2 * processor_idle - idle state submodule to the ACPI processor driver
4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6 * Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
7 * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
8 * - Added processor hotplug support
9 * Copyright (C) 2005 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
10 * - Added support for C3 on SMP
12 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or (at
17 * your option) any later version.
19 * This program is distributed in the hope that it will be useful, but
20 * WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 * General Public License for more details.
24 * You should have received a copy of the GNU General Public License along
25 * with this program; if not, write to the Free Software Foundation, Inc.,
26 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
28 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
31 #include <linux/module.h>
32 #include <linux/acpi.h>
33 #include <linux/dmi.h>
34 #include <linux/sched.h> /* need_resched() */
35 #include <linux/clockchips.h>
36 #include <linux/cpuidle.h>
37 #include <linux/syscore_ops.h>
40 * Include the apic definitions for x86 to have the APIC timer related defines
41 * available also for UP (on SMP it gets magically included via linux/smp.h).
42 * asm/acpi.h is not an option, as it would require more include magic. Also
43 * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
49 #include <acpi/acpi_bus.h>
50 #include <acpi/processor.h>
52 #define PREFIX "ACPI: "
54 #define ACPI_PROCESSOR_CLASS "processor"
55 #define _COMPONENT ACPI_PROCESSOR_COMPONENT
56 ACPI_MODULE_NAME("processor_idle");
58 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
59 module_param(max_cstate, uint, 0000);
60 static unsigned int nocst __read_mostly;
61 module_param(nocst, uint, 0000);
62 static int bm_check_disable __read_mostly;
63 module_param(bm_check_disable, uint, 0000);
65 static unsigned int latency_factor __read_mostly = 2;
66 module_param(latency_factor, uint, 0644);
68 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
70 static DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX],
73 static int disabled_by_idle_boot_param(void)
75 return boot_option_idle_override == IDLE_POLL ||
76 boot_option_idle_override == IDLE_HALT;
80 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
81 * For now disable this. Probably a bug somewhere else.
83 * To skip this limit, boot/load with a large max_cstate limit.
85 static int set_max_cstate(const struct dmi_system_id *id)
87 if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
90 printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
91 " Override with \"processor.max_cstate=%d\"\n", id->ident,
92 (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
94 max_cstate = (long)id->driver_data;
99 static struct dmi_system_id processor_power_dmi_table[] = {
100 { set_max_cstate, "Clevo 5600D", {
101 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
102 DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
104 { set_max_cstate, "Pavilion zv5000", {
105 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
106 DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
108 { set_max_cstate, "Asus L8400B", {
109 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
110 DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
117 * Callers should disable interrupts before the call and enable
118 * interrupts after return.
120 static void acpi_safe_halt(void)
122 current_thread_info()->status &= ~TS_POLLING;
124 * TS_POLLING-cleared state must be visible before we
128 if (!need_resched()) {
132 current_thread_info()->status |= TS_POLLING;
135 #ifdef ARCH_APICTIMER_STOPS_ON_C3
138 * Some BIOS implementations switch to C3 in the published C2 state.
139 * This seems to be a common problem on AMD boxen, but other vendors
140 * are affected too. We pick the most conservative approach: we assume
141 * that the local APIC stops in both C2 and C3.
143 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
144 struct acpi_processor_cx *cx)
146 struct acpi_processor_power *pwr = &pr->power;
147 u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
149 if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
152 if (amd_e400_c1e_detected)
153 type = ACPI_STATE_C1;
156 * Check, if one of the previous states already marked the lapic
159 if (pwr->timer_broadcast_on_state < state)
162 if (cx->type >= type)
163 pr->power.timer_broadcast_on_state = state;
166 static void __lapic_timer_propagate_broadcast(void *arg)
168 struct acpi_processor *pr = (struct acpi_processor *) arg;
169 unsigned long reason;
171 reason = pr->power.timer_broadcast_on_state < INT_MAX ?
