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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/i386/kernel/cpu/cpufreq/speedstep-lib.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/speedstep-lib.c')
-rw-r--r--arch/i386/kernel/cpu/cpufreq/speedstep-lib.c385
1 files changed, 385 insertions, 0 deletions
diff --git a/arch/i386/kernel/cpu/cpufreq/speedstep-lib.c b/arch/i386/kernel/cpu/cpufreq/speedstep-lib.c
new file mode 100644
index 000000000000..8ba430a9c3a2
--- /dev/null
+++ b/arch/i386/kernel/cpu/cpufreq/speedstep-lib.c
@@ -0,0 +1,385 @@
1/*
2 * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
3 *
4 * Licensed under the terms of the GNU GPL License version 2.
5 *
6 * Library for common functions for Intel SpeedStep v.1 and v.2 support
7 *
8 * BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous*
9 */
10
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/moduleparam.h>
14#include <linux/init.h>
15#include <linux/cpufreq.h>
16#include <linux/pci.h>
17#include <linux/slab.h>
18
19#include <asm/msr.h>
20#include "speedstep-lib.h"
21
22#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "speedstep-lib", msg)
23
24#ifdef CONFIG_X86_SPEEDSTEP_RELAXED_CAP_CHECK
25static int relaxed_check = 0;
26#else
27#define relaxed_check 0
28#endif
29
30/*********************************************************************
31 * GET PROCESSOR CORE SPEED IN KHZ *
32 *********************************************************************/
33
34static unsigned int pentium3_get_frequency (unsigned int processor)
35{
36 /* See table 14 of p3_ds.pdf and table 22 of 29834003.pdf */
37 struct {
38 unsigned int ratio; /* Frequency Multiplier (x10) */
39 u8 bitmap; /* power on configuration bits
40 [27, 25:22] (in MSR 0x2a) */
41 } msr_decode_mult [] = {
42 { 30, 0x01 },
43 { 35, 0x05 },
44 { 40, 0x02 },
45 { 45, 0x06 },
46 { 50, 0x00 },
47 { 55, 0x04 },
48 { 60, 0x0b },
49 { 65, 0x0f },
50 { 70, 0x09 },
51 { 75, 0x0d },
52 { 80, 0x0a },
53 { 85, 0x26 },
54 { 90, 0x20 },
55 { 100, 0x2b },
56 { 0, 0xff } /* error or unknown value */
57 };
58
59 /* PIII(-M) FSB settings: see table b1-b of 24547206.pdf */
60 struct {
61 unsigned int value; /* Front Side Bus speed in MHz */
62 u8 bitmap; /* power on configuration bits [18: 19]
63 (in MSR 0x2a) */
64 } msr_decode_fsb [] = {
65 { 66, 0x0 },
66 { 100, 0x2 },
67 { 133, 0x1 },
68 { 0, 0xff}
69 };
70
71 u32 msr_lo, msr_tmp;
72 int i = 0, j = 0;
73
74 /* read MSR 0x2a - we only need the low 32 bits */
75 rdmsr(MSR_IA32_EBL_CR_POWERON, msr_lo, msr_tmp);
76 dprintk("P3 - MSR_IA32_EBL_CR_POWERON: 0x%x 0x%x\n", msr_lo, msr_tmp);
77 msr_tmp = msr_lo;
78
79 /* decode the FSB */
80 msr_tmp &= 0x00c0000;
81 msr_tmp >>= 18;
82 while (msr_tmp != msr_decode_fsb[i].bitmap) {
83 if (msr_decode_fsb[i].bitmap == 0xff)
84 return 0;
85 i++;
86 }
87
88 /* decode the multiplier */
89 if (processor == SPEEDSTEP_PROCESSOR_PIII_C_EARLY) {
90 dprintk("workaround for early PIIIs\n");
91 msr_lo &= 0x03c00000;
92 } else
93 msr_lo &= 0x0bc00000;
94 msr_lo >>= 22;
95 while (msr_lo != msr_decode_mult[j].bitmap) {
96 if (msr_decode_mult[j].bitmap == 0xff)
97 return 0;
98 j++;
99 }
100
101 dprintk("speed is %u\n", (msr_decode_mult[j].ratio * msr_decode_fsb[i].value * 100));
102
103 return (msr_decode_mult[j].ratio * msr_decode_fsb[i].value * 100);
104}
105
106
107static unsigned int pentiumM_get_frequency(void)
108{
109 u32 msr_lo, msr_tmp;
110
111 rdmsr(MSR_IA32_EBL_CR_POWERON, msr_lo, msr_tmp);
112 dprintk("PM - MSR_IA32_EBL_CR_POWERON: 0x%x 0x%x\n", msr_lo, msr_tmp);
113
114 /* see table B-2 of 24547212.pdf */
115 if (msr_lo & 0x00040000) {
116 printk(KERN_DEBUG "speedstep-lib: PM - invalid FSB: 0x%x 0x%x\n", msr_lo, msr_tmp);
117 return 0;
118 }
119
120 msr_tmp = (msr_lo >> 22) & 0x1f;
121 dprintk("bits 22-26 are 0x%x, speed is %u\n", msr_tmp, (msr_tmp * 100 * 1000));
122
123 return (msr_tmp * 100 * 1000);
124}
125
126
127static unsigned int pentium4_get_frequency(void)
128{
129 struct cpuinfo_x86 *c = &boot_cpu_data;
130 u32 msr_lo, msr_hi, mult;
131 unsigned int fsb = 0;
132
133 rdmsr(0x2c, msr_lo, msr_hi);
134
135 dprintk("P4 - MSR_EBC_FREQUENCY_ID: 0x%x 0x%x\n", msr_lo, msr_hi);
136
137 /* decode the FSB: see IA-32 Intel (C) Architecture Software
138 * Developer's Manual, Volume 3: System Prgramming Guide,
139 * revision #12 in Table B-1: MSRs in the Pentium 4 and
140 * Intel Xeon Processors, on page B-4 and B-5.
