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 /* Actually this shouldn't be __cpuinitdata, would be better to fix the
100 callers to only run once -AK */
101 static struct dmi_system_id __cpuinitdata processor_power_dmi_table
[] = {
102 { set_max_cstate
, "Clevo 5600D", {
103 DMI_MATCH(DMI_BIOS_VENDOR
,"Phoenix Technologies LTD"),
104 DMI_MATCH(DMI_BIOS_VERSION
,"SHE845M0.86C.0013.D.0302131307")},
106 { set_max_cstate
, "Pavilion zv5000", {
107 DMI_MATCH(DMI_SYS_VENDOR
, "Hewlett-Packard"),
108 DMI_MATCH(DMI_PRODUCT_NAME
,"Pavilion zv5000 (DS502A#ABA)")},
110 { set_max_cstate
, "Asus L8400B", {
111 DMI_MATCH(DMI_SYS_VENDOR
, "ASUSTeK Computer Inc."),
112 DMI_MATCH(DMI_PRODUCT_NAME
,"L8400B series Notebook PC")},
119 * Callers should disable interrupts before the call and enable
120 * interrupts after return.
122 static void acpi_safe_halt(void)
124 current_thread_info()->status
&= ~TS_POLLING
;
126 * TS_POLLING-cleared state must be visible before we
130 if (!need_resched()) {
134 current_thread_info()->status
|= TS_POLLING
;
137 #ifdef ARCH_APICTIMER_STOPS_ON_C3
140 * Some BIOS implementations switch to C3 in the published C2 state.
141 * This seems to be a common problem on AMD boxen, but other vendors
142 * are affected too. We pick the most conservative approach: we assume
143 * that the local APIC stops in both C2 and C3.
145 static void lapic_timer_check_state(int state
, struct acpi_processor
*pr
,
146 struct acpi_processor_cx
*cx
)
148 struct acpi_processor_power
*pwr
= &pr
->power
;
149 u8 type
= local_apic_timer_c2_ok
? ACPI_STATE_C3
: ACPI_STATE_C2
;
151 if (cpu_has(&cpu_data(pr
->id
), X86_FEATURE_ARAT
))
154 if (amd_e400_c1e_detected
)
155 type
= ACPI_STATE_C1
;
158 * Check, if one of the previous states already marked the lapic
161 if (pwr
->timer_broadcast_on_state
< state
)
164 if (cx
->type
>= type
)
165 pr
->power
.timer_broadcast_on_state
= state
;
168 static void __lapic_timer_propagate_broadcast(void *arg
)
170 struct acpi_processor
*pr
= (struct acpi_processor
*) arg
;
171 unsigned long reason
;
173 reason
= pr
->power
.timer_broadcast_on_state
< INT_MAX
?
174 CLOCK_EVT_NOTIFY_BROADCAST_ON
: CLOCK_EVT_NOTIFY_BROADCAST_OFF
;
176 clockevents_notify(reason
, &pr
->id
);
179 static void lapic_timer_propagate_broadcast(struct acpi_processor
*pr
)
181 smp_call_function_single(pr
->id
, __lapic_timer_propagate_broadcast
,
185 /* Power(C) State timer broadcast control */
186 static void lapic_timer_state_broadcast(struct acpi_processor
*pr
,
187 struct acpi_processor_cx
*cx
,
190 int state
= cx
- pr
->power
.states
;
192 if (state
>= pr
->power
.timer_broadcast_on_state
) {
193 unsigned long reason
;
195 reason
= broadcast
? CLOCK_EVT_NOTIFY_BROADCAST_ENTER
:
196 CLOCK_EVT_NOTIFY_BROADCAST_EXIT
;
197 clockevents_notify(reason
, &pr
->id
);
203 static void lapic_timer_check_state(int state
, struct acpi_processor
*pr
,
204 struct acpi_processor_cx
*cstate
) { }
205 static void lapic_timer_propagate_broadcast(struct acpi_processor
*pr
) { }
206 static void lapic_timer_state_broadcast(struct acpi_processor
*pr
,
207 struct acpi_processor_cx
*cx
,
214 #ifdef CONFIG_PM_SLEEP
215 static u32 saved_bm_rld
;
217 int acpi_processor_suspend(void)
219 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD
, &saved_bm_rld
);
223 void acpi_processor_resume(void)
227 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD
, &resumed_bm_rld
);
228 if (resumed_bm_rld
== saved_bm_rld
)
231 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD
, saved_bm_rld
);
234 static struct syscore_ops acpi_processor_syscore_ops
= {
235 .suspend
= acpi_processor_suspend
,
236 .resume
= acpi_processor_resume
,
239 void acpi_processor_syscore_init(void)
241 register_syscore_ops(&acpi_processor_syscore_ops
);
244 void acpi_processor_syscore_exit(void)
246 unregister_syscore_ops(&acpi_processor_syscore_ops
);
248 #endif /* CONFIG_PM_SLEEP */
250 #if defined(CONFIG_X86)
251 static void tsc_check_state(int state
)
253 switch (boot_cpu_data
.x86_vendor
) {
255 case X86_VENDOR_INTEL
:
257 * AMD Fam10h TSC will tick in all
258 * C/P/S0/S1 states when this bit is set.