172 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
174 clockevents_notify(reason, &pr->id);
177 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
179 smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
183 /* Power(C) State timer broadcast control */
184 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
185 struct acpi_processor_cx *cx,
188 int state = cx - pr->power.states;
190 if (state >= pr->power.timer_broadcast_on_state) {
191 unsigned long reason;
193 reason = broadcast ? CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
194 CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
195 clockevents_notify(reason, &pr->id);
201 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
202 struct acpi_processor_cx *cstate) { }
203 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
204 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
205 struct acpi_processor_cx *cx,
212 #ifdef CONFIG_PM_SLEEP
213 static u32 saved_bm_rld;
215 static int acpi_processor_suspend(void)
217 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
221 static void acpi_processor_resume(void)
225 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
226 if (resumed_bm_rld == saved_bm_rld)
229 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
232 static struct syscore_ops acpi_processor_syscore_ops = {
233 .suspend = acpi_processor_suspend,
234 .resume = acpi_processor_resume,
237 void acpi_processor_syscore_init(void)
239 register_syscore_ops(&acpi_processor_syscore_ops);
242 void acpi_processor_syscore_exit(void)
244 unregister_syscore_ops(&acpi_processor_syscore_ops);
246 #endif /* CONFIG_PM_SLEEP */
248 #if defined(CONFIG_X86)
249 static void tsc_check_state(int state)
251 switch (boot_cpu_data.x86_vendor) {
253 case X86_VENDOR_INTEL:
255 * AMD Fam10h TSC will tick in all
256 * C/P/S0/S1 states when this bit is set.
258 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
263 /* TSC could halt in idle, so notify users */
264 if (state > ACPI_STATE_C1)
265 mark_tsc_unstable("TSC halts in idle");
269 static void tsc_check_state(int state) { return; }
272 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
278 /* if info is obtained from pblk/fadt, type equals state */
279 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
280 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
282 #ifndef CONFIG_HOTPLUG_CPU
284 * Check for P_LVL2_UP flag before entering C2 and above on
287 if ((num_online_cpus() > 1) &&
288 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
292 /* determine C2 and C3 address from pblk */
293 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
294 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
296 /* determine latencies from FADT */
297 pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
298 pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
301 * FADT specified C2 latency must be less than or equal to
304 if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
305 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
306 "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
308 pr->power.states[ACPI_STATE_C2].address = 0;
312 * FADT supplied C3 latency must be less than or equal to
315 if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
316 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
317 "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
319 pr->power.states[ACPI_STATE_C3].address = 0;
322 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
323 "lvl2[0x%08x] lvl3[0x%08x]\n",
324 pr->power.states[ACPI_STATE_C2].address,
325 pr->power.states[ACPI_STATE_C3].address));
330 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
332 if (!pr->power.states[ACPI_STATE_C1].valid) {
333 /* set the first C-State to C1 */
334 /* all processors need to support C1 */
335 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
336 pr->power.states[ACPI_STATE_C1].valid = 1;
337 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
339 /* the C0 state only exists as a filler in our array */
340 pr->power.states[ACPI_STATE_C0].valid = 1;
344 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
346 acpi_status status = 0;
350 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
351 union acpi_object *cst;
359 status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
360 if (ACPI_FAILURE(status)) {
361 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
365 cst = buffer.pointer;
367 /* There must be at least 2 elements */
368 if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
369 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
374 count = cst->package.elements[0].integer.value;
376 /* Validate number of power states. */
377 if (count < 1 || count != cst->package.count - 1) {
378 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
383 /* Tell driver that at least _CST is supported. */
384 pr->flags.has_cst = 1;
386 for (i = 1; i <= count; i++) {
387 union acpi_object *element;
388 union acpi_object *obj;
389 struct acpi_power_register *reg;
390 struct acpi_processor_cx cx;
392 memset(&cx, 0, sizeof(cx));
394 element = &(cst->package.elements[i]);
395 if (element->type != ACPI_TYPE_PACKAGE)
398 if (element->package.count != 4)
401 obj = &(element->package.elements[0]);
403 if (obj->type != ACPI_TYPE_BUFFER)
406 reg = (struct acpi_power_register *)obj->buffer.pointer;
408 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
409 (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
412 /* There should be an easy way to extract an integer... */
413 obj = &(element->package.elements[1]);
414 if (obj->type != ACPI_TYPE_INTEGER)
417 cx.type = obj->integer.value;
419 * Some buggy BIOSes won't list C1 in _CST -
420 * Let acpi_processor_get_power_info_default() handle them later
422 if (i == 1 && cx.type != ACPI_STATE_C1)
425 cx.address = reg->address;
426 cx.index = current_count + 1;
428 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
429 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
430 if (acpi_processor_ffh_cstate_probe
431 (pr->id, &cx, reg) == 0) {
432 cx.entry_method = ACPI_CSTATE_FFH;
433 } else if (cx.type == ACPI_STATE_C1) {
435 * C1 is a special case where FIXED_HARDWARE
436 * can be handled in non-MWAIT way as well.
