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>
38 #include <acpi/processor.h>
41 * Include the apic definitions for x86 to have the APIC timer related defines
42 * available also for UP (on SMP it gets magically included via linux/smp.h).
43 * asm/acpi.h is not an option, as it would require more include magic. Also
44 * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
50 #define PREFIX "ACPI: "
52 #define ACPI_PROCESSOR_CLASS "processor"
53 #define _COMPONENT ACPI_PROCESSOR_COMPONENT
54 ACPI_MODULE_NAME("processor_idle");
56 static unsigned int max_cstate __read_mostly
= ACPI_PROCESSOR_MAX_POWER
;
57 module_param(max_cstate
, uint
, 0000);
58 static unsigned int nocst __read_mostly
;
59 module_param(nocst
, uint
, 0000);
60 static int bm_check_disable __read_mostly
;
61 module_param(bm_check_disable
, uint
, 0000);
63 static unsigned int latency_factor __read_mostly
= 2;
64 module_param(latency_factor
, uint
, 0644);
66 static DEFINE_PER_CPU(struct cpuidle_device
*, acpi_cpuidle_device
);
68 static DEFINE_PER_CPU(struct acpi_processor_cx
* [CPUIDLE_STATE_MAX
],
71 static int disabled_by_idle_boot_param(void)
73 return boot_option_idle_override
== IDLE_POLL
||
74 boot_option_idle_override
== IDLE_HALT
;
78 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
79 * For now disable this. Probably a bug somewhere else.
81 * To skip this limit, boot/load with a large max_cstate limit.
83 static int set_max_cstate(const struct dmi_system_id
*id
)
85 if (max_cstate
> ACPI_PROCESSOR_MAX_POWER
)
88 printk(KERN_NOTICE PREFIX
"%s detected - limiting to C%ld max_cstate."
89 " Override with \"processor.max_cstate=%d\"\n", id
->ident
,
90 (long)id
->driver_data
, ACPI_PROCESSOR_MAX_POWER
+ 1);
92 max_cstate
= (long)id
->driver_data
;
97 static struct dmi_system_id processor_power_dmi_table
[] = {
98 { set_max_cstate
, "Clevo 5600D", {
99 DMI_MATCH(DMI_BIOS_VENDOR
,"Phoenix Technologies LTD"),
100 DMI_MATCH(DMI_BIOS_VERSION
,"SHE845M0.86C.0013.D.0302131307")},
102 { set_max_cstate
, "Pavilion zv5000", {
103 DMI_MATCH(DMI_SYS_VENDOR
, "Hewlett-Packard"),
104 DMI_MATCH(DMI_PRODUCT_NAME
,"Pavilion zv5000 (DS502A#ABA)")},
106 { set_max_cstate
, "Asus L8400B", {
107 DMI_MATCH(DMI_SYS_VENDOR
, "ASUSTeK Computer Inc."),
108 DMI_MATCH(DMI_PRODUCT_NAME
,"L8400B series Notebook PC")},
115 * Callers should disable interrupts before the call and enable
116 * interrupts after return.
118 static void acpi_safe_halt(void)
120 if (!tif_need_resched()) {
126 #ifdef ARCH_APICTIMER_STOPS_ON_C3
129 * Some BIOS implementations switch to C3 in the published C2 state.
130 * This seems to be a common problem on AMD boxen, but other vendors
131 * are affected too. We pick the most conservative approach: we assume
132 * that the local APIC stops in both C2 and C3.
134 static void lapic_timer_check_state(int state
, struct acpi_processor
*pr
,
135 struct acpi_processor_cx
*cx
)
137 struct acpi_processor_power
*pwr
= &pr
->power
;
138 u8 type
= local_apic_timer_c2_ok
? ACPI_STATE_C3
: ACPI_STATE_C2
;
140 if (cpu_has(&cpu_data(pr
->id
), X86_FEATURE_ARAT
))
143 if (amd_e400_c1e_detected
)
144 type
= ACPI_STATE_C1
;
147 * Check, if one of the previous states already marked the lapic
150 if (pwr
->timer_broadcast_on_state
< state
)
153 if (cx
->type
>= type
)
154 pr
->power
.timer_broadcast_on_state
= state
;
157 static void __lapic_timer_propagate_broadcast(void *arg
)
159 struct acpi_processor
*pr
= (struct acpi_processor
*) arg
;
160 unsigned long reason
;
162 reason
= pr
->power
.timer_broadcast_on_state
< INT_MAX
?
