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")
52 #define ACPI_PROCESSOR_FILE_POWER "power"
53 #define US_TO_PM_TIMER_TICKS(t) ((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
54 #define C2_OVERHEAD 4 /* 1us (3.579 ticks per us) */
55 #define C3_OVERHEAD 4 /* 1us (3.579 ticks per us) */
56 static void (*pm_idle_save
) (void);
57 module_param(max_cstate
, uint
, 0644);
59 static unsigned int nocst
= 0;
60 module_param(nocst
, uint
, 0000);
63 * bm_history -- bit-mask with a bit per jiffy of bus-master activity
64 * 1000 HZ: 0xFFFFFFFF: 32 jiffies = 32ms
65 * 800 HZ: 0xFFFFFFFF: 32 jiffies = 40ms
66 * 100 HZ: 0x0000000F: 4 jiffies = 40ms
67 * reduce history for more aggressive entry into C3
69 static unsigned int bm_history
=
70 (HZ
>= 800 ? 0xFFFFFFFF : ((1U << (HZ
/ 25)) - 1));
71 module_param(bm_history
, uint
, 0644);
72 /* --------------------------------------------------------------------------
74 -------------------------------------------------------------------------- */
77 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
78 * For now disable this. Probably a bug somewhere else.
80 * To skip this limit, boot/load with a large max_cstate limit.
82 static int set_max_cstate(struct dmi_system_id
*id
)
84 if (max_cstate
> ACPI_PROCESSOR_MAX_POWER
)
87 printk(KERN_NOTICE PREFIX
"%s detected - limiting to C%ld max_cstate."
88 " Override with \"processor.max_cstate=%d\"\n", id
->ident
,
89 (long)id
->driver_data
, ACPI_PROCESSOR_MAX_POWER
+ 1);
91 max_cstate
= (long)id
->driver_data
;
96 static struct dmi_system_id __initdata processor_power_dmi_table
[] = {
97 {set_max_cstate
, "IBM ThinkPad R40e", {
98 DMI_MATCH(DMI_BIOS_VENDOR
,
100 DMI_MATCH(DMI_BIOS_VERSION
,
103 {set_max_cstate
, "Medion 41700", {
104 DMI_MATCH(DMI_BIOS_VENDOR
,
105 "Phoenix Technologies LTD"),
106 DMI_MATCH(DMI_BIOS_VERSION
,
107 "R01-A1J")}, (void *)1},
108 {set_max_cstate
, "Clevo 5600D", {
109 DMI_MATCH(DMI_BIOS_VENDOR
,
110 "Phoenix Technologies LTD"),
111 DMI_MATCH(DMI_BIOS_VERSION
,
112 "SHE845M0.86C.0013.D.0302131307")},
117 static inline u32
ticks_elapsed(u32 t1
, u32 t2
)
121 else if (!acpi_fadt
.tmr_val_ext
)
122 return (((0x00FFFFFF - t1
) + t2
) & 0x00FFFFFF);
124 return ((0xFFFFFFFF - t1
) + t2
);
128 acpi_processor_power_activate(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,
149 ACPI_MTX_DO_NOT_LOCK
);
154 /* Prepare to use new state. */
157 /* Enable bus master reload */
158 if (old
->type
!= ACPI_STATE_C3
&& pr
->flags
.bm_check
)
159 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD
, 1,
160 ACPI_MTX_DO_NOT_LOCK
);
164 pr
->power
.state
= new;
169 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
[raw_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 */
302 ticks_elapsed(t1
, t2
) - cx
->latency_ticks
- C2_OVERHEAD
;
307 if (pr
->flags
.bm_check
) {
308 if (atomic_inc_return(&c3_cpu_count
) ==
311 * All CPUs are trying to go to C3
312 * Disable bus master arbitration
314 acpi_set_register(ACPI_BITREG_ARB_DISABLE
, 1,
315 ACPI_MTX_DO_NOT_LOCK
);
318 /* SMP with no shared cache... Invalidate cache */
319 ACPI_FLUSH_CPU_CACHE();
322 /* Get start time (ticks) */
323 t1
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
326 /* Dummy op - must do something useless after P_LVL3 read */
327 t2
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
328 /* Get end time (ticks) */
329 t2
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
330 if (pr
->flags
.bm_check
) {
331 /* Enable bus master arbitration */
332 atomic_dec(&c3_cpu_count
);
333 acpi_set_register(ACPI_BITREG_ARB_DISABLE
, 0,
334 ACPI_MTX_DO_NOT_LOCK
);
337 /* Re-enable interrupts */
339 /* Compute time (ticks) that we were actually asleep */
341 ticks_elapsed(t1
, t2
) - cx
->latency_ticks
- C3_OVERHEAD
;
349 next_state
= pr
->power
.state
;
354 * Track the number of longs (time asleep is greater than threshold)
355 * and promote when the count threshold is reached. Note that bus
356 * mastering activity may prevent promotions.
