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/sort.h>
20 #include <linux/tick.h>
21 #include <linux/cpuidle.h>
22 #include <linux/cpu.h>
23 #include <acpi/processor.h>
26 * Include the apic definitions for x86 to have the APIC timer related defines
27 * available also for UP (on SMP it gets magically included via linux/smp.h).
28 * asm/acpi.h is not an option, as it would require more include magic. Also
29 * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
36 #define ACPI_PROCESSOR_CLASS "processor"
37 #define _COMPONENT ACPI_PROCESSOR_COMPONENT
38 ACPI_MODULE_NAME("processor_idle");
40 #define ACPI_IDLE_STATE_START (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0)
42 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
43 module_param(max_cstate, uint, 0000);
44 static unsigned int nocst __read_mostly;
45 module_param(nocst, uint, 0000);
46 static int bm_check_disable __read_mostly;
47 module_param(bm_check_disable, uint, 0000);
49 static unsigned int latency_factor __read_mostly = 2;
50 module_param(latency_factor, uint, 0644);
52 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
54 struct cpuidle_driver acpi_idle_driver = {
59 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
61 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
63 static int disabled_by_idle_boot_param(void)
65 return boot_option_idle_override == IDLE_POLL ||
66 boot_option_idle_override == IDLE_HALT;
70 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
71 * For now disable this. Probably a bug somewhere else.
73 * To skip this limit, boot/load with a large max_cstate limit.
75 static int set_max_cstate(const struct dmi_system_id *id)
77 if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
80 pr_notice("%s detected - limiting to C%ld max_cstate."
81 " Override with \"processor.max_cstate=%d\"\n", id->ident,
82 (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
84 max_cstate = (long)id->driver_data;
89 static const struct dmi_system_id processor_power_dmi_table[] = {
90 { set_max_cstate, "Clevo 5600D", {
91 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
92 DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
94 { set_max_cstate, "Pavilion zv5000", {
95 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
96 DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
98 { set_max_cstate, "Asus L8400B", {
99 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
100 DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
107 * Callers should disable interrupts before the call and enable
108 * interrupts after return.
110 static void __cpuidle acpi_safe_halt(void)
112 if (!tif_need_resched()) {
118 #ifdef ARCH_APICTIMER_STOPS_ON_C3
121 * Some BIOS implementations switch to C3 in the published C2 state.
122 * This seems to be a common problem on AMD boxen, but other vendors
123 * are affected too. We pick the most conservative approach: we assume
124 * that the local APIC stops in both C2 and C3.
126 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
127 struct acpi_processor_cx *cx)
129 struct acpi_processor_power *pwr = &pr->power;
130 u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
132 if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
135 if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E))
136 type = ACPI_STATE_C1;
139 * Check, if one of the previous states already marked the lapic
142 if (pwr->timer_broadcast_on_state < state)
145 if (cx->type >= type)
146 pr->power.timer_broadcast_on_state = state;
149 static void __lapic_timer_propagate_broadcast(void *arg)
151 struct acpi_processor *pr = (struct acpi_processor *) arg;
153 if (pr->power.timer_broadcast_on_state < INT_MAX)
154 tick_broadcast_enable();
156 tick_broadcast_disable();
159 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
161 smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
165 /* Power(C) State timer broadcast control */
166 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr,
167 struct acpi_processor_cx *cx)
169 return cx - pr->power.states >= pr->power.timer_broadcast_on_state;
174 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
175 struct acpi_processor_cx *cstate) { }
176 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
178 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr,
179 struct acpi_processor_cx *cx)
186 #if defined(CONFIG_X86)
187 static void tsc_check_state(int state)
189 switch (boot_cpu_data.x86_vendor) {
190 case X86_VENDOR_HYGON:
192 case X86_VENDOR_INTEL:
193 case X86_VENDOR_CENTAUR:
194 case X86_VENDOR_ZHAOXIN:
196 * AMD Fam10h TSC will tick in all
197 * C/P/S0/S1 states when this bit is set.
