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 ACPI_IDLE_STATE_START (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0)
37 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
38 module_param(max_cstate, uint, 0000);
39 static unsigned int nocst __read_mostly;
40 module_param(nocst, uint, 0000);
41 static int bm_check_disable __read_mostly;
42 module_param(bm_check_disable, uint, 0000);
44 static unsigned int latency_factor __read_mostly = 2;
45 module_param(latency_factor, uint, 0644);
47 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
49 struct cpuidle_driver acpi_idle_driver = {
54 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
56 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
58 static int disabled_by_idle_boot_param(void)
60 return boot_option_idle_override == IDLE_POLL ||
61 boot_option_idle_override == IDLE_HALT;
65 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
66 * For now disable this. Probably a bug somewhere else.
68 * To skip this limit, boot/load with a large max_cstate limit.
70 static int set_max_cstate(const struct dmi_system_id *id)
72 if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
75 pr_notice("%s detected - limiting to C%ld max_cstate."
76 " Override with \"processor.max_cstate=%d\"\n", id->ident,
77 (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
79 max_cstate = (long)id->driver_data;
84 static const struct dmi_system_id processor_power_dmi_table[] = {
85 { set_max_cstate, "Clevo 5600D", {
86 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
87 DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
89 { set_max_cstate, "Pavilion zv5000", {
90 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
91 DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
93 { set_max_cstate, "Asus L8400B", {
94 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
95 DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
102 * Callers should disable interrupts before the call and enable
103 * interrupts after return.
105 static void __cpuidle acpi_safe_halt(void)
107 if (!tif_need_resched()) {
113 #ifdef ARCH_APICTIMER_STOPS_ON_C3
116 * Some BIOS implementations switch to C3 in the published C2 state.
117 * This seems to be a common problem on AMD boxen, but other vendors
118 * are affected too. We pick the most conservative approach: we assume
119 * that the local APIC stops in both C2 and C3.
121 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
122 struct acpi_processor_cx *cx)
124 struct acpi_processor_power *pwr = &pr->power;
125 u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
127 if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
130 if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E))
131 type = ACPI_STATE_C1;
134 * Check, if one of the previous states already marked the lapic
137 if (pwr->timer_broadcast_on_state < state)
140 if (cx->type >= type)
141 pr->power.timer_broadcast_on_state = state;
144 static void __lapic_timer_propagate_broadcast(void *arg)
146 struct acpi_processor *pr = (struct acpi_processor *) arg;
148 if (pr->power.timer_broadcast_on_state < INT_MAX)
149 tick_broadcast_enable();
151 tick_broadcast_disable();
154 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
156 smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
160 /* Power(C) State timer broadcast control */
161 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr,
162 struct acpi_processor_cx *cx)
164 return cx - pr->power.states >= pr->power.timer_broadcast_on_state;
169 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
170 struct acpi_processor_cx *cstate) { }
171 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
173 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr,
174 struct acpi_processor_cx *cx)
181 #if defined(CONFIG_X86)
182 static void tsc_check_state(int state)
184 switch (boot_cpu_data.x86_vendor) {
185 case X86_VENDOR_HYGON:
187 case X86_VENDOR_INTEL:
188 case X86_VENDOR_CENTAUR:
189 case X86_VENDOR_ZHAOXIN:
191 * AMD Fam10h TSC will tick in all
192 * C/P/S0/S1 states when this bit is set.
