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, 2005 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/module.h>
32 #include <linux/acpi.h>
33 #include <linux/dmi.h>
34 #include <linux/sched.h> /* need_resched() */
35 #include <linux/clockchips.h>
36 #include <linux/cpuidle.h>
37 #include <linux/syscore_ops.h>
40 * Include the apic definitions for x86 to have the APIC timer related defines
41 * available also for UP (on SMP it gets magically included via linux/smp.h).
42 * asm/acpi.h is not an option, as it would require more include magic. Also
43 * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
49 #include <acpi/acpi_bus.h>
50 #include <acpi/processor.h>
52 #define PREFIX "ACPI: "
54 #define ACPI_PROCESSOR_CLASS "processor"
55 #define _COMPONENT ACPI_PROCESSOR_COMPONENT
56 ACPI_MODULE_NAME("processor_idle");
58 static unsigned int max_cstate __read_mostly
= ACPI_PROCESSOR_MAX_POWER
;
59 module_param(max_cstate
, uint
, 0000);
60 static unsigned int nocst __read_mostly
;
61 module_param(nocst
, uint
, 0000);
62 static int bm_check_disable __read_mostly
;
63 module_param(bm_check_disable
, uint
, 0000);
65 static unsigned int latency_factor __read_mostly
= 2;
66 module_param(latency_factor
, uint
, 0644);
68 static DEFINE_PER_CPU(struct cpuidle_device
*, acpi_cpuidle_device
);
70 static DEFINE_PER_CPU(struct acpi_processor_cx
* [CPUIDLE_STATE_MAX
],
73 static int disabled_by_idle_boot_param(void)
75 return boot_option_idle_override
== IDLE_POLL
||
76 boot_option_idle_override
== IDLE_HALT
;
80 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
81 * For now disable this. Probably a bug somewhere else.
83 * To skip this limit, boot/load with a large max_cstate limit.
85 static int set_max_cstate(const struct dmi_system_id
*id
)
87 if (max_cstate
> ACPI_PROCESSOR_MAX_POWER
)
90 printk(KERN_NOTICE PREFIX
"%s detected - limiting to C%ld max_cstate."
91 " Override with \"processor.max_cstate=%d\"\n", id
->ident
,
92 (long)id
->driver_data
, ACPI_PROCESSOR_MAX_POWER
+ 1);
94 max_cstate
= (long)id
->driver_data
;
99 static struct dmi_system_id processor_power_dmi_table
[] = {
100 { set_max_cstate
, "Clevo 5600D", {
101 DMI_MATCH(DMI_BIOS_VENDOR
,"Phoenix Technologies LTD"),
102 DMI_MATCH(DMI_BIOS_VERSION
,"SHE845M0.86C.0013.D.0302131307")},
104 { set_max_cstate
, "Pavilion zv5000", {
105 DMI_MATCH(DMI_SYS_VENDOR
, "Hewlett-Packard"),
106 DMI_MATCH(DMI_PRODUCT_NAME
,"Pavilion zv5000 (DS502A#ABA)")},
108 { set_max_cstate
, "Asus L8400B", {
109 DMI_MATCH(DMI_SYS_VENDOR
, "ASUSTeK Computer Inc."),
110 DMI_MATCH(DMI_PRODUCT_NAME
,"L8400B series Notebook PC")},
117 * Callers should disable interrupts before the call and enable
118 * interrupts after return.
120 static void acpi_safe_halt(void)
122 if (!tif_need_resched()) {
128 #ifdef ARCH_APICTIMER_STOPS_ON_C3
131 * Some BIOS implementations switch to C3 in the published C2 state.
132 * This seems to be a common problem on AMD boxen, but other vendors
133 * are affected too. We pick the most conservative approach: we assume
134 * that the local APIC stops in both C2 and C3.
136 static void lapic_timer_check_state(int state
, struct acpi_processor
*pr
,
137 struct acpi_processor_cx
*cx
)
139 struct acpi_processor_power
*pwr
= &pr
->power
;
140 u8 type
= local_apic_timer_c2_ok
? ACPI_STATE_C3
: ACPI_STATE_C2
;
142 if (cpu_has(&cpu_data(pr
->id
), X86_FEATURE_ARAT
))
145 if (amd_e400_c1e_detected
)
146 type
= ACPI_STATE_C1
;
149 * Check, if one of the previous states already marked the lapic
152 if (pwr
->timer_broadcast_on_state
< state
)
155 if (cx
->type
>= type
)
156 pr
->power
.timer_broadcast_on_state
= state
;
159 static void __lapic_timer_propagate_broadcast(void *arg
)
161 struct acpi_processor
*pr
= (struct acpi_processor
*) arg
;
162 unsigned long reason
;
164 reason
= pr
->power
.timer_broadcast_on_state
< INT_MAX
?
