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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> | |
20 | #include <linux/pci.h> | |
21 | #include <linux/slab.h> | |
22 | #include <linux/delay.h> | |
23 | #include <asm/ist.h> | |
24 | ||
25 | #include "speedstep-lib.h" | |
26 | ||
27 | /* speedstep system management interface port/command. | |
28 | * | |
29 | * These parameters are got from IST-SMI BIOS call. | |
30 | * If user gives it, these are used. | |
32ee8c3e | 31 | * |
1da177e4 | 32 | */ |
32ee8c3e DJ |
33 | static int smi_port = 0; |
34 | static int smi_cmd = 0; | |
35 | static unsigned int smi_sig = 0; | |
1da177e4 LT |
36 | |
37 | /* info about the processor */ | |
32ee8c3e | 38 | static unsigned int speedstep_processor = 0; |
1da177e4 | 39 | |
32ee8c3e DJ |
40 | /* |
41 | * There are only two frequency states for each processor. Values | |
1da177e4 LT |
42 | * are in kHz for the time being. |
43 | */ | |
44 | static struct cpufreq_frequency_table speedstep_freqs[] = { | |
32ee8c3e | 45 | {SPEEDSTEP_HIGH, 0}, |
1da177e4 LT |
46 | {SPEEDSTEP_LOW, 0}, |
47 | {0, CPUFREQ_TABLE_END}, | |
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 failed, e.g. because | |
56 | * of DMA activity going on? */ | |
57 | #define SMI_TRIES 5 | |
58 | ||
59 | #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "speedstep-smi", msg) | |
60 | ||
61 | /** | |
62 | * speedstep_smi_ownership | |
63 | */ | |
64 | static int speedstep_smi_ownership (void) | |
65 | { | |
66 | u32 command, result, magic; | |
67 | u32 function = GET_SPEEDSTEP_OWNER; | |
68 | unsigned char magic_data[] = "Copyright (c) 1999 Intel Corporation"; | |
69 | ||
70 | command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff); | |
71 | magic = virt_to_phys(magic_data); | |
72 | ||
73 | dprintk("trying to obtain ownership with command %x at port %x\n", command, smi_port); | |
74 | ||
75 | __asm__ __volatile__( | |
76 | "out %%al, (%%dx)\n" | |
77 | : "=D" (result) | |
f081a529 AM |
78 | : "a" (command), "b" (function), "c" (0), "d" (smi_port), |
79 | "D" (0), "S" (magic) | |
80 | : "memory" | |
1da177e4 LT |
81 | ); |
82 | ||
83 | dprintk("result is %x\n", result); | |
84 | ||
85 | return result; | |
86 | } | |
87 | ||
88 | /** | |
89 | * speedstep_smi_get_freqs - get SpeedStep preferred & current freq. | |
90 | * @low: the low frequency value is placed here | |
91 | * @high: the high frequency value is placed here | |
92 | * | |
93 | * Only available on later SpeedStep-enabled systems, returns false results or | |
94 | * even hangs [cf. bugme.osdl.org # 1422] on earlier systems. Empirical testing | |
95 | * shows that the latter occurs if !(ist_info.event & 0xFFFF). | |
96 | */ | |
97 | static int speedstep_smi_get_freqs (unsigned int *low, unsigned int *high) | |
98 | { | |
99 | u32 command, result = 0, edi, high_mhz, low_mhz; | |
100 | u32 state=0; | |
101 | u32 function = GET_SPEEDSTEP_FREQS; | |
102 | ||
103 | if (!(ist_info.event & 0xFFFF)) { | |
ce38b51e | 104 | dprintk("bug #1422 -- can't read freqs from BIOS\n"); |
1da177e4 LT |
105 | return -ENODEV; |
106 | } | |
107 | ||
108 | command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff); | |
109 | ||
110 | dprintk("trying to determine frequencies with command %x at port %x\n", command, smi_port); | |
111 | ||
112 | __asm__ __volatile__("movl $0, %%edi\n" | |
113 | "out %%al, (%%dx)\n" | |
114 | : "=a" (result), "=b" (high_mhz), "=c" (low_mhz), "=d" (state), "=D" (edi) | |
115 | : "a" (command), "b" (function), "c" (state), "d" (smi_port), "S" (0) | |
116 | ); | |
117 | ||
118 | dprintk("result %x, low_freq %u, high_freq %u\n", result, low_mhz, high_mhz); | |