437 * In that case, save this _CST entry info.
438 * Otherwise, ignore this info and continue.
440 cx.entry_method = ACPI_CSTATE_HALT;
441 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
445 if (cx.type == ACPI_STATE_C1 &&
446 (boot_option_idle_override == IDLE_NOMWAIT)) {
448 * In most cases the C1 space_id obtained from
449 * _CST object is FIXED_HARDWARE access mode.
450 * But when the option of idle=halt is added,
451 * the entry_method type should be changed from
452 * CSTATE_FFH to CSTATE_HALT.
453 * When the option of idle=nomwait is added,
454 * the C1 entry_method type should be
457 cx.entry_method = ACPI_CSTATE_HALT;
458 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
461 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
465 if (cx.type == ACPI_STATE_C1) {
469 obj = &(element->package.elements[2]);
470 if (obj->type != ACPI_TYPE_INTEGER)
473 cx.latency = obj->integer.value;
475 obj = &(element->package.elements[3]);
476 if (obj->type != ACPI_TYPE_INTEGER)
480 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
483 * We support total ACPI_PROCESSOR_MAX_POWER - 1
484 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
486 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
488 "Limiting number of power states to max (%d)\n",
489 ACPI_PROCESSOR_MAX_POWER);
491 "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
496 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
499 /* Validate number of power states discovered */
500 if (current_count < 2)
504 kfree(buffer.pointer);
509 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
510 struct acpi_processor_cx *cx)
512 static int bm_check_flag = -1;
513 static int bm_control_flag = -1;
520 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
521 * DMA transfers are used by any ISA device to avoid livelock.
522 * Note that we could disable Type-F DMA (as recommended by
523 * the erratum), but this is known to disrupt certain ISA
524 * devices thus we take the conservative approach.
526 else if (errata.piix4.fdma) {
527 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
528 "C3 not supported on PIIX4 with Type-F DMA\n"));
532 /* All the logic here assumes flags.bm_check is same across all CPUs */
533 if (bm_check_flag == -1) {
534 /* Determine whether bm_check is needed based on CPU */
535 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
536 bm_check_flag = pr->flags.bm_check;
537 bm_control_flag = pr->flags.bm_control;
539 pr->flags.bm_check = bm_check_flag;
540 pr->flags.bm_control = bm_control_flag;
543 if (pr->flags.bm_check) {
544 if (!pr->flags.bm_control) {
545 if (pr->flags.has_cst != 1) {
546 /* bus mastering control is necessary */
547 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
548 "C3 support requires BM control\n"));
551 /* Here we enter C3 without bus mastering */
552 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
553 "C3 support without BM control\n"));
558 * WBINVD should be set in fadt, for C3 state to be
559 * supported on when bm_check is not required.
561 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
562 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
563 "Cache invalidation should work properly"
564 " for C3 to be enabled on SMP systems\n"));
570 * Otherwise we've met all of our C3 requirements.
571 * Normalize the C3 latency to expidite policy. Enable
572 * checking of bus mastering status (bm_check) so we can
573 * use this in our C3 policy
578 * On older chipsets, BM_RLD needs to be set
579 * in order for Bus Master activity to wake the
580 * system from C3. Newer chipsets handle DMA
581 * during C3 automatically and BM_RLD is a NOP.
582 * In either case, the proper way to
583 * handle BM_RLD is to set it and leave it set.
585 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
590 static int acpi_processor_power_verify(struct acpi_processor *pr)
593 unsigned int working = 0;
595 pr->power.timer_broadcast_on_state = INT_MAX;
597 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
598 struct acpi_processor_cx *cx = &pr->power.states[i];
612 acpi_processor_power_verify_c3(pr, cx);
618 lapic_timer_check_state(i, pr, cx);
619 tsc_check_state(cx->type);
623 lapic_timer_propagate_broadcast(pr);
628 static int acpi_processor_get_power_info(struct acpi_processor *pr)
634 /* NOTE: the idle thread may not be running while calling
637 /* Zero initialize all the C-states info. */
638 memset(pr->power.states, 0, sizeof(pr->power.states));
640 result = acpi_processor_get_power_info_cst(pr);
641 if (result == -ENODEV)
642 result = acpi_processor_get_power_info_fadt(pr);
647 acpi_processor_get_power_info_default(pr);
649 pr->power.count = acpi_processor_power_verify(pr);
652 * if one state of type C2 or C3 is available, mark this
653 * CPU as being "idle manageable"
655 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
656 if (pr->power.states[i].valid) {
658 if (pr->power.states[i].type >= ACPI_STATE_C2)
667 * acpi_idle_bm_check - checks if bus master activity was detected
669 static int acpi_idle_bm_check(void)
673 if (bm_check_disable)
676 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
678 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
680 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
681 * the true state of bus mastering activity; forcing us to
682 * manually check the BMIDEA bit of each IDE channel.
684 else if (errata.piix4.bmisx) {
685 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
686 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
693 * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
696 * Caller disables interrupt before call and enables interrupt after return.
698 static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
700 /* Don't trace irqs off for idle */
701 stop_critical_timings();
702 if (cx->entry_method == ACPI_CSTATE_FFH) {
703 /* Call into architectural FFH based C-state */
704 acpi_processor_ffh_cstate_enter(cx);
705 } else if (cx->entry_method == ACPI_CSTATE_HALT) {
708 /* IO port based C-state */
710 /* Dummy wait op - must do something useless after P_LVL2 read
711 because chipsets cannot guarantee that STPCLK# signal
712 gets asserted in time to freeze execution properly. */
713 inl(acpi_gbl_FADT.xpm_timer_block.address);
715 start_critical_timings();
719 * acpi_idle_enter_c1 - enters an ACPI C1 state-type
720 * @dev: the target CPU
721 * @drv: cpuidle driver containing cpuidle state info
722 * @index: index of target state
724 * This is equivalent to the HALT instruction.
726 static int acpi_idle_enter_c1(struct cpuidle_device *dev,
727 struct cpuidle_driver *drv, int index)
729 struct acpi_processor *pr;
730 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
732 pr = __this_cpu_read(processors);
737 lapic_timer_state_broadcast(pr, cx, 1);
738 acpi_idle_do_entry(cx);
740 lapic_timer_state_broadcast(pr, cx, 0);
747 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
748 * @dev: the target CPU
749 * @index: the index of suggested state
751 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
753 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
755 ACPI_FLUSH_CPU_CACHE();
759 if (cx->entry_method == ACPI_CSTATE_HALT)
761 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
763 /* See comment in acpi_idle_do_entry() */
764 inl(acpi_gbl_FADT.xpm_timer_block.address);
774 * acpi_idle_enter_simple - enters an ACPI state without BM handling
775 * @dev: the target CPU
776 * @drv: cpuidle driver with cpuidle state information
777 * @index: the index of suggested state
779 static int acpi_idle_enter_simple(struct cpuidle_device *dev,
780 struct cpuidle_driver *drv, int index)
782 struct acpi_processor *pr;
783 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
785 pr = __this_cpu_read(processors);
790 if (cx->entry_method != ACPI_CSTATE_FFH) {
791 current_thread_info()->status &= ~TS_POLLING;
793 * TS_POLLING-cleared state must be visible before we test
798 if (unlikely(need_resched())) {
799 current_thread_info()->status |= TS_POLLING;
805 * Must be done before busmaster disable as we might need to
808 lapic_timer_state_broadcast(pr, cx, 1);
810 if (cx->type == ACPI_STATE_C3)
811 ACPI_FLUSH_CPU_CACHE();
813 /* Tell the scheduler that we are going deep-idle: */
814 sched_clock_idle_sleep_event();
815 acpi_idle_do_entry(cx);
817 sched_clock_idle_wakeup_event(0);
819 if (cx->entry_method != ACPI_CSTATE_FFH)
820 current_thread_info()->status |= TS_POLLING;
822 lapic_timer_state_broadcast(pr, cx, 0);
826 static int c3_cpu_count;
827 static DEFINE_RAW_SPINLOCK(c3_lock);
830 * acpi_idle_enter_bm - enters C3 with proper BM handling
831 * @dev: the target CPU
832 * @drv: cpuidle driver containing state data
833 * @index: the index of suggested state
835 * If BM is detected, the deepest non-C3 idle state is entered instead.