357 * Do not promote above max_cstate.
359 if (cx
->promotion
.state
&&
360 ((cx
->promotion
.state
- pr
->power
.states
) <= max_cstate
)) {
361 if (sleep_ticks
> cx
->promotion
.threshold
.ticks
) {
362 cx
->promotion
.count
++;
363 cx
->demotion
.count
= 0;
364 if (cx
->promotion
.count
>=
365 cx
->promotion
.threshold
.count
) {
366 if (pr
->flags
.bm_check
) {
368 (pr
->power
.bm_activity
& cx
->
369 promotion
.threshold
.bm
)) {
375 next_state
= cx
->promotion
.state
;
385 * Track the number of shorts (time asleep is less than time threshold)
386 * and demote when the usage threshold is reached.
388 if (cx
->demotion
.state
) {
389 if (sleep_ticks
< cx
->demotion
.threshold
.ticks
) {
390 cx
->demotion
.count
++;
391 cx
->promotion
.count
= 0;
392 if (cx
->demotion
.count
>= cx
->demotion
.threshold
.count
) {
393 next_state
= cx
->demotion
.state
;
401 * Demote if current state exceeds max_cstate
403 if ((pr
->power
.state
- pr
->power
.states
) > max_cstate
) {
404 if (cx
->demotion
.state
)
405 next_state
= cx
->demotion
.state
;
411 * If we're going to start using a new Cx state we must clean up
412 * from the previous and prepare to use the new.
414 if (next_state
!= pr
->power
.state
)
415 acpi_processor_power_activate(pr
, next_state
);
420 /* do C1 instead of busy loop */
428 static int acpi_processor_set_power_policy(struct acpi_processor
*pr
)
431 unsigned int state_is_set
= 0;
432 struct acpi_processor_cx
*lower
= NULL
;
433 struct acpi_processor_cx
*higher
= NULL
;
434 struct acpi_processor_cx
*cx
;
436 ACPI_FUNCTION_TRACE("acpi_processor_set_power_policy");
439 return_VALUE(-EINVAL
);
442 * This function sets the default Cx state policy (OS idle handler).
443 * Our scheme is to promote quickly to C2 but more conservatively
444 * to C3. We're favoring C2 for its characteristics of low latency
445 * (quick response), good power savings, and ability to allow bus
446 * mastering activity. Note that the Cx state policy is completely
447 * customizable and can be altered dynamically.