165 CLOCK_EVT_NOTIFY_BROADCAST_ON
: CLOCK_EVT_NOTIFY_BROADCAST_OFF
;
167 clockevents_notify(reason
, &pr
->id
);
170 static void lapic_timer_propagate_broadcast(struct acpi_processor
*pr
)
172 smp_call_function_single(pr
->id
, __lapic_timer_propagate_broadcast
,
176 /* Power(C) State timer broadcast control */
177 static void lapic_timer_state_broadcast(struct acpi_processor
*pr
,
178 struct acpi_processor_cx
*cx
,
181 int state
= cx
- pr
->power
.states
;
183 if (state
>= pr
->power
.timer_broadcast_on_state
) {
184 unsigned long reason
;
186 reason
= broadcast
? CLOCK_EVT_NOTIFY_BROADCAST_ENTER
:
187 CLOCK_EVT_NOTIFY_BROADCAST_EXIT
;
188 clockevents_notify(reason
, &pr
->id
);
194 static void lapic_timer_check_state(int state
, struct acpi_processor
*pr
,
195 struct acpi_processor_cx
*cstate
) { }
196 static void lapic_timer_propagate_broadcast(struct acpi_processor
*pr
) { }
197 static void lapic_timer_state_broadcast(struct acpi_processor
*pr
,
198 struct acpi_processor_cx
*cx
,
205 #ifdef CONFIG_PM_SLEEP
206 static u32 saved_bm_rld
;
208 static int acpi_processor_suspend(void)
210 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD
, &saved_bm_rld
);
214 static void acpi_processor_resume(void)
218 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD
, &resumed_bm_rld
);
219 if (resumed_bm_rld
== saved_bm_rld
)
222 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD
, saved_bm_rld
);
225 static struct syscore_ops acpi_processor_syscore_ops
= {
226 .suspend
= acpi_processor_suspend
,
227 .resume
= acpi_processor_resume
,
230 void acpi_processor_syscore_init(void)
232 register_syscore_ops(&acpi_processor_syscore_ops
);
235 void acpi_processor_syscore_exit(void)
237 unregister_syscore_ops(&acpi_processor_syscore_ops
);
239 #endif /* CONFIG_PM_SLEEP */
241 #if defined(CONFIG_X86)
242 static void tsc_check_state(int state
)
244 switch (boot_cpu_data
.x86_vendor
) {
246 case X86_VENDOR_INTEL
:
248 * AMD Fam10h TSC will tick in all
249 * C/P/S0/S1 states when this bit is set.
251 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC
))
256 /* TSC could halt in idle, so notify users */
257 if (state
> ACPI_STATE_C1
)
258 mark_tsc_unstable("TSC halts in idle");
262 static void tsc_check_state(int state
) { return; }
265 static int acpi_processor_get_power_info_fadt(struct acpi_processor
*pr
)
271 /* if info is obtained from pblk/fadt, type equals state */
272 pr
->power
.states
[ACPI_STATE_C2
].type
= ACPI_STATE_C2
;
273 pr
->power
.states
[ACPI_STATE_C3
].type
= ACPI_STATE_C3
;
275 #ifndef CONFIG_HOTPLUG_CPU
277 * Check for P_LVL2_UP flag before entering C2 and above on
280 if ((num_online_cpus() > 1) &&
281 !(acpi_gbl_FADT
.flags
& ACPI_FADT_C2_MP_SUPPORTED
))
285 /* determine C2 and C3 address from pblk */
286 pr
->power
.states
[ACPI_STATE_C2
].address
= pr
->pblk
+ 4;
287 pr
->power
.states
[ACPI_STATE_C3
].address
= pr
->pblk
+ 5;
289 /* determine latencies from FADT */
290 pr
->power
.states
[ACPI_STATE_C2
].latency
= acpi_gbl_FADT
.c2_latency
;
291 pr
->power
.states
[ACPI_STATE_C3
].latency
= acpi_gbl_FADT
.c3_latency
;
294 * FADT specified C2 latency must be less than or equal to
297 if (acpi_gbl_FADT
.c2_latency
> ACPI_PROCESSOR_MAX_C2_LATENCY
) {
298 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
299 "C2 latency too large [%d]\n", acpi_gbl_FADT
.c2_latency
));
