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>
42 #include <asm/uaccess.h>
44 #include <acpi/acpi_bus.h>
45 #include <acpi/processor.h>
47 #define ACPI_PROCESSOR_COMPONENT 0x01000000
48 #define ACPI_PROCESSOR_CLASS "processor"
49 #define ACPI_PROCESSOR_DRIVER_NAME "ACPI Processor Driver"
50 #define _COMPONENT ACPI_PROCESSOR_COMPONENT
51 ACPI_MODULE_NAME ("acpi_processor")
53 #define ACPI_PROCESSOR_FILE_POWER "power"
55 #define US_TO_PM_TIMER_TICKS(t) ((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
56 #define C2_OVERHEAD 4 /* 1us (3.579 ticks per us) */
57 #define C3_OVERHEAD 4 /* 1us (3.579 ticks per us) */
59 static void (*pm_idle_save
)(void);
60 module_param(max_cstate
, uint
, 0644);
62 static unsigned int nocst
= 0;
63 module_param(nocst
, uint
, 0000);
66 * bm_history -- bit-mask with a bit per jiffy of bus-master activity
67 * 1000 HZ: 0xFFFFFFFF: 32 jiffies = 32ms
68 * 800 HZ: 0xFFFFFFFF: 32 jiffies = 40ms
69 * 100 HZ: 0x0000000F: 4 jiffies = 40ms
70 * reduce history for more aggressive entry into C3
72 static unsigned int bm_history
= (HZ
>= 800 ? 0xFFFFFFFF : ((1U << (HZ
/ 25)) - 1));
73 module_param(bm_history
, uint
, 0644);
74 /* --------------------------------------------------------------------------
76 -------------------------------------------------------------------------- */
79 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
80 * For now disable this. Probably a bug somewhere else.
82 * To skip this limit, boot/load with a large max_cstate limit.
84 static int no_c2c3(struct dmi_system_id
*id
)
86 if (max_cstate
> ACPI_PROCESSOR_MAX_POWER
)
89 printk(KERN_NOTICE PREFIX
"%s detected - C2,C3 disabled."
90 " Override with \"processor.max_cstate=%d\"\n", id
->ident
,
91 ACPI_PROCESSOR_MAX_POWER
+ 1);
101 static struct dmi_system_id __initdata processor_power_dmi_table
[] = {
102 { no_c2c3
, "IBM ThinkPad R40e", {
103 DMI_MATCH(DMI_BIOS_VENDOR
,"IBM"),
104 DMI_MATCH(DMI_BIOS_VERSION
,"1SET60WW") }},
105 { no_c2c3
, "Medion 41700", {
106 DMI_MATCH(DMI_BIOS_VENDOR
,"Phoenix Technologies LTD"),
107 DMI_MATCH(DMI_BIOS_VERSION
,"R01-A1J") }},
119 else if (!acpi_fadt
.tmr_val_ext
)
120 return (((0x00FFFFFF - t1
) + t2
) & 0x00FFFFFF);
122 return ((0xFFFFFFFF - t1
) + t2
);
127 acpi_processor_power_activate (
128 struct acpi_processor
*pr
,
129 struct acpi_processor_cx
*new)
131 struct acpi_processor_cx
*old
;
136 old
= pr
->power
.state
;
139 old
->promotion
.count
= 0;
140 new->demotion
.count
= 0;
142 /* Cleanup from old state. */
146 /* Disable bus master reload */
147 if (new->type
!= ACPI_STATE_C3
&& pr
->flags
.bm_check
)
148 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD
, 0, ACPI_MTX_DO_NOT_LOCK
);
153 /* Prepare to use new state. */
156 /* Enable bus master reload */
157 if (old
->type
!= ACPI_STATE_C3
&& pr
->flags
.bm_check
)
158 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD
, 1, ACPI_MTX_DO_NOT_LOCK
);
162 pr
->power
.state
= new;
168 static atomic_t c3_cpu_count
;
171 static void acpi_processor_idle (void)
173 struct acpi_processor
*pr
= NULL
;
174 struct acpi_processor_cx
*cx
= NULL
;
175 struct acpi_processor_cx
*next_state
= NULL
;
179 pr
= processors
[_smp_processor_id()];
184 * Interrupts must be disabled during bus mastering calculations and
185 * for C2/C3 transitions.
