Commit | Line | Data |
---|---|---|
1da177e4 LT |
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 License version 2. | |
7 | * | |
8 | */ | |
9 | ||
10 | ||
11 | /********************************************************************* | |
12 | * SPEEDSTEP - DEFINITIONS * | |
13 | *********************************************************************/ | |
14 | ||
15 | #include <linux/kernel.h> | |
32ee8c3e DJ |
16 | #include <linux/module.h> |
17 | #include <linux/moduleparam.h> | |
1da177e4 LT |
18 | #include <linux/init.h> |
19 | #include <linux/cpufreq.h> | |
1da177e4 | 20 | #include <linux/delay.h> |
bbfebd66 | 21 | #include <linux/io.h> |
1da177e4 LT |
22 | #include <asm/ist.h> |
23 | ||
24 | #include "speedstep-lib.h" | |
25 | ||
26 | /* speedstep system management interface port/command. | |
27 | * | |
28 | * These parameters are got from IST-SMI BIOS call. | |
29 | * If user gives it, these are used. | |
32ee8c3e | 30 | * |
1da177e4 | 31 | */ |
bbfebd66 DJ |
32 | static int smi_port; |
33 | static int smi_cmd; | |
34 | static unsigned int smi_sig; | |
1da177e4 LT |
35 | |
36 | /* info about the processor */ | |
1cce76c2 | 37 | static enum speedstep_processor speedstep_processor; |
1da177e4 | 38 | |
32ee8c3e DJ |
39 | /* |
40 | * There are only two frequency states for each processor. Values | |
1da177e4 LT |
41 | * are in kHz for the time being. |
42 | */ | |
43 | static struct cpufreq_frequency_table speedstep_freqs[] = { | |
32ee8c3e | 44 | {SPEEDSTEP_HIGH, 0}, |
1da177e4 LT |
45 | {SPEEDSTEP_LOW, 0}, |
46 | {0, CPUFREQ_TABLE_END}, | |
47 | }; | |
48 | ||
49 | #define GET_SPEEDSTEP_OWNER 0 | |
50 | #define GET_SPEEDSTEP_STATE 1 | |
51 | #define SET_SPEEDSTEP_STATE 2 | |
52 | #define GET_SPEEDSTEP_FREQS 4 | |
53 | ||
54 | /* how often shall the SMI call be tried if it failed, e.g. because | |
55 | * of DMA activity going on? */ | |
56 | #define SMI_TRIES 5 | |
57 | ||
1da177e4 LT |
58 | /** |
59 | * speedstep_smi_ownership | |
60 | */ | |
bbfebd66 | 61 | static int speedstep_smi_ownership(void) |
1da177e4 | 62 | { |
c6e8256a | 63 | u32 command, result, magic, dummy; |
1da177e4 LT |
64 | u32 function = GET_SPEEDSTEP_OWNER; |
65 | unsigned char magic_data[] = "Copyright (c) 1999 Intel Corporation"; | |
66 | ||
67 | command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff); | |
68 | magic = virt_to_phys(magic_data); | |
69 | ||
2d06d8c4 | 70 | pr_debug("trying to obtain ownership with command %x at port %x\n", |
bbfebd66 | 71 | command, smi_port); |
1da177e4 LT |
72 | |
73 | __asm__ __volatile__( | |
c6e8256a | 74 | "push %%ebp\n" |
1da177e4 | 75 | "out %%al, (%%dx)\n" |
c6e8256a | 76 | "pop %%ebp\n" |
bbfebd66 DJ |
77 | : "=D" (result), |
78 | "=a" (dummy), "=b" (dummy), "=c" (dummy), "=d" (dummy), | |
79 | "=S" (dummy) | |
f081a529 | 80 | : "a" (command), "b" (function), "c" (0), "d" (smi_port), |
bbfebd66 | 81 | "D" (0), "S" (magic) |
f081a529 | 82 | : "memory" |
1da177e4 LT |
83 | ); |
84 | ||
2d06d8c4 | 85 | pr_debug("result is %x\n", result); |
1da177e4 LT |
86 | |
87 | return result; | |
88 | } | |
89 | ||
90 | /** | |
91 | * speedstep_smi_get_freqs - get SpeedStep preferred & current freq. | |
92 | * @low: the low frequency value is placed here | |
93 | * @high: the high frequency value is placed here | |
94 | * | |
95 | * Only available on later SpeedStep-enabled systems, returns false results or | |