194 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
198 /* TSC could halt in idle, so notify users */
199 if (state > ACPI_STATE_C1)
200 mark_tsc_unstable("TSC halts in idle");
204 static void tsc_check_state(int state) { return; }
207 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
213 /* if info is obtained from pblk/fadt, type equals state */
214 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
215 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
217 #ifndef CONFIG_HOTPLUG_CPU
219 * Check for P_LVL2_UP flag before entering C2 and above on
222 if ((num_online_cpus() > 1) &&
223 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
227 /* determine C2 and C3 address from pblk */
228 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
229 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
231 /* determine latencies from FADT */
232 pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
233 pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
236 * FADT specified C2 latency must be less than or equal to
239 if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
240 acpi_handle_debug(pr->handle, "C2 latency too large [%d]\n",
241 acpi_gbl_FADT.c2_latency);
243 pr->power.states[ACPI_STATE_C2].address = 0;
247 * FADT supplied C3 latency must be less than or equal to
250 if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
251 acpi_handle_debug(pr->handle, "C3 latency too large [%d]\n",
252 acpi_gbl_FADT.c3_latency);
254 pr->power.states[ACPI_STATE_C3].address = 0;
257 acpi_handle_debug(pr->handle, "lvl2[0x%08x] lvl3[0x%08x]\n",
258 pr->power.states[ACPI_STATE_C2].address,
259 pr->power.states[ACPI_STATE_C3].address);
261 snprintf(pr->power.states[ACPI_STATE_C2].desc,
262 ACPI_CX_DESC_LEN, "ACPI P_LVL2 IOPORT 0x%x",
263 pr->power.states[ACPI_STATE_C2].address);
264 snprintf(pr->power.states[ACPI_STATE_C3].desc,
265 ACPI_CX_DESC_LEN, "ACPI P_LVL3 IOPORT 0x%x",
266 pr->power.states[ACPI_STATE_C3].address);
271 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
273 if (!pr->power.states[ACPI_STATE_C1].valid) {
274 /* set the first C-State to C1 */
275 /* all processors need to support C1 */
276 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
277 pr->power.states[ACPI_STATE_C1].valid = 1;
278 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
280 snprintf(pr->power.states[ACPI_STATE_C1].desc,
281 ACPI_CX_DESC_LEN, "ACPI HLT");
283 /* the C0 state only exists as a filler in our array */
284 pr->power.states[ACPI_STATE_C0].valid = 1;
288 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
295 ret = acpi_processor_evaluate_cst(pr->handle, pr->id, &pr->power);
299 if (!pr->power.count)
302 pr->flags.has_cst = 1;
306 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
307 struct acpi_processor_cx *cx)
309 static int bm_check_flag = -1;
310 static int bm_control_flag = -1;
317 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
318 * DMA transfers are used by any ISA device to avoid livelock.
319 * Note that we could disable Type-F DMA (as recommended by
320 * the erratum), but this is known to disrupt certain ISA
321 * devices thus we take the conservative approach.
323 else if (errata.piix4.fdma) {
324 acpi_handle_debug(pr->handle,
325 "C3 not supported on PIIX4 with Type-F DMA\n");
329 /* All the logic here assumes flags.bm_check is same across all CPUs */
330 if (bm_check_flag == -1) {
331 /* Determine whether bm_check is needed based on CPU */
332 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
333 bm_check_flag = pr->flags.bm_check;
334 bm_control_flag = pr->flags.bm_control;
336 pr->flags.bm_check = bm_check_flag;
337 pr->flags.bm_control = bm_control_flag;
340 if (pr->flags.bm_check) {
341 if (!pr->flags.bm_control) {
342 if (pr->flags.has_cst != 1) {
343 /* bus mastering control is necessary */
344 acpi_handle_debug(pr->handle,
345 "C3 support requires BM control\n");
348 /* Here we enter C3 without bus mastering */
349 acpi_handle_debug(pr->handle,
350 "C3 support without BM control\n");
355 * WBINVD should be set in fadt, for C3 state to be
356 * supported on when bm_check is not required.
358 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
359 acpi_handle_debug(pr->handle,
360 "Cache invalidation should work properly"
361 " for C3 to be enabled on SMP systems\n");
367 * Otherwise we've met all of our C3 requirements.
368 * Normalize the C3 latency to expidite policy. Enable
369 * checking of bus mastering status (bm_check) so we can
370 * use this in our C3 policy
375 * On older chipsets, BM_RLD needs to be set
376 * in order for Bus Master activity to wake the
377 * system from C3. Newer chipsets handle DMA
378 * during C3 automatically and BM_RLD is a NOP.
379 * In either case, the proper way to
380 * handle BM_RLD is to set it and leave it set.
382 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
387 static int acpi_processor_power_verify(struct acpi_processor *pr)
390 unsigned int working = 0;
392 pr->power.timer_broadcast_on_state = INT_MAX;
394 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
395 struct acpi_processor_cx *cx = &pr->power.states[i];
409 acpi_processor_power_verify_c3(pr, cx);
415 lapic_timer_check_state(i, pr, cx);
416 tsc_check_state(cx->type);
420 lapic_timer_propagate_broadcast(pr);
425 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
431 /* NOTE: the idle thread may not be running while calling
434 /* Zero initialize all the C-states info. */
435 memset(pr->power.states, 0, sizeof(pr->power.states));
437 result = acpi_processor_get_power_info_cst(pr);
438 if (result == -ENODEV)
439 result = acpi_processor_get_power_info_fadt(pr);
444 acpi_processor_get_power_info_default(pr);
446 pr->power.count = acpi_processor_power_verify(pr);
449 * if one state of type C2 or C3 is available, mark this
450 * CPU as being "idle manageable"
452 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
453 if (pr->power.states[i].valid) {
463 * acpi_idle_bm_check - checks if bus master activity was detected
465 static int acpi_idle_bm_check(void)
469 if (bm_check_disable)
472 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
474 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
476 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
477 * the true state of bus mastering activity; forcing us to
478 * manually check the BMIDEA bit of each IDE channel.
480 else if (errata.piix4.bmisx) {
481 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
482 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
488 static void wait_for_freeze(void)
491 /* No delay is needed if we are in guest */
492 if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
495 /* Dummy wait op - must do something useless after P_LVL2 read
496 because chipsets cannot guarantee that STPCLK# signal
497 gets asserted in time to freeze execution properly. */
498 inl(acpi_gbl_FADT.xpm_timer_block.address);
502 * acpi_idle_do_entry - enter idle state using the appropriate method
505 * Caller disables interrupt before call and enables interrupt after return.
507 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
509 if (cx->entry_method == ACPI_CSTATE_FFH) {
510 /* Call into architectural FFH based C-state */
511 acpi_processor_ffh_cstate_enter(cx);
512 } else if (cx->entry_method == ACPI_CSTATE_HALT) {
515 /* IO port based C-state */
522 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
523 * @dev: the target CPU
524 * @index: the index of suggested state
526 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
528 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
530 ACPI_FLUSH_CPU_CACHE();
534 if (cx->entry_method == ACPI_CSTATE_HALT)
536 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
542 #if defined(CONFIG_X86) && defined(CONFIG_HOTPLUG_CPU)
551 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
553 return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
554 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
557 static int c3_cpu_count;
558 static DEFINE_RAW_SPINLOCK(c3_lock);
561 * acpi_idle_enter_bm - enters C3 with proper BM handling
562 * @drv: cpuidle driver
563 * @pr: Target processor
564 * @cx: Target state context
565 * @index: index of target state
567 static int acpi_idle_enter_bm(struct cpuidle_driver *drv,
568 struct acpi_processor *pr,
569 struct acpi_processor_cx *cx,
572 static struct acpi_processor_cx safe_cx = {
573 .entry_method = ACPI_CSTATE_HALT,
578 * bm_check implies we need ARB_DIS
579 * bm_control implies whether we can do ARB_DIS
581 * That leaves a case where bm_check is set and bm_control is not set.
582 * In that case we cannot do much, we enter C3 without doing anything.
