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);
58 module_param(max_cstate
, uint
, 0644);
60 static unsigned int nocst
= 0;
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
=
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 static struct dmi_system_id __initdata processor_power_dmi_table
[] = {
98 {set_max_cstate
, "IBM ThinkPad R40e", {
99 DMI_MATCH(DMI_BIOS_VENDOR
,
101 DMI_MATCH(DMI_BIOS_VERSION
,
104 {set_max_cstate
, "Medion 41700", {
105 DMI_MATCH(DMI_BIOS_VENDOR
,
106 "Phoenix Technologies LTD"),
107 DMI_MATCH(DMI_BIOS_VERSION
,
108 "R01-A1J")}, (void *)1},
109 {set_max_cstate
, "Clevo 5600D", {
110 DMI_MATCH(DMI_BIOS_VENDOR
,
111 "Phoenix Technologies LTD"),
112 DMI_MATCH(DMI_BIOS_VERSION
,
113 "SHE845M0.86C.0013.D.0302131307")},
118 static inline u32
ticks_elapsed(u32 t1
, u32 t2
)
122 else if (!acpi_fadt
.tmr_val_ext
)
123 return (((0x00FFFFFF - t1
) + t2
) & 0x00FFFFFF);
125 return ((0xFFFFFFFF - t1
) + t2
);
129 acpi_processor_power_activate(struct acpi_processor
*pr
,
130 struct acpi_processor_cx
*new)
132 struct acpi_processor_cx
*old
;
137 old
= pr
->power
.state
;
140 old
->promotion
.count
= 0;
141 new->demotion
.count
= 0;
143 /* Cleanup from old state. */
147 /* Disable bus master reload */
148 if (new->type
!= ACPI_STATE_C3
&& pr
->flags
.bm_check
)
149 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD
, 0,
150 ACPI_MTX_DO_NOT_LOCK
);
155 /* Prepare to use new state. */
158 /* Enable bus master reload */
159 if (old
->type
!= ACPI_STATE_C3
&& pr
->flags
.bm_check
)
160 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD
, 1,
161 ACPI_MTX_DO_NOT_LOCK
);
165 pr
->power
.state
= new;
170 static atomic_t c3_cpu_count
;
172 static void acpi_processor_idle(void)
174 struct acpi_processor
*pr
= NULL
;
175 struct acpi_processor_cx
*cx
= NULL
;
176 struct acpi_processor_cx
*next_state
= NULL
;
180 pr
= processors
[raw_smp_processor_id()];
185 * Interrupts must be disabled during bus mastering calculations and
186 * for C2/C3 transitions.
191 * Check whether we truly need to go idle, or should
194 if (unlikely(need_resched())) {
199 cx
= pr
->power
.state
;
206 * Check for bus mastering activity (if required), record, and check
209 if (pr
->flags
.bm_check
) {
211 unsigned long diff
= jiffies
- pr
->power
.bm_check_timestamp
;
217 /* if we didn't get called, assume there was busmaster activity */
220 pr
->power
.bm_activity
|= 0x1;
221 pr
->power
.bm_activity
<<= 1;
224 acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS
,
225 &bm_status
, ACPI_MTX_DO_NOT_LOCK
);
227 pr
->power
.bm_activity
++;
228 acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS
,
229 1, ACPI_MTX_DO_NOT_LOCK
);
232 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
233 * the true state of bus mastering activity; forcing us to
234 * manually check the BMIDEA bit of each IDE channel.
236 else if (errata
.piix4
.bmisx
) {
237 if ((inb_p(errata
.piix4
.bmisx
+ 0x02) & 0x01)
238 || (inb_p(errata
.piix4
.bmisx
+ 0x0A) & 0x01))
239 pr
->power
.bm_activity
++;
242 pr
->power
.bm_check_timestamp
= jiffies
;
245 * Apply bus mastering demotion policy. Automatically demote
246 * to avoid a faulty transition. Note that the processor
247 * won't enter a low-power state during this call (to this
248 * funciton) but should upon the next.
250 * TBD: A better policy might be to fallback to the demotion
251 * state (use it for this quantum only) istead of
252 * demoting -- and rely on duration as our sole demotion
253 * qualification. This may, however, introduce DMA
254 * issues (e.g. floppy DMA transfer overrun/underrun).