190 * Check whether we truly need to go idle, or should
193 if (unlikely(need_resched())) {
198 cx
= pr
->power
.state
;
205 * Check for bus mastering activity (if required), record, and check
208 if (pr
->flags
.bm_check
) {
210 unsigned long diff
= jiffies
- pr
->power
.bm_check_timestamp
;
216 /* if we didn't get called, assume there was busmaster activity */
219 pr
->power
.bm_activity
|= 0x1;
220 pr
->power
.bm_activity
<<= 1;
223 acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS
,
224 &bm_status
, ACPI_MTX_DO_NOT_LOCK
);
226 pr
->power
.bm_activity
++;
227 acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS
,
228 1, ACPI_MTX_DO_NOT_LOCK
);
231 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
232 * the true state of bus mastering activity; forcing us to
233 * manually check the BMIDEA bit of each IDE channel.
235 else if (errata
.piix4
.bmisx
) {
236 if ((inb_p(errata
.piix4
.bmisx
+ 0x02) & 0x01)
237 || (inb_p(errata
.piix4
.bmisx
+ 0x0A) & 0x01))
238 pr
->power
.bm_activity
++;
241 pr
->power
.bm_check_timestamp
= jiffies
;
244 * Apply bus mastering demotion policy. Automatically demote
245 * to avoid a faulty transition. Note that the processor
246 * won't enter a low-power state during this call (to this
247 * funciton) but should upon the next.
249 * TBD: A better policy might be to fallback to the demotion
250 * state (use it for this quantum only) istead of
251 * demoting -- and rely on duration as our sole demotion
252 * qualification. This may, however, introduce DMA
253 * issues (e.g. floppy DMA transfer overrun/underrun).
255 if (pr
->power
.bm_activity
& cx
->demotion
.threshold
.bm
) {
257 next_state
= cx
->demotion
.state
;
267 * Invoke the current Cx state to put the processor to sleep.
274 * Use the appropriate idle routine, the one that would
275 * be used without acpi C-states.
282 * TBD: Can't get time duration while in C1, as resumes
283 * go to an ISR rather than here. Need to instrument
284 * base interrupt handler.
286 sleep_ticks
= 0xFFFFFFFF;
290 /* Get start time (ticks) */
291 t1
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
294 /* Dummy op - must do something useless after P_LVL2 read */
295 t2
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
296 /* Get end time (ticks) */
297 t2
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
298 /* Re-enable interrupts */
300 /* Compute time (ticks) that we were actually asleep */
301 sleep_ticks
= ticks_elapsed(t1
, t2
) - cx
->latency_ticks
- C2_OVERHEAD
;
306 if (pr
->flags
.bm_check
) {
307 if (atomic_inc_return(&c3_cpu_count
) ==
310 * All CPUs are trying to go to C3
311 * Disable bus master arbitration
313 acpi_set_register(ACPI_BITREG_ARB_DISABLE
, 1,
314 ACPI_MTX_DO_NOT_LOCK
);
317 /* SMP with no shared cache... Invalidate cache */
318 ACPI_FLUSH_CPU_CACHE();
321 /* Get start time (ticks) */
322 t1
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
325 /* Dummy op - must do something useless after P_LVL3 read */
326 t2
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
327 /* Get end time (ticks) */
328 t2
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
329 if (pr
->flags
.bm_check
) {
330 /* Enable bus master arbitration */
331 atomic_dec(&c3_cpu_count
);
332 acpi_set_register(ACPI_BITREG_ARB_DISABLE
, 0, ACPI_MTX_DO_NOT_LOCK
);
335 /* Re-enable interrupts */
337 /* Compute time (ticks) that we were actually asleep */
338 sleep_ticks
= ticks_elapsed(t1
, t2
) - cx
->latency_ticks
- C3_OVERHEAD
;
346 next_state
= pr
->power
.state
;
351 * Track the number of longs (time asleep is greater than threshold)
352 * and promote when the count threshold is reached. Note that bus
353 * mastering activity may prevent promotions.