584 bool dis_bm = pr->flags.bm_control;
586 /* If we can skip BM, demote to a safe state. */
587 if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
589 index = drv->safe_state_index;
591 cx = this_cpu_read(acpi_cstate[index]);
599 raw_spin_lock(&c3_lock);
601 /* Disable bus master arbitration when all CPUs are in C3 */
602 if (c3_cpu_count == num_online_cpus())
603 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
604 raw_spin_unlock(&c3_lock);
609 acpi_idle_do_entry(cx);
613 /* Re-enable bus master arbitration */
615 raw_spin_lock(&c3_lock);
616 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
618 raw_spin_unlock(&c3_lock);
624 static int acpi_idle_enter(struct cpuidle_device *dev,
625 struct cpuidle_driver *drv, int index)
627 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
628 struct acpi_processor *pr;
630 pr = __this_cpu_read(processors);
634 if (cx->type != ACPI_STATE_C1) {
635 if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check)
636 return acpi_idle_enter_bm(drv, pr, cx, index);
638 /* C2 to C1 demotion. */
639 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
640 index = ACPI_IDLE_STATE_START;
641 cx = per_cpu(acpi_cstate[index], dev->cpu);
645 if (cx->type == ACPI_STATE_C3)
646 ACPI_FLUSH_CPU_CACHE();
648 acpi_idle_do_entry(cx);
653 static int acpi_idle_enter_s2idle(struct cpuidle_device *dev,
654 struct cpuidle_driver *drv, int index)
656 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
658 if (cx->type == ACPI_STATE_C3) {
659 struct acpi_processor *pr = __this_cpu_read(processors);
664 if (pr->flags.bm_check) {
665 u8 bm_sts_skip = cx->bm_sts_skip;
667 /* Don't check BM_STS, do an unconditional ARB_DIS for S2IDLE */
669 acpi_idle_enter_bm(drv, pr, cx, index);
670 cx->bm_sts_skip = bm_sts_skip;
674 ACPI_FLUSH_CPU_CACHE();
677 acpi_idle_do_entry(cx);
682 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
683 struct cpuidle_device *dev)
685 int i, count = ACPI_IDLE_STATE_START;
686 struct acpi_processor_cx *cx;
687 struct cpuidle_state *state;
692 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
693 state = &acpi_idle_driver.states[count];
694 cx = &pr->power.states[i];
699 per_cpu(acpi_cstate[count], dev->cpu) = cx;
701 if (lapic_timer_needs_broadcast(pr, cx))
702 state->flags |= CPUIDLE_FLAG_TIMER_STOP;
704 if (cx->type == ACPI_STATE_C3) {
705 state->flags |= CPUIDLE_FLAG_TLB_FLUSHED;
706 if (pr->flags.bm_check)
707 state->flags |= CPUIDLE_FLAG_RCU_IDLE;
711 if (count == CPUIDLE_STATE_MAX)
721 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
724 struct acpi_processor_cx *cx;
725 struct cpuidle_state *state;
726 struct cpuidle_driver *drv = &acpi_idle_driver;
731 if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
732 cpuidle_poll_state_init(drv);
738 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
739 cx = &pr->power.states[i];
744 state = &drv->states[count];
745 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
746 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
747 state->exit_latency = cx->latency;
748 state->target_residency = cx->latency * latency_factor;
749 state->enter = acpi_idle_enter;
752 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
753 state->enter_dead = acpi_idle_play_dead;
754 drv->safe_state_index = count;
757 * Halt-induced C1 is not good for ->enter_s2idle, because it
758 * re-enables interrupts on exit. Moreover, C1 is generally not
759 * particularly interesting from the suspend-to-idle angle, so
760 * avoid C1 and the situations in which we may need to fall back
763 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
764 state->enter_s2idle = acpi_idle_enter_s2idle;
767 if (count == CPUIDLE_STATE_MAX)
771 drv->state_count = count;
779 static inline void acpi_processor_cstate_first_run_checks(void)
781 static int first_run;
785 dmi_check_system(processor_power_dmi_table);
786 max_cstate = acpi_processor_cstate_check(max_cstate);
787 if (max_cstate < ACPI_C_STATES_MAX)
788 pr_notice("processor limited to max C-state %d\n", max_cstate);
795 acpi_processor_claim_cst_control();
799 static inline int disabled_by_idle_boot_param(void) { return 0; }
800 static inline void acpi_processor_cstate_first_run_checks(void) { }
801 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
806 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