119 | ||
120 | /* abort if results are obviously incorrect... */ | |
121 | if ((high_mhz + low_mhz) < 600) | |
122 | return -EINVAL; | |
123 | ||
124 | *high = high_mhz * 1000; | |
125 | *low = low_mhz * 1000; | |
126 | ||
127 | return result; | |
32ee8c3e | 128 | } |
1da177e4 LT |
129 | |
130 | /** | |
131 | * speedstep_get_state - set the SpeedStep state | |
132 | * @state: processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH) | |
133 | * | |
134 | */ | |
135 | static int speedstep_get_state (void) | |
136 | { | |
137 | u32 function=GET_SPEEDSTEP_STATE; | |
138 | u32 result, state, edi, command; | |
139 | ||
140 | command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff); | |
141 | ||
142 | dprintk("trying to determine current setting with command %x at port %x\n", command, smi_port); | |
143 | ||
144 | __asm__ __volatile__("movl $0, %%edi\n" | |
145 | "out %%al, (%%dx)\n" | |
146 | : "=a" (result), "=b" (state), "=D" (edi) | |
147 | : "a" (command), "b" (function), "c" (0), "d" (smi_port), "S" (0) | |
148 | ); | |
149 | ||
150 | dprintk("state is %x, result is %x\n", state, result); | |
151 | ||
152 | return (state & 1); | |
153 | } | |
154 | ||
155 | ||
156 | /** | |
157 | * speedstep_set_state - set the SpeedStep state | |
158 | * @state: new processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH) | |
159 | * | |
160 | */ | |
161 | static void speedstep_set_state (unsigned int state) | |
162 | { | |
163 | unsigned int result = 0, command, new_state; | |
164 | unsigned long flags; | |
165 | unsigned int function=SET_SPEEDSTEP_STATE; | |
166 | unsigned int retry = 0; | |
167 | ||
168 | if (state > 0x1) | |
169 | return; | |
170 | ||
171 | /* Disable IRQs */ | |
172 | local_irq_save(flags); | |
173 | ||
174 | command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff); | |
175 | ||
176 | dprintk("trying to set frequency to state %u with command %x at port %x\n", state, command, smi_port); | |
177 | ||
178 | do { | |
179 | if (retry) { | |
180 | dprintk("retry %u, previous result %u, waiting...\n", retry, result); | |
181 | mdelay(retry * 50); | |
182 | } | |
183 | retry++; | |
184 | __asm__ __volatile__( | |
185 | "movl $0, %%edi\n" | |
186 | "out %%al, (%%dx)\n" | |
187 | : "=b" (new_state), "=D" (result) | |
188 | : "a" (command), "b" (function), "c" (state), "d" (smi_port), "S" (0) | |
189 | ); | |
190 | } while ((new_state != state) && (retry <= SMI_TRIES)); | |
191 | ||
192 | /* enable IRQs */ | |
193 | local_irq_restore(flags); | |
194 | ||
195 | if (new_state == state) { | |
196 | dprintk("change to %u MHz succeeded after %u tries with result %u\n", (speedstep_freqs[new_state].frequency / 1000), retry, result); | |
197 | } else { | |
198 | printk(KERN_ERR "cpufreq: change failed with new_state %u and result %u\n", new_state, result); | |
199 | } | |
200 | ||
201 | return; | |
202 | } | |
203 | ||
204 | ||
205 | /** | |
206 | * speedstep_target - set a new CPUFreq policy | |
207 | * @policy: new policy | |
208 | * @target_freq: new freq | |
32ee8c3e | 209 | * @relation: |
1da177e4 LT |
210 | * |
211 | * Sets a new CPUFreq policy/freq. | |
212 | */ | |
213 | static int speedstep_target (struct cpufreq_policy *policy, | |
214 | unsigned int target_freq, unsigned int relation) | |
215 | { | |
216 | unsigned int newstate = 0; | |
217 | struct cpufreq_freqs freqs; | |
218 | ||
219 | if (cpufreq_frequency_table_target(policy, &speedstep_freqs[0], target_freq, relation, &newstate)) | |
220 | return -EINVAL; | |
221 | ||
222 | freqs.old = speedstep_freqs[speedstep_get_state()].frequency; | |