256 if (pr
->power
.bm_activity
& cx
->demotion
.threshold
.bm
) {
258 next_state
= cx
->demotion
.state
;
268 * Invoke the current Cx state to put the processor to sleep.
275 * Use the appropriate idle routine, the one that would
276 * be used without acpi C-states.
283 * TBD: Can't get time duration while in C1, as resumes
284 * go to an ISR rather than here. Need to instrument
285 * base interrupt handler.
287 sleep_ticks
= 0xFFFFFFFF;
291 /* Get start time (ticks) */
292 t1
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
295 /* Dummy op - must do something useless after P_LVL2 read */
296 t2
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
297 /* Get end time (ticks) */
298 t2
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
299 /* Re-enable interrupts */
301 /* Compute time (ticks) that we were actually asleep */
303 ticks_elapsed(t1
, t2
) - cx
->latency_ticks
- C2_OVERHEAD
;
308 if (pr
->flags
.bm_check
) {
309 if (atomic_inc_return(&c3_cpu_count
) ==
312 * All CPUs are trying to go to C3
313 * Disable bus master arbitration
315 acpi_set_register(ACPI_BITREG_ARB_DISABLE
, 1,
316 ACPI_MTX_DO_NOT_LOCK
);
319 /* SMP with no shared cache... Invalidate cache */
320 ACPI_FLUSH_CPU_CACHE();
323 /* Get start time (ticks) */
324 t1
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
327 /* Dummy op - must do something useless after P_LVL3 read */
328 t2
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
329 /* Get end time (ticks) */
330 t2
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
331 if (pr
->flags
.bm_check
) {
332 /* Enable bus master arbitration */
333 atomic_dec(&c3_cpu_count
);
334 acpi_set_register(ACPI_BITREG_ARB_DISABLE
, 0,
335 ACPI_MTX_DO_NOT_LOCK
);
338 /* Re-enable interrupts */
340 /* Compute time (ticks) that we were actually asleep */
342 ticks_elapsed(t1
, t2
) - cx
->latency_ticks
- C3_OVERHEAD
;
350 next_state
= pr
->power
.state
;
355 * Track the number of longs (time asleep is greater than threshold)
356 * and promote when the count threshold is reached. Note that bus
357 * mastering activity may prevent promotions.
358 * Do not promote above max_cstate.
360 if (cx
->promotion
.state
&&
361 ((cx
->promotion
.state
- pr
->power
.states
) <= max_cstate
)) {
362 if (sleep_ticks
> cx
->promotion
.threshold
.ticks
) {
363 cx
->promotion
.count
++;
364 cx
->demotion
.count
= 0;
365 if (cx
->promotion
.count
>=
366 cx
->promotion
.threshold
.count
) {
367 if (pr
->flags
.bm_check
) {
369 (pr
->power
.bm_activity
& cx
->
370 promotion
.threshold
.bm
)) {
376 next_state
= cx
->promotion
.state
;
386 * Track the number of shorts (time asleep is less than time threshold)
387 * and demote when the usage threshold is reached.
389 if (cx
->demotion
.state
) {
390 if (sleep_ticks
< cx
->demotion
.threshold
.ticks
) {
391 cx
->demotion
.count
++;
392 cx
->promotion
.count
= 0;
393 if (cx
->demotion
.count
>= cx
->demotion
.threshold
.count
) {
394 next_state
= cx
->demotion
.state
;
402 * Demote if current state exceeds max_cstate
404 if ((pr
->power
.state
- pr
->power
.states
) > max_cstate
) {
405 if (cx
->demotion
.state
)
406 next_state
= cx
->demotion
.state
;
412 * If we're going to start using a new Cx state we must clean up
413 * from the previous and prepare to use the new.
415 if (next_state
!= pr
->power
.state
)
416 acpi_processor_power_activate(pr
, next_state
);
421 /* do C1 instead of busy loop */
429 static int acpi_processor_set_power_policy(struct acpi_processor
*pr
)
432 unsigned int state_is_set
= 0;
433 struct acpi_processor_cx
*lower
= NULL
;
434 struct acpi_processor_cx
*higher
= NULL
;
435 struct acpi_processor_cx
*cx
;
437 ACPI_FUNCTION_TRACE("acpi_processor_set_power_policy");
440 return_VALUE(-EINVAL
);
443 * This function sets the default Cx state policy (OS idle handler).
