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>
39 * Include the apic definitions for x86 to have the APIC timer related defines
40 * available also for UP (on SMP it gets magically included via linux/smp.h).
41 * asm/acpi.h is not an option, as it would require more include magic. Also
42 * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
48 #include <acpi/acpi_bus.h>
49 #include <acpi/processor.h>
51 #define PREFIX "ACPI: "
53 #define ACPI_PROCESSOR_CLASS "processor"
54 #define _COMPONENT ACPI_PROCESSOR_COMPONENT
55 ACPI_MODULE_NAME("processor_idle");
57 static unsigned int max_cstate __read_mostly
= ACPI_PROCESSOR_MAX_POWER
;
58 module_param(max_cstate
, uint
, 0000);
59 static unsigned int nocst __read_mostly
;
60 module_param(nocst
, uint
, 0000);
61 static int bm_check_disable __read_mostly
;
62 module_param(bm_check_disable
, uint
, 0000);
64 static unsigned int latency_factor __read_mostly
= 2;
65 module_param(latency_factor
, uint
, 0644);
67 static DEFINE_PER_CPU(struct cpuidle_device
*, acpi_cpuidle_device
);
69 static struct acpi_processor_cx
*acpi_cstate
[CPUIDLE_STATE_MAX
];
71 static int disabled_by_idle_boot_param(void)
73 return boot_option_idle_override
== IDLE_POLL
||
74 boot_option_idle_override
== IDLE_HALT
;
78 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
79 * For now disable this. Probably a bug somewhere else.
81 * To skip this limit, boot/load with a large max_cstate limit.
83 static int set_max_cstate(const struct dmi_system_id
*id
)
85 if (max_cstate
> ACPI_PROCESSOR_MAX_POWER
)
88 printk(KERN_NOTICE PREFIX
"%s detected - limiting to C%ld max_cstate."
89 " Override with \"processor.max_cstate=%d\"\n", id
->ident
,
90 (long)id
->driver_data
, ACPI_PROCESSOR_MAX_POWER
+ 1);
92 max_cstate
= (long)id
->driver_data
;
97 /* Actually this shouldn't be __cpuinitdata, would be better to fix the
98 callers to only run once -AK */
99 static struct dmi_system_id __cpuinitdata 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 static u32 saved_bm_rld
;
214 static void acpi_idle_bm_rld_save(void)
216 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD
, &saved_bm_rld
);
218 static void acpi_idle_bm_rld_restore(void)
222 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD
, &resumed_bm_rld
);
224 if (resumed_bm_rld
!= saved_bm_rld
)
225 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD
, saved_bm_rld
);
228 int acpi_processor_suspend(struct device
*dev
)
230 acpi_idle_bm_rld_save();
234 int acpi_processor_resume(struct device
*dev
)
236 acpi_idle_bm_rld_restore();
240 #if defined(CONFIG_X86)
241 static void tsc_check_state(int state
)
243 switch (boot_cpu_data
.x86_vendor
) {
245 case X86_VENDOR_INTEL
:
247 * AMD Fam10h TSC will tick in all
248 * C/P/S0/S1 states when this bit is set.