451 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
; i
++) {
452 cx
= &pr
->power
.states
[i
];
457 pr
->power
.state
= cx
;
463 return_VALUE(-ENODEV
);
466 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
; i
++) {
467 cx
= &pr
->power
.states
[i
];
472 cx
->demotion
.state
= lower
;
473 cx
->demotion
.threshold
.ticks
= cx
->latency_ticks
;
474 cx
->demotion
.threshold
.count
= 1;
475 if (cx
->type
== ACPI_STATE_C3
)
476 cx
->demotion
.threshold
.bm
= bm_history
;
483 for (i
= (ACPI_PROCESSOR_MAX_POWER
- 1); i
> 0; i
--) {
484 cx
= &pr
->power
.states
[i
];
489 cx
->promotion
.state
= higher
;
490 cx
->promotion
.threshold
.ticks
= cx
->latency_ticks
;
491 if (cx
->type
>= ACPI_STATE_C2
)
492 cx
->promotion
.threshold
.count
= 4;
494 cx
->promotion
.threshold
.count
= 10;
495 if (higher
->type
== ACPI_STATE_C3
)
496 cx
->promotion
.threshold
.bm
= bm_history
;
505 static int acpi_processor_get_power_info_fadt(struct acpi_processor
*pr
)
509 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_fadt");
512 return_VALUE(-EINVAL
);
515 return_VALUE(-ENODEV
);
517 for (i
= 0; i
< ACPI_PROCESSOR_MAX_POWER
; i
++)
518 memset(pr
->power
.states
, 0, sizeof(struct acpi_processor_cx
));
520 /* if info is obtained from pblk/fadt, type equals state */
521 pr
->power
.states
[ACPI_STATE_C1
].type
= ACPI_STATE_C1
;
522 pr
->power
.states
[ACPI_STATE_C2
].type
= ACPI_STATE_C2
;
523 pr
->power
.states
[ACPI_STATE_C3
].type
= ACPI_STATE_C3
;
525 /* the C0 state only exists as a filler in our array,
526 * and all processors need to support C1 */
527 pr
->power
.states
[ACPI_STATE_C0
].valid
= 1;
528 pr
->power
.states
[ACPI_STATE_C1
].valid
= 1;
530 /* determine C2 and C3 address from pblk */
531 pr
->power
.states
[ACPI_STATE_C2
].address
= pr
->pblk
+ 4;
532 pr
->power
.states
[ACPI_STATE_C3
].address
= pr
->pblk
+ 5;
534 /* determine latencies from FADT */
535 pr
->power
.states
[ACPI_STATE_C2
].latency
= acpi_fadt
.plvl2_lat
;
536 pr
->power
.states
[ACPI_STATE_C3
].latency
= acpi_fadt
.plvl3_lat
;
538 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
539 "lvl2[0x%08x] lvl3[0x%08x]\n",
540 pr
->power
.states
[ACPI_STATE_C2
].address
,
541 pr
->power
.states
[ACPI_STATE_C3
].address
));
546 static int acpi_processor_get_power_info_default_c1(struct acpi_processor
*pr
)
550 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_default_c1");
552 for (i
= 0; i
< ACPI_PROCESSOR_MAX_POWER
; i
++)
553 memset(&(pr
->power
.states
[i
]), 0,
554 sizeof(struct acpi_processor_cx
));
556 /* if info is obtained from pblk/fadt, type equals state */
557 pr
->power
.states
[ACPI_STATE_C1
].type
= ACPI_STATE_C1
;
558 pr
->power
.states
[ACPI_STATE_C2
].type
= ACPI_STATE_C2
;
559 pr
->power
.states
[ACPI_STATE_C3
].type
= ACPI_STATE_C3
;
561 /* the C0 state only exists as a filler in our array,
562 * and all processors need to support C1 */
563 pr
->power
.states
[ACPI_STATE_C0
].valid
= 1;
564 pr
->power
.states
[ACPI_STATE_C1
].valid
= 1;
569 static int acpi_processor_get_power_info_cst(struct acpi_processor
*pr
)
571 acpi_status status
= 0;
574 struct acpi_buffer buffer
= { ACPI_ALLOCATE_BUFFER
, NULL
};
575 union acpi_object
*cst
;
577 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_cst");
580 return_VALUE(-ENODEV
);
583 for (i
= 0; i
< ACPI_PROCESSOR_MAX_POWER
; i
++)
584 memset(&(pr
->power
.states
[i
]), 0,
585 sizeof(struct acpi_processor_cx
));
587 status
= acpi_evaluate_object(pr
->handle
, "_CST", NULL
, &buffer
);
588 if (ACPI_FAILURE(status
)) {
589 ACPI_DEBUG_PRINT((ACPI_DB_INFO
, "No _CST, giving up\n"));
590 return_VALUE(-ENODEV
);
593 cst
