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1da177e4 LT |
1 | /* |
2 | * acpi-cpufreq.c - ACPI Processor P-States Driver ($Revision: 1.3 $) | |
3 | * | |
4 | * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> | |
5 | * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> | |
6 | * Copyright (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de> | |
7 | * | |
8 | * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or modify | |
11 | * it under the terms of the GNU General Public License as published by | |
12 | * the Free Software Foundation; either version 2 of the License, or (at | |
13 | * your option) any later version. | |
14 | * | |
15 | * This program is distributed in the hope that it will be useful, but | |
16 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
18 | * General Public License for more details. | |
19 | * | |
20 | * You should have received a copy of the GNU General Public License along | |
21 | * with this program; if not, write to the Free Software Foundation, Inc., | |
22 | * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. | |
23 | * | |
24 | * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
25 | */ | |
26 | ||
27 | #include <linux/config.h> | |
28 | #include <linux/kernel.h> | |
29 | #include <linux/module.h> | |
30 | #include <linux/init.h> | |
31 | #include <linux/cpufreq.h> | |
32 | #include <linux/proc_fs.h> | |
33 | #include <linux/seq_file.h> | |
d395bf12 | 34 | #include <linux/compiler.h> |
4e57b681 | 35 | #include <linux/sched.h> /* current */ |
1da177e4 LT |
36 | #include <asm/io.h> |
37 | #include <asm/delay.h> | |
38 | #include <asm/uaccess.h> | |
39 | ||
40 | #include <linux/acpi.h> | |
41 | #include <acpi/processor.h> | |
42 | ||
1da177e4 LT |
43 | #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "acpi-cpufreq", msg) |
44 | ||
45 | MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski"); | |
46 | MODULE_DESCRIPTION("ACPI Processor P-States Driver"); | |
47 | MODULE_LICENSE("GPL"); | |
48 | ||
49 | ||
50 | struct cpufreq_acpi_io { | |
51 | struct acpi_processor_performance acpi_data; | |
52 | struct cpufreq_frequency_table *freq_table; | |
53 | unsigned int resume; | |
54 | }; | |
55 | ||
56 | static struct cpufreq_acpi_io *acpi_io_data[NR_CPUS]; | |
57 | ||
58 | static struct cpufreq_driver acpi_cpufreq_driver; | |
59 | ||
d395bf12 VP |
60 | static unsigned int acpi_pstate_strict; |
61 | ||
1da177e4 LT |
62 | static int |
63 | acpi_processor_write_port( | |
64 | u16 port, | |
65 | u8 bit_width, | |
66 | u32 value) | |
67 | { | |
68 | if (bit_width <= 8) { | |
69 | outb(value, port); | |
70 | } else if (bit_width <= 16) { | |
71 | outw(value, port); | |
72 | } else if (bit_width <= 32) { | |
73 | outl(value, port); | |
74 | } else { | |
75 | return -ENODEV; | |
76 | } | |
77 | return 0; | |
78 | } | |
79 | ||
80 | static int | |
81 | acpi_processor_read_port( | |
82 | u16 port, | |
83 | u8 bit_width, | |
84 | u32 *ret) | |
85 | { | |
86 | *ret = 0; | |
87 | if (bit_width <= 8) { | |
88 | *ret = inb(port); | |
89 | } else if (bit_width <= 16) { | |
90 | *ret = inw(port); | |
91 | } else if (bit_width <= 32) { | |
92 | *ret = inl(port); | |
93 | } else { | |
94 | return -ENODEV; | |
95 | } | |
96 | return 0; | |
97 | } | |
98 | ||
99 | static int | |