260 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC
))
265 /* TSC could halt in idle, so notify users */
266 if (state
> ACPI_STATE_C1
)
267 mark_tsc_unstable("TSC halts in idle");
271 static void tsc_check_state(int state
) { return; }
274 static int acpi_processor_get_power_info_fadt(struct acpi_processor
*pr
)
283 /* if info is obtained from pblk/fadt, type equals state */
284 pr
->power
.states
[ACPI_STATE_C2
].type
= ACPI_STATE_C2
;
285 pr
->power
.states
[ACPI_STATE_C3
].type
= ACPI_STATE_C3
;
287 #ifndef CONFIG_HOTPLUG_CPU
289 * Check for P_LVL2_UP flag before entering C2 and above on
292 if ((num_online_cpus() > 1) &&
293 !(acpi_gbl_FADT
.flags
& ACPI_FADT_C2_MP_SUPPORTED
))
297 /* determine C2 and C3 address from pblk */
298 pr
->power
.states
[ACPI_STATE_C2
].address
= pr
->pblk
+ 4;
299 pr
->power
.states
[ACPI_STATE_C3
].address
= pr
->pblk
+ 5;
301 /* determine latencies from FADT */
302 pr
->power
.states
[ACPI_STATE_C2
].latency
= acpi_gbl_FADT
.c2_latency
;
303 pr
->power
.states
[ACPI_STATE_C3
].latency
= acpi_gbl_FADT
.c3_latency
;
306 * FADT specified C2 latency must be less than or equal to
309 if (acpi_gbl_FADT
.c2_latency
> ACPI_PROCESSOR_MAX_C2_LATENCY
) {
310 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
311 "C2 latency too large [%d]\n", acpi_gbl_FADT
.c2_latency
));
313 pr
->power
.states
[ACPI_STATE_C2
].address
= 0;
317 * FADT supplied C3 latency must be less than or equal to
320 if (acpi_gbl_FADT
.c3_latency
> ACPI_PROCESSOR_MAX_C3_LATENCY
) {
321 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
322 "C3 latency too large [%d]\n", acpi_gbl_FADT
.c3_latency
));
324 pr
->power
.states
[ACPI_STATE_C3
].address
= 0;
327 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
328 "lvl2[0x%08x] lvl3[0x%08x]\n",
329 pr
->power
.states
[ACPI_STATE_C2
].address
,
330 pr
->power
.states
[ACPI_STATE_C3
].address
));
335 static int acpi_processor_get_power_info_default(struct acpi_processor
*pr
)
337 if (!pr
->power
.states
[ACPI_STATE_C1
].valid
) {
338 /* set the first C-State to C1 */
339 /* all processors need to support C1 */
340 pr
->power
.states
[ACPI_STATE_C1
].type
= ACPI_STATE_C1
;
341 pr
->power
.states
[ACPI_STATE_C1
].valid
= 1;
342 pr
->power
.states
[ACPI_STATE_C1
].entry_method
= ACPI_CSTATE_HALT
;
344 /* the C0 state only exists as a filler in our array */
345 pr
->power
.states
[ACPI_STATE_C0
].valid
= 1;
349 static int acpi_processor_get_power_info_cst(struct acpi_processor
*pr
)
351 acpi_status status
= 0;
355 struct acpi_buffer buffer
= { ACPI_ALLOCATE_BUFFER
, NULL
};
356 union acpi_object
