![Nick Piggin](/assets/img/avatar_default.png)
Make some changes to the NEED_RESCHED and POLLING_NRFLAG to reduce confusion, and make their semantics rigid. Improves efficiency of resched_task and some cpu_idle routines. * In resched_task: - TIF_NEED_RESCHED is only cleared with the task's runqueue lock held, and as we hold it during resched_task, then there is no need for an atomic test and set there. The only other time this should be set is when the task's quantum expires, in the timer interrupt - this is protected against because the rq lock is irq-safe. - If TIF_NEED_RESCHED is set, then we don't need to do anything. It won't get unset until the task get's schedule()d off. - If we are running on the same CPU as the task we resched, then set TIF_NEED_RESCHED and no further action is required. - If we are running on another CPU, and TIF_POLLING_NRFLAG is *not* set after TIF_NEED_RESCHED has been set, then we need to send an IPI. Using these rules, we are able to remove the test and set operation in resched_task, and make clear the previously vague semantics of POLLING_NRFLAG. * In idle routines: - Enter cpu_idle with preempt disabled. When the need_resched() condition becomes true, explicitly call schedule(). This makes things a bit clearer (IMO), but haven't updated all architectures yet. - Many do a test and clear of TIF_NEED_RESCHED for some reason. According to the resched_task rules, this isn't needed (and actually breaks the assumption that TIF_NEED_RESCHED is only cleared with the runqueue lock held). So remove that. Generally one less locked memory op when switching to the idle thread. - Many idle routines clear TIF_POLLING_NRFLAG, and only set it in the inner most polling idle loops. The above resched_task semantics allow it to be set until before the last time need_resched() is checked before going into a halt requiring interrupt wakeup. Many idle routines simply never enter such a halt, and so POLLING_NRFLAG can be always left set, completely eliminating resched IPIs when rescheduling the idle task. POLLING_NRFLAG width can be increased, to reduce the chance of resched IPIs. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Con Kolivas <kernel@kolivas.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
1089 lines
28 KiB
C
1089 lines
28 KiB
C
/*
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* processor_idle - idle state submodule to the ACPI processor driver
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*
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* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
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* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
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* Copyright (C) 2004 Dominik Brodowski <linux@brodo.de>
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* Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
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* - Added processor hotplug support
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* Copyright (C) 2005 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
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* - Added support for C3 on SMP
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*
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* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or (at
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* your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
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*
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* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/cpufreq.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/acpi.h>
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#include <linux/dmi.h>
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#include <linux/moduleparam.h>
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#include <linux/sched.h> /* need_resched() */
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#include <asm/io.h>
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#include <asm/uaccess.h>
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#include <acpi/acpi_bus.h>
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#include <acpi/processor.h>
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#define ACPI_PROCESSOR_COMPONENT 0x01000000
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#define ACPI_PROCESSOR_CLASS "processor"
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#define ACPI_PROCESSOR_DRIVER_NAME "ACPI Processor Driver"
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#define _COMPONENT ACPI_PROCESSOR_COMPONENT
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ACPI_MODULE_NAME("acpi_processor")
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#define ACPI_PROCESSOR_FILE_POWER "power"
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#define US_TO_PM_TIMER_TICKS(t) ((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
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#define C2_OVERHEAD 4 /* 1us (3.579 ticks per us) */
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#define C3_OVERHEAD 4 /* 1us (3.579 ticks per us) */
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static void (*pm_idle_save) (void);
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module_param(max_cstate, uint, 0644);
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static unsigned int nocst = 0;
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module_param(nocst, uint, 0000);
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/*
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* bm_history -- bit-mask with a bit per jiffy of bus-master activity
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* 1000 HZ: 0xFFFFFFFF: 32 jiffies = 32ms
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* 800 HZ: 0xFFFFFFFF: 32 jiffies = 40ms
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* 100 HZ: 0x0000000F: 4 jiffies = 40ms
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* reduce history for more aggressive entry into C3
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*/
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static unsigned int bm_history =
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(HZ >= 800 ? 0xFFFFFFFF : ((1U << (HZ / 25)) - 1));
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module_param(bm_history, uint, 0644);
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/* --------------------------------------------------------------------------
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Power Management
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-------------------------------------------------------------------------- */
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/*
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* IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
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* For now disable this. Probably a bug somewhere else.
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*
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* To skip this limit, boot/load with a large max_cstate limit.
