2 * processor_idle - idle state submodule to the ACPI processor driver
4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6 * Copyright (C) 2004 Dominik Brodowski <linux@brodo.de>
7 * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
8 * - Added processor hotplug support
9 * Copyright (C) 2005 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
10 * - Added support for C3 on SMP
12 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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.
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.
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.
28 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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>
40 #include <linux/sched.h> /* need_resched() */
43 #include <asm/uaccess.h>
45 #include <acpi/acpi_bus.h>
46 #include <acpi/processor.h>
48 #define ACPI_PROCESSOR_COMPONENT 0x01000000
49 #define ACPI_PROCESSOR_CLASS "processor"
50 #define ACPI_PROCESSOR_DRIVER_NAME "ACPI Processor Driver"
51 #define _COMPONENT ACPI_PROCESSOR_COMPONENT
52 ACPI_MODULE_NAME("acpi_processor")
53 #define ACPI_PROCESSOR_FILE_POWER "power"
54 #define US_TO_PM_TIMER_TICKS(t) ((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
55 #define C2_OVERHEAD 4 /* 1us (3.579 ticks per us) */
56 #define C3_OVERHEAD 4 /* 1us (3.579 ticks per us) */
57 static void (*pm_idle_save
) (void) __read_mostly
;
58 module_param(max_cstate
, uint
, 0644);
60 static unsigned int nocst __read_mostly
;
61 module_param(nocst
, uint
, 0000);
64 * bm_history -- bit-mask with a bit per jiffy of bus-master activity
65 * 1000 HZ: 0xFFFFFFFF: 32 jiffies = 32ms
66 * 800 HZ: 0xFFFFFFFF: 32 jiffies = 40ms
67 * 100 HZ: 0x0000000F: 4 jiffies = 40ms
68 * reduce history for more aggressive entry into C3
70 static unsigned int bm_history __read_mostly
=
71 (HZ
>= 800 ? 0xFFFFFFFF : ((1U << (HZ
/ 25)) - 1));
72 module_param(bm_history
, uint
, 0644);
73 /* --------------------------------------------------------------------------
75 -------------------------------------------------------------------------- */
78 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
79 * For now disable this. Probably a bug somewhere else.
81 * To skip this limit, boot/load with a large max_cstate limit.
83 static int set_max_cstate(struct dmi_system_id
*id
)
85 if (max_cstate
> ACPI_PROCESSOR_MAX_POWER
)
88 printk(KERN_NOTICE PREFIX
"%s detected - limiting to C%ld max_cstate."
89 " Override with \"processor.max_cstate=%d\"\n", id
->ident
,
90 (long)id
->driver_data
, ACPI_PROCESSOR_MAX_POWER
+ 1);
92 max_cstate
= (long)id
->driver_data
;
97 /* Actually this shouldn't be __cpuinitdata, would be better to fix the
98 callers to only run once -AK */
99 static struct dmi_system_id __cpuinitdata processor_power_dmi_table
[] = {
100 { set_max_cstate
, "IBM ThinkPad R40e", {
101 DMI_MATCH(DMI_BIOS_VENDOR
,"IBM"),
102 DMI_MATCH(DMI_BIOS_VERSION
,"1SET60WW")}, (void *)1},
103 { set_max_cstate
, "IBM ThinkPad R40e", {
104 DMI_MATCH(DMI_BIOS_VENDOR
,"IBM"),
105 DMI_MATCH(DMI_BIOS_VERSION
,"1SET43WW") }, (void*)1},
106 { set_max_cstate
, "IBM ThinkPad R40e", {
107 DMI_MATCH(DMI_BIOS_VENDOR
,"IBM"),
108 DMI_MATCH(DMI_BIOS_VERSION
,"1SET45WW") }, (void*)1},
109 { set_max_cstate
, "IBM ThinkPad R40e", {
110 DMI_MATCH(DMI_BIOS_VENDOR
,"IBM"),
111 DMI_MATCH(DMI_BIOS_VERSION