250 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC
))
255 /* TSC could halt in idle, so notify users */
256 if (state
> ACPI_STATE_C1
)
257 mark_tsc_unstable("TSC halts in idle");
261 static void tsc_check_state(int state
) { return; }
264 static int acpi_processor_get_power_info_fadt(struct acpi_processor
*pr
)
273 /* if info is obtained from pblk/fadt, type equals state */
274 pr
->power
.states
[ACPI_STATE_C2
].type
= ACPI_STATE_C2
;
275 pr
->power
.states
[ACPI_STATE_C3
].type
= ACPI_STATE_C3
;
277 #ifndef CONFIG_HOTPLUG_CPU
279 * Check for P_LVL2_UP flag before entering C2 and above on
282 if ((num_online_cpus() > 1) &&
283 !(acpi_gbl_FADT
.flags
& ACPI_FADT_C2_MP_SUPPORTED
))
287 /* determine C2 and C3 address from pblk */
288 pr
->power
.states
[ACPI_STATE_C2
].address
= pr
->pblk
+ 4;
289 pr
->power
.states
[ACPI_STATE_C3
].address
= pr
->pblk
+ 5;
291 /* determine latencies from FADT */
292 pr
->power
.states
[ACPI_STATE_C2
].latency
= acpi_gbl_FADT
.c2_latency
;
293 pr
->power
.states
[ACPI_STATE_C3
].latency
= acpi_gbl_FADT
.c3_latency
;
296 * FADT specified C2 latency must be less than or equal to
299 if (acpi_gbl_FADT
.c2_latency
> ACPI_PROCESSOR_MAX_C2_LATENCY
) {
300 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
301 "C2 latency too large [%d]\n", acpi_gbl_FADT
.c2_latency
));
303 pr
->power
.states
[ACPI_STATE_C2
].address
= 0;
307 * FADT supplied C3 latency must be less than or equal to
310 if (acpi_gbl_FADT
.c3_latency
> ACPI_PROCESSOR_MAX_C3_LATENCY
) {
311 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
312 "C3 latency too large [%d]\n", acpi_gbl_FADT
.c3_latency
));
314 pr
->power
.states
[ACPI_STATE_C3
].address
= 0;
317 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
318 "lvl2[0x%08x] lvl3[0x%08x]\n",
319 pr
->power
.states
[ACPI_STATE_C2
].address
,
320 pr
->power
.states
[ACPI_STATE_C3
].address
));
325 static int acpi_processor_get_power_info_default(struct acpi_processor
*pr
)
327 if (!pr
->power
.states
[ACPI_STATE_C1
].valid
) {
328 /* set the first C-State to C1 */
329 /* all processors need to support C1 */
330 pr
->power
.states
[ACPI_STATE_C1
].type
= ACPI_STATE_C1
;
331 pr
->power
.states
[ACPI_STATE_C1
].valid
= 1;
332 pr
->power
.states
[ACPI_STATE_C1
].entry_method
= ACPI_CSTATE_HALT
;
334 /* the C0 state only exists as a filler in our array */
335 pr
->power
.states
[ACPI_STATE_C0
].valid
= 1;
339 static int acpi_processor_get_power_info_cst(struct acpi_processor
*pr
)
341 acpi_status status
= 0;
345 struct acpi_buffer buffer
= { ACPI_ALLOCATE_BUFFER
, NULL
};
346 union acpi_object
*cst
;
354 status
= acpi_evaluate_object(pr
->handle
, "_CST", NULL
, &buffer
);
355 if (ACPI_FAILURE(status
)) {
356 ACPI_DEBUG_PRINT((ACPI_DB_INFO
, "No _CST, giving up\n"));
360 cst
= buffer
.pointer
;
362 /* There must be at least 2 elements */
363 if (!cst
|| (cst
->type
!= ACPI_TYPE_PACKAGE
) || cst
->package
.count
< 2) {
364 printk(KERN_ERR PREFIX
"not enough elements in _CST\n");
369 count
= cst
->package
.elements
[0].integer
.value
;
371 /* Validate number of power states. */
372 if (count
< 1 || count
!= cst
->package
.count
- 1) {
373 printk(KERN_ERR PREFIX
"count given by _CST is not valid\n");
378 /* Tell driver that at least _CST is supported. */
379 pr
->flags
.has_cst
= 1;
381 for (i
= 1; i
<= count
; i
++) {
382 union acpi_object
*element
;
383 union acpi_object
*obj
;
384 struct acpi_power_register
*reg
;
385 struct acpi_processor_cx cx
;
387 memset(&cx
, 0, sizeof(cx
));
389 element
= &(cst
->package
.elements
[i
]);
390 if (element
->type
!= ACPI_TYPE_PACKAGE
)
393 if (element
->package
.count
!= 4)
396 obj
= &(element
->package
.elements
[0]);
398 if (obj
->type
!= ACPI_TYPE_BUFFER
)
401 reg
= (struct acpi_power_register
*)obj
->buffer
.pointer
;
403 if (reg
->space_id
!= ACPI_ADR_SPACE_SYSTEM_IO
&&
404 (reg
->space_id
!= ACPI_ADR_SPACE_FIXED_HARDWARE
))
407 /* There should be an easy way to extract an integer... */
408 obj
= &(element
->package
.elements
[1]);
409 if (obj
->type
!= ACPI_TYPE_INTEGER
)
412 cx
.type
= obj
->integer
.value
;
414 * Some buggy BIOSes won't list C1 in _CST -
415 * Let acpi_processor_get_power_info_default() handle them later
417 if (i
== 1 && cx
.type
!= ACPI_STATE_C1
)
420 cx
.address
= reg
->address
;
421 cx
.index
= current_count
+ 1;
423 cx
.entry_method
= ACPI_CSTATE_SYSTEMIO
;
424 if (reg
->space_id
== ACPI_ADR_SPACE_FIXED_HARDWARE
) {
425 if (acpi_processor_ffh_cstate_probe
426 (pr
->id
, &cx
, reg
) == 0) {
427 cx
.entry_method
= ACPI_CSTATE_FFH
;
428 } else if (cx
.type
== ACPI_STATE_C1
) {
430 * C1 is a special case where FIXED_HARDWARE
431 * can be handled in non-MWAIT way as well.