100 | acpi_processor_set_performance ( | |
101 | struct cpufreq_acpi_io *data, | |
102 | unsigned int cpu, | |
103 | int state) | |
104 | { | |
105 | u16 port = 0; | |
106 | u8 bit_width = 0; | |
107 | int ret = 0; | |
108 | u32 value = 0; | |
109 | int i = 0; | |
110 | struct cpufreq_freqs cpufreq_freqs; | |
111 | cpumask_t saved_mask; | |
112 | int retval; | |
113 | ||
114 | dprintk("acpi_processor_set_performance\n"); | |
115 | ||
116 | /* | |
117 | * TBD: Use something other than set_cpus_allowed. | |
118 | * As set_cpus_allowed is a bit racy, | |
119 | * with any other set_cpus_allowed for this process. | |
120 | */ | |
121 | saved_mask = current->cpus_allowed; | |
122 | set_cpus_allowed(current, cpumask_of_cpu(cpu)); | |
123 | if (smp_processor_id() != cpu) { | |
124 | return (-EAGAIN); | |
125 | } | |
126 | ||
127 | if (state == data->acpi_data.state) { | |
128 | if (unlikely(data->resume)) { | |
129 | dprintk("Called after resume, resetting to P%d\n", state); | |
130 | data->resume = 0; | |
131 | } else { | |
132 | dprintk("Already at target state (P%d)\n", state); | |
133 | retval = 0; | |
134 | goto migrate_end; | |
135 | } | |
136 | } | |
137 | ||
138 | dprintk("Transitioning from P%d to P%d\n", | |
139 | data->acpi_data.state, state); | |
140 | ||
141 | /* cpufreq frequency struct */ | |
142 | cpufreq_freqs.cpu = cpu; | |
143 | cpufreq_freqs.old = data->freq_table[data->acpi_data.state].frequency; | |
144 | cpufreq_freqs.new = data->freq_table[state].frequency; | |
145 | ||
146 | /* notify cpufreq */ | |
147 | cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE); | |
148 | ||
149 | /* | |
150 | * First we write the target state's 'control' value to the | |
151 | * control_register. | |
152 | */ | |
153 | ||
154 | port = data->acpi_data.control_register.address; | |
155 | bit_width = data->acpi_data.control_register.bit_width; | |
156 | value = (u32) data->acpi_data.states[state].control; | |
157 | ||
158 | dprintk("Writing 0x%08x to port 0x%04x\n", value, port); | |
159 | ||
160 | ret = acpi_processor_write_port(port, bit_width, value); | |
161 | if (ret) { | |
162 | dprintk("Invalid port width 0x%04x\n", bit_width); | |
163 | retval = ret; | |
164 | goto migrate_end; | |
165 | } | |
166 | ||
167 | /* | |
d395bf12 VP |
168 | * Assume the write went through when acpi_pstate_strict is not used. |
169 | * As read status_register is an expensive operation and there | |
170 | * are no specific error cases where an IO port write will fail. | |
1da177e4 | 171 | */ |
d395bf12 VP |
172 | if (acpi_pstate_strict) { |
173 | /* Then we read the 'status_register' and compare the value | |
174 | * with the target state's 'status' to make sure the | |
175 | * transition was successful. | |
176 | * Note that we'll poll for up to 1ms (100 cycles of 10us) | |
177 | * before giving up. | |
178 | */ | |
179 | ||
180 | port = data->acpi_data.status_register.address; | |
181 | bit_width = data->acpi_data.status_register.bit_width; | |
182 | ||
183 | dprintk("Looking for 0x%08x from port 0x%04x\n", | |
184 | (u32) data->acpi_data.states[state].status, port); | |
185 | ||
186 | for (i=0; i<100; i++) { | |
187 | ret = acpi_processor_read_port(port, bit_width, &value); | |
188 | if (ret) { | |
189 | dprintk("Invalid port width 0x%04x\n", bit_width); | |