,"1SET47WW") }, (void*)1},
112 { set_max_cstate
, "IBM ThinkPad R40e", {
113 DMI_MATCH(DMI_BIOS_VENDOR
,"IBM"),
114 DMI_MATCH(DMI_BIOS_VERSION
,"1SET50WW") }, (void*)1},
115 { set_max_cstate
, "IBM ThinkPad R40e", {
116 DMI_MATCH(DMI_BIOS_VENDOR
,"IBM"),
117 DMI_MATCH(DMI_BIOS_VERSION
,"1SET52WW") }, (void*)1},
118 { set_max_cstate
, "IBM ThinkPad R40e", {
119 DMI_MATCH(DMI_BIOS_VENDOR
,"IBM"),
120 DMI_MATCH(DMI_BIOS_VERSION
,"1SET55WW") }, (void*)1},
121 { set_max_cstate
, "IBM ThinkPad R40e", {
122 DMI_MATCH(DMI_BIOS_VENDOR
,"IBM"),
123 DMI_MATCH(DMI_BIOS_VERSION
,"1SET56WW") }, (void*)1},
124 { set_max_cstate
, "IBM ThinkPad R40e", {
125 DMI_MATCH(DMI_BIOS_VENDOR
,"IBM"),
126 DMI_MATCH(DMI_BIOS_VERSION
,"1SET59WW") }, (void*)1},
127 { set_max_cstate
, "IBM ThinkPad R40e", {
128 DMI_MATCH(DMI_BIOS_VENDOR
,"IBM"),
129 DMI_MATCH(DMI_BIOS_VERSION
,"1SET60WW") }, (void*)1},
130 { set_max_cstate
, "IBM ThinkPad R40e", {
131 DMI_MATCH(DMI_BIOS_VENDOR
,"IBM"),
132 DMI_MATCH(DMI_BIOS_VERSION
,"1SET61WW") }, (void*)1},
133 { set_max_cstate
, "IBM ThinkPad R40e", {
134 DMI_MATCH(DMI_BIOS_VENDOR
,"IBM"),
135 DMI_MATCH(DMI_BIOS_VERSION
,"1SET62WW") }, (void*)1},
136 { set_max_cstate
, "IBM ThinkPad R40e", {
137 DMI_MATCH(DMI_BIOS_VENDOR
,"IBM"),
138 DMI_MATCH(DMI_BIOS_VERSION
,"1SET64WW") }, (void*)1},
139 { set_max_cstate
, "IBM ThinkPad R40e", {
140 DMI_MATCH(DMI_BIOS_VENDOR
,"IBM"),
141 DMI_MATCH(DMI_BIOS_VERSION
,"1SET65WW") }, (void*)1},
142 { set_max_cstate
, "IBM ThinkPad R40e", {
143 DMI_MATCH(DMI_BIOS_VENDOR
,"IBM"),
144 DMI_MATCH(DMI_BIOS_VERSION
,"1SET68WW") }, (void*)1},
145 { set_max_cstate
, "Medion 41700", {
146 DMI_MATCH(DMI_BIOS_VENDOR
,"Phoenix Technologies LTD"),
147 DMI_MATCH(DMI_BIOS_VERSION
,"R01-A1J")}, (void *)1},
148 { set_max_cstate
, "Clevo 5600D", {
149 DMI_MATCH(DMI_BIOS_VENDOR
,"Phoenix Technologies LTD"),
150 DMI_MATCH(DMI_BIOS_VERSION
,"SHE845M0.86C.0013.D.0302131307")},
155 static inline u32
ticks_elapsed(u32 t1
, u32 t2
)
159 else if (!acpi_fadt
.tmr_val_ext
)
160 return (((0x00FFFFFF - t1
) + t2
) & 0x00FFFFFF);
162 return ((0xFFFFFFFF - t1
) + t2
);
166 acpi_processor_power_activate(struct acpi_processor
*pr
,
167 struct acpi_processor_cx
*new)
169 struct acpi_processor_cx
*old
;
174 old
= pr
->power
.state
;
177 old
->promotion
.count
= 0;
178 new->demotion
.count
= 0;
180 /* Cleanup from old state. */
184 /* Disable bus master reload */
185 if (new->type
!= ACPI_STATE_C3
&& pr
->flags
.bm_check
)
186 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD
, 0,
187 ACPI_MTX_DO_NOT_LOCK
);
192 /* Prepare to use new state. */
195 /* Enable bus master reload */
196 if (old
->type
!= ACPI_STATE_C3
&& pr
->flags
.bm_check
)
197 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD
, 1,
198 ACPI_MTX_DO_NOT_LOCK
);
202 pr
->power
.state
= new;
207 static void acpi_safe_halt(void)
209 current_thread_info()->status
&= ~TS_POLLING
;
210 smp_mb__after_clear_bit();
213 current_thread_info()->status
|= TS_POLLING
;
216 static atomic_t c3_cpu_count
;
218 static void acpi_processor_idle(void)
220 struct acpi_processor
*pr
= NULL
;
221 struct acpi_processor_cx
*cx
= NULL
;
222 struct acpi_processor_cx
*next_state
= NULL
;
226 pr
= processors
[smp_processor_id()];
231 * Interrupts must be disabled during bus mastering calculations and
232 * for C2/C3 transitions.