432 * In that case, save this _CST entry info.
433 * Otherwise, ignore this info and continue.
435 cx
.entry_method
= ACPI_CSTATE_HALT
;
436 snprintf(cx
.desc
, ACPI_CX_DESC_LEN
, "ACPI HLT");
440 if (cx
.type
== ACPI_STATE_C1
&&
441 (boot_option_idle_override
== IDLE_NOMWAIT
)) {
443 * In most cases the C1 space_id obtained from
444 * _CST object is FIXED_HARDWARE access mode.
445 * But when the option of idle=halt is added,
446 * the entry_method type should be changed from
447 * CSTATE_FFH to CSTATE_HALT.
448 * When the option of idle=nomwait is added,
449 * the C1 entry_method type should be
452 cx
.entry_method
= ACPI_CSTATE_HALT
;
453 snprintf(cx
.desc
, ACPI_CX_DESC_LEN
, "ACPI HLT");
456 snprintf(cx
.desc
, ACPI_CX_DESC_LEN
, "ACPI IOPORT 0x%x",
460 if (cx
.type
== ACPI_STATE_C1
) {
464 obj
= &(element
->package
.elements
[2]);
465 if (obj
->type
!= ACPI_TYPE_INTEGER
)
468 cx
.latency
= obj
->integer
.value
;
470 obj
= &(element
->package
.elements
[3]);
471 if (obj
->type
!= ACPI_TYPE_INTEGER
)
475 memcpy(&(pr
->power
.states
[current_count
]), &cx
, sizeof(cx
));
478 * We support total ACPI_PROCESSOR_MAX_POWER - 1
479 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
481 if (current_count
>= (ACPI_PROCESSOR_MAX_POWER
- 1)) {
483 "Limiting number of power states to max (%d)\n",
484 ACPI_PROCESSOR_MAX_POWER
);
486 "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
491 ACPI_DEBUG_PRINT((ACPI_DB_INFO
, "Found %d power states\n",
494 /* Validate number of power states discovered */
495 if (current_count
< 2)
499 kfree(buffer
.pointer
);
504 static void acpi_processor_power_verify_c3(struct acpi_processor
*pr
,
505 struct acpi_processor_cx
*cx
)
507 static int bm_check_flag
= -1;
508 static int bm_control_flag
= -1;
515 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
516 * DMA transfers are used by any ISA device to avoid livelock.
517 * Note that we could disable Type-F DMA (as recommended by
518 * the erratum), but this is known to disrupt certain ISA
519 * devices thus we take the conservative approach.
521 else if (errata
.piix4
.fdma
) {
522 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
523 "C3 not supported on PIIX4 with Type-F DMA\n"));
527 /* All the logic here assumes flags.bm_check is same across all CPUs */
528 if (bm_check_flag
== -1) {
529 /* Determine whether bm_check is needed based on CPU */
530 acpi_processor_power_init_bm_check(&(pr
->flags
), pr
->id
);
531 bm_check_flag
= pr
->flags
.bm_check
;
532 bm_control_flag
= pr
->flags
.bm_control
;
534 pr
->flags
.bm_check
= bm_check_flag
;
535 pr
->flags
.bm_control
= bm_control_flag
;
538 if (pr
->flags
.bm_check
) {
539 if (!pr
->flags
.bm_control
) {
540 if (pr
->flags
.has_cst
!= 1) {
541 /* bus mastering control is necessary */
542 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
543 "C3 support requires BM control\n"));
546 /* Here we enter C3 without bus mastering */
547 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
548 "C3 support without BM control\n"));
553 * WBINVD should be set in fadt, for C3 state to be
554 * supported on when bm_check is not required.