= (union acpi_object
*)buffer
.pointer
;
595 /* There must be at least 2 elements */
596 if (!cst
|| (cst
->type
!= ACPI_TYPE_PACKAGE
) || cst
->package
.count
< 2) {
597 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
598 "not enough elements in _CST\n"));
603 count
= cst
->package
.elements
[0].integer
.value
;
605 /* Validate number of power states. */
606 if (count
< 1 || count
!= cst
->package
.count
- 1) {
607 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
608 "count given by _CST is not valid\n"));
613 /* We support up to ACPI_PROCESSOR_MAX_POWER. */
614 if (count
> ACPI_PROCESSOR_MAX_POWER
) {
616 "Limiting number of power states to max (%d)\n",
617 ACPI_PROCESSOR_MAX_POWER
);
619 "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
620 count
= ACPI_PROCESSOR_MAX_POWER
;
623 /* Tell driver that at least _CST is supported. */
624 pr
->flags
.has_cst
= 1;
626 for (i
= 1; i
<= count
; i
++) {
627 union acpi_object
*element
;
628 union acpi_object
*obj
;
629 struct acpi_power_register
*reg
;
630 struct acpi_processor_cx cx
;
632 memset(&cx
, 0, sizeof(cx
));
634 element
= (union acpi_object
*)&(cst
->package
.elements
[i
]);
635 if (element
->type
!= ACPI_TYPE_PACKAGE
)
638 if (element
->package
.count
!= 4)
641 obj
= (union acpi_object
*)&(element
->package
.elements
[0]);
643 if (obj
->type
!= ACPI_TYPE_BUFFER
)
646 reg
= (struct acpi_power_register
*)obj
->buffer
.pointer
;
648 if (reg
->space_id
!= ACPI_ADR_SPACE_SYSTEM_IO
&&
649 (reg
->space_id
!= ACPI_ADR_SPACE_FIXED_HARDWARE
))
652 cx
.address
= (reg
->space_id
== ACPI_ADR_SPACE_FIXED_HARDWARE
) ?
655 /* There should be an easy way to extract an integer... */
656 obj
= (union acpi_object
*)&(element
->package
.elements
[1]);
657 if (obj
->type
!= ACPI_TYPE_INTEGER
)
660 cx
.type
= obj
->integer
.value
;
662 if ((cx
.type
!= ACPI_STATE_C1
) &&
663 (reg
->space_id
!= ACPI_ADR_SPACE_SYSTEM_IO
))
666 if ((cx
.type
< ACPI_STATE_C1
) || (cx
.type
> ACPI_STATE_C3
))
669 obj
= (union acpi_object
*)&(element
->package
.elements
[2]);
670 if (obj
->type
!= ACPI_TYPE_INTEGER
)
673 cx
.latency
= obj
->integer
.value
;
675 obj
= (union acpi_object
*)&(element
->package
.elements
[3]);
676 if (obj
->type
!= ACPI_TYPE_INTEGER
)
679 cx
.power
= obj
->integer
.value
;
682 memcpy(&(pr
->power
.states
[pr
->power
.count
]), &cx
, sizeof(cx
));
685 ACPI_DEBUG_PRINT((ACPI_DB_INFO
, "Found %d power states\n",
688 /* Validate number of power states discovered */
689 if (pr
->power
.count
< 2)
693 acpi_os_free(buffer
.pointer
);
695 return_VALUE(status
);
698 static void acpi_processor_power_verify_c2(struct acpi_processor_cx
*cx
)
700 ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c2");
706 * C2 latency must be less than or equal to 100
709 else if (cx
->latency
> ACPI_PROCESSOR_MAX_C2_LATENCY
) {
710 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
711 "latency too large [%d]\n", cx
->latency
));
716 * Otherwise we've met all of our C2 requirements.
717 * Normalize the C2 latency to expidite policy
720 cx
->latency_ticks
= US_TO_PM_TIMER_TICKS(cx
->latency
);
725 static void acpi_processor_power_verify_c3(struct acpi_processor
*pr
,
726 struct acpi_processor_cx
*cx
)
728 static int bm_check_flag
;
730 ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c3");
736 * C3 latency must be less than or equal to 1000
739 else if (cx
->latency
> ACPI_PROCESSOR_MAX_C3_LATENCY
) {
740 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
741 "latency too large [%d]\n", cx
->latency
));
746 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
747 * DMA transfers are used by any ISA device to avoid livelock.