837 static int acpi_idle_enter_bm(struct cpuidle_device *dev,
838 struct cpuidle_driver *drv, int index)
840 struct acpi_processor *pr;
841 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
843 pr = __this_cpu_read(processors);
848 if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
849 if (drv->safe_state_index >= 0) {
850 return drv->states[drv->safe_state_index].enter(dev,
851 drv, drv->safe_state_index);
858 if (cx->entry_method != ACPI_CSTATE_FFH) {
859 current_thread_info()->status &= ~TS_POLLING;
861 * TS_POLLING-cleared state must be visible before we test
866 if (unlikely(need_resched())) {
867 current_thread_info()->status |= TS_POLLING;
872 acpi_unlazy_tlb(smp_processor_id());
874 /* Tell the scheduler that we are going deep-idle: */
875 sched_clock_idle_sleep_event();
877 * Must be done before busmaster disable as we might need to
880 lapic_timer_state_broadcast(pr, cx, 1);
884 * bm_check implies we need ARB_DIS
885 * !bm_check implies we need cache flush
886 * bm_control implies whether we can do ARB_DIS
888 * That leaves a case where bm_check is set and bm_control is
889 * not set. In that case we cannot do much, we enter C3
890 * without doing anything.
892 if (pr->flags.bm_check && pr->flags.bm_control) {
893 raw_spin_lock(&c3_lock);
895 /* Disable bus master arbitration when all CPUs are in C3 */
896 if (c3_cpu_count == num_online_cpus())
897 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
898 raw_spin_unlock(&c3_lock);
899 } else if (!pr->flags.bm_check) {
900 ACPI_FLUSH_CPU_CACHE();
903 acpi_idle_do_entry(cx);
905 /* Re-enable bus master arbitration */
906 if (pr->flags.bm_check && pr->flags.bm_control) {
907 raw_spin_lock(&c3_lock);
908 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
910 raw_spin_unlock(&c3_lock);
913 sched_clock_idle_wakeup_event(0);
915 if (cx->entry_method != ACPI_CSTATE_FFH)
916 current_thread_info()->status |= TS_POLLING;
918 lapic_timer_state_broadcast(pr, cx, 0);
922 struct cpuidle_driver acpi_idle_driver = {
924 .owner = THIS_MODULE,
928 * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE
929 * device i.e. per-cpu data
931 * @pr: the ACPI processor
932 * @dev : the cpuidle device
934 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
935 struct cpuidle_device *dev)
937 int i, count = CPUIDLE_DRIVER_STATE_START;
938 struct acpi_processor_cx *cx;
940 if (!pr->flags.power_setup_done)
943 if (pr->flags.power == 0) {
955 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
956 cx = &pr->power.states[i];
961 #ifdef CONFIG_HOTPLUG_CPU
962 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
963 !pr->flags.has_cst &&
964 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
967 per_cpu(acpi_cstate[count], dev->cpu) = cx;
970 if (count == CPUIDLE_STATE_MAX)
974 dev->state_count = count;
983 * acpi_processor_setup_cpuidle states- prepares and configures cpuidle
984 * global state data i.e. idle routines
986 * @pr: the ACPI processor
988 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
990 int i, count = CPUIDLE_DRIVER_STATE_START;
991 struct acpi_processor_cx *cx;
992 struct cpuidle_state *state;
993 struct cpuidle_driver *drv = &acpi_idle_driver;
995 if (!pr->flags.power_setup_done)
998 if (pr->flags.power == 0)
1001 drv->safe_state_index = -1;
1002 for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
1003 drv->states[i].name[0] = '\0';
1004 drv->states[i].desc[0] = '\0';
1007 if (max_cstate == 0)
1010 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
1011 cx = &pr->power.states[i];
1016 #ifdef CONFIG_HOTPLUG_CPU
1017 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
1018 !pr->flags.has_cst &&
1019 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
1023 state = &drv->states[count];
1024 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
1025 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1026 state->exit_latency = cx->latency;
1027 state->target_residency = cx->latency * latency_factor;
1032 if (cx->entry_method == ACPI_CSTATE_FFH)
1033 state->flags |= CPUIDLE_FLAG_TIME_VALID;
1035 state->enter = acpi_idle_enter_c1;
1036 state->enter_dead = acpi_idle_play_dead;
1037 drv->safe_state_index = count;
1041 state->flags |= CPUIDLE_FLAG_TIME_VALID;
1042 state->enter = acpi_idle_enter_simple;
1043 state->enter_dead = acpi_idle_play_dead;
1044 drv->safe_state_index = count;
1048 state->flags |= CPUIDLE_FLAG_TIME_VALID;
1049 state->enter = pr->flags.bm_check ?