354 * Do not promote above max_cstate.
356 if (cx
->promotion
.state
&&
357 ((cx
->promotion
.state
- pr
->power
.states
) <= max_cstate
)) {
358 if (sleep_ticks
> cx
->promotion
.threshold
.ticks
) {
359 cx
->promotion
.count
++;
360 cx
->demotion
.count
= 0;
361 if (cx
->promotion
.count
>= cx
->promotion
.threshold
.count
) {
362 if (pr
->flags
.bm_check
) {
363 if (!(pr
->power
.bm_activity
& cx
->promotion
.threshold
.bm
)) {
364 next_state
= cx
->promotion
.state
;
369 next_state
= cx
->promotion
.state
;
379 * Track the number of shorts (time asleep is less than time threshold)
380 * and demote when the usage threshold is reached.
382 if (cx
->demotion
.state
) {
383 if (sleep_ticks
< cx
->demotion
.threshold
.ticks
) {
384 cx
->demotion
.count
++;
385 cx
->promotion
.count
= 0;
386 if (cx
->demotion
.count
>= cx
->demotion
.threshold
.count
) {
387 next_state
= cx
->demotion
.state
;
395 * Demote if current state exceeds max_cstate
397 if ((pr
->power
.state
- pr
->power
.states
) > max_cstate
) {
398 if (cx
->demotion
.state
)
399 next_state
= cx
->demotion
.state
;
405 * If we're going to start using a new Cx state we must clean up
406 * from the previous and prepare to use the new.
408 if (next_state
!= pr
->power
.state
)
409 acpi_processor_power_activate(pr
, next_state
);
414 /* do C1 instead of busy loop */
424 acpi_processor_set_power_policy (
425 struct acpi_processor
*pr
)
428 unsigned int state_is_set
= 0;
429 struct acpi_processor_cx
*lower
= NULL
;
430 struct acpi_processor_cx
*higher
= NULL
;
431 struct acpi_processor_cx
*cx
;
433 ACPI_FUNCTION_TRACE("acpi_processor_set_power_policy");
436 return_VALUE(-EINVAL
);
439 * This function sets the default Cx state policy (OS idle handler).
440 * Our scheme is to promote quickly to C2 but more conservatively
441 * to C3. We're favoring C2 for its characteristics of low latency
442 * (quick response), good power savings, and ability to allow bus
443 * mastering activity. Note that the Cx state policy is completely
444 * customizable and can be altered dynamically.
448 for (i
=1; i
< ACPI_PROCESSOR_MAX_POWER
; i
++) {
449 cx
= &pr
->power
.states
[i
];
454 pr
->power
.state
= cx
;
460 return_VALUE(-ENODEV
);
463 for (i
=1; i
< ACPI_PROCESSOR_MAX_POWER
; i
++) {
464 cx
= &pr
->power
.states
[i
];
469 cx
->demotion
.state
= lower
;
470 cx
->demotion
.threshold
.ticks
= cx
->latency_ticks
;
471 cx
->demotion
.threshold
.count
= 1;
472 if (cx
->type
== ACPI_STATE_C3
)
473 cx
->demotion
.threshold
.bm
= bm_history
;
480 for (i
= (ACPI_PROCESSOR_MAX_POWER
- 1); i
> 0; i
--) {
481 cx
= &pr
->power
.states
[i
];
486 cx
->promotion
.state
= higher
;
487 cx
->promotion
.threshold
.ticks
= cx
->latency_ticks
;
488 if (cx
->type
>= ACPI_STATE_C2
)
489 cx
->promotion
.threshold
.count
= 4;
491 cx
->promotion
.threshold
.count
= 10;
492 if (higher
->type
== ACPI_STATE_C3
)
493 cx
->promotion
.threshold
.bm
= bm_history
;
503 static int acpi_processor_get_power_info_fadt (struct acpi_processor
*pr
)
507 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_fadt");
510 return_VALUE(-EINVAL
);
513 return_VALUE(-ENODEV
);
515 for (i
= 0; i
< ACPI_PROCESSOR_MAX_POWER
; i
++)
516 memset(pr
->power
.states
, 0, sizeof(struct acpi_processor_cx
));
518 /* if info is obtained from pblk/fadt, type equals state */
519 pr
->power
.states
[ACPI_STATE_C1
].type
= ACPI_STATE_C1
;
520 pr
->power
.states
[ACPI_STATE_C2
].type
= ACPI_STATE_C2
;
521 pr
->power
.states
[ACPI_STATE_C3
].type
= ACPI_STATE_C3
;
523 /* the C0 state only exists as a filler in our array,
524 * and all processors need to support C1 */
525 pr
->power
.states
