1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * processor_idle - idle state submodule to the ACPI processor driver
5 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
6 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
7 * Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
8 * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
9 * - Added processor hotplug support
10 * Copyright (C) 2005 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
11 * - Added support for C3 on SMP
13 #define pr_fmt(fmt) "ACPI: " fmt
15 #include <linux/module.h>
16 #include <linux/acpi.h>
17 #include <linux/dmi.h>
18 #include <linux/sched.h> /* need_resched() */
19 #include <linux/tick.h>
20 #include <linux/cpuidle.h>
21 #include <linux/cpu.h>
22 #include <acpi/processor.h>
25 * Include the apic definitions for x86 to have the APIC timer related defines
26 * available also for UP (on SMP it gets magically included via linux/smp.h).
27 * asm/acpi.h is not an option, as it would require more include magic. Also
28 * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
35 #define _COMPONENT ACPI_PROCESSOR_COMPONENT
36 ACPI_MODULE_NAME("processor_idle");
38 #define ACPI_IDLE_STATE_START (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0)
40 static unsigned int max_cstate __read_mostly
= ACPI_PROCESSOR_MAX_POWER
;
41 module_param(max_cstate
, uint
, 0000);
42 static unsigned int nocst __read_mostly
;
43 module_param(nocst
, uint
, 0000);
44 static int bm_check_disable __read_mostly
;
45 module_param(bm_check_disable
, uint
, 0000);
47 static unsigned int latency_factor __read_mostly
= 2;
48 module_param(latency_factor
, uint
, 0644);
50 static DEFINE_PER_CPU(struct cpuidle_device
*, acpi_cpuidle_device
);
52 struct cpuidle_driver acpi_idle_driver
= {
57 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
59 DEFINE_PER_CPU(struct acpi_processor_cx
* [CPUIDLE_STATE_MAX
], acpi_cstate
);
61 static int disabled_by_idle_boot_param(void)
63 return boot_option_idle_override
== IDLE_POLL
||
64 boot_option_idle_override
== IDLE_HALT
;
68 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
69 * For now disable this. Probably a bug somewhere else.
71 * To skip this limit, boot/load with a large max_cstate limit.
73 static int set_max_cstate(const struct dmi_system_id
*id
)
75 if (max_cstate
> ACPI_PROCESSOR_MAX_POWER
)
78 pr_notice("%s detected - limiting to C%ld max_cstate."
79 " Override with \"processor.max_cstate=%d\"\n", id
->ident
,
80 (long)id
->driver_data
, ACPI_PROCESSOR_MAX_POWER
+ 1);
82 max_cstate
= (long)id
->driver_data
;
87 static const struct dmi_system_id processor_power_dmi_table
[] = {
88 { set_max_cstate
, "Clevo 5600D", {
89 DMI_MATCH(DMI_BIOS_VENDOR
,"Phoenix Technologies LTD"),
90 DMI_MATCH(DMI_BIOS_VERSION
,"SHE845M0.86C.0013.D.0302131307")},
92 { set_max_cstate
, "Pavilion zv5000", {
93 DMI_MATCH(DMI_SYS_VENDOR
, "Hewlett-Packard"),
94 DMI_MATCH(DMI_PRODUCT_NAME
,"Pavilion zv5000 (DS502A#ABA)")},
96 { set_max_cstate
, "Asus L8400B", {
97 DMI_MATCH(DMI_SYS_VENDOR
, "ASUSTeK Computer Inc."),
98 DMI_MATCH(DMI_PRODUCT_NAME
,"L8400B series Notebook PC")},
105 * Callers should disable interrupts before the call and enable
106 * interrupts after return.
108 static void __cpuidle
acpi_safe_halt(void)
110 if (!tif_need_resched()) {
116 #ifdef ARCH_APICTIMER_STOPS_ON_C3
119 * Some BIOS implementations switch to C3 in the published C2 state.
120 * This seems to be a common problem on AMD boxen, but other vendors
121 * are affected too. We pick the most conservative approach: we assume
122 * that the local APIC stops in both C2 and C3.
124 static void lapic_timer_check_state(int state
, struct acpi_processor
*pr
,
125 struct acpi_processor_cx
*cx
)
127 struct acpi_processor_power
*pwr
= &pr
->power
;
128 u8 type
= local_apic_timer_c2_ok
? ACPI_STATE_C3
: ACPI_STATE_C2
;
130 if (cpu_has(&cpu_data(pr
->id
), X86_FEATURE_ARAT
))
133 if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E
))
134 type
= ACPI_STATE_C1
;
137 * Check, if one of the previous states already marked the lapic
140 if (pwr
->timer_broadcast_on_state
< state
)
143 if (cx
->type
>= type
)
144 pr
->power
.timer_broadcast_on_state
= state
;
147 static void __lapic_timer_propagate_broadcast(void *arg
)
149 struct acpi_processor
*pr
= (struct acpi_processor
*) arg
;
151 if (pr
->power
.timer_broadcast_on_state
< INT_MAX
)
152 tick_broadcast_enable();
154 tick_broadcast_disable();
157 static void lapic_timer_propagate_broadcast(struct acpi_processor
*pr
)
159 smp_call_function_single(pr
->id
, __lapic_timer_propagate_broadcast
,
163 /* Power(C) State timer broadcast control */
164 static bool lapic_timer_needs_broadcast(struct acpi_processor
*pr
,
165 struct acpi_processor_cx
*cx
)
167 return cx
- pr
->power
.states
>= pr
->power
.timer_broadcast_on_state
;
172 static void lapic_timer_check_state(int state
, struct acpi_processor
*pr
,
173 struct acpi_processor_cx
*cstate
) { }
174 static void lapic_timer_propagate_broadcast(struct acpi_processor
*pr
) { }
176 static bool lapic_timer_needs_broadcast(struct acpi_processor
*pr
,
177 struct acpi_processor_cx
*cx
)
184 #if defined(CONFIG_X86)
185 static void tsc_check_state(int state
)
187 switch (boot_cpu_data
.x86_vendor
) {
188 case X86_VENDOR_HYGON
:
190 case X86_VENDOR_INTEL
:
191 case X86_VENDOR_CENTAUR
:
192 case X86_VENDOR_ZHAOXIN
:
194 * AMD Fam10h TSC will tick in all
195 * C/P/S0/S1 states when this bit is set.
197 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC
))
201 /* TSC could halt in idle, so notify users */
202 if (state
> ACPI_STATE_C1
)
203 mark_tsc_unstable("TSC halts in idle");
207 static void tsc_check_state(int state
) { return; }
210 static int acpi_processor_get_power_info_fadt(struct acpi_processor
*pr
)
216 /* if info is obtained from pblk/fadt, type equals state */
217 pr
->power
.states
[ACPI_STATE_C2
].type
= ACPI_STATE_C2
;
218 pr
->power
.states
[ACPI_STATE_C3
].type
= ACPI_STATE_C3
;
220 #ifndef CONFIG_HOTPLUG_CPU
222 * Check for P_LVL2_UP flag before entering C2 and above on
225 if ((num_online_cpus() > 1) &&
226 !(acpi_gbl_FADT
.flags
& ACPI_FADT_C2_MP_SUPPORTED
))
230 /* determine C2 and C3 address from pblk */
231 pr
->power
.states
[ACPI_STATE_C2
].address
= pr
->pblk
+ 4;
232 pr
->power
.states
[ACPI_STATE_C3
].address
= pr
->pblk
+ 5;
234 /* determine latencies from FADT */
235 pr
->power
.states
[ACPI_STATE_C2
].latency
= acpi_gbl_FADT
.c2_latency
;
236 pr
->power
.states
[ACPI_STATE_C3
].latency
= acpi_gbl_FADT
.c3_latency
;
239 * FADT specified C2 latency must be less than or equal to
242 if (acpi_gbl_FADT
.c2_latency
> ACPI_PROCESSOR_MAX_C2_LATENCY
) {
243 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
244 "C2 latency too large [%d]\n", acpi_gbl_FADT
.c2_latency
));
246 pr
->power
.states
[ACPI_STATE_C2
].address
= 0;
250 * FADT supplied C3 latency must be less than or equal to
253 if (acpi_gbl_FADT
.c3_latency
> ACPI_PROCESSOR_MAX_C3_LATENCY
) {
254 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
255 "C3 latency too large [%d]\n", acpi_gbl_FADT
.c3_latency
));
257 pr
->power
.states
[ACPI_STATE_C3
].address
= 0;
260 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
261 "lvl2[0x%08x] lvl3[0x%08x]\n",
262 pr
->power
.states
[ACPI_STATE_C2
].address
,
263 pr
->power
.states
[ACPI_STATE_C3
].address
));
265 snprintf(pr
->power
.states
[ACPI_STATE_C2
].desc
,
266 ACPI_CX_DESC_LEN
, "ACPI P_LVL2 IOPORT 0x%x",
267 pr
->power
.states
[ACPI_STATE_C2
].address
);
268 snprintf(pr
->power
.states
[ACPI_STATE_C3
].desc
,
269 ACPI_CX_DESC_LEN
, "ACPI P_LVL3 IOPORT 0x%x",
270 pr
->power
.states
[ACPI_STATE_C3
].address
);
275 static int acpi_processor_get_power_info_default(struct acpi_processor
*pr
)
277 if (!pr
->power
.states
[ACPI_STATE_C1
].valid
) {
278 /* set the first C-State to C1 */
279 /* all processors need to support C1 */
280 pr
->power
.states
[ACPI_STATE_C1
].type
= ACPI_STATE_C1
;
281 pr
->power
.states
[ACPI_STATE_C1
].valid
= 1;
282 pr
->power
.states
[ACPI_STATE_C1
].entry_method
= ACPI_CSTATE_HALT
;
284 snprintf(pr
->power
.states
[ACPI_STATE_C1
].desc
,
285 ACPI_CX_DESC_LEN
, "ACPI HLT");
287 /* the C0 state only exists as a filler in our array */
288 pr
->power
.states
[ACPI_STATE_C0
].valid
= 1;
292 static int acpi_processor_get_power_info_cst(struct acpi_processor
*pr
)
299 ret
= acpi_processor_evaluate_cst(pr
->handle
, pr
->id
, &pr
->power
);
303 if (!pr
->power
.count
)
306 pr
->flags
.has_cst
= 1;
310 static void acpi_processor_power_verify_c3(struct acpi_processor
*pr
,
311 struct acpi_processor_cx
*cx
)
313 static int bm_check_flag
= -1;
314 static int bm_control_flag
= -1;
321 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
322 * DMA transfers are used by any ISA device to avoid livelock.
323 * Note that we could disable Type-F DMA (as recommended by
324 * the erratum), but this is known to disrupt certain ISA
325 * devices thus we take the conservative approach.
327 else if (errata
.piix4
.fdma
) {
328 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
329 "C3 not supported on PIIX4 with Type-F DMA\n"));
333 /* All the logic here assumes flags.bm_check is same across all CPUs */
334 if (bm_check_flag
== -1) {
335 /* Determine whether bm_check is needed based on CPU */
336 acpi_processor_power_init_bm_check(&(pr
->flags
), pr
->id
);
337 bm_check_flag
= pr
->flags
.bm_check
;
338 bm_control_flag
= pr
->flags
.bm_control
;
340 pr
->flags
.bm_check
= bm_check_flag
;
341 pr
->flags
.bm_control
= bm_control_flag
;
344 if (pr
->flags
.bm_check
) {
345 if (!pr
->flags
.bm_control
) {
346 if (pr
->flags
.has_cst
!= 1) {
347 /* bus mastering control is necessary */
348 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
349 "C3 support requires BM control\n"));
352 /* Here we enter C3 without bus mastering */
353 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
354 "C3 support without BM control\n"));
359 * WBINVD should be set in fadt, for C3 state to be
360 * supported on when bm_check is not required.
362 if (!(acpi_gbl_FADT
.flags
& ACPI_FADT_WBINVD
)) {
363 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
364 "Cache invalidation should work properly"
365 " for C3 to be enabled on SMP systems\n"));
371 * Otherwise we've met all of our C3 requirements.
372 * Normalize the C3 latency to expidite policy. Enable
373 * checking of bus mastering status (bm_check) so we can
374 * use this in our C3 policy
379 * On older chipsets, BM_RLD needs to be set
380 * in order for Bus Master activity to wake the
381 * system from C3. Newer chipsets handle DMA
382 * during C3 automatically and BM_RLD is a NOP.
383 * In either case, the proper way to
384 * handle BM_RLD is to set it and leave it set.
386 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD
, 1);
391 static int acpi_processor_power_verify(struct acpi_processor
*pr
)
394 unsigned int working
= 0;
396 pr
->power
.timer_broadcast_on_state
= INT_MAX
;
398 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
&& i
<= max_cstate
; i
++) {
399 struct acpi_processor_cx
*cx
= &pr
->power
.states
[i
];
413 acpi_processor_power_verify_c3(pr
, cx
);
419 lapic_timer_check_state(i
, pr
, cx
);
420 tsc_check_state(cx
->type
);
424 lapic_timer_propagate_broadcast(pr
);
429 static int acpi_processor_get_cstate_info(struct acpi_processor
*pr
)
435 /* NOTE: the idle thread may not be running while calling
438 /* Zero initialize all the C-states info. */
439 memset(pr
->power
.states
, 0, sizeof(pr
->power
.states
));
441 result
= acpi_processor_get_power_info_cst(pr
);
442 if (result
== -ENODEV
)
443 result
= acpi_processor_get_power_info_fadt(pr
);
448 acpi_processor_get_power_info_default(pr
);
450 pr
->power
.count
= acpi_processor_power_verify(pr
);
453 * if one state of type C2 or C3 is available, mark this
454 * CPU as being "idle manageable"
456 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
; i
++) {
457 if (pr
->power
.states
[i
].valid
) {
467 * acpi_idle_bm_check - checks if bus master activity was detected
469 static int acpi_idle_bm_check(void)
473 if (bm_check_disable
)
476 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS
, &bm_status
);
478 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS
, 1);
480 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
481 * the true state of bus mastering activity; forcing us to
482 * manually check the BMIDEA bit of each IDE channel.
484 else if (errata
.piix4
.bmisx
) {
485 if ((inb_p(errata
.piix4
.bmisx
+ 0x02) & 0x01)
486 || (inb_p(errata
.piix4
.bmisx
+ 0x0A) & 0x01))
492 static void wait_for_freeze(void)
495 /* No delay is needed if we are in guest */
496 if (boot_cpu_has(X86_FEATURE_HYPERVISOR
))
499 /* Dummy wait op - must do something useless after P_LVL2 read
500 because chipsets cannot guarantee that STPCLK# signal
501 gets asserted in time to freeze execution properly. */
502 inl(acpi_gbl_FADT
.xpm_timer_block
.address
);
506 * acpi_idle_do_entry - enter idle state using the appropriate method
509 * Caller disables interrupt before call and enables interrupt after return.
511 static void __cpuidle
acpi_idle_do_entry(struct acpi_processor_cx
*cx
)
513 if (cx
->entry_method
== ACPI_CSTATE_FFH
) {
514 /* Call into architectural FFH based C-state */
515 acpi_processor_ffh_cstate_enter(cx
);
516 } else if (cx
->entry_method
== ACPI_CSTATE_HALT
) {
519 /* IO port based C-state */
526 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
527 * @dev: the target CPU
528 * @index: the index of suggested state
530 static int acpi_idle_play_dead(struct cpuidle_device
*dev
, int index
)
532 struct acpi_processor_cx
*cx
= per_cpu(acpi_cstate
[index
], dev
->cpu
);
534 ACPI_FLUSH_CPU_CACHE();
538 if (cx
->entry_method
== ACPI_CSTATE_HALT
)
540 else if (cx
->entry_method
== ACPI_CSTATE_SYSTEMIO
) {
546 #if defined(CONFIG_X86) && defined(CONFIG_HOTPLUG_CPU)
547 /* If NMI wants to wake up CPU0, start CPU0. */
557 static bool acpi_idle_fallback_to_c1(struct acpi_processor
*pr
)
559 return IS_ENABLED(CONFIG_HOTPLUG_CPU
) && !pr
->flags
.has_cst
&&
560 !(acpi_gbl_FADT
.flags
& ACPI_FADT_C2_MP_SUPPORTED
);
563 static int c3_cpu_count
;
564 static DEFINE_RAW_SPINLOCK(c3_lock
);
567 * acpi_idle_enter_bm - enters C3 with proper BM handling
568 * @drv: cpuidle driver
569 * @pr: Target processor
570 * @cx: Target state context
571 * @index: index of target state
573 static int acpi_idle_enter_bm(struct cpuidle_driver
*drv
,
574 struct acpi_processor
*pr
,
575 struct acpi_processor_cx
*cx
,
578 static struct acpi_processor_cx safe_cx
= {
579 .entry_method
= ACPI_CSTATE_HALT
,
584 * bm_check implies we need ARB_DIS
585 * bm_control implies whether we can do ARB_DIS
587 * That leaves a case where bm_check is set and bm_control is not set.
588 * In that case we cannot do much, we enter C3 without doing anything.
590 bool dis_bm
= pr
->flags
.bm_control
;
592 /* If we can skip BM, demote to a safe state. */
593 if (!cx
->bm_sts_skip
&& acpi_idle_bm_check()) {
595 index
= drv
->safe_state_index
;
597 cx
= this_cpu_read(acpi_cstate
[index
]);
605 raw_spin_lock(&c3_lock
);
607 /* Disable bus master arbitration when all CPUs are in C3 */
608 if (c3_cpu_count
== num_online_cpus())
609 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE
, 1);
610 raw_spin_unlock(&c3_lock
);
615 acpi_idle_do_entry(cx
);
619 /* Re-enable bus master arbitration */
621 raw_spin_lock(&c3_lock
);
622 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE
, 0);
624 raw_spin_unlock(&c3_lock
);
630 static int acpi_idle_enter(struct cpuidle_device
*dev
,
631 struct cpuidle_driver
*drv
, int index
)
633 struct acpi_processor_cx
*cx
= per_cpu(acpi_cstate
[index
], dev
->cpu
);
634 struct acpi_processor
*pr
;
636 pr
= __this_cpu_read(processors
);
640 if (cx
->type
!= ACPI_STATE_C1
) {
641 if (cx
->type
== ACPI_STATE_C3
&& pr
->flags
.bm_check
)
642 return acpi_idle_enter_bm(drv
, pr
, cx
, index
);
644 /* C2 to C1 demotion. */
645 if (acpi_idle_fallback_to_c1(pr
) && num_online_cpus() > 1) {
646 index
= ACPI_IDLE_STATE_START
;
647 cx
= per_cpu(acpi_cstate
[index
], dev
->cpu
);
651 if (cx
->type
== ACPI_STATE_C3
)
652 ACPI_FLUSH_CPU_CACHE();
654 acpi_idle_do_entry(cx
);
659 static int acpi_idle_enter_s2idle(struct cpuidle_device
*dev
,
660 struct cpuidle_driver
*drv
, int index
)
662 struct acpi_processor_cx
*cx
= per_cpu(acpi_cstate
[index
], dev
->cpu
);
664 if (cx
->type
== ACPI_STATE_C3
) {
665 struct acpi_processor
*pr
= __this_cpu_read(processors
);
670 if (pr
->flags
.bm_check
) {
671 u8 bm_sts_skip
= cx
->bm_sts_skip
;
673 /* Don't check BM_STS, do an unconditional ARB_DIS for S2IDLE */
675 acpi_idle_enter_bm(drv
, pr
, cx
, index
);
676 cx
->bm_sts_skip
= bm_sts_skip
;
680 ACPI_FLUSH_CPU_CACHE();
683 acpi_idle_do_entry(cx
);
688 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor
*pr
,
689 struct cpuidle_device
*dev
)
691 int i
, count
= ACPI_IDLE_STATE_START
;
692 struct acpi_processor_cx
*cx
;
693 struct cpuidle_state
*state
;
698 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
&& i
<= max_cstate
; i
++) {
699 state
= &acpi_idle_driver
.states
[count
];
700 cx
= &pr
->power
.states
[i
];
705 per_cpu(acpi_cstate
[count
], dev
->cpu
) = cx
;
707 if (lapic_timer_needs_broadcast(pr
, cx
))
708 state
->flags
|= CPUIDLE_FLAG_TIMER_STOP
;
710 if (cx
->type
== ACPI_STATE_C3
) {
711 state
->flags
|= CPUIDLE_FLAG_TLB_FLUSHED
;
712 if (pr
->flags
.bm_check
)
713 state
->flags
|= CPUIDLE_FLAG_RCU_IDLE
;
717 if (count
== CPUIDLE_STATE_MAX
)
727 static int acpi_processor_setup_cstates(struct acpi_processor
*pr
)
730 struct acpi_processor_cx
*cx
;
731 struct cpuidle_state
*state
;
732 struct cpuidle_driver
*drv
= &acpi_idle_driver
;
737 if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX
)) {
738 cpuidle_poll_state_init(drv
);
744 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
&& i
<= max_cstate
; i
++) {
745 cx
= &pr
->power
.states
[i
];
750 state
= &drv
->states
[count
];
751 snprintf(state
->name
, CPUIDLE_NAME_LEN
, "C%d", i
);
752 strlcpy(state
->desc
, cx
->desc
, CPUIDLE_DESC_LEN
);
753 state
->exit_latency
= cx
->latency
;
754 state
->target_residency
= cx
->latency
* latency_factor
;
755 state
->enter
= acpi_idle_enter
;
758 if (cx
->type
== ACPI_STATE_C1
|| cx
->type
== ACPI_STATE_C2
) {
759 state
->enter_dead
= acpi_idle_play_dead
;
760 drv
->safe_state_index
= count
;
763 * Halt-induced C1 is not good for ->enter_s2idle, because it
764 * re-enables interrupts on exit. Moreover, C1 is generally not
765 * particularly interesting from the suspend-to-idle angle, so
766 * avoid C1 and the situations in which we may need to fall back
769 if (cx
->type
!= ACPI_STATE_C1
&& !acpi_idle_fallback_to_c1(pr
))
770 state
->enter_s2idle
= acpi_idle_enter_s2idle
;
773 if (count
== CPUIDLE_STATE_MAX
)
777 drv
->state_count
= count
;
785 static inline void acpi_processor_cstate_first_run_checks(void)
787 static int first_run
;
791 dmi_check_system(processor_power_dmi_table
);
792 max_cstate
= acpi_processor_cstate_check(max_cstate
);
793 if (max_cstate
< ACPI_C_STATES_MAX
)
794 pr_notice("ACPI: processor limited to max C-state %d\n",
801 acpi_processor_claim_cst_control();
805 static inline int disabled_by_idle_boot_param(void) { return 0; }
806 static inline void acpi_processor_cstate_first_run_checks(void) { }
807 static int acpi_processor_get_cstate_info(struct acpi_processor
*pr
)
812 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor
*pr
,
813 struct cpuidle_device
*dev
)
818 static int acpi_processor_setup_cstates(struct acpi_processor
*pr
)
823 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
825 struct acpi_lpi_states_array
{
827 unsigned int composite_states_size
;
828 struct acpi_lpi_state
*entries
;
829 struct acpi_lpi_state
*composite_states
[ACPI_PROCESSOR_MAX_POWER
];
832 static int obj_get_integer(union acpi_object
*obj
, u32
*value
)
834 if (obj
->type
!= ACPI_TYPE_INTEGER
)
837 *value
= obj
->integer
.value
;
841 static int acpi_processor_evaluate_lpi(acpi_handle handle
,
842 struct acpi_lpi_states_array
*info
)
846 int pkg_count
, state_idx
= 1, loop
;
847 struct acpi_buffer buffer
= { ACPI_ALLOCATE_BUFFER
, NULL
};
848 union acpi_object
*lpi_data
;
849 struct acpi_lpi_state
*lpi_state
;
851 status
= acpi_evaluate_object(handle
, "_LPI", NULL
, &buffer
);
852 if (ACPI_FAILURE(status
)) {
853 ACPI_DEBUG_PRINT((ACPI_DB_INFO
, "No _LPI, giving up\n"));
857 lpi_data
= buffer
.pointer
;
859 /* There must be at least 4 elements = 3 elements + 1 package */
860 if (!lpi_data
|| lpi_data
->type
!= ACPI_TYPE_PACKAGE
||
861 lpi_data
->package
.count
< 4) {
862 pr_debug("not enough elements in _LPI\n");
867 pkg_count
= lpi_data
->package
.elements
[2].integer
.value
;
869 /* Validate number of power states. */
870 if (pkg_count
< 1 || pkg_count
!= lpi_data
->package
.count
- 3) {
871 pr_debug("count given by _LPI is not valid\n");
876 lpi_state
= kcalloc(pkg_count
, sizeof(*lpi_state
), GFP_KERNEL
);
882 info
->size
= pkg_count
;
883 info
->entries
= lpi_state
;
885 /* LPI States start at index 3 */
886 for (loop
= 3; state_idx
<= pkg_count
; loop
++, state_idx
++, lpi_state
++) {
887 union acpi_object
*element
, *pkg_elem
, *obj
;
889 element
= &lpi_data
->package
.elements
[loop
];
890 if (element
->type
!= ACPI_TYPE_PACKAGE
|| element
->package
.count
< 7)
893 pkg_elem
= element
->package
.elements
;
896 if (obj
->type
== ACPI_TYPE_BUFFER
) {
897 struct acpi_power_register
*reg
;
899 reg
= (struct acpi_power_register
*)obj
->buffer
.pointer
;
900 if (reg
->space_id
!= ACPI_ADR_SPACE_SYSTEM_IO
&&
901 reg
->space_id
!= ACPI_ADR_SPACE_FIXED_HARDWARE
)
904 lpi_state
->address
= reg
->address
;
905 lpi_state
->entry_method
=
906 reg
->space_id
== ACPI_ADR_SPACE_FIXED_HARDWARE
?
907 ACPI_CSTATE_FFH
: ACPI_CSTATE_SYSTEMIO
;
908 } else if (obj
->type
== ACPI_TYPE_INTEGER
) {
909 lpi_state
->entry_method
= ACPI_CSTATE_INTEGER
;
910 lpi_state
->address
= obj
->integer
.value
;
915 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
918 if (obj
->type
== ACPI_TYPE_STRING
)
919 strlcpy(lpi_state
->desc
, obj
->string
.pointer
,
922 lpi_state
->index
= state_idx
;
923 if (obj_get_integer(pkg_elem
+ 0, &lpi_state
->min_residency
)) {
924 pr_debug("No min. residency found, assuming 10 us\n");
925 lpi_state
->min_residency
= 10;
928 if (obj_get_integer(pkg_elem
+ 1, &lpi_state
->wake_latency
)) {
929 pr_debug("No wakeup residency found, assuming 10 us\n");
930 lpi_state
->wake_latency
= 10;
933 if (obj_get_integer(pkg_elem
+ 2, &lpi_state
->flags
))
934 lpi_state
->flags
= 0;
936 if (obj_get_integer(pkg_elem
+ 3, &lpi_state
->arch_flags
))
937 lpi_state
->arch_flags
= 0;
939 if (obj_get_integer(pkg_elem
+ 4, &lpi_state
->res_cnt_freq
))
940 lpi_state
->res_cnt_freq
= 1;
942 if (obj_get_integer(pkg_elem
+ 5, &lpi_state
->enable_parent_state
))
943 lpi_state
->enable_parent_state
= 0;
946 acpi_handle_debug(handle
, "Found %d power states\n", state_idx
);
948 kfree(buffer
.pointer
);
953 * flat_state_cnt - the number of composite LPI states after the process of flattening
955 static int flat_state_cnt
;
958 * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
960 * @local: local LPI state
961 * @parent: parent LPI state
962 * @result: composite LPI state
964 static bool combine_lpi_states(struct acpi_lpi_state
*local
,
965 struct acpi_lpi_state
*parent
,
966 struct acpi_lpi_state
*result
)
968 if (parent
->entry_method
== ACPI_CSTATE_INTEGER
) {
969 if (!parent
->address
) /* 0 means autopromotable */
971 result
->address
= local
->address
+ parent
->address
;
973 result
->address
= parent
->address
;
976 result
->min_residency
= max(local
->min_residency
, parent
->min_residency
);
977 result
->wake_latency
= local
->wake_latency
+ parent
->wake_latency
;
978 result
->enable_parent_state
= parent
->enable_parent_state
;
979 result
->entry_method
= local
->entry_method
;
981 result
->flags
= parent
->flags
;
982 result
->arch_flags
= parent
->arch_flags
;
983 result
->index
= parent
->index
;
985 strlcpy(result
->desc
, local
->desc
, ACPI_CX_DESC_LEN
);
986 strlcat(result
->desc
, "+", ACPI_CX_DESC_LEN
);
987 strlcat(result
->desc
, parent
->desc
, ACPI_CX_DESC_LEN
);
991 #define ACPI_LPI_STATE_FLAGS_ENABLED BIT(0)
993 static void stash_composite_state(struct acpi_lpi_states_array
*curr_level
,
994 struct acpi_lpi_state
*t
)
996 curr_level
->composite_states
[curr_level
->composite_states_size
++] = t
;
999 static int flatten_lpi_states(struct acpi_processor
*pr
,
1000 struct acpi_lpi_states_array
*curr_level
,
1001 struct acpi_lpi_states_array
*prev_level
)
1003 int i
, j
, state_count
= curr_level
->size
;
1004 struct acpi_lpi_state
*p
, *t
= curr_level
->entries
;
1006 curr_level
->composite_states_size
= 0;
1007 for (j
= 0; j
< state_count
; j
++, t
++) {
1008 struct acpi_lpi_state
*flpi
;
1010 if (!(t
->flags
& ACPI_LPI_STATE_FLAGS_ENABLED
))
1013 if (flat_state_cnt
>= ACPI_PROCESSOR_MAX_POWER
) {
1014 pr_warn("Limiting number of LPI states to max (%d)\n",
1015 ACPI_PROCESSOR_MAX_POWER
);
1016 pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1020 flpi
= &pr
->power
.lpi_states
[flat_state_cnt
];
1022 if (!prev_level
) { /* leaf/processor node */
1023 memcpy(flpi
, t
, sizeof(*t
));
1024 stash_composite_state(curr_level
, flpi
);
1029 for (i
= 0; i
< prev_level
->composite_states_size
; i
++) {
1030 p
= prev_level
->composite_states
[i
];
1031 if (t
->index
<= p
->enable_parent_state
&&
1032 combine_lpi_states(p
, t
, flpi
)) {
1033 stash_composite_state(curr_level
, flpi
);
1040 kfree(curr_level
->entries
);