237 * Check whether we truly need to go idle, or should
240 if (unlikely(need_resched())) {
245 cx
= pr
->power
.state
;
257 * Check for bus mastering activity (if required), record, and check
260 if (pr
->flags
.bm_check
) {
262 unsigned long diff
= jiffies
- pr
->power
.bm_check_timestamp
;
268 /* if we didn't get called, assume there was busmaster activity */
271 pr
->power
.bm_activity
|= 0x1;
272 pr
->power
.bm_activity
<<= 1;
275 acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS
,
276 &bm_status
, ACPI_MTX_DO_NOT_LOCK
);
278 pr
->power
.bm_activity
++;
279 acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS
,
280 1, ACPI_MTX_DO_NOT_LOCK
);
283 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
284 * the true state of bus mastering activity; forcing us to
285 * manually check the BMIDEA bit of each IDE channel.
287 else if (errata
.piix4
.bmisx
) {
288 if ((inb_p(errata
.piix4
.bmisx
+ 0x02) & 0x01)
289 || (inb_p(errata
.piix4
.bmisx
+ 0x0A) & 0x01))
290 pr
->power
.bm_activity
++;
293 pr
->power
.bm_check_timestamp
= jiffies
;
296 * Apply bus mastering demotion policy. Automatically demote
297 * to avoid a faulty transition. Note that the processor
298 * won't enter a low-power state during this call (to this
299 * funciton) but should upon the next.
301 * TBD: A better policy might be to fallback to the demotion
302 * state (use it for this quantum only) istead of
303 * demoting -- and rely on duration as our sole demotion
304 * qualification. This may, however, introduce DMA
305 * issues (e.g. floppy DMA transfer overrun/underrun).
307 if (pr
->power
.bm_activity
& cx
->demotion
.threshold
.bm
) {
309 next_state
= cx
->demotion
.state
;
314 #ifdef CONFIG_HOTPLUG_CPU
316 * Check for P_LVL2_UP flag before entering C2 and above on
317 * an SMP system. We do it here instead of doing it at _CST/P_LVL
318 * detection phase, to work cleanly with logical CPU hotplug.
320 if ((cx
->type
!= ACPI_STATE_C1
) && (num_online_cpus() > 1) &&
321 !pr
->flags
.has_cst
&& !acpi_fadt
.plvl2_up
)
322 cx
= &pr
->power
.states
[ACPI_STATE_C1
];
330 * Invoke the current Cx state to put the processor to sleep.
332 if (cx
->type
== ACPI_STATE_C2
|| cx
->type
== ACPI_STATE_C3
) {
333 current_thread_info()->status
&= ~TS_POLLING
;
334 smp_mb__after_clear_bit();
335 if (need_resched()) {
336 current_thread_info()->status
|= TS_POLLING
;
347 * Use the appropriate idle routine, the one that would
348 * be used without acpi C-states.
356 * TBD: Can't get time duration while in C1, as resumes
357 * go to an ISR rather than here. Need to instrument
358 * base interrupt handler.
