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2025cf9e | 1 | // SPDX-License-Identifier: GPL-2.0-only |
8e0af514 SL |
2 | /* |
3 | * acpi_pad.c ACPI Processor Aggregator Driver | |
4 | * | |
5 | * Copyright (c) 2009, Intel Corporation. | |
8e0af514 SL |
6 | */ |
7 | ||
8 | #include <linux/kernel.h> | |
9 | #include <linux/cpumask.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/init.h> | |
12 | #include <linux/types.h> | |
13 | #include <linux/kthread.h> | |
ae7e81c0 | 14 | #include <uapi/linux/sched/types.h> |
8e0af514 SL |
15 | #include <linux/freezer.h> |
16 | #include <linux/cpu.h> | |
979081e7 | 17 | #include <linux/tick.h> |
5a0e3ad6 | 18 | #include <linux/slab.h> |
8b48463f | 19 | #include <linux/acpi.h> |
2a606a18 | 20 | #include <linux/perf_event.h> |
dd0261bb | 21 | #include <linux/platform_device.h> |
bc83cccc | 22 | #include <asm/mwait.h> |
e311404f | 23 | #include <xen/xen.h> |
8e0af514 | 24 | |
a40770a9 | 25 | #define ACPI_PROCESSOR_AGGREGATOR_CLASS "acpi_pad" |
8e0af514 SL |
26 | #define ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME "Processor Aggregator" |
27 | #define ACPI_PROCESSOR_AGGREGATOR_NOTIFY 0x80 | |
117478c9 AW |
28 | |
29 | #define ACPI_PROCESSOR_AGGREGATOR_STATUS_SUCCESS 0 | |
30 | #define ACPI_PROCESSOR_AGGREGATOR_STATUS_NO_ACTION 1 | |
31 | ||
8e0af514 | 32 | static DEFINE_MUTEX(isolated_cpus_lock); |
5f160126 | 33 | static DEFINE_MUTEX(round_robin_lock); |
8e0af514 | 34 | |
8e0af514 | 35 | static unsigned long power_saving_mwait_eax; |
0dc698b9 VP |
36 | |
37 | static unsigned char tsc_detected_unstable; | |
38 | static unsigned char tsc_marked_unstable; | |
39 | ||
8e0af514 SL |
40 | static void power_saving_mwait_init(void) |
41 | { | |
42 | unsigned int eax, ebx, ecx, edx; | |
43 | unsigned int highest_cstate = 0; | |
44 | unsigned int highest_subcstate = 0; | |
45 | int i; | |
46 | ||
47 | if (!boot_cpu_has(X86_FEATURE_MWAIT)) | |
48 | return; | |
49 | if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF) | |
50 | return; | |
51 | ||
52 | cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &edx); | |
53 | ||
54 | if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) || | |
55 | !(ecx & CPUID5_ECX_INTERRUPT_BREAK)) | |
56 | return; | |
57 | ||
58 | edx >>= MWAIT_SUBSTATE_SIZE; | |
59 | for (i = 0; i < 7 && edx; i++, edx >>= MWAIT_SUBSTATE_SIZE) { | |
60 | if (edx & MWAIT_SUBSTATE_MASK) { | |
61 | highest_cstate = i; | |
62 | highest_subcstate = edx & MWAIT_SUBSTATE_MASK; | |
63 | } | |
64 | } | |
65 | power_saving_mwait_eax = (highest_cstate << MWAIT_SUBSTATE_SIZE) | | |
66 | (highest_subcstate - 1); | |
67 | ||
592913ec | 68 | #if defined(CONFIG_X86) |
8e0af514 | 69 | switch (boot_cpu_data.x86_vendor) { |
7377ed4b | 70 | case X86_VENDOR_HYGON: |
8e0af514 SL |
71 | case X86_VENDOR_AMD: |
72 | case X86_VENDOR_INTEL: | |
773b2f30 | 73 | case X86_VENDOR_ZHAOXIN: |
b72f301c | 74 | case X86_VENDOR_CENTAUR: |
8e0af514 SL |
75 | /* |
76 | * AMD Fam10h TSC will tick in all | |
77 | * C/P/S0/S1 states when this bit is set. | |
78 | */ | |
8aa4b14e CG |