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*/
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static int set_max_cstate(struct dmi_system_id *id)
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{
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if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
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return 0;
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printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
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" Override with \"processor.max_cstate=%d\"\n", id->ident,
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(long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
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max_cstate = (long)id->driver_data;
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return 0;
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}
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static struct dmi_system_id __initdata processor_power_dmi_table[] = {
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{set_max_cstate, "IBM ThinkPad R40e", {
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DMI_MATCH(DMI_BIOS_VENDOR,
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"IBM"),
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DMI_MATCH(DMI_BIOS_VERSION,
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"1SET60WW")},
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(void *)1},
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{set_max_cstate, "Medion 41700", {
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DMI_MATCH(DMI_BIOS_VENDOR,
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"Phoenix Technologies LTD"),
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DMI_MATCH(DMI_BIOS_VERSION,
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"R01-A1J")}, (void *)1},
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{set_max_cstate, "Clevo 5600D", {
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DMI_MATCH(DMI_BIOS_VENDOR,
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"Phoenix Technologies LTD"),
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DMI_MATCH(DMI_BIOS_VERSION,
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"SHE845M0.86C.0013.D.0302131307")},
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(void *)2},
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{},
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};
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static inline u32 ticks_elapsed(u32 t1, u32 t2)
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{
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if (t2 >= t1)
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return (t2 - t1);
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else if (!acpi_fadt.tmr_val_ext)
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return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
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else
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return ((0xFFFFFFFF - t1) + t2);
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}
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static void
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acpi_processor_power_activate(struct acpi_processor *pr,
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struct acpi_processor_cx *new)
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{
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struct acpi_processor_cx *old;
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if (!pr || !new)
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return;
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old = pr->power.state;
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if (old)
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old->promotion.count = 0;
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new->demotion.count = 0;
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/* Cleanup from old state. */
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if (old) {
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switch (old->type) {
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case ACPI_STATE_C3:
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/* Disable bus master reload */
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if (new->type != ACPI_STATE_C3 && pr->flags.bm_check)
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acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0,
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ACPI_MTX_DO_NOT_LOCK);
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break;
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}
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}
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/* Prepare to use new state. */
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switch (new->type) {
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case ACPI_STATE_C3:
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/* Enable bus master reload */
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if (old->type != ACPI_STATE_C3 && pr->flags.bm_check)
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acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1,
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ACPI_MTX_DO_NOT_LOCK);
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break;
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}
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pr->power.state = new;
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return;
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}
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static void acpi_safe_halt(void)
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{
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int polling = test_thread_flag(TIF_POLLING_NRFLAG);
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if (polling) {
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clear_thread_flag(TIF_POLLING_NRFLAG);
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smp_mb__after_clear_bit();
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}
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if (!need_resched())
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safe_halt();
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if (polling)
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set_thread_flag(TIF_POLLING_NRFLAG);
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}
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static atomic_t c3_cpu_count;
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static void acpi_processor_idle(void)
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{
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struct acpi_processor *pr = NULL;
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struct acpi_processor_cx *cx = NULL;
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struct acpi_processor_cx *next_state = NULL;
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int sleep_ticks = 0;
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u32 t1, t2 = 0;
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pr = processors[smp_processor_id()];
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if (!pr)
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return;
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/*
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* Interrupts must be disabled during bus mastering calculations and
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* for C2/C3 transitions.
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*/
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local_irq_disable();
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/*
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* Check whether we truly need to go idle, or should
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* reschedule:
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*/
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if (unlikely(need_resched())) {
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local_irq_enable();
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return;
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}
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cx = pr->power.state;
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if (!cx) {
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if (pm_idle_save)
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pm_idle_save();
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else
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acpi_safe_halt();
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return;
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}
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/*
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* Check BM Activity
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* -----------------
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* Check for bus mastering activity (if required), record, and check
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* for demotion.
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*/
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if (pr->flags.bm_check) {
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u32 bm_status = 0;
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unsigned long diff = jiffies - pr->power.bm_check_timestamp;
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if (diff > 32)
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diff = 32;
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while (diff) {
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/* if we didn't get called, assume there was busmaster activity */
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diff--;
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if (diff)
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pr->power.bm_activity |= 0x1;
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pr->power.bm_activity <<= 1;
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}
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acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS,
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&bm_status, ACPI_MTX_DO_NOT_LOCK);
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if (bm_status) {
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pr->power.bm_activity++;
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acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS,
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1, ACPI_MTX_DO_NOT_LOCK);
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}
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/*
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* PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
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* the true state of bus mastering activity; forcing us to
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* manually check the BMIDEA bit of each IDE channel.
