diff options
author | Ingo Molnar <mingo@elte.hu> | 2009-10-29 04:02:15 -0400 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2009-10-29 04:02:20 -0400 |
commit | 9de09ace8d518141a4375e1d216ab64db4377799 (patch) | |
tree | da8e7a77f4ea91eb3bb73fc6da72ecf8c99e1c16 /drivers/acpi/acpi_pad.c | |
parent | 1beee96bae0daf7f491356777c3080cc436950f5 (diff) | |
parent | 6d3f1e12f46a2f9a1bb7e7aa433df8dd31ce5647 (diff) |
Merge branch 'tracing/urgent' into tracing/core
Merge reason: Pick up fixes and move base from -rc1 to -rc5.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'drivers/acpi/acpi_pad.c')
-rw-r--r-- | drivers/acpi/acpi_pad.c | 514 |
1 files changed, 514 insertions, 0 deletions
diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c new file mode 100644 index 000000000000..0d2cdb86158b --- /dev/null +++ b/drivers/acpi/acpi_pad.c | |||
@@ -0,0 +1,514 @@ | |||
1 | /* | ||
2 | * acpi_pad.c ACPI Processor Aggregator Driver | ||
3 | * | ||
4 | * Copyright (c) 2009, Intel Corporation. | ||
5 | * | ||
6 | * This program is free software; you can redistribute it and/or modify it | ||
7 | * under the terms and conditions of the GNU General Public License, | ||
8 | * version 2, as published by the Free Software Foundation. | ||
9 | * | ||
10 | * This program is distributed in the hope it will be useful, but WITHOUT | ||
11 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | ||
12 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | ||
13 | * more details. | ||
14 | * | ||
15 | * You should have received a copy of the GNU General Public License along with | ||
16 | * this program; if not, write to the Free Software Foundation, Inc., | ||
17 | * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. | ||
18 | * | ||
19 | */ | ||
20 | |||
21 | #include <linux/kernel.h> | ||
22 | #include <linux/cpumask.h> | ||
23 | #include <linux/module.h> | ||
24 | #include <linux/init.h> | ||
25 | #include <linux/types.h> | ||
26 | #include <linux/kthread.h> | ||
27 | #include <linux/freezer.h> | ||
28 | #include <linux/cpu.h> | ||
29 | #include <linux/clockchips.h> | ||
30 | #include <acpi/acpi_bus.h> | ||
31 | #include <acpi/acpi_drivers.h> | ||
32 | |||
33 | #define ACPI_PROCESSOR_AGGREGATOR_CLASS "processor_aggregator" | ||
34 | #define ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME "Processor Aggregator" | ||
35 | #define ACPI_PROCESSOR_AGGREGATOR_NOTIFY 0x80 | ||
36 | static DEFINE_MUTEX(isolated_cpus_lock); | ||
37 | |||
38 | #define MWAIT_SUBSTATE_MASK (0xf) | ||
39 | #define MWAIT_CSTATE_MASK (0xf) | ||
40 | #define MWAIT_SUBSTATE_SIZE (4) | ||
41 | #define CPUID_MWAIT_LEAF (5) | ||
42 | #define CPUID5_ECX_EXTENSIONS_SUPPORTED (0x1) | ||
43 | #define CPUID5_ECX_INTERRUPT_BREAK (0x2) | ||
44 | static unsigned long power_saving_mwait_eax; | ||
45 | static void power_saving_mwait_init(void) | ||
46 | { | ||
47 | unsigned int eax, ebx, ecx, edx; | ||
48 | unsigned int highest_cstate = 0; | ||
49 | unsigned int highest_subcstate = 0; | ||
50 | int i; | ||
51 | |||
52 | if (!boot_cpu_has(X86_FEATURE_MWAIT)) | ||
53 | return; | ||
54 | if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF) | ||
55 | return; | ||
56 | |||