*cst
;
364 status
= acpi_evaluate_object(pr
->handle
, "_CST", NULL
, &buffer
);
365 if (ACPI_FAILURE(status
)) {
366 ACPI_DEBUG_PRINT((ACPI_DB_INFO
, "No _CST, giving up\n"));
370 cst
= buffer
.pointer
;
372 /* There must be at least 2 elements */
373 if (!cst
|| (cst
->type
!= ACPI_TYPE_PACKAGE
) || cst
->package
.count
< 2) {
374 printk(KERN_ERR PREFIX
"not enough elements in _CST\n");
379 count
= cst
->package
.elements
[0].integer
.value
;
381 /* Validate number of power states. */
382 if (count
< 1 || count
!= cst
->package
.count
- 1) {
383 printk(KERN_ERR PREFIX
"count given by _CST is not valid\n");
388 /* Tell driver that at least _CST is supported. */
389 pr
->flags
.has_cst
= 1;
391 for (i
= 1; i
<= count
; i
++) {
392 union acpi_object
*element
;
393 union acpi_object
*obj
;
394 struct acpi_power_register
*reg
;
395 struct acpi_processor_cx cx
;
397 memset(&cx
, 0, sizeof(cx
));
399 element
= &(cst
->package
.elements
[i
]);
400 if (element
->type
!= ACPI_TYPE_PACKAGE
)
403 if (element
->package
.count
!= 4)
406 obj
= &(element
->package
.elements
[0]);
408 if (obj
->type
!= ACPI_TYPE_BUFFER
)
411 reg
= (struct acpi_power_register
*)obj
->buffer
.pointer
;
413 if (reg
->space_id
!= ACPI_ADR_SPACE_SYSTEM_IO
&&
414 (reg
->space_id
!= ACPI_ADR_SPACE_FIXED_HARDWARE
))
417 /* There should be an easy way to extract an integer... */
418 obj
= &(element
->package
.elements
[1]);
419 if (obj
->type
!= ACPI_TYPE_INTEGER
)
422 cx
.type
= obj
->integer
.value
;
424 * Some buggy BIOSes won't list C1 in _CST -
425 * Let acpi_processor_get_power_info_default() handle them later
427 if (i
== 1 && cx
.type
!= ACPI_STATE_C1
)
430 cx
.address
= reg
->address
;
431 cx
.index
= current_count
+ 1;
433 cx
.entry_method
= ACPI_CSTATE_SYSTEMIO
;
434 if (reg
->space_id
== ACPI_ADR_SPACE_FIXED_HARDWARE
) {
435 if (acpi_processor_ffh_cstate_probe
436 (pr
->id
, &cx
, reg
) == 0) {
437 cx
.entry_method
= ACPI_CSTATE_FFH
;
438 } else if (cx
.type
== ACPI_STATE_C1
) {
440 * C1 is a special case where FIXED_HARDWARE
441 * can be handled in non-MWAIT way as well.
442 * In that case, save this _CST entry info.
443 * Otherwise, ignore this info and continue.
445 cx
.entry_method
= ACPI_CSTATE_HALT
;
446 snprintf(cx
.desc
, ACPI_CX_DESC_LEN
, "ACPI HLT");
450 if (cx
.type
== ACPI_STATE_C1
&&
451 (boot_option_idle_override
== IDLE_NOMWAIT
)) {
453 * In most cases the C1 space_id obtained from
454 * _CST object is FIXED_HARDWARE access mode.
455 * But when the option of idle=halt is added,
456 * the entry_method type should be changed from
457 * CSTATE_FFH to CSTATE_HALT.
458 * When the option of idle=nomwait is added,
459 * the C1 entry_method type should be
462 cx
.entry_method
= ACPI_CSTATE_HALT
;
463 snprintf(cx
.desc
, ACPI_CX_DESC_LEN
, "ACPI HLT");
466 snprintf(cx
.desc
, ACPI_CX_DESC_LEN
, "ACPI IOPORT 0x%x",
470 if (cx
.type
== ACPI_STATE_C1
) {
474 obj
= &(element
->package
.elements
[2]);
475 if (obj
->type
!= ACPI_TYPE_INTEGER
)
478 cx
.latency
= obj
->integer
.value
;
480 obj
= &(element
->package
.elements
[3]);
481 if (obj
->type
!= ACPI_TYPE_INTEGER
)
485 memcpy(&(pr
->power
.states
[current_count
]), &cx
, sizeof(cx
));
488 * We support total ACPI_PROCESSOR_MAX_POWER - 1
489 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
491 if (current_count
>= (ACPI_PROCESSOR_MAX_POWER
- 1)) {
493 "Limiting number of power states to max (%d)\n",
494 ACPI_PROCESSOR_MAX_POWER
);
496 "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
501 ACPI_DEBUG_PRINT((ACPI_DB_INFO
, "Found %d power states\n",
504 /* Validate number of power states discovered */
505 if (current_count
< 2)
509 kfree(buffer
.pointer
);
514 static void acpi_processor_power_verify_c3(struct acpi_processor
*pr
,
515 struct acpi_processor_cx
*cx
)
517 static int bm_check_flag
= -1;
518 static int bm_control_flag
= -1;
525 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
526 * DMA transfers are used by any ISA device to avoid livelock.
527 * Note that we could disable Type-F DMA (as recommended by
528 * the erratum), but this is known to disrupt certain ISA
529 * devices thus we take the conservative approach.
531 else if (errata
.piix4
.fdma
) {
532 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
533 "C3 not supported on PIIX4 with Type-F DMA\n"));
537 /* All the logic here assumes flags.bm_check is same across all CPUs */
538 if (bm_check_flag
== -1) {
539 /* Determine whether bm_check is needed based on CPU */
540 acpi_processor_power_init_bm_check(&(pr
->flags
), pr
->id
);
541 bm_check_flag
= pr
->flags
.bm_check
;
542 bm_control_flag
= pr
->flags
.bm_control
;
544 pr
->flags
.bm_check
= bm_check_flag
;
545 pr
->flags
.bm_control
= bm_control_flag
;
548 if (pr
->flags
.bm_check
) {
549 if (!pr
->flags
.bm_control
) {
550 if (pr
->flags
.has_cst
!= 1) {
551 /* bus mastering control is necessary */
552 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
553 "C3 support requires BM control\n"));
556 /* Here we enter C3 without bus mastering */
557 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
558 "C3 support without BM control\n"));
563 * WBINVD should be set in fadt, for C3 state to be
564 * supported on when bm_check is not required.
566 if (!(acpi_gbl_FADT
.flags
& ACPI_FADT_WBINVD
)) {
567 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
568 "Cache invalidation should work properly"
569 " for C3 to be enabled on SMP systems\n"));
575 * Otherwise we've met all of our C3 requirements.
576 * Normalize the C3 latency to expidite policy. Enable
577 * checking of bus mastering status (bm_check) so we can
578 * use this in our C3 policy
583 * On older chipsets, BM_RLD needs to be set
584 * in order for Bus Master activity to wake the
585 * system from C3. Newer chipsets handle DMA
586 * during C3 automatically and BM_RLD is a NOP.
587 * In either case, the proper way to
588 * handle BM_RLD is to set it and leave it set.
590 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD
, 1);
595 static int acpi_processor_power_verify(struct acpi_processor
*pr
)
598 unsigned int working
= 0;
600 pr
->power
.timer_broadcast_on_state
= INT_MAX
;
602 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
&& i
<= max_cstate
; i
++) {
603 struct acpi_processor_cx
*cx
= &pr
->power
.states
[i
];
617 acpi_processor_power_verify_c3(pr
, cx
);
623 lapic_timer_check_state(i
, pr
, cx
);
624 tsc_check_state(cx
->type
);
628 lapic_timer_propagate_broadcast(pr
);
633 static int acpi_processor_get_power_info(struct acpi_processor
*pr
)
639 /* NOTE: the idle thread may not be running while calling
642 /* Zero initialize all the C-states info. */
643 memset(pr
->power
.states
, 0, sizeof(pr
->power
.states
));
645 result
= acpi_processor_get_power_info_cst(pr
);
646 if (result
== -ENODEV
)
647 result
= acpi_processor_get_power_info_fadt(pr
);
652 acpi_processor_get_power_info_default(pr
);
654 pr
->power
.count
= acpi_processor_power_verify(pr
);
657 * if one state of type C2 or C3 is available, mark this
658 * CPU as being "idle manageable"
660 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
; i
++) {
661 if (pr
->power
.states
[i
].valid
) {
663 if (pr
->power
.states
[i
].type
>= ACPI_STATE_C2
)
672 * acpi_idle_bm_check - checks if bus master activity was detected
674 static int acpi_idle_bm_check(void)
678 if (bm_check_disable
)
681 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS
, &bm_status
);
683 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS
, 1);
685 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
686 * the true state of bus mastering activity; forcing us to
687 * manually check the BMIDEA bit of each IDE channel.