556 if (!(acpi_gbl_FADT
.flags
& ACPI_FADT_WBINVD
)) {
557 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
558 "Cache invalidation should work properly"
559 " for C3 to be enabled on SMP systems\n"));
565 * Otherwise we've met all of our C3 requirements.
566 * Normalize the C3 latency to expidite policy. Enable
567 * checking of bus mastering status (bm_check) so we can
568 * use this in our C3 policy
573 * On older chipsets, BM_RLD needs to be set
574 * in order for Bus Master activity to wake the
575 * system from C3. Newer chipsets handle DMA
576 * during C3 automatically and BM_RLD is a NOP.
577 * In either case, the proper way to
578 * handle BM_RLD is to set it and leave it set.
580 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD
, 1);
585 static int acpi_processor_power_verify(struct acpi_processor
*pr
)
588 unsigned int working
= 0;
590 pr
->power
.timer_broadcast_on_state
= INT_MAX
;
592 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
&& i
<= max_cstate
; i
++) {
593 struct acpi_processor_cx
*cx
= &pr
->power
.states
[i
];
607 acpi_processor_power_verify_c3(pr
, cx
);
613 lapic_timer_check_state(i
, pr
, cx
);
614 tsc_check_state(cx
->type
);
618 lapic_timer_propagate_broadcast(pr
);
623 static int acpi_processor_get_power_info(struct acpi_processor
*pr
)
629 /* NOTE: the idle thread may not be running while calling
632 /* Zero initialize all the C-states info. */
633 memset(pr
->power
.states
, 0, sizeof(pr
->power
.states
));
635 result
= acpi_processor_get_power_info_cst(pr
);
636 if (result
== -ENODEV
)
637 result
= acpi_processor_get_power_info_fadt(pr
);
642 acpi_processor_get_power_info_default(pr
);
644 pr
->power
.count
= acpi_processor_power_verify(pr
);
647 * if one state of type C2 or C3 is available, mark this
648 * CPU as being "idle manageable"
650 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
; i
++) {
651 if (pr
->power
.states
[i
].valid
) {
653 if (pr
->power
.states
[i
].type
>= ACPI_STATE_C2
)
662 * acpi_idle_bm_check - checks if bus master activity was detected
664 static int acpi_idle_bm_check(void)
668 if (bm_check_disable
)
671 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS
, &bm_status
);
673 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS
, 1);
675 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
676 * the true state of bus mastering activity; forcing us to
677 * manually check the BMIDEA bit of each IDE channel.
679 else if (errata
.piix4
.bmisx
) {
680 if ((inb_p(errata
.piix4
.bmisx
+ 0x02) & 0x01)
681 || (inb_p(errata
.piix4
.bmisx
+ 0x0A) & 0x01))
688 * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
691 * Caller disables interrupt before call and enables interrupt after return.
693 static inline void acpi_idle_do_entry(struct acpi_processor_cx
*cx
)
695 /* Don't trace irqs off for idle */
696 stop_critical_timings();
697 if (cx
->entry_method
== ACPI_CSTATE_FFH
) {
698 /* Call into architectural FFH based C-state */
699 acpi_processor_ffh_cstate_enter(cx
);
700 } else if (cx
->entry_method
== ACPI_CSTATE_HALT
) {
703 /* IO port based C-state */
705 /* Dummy wait op - must do something useless after P_LVL2 read
706 because chipsets cannot guarantee that STPCLK# signal
707 gets asserted in time to freeze execution properly. */
708 inl(acpi_gbl_FADT
.xpm_timer_block
.address
);
710 start_critical_timings();
714 * acpi_idle_enter_c1 - enters an ACPI C1 state-type
715 * @dev: the target CPU
716 * @drv: cpuidle driver containing cpuidle state info
717 * @index: index of target state
719 * This is equivalent to the HALT instruction.
721 static int acpi_idle_enter_c1(struct cpuidle_device
*dev
,
722 struct cpuidle_driver
*drv
, int index
)
724 struct acpi_processor
*pr
;
725 struct acpi_processor_cx
*cx
= acpi_cstate
[index
];
727 pr
= __this_cpu_read(processors
);
732 lapic_timer_state_broadcast(pr
, cx
, 1);
733 acpi_idle_do_entry(cx
);
735 lapic_timer_state_broadcast(pr
, cx
, 0);
742 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
743 * @dev: the target CPU
744 * @index: the index of suggested state
746 static int acpi_idle_play_dead(struct cpuidle_device
*dev
, int index
)
748 struct acpi_processor_cx
*cx
= acpi_cstate
[index
];
750 ACPI_FLUSH_CPU_CACHE();
754 if (cx
->entry_method
== ACPI_CSTATE_HALT
)
756 else if (cx
->entry_method
== ACPI_CSTATE_SYSTEMIO
) {
758 /* See comment in acpi_idle_do_entry() */
759 inl(acpi_gbl_FADT
.xpm_timer_block
.address
);
769 * acpi_idle_enter_simple - enters an ACPI state without BM handling
770 * @dev: the target CPU
771 * @drv: cpuidle driver with cpuidle state information
772 * @index: the index of suggested state
774 static int acpi_idle_enter_simple(struct cpuidle_device
*dev
,
775 struct cpuidle_driver
*drv
, int index
)
777 struct acpi_processor
*pr
;
778 struct acpi_processor_cx
*cx
= acpi_cstate
[index
];
780 pr
= __this_cpu_read(processors
);
785 if (cx
->entry_method
!= ACPI_CSTATE_FFH
) {
786 current_thread_info()->status
&= ~TS_POLLING
;
788 * TS_POLLING-cleared state must be visible before we test
793 if (unlikely(need_resched())) {
794 current_thread_info()->status
|= TS_POLLING
;
800 * Must be done before busmaster disable as we might need to
803 lapic_timer_state_broadcast(pr
, cx
, 1);
805 if (cx
->type
== ACPI_STATE_C3
)
806 ACPI_FLUSH_CPU_CACHE();
808 /* Tell the scheduler that we are going deep-idle: */
809 sched_clock_idle_sleep_event();
810 acpi_idle_do_entry(cx
);
812 sched_clock_idle_wakeup_event(0);
814 if (cx
->entry_method
!= ACPI_CSTATE_FFH
)
815 current_thread_info()->status
|= TS_POLLING
;
817 lapic_timer_state_broadcast(pr
, cx
, 0);
821 static int c3_cpu_count
;
822 static DEFINE_RAW_SPINLOCK(c3_lock
);
825 * acpi_idle_enter_bm - enters C3 with proper BM handling
826 * @dev: the target CPU
827 * @drv: cpuidle driver containing state data
828 * @index: the index of suggested state
830 * If BM is detected, the deepest non-C3 idle state is entered instead.
832 static int acpi_idle_enter_bm(struct cpuidle_device
*dev
,
833 struct cpuidle_driver
*drv
, int index
)
835 struct acpi_processor
*pr
;
836 struct acpi_processor_cx
*cx
= acpi_cstate
[index
];
838 pr
= __this_cpu_read(processors
);
843 if (!cx
->bm_sts_skip
&& acpi_idle_bm_check()) {
844 if (drv
->safe_state_index
>= 0) {
845 return drv
->states
[drv
->safe_state_index
].enter(dev
,
846 drv
, drv
->safe_state_index
);
853 if (cx
->entry_method
!= ACPI_CSTATE_FFH
) {
854 current_thread_info()->status
&= ~TS_POLLING
;
856 * TS_POLLING-cleared state must be visible before we test
861 if (unlikely(need_resched())) {
862 current_thread_info()->status
|= TS_POLLING
;
867 acpi_unlazy_tlb(smp_processor_id());
869 /* Tell the scheduler that we are going deep-idle: */
870 sched_clock_idle_sleep_event();
872 * Must be done before busmaster disable as we might need to
875 lapic_timer_state_broadcast(pr
, cx
, 1);
879 * bm_check implies we need ARB_DIS
880 * !bm_check implies we need cache flush
881 * bm_control implies whether we can do ARB_DIS
883 * That leaves a case where bm_check is set and bm_control is
884 * not set. In that case we cannot do much, we enter C3
885 * without doing anything.
