When doing an nmi backtrace of many cores, most of which are idle, the
output is a little overwhelming and very uninformative.  Suppress
messages for cpus that are idling when they are interrupted and just
emit one line, "NMI backtrace for N skipped: idling at pc 0xNNN".

We do this by grouping all the cpuidle code together into a new
.cpuidle.text section, and then checking the address of the interrupted
PC to see if it lies within that section.

This commit suitably tags x86 and tile idle routines, and only adds in
the minimal framework for other architectures.

Link: http://lkml.kernel.org/r/1472487169-14923-5-git-send-email-cmetcalf@mellanox.comSigned-off-by: NChris Metcalf <cmetcalf@mellanox.com>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Daniel Thompson <daniel.thompson@linaro.org> [arm]
Tested-by: NPetr Mladek <pmladek@suse.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

ACPI 6.0 introduced an optional object _LPI that provides an alternate
method to describe Low Power Idle states. It defines the local power
states for each node in a hierarchical processor topology. The OSPM can
use _LPI object to select a local power state for each level of processor
hierarchy in the system. They used to produce a composite power state
request that is presented to the platform by the OSPM.

Since multiple processors affect the idle state for any non-leaf hierarchy
node, coordination of idle state requests between the processors is
required. ACPI supports two different coordination schemes: Platform
coordinated and  OS initiated.

This patch adds initial support for Platform coordination scheme of LPI.
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI 6.0 adds a new method to specify the CPU idle states(C-states)
called Low Power Idle(LPI) states. Since new architectures like ARM64
use only LPIs, introduce ACPI_PROCESSOR_CSTATE to encapsulate all the
code supporting the old style C-states(_CST).

This patch will help to extend the processor_idle module to support
LPI.
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

$ make tags
  GEN     tags
ctags: Warning: drivers/acpi/processor_idle.c:64: null expansion of name pattern "\1"
ctags: Warning: drivers/xen/events/events_2l.c:41: null expansion of name pattern "\1"
ctags: Warning: kernel/locking/lockdep.c:151: null expansion of name pattern "\1"
ctags: Warning: kernel/rcu/rcutorture.c:133: null expansion of name pattern "\1"
ctags: Warning: kernel/rcu/rcutorture.c:135: null expansion of name pattern "\1"
ctags: Warning: kernel/workqueue.c:323: null expansion of name pattern "\1"
ctags: Warning: net/ipv4/syncookies.c:53: null expansion of name pattern "\1"
ctags: Warning: net/ipv6/syncookies.c:44: null expansion of name pattern "\1"
ctags: Warning: net/rds/page.c:45: null expansion of name pattern "\1"

Which are all the result of the DEFINE_PER_CPU pattern:

  scripts/tags.sh:200:	'/\<DEFINE_PER_CPU([^,]*, *\([[:alnum:]_]*\)/\1/v/'
  scripts/tags.sh:201:	'/\<DEFINE_PER_CPU_SHARED_ALIGNED([^,]*, *\([[:alnum:]_]*\)/\1/v/'

The below cures them. All except the workqueue one are within reasonable
distance of the 80 char limit. TJ do you have any preference on how to
fix the wq one, or shall we just not care its too long?
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

acpi_processor_sleep is neither related nor used by CPUIdle framework.
It's used in system suspend/resume path as a syscore operation. It makes
more sense to move it to acpi/sleep.c where all the S-state transition
(a.k.a. Linux system suspend/hiberate) related code are present.

Also make it depend on CONFIG_ACPI_SYSTEM_POWER_STATES_SUPPORT so that
it's not compiled on architecture like ARM64 where S-states are not
yet defined in ACPI.
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Like few of the other ACPI modules, replace PREFIX with pr_fmt and
change all the printk call sites to use pr_* companion functions
in processor_idle.
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There is no need to carry potentially outdated Free Software Foundation
mailing address in file headers since the COPYING file includes it.
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There is no need to have processor_power_dmi_table[] writeable, constify
it.
Signed-off-by: NMathias Krause <minipli@googlemail.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Fix a bug that leads to showing the name and description of C-state C0
as "<null>" in sysfs after the ACPI C-states changed (e.g. after AC->DC
or DC->AC
transition).