360 sleep_ticks
= 0xFFFFFFFF;
364 /* Get start time (ticks) */
365 t1
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
368 /* Dummy op - must do something useless after P_LVL2 read */
369 t2
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
370 /* Get end time (ticks) */
371 t2
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
373 #ifdef CONFIG_GENERIC_TIME
374 /* TSC halts in C2, so notify users */
377 /* Re-enable interrupts */
379 current_thread_info()->status
|= TS_POLLING
;
380 /* Compute time (ticks) that we were actually asleep */
382 ticks_elapsed(t1
, t2
) - cx
->latency_ticks
- C2_OVERHEAD
;
387 if (pr
->flags
.bm_check
) {
388 if (atomic_inc_return(&c3_cpu_count
) ==
391 * All CPUs are trying to go to C3
392 * Disable bus master arbitration
394 acpi_set_register(ACPI_BITREG_ARB_DISABLE
, 1,
395 ACPI_MTX_DO_NOT_LOCK
);
398 /* SMP with no shared cache... Invalidate cache */
399 ACPI_FLUSH_CPU_CACHE();
402 /* Get start time (ticks) */
403 t1
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
406 /* Dummy op - must do something useless after P_LVL3 read */
407 t2
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
408 /* Get end time (ticks) */
409 t2
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
410 if (pr
->flags
.bm_check
) {
411 /* Enable bus master arbitration */
412 atomic_dec(&c3_cpu_count
);
413 acpi_set_register(ACPI_BITREG_ARB_DISABLE
, 0,
414 ACPI_MTX_DO_NOT_LOCK
);
417 #ifdef CONFIG_GENERIC_TIME
418 /* TSC halts in C3, so notify users */
421 /* Re-enable interrupts */
423 current_thread_info()->status
|= TS_POLLING
;
424 /* Compute time (ticks) that we were actually asleep */
426 ticks_elapsed(t1
, t2
) - cx
->latency_ticks
- C3_OVERHEAD
;
434 next_state
= pr
->power
.state
;
436 #ifdef CONFIG_HOTPLUG_CPU
437 /* Don't do promotion/demotion */
438 if ((cx
->type
== ACPI_STATE_C1
) && (num_online_cpus() > 1) &&
439 !pr
->flags
.has_cst
&& !acpi_fadt
.plvl2_up
) {
448 * Track the number of longs (time asleep is greater than threshold)
449 * and promote when the count threshold is reached. Note that bus
450 * mastering activity may prevent promotions.
451 * Do not promote above max_cstate.
453 if (cx
->promotion
.state
&&
454 ((cx
->promotion
.state
- pr
->power
.states
) <= max_cstate
)) {
455 if (sleep_ticks
> cx
->promotion
.threshold
.ticks
) {
456 cx
->promotion
.count
++;
457 cx
->demotion
.count
= 0;
458 if (cx
->promotion
.count
>=
459 cx
->promotion
.threshold
.count
) {
460 if (pr
->flags
.bm_check
) {
462 (pr
->power
.bm_activity
& cx
->
463 promotion
.threshold
.bm
)) {
469 next_state
= cx
->promotion
.state
;
479 * Track the number of shorts (time asleep is less than time threshold)
480 * and demote when the usage threshold is reached.
482 if (cx
->demotion
.state
) {
483 if (sleep_ticks
< cx
->demotion
.threshold
.ticks
) {
484 cx
->demotion
.count
++;
485 cx
->promotion
.count
= 0;
486 if (cx
->demotion
.count
>= cx
->demotion
.threshold
.count
) {
487 next_state
= cx
->demotion
.state
;
495 * Demote if current state exceeds max_cstate
497 if ((pr
->power
.state
- pr
->power
.states
) > max_cstate
) {
498 if (cx
->demotion
.state
)
499 next_state
= cx
->demotion
.state
;
505 * If we're going to start using a new Cx state we must clean up
506 * from the previous and prepare to use the new.
508 if (next_state
!= pr
->power
.state
)
509 acpi_processor_power_activate(pr
, next_state
);
512 static int acpi_processor_set_power_policy(struct acpi_processor
*pr
)
515 unsigned int state_is_set
= 0;
516 struct acpi_processor_cx
*lower
= NULL
;
517 struct acpi_processor_cx
*higher
= NULL
;
518 struct acpi_processor_cx
*cx
;
520 ACPI_FUNCTION_TRACE("acpi_processor_set_power_policy");
523 return_VALUE(-EINVAL
);
526 * This function sets the default Cx state policy (OS idle handler).
527 * Our scheme is to promote quickly to C2 but more conservatively
528 * to C3. We're favoring C2 for its characteristics of low latency
529 * (quick response), good power savings, and ability to allow bus
530 * mastering activity. Note that the Cx state policy is completely
531 * customizable and can be altered dynamically.