141 */
142 if (c->x86_model < 2)
143 fsb = 100 * 1000;
144 else {
145 u8 fsb_code = (msr_lo >> 16) & 0x7;
146 switch (fsb_code) {
147 case 0:
148 fsb = 100 * 1000;
149 break;
150 case 1:
151 fsb = 13333 * 10;
152 break;
153 case 2:
154 fsb = 200 * 1000;
155 break;
156 }
157 }
158
159 if (!fsb)
160 printk(KERN_DEBUG "speedstep-lib: couldn't detect FSB speed. Please send an e-mail to <linux@brodo.de>\n");
161
162 /* Multiplier. */
163 if (c->x86_model < 2)
164 mult = msr_lo >> 27;
165 else
166 mult = msr_lo >> 24;
167
168 dprintk("P4 - FSB %u kHz; Multiplier %u; Speed %u kHz\n", fsb, mult, (fsb * mult));
169
170 return (fsb * mult);
171}
172
173
174unsigned int speedstep_get_processor_frequency(unsigned int processor)
175{
176 switch (processor) {
177 case SPEEDSTEP_PROCESSOR_PM:
178 return pentiumM_get_frequency();
179 case SPEEDSTEP_PROCESSOR_P4D:
180 case SPEEDSTEP_PROCESSOR_P4M:
181 return pentium4_get_frequency();
182 case SPEEDSTEP_PROCESSOR_PIII_T:
183 case SPEEDSTEP_PROCESSOR_PIII_C:
184 case SPEEDSTEP_PROCESSOR_PIII_C_EARLY:
185 return pentium3_get_frequency(processor);
186 default:
187 return 0;
188 };
189 return 0;
190}
191EXPORT_SYMBOL_GPL(speedstep_get_processor_frequency);
192
193
194/*********************************************************************
195 * DETECT SPEEDSTEP-CAPABLE PROCESSOR *
196 *********************************************************************/
197
198unsigned int speedstep_detect_processor (void)
199{
200 struct cpuinfo_x86 *c = cpu_data;
201 u32 ebx, msr_lo, msr_hi;
202
203 dprintk("x86: %x, model: %x\n", c->x86, c->x86_model);
204
205 if ((c->x86_vendor != X86_VENDOR_INTEL) ||
206 ((c->x86 != 6) && (c->x86 != 0xF)))
207 return 0;
208
209 if (c->x86 == 0xF) {
210 /* Intel Mobile Pentium 4-M
211 * or Intel Mobile Pentium 4 with 533 MHz FSB */
212 if (c->x86_model != 2)
213 return 0;
214
215 ebx = cpuid_ebx(0x00000001);
216 ebx &= 0x000000FF;
217
218 dprintk("ebx value is %x, x86_mask is %x\n", ebx, c->x86_mask);
219
220 switch (c->x86_mask) {
221 case 4:
222 /*
223 * B-stepping [M-P4-M]
224 * sample has ebx = 0x0f, production has 0x0e.
225 */
226 if ((ebx == 0x0e) || (ebx == 0x0f))
227 return SPEEDSTEP_PROCESSOR_P4M;
228 break;
229 case 7:
230 /*
231 * C-stepping [M-P4-M]
232 * needs to have ebx=0x0e, else it's a celeron:
233 * cf. 25130917.pdf / page 7, footnote 5 even
234 * though 25072120.pdf / page 7 doesn't say
235 * samples are only of B-stepping...
236 */
237 if (ebx == 0x0e)
238 return SPEEDSTEP_PROCESSOR_P4M;
239 break;
240 case 9:
241 /*
242 * D-stepping [M-P4-M or M-P4/533]
243 *
244 * this is totally strange: CPUID 0x0F29 is
245 * used by M-P4-M, M-P4/533 and(!) Celeron CPUs.
246 * The latter need to be sorted out as they don't
247 * support speedstep.
248 * Celerons with CPUID 0x0F29 may have either
249 * ebx=0x8 or 0xf -- 25130917.pdf doesn't say anything
250 * specific.