199 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
203 /* TSC could halt in idle, so notify users */
204 if (state > ACPI_STATE_C1)
205 mark_tsc_unstable("TSC halts in idle");
209 static void tsc_check_state(int state) { return; }
212 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
218 /* if info is obtained from pblk/fadt, type equals state */
219 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
220 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
222 #ifndef CONFIG_HOTPLUG_CPU
224 * Check for P_LVL2_UP flag before entering C2 and above on
227 if ((num_online_cpus() > 1) &&
228 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
232 /* determine C2 and C3 address from pblk */
233 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
234 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
236 /* determine latencies from FADT */
237 pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
238 pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
241 * FADT specified C2 latency must be less than or equal to
244 if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
245 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
246 "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
248 pr->power.states[ACPI_STATE_C2].address = 0;
252 * FADT supplied C3 latency must be less than or equal to
255 if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
256 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
257 "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
259 pr->power.states[ACPI_STATE_C3].address = 0;
262 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
263 "lvl2[0x%08x] lvl3[0x%08x]\n",
264 pr->power.states[ACPI_STATE_C2].address,
265 pr->power.states[ACPI_STATE_C3].address));
267 snprintf(pr->power.states[ACPI_STATE_C2].desc,
268 ACPI_CX_DESC_LEN, "ACPI P_LVL2 IOPORT 0x%x",
269 pr->power.states[ACPI_STATE_C2].address);
270 snprintf(pr->power.states[ACPI_STATE_C3].desc,
271 ACPI_CX_DESC_LEN, "ACPI P_LVL3 IOPORT 0x%x",
272 pr->power.states[ACPI_STATE_C3].address);
277 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
279 if (!pr->power.states[ACPI_STATE_C1].valid) {
280 /* set the first C-State to C1 */
281 /* all processors need to support C1 */
282 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
283 pr->power.states[ACPI_STATE_C1].valid = 1;
284 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
286 snprintf(pr->power.states[ACPI_STATE_C1].desc,
287 ACPI_CX_DESC_LEN, "ACPI HLT");
289 /* the C0 state only exists as a filler in our array */
290 pr->power.states[ACPI_STATE_C0].valid = 1;
294 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
301 ret = acpi_processor_evaluate_cst(pr->handle, pr->id, &pr->power);
305 if (!pr->power.count)
308 pr->flags.has_cst = 1;
312 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
313 struct acpi_processor_cx *cx)
315 static int bm_check_flag = -1;
316 static int bm_control_flag = -1;
323 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
324 * DMA transfers are used by any ISA device to avoid livelock.
325 * Note that we could disable Type-F DMA (as recommended by
326 * the erratum), but this is known to disrupt certain ISA
327 * devices thus we take the conservative approach.
329 else if (errata.piix4.fdma) {
330 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
331 "C3 not supported on PIIX4 with Type-F DMA\n"));
335 /* All the logic here assumes flags.bm_check is same across all CPUs */
336 if (bm_check_flag == -1) {
337 /* Determine whether bm_check is needed based on CPU */
338 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
339 bm_check_flag = pr->flags.bm_check;
340 bm_control_flag = pr->flags.bm_control;
342 pr->flags.bm_check = bm_check_flag;
343 pr->flags.bm_control = bm_control_flag;
346 if (pr->flags.bm_check) {
347 if (!pr->flags.bm_control) {
348 if (pr->flags.has_cst != 1) {
349 /* bus mastering control is necessary */
350 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
351 "C3 support requires BM control\n"));
354 /* Here we enter C3 without bus mastering */
355 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
356 "C3 support without BM control\n"));
361 * WBINVD should be set in fadt, for C3 state to be
362 * supported on when bm_check is not required.
364 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
365 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
366 "Cache invalidation should work properly"
367 " for C3 to be enabled on SMP systems\n"));
373 * Otherwise we've met all of our C3 requirements.
374 * Normalize the C3 latency to expidite policy. Enable
375 * checking of bus mastering status (bm_check) so we can
376 * use this in our C3 policy
381 * On older chipsets, BM_RLD needs to be set
382 * in order for Bus Master activity to wake the
383 * system from C3. Newer chipsets handle DMA
384 * during C3 automatically and BM_RLD is a NOP.
385 * In either case, the proper way to
386 * handle BM_RLD is to set it and leave it set.