190 | retval = ret; | |
191 | goto migrate_end; | |
192 | } | |
193 | if (value == (u32) data->acpi_data.states[state].status) | |
194 | break; | |
195 | udelay(10); | |
1da177e4 | 196 | } |
d395bf12 VP |
197 | } else { |
198 | i = 0; | |
199 | value = (u32) data->acpi_data.states[state].status; | |
1da177e4 LT |
200 | } |
201 | ||
202 | /* notify cpufreq */ | |
203 | cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE); | |
204 | ||
d395bf12 | 205 | if (unlikely(value != (u32) data->acpi_data.states[state].status)) { |
1da177e4 LT |
206 | unsigned int tmp = cpufreq_freqs.new; |
207 | cpufreq_freqs.new = cpufreq_freqs.old; | |
208 | cpufreq_freqs.old = tmp; | |
209 | cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE); | |
210 | cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE); | |
211 | printk(KERN_WARNING "acpi-cpufreq: Transition failed\n"); | |
212 | retval = -ENODEV; | |
213 | goto migrate_end; | |
214 | } | |
215 | ||
216 | dprintk("Transition successful after %d microseconds\n", i * 10); | |
217 | ||
218 | data->acpi_data.state = state; | |
219 | ||
220 | retval = 0; | |
221 | migrate_end: | |
222 | set_cpus_allowed(current, saved_mask); | |
223 | return (retval); | |
224 | } | |
225 | ||
226 | ||
227 | static int | |
228 | acpi_cpufreq_target ( | |
229 | struct cpufreq_policy *policy, | |
230 | unsigned int target_freq, | |
231 | unsigned int relation) | |
232 | { | |
233 | struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu]; | |
234 | unsigned int next_state = 0; | |
235 | unsigned int result = 0; | |
236 | ||
237 | dprintk("acpi_cpufreq_setpolicy\n"); | |
238 | ||
239 | result = cpufreq_frequency_table_target(policy, | |
240 | data->freq_table, | |
241 | target_freq, | |
242 | relation, | |
243 | &next_state); | |
244 | if (result) | |
245 | return (result); | |
246 | ||
247 | result = acpi_processor_set_performance (data, policy->cpu, next_state); | |
248 | ||
249 | return (result); | |
250 | } | |
251 | ||
252 | ||
253 | static int | |
254 | acpi_cpufreq_verify ( | |
255 | struct cpufreq_policy *policy) | |
256 | { | |
257 | unsigned int result = 0; | |
258 | struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu]; | |
259 | ||
260 | dprintk("acpi_cpufreq_verify\n"); | |
261 | ||
262 | result = cpufreq_frequency_table_verify(policy, | |
263 | data->freq_table); | |
264 | ||
265 | return (result); | |
266 | } | |
267 | ||
268 | ||
269 | static unsigned long | |
270 | acpi_cpufreq_guess_freq ( | |
271 | struct cpufreq_acpi_io *data, | |
272 | unsigned int cpu) | |
273 | { | |
274 | if (cpu_khz) { | |
275 | /* search the closest match to cpu_khz */ | |
276 | unsigned int i; | |
277 | unsigned long freq; | |
278 | unsigned long freqn = data->acpi_data.states[0].core_frequency * 1000; | |
279 | ||
280 | for (i=0; i < (data->acpi_data.state_count - 1); i++) { | |
281 | freq = freqn; | |
282 | freqn = data->acpi_data.states[i+1].core_frequency * 1000; | |
283 | if ((2 * cpu_khz) > (freqn + freq)) { | |
284 | data->acpi_data.state = i; | |
285 | return (freq); | |
286 | } | |
287 | } | |
288 | data->acpi_data.state = data->acpi_data.state_count - 1; | |
289 | return (freqn); | |
290 | } else | |
291 | /* assume CPU is at P0... */ | |
292 | data->acpi_data.state = 0; | |