251 * M-P4-Ms may have either ebx=0xe or 0xf [see above]
252 * M-P4/533 have either ebx=0xe or 0xf. [25317607.pdf]
253 * also, M-P4M HTs have ebx=0x8, too
254 * For now, they are distinguished by the model_id string
255 */
256 if ((ebx == 0x0e) || (strstr(c->x86_model_id,"Mobile Intel(R) Pentium(R) 4") != NULL))
257 return SPEEDSTEP_PROCESSOR_P4M;
258 break;
259 default:
260 break;
261 }
262 return 0;
263 }
264
265 switch (c->x86_model) {
266 case 0x0B: /* Intel PIII [Tualatin] */
267 /* cpuid_ebx(1) is 0x04 for desktop PIII,
268 0x06 for mobile PIII-M */
269 ebx = cpuid_ebx(0x00000001);
270 dprintk("ebx is %x\n", ebx);
271
272 ebx &= 0x000000FF;
273
274 if (ebx != 0x06)
275 return 0;
276
277 /* So far all PIII-M processors support SpeedStep. See
278 * Intel's 24540640.pdf of June 2003
279 */
280
281 return SPEEDSTEP_PROCESSOR_PIII_T;
282
283 case 0x08: /* Intel PIII [Coppermine] */
284
285 /* all mobile PIII Coppermines have FSB 100 MHz
286 * ==> sort out a few desktop PIIIs. */
287 rdmsr(MSR_IA32_EBL_CR_POWERON, msr_lo, msr_hi);
288 dprintk("Coppermine: MSR_IA32_EBL_CR_POWERON is 0x%x, 0x%x\n", msr_lo, msr_hi);
289 msr_lo &= 0x00c0000;
290 if (msr_lo != 0x0080000)
291 return 0;
292
293 /*
294 * If the processor is a mobile version,
295 * platform ID has bit 50 set
296 * it has SpeedStep technology if either
297 * bit 56 or 57 is set
298 */
299 rdmsr(MSR_IA32_PLATFORM_ID, msr_lo, msr_hi);
300 dprintk("Coppermine: MSR_IA32_PLATFORM ID is 0x%x, 0x%x\n", msr_lo, msr_hi);
301 if ((msr_hi & (1<<18)) && (relaxed_check ? 1 : (msr_hi & (3<<24)))) {
302 if (c->x86_mask == 0x01) {
303 dprintk("early PIII version\n");
304 return SPEEDSTEP_PROCESSOR_PIII_C_EARLY;
305 } else
306 return SPEEDSTEP_PROCESSOR_PIII_C;
307 }
308
309 default:
310 return 0;
311 }
312}
313EXPORT_SYMBOL_GPL(speedstep_detect_processor);
314
315
316/*********************************************************************
317 * DETECT SPEEDSTEP SPEEDS *
318 *********************************************************************/
319
320unsigned int speedstep_get_freqs(unsigned int processor,
321 unsigned int *low_speed,
322 unsigned int *high_speed,
323 void (*set_state) (unsigned int state))
324{
325 unsigned int prev_speed;
326 unsigned int ret = 0;
327 unsigned long flags;
328
329 if ((!processor) || (!low_speed) || (!high_speed) || (!set_state))
330 return -EINVAL;
331
332 dprintk("trying to determine both speeds\n");
333
334 /* get current speed */
335 prev_speed = speedstep_get_processor_frequency(processor);
336 if (!prev_speed)
337 return -EIO;
338
339 dprintk("previous seped is %u\n", prev_speed);
340
341 local_irq_save(flags);
342
343 /* switch to low state */
344 set_state(SPEEDSTEP_LOW);
345 *low_speed = speedstep_get_processor_frequency(processor);
346 if (!*low_speed) {
347 ret = -EIO;
348 goto out;
349 }
350
351 dprintk("low seped is %u\n", *low_speed);
352
353 /* switch to high state */
354 set_state(SPEEDSTEP_HIGH);
355 *high_speed = speedstep_get_processor_frequency(processor);
356 if (!*high_speed) {
357 ret = -EIO;
358 goto out;
359 }
360
361 dprintk("high seped is %u\n", *high_speed);
362
363 if (*low_speed == *high_speed) {
364 ret = -ENODEV;
365 goto out;
366 }
367
368 /* switch to previous state, if necessary */
369 if (*high_speed != prev_speed)
370 set_state(SPEEDSTEP_LOW);
371
372 out:
373 local_irq_restore(flags);
374 return (ret);
375}
376EXPORT_SYMBOL_GPL(speedstep_get_freqs);
377
378#ifdef CONFIG_X86_SPEEDSTEP_RELAXED_CAP_CHECK
379module_param(relaxed_check, int, 0444);
380MODULE_PARM_DESC(relaxed_check, "Don't do all checks for speedstep capability.");
381#endif
382
383MODULE_AUTHOR ("Dominik Brodowski <linux@brodo.de>");
384MODULE_DESCRIPTION ("Library for Intel SpeedStep 1 or 2 cpufreq drivers.");
385MODULE_LICENSE ("GPL");