163 CLOCK_EVT_NOTIFY_BROADCAST_ON
: CLOCK_EVT_NOTIFY_BROADCAST_OFF
;
165 clockevents_notify(reason
, &pr
->id
);
168 static void lapic_timer_propagate_broadcast(struct acpi_processor
*pr
)
170 smp_call_function_single(pr
->id
, __lapic_timer_propagate_broadcast
,
174 /* Power(C) State timer broadcast control */
175 static void lapic_timer_state_broadcast(struct acpi_processor
*pr
,
176 struct acpi_processor_cx
*cx
,
179 int state
= cx
- pr
->power
.states
;
181 if (state
>= pr
->power
.timer_broadcast_on_state
) {
182 unsigned long reason
;
184 reason
= broadcast
? CLOCK_EVT_NOTIFY_BROADCAST_ENTER
:
185 CLOCK_EVT_NOTIFY_BROADCAST_EXIT
;
186 clockevents_notify(reason
, &pr
->id
);
192 static void lapic_timer_check_state(int state
, struct acpi_processor
*pr
,
193 struct acpi_processor_cx
*cstate
) { }
194 static void lapic_timer_propagate_broadcast(struct acpi_processor
*pr
) { }
195 static void lapic_timer_state_broadcast(struct acpi_processor
*pr
,
196 struct acpi_processor_cx
*cx
,
203 #ifdef CONFIG_PM_SLEEP
204 static u32 saved_bm_rld
;
206 static int acpi_processor_suspend(void)
208 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD
, &saved_bm_rld
);
212 static void acpi_processor_resume(void)
214 u32 resumed_bm_rld
= 0;
216 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD
, &resumed_bm_rld
);
217 if (resumed_bm_rld
== saved_bm_rld
)
220 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD
, saved_bm_rld
);
223 static struct syscore_ops acpi_processor_syscore_ops
= {
224 .suspend
= acpi_processor_suspend
,
225 .resume
= acpi_processor_resume
,
228 void acpi_processor_syscore_init(void)
230 register_syscore_ops(&acpi_processor_syscore_ops
);
233 void acpi_processor_syscore_exit(void)
235 unregister_syscore_ops(&acpi_processor_syscore_ops
);
237 #endif /* CONFIG_PM_SLEEP */
239 #if defined(CONFIG_X86)
240 static void tsc_check_state(int state
)
242 switch (boot_cpu_data
.x86_vendor
) {
244 case X86_VENDOR_INTEL
:
246 * AMD Fam10h TSC will tick in all
247 * C/P/S0/S1 states when this bit is set.
249 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC
))
254 /* TSC could halt in idle, so notify users */
255 if (state
> ACPI_STATE_C1
)
256 mark_tsc_unstable("TSC halts in idle");
260 static void tsc_check_state(int state
) { return; }
263 static int acpi_processor_get_power_info_fadt(struct acpi_processor
*pr
)
269 /* if info is obtained from pblk/fadt, type equals state */
270 pr
->power
.states
[ACPI_STATE_C2
].type
= ACPI_STATE_C2
;
271 pr
->power
.states
[ACPI_STATE_C3
].type
= ACPI_STATE_C3
;
273 #ifndef CONFIG_HOTPLUG_CPU
275 * Check for P_LVL2_UP flag before entering C2 and above on
278 if ((num_online_cpus() > 1) &&
279 !(acpi_gbl_FADT
.flags
& ACPI_FADT_C2_MP_SUPPORTED
))
283 /* determine C2 and C3 address from pblk */
284 pr
->power
.states
[ACPI_STATE_C2
].address
= pr
->pblk
+ 4;
285 pr
->power
.states
[ACPI_STATE_C3
].address
= pr
->pblk
+ 5;
287 /* determine latencies from FADT */
288 pr
->power
.states
[ACPI_STATE_C2
].latency
= acpi_gbl_FADT
.c2_latency
;
289 pr
->power
.states
[ACPI_STATE_C3
].latency
= acpi_gbl_FADT
.c3_latency
;
292 * FADT specified C2 latency must be less than or equal to
295 if (acpi_gbl_FADT
.c2_latency
> ACPI_PROCESSOR_MAX_C2_LATENCY
) {
296 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
297 "C2 latency too large [%d]\n", acpi_gbl_FADT