807 struct cpuidle_device *dev)
812 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
817 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
819 struct acpi_lpi_states_array {
821 unsigned int composite_states_size;
822 struct acpi_lpi_state *entries;
823 struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
826 static int obj_get_integer(union acpi_object *obj, u32 *value)
828 if (obj->type != ACPI_TYPE_INTEGER)
831 *value = obj->integer.value;
835 static int acpi_processor_evaluate_lpi(acpi_handle handle,
836 struct acpi_lpi_states_array *info)
840 int pkg_count, state_idx = 1, loop;
841 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
842 union acpi_object *lpi_data;
843 struct acpi_lpi_state *lpi_state;
845 status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
846 if (ACPI_FAILURE(status)) {
847 acpi_handle_debug(handle, "No _LPI, giving up\n");
851 lpi_data = buffer.pointer;
853 /* There must be at least 4 elements = 3 elements + 1 package */
854 if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
855 lpi_data->package.count < 4) {
856 pr_debug("not enough elements in _LPI\n");
861 pkg_count = lpi_data->package.elements[2].integer.value;
863 /* Validate number of power states. */
864 if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
865 pr_debug("count given by _LPI is not valid\n");
870 lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
876 info->size = pkg_count;
877 info->entries = lpi_state;
879 /* LPI States start at index 3 */
880 for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
881 union acpi_object *element, *pkg_elem, *obj;
883 element = &lpi_data->package.elements[loop];
884 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
887 pkg_elem = element->package.elements;
890 if (obj->type == ACPI_TYPE_BUFFER) {
891 struct acpi_power_register *reg;
893 reg = (struct acpi_power_register *)obj->buffer.pointer;
894 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
895 reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
898 lpi_state->address = reg->address;
899 lpi_state->entry_method =
900 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
901 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
902 } else if (obj->type == ACPI_TYPE_INTEGER) {
903 lpi_state->entry_method = ACPI_CSTATE_INTEGER;
904 lpi_state->address = obj->integer.value;
909 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
912 if (obj->type == ACPI_TYPE_STRING)
913 strlcpy(lpi_state->desc, obj->string.pointer,
916 lpi_state->index = state_idx;
917 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
918 pr_debug("No min. residency found, assuming 10 us\n");
919 lpi_state->min_residency = 10;
922 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
923 pr_debug("No wakeup residency found, assuming 10 us\n");
924 lpi_state->wake_latency = 10;
927 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
928 lpi_state->flags = 0;
930 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
931 lpi_state->arch_flags = 0;
933 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
934 lpi_state->res_cnt_freq = 1;
936 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
937 lpi_state->enable_parent_state = 0;
940 acpi_handle_debug(handle, "Found %d power states\n", state_idx);
942 kfree(buffer.pointer);
947 * flat_state_cnt - the number of composite LPI states after the process of flattening
949 static int flat_state_cnt;
952 * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
954 * @local: local LPI state
955 * @parent: parent LPI state
956 * @result: composite LPI state
958 static bool combine_lpi_states(struct acpi_lpi_state *local,
959 struct acpi_lpi_state *parent,
960 struct acpi_lpi_state *result)
962 if (parent->entry_method == ACPI_CSTATE_INTEGER) {
963 if (!parent->address) /* 0 means autopromotable */
965 result->address = local->address + parent->address;
967 result->address = parent->address;
970 result->min_residency = max(local->min_residency, parent->min_residency);
971 result->wake_latency = local->wake_latency + parent->wake_latency;
972 result->enable_parent_state = parent->enable_parent_state;
973 result->entry_method = local->entry_method;
975 result->flags = parent->flags;
976 result->arch_flags = parent->arch_flags;
977 result->index = parent->index;
979 strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