887 if (pr
->flags
.bm_check
&& pr
->flags
.bm_control
) {
888 raw_spin_lock(&c3_lock
);
890 /* Disable bus master arbitration when all CPUs are in C3 */
891 if (c3_cpu_count
== num_online_cpus())
892 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE
, 1);
893 raw_spin_unlock(&c3_lock
);
894 } else if (!pr
->flags
.bm_check
) {
895 ACPI_FLUSH_CPU_CACHE();
898 acpi_idle_do_entry(cx
);
900 /* Re-enable bus master arbitration */
901 if (pr
->flags
.bm_check
&& pr
->flags
.bm_control
) {
902 raw_spin_lock(&c3_lock
);
903 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE
, 0);
905 raw_spin_unlock(&c3_lock
);
908 sched_clock_idle_wakeup_event(0);
910 if (cx
->entry_method
!= ACPI_CSTATE_FFH
)
911 current_thread_info()->status
|= TS_POLLING
;
913 lapic_timer_state_broadcast(pr
, cx
, 0);
917 struct cpuidle_driver acpi_idle_driver
= {
919 .owner
= THIS_MODULE
,
920 .en_core_tk_irqen
= 1,
924 * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE
925 * device i.e. per-cpu data
927 * @pr: the ACPI processor
928 * @dev : the cpuidle device
930 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor
*pr
,
931 struct cpuidle_device
*dev
)
933 int i
, count
= CPUIDLE_DRIVER_STATE_START
;
934 struct acpi_processor_cx
*cx
;
936 if (!pr
->flags
.power_setup_done
)
939 if (pr
->flags
.power
== 0) {
951 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
&& i
<= max_cstate
; i
++) {
952 cx
= &pr
->power
.states
[i
];
957 #ifdef CONFIG_HOTPLUG_CPU
958 if ((cx
->type
!= ACPI_STATE_C1
) && (num_online_cpus() > 1) &&
959 !pr
->flags
.has_cst
&&
960 !(acpi_gbl_FADT
.flags
& ACPI_FADT_C2_MP_SUPPORTED
))
963 acpi_cstate
[count
] = cx
;
966 if (count
== CPUIDLE_STATE_MAX
)
970 dev
->state_count
= count
;
979 * acpi_processor_setup_cpuidle states- prepares and configures cpuidle
980 * global state data i.e. idle routines
982 * @pr: the ACPI processor
984 static int acpi_processor_setup_cpuidle_states(struct acpi_processor
*pr
)
986 int i
, count
= CPUIDLE_DRIVER_STATE_START
;
987 struct acpi_processor_cx
*cx
;
988 struct cpuidle_state
*state
;
989 struct cpuidle_driver
*drv
= &acpi_idle_driver
;
991 if (!pr
->flags
.power_setup_done
)
994 if (pr
->flags
.power
== 0)
997 drv
->safe_state_index
= -1;
998 for (i
= 0; i
< CPUIDLE_STATE_MAX
; i
++) {
999 drv
->states
[i
].name
[0] = '\0';
1000 drv
->states
[i
].desc
[0] = '\0';
1003 if (max_cstate
== 0)
1006 for (i
= 1; i
< ACPI_PROCESSOR_MAX_POWER
&& i
<= max_cstate
; i
++) {
1007 cx
= &pr
->power
.states
[i
];
1012 #ifdef CONFIG_HOTPLUG_CPU
1013 if ((cx
->type
!= ACPI_STATE_C1
) && (num_online_cpus() > 1) &&
1014 !pr
->flags
.has_cst
&&
1015 !(acpi_gbl_FADT
.flags
& ACPI_FADT_C2_MP_SUPPORTED
))
1019 state
= &drv
->states
[count
];
1020 snprintf(state
->name
, CPUIDLE_NAME_LEN
, "C%d", i
);
1021 strncpy(state
->desc
, cx
->desc
, CPUIDLE_DESC_LEN
);
1022 state
->exit_latency
= cx
->latency
;
1023 state
->target_residency
= cx
->latency
* latency_factor
;
1028 if (cx
->entry_method
== ACPI_CSTATE_FFH
)
1029 state
->flags
|= CPUIDLE_FLAG_TIME_VALID
;
1031 state
->enter
= acpi_idle_enter_c1
;
1032 state
->enter_dead
= acpi_idle_play_dead
;
1033 drv
->safe_state_index
= count
;
1037 state
->flags
|= CPUIDLE_FLAG_TIME_VALID
;
1038 state
->enter
= acpi_idle_enter_simple
;
1039 state
->enter_dead
= acpi_idle_play_dead
;
1040 drv
->safe_state_index
= count
;
1044 state
->flags
|= CPUIDLE_FLAG_TIME_VALID
;
1045 state
->enter
= pr
->flags
.bm_check
?