.c2_latency
));
299 pr
->power
.states
[ACPI_STATE_C2
].address
= 0;
303 * FADT supplied C3 latency must be less than or equal to
306 if (acpi_gbl_FADT
.c3_latency
> ACPI_PROCESSOR_MAX_C3_LATENCY
) {
307 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
308 "C3 latency too large [%d]\n", acpi_gbl_FADT
.c3_latency
));
310 pr
->power
.states
[ACPI_STATE_C3
].address
= 0;
313 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
314 "lvl2[0x%08x] lvl3[0x%08x]\n",
315 pr
->power
.states
[ACPI_STATE_C2
].address
,
316 pr
->power
.states
[ACPI_STATE_C3
].address
));
321 static int acpi_processor_get_power_info_default(struct acpi_processor
*pr
)
323 if (!pr
->power
.states
[ACPI_STATE_C1
].valid
) {
324 /* set the first C-State to C1 */
325 /* all processors need to support C1 */
326 pr
->power
.states
[ACPI_STATE_C1
].type
= ACPI_STATE_C1
;
327 pr
->power
.states
[ACPI_STATE_C1
].valid
= 1;
328 pr
->power
.states
[ACPI_STATE_C1
].entry_method
= ACPI_CSTATE_HALT
;
330 /* the C0 state only exists as a filler in our array */
331 pr
->power
.states
[ACPI_STATE_C0
].valid
= 1;
335 static int acpi_processor_get_power_info_cst(struct acpi_processor
*pr
)
341 struct acpi_buffer buffer
= { ACPI_ALLOCATE_BUFFER
, NULL
};
342 union acpi_object
*cst
;
350 status
= acpi_evaluate_object(pr
->handle
, "_CST", NULL
, &buffer
);
351 if (ACPI_FAILURE(status
)) {
352 ACPI_DEBUG_PRINT((ACPI_DB_INFO
, "No _CST, giving up\n"));
356 cst
= buffer
.pointer
;
358 /* There must be at least 2 elements */
359 if (!cst
|| (cst
->type
!= ACPI_TYPE_PACKAGE
) || cst
->package
.count
< 2) {
360 printk(KERN_ERR PREFIX
"not enough elements in _CST\n");
365 count
= cst
->package
.elements
[0].integer
.value
;
367 /* Validate number of power states. */
368 if (count
< 1 || count
!= cst
->package
.count
- 1) {
369 printk(KERN_ERR PREFIX
"count given by _CST is not valid\n");
374 /* Tell driver that at least _CST is supported. */
375 pr
->flags
.has_cst
= 1;
377 for (i
= 1; i
<= count
; i
++) {
378 union acpi_object
*element
;
379 union acpi_object
*obj
;
380 struct acpi_power_register
*reg
;
381 struct acpi_processor_cx cx
;
383 memset(&cx
, 0, sizeof(cx
));
385 element
= &(cst
->package
.elements
[i
]);
386 if (element
->type
!= ACPI_TYPE_PACKAGE
)
389 if (element
->package
.count
!= 4)
392 obj
= &(element
->package
.elements
[0]);
394 if (obj
->type
!= ACPI_TYPE_BUFFER
)
397 reg
= (struct acpi_power_register
*)obj
->buffer
.pointer
;
399 if (reg
->space_id
!= ACPI_ADR_SPACE_SYSTEM_IO
&&
400 (reg
->space_id
!= ACPI_ADR_SPACE_FIXED_HARDWARE
))
403 /* There should be an easy way to extract an integer... */
404 obj
= &(element
->package
.elements
[1]);
405 if (obj
->type
!= ACPI_TYPE_INTEGER
)
408 cx
.type
= obj
->integer
.value
;
410 * Some buggy BIOSes won't list C1 in _CST -
411 * Let acpi_processor_get_power_info_default() handle them later
413 if (i
== 1 && cx
.type
!= ACPI_STATE_C1
)
416 cx
.address
= reg
->address
;
417 cx
.index
= current_count
+ 1;
419 cx
.entry_method
= ACPI_CSTATE_SYSTEMIO
;
420 if (reg
->space_id
== ACPI_ADR_SPACE_FIXED_HARDWARE
) {
421 if (acpi_processor_ffh_cstate_probe
422 (pr
->id
, &cx
, reg
) == 0) {
423 cx
.entry_method
= ACPI_CSTATE_FFH
;
424 } else if (cx
.type
== ACPI_STATE_C1
) {
426 * C1 is a special case where FIXED_HARDWARE
427 * can be handled in non-MWAIT way as well.