293 | return data->acpi_data.states[0].core_frequency * 1000; | |
294 | ||
295 | } | |
296 | ||
297 | ||
1da177e4 LT |
298 | static int |
299 | acpi_cpufreq_cpu_init ( | |
300 | struct cpufreq_policy *policy) | |
301 | { | |
302 | unsigned int i; | |
303 | unsigned int cpu = policy->cpu; | |
304 | struct cpufreq_acpi_io *data; | |
305 | unsigned int result = 0; | |
152bf8c5 | 306 | struct cpuinfo_x86 *c = &cpu_data[policy->cpu]; |
1da177e4 | 307 | |
1da177e4 | 308 | dprintk("acpi_cpufreq_cpu_init\n"); |
1da177e4 | 309 | |
bfdc708d | 310 | data = kzalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL); |
1da177e4 LT |
311 | if (!data) |
312 | return (-ENOMEM); | |
1da177e4 LT |
313 | |
314 | acpi_io_data[cpu] = data; | |
315 | ||
1da177e4 | 316 | result = acpi_processor_register_performance(&data->acpi_data, cpu); |
1da177e4 LT |
317 | |
318 | if (result) | |
319 | goto err_free; | |
320 | ||
152bf8c5 | 321 | if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) { |
1da177e4 LT |
322 | acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS; |
323 | } | |
324 | ||
325 | /* capability check */ | |
326 | if (data->acpi_data.state_count <= 1) { | |
327 | dprintk("No P-States\n"); | |
328 | result = -ENODEV; | |
329 | goto err_unreg; | |
330 | } | |
331 | if ((data->acpi_data.control_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO) || | |
332 | (data->acpi_data.status_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO)) { | |
333 | dprintk("Unsupported address space [%d, %d]\n", | |
334 | (u32) (data->acpi_data.control_register.space_id), | |
335 | (u32) (data->acpi_data.status_register.space_id)); | |
336 | result = -ENODEV; | |
337 | goto err_unreg; | |
338 | } | |
339 | ||
340 | /* alloc freq_table */ | |
341 | data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) * (data->acpi_data.state_count + 1), GFP_KERNEL); | |
342 | if (!data->freq_table) { | |
343 | result = -ENOMEM; | |
344 | goto err_unreg; | |
345 | } | |
346 | ||
347 | /* detect transition latency */ | |
348 | policy->cpuinfo.transition_latency = 0; | |
349 | for (i=0; i<data->acpi_data.state_count; i++) { | |
350 | if ((data->acpi_data.states[i].transition_latency * 1000) > policy->cpuinfo.transition_latency) | |
351 | policy->cpuinfo.transition_latency = data->acpi_data.states[i].transition_latency * 1000; | |
352 | } | |
353 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | |
354 | ||
355 | /* The current speed is unknown and not detectable by ACPI... */ | |
356 | policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu); | |
357 | ||
358 | /* table init */ | |
359 | for (i=0; i<=data->acpi_data.state_count; i++) | |
360 | { | |
361 | data->freq_table[i].index = i; | |
362 | if (i<data->acpi_data.state_count) | |
363 | data->freq_table[i].frequency = data->acpi_data.states[i].core_frequency * 1000; | |
364 | else | |
365 | data->freq_table[i].frequency = CPUFREQ_TABLE_END; | |
366 | } | |
367 | ||
368 | result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table); | |
369 | if (result) { | |
370 | goto err_freqfree; | |
371 | } | |
372 | ||
373 | /* notify BIOS that we exist */ | |
374 | acpi_processor_notify_smm(THIS_MODULE); | |
375 | ||
376 | printk(KERN_INFO "acpi-cpufreq: CPU%u - ACPI performance management activated.\n", | |
377 | cpu); | |