[ACPI_STATE_C0
].valid
= 1;
526 pr
->power
.states
[ACPI_STATE_C1
].valid
= 1;
528 /* determine C2 and C3 address from pblk */
529 pr
->power
.states
[ACPI_STATE_C2
].address
= pr
->pblk
+ 4;
530 pr
->power
.states
[ACPI_STATE_C3
].address
= pr
->pblk
+ 5;
532 /* determine latencies from FADT */
533 pr
->power
.states
[ACPI_STATE_C2
].latency
= acpi_fadt
.plvl2_lat
;
534 pr
->power
.states
[ACPI_STATE_C3
].latency
= acpi_fadt
.plvl3_lat
;
536 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
537 "lvl2[0x%08x] lvl3[0x%08x]\n",
538 pr
->power
.states
[ACPI_STATE_C2
].address
,
539 pr
->power
.states
[ACPI_STATE_C3
].address
));
545 static int acpi_processor_get_power_info_default_c1 (struct acpi_processor
*pr
)
549 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_default_c1");
551 for (i
= 0; i
< ACPI_PROCESSOR_MAX_POWER
; i
++)
552 memset(pr
->power
.states
, 0, sizeof(struct acpi_processor_cx
));
554 /* if info is obtained from pblk/fadt, type equals state */
555 pr
->power
.states
[ACPI_STATE_C1
].type
= ACPI_STATE_C1
;
556 pr
->power
.states
[ACPI_STATE_C2
].type
= ACPI_STATE_C2
;
557 pr
->power
.states
[ACPI_STATE_C3
].type
= ACPI_STATE_C3
;
559 /* the C0 state only exists as a filler in our array,
560 * and all processors need to support C1 */
561 pr
->power
.states
[ACPI_STATE_C0
].valid
= 1;
562 pr
->power
.states
[ACPI_STATE_C1
].valid
= 1;
568 static int acpi_processor_get_power_info_cst (struct acpi_processor
*pr
)
570 acpi_status status
= 0;
573 struct acpi_buffer buffer
= {ACPI_ALLOCATE_BUFFER
, NULL
};
574 union acpi_object
*cst
;
576 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_cst");
579 return_VALUE(-ENODEV
);
582 for (i
= 0; i
< ACPI_PROCESSOR_MAX_POWER
; i
++)
583 memset(pr
->power
.states
, 0, sizeof(struct acpi_processor_cx
));
585 status
= acpi_evaluate_object(pr
->handle
, "_CST", NULL
, &buffer
);
586 if (ACPI_FAILURE(status
)) {
587 ACPI_DEBUG_PRINT((ACPI_DB_INFO
, "No _CST, giving up\n"));
588 return_VALUE(-ENODEV
);
591 cst
= (union acpi_object
*) buffer
.pointer
;
593 /* There must be at least 2 elements */
594 if (!cst
|| (cst
->type
!= ACPI_TYPE_PACKAGE
) || cst
->package
.count
< 2) {
595 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
, "not enough elements in _CST\n"));
600 count
= cst
->package
.elements
[0].integer
.value
;
602 /* Validate number of power states. */
603 if (count
< 1 || count
!= cst
->package
.count
- 1) {
604 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
, "count given by _CST is not valid\n"));
609 /* We support up to ACPI_PROCESSOR_MAX_POWER. */
610 if (count
> ACPI_PROCESSOR_MAX_POWER
) {
611 printk(KERN_WARNING
"Limiting number of power states to max (%d)\n", ACPI_PROCESSOR_MAX_POWER
);
612 printk(KERN_WARNING
"Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
613 count
= ACPI_PROCESSOR_MAX_POWER
;
616 /* Tell driver that at least _CST is supported. */
617 pr
->flags
.has_cst
= 1;
619 for (i
= 1; i
<= count
; i
++) {
620 union acpi_object
*element
;
621 union acpi_object
*obj
;
622 struct acpi_power_register
*reg
;
623 struct acpi_processor_cx cx
;
625 memset(&cx
, 0, sizeof(cx
));
627 element
= (union acpi_object
*) &(cst
->package
.elements
[i
]);
628 if (element
->type
!= ACPI_TYPE_PACKAGE
)
631 if (element
->package
.count
!= 4)
634 obj
= (union acpi_object
*) &(element
->package
.elements
[0]);
636 if (obj
->type
!= ACPI_TYPE_BUFFER
)
639 reg
= (struct acpi_power_register
*) obj
->buffer
.pointer
;
641 if (reg
->space_id
!= ACPI_ADR_SPACE_SYSTEM_IO
&&
642 (reg
->space_id
!= ACPI_ADR_SPACE_FIXED_HARDWARE
))
645 cx
.address
= (reg
->space_id
== ACPI_ADR_SPACE_FIXED_HARDWARE
) ?