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*/
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else if (errata.piix4.bmisx) {
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if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
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|| (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
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pr->power.bm_activity++;
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}
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pr->power.bm_check_timestamp = jiffies;
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/*
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* Apply bus mastering demotion policy. Automatically demote
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* to avoid a faulty transition. Note that the processor
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* won't enter a low-power state during this call (to this
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* funciton) but should upon the next.
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*
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* TBD: A better policy might be to fallback to the demotion
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* state (use it for this quantum only) istead of
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* demoting -- and rely on duration as our sole demotion
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* qualification. This may, however, introduce DMA
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* issues (e.g. floppy DMA transfer overrun/underrun).
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*/
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if (pr->power.bm_activity & cx->demotion.threshold.bm) {
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local_irq_enable();
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next_state = cx->demotion.state;
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goto end;
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}
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}
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cx->usage++;
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/*
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* Sleep:
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* ------
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* Invoke the current Cx state to put the processor to sleep.
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*/
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switch (cx->type) {
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case ACPI_STATE_C1:
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/*
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* Invoke C1.
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* Use the appropriate idle routine, the one that would
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* be used without acpi C-states.
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*/
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if (pm_idle_save)
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pm_idle_save();
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else
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acpi_safe_halt();
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/*
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* TBD: Can't get time duration while in C1, as resumes
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* go to an ISR rather than here. Need to instrument
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* base interrupt handler.
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*/
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sleep_ticks = 0xFFFFFFFF;
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break;
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case ACPI_STATE_C2:
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/* Get start time (ticks) */
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t1 = inl(acpi_fadt.xpm_tmr_blk.address);
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/* Invoke C2 */
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inb(cx->address);
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/* Dummy op - must do something useless after P_LVL2 read */
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t2 = inl(acpi_fadt.xpm_tmr_blk.address);
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/* Get end time (ticks) */
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t2 = inl(acpi_fadt.xpm_tmr_blk.address);
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/* Re-enable interrupts */
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local_irq_enable();
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/* Compute time (ticks) that we were actually asleep */
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sleep_ticks =
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ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD;
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break;
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case ACPI_STATE_C3:
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if (pr->flags.bm_check) {
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if (atomic_inc_return(&c3_cpu_count) ==
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num_online_cpus()) {
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/*
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* All CPUs are trying to go to C3
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* Disable bus master arbitration
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*/
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acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1,
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ACPI_MTX_DO_NOT_LOCK);
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}
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} else {
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/* SMP with no shared cache... Invalidate cache */
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ACPI_FLUSH_CPU_CACHE();
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}
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/* Get start time (ticks) */
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t1 = inl(acpi_fadt.xpm_tmr_blk.address);
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/* Invoke C3 */
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inb(cx->address);
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/* Dummy op - must do something useless after P_LVL3 read */
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t2 = inl(acpi_fadt.xpm_tmr_blk.address);
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/* Get end time (ticks) */
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t2 = inl(acpi_fadt.xpm_tmr_blk.address);
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if (pr->flags.bm_check) {
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/* Enable bus master arbitration */
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atomic_dec(&c3_cpu_count);
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acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0,
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ACPI_MTX_DO_NOT_LOCK);
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}
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/* Re-enable interrupts */
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local_irq_enable();
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/* Compute time (ticks) that we were actually asleep */
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sleep_ticks =
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ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD;
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break;
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default:
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local_irq_enable();
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return;
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}
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next_state = pr->power.state;
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/*
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* Promotion?
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* ----------
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* Track the number of longs (time asleep is greater than threshold)
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* and promote when the count threshold is reached. Note that bus
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* mastering activity may prevent promotions.
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* Do not promote above max_cstate.
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*/
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if (cx->promotion.state &&
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((cx->promotion.state - pr->power.states) <= max_cstate)) {
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if (sleep_ticks > cx->promotion.threshold.ticks) {
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cx->promotion.count++;
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cx->demotion.count = 0;
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if (cx->promotion.count >=
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cx->promotion.threshold.count) {
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if (pr->flags.bm_check) {
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if (!
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(pr->power.bm_activity & cx->
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promotion.threshold.bm)) {
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next_state =
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cx->promotion.state;
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goto end;
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}
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} else {
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next_state = cx->promotion.state;
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goto end;
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}
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}
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}
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}
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/*
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* Demotion?
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* ---------
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* Track the number of shorts (time asleep is less than time threshold)
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* and demote when the usage threshold is reached.