444 * Our scheme is to promote quickly to C2 but more conservatively
445 * to C3. We're favoring C2 for its characteristics of low latency
446 * (quick response), good power savings, and ability to allow bus
447 * mastering activity. Note that the Cx state policy is completely
448 * customizable and can be altered dynamically.
452 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
; i
++) {
453 cx
= &pr
->power
.states
[i
];
458 pr
->power
.state
= cx
;
464 return_VALUE(-ENODEV
);
467 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
; i
++) {
468 cx
= &pr
->power
.states
[i
];
473 cx
->demotion
.state
= lower
;
474 cx
->demotion
.threshold
.ticks
= cx
->latency_ticks
;
475 cx
->demotion
.threshold
.count
= 1;
476 if (cx
->type
== ACPI_STATE_C3
)
477 cx
->demotion
.threshold
.bm
= bm_history
;
484 for (i
= (ACPI_PROCESSOR_MAX_POWER
- 1); i
> 0; i
--) {
485 cx
= &pr
->power
.states
[i
];
490 cx
->promotion
.state
= higher
;
491 cx
->promotion
.threshold
.ticks
= cx
->latency_ticks
;
492 if (cx
->type
>= ACPI_STATE_C2
)
493 cx
->promotion
.threshold
.count
= 4;
495 cx
->promotion
.threshold
.count
= 10;
496 if (higher
->type
== ACPI_STATE_C3
)
497 cx
->promotion
.threshold
.bm
= bm_history
;
506 static int acpi_processor_get_power_info_fadt(struct acpi_processor
*pr
)
510 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_fadt");
513 return_VALUE(-EINVAL
);
516 return_VALUE(-ENODEV
);
518 for (i
= 0; i
< ACPI_PROCESSOR_MAX_POWER
; i
++)
519 memset(pr
->power
.states
, 0, sizeof(struct acpi_processor_cx
));
521 /* if info is obtained from pblk/fadt, type equals state */
522 pr
->power
.states
[ACPI_STATE_C1
].type
= ACPI_STATE_C1
;
523 pr
->power
.states
[ACPI_STATE_C2
].type
= ACPI_STATE_C2
;
524 pr
->power
.states
[ACPI_STATE_C3
].type
= ACPI_STATE_C3
;
526 /* the C0 state only exists as a filler in our array,
527 * and all processors need to support C1 */
528 pr
->power
.states
[ACPI_STATE_C0
].valid
= 1;
529 pr
->power
.states
[ACPI_STATE_C1
].valid
= 1;
531 /* determine C2 and C3 address from pblk */
532 pr
->power
.states
[ACPI_STATE_C2
].address
= pr
->pblk
+ 4;
533 pr
->power
.states
[ACPI_STATE_C3
].address
= pr
->pblk
+ 5;
535 /* determine latencies from FADT */
536 pr
->power
.states
[ACPI_STATE_C2
].latency
= acpi_fadt
.plvl2_lat
;
537 pr
->power
.states
[ACPI_STATE_C3
].latency
= acpi_fadt
.plvl3_lat
;
539 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
540 "lvl2[0x%08x] lvl3[0x%08x]\n",
541 pr
->power
.states
[ACPI_STATE_C2
].address
,
542 pr
->power
.states
[ACPI_STATE_C3
].address
));
547 static int acpi_processor_get_power_info_default_c1(struct acpi_processor
*pr
)
551 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_default_c1");
553 for (i
= 0; i
< ACPI_PROCESSOR_MAX_POWER
; i
++)
554 memset(&(pr
->power
.states
[i
]), 0,
555 sizeof(struct acpi_processor_cx
));
557 /* if info is obtained from pblk/fadt, type equals state */
558 pr
->power
.states
[ACPI_STATE_C1
].type
= ACPI_STATE_C1
;
559 pr
->power
.states
[ACPI_STATE_C2
].type
= ACPI_STATE_C2
;
560 pr
->power
.states
[ACPI_STATE_C3
].type
= ACPI_STATE_C3
;
562 /* the C0 state only exists as a filler in our array,
563 * and all processors need to support C1 */
564 pr
->power
.states
[ACPI_STATE_C0
].valid
= 1;
565 pr
->power
.states
[ACPI_STATE_C1
].valid
= 1;
570 static int acpi_processor_get_power_info_cst(struct acpi_processor
*pr
)
572 acpi_status status
= 0;
575 struct acpi_buffer buffer
