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1 /* 1
2 * Intel SpeedStep SMI driver.
3 *
4 * (C) 2003 Hiroshi Miura <miura@da-cha.org>
5 *
6 * Licensed under the terms of the GNU GPL Li
7 *
8 */
9
10
11 /*********************************************
12 * SPEEDSTEP - DEFINITI
13 *********************************************
14
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/moduleparam.h>
18 #include <linux/init.h>
19 #include <linux/cpufreq.h>
20 #include <linux/slab.h>
21 #include <linux/delay.h>
22 #include <linux/io.h>
23 #include <asm/ist.h>
24
25 #include "speedstep-lib.h"
26
27 /* speedstep system management interface port/
28 *
29 * These parameters are got from IST-SMI BIOS
30 * If user gives it, these are used.
31 *
32 */
33 static int smi_port;
34 static int smi_cmd;
35 static unsigned int smi_sig;
36
37 /* info about the processor */
38 static unsigned int speedstep_processor;
39
40 /*
41 * There are only two frequency states for eac
42 * are in kHz for the time being.
43 */
44 static struct cpufreq_frequency_table speedste
45 {SPEEDSTEP_HIGH, 0},
46 {SPEEDSTEP_LOW, 0},
47 {0, CPUFREQ_TABLE_
48 };
49
50 #define GET_SPEEDSTEP_OWNER 0
51 #define GET_SPEEDSTEP_STATE 1
52 #define SET_SPEEDSTEP_STATE 2
53 #define GET_SPEEDSTEP_FREQS 4
54
55 /* how often shall the SMI call be tried if it
56 * of DMA activity going on? */
57 #define SMI_TRIES 5
58
59 #define dprintk(msg...) cpufreq_debug_printk(C
60 "speedstep-smi", msg)
61
62 /**
63 * speedstep_smi_ownership
64 */
65 static int speedstep_smi_ownership(void)
66 {
67 u32 command, result, magic, dummy;
68 u32 function = GET_SPEEDSTEP_OWNER;
69 unsigned char magic_data[] = "Copyrigh
70
71 command = (smi_sig & 0xffffff00) | (sm
72 magic = virt_to_phys(magic_data);
73
74 dprintk("trying to obtain ownership wi
75 command, smi_port);
76
77 __asm__ __volatile__(
78 "push %%ebp\n"
79 "out %%al, (%%dx)\n"
80 "pop %%ebp\n"
81 : "=D" (result),
82 "=a" (dummy), "=b" (dummy),
83 "=S" (dummy)
84 : "a" (command), "b" (function
85 "D" (0), "S" (magic)
86 : "memory"
87 );
88
89 dprintk("result is %x\n", result);
90
91 return result;
92 }
93
94 /**
95 * speedstep_smi_get_freqs - get SpeedStep pre
96 * @low: the low frequency value is placed her
97 * @high: the high frequency value is placed h
98 *
99 * Only available on later SpeedStep-enabled s
100 * even hangs [cf. bugme.osdl.org # 1422] on e
101 * shows that the latter occurs if !(ist_info.
102 */
103 static int speedstep_smi_get_freqs(unsigned in
104 {
105 u32 command, result = 0, edi, high_mhz
106 u32 state = 0;
107 u32 function = GET_SPEEDSTEP_FREQS;
108
109 if (!(ist_info.event & 0xFFFF)) {
110 dprintk("bug #1422 -- can't re
111 return -ENODEV;
112 }
113
114 command = (smi_sig & 0xffffff00) | (sm
115
116 dprintk("trying to determine frequenci
117 command, smi_port);
118
119 __asm__ __volatile__(
120 "push %%ebp\n"
121 "out %%al, (%%dx)\n"
122 "pop %%ebp"
123 : "=a" (result),
124 "=b" (high_mhz),
125 "=c" (low_mhz),
126 "=d" (state), "=D" (edi), "=
127 : "a" (command),
128 "b" (function),
129 "c" (state),
130 "d" (smi_port), "S" (0), "D"
131 );
132
133 dprintk("result %x, low_freq %u, high_
134 result, low_mhz, high_
135
136 /* abort if results are obviously inco
137 if ((high_mhz + low_mhz) < 600)
138 return -EINVAL;
139
140 *high = high_mhz * 1000;
141 *low = low_mhz * 1000;
142
143 return result;
144 }
145
146 /**
147 * speedstep_get_state - set the SpeedStep sta
148 * @state: processor frequency state (SPEEDSTE