96 | * even hangs [cf. bugme.osdl.org # 1422] on earlier systems. Empirical testing | |
97 | * shows that the latter occurs if !(ist_info.event & 0xFFFF). | |
98 | */ | |
bbfebd66 | 99 | static int speedstep_smi_get_freqs(unsigned int *low, unsigned int *high) |
1da177e4 | 100 | { |
c6e8256a | 101 | u32 command, result = 0, edi, high_mhz, low_mhz, dummy; |
bbfebd66 | 102 | u32 state = 0; |
1da177e4 LT |
103 | u32 function = GET_SPEEDSTEP_FREQS; |
104 | ||
105 | if (!(ist_info.event & 0xFFFF)) { | |
2d06d8c4 | 106 | pr_debug("bug #1422 -- can't read freqs from BIOS\n"); |
1da177e4 LT |
107 | return -ENODEV; |
108 | } | |
109 | ||
110 | command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff); | |
111 | ||
2d06d8c4 | 112 | pr_debug("trying to determine frequencies with command %x at port %x\n", |
bbfebd66 | 113 | command, smi_port); |
1da177e4 | 114 | |
c6e8256a SD |
115 | __asm__ __volatile__( |
116 | "push %%ebp\n" | |
1da177e4 | 117 | "out %%al, (%%dx)\n" |
c6e8256a | 118 | "pop %%ebp" |
bbfebd66 DJ |
119 | : "=a" (result), |
120 | "=b" (high_mhz), | |
121 | "=c" (low_mhz), | |
122 | "=d" (state), "=D" (edi), "=S" (dummy) | |
123 | : "a" (command), | |
124 | "b" (function), | |
125 | "c" (state), | |
126 | "d" (smi_port), "S" (0), "D" (0) | |
1da177e4 LT |
127 | ); |
128 | ||
2d06d8c4 | 129 | pr_debug("result %x, low_freq %u, high_freq %u\n", |
bbfebd66 | 130 | result, low_mhz, high_mhz); |
1da177e4 LT |
131 | |
132 | /* abort if results are obviously incorrect... */ | |
133 | if ((high_mhz + low_mhz) < 600) | |
134 | return -EINVAL; | |
135 | ||
136 | *high = high_mhz * 1000; | |
137 | *low = low_mhz * 1000; | |
138 | ||
139 | return result; | |
32ee8c3e | 140 | } |
1da177e4 LT |
141 | |
142 | /** | |
143 | * speedstep_get_state - set the SpeedStep state | |
144 | * @state: processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH) | |
145 | * | |
146 | */ | |
bbfebd66 | 147 | static int speedstep_get_state(void) |
1da177e4 | 148 | { |
bbfebd66 | 149 | u32 function = GET_SPEEDSTEP_STATE; |
c6e8256a | 150 | u32 result, state, edi, command, dummy; |
1da177e4 LT |
151 | |
152 | command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff); | |
153 | ||
2d06d8c4 | 154 | pr_debug("trying to determine current setting with command %x " |
bbfebd66 | 155 | "at port %x\n", command, smi_port); |
1da177e4 | 156 | |
c6e8256a SD |
157 | __asm__ __volatile__( |
158 | "push %%ebp\n" | |
1da177e4 | 159 | "out %%al, (%%dx)\n" |
c6e8256a | 160 | "pop %%ebp\n" |
bbfebd66 DJ |
161 | : "=a" (result), |
162 | "=b" (state), "=D" (edi), | |
163 | "=c" (dummy), "=d" (dummy), "=S" (dummy) | |
164 | : "a" (command), "b" (function), "c" (0), | |
165 | "d" (smi_port), "S" (0), "D" (0) | |
1da177e4 LT |
166 | ); |
167 | ||
2d06d8c4 | 168 | pr_debug("state is %x, result is %x\n", state, result); |
1da177e4 | 169 | |
bbfebd66 | 170 | return state & 1; |
1da177e4 LT |
171 | } |
172 | ||
173 | ||
174 | /** | |
175 | * speedstep_set_state - set the SpeedStep state | |
176 | * @state: new processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH) | |
177 | * | |
178 | */ | |
bbfebd66 | 179 | static void speedstep_set_state(unsigned int state) |
1da177e4 | 180 | { |
c6e8256a | 181 | unsigned int result = 0, command, new_state, dummy; |
1da177e4 | 182 | unsigned long flags; |
bbfebd66 | 183 | unsigned int function = SET_SPEEDSTEP_STATE; |
1da177e4 LT |
184 | unsigned int retry = 0; |
185 | ||
186 | if (state > 0x1) | |
187 | return; | |
188 | ||
189 | /* Disable IRQs */ | |
190 | local_irq_save(flags); | |
191 | ||
192 | command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff); | |
193 | ||
2d06d8c4 | 194 | pr_debug("trying to set frequency to state %u " |
bbfebd66 DJ |
195 | "with command %x at port %x\n", |
196 | state, command, smi_port); | |
1da177e4 LT |
197 | |
198 | do { | |
199 | if (retry) { | |
2d06d8c4 | 200 | pr_debug("retry %u, previous result %u, waiting...\n", |
bbfebd66 | 201 | retry, result); |
1da177e4 LT |
202 | mdelay(retry * 50); |
203 | } | |
204 | retry++; | |
205 | __asm__ __volatile__( | |
c6e8256a | 206 | "push %%ebp\n" |
1da177e4 | 207 | "out %%al, (%%dx)\n" |
c6e8256a | 208 | "pop %%ebp" |
bbfebd66 DJ |
209 | : "=b" (new_state), "=D" (result), |
210 | "=c" (dummy), "=a" (dummy), | |
211 | "=d" (dummy), "=S" (dummy) | |
212 | : "a" (command), "b" (function), "c" (state), | |
213 | "d" (smi_port), "S" (0), "D" (0) | |
1da177e4 LT |
214 | ); |
215 | } while ((new_state != state) && (retry <= SMI_TRIES)); | |
216 | ||
217 | /* enable IRQs */ | |
218 | local_irq_restore(flags); | |
219 | ||
bbfebd66 | 220 | if (new_state == state) |
2d06d8c4 | 221 | pr_debug("change to %u MHz succeeded after %u tries " |
bbfebd66 DJ |
222 | "with result %u\n", |
223 | (speedstep_freqs[new_state].frequency / 1000), | |
224 | retry, result); | |
225 | else | |
226 | printk(KERN_ERR "cpufreq: change to state %u " | |
227 | "failed with new_state %u and result %u\n", | |
228 | state, new_state, result); | |
1da177e4 LT |
229 | |
230 | return; | |
231 | } | |
232 | ||
233 | ||
234 | /** | |
235 | * speedstep_target - set a new CPUFreq policy | |
236 | * @policy: new policy | |
237 | * @target_freq: new freq | |
32ee8c3e | 238 | * @relation: |
1da177e4 LT |
239 | * |
240 | * Sets a new CPUFreq policy/freq. | |
241 | */ | |
bbfebd66 | 242 | static int speedstep_target(struct cpufreq_policy *policy, |
1da177e4 LT |
243 | unsigned int target_freq, unsigned int relation) |
244 | { | |
245 | unsigned int newstate = 0; | |
246 | struct cpufreq_freqs freqs; | |
247 | ||
bbfebd66 DJ |
248 | if (cpufreq_frequency_table_target(policy, &speedstep_freqs[0], |
249 | target_freq, relation, &newstate)) | |
1da177e4 LT |
250 | return -EINVAL; |
251 | ||
252 | freqs.old = speedstep_freqs[speedstep_get_state()].frequency; | |
253 | freqs.new = speedstep_freqs[newstate].frequency; | |
254 | freqs.cpu = 0; /* speedstep.c is UP only driver */ | |
255 | ||
256 | if (freqs.old == freqs.new) | |
257 | return 0; | |
258 | ||
259 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
260 | speedstep_set_state(newstate); | |
261 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
262 | ||
263 | return 0; | |
264 | } | |
265 | ||
266 | ||
267 | /** | |
268 | * speedstep_verify - verifies a new CPUFreq policy | |
269 | * @policy: new policy | |
270 | * | |
271 | * Limit must be within speedstep_low_freq and speedstep_high_freq, with | |
272 | * at least one border included. | |
273 | */ | |
bbfebd66 | 274 | static int speedstep_verify(struct cpufreq_policy *policy) |
1da177e4 LT |
275 | { |
276 | return cpufreq_frequency_table_verify(policy, &speedstep_freqs[0]); | |
277 | } | |
278 | ||
279 | ||
280 | static int speedstep_cpu_init(struct cpufreq_policy *policy) | |
281 | { | |