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*/
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if (cx->demotion.state) {
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if (sleep_ticks < cx->demotion.threshold.ticks) {
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cx->demotion.count++;
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cx->promotion.count = 0;
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if (cx->demotion.count >= cx->demotion.threshold.count) {
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next_state = cx->demotion.state;
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goto end;
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}
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}
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}
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end:
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/*
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* Demote if current state exceeds max_cstate
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*/
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if ((pr->power.state - pr->power.states) > max_cstate) {
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if (cx->demotion.state)
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next_state = cx->demotion.state;
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}
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/*
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* New Cx State?
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* -------------
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* If we're going to start using a new Cx state we must clean up
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* from the previous and prepare to use the new.
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*/
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if (next_state != pr->power.state)
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acpi_processor_power_activate(pr, next_state);
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}
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static int acpi_processor_set_power_policy(struct acpi_processor *pr)
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{
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unsigned int i;
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unsigned int state_is_set = 0;
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struct acpi_processor_cx *lower = NULL;
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struct acpi_processor_cx *higher = NULL;
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struct acpi_processor_cx *cx;
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ACPI_FUNCTION_TRACE("acpi_processor_set_power_policy");
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if (!pr)
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return_VALUE(-EINVAL);
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/*
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* This function sets the default Cx state policy (OS idle handler).
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* Our scheme is to promote quickly to C2 but more conservatively
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* to C3. We're favoring C2 for its characteristics of low latency
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* (quick response), good power savings, and ability to allow bus
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* mastering activity. Note that the Cx state policy is completely
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* customizable and can be altered dynamically.
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*/
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/* startup state */
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for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
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cx = &pr->power.states[i];
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if (!cx->valid)
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continue;
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if (!state_is_set)
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pr->power.state = cx;
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state_is_set++;
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break;
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}
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if (!state_is_set)
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return_VALUE(-ENODEV);
|
|
|
|
/* demotion */
|
|
for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
|
|
cx = &pr->power.states[i];
|
|
if (!cx->valid)
|
|
continue;
|
|
|
|
if (lower) {
|
|
cx->demotion.state = lower;
|
|
cx->demotion.threshold.ticks = cx->latency_ticks;
|
|
cx->demotion.threshold.count = 1;
|
|
if (cx->type == ACPI_STATE_C3)
|
|
cx->demotion.threshold.bm = bm_history;
|
|
}
|
|
|
|
lower = cx;
|
|
}
|
|
|
|
/* promotion */
|
|
for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) {
|
|
cx = &pr->power.states[i];
|
|
if (!cx->valid)
|
|
continue;
|
|
|
|
if (higher) {
|
|
cx->promotion.state = higher;
|
|
cx->promotion.threshold.ticks = cx->latency_ticks;
|
|
if (cx->type >= ACPI_STATE_C2)
|
|
cx->promotion.threshold.count = 4;
|
|
else
|
|
cx->promotion.threshold.count = 10;
|
|
if (higher->type == ACPI_STATE_C3)
|
|
cx->promotion.threshold.bm = bm_history;
|
|
}
|
|
|
|
higher = cx;
|
|
}
|
|
|
|
return_VALUE(0);
|
|
}
|
|
|
|
static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
|
|
{
|
|
int i;
|
|
|
|
ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_fadt");
|
|
|
|
if (!pr)
|
|
return_VALUE(-EINVAL);
|
|
|
|
if (!pr->pblk)
|
|
return_VALUE(-ENODEV);
|
|
|
|
