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 set_max_cstate(struct dmi_system_id
*id
)
86 if (max_cstate
> ACPI_PROCESSOR_MAX_POWER
)
89 printk(KERN_NOTICE PREFIX
"%s detected - %s disabled."
90 " Override with \"processor.max_cstate=%d\"\n", id
->ident
,
91 ((int)id
->driver_data
== 1)? "C2,C3":"C3",
92 ACPI_PROCESSOR_MAX_POWER
+ 1);
94 max_cstate
= (int)id
->driver_data
;
100 static struct dmi_system_id __initdata processor_power_dmi_table
[] = {
101 { set_max_cstate
, "IBM ThinkPad R40e", {
102 DMI_MATCH(DMI_BIOS_VENDOR
,"IBM"),
103 DMI_MATCH(DMI_BIOS_VERSION
,"1SET60WW") }, (void*)1},
104 { set_max_cstate
, "Medion 41700", {
105 DMI_MATCH(DMI_BIOS_VENDOR
,"Phoenix Technologies LTD"),
106 DMI_MATCH(DMI_BIOS_VERSION
,"R01-A1J") }, (void*)1},
107 { set_max_cstate
, "Clevo 5600D", {
108 DMI_MATCH(DMI_BIOS_VENDOR
,"Phoenix Technologies LTD"),
109 DMI_MATCH(DMI_BIOS_VERSION
,"SHE845M0.86C.0013.D.0302131307") },
122 else if (!acpi_fadt
.tmr_val_ext
)
123 return (((0x00FFFFFF - t1
) + t2
) & 0x00FFFFFF);
125 return ((0xFFFFFFFF - t1
) + t2
);
130 acpi_processor_power_activate (
131 struct acpi_processor
*pr
,
132 struct acpi_processor_cx
*new)
134 struct acpi_processor_cx
*old
;
139 old
= pr
->power
.state
;
142 old
->promotion
.count
= 0;
143 new->demotion
.count
= 0;
145 /* Cleanup from old state. */
149 /* Disable bus master reload */
150 if (new->type
!= ACPI_STATE_C3
&& pr
->flags
.bm_check
)
151 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD
, 0, ACPI_MTX_DO_NOT_LOCK
);
156 /* Prepare to use new state. */
159 /* Enable bus master reload */
160 if (old
->type
!= ACPI_STATE_C3
&& pr
->flags
.bm_check
)
161 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD
, 1, ACPI_MTX_DO_NOT_LOCK
);
165 pr
->power
.state
= new;
171 static atomic_t c3_cpu_count
;
174 static void acpi_processor_idle (void)
176 struct acpi_processor
*pr
= NULL
;
177 struct acpi_processor_cx
*cx
= NULL
;
178 struct acpi_processor_cx
*next_state
= NULL
;
182 pr
= processors
[_smp_processor_id()];
187 * Interrupts must be disabled during bus mastering calculations and
188 * for C2/C3 transitions.
193 * Check whether we truly need to go idle, or should
196 if (unlikely(need_resched())) {
201 cx
= pr
->power
.state
;
208 * Check for bus mastering activity (if required), record, and check
211 if (pr
->flags
.bm_check
) {
213 unsigned long diff
= jiffies
- pr
->power
.bm_check_timestamp
;
219 /* if we didn't get called, assume there was busmaster activity */
222 pr
->power
.bm_activity
|= 0x1;
223 pr
->power
.bm_activity
<<= 1;
226 acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS
,
227 &bm_status
, ACPI_MTX_DO_NOT_LOCK
);
229 pr
->power
.bm_activity
++;
230 acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS
,
231 1, ACPI_MTX_DO_NOT_LOCK
);
234 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
235 * the true state of bus mastering activity; forcing us to
236 * manually check the BMIDEA bit of each IDE channel.
238 else if (errata
.piix4
.bmisx
) {
239 if ((inb_p(errata
.piix4
.bmisx
+ 0x02) & 0x01)
240 || (inb_p(errata
.piix4
.bmisx
+ 0x0A) & 0x01))
241 pr
->power
.bm_activity
++;
244 pr
->power
.bm_check_timestamp
= jiffies
;
247 * Apply bus mastering demotion policy. Automatically demote
248 * to avoid a faulty transition. Note that the processor
249 * won't enter a low-power state during this call (to this
250 * funciton) but should upon the next.