689 else if (errata
.piix4
.bmisx
) {
690 if ((inb_p(errata
.piix4
.bmisx
+ 0x02) & 0x01)
691 || (inb_p(errata
.piix4
.bmisx
+ 0x0A) & 0x01))
698 * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
701 * Caller disables interrupt before call and enables interrupt after return.
703 static inline void acpi_idle_do_entry(struct acpi_processor_cx
*cx
)
705 /* Don't trace irqs off for idle */
706 stop_critical_timings();
707 if (cx
->entry_method
== ACPI_CSTATE_FFH
) {
708 /* Call into architectural FFH based C-state */
709 acpi_processor_ffh_cstate_enter(cx
);
710 } else if (cx
->entry_method
== ACPI_CSTATE_HALT
) {
713 /* IO port based C-state */
715 /* Dummy wait op - must do something useless after P_LVL2 read
716 because chipsets cannot guarantee that STPCLK# signal
717 gets asserted in time to freeze execution properly. */
718 inl(acpi_gbl_FADT
.xpm_timer_block
.address
);
720 start_critical_timings();
724 * acpi_idle_enter_c1 - enters an ACPI C1 state-type
725 * @dev: the target CPU
726 * @drv: cpuidle driver containing cpuidle state info
727 * @index: index of target state
729 * This is equivalent to the HALT instruction.
731 static int acpi_idle_enter_c1(struct cpuidle_device
*dev
,
732 struct cpuidle_driver
*drv
, int index
)
734 struct acpi_processor
*pr
;
735 struct acpi_processor_cx
*cx
= per_cpu(acpi_cstate
[index
], dev
->cpu
);
737 pr
= __this_cpu_read(processors
);
742 lapic_timer_state_broadcast(pr
, cx
, 1);
743 acpi_idle_do_entry(cx
);
745 lapic_timer_state_broadcast(pr
, cx
, 0);
752 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
753 * @dev: the target CPU
754 * @index: the index of suggested state
756 static int acpi_idle_play_dead(struct cpuidle_device
*dev
, int index
)
758 struct acpi_processor_cx
*cx
= per_cpu(acpi_cstate
[index
], dev
->cpu
);
760 ACPI_FLUSH_CPU_CACHE();
764 if (cx
->entry_method
== ACPI_CSTATE_HALT
)
766 else if (cx
->entry_method
== ACPI_CSTATE_SYSTEMIO
) {
768 /* See comment in acpi_idle_do_entry() */
769 inl(acpi_gbl_FADT
.xpm_timer_block
.address
);
779 * acpi_idle_enter_simple - enters an ACPI state without BM handling
780 * @dev: the target CPU
781 * @drv: cpuidle driver with cpuidle state information
782 * @index: the index of suggested state
784 static int acpi_idle_enter_simple(struct cpuidle_device
*dev
,
785 struct cpuidle_driver
*drv
, int index
)
787 struct acpi_processor
*pr
;
788 struct acpi_processor_cx
*cx
= per_cpu(acpi_cstate
[index
], dev
->cpu
);
790 pr
= __this_cpu_read(processors
);
795 if (cx
->entry_method
!= ACPI_CSTATE_FFH
) {
796 current_thread_info()->status
&= ~TS_POLLING
;
798 * TS_POLLING-cleared state must be visible before we test
803 if (unlikely(need_resched())) {
804 current_thread_info()->status
|= TS_POLLING
;
810 * Must be done before busmaster disable as we might need to
813 lapic_timer_state_broadcast(pr
, cx
, 1);
815 if (cx
->type
== ACPI_STATE_C3
)
816 ACPI_FLUSH_CPU_CACHE();
818 /* Tell the scheduler that we are going deep-idle: */
819 sched_clock_idle_sleep_event();
820 acpi_idle_do_entry(cx
);
822 sched_clock_idle_wakeup_event(0);
824 if (cx
->entry_method
!= ACPI_CSTATE_FFH
)
825 current_thread_info()->status
|= TS_POLLING
;
827 lapic_timer_state_broadcast(pr
, cx
, 0);
831 static int c3_cpu_count
;
832 static DEFINE_RAW_SPINLOCK(c3_lock
);
835 * acpi_idle_enter_bm - enters C3 with proper BM handling
836 * @dev: the target CPU
837 * @drv: cpuidle driver containing state data
838 * @index: the index of suggested state
840 * If BM is detected, the deepest non-C3 idle state is entered instead.