428 * In that case, save this _CST entry info.
429 * Otherwise, ignore this info and continue.
431 cx
.entry_method
= ACPI_CSTATE_HALT
;
432 snprintf(cx
.desc
, ACPI_CX_DESC_LEN
, "ACPI HLT");
436 if (cx
.type
== ACPI_STATE_C1
&&
437 (boot_option_idle_override
== IDLE_NOMWAIT
)) {
439 * In most cases the C1 space_id obtained from
440 * _CST object is FIXED_HARDWARE access mode.
441 * But when the option of idle=halt is added,
442 * the entry_method type should be changed from
443 * CSTATE_FFH to CSTATE_HALT.
444 * When the option of idle=nomwait is added,
445 * the C1 entry_method type should be
448 cx
.entry_method
= ACPI_CSTATE_HALT
;
449 snprintf(cx
.desc
, ACPI_CX_DESC_LEN
, "ACPI HLT");
452 snprintf(cx
.desc
, ACPI_CX_DESC_LEN
, "ACPI IOPORT 0x%x",
456 if (cx
.type
== ACPI_STATE_C1
) {
460 obj
= &(element
->package
.elements
[2]);
461 if (obj
->type
!= ACPI_TYPE_INTEGER
)
464 cx
.latency
= obj
->integer
.value
;
466 obj
= &(element
->package
.elements
[3]);
467 if (obj
->type
!= ACPI_TYPE_INTEGER
)
471 memcpy(&(pr
->power
.states
[current_count
]), &cx
, sizeof(cx
));
474 * We support total ACPI_PROCESSOR_MAX_POWER - 1
475 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
477 if (current_count
>= (ACPI_PROCESSOR_MAX_POWER
- 1)) {
479 "Limiting number of power states to max (%d)\n",
480 ACPI_PROCESSOR_MAX_POWER
);
482 "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
487 ACPI_DEBUG_PRINT((ACPI_DB_INFO
, "Found %d power states\n",
490 /* Validate number of power states discovered */
491 if (current_count
< 2)
495 kfree(buffer
.pointer
);
500 static void acpi_processor_power_verify_c3(struct acpi_processor
*pr
,
501 struct acpi_processor_cx
*cx
)
503 static int bm_check_flag
= -1;
504 static int bm_control_flag
= -1;
511 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
512 * DMA transfers are used by any ISA device to avoid livelock.
513 * Note that we could disable Type-F DMA (as recommended by
514 * the erratum), but this is known to disrupt certain ISA
515 * devices thus we take the conservative approach.
517 else if (errata
.piix4
.fdma
) {
518 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
519 "C3 not supported on PIIX4 with Type-F DMA\n"));
523 /* All the logic here assumes flags.bm_check is same across all CPUs */
524 if (bm_check_flag
== -1) {
525 /* Determine whether bm_check is needed based on CPU */
526 acpi_processor_power_init_bm_check(&(pr
->flags
), pr
->id
);
527 bm_check_flag
= pr
->flags
.bm_check
;
528 bm_control_flag
= pr
->flags
.bm_control
;
530 pr
->flags
.bm_check
= bm_check_flag
;
531 pr
->flags
.bm_control
= bm_control_flag
;
534 if (pr
->flags
.bm_check
) {
535 if (!pr
->flags
.bm_control
) {
536 if (pr
->flags
.has_cst
!= 1) {
537 /* bus mastering control is necessary */
538 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
539 "C3 support requires BM control\n"));
542 /* Here we enter C3 without bus mastering */
543 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
544 "C3 support without BM control\n"));
549 * WBINVD should be set in fadt, for C3 state to be
550 * supported on when bm_check is not required.