301 pr
->power
.states
[ACPI_STATE_C2
].address
= 0;
305 * FADT supplied C3 latency must be less than or equal to
308 if (acpi_gbl_FADT
.c3_latency
> ACPI_PROCESSOR_MAX_C3_LATENCY
) {
309 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
310 "C3 latency too large [%d]\n", acpi_gbl_FADT
.c3_latency
));
312 pr
->power
.states
[ACPI_STATE_C3
].address
= 0;
315 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
316 "lvl2[0x%08x] lvl3[0x%08x]\n",
317 pr
->power
.states
[ACPI_STATE_C2
].address
,
318 pr
->power
.states
[ACPI_STATE_C3
].address
));
323 static int acpi_processor_get_power_info_default(struct acpi_processor
*pr
)
325 if (!pr
->power
.states
[ACPI_STATE_C1
].valid
) {
326 /* set the first C-State to C1 */
327 /* all processors need to support C1 */
328 pr
->power
.states
[ACPI_STATE_C1
].type
= ACPI_STATE_C1
;
329 pr
->power
.states
[ACPI_STATE_C1
].valid
= 1;
330 pr
->power
.states
[ACPI_STATE_C1
].entry_method
= ACPI_CSTATE_HALT
;
332 /* the C0 state only exists as a filler in our array */
333 pr
->power
.states
[ACPI_STATE_C0
].valid
= 1;
337 static int acpi_processor_get_power_info_cst(struct acpi_processor
*pr
)
339 acpi_status status
= 0;
343 struct acpi_buffer buffer
= { ACPI_ALLOCATE_BUFFER
, NULL
};
344 union acpi_object
*cst
;
352 status
= acpi_evaluate_object(pr
->handle
, "_CST", NULL
, &buffer
);
353 if (ACPI_FAILURE(status
)) {
354 ACPI_DEBUG_PRINT((ACPI_DB_INFO
, "No _CST, giving up\n"));
358 cst
= buffer
.pointer
;
360 /* There must be at least 2 elements */
361 if (!cst
|| (cst
->type
!= ACPI_TYPE_PACKAGE
) || cst
->package
.count
< 2) {
362 printk(KERN_ERR PREFIX
"not enough elements in _CST\n");
367 count
= cst
->package
.elements
[0].integer
.value
;
369 /* Validate number of power states. */
370 if (count
< 1 || count
!= cst
->package
.count
- 1) {
371 printk(KERN_ERR PREFIX
"count given by _CST is not valid\n");
376 /* Tell driver that at least _CST is supported. */
377 pr
->flags
.has_cst
= 1;
379 for (i
= 1; i
<= count
; i
++) {
380 union acpi_object
*element
;
381 union acpi_object
*obj
;
382 struct acpi_power_register
*reg
;
383 struct acpi_processor_cx cx
;
385 memset(&cx
, 0, sizeof(cx
));
387 element
= &(cst
->package
.elements
[i
]);
388 if (element
->type
!= ACPI_TYPE_PACKAGE
)
391 if (element
->package
.count
!= 4)
394 obj
= &(element
->package
.elements
[0]);
396 if (obj
->type
!= ACPI_TYPE_BUFFER
)
399 reg
= (struct acpi_power_register
*)obj
->buffer
.pointer
;
401 if (reg
->space_id
!= ACPI_ADR_SPACE_SYSTEM_IO
&&
402 (reg
->space_id
!= ACPI_ADR_SPACE_FIXED_HARDWARE
))
405 /* There should be an easy way to extract an integer... */
406 obj
= &(element
->package
.elements
[1]);
407 if (obj
->type
!= ACPI_TYPE_INTEGER
)
410 cx
.type
= obj
->integer
.value
;
412 * Some buggy BIOSes won't list C1 in _CST -
413 * Let acpi_processor_get_power_info_default() handle them later
415 if (i
== 1 && cx
.type
!= ACPI_STATE_C1
)
418 cx
.address
= reg
->address
;
419 cx
.index
= current_count
+ 1;
421 cx
.entry_method
= ACPI_CSTATE_SYSTEMIO
;
422 if (reg
->space_id
== ACPI_ADR_SPACE_FIXED_HARDWARE
) {
423 if (acpi_processor_ffh_cstate_probe
424 (pr
->id
, &cx
, reg
) == 0) {
425 cx
.entry_method
= ACPI_CSTATE_FFH
;
426 } else if (cx
.type
== ACPI_STATE_C1
) {
428 * C1 is a special case where FIXED_HARDWARE
429 * can be handled in non-MWAIT way as well.
430 * In that case, save this _CST entry info.
431 * Otherwise, ignore this info and continue.
433 cx
.entry_method
= ACPI_CSTATE_HALT
;
434 snprintf(cx
.desc
, ACPI_CX_DESC_LEN
, "ACPI HLT");
438 if (cx
.type
== ACPI_STATE_C1
&&
439 (boot_option_idle_override
== IDLE_NOMWAIT
)) {
441 * In most cases the C1 space_id obtained from
442 * _CST object is FIXED_HARDWARE access mode.
443 * But when the option of idle=halt is added,
444 * the entry_method type should be changed from
445 * CSTATE_FFH to CSTATE_HALT.
446 * When the option of idle=nomwait is added,
447 * the C1 entry_method type should be
450 cx
.entry_method
= ACPI_CSTATE_HALT
;
451 snprintf(cx
.desc
, ACPI_CX_DESC_LEN
, "ACPI HLT");
454 snprintf(cx
.desc
, ACPI_CX_DESC_LEN
, "ACPI IOPORT 0x%x",
458 if (cx
.type
== ACPI_STATE_C1
) {
462 obj
= &(element
->package
.elements
[2]);
463 if (obj
->type
!= ACPI_TYPE_INTEGER
)
466 cx
.latency
= obj
->integer
.value
;
468 obj
= &(element
->package
.elements
[3]);
469 if (obj
->type
!= ACPI_TYPE_INTEGER
)
473 memcpy(&(pr
->power
.states
[current_count
]), &cx
, sizeof(cx
));
476 * We support total ACPI_PROCESSOR_MAX_POWER - 1
477 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
479 if (current_count
>= (ACPI_PROCESSOR_MAX_POWER
- 1)) {
481 "Limiting number of power states to max (%d)\n",
482 ACPI_PROCESSOR_MAX_POWER
);
484 "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
489 ACPI_DEBUG_PRINT((ACPI_DB_INFO
, "Found %d power states\n",
492 /* Validate number of power states discovered */
493 if (current_count
< 2)
497 kfree(buffer
.pointer
);
502 static void acpi_processor_power_verify_c3(struct acpi_processor
*pr
,
503 struct acpi_processor_cx
*cx
)
505 static int bm_check_flag
= -1;
506 static int bm_control_flag
= -1;
513 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
514 * DMA transfers are used by any ISA device to avoid livelock.
515 * Note that we could disable Type-F DMA (as recommended by
516 * the erratum), but this is known to disrupt certain ISA
517 * devices thus we take the conservative approach.
519 else if (errata
.piix4
.fdma
) {
520 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
521 "C3 not supported on PIIX4 with Type-F DMA\n"));
525 /* All the logic here assumes flags.bm_check is same across all CPUs */
526 if (bm_check_flag
== -1) {
527 /* Determine whether bm_check is needed based on CPU */
528 acpi_processor_power_init_bm_check(&(pr
->flags
), pr
->id
);
529 bm_check_flag
= pr
->flags
.bm_check
;
530 bm_control_flag
= pr
->flags
.bm_control
;
532 pr
->flags
.bm_check
= bm_check_flag
;
533 pr
->flags
.bm_control
= bm_control_flag
;
536 if (pr
->flags
.bm_check
) {
537 if (!pr
->flags
.bm_control
) {
538 if (pr
->flags
.has_cst
!= 1) {
539 /* bus mastering control is necessary */
540 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
541 "C3 support requires BM control\n"));
544 /* Here we enter C3 without bus mastering */
545 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
546 "C3 support without BM control\n"));
551 * WBINVD should be set in fadt, for C3 state to be
552 * supported on when bm_check is not required.
554 if (!(acpi_gbl_FADT
.flags
& ACPI_FADT_WBINVD
)) {
555 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
556 "Cache invalidation should work properly"
557 " for C3 to be enabled on SMP systems\n"));
563 * Otherwise we've met all of our C3 requirements.