57 | cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &edx); | ||
58 | |||
59 | if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) || | ||
60 | !(ecx & CPUID5_ECX_INTERRUPT_BREAK)) | ||
61 | return; | ||
62 | |||
63 | edx >>= MWAIT_SUBSTATE_SIZE; | ||
64 | for (i = 0; i < 7 && edx; i++, edx >>= MWAIT_SUBSTATE_SIZE) { | ||
65 | if (edx & MWAIT_SUBSTATE_MASK) { | ||
66 | highest_cstate = i; | ||
67 | highest_subcstate = edx & MWAIT_SUBSTATE_MASK; | ||
68 | } | ||
69 | } | ||
70 | power_saving_mwait_eax = (highest_cstate << MWAIT_SUBSTATE_SIZE) | | ||
71 | (highest_subcstate - 1); | ||
72 | |||
73 | for_each_online_cpu(i) | ||
74 | clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ON, &i); | ||
75 | |||
76 | #if defined(CONFIG_GENERIC_TIME) && defined(CONFIG_X86) | ||
77 | switch (boot_cpu_data.x86_vendor) { | ||
78 | case X86_VENDOR_AMD: | ||
79 | case X86_VENDOR_INTEL: | ||
80 | /* | ||
81 | * AMD Fam10h TSC will tick in all | ||
82 | * C/P/S0/S1 states when this bit is set. | ||
83 | */ | ||
84 | if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC)) | ||
85 | return; | ||
86 | |||
87 | /*FALL THROUGH*/ | ||
88 | default: | ||
89 | /* TSC could halt in idle, so notify users */ | ||
90 | mark_tsc_unstable("TSC halts in idle"); | ||
91 | } | ||
92 | #endif | ||
93 | } | ||
94 | |||
95 | static unsigned long cpu_weight[NR_CPUS]; | ||
96 | static int tsk_in_cpu[NR_CPUS] = {[0 ... NR_CPUS-1] = -1}; | ||
97 | static DECLARE_BITMAP(pad_busy_cpus_bits, NR_CPUS); | ||
98 | static void round_robin_cpu(unsigned int tsk_index) | ||
99 | { | ||
100 | struct cpumask *pad_busy_cpus = to_cpumask(pad_busy_cpus_bits); | ||
101 | cpumask_var_t tmp; | ||
102 | int cpu; | ||
103 | unsigned long min_weight = -1, preferred_cpu; | ||
104 | |||
105 | if (!alloc_cpumask_var(&tmp, GFP_KERNEL)) | ||
106 | return; | ||
107 | |||
108 | mutex_lock(&isolated_cpus_lock); | ||
109 | cpumask_clear(tmp); | ||
110 | for_each_cpu(cpu, pad_busy_cpus) | ||
111 | cpumask_or(tmp, tmp, topology_thread_cpumask(cpu)); | ||
112 | cpumask_andnot(tmp, cpu_online_mask, tmp); | ||
113 | /* avoid HT sibilings if possible */ | ||
114 | if (cpumask_empty(tmp)) | ||
115 | cpumask_andnot(tmp, cpu_online_mask, pad_busy_cpus); | ||
116 | if (cpumask_empty(tmp)) { | ||
117 | mutex_unlock(&isolated_cpus_lock); | ||
118 | return; | ||
119 | } | ||
120 | for_each_cpu(cpu, tmp) { | ||
121 | if (cpu_weight[cpu] < min_weight) { | ||
122 | min_weight = cpu_weight[cpu]; | ||
123 | preferred_cpu = cpu; | ||
124 | } | ||
125 | } | ||
126 | |||
127 | if (tsk_in_cpu[tsk_index] != -1) | ||
128 | cpumask_clear_cpu(tsk_in_cpu[tsk_index], pad_busy_cpus); | ||
129 | tsk_in_cpu[tsk_index] = preferred_cpu; | ||
130 | cpumask_set_cpu(preferred_cpu, pad_busy_cpus); | ||
131 | cpu_weight[preferred_cpu]++; | ||
132 | mutex_unlock(&isolated_cpus_lock); | ||
133 | |||
134 | set_cpus_allowed_ptr(current, cpumask_of(preferred_cpu)); | ||
135 | } | ||
136 | |||
137 | static void exit_round_robin(unsigned int tsk_index) | ||
138 | { | ||
139 | struct cpumask *pad_busy_cpus = to_cpumask(pad_busy_cpus_bits); | ||
140 | cpumask_clear_cpu(tsk_in_cpu[tsk_index], pad_busy_cpus); | ||
141 | tsk_in_cpu[tsk_index] = -1; | ||