552 if (!(acpi_gbl_FADT
.flags
& ACPI_FADT_WBINVD
)) {
553 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
554 "Cache invalidation should work properly"
555 " for C3 to be enabled on SMP systems\n"));
561 * Otherwise we've met all of our C3 requirements.
562 * Normalize the C3 latency to expidite policy. Enable
563 * checking of bus mastering status (bm_check) so we can
564 * use this in our C3 policy
569 * On older chipsets, BM_RLD needs to be set
570 * in order for Bus Master activity to wake the
571 * system from C3. Newer chipsets handle DMA
572 * during C3 automatically and BM_RLD is a NOP.
573 * In either case, the proper way to
574 * handle BM_RLD is to set it and leave it set.
576 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD
, 1);
581 static int acpi_processor_power_verify(struct acpi_processor
*pr
)
584 unsigned int working
= 0;
586 pr
->power
.timer_broadcast_on_state
= INT_MAX
;
588 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
&& i
<= max_cstate
; i
++) {
589 struct acpi_processor_cx
*cx
= &pr
->power
.states
[i
];
603 acpi_processor_power_verify_c3(pr
, cx
);
609 lapic_timer_check_state(i
, pr
, cx
);
610 tsc_check_state(cx
->type
);
614 lapic_timer_propagate_broadcast(pr
);
619 static int acpi_processor_get_power_info(struct acpi_processor
*pr
)
625 /* NOTE: the idle thread may not be running while calling
628 /* Zero initialize all the C-states info. */
629 memset(pr
->power
.states
, 0, sizeof(pr
->power
.states
));
631 result
= acpi_processor_get_power_info_cst(pr
);
632 if (result
== -ENODEV
)
633 result
= acpi_processor_get_power_info_fadt(pr
);
638 acpi_processor_get_power_info_default(pr
);
640 pr
->power
.count
= acpi_processor_power_verify(pr
);
643 * if one state of type C2 or C3 is available, mark this
644 * CPU as being "idle manageable"
646 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
; i
++) {
647 if (pr
->power
.states
[i
].valid
) {
649 if (pr
->power
.states
[i
].type
>= ACPI_STATE_C2
)
658 * acpi_idle_bm_check - checks if bus master activity was detected
660 static int acpi_idle_bm_check(void)
664 if (bm_check_disable
)
667 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS
, &bm_status
);
669 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS
, 1);
671 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
672 * the true state of bus mastering activity; forcing us to
673 * manually check the BMIDEA bit of each IDE channel.
675 else if (errata
.piix4
.bmisx
) {
676 if ((inb_p(errata
.piix4
.bmisx
+ 0x02) & 0x01)
677 || (inb_p(errata
.piix4
.bmisx
+ 0x0A) & 0x01))
684 * acpi_idle_do_entry - enter idle state using the appropriate method
687 * Caller disables interrupt before call and enables interrupt after return.
689 static void acpi_idle_do_entry(struct acpi_processor_cx
*cx
)
691 if (cx
->entry_method
== ACPI_CSTATE_FFH
) {
692 /* Call into architectural FFH based C-state */
693 acpi_processor_ffh_cstate_enter(cx
);
694 } else if (cx
->entry_method
== ACPI_CSTATE_HALT
) {
697 /* IO port based C-state */
699 /* Dummy wait op - must do something useless after P_LVL2 read
700 because chipsets cannot guarantee that STPCLK# signal
701 gets asserted in time to freeze execution properly. */
702 inl(acpi_gbl_FADT
.xpm_timer_block
.address
);
707 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
708 * @dev: the target CPU
709 * @index: the index of suggested state
711 static int acpi_idle_play_dead(struct cpuidle_device
*dev
, int index
)
713 struct acpi_processor_cx
*cx
= per_cpu(acpi_cstate
[index
], dev
->cpu
);
715 ACPI_FLUSH_CPU_CACHE();
719 if (cx
->entry_method
== ACPI_CSTATE_HALT
)
721 else if (cx
->entry_method
== ACPI_CSTATE_SYSTEMIO
) {
723 /* See comment in acpi_idle_do_entry() */
724 inl(acpi_gbl_FADT
.xpm_timer_block
.address
);
733 static bool acpi_idle_fallback_to_c1(struct acpi_processor
*pr
)
735 return IS_ENABLED(CONFIG_HOTPLUG_CPU
) && !pr
->flags
.has_cst
&&
736 !(acpi_gbl_FADT
.flags
& ACPI_FADT_C2_MP_SUPPORTED
);
739 static int c3_cpu_count
;
740 static DEFINE_RAW_SPINLOCK(c3_lock
);
743 * acpi_idle_enter_bm - enters C3 with proper BM handling
744 * @pr: Target processor
745 * @cx: Target state context
746 * @timer_bc: Whether or not to change timer mode to broadcast
748 static void acpi_idle_enter_bm(struct acpi_processor
*pr
,
749 struct acpi_processor_cx
*cx
, bool timer_bc
)
751 acpi_unlazy_tlb(smp_processor_id());
754 * Must be done before busmaster disable as we might need to
758 lapic_timer_state_broadcast(pr
, cx
, 1);
762 * bm_check implies we need ARB_DIS
763 * bm_control implies whether we can do ARB_DIS
765 * That leaves a case where bm_check is set and bm_control is
766 * not set. In that case we cannot do much, we enter C3
767 * without doing anything.
769 if (pr
->flags
.bm_control
) {
770 raw_spin_lock(&c3_lock
);
772 /* Disable bus master arbitration when all CPUs are in C3 */
773 if (c3_cpu_count
== num_online_cpus())
774 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE
, 1);
775 raw_spin_unlock(&c3_lock
);
778 acpi_idle_do_entry(cx
);
780 /* Re-enable bus master arbitration */
781 if (pr
->flags
.bm_control
) {
782 raw_spin_lock(&c3_lock
);
783 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE
, 0);
785 raw_spin_unlock(&c3_lock
);
789 lapic_timer_state_broadcast(pr
, cx
, 0);
792 static int acpi_idle_enter(struct cpuidle_device
*dev
,
793 struct cpuidle_driver
*drv
, int index
)
795 struct acpi_processor_cx
*cx
= per_cpu(acpi_cstate
[index
], dev
->cpu
);
796 struct acpi_processor
*pr
;
798 pr
= __this_cpu_read(processors
);
802 if (cx
->type
!= ACPI_STATE_C1
) {
803 if (acpi_idle_fallback_to_c1(pr
) && num_online_cpus() > 1) {
804 index
= CPUIDLE_DRIVER_STATE_START
;
805 cx
= per_cpu(acpi_cstate
[index
], dev
->cpu
);
806 } else if (cx
->type
== ACPI_STATE_C3
&& pr
->flags
.bm_check
) {
807 if (cx
->bm_sts_skip
|| !acpi_idle_bm_check()) {
808 acpi_idle_enter_bm(pr
, cx
, true);
810 } else if (drv
->safe_state_index
>= 0) {
811 index
= drv
->safe_state_index
;
812 cx
= per_cpu(acpi_cstate
[index
], dev
->cpu
);
820 lapic_timer_state_broadcast(pr
, cx
, 1);
822 if (cx
->type
== ACPI_STATE_C3
)
823 ACPI_FLUSH_CPU_CACHE();
825 acpi_idle_do_entry(cx
);
827 lapic_timer_state_broadcast(pr
, cx
, 0);
832 static void acpi_idle_enter_freeze(struct cpuidle_device
*dev
,