535 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
; i
++) {
536 cx
= &pr
->power
.states
[i
];
541 pr
->power
.state
= cx
;
547 return_VALUE(-ENODEV
);
550 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
; i
++) {
551 cx
= &pr
->power
.states
[i
];
556 cx
->demotion
.state
= lower
;
557 cx
->demotion
.threshold
.ticks
= cx
->latency_ticks
;
558 cx
->demotion
.threshold
.count
= 1;
559 if (cx
->type
== ACPI_STATE_C3
)
560 cx
->demotion
.threshold
.bm
= bm_history
;
567 for (i
= (ACPI_PROCESSOR_MAX_POWER
- 1); i
> 0; i
--) {
568 cx
= &pr
->power
.states
[i
];
573 cx
->promotion
.state
= higher
;
574 cx
->promotion
.threshold
.ticks
= cx
->latency_ticks
;
575 if (cx
->type
>= ACPI_STATE_C2
)
576 cx
->promotion
.threshold
.count
= 4;
578 cx
->promotion
.threshold
.count
= 10;
579 if (higher
->type
== ACPI_STATE_C3
)
580 cx
->promotion
.threshold
.bm
= bm_history
;
589 static int acpi_processor_get_power_info_fadt(struct acpi_processor
*pr
)
591 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_fadt");
594 return_VALUE(-EINVAL
);
597 return_VALUE(-ENODEV
);
599 /* if info is obtained from pblk/fadt, type equals state */
600 pr
->power
.states
[ACPI_STATE_C2
].type
= ACPI_STATE_C2
;
601 pr
->power
.states
[ACPI_STATE_C3
].type
= ACPI_STATE_C3
;
603 #ifndef CONFIG_HOTPLUG_CPU
605 * Check for P_LVL2_UP flag before entering C2 and above on
608 if ((num_online_cpus() > 1) && !acpi_fadt
.plvl2_up
)
609 return_VALUE(-ENODEV
);
612 /* determine C2 and C3 address from pblk */
613 pr
->power
.states
[ACPI_STATE_C2
].address
= pr
->pblk
+ 4;
614 pr
->power
.states
[ACPI_STATE_C3
].address
= pr
->pblk
+ 5;
616 /* determine latencies from FADT */
617 pr
->power
.states
[ACPI_STATE_C2
].latency
= acpi_fadt
.plvl2_lat
;
618 pr
->power
.states
[ACPI_STATE_C3
].latency
= acpi_fadt
.plvl3_lat
;
620 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
621 "lvl2[0x%08x] lvl3[0x%08x]\n",
622 pr
->power
.states
[ACPI_STATE_C2
].address
,
623 pr
->power
.states
[ACPI_STATE_C3
].address
));
628 static int acpi_processor_get_power_info_default_c1(struct acpi_processor
*pr
)
630 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_default_c1");
632 /* Zero initialize all the C-states info. */
633 memset(pr
->power
.states
, 0, sizeof(pr
->power
.states
));
635 /* set the first C-State to C1 */
636 pr
->power
.states
[ACPI_STATE_C1
].type
= ACPI_STATE_C1
;
638 /* the C0 state only exists as a filler in our array,
639 * and all processors need to support C1 */
640 pr
->power
.states
[ACPI_STATE_C0
].valid
= 1;
641 pr
->power
.states
[ACPI_STATE_C1
].valid
= 1;
646 static int acpi_processor_get_power_info_cst(struct acpi_processor
*pr
)
648 acpi_status status
= 0;
652 struct acpi_buffer buffer
= { ACPI_ALLOCATE_BUFFER
, NULL
};
653 union acpi_object
*cst
;
655 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_cst");
658 return_VALUE(-ENODEV
);
662 /* Zero initialize C2 onwards and prepare for fresh CST lookup */
663 for (i
= 2; i
< ACPI_PROCESSOR_MAX_POWER
; i
++)
664 memset(&(pr
->power
.states
[i
]), 0,
665 sizeof(struct acpi_processor_cx
));
667 status
= acpi_evaluate_object(pr
->handle
, "_CST", NULL
, &buffer
);
668 if (ACPI_FAILURE(status
)) {
669 ACPI_DEBUG_PRINT((ACPI_DB_INFO
, "No _CST, giving up\n"));
670 return_VALUE(-ENODEV
);
673 cst
= (union acpi_object
*)buffer
.pointer
;
675 /* There must be at least 2 elements */
676 if (!cst
|| (cst
->type
!= ACPI_TYPE_PACKAGE
) || cst
->package
.count
< 2) {
677 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
678 "not enough elements in _CST\n"));
683 count
= cst
->package
.elements
[0].integer
.value
;
685 /* Validate number of power states. */
686 if (count
< 1 || count
!= cst
->package
.count
- 1) {
687 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
688 "count given by _CST is not valid\n"));
693 /* Tell driver that at least _CST is supported. */
694 pr
->flags
.has_cst
= 1;
696 for (i
= 1; i
<= count
; i
++) {
697 union acpi_object
*element
;
698 union acpi_object
*obj
;
699 struct acpi_power_register
*reg
;
700 struct acpi_processor_cx cx
;
702 memset(&cx
, 0, sizeof(cx
));
704 element
= (union acpi_object
*)&(cst
->package
.elements
[i
]);
705 if (element
->type
!= ACPI_TYPE_PACKAGE
)
708 if (element
->package
.count
!= 4)
711 obj
= (union acpi_object
*)&(element
->package
.elements
[0]);
713 if (obj
->type
!= ACPI_TYPE_BUFFER
)
716 reg
= (struct acpi_power_register
*)obj
->buffer
.pointer
;
718 if (reg
->space_id
!= ACPI_ADR_SPACE_SYSTEM_IO
&&
719 (reg
->space_id
!= ACPI_ADR_SPACE_FIXED_HARDWARE
))
722 cx
.address
= (reg
->space_id
== ACPI_ADR_SPACE_FIXED_HARDWARE
) ?