282 | int result; | |
bbfebd66 DJ |
283 | unsigned int speed, state; |
284 | unsigned int *low, *high; | |
1da177e4 LT |
285 | |
286 | /* capability check */ | |
287 | if (policy->cpu != 0) | |
288 | return -ENODEV; | |
289 | ||
290 | result = speedstep_smi_ownership(); | |
291 | if (result) { | |
2d06d8c4 | 292 | pr_debug("fails in acquiring ownership of a SMI interface.\n"); |
1da177e4 LT |
293 | return -EINVAL; |
294 | } | |
295 | ||
296 | /* detect low and high frequency */ | |
bbfebd66 DJ |
297 | low = &speedstep_freqs[SPEEDSTEP_LOW].frequency; |
298 | high = &speedstep_freqs[SPEEDSTEP_HIGH].frequency; | |
299 | ||
300 | result = speedstep_smi_get_freqs(low, high); | |
1da177e4 | 301 | if (result) { |
bbfebd66 DJ |
302 | /* fall back to speedstep_lib.c dection mechanism: |
303 | * try both states out */ | |
2d06d8c4 | 304 | pr_debug("could not detect low and high frequencies " |
bbfebd66 | 305 | "by SMI call.\n"); |
1da177e4 | 306 | result = speedstep_get_freqs(speedstep_processor, |
bbfebd66 | 307 | low, high, |
1a10760c | 308 | NULL, |
1da177e4 LT |
309 | &speedstep_set_state); |
310 | ||
311 | if (result) { | |
2d06d8c4 | 312 | pr_debug("could not detect two different speeds" |
bbfebd66 | 313 | " -- aborting.\n"); |
1da177e4 LT |
314 | return result; |
315 | } else | |
2d06d8c4 | 316 | pr_debug("workaround worked.\n"); |
1da177e4 LT |
317 | } |
318 | ||
319 | /* get current speed setting */ | |
320 | state = speedstep_get_state(); | |
321 | speed = speedstep_freqs[state].frequency; | |
322 | ||
2d06d8c4 | 323 | pr_debug("currently at %s speed setting - %i MHz\n", |
bbfebd66 DJ |
324 | (speed == speedstep_freqs[SPEEDSTEP_LOW].frequency) |
325 | ? "low" : "high", | |
1da177e4 LT |
326 | (speed / 1000)); |
327 | ||
328 | /* cpuinfo and default policy values */ | |
1da177e4 LT |
329 | policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; |
330 | policy->cur = speed; | |
331 | ||
332 | result = cpufreq_frequency_table_cpuinfo(policy, speedstep_freqs); | |
333 | if (result) | |
bbfebd66 | 334 | return result; |
1da177e4 | 335 | |
32ee8c3e | 336 | cpufreq_frequency_table_get_attr(speedstep_freqs, policy->cpu); |
1da177e4 LT |
337 | |
338 | return 0; | |
339 | } | |
340 | ||
341 | static int speedstep_cpu_exit(struct cpufreq_policy *policy) | |
342 | { | |
343 | cpufreq_frequency_table_put_attr(policy->cpu); | |
344 | return 0; | |
345 | } | |
346 | ||
347 | static unsigned int speedstep_get(unsigned int cpu) | |
348 | { | |
349 | if (cpu) | |
350 | return -ENODEV; | |
bbfebd66 | 351 | return speedstep_get_frequency(speedstep_processor); |
1da177e4 LT |
352 | } |
353 | ||
354 | ||
355 | static int speedstep_resume(struct cpufreq_policy *policy) | |
356 | { | |
357 | int result = speedstep_smi_ownership(); | |
358 | ||
359 | if (result) | |
2d06d8c4 | 360 | pr_debug("fails in re-acquiring ownership of a SMI interface.\n"); |
1da177e4 LT |
361 | |
362 | return result; | |
363 | } | |
364 | ||
bbfebd66 | 365 | static struct freq_attr *speedstep_attr[] = { |
1da177e4 LT |
366 | &cpufreq_freq_attr_scaling_available_freqs, |
367 | NULL, | |
368 | }; | |
369 | ||
221dee28 | 370 | static struct cpufreq_driver speedstep_driver = { |
1da177e4 | 371 | .name = "speedstep-smi", |
32ee8c3e DJ |
372 | .verify = speedstep_verify, |
373 | .target = speedstep_target, | |
1da177e4 LT |
374 | .init = speedstep_cpu_init, |
375 | .exit = speedstep_cpu_exit, | |