388 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
393 static int acpi_cst_latency_cmp(const void *a, const void *b)
395 const struct acpi_processor_cx *x = a, *y = b;
397 if (!(x->valid && y->valid))
399 if (x->latency > y->latency)
401 if (x->latency < y->latency)
405 static void acpi_cst_latency_swap(void *a, void *b, int n)
407 struct acpi_processor_cx *x = a, *y = b;
410 if (!(x->valid && y->valid))
413 x->latency = y->latency;
417 static int acpi_processor_power_verify(struct acpi_processor *pr)
420 unsigned int working = 0;
421 unsigned int last_latency = 0;
422 unsigned int last_type = 0;
423 bool buggy_latency = false;
425 pr->power.timer_broadcast_on_state = INT_MAX;
427 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
428 struct acpi_processor_cx *cx = &pr->power.states[i];
442 acpi_processor_power_verify_c3(pr, cx);
447 if (cx->type >= last_type && cx->latency < last_latency)
448 buggy_latency = true;
449 last_latency = cx->latency;
450 last_type = cx->type;
452 lapic_timer_check_state(i, pr, cx);
453 tsc_check_state(cx->type);
458 pr_notice("FW issue: working around C-state latencies out of order\n");
459 sort(&pr->power.states[1], max_cstate,
460 sizeof(struct acpi_processor_cx),
461 acpi_cst_latency_cmp,
462 acpi_cst_latency_swap);
465 lapic_timer_propagate_broadcast(pr);
470 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
476 /* NOTE: the idle thread may not be running while calling
479 /* Zero initialize all the C-states info. */
480 memset(pr->power.states, 0, sizeof(pr->power.states));
482 result = acpi_processor_get_power_info_cst(pr);
483 if (result == -ENODEV)
484 result = acpi_processor_get_power_info_fadt(pr);
489 acpi_processor_get_power_info_default(pr);
491 pr->power.count = acpi_processor_power_verify(pr);
494 * if one state of type C2 or C3 is available, mark this
495 * CPU as being "idle manageable"
497 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
498 if (pr->power.states[i].valid) {
508 * acpi_idle_bm_check - checks if bus master activity was detected
510 static int acpi_idle_bm_check(void)
514 if (bm_check_disable)
517 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
519 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
521 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
522 * the true state of bus mastering activity; forcing us to
523 * manually check the BMIDEA bit of each IDE channel.
525 else if (errata.piix4.bmisx) {
526 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
527 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
533 static void wait_for_freeze(void)
536 /* No delay is needed if we are in guest */
537 if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
540 /* Dummy wait op - must do something useless after P_LVL2 read
541 because chipsets cannot guarantee that STPCLK# signal
542 gets asserted in time to freeze execution properly. */
543 inl(acpi_gbl_FADT.xpm_timer_block.address);
547 * acpi_idle_do_entry - enter idle state using the appropriate method
550 * Caller disables interrupt before call and enables interrupt after return.
552 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
554 if (cx->entry_method == ACPI_CSTATE_FFH) {
555 /* Call into architectural FFH based C-state */
556 acpi_processor_ffh_cstate_enter(cx);
557 } else if (cx->entry_method == ACPI_CSTATE_HALT) {
560 /* IO port based C-state */
567 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
568 * @dev: the target CPU
569 * @index: the index of suggested state
571 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
573 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
575 ACPI_FLUSH_CPU_CACHE();
579 if (cx->entry_method == ACPI_CSTATE_HALT)
581 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
587 #if defined(CONFIG_X86) && defined(CONFIG_HOTPLUG_CPU)
596 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
598 return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
599 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
602 static int c3_cpu_count;
603 static DEFINE_RAW_SPINLOCK(c3_lock);
606 * acpi_idle_enter_bm - enters C3 with proper BM handling
607 * @drv: cpuidle driver
608 * @pr: Target processor
609 * @cx: Target state context
610 * @index: index of target state
612 static int __cpuidle acpi_idle_enter_bm(struct cpuidle_driver *drv,
613 struct acpi_processor *pr,
614 struct acpi_processor_cx *cx,
617 static struct acpi_processor_cx safe_cx = {
618 .entry_method = ACPI_CSTATE_HALT,
623 * bm_check implies we need ARB_DIS
624 * bm_control implies whether we can do ARB_DIS
626 * That leaves a case where bm_check is set and bm_control is not set.
627 * In that case we cannot do much, we enter C3 without doing anything.
629 bool dis_bm = pr->flags.bm_control;
631 /* If we can skip BM, demote to a safe state. */
632 if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
634 index = drv->safe_state_index;
636 cx = this_cpu_read(acpi_cstate[index]);
644 raw_spin_lock(&c3_lock);
646 /* Disable bus master arbitration when all CPUs are in C3 */
647 if (c3_cpu_count == num_online_cpus())
648 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
649 raw_spin_unlock(&c3_lock);
654 acpi_idle_do_entry(cx);
658 /* Re-enable bus master arbitration */
660 raw_spin_lock(&c3_lock);
661 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
663 raw_spin_unlock(&c3_lock);
669 static int __cpuidle acpi_idle_enter(struct cpuidle_device *dev,
670 struct cpuidle_driver *drv, int index)
672 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
673 struct acpi_processor *pr;
675 pr = __this_cpu_read(processors);
679 if (cx->type != ACPI_STATE_C1) {
680 if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check)
681 return acpi_idle_enter_bm(drv, pr, cx, index);
683 /* C2 to C1 demotion. */
684 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
685 index = ACPI_IDLE_STATE_START;
686 cx = per_cpu(acpi_cstate[index], dev->cpu);
690 if (cx->type == ACPI_STATE_C3)
691 ACPI_FLUSH_CPU_CACHE();
693 acpi_idle_do_entry(cx);
698 static int __cpuidle acpi_idle_enter_s2idle(struct cpuidle_device *dev,
699 struct cpuidle_driver *drv, int index)
701 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
703 if (cx->type == ACPI_STATE_C3) {
704 struct acpi_processor *pr = __this_cpu_read(processors);
709 if (pr->flags.bm_check) {
710 u8 bm_sts_skip = cx->bm_sts_skip;
712 /* Don't check BM_STS, do an unconditional ARB_DIS for S2IDLE */
714 acpi_idle_enter_bm(drv, pr, cx, index);
715 cx->bm_sts_skip = bm_sts_skip;
719 ACPI_FLUSH_CPU_CACHE();
722 acpi_idle_do_entry(cx);
727 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
728 struct cpuidle_device *dev)
730 int i, count = ACPI_IDLE_STATE_START;
731 struct acpi_processor_cx *cx;
732 struct cpuidle_state *state;
737 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
738 state = &acpi_idle_driver.states[count];
739 cx = &pr->power.states[i];
744 per_cpu(acpi_cstate[count], dev->cpu) = cx;
746 if (lapic_timer_needs_broadcast(pr, cx))
747 state->flags |= CPUIDLE_FLAG_TIMER_STOP;
749 if (cx->type == ACPI_STATE_C3) {
750 state->flags |= CPUIDLE_FLAG_TLB_FLUSHED;
751 if (pr->flags.bm_check)
752 state->flags |= CPUIDLE_FLAG_RCU_IDLE;
756 if (count == CPUIDLE_STATE_MAX)
766 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
769 struct acpi_processor_cx *cx;
770 struct cpuidle_state *state;
771 struct cpuidle_driver *drv = &acpi_idle_driver;
776 if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
777 cpuidle_poll_state_init(drv);
783 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
784 cx = &pr->power.states[i];
789 state = &drv->states[count];
790 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
791 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
792 state->exit_latency = cx->latency;
793 state->target_residency = cx->latency * latency_factor;
794 state->enter = acpi_idle_enter;
797 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
798 state->enter_dead = acpi_idle_play_dead;
799 drv->safe_state_index = count;
802 * Halt-induced C1 is not good for ->enter_s2idle, because it
803 * re-enables interrupts on exit. Moreover, C1 is generally not
804 * particularly interesting from the suspend-to-idle angle, so
805 * avoid C1 and the situations in which we may need to fall back
808 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
809 state->enter_s2idle = acpi_idle_enter_s2idle;
812 if (count == CPUIDLE_STATE_MAX)
816 drv->state_count = count;
824 static inline void acpi_processor_cstate_first_run_checks(void)
826 static int first_run;
830 dmi_check_system(processor_power_dmi_table);
831 max_cstate = acpi_processor_cstate_check(max_cstate);
832 if (max_cstate < ACPI_C_STATES_MAX)
833 pr_notice("ACPI: processor limited to max C-state %d\n",
840 acpi_processor_claim_cst_control();
844 static inline int disabled_by_idle_boot_param(void) { return 0; }
845 static inline void acpi_processor_cstate_first_run_checks(void) { }
846 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
851 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
852 struct cpuidle_device *dev)
857 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
862 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
864 struct acpi_lpi_states_array {
866 unsigned int composite_states_size;
867 struct acpi_lpi_state *entries;
868 struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
871 static int obj_get_integer(union acpi_object *obj, u32 *value)
873 if (obj->type != ACPI_TYPE_INTEGER)
876 *value = obj->integer.value;
880 static int acpi_processor_evaluate_lpi(acpi_handle handle,
881 struct acpi_lpi_states_array *info)
885 int pkg_count, state_idx = 1, loop;
886 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
887 union acpi_object *lpi_data;
888 struct acpi_lpi_state *lpi_state;
890 status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
891 if (ACPI_FAILURE(status)) {
892 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n"));
896 lpi_data = buffer.pointer;
898 /* There must be at least 4 elements = 3 elements + 1 package */
899 if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
900 lpi_data->package.count < 4) {
901 pr_debug("not enough elements in _LPI\n");
906 pkg_count = lpi_data->package.elements[2].integer.value;
908 /* Validate number of power states. */
909 if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
910 pr_debug("count given by _LPI is not valid\n");
915 lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
921 info->size = pkg_count;
922 info->entries = lpi_state;
924 /* LPI States start at index 3 */
925 for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
926 union acpi_object *element, *pkg_elem, *obj;
928 element = &lpi_data->package.elements[loop];
929 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
932 pkg_elem = element->package.elements;
935 if (obj->type == ACPI_TYPE_BUFFER) {
936 struct acpi_power_register *reg;
938 reg = (struct acpi_power_register *)obj->buffer.pointer;
939 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
940 reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
943 lpi_state->address = reg->address;
944 lpi_state->entry_method =
945 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
946 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
947 } else if (obj->type == ACPI_TYPE_INTEGER) {
948 lpi_state->entry_method = ACPI_CSTATE_INTEGER;
949 lpi_state->address = obj->integer.value;
954 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
957 if (obj->type == ACPI_TYPE_STRING)
958 strlcpy(lpi_state->desc, obj->string.pointer,
961 lpi_state->index = state_idx;
962 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
963 pr_debug("No min. residency found, assuming 10 us\n");
964 lpi_state->min_residency = 10;
967 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
968 pr_debug("No wakeup residency found, assuming 10 us\n");
969 lpi_state->wake_latency = 10;
972 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
973 lpi_state->flags = 0;
975 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
976 lpi_state->arch_flags = 0;
978 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
979 lpi_state->res_cnt_freq = 1;
981 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
982 lpi_state->enable_parent_state = 0;
985 acpi_handle_debug(handle, "Found %d power states\n", state_idx);
987 kfree(buffer.pointer);
992 * flat_state_cnt - the number of composite LPI states after the process of flattening
994 static int flat_state_cnt;
997 * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
999 * @local: local LPI state
1000 * @parent: parent LPI state
1001 * @result: composite LPI state
1003 static bool combine_lpi_states(struct acpi_lpi_state *local,
1004 struct acpi_lpi_state *parent,
1005 struct acpi_lpi_state *result)
1007 if (parent->entry_method == ACPI_CSTATE_INTEGER) {
1008 if (!parent->address) /* 0 means autopromotable */
1010 result->address = local->address + parent->address;
1012 result->address = parent->address;
1015 result->min_residency = max(local->min_residency, parent->min_residency);
1016 result->wake_latency = local->wake_latency + parent->wake_latency;
1017 result->enable_parent_state = parent->enable_parent_state;
1018 result->entry_method = local->entry_method;
1020 result->flags = parent->flags;
1021 result->arch_flags = parent->arch_flags;
1022 result->index = parent->index;
1024 strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
1025 strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
1026 strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
1030 #define ACPI_LPI_STATE_FLAGS_ENABLED BIT(0)
1032 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
1033 struct acpi_lpi_state *t)
1035 curr_level->composite_states[curr_level->composite_states_size++] = t;
1038 static int flatten_lpi_states(struct acpi_processor *pr,
1039 struct acpi_lpi_states_array *curr_level,
1040 struct acpi_lpi_states_array *prev_level)
1042 int i, j, state_count = curr_level->size;
1043 struct acpi_lpi_state *p, *t = curr_level->entries;
1045 curr_level->composite_states_size = 0;
1046 for (j = 0; j < state_count; j++, t++) {
1047 struct acpi_lpi_state *flpi;
1049 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1052 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1053 pr_warn("Limiting number of LPI states to max (%d)\n",
1054 ACPI_PROCESSOR_MAX_POWER);
1055 pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1059 flpi = &pr->power.lpi_states[flat_state_cnt];
1061 if (!prev_level) { /* leaf/processor node */
1062 memcpy(flpi, t, sizeof(*t));
1063 stash_composite_state(curr_level, flpi);
1068 for (i = 0; i < prev_level->composite_states_size; i++) {
1069 p = prev_level->composite_states[i];
1070 if (t->index <= p->enable_parent_state &&
1071 combine_lpi_states(p, t, flpi)) {
1072 stash_composite_state(curr_level, flpi);
1079 kfree(curr_level->entries);
1083 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1088 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1092 acpi_handle handle = pr->handle, pr_ahandle;
1093 struct acpi_device *d = NULL;
1094 struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1096 /* make sure our architecture has support */
1097 ret = acpi_processor_ffh_lpi_probe(pr->id);
1098 if (ret == -EOPNOTSUPP)
1101 if (!osc_pc_lpi_support_confirmed)
1104 if (!acpi_has_method(handle, "_LPI"))
1110 handle = pr->handle;
1111 ret = acpi_processor_evaluate_lpi(handle, prev);
1114 flatten_lpi_states(pr, prev, NULL);
1116 status = acpi_get_parent(handle, &pr_ahandle);
1117 while (ACPI_SUCCESS(status)) {
1118 acpi_bus_get_device(pr_ahandle, &d);
1119 handle = pr_ahandle;
1121 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1124 /* can be optional ? */
1125 if (!acpi_has_method(handle, "_LPI"))
1128 ret = acpi_processor_evaluate_lpi(handle, curr);
1132 /* flatten all the LPI states in this level of hierarchy */
1133 flatten_lpi_states(pr, curr, prev);
1135 tmp = prev, prev = curr, curr = tmp;
1137 status = acpi_get_parent(handle, &pr_ahandle);
1140 pr->power.count = flat_state_cnt;
1141 /* reset the index after flattening */
1142 for (i = 0; i < pr->power.count; i++)
1143 pr->power.lpi_states[i].index = i;
1145 /* Tell driver that _LPI is supported. */
1146 pr->flags.has_lpi = 1;
1147 pr->flags.power = 1;
1152 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1158 * acpi_idle_lpi_enter - enters an ACPI any LPI state
1159 * @dev: the target CPU
1160 * @drv: cpuidle driver containing cpuidle state info
1161 * @index: index of target state
1163 * Return: 0 for success or negative value for error
1165 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1166 struct cpuidle_driver *drv, int index)
1168 struct acpi_processor *pr;
1169 struct acpi_lpi_state *lpi;
1171 pr = __this_cpu_read(processors);
1176 lpi = &pr->power.lpi_states[index];
1177 if (lpi->entry_method == ACPI_CSTATE_FFH)
1178 return acpi_processor_ffh_lpi_enter(lpi);
1183 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1186 struct acpi_lpi_state *lpi;
1187 struct cpuidle_state *state;
1188 struct cpuidle_driver *drv = &acpi_idle_driver;
1190 if (!pr->flags.has_lpi)
1193 for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1194 lpi = &pr->power.lpi_states[i];
1196 state = &drv->states[i];
1197 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1198 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1199 state->exit_latency = lpi->wake_latency;
1200 state->target_residency = lpi->min_residency;
1201 if (lpi->arch_flags)
1202 state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1203 state->enter = acpi_idle_lpi_enter;
1204 drv->safe_state_index = i;
1207 drv->state_count = i;
1213 * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1214 * global state data i.e. idle routines
1216 * @pr: the ACPI processor
1218 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1221 struct cpuidle_driver *drv = &acpi_idle_driver;