648 /* There should be an easy way to extract an integer... */
649 obj
= (union acpi_object
*) &(element
->package
.elements
[1]);
650 if (obj
->type
!= ACPI_TYPE_INTEGER
)
653 cx
.type
= obj
->integer
.value
;
655 if ((cx
.type
!= ACPI_STATE_C1
) &&
656 (reg
->space_id
!= ACPI_ADR_SPACE_SYSTEM_IO
))
659 if ((cx
.type
< ACPI_STATE_C1
) ||
660 (cx
.type
> ACPI_STATE_C3
))
663 obj
= (union acpi_object
*) &(element
->package
.elements
[2]);
664 if (obj
->type
!= ACPI_TYPE_INTEGER
)
667 cx
.latency
= obj
->integer
.value
;
669 obj
= (union acpi_object
*) &(element
->package
.elements
[3]);
670 if (obj
->type
!= ACPI_TYPE_INTEGER
)
673 cx
.power
= obj
->integer
.value
;
676 memcpy(&(pr
->power
.states
[pr
->power
.count
]), &cx
, sizeof(cx
));
679 ACPI_DEBUG_PRINT((ACPI_DB_INFO
, "Found %d power states\n", pr
->power
.count
));
681 /* Validate number of power states discovered */
682 if (pr
->power
.count
< 2)
686 acpi_os_free(buffer
.pointer
);
688 return_VALUE(status
);
692 static void acpi_processor_power_verify_c2(struct acpi_processor_cx
*cx
)
694 ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c2");
700 * C2 latency must be less than or equal to 100
703 else if (cx
->latency
> ACPI_PROCESSOR_MAX_C2_LATENCY
) {
704 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
705 "latency too large [%d]\n",
711 * Otherwise we've met all of our C2 requirements.
712 * Normalize the C2 latency to expidite policy
715 cx
->latency_ticks
= US_TO_PM_TIMER_TICKS(cx
->latency
);
721 static void acpi_processor_power_verify_c3(
722 struct acpi_processor
*pr
,
723 struct acpi_processor_cx
*cx
)
725 static int bm_check_flag
;
727 ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c3");
733 * C3 latency must be less than or equal to 1000
736 else if (cx
->latency
> ACPI_PROCESSOR_MAX_C3_LATENCY
) {
737 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
738 "latency too large [%d]\n",
744 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
745 * DMA transfers are used by any ISA device to avoid livelock.
746 * Note that we could disable Type-F DMA (as recommended by
747 * the erratum), but this is known to disrupt certain ISA
748 * devices thus we take the conservative approach.