748 * Note that we could disable Type-F DMA (as recommended by
749 * the erratum), but this is known to disrupt certain ISA
750 * devices thus we take the conservative approach.
752 else if (errata
.piix4
.fdma
) {
753 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
754 "C3 not supported on PIIX4 with Type-F DMA\n"));
758 /* All the logic here assumes flags.bm_check is same across all CPUs */
759 if (!bm_check_flag
) {
760 /* Determine whether bm_check is needed based on CPU */
761 acpi_processor_power_init_bm_check(&(pr
->flags
), pr
->id
);
762 bm_check_flag
= pr
->flags
.bm_check
;
764 pr
->flags
.bm_check
= bm_check_flag
;
767 if (pr
->flags
.bm_check
) {
768 /* bus mastering control is necessary */
769 if (!pr
->flags
.bm_control
) {
770 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
771 "C3 support requires bus mastering control\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
);
801 static int acpi_processor_power_verify(struct acpi_processor
*pr
)
804 unsigned int working
= 0;
806 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
; i
++) {
807 struct acpi_processor_cx
*cx
= &pr
->power
.states
[i
];
815 acpi_processor_power_verify_c2(cx
);
819 acpi_processor_power_verify_c3(pr
, cx
);
830 static int acpi_processor_get_power_info(struct acpi_processor
*pr
)
835 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info");
837 /* NOTE: the idle thread may not be running while calling
840 result
= acpi_processor_get_power_info_cst(pr
);
841 if ((result
) || (acpi_processor_power_verify(pr
) < 2)) {
842 result
= acpi_processor_get_power_info_fadt(pr
);
843 if ((result
) || (acpi_processor_power_verify(pr
) < 2))
844 result
= acpi_processor_get_power_info_default_c1(pr
);
850 * Now that we know which states are supported, set the default
851 * policy. Note that this policy can be changed dynamically
852 * (e.g. encourage deeper sleeps to conserve battery life when
855 result
= acpi_processor_set_power_policy(pr
);
857 return_VALUE(result
);
860 * if one state of type C2 or C3 is available, mark this
861 * CPU as being "idle manageable"
863 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
; i
++) {
864 if (pr
->power
.states
[i
].valid
) {
873 int acpi_processor_cst_has_changed(struct acpi_processor
*pr
)
877 ACPI_FUNCTION_TRACE("acpi_processor_cst_has_changed");
880 return_VALUE(-EINVAL
);
883 return_VALUE(-ENODEV
);
886 if (!pr
->flags
.power_setup_done
)
887 return_VALUE(-ENODEV
);
889 /* Fall back to the default idle loop */
890 pm_idle
= pm_idle_save
;
891 synchronize_sched(); /* Relies on interrupts forcing exit from idle. */
894 result
= acpi_processor_get_power_info(pr
);
895 if ((pr
->flags
.power
== 1) && (pr
->flags
.power_setup_done
))
896 pm_idle
= acpi_processor_idle
;
898 return_VALUE(result
);
903 static int acpi_processor_power_seq_show(struct seq_file
*seq
, void *offset
)
905 struct acpi_processor
*pr
= (struct acpi_processor
*)seq
->private;
908 ACPI_FUNCTION_TRACE("acpi_processor_power_seq_show");
913 seq_printf(seq
, "active state: C%zd\n"
915 "bus master activity: %08x\n",
916 pr
->power
.state
? pr
->power
.state
- pr
->power
.states
: 0,
917 max_cstate
, (unsigned)pr
->power
.bm_activity
);
919 seq_puts(seq
, "states:\n");
921 for (i
= 1; i
<= pr
->power
.count
; i
++) {
922 seq_printf(seq
, " %cC%d: ",
923 (&pr
->power
.states
[i
] ==
924 pr
->power
.state
? '*' : ' '), i
);
926 if (!pr