142 | } | ||
143 | |||
144 | static unsigned int idle_pct = 5; /* percentage */ | ||
145 | static unsigned int round_robin_time = 10; /* second */ | ||
146 | static int power_saving_thread(void *data) | ||
147 | { | ||
148 | struct sched_param param = {.sched_priority = 1}; | ||
149 | int do_sleep; | ||
150 | unsigned int tsk_index = (unsigned long)data; | ||
151 | u64 last_jiffies = 0; | ||
152 | |||
153 | sched_setscheduler(current, SCHED_RR, ¶m); | ||
154 | |||
155 | while (!kthread_should_stop()) { | ||
156 | int cpu; | ||
157 | u64 expire_time; | ||
158 | |||
159 | try_to_freeze(); | ||
160 | |||
161 | /* round robin to cpus */ | ||
162 | if (last_jiffies + round_robin_time * HZ < jiffies) { | ||
163 | last_jiffies = jiffies; | ||
164 | round_robin_cpu(tsk_index); | ||
165 | } | ||
166 | |||
167 | do_sleep = 0; | ||
168 | |||
169 | current_thread_info()->status &= ~TS_POLLING; | ||
170 | /* | ||
171 | * TS_POLLING-cleared state must be visible before we test | ||
172 | * NEED_RESCHED: | ||
173 | */ | ||
174 | smp_mb(); | ||
175 | |||
176 | expire_time = jiffies + HZ * (100 - idle_pct) / 100; | ||
177 | |||
178 | while (!need_resched()) { | ||
179 | local_irq_disable(); | ||
180 | cpu = smp_processor_id(); | ||
181 | clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, | ||
182 | &cpu); | ||
183 | stop_critical_timings(); | ||
184 | |||
185 | __monitor((void *)¤t_thread_info()->flags, 0, 0); | ||
186 | smp_mb(); | ||
187 | if (!need_resched()) | ||
188 | __mwait(power_saving_mwait_eax, 1); | ||
189 | |||
190 | start_critical_timings(); | ||
191 | clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, | ||
192 | &cpu); | ||
193 | local_irq_enable(); | ||
194 | |||
195 | if (jiffies > expire_time) { | ||
196 | do_sleep = 1; | ||
197 | break; | ||
198 | } | ||
199 | } | ||
200 | |||
201 | current_thread_info()->status |= TS_POLLING; | ||
202 | |||
203 | /* | ||
204 | * current sched_rt has threshold for rt task running time. | ||
205 | * When a rt task uses 95% CPU time, the rt thread will be | ||
206 | * scheduled out for 5% CPU time to not starve other tasks. But | ||
207 | * the mechanism only works when all CPUs have RT task running, | ||
208 | * as if one CPU hasn't RT task, RT task from other CPUs will | ||
209 | * borrow CPU time from this CPU and cause RT task use > 95% | ||
210 | * CPU time. To make 'avoid staration' work, takes a nap here. | ||
211 | */ | ||
212 | if (do_sleep) | ||
213 | schedule_timeout_killable(HZ * idle_pct / 100); | ||
214 | } | ||
215 | |||
216 | exit_round_robin(tsk_index); | ||
217 | return 0; | ||
218 | } | ||
219 | |||
220 | static struct task_struct *ps_tsks[NR_CPUS]; | ||
221 | static unsigned int ps_tsk_num; | ||
222 | static int create_power_saving_task(void) | ||
223 | { | ||
224 | ps_tsks[ps_tsk_num] = kthread_run(power_saving_thread, | ||
225 | (void *)(unsigned long)ps_tsk_num, | ||
226 | "power_saving/%d", ps_tsk_num); | ||
227 | if (ps_tsks[ps_tsk_num]) { | ||
228 | ps_tsk_num++; | ||
229 | return 0; | ||
230 | } | ||
231 | return -EINVAL; | ||
232 | } | ||
233 | |||
234 | static void destroy_power_saving_task(void) | ||
235 | { | ||
236 | if (ps_tsk_num > 0) { | ||
237 | ps_tsk_num--; | ||