980 strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
981 strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
985 #define ACPI_LPI_STATE_FLAGS_ENABLED BIT(0)
987 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
988 struct acpi_lpi_state *t)
990 curr_level->composite_states[curr_level->composite_states_size++] = t;
993 static int flatten_lpi_states(struct acpi_processor *pr,
994 struct acpi_lpi_states_array *curr_level,
995 struct acpi_lpi_states_array *prev_level)
997 int i, j, state_count = curr_level->size;
998 struct acpi_lpi_state *p, *t = curr_level->entries;
1000 curr_level->composite_states_size = 0;
1001 for (j = 0; j < state_count; j++, t++) {
1002 struct acpi_lpi_state *flpi;
1004 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1007 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1008 pr_warn("Limiting number of LPI states to max (%d)\n",
1009 ACPI_PROCESSOR_MAX_POWER);
1010 pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1014 flpi = &pr->power.lpi_states[flat_state_cnt];
1016 if (!prev_level) { /* leaf/processor node */
1017 memcpy(flpi, t, sizeof(*t));
1018 stash_composite_state(curr_level, flpi);
1023 for (i = 0; i < prev_level->composite_states_size; i++) {
1024 p = prev_level->composite_states[i];
1025 if (t->index <= p->enable_parent_state &&
1026 combine_lpi_states(p, t, flpi)) {
1027 stash_composite_state(curr_level, flpi);
1034 kfree(curr_level->entries);
1038 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1042 acpi_handle handle = pr->handle, pr_ahandle;
1043 struct acpi_device *d = NULL;
1044 struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1046 if (!osc_pc_lpi_support_confirmed)
1049 if (!acpi_has_method(handle, "_LPI"))
1055 handle = pr->handle;
1056 ret = acpi_processor_evaluate_lpi(handle, prev);
1059 flatten_lpi_states(pr, prev, NULL);
1061 status = acpi_get_parent(handle, &pr_ahandle);
1062 while (ACPI_SUCCESS(status)) {
1063 acpi_bus_get_device(pr_ahandle, &d);
1064 handle = pr_ahandle;
1066 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1069 /* can be optional ? */
1070 if (!acpi_has_method(handle, "_LPI"))
1073 ret = acpi_processor_evaluate_lpi(handle, curr);
1077 /* flatten all the LPI states in this level of hierarchy */
1078 flatten_lpi_states(pr, curr, prev);
1080 tmp = prev, prev = curr, curr = tmp;
1082 status = acpi_get_parent(handle, &pr_ahandle);
1085 pr->power.count = flat_state_cnt;
1086 /* reset the index after flattening */
1087 for (i = 0; i < pr->power.count; i++)
1088 pr->power.lpi_states[i].index = i;
1090 /* Tell driver that _LPI is supported. */
1091 pr->flags.has_lpi = 1;
1092 pr->flags.power = 1;
1097 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1102 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1108 * acpi_idle_lpi_enter - enters an ACPI any LPI state
1109 * @dev: the target CPU
1110 * @drv: cpuidle driver containing cpuidle state info
1111 * @index: index of target state
1113 * Return: 0 for success or negative value for error
1115 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1116 struct cpuidle_driver *drv, int index)
1118 struct acpi_processor *pr;
1119 struct acpi_lpi_state *lpi;
1121 pr = __this_cpu_read(processors);
1126 lpi = &pr->power.lpi_states[index];
1127 if (lpi->entry_method == ACPI_CSTATE_FFH)
1128 return acpi_processor_ffh_lpi_enter(lpi);
1133 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1136 struct acpi_lpi_state *lpi;
1137 struct cpuidle_state *state;
1138 struct cpuidle_driver *drv = &acpi_idle_driver;
1140 if (!pr->flags.has_lpi)
1143 for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1144 lpi = &pr->power.lpi_states[i];
1146 state = &drv->states[i];
1147 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1148 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1149 state->exit_latency = lpi->wake_latency;
1150 state->target_residency = lpi->min_residency;
1151 if (lpi->arch_flags)
1152 state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1153 state->enter = acpi_idle_lpi_enter;
1154 drv->safe_state_index = i;
1157 drv->state_count = i;
1163 * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1164 * global state data i.e. idle routines
1166 * @pr: the ACPI processor
1168 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1171 struct cpuidle_driver *drv = &acpi_idle_driver;