= { ACPI_ALLOCATE_BUFFER
, NULL
};
576 union acpi_object
*cst
;
578 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_cst");
581 return_VALUE(-ENODEV
);
584 for (i
= 0; i
< ACPI_PROCESSOR_MAX_POWER
; i
++)
585 memset(&(pr
->power
.states
[i
]), 0,
586 sizeof(struct acpi_processor_cx
));
588 status
= acpi_evaluate_object(pr
->handle
, "_CST", NULL
, &buffer
);
589 if (ACPI_FAILURE(status
)) {
590 ACPI_DEBUG_PRINT((ACPI_DB_INFO
, "No _CST, giving up\n"));
591 return_VALUE(-ENODEV
);
594 cst
= (union acpi_object
*)buffer
.pointer
;
596 /* There must be at least 2 elements */
597 if (!cst
|| (cst
->type
!= ACPI_TYPE_PACKAGE
) || cst
->package
.count
< 2) {
598 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
599 "not enough elements in _CST\n"));
604 count
= cst
->package
.elements
[0].integer
.value
;
606 /* Validate number of power states. */
607 if (count
< 1 || count
!= cst
->package
.count
- 1) {
608 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
609 "count given by _CST is not valid\n"));
614 /* We support up to ACPI_PROCESSOR_MAX_POWER. */
615 if (count
> ACPI_PROCESSOR_MAX_POWER
) {
617 "Limiting number of power states to max (%d)\n",
618 ACPI_PROCESSOR_MAX_POWER
);
620 "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
621 count
= ACPI_PROCESSOR_MAX_POWER
;
624 /* Tell driver that at least _CST is supported. */
625 pr
->flags
.has_cst
= 1;
627 for (i
= 1; i
<= count
; i
++) {
628 union acpi_object
*element
;
629 union acpi_object
*obj
;
630 struct acpi_power_register
*reg
;
631 struct acpi_processor_cx cx
;
633 memset(&cx
, 0, sizeof(cx
));
635 element
= (union acpi_object
*)&(cst
->package
.elements
[i
]);
636 if (element
->type
!= ACPI_TYPE_PACKAGE
)
639 if (element
->package
.count
!= 4)
642 obj
= (union acpi_object
*)&(element
->package
.elements
[0]);
644 if (obj
->type
!= ACPI_TYPE_BUFFER
)
647 reg
= (struct acpi_power_register
*)obj
->buffer
.pointer
;
649 if (reg
->space_id
!= ACPI_ADR_SPACE_SYSTEM_IO
&&
650 (reg
->space_id
!= ACPI_ADR_SPACE_FIXED_HARDWARE
))
653 cx
.address
= (reg
->space_id
== ACPI_ADR_SPACE_FIXED_HARDWARE
) ?
656 /* There should be an easy way to extract an integer... */
657 obj
= (union acpi_object
*)&(element
->package
.elements
[1]);
658 if (obj
->type
!= ACPI_TYPE_INTEGER
)
661 cx
.type
= obj
->integer
.value
;
663 if ((cx
.type
!= ACPI_STATE_C1
) &&
664 (reg
->space_id
!= ACPI_ADR_SPACE_SYSTEM_IO
))
667 if ((cx
.type
< ACPI_STATE_C1
) || (cx
.type
> ACPI_STATE_C3
))
670 obj
= (union acpi_object
*)&(element
->package
.elements
[2]);
671 if (obj
->type
!= ACPI_TYPE_INTEGER
)
674 cx
.latency
= obj
->integer
.value
;
676 obj
= (union acpi_object
*)&(element
->package
.elements
[3]);
677 if (obj
->type
!= ACPI_TYPE_INTEGER
)
680 cx
.power
= obj
->integer
.value
;
683 memcpy(&(pr
->power
.states
[pr
->power
.count
]), &cx
, sizeof(cx
));
686 ACPI_DEBUG_PRINT((ACPI_DB_INFO
, "Found %d power states\n",
689 /* Validate number of power states discovered */
690 if (pr
->power
.count
< 2)
694 acpi_os_free(buffer
.pointer
);
696 return_VALUE(status
);
699 static void acpi_processor_power_verify_c2(struct acpi_processor_cx
*cx
)
701 ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c2");
707 * C2 latency must be less than or equal to 100
710 else if (cx
->latency
> ACPI_PROCESSOR_MAX_C2_LATENCY
) {
711 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
712 "latency too large [%d]\n", cx
->latency
));
717 * Otherwise we've met all of our C2 requirements.