833 struct cpuidle_driver
*drv
, int index
)
835 struct acpi_processor_cx
*cx
= per_cpu(acpi_cstate
[index
], dev
->cpu
);
837 if (cx
->type
== ACPI_STATE_C3
) {
838 struct acpi_processor
*pr
= __this_cpu_read(processors
);
843 if (pr
->flags
.bm_check
) {
844 acpi_idle_enter_bm(pr
, cx
, false);
847 ACPI_FLUSH_CPU_CACHE();
850 acpi_idle_do_entry(cx
);
853 struct cpuidle_driver acpi_idle_driver
= {
855 .owner
= THIS_MODULE
,
859 * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE
860 * device i.e. per-cpu data
862 * @pr: the ACPI processor
863 * @dev : the cpuidle device
865 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor
*pr
,
866 struct cpuidle_device
*dev
)
868 int i
, count
= CPUIDLE_DRIVER_STATE_START
;
869 struct acpi_processor_cx
*cx
;
871 if (!pr
->flags
.power_setup_done
)
874 if (pr
->flags
.power
== 0) {
886 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
&& i
<= max_cstate
; i
++) {
887 cx
= &pr
->power
.states
[i
];
892 per_cpu(acpi_cstate
[count
], dev
->cpu
) = cx
;
895 if (count
== CPUIDLE_STATE_MAX
)
906 * acpi_processor_setup_cpuidle states- prepares and configures cpuidle
907 * global state data i.e. idle routines
909 * @pr: the ACPI processor
911 static int acpi_processor_setup_cpuidle_states(struct acpi_processor
*pr
)
913 int i
, count
= CPUIDLE_DRIVER_STATE_START
;
914 struct acpi_processor_cx
*cx
;
915 struct cpuidle_state
*state
;
916 struct cpuidle_driver
*drv
= &acpi_idle_driver
;
918 if (!pr
->flags
.power_setup_done
)
921 if (pr
->flags
.power
== 0)
924 drv
->safe_state_index
= -1;
925 for (i
= 0; i
< CPUIDLE_STATE_MAX
; i
++) {
926 drv
->states
[i
].name
[0] = '\0';
927 drv
->states
[i
].desc
[0] = '\0';
933 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
&& i
<= max_cstate
; i
++) {
934 cx
= &pr
->power
.states
[i
];
939 state
= &drv
->states
[count
];
940 snprintf(state
->name
, CPUIDLE_NAME_LEN
, "C%d", i
);
941 strncpy(state
->desc
, cx
->desc
, CPUIDLE_DESC_LEN
);
942 state
->exit_latency
= cx
->latency
;
943 state
->target_residency
= cx
->latency
* latency_factor
;
944 state
->enter
= acpi_idle_enter
;
947 if (cx
->type
== ACPI_STATE_C1
|| cx
->type
== ACPI_STATE_C2
) {
948 state
->enter_dead
= acpi_idle_play_dead
;
949 drv
->safe_state_index
= count
;
952 * Halt-induced C1 is not good for ->enter_freeze, because it
953 * re-enables interrupts on exit. Moreover, C1 is generally not
954 * particularly interesting from the suspend-to-idle angle, so
955 * avoid C1 and the situations in which we may need to fall back
958 if (cx
->type
!= ACPI_STATE_C1
&& !acpi_idle_fallback_to_c1(pr
))
959 state
->enter_freeze
= acpi_idle_enter_freeze
;
962 if (count
== CPUIDLE_STATE_MAX
)
966 drv
->state_count
= count
;
974 int acpi_processor_hotplug(struct acpi_processor
*pr
)
977 struct cpuidle_device
*dev
;
979 if (disabled_by_idle_boot_param())
985 if (!pr
->flags
.power_setup_done
)
988 dev
= per_cpu(acpi_cpuidle_device
, pr
->id
);
989 cpuidle_pause_and_lock();
990 cpuidle_disable_device(dev
);
991 acpi_processor_get_power_info(pr
);
992 if (pr
->flags
.power
) {
993 acpi_processor_setup_cpuidle_cx(pr
, dev
);
994 ret
= cpuidle_enable_device(dev
);
996 cpuidle_resume_and_unlock();
1001 int acpi_processor_cst_has_changed(struct acpi_processor
*pr
)
1004 struct acpi_processor
*_pr
;
1005 struct cpuidle_device
*dev
;
1007 if (disabled_by_idle_boot_param())
1013 if (!pr
->flags
.power_setup_done
)
1017 * FIXME: Design the ACPI notification to make it once per
1018 * system instead of once per-cpu. This condition is a hack
1019 * to make the code that updates C-States be called once.