376 | .get = speedstep_get, | |
377 | .resume = speedstep_resume, | |
378 | .owner = THIS_MODULE, | |
379 | .attr = speedstep_attr, | |
380 | }; | |
381 | ||
382 | /** | |
383 | * speedstep_init - initializes the SpeedStep CPUFreq driver | |
384 | * | |
385 | * Initializes the SpeedStep support. Returns -ENODEV on unsupported | |
386 | * BIOS, -EINVAL on problems during initiatization, and zero on | |
387 | * success. | |
388 | */ | |
389 | static int __init speedstep_init(void) | |
390 | { | |
391 | speedstep_processor = speedstep_detect_processor(); | |
392 | ||
393 | switch (speedstep_processor) { | |
bbfebd66 DJ |
394 | case SPEEDSTEP_CPU_PIII_T: |
395 | case SPEEDSTEP_CPU_PIII_C: | |
396 | case SPEEDSTEP_CPU_PIII_C_EARLY: | |
1da177e4 LT |
397 | break; |
398 | default: | |
399 | speedstep_processor = 0; | |
400 | } | |
401 | ||
402 | if (!speedstep_processor) { | |
2d06d8c4 | 403 | pr_debug("No supported Intel CPU detected.\n"); |
1da177e4 LT |
404 | return -ENODEV; |
405 | } | |
406 | ||
2d06d8c4 DB |
407 | pr_debug("signature:0x%.8ulx, command:0x%.8ulx, " |
408 | "event:0x%.8ulx, perf_level:0x%.8ulx.\n", | |
bbfebd66 DJ |
409 | ist_info.signature, ist_info.command, |
410 | ist_info.event, ist_info.perf_level); | |
1da177e4 | 411 | |
32ee8c3e | 412 | /* Error if no IST-SMI BIOS or no PARM |
1da177e4 | 413 | sig= 'ISGE' aka 'Intel Speedstep Gate E' */ |
32ee8c3e | 414 | if ((ist_info.signature != 0x47534943) && ( |
1da177e4 LT |
415 | (smi_port == 0) || (smi_cmd == 0))) |
416 | return -ENODEV; | |
417 | ||
418 | if (smi_sig == 1) | |
419 | smi_sig = 0x47534943; | |
420 | else | |
421 | smi_sig = ist_info.signature; | |
422 | ||
423 | /* setup smi_port from MODLULE_PARM or BIOS */ | |
32ee8c3e | 424 | if ((smi_port > 0xff) || (smi_port < 0)) |
1da177e4 | 425 | return -EINVAL; |
32ee8c3e | 426 | else if (smi_port == 0) |
1da177e4 | 427 | smi_port = ist_info.command & 0xff; |
1da177e4 | 428 | |
32ee8c3e | 429 | if ((smi_cmd > 0xff) || (smi_cmd < 0)) |
1da177e4 | 430 | return -EINVAL; |
32ee8c3e | 431 | else if (smi_cmd == 0) |
1da177e4 | 432 | smi_cmd = (ist_info.command >> 16) & 0xff; |
1da177e4 LT |
433 | |
434 | return cpufreq_register_driver(&speedstep_driver); | |
435 | } | |
436 | ||
437 | ||
438 | /** | |
439 | * speedstep_exit - unregisters SpeedStep support | |
440 | * | |
441 | * Unregisters SpeedStep support. | |
442 | */ | |
443 | static void __exit speedstep_exit(void) | |
444 | { | |
445 | cpufreq_unregister_driver(&speedstep_driver); | |
446 | } | |
447 | ||
bbfebd66 DJ |
448 | module_param(smi_port, int, 0444); |
449 | module_param(smi_cmd, int, 0444); | |
450 | module_param(smi_sig, uint, 0444); | |
1da177e4 | 451 | |
bbfebd66 DJ |
452 | MODULE_PARM_DESC(smi_port, "Override the BIOS-given IST port with this value " |
453 | "-- Intel's default setting is 0xb2"); | |
454 | MODULE_PARM_DESC(smi_cmd, "Override the BIOS-given IST command with this value " | |
455 | "-- Intel's default setting is 0x82"); | |
456 | MODULE_PARM_DESC(smi_sig, "Set to 1 to fake the IST signature when using the " | |
457 | "SMI interface."); | |
1da177e4 | 458 | |
bbfebd66 DJ |
459 | MODULE_AUTHOR("Hiroshi Miura"); |
460 | MODULE_DESCRIPTION("Speedstep driver for IST applet SMI interface."); | |
461 | MODULE_LICENSE("GPL"); | |
1da177e4 LT |
462 | |
463 | module_init(speedstep_init); | |
464 | module_exit(speedstep_exit); |