238 | kthread_stop(ps_tsks[ps_tsk_num]); | ||
239 | } | ||
240 | } | ||
241 | |||
242 | static void set_power_saving_task_num(unsigned int num) | ||
243 | { | ||
244 | if (num > ps_tsk_num) { | ||
245 | while (ps_tsk_num < num) { | ||
246 | if (create_power_saving_task()) | ||
247 | return; | ||
248 | } | ||
249 | } else if (num < ps_tsk_num) { | ||
250 | while (ps_tsk_num > num) | ||
251 | destroy_power_saving_task(); | ||
252 | } | ||
253 | } | ||
254 | |||
255 | static int acpi_pad_idle_cpus(unsigned int num_cpus) | ||
256 | { | ||
257 | get_online_cpus(); | ||
258 | |||
259 | num_cpus = min_t(unsigned int, num_cpus, num_online_cpus()); | ||
260 | set_power_saving_task_num(num_cpus); | ||
261 | |||
262 | put_online_cpus(); | ||
263 | return 0; | ||
264 | } | ||
265 | |||
266 | static uint32_t acpi_pad_idle_cpus_num(void) | ||
267 | { | ||
268 | return ps_tsk_num; | ||
269 | } | ||
270 | |||
271 | static ssize_t acpi_pad_rrtime_store(struct device *dev, | ||
272 | struct device_attribute *attr, const char *buf, size_t count) | ||
273 | { | ||
274 | unsigned long num; | ||
275 | if (strict_strtoul(buf, 0, &num)) | ||
276 | return -EINVAL; | ||
277 | if (num < 1 || num >= 100) | ||
278 | return -EINVAL; | ||
279 | mutex_lock(&isolated_cpus_lock); | ||
280 | round_robin_time = num; | ||
281 | mutex_unlock(&isolated_cpus_lock); | ||
282 | return count; | ||
283 | } | ||
284 | |||
285 | static ssize_t acpi_pad_rrtime_show(struct device *dev, | ||
286 | struct device_attribute *attr, char *buf) | ||
287 | { | ||
288 | return scnprintf(buf, PAGE_SIZE, "%d", round_robin_time); | ||
289 | } | ||
290 | static DEVICE_ATTR(rrtime, S_IRUGO|S_IWUSR, | ||
291 | acpi_pad_rrtime_show, | ||
292 | acpi_pad_rrtime_store); | ||
293 | |||
294 | static ssize_t acpi_pad_idlepct_store(struct device *dev, | ||
295 | struct device_attribute *attr, const char *buf, size_t count) | ||
296 | { | ||
297 | unsigned long num; | ||
298 | if (strict_strtoul(buf, 0, &num)) | ||
299 | return -EINVAL; | ||
300 | if (num < 1 || num >= 100) | ||
301 | return -EINVAL; | ||
302 | mutex_lock(&isolated_cpus_lock); | ||
303 | idle_pct = num; | ||
304 | mutex_unlock(&isolated_cpus_lock); | ||
305 | return count; | ||
306 | } | ||
307 | |||
308 | static ssize_t acpi_pad_idlepct_show(struct device *dev, | ||
309 | struct device_attribute *attr, char *buf) | ||
310 | { | ||
311 | return scnprintf(buf, PAGE_SIZE, "%d", idle_pct); | ||
312 | } | ||
313 | static DEVICE_ATTR(idlepct, S_IRUGO|S_IWUSR, | ||
314 | acpi_pad_idlepct_show, | ||
315 | acpi_pad_idlepct_store); | ||
316 | |||
317 | static ssize_t acpi_pad_idlecpus_store(struct device *dev, | ||
318 | struct device_attribute *attr, const char *buf, size_t count) | ||
319 | { | ||
320 | unsigned long num; | ||
321 | if (strict_strtoul(buf, 0, &num)) | ||
322 | return -EINVAL; | ||
323 | mutex_lock(&isolated_cpus_lock); | ||
324 | acpi_pad_idle_cpus(num); | ||
325 | mutex_unlock(&isolated_cpus_lock); | ||
326 | return count; | ||
327 | } | ||
328 | |||
329 | static ssize_t acpi_pad_idlecpus_show(struct device *dev, | ||
330 | struct device_attribute *attr, char *buf) | ||
331 | { | ||
332 | return cpumask_scnprintf(buf, PAGE_SIZE, | ||