378 | for (i = 0; i < data->acpi_data.state_count; i++) | |
379 | dprintk(" %cP%d: %d MHz, %d mW, %d uS\n", | |
380 | (i == data->acpi_data.state?'*':' '), i, | |
381 | (u32) data->acpi_data.states[i].core_frequency, | |
382 | (u32) data->acpi_data.states[i].power, | |
383 | (u32) data->acpi_data.states[i].transition_latency); | |
384 | ||
385 | cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu); | |
4b31e774 DB |
386 | |
387 | /* | |
388 | * the first call to ->target() should result in us actually | |
389 | * writing something to the appropriate registers. | |
390 | */ | |
391 | data->resume = 1; | |
392 | ||
1da177e4 LT |
393 | return (result); |
394 | ||
395 | err_freqfree: | |
396 | kfree(data->freq_table); | |
397 | err_unreg: | |
398 | acpi_processor_unregister_performance(&data->acpi_data, cpu); | |
399 | err_free: | |
400 | kfree(data); | |
401 | acpi_io_data[cpu] = NULL; | |
402 | ||
403 | return (result); | |
404 | } | |
405 | ||
406 | ||
407 | static int | |
408 | acpi_cpufreq_cpu_exit ( | |
409 | struct cpufreq_policy *policy) | |
410 | { | |
411 | struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu]; | |
412 | ||
413 | ||
414 | dprintk("acpi_cpufreq_cpu_exit\n"); | |
415 | ||
416 | if (data) { | |
417 | cpufreq_frequency_table_put_attr(policy->cpu); | |
418 | acpi_io_data[policy->cpu] = NULL; | |
419 | acpi_processor_unregister_performance(&data->acpi_data, policy->cpu); | |
420 | kfree(data); | |
421 | } | |
422 | ||
423 | return (0); | |
424 | } | |
425 | ||
426 | static int | |
427 | acpi_cpufreq_resume ( | |
428 | struct cpufreq_policy *policy) | |
429 | { | |
430 | struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu]; | |
431 | ||
432 | ||
433 | dprintk("acpi_cpufreq_resume\n"); | |
434 | ||
435 | data->resume = 1; | |
436 | ||
437 | return (0); | |
438 | } | |
439 | ||
440 | ||
441 | static struct freq_attr* acpi_cpufreq_attr[] = { | |
442 | &cpufreq_freq_attr_scaling_available_freqs, | |
443 | NULL, | |
444 | }; | |
445 | ||
446 | static struct cpufreq_driver acpi_cpufreq_driver = { | |
447 | .verify = acpi_cpufreq_verify, | |
448 | .target = acpi_cpufreq_target, | |
449 | .init = acpi_cpufreq_cpu_init, | |
450 | .exit = acpi_cpufreq_cpu_exit, | |
451 | .resume = acpi_cpufreq_resume, | |
452 | .name = "acpi-cpufreq", | |
453 | .owner = THIS_MODULE, | |
454 | .attr = acpi_cpufreq_attr, | |
455 | }; | |
456 | ||
457 | ||
458 | static int __init | |
459 | acpi_cpufreq_init (void) | |
460 | { | |
461 | int result = 0; | |
462 | ||
463 | dprintk("acpi_cpufreq_init\n"); | |
464 | ||
465 | result = cpufreq_register_driver(&acpi_cpufreq_driver); | |
466 | ||
467 | return (result); | |
468 | } | |
469 | ||
470 | ||
471 | static void __exit | |
472 | acpi_cpufreq_exit (void) | |
473 | { | |
474 | dprintk("acpi_cpufreq_exit\n"); | |
475 | ||
476 | cpufreq_unregister_driver(&acpi_cpufreq_driver); | |
477 | ||
478 | return; | |
479 | } | |
480 | ||
d395bf12 VP |
481 | module_param(acpi_pstate_strict, uint, 0644); |
482 | MODULE_PARM_DESC(acpi_pstate_strict, "value 0 or non-zero. non-zero -> strict ACPI checks are performed during frequency changes."); | |
1da177e4 LT |
483 | |
484 | late_initcall(acpi_cpufreq_init); | |
485 | module_exit(acpi_cpufreq_exit); | |
486 | ||
487 | MODULE_ALIAS("acpi"); |