842 static int acpi_idle_enter_bm(struct cpuidle_device
*dev
,
843 struct cpuidle_driver
*drv
, int index
)
845 struct acpi_processor
*pr
;
846 struct acpi_processor_cx
*cx
= per_cpu(acpi_cstate
[index
], dev
->cpu
);
848 pr
= __this_cpu_read(processors
);
853 if (!cx
->bm_sts_skip
&& acpi_idle_bm_check()) {
854 if (drv
->safe_state_index
>= 0) {
855 return drv
->states
[drv
->safe_state_index
].enter(dev
,
856 drv
, drv
->safe_state_index
);
863 if (cx
->entry_method
!= ACPI_CSTATE_FFH
) {
864 current_thread_info()->status
&= ~TS_POLLING
;
866 * TS_POLLING-cleared state must be visible before we test
871 if (unlikely(need_resched())) {
872 current_thread_info()->status
|= TS_POLLING
;
877 acpi_unlazy_tlb(smp_processor_id());
879 /* Tell the scheduler that we are going deep-idle: */
880 sched_clock_idle_sleep_event();
882 * Must be done before busmaster disable as we might need to
885 lapic_timer_state_broadcast(pr
, cx
, 1);
889 * bm_check implies we need ARB_DIS
890 * !bm_check implies we need cache flush
891 * bm_control implies whether we can do ARB_DIS
893 * That leaves a case where bm_check is set and bm_control is
894 * not set. In that case we cannot do much, we enter C3
895 * without doing anything.
897 if (pr
->flags
.bm_check
&& pr
->flags
.bm_control
) {
898 raw_spin_lock(&c3_lock
);
900 /* Disable bus master arbitration when all CPUs are in C3 */
901 if (c3_cpu_count
== num_online_cpus())
902 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE
, 1);
903 raw_spin_unlock(&c3_lock
);
904 } else if (!pr
->flags
.bm_check
) {
905 ACPI_FLUSH_CPU_CACHE();
908 acpi_idle_do_entry(cx
);
910 /* Re-enable bus master arbitration */
911 if (pr
->flags
.bm_check
&& pr
->flags
.bm_control
) {
912 raw_spin_lock(&c3_lock
);
913 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE
, 0);
915 raw_spin_unlock(&c3_lock
);
918 sched_clock_idle_wakeup_event(0);
920 if (cx
->entry_method
!= ACPI_CSTATE_FFH
)
921 current_thread_info()->status
|= TS_POLLING
;
923 lapic_timer_state_broadcast(pr
, cx
, 0);
927 struct cpuidle_driver acpi_idle_driver
= {
929 .owner
= THIS_MODULE
,
933 * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE
934 * device i.e. per-cpu data
936 * @pr: the ACPI processor
937 * @dev : the cpuidle device
939 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor
*pr
,
940 struct cpuidle_device
*dev
)
942 int i
, count
= CPUIDLE_DRIVER_STATE_START
;
943 struct acpi_processor_cx
*cx
;
945 if (!pr
->flags
.power_setup_done
)
948 if (pr
->flags
.power
== 0) {
960 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
&& i
<= max_cstate
; i
++) {
961 cx
= &pr
->power
.states
[i
];
966 #ifdef CONFIG_HOTPLUG_CPU
967 if ((cx
->type
!= ACPI_STATE_C1
) && (num_online_cpus() > 1) &&
968 !pr
->flags
.has_cst
&&
969 !(acpi_gbl_FADT
.flags
& ACPI_FADT_C2_MP_SUPPORTED
))
972 per_cpu(acpi_cstate
[count