252 * TBD: A better policy might be to fallback to the demotion
253 * state (use it for this quantum only) istead of
254 * demoting -- and rely on duration as our sole demotion
255 * qualification. This may, however, introduce DMA
256 * issues (e.g. floppy DMA transfer overrun/underrun).
258 if (pr
->power
.bm_activity
& cx
->demotion
.threshold
.bm
) {
260 next_state
= cx
->demotion
.state
;
270 * Invoke the current Cx state to put the processor to sleep.
277 * Use the appropriate idle routine, the one that would
278 * be used without acpi C-states.
285 * TBD: Can't get time duration while in C1, as resumes
286 * go to an ISR rather than here. Need to instrument
287 * base interrupt handler.
289 sleep_ticks
= 0xFFFFFFFF;
293 /* Get start time (ticks) */
294 t1
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
297 /* Dummy op - must do something useless after P_LVL2 read */
298 t2
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
299 /* Get end time (ticks) */
300 t2
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
301 /* Re-enable interrupts */
303 /* Compute time (ticks) that we were actually asleep */
304 sleep_ticks
= ticks_elapsed(t1
, t2
) - cx
->latency_ticks
- C2_OVERHEAD
;
309 if (pr
->flags
.bm_check
) {
310 if (atomic_inc_return(&c3_cpu_count
) ==
313 * All CPUs are trying to go to C3
314 * Disable bus master arbitration
316 acpi_set_register(ACPI_BITREG_ARB_DISABLE
, 1,
317 ACPI_MTX_DO_NOT_LOCK
);
320 /* SMP with no shared cache... Invalidate cache */
321 ACPI_FLUSH_CPU_CACHE();
324 /* Get start time (ticks) */
325 t1
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
328 /* Dummy op - must do something useless after P_LVL3 read */
329 t2
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
330 /* Get end time (ticks) */
331 t2
= inl(acpi_fadt
.xpm_tmr_blk
.address
);
332 if (pr
->flags
.bm_check
) {
333 /* Enable bus master arbitration */
334 atomic_dec(&c3_cpu_count
);
335 acpi_set_register(ACPI_BITREG_ARB_DISABLE
, 0, ACPI_MTX_DO_NOT_LOCK
);
338 /* Re-enable interrupts */
340 /* Compute time (ticks) that we were actually asleep */
341 sleep_ticks
= 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
>= cx
->promotion
.threshold
.count
) {
365 if (pr
->flags
.bm_check
) {
366 if (!(pr
->power
.bm_activity
& cx
->promotion
.threshold
.bm
)) {
367 next_state
= cx
->promotion
.state
;
372 next_state
= cx
->promotion
.state
;
382 * Track the number of shorts (time asleep is less than time threshold)
383 * and demote when the usage threshold is reached.
385 if (cx
->demotion
.state
) {
386 if (sleep_ticks
< cx
->demotion
.threshold
.ticks
) {
387 cx
->demotion
.count
++;
388 cx
->promotion
.count
= 0;
389 if (cx
->demotion
.count
>= cx
->demotion
.threshold
.count
) {
390 next_state
= cx
->demotion
.state
;
398 * Demote if current state exceeds max_cstate
400 if ((pr
->power
.state
- pr
->power
.states
) > max_cstate
) {
401 if (cx
->demotion
.state
)
402 next_state
= cx
->demotion
.state
;
408 * If we're going to start using a new Cx state we must clean up
409 * from the previous and prepare to use the new.