718 * Normalize the C2 latency to expidite policy
721 cx
->latency_ticks
= US_TO_PM_TIMER_TICKS(cx
->latency
);
726 static void acpi_processor_power_verify_c3(struct acpi_processor
*pr
,
727 struct acpi_processor_cx
*cx
)
729 static int bm_check_flag
;
731 ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c3");
737 * C3 latency must be less than or equal to 1000
740 else if (cx
->latency
> ACPI_PROCESSOR_MAX_C3_LATENCY
) {
741 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
742 "latency too large [%d]\n", cx
->latency
));
747 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
748 * DMA transfers are used by any ISA device to avoid livelock.
749 * Note that we could disable Type-F DMA (as recommended by
750 * the erratum), but this is known to disrupt certain ISA
751 * devices thus we take the conservative approach.
753 else if (errata
.piix4
.fdma
) {
754 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
755 "C3 not supported on PIIX4 with Type-F DMA\n"));
759 /* All the logic here assumes flags.bm_check is same across all CPUs */
760 if (!bm_check_flag
) {
761 /* Determine whether bm_check is needed based on CPU */
762 acpi_processor_power_init_bm_check(&(pr
->flags
), pr
->id
);
763 bm_check_flag
= pr
->flags
.bm_check
;
765 pr
->flags
.bm_check
= bm_check_flag
;
768 if (pr
->flags
.bm_check
) {
769 /* bus mastering control is necessary */
770 if (!pr
->flags
.bm_control
) {
771 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
772 "C3 support requires bus mastering control\n"));
777 * WBINVD should be set in fadt, for C3 state to be
778 * supported on when bm_check is not required.
780 if (acpi_fadt
.wb_invd
!= 1) {
781 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
782 "Cache invalidation should work properly"
783 " for C3 to be enabled on SMP systems\n"));
786 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD
,
787 0, ACPI_MTX_DO_NOT_LOCK
);
791 * Otherwise we've met all of our C3 requirements.
792 * Normalize the C3 latency to expidite policy. Enable
793 * checking of bus mastering status (bm_check) so we can
794 * use this in our C3 policy
797 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(struct acpi_processor
*pr
)
836 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info");
838 /* NOTE: the idle thread may not be running while calling
841 result
= acpi_processor_get_power_info_cst(pr
);
842 if ((result
) || (acpi_processor_power_verify(pr
) < 2)) {
843 result
= acpi_processor_get_power_info_fadt(pr
);
844 if ((result
) || (acpi_processor_power_verify(pr
) < 2))
845 result
= acpi_processor_get_power_info_default_c1(pr
);
851 * Now that we know which states are supported, set the default
852 * policy. Note that this policy can be changed dynamically
853 * (e.g. encourage deeper sleeps to conserve battery life when
856 result
= acpi_processor_set_power_policy(pr
);
858 return_VALUE(result
);
861 * if one state of type C2 or C3 is available, mark this
862 * CPU as being "idle manageable"
864 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
; i
++) {
865 if (pr
->power
.states
[i
].valid
) {
874 int acpi_processor_cst_has_changed(struct acpi_processor
*pr
)
878 ACPI_FUNCTION_TRACE("acpi_processor_cst_has_changed");
881 return_VALUE(-EINVAL
);
884 return_VALUE(-ENODEV
);
887 if (!pr
->flags
.power_setup_done
)
888 return_VALUE(-ENODEV
);
890 /* Fall back to the default idle loop */
891 pm_idle
= pm_idle_save
;
892 synchronize_sched(); /* Relies on interrupts forcing exit from idle. */
895 result
= acpi_processor_get_power_info(pr
);
896 if ((pr
->flags
.power
== 1) && (pr
->flags
.power_setup_done
))
897 pm_idle
= acpi_processor_idle
;
899 return_VALUE(result
);
904 static int acpi_processor_power_seq_show(struct seq_file
*seq
, void *offset
)
906 struct acpi_processor
*pr
= (struct acpi_processor
*)seq
->private;
909 ACPI_FUNCTION_TRACE("acpi_processor_power_seq_show");
914 seq_printf(seq
, "active state: C%zd\n"
916 "bus master activity: %08x\n",
917 pr
->power
.state
? pr
->power
.state
- pr
->power
.states
: 0,
918 max_cstate
, (unsigned)pr
->power
.bm_activity
);
920 seq_puts(seq
, "states:\n");
922 for (i
= 1; i
<= pr
->power
.count
; i
++) {
923 seq_printf(seq
, " %cC%d: ",
924 (&pr
->power
.states
[i
] ==
925 pr
->power
.state
? '*' : ' '), i
);
927 if (!pr
->power
.states
[i
].valid
) {
928 seq_puts(seq
, "<not supported>\n");
932 switch (pr
->power
.states
[i
].type
) {
934 seq_printf(seq
, "type[C1] ");
937 seq_printf(seq
, "type[C2] ");
940 seq_printf(seq
, "type[C3] ");
943 seq_printf(seq
, "type[--] ");
947 if (pr
->power
.states
[i
].promotion
.state
)
948 seq_printf(seq
, "promotion[C%zd] ",
949 (pr
->power
.states
[i
].promotion
.state
-
952 seq_puts(seq
, "promotion[--] ");
954 if (pr
->power
.states
[i
].demotion
.state
)
955 seq_printf(seq
, "demotion[C%zd] ",
956 (pr
->power
.states
[i
].demotion
.state
-
959 seq_puts(seq
, "demotion[--] ");
961 seq_printf(seq
, "latency[%03d] usage[%08d]\n",
962 pr
->power
.states
[i
].latency
,
963 pr
->power
.states
[i
].usage
);
970 static int acpi_processor_power_open_fs(struct inode
*inode
, struct file
*file
)
972 return single_open(file
, acpi_processor_power_seq_show
,
976 static struct file_operations acpi_processor_power_fops
= {
977 .open
= acpi_processor_power_open_fs
,
980 .release
= single_release
,
983 int acpi_processor_power_init(struct acpi_processor
*pr
,
984 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
)
997 "ACPI: processor limited to max C-state %d\n",
1003 return_VALUE(-EINVAL
);
1005 if (acpi_fadt
.cst_cnt
&& !nocst
) {
1007 acpi_os_write_port(acpi_fadt
.smi_cmd
, acpi_fadt
.cst_cnt
, 8);
1008 if (ACPI_FAILURE(status
)) {
1009 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
1010 "Notifying BIOS of _CST ability failed\n"));
1014 acpi_processor_power_init_pdc(&(pr
->power
), pr
->id
);
1015 acpi_processor_set_pdc(pr
, pr
->power
.pdc
);
1016 acpi_processor_get_power_info(pr
);
1019 * Install the idle handler if processor power management is supported.
1020 * Note that we use previously set idle handler will be used on
1021 * platforms that only support C1.
1023 if ((pr
->flags
.power
) && (!boot_option_idle_override
)) {
1024 printk(KERN_INFO PREFIX
"CPU%d (power states:", pr
->id
);
1025 for (i
= 1; i
<= pr
->power
.count
; i
++)
1026 if (pr
->power
.states
[i
].valid
)
1027 printk(" C%d[C%d]", i
,
1028 pr
->power
.states
[i
].type
);
1032 pm_idle_save
= pm_idle
;
1033 pm_idle
= acpi_processor_idle
;
1038 entry
= create_proc_entry(ACPI_PROCESSOR_FILE_POWER
,
1039 S_IRUGO
, acpi_device_dir(device
));
1041 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
1042 "Unable to create '%s' fs entry\n",
1043 ACPI_PROCESSOR_FILE_POWER
));
1045 entry
->proc_fops
= &acpi_processor_power_fops
;
1046 entry
->data
= acpi_driver_data(device
);
1047 entry
->owner
= THIS_MODULE
;
1050 pr
->flags
.power_setup_done
= 1;
1055 int acpi_processor_power_exit(struct acpi_processor
*pr
,
1056 struct acpi_device
*device
)
1058 ACPI_FUNCTION_TRACE("acpi_processor_power_exit");
1060 pr
->flags
.power_setup_done
= 0;
1062 if (acpi_device_dir(device
))
1063 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER
,
1064 acpi_device_dir(device
));
1066 /* Unregister the idle handler when processor #0 is removed. */
1068 pm_idle
= pm_idle_save
;
1071 * We are about to unload the current idle thread pm callback
1072 * (pm_idle), Wait for all processors to update cached/local
1073 * copies of pm_idle before proceeding.