for (i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++)
|
|
memset(pr->power.states, 0, sizeof(struct acpi_processor_cx));
|
|
|
|
/* if info is obtained from pblk/fadt, type equals state */
|
|
pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
|
|
pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
|
|
pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
|
|
|
|
/* the C0 state only exists as a filler in our array,
|
|
* and all processors need to support C1 */
|
|
pr->power.states[ACPI_STATE_C0].valid = 1;
|
|
pr->power.states[ACPI_STATE_C1].valid = 1;
|
|
|
|
/* determine C2 and C3 address from pblk */
|
|
pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
|
|
pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
|
|
|
|
/* determine latencies from FADT */
|
|
pr->power.states[ACPI_STATE_C2].latency = acpi_fadt.plvl2_lat;
|
|
pr->power.states[ACPI_STATE_C3].latency = acpi_fadt.plvl3_lat;
|
|
|
|
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
|
|
"lvl2[0x%08x] lvl3[0x%08x]\n",
|
|
pr->power.states[ACPI_STATE_C2].address,
|
|
pr->power.states[ACPI_STATE_C3].address));
|
|
|
|
return_VALUE(0);
|
|
}
|
|
|
|
static int acpi_processor_get_power_info_default_c1(struct acpi_processor *pr)
|
|
{
|
|
int i;
|
|
|
|
ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_default_c1");
|
|
|
|
for (i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++)
|
|
memset(&(pr->power.states[i]), 0,
|
|
sizeof(struct acpi_processor_cx));
|
|
|
|
/* if info is obtained from pblk/fadt, type equals state */
|
|
pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
|
|
pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
|
|
pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
|
|
|
|
/* the C0 state only exists as a filler in our array,
|
|
* and all processors need to support C1 */
|
|
pr->power.states[ACPI_STATE_C0].valid = 1;
|
|
pr->power.states[ACPI_STATE_C1].valid = 1;
|
|
|
|
return_VALUE(0);
|
|
}
|
|
|
|
static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
|
|
{
|
|
acpi_status status = 0;
|
|
acpi_integer count;
|
|
int i;
|
|
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
|
|
union acpi_object *cst;
|
|
|
|
ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_cst");
|
|
|
|
if (nocst)
|
|
return_VALUE(-ENODEV);
|
|
|
|
pr->power.count = 0;
|
|
for (i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++)
|
|
memset(&(pr->power.states[i]), 0,
|
|
sizeof(struct acpi_processor_cx));
|
|
|
|
status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
|
|
if (ACPI_FAILURE(status)) {
|
|
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
|
|
return_VALUE(-ENODEV);
|
|
}
|
|
|
|
cst = (union acpi_object *)buffer.pointer;
|
|
|
|
/* There must be at least 2 elements */
|
|
if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
|
|
ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
|
|
"not enough elements in _CST\n"));
|
|
status = -EFAULT;
|
|
goto end;
|
|
}
|
|
|
|
count = cst->package.elements[0].integer.value;
|
|
|
|
/* Validate number of power states. */
|
|
if (count < 1 || count != cst->package.count - 1) {
|
|
ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
|
|
"count given by _CST is not valid\n"));
|
|
status = -EFAULT;
|
|
goto end;
|
|
}
|
|
|
|
/* We support up to ACPI_PROCESSOR_MAX_POWER. */
|
|
if (count > ACPI_PROCESSOR_MAX_POWER) {
|
|
printk(KERN_WARNING
|
|
"Limiting number of power states to max (%d)\n",
|
|
ACPI_PROCESSOR_MAX_POWER);
|
|
printk(KERN_WARNING
|
|
"Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
|
|
count = ACPI_PROCESSOR_MAX_POWER;
|
|
}
|
|
|
|
/* Tell driver that at least _CST is supported. */
|
|
pr->flags.has_cst = 1;
|
|
|
|
for (i = 1; i <= count; i++) {
|
|
union acpi_object *element;
|
|
union acpi_object *obj;
|
|
struct acpi_power_register *reg;
|
|
struct acpi_processor_cx cx;
|
|
|
|
memset(&cx, 0, sizeof(cx));
|
|
|
|
element = (union acpi_object *)&(cst->package.elements[i]);
|
|
if (element->type != ACPI_TYPE_PACKAGE)
|
|
continue;
|
|
|
|
if (element->package.count != 4)
|
|
continue;
|
|
|
|
obj = (union acpi_object *)&(element->package.elements[0]);
|
|
|
|
if (obj->type != ACPI_TYPE_BUFFER)
|
|
continue;
|
|
|
|
reg = (struct acpi_power_register *)obj->buffer.pointer;
|
|
|
|
if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
|
|
(reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
|
|
continue;
|
|
|
|
cx.address = (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) ?
|
|
0 : reg->address;
|
|
|
|
/* There should be an easy way to extract an integer... */
|
|
obj = (union acpi_object *)&(element->package.elements[1]);
|
|
if (obj->type != ACPI_TYPE_INTEGER)
|
|
continue;
|
|
|
|
cx.type = obj->integer.value;
|
|
|
|
if ((cx.type != ACPI_STATE_C1) &&
|
|
(reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO))
|
|
continue;
|
|
|
|
if ((cx.type < ACPI_STATE_C1) || (cx.type > ACPI_STATE_C3))
|
|
continue;
|
|
|
|
obj = (union acpi_object *)&(element->package.elements[2]);
|
|
if (obj->type != ACPI_TYPE_INTEGER)
|
|
continue;
|
|
|
|
cx.latency = obj->integer.value;
|
|
|
|
obj = (union acpi_object *)&(element->package.elements[3]);
|
|
if (obj->type != ACPI_TYPE_INTEGER)
|
|
continue;
|
|
|
|
cx.power = obj->integer.value;
|
|
|
|
(pr->power.count)++;
|
|
memcpy(&(pr->power.states[pr->power.count]), &cx, sizeof(cx));
|
|
}
|
|
|
|
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
|
|
pr->power.count));
|
|
|
|
/* Validate number of power states discovered */
|
|
if (pr->power.count < 2)
|
|
status = -ENODEV;
|
|
|
|
end:
|
|
acpi_os_free(buffer.pointer);
|
|
|
|
return_VALUE(status);
|
|
}
|
|
|
|
static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
|
|
{
|
|
ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c2");
|
|
|
|
if (!cx->address)
|
|
return_VOID;
|
|
|
|
/*
|
|
* C2 latency must be less than or equal to 100
|
|
* microseconds.