149 *
150 */
151 static int speedstep_get_state(void)
152 {
153 u32 function = GET_SPEEDSTEP_STATE;
154 u32 result, state, edi, command, dummy
155
156 command = (smi_sig & 0xffffff00) | (sm
157
158 dprintk("trying to determine current s
159 "at port %x\n", command, smi_p
160
161 __asm__ __volatile__(
162 "push %%ebp\n"
163 "out %%al, (%%dx)\n"
164 "pop %%ebp\n"
165 : "=a" (result),
166 "=b" (state), "=D" (edi),
167 "=c" (dummy), "=d" (dummy),
168 : "a" (command), "b" (function
169 "d" (smi_port), "S" (0), "D"
170 );
171
172 dprintk("state is %x, result is %x\n",
173
174 return state & 1;
175 }
176
177
178 /**
179 * speedstep_set_state - set the SpeedStep sta
180 * @state: new processor frequency state (SPEE
181 *
182 */
183 static void speedstep_set_state(unsigned int s
184 {
185 unsigned int result = 0, command, new_
186 unsigned long flags;
187 unsigned int function = SET_SPEEDSTEP_
188 unsigned int retry = 0;
189
190 if (state > 0x1)
191 return;
192
193 /* Disable IRQs */
194 local_irq_save(flags);
195
196 command = (smi_sig & 0xffffff00) | (sm
197
198 dprintk("trying to set frequency to st
199 "with command %x at port %x\n"
200 state, command, smi_port);
201
202 do {
203 if (retry) {
204 dprintk("retry %u, pre
205 retry,
206 mdelay(retry * 50);
207 }
208 retry++;
209 __asm__ __volatile__(
210 "push %%ebp\n"
211 "out %%al, (%%dx)\n"
212 "pop %%ebp"
213 : "=b" (new_state), "=
214 "=c" (dummy), "=a" (
215 "=d" (dummy), "=S" (
216 : "a" (command), "b" (
217 "d" (smi_port), "S"
218 );
219 } while ((new_state != state) && (retr
220
221 /* enable IRQs */
222 local_irq_restore(flags);
223
224 if (new_state == state)
225 dprintk("change to %u MHz succ
226 "with result %u\n",
227 (speedstep_freqs[new_s
228 retry, result);
229 else
230 printk(KERN_ERR "cpufreq: chan
231 "failed with new_state
232 state, new_state, resu
233
234 return;
235 }
236
237
238 /**
239 * speedstep_target - set a new CPUFreq policy
240 * @policy: new policy
241 * @target_freq: new freq
242 * @relation:
243 *
244 * Sets a new CPUFreq policy/freq.
245 */
246 static int speedstep_target(struct cpufreq_pol
247 unsigned int target_fr
248 {
249 unsigned int newstate = 0;
250 struct cpufreq_freqs freqs;
251
252 if (cpufreq_frequency_table_target(pol
253 target_freq, r
254 return -EINVAL;
255
256 freqs.old = speedstep_freqs[speedstep_
257 freqs.new = speedstep_freqs[newstate].
258 freqs.cpu = 0; /* speedstep.c is UP on
259
260 if (freqs.old == freqs.new)
261 return 0;
262
263 cpufreq_notify_transition(&freqs, CPUF
264 speedstep_set_state(newstate);
265 cpufreq_notify_transition(&freqs, CPUF
266
267 return 0;
268 }
269
270
271 /**
272 * speedstep_verify - verifies a new CPUFreq p
273 * @policy: new policy
274 *
275 * Limit must be within speedstep_low_freq and
276 * at least one border included.
277 */
278 static int speedstep_verify(struct cpufreq_pol
279 {
280 return cpufreq_frequency_table_verify(
281 }
282
283
284 static int speedstep_cpu_init(struct cpufreq_p
285 {
286 int result;
287 unsigned int speed, state;
288 unsigned int *low, *high;
289
290 /* capability check */
291 if (policy->cpu != 0)
292 return -ENODEV;
293
294 result = speedstep_smi_ownership();
295 if (result) {
296 dprintk("fails in aquiring own
297 return -EINVAL;
298 }
299
300 /* detect low and high frequency */
301 low = &speedstep_freqs[SPEEDSTEP_LOW].
302 high = &speedstep_freqs[SPEEDSTEP_HIGH
303
304 result = speedstep_smi_get_freqs(low,
305 if (result) {
306 /* fall back to speedstep_lib.
307 * try both states out */
308 dprintk("could not detect low
309 "by SMI call.\
310 result = speedstep_get_freqs(s
311 low, high,
312 NULL,
313 &speedstep_set
314
315 if (result) {
316 dprintk("could not det
317 " -- a
318 return result;
319 } else
320 dprintk("workaround wo
321 }
322
323 /* get current speed setting */
324 state = speedstep_get_state();
325 speed = speedstep_freqs[state].frequen
326
327 dprintk("currently at %s speed setting
328 (speed == speedstep_freqs[SPEE
329 ? "low" : "high",
330 (speed / 1000));
331
332 /* cpuinfo and default policy values *
333 policy->cpuinfo.transition_latency = C
334 policy->cur = speed;
335
336 result = cpufreq_frequency_table_cpuin
337 if (result)
338 return result;
339
340 cpufreq_frequency_table_get_attr(speed
341
342 return 0;
343 }
344
345 static int speedstep_cpu_exit(struct cpufreq_p
346 {
347 cpufreq_frequency_table_put_attr(polic
348 return 0;
349 }
350
351 static unsigned int speedstep_get(unsigned int
352 {
353 if (cpu)
354 return -ENODEV;
355 return speedstep_get_frequency(speedst
356 }
357
358
359 static int speedstep_resume(struct cpufreq_pol
360 {
361 int result = speedstep_smi_ownership()
362
363 if (result)
364 dprintk("fails in re-aquiring
365
366 return result;
367 }
368
369 static struct freq_attr *speedstep_attr[] = {
370 &cpufreq_freq_attr_scaling_available_f
371 NULL,
372 };
373
374 static struct cpufreq_driver speedstep_driver
375 .name = "speedstep-smi",
376 .verify = speedstep_verify,
377 .target = speedstep_target,
378 .init = speedstep_cpu_init,
379 .exit = speedstep_cpu_exit,
380 .get = speedstep_get,
381 .resume = speedstep_resume,
382 .owner = THIS_MODULE,
383 .attr = speedstep_attr,
384 };
385
386 /**
387 * speedstep_init - initializes the SpeedStep
388 *
389 * Initializes the SpeedStep support. Return
390 * BIOS, -EINVAL on problems during initiatiza
391 * success.
392 */
393 static int __init speedstep_init(void)
394 {
395 speedstep_processor = speedstep_detect
396
397 switch (speedstep_processor) {
398 case SPEEDSTEP_CPU_PIII_T:
399 case SPEEDSTEP_CPU_PIII_C:
400 case SPEEDSTEP_CPU_PIII_C_EARLY:
401 break;
402 default:
403 speedstep_processor = 0;
404 }
405
406 if (!speedstep_processor) {
407 dprintk("No supported Intel CP
408 return -ENODEV;
409 }
410
411 dprintk("signature:0x%.8lx, command:0x
412 "event:0x%.8lx, perf_level:0x%
413 ist_info.signature, ist_info.c
414 ist_info.event, ist_info.perf_
415
416 /* Error if no IST-SMI BIOS or no PARM
417 sig= 'ISGE' aka 'Intel Speeds
418 if ((ist_info.signature != 0x47534943
419 (smi_port == 0) || (smi_cmd == 0))
420 return -ENODEV;
421
422 if (smi_sig == 1)
423 smi_sig = 0x47534943;
424 else
425 smi_sig = ist_info.signature;
426
427 /* setup smi_port from MODLULE_PARM or
428 if ((smi_port > 0xff) || (smi_port < 0
429 return -EINVAL;
430 else if (smi_port == 0)
431 smi_port = ist_info.command &
432
433 if ((smi_cmd > 0xff) || (smi_cmd < 0))
434 return -EINVAL;
435 else if (smi_cmd == 0)
436 smi_cmd = (ist_info.command >>
437
438 return cpufreq_register_driver(&speeds
439 }
440
441
442 /**
443 * speedstep_exit - unregisters SpeedStep supp
444 *
445 * Unregisters SpeedStep support.
446 */
447 static void __exit speedstep_exit(void)
448 {
449 cpufreq_unregister_driver(&speedstep_d
450 }
451
452 module_param(smi_port, int, 0444);
453 module_param(smi_cmd, int, 0444);
454 module_param(smi_sig, uint, 0444);
455
456 MODULE_PARM_DESC(smi_port, "Override the BIOS-
457 "-- Intel's default setting is
458 MODULE_PARM_DESC(smi_cmd, "Override the BIOS-g
459 "-- Intel's default setting is
460 MODULE_PARM_DESC(smi_sig, "Set to 1 to fake th
461 "SMI interface.");
462
463 MODULE_AUTHOR("Hiroshi Miura");
464 MODULE_DESCRIPTION("Speedstep driver for IST a
465 MODULE_LICENSE("GPL");
466
467 module_init(speedstep_init);
468 module_exit(speedstep_exit);
469
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