223 | freqs.new = speedstep_freqs[newstate].frequency; | |
224 | freqs.cpu = 0; /* speedstep.c is UP only driver */ | |
225 | ||
226 | if (freqs.old == freqs.new) | |
227 | return 0; | |
228 | ||
229 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
230 | speedstep_set_state(newstate); | |
231 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
232 | ||
233 | return 0; | |
234 | } | |
235 | ||
236 | ||
237 | /** | |
238 | * speedstep_verify - verifies a new CPUFreq policy | |
239 | * @policy: new policy | |
240 | * | |
241 | * Limit must be within speedstep_low_freq and speedstep_high_freq, with | |
242 | * at least one border included. | |
243 | */ | |
244 | static int speedstep_verify (struct cpufreq_policy *policy) | |
245 | { | |
246 | return cpufreq_frequency_table_verify(policy, &speedstep_freqs[0]); | |
247 | } | |
248 | ||
249 | ||
250 | static int speedstep_cpu_init(struct cpufreq_policy *policy) | |
251 | { | |
252 | int result; | |
253 | unsigned int speed,state; | |
254 | ||
255 | /* capability check */ | |
256 | if (policy->cpu != 0) | |
257 | return -ENODEV; | |
258 | ||
259 | result = speedstep_smi_ownership(); | |
260 | if (result) { | |
261 | dprintk("fails in aquiring ownership of a SMI interface.\n"); | |
262 | return -EINVAL; | |
263 | } | |
264 | ||
265 | /* detect low and high frequency */ | |
266 | result = speedstep_smi_get_freqs(&speedstep_freqs[SPEEDSTEP_LOW].frequency, | |
267 | &speedstep_freqs[SPEEDSTEP_HIGH].frequency); | |
268 | if (result) { | |
269 | /* fall back to speedstep_lib.c dection mechanism: try both states out */ | |
270 | dprintk("could not detect low and high frequencies by SMI call.\n"); | |
271 | result = speedstep_get_freqs(speedstep_processor, | |
272 | &speedstep_freqs[SPEEDSTEP_LOW].frequency, | |
273 | &speedstep_freqs[SPEEDSTEP_HIGH].frequency, | |
1a10760c | 274 | NULL, |
1da177e4 LT |
275 | &speedstep_set_state); |
276 | ||
277 | if (result) { | |
278 | dprintk("could not detect two different speeds -- aborting.\n"); | |
279 | return result; | |
280 | } else | |
281 | dprintk("workaround worked.\n"); | |
282 | } | |
283 | ||
284 | /* get current speed setting */ | |
285 | state = speedstep_get_state(); | |
286 | speed = speedstep_freqs[state].frequency; | |
287 | ||
32ee8c3e | 288 | dprintk("currently at %s speed setting - %i MHz\n", |
1da177e4 LT |
289 | (speed == speedstep_freqs[SPEEDSTEP_LOW].frequency) ? "low" : "high", |
290 | (speed / 1000)); | |
291 | ||
292 | /* cpuinfo and default policy values */ | |
293 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | |
294 | policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; | |
295 | policy->cur = speed; | |
296 | ||
297 | result = cpufreq_frequency_table_cpuinfo(policy, speedstep_freqs); | |
298 | if (result) | |
299 | return (result); | |
300 | ||
32ee8c3e | 301 | cpufreq_frequency_table_get_attr(speedstep_freqs, policy->cpu); |
1da177e4 LT |
302 | |
303 | return 0; | |
304 | } | |
305 | ||
306 | static int speedstep_cpu_exit(struct cpufreq_policy *policy) | |
307 | { | |
308 | cpufreq_frequency_table_put_attr(policy->cpu); | |
309 | return 0; | |
310 | } | |
311 | ||
312 | static unsigned int speedstep_get(unsigned int cpu) | |
313 | { | |
314 | if (cpu) | |
315 | return -ENODEV; | |
316 | return speedstep_get_processor_frequency(speedstep_processor); | |
317 | } | |
318 | ||
319 | ||
320 | static int speedstep_resume(struct cpufreq_policy *policy) | |
321 | { | |
322 | int result = speedstep_smi_ownership(); | |
323 | ||
324 | if (result) | |
325 | dprintk("fails in re-aquiring ownership of a SMI interface.\n"); | |
326 | ||
327 | return result; | |
328 | } | |
329 | ||