1223 if (!pr->flags.power_setup_done || !pr->flags.power)
1226 drv->safe_state_index = -1;
1227 for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1228 drv->states[i].name[0] = '\0';
1229 drv->states[i].desc[0] = '\0';
1232 if (pr->flags.has_lpi)
1233 return acpi_processor_setup_lpi_states(pr);
1235 return acpi_processor_setup_cstates(pr);
1239 * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1240 * device i.e. per-cpu data
1242 * @pr: the ACPI processor
1243 * @dev : the cpuidle device
1245 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1246 struct cpuidle_device *dev)
1248 if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1252 if (pr->flags.has_lpi)
1253 return acpi_processor_ffh_lpi_probe(pr->id);
1255 return acpi_processor_setup_cpuidle_cx(pr, dev);
1258 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1262 ret = acpi_processor_get_lpi_info(pr);
1264 ret = acpi_processor_get_cstate_info(pr);
1269 int acpi_processor_hotplug(struct acpi_processor *pr)
1272 struct cpuidle_device *dev;
1274 if (disabled_by_idle_boot_param())
1277 if (!pr->flags.power_setup_done)
1280 dev = per_cpu(acpi_cpuidle_device, pr->id);
1281 cpuidle_pause_and_lock();
1282 cpuidle_disable_device(dev);
1283 ret = acpi_processor_get_power_info(pr);
1284 if (!ret && pr->flags.power) {
1285 acpi_processor_setup_cpuidle_dev(pr, dev);
1286 ret = cpuidle_enable_device(dev);
1288 cpuidle_resume_and_unlock();
1293 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1296 struct acpi_processor *_pr;
1297 struct cpuidle_device *dev;
1299 if (disabled_by_idle_boot_param())
1302 if (!pr->flags.power_setup_done)
1306 * FIXME: Design the ACPI notification to make it once per
1307 * system instead of once per-cpu. This condition is a hack
1308 * to make the code that updates C-States be called once.
1311 if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1313 /* Protect against cpu-hotplug */
1315 cpuidle_pause_and_lock();
1317 /* Disable all cpuidle devices */
1318 for_each_online_cpu(cpu) {
1319 _pr = per_cpu(processors, cpu);
1320 if (!_pr || !_pr->flags.power_setup_done)
1322 dev = per_cpu(acpi_cpuidle_device, cpu);
1323 cpuidle_disable_device(dev);
1326 /* Populate Updated C-state information */
1327 acpi_processor_get_power_info(pr);
1328 acpi_processor_setup_cpuidle_states(pr);
1330 /* Enable all cpuidle devices */
1331 for_each_online_cpu(cpu) {
1332 _pr = per_cpu(processors, cpu);
1333 if (!_pr || !_pr->flags.power_setup_done)
1335 acpi_processor_get_power_info(_pr);
1336 if (_pr->flags.power) {
1337 dev = per_cpu(acpi_cpuidle_device, cpu);
1338 acpi_processor_setup_cpuidle_dev(_pr, dev);
1339 cpuidle_enable_device(dev);
1342 cpuidle_resume_and_unlock();
1349 static int acpi_processor_registered;
1351 int acpi_processor_power_init(struct acpi_processor *pr)
1354 struct cpuidle_device *dev;
1356 if (disabled_by_idle_boot_param())
1359 acpi_processor_cstate_first_run_checks();
1361 if (!acpi_processor_get_power_info(pr))
1362 pr->flags.power_setup_done = 1;
1365 * Install the idle handler if processor power management is supported.
1366 * Note that we use previously set idle handler will be used on
1367 * platforms that only support C1.
1369 if (pr->flags.power) {
1370 /* Register acpi_idle_driver if not already registered */
1371 if (!acpi_processor_registered) {
1372 acpi_processor_setup_cpuidle_states(pr);
1373 retval = cpuidle_register_driver(&acpi_idle_driver);
1376 pr_debug("%s registered with cpuidle\n",
1377 acpi_idle_driver.name);
1380 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1383 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1385 acpi_processor_setup_cpuidle_dev(pr, dev);
1387 /* Register per-cpu cpuidle_device. Cpuidle driver
1388 * must already be registered before registering device
1390 retval = cpuidle_register_device(dev);
1392 if (acpi_processor_registered == 0)
1393 cpuidle_unregister_driver(&acpi_idle_driver);
1396 acpi_processor_registered++;
1401 int acpi_processor_power_exit(struct acpi_processor *pr)
1403 struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1405 if (disabled_by_idle_boot_param())
1408 if (pr->flags.power) {
1409 cpuidle_unregister_device(dev);
1410 acpi_processor_registered--;
1411 if (acpi_processor_registered == 0)
1412 cpuidle_unregister_driver(&acpi_idle_driver);
1415 pr->flags.power_setup_done = 0;