564 * Normalize the C3 latency to expidite policy. Enable
565 * checking of bus mastering status (bm_check) so we can
566 * use this in our C3 policy
571 * On older chipsets, BM_RLD needs to be set
572 * in order for Bus Master activity to wake the
573 * system from C3. Newer chipsets handle DMA
574 * during C3 automatically and BM_RLD is a NOP.
575 * In either case, the proper way to
576 * handle BM_RLD is to set it and leave it set.
578 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD
, 1);
583 static int acpi_processor_power_verify(struct acpi_processor
*pr
)
586 unsigned int working
= 0;
588 pr
->power
.timer_broadcast_on_state
= INT_MAX
;
590 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
&& i
<= max_cstate
; i
++) {
591 struct acpi_processor_cx
*cx
= &pr
->power
.states
[i
];
605 acpi_processor_power_verify_c3(pr
, cx
);
611 lapic_timer_check_state(i
, pr
, cx
);
612 tsc_check_state(cx
->type
);
616 lapic_timer_propagate_broadcast(pr
);
621 static int acpi_processor_get_power_info(struct acpi_processor
*pr
)
627 /* NOTE: the idle thread may not be running while calling
630 /* Zero initialize all the C-states info. */
631 memset(pr
->power
.states
, 0, sizeof(pr
->power
.states
));
633 result
= acpi_processor_get_power_info_cst(pr
);
634 if (result
== -ENODEV
)
635 result
= acpi_processor_get_power_info_fadt(pr
);
640 acpi_processor_get_power_info_default(pr
);
642 pr
->power
.count
= acpi_processor_power_verify(pr
);
645 * if one state of type C2 or C3 is available, mark this
646 * CPU as being "idle manageable"
648 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
; i
++) {
649 if (pr
->power
.states
[i
].valid
) {
651 if (pr
->power
.states
[i
].type
>= ACPI_STATE_C2
)
660 * acpi_idle_bm_check - checks if bus master activity was detected
662 static int acpi_idle_bm_check(void)
666 if (bm_check_disable
)
669 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS
, &bm_status
);
671 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS
, 1);
673 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
674 * the true state of bus mastering activity; forcing us to
675 * manually check the BMIDEA bit of each IDE channel.
677 else if (errata
.piix4
.bmisx
) {
678 if ((inb_p(errata
.piix4
.bmisx
+ 0x02) & 0x01)
679 || (inb_p(errata
.piix4
.bmisx
+ 0x0A) & 0x01))
686 * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
689 * Caller disables interrupt before call and enables interrupt after return.
691 static inline void acpi_idle_do_entry(struct acpi_processor_cx
*cx
)
693 /* Don't trace irqs off for idle */
694 stop_critical_timings();
695 if (cx
->entry_method
== ACPI_CSTATE_FFH
) {
696 /* Call into architectural FFH based C-state */
697 acpi_processor_ffh_cstate_enter(cx
);
698 } else if (cx
->entry_method
== ACPI_CSTATE_HALT
) {
701 /* IO port based C-state */
703 /* Dummy wait op - must do something useless after P_LVL2 read
704 because chipsets cannot guarantee that STPCLK# signal
705 gets asserted in time to freeze execution properly. */
706 inl(acpi_gbl_FADT
.xpm_timer_block
.address
);
708 start_critical_timings();
712 * acpi_idle_enter_c1 - enters an ACPI C1 state-type
713 * @dev: the target CPU
714 * @drv: cpuidle driver containing cpuidle state info
715 * @index: index of target state
717 * This is equivalent to the HALT instruction.