330 | static struct freq_attr* speedstep_attr[] = { | |
331 | &cpufreq_freq_attr_scaling_available_freqs, | |
332 | NULL, | |
333 | }; | |
334 | ||
221dee28 | 335 | static struct cpufreq_driver speedstep_driver = { |
1da177e4 | 336 | .name = "speedstep-smi", |
32ee8c3e DJ |
337 | .verify = speedstep_verify, |
338 | .target = speedstep_target, | |
1da177e4 LT |
339 | .init = speedstep_cpu_init, |
340 | .exit = speedstep_cpu_exit, | |
341 | .get = speedstep_get, | |
342 | .resume = speedstep_resume, | |
343 | .owner = THIS_MODULE, | |
344 | .attr = speedstep_attr, | |
345 | }; | |
346 | ||
347 | /** | |
348 | * speedstep_init - initializes the SpeedStep CPUFreq driver | |
349 | * | |
350 | * Initializes the SpeedStep support. Returns -ENODEV on unsupported | |
351 | * BIOS, -EINVAL on problems during initiatization, and zero on | |
352 | * success. | |
353 | */ | |
354 | static int __init speedstep_init(void) | |
355 | { | |
356 | speedstep_processor = speedstep_detect_processor(); | |
357 | ||
358 | switch (speedstep_processor) { | |
359 | case SPEEDSTEP_PROCESSOR_PIII_T: | |
360 | case SPEEDSTEP_PROCESSOR_PIII_C: | |
361 | case SPEEDSTEP_PROCESSOR_PIII_C_EARLY: | |
362 | break; | |
363 | default: | |
364 | speedstep_processor = 0; | |
365 | } | |
366 | ||
367 | if (!speedstep_processor) { | |
368 | dprintk ("No supported Intel CPU detected.\n"); | |
369 | return -ENODEV; | |
370 | } | |
371 | ||
32ee8c3e | 372 | dprintk("signature:0x%.8lx, command:0x%.8lx, event:0x%.8lx, perf_level:0x%.8lx.\n", |
1da177e4 LT |
373 | ist_info.signature, ist_info.command, ist_info.event, ist_info.perf_level); |
374 | ||
32ee8c3e | 375 | /* Error if no IST-SMI BIOS or no PARM |
1da177e4 | 376 | sig= 'ISGE' aka 'Intel Speedstep Gate E' */ |
32ee8c3e | 377 | if ((ist_info.signature != 0x47534943) && ( |
1da177e4 LT |
378 | (smi_port == 0) || (smi_cmd == 0))) |
379 | return -ENODEV; | |
380 | ||
381 | if (smi_sig == 1) | |
382 | smi_sig = 0x47534943; | |
383 | else | |
384 | smi_sig = ist_info.signature; | |
385 | ||
386 | /* setup smi_port from MODLULE_PARM or BIOS */ | |
32ee8c3e | 387 | if ((smi_port > 0xff) || (smi_port < 0)) |
1da177e4 | 388 | return -EINVAL; |
32ee8c3e | 389 | else if (smi_port == 0) |
1da177e4 | 390 | smi_port = ist_info.command & 0xff; |
1da177e4 | 391 | |
32ee8c3e | 392 | if ((smi_cmd > 0xff) || (smi_cmd < 0)) |
1da177e4 | 393 | return -EINVAL; |
32ee8c3e | 394 | else if (smi_cmd == 0) |
1da177e4 | 395 | smi_cmd = (ist_info.command >> 16) & 0xff; |
1da177e4 LT |
396 | |
397 | return cpufreq_register_driver(&speedstep_driver); | |
398 | } | |
399 | ||
400 | ||
401 | /** | |
402 | * speedstep_exit - unregisters SpeedStep support | |
403 | * | |
404 | * Unregisters SpeedStep support. | |
405 | */ | |
406 | static void __exit speedstep_exit(void) | |
407 | { | |
408 | cpufreq_unregister_driver(&speedstep_driver); | |
409 | } | |
410 | ||
411 | module_param(smi_port, int, 0444); | |
412 | module_param(smi_cmd, int, 0444); | |
413 | module_param(smi_sig, uint, 0444); | |
414 | ||
415 | MODULE_PARM_DESC(smi_port, "Override the BIOS-given IST port with this value -- Intel's default setting is 0xb2"); | |
416 | MODULE_PARM_DESC(smi_cmd, "Override the BIOS-given IST command with this value -- Intel's default setting is 0x82"); | |
417 | MODULE_PARM_DESC(smi_sig, "Set to 1 to fake the IST signature when using the SMI interface."); | |
418 | ||
419 | MODULE_AUTHOR ("Hiroshi Miura"); | |
420 | MODULE_DESCRIPTION ("Speedstep driver for IST applet SMI interface."); | |
421 | MODULE_LICENSE ("GPL"); | |
422 | ||
423 | module_init(speedstep_init); | |
424 | module_exit(speedstep_exit); |