|
|
*/
|
|
else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
|
|
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
|
|
"latency too large [%d]\n", cx->latency));
|
|
return_VOID;
|
|
}
|
|
|
|
/*
|
|
* Otherwise we've met all of our C2 requirements.
|
|
* Normalize the C2 latency to expidite policy
|
|
*/
|
|
cx->valid = 1;
|
|
cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
|
|
|
|
return_VOID;
|
|
}
|
|
|
|
static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
|
|
struct acpi_processor_cx *cx)
|
|
{
|
|
static int bm_check_flag;
|
|
|
|
ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c3");
|
|
|
|
if (!cx->address)
|
|
return_VOID;
|
|
|
|
/*
|
|
* C3 latency must be less than or equal to 1000
|
|
* microseconds.
|
|
*/
|
|
else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
|
|
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
|
|
"latency too large [%d]\n", cx->latency));
|
|
return_VOID;
|
|
}
|
|
|
|
/*
|
|
* PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
|
|
* DMA transfers are used by any ISA device to avoid livelock.
|
|
* Note that we could disable Type-F DMA (as recommended by
|
|
* the erratum), but this is known to disrupt certain ISA
|
|
* devices thus we take the conservative approach.
|
|
*/
|
|
else if (errata.piix4.fdma) {
|
|
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
|
|
"C3 not supported on PIIX4 with Type-F DMA\n"));
|
|
return_VOID;
|
|
}
|
|
|
|
/* All the logic here assumes flags.bm_check is same across all CPUs */
|
|
if (!bm_check_flag) {
|
|
/* Determine whether bm_check is needed based on CPU */
|
|
acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
|
|
bm_check_flag = pr->flags.bm_check;
|
|
} else {
|
|
pr->flags.bm_check = bm_check_flag;
|
|
}
|
|
|
|
if (pr->flags.bm_check) {
|
|
/* bus mastering control is necessary */
|
|
if (!pr->flags.bm_control) {
|
|
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
|
|
"C3 support requires bus mastering control\n"));
|
|
return_VOID;
|
|
}
|
|
} else {
|
|
/*
|
|
* WBINVD should be set in fadt, for C3 state to be
|
|
* supported on when bm_check is not required.
|
|
*/
|
|
if (acpi_fadt.wb_invd != 1) {
|
|
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
|
|
"Cache invalidation should work properly"
|
|
" for C3 to be enabled on SMP systems\n"));
|
|
return_VOID;
|
|
}
|
|
acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD,
|
|
0, ACPI_MTX_DO_NOT_LOCK);
|
|
}
|
|
|
|
/*
|
|
* Otherwise we've met all of our C3 requirements.
|
|
* Normalize the C3 latency to expidite policy. Enable
|
|
* checking of bus mastering status (bm_check) so we can
|
|
* use this in our C3 policy
|
|
*/
|
|
cx->valid = 1;
|
|
cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
|
|
|
|
return_VOID;
|
|
}
|
|
|
|
static int acpi_processor_power_verify(struct acpi_processor *pr)
|
|
{
|
|
unsigned int i;
|
|
unsigned int working = 0;
|
|
|
|
for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
|
|
struct acpi_processor_cx *cx = &pr->power.states[i];
|
|
|
|
switch (cx->type) {
|
|
case ACPI_STATE_C1:
|
|
cx->valid = 1;
|
|
break;
|
|
|
|
case ACPI_STATE_C2:
|
|
acpi_processor_power_verify_c2(cx);
|
|
break;
|
|
|
|
case ACPI_STATE_C3:
|
|
acpi_processor_power_verify_c3(pr, cx);
|
|
break;
|
|
}
|
|
|
|
if (cx->valid)
|
|
working++;
|
|
}
|
|
|
|
return (working);
|
|
}
|
|
|
|
static int acpi_processor_get_power_info(struct acpi_processor *pr)
|
|
{
|
|
unsigned int i;
|
|
int result;
|
|
|
|
ACPI_FUNCTION_TRACE("acpi_processor_get_power_info");
|
|
|
|
/* NOTE: the idle thread may not be running while calling
|
|
* this function */
|
|
|
|
result = acpi_processor_get_power_info_cst(pr);
|
|
if ((result) || (acpi_processor_power_verify(pr) < 2)) {
|
|
result = acpi_processor_get_power_info_fadt(pr);
|
|
if ((result) || (acpi_processor_power_verify(pr) < 2))
|
|
result = acpi_processor_get_power_info_default_c1(pr);
|
|
}
|
|
|
|
/*
|
|
* Set Default Policy
|
|
* ------------------
|
|
* Now that we know which states are supported, set the default
|
|
* policy. Note that this policy can be changed dynamically
|
|
* (e.g. encourage deeper sleeps to conserve battery life when
|
|
* not on AC).