725 /* There should be an easy way to extract an integer... */
726 obj
= (union acpi_object
*)&(element
->package
.elements
[1]);
727 if (obj
->type
!= ACPI_TYPE_INTEGER
)
730 cx
.type
= obj
->integer
.value
;
732 if ((cx
.type
!= ACPI_STATE_C1
) &&
733 (reg
->space_id
!= ACPI_ADR_SPACE_SYSTEM_IO
))
736 if ((cx
.type
< ACPI_STATE_C2
) || (cx
.type
> ACPI_STATE_C3
))
739 obj
= (union acpi_object
*)&(element
->package
.elements
[2]);
740 if (obj
->type
!= ACPI_TYPE_INTEGER
)
743 cx
.latency
= obj
->integer
.value
;
745 obj
= (union acpi_object
*)&(element
->package
.elements
[3]);
746 if (obj
->type
!= ACPI_TYPE_INTEGER
)
749 cx
.power
= obj
->integer
.value
;
752 memcpy(&(pr
->power
.states
[current_count
]), &cx
, sizeof(cx
));
755 * We support total ACPI_PROCESSOR_MAX_POWER - 1
756 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
758 if (current_count
>= (ACPI_PROCESSOR_MAX_POWER
- 1)) {
760 "Limiting number of power states to max (%d)\n",
761 ACPI_PROCESSOR_MAX_POWER
);
763 "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
768 ACPI_DEBUG_PRINT((ACPI_DB_INFO
, "Found %d power states\n",
771 /* Validate number of power states discovered */
772 if (current_count
< 2)
776 acpi_os_free(buffer
.pointer
);
778 return_VALUE(status
);
781 static void acpi_processor_power_verify_c2(struct acpi_processor_cx
*cx
)
783 ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c2");
789 * C2 latency must be less than or equal to 100
792 else if (cx
->latency
> ACPI_PROCESSOR_MAX_C2_LATENCY
) {
793 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
794 "latency too large [%d]\n", cx
->latency
));
799 * Otherwise we've met all of our C2 requirements.
800 * Normalize the C2 latency to expidite policy
803 cx
->latency_ticks
= US_TO_PM_TIMER_TICKS(cx
->latency
);
808 static void acpi_processor_power_verify_c3(struct acpi_processor
*pr
,
809 struct acpi_processor_cx
*cx
)
811 static int bm_check_flag
;
813 ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c3");
819 * C3 latency must be less than or equal to 1000
822 else if (cx
->latency
> ACPI_PROCESSOR_MAX_C3_LATENCY
) {
823 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
824 "latency too large [%d]\n", cx
->latency
));
829 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
830 * DMA transfers are used by any ISA device to avoid livelock.
831 * Note that we could disable Type-F DMA (as recommended by
832 * the erratum), but this is known to disrupt certain ISA
833 * devices thus we take the conservative approach.
835 else if (errata
.piix4
.fdma
) {
836 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
837 "C3 not supported on PIIX4 with Type-F DMA\n"));
841 /* All the logic here assumes flags.bm_check is same across all CPUs */
842 if (!bm_check_flag
) {
843 /* Determine whether bm_check is needed based on CPU */
844 acpi_processor_power_init_bm_check(&(pr
->flags
), pr
->id
);
845 bm_check_flag
= pr
->flags
.bm_check
;
847 pr
->flags
.bm_check
= bm_check_flag
;
850 if (pr
->flags
.bm_check
) {
851 /* bus mastering control is necessary */
852 if (!pr
->flags
.bm_control
) {
853 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
854 "C3 support requires bus mastering control\n"));
859 * WBINVD should be set in fadt, for C3 state to be
860 * supported on when bm_check is not required.