1046 acpi_idle_enter_bm
:
1047 acpi_idle_enter_simple
;
1052 if (count
== CPUIDLE_STATE_MAX
)
1056 drv
->state_count
= count
;
1064 int acpi_processor_hotplug(struct acpi_processor
*pr
)
1067 struct cpuidle_device
*dev
;
1069 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())
1110 if (!pr
->flags
.power_setup_done
)
1114 * FIXME: Design the ACPI notification to make it once per
1115 * system instead of once per-cpu. This condition is a hack
1116 * to make the code that updates C-States be called once.
1119 if (pr
->id
== 0 && cpuidle_get_driver() == &acpi_idle_driver
) {
1121 cpuidle_pause_and_lock();
1122 /* Protect against cpu-hotplug */
1125 /* Disable all cpuidle devices */
1126 for_each_online_cpu(cpu
) {
1127 _pr
= per_cpu(processors
, cpu
);
1128 if (!_pr
|| !_pr
->flags
.power_setup_done
)
1130 dev
= per_cpu(acpi_cpuidle_device
, cpu
);
1131 cpuidle_disable_device(dev
);
1134 /* Populate Updated C-state information */
1135 acpi_processor_get_power_info(pr
);
1136 acpi_processor_setup_cpuidle_states(pr
);
1138 /* Enable all cpuidle devices */
1139 for_each_online_cpu(cpu
) {
1140 _pr
= per_cpu(processors
, cpu
);
1141 if (!_pr
|| !_pr
->flags
.power_setup_done
)
1143 acpi_processor_get_power_info(_pr
);
1144 if (_pr
->flags
.power
) {
1145 dev
= per_cpu(acpi_cpuidle_device
, cpu
);
1146 acpi_processor_setup_cpuidle_cx(_pr
, dev
);
1147 cpuidle_enable_device(dev
);
1151 cpuidle_resume_and_unlock();
1157 static int acpi_processor_registered
;
1159 int __cpuinit
acpi_processor_power_init(struct acpi_processor
*pr
)
1161 acpi_status status
= 0;
1163 struct cpuidle_device
*dev
;
1164 static int first_run
;
1166 if (disabled_by_idle_boot_param())
1170 dmi_check_system(processor_power_dmi_table
);
1171 max_cstate
= acpi_processor_cstate_check(max_cstate
);
1172 if (max_cstate
< ACPI_C_STATES_MAX
)
1174 "ACPI: processor limited to max C-state %d\n",
1182 if (acpi_gbl_FADT
.cst_control
&& !nocst
) {
1184 acpi_os_write_port(acpi_gbl_FADT
.smi_command
, acpi_gbl_FADT
.cst_control
, 8);
1185 if (ACPI_FAILURE(status
)) {
1186 ACPI_EXCEPTION((AE_INFO
, status
,
1187 "Notifying BIOS of _CST ability failed"));
1191 acpi_processor_get_power_info(pr
);
1192 pr
->flags
.power_setup_done
= 1;
1195 * Install the idle handler if processor power management is supported.
1196 * Note that we use previously set idle handler will be used on
1197 * platforms that only support C1.
1199 if (pr
->flags
.power
) {
1200 /* Register acpi_idle_driver if not already registered */
1201 if (!acpi_processor_registered
) {
1202 acpi_processor_setup_cpuidle_states(pr
);
1203 retval
= cpuidle_register_driver(&acpi_idle_driver
);
1206 printk(KERN_DEBUG
"ACPI: %s registered with cpuidle\n",
1207 acpi_idle_driver
.name
);
1210 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
1213 per_cpu(acpi_cpuidle_device
, pr
->id
) = dev
;
1215 acpi_processor_setup_cpuidle_cx(pr
, dev
);
1217 /* Register per-cpu cpuidle_device. Cpuidle driver
1218 * must already be registered before registering device
1220 retval
= cpuidle_register_device(dev
);
1222 if (acpi_processor_registered
== 0)
1223 cpuidle_unregister_driver(&acpi_idle_driver
);
1226 acpi_processor_registered
++;
1231 int acpi_processor_power_exit(struct acpi_processor
*pr
)
1233 struct cpuidle_device
*dev
= per_cpu(acpi_cpuidle_device
, pr
->id
);
1235 if (disabled_by_idle_boot_param())
1238 if (pr
->flags
.power
) {
1239 cpuidle_unregister_device(dev
);
1240 acpi_processor_registered
--;
1241 if (acpi_processor_registered
== 0)
1242 cpuidle_unregister_driver(&acpi_idle_driver
);
1245 pr
->flags
.power_setup_done
= 0;