|
|
*/
|
|
result = acpi_processor_set_power_policy(pr);
|
|
if (result)
|
|
return_VALUE(result);
|
|
|
|
/*
|
|
* if one state of type C2 or C3 is available, mark this
|
|
* CPU as being "idle manageable"
|
|
*/
|
|
for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
|
|
if (pr->power.states[i].valid) {
|
|
pr->power.count = i;
|
|
pr->flags.power = 1;
|
|
}
|
|
}
|
|
|
|
return_VALUE(0);
|
|
}
|
|
|
|
int acpi_processor_cst_has_changed(struct acpi_processor *pr)
|
|
{
|
|
int result = 0;
|
|
|
|
ACPI_FUNCTION_TRACE("acpi_processor_cst_has_changed");
|
|
|
|
if (!pr)
|
|
return_VALUE(-EINVAL);
|
|
|
|
if (nocst) {
|
|
return_VALUE(-ENODEV);
|
|
}
|
|
|
|
if (!pr->flags.power_setup_done)
|
|
return_VALUE(-ENODEV);
|
|
|
|
/* Fall back to the default idle loop */
|
|
pm_idle = pm_idle_save;
|
|
synchronize_sched(); /* Relies on interrupts forcing exit from idle. */
|
|
|
|
pr->flags.power = 0;
|
|
result = acpi_processor_get_power_info(pr);
|
|
if ((pr->flags.power == 1) && (pr->flags.power_setup_done))
|
|
pm_idle = acpi_processor_idle;
|
|
|
|
return_VALUE(result);
|
|
}
|
|
|
|
/* proc interface */
|
|
|
|
static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
|
|
{
|
|
struct acpi_processor *pr = (struct acpi_processor *)seq->private;
|
|
unsigned int i;
|
|
|
|
ACPI_FUNCTION_TRACE("acpi_processor_power_seq_show");
|
|
|
|
if (!pr)
|
|
goto end;
|
|
|
|
seq_printf(seq, "active state: C%zd\n"
|
|
"max_cstate: C%d\n"
|
|
"bus master activity: %08x\n",
|
|
pr->power.state ? pr->power.state - pr->power.states : 0,
|
|
max_cstate, (unsigned)pr->power.bm_activity);
|
|
|
|
seq_puts(seq, "states:\n");
|
|
|
|
for (i = 1; i <= pr->power.count; i++) {
|
|
seq_printf(seq, " %cC%d: ",
|
|
(&pr->power.states[i] ==
|
|
pr->power.state ? '*' : ' '), i);
|
|
|
|
if (!pr->power.states[i].valid) {
|
|
seq_puts(seq, "<not supported>\n");
|
|
continue;
|
|
}
|
|
|
|
switch (pr->power.states[i].type) {
|
|
case ACPI_STATE_C1:
|
|
seq_printf(seq, "type[C1] ");
|
|
break;
|
|
case ACPI_STATE_C2:
|
|
seq_printf(seq, "type[C2] ");
|
|
break;
|
|
case ACPI_STATE_C3:
|
|
seq_printf(seq, "type[C3] ");
|
|
break;
|
|
default:
|
|
seq_printf(seq, "type[--] ");
|
|
break;
|
|
}
|
|
|
|
if (pr->power.states[i].promotion.state)
|
|
seq_printf(seq, "promotion[C%zd] ",
|
|
(pr->power.states[i].promotion.state -
|
|
pr->power.states));
|
|
else
|
|
seq_puts(seq, "promotion[--] ");
|
|
|
|
if (pr->power.states[i].demotion.state)
|
|
seq_printf(seq, "demotion[C%zd] ",
|
|
(pr->power.states[i].demotion.state -
|
|
pr->power.states));
|
|
else
|
|
seq_puts(seq, "demotion[--] ");
|
|
|
|
seq_printf(seq, "latency[%03d] usage[%08d]\n",
|
|
pr->power.states[i].latency,
|
|
pr->power.states[i].usage);
|
|
}
|
|
|
|
end:
|
|
return_VALUE(0);
|
|
}
|
|
|
|
static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
|
|
{
|
|
return single_open(file, acpi_processor_power_seq_show,
|
|
PDE(inode)->data);
|
|