1173 if (!pr->flags.power_setup_done || !pr->flags.power)
1176 drv->safe_state_index = -1;
1177 for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1178 drv->states[i].name[0] = '\0';
1179 drv->states[i].desc[0] = '\0';
1182 if (pr->flags.has_lpi)
1183 return acpi_processor_setup_lpi_states(pr);
1185 return acpi_processor_setup_cstates(pr);
1189 * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1190 * device i.e. per-cpu data
1192 * @pr: the ACPI processor
1193 * @dev : the cpuidle device
1195 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1196 struct cpuidle_device *dev)
1198 if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1202 if (pr->flags.has_lpi)
1203 return acpi_processor_ffh_lpi_probe(pr->id);
1205 return acpi_processor_setup_cpuidle_cx(pr, dev);
1208 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1212 ret = acpi_processor_get_lpi_info(pr);
1214 ret = acpi_processor_get_cstate_info(pr);
1219 int acpi_processor_hotplug(struct acpi_processor *pr)
1222 struct cpuidle_device *dev;
1224 if (disabled_by_idle_boot_param())
1227 if (!pr->flags.power_setup_done)
1230 dev = per_cpu(acpi_cpuidle_device, pr->id);
1231 cpuidle_pause_and_lock();
1232 cpuidle_disable_device(dev);
1233 ret = acpi_processor_get_power_info(pr);
1234 if (!ret && pr->flags.power) {
1235 acpi_processor_setup_cpuidle_dev(pr, dev);
1236 ret = cpuidle_enable_device(dev);
1238 cpuidle_resume_and_unlock();
1243 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1246 struct acpi_processor *_pr;
1247 struct cpuidle_device *dev;
1249 if (disabled_by_idle_boot_param())
1252 if (!pr->flags.power_setup_done)
1256 * FIXME: Design the ACPI notification to make it once per
1257 * system instead of once per-cpu. This condition is a hack
1258 * to make the code that updates C-States be called once.
1261 if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1263 /* Protect against cpu-hotplug */
1265 cpuidle_pause_and_lock();
1267 /* Disable all cpuidle devices */
1268 for_each_online_cpu(cpu) {
1269 _pr = per_cpu(processors, cpu);
1270 if (!_pr || !_pr->flags.power_setup_done)
1272 dev = per_cpu(acpi_cpuidle_device, cpu);
1273 cpuidle_disable_device(dev);
1276 /* Populate Updated C-state information */
1277 acpi_processor_get_power_info(pr);
1278 acpi_processor_setup_cpuidle_states(pr);
1280 /* Enable all cpuidle devices */
1281 for_each_online_cpu(cpu) {
1282 _pr = per_cpu(processors, cpu);
1283 if (!_pr || !_pr->flags.power_setup_done)
1285 acpi_processor_get_power_info(_pr);
1286 if (_pr->flags.power) {
1287 dev = per_cpu(acpi_cpuidle_device, cpu);
1288 acpi_processor_setup_cpuidle_dev(_pr, dev);
1289 cpuidle_enable_device(dev);
1292 cpuidle_resume_and_unlock();
1299 static int acpi_processor_registered;
1301 int acpi_processor_power_init(struct acpi_processor *pr)
1304 struct cpuidle_device *dev;
1306 if (disabled_by_idle_boot_param())
1309 acpi_processor_cstate_first_run_checks();
1311 if (!acpi_processor_get_power_info(pr))
1312 pr->flags.power_setup_done = 1;
1315 * Install the idle handler if processor power management is supported.
1316 * Note that we use previously set idle handler will be used on
1317 * platforms that only support C1.
1319 if (pr->flags.power) {
1320 /* Register acpi_idle_driver if not already registered */
1321 if (!acpi_processor_registered) {
1322 acpi_processor_setup_cpuidle_states(pr);
1323 retval = cpuidle_register_driver(&acpi_idle_driver);
1326 pr_debug("%s registered with cpuidle\n",
1327 acpi_idle_driver.name);
1330 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1333 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1335 acpi_processor_setup_cpuidle_dev(pr, dev);
1337 /* Register per-cpu cpuidle_device. Cpuidle driver
1338 * must already be registered before registering device
1340 retval = cpuidle_register_device(dev);
1342 if (acpi_processor_registered == 0)
1343 cpuidle_unregister_driver(&acpi_idle_driver);
1346 acpi_processor_registered++;
1351 int acpi_processor_power_exit(struct acpi_processor *pr)
1353 struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1355 if (disabled_by_idle_boot_param())
1358 if (pr->flags.power) {
1359 cpuidle_unregister_device(dev);
1360 acpi_processor_registered--;
1361 if (acpi_processor_registered == 0)
1362 cpuidle_unregister_driver(&acpi_idle_driver);
1365 pr->flags.power_setup_done = 0;