79 | if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC)) |
80 | tsc_detected_unstable = 1; | |
8aa4b14e | 81 | break; |
8e0af514 | 82 | default: |
3ff70551 | 83 | /* TSC could halt in idle */ |
0dc698b9 | 84 | tsc_detected_unstable = 1; |
8e0af514 SL |
85 | } |
86 | #endif | |
87 | } | |
88 | ||
89 | static unsigned long cpu_weight[NR_CPUS]; | |
90 | static int tsk_in_cpu[NR_CPUS] = {[0 ... NR_CPUS-1] = -1}; | |
91 | static DECLARE_BITMAP(pad_busy_cpus_bits, NR_CPUS); | |
92 | static void round_robin_cpu(unsigned int tsk_index) | |
93 | { | |
94 | struct cpumask *pad_busy_cpus = to_cpumask(pad_busy_cpus_bits); | |
95 | cpumask_var_t tmp; | |
96 | int cpu; | |
f67538f8 | 97 | unsigned long min_weight = -1; |
134043cd | 98 | unsigned long preferred_cpu; |
8e0af514 SL |
99 | |
100 | if (!alloc_cpumask_var(&tmp, GFP_KERNEL)) | |
101 | return; | |
102 | ||
5f160126 | 103 | mutex_lock(&round_robin_lock); |
8e0af514 SL |
104 | cpumask_clear(tmp); |
105 | for_each_cpu(cpu, pad_busy_cpus) | |
06931e62 | 106 | cpumask_or(tmp, tmp, topology_sibling_cpumask(cpu)); |
8e0af514 | 107 | cpumask_andnot(tmp, cpu_online_mask, tmp); |
51a23b1b | 108 | /* avoid HT siblings if possible */ |
8e0af514 SL |
109 | if (cpumask_empty(tmp)) |
110 | cpumask_andnot(tmp, cpu_online_mask, pad_busy_cpus); | |
111 | if (cpumask_empty(tmp)) { | |
5f160126 | 112 | mutex_unlock(&round_robin_lock); |
8b29d29a | 113 | free_cpumask_var(tmp); |
8e0af514 SL |
114 | return; |
115 | } | |
116 | for_each_cpu(cpu, tmp) { | |
117 | if (cpu_weight[cpu] < min_weight) { | |
118 | min_weight = cpu_weight[cpu]; | |
119 | preferred_cpu = cpu; | |
120 | } | |
121 | } | |
122 | ||
123 | if (tsk_in_cpu[tsk_index] != -1) | |
124 | cpumask_clear_cpu(tsk_in_cpu[tsk_index], pad_busy_cpus); | |
125 | tsk_in_cpu[tsk_index] = preferred_cpu; | |
126 | cpumask_set_cpu(preferred_cpu, pad_busy_cpus); | |
127 | cpu_weight[preferred_cpu]++; | |
5f160126 | 128 | mutex_unlock(&round_robin_lock); |
8e0af514 SL |
129 | |
130 | set_cpus_allowed_ptr(current, cpumask_of(preferred_cpu)); | |
8b29d29a LS |
131 | |
132 | free_cpumask_var(tmp); | |
8e0af514 SL |
133 | } |
134 | ||
135 | static void exit_round_robin(unsigned int tsk_index) | |
136 | { | |
137 | struct cpumask *pad_busy_cpus = to_cpumask(pad_busy_cpus_bits); | |
c8eb628c | 138 | |
0a2ed70a SN |
139 | if (tsk_in_cpu[tsk_index] != -1) { |
140 | cpumask_clear_cpu(tsk_in_cpu[tsk_index], pad_busy_cpus); | |
141 | tsk_in_cpu[tsk_index] = -1; | |
142 | } | |
8e0af514 SL |
143 | } |
144 | ||
145 | static unsigned int idle_pct = 5; /* percentage */ | |
fa7584e1 | 146 | static unsigned int round_robin_time = 1; /* second */ |
8e0af514 SL |
147 | static int power_saving_thread(void *data) |
148 | { | |
8e0af514 SL |
149 | int do_sleep; |
150 | unsigned int tsk_index = (unsigned long)data; | |
151 | u64 last_jiffies = 0; | |
152 | ||
4ca6c1a0 | 153 | sched_set_fifo_low(current); |
8e0af514 SL |
154 | |
155 | while (!kthread_should_stop()) { | |
4ff248f3 | 156 | unsigned long expire_time; |
8e0af514 | 157 | |
8e0af514 | 158 | /* round robin to cpus */ |
4ff248f3 MS |
159 | expire_time = last_jiffies + round_robin_time * HZ; |
160 | if (time_before(expire_time, jiffies)) { | |
8e0af514 SL |
161 | last_jiffies = jiffies; |
162 | round_robin_cpu(tsk_index); | |
163 | } | |
164 | ||
165 | do_sleep = 0; | |
166 | ||
8e0af514 SL |
167 | expire_time = jiffies + HZ * (100 - idle_pct) / 100; |
168 | ||
169 | while (!need_resched()) { | |
0dc698b9 VP |
170 | if (tsc_detected_unstable && !tsc_marked_unstable) { |
171 | /* TSC could halt in idle, so notify users */ | |
172 | mark_tsc_unstable("TSC halts in idle"); | |
173 | tsc_marked_unstable = 1; | |
174 | } | |
8e0af514 | 175 | local_irq_disable(); |
2a606a18 SE |
176 | |
177 | perf_lopwr_cb(true); | |
178 | ||
979081e7 | 179 | tick_broadcast_enable(); |
c7952135 | 180 | tick_broadcast_enter(); |
8e0af514 SL |
181 | stop_critical_timings(); |
182 | ||
16824255 | 183 | mwait_idle_with_hints(power_saving_mwait_eax, 1); |
8e0af514 SL |
184 | |
185 | start_critical_timings(); | |
c7952135 | 186 | tick_broadcast_exit(); |
2a606a18 SE |
187 | |
188 | perf_lopwr_cb(false); | |
189 | ||
8e0af514 SL |
190 | local_irq_enable(); |
191 | ||
4ff248f3 | 192 | if (time_before(expire_time, jiffies)) { |
8e0af514 SL |
193 | do_sleep = 1; |
194 | break; | |
195 | } | |
196 | } | |
197 | ||
8e0af514 SL |
198 | /* |
199 | * current sched_rt has threshold for rt task running time. | |
200 | * When a rt task uses 95% CPU time, the rt thread will be | |
201 | * scheduled out for 5% CPU time to not starve other tasks. But | |
202 | * the mechanism only works when all CPUs have RT task running, | |
203 | * as if one CPU hasn't RT task, RT task from other CPUs will | |
204 | * borrow CPU time from this CPU and cause RT task use > 95% | |
3b8cb427 | 205 | * CPU time. To make 'avoid starvation' work, takes a nap here. |
8e0af514 | 206 | */ |
5b59c69e | 207 | if (unlikely(do_sleep)) |
8e0af514 | 208 | schedule_timeout_killable(HZ * idle_pct / 100); |
5b59c69e TC |
209 | |
210 | /* If an external event has set the need_resched flag, then | |
211 | * we need to deal with it, or this loop will continue to | |
212 | * spin without calling __mwait(). | |
213 | */ | |
214 | if (unlikely(need_resched())) | |
215 | schedule(); | |
8e0af514 SL |
216 | } |
217 | ||
218 | exit_round_robin(tsk_index); | |
219 | return 0; | |
220 | } | |
221 | ||
222 | static struct task_struct *ps_tsks[NR_CPUS]; | |
223 | static unsigned int ps_tsk_num; | |
224 | static int create_power_saving_task(void) | |
225 | { | |
5d7e4386 | 226 | int rc; |
3b8cb427 | 227 | |
8e0af514 SL |
228 | ps_tsks[ps_tsk_num] = kthread_run(power_saving_thread, |
229 | (void *)(unsigned long)ps_tsk_num, | |
150ed86f | 230 | "acpi_pad/%d", ps_tsk_num); |
5d7e4386 RR |
231 | |
232 | if (IS_ERR(ps_tsks[ps_tsk_num])) { | |
233 | rc = PTR_ERR(ps_tsks[ps_tsk_num]); | |
3b8cb427 | 234 | ps_tsks[ps_tsk_num] = NULL; |
5d7e4386 RR |
235 | } else { |
236 | rc = 0; | |
237 | ps_tsk_num++; | |
238 | } | |
3b8cb427 CG |
239 | |
240 | return rc; | |
8e0af514 SL |
241 | } |
242 | ||