719 static int acpi_idle_enter_c1(struct cpuidle_device
*dev
,
720 struct cpuidle_driver
*drv
, int index
)
722 struct acpi_processor
*pr
;
723 struct acpi_processor_cx
*cx
= per_cpu(acpi_cstate
[index
], dev
->cpu
);
725 pr
= __this_cpu_read(processors
);
730 if (cx
->entry_method
== ACPI_CSTATE_FFH
) {
731 if (current_set_polling_and_test())
735 lapic_timer_state_broadcast(pr
, cx
, 1);
736 acpi_idle_do_entry(cx
);
738 lapic_timer_state_broadcast(pr
, cx
, 0);
745 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
746 * @dev: the target CPU
747 * @index: the index of suggested state
749 static int acpi_idle_play_dead(struct cpuidle_device
*dev
, int index
)
751 struct acpi_processor_cx
*cx
= per_cpu(acpi_cstate
[index
], dev
->cpu
);
753 ACPI_FLUSH_CPU_CACHE();
757 if (cx
->entry_method
== ACPI_CSTATE_HALT
)
759 else if (cx
->entry_method
== ACPI_CSTATE_SYSTEMIO
) {
761 /* See comment in acpi_idle_do_entry() */
762 inl(acpi_gbl_FADT
.xpm_timer_block
.address
);
772 * acpi_idle_enter_simple - enters an ACPI state without BM handling
773 * @dev: the target CPU
774 * @drv: cpuidle driver with cpuidle state information
775 * @index: the index of suggested state
777 static int acpi_idle_enter_simple(struct cpuidle_device
*dev
,
778 struct cpuidle_driver
*drv
, int index
)
780 struct acpi_processor
*pr
;
781 struct acpi_processor_cx
*cx
= per_cpu(acpi_cstate
[index
], dev
->cpu
);
783 pr
= __this_cpu_read(processors
);
788 if (cx
->entry_method
== ACPI_CSTATE_FFH
) {
789 if (current_set_polling_and_test())
794 * Must be done before busmaster disable as we might need to
797 lapic_timer_state_broadcast(pr
, cx
, 1);
799 if (cx
->type
== ACPI_STATE_C3
)
800 ACPI_FLUSH_CPU_CACHE();
802 /* Tell the scheduler that we are going deep-idle: */
803 sched_clock_idle_sleep_event();
804 acpi_idle_do_entry(cx
);
806 sched_clock_idle_wakeup_event(0);
808 lapic_timer_state_broadcast(pr
, cx
, 0);
812 static int c3_cpu_count
;
813 static DEFINE_RAW_SPINLOCK(c3_lock
);
816 * acpi_idle_enter_bm - enters C3 with proper BM handling
817 * @dev: the target CPU
818 * @drv: cpuidle driver containing state data
819 * @index: the index of suggested state
821 * If BM is detected, the deepest non-C3 idle state is entered instead.
823 static int acpi_idle_enter_bm(struct cpuidle_device
*dev
,
824 struct cpuidle_driver
*drv
, int index
)
826 struct acpi_processor
*pr
;
827 struct acpi_processor_cx
*cx
= per_cpu(acpi_cstate
[index
], dev
->cpu
);
829 pr
= __this_cpu_read(processors
);
834 if (!cx
->bm_sts_skip
&& acpi_idle_bm_check()) {
835 if (drv
->safe_state_index
>= 0) {
836 return drv
->states
[drv
->safe_state_index
].enter(dev
,
837 drv
, drv
->safe_state_index
);
844 if (cx
->entry_method
== ACPI_CSTATE_FFH
) {
845 if (current_set_polling_and_test())
849 acpi_unlazy_tlb(smp_processor_id());
851 /* Tell the scheduler that we are going deep-idle: */
852 sched_clock_idle_sleep_event();
854 * Must be done before busmaster disable as we might need to
857 lapic_timer_state_broadcast(pr
, cx
, 1);
861 * bm_check implies we need ARB_DIS
862 * !bm_check implies we need cache flush
863 * bm_control implies whether we can do ARB_DIS
865 * That leaves a case where bm_check is set and bm_control is
866 * not set. In that case we cannot do much, we enter C3
867 * without doing anything.