The function poll_idle_init() in drivers/cpuidle/driver.c initializes the
state 0 during cpuidle_register_driver(), so we better do not overwrite it
again with '\0' during acpi_processor_cst_has_changed().
Signed-off-by: NThomas Schlichter <thomas.schlichter@web.de>
Reviewed-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: 3.13+ <stable@vger.kernel.org> # 3.13+
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Replace the clockevents_notify() call with an explicit function call.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/2653377.MSAlfA939I@vostro.rjw.lanSigned-off-by: NIngo Molnar <mingo@kernel.org>

Replace the clockevents_notify() call with an explicit function call.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/25071624.dkenaL3SGT@vostro.rjw.lanSigned-off-by: NIngo Molnar <mingo@kernel.org>

Add an ->enter_freeze callback routine, acpi_idle_enter_freeze(), to
the ACPI cpuidle driver and point ->enter_freeze to it for all the
C2-type and C3-type states that don't need to fall back to C1
(which may be halt-induced and that will re-enable interrupts on
exit from idle, which ->enter_freeze cannot do).
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>

Introduce a common ->enter callback routine for the ACPI cpuidle
driver, acpi_idle_enter(), which helps to reduce code complexity,
size and duplication and prevents theoretically possible failues that
an incorrect routine may be run to enter the given idle state due to
a firmware bug (eg. when _CST returns a different set of states for
each processor).
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

acpi_idle_enter_c1() and acpi_idle_enter_simple() are close enough to
each other that they can be merged into one function which reduces
duplication of code quite a bit.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Since acpi_idle_enter_bm() is only used if flags.bm_check is set for
the given acpi_processor object, it doesn't make sense to check that
flag in there.

For this reason, drop flags.bm_check tests (and some code depending
on them) from acpi_idle_enter_bm().
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

White space in the switch statement in acpi_processor_setup_cpuidle_states()
does not adhere to the kernel coding style and that makes the code
difficult to read.  Clean that up.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The comment about bus master disable in acpi_idle_enter_simple() is
irrelevant, because the function doesn't disable bus mastering, so
drop it.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

acpi_idle_enter_simple() and acpi_idle_enter_bm() both check
if C2/C3 type entry is supported on MP in the same way, so move
those checks to a separate function and call it from both
places (and it doesn't need to check if the state type is not
C1, because the functions in question won't be called otherwise).

While at it, use IS_ENABLED() for the CONFIG_HOTPLUG_CPU check.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

acpi_idle_enter_simple() and acpi_idle_enter_bm() don't need to
call sched_clock_idle_sleep/wakeup_event(), because that's taken
care of by the core already.  Namely, sched_clock_idle_sleep_event()
is called by tick_nohz_start_idle() called by __tick_nohz_idle_enter()
which in turn is called by tick_nohz_idle_enter() and that is called
by cpu_idle_loop().  Analogously for sched_clock_idle_wakeup_event().

For this reason, drop those calls from the ACPI cpuidle driver's
->enter callback routines.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Since the cpuidle core calls stop_critical_timings() and
start_critical_timings() around the execution of ->enter callbacks,
acpi_idle_do_entry() doesn't need to do that (and really shouldn't).

Also using "inline" on it is pointless and the kerneldoc entry does
not reflect the actual situation any more.

Fix all of the above.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

CPUIDLE_FLAG_TIME_INVALID is no longer checked
by menu or ladder cpuidle governors, so don't
bother setting or defining it.

It was originally invented to account for the fact that
acpi_safe_halt() enables interrupts to invoke HLT.
That would allow interrupt service routines to be included
in the last_idle duration measurements made in cpuidle_enter_state(),
potentially returning a duration much larger than reality.

But menu and ladder can gracefully handle erroneously large duration
intervals without checking for CPUIDLE_FLAG_TIME_INVALID.
Further, if they don't check CPUIDLE_FLAG_TIME_INVALID, they
can also benefit from the instances when the duration interval
is not erroneously large.
Signed-off-by: NLen Brown <len.brown@intel.com>
Acked-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

It's incorrect to assign a signed value to an unsigned acpi_status
variable. This patch fixes it by using a signed integer to return
error values.
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The only place where the time is invalid is when the ACPI_CSTATE_FFH entry
method is not set. Otherwise for all the drivers, the time can be correctly
measured.

Instead of duplicating the CPUIDLE_FLAG_TIME_VALID flag in all the drivers
for all the states, just invert the logic by replacing it by the flag
CPUIDLE_FLAG_TIME_INVALID, hence we can set this flag only for the acpi idle
driver, remove the former flag from all the drivers and invert the logic with
this flag in the different governor.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There is a following AB-BA dependency between cpu_hotplug.lock and
cpuidle_lock:

1) cpu_hotplug.lock -> cpuidle_lock
enable_nonboot_cpus()
 _cpu_up()
  cpu_hotplug_begin()
   LOCK(cpu_hotplug.lock)
 cpu_notify()
  ...
  acpi_processor_hotplug()
   cpuidle_pause_and_lock()
    LOCK(cpuidle_lock)

2) cpuidle_lock -> cpu_hotplug.lock
acpi_os_execute_deferred() workqueue
 ...
 acpi_processor_cst_has_changed()
  cpuidle_pause_and_lock()
   LOCK(cpuidle_lock)
  get_online_cpus()
   LOCK(cpu_hotplug.lock)

Fix this by reversing the order acpi_processor_cst_has_changