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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * processor_idle - idle state submodule to the ACPI processor driver
3 *
4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
Dominik Brodowskic5ab81c2006-06-24 19:37:00 -04006 * Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
8 * - Added processor hotplug support
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -04009 * Copyright (C) 2005 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
10 * - Added support for C3 on SMP
Linus Torvalds1da177e2005-04-16 15:20:36 -070011 *
12 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or (at
17 * your option) any later version.
18 *
19 * This program is distributed in the hope that it will be useful, but
20 * WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 * General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License along
25 * with this program; if not, write to the Free Software Foundation, Inc.,
26 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
27 *
28 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
29 */
30
31#include <linux/kernel.h>
32#include <linux/module.h>
33#include <linux/init.h>
34#include <linux/cpufreq.h>
35#include <linux/proc_fs.h>
36#include <linux/seq_file.h>
37#include <linux/acpi.h>
38#include <linux/dmi.h>
39#include <linux/moduleparam.h>
Tim Schmielau4e57b682005-10-30 15:03:48 -080040#include <linux/sched.h> /* need_resched() */
Arjan van de Ven5c875792006-09-30 23:27:17 -070041#include <linux/latency.h>
Thomas Gleixnere9e2cdb2007-02-16 01:28:04 -080042#include <linux/clockchips.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070043
Thomas Gleixner34349332007-02-16 01:27:54 -080044/*
45 * Include the apic definitions for x86 to have the APIC timer related defines
46 * available also for UP (on SMP it gets magically included via linux/smp.h).
47 * asm/acpi.h is not an option, as it would require more include magic. Also
48 * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
49 */
50#ifdef CONFIG_X86
51#include <asm/apic.h>
52#endif
53
Linus Torvalds1da177e2005-04-16 15:20:36 -070054#include <asm/io.h>
55#include <asm/uaccess.h>
56
57#include <acpi/acpi_bus.h>
58#include <acpi/processor.h>
59
60#define ACPI_PROCESSOR_COMPONENT 0x01000000
61#define ACPI_PROCESSOR_CLASS "processor"
Linus Torvalds1da177e2005-04-16 15:20:36 -070062#define _COMPONENT ACPI_PROCESSOR_COMPONENT
Len Brownf52fd662007-02-12 22:42:12 -050063ACPI_MODULE_NAME("processor_idle");
Linus Torvalds1da177e2005-04-16 15:20:36 -070064#define ACPI_PROCESSOR_FILE_POWER "power"
Linus Torvalds1da177e2005-04-16 15:20:36 -070065#define US_TO_PM_TIMER_TICKS(t) ((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
Ingo Molnar2aa44d02007-08-23 15:18:02 +020066#define PM_TIMER_TICK_NS (1000000000ULL/PM_TIMER_FREQUENCY)
Linus Torvalds1da177e2005-04-16 15:20:36 -070067#define C2_OVERHEAD 4 /* 1us (3.579 ticks per us) */
68#define C3_OVERHEAD 4 /* 1us (3.579 ticks per us) */
Andreas Mohrb6835052006-04-27 05:25:00 -040069static void (*pm_idle_save) (void) __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070070module_param(max_cstate, uint, 0644);
71
Andreas Mohrb6835052006-04-27 05:25:00 -040072static unsigned int nocst __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070073module_param(nocst, uint, 0000);
74
75/*
76 * bm_history -- bit-mask with a bit per jiffy of bus-master activity
77 * 1000 HZ: 0xFFFFFFFF: 32 jiffies = 32ms
78 * 800 HZ: 0xFFFFFFFF: 32 jiffies = 40ms
79 * 100 HZ: 0x0000000F: 4 jiffies = 40ms
80 * reduce history for more aggressive entry into C3
81 */
Andreas Mohrb6835052006-04-27 05:25:00 -040082static unsigned int bm_history __read_mostly =
Len Brown4be44fc2005-08-05 00:44:28 -040083 (HZ >= 800 ? 0xFFFFFFFF : ((1U << (HZ / 25)) - 1));
Linus Torvalds1da177e2005-04-16 15:20:36 -070084module_param(bm_history, uint, 0644);
85/* --------------------------------------------------------------------------
86 Power Management
87 -------------------------------------------------------------------------- */
88
89/*
90 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
91 * For now disable this. Probably a bug somewhere else.
92 *
93 * To skip this limit, boot/load with a large max_cstate limit.
94 */
David Shaohua Li335f16b2005-06-22 18:37:00 -040095static int set_max_cstate(struct dmi_system_id *id)
Linus Torvalds1da177e2005-04-16 15:20:36 -070096{
97 if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
98 return 0;
99
Len Brown3d356002005-08-03 00:22:52 -0400100 printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
Len Brown4be44fc2005-08-05 00:44:28 -0400101 " Override with \"processor.max_cstate=%d\"\n", id->ident,
102 (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103
Len Brown3d356002005-08-03 00:22:52 -0400104 max_cstate = (long)id->driver_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105
106 return 0;
107}
108
Ashok Raj7ded5682006-02-03 21:51:23 +0100109/* Actually this shouldn't be __cpuinitdata, would be better to fix the
110 callers to only run once -AK */
111static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
Thomas Rosner876c1842006-01-06 01:31:00 -0500112 { set_max_cstate, "IBM ThinkPad R40e", {
113 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
Bartlomiej Swierczf8313352006-05-29 07:16:00 -0400114 DMI_MATCH(DMI_BIOS_VERSION,"1SET70WW")}, (void *)1},
115 { set_max_cstate, "IBM ThinkPad R40e", {
116 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
Thomas Rosner876c1842006-01-06 01:31:00 -0500117 DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW")}, (void *)1},
118 { set_max_cstate, "IBM ThinkPad R40e", {
119 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
120 DMI_MATCH(DMI_BIOS_VERSION,"1SET43WW") }, (void*)1},
121 { set_max_cstate, "IBM ThinkPad R40e", {
122 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
123 DMI_MATCH(DMI_BIOS_VERSION,"1SET45WW") }, (void*)1},
124 { set_max_cstate, "IBM ThinkPad R40e", {
125 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
126 DMI_MATCH(DMI_BIOS_VERSION,"1SET47WW") }, (void*)1},
127 { set_max_cstate, "IBM ThinkPad R40e", {
128 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
129 DMI_MATCH(DMI_BIOS_VERSION,"1SET50WW") }, (void*)1},
130 { set_max_cstate, "IBM ThinkPad R40e", {
131 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
132 DMI_MATCH(DMI_BIOS_VERSION,"1SET52WW") }, (void*)1},
133 { set_max_cstate, "IBM ThinkPad R40e", {
134 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
135 DMI_MATCH(DMI_BIOS_VERSION,"1SET55WW") }, (void*)1},
136 { set_max_cstate, "IBM ThinkPad R40e", {
137 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
138 DMI_MATCH(DMI_BIOS_VERSION,"1SET56WW") }, (void*)1},
139 { set_max_cstate, "IBM ThinkPad R40e", {
140 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
141 DMI_MATCH(DMI_BIOS_VERSION,"1SET59WW") }, (void*)1},
142 { set_max_cstate, "IBM ThinkPad R40e", {
143 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
144 DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW") }, (void*)1},
145 { set_max_cstate, "IBM ThinkPad R40e", {
146 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
147 DMI_MATCH(DMI_BIOS_VERSION,"1SET61WW") }, (void*)1},
148 { set_max_cstate, "IBM ThinkPad R40e", {
149 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
150 DMI_MATCH(DMI_BIOS_VERSION,"1SET62WW") }, (void*)1},
151 { set_max_cstate, "IBM ThinkPad R40e", {
152 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
153 DMI_MATCH(DMI_BIOS_VERSION,"1SET64WW") }, (void*)1},
154 { set_max_cstate, "IBM ThinkPad R40e", {
155 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
156 DMI_MATCH(DMI_BIOS_VERSION,"1SET65WW") }, (void*)1},
157 { set_max_cstate, "IBM ThinkPad R40e", {
158 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
159 DMI_MATCH(DMI_BIOS_VERSION,"1SET68WW") }, (void*)1},
160 { set_max_cstate, "Medion 41700", {
161 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
162 DMI_MATCH(DMI_BIOS_VERSION,"R01-A1J")}, (void *)1},
163 { set_max_cstate, "Clevo 5600D", {
164 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
165 DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
Len Brown4be44fc2005-08-05 00:44:28 -0400166 (void *)2},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 {},
168};
169
Len Brown4be44fc2005-08-05 00:44:28 -0400170static inline u32 ticks_elapsed(u32 t1, u32 t2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171{
172 if (t2 >= t1)
173 return (t2 - t1);
Alexey Starikovskiycee324b2007-02-02 19:48:22 +0300174 else if (!(acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
176 else
177 return ((0xFFFFFFFF - t1) + t2);
178}
179
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180static void
Len Brown4be44fc2005-08-05 00:44:28 -0400181acpi_processor_power_activate(struct acpi_processor *pr,
182 struct acpi_processor_cx *new)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183{
Len Brown4be44fc2005-08-05 00:44:28 -0400184 struct acpi_processor_cx *old;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185
186 if (!pr || !new)
187 return;
188
189 old = pr->power.state;
190
191 if (old)
192 old->promotion.count = 0;
Len Brown4be44fc2005-08-05 00:44:28 -0400193 new->demotion.count = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194
195 /* Cleanup from old state. */
196 if (old) {
197 switch (old->type) {
198 case ACPI_STATE_C3:
199 /* Disable bus master reload */
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400200 if (new->type != ACPI_STATE_C3 && pr->flags.bm_check)
Bob Moored8c71b62007-02-02 19:48:21 +0300201 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 break;
203 }
204 }
205
206 /* Prepare to use new state. */
207 switch (new->type) {
208 case ACPI_STATE_C3:
209 /* Enable bus master reload */
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400210 if (old->type != ACPI_STATE_C3 && pr->flags.bm_check)
Bob Moored8c71b62007-02-02 19:48:21 +0300211 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 break;
213 }
214
215 pr->power.state = new;
216
217 return;
218}
219
Nick Piggin64c7c8f2005-11-08 21:39:04 -0800220static void acpi_safe_halt(void)
221{
Andi Kleen495ab9c2006-06-26 13:59:11 +0200222 current_thread_info()->status &= ~TS_POLLING;
Ingo Molnar0888f062006-12-22 01:11:56 -0800223 /*
224 * TS_POLLING-cleared state must be visible before we
225 * test NEED_RESCHED:
226 */
227 smp_mb();
Nick Piggin64c7c8f2005-11-08 21:39:04 -0800228 if (!need_resched())
229 safe_halt();
Andi Kleen495ab9c2006-06-26 13:59:11 +0200230 current_thread_info()->status |= TS_POLLING;
Nick Piggin64c7c8f2005-11-08 21:39:04 -0800231}
232
Len Brown4be44fc2005-08-05 00:44:28 -0400233static atomic_t c3_cpu_count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -0700235/* Common C-state entry for C2, C3, .. */
236static void acpi_cstate_enter(struct acpi_processor_cx *cstate)
237{
238 if (cstate->space_id == ACPI_CSTATE_FFH) {
239 /* Call into architectural FFH based C-state */
240 acpi_processor_ffh_cstate_enter(cstate);
241 } else {
242 int unused;
243 /* IO port based C-state */
244 inb(cstate->address);
245 /* Dummy wait op - must do something useless after P_LVL2 read
246 because chipsets cannot guarantee that STPCLK# signal
247 gets asserted in time to freeze execution properly. */
Alexey Starikovskiycee324b2007-02-02 19:48:22 +0300248 unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -0700249 }
250}
251
Thomas Gleixner169a0ab2007-02-16 01:27:55 -0800252#ifdef ARCH_APICTIMER_STOPS_ON_C3
253
254/*
255 * Some BIOS implementations switch to C3 in the published C2 state.
Linus Torvalds296d93c2007-03-23 08:03:47 -0700256 * This seems to be a common problem on AMD boxen, but other vendors
257 * are affected too. We pick the most conservative approach: we assume
258 * that the local APIC stops in both C2 and C3.
Thomas Gleixner169a0ab2007-02-16 01:27:55 -0800259 */
260static void acpi_timer_check_state(int state, struct acpi_processor *pr,
261 struct acpi_processor_cx *cx)
262{
263 struct acpi_processor_power *pwr = &pr->power;
Thomas Gleixnere585bef2007-03-23 16:08:01 +0100264 u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
Thomas Gleixner169a0ab2007-02-16 01:27:55 -0800265
266 /*
267 * Check, if one of the previous states already marked the lapic
268 * unstable
269 */
270 if (pwr->timer_broadcast_on_state < state)
271 return;
272
Thomas Gleixnere585bef2007-03-23 16:08:01 +0100273 if (cx->type >= type)
Linus Torvalds296d93c2007-03-23 08:03:47 -0700274 pr->power.timer_broadcast_on_state = state;
Thomas Gleixner169a0ab2007-02-16 01:27:55 -0800275}
276
277static void acpi_propagate_timer_broadcast(struct acpi_processor *pr)
278{
Thomas Gleixnere9e2cdb2007-02-16 01:28:04 -0800279#ifdef CONFIG_GENERIC_CLOCKEVENTS
280 unsigned long reason;
281
282 reason = pr->power.timer_broadcast_on_state < INT_MAX ?
283 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
284
285 clockevents_notify(reason, &pr->id);
286#else
Thomas Gleixner169a0ab2007-02-16 01:27:55 -0800287 cpumask_t mask = cpumask_of_cpu(pr->id);
288
Linus Torvalds296d93c2007-03-23 08:03:47 -0700289 if (pr->power.timer_broadcast_on_state < INT_MAX)
Thomas Gleixner169a0ab2007-02-16 01:27:55 -0800290 on_each_cpu(switch_APIC_timer_to_ipi, &mask, 1, 1);
Linus Torvalds296d93c2007-03-23 08:03:47 -0700291 else
Thomas Gleixner169a0ab2007-02-16 01:27:55 -0800292 on_each_cpu(switch_ipi_to_APIC_timer, &mask, 1, 1);
Thomas Gleixnere9e2cdb2007-02-16 01:28:04 -0800293#endif
294}
295
296/* Power(C) State timer broadcast control */
297static void acpi_state_timer_broadcast(struct acpi_processor *pr,
298 struct acpi_processor_cx *cx,
299 int broadcast)
300{
301#ifdef CONFIG_GENERIC_CLOCKEVENTS
302
303 int state = cx - pr->power.states;
304
305 if (state >= pr->power.timer_broadcast_on_state) {
306 unsigned long reason;
307
308 reason = broadcast ? CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
309 CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
310 clockevents_notify(reason, &pr->id);
311 }
312#endif
Thomas Gleixner169a0ab2007-02-16 01:27:55 -0800313}
314
315#else
316
317static void acpi_timer_check_state(int state, struct acpi_processor *pr,
318 struct acpi_processor_cx *cstate) { }
319static void acpi_propagate_timer_broadcast(struct acpi_processor *pr) { }
Thomas Gleixnere9e2cdb2007-02-16 01:28:04 -0800320static void acpi_state_timer_broadcast(struct acpi_processor *pr,
321 struct acpi_processor_cx *cx,
322 int broadcast)
323{
324}
Thomas Gleixner169a0ab2007-02-16 01:27:55 -0800325
326#endif
327
Len Brown4be44fc2005-08-05 00:44:28 -0400328static void acpi_processor_idle(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329{
Len Brown4be44fc2005-08-05 00:44:28 -0400330 struct acpi_processor *pr = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 struct acpi_processor_cx *cx = NULL;
332 struct acpi_processor_cx *next_state = NULL;
Len Brown4be44fc2005-08-05 00:44:28 -0400333 int sleep_ticks = 0;
334 u32 t1, t2 = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 /*
337 * Interrupts must be disabled during bus mastering calculations and
338 * for C2/C3 transitions.
339 */
340 local_irq_disable();
341
Venkatesh Pallipadid5a3d322007-06-15 19:36:00 -0400342 pr = processors[smp_processor_id()];
343 if (!pr) {
344 local_irq_enable();
345 return;
346 }
347
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 /*
349 * Check whether we truly need to go idle, or should
350 * reschedule:
351 */
352 if (unlikely(need_resched())) {
353 local_irq_enable();
354 return;
355 }
356
357 cx = pr->power.state;
Nick Piggin64c7c8f2005-11-08 21:39:04 -0800358 if (!cx) {
359 if (pm_idle_save)
360 pm_idle_save();
361 else
362 acpi_safe_halt();
363 return;
364 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365
366 /*
367 * Check BM Activity
368 * -----------------
369 * Check for bus mastering activity (if required), record, and check
370 * for demotion.
371 */
372 if (pr->flags.bm_check) {
Len Brown4be44fc2005-08-05 00:44:28 -0400373 u32 bm_status = 0;
374 unsigned long diff = jiffies - pr->power.bm_check_timestamp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375
Dominik Brodowskic5ab81c2006-06-24 19:37:00 -0400376 if (diff > 31)
377 diff = 31;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378
Dominik Brodowskic5ab81c2006-06-24 19:37:00 -0400379 pr->power.bm_activity <<= diff;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380
Bob Moored8c71b62007-02-02 19:48:21 +0300381 acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 if (bm_status) {
Dominik Brodowskic5ab81c2006-06-24 19:37:00 -0400383 pr->power.bm_activity |= 0x1;
Bob Moored8c71b62007-02-02 19:48:21 +0300384 acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 }
386 /*
387 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
388 * the true state of bus mastering activity; forcing us to
389 * manually check the BMIDEA bit of each IDE channel.
390 */
391 else if (errata.piix4.bmisx) {
392 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
Len Brown4be44fc2005-08-05 00:44:28 -0400393 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
Dominik Brodowskic5ab81c2006-06-24 19:37:00 -0400394 pr->power.bm_activity |= 0x1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395 }
396
397 pr->power.bm_check_timestamp = jiffies;
398
399 /*
Dominik Brodowskic4a001b2006-06-24 19:37:00 -0400400 * If bus mastering is or was active this jiffy, demote
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401 * to avoid a faulty transition. Note that the processor
402 * won't enter a low-power state during this call (to this
Dominik Brodowskic4a001b2006-06-24 19:37:00 -0400403 * function) but should upon the next.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 *
405 * TBD: A better policy might be to fallback to the demotion
406 * state (use it for this quantum only) istead of
407 * demoting -- and rely on duration as our sole demotion
408 * qualification. This may, however, introduce DMA
409 * issues (e.g. floppy DMA transfer overrun/underrun).
410 */
Dominik Brodowskic4a001b2006-06-24 19:37:00 -0400411 if ((pr->power.bm_activity & 0x1) &&
412 cx->demotion.threshold.bm) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413 local_irq_enable();
414 next_state = cx->demotion.state;
415 goto end;
416 }
417 }
418
Venkatesh Pallipadi4c033552005-09-15 12:20:00 -0400419#ifdef CONFIG_HOTPLUG_CPU
420 /*
421 * Check for P_LVL2_UP flag before entering C2 and above on
422 * an SMP system. We do it here instead of doing it at _CST/P_LVL
423 * detection phase, to work cleanly with logical CPU hotplug.
424 */
425 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
Alexey Starikovskiycee324b2007-02-02 19:48:22 +0300426 !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
David Shaohua Li1e483962005-12-01 17:00:00 -0500427 cx = &pr->power.states[ACPI_STATE_C1];
Venkatesh Pallipadi4c033552005-09-15 12:20:00 -0400428#endif
David Shaohua Li1e483962005-12-01 17:00:00 -0500429
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 /*
431 * Sleep:
432 * ------
433 * Invoke the current Cx state to put the processor to sleep.
434 */
Nick Piggin2a298a32005-12-02 12:44:19 +1100435 if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) {
Andi Kleen495ab9c2006-06-26 13:59:11 +0200436 current_thread_info()->status &= ~TS_POLLING;
Ingo Molnar0888f062006-12-22 01:11:56 -0800437 /*
438 * TS_POLLING-cleared state must be visible before we
439 * test NEED_RESCHED:
440 */
441 smp_mb();
Nick Piggin2a298a32005-12-02 12:44:19 +1100442 if (need_resched()) {
Andi Kleen495ab9c2006-06-26 13:59:11 +0200443 current_thread_info()->status |= TS_POLLING;
Linus Torvaldsaf2eb172005-12-02 23:09:06 -0800444 local_irq_enable();
Nick Piggin2a298a32005-12-02 12:44:19 +1100445 return;
446 }
447 }
448
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 switch (cx->type) {
450
451 case ACPI_STATE_C1:
452 /*
453 * Invoke C1.
454 * Use the appropriate idle routine, the one that would
455 * be used without acpi C-states.
456 */
457 if (pm_idle_save)
458 pm_idle_save();
459 else
Nick Piggin64c7c8f2005-11-08 21:39:04 -0800460 acpi_safe_halt();
461
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 /*
Len Brown4be44fc2005-08-05 00:44:28 -0400463 * TBD: Can't get time duration while in C1, as resumes
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464 * go to an ISR rather than here. Need to instrument
465 * base interrupt handler.
Ingo Molnar2aa44d02007-08-23 15:18:02 +0200466 *
467 * Note: the TSC better not stop in C1, sched_clock() will
468 * skew otherwise.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 */
470 sleep_ticks = 0xFFFFFFFF;
471 break;
472
473 case ACPI_STATE_C2:
474 /* Get start time (ticks) */
Alexey Starikovskiycee324b2007-02-02 19:48:22 +0300475 t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
Ingo Molnar2aa44d02007-08-23 15:18:02 +0200476 /* Tell the scheduler that we are going deep-idle: */
477 sched_clock_idle_sleep_event();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478 /* Invoke C2 */
Thomas Gleixnere9e2cdb2007-02-16 01:28:04 -0800479 acpi_state_timer_broadcast(pr, cx, 1);
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -0700480 acpi_cstate_enter(cx);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 /* Get end time (ticks) */
Alexey Starikovskiycee324b2007-02-02 19:48:22 +0300482 t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
john stultz539eb112006-06-26 00:25:10 -0700483
Tony Luck0aa366f2007-07-20 11:22:30 -0700484#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC)
john stultz539eb112006-06-26 00:25:10 -0700485 /* TSC halts in C2, so notify users */
john stultz5a90cf22007-05-02 19:27:08 +0200486 mark_tsc_unstable("possible TSC halt in C2");
john stultz539eb112006-06-26 00:25:10 -0700487#endif
Ingo Molnar2aa44d02007-08-23 15:18:02 +0200488 /* Compute time (ticks) that we were actually asleep */
489 sleep_ticks = ticks_elapsed(t1, t2);
490
491 /* Tell the scheduler how much we idled: */
492 sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
493
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 /* Re-enable interrupts */
495 local_irq_enable();
Ingo Molnar2aa44d02007-08-23 15:18:02 +0200496 /* Do not account our idle-switching overhead: */
497 sleep_ticks -= cx->latency_ticks + C2_OVERHEAD;
498
Andi Kleen495ab9c2006-06-26 13:59:11 +0200499 current_thread_info()->status |= TS_POLLING;
Thomas Gleixnere9e2cdb2007-02-16 01:28:04 -0800500 acpi_state_timer_broadcast(pr, cx, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 break;
502
503 case ACPI_STATE_C3:
Venkatesh Pallipadi18eab852007-06-15 19:37:00 -0400504 /*
505 * disable bus master
506 * bm_check implies we need ARB_DIS
507 * !bm_check implies we need cache flush
508 * bm_control implies whether we can do ARB_DIS
509 *
510 * That leaves a case where bm_check is set and bm_control is
511 * not set. In that case we cannot do much, we enter C3
512 * without doing anything.
513 */
514 if (pr->flags.bm_check && pr->flags.bm_control) {
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400515 if (atomic_inc_return(&c3_cpu_count) ==
Len Brown4be44fc2005-08-05 00:44:28 -0400516 num_online_cpus()) {
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400517 /*
518 * All CPUs are trying to go to C3
519 * Disable bus master arbitration
520 */
Bob Moored8c71b62007-02-02 19:48:21 +0300521 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1);
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400522 }
Venkatesh Pallipadi18eab852007-06-15 19:37:00 -0400523 } else if (!pr->flags.bm_check) {
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400524 /* SMP with no shared cache... Invalidate cache */
525 ACPI_FLUSH_CPU_CACHE();
526 }
Len Brown4be44fc2005-08-05 00:44:28 -0400527
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528 /* Get start time (ticks) */
Alexey Starikovskiycee324b2007-02-02 19:48:22 +0300529 t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530 /* Invoke C3 */
Thomas Gleixnere9e2cdb2007-02-16 01:28:04 -0800531 acpi_state_timer_broadcast(pr, cx, 1);
Ingo Molnar2aa44d02007-08-23 15:18:02 +0200532 /* Tell the scheduler that we are going deep-idle: */
533 sched_clock_idle_sleep_event();
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -0700534 acpi_cstate_enter(cx);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535 /* Get end time (ticks) */
Alexey Starikovskiycee324b2007-02-02 19:48:22 +0300536 t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
Venkatesh Pallipadi18eab852007-06-15 19:37:00 -0400537 if (pr->flags.bm_check && pr->flags.bm_control) {
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400538 /* Enable bus master arbitration */
539 atomic_dec(&c3_cpu_count);
Bob Moored8c71b62007-02-02 19:48:21 +0300540 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400541 }
542
Tony Luck0aa366f2007-07-20 11:22:30 -0700543#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC)
john stultz539eb112006-06-26 00:25:10 -0700544 /* TSC halts in C3, so notify users */
john stultz5a90cf22007-05-02 19:27:08 +0200545 mark_tsc_unstable("TSC halts in C3");
john stultz539eb112006-06-26 00:25:10 -0700546#endif
Ingo Molnar2aa44d02007-08-23 15:18:02 +0200547 /* Compute time (ticks) that we were actually asleep */
548 sleep_ticks = ticks_elapsed(t1, t2);
549 /* Tell the scheduler how much we idled: */
550 sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
551
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 /* Re-enable interrupts */
553 local_irq_enable();
Ingo Molnar2aa44d02007-08-23 15:18:02 +0200554 /* Do not account our idle-switching overhead: */
555 sleep_ticks -= cx->latency_ticks + C3_OVERHEAD;
556
Andi Kleen495ab9c2006-06-26 13:59:11 +0200557 current_thread_info()->status |= TS_POLLING;
Thomas Gleixnere9e2cdb2007-02-16 01:28:04 -0800558 acpi_state_timer_broadcast(pr, cx, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 break;
560
561 default:
562 local_irq_enable();
563 return;
564 }
Dominik Brodowskia3c65982006-06-24 19:37:00 -0400565 cx->usage++;
566 if ((cx->type != ACPI_STATE_C1) && (sleep_ticks > 0))
567 cx->time += sleep_ticks;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568
569 next_state = pr->power.state;
570
David Shaohua Li1e483962005-12-01 17:00:00 -0500571#ifdef CONFIG_HOTPLUG_CPU
572 /* Don't do promotion/demotion */
573 if ((cx->type == ACPI_STATE_C1) && (num_online_cpus() > 1) &&
Alexey Starikovskiycee324b2007-02-02 19:48:22 +0300574 !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) {
David Shaohua Li1e483962005-12-01 17:00:00 -0500575 next_state = cx;
576 goto end;
577 }
578#endif
579
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580 /*
581 * Promotion?
582 * ----------
583 * Track the number of longs (time asleep is greater than threshold)
584 * and promote when the count threshold is reached. Note that bus
585 * mastering activity may prevent promotions.
586 * Do not promote above max_cstate.
587 */
588 if (cx->promotion.state &&
589 ((cx->promotion.state - pr->power.states) <= max_cstate)) {
Arjan van de Ven5c875792006-09-30 23:27:17 -0700590 if (sleep_ticks > cx->promotion.threshold.ticks &&
591 cx->promotion.state->latency <= system_latency_constraint()) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592 cx->promotion.count++;
Len Brown4be44fc2005-08-05 00:44:28 -0400593 cx->demotion.count = 0;
594 if (cx->promotion.count >=
595 cx->promotion.threshold.count) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596 if (pr->flags.bm_check) {
Len Brown4be44fc2005-08-05 00:44:28 -0400597 if (!
598 (pr->power.bm_activity & cx->
599 promotion.threshold.bm)) {
600 next_state =
601 cx->promotion.state;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 goto end;
603 }
Len Brown4be44fc2005-08-05 00:44:28 -0400604 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605 next_state = cx->promotion.state;
606 goto end;
607 }
608 }
609 }
610 }
611
612 /*
613 * Demotion?
614 * ---------
615 * Track the number of shorts (time asleep is less than time threshold)
616 * and demote when the usage threshold is reached.
617 */
618 if (cx->demotion.state) {
619 if (sleep_ticks < cx->demotion.threshold.ticks) {
620 cx->demotion.count++;
621 cx->promotion.count = 0;
622 if (cx->demotion.count >= cx->demotion.threshold.count) {
623 next_state = cx->demotion.state;
624 goto end;
625 }
626 }
627 }
628
Len Brown4be44fc2005-08-05 00:44:28 -0400629 end:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630 /*
631 * Demote if current state exceeds max_cstate
Arjan van de Ven5c875792006-09-30 23:27:17 -0700632 * or if the latency of the current state is unacceptable
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633 */
Arjan van de Ven5c875792006-09-30 23:27:17 -0700634 if ((pr->power.state - pr->power.states) > max_cstate ||
635 pr->power.state->latency > system_latency_constraint()) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636 if (cx->demotion.state)
637 next_state = cx->demotion.state;
638 }
639
640 /*
641 * New Cx State?
642 * -------------
643 * If we're going to start using a new Cx state we must clean up
644 * from the previous and prepare to use the new.
645 */
646 if (next_state != pr->power.state)
647 acpi_processor_power_activate(pr, next_state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648}
649
Len Brown4be44fc2005-08-05 00:44:28 -0400650static int acpi_processor_set_power_policy(struct acpi_processor *pr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651{
652 unsigned int i;
653 unsigned int state_is_set = 0;
654 struct acpi_processor_cx *lower = NULL;
655 struct acpi_processor_cx *higher = NULL;
656 struct acpi_processor_cx *cx;
657
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658
659 if (!pr)
Patrick Mocheld550d982006-06-27 00:41:40 -0400660 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661
662 /*
663 * This function sets the default Cx state policy (OS idle handler).
664 * Our scheme is to promote quickly to C2 but more conservatively
665 * to C3. We're favoring C2 for its characteristics of low latency
666 * (quick response), good power savings, and ability to allow bus
667 * mastering activity. Note that the Cx state policy is completely
668 * customizable and can be altered dynamically.
669 */
670
671 /* startup state */
Len Brown4be44fc2005-08-05 00:44:28 -0400672 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673 cx = &pr->power.states[i];
674 if (!cx->valid)
675 continue;
676
677 if (!state_is_set)
678 pr->power.state = cx;
679 state_is_set++;
680 break;
Len Brown4be44fc2005-08-05 00:44:28 -0400681 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682
683 if (!state_is_set)
Patrick Mocheld550d982006-06-27 00:41:40 -0400684 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685
686 /* demotion */
Len Brown4be44fc2005-08-05 00:44:28 -0400687 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688 cx = &pr->power.states[i];
689 if (!cx->valid)
690 continue;
691
692 if (lower) {
693 cx->demotion.state = lower;
694 cx->demotion.threshold.ticks = cx->latency_ticks;
695 cx->demotion.threshold.count = 1;
696 if (cx->type == ACPI_STATE_C3)
697 cx->demotion.threshold.bm = bm_history;
698 }
699
700 lower = cx;
701 }
702
703 /* promotion */
704 for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) {
705 cx = &pr->power.states[i];
706 if (!cx->valid)
707 continue;
708
709 if (higher) {
Len Brown4be44fc2005-08-05 00:44:28 -0400710 cx->promotion.state = higher;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711 cx->promotion.threshold.ticks = cx->latency_ticks;
712 if (cx->type >= ACPI_STATE_C2)
713 cx->promotion.threshold.count = 4;
714 else
715 cx->promotion.threshold.count = 10;
716 if (higher->type == ACPI_STATE_C3)
717 cx->promotion.threshold.bm = bm_history;
718 }
719
720 higher = cx;
721 }
722
Patrick Mocheld550d982006-06-27 00:41:40 -0400723 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724}
725
Len Brown4be44fc2005-08-05 00:44:28 -0400726static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728
729 if (!pr)
Patrick Mocheld550d982006-06-27 00:41:40 -0400730 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731
732 if (!pr->pblk)
Patrick Mocheld550d982006-06-27 00:41:40 -0400733 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735 /* if info is obtained from pblk/fadt, type equals state */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
737 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
738
Venkatesh Pallipadi4c033552005-09-15 12:20:00 -0400739#ifndef CONFIG_HOTPLUG_CPU
740 /*
741 * Check for P_LVL2_UP flag before entering C2 and above on
742 * an SMP system.
743 */
Alexey Starikovskiyad71860a2007-02-02 19:48:19 +0300744 if ((num_online_cpus() > 1) &&
Alexey Starikovskiycee324b2007-02-02 19:48:22 +0300745 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
Patrick Mocheld550d982006-06-27 00:41:40 -0400746 return -ENODEV;
Venkatesh Pallipadi4c033552005-09-15 12:20:00 -0400747#endif
748
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 /* determine C2 and C3 address from pblk */
750 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
751 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
752
753 /* determine latencies from FADT */
Alexey Starikovskiycee324b2007-02-02 19:48:22 +0300754 pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.C2latency;
755 pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.C3latency;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756
757 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
758 "lvl2[0x%08x] lvl3[0x%08x]\n",
759 pr->power.states[ACPI_STATE_C2].address,
760 pr->power.states[ACPI_STATE_C3].address));
761
Patrick Mocheld550d982006-06-27 00:41:40 -0400762 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763}
764
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -0700765static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
Venkatesh Pallipadiacf05f42005-03-31 23:23:15 -0500766{
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -0700767 if (!pr->power.states[ACPI_STATE_C1].valid) {
768 /* set the first C-State to C1 */
769 /* all processors need to support C1 */
770 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
771 pr->power.states[ACPI_STATE_C1].valid = 1;
772 }
773 /* the C0 state only exists as a filler in our array */
Venkatesh Pallipadiacf05f42005-03-31 23:23:15 -0500774 pr->power.states[ACPI_STATE_C0].valid = 1;
Patrick Mocheld550d982006-06-27 00:41:40 -0400775 return 0;
Venkatesh Pallipadiacf05f42005-03-31 23:23:15 -0500776}
777
Len Brown4be44fc2005-08-05 00:44:28 -0400778static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779{
Len Brown4be44fc2005-08-05 00:44:28 -0400780 acpi_status status = 0;
781 acpi_integer count;
Janosch Machowinskicf824782005-08-20 08:02:00 -0400782 int current_count;
Len Brown4be44fc2005-08-05 00:44:28 -0400783 int i;
784 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
785 union acpi_object *cst;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788 if (nocst)
Patrick Mocheld550d982006-06-27 00:41:40 -0400789 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -0700791 current_count = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792
793 status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
794 if (ACPI_FAILURE(status)) {
795 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
Patrick Mocheld550d982006-06-27 00:41:40 -0400796 return -ENODEV;
Len Brown4be44fc2005-08-05 00:44:28 -0400797 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798
Jan Engelhardt50dd0962006-10-01 00:28:50 +0200799 cst = buffer.pointer;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800
801 /* There must be at least 2 elements */
802 if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
Len Brown64684632006-06-26 23:41:38 -0400803 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804 status = -EFAULT;
805 goto end;
806 }
807
808 count = cst->package.elements[0].integer.value;
809
810 /* Validate number of power states. */
811 if (count < 1 || count != cst->package.count - 1) {
Len Brown64684632006-06-26 23:41:38 -0400812 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700813 status = -EFAULT;
814 goto end;
815 }
816
Linus Torvalds1da177e2005-04-16 15:20:36 -0700817 /* Tell driver that at least _CST is supported. */
818 pr->flags.has_cst = 1;
819
820 for (i = 1; i <= count; i++) {
821 union acpi_object *element;
822 union acpi_object *obj;
823 struct acpi_power_register *reg;
824 struct acpi_processor_cx cx;
825
826 memset(&cx, 0, sizeof(cx));
827
Jan Engelhardt50dd0962006-10-01 00:28:50 +0200828 element = &(cst->package.elements[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829 if (element->type != ACPI_TYPE_PACKAGE)
830 continue;
831
832 if (element->package.count != 4)
833 continue;
834
Jan Engelhardt50dd0962006-10-01 00:28:50 +0200835 obj = &(element->package.elements[0]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700836
837 if (obj->type != ACPI_TYPE_BUFFER)
838 continue;
839
Len Brown4be44fc2005-08-05 00:44:28 -0400840 reg = (struct acpi_power_register *)obj->buffer.pointer;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841
842 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
Len Brown4be44fc2005-08-05 00:44:28 -0400843 (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844 continue;
845
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846 /* There should be an easy way to extract an integer... */
Jan Engelhardt50dd0962006-10-01 00:28:50 +0200847 obj = &(element->package.elements[1]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848 if (obj->type != ACPI_TYPE_INTEGER)
849 continue;
850
851 cx.type = obj->integer.value;
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -0700852 /*
853 * Some buggy BIOSes won't list C1 in _CST -
854 * Let acpi_processor_get_power_info_default() handle them later
855 */
856 if (i == 1 && cx.type != ACPI_STATE_C1)
857 current_count++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -0700859 cx.address = reg->address;
860 cx.index = current_count + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -0700862 cx.space_id = ACPI_CSTATE_SYSTEMIO;
863 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
864 if (acpi_processor_ffh_cstate_probe
865 (pr->id, &cx, reg) == 0) {
866 cx.space_id = ACPI_CSTATE_FFH;
867 } else if (cx.type != ACPI_STATE_C1) {
868 /*
869 * C1 is a special case where FIXED_HARDWARE
870 * can be handled in non-MWAIT way as well.
871 * In that case, save this _CST entry info.
872 * That is, we retain space_id of SYSTEM_IO for
873 * halt based C1.
874 * Otherwise, ignore this info and continue.
875 */
876 continue;
877 }
878 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879
Jan Engelhardt50dd0962006-10-01 00:28:50 +0200880 obj = &(element->package.elements[2]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881 if (obj->type != ACPI_TYPE_INTEGER)
882 continue;
883
884 cx.latency = obj->integer.value;
885
Jan Engelhardt50dd0962006-10-01 00:28:50 +0200886 obj = &(element->package.elements[3]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887 if (obj->type != ACPI_TYPE_INTEGER)
888 continue;
889
890 cx.power = obj->integer.value;
891
Janosch Machowinskicf824782005-08-20 08:02:00 -0400892 current_count++;
893 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
894
895 /*
896 * We support total ACPI_PROCESSOR_MAX_POWER - 1
897 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
898 */
899 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
900 printk(KERN_WARNING
901 "Limiting number of power states to max (%d)\n",
902 ACPI_PROCESSOR_MAX_POWER);
903 printk(KERN_WARNING
904 "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
905 break;
906 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907 }
908
Len Brown4be44fc2005-08-05 00:44:28 -0400909 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
Janosch Machowinskicf824782005-08-20 08:02:00 -0400910 current_count));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911
912 /* Validate number of power states discovered */
Janosch Machowinskicf824782005-08-20 08:02:00 -0400913 if (current_count < 2)
Venkatesh Pallipadi6d93c642005-09-15 12:19:00 -0400914 status = -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915
Len Brown4be44fc2005-08-05 00:44:28 -0400916 end:
Len Brown02438d82006-06-30 03:19:10 -0400917 kfree(buffer.pointer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918
Patrick Mocheld550d982006-06-27 00:41:40 -0400919 return status;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920}
921
Linus Torvalds1da177e2005-04-16 15:20:36 -0700922static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
923{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924
925 if (!cx->address)
Patrick Mocheld550d982006-06-27 00:41:40 -0400926 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927
928 /*
929 * C2 latency must be less than or equal to 100
930 * microseconds.
931 */
932 else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
933 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
Len Brown4be44fc2005-08-05 00:44:28 -0400934 "latency too large [%d]\n", cx->latency));
Patrick Mocheld550d982006-06-27 00:41:40 -0400935 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700936 }
937
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938 /*
939 * Otherwise we've met all of our C2 requirements.
940 * Normalize the C2 latency to expidite policy
941 */
942 cx->valid = 1;
943 cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
944
Patrick Mocheld550d982006-06-27 00:41:40 -0400945 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946}
947
Len Brown4be44fc2005-08-05 00:44:28 -0400948static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
949 struct acpi_processor_cx *cx)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950{
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400951 static int bm_check_flag;
952
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953
954 if (!cx->address)
Patrick Mocheld550d982006-06-27 00:41:40 -0400955 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956
957 /*
958 * C3 latency must be less than or equal to 1000
959 * microseconds.
960 */
961 else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
962 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
Len Brown4be44fc2005-08-05 00:44:28 -0400963 "latency too large [%d]\n", cx->latency));
Patrick Mocheld550d982006-06-27 00:41:40 -0400964 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965 }
966
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967 /*
968 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
969 * DMA transfers are used by any ISA device to avoid livelock.
970 * Note that we could disable Type-F DMA (as recommended by
971 * the erratum), but this is known to disrupt certain ISA
972 * devices thus we take the conservative approach.
973 */
974 else if (errata.piix4.fdma) {
975 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
Len Brown4be44fc2005-08-05 00:44:28 -0400976 "C3 not supported on PIIX4 with Type-F DMA\n"));
Patrick Mocheld550d982006-06-27 00:41:40 -0400977 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978 }
979
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400980 /* All the logic here assumes flags.bm_check is same across all CPUs */
981 if (!bm_check_flag) {
982 /* Determine whether bm_check is needed based on CPU */
983 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
984 bm_check_flag = pr->flags.bm_check;
985 } else {
986 pr->flags.bm_check = bm_check_flag;
987 }
988
989 if (pr->flags.bm_check) {
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400990 if (!pr->flags.bm_control) {
Venki Pallipadied3110e2007-07-31 12:04:31 -0700991 if (pr->flags.has_cst != 1) {
992 /* bus mastering control is necessary */
993 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
994 "C3 support requires BM control\n"));
995 return;
996 } else {
997 /* Here we enter C3 without bus mastering */
998 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
999 "C3 support without BM control\n"));
1000 }
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -04001001 }
1002 } else {
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -04001003 /*
1004 * WBINVD should be set in fadt, for C3 state to be
1005 * supported on when bm_check is not required.
1006 */
Alexey Starikovskiycee324b2007-02-02 19:48:22 +03001007 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -04001008 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
Len Brown4be44fc2005-08-05 00:44:28 -04001009 "Cache invalidation should work properly"
1010 " for C3 to be enabled on SMP systems\n"));
Patrick Mocheld550d982006-06-27 00:41:40 -04001011 return;
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -04001012 }
Bob Moored8c71b62007-02-02 19:48:21 +03001013 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -04001014 }
1015
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016 /*
1017 * Otherwise we've met all of our C3 requirements.