1050 acpi_idle_enter_bm :
1051 acpi_idle_enter_simple;
1056 if (count == CPUIDLE_STATE_MAX)
1060 drv->state_count = count;
1068 int acpi_processor_hotplug(struct acpi_processor *pr)
1071 struct cpuidle_device *dev;
1073 if (disabled_by_idle_boot_param())
1079 if (!pr->flags.power_setup_done)
1082 dev = per_cpu(acpi_cpuidle_device, pr->id);
1083 cpuidle_pause_and_lock();
1084 cpuidle_disable_device(dev);
1085 acpi_processor_get_power_info(pr);
1086 if (pr->flags.power) {
1087 acpi_processor_setup_cpuidle_cx(pr, dev);
1088 ret = cpuidle_enable_device(dev);
1090 cpuidle_resume_and_unlock();
1095 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1098 struct acpi_processor *_pr;
1099 struct cpuidle_device *dev;
1101 if (disabled_by_idle_boot_param())
1107 if (!pr->flags.power_setup_done)
1111 * FIXME: Design the ACPI notification to make it once per
1112 * system instead of once per-cpu. This condition is a hack
1113 * to make the code that updates C-States be called once.
1116 if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1118 cpuidle_pause_and_lock();
1119 /* Protect against cpu-hotplug */
1122 /* Disable all cpuidle devices */
1123 for_each_online_cpu(cpu) {
1124 _pr = per_cpu(processors, cpu);
1125 if (!_pr || !_pr->flags.power_setup_done)
1127 dev = per_cpu(acpi_cpuidle_device, cpu);
1128 cpuidle_disable_device(dev);
1131 /* Populate Updated C-state information */
1132 acpi_processor_get_power_info(pr);
1133 acpi_processor_setup_cpuidle_states(pr);
1135 /* Enable all cpuidle devices */
1136 for_each_online_cpu(cpu) {
1137 _pr = per_cpu(processors, cpu);
1138 if (!_pr || !_pr->flags.power_setup_done)
1140 acpi_processor_get_power_info(_pr);
1141 if (_pr->flags.power) {
1142 dev = per_cpu(acpi_cpuidle_device, cpu);
1143 acpi_processor_setup_cpuidle_cx(_pr, dev);
1144 cpuidle_enable_device(dev);
1148 cpuidle_resume_and_unlock();
1154 static int acpi_processor_registered;
1156 int acpi_processor_power_init(struct acpi_processor *pr)
1158 acpi_status status = 0;
1160 struct cpuidle_device *dev;
1161 static int first_run;
1163 if (disabled_by_idle_boot_param())
1167 dmi_check_system(processor_power_dmi_table);
1168 max_cstate = acpi_processor_cstate_check(max_cstate);
1169 if (max_cstate < ACPI_C_STATES_MAX)
1171 "ACPI: processor limited to max C-state %d\n",
1176 if (acpi_gbl_FADT.cst_control && !nocst) {
1178 acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1179 if (ACPI_FAILURE(status)) {
1180 ACPI_EXCEPTION((AE_INFO, status,
1181 "Notifying BIOS of _CST ability failed"));
1185 acpi_processor_get_power_info(pr);
1186 pr->flags.power_setup_done = 1;
1189 * Install the idle handler if processor power management is supported.
1190 * Note that we use previously set idle handler will be used on
1191 * platforms that only support C1.
1193 if (pr->flags.power) {
1194 /* Register acpi_idle_driver if not already registered */
1195 if (!acpi_processor_registered) {
1196 acpi_processor_setup_cpuidle_states(pr);
1197 retval = cpuidle_register_driver(&acpi_idle_driver);
1200 printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n",
1201 acpi_idle_driver.name);
1204 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1207 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1209 acpi_processor_setup_cpuidle_cx(pr, dev);
1211 /* Register per-cpu cpuidle_device. Cpuidle driver
1212 * must already be registered before registering device
1214 retval = cpuidle_register_device(dev);
1216 if (acpi_processor_registered == 0)
1217 cpuidle_unregister_driver(&acpi_idle_driver);
1220 acpi_processor_registered++;
1225 int acpi_processor_power_exit(struct acpi_processor *pr)
1227 struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1229 if (disabled_by_idle_boot_param())
1232 if (pr->flags.power) {
1233 cpuidle_unregister_device(dev);
1234 acpi_processor_registered--;
1235 if (acpi_processor_registered == 0)
1236 cpuidle_unregister_driver(&acpi_idle_driver);
1239 pr->flags.power_setup_done = 0;