411 if (next_state
!= pr
->power
.state
)
412 acpi_processor_power_activate(pr
, next_state
);
417 /* do C1 instead of busy loop */
427 acpi_processor_set_power_policy (
428 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
;
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
));
548 static int acpi_processor_get_power_info_default_c1 (struct acpi_processor
*pr
)
552 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_default_c1");
554 for (i
= 0; i
< ACPI_PROCESSOR_MAX_POWER
; i
++)
555 memset(&(pr
->power
.states
[i
]), 0,
556 sizeof(struct acpi_processor_cx
));
558 /* if info is obtained from pblk/fadt, type equals state */
559 pr
->power
.states
[ACPI_STATE_C1
].type
= ACPI_STATE_C1
;
560 pr
->power
.states
[ACPI_STATE_C2
].type
= ACPI_STATE_C2
;
561 pr
->power
.states
[ACPI_STATE_C3
].type
= ACPI_STATE_C3
;
563 /* the C0 state only exists as a filler in our array,
564 * and all processors need to support C1 */
565 pr
->power
.states
[ACPI_STATE_C0
].valid
= 1;
566 pr
->power
.states
[ACPI_STATE_C1
].valid
= 1;
572 static int acpi_processor_get_power_info_cst (struct acpi_processor
*pr
)
574 acpi_status status
= 0;
577 struct acpi_buffer buffer
= {ACPI_ALLOCATE_BUFFER
, NULL
};
578 union acpi_object
*cst
;
580 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_cst");
583 return_VALUE(-ENODEV
);
586 for (i
= 0; i
< ACPI_PROCESSOR_MAX_POWER
; i
++)
587 memset(&(pr
->power
.states
[i
]), 0,
588 sizeof(struct acpi_processor_cx
));
590 status
= acpi_evaluate_object(pr
->handle
, "_CST", NULL
, &buffer
);
591 if (ACPI_FAILURE(status
)) {
592 ACPI_DEBUG_PRINT((ACPI_DB_INFO
, "No _CST, giving up\n"));
593 return_VALUE(-ENODEV
);
596 cst
= (union acpi_object
*) buffer
.pointer
;
598 /* There must be at least 2 elements */
599 if (!cst
|| (cst
->type
!= ACPI_TYPE_PACKAGE
) || cst
->package
.count
< 2) {
600 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
, "not enough elements in _CST\n"));
605 count
= cst
->package
.elements
[0].integer
.value
;
607 /* Validate number of power states. */
608 if (count
< 1 || count
!= cst
->package
.count
- 1) {
609 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
, "count given by _CST is not valid\n"));
614 /* We support up to ACPI_PROCESSOR_MAX_POWER. */
615 if (count
> ACPI_PROCESSOR_MAX_POWER
) {
616 printk(KERN_WARNING
"Limiting number of power states to max (%d)\n", ACPI_PROCESSOR_MAX_POWER
);
617 printk(KERN_WARNING
"Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
618 count
= ACPI_PROCESSOR_MAX_POWER
;
621 /* Tell driver that at least _CST is supported. */
622 pr
->flags
.has_cst
= 1;
624 for (i
= 1; i
<= count
; i
++) {
625 union acpi_object
*element
;
626 union acpi_object
*obj
;
627 struct acpi_power_register
*reg
;
628 struct acpi_processor_cx cx
;
630 memset(&cx
, 0, sizeof(cx
));
632 element
= (union acpi_object
*) &(cst
->package
.elements
[i
]);
633 if (element
->type
!= ACPI_TYPE_PACKAGE
)
636 if (element
->package
.count
!= 4)
639 obj
= (union acpi_object
*) &(element
->package
.elements
[0]);
641 if (obj
->type
!= ACPI_TYPE_BUFFER
)
644 reg
= (struct acpi_power_register
*) obj
->buffer
.pointer
;
646 if (reg
->space_id
!= ACPI_ADR_SPACE_SYSTEM_IO
&&
647 (reg
->space_id
!= ACPI_ADR_SPACE_FIXED_HARDWARE
))
650 cx
.address
= (reg
->space_id
== ACPI_ADR_SPACE_FIXED_HARDWARE
) ?
653 /* There should be an easy way to extract an integer... */
654 obj
= (union acpi_object
*) &(element
->package
.elements
[1]);
655 if (obj
->type
!= ACPI_TYPE_INTEGER
)
658 cx
.type
= obj
->integer
.value
;
660 if ((cx
.type
!= ACPI_STATE_C1
) &&
661 (reg
->space_id
!= ACPI_ADR_SPACE_SYSTEM_IO
))
664 if ((cx
.type
< ACPI_STATE_C1
) ||
665 (cx
.type
> ACPI_STATE_C3
))
668 obj
= (union acpi_object
*) &(element
->package
.elements
[2]);
669 if (obj
->type
!= ACPI_TYPE_INTEGER
)
672 cx
.latency
= obj
->integer
.value
;
674 obj
= (union acpi_object
*) &(element
->package
.elements
[3]);
675 if (obj
->type
!= ACPI_TYPE_INTEGER
)
678 cx
.power
= obj
->integer
.value
;
681 memcpy(&(pr
->power
.states
[pr
->power
.count
]), &cx
, sizeof(cx
));
684 ACPI_DEBUG_PRINT((ACPI_DB_INFO
, "Found %d power states\n", pr
->power
.count
));
686 /* Validate number of power states discovered */
687 if (pr
->power
.count
< 2)
691 acpi_os_free(buffer
.pointer
);
693 return_VALUE(status
);
697 static void acpi_processor_power_verify_c2(struct acpi_processor_cx
*cx
)
699 ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c2");
705 * C2 latency must be less than or equal to 100
708 else if (cx
->latency
> ACPI_PROCESSOR_MAX_C2_LATENCY
) {
709 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
710 "latency too large [%d]\n",
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
);
726 static void acpi_processor_power_verify_c3(
727 struct acpi_processor
*pr
,
728 struct acpi_processor_cx
*cx
)
730 static int bm_check_flag
;
732 ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c3");
738 * C3 latency must be less than or equal to 1000
741 else if (cx
->latency
> ACPI_PROCESSOR_MAX_C3_LATENCY
) {
742 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
743 "latency too large [%d]\n",
749 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
750 * DMA transfers are used by any ISA device to avoid livelock.
751 * Note that we could disable Type-F DMA (as recommended by
752 * the erratum), but this is known to disrupt certain ISA
753 * devices thus we take the conservative approach.
755 else if (errata
.piix4
.fdma
) {
756 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
757 "C3 not supported on PIIX4 with Type-F DMA\n"));
761 /* All the logic here assumes flags.bm_check is same across all CPUs */
762 if (!bm_check_flag
) {
763 /* Determine whether bm_check is needed based on CPU */
764 acpi_processor_power_init_bm_check(&(pr
->flags
), pr
->id
);
765 bm_check_flag
= pr
->flags
.bm_check
;
767 pr
->flags
.bm_check
= bm_check_flag
;
770 if (pr
->flags
.bm_check
) {
771 /* bus mastering control is necessary */
772 if (!pr
->flags
.bm_control
) {
773 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
774 "C3 support requires bus mastering control\n"));
779 * WBINVD should be set in fadt, for C3 state to be
780 * supported on when bm_check is not required.
782 if (acpi_fadt
.wb_invd
!= 1) {
783 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
784 "Cache invalidation should work properly"
785 " for C3 to be enabled on SMP systems\n"));
788 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD
,
789 0, ACPI_MTX_DO_NOT_LOCK
);
793 * Otherwise we've met all of our C3 requirements.
794 * Normalize the C3 latency to expidite policy. Enable
795 * checking of bus mastering status (bm_check) so we can
796 * use this in our C3 policy
799 cx
->latency_ticks
= US_TO_PM_TIMER_TICKS(cx
->latency
);
805 static int acpi_processor_power_verify(struct acpi_processor
*pr
)
808 unsigned int working
= 0;
810 for (i
=1; i
< ACPI_PROCESSOR_MAX_POWER
; i
++) {
811 struct acpi_processor_cx
*cx
= &pr
->power
.states
[i
];
819 acpi_processor_power_verify_c2(cx
);
823 acpi_processor_power_verify_c3(pr
, cx
);
834 static int acpi_processor_get_power_info (
835 struct acpi_processor
*pr
)
840 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info");
842 /* NOTE: the idle thread may not be running while calling
845 result
= acpi_processor_get_power_info_cst(pr
);
846 if ((result