1018 * Normalize the C3 latency to expidite policy. Enable
1019 * checking of bus mastering status (bm_check) so we can
1020 * use this in our C3 policy
1021 */
1022 cx->valid = 1;
1023 cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001024
Patrick Mocheld550d982006-06-27 00:41:40 -04001025 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001026}
1027
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028static int acpi_processor_power_verify(struct acpi_processor *pr)
1029{
1030 unsigned int i;
1031 unsigned int working = 0;
Venkatesh Pallipadi6eb0a0f2006-01-11 22:44:21 +01001032
Thomas Gleixner169a0ab2007-02-16 01:27:55 -08001033 pr->power.timer_broadcast_on_state = INT_MAX;
Venkatesh Pallipadi6eb0a0f2006-01-11 22:44:21 +01001034
Len Brown4be44fc2005-08-05 00:44:28 -04001035 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001036 struct acpi_processor_cx *cx = &pr->power.states[i];
1037
1038 switch (cx->type) {
1039 case ACPI_STATE_C1:
1040 cx->valid = 1;
1041 break;
1042
1043 case ACPI_STATE_C2:
1044 acpi_processor_power_verify_c2(cx);
Linus Torvalds296d93c2007-03-23 08:03:47 -07001045 if (cx->valid)
Thomas Gleixner169a0ab2007-02-16 01:27:55 -08001046 acpi_timer_check_state(i, pr, cx);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001047 break;
1048
1049 case ACPI_STATE_C3:
1050 acpi_processor_power_verify_c3(pr, cx);
Linus Torvalds296d93c2007-03-23 08:03:47 -07001051 if (cx->valid)
Thomas Gleixner169a0ab2007-02-16 01:27:55 -08001052 acpi_timer_check_state(i, pr, cx);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001053 break;
1054 }
1055
1056 if (cx->valid)
1057 working++;
1058 }
1059
Thomas Gleixner169a0ab2007-02-16 01:27:55 -08001060 acpi_propagate_timer_broadcast(pr);
Andi Kleenbd663342006-03-25 16:31:07 +01001061
Linus Torvalds1da177e2005-04-16 15:20:36 -07001062 return (working);
1063}
1064
Len Brown4be44fc2005-08-05 00:44:28 -04001065static int acpi_processor_get_power_info(struct acpi_processor *pr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001066{
1067 unsigned int i;
1068 int result;
1069
Linus Torvalds1da177e2005-04-16 15:20:36 -07001070
1071 /* NOTE: the idle thread may not be running while calling
1072 * this function */
1073
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -07001074 /* Zero initialize all the C-states info. */
1075 memset(pr->power.states, 0, sizeof(pr->power.states));
1076
Linus Torvalds1da177e2005-04-16 15:20:36 -07001077 result = acpi_processor_get_power_info_cst(pr);
Venkatesh Pallipadi6d93c642005-09-15 12:19:00 -04001078 if (result == -ENODEV)
Darrick J. Wongc5a114f2006-10-19 23:28:28 -07001079 result = acpi_processor_get_power_info_fadt(pr);
Venkatesh Pallipadi6d93c642005-09-15 12:19:00 -04001080
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -07001081 if (result)
1082 return result;
1083
1084 acpi_processor_get_power_info_default(pr);
1085
Janosch Machowinskicf824782005-08-20 08:02:00 -04001086 pr->power.count = acpi_processor_power_verify(pr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001087
1088 /*
1089 * Set Default Policy
1090 * ------------------
1091 * Now that we know which states are supported, set the default
1092 * policy. Note that this policy can be changed dynamically
1093 * (e.g. encourage deeper sleeps to conserve battery life when
1094 * not on AC).
1095 */
1096 result = acpi_processor_set_power_policy(pr);
1097 if (result)
Patrick Mocheld550d982006-06-27 00:41:40 -04001098 return result;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001099
1100 /*
1101 * if one state of type C2 or C3 is available, mark this
1102 * CPU as being "idle manageable"
1103 */
1104 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
Venkatesh Pallipadiacf05f42005-03-31 23:23:15 -05001105 if (pr->power.states[i].valid) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001106 pr->power.count = i;
Linus Torvalds2203d6e2005-11-18 07:29:51 -08001107 if (pr->power.states[i].type >= ACPI_STATE_C2)
1108 pr->flags.power = 1;
Venkatesh Pallipadiacf05f42005-03-31 23:23:15 -05001109 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001110 }
1111
Patrick Mocheld550d982006-06-27 00:41:40 -04001112 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001113}
1114
Len Brown4be44fc2005-08-05 00:44:28 -04001115int acpi_processor_cst_has_changed(struct acpi_processor *pr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001116{
Len Brown4be44fc2005-08-05 00:44:28 -04001117 int result = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001118
Linus Torvalds1da177e2005-04-16 15:20:36 -07001119
1120 if (!pr)
Patrick Mocheld550d982006-06-27 00:41:40 -04001121 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122
Len Brown4be44fc2005-08-05 00:44:28 -04001123 if (nocst) {
Patrick Mocheld550d982006-06-27 00:41:40 -04001124 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001125 }
1126
1127 if (!pr->flags.power_setup_done)
Patrick Mocheld550d982006-06-27 00:41:40 -04001128 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001129
1130 /* Fall back to the default idle loop */
1131 pm_idle = pm_idle_save;
Len Brown4be44fc2005-08-05 00:44:28 -04001132 synchronize_sched(); /* Relies on interrupts forcing exit from idle. */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001133
1134 pr->flags.power = 0;
1135 result = acpi_processor_get_power_info(pr);
1136 if ((pr->flags.power == 1) && (pr->flags.power_setup_done))
1137 pm_idle = acpi_processor_idle;
1138
Patrick Mocheld550d982006-06-27 00:41:40 -04001139 return result;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001140}
1141
1142/* proc interface */
1143
1144static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
1145{
Jan Engelhardt50dd0962006-10-01 00:28:50 +02001146 struct acpi_processor *pr = seq->private;
Len Brown4be44fc2005-08-05 00:44:28 -04001147 unsigned int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001148
Linus Torvalds1da177e2005-04-16 15:20:36 -07001149
1150 if (!pr)
1151 goto end;
1152
1153 seq_printf(seq, "active state: C%zd\n"
Len Brown4be44fc2005-08-05 00:44:28 -04001154 "max_cstate: C%d\n"
Arjan van de Ven5c875792006-09-30 23:27:17 -07001155 "bus master activity: %08x\n"
1156 "maximum allowed latency: %d usec\n",
Len Brown4be44fc2005-08-05 00:44:28 -04001157 pr->power.state ? pr->power.state - pr->power.states : 0,
Arjan van de Ven5c875792006-09-30 23:27:17 -07001158 max_cstate, (unsigned)pr->power.bm_activity,
1159 system_latency_constraint());
Linus Torvalds1da177e2005-04-16 15:20:36 -07001160
1161 seq_puts(seq, "states:\n");
1162
1163 for (i = 1; i <= pr->power.count; i++) {
1164 seq_printf(seq, " %cC%d: ",
Len Brown4be44fc2005-08-05 00:44:28 -04001165 (&pr->power.states[i] ==
1166 pr->power.state ? '*' : ' '), i);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001167
1168 if (!pr->power.states[i].valid) {
1169 seq_puts(seq, "<not supported>\n");
1170 continue;
1171 }
1172
1173 switch (pr->power.states[i].type) {
1174 case ACPI_STATE_C1:
1175 seq_printf(seq, "type[C1] ");
1176 break;
1177 case ACPI_STATE_C2:
1178 seq_printf(seq, "type[C2] ");
1179 break;
1180 case ACPI_STATE_C3:
1181 seq_printf(seq, "type[C3] ");
1182 break;
1183 default:
1184 seq_printf(seq, "type[--] ");
1185 break;
1186 }
1187
1188 if (pr->power.states[i].promotion.state)
1189 seq_printf(seq, "promotion[C%zd] ",
Len Brown4be44fc2005-08-05 00:44:28 -04001190 (pr->power.states[i].promotion.state -
1191 pr->power.states));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001192 else
1193 seq_puts(seq, "promotion[--] ");
1194
1195 if (pr->power.states[i].demotion.state)
1196 seq_printf(seq, "demotion[C%zd] ",
Len Brown4be44fc2005-08-05 00:44:28 -04001197 (pr->power.states[i].demotion.state -
1198 pr->power.states));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001199 else
1200 seq_puts(seq, "demotion[--] ");
1201
Dominik Brodowskia3c65982006-06-24 19:37:00 -04001202 seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n",
Len Brown4be44fc2005-08-05 00:44:28 -04001203 pr->power.states[i].latency,
Dominik Brodowskia3c65982006-06-24 19:37:00 -04001204 pr->power.states[i].usage,
Alexey Starikovskiyb0b7eaa2007-01-25 22:39:44 -05001205 (unsigned long long)pr->power.states[i].time);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001206 }
1207
Len Brown4be44fc2005-08-05 00:44:28 -04001208 end:
Patrick Mocheld550d982006-06-27 00:41:40 -04001209 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001210}
1211
1212static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
1213{
1214 return single_open(file, acpi_processor_power_seq_show,
Len Brown4be44fc2005-08-05 00:44:28 -04001215 PDE(inode)->data);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001216}
1217
Arjan van de Vend7508032006-07-04 13:06:00 -04001218static const struct file_operations acpi_processor_power_fops = {
Len Brown4be44fc2005-08-05 00:44:28 -04001219 .open = acpi_processor_power_open_fs,
1220 .read = seq_read,
1221 .llseek = seq_lseek,
1222 .release = single_release,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001223};
1224
Andrew Morton1fec74a2006-10-17 00:09:58 -07001225#ifdef CONFIG_SMP
Arjan van de Ven5c875792006-09-30 23:27:17 -07001226static void smp_callback(void *v)
1227{
1228 /* we already woke the CPU up, nothing more to do */
1229}
1230
1231/*
1232 * This function gets called when a part of the kernel has a new latency
1233 * requirement. This means we need to get all processors out of their C-state,
1234 * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that
1235 * wakes them all right up.