1044 static int acpi_processor_get_lpi_info(struct acpi_processor
*pr
)
1048 acpi_handle handle
= pr
->handle
, pr_ahandle
;
1049 struct acpi_device
*d
= NULL
;
1050 struct acpi_lpi_states_array info
[2], *tmp
, *prev
, *curr
;
1052 if (!osc_pc_lpi_support_confirmed
)
1055 if (!acpi_has_method(handle
, "_LPI"))
1061 handle
= pr
->handle
;
1062 ret
= acpi_processor_evaluate_lpi(handle
, prev
);
1065 flatten_lpi_states(pr
, prev
, NULL
);
1067 status
= acpi_get_parent(handle
, &pr_ahandle
);
1068 while (ACPI_SUCCESS(status
)) {
1069 acpi_bus_get_device(pr_ahandle
, &d
);
1070 handle
= pr_ahandle
;
1072 if (strcmp(acpi_device_hid(d
), ACPI_PROCESSOR_CONTAINER_HID
))
1075 /* can be optional ? */
1076 if (!acpi_has_method(handle
, "_LPI"))
1079 ret
= acpi_processor_evaluate_lpi(handle
, curr
);
1083 /* flatten all the LPI states in this level of hierarchy */
1084 flatten_lpi_states(pr
, curr
, prev
);
1086 tmp
= prev
, prev
= curr
, curr
= tmp
;
1088 status
= acpi_get_parent(handle
, &pr_ahandle
);
1091 pr
->power
.count
= flat_state_cnt
;
1092 /* reset the index after flattening */
1093 for (i
= 0; i
< pr
->power
.count
; i
++)
1094 pr
->power
.lpi_states
[i
].index
= i
;
1096 /* Tell driver that _LPI is supported. */
1097 pr
->flags
.has_lpi
= 1;
1098 pr
->flags
.power
= 1;
1103 int __weak
acpi_processor_ffh_lpi_probe(unsigned int cpu
)
1108 int __weak
acpi_processor_ffh_lpi_enter(struct acpi_lpi_state
*lpi
)
1114 * acpi_idle_lpi_enter - enters an ACPI any LPI state
1115 * @dev: the target CPU
1116 * @drv: cpuidle driver containing cpuidle state info
1117 * @index: index of target state
1119 * Return: 0 for success or negative value for error
1121 static int acpi_idle_lpi_enter(struct cpuidle_device
*dev
,
1122 struct cpuidle_driver
*drv
, int index
)
1124 struct acpi_processor
*pr
;
1125 struct acpi_lpi_state
*lpi
;
1127 pr
= __this_cpu_read(processors
);
1132 lpi
= &pr
->power
.lpi_states
[index
];
1133 if (lpi
->entry_method
== ACPI_CSTATE_FFH
)
1134 return acpi_processor_ffh_lpi_enter(lpi
);
1139 static int acpi_processor_setup_lpi_states(struct acpi_processor
*pr
)
1142 struct acpi_lpi_state
*lpi
;
1143 struct cpuidle_state
*state
;
1144 struct cpuidle_driver
*drv
= &acpi_idle_driver
;
1146 if (!pr
->flags
.has_lpi
)
1149 for (i
= 0; i
< pr
->power
.count
&& i
< CPUIDLE_STATE_MAX
; i
++) {
1150 lpi
= &pr
->power
.lpi_states
[i
];
1152 state
= &drv
->states
[i
];
1153 snprintf(state
->name
, CPUIDLE_NAME_LEN
, "LPI-%d", i
);
1154 strlcpy(state
->desc
, lpi
->desc
, CPUIDLE_DESC_LEN
);
1155 state
->exit_latency
= lpi
->wake_latency
;
1156 state
->target_residency
= lpi
->min_residency
;
1157 if (lpi
->arch_flags
)
1158 state
->flags
|= CPUIDLE_FLAG_TIMER_STOP
;
1159 state
->enter
= acpi_idle_lpi_enter
;
1160 drv
->safe_state_index
= i
;
1163 drv
->state_count
= i
;
1169 * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1170 * global state data i.e. idle routines
1172 * @pr: the ACPI processor
1174 static int acpi_processor_setup_cpuidle_states(struct acpi_processor
*pr
)
1177 struct cpuidle_driver
*drv
= &acpi_idle_driver
;
1179 if (!pr
->flags
.power_setup_done
|| !pr
->flags
.power
)
1182 drv
->safe_state_index
= -1;
1183 for (i
= ACPI_IDLE_STATE_START
; i
< CPUIDLE_STATE_MAX
; i
++) {
1184 drv
->states
[i
].name
[0] = '\0';
1185 drv
->states
[i
].desc
[0] = '\0';
1188 if (pr
->flags
.has_lpi
)
1189 return acpi_processor_setup_lpi_states(pr
);
1191 return acpi_processor_setup_cstates(pr
);
1195 * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1196 * device i.e. per-cpu data
1198 * @pr: the ACPI processor
1199 * @dev : the cpuidle device
1201 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor
*pr
,
1202 struct cpuidle_device
*dev
)
1204 if (!pr
->flags
.power_setup_done
|| !pr
->flags
.power
|| !dev
)
1208 if (pr
->flags
.has_lpi
)
1209 return acpi_processor_ffh_lpi_probe(pr
->id
);
1211 return acpi_processor_setup_cpuidle_cx(pr
, dev
);
1214 static int acpi_processor_get_power_info(struct acpi_processor
*pr
)
1218 ret
= acpi_processor_get_lpi_info(pr
);
1220 ret
= acpi_processor_get_cstate_info(pr
);
1225 int acpi_processor_hotplug(struct acpi_processor
*pr
)
1228 struct cpuidle_device
*dev
;
1230 if (disabled_by_idle_boot_param())
1233 if (!pr
->flags
.power_setup_done
)
1236 dev
= per_cpu(acpi_cpuidle_device
, pr
->id
);
1237 cpuidle_pause_and_lock();
1238 cpuidle_disable_device(dev
);
1239 ret
= acpi_processor_get_power_info(pr
);
1240 if (!ret
&& pr
->flags
.power
) {
1241 acpi_processor_setup_cpuidle_dev(pr
, dev
);
1242 ret
= cpuidle_enable_device(dev
);
1244 cpuidle_resume_and_unlock();
1249 int acpi_processor_power_state_has_changed(struct acpi_processor
*pr
)
1252 struct acpi_processor
*_pr
;
1253 struct cpuidle_device
*dev
;
1255 if (disabled_by_idle_boot_param())
1258 if (!pr
->flags
.power_setup_done
)
1262 * FIXME: Design the ACPI notification to make it once per
1263 * system instead of once per-cpu. This condition is a hack
1264 * to make the code that updates C-States be called once.
1267 if (pr
->id
== 0 && cpuidle_get_driver() == &acpi_idle_driver
) {
1269 /* Protect against cpu-hotplug */
1271 cpuidle_pause_and_lock();
1273 /* Disable all cpuidle devices */
1274 for_each_online_cpu(cpu
) {
1275 _pr
= per_cpu(processors
, cpu
);
1276 if (!_pr
|| !_pr
->flags
.power_setup_done
)
1278 dev
= per_cpu(acpi_cpuidle_device
, cpu
);
1279 cpuidle_disable_device(dev
);
1282 /* Populate Updated C-state information */
1283 acpi_processor_get_power_info(pr
);
1284 acpi_processor_setup_cpuidle_states(pr
);
1286 /* Enable all cpuidle devices */
1287 for_each_online_cpu(cpu
) {
1288 _pr
= per_cpu(processors
, cpu
);
1289 if (!_pr
|| !_pr
->flags
.power_setup_done
)
1291 acpi_processor_get_power_info(_pr
);
1292 if (_pr
->flags
.power
) {
1293 dev
= per_cpu(acpi_cpuidle_device
, cpu
);
1294 acpi_processor_setup_cpuidle_dev(_pr
, dev
);
1295 cpuidle_enable_device(dev
);
1298 cpuidle_resume_and_unlock();
1305 static int acpi_processor_registered
;
1307 int acpi_processor_power_init(struct acpi_processor
*pr
)
1310 struct cpuidle_device
*dev
;
1312 if (disabled_by_idle_boot_param())
1315 acpi_processor_cstate_first_run_checks();
1317 if (!acpi_processor_get_power_info(pr
))
1318 pr
->flags
.power_setup_done
= 1;
1321 * Install the idle handler if processor power management is supported.
1322 * Note that we use previously set idle handler will be used on
1323 * platforms that only support C1.
1325 if (pr
->flags
.power
) {
1326 /* Register acpi_idle_driver if not already registered */
1327 if (!acpi_processor_registered
) {
1328 acpi_processor_setup_cpuidle_states(pr
);
1329 retval
= cpuidle_register_driver(&acpi_idle_driver
);
1332 pr_debug("%s registered with cpuidle\n",
1333 acpi_idle_driver
.name
);
1336 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
1339 per_cpu(acpi_cpuidle_device
, pr
->id
) = dev
;
1341 acpi_processor_setup_cpuidle_dev(pr
, dev
);
1343 /* Register per-cpu cpuidle_device. Cpuidle driver
1344 * must already be registered before registering device
1346 retval
= cpuidle_register_device(dev
);
1348 if (acpi_processor_registered
== 0)
1349 cpuidle_unregister_driver(&acpi_idle_driver
);
1352 acpi_processor_registered
++;
1357 int acpi_processor_power_exit(struct acpi_processor
*pr
)
1359 struct cpuidle_device
*dev
= per_cpu(acpi_cpuidle_device
, pr
->id
);
1361 if (disabled_by_idle_boot_param())
1364 if (pr
->flags
.power
) {
1365 cpuidle_unregister_device(dev
);
1366 acpi_processor_registered
--;
1367 if (acpi_processor_registered
== 0)
1368 cpuidle_unregister_driver(&acpi_idle_driver
);
1371 pr
->flags
.power_setup_done
= 0;