750 else if (errata
.piix4
.fdma
) {
751 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
752 "C3 not supported on PIIX4 with Type-F DMA\n"));
756 /* All the logic here assumes flags.bm_check is same across all CPUs */
757 if (!bm_check_flag
) {
758 /* Determine whether bm_check is needed based on CPU */
759 acpi_processor_power_init_bm_check(&(pr
->flags
), pr
->id
);
760 bm_check_flag
= pr
->flags
.bm_check
;
762 pr
->flags
.bm_check
= bm_check_flag
;
765 if (pr
->flags
.bm_check
) {
766 printk("Disabling BM access before entering C3\n");
767 /* bus mastering control is necessary */
768 if (!pr
->flags
.bm_control
) {
769 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
770 "C3 support requires bus mastering control\n"));
774 printk("Invalidating cache before entering C3\n");
776 * WBINVD should be set in fadt, for C3 state to be
777 * supported on when bm_check is not required.
779 if (acpi_fadt
.wb_invd
!= 1) {
780 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
781 "Cache invalidation should work properly"
782 " for C3 to be enabled on SMP systems\n"));
785 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD
,
786 0, ACPI_MTX_DO_NOT_LOCK
);
790 * Otherwise we've met all of our C3 requirements.
791 * Normalize the C3 latency to expidite policy. Enable
792 * checking of bus mastering status (bm_check) so we can
793 * use this in our C3 policy
796 cx
->latency_ticks
= US_TO_PM_TIMER_TICKS(cx
->latency
);
802 static int acpi_processor_power_verify(struct acpi_processor
*pr
)
805 unsigned int working
= 0;
807 for (i
=1; i
< ACPI_PROCESSOR_MAX_POWER
; i
++) {
808 struct acpi_processor_cx
*cx
= &pr
->power
.states
[i
];
816 acpi_processor_power_verify_c2(cx
);
820 acpi_processor_power_verify_c3(pr
, cx
);
831 static int acpi_processor_get_power_info (
832 struct acpi_processor
*pr
)
837 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info");
839 /* NOTE: the idle thread may not be running while calling
842 result
= acpi_processor_get_power_info_cst(pr
);
843 if ((result
) || (acpi_processor_power_verify(pr
) < 2)) {
844 result
= acpi_processor_get_power_info_fadt(pr
);
846 result
= acpi_processor_get_power_info_default_c1(pr
);
852 * Now that we know which states are supported, set the default
853 * policy. Note that this policy can be changed dynamically
854 * (e.g. encourage deeper sleeps to conserve battery life when
857 result
= acpi_processor_set_power_policy(pr
);
859 return_VALUE(result
);
862 * if one state of type C2 or C3 is available, mark this
863 * CPU as being "idle manageable"
865 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
; i
++) {
866 if (pr
->power
.states
[i
].valid
) {
875 int acpi_processor_cst_has_changed (struct acpi_processor
*pr
)
879 ACPI_FUNCTION_TRACE("acpi_processor_cst_has_changed");
882 return_VALUE(-EINVAL
);
885 return_VALUE(-ENODEV
);
888 if (!pr
->flags
.power_setup_done
)
889 return_VALUE(-ENODEV
);
891 /* Fall back to the default idle loop */
892 pm_idle
= pm_idle_save
;
893 synchronize_sched(); /* Relies on interrupts forcing exit from idle. */
896 result
= acpi_processor_get_power_info(pr
);
897 if ((pr
->flags
.power
== 1) && (pr
->flags
.power_setup_done
))
898 pm_idle
= acpi_processor_idle
;
900 return_VALUE(result
);
905 static int acpi_processor_power_seq_show(struct seq_file
*seq
, void *offset
)
907 struct acpi_processor
*pr
= (struct acpi_processor
*)seq
->private;
910 ACPI_FUNCTION_TRACE("acpi_processor_power_seq_show");
915 seq_printf(seq
, "active state: C%zd\n"
917 "bus master activity: %08x\n",
918 pr
->power
.state
? pr
->power
.state
- pr
->power
.states
: 0,
920 (unsigned)pr