243 | static void destroy_power_saving_task(void) | |
244 | { | |
245 | if (ps_tsk_num > 0) { | |
246 | ps_tsk_num--; | |
247 | kthread_stop(ps_tsks[ps_tsk_num]); | |
3b8cb427 | 248 | ps_tsks[ps_tsk_num] = NULL; |
8e0af514 SL |
249 | } |
250 | } | |
251 | ||
252 | static void set_power_saving_task_num(unsigned int num) | |
253 | { | |
254 | if (num > ps_tsk_num) { | |
255 | while (ps_tsk_num < num) { | |
256 | if (create_power_saving_task()) | |
257 | return; | |
258 | } | |
259 | } else if (num < ps_tsk_num) { | |
260 | while (ps_tsk_num > num) | |
261 | destroy_power_saving_task(); | |
262 | } | |
263 | } | |
264 | ||
3b8cb427 | 265 | static void acpi_pad_idle_cpus(unsigned int num_cpus) |
8e0af514 | 266 | { |
95ac7067 | 267 | cpus_read_lock(); |
8e0af514 SL |
268 | |
269 | num_cpus = min_t(unsigned int, num_cpus, num_online_cpus()); | |
270 | set_power_saving_task_num(num_cpus); | |
271 | ||
95ac7067 | 272 | cpus_read_unlock(); |
8e0af514 SL |
273 | } |
274 | ||
275 | static uint32_t acpi_pad_idle_cpus_num(void) | |
276 | { | |
277 | return ps_tsk_num; | |
278 | } | |
279 | ||
0f39ee83 | 280 | static ssize_t rrtime_store(struct device *dev, |
8e0af514 SL |
281 | struct device_attribute *attr, const char *buf, size_t count) |
282 | { | |
283 | unsigned long num; | |
c8eb628c | 284 | |
73d4511a | 285 | if (kstrtoul(buf, 0, &num)) |
8e0af514 SL |
286 | return -EINVAL; |
287 | if (num < 1 || num >= 100) | |
288 | return -EINVAL; | |
289 | mutex_lock(&isolated_cpus_lock); | |
290 | round_robin_time = num; | |
291 | mutex_unlock(&isolated_cpus_lock); | |
292 | return count; | |
293 | } | |
294 | ||
0f39ee83 | 295 | static ssize_t rrtime_show(struct device *dev, |
8e0af514 SL |
296 | struct device_attribute *attr, char *buf) |
297 | { | |
92266c65 | 298 | return sysfs_emit(buf, "%d\n", round_robin_time); |
8e0af514 | 299 | } |
0f39ee83 | 300 | static DEVICE_ATTR_RW(rrtime); |
8e0af514 | 301 | |
0f39ee83 | 302 | static ssize_t idlepct_store(struct device *dev, |
8e0af514 SL |
303 | struct device_attribute *attr, const char *buf, size_t count) |
304 | { | |
305 | unsigned long num; | |
c8eb628c | 306 | |
73d4511a | 307 | if (kstrtoul(buf, 0, &num)) |
8e0af514 SL |
308 | return -EINVAL; |
309 | if (num < 1 || num >= 100) | |
310 | return -EINVAL; | |
311 | mutex_lock(&isolated_cpus_lock); | |
312 | idle_pct = num; | |
313 | mutex_unlock(&isolated_cpus_lock); | |
314 | return count; | |
315 | } | |
316 | ||
0f39ee83 | 317 | static ssize_t idlepct_show(struct device *dev, |
8e0af514 SL |
318 | struct device_attribute *attr, char *buf) |
319 | { | |
92266c65 | 320 | return sysfs_emit(buf, "%d\n", idle_pct); |
8e0af514 | 321 | } |
0f39ee83 | 322 | static DEVICE_ATTR_RW(idlepct); |
8e0af514 | 323 | |
0f39ee83 | 324 | static ssize_t idlecpus_store(struct device *dev, |
8e0af514 SL |
325 | struct device_attribute *attr, const char *buf, size_t count) |
326 | { | |
327 | unsigned long num; | |
c8eb628c | 328 | |
73d4511a | 329 | if (kstrtoul(buf, 0, &num)) |
8e0af514 SL |
330 | return -EINVAL; |
331 | mutex_lock(&isolated_cpus_lock); | |