1236 */
1237static int acpi_processor_latency_notify(struct notifier_block *b,
1238 unsigned long l, void *v)
1239{
1240 smp_call_function(smp_callback, NULL, 0, 1);
1241 return NOTIFY_OK;
1242}
1243
1244static struct notifier_block acpi_processor_latency_notifier = {
1245 .notifier_call = acpi_processor_latency_notify,
1246};
Andrew Morton1fec74a2006-10-17 00:09:58 -07001247#endif
Arjan van de Ven5c875792006-09-30 23:27:17 -07001248
Pierre Ossman7af8b662006-10-10 14:20:31 -07001249int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
Len Brown4be44fc2005-08-05 00:44:28 -04001250 struct acpi_device *device)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001251{
Len Brown4be44fc2005-08-05 00:44:28 -04001252 acpi_status status = 0;
Andreas Mohrb6835052006-04-27 05:25:00 -04001253 static int first_run;
Len Brown4be44fc2005-08-05 00:44:28 -04001254 struct proc_dir_entry *entry = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001255 unsigned int i;
1256
Linus Torvalds1da177e2005-04-16 15:20:36 -07001257
1258 if (!first_run) {
1259 dmi_check_system(processor_power_dmi_table);
1260 if (max_cstate < ACPI_C_STATES_MAX)
Len Brown4be44fc2005-08-05 00:44:28 -04001261 printk(KERN_NOTICE
1262 "ACPI: processor limited to max C-state %d\n",
1263 max_cstate);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001264 first_run++;
Andrew Morton1fec74a2006-10-17 00:09:58 -07001265#ifdef CONFIG_SMP
Arjan van de Ven5c875792006-09-30 23:27:17 -07001266 register_latency_notifier(&acpi_processor_latency_notifier);
Andrew Morton1fec74a2006-10-17 00:09:58 -07001267#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001268 }
1269
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -04001270 if (!pr)
Patrick Mocheld550d982006-06-27 00:41:40 -04001271 return -EINVAL;
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -04001272
Alexey Starikovskiycee324b2007-02-02 19:48:22 +03001273 if (acpi_gbl_FADT.cst_control && !nocst) {
Len Brown4be44fc2005-08-05 00:44:28 -04001274 status =
Alexey Starikovskiycee324b2007-02-02 19:48:22 +03001275 acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001276 if (ACPI_FAILURE(status)) {
Thomas Renningera6fc6722006-06-26 23:58:43 -04001277 ACPI_EXCEPTION((AE_INFO, status,
1278 "Notifying BIOS of _CST ability failed"));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001279 }
1280 }
1281
Linus Torvalds1da177e2005-04-16 15:20:36 -07001282 acpi_processor_get_power_info(pr);
1283
1284 /*
1285 * Install the idle handler if processor power management is supported.
1286 * Note that we use previously set idle handler will be used on
1287 * platforms that only support C1.
1288 */
1289 if ((pr->flags.power) && (!boot_option_idle_override)) {
1290 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1291 for (i = 1; i <= pr->power.count; i++)
1292 if (pr->power.states[i].valid)
Len Brown4be44fc2005-08-05 00:44:28 -04001293 printk(" C%d[C%d]", i,
1294 pr->power.states[i].type);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001295 printk(")\n");
1296
1297 if (pr->id == 0) {
1298 pm_idle_save = pm_idle;
1299 pm_idle = acpi_processor_idle;
1300 }
1301 }
1302
1303 /* 'power' [R] */
1304 entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER,
Len Brown4be44fc2005-08-05 00:44:28 -04001305 S_IRUGO, acpi_device_dir(device));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001306 if (!entry)
Thomas Renningera6fc6722006-06-26 23:58:43 -04001307 return -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001308 else {
1309 entry->proc_fops = &acpi_processor_power_fops;
1310 entry->data = acpi_driver_data(device);
1311 entry->owner = THIS_MODULE;
1312 }
1313
1314 pr->flags.power_setup_done = 1;
1315
Patrick Mocheld550d982006-06-27 00:41:40 -04001316 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001317}
1318
Len Brown4be44fc2005-08-05 00:44:28 -04001319int acpi_processor_power_exit(struct acpi_processor *pr,
1320 struct acpi_device *device)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001321{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001322
1323 pr->flags.power_setup_done = 0;
1324
1325 if (acpi_device_dir(device))
Len Brown4be44fc2005-08-05 00:44:28 -04001326 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1327 acpi_device_dir(device));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001328
1329 /* Unregister the idle handler when processor #0 is removed. */
1330 if (pr->id == 0) {
1331 pm_idle = pm_idle_save;
1332
1333 /*
1334 * We are about to unload the current idle thread pm callback
1335 * (pm_idle), Wait for all processors to update cached/local
1336 * copies of pm_idle before proceeding.
1337 */
1338 cpu_idle_wait();
Andrew Morton1fec74a2006-10-17 00:09:58 -07001339#ifdef CONFIG_SMP
Arjan van de Ven5c875792006-09-30 23:27:17 -07001340 unregister_latency_notifier(&acpi_processor_latency_notifier);
Andrew Morton1fec74a2006-10-17 00:09:58 -07001341#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001342 }
1343
Patrick Mocheld550d982006-06-27 00:41:40 -04001344 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001345}