1022 if (pr
->id
== 0 && cpuidle_get_driver() == &acpi_idle_driver
) {
1024 /* Protect against cpu-hotplug */
1026 cpuidle_pause_and_lock();
1028 /* Disable all cpuidle devices */
1029 for_each_online_cpu(cpu
) {
1030 _pr
= per_cpu(processors
, cpu
);
1031 if (!_pr
|| !_pr
->flags
.power_setup_done
)
1033 dev
= per_cpu(acpi_cpuidle_device
, cpu
);
1034 cpuidle_disable_device(dev
);
1037 /* Populate Updated C-state information */
1038 acpi_processor_get_power_info(pr
);
1039 acpi_processor_setup_cpuidle_states(pr
);
1041 /* Enable all cpuidle devices */
1042 for_each_online_cpu(cpu
) {
1043 _pr
= per_cpu(processors
, cpu
);
1044 if (!_pr
|| !_pr
->flags
.power_setup_done
)
1046 acpi_processor_get_power_info(_pr
);
1047 if (_pr
->flags
.power
) {
1048 dev
= per_cpu(acpi_cpuidle_device
, cpu
);
1049 acpi_processor_setup_cpuidle_cx(_pr
, dev
);
1050 cpuidle_enable_device(dev
);
1053 cpuidle_resume_and_unlock();
1060 static int acpi_processor_registered
;
1062 int acpi_processor_power_init(struct acpi_processor
*pr
)
1066 struct cpuidle_device
*dev
;
1067 static int first_run
;
1069 if (disabled_by_idle_boot_param())
1073 dmi_check_system(processor_power_dmi_table
);
1074 max_cstate
= acpi_processor_cstate_check(max_cstate
);
1075 if (max_cstate
< ACPI_C_STATES_MAX
)
1077 "ACPI: processor limited to max C-state %d\n",
1082 if (acpi_gbl_FADT
.cst_control
&& !nocst
) {
1084 acpi_os_write_port(acpi_gbl_FADT
.smi_command
, acpi_gbl_FADT
.cst_control
, 8);
1085 if (ACPI_FAILURE(status
)) {
1086 ACPI_EXCEPTION((AE_INFO
, status
,
1087 "Notifying BIOS of _CST ability failed"));
1091 acpi_processor_get_power_info(pr
);
1092 pr
->flags
.power_setup_done
= 1;
1095 * Install the idle handler if processor power management is supported.
1096 * Note that we use previously set idle handler will be used on
1097 * platforms that only support C1.
1099 if (pr
->flags
.power
) {
1100 /* Register acpi_idle_driver if not already registered */
1101 if (!acpi_processor_registered
) {
1102 acpi_processor_setup_cpuidle_states(pr
);
1103 retval
= cpuidle_register_driver(&acpi_idle_driver
);
1106 printk(KERN_DEBUG
"ACPI: %s registered with cpuidle\n",
1107 acpi_idle_driver
.name
);
1110 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
1113 per_cpu(acpi_cpuidle_device
, pr
->id
) = dev
;
1115 acpi_processor_setup_cpuidle_cx(pr
, dev
);
1117 /* Register per-cpu cpuidle_device. Cpuidle driver
1118 * must already be registered before registering device
1120 retval
= cpuidle_register_device(dev
);
1122 if (acpi_processor_registered
== 0)
1123 cpuidle_unregister_driver(&acpi_idle_driver
);
1126 acpi_processor_registered
++;
1131 int acpi_processor_power_exit(struct acpi_processor
*pr
)
1133 struct cpuidle_device
*dev
= per_cpu(acpi_cpuidle_device
, pr
->id
);
1135 if (disabled_by_idle_boot_param())
1138 if (pr
->flags
.power
) {
1139 cpuidle_unregister_device(dev
);
1140 acpi_processor_registered
--;
1141 if (acpi_processor_registered
== 0)
1142 cpuidle_unregister_driver(&acpi_idle_driver
);
1145 pr
->flags
.power_setup_done
= 0;