) || (acpi_processor_power_verify(pr
) < 2)) {
847 result
= acpi_processor_get_power_info_fadt(pr
);
848 if ((result
) || (acpi_processor_power_verify(pr
) < 2))
849 result
= acpi_processor_get_power_info_default_c1(pr
);
855 * Now that we know which states are supported, set the default
856 * policy. Note that this policy can be changed dynamically
857 * (e.g. encourage deeper sleeps to conserve battery life when
860 result
= acpi_processor_set_power_policy(pr
);
862 return_VALUE(result
);
865 * if one state of type C2 or C3 is available, mark this
866 * CPU as being "idle manageable"
868 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
; i
++) {
869 if (pr
->power
.states
[i
].valid
) {
878 int acpi_processor_cst_has_changed (struct acpi_processor
*pr
)
882 ACPI_FUNCTION_TRACE("acpi_processor_cst_has_changed");
885 return_VALUE(-EINVAL
);
888 return_VALUE(-ENODEV
);
891 if (!pr
->flags
.power_setup_done
)
892 return_VALUE(-ENODEV
);
894 /* Fall back to the default idle loop */
895 pm_idle
= pm_idle_save
;
896 synchronize_sched(); /* Relies on interrupts forcing exit from idle. */
899 result
= acpi_processor_get_power_info(pr
);
900 if ((pr
->flags
.power
== 1) && (pr
->flags
.power_setup_done
))
901 pm_idle
= acpi_processor_idle
;
903 return_VALUE(result
);
908 static int acpi_processor_power_seq_show(struct seq_file
*seq
, void *offset
)
910 struct acpi_processor
*pr
= (struct acpi_processor
*)seq
->private;
913 ACPI_FUNCTION_TRACE("acpi_processor_power_seq_show");
918 seq_printf(seq
, "active state: C%zd\n"
920 "bus master activity: %08x\n",
921 pr
->power
.state
? pr
->power
.state
- pr
->power
.states
: 0,
923 (unsigned)pr
->power
.bm_activity
);
925 seq_puts(seq
, "states:\n");
927 for (i
= 1; i
<= pr
->power
.count
; i
++) {
928 seq_printf(seq
, " %cC%d: ",
929 (&pr
->power
.states
[i
] == pr
->power
.state
?'*':' '), i
);
931 if (!pr
->power
.states
[i
].valid
) {
932 seq_puts(seq
, "<not supported>\n");
936 switch (pr
->power
.states
[i
].type
) {
938 seq_printf(seq
, "type[C1] ");
941 seq_printf(seq
, "type[C2] ");
944 seq_printf(seq
, "type[C3] ");
947 seq_printf(seq
, "type[--] ");
951 if (pr
->power
.states
[i
].promotion
.state
)
952 seq_printf(seq
, "promotion[C%zd] ",
953 (pr
->power
.states
[i
].promotion
.state
-
956 seq_puts(seq
, "promotion[--] ");
958 if (pr
->power
.states
[i
].demotion
.state
)
959 seq_printf(seq
, "demotion[C%zd] ",
960 (pr
->power
.states
[i
].demotion
.state
-
963 seq_puts(seq
, "demotion[--] ");
965 seq_printf(seq
, "latency[%03d] usage[%08d]\n",
966 pr
->power
.states
[i
].latency
,
967 pr
->power
.states
[i
].usage
);
974 static int acpi_processor_power_open_fs(struct inode
*inode
, struct file
*file
)
976 return single_open(file
, acpi_processor_power_seq_show
,
980 static struct file_operations acpi_processor_power_fops
= {
981 .open
= acpi_processor_power_open_fs
,
984 .release
= single_release
,
987 int acpi_processor_power_init(struct acpi_processor
*pr
, struct acpi_device
*device
)
989 acpi_status status
= 0;
990 static int first_run
= 0;
991 struct proc_dir_entry
*entry
= NULL
;
994 ACPI_FUNCTION_TRACE("acpi_processor_power_init");
997 dmi_check_system(processor_power_dmi_table
);
998 if (max_cstate
< ACPI_C_STATES_MAX
)
999 printk(KERN_NOTICE
"ACPI: processor limited to max C-state %d\n", max_cstate
);
1004 return_VALUE(-EINVAL
);
1006 if (acpi_fadt
.cst_cnt
&& !nocst
) {
1007 status
= 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
, 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
, struct acpi_device
*device
)
1056 ACPI_FUNCTION_TRACE("acpi_processor_power_exit");
1058 pr
->flags
.power_setup_done
= 0;
1060 if (acpi_device_dir(device
))
1061 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER
,acpi_device_dir(device
));
1063 /* Unregister the idle handler when processor #0 is removed. */
1065 pm_idle
= pm_idle_save
;
1068 * We are about to unload the current idle thread pm callback
1069 * (pm_idle), Wait for all processors to update cached/local
1070 * copies of pm_idle before proceeding.