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Commit | Line | Data |
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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> | |
1da177e4 | 20 | #include <linux/delay.h> |
bbfebd66 | 21 | #include <linux/io.h> |
1da177e4 | 22 | #include <asm/ist.h> |
fa8031ae | 23 | #include <asm/cpu_device_id.h> |
1da177e4 LT |
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 | */ |
bbfebd66 DJ |
33 | static int smi_port; |
34 | static int smi_cmd; | |
35 | static unsigned int smi_sig; | |
1da177e4 LT |
36 | |
37 | /* info about the processor */ | |
1cce76c2 | 38 | static enum speedstep_processor speedstep_processor; |
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 | ||
1da177e4 LT |
59 | /** |
60 | * speedstep_smi_ownership | |
61 | */ | |
bbfebd66 | 62 | static int speedstep_smi_ownership(void) |
1da177e4 | 63 | { |
c6e8256a | 64 | u32 command, result, magic, dummy; |
1da177e4 LT |
65 | u32 function = GET_SPEEDSTEP_OWNER; |
66 | unsigned char magic_data[] = "Copyright (c) 1999 Intel Corporation"; | |
67 | ||
68 | command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff); | |
69 | magic = virt_to_phys(magic_data); | |
70 | ||
2d06d8c4 | 71 | pr_debug("trying to obtain ownership with command %x at port %x\n", |
bbfebd66 | 72 | command, smi_port); |
1da177e4 LT |
73 | |
74 | __asm__ __volatile__( | |
c6e8256a | 75 | "push %%ebp\n" |
1da177e4 | 76 | "out %%al, (%%dx)\n" |
c6e8256a | 77 | "pop %%ebp\n" |
bbfebd66 DJ |
78 | : "=D" (result), |
79 | "=a" (dummy), "=b" (dummy), "=c" (dummy), "=d" (dummy), | |
80 | "=S" (dummy) | |
f081a529 | 81 | : "a" (command), "b" (function), "c" (0), "d" (smi_port), |
bbfebd66 | 82 | "D" (0), "S" (magic) |
f081a529 | 83 | : "memory" |
1da177e4 LT |
84 | ); |
85 | ||
2d06d8c4 | 86 | pr_debug("result is %x\n", result); |
1da177e4 LT |
87 | |
88 | return result; | |
89 | } | |
90 | ||
91 | /** | |
92 | * speedstep_smi_get_freqs - get SpeedStep preferred & current freq. | |
93 | * @low: the low frequency value is placed here | |
94 | * @high: the high frequency value is placed here | |
95 | * | |
96 | * Only available on later SpeedStep-enabled systems, returns false results or | |
97 | * even hangs [cf. bugme.osdl.org # 1422] on earlier systems. Empirical testing | |
98 | * shows that the latter occurs if !(ist_info.event & 0xFFFF). | |
99 | */ | |
bbfebd66 | 100 | static int speedstep_smi_get_freqs(unsigned int *low, unsigned int *high) |
1da177e4 | 101 | { |
c6e8256a | 102 | u32 command, result = 0, edi, high_mhz, low_mhz, dummy; |
bbfebd66 | 103 | u32 state = 0; |
1da177e4 LT |
104 | u32 function = GET_SPEEDSTEP_FREQS; |
105 | ||
106 | if (!(ist_info.event & 0xFFFF)) { | |
2d06d8c4 | 107 | pr_debug("bug #1422 -- can't read freqs from BIOS\n"); |
1da177e4 LT |
108 | return -ENODEV; |
109 | } | |
110 | ||
111 | command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff); | |
112 | ||
2d06d8c4 | 113 | pr_debug("trying to determine frequencies with command %x at port %x\n", |
bbfebd66 | 114 | command, smi_port); |
1da177e4 | 115 | |
c6e8256a SD |
116 | __asm__ __volatile__( |
117 | "push %%ebp\n" | |
1da177e4 | 118 | "out %%al, (%%dx)\n" |
c6e8256a | 119 | "pop %%ebp" |