333 | to_cpumask(pad_busy_cpus_bits)); | ||
334 | } | ||
335 | static DEVICE_ATTR(idlecpus, S_IRUGO|S_IWUSR, | ||
336 | acpi_pad_idlecpus_show, | ||
337 | acpi_pad_idlecpus_store); | ||
338 | |||
339 | static int acpi_pad_add_sysfs(struct acpi_device *device) | ||
340 | { | ||
341 | int result; | ||
342 | |||
343 | result = device_create_file(&device->dev, &dev_attr_idlecpus); | ||
344 | if (result) | ||
345 | return -ENODEV; | ||
346 | result = device_create_file(&device->dev, &dev_attr_idlepct); | ||
347 | if (result) { | ||
348 | device_remove_file(&device->dev, &dev_attr_idlecpus); | ||
349 | return -ENODEV; | ||
350 | } | ||
351 | result = device_create_file(&device->dev, &dev_attr_rrtime); | ||
352 | if (result) { | ||
353 | device_remove_file(&device->dev, &dev_attr_idlecpus); | ||
354 | device_remove_file(&device->dev, &dev_attr_idlepct); | ||
355 | return -ENODEV; | ||
356 | } | ||
357 | return 0; | ||
358 | } | ||
359 | |||
360 | static void acpi_pad_remove_sysfs(struct acpi_device *device) | ||
361 | { | ||
362 | device_remove_file(&device->dev, &dev_attr_idlecpus); | ||
363 | device_remove_file(&device->dev, &dev_attr_idlepct); | ||
364 | device_remove_file(&device->dev, &dev_attr_rrtime); | ||
365 | } | ||
366 | |||
367 | /* Query firmware how many CPUs should be idle */ | ||
368 | static int acpi_pad_pur(acpi_handle handle, int *num_cpus) | ||
369 | { | ||
370 | struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL}; | ||
371 | acpi_status status; | ||
372 | union acpi_object *package; | ||
373 | int rev, num, ret = -EINVAL; | ||
374 | |||
375 | status = acpi_evaluate_object(handle, "_PUR", NULL, &buffer); | ||
376 | if (ACPI_FAILURE(status)) | ||
377 | return -EINVAL; | ||
378 | package = buffer.pointer; | ||
379 | if (package->type != ACPI_TYPE_PACKAGE || package->package.count != 2) | ||
380 | goto out; | ||
381 | rev = package->package.elements[0].integer.value; | ||
382 | num = package->package.elements[1].integer.value; | ||
383 | if (rev != 1) | ||
384 | goto out; | ||
385 | *num_cpus = num; | ||
386 | ret = 0; | ||
387 | out: | ||
388 | kfree(buffer.pointer); | ||
389 | return ret; | ||
390 | } | ||
391 | |||
392 | /* Notify firmware how many CPUs are idle */ | ||
393 | static void acpi_pad_ost(acpi_handle handle, int stat, | ||
394 | uint32_t idle_cpus) | ||
395 | { | ||
396 | union acpi_object params[3] = { | ||
397 | {.type = ACPI_TYPE_INTEGER,}, | ||
398 | {.type = ACPI_TYPE_INTEGER,}, | ||
399 | {.type = ACPI_TYPE_BUFFER,}, | ||
400 | }; | ||
401 | struct acpi_object_list arg_list = {3, params}; | ||
402 | |||
403 | params[0].integer.value = ACPI_PROCESSOR_AGGREGATOR_NOTIFY; | ||
404 | params[1].integer.value = stat; | ||
405 | params[2].buffer.length = 4; | ||
406 | params[2].buffer.pointer = (void *)&idle_cpus; | ||
407 | acpi_evaluate_object(handle, "_OST", &arg_list, NULL); | ||
408 | } | ||
409 | |||
410 | static void acpi_pad_handle_notify(acpi_handle handle) | ||
411 | { | ||
412 | int num_cpus, ret; | ||
413 | uint32_t idle_cpus; | ||
414 | |||
415 | mutex_lock(&isolated_cpus_lock); | ||
416 | if (acpi_pad_pur(handle, &num_cpus)) { | ||
417 | mutex_unlock(&isolated_cpus_lock); | ||