->power
.bm_activity
);
922 seq_puts(seq
, "states:\n");
924 for (i
= 1; i
<= pr
->power
.count
; i
++) {
925 seq_printf(seq
, " %cC%d: ",
926 (&pr
->power
.states
[i
] == pr
->power
.state
?'*':' '), i
);
928 if (!pr
->power
.states
[i
].valid
) {
929 seq_puts(seq
, "<not supported>\n");
933 switch (pr
->power
.states
[i
].type
) {
935 seq_printf(seq
, "type[C1] ");
938 seq_printf(seq
, "type[C2] ");
941 seq_printf(seq
, "type[C3] ");
944 seq_printf(seq
, "type[--] ");
948 if (pr
->power
.states
[i
].promotion
.state
)
949 seq_printf(seq
, "promotion[C%zd] ",
950 (pr
->power
.states
[i
].promotion
.state
-
953 seq_puts(seq
, "promotion[--] ");
955 if (pr
->power
.states
[i
].demotion
.state
)
956 seq_printf(seq
, "demotion[C%zd] ",
957 (pr
->power
.states
[i
].demotion
.state
-
960 seq_puts(seq
, "demotion[--] ");
962 seq_printf(seq
, "latency[%03d] usage[%08d]\n",
963 pr
->power
.states
[i
].latency
,
964 pr
->power
.states
[i
].usage
);
971 static int acpi_processor_power_open_fs(struct inode
*inode
, struct file
*file
)
973 return single_open(file
, acpi_processor_power_seq_show
,
977 static struct file_operations acpi_processor_power_fops
= {
978 .open
= acpi_processor_power_open_fs
,
981 .release
= single_release
,
984 int acpi_processor_power_init(struct acpi_processor
*pr
, struct acpi_device
*device
)
986 acpi_status status
= 0;
987 static int first_run
= 0;
988 struct proc_dir_entry
*entry
= NULL
;
991 ACPI_FUNCTION_TRACE("acpi_processor_power_init");
994 dmi_check_system(processor_power_dmi_table
);
995 if (max_cstate
< ACPI_C_STATES_MAX
)
996 printk(KERN_NOTICE
"ACPI: processor limited to max C-state %d\n", max_cstate
);
1001 return_VALUE(-EINVAL
);
1003 if (acpi_fadt
.cst_cnt
&& !nocst
) {
1004 status
= acpi_os_write_port(acpi_fadt
.smi_cmd
, acpi_fadt
.cst_cnt
, 8);
1005 if (ACPI_FAILURE(status
)) {
1006 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
1007 "Notifying BIOS of _CST ability failed\n"));
1011 acpi_processor_power_init_pdc(&(pr
->power
), pr
->id
);
1012 acpi_processor_set_pdc(pr
, pr
->power
.pdc
);
1013 acpi_processor_get_power_info(pr
);
1016 * Install the idle handler if processor power management is supported.
1017 * Note that we use previously set idle handler will be used on
1018 * platforms that only support C1.
1020 if ((pr
->flags
.power
) && (!boot_option_idle_override
)) {
1021 printk(KERN_INFO PREFIX
"CPU%d (power states:", pr
->id
);
1022 for (i
= 1; i
<= pr
->power
.count
; i
++)
1023 if (pr
->power
.states
[i
].valid
)
1024 printk(" C%d[C%d]", i
, pr
->power
.states
[i
].type
);
1028 pm_idle_save
= pm_idle
;
1029 pm_idle
= acpi_processor_idle
;
1034 entry
= create_proc_entry(ACPI_PROCESSOR_FILE_POWER
,
1035 S_IRUGO
, acpi_device_dir(device
));
1037 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
1038 "Unable to create '%s' fs entry\n",
1039 ACPI_PROCESSOR_FILE_POWER
));
1041 entry
->proc_fops
= &acpi_processor_power_fops
;
1042 entry
->data
= acpi_driver_data(device
);
1043 entry
->owner
= THIS_MODULE
;
1046 pr
->flags
.power_setup_done
= 1;
1051 int acpi_processor_power_exit(struct acpi_processor
*pr
, struct acpi_device
*device
)
1053 ACPI_FUNCTION_TRACE("acpi_processor_power_exit");
1055 pr
->flags
.power_setup_done
= 0;
1057 if (acpi_device_dir(device
))
1058 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER
,acpi_device_dir(device
));
1060 /* Unregister the idle handler when processor #0 is removed. */
1062 pm_idle
= pm_idle_save
;
1065 * We are about to unload the current idle thread pm callback
1066 * (pm_idle), Wait for all processors to update cached/local
1067 * copies of pm_idle before proceeding.