bbfebd66 DJ |
120 | : "=a" (result), |
121 | "=b" (high_mhz), | |
122 | "=c" (low_mhz), | |
123 | "=d" (state), "=D" (edi), "=S" (dummy) | |
124 | : "a" (command), | |
125 | "b" (function), | |
126 | "c" (state), | |
127 | "d" (smi_port), "S" (0), "D" (0) | |
1da177e4 LT |
128 | ); |
129 | ||
2d06d8c4 | 130 | pr_debug("result %x, low_freq %u, high_freq %u\n", |
bbfebd66 | 131 | result, low_mhz, high_mhz); |
1da177e4 LT |
132 | |
133 | /* abort if results are obviously incorrect... */ | |
134 | if ((high_mhz + low_mhz) < 600) | |
135 | return -EINVAL; | |
136 | ||
137 | *high = high_mhz * 1000; | |
138 | *low = low_mhz * 1000; | |
139 | ||
140 | return result; | |
32ee8c3e | 141 | } |
1da177e4 | 142 | |
1da177e4 LT |
143 | /** |
144 | * speedstep_set_state - set the SpeedStep state | |
145 | * @state: new processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH) | |
146 | * | |
147 | */ | |
bbfebd66 | 148 | static void speedstep_set_state(unsigned int state) |
1da177e4 | 149 | { |
c6e8256a | 150 | unsigned int result = 0, command, new_state, dummy; |
1da177e4 | 151 | unsigned long flags; |
bbfebd66 | 152 | unsigned int function = SET_SPEEDSTEP_STATE; |
1da177e4 LT |
153 | unsigned int retry = 0; |
154 | ||
155 | if (state > 0x1) | |
156 | return; | |
157 | ||
158 | /* Disable IRQs */ | |
159 | local_irq_save(flags); | |
160 | ||
161 | command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff); | |
162 | ||
2d06d8c4 | 163 | pr_debug("trying to set frequency to state %u " |
bbfebd66 DJ |
164 | "with command %x at port %x\n", |
165 | state, command, smi_port); | |
1da177e4 LT |
166 | |
167 | do { | |
168 | if (retry) { | |
2d06d8c4 | 169 | pr_debug("retry %u, previous result %u, waiting...\n", |
bbfebd66 | 170 | retry, result); |
1da177e4 LT |
171 | mdelay(retry * 50); |
172 | } | |
173 | retry++; | |
174 | __asm__ __volatile__( | |
c6e8256a | 175 | "push %%ebp\n" |
1da177e4 | 176 | "out %%al, (%%dx)\n" |
c6e8256a | 177 | "pop %%ebp" |
bbfebd66 DJ |
178 | : "=b" (new_state), "=D" (result), |
179 | "=c" (dummy), "=a" (dummy), | |
180 | "=d" (dummy), "=S" (dummy) | |
181 | : "a" (command), "b" (function), "c" (state), | |
182 | "d" (smi_port), "S" (0), "D" (0) | |
1da177e4 LT |
183 | ); |
184 | } while ((new_state != state) && (retry <= SMI_TRIES)); | |
185 | ||
186 | /* enable IRQs */ | |
187 | local_irq_restore(flags); | |
188 | ||
bbfebd66 | 189 | if (new_state == state) |
2d06d8c4 | 190 | pr_debug("change to %u MHz succeeded after %u tries " |
bbfebd66 DJ |
191 | "with result %u\n", |
192 | (speedstep_freqs[new_state].frequency / 1000), | |
193 | retry, result); | |
194 | else | |
195 | printk(KERN_ERR "cpufreq: change to state %u " | |
196 | "failed with new_state %u and result %u\n", | |
197 | state, new_state, result); | |
1da177e4 LT |
198 | |
199 | return; | |
200 | } | |
201 | ||
202 | ||
203 | /** | |
204 | * speedstep_target - set a new CPUFreq policy | |
205 | * @policy: new policy | |
9c0ebcf7 | 206 | * @index: index of new freq |
1da177e4 LT |
207 | * |
208 | * Sets a new CPUFreq policy/freq. | |
209 | */ | |
9c0ebcf7 | 210 | static int speedstep_target(struct cpufreq_policy *policy, unsigned int index) |
1da177e4 | 211 | { |