869 if (pr
->flags
.bm_check
&& pr
->flags
.bm_control
) {
870 raw_spin_lock(&c3_lock
);
872 /* Disable bus master arbitration when all CPUs are in C3 */
873 if (c3_cpu_count
== num_online_cpus())
874 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE
, 1);
875 raw_spin_unlock(&c3_lock
);
876 } else if (!pr
->flags
.bm_check
) {
877 ACPI_FLUSH_CPU_CACHE();
880 acpi_idle_do_entry(cx
);
882 /* Re-enable bus master arbitration */
883 if (pr
->flags
.bm_check
&& pr
->flags
.bm_control
) {
884 raw_spin_lock(&c3_lock
);
885 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE
, 0);
887 raw_spin_unlock(&c3_lock
);
890 sched_clock_idle_wakeup_event(0);
892 lapic_timer_state_broadcast(pr
, cx
, 0);
896 struct cpuidle_driver acpi_idle_driver
= {
898 .owner
= THIS_MODULE
,
902 * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE
903 * device i.e. per-cpu data
905 * @pr: the ACPI processor
906 * @dev : the cpuidle device
908 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor
*pr
,
909 struct cpuidle_device
*dev
)
911 int i
, count
= CPUIDLE_DRIVER_STATE_START
;
912 struct acpi_processor_cx
*cx
;
914 if (!pr
->flags
.power_setup_done
)
917 if (pr
->flags
.power
== 0) {
929 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
&& i
<= max_cstate
; i
++) {
930 cx
= &pr
->power
.states
[i
];
935 #ifdef CONFIG_HOTPLUG_CPU
936 if ((cx
->type
!= ACPI_STATE_C1
) && (num_online_cpus() > 1) &&
937 !pr
->flags
.has_cst
&&
938 !(acpi_gbl_FADT
.flags
& ACPI_FADT_C2_MP_SUPPORTED
))
941 per_cpu(acpi_cstate
[count
], dev
->cpu
) = cx
;
944 if (count
== CPUIDLE_STATE_MAX
)
948 dev
->state_count
= count
;
957 * acpi_processor_setup_cpuidle states- prepares and configures cpuidle
958 * global state data i.e. idle routines
960 * @pr: the ACPI processor
962 static int acpi_processor_setup_cpuidle_states(struct acpi_processor
*pr
)
964 int i
, count
= CPUIDLE_DRIVER_STATE_START
;
965 struct acpi_processor_cx
*cx
;
966 struct cpuidle_state
*state
;
967 struct cpuidle_driver
*drv
= &acpi_idle_driver
;
969 if (!pr
->flags
.power_setup_done
)
972 if (pr
->flags
.power
== 0)
975 drv
->safe_state_index
= -1;
976 for (i
= 0; i
< CPUIDLE_STATE_MAX
; i
++) {
977 drv
->states
[i
].name
[0] = '\0';
978 drv
->states
[i
].desc
[0] = '\0';
984 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
&& i
<= max_cstate
; i
++) {
985 cx
= &pr
->power
.states
[i
];
990 #ifdef CONFIG_HOTPLUG_CPU
991 if ((cx
->type
!= ACPI_STATE_C1
) && (num_online_cpus() > 1) &&
992 !pr
->flags
.has_cst
&&
993 !(acpi_gbl_FADT
.flags
& ACPI_FADT_C2_MP_SUPPORTED
))
997 state
= &drv
->states
[count
];
998 snprintf(state
->name
, CPUIDLE_NAME_LEN
, "C%d", i
);
999 strncpy(state
->desc
, cx
->desc
, CPUIDLE_DESC_LEN
);
1000 state
->exit_latency
= cx
->latency
;
1001 state
->target_residency
= cx
->latency
* latency_factor
;
1006 if (cx
->entry_method
== ACPI_CSTATE_FFH
)
1007 state
->flags
|= CPUIDLE_FLAG_TIME_VALID
;
1009 state
->enter
= acpi_idle_enter_c1
;
1010 state
->enter_dead
= acpi_idle_play_dead
;
1011 drv
->safe_state_index
= count
;
1015 state
->flags
|= CPUIDLE_FLAG_TIME_VALID
;
1016 state
->enter
= acpi_idle_enter_simple
;
1017 state
->enter_dead
= acpi_idle_play_dead
;
1018 drv
->safe_state_index
= count
;
1022 state
->flags
|= CPUIDLE_FLAG_TIME_VALID
;
1023 state
->enter
= pr
->flags
.bm_check
?
1024 acpi_idle_enter_bm
:
1025 acpi_idle_enter_simple
;
1030 if (count
== CPUIDLE_STATE_MAX
)
1034 drv
->state_count
= count
;
1042 int acpi_processor_hotplug(struct acpi_processor
*pr
)
1045 struct cpuidle_device
*dev
;
1047 if (disabled_by_idle_boot_param())
1053 if (!pr
->flags
.power_setup_done
)
1056 dev
= per_cpu(acpi_cpuidle_device
, pr
->id
);
1057 cpuidle_pause_and_lock();
1058 cpuidle_disable_device(dev
);
1059 acpi_processor_get_power_info(pr
);
1060 if (pr
->flags
.power
) {
1061 acpi_processor_setup_cpuidle_cx(pr
, dev
);
1062 ret
= cpuidle_enable_device(dev
);
1064 cpuidle_resume_and_unlock();
1069 int acpi_processor_cst_has_changed(struct acpi_processor
*pr
)
1072 struct acpi_processor
*_pr
;
1073 struct cpuidle_device
*dev
;
1075 if (disabled_by_idle_boot_param())
1081 if (!pr
->flags
.power_setup_done
)
1085 * FIXME: Design the ACPI notification to make it once per
1086 * system instead of once per-cpu. This condition is a hack
1087 * to make the code that updates C-States be called once.