862 if (acpi_fadt
.wb_invd
!= 1) {
863 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
864 "Cache invalidation should work properly"
865 " for C3 to be enabled on SMP systems\n"));
868 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD
,
869 0, ACPI_MTX_DO_NOT_LOCK
);
873 * Otherwise we've met all of our C3 requirements.
874 * Normalize the C3 latency to expidite policy. Enable
875 * checking of bus mastering status (bm_check) so we can
876 * use this in our C3 policy
879 cx
->latency_ticks
= US_TO_PM_TIMER_TICKS(cx
->latency
);
884 static int acpi_processor_power_verify(struct acpi_processor
*pr
)
887 unsigned int working
= 0;
889 #ifdef ARCH_APICTIMER_STOPS_ON_C3
890 int timer_broadcast
= 0;
891 cpumask_t mask
= cpumask_of_cpu(pr
->id
);
892 on_each_cpu(switch_ipi_to_APIC_timer
, &mask
, 1, 1);
895 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
; i
++) {
896 struct acpi_processor_cx
*cx
= &pr
->power
.states
[i
];
904 acpi_processor_power_verify_c2(cx
);
905 #ifdef ARCH_APICTIMER_STOPS_ON_C3
906 /* Some AMD systems fake C3 as C2, but still
907 have timer troubles */
909 boot_cpu_data
.x86_vendor
== X86_VENDOR_AMD
)
915 acpi_processor_power_verify_c3(pr
, cx
);
916 #ifdef ARCH_APICTIMER_STOPS_ON_C3
927 #ifdef ARCH_APICTIMER_STOPS_ON_C3
929 on_each_cpu(switch_APIC_timer_to_ipi
, &mask
, 1, 1);
935 static int acpi_processor_get_power_info(struct acpi_processor
*pr
)
940 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info");
942 /* NOTE: the idle thread may not be running while calling
945 /* Adding C1 state */
946 acpi_processor_get_power_info_default_c1(pr
);
947 result
= acpi_processor_get_power_info_cst(pr
);
948 if (result
== -ENODEV
)
949 acpi_processor_get_power_info_fadt(pr
);
951 pr
->power
.count
= acpi_processor_power_verify(pr
);
956 * Now that we know which states are supported, set the default
957 * policy. Note that this policy can be changed dynamically
958 * (e.g. encourage deeper sleeps to conserve battery life when
961 result
= acpi_processor_set_power_policy(pr
);
963 return_VALUE(result
);
966 * if one state of type C2 or C3 is available, mark this
967 * CPU as being "idle manageable"
969 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
; i
++) {
970 if (pr
->power
.states
[i
].valid
) {
972 if (pr
->power
.states
[i
].type
>= ACPI_STATE_C2
)
980 int acpi_processor_cst_has_changed(struct acpi_processor
*pr
)
984 ACPI_FUNCTION_TRACE("acpi_processor_cst_has_changed");
987 return_VALUE(-EINVAL
);
990 return_VALUE(-ENODEV
);
993 if (!pr
->flags
.power_setup_done
)
994 return_VALUE(-ENODEV
);
996 /* Fall back to the default idle loop */
997 pm_idle
= pm_idle_save
;
998 synchronize_sched(); /* Relies on interrupts forcing exit from idle. */
1000 pr
->flags
.power
= 0;
1001 result
= acpi_processor_get_power_info(pr
);
1002 if ((pr
->flags
.power
== 1) && (pr
->flags
.power_setup_done
))
1003 pm_idle
= acpi_processor_idle
;
1005 return_VALUE(result
);
1008 /* proc interface */
1010 static int acpi_processor_power_seq_show(struct seq_file
*seq
, void *offset
)
1012 struct acpi_processor
*pr
= (struct acpi_processor
*)seq
->private;
1015 ACPI_FUNCTION_TRACE("acpi_processor_power_seq_show");
1020 seq_printf(seq
, "active state: C%zd\n"
1022 "bus master activity: %08x\n",
1023 pr
->power
.state
? pr
->power
.state
- pr
->power
.states
: 0,
1024 max_cstate
, (unsigned)pr
->power
.bm_activity
);
1026 seq_puts(seq
, "states:\n");
1028 for (i
= 1; i
<= pr
->power
.count