], dev
->cpu
) = cx
;
975 if (count
== CPUIDLE_STATE_MAX
)
979 dev
->state_count
= count
;
988 * acpi_processor_setup_cpuidle states- prepares and configures cpuidle
989 * global state data i.e. idle routines
991 * @pr: the ACPI processor
993 static int acpi_processor_setup_cpuidle_states(struct acpi_processor
*pr
)
995 int i
, count
= CPUIDLE_DRIVER_STATE_START
;
996 struct acpi_processor_cx
*cx
;
997 struct cpuidle_state
*state
;
998 struct cpuidle_driver
*drv
= &acpi_idle_driver
;
1000 if (!pr
->flags
.power_setup_done
)
1003 if (pr
->flags
.power
== 0)
1006 drv
->safe_state_index
= -1;
1007 for (i
= 0; i
< CPUIDLE_STATE_MAX
; i
++) {
1008 drv
->states
[i
].name
[0] = '\0';
1009 drv
->states
[i
].desc
[0] = '\0';
1012 if (max_cstate
== 0)
1015 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
&& i
<= max_cstate
; i
++) {
1016 cx
= &pr
->power
.states
[i
];
1021 #ifdef CONFIG_HOTPLUG_CPU
1022 if ((cx
->type
!= ACPI_STATE_C1
) && (num_online_cpus() > 1) &&
1023 !pr
->flags
.has_cst
&&
1024 !(acpi_gbl_FADT
.flags
& ACPI_FADT_C2_MP_SUPPORTED
))
1028 state
= &drv
->states
[count
];
1029 snprintf(state
->name
, CPUIDLE_NAME_LEN
, "C%d", i
);
1030 strncpy(state
->desc
, cx
->desc
, CPUIDLE_DESC_LEN
);
1031 state
->exit_latency
= cx
->latency
;
1032 state
->target_residency
= cx
->latency
* latency_factor
;
1037 if (cx
->entry_method
== ACPI_CSTATE_FFH
)
1038 state
->flags
|= CPUIDLE_FLAG_TIME_VALID
;
1040 state
->enter
= acpi_idle_enter_c1
;
1041 state
->enter_dead
= acpi_idle_play_dead
;
1042 drv
->safe_state_index
= count
;
1046 state
->flags
|= CPUIDLE_FLAG_TIME_VALID
;
1047 state
->enter
= acpi_idle_enter_simple
;
1048 state
->enter_dead
= acpi_idle_play_dead
;
1049 drv
->safe_state_index
= count
;
1053 state
->flags
|= CPUIDLE_FLAG_TIME_VALID
;
1054 state
->enter
= pr
->flags
.bm_check
?
1055 acpi_idle_enter_bm
:
1056 acpi_idle_enter_simple
;
1061 if (count
== CPUIDLE_STATE_MAX
)
1065 drv
->state_count
= count
;
1073 int acpi_processor_hotplug(struct acpi_processor
*pr
)
1076 struct cpuidle_device
*dev
;
1078 if (disabled_by_idle_boot_param())
1088 if (!pr
->flags
.power_setup_done
)
1091 dev
= per_cpu(acpi_cpuidle_device
, pr
->id
);
1092 cpuidle_pause_and_lock();
1093 cpuidle_disable_device(dev
);
1094 acpi_processor_get_power_info(pr
);
1095 if (pr
->flags
.power
) {
1096 acpi_processor_setup_cpuidle_cx(pr
, dev
);
1097 ret
= cpuidle_enable_device(dev
);
1099 cpuidle_resume_and_unlock();
1104 int acpi_processor_cst_has_changed(struct acpi_processor
*pr
)
1107 struct acpi_processor
*_pr
;
1108 struct cpuidle_device
*dev
;
1110 if (disabled_by_idle_boot_param())
1119 if (!pr
->flags
.power_setup_done
)
1123 * FIXME: Design the ACPI notification to make it once per
1124 * system instead of once per-cpu. This condition is a hack
1125 * to make the code that updates C-States be called once.