9c0ebcf7 | 212 | speedstep_set_state(index); |
1da177e4 LT |
213 | |
214 | return 0; | |
215 | } | |
216 | ||
217 | ||
1da177e4 LT |
218 | static int speedstep_cpu_init(struct cpufreq_policy *policy) |
219 | { | |
220 | int result; | |
bbfebd66 | 221 | unsigned int *low, *high; |
1da177e4 LT |
222 | |
223 | /* capability check */ | |
224 | if (policy->cpu != 0) | |
225 | return -ENODEV; | |
226 | ||
227 | result = speedstep_smi_ownership(); | |
228 | if (result) { | |
2d06d8c4 | 229 | pr_debug("fails in acquiring ownership of a SMI interface.\n"); |
1da177e4 LT |
230 | return -EINVAL; |
231 | } | |
232 | ||
233 | /* detect low and high frequency */ | |
bbfebd66 DJ |
234 | low = &speedstep_freqs[SPEEDSTEP_LOW].frequency; |
235 | high = &speedstep_freqs[SPEEDSTEP_HIGH].frequency; | |
236 | ||
237 | result = speedstep_smi_get_freqs(low, high); | |
1da177e4 | 238 | if (result) { |
bbfebd66 DJ |
239 | /* fall back to speedstep_lib.c dection mechanism: |
240 | * try both states out */ | |
2d06d8c4 | 241 | pr_debug("could not detect low and high frequencies " |
bbfebd66 | 242 | "by SMI call.\n"); |
1da177e4 | 243 | result = speedstep_get_freqs(speedstep_processor, |
bbfebd66 | 244 | low, high, |
1a10760c | 245 | NULL, |
1da177e4 LT |
246 | &speedstep_set_state); |
247 | ||
248 | if (result) { | |
2d06d8c4 | 249 | pr_debug("could not detect two different speeds" |
bbfebd66 | 250 | " -- aborting.\n"); |
1da177e4 LT |
251 | return result; |
252 | } else | |
2d06d8c4 | 253 | pr_debug("workaround worked.\n"); |
1da177e4 LT |
254 | } |
255 | ||
1da177e4 | 256 | policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; |
5f3a2d39 | 257 | return cpufreq_table_validate_and_show(policy, speedstep_freqs); |
1da177e4 LT |
258 | } |
259 | ||
1da177e4 LT |
260 | static unsigned int speedstep_get(unsigned int cpu) |
261 | { | |
262 | if (cpu) | |
263 | return -ENODEV; | |
bbfebd66 | 264 | return speedstep_get_frequency(speedstep_processor); |
1da177e4 LT |
265 | } |
266 | ||
267 | ||
268 | static int speedstep_resume(struct cpufreq_policy *policy) | |
269 | { | |
270 | int result = speedstep_smi_ownership(); | |
271 | ||
272 | if (result) | |
2d06d8c4 | 273 | pr_debug("fails in re-acquiring ownership of a SMI interface.\n"); |
1da177e4 LT |
274 | |
275 | return result; | |
276 | } | |
277 | ||
221dee28 | 278 | static struct cpufreq_driver speedstep_driver = { |
1da177e4 | 279 | .name = "speedstep-smi", |
3be1394a | 280 | .verify = cpufreq_generic_frequency_table_verify, |
9c0ebcf7 | 281 | .target_index = speedstep_target, |
1da177e4 | 282 | .init = speedstep_cpu_init, |
1da177e4 LT |
283 | .get = speedstep_get, |
284 | .resume = speedstep_resume, | |
3be1394a | 285 | .attr = cpufreq_generic_attr, |
1da177e4 LT |
286 | }; |
287 | ||
fa8031ae AK |
288 | static const struct x86_cpu_id ss_smi_ids[] = { |
289 | { X86_VENDOR_INTEL, 6, 0xb, }, | |
290 | { X86_VENDOR_INTEL, 6, 0x8, }, | |
291 | { X86_VENDOR_INTEL, 15, 2 }, | |
292 | {} | |
293 | }; | |
294 | #if 0 | |
295 | /* Not auto loaded currently */ | |
296 | MODULE_DEVICE_TABLE(x86cpu, ss_smi_ids); | |
297 | #endif | |
298 | ||
1da177e4 LT |
299 | /** |
300 | * speedstep_init - initializes the SpeedStep CPUFreq driver | |
301 | * | |