418 | return; | ||
419 | } | ||
420 | ret = acpi_pad_idle_cpus(num_cpus); | ||
421 | idle_cpus = acpi_pad_idle_cpus_num(); | ||
422 | if (!ret) | ||
423 | acpi_pad_ost(handle, 0, idle_cpus); | ||
424 | else | ||
425 | acpi_pad_ost(handle, 1, 0); | ||
426 | mutex_unlock(&isolated_cpus_lock); | ||
427 | } | ||
428 | |||
429 | static void acpi_pad_notify(acpi_handle handle, u32 event, | ||
430 | void *data) | ||
431 | { | ||
432 | struct acpi_device *device = data; | ||
433 | |||
434 | switch (event) { | ||
435 | case ACPI_PROCESSOR_AGGREGATOR_NOTIFY: | ||
436 | acpi_pad_handle_notify(handle); | ||
437 | acpi_bus_generate_proc_event(device, event, 0); | ||
438 | acpi_bus_generate_netlink_event(device->pnp.device_class, | ||
439 | dev_name(&device->dev), event, 0); | ||
440 | break; | ||
441 | default: | ||
442 | printk(KERN_WARNING"Unsupported event [0x%x]\n", event); | ||
443 | break; | ||
444 | } | ||
445 | } | ||
446 | |||
447 | static int acpi_pad_add(struct acpi_device *device) | ||
448 | { | ||
449 | acpi_status status; | ||
450 | |||
451 | strcpy(acpi_device_name(device), ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME); | ||
452 | strcpy(acpi_device_class(device), ACPI_PROCESSOR_AGGREGATOR_CLASS); | ||
453 | |||
454 | if (acpi_pad_add_sysfs(device)) | ||
455 | return -ENODEV; | ||
456 | |||
457 | status = acpi_install_notify_handler(device->handle, | ||
458 | ACPI_DEVICE_NOTIFY, acpi_pad_notify, device); | ||
459 | if (ACPI_FAILURE(status)) { | ||
460 | acpi_pad_remove_sysfs(device); | ||
461 | return -ENODEV; | ||
462 | } | ||
463 | |||
464 | return 0; | ||
465 | } | ||
466 | |||
467 | static int acpi_pad_remove(struct acpi_device *device, | ||
468 | int type) | ||
469 | { | ||
470 | mutex_lock(&isolated_cpus_lock); | ||
471 | acpi_pad_idle_cpus(0); | ||
472 | mutex_unlock(&isolated_cpus_lock); | ||
473 | |||
474 | acpi_remove_notify_handler(device->handle, | ||
475 | ACPI_DEVICE_NOTIFY, acpi_pad_notify); | ||
476 | acpi_pad_remove_sysfs(device); | ||
477 | return 0; | ||
478 | } | ||
479 | |||
480 | static const struct acpi_device_id pad_device_ids[] = { | ||
481 | {"ACPI000C", 0}, | ||
482 | {"", 0}, | ||
483 | }; | ||
484 | MODULE_DEVICE_TABLE(acpi, pad_device_ids); | ||
485 | |||
486 | static struct acpi_driver acpi_pad_driver = { | ||
487 | .name = "processor_aggregator", | ||
488 | .class = ACPI_PROCESSOR_AGGREGATOR_CLASS, | ||
489 | .ids = pad_device_ids, | ||
490 | .ops = { | ||
491 | .add = acpi_pad_add, | ||
492 | .remove = acpi_pad_remove, | ||
493 | }, | ||
494 | }; | ||
495 | |||
496 | static int __init acpi_pad_init(void) | ||
497 | { | ||
498 | power_saving_mwait_init(); | ||
499 | if (power_saving_mwait_eax == 0) | ||
500 | return -EINVAL; | ||
501 | |||
502 | return acpi_bus_register_driver(&acpi_pad_driver); | ||
503 | } | ||
504 | |||
505 | static void __exit acpi_pad_exit(void) | ||
506 | { | ||
507 | acpi_bus_unregister_driver(&acpi_pad_driver); | ||
508 | } | ||
509 | |||
510 | module_init(acpi_pad_init); | ||
511 | module_exit(acpi_pad_exit); | ||
512 | MODULE_AUTHOR("Shaohua Li<shaohua.li@intel.com>"); | ||
513 | MODULE_DESCRIPTION("ACPI Processor Aggregator Driver"); | ||
514 | MODULE_LICENSE("GPL"); | ||