 0x7; | ||
276 | } else | ||
277 | l = DC_DISABLE; | ||
278 | |||
279 | if (l != DC_DISABLE) | ||
280 | return (stock_freq * l / 8); | ||
281 | |||
282 | return stock_freq; | ||
283 | } | ||
284 | |||
285 | static struct freq_attr* p4clockmod_attr[] = { | ||
286 | &cpufreq_freq_attr_scaling_available_freqs, | ||
287 | NULL, | ||
288 | }; | ||
289 | |||
290 | static struct cpufreq_driver p4clockmod_driver = { | ||
291 | .verify = cpufreq_p4_verify, | ||
292 | .target = cpufreq_p4_target, | ||
293 | .init = cpufreq_p4_cpu_init, | ||
294 | .exit = cpufreq_p4_cpu_exit, | ||
295 | .get = cpufreq_p4_get, | ||
296 | .name = "p4-clockmod", | ||
297 | .owner = THIS_MODULE, | ||
298 | .attr = p4clockmod_attr, | ||
299 | }; | ||
300 | |||
301 | |||
302 | static int __init cpufreq_p4_init(void) | ||
303 | { | ||
304 | struct cpuinfo_x86 *c = cpu_data; | ||
305 | int ret; | ||
306 | |||
307 | /* | ||
308 | * THERM_CONTROL is architectural for IA32 now, so | ||
309 | * we can rely on the capability checks | ||
310 | */ | ||
311 | if (c->x86_vendor != X86_VENDOR_INTEL) | ||
312 | return -ENODEV; | ||
313 | |||
314 | if (!test_bit(X86_FEATURE_ACPI, c->x86_capability) || | ||
315 | !test_bit(X86_FEATURE_ACC, c->x86_capability)) | ||
316 | return -ENODEV; | ||
317 | |||
318 | ret = cpufreq_register_driver(&p4clockmod_driver); | ||
319 | if (!ret) | ||
320 | printk(KERN_INFO PFX "P4/Xeon(TM) CPU On-Demand Clock Modulation available\n"); | ||
321 | |||
322 | return (ret); | ||
323 | } | ||
324 | |||
325 | |||
326 | static void __exit cpufreq_p4_exit(void) | ||
327 | { | ||
328 | cpufreq_unregister_driver(&p4clockmod_driver); | ||
329 | } | ||
330 | |||
331 | |||
332 | MODULE_AUTHOR ("Zwane Mwaikambo <zwane@commfireservices.com>"); | ||
333 | MODULE_DESCRIPTION ("cpufreq driver for Pentium(TM) 4/Xeon(TM)"); | ||
334 | MODULE_LICENSE ("GPL"); | ||
335 | |||
336 | late_initcall(cpufreq_p4_init); | ||
337 | module_exit(cpufreq_p4_exit); | ||