->power
.states
[i
].valid
) {
927 seq_puts(seq
, "<not supported>\n");
931 switch (pr
->power
.states
[i
].type
) {
933 seq_printf(seq
, "type[C1] ");
936 seq_printf(seq
, "type[C2] ");
939 seq_printf(seq
, "type[C3] ");
942 seq_printf(seq
, "type[--] ");
946 if (pr
->power
.states
[i
].promotion
.state
)
947 seq_printf(seq
, "promotion[C%zd] ",
948 (pr
->power
.states
[i
].promotion
.state
-
951 seq_puts(seq
, "promotion[--] ");
953 if (pr
->power
.states
[i
].demotion
.state
)
954 seq_printf(seq
, "demotion[C%zd] ",
955 (pr
->power
.states
[i
].demotion
.state
-
958 seq_puts(seq
, "demotion[--] ");
960 seq_printf(seq
, "latency[%03d] usage[%08d]\n",
961 pr
->power
.states
[i
].latency
,
962 pr
->power
.states
[i
].usage
);
969 static int acpi_processor_power_open_fs(struct inode
*inode
, struct file
*file
)
971 return single_open(file
, acpi_processor_power_seq_show
,
975 static struct file_operations acpi_processor_power_fops
= {
976 .open
= acpi_processor_power_open_fs
,
979 .release
= single_release
,
982 int acpi_processor_power_init(struct acpi_processor
*pr
,
983 struct acpi_device
*device
)
985 acpi_status status
= 0;
986 static int first_run
= 0;
987 struct proc_dir_entry
*entry
= NULL
;
990 ACPI_FUNCTION_TRACE("acpi_processor_power_init");
993 dmi_check_system(processor_power_dmi_table
);
994 if (max_cstate
< ACPI_C_STATES_MAX
)
996 "ACPI: processor limited to max C-state %d\n",
1002 return_VALUE(-EINVAL
);
1004 if (acpi_fadt
.cst_cnt
&& !nocst
) {
1006 acpi_os_write_port(acpi_fadt
.smi_cmd
, acpi_fadt
.cst_cnt
, 8);
1007 if (ACPI_FAILURE(status
)) {
1008 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
1009 "Notifying BIOS of _CST ability failed\n"));
1013 acpi_processor_power_init_pdc(&(pr
->power
), pr
->id
);
1014 acpi_processor_set_pdc(pr
, pr
->power
.pdc
);
1015 acpi_processor_get_power_info(pr
);
1018 * Install the idle handler if processor power management is supported.
1019 * Note that we use previously set idle handler will be used on
1020 * platforms that only support C1.
1022 if ((pr
->flags
.power
) && (!boot_option_idle_override
)) {
1023 printk(KERN_INFO PREFIX
"CPU%d (power states:", pr
->id
);
1024 for (i
= 1; i
<= pr
->power
.count
; i
++)
1025 if (pr
->power
.states
[i
].valid
)
1026 printk(" C%d[C%d]", i
,
1027 pr
->power
.states
[i
].type
);
1031 pm_idle_save
= pm_idle
;
1032 pm_idle
= acpi_processor_idle
;
1037 entry
= create_proc_entry(ACPI_PROCESSOR_FILE_POWER
,
1038 S_IRUGO
, acpi_device_dir(device
));
1040 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
1041 "Unable to create '%s' fs entry\n",
1042 ACPI_PROCESSOR_FILE_POWER
));
1044 entry
->proc_fops
= &acpi_processor_power_fops
;
1045 entry
->data
= acpi_driver_data(device
);
1046 entry
->owner
= THIS_MODULE
;
1049 pr
->flags
.power_setup_done
= 1;
1054 int acpi_processor_power_exit(struct acpi_processor
*pr
,
1055 struct acpi_device
*device
)
1057 ACPI_FUNCTION_TRACE("acpi_processor_power_exit");
1059 pr
->flags
.power_setup_done
= 0;
1061 if (acpi_device_dir(device
))
1062 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER
,
1063 acpi_device_dir(device
));
1065 /* Unregister the idle handler when processor #0 is removed. */
1067 pm_idle
= pm_idle_save
;
1070 * We are about to unload the current idle thread pm callback
1071 * (pm_idle), Wait for all processors to update cached/local
1072 * copies of pm_idle before proceeding.