302 | * Initializes the SpeedStep support. Returns -ENODEV on unsupported | |
303 | * BIOS, -EINVAL on problems during initiatization, and zero on | |
304 | * success. | |
305 | */ | |
306 | static int __init speedstep_init(void) | |
307 | { | |
fa8031ae AK |
308 | if (!x86_match_cpu(ss_smi_ids)) |
309 | return -ENODEV; | |
310 | ||
1da177e4 LT |
311 | speedstep_processor = speedstep_detect_processor(); |
312 | ||
313 | switch (speedstep_processor) { | |
bbfebd66 DJ |
314 | case SPEEDSTEP_CPU_PIII_T: |
315 | case SPEEDSTEP_CPU_PIII_C: | |
316 | case SPEEDSTEP_CPU_PIII_C_EARLY: | |
1da177e4 LT |
317 | break; |
318 | default: | |
319 | speedstep_processor = 0; | |
320 | } | |
321 | ||
322 | if (!speedstep_processor) { | |
2d06d8c4 | 323 | pr_debug("No supported Intel CPU detected.\n"); |
1da177e4 LT |
324 | return -ENODEV; |
325 | } | |
326 | ||
2d06d8c4 DB |
327 | pr_debug("signature:0x%.8ulx, command:0x%.8ulx, " |
328 | "event:0x%.8ulx, perf_level:0x%.8ulx.\n", | |
bbfebd66 DJ |
329 | ist_info.signature, ist_info.command, |
330 | ist_info.event, ist_info.perf_level); | |
1da177e4 | 331 | |
32ee8c3e | 332 | /* Error if no IST-SMI BIOS or no PARM |
1da177e4 | 333 | sig= 'ISGE' aka 'Intel Speedstep Gate E' */ |
32ee8c3e | 334 | if ((ist_info.signature != 0x47534943) && ( |
1da177e4 LT |
335 | (smi_port == 0) || (smi_cmd == 0))) |
336 | return -ENODEV; | |
337 | ||
338 | if (smi_sig == 1) | |
339 | smi_sig = 0x47534943; | |
340 | else | |
341 | smi_sig = ist_info.signature; | |
342 | ||
343 | /* setup smi_port from MODLULE_PARM or BIOS */ | |
32ee8c3e | 344 | if ((smi_port > 0xff) || (smi_port < 0)) |
1da177e4 | 345 | return -EINVAL; |
32ee8c3e | 346 | else if (smi_port == 0) |
1da177e4 | 347 | smi_port = ist_info.command & 0xff; |
1da177e4 | 348 | |
32ee8c3e | 349 | if ((smi_cmd > 0xff) || (smi_cmd < 0)) |
1da177e4 | 350 | return -EINVAL; |
32ee8c3e | 351 | else if (smi_cmd == 0) |
1da177e4 | 352 | smi_cmd = (ist_info.command >> 16) & 0xff; |
1da177e4 LT |
353 | |
354 | return cpufreq_register_driver(&speedstep_driver); | |
355 | } | |
356 | ||
357 | ||
358 | /** | |
359 | * speedstep_exit - unregisters SpeedStep support | |
360 | * | |
361 | * Unregisters SpeedStep support. | |
362 | */ | |
363 | static void __exit speedstep_exit(void) | |
364 | { | |
365 | cpufreq_unregister_driver(&speedstep_driver); | |
366 | } | |
367 | ||
bbfebd66 DJ |
368 | module_param(smi_port, int, 0444); |
369 | module_param(smi_cmd, int, 0444); | |
370 | module_param(smi_sig, uint, 0444); | |
1da177e4 | 371 | |
bbfebd66 DJ |
372 | MODULE_PARM_DESC(smi_port, "Override the BIOS-given IST port with this value " |
373 | "-- Intel's default setting is 0xb2"); | |
374 | MODULE_PARM_DESC(smi_cmd, "Override the BIOS-given IST command with this value " | |
375 | "-- Intel's default setting is 0x82"); | |
376 | MODULE_PARM_DESC(smi_sig, "Set to 1 to fake the IST signature when using the " | |
377 | "SMI interface."); | |
1da177e4 | 378 | |
bbfebd66 DJ |
379 | MODULE_AUTHOR("Hiroshi Miura"); |
380 | MODULE_DESCRIPTION("Speedstep driver for IST applet SMI interface."); | |
381 | MODULE_LICENSE("GPL"); | |
1da177e4 LT |
382 | |
383 | module_init(speedstep_init); | |
384 | module_exit(speedstep_exit); |