}
|
|
|
|
static struct file_operations acpi_processor_power_fops = {
|
|
.open = acpi_processor_power_open_fs,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = single_release,
|
|
};
|
|
|
|
int acpi_processor_power_init(struct acpi_processor *pr,
|
|
struct acpi_device *device)
|
|
{
|
|
acpi_status status = 0;
|
|
static int first_run = 0;
|
|
struct proc_dir_entry *entry = NULL;
|
|
unsigned int i;
|
|
|
|
ACPI_FUNCTION_TRACE("acpi_processor_power_init");
|
|
|
|
if (!first_run) {
|
|
dmi_check_system(processor_power_dmi_table);
|
|
if (max_cstate < ACPI_C_STATES_MAX)
|
|
printk(KERN_NOTICE
|
|
"ACPI: processor limited to max C-state %d\n",
|
|
max_cstate);
|
|
first_run++;
|
|
}
|
|
|
|
if (!pr)
|
|
return_VALUE(-EINVAL);
|
|
|
|
if (acpi_fadt.cst_cnt && !nocst) {
|
|
status =
|
|
acpi_os_write_port(acpi_fadt.smi_cmd, acpi_fadt.cst_cnt, 8);
|
|
if (ACPI_FAILURE(status)) {
|
|
ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
|
|
"Notifying BIOS of _CST ability failed\n"));
|
|
}
|
|
}
|
|
|
|
acpi_processor_power_init_pdc(&(pr->power), pr->id);
|
|
acpi_processor_set_pdc(pr, pr->power.pdc);
|
|
acpi_processor_get_power_info(pr);
|
|
|
|
/*
|
|
* Install the idle handler if processor power management is supported.
|
|
* Note that we use previously set idle handler will be used on
|
|
* platforms that only support C1.
|
|
*/
|
|
if ((pr->flags.power) && (!boot_option_idle_override)) {
|
|
printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
|
|
for (i = 1; i <= pr->power.count; i++)
|
|
if (pr->power.states[i].valid)
|
|
printk(" C%d[C%d]", i,
|
|
pr->power.states[i].type);
|
|
printk(")\n");
|
|
|
|
if (pr->id == 0) {
|
|
pm_idle_save = pm_idle;
|
|
pm_idle = acpi_processor_idle;
|
|
}
|
|
}
|
|
|
|
/* 'power' [R] */
|
|
entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER,
|
|
S_IRUGO, acpi_device_dir(device));
|
|
if (!entry)
|
|
ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
|
|
"Unable to create '%s' fs entry\n",
|
|
ACPI_PROCESSOR_FILE_POWER));
|
|
else {
|
|
entry->proc_fops = &acpi_processor_power_fops;
|
|
entry->data = acpi_driver_data(device);
|
|
entry->owner = THIS_MODULE;
|
|
}
|
|
|
|
pr->flags.power_setup_done = 1;
|
|
|
|
return_VALUE(0);
|
|
}
|
|
|
|
int acpi_processor_power_exit(struct acpi_processor *pr,
|
|
struct acpi_device *device)
|
|
{
|
|
ACPI_FUNCTION_TRACE("acpi_processor_power_exit");
|
|
|
|
pr->flags.power_setup_done = 0;
|
|
|
|
if (acpi_device_dir(device))
|
|
remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
|
|
acpi_device_dir(device));
|
|
|
|
/* Unregister the idle handler when processor #0 is removed. */
|
|
if (pr->id == 0) {
|
|
pm_idle = pm_idle_save;
|
|
|
|
/*
|
|
* We are about to unload the current idle thread pm callback
|
|
* (pm_idle), Wait for all processors to update cached/local
|
|
* copies of pm_idle before proceeding.
|
|
*/
|
|
cpu_idle_wait();
|
|
}
|
|
|
|
return_VALUE(0);
|
|
}
|