; i
++) {
1029 seq_printf(seq
, " %cC%d: ",
1030 (&pr
->power
.states
[i
] ==
1031 pr
->power
.state
? '*' : ' '), i
);
1033 if (!pr
->power
.states
[i
].valid
) {
1034 seq_puts(seq
, "<not supported>\n");
1038 switch (pr
->power
.states
[i
].type
) {
1040 seq_printf(seq
, "type[C1] ");
1043 seq_printf(seq
, "type[C2] ");
1046 seq_printf(seq
, "type[C3] ");
1049 seq_printf(seq
, "type[--] ");
1053 if (pr
->power
.states
[i
].promotion
.state
)
1054 seq_printf(seq
, "promotion[C%zd] ",
1055 (pr
->power
.states
[i
].promotion
.state
-
1058 seq_puts(seq
, "promotion[--] ");
1060 if (pr
->power
.states
[i
].demotion
.state
)
1061 seq_printf(seq
, "demotion[C%zd] ",
1062 (pr
->power
.states
[i
].demotion
.state
-
1065 seq_puts(seq
, "demotion[--] ");
1067 seq_printf(seq
, "latency[%03d] usage[%08d]\n",
1068 pr
->power
.states
[i
].latency
,
1069 pr
->power
.states
[i
].usage
);
1076 static int acpi_processor_power_open_fs(struct inode
*inode
, struct file
*file
)
1078 return single_open(file
, acpi_processor_power_seq_show
,
1082 static struct file_operations acpi_processor_power_fops
= {
1083 .open
= acpi_processor_power_open_fs
,
1085 .llseek
= seq_lseek
,
1086 .release
= single_release
,
1089 int acpi_processor_power_init(struct acpi_processor
*pr
,
1090 struct acpi_device
*device
)
1092 acpi_status status
= 0;
1093 static int first_run
;
1094 struct proc_dir_entry
*entry
= NULL
;
1097 ACPI_FUNCTION_TRACE("acpi_processor_power_init");
1100 dmi_check_system(processor_power_dmi_table
);
1101 if (max_cstate
< ACPI_C_STATES_MAX
)
1103 "ACPI: processor limited to max C-state %d\n",
1109 return_VALUE(-EINVAL
);
1111 if (acpi_fadt
.cst_cnt
&& !nocst
) {
1113 acpi_os_write_port(acpi_fadt
.smi_cmd
, acpi_fadt
.cst_cnt
, 8);
1114 if (ACPI_FAILURE(status
)) {
1115 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
1116 "Notifying BIOS of _CST ability failed\n"));
1120 acpi_processor_get_power_info(pr
);
1123 * Install the idle handler if processor power management is supported.
1124 * Note that we use previously set idle handler will be used on
1125 * platforms that only support C1.
1127 if ((pr
->flags
.power
) && (!boot_option_idle_override
)) {
1128 printk(KERN_INFO PREFIX
"CPU%d (power states:", pr
->id
);
1129 for (i
= 1; i
<= pr
->power
.count
; i
++)
1130 if (pr
->power
.states
[i
].valid
)
1131 printk(" C%d[C%d]", i
,
1132 pr
->power
.states
[i
].type
);
1136 pm_idle_save
= pm_idle
;
1137 pm_idle
= acpi_processor_idle
;
1142 entry
= create_proc_entry(ACPI_PROCESSOR_FILE_POWER
,
1143 S_IRUGO
, acpi_device_dir(device
));
1145 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
1146 "Unable to create '%s' fs entry\n",
1147 ACPI_PROCESSOR_FILE_POWER
));
1149 entry
->proc_fops
= &acpi_processor_power_fops
;
1150 entry
->data
= acpi_driver_data(device
);
1151 entry
->owner
= THIS_MODULE
;
1154 pr
->flags
.power_setup_done
= 1;
1159 int acpi_processor_power_exit(struct acpi_processor
*pr
,
1160 struct acpi_device
*device
)
1162 ACPI_FUNCTION_TRACE("acpi_processor_power_exit");
1164 pr
->flags
.power_setup_done
= 0;
1166 if (acpi_device_dir(device
))
1167 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER
,
1168 acpi_device_dir(device
));
1170 /* Unregister the idle handler when processor #0 is removed. */
1172 pm_idle
= pm_idle_save
;
1175 * We are about to unload the current idle thread pm callback
1176 * (pm_idle), Wait for all processors to update cached/local
1177 * copies of pm_idle before proceeding.