1128 if (pr
->id
== 0 && cpuidle_get_driver() == &acpi_idle_driver
) {
1130 cpuidle_pause_and_lock();
1131 /* Protect against cpu-hotplug */
1134 /* Disable all cpuidle devices */
1135 for_each_online_cpu(cpu
) {
1136 _pr
= per_cpu(processors
, cpu
);
1137 if (!_pr
|| !_pr
->flags
.power_setup_done
)
1139 dev
= per_cpu(acpi_cpuidle_device
, cpu
);
1140 cpuidle_disable_device(dev
);
1143 /* Populate Updated C-state information */
1144 acpi_processor_get_power_info(pr
);
1145 acpi_processor_setup_cpuidle_states(pr
);
1147 /* Enable all cpuidle devices */
1148 for_each_online_cpu(cpu
) {
1149 _pr
= per_cpu(processors
, cpu
);
1150 if (!_pr
|| !_pr
->flags
.power_setup_done
)
1152 acpi_processor_get_power_info(_pr
);
1153 if (_pr
->flags
.power
) {
1154 dev
= per_cpu(acpi_cpuidle_device
, cpu
);
1155 acpi_processor_setup_cpuidle_cx(_pr
, dev
);
1156 cpuidle_enable_device(dev
);
1160 cpuidle_resume_and_unlock();
1166 static int acpi_processor_registered
;
1168 int __cpuinit
acpi_processor_power_init(struct acpi_processor
*pr
)
1170 acpi_status status
= 0;
1172 struct cpuidle_device
*dev
;
1173 static int first_run
;
1175 if (disabled_by_idle_boot_param())
1179 dmi_check_system(processor_power_dmi_table
);
1180 max_cstate
= acpi_processor_cstate_check(max_cstate
);
1181 if (max_cstate
< ACPI_C_STATES_MAX
)
1183 "ACPI: processor limited to max C-state %d\n",
1191 if (acpi_gbl_FADT
.cst_control
&& !nocst
) {
1193 acpi_os_write_port(acpi_gbl_FADT
.smi_command
, acpi_gbl_FADT
.cst_control
, 8);
1194 if (ACPI_FAILURE(status
)) {
1195 ACPI_EXCEPTION((AE_INFO
, status
,
1196 "Notifying BIOS of _CST ability failed"));
1200 acpi_processor_get_power_info(pr
);
1201 pr
->flags
.power_setup_done
= 1;
1204 * Install the idle handler if processor power management is supported.
1205 * Note that we use previously set idle handler will be used on
1206 * platforms that only support C1.
1208 if (pr
->flags
.power
) {
1209 /* Register acpi_idle_driver if not already registered */
1210 if (!acpi_processor_registered
) {
1211 acpi_processor_setup_cpuidle_states(pr
);
1212 retval
= cpuidle_register_driver(&acpi_idle_driver
);
1215 printk(KERN_DEBUG
"ACPI: %s registered with cpuidle\n",
1216 acpi_idle_driver
.name
);
1219 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
1222 per_cpu(acpi_cpuidle_device
, pr
->id
) = dev
;
1224 acpi_processor_setup_cpuidle_cx(pr
, dev
);
1226 /* Register per-cpu cpuidle_device. Cpuidle driver
1227 * must already be registered before registering device
1229 retval
= cpuidle_register_device(dev
);
1231 if (acpi_processor_registered
== 0)
1232 cpuidle_unregister_driver(&acpi_idle_driver
);
1235 acpi_processor_registered
++;
1240 int acpi_processor_power_exit(struct acpi_processor
*pr
)
1242 struct cpuidle_device
*dev
= per_cpu(acpi_cpuidle_device
, pr
->id
);
1244 if (disabled_by_idle_boot_param())
1247 if (pr
->flags
.power
) {
1248 cpuidle_unregister_device(dev
);
1249 acpi_processor_registered
--;
1250 if (acpi_processor_registered
== 0)
1251 cpuidle_unregister_driver(&acpi_idle_driver
);
1254 pr
->flags
.power_setup_done
= 0;