1090 if (pr
->id
== 0 && cpuidle_get_driver() == &acpi_idle_driver
) {
1092 cpuidle_pause_and_lock();
1093 /* Protect against cpu-hotplug */
1096 /* Disable all cpuidle devices */
1097 for_each_online_cpu(cpu
) {
1098 _pr
= per_cpu(processors
, cpu
);
1099 if (!_pr
|| !_pr
->flags
.power_setup_done
)
1101 dev
= per_cpu(acpi_cpuidle_device
, cpu
);
1102 cpuidle_disable_device(dev
);
1105 /* Populate Updated C-state information */
1106 acpi_processor_get_power_info(pr
);
1107 acpi_processor_setup_cpuidle_states(pr
);
1109 /* Enable all cpuidle devices */
1110 for_each_online_cpu(cpu
) {
1111 _pr
= per_cpu(processors
, cpu
);
1112 if (!_pr
|| !_pr
->flags
.power_setup_done
)
1114 acpi_processor_get_power_info(_pr
);
1115 if (_pr
->flags
.power
) {
1116 dev
= per_cpu(acpi_cpuidle_device
, cpu
);
1117 acpi_processor_setup_cpuidle_cx(_pr
, dev
);
1118 cpuidle_enable_device(dev
);
1122 cpuidle_resume_and_unlock();
1128 static int acpi_processor_registered
;
1130 int acpi_processor_power_init(struct acpi_processor
*pr
)
1132 acpi_status status
= 0;
1134 struct cpuidle_device
*dev
;
1135 static int first_run
;
1137 if (disabled_by_idle_boot_param())
1141 dmi_check_system(processor_power_dmi_table
);
1142 max_cstate
= acpi_processor_cstate_check(max_cstate
);
1143 if (max_cstate
< ACPI_C_STATES_MAX
)
1145 "ACPI: processor limited to max C-state %d\n",
1150 if (acpi_gbl_FADT
.cst_control
&& !nocst
) {
1152 acpi_os_write_port(acpi_gbl_FADT
.smi_command
, acpi_gbl_FADT
.cst_control
, 8);
1153 if (ACPI_FAILURE(status
)) {
1154 ACPI_EXCEPTION((AE_INFO
, status
,
1155 "Notifying BIOS of _CST ability failed"));
1159 acpi_processor_get_power_info(pr
);
1160 pr
->flags
.power_setup_done
= 1;
1163 * Install the idle handler if processor power management is supported.
1164 * Note that we use previously set idle handler will be used on
1165 * platforms that only support C1.
1167 if (pr
->flags
.power
) {
1168 /* Register acpi_idle_driver if not already registered */
1169 if (!acpi_processor_registered
) {
1170 acpi_processor_setup_cpuidle_states(pr
);
1171 retval
= cpuidle_register_driver(&acpi_idle_driver
);
1174 printk(KERN_DEBUG
"ACPI: %s registered with cpuidle\n",
1175 acpi_idle_driver
.name
);
1178 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
1181 per_cpu(acpi_cpuidle_device
, pr
->id
) = dev
;
1183 acpi_processor_setup_cpuidle_cx(pr
, dev
);
1185 /* Register per-cpu cpuidle_device. Cpuidle driver
1186 * must already be registered before registering device
1188 retval
= cpuidle_register_device(dev
);
1190 if (acpi_processor_registered
== 0)
1191 cpuidle_unregister_driver(&acpi_idle_driver
);
1194 acpi_processor_registered
++;
1199 int acpi_processor_power_exit(struct acpi_processor
*pr
)
1201 struct cpuidle_device
*dev
= per_cpu(acpi_cpuidle_device
, pr
->id
);
1203 if (disabled_by_idle_boot_param())
1206 if (pr
->flags
.power
) {
1207 cpuidle_unregister_device(dev
);
1208 acpi_processor_registered
--;
1209 if (acpi_processor_registered
== 0)
1210 cpuidle_unregister_driver(&acpi_idle_driver
);
1213 pr
->flags
.power_setup_done
= 0;