332 | acpi_pad_idle_cpus(num); | |
333 | mutex_unlock(&isolated_cpus_lock); | |
334 | return count; | |
335 | } | |
336 | ||
0f39ee83 | 337 | static ssize_t idlecpus_show(struct device *dev, |
8e0af514 SL |
338 | struct device_attribute *attr, char *buf) |
339 | { | |
5aaba363 SH |
340 | return cpumap_print_to_pagebuf(false, buf, |
341 | to_cpumask(pad_busy_cpus_bits)); | |
8e0af514 | 342 | } |
5aaba363 | 343 | |
0f39ee83 | 344 | static DEVICE_ATTR_RW(idlecpus); |
8e0af514 | 345 | |
d7228c71 MW |
346 | static struct attribute *acpi_pad_attrs[] = { |
347 | &dev_attr_idlecpus.attr, | |
348 | &dev_attr_idlepct.attr, | |
349 | &dev_attr_rrtime.attr, | |
350 | NULL | |
351 | }; | |
8e0af514 | 352 | |
d7228c71 | 353 | ATTRIBUTE_GROUPS(acpi_pad); |
8e0af514 | 354 | |
c9ad8e06 LB |
355 | /* |
356 | * Query firmware how many CPUs should be idle | |
357 | * return -1 on failure | |
358 | */ | |
359 | static int acpi_pad_pur(acpi_handle handle) | |
8e0af514 SL |
360 | { |
361 | struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL}; | |
8e0af514 | 362 | union acpi_object *package; |
c9ad8e06 | 363 | int num = -1; |
8e0af514 | 364 | |
3b8cb427 | 365 | if (ACPI_FAILURE(acpi_evaluate_object(handle, "_PUR", NULL, &buffer))) |
c9ad8e06 | 366 | return num; |
3b8cb427 CG |
367 | |
368 | if (!buffer.length || !buffer.pointer) | |
c9ad8e06 | 369 | return num; |
3b8cb427 | 370 | |
8e0af514 | 371 | package = buffer.pointer; |
c9ad8e06 LB |
372 | |
373 | if (package->type == ACPI_TYPE_PACKAGE && | |
374 | package->package.count == 2 && | |
375 | package->package.elements[0].integer.value == 1) /* rev 1 */ | |
376 | ||
377 | num = package->package.elements[1].integer.value; | |
378 | ||
8e0af514 | 379 | kfree(buffer.pointer); |
c9ad8e06 | 380 | return num; |
8e0af514 SL |
381 | } |
382 | ||
8e0af514 SL |
383 | static void acpi_pad_handle_notify(acpi_handle handle) |
384 | { | |
3b8cb427 | 385 | int num_cpus; |
8e0af514 | 386 | uint32_t idle_cpus; |
8b296d94 JL |
387 | struct acpi_buffer param = { |
388 | .length = 4, | |
389 | .pointer = (void *)&idle_cpus, | |
390 | }; | |
117478c9 | 391 | u32 status; |
8e0af514 SL |
392 | |
393 | mutex_lock(&isolated_cpus_lock); | |
c9ad8e06 LB |
394 | num_cpus = acpi_pad_pur(handle); |
395 | if (num_cpus < 0) { | |
117478c9 AW |
396 | /* The ACPI specification says that if no action was performed when |
397 | * processing the _PUR object, _OST should still be evaluated, albeit | |
398 | * with a different status code. | |
399 | */ | |
400 | status = ACPI_PROCESSOR_AGGREGATOR_STATUS_NO_ACTION; | |
401 | } else { | |
402 | status = ACPI_PROCESSOR_AGGREGATOR_STATUS_SUCCESS; | |
403 | acpi_pad_idle_cpus(num_cpus); | |
8e0af514 | 404 | } |
117478c9 | 405 | |
8e0af514 | 406 | idle_cpus = acpi_pad_idle_cpus_num(); |
117478c9 | 407 | acpi_evaluate_ost(handle, ACPI_PROCESSOR_AGGREGATOR_NOTIFY, status, ¶m); |
8e0af514 SL |
408 | mutex_unlock(&isolated_cpus_lock); |
409 | } | |
410 | ||
411 | static void acpi_pad_notify(acpi_handle handle, u32 event, | |
412 | void *data) | |
413 | { | |
5ccd40c5 | 414 | struct acpi_device *adev = data; |
8e0af514 SL |
415 | |
416 | switch (event) { | |
417 | case ACPI_PROCESSOR_AGGREGATOR_NOTIFY: | |
418 | acpi_pad_handle_notify(handle); | |
5ccd40c5 MW |
419 | acpi_bus_generate_netlink_event(adev->pnp.device_class, |
420 | dev_name(&adev->dev), event, 0); | |
8e0af514 SL |
421 | break; |
422 | default: | |
73d4511a | 423 | pr_warn("Unsupported event [0x%x]\n", event); |
8e0af514 SL |
424 | break; |
425 | } | |
426 | } | |
427 | ||
dd0261bb | 428 | static int acpi_pad_probe(struct platform_device *pdev) |
8e0af514 | 429 | { |
5ccd40c5 | 430 | struct acpi_device *adev = ACPI_COMPANION(&pdev->dev); |
8e0af514 SL |
431 | acpi_status status; |
432 | ||
4fe1135c MQAM |
433 | strscpy(acpi_device_name(adev), ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME); |
434 | strscpy(acpi_device_class(adev), ACPI_PROCESSOR_AGGREGATOR_CLASS); | |
5ccd40c5 MW |
435 | |
436 | status = acpi_install_notify_handler(adev->handle, | |
437 | ACPI_DEVICE_NOTIFY, acpi_pad_notify, adev); | |
8e0af514 | 438 | |
d7228c71 | 439 | if (ACPI_FAILURE(status)) |
8e0af514 | 440 | return -ENODEV; |
8e0af514 SL |
441 | |
442 | return 0; | |
443 | } | |
444 | ||
dd0261bb | 445 | static void acpi_pad_remove(struct platform_device *pdev) |
8e0af514 | 446 | { |
5ccd40c5 | 447 | struct acpi_device *adev = ACPI_COMPANION(&pdev->dev); |
dd0261bb | 448 | |
8e0af514 SL |
449 | mutex_lock(&isolated_cpus_lock); |
450 | acpi_pad_idle_cpus(0); | |
451 | mutex_unlock(&isolated_cpus_lock); | |
452 | ||
5ccd40c5 | 453 | acpi_remove_notify_handler(adev->handle, |
8e0af514 | 454 | ACPI_DEVICE_NOTIFY, acpi_pad_notify); |
8e0af514 SL |
455 | } |
456 | ||
457 | static const struct acpi_device_id pad_device_ids[] = { | |
458 | {"ACPI000C", 0}, | |
459 | {"", 0}, | |
460 | }; | |
461 | MODULE_DEVICE_TABLE(acpi, pad_device_ids); | |
462 | ||
dd0261bb MW |
463 | static struct platform_driver acpi_pad_driver = { |
464 | .probe = acpi_pad_probe, | |
465 | .remove_new = acpi_pad_remove, | |
466 | .driver = { | |
d7228c71 | 467 | .dev_groups = acpi_pad_groups, |
dd0261bb MW |
468 | .name = "processor_aggregator", |
469 | .acpi_match_table = pad_device_ids, | |
8e0af514 SL |
470 | }, |
471 | }; | |
472 | ||
473 | static int __init acpi_pad_init(void) | |
474 | { | |
e311404f JG |
475 | /* Xen ACPI PAD is used when running as Xen Dom0. */ |
476 | if (xen_initial_domain()) | |
477 | return -ENODEV; | |
478 | ||
8e0af514 SL |
479 | power_saving_mwait_init(); |
480 | if (power_saving_mwait_eax == 0) | |
481 | return -EINVAL; | |
482 | ||
dd0261bb | 483 | return platform_driver_register(&acpi_pad_driver); |
8e0af514 SL |
484 | } |
485 | ||
486 | static void __exit acpi_pad_exit(void) | |
487 | { | |
dd0261bb | 488 | platform_driver_unregister(&acpi_pad_driver); |
8e0af514 SL |
489 | } |
490 | ||
491 | module_init(acpi_pad_init); | |
492 | module_exit(acpi_pad_exit); | |
493 | MODULE_AUTHOR("Shaohua Li<shaohua.li@intel.com>"); | |
494 | MODULE_DESCRIPTION("ACPI Processor Aggregator Driver"); | |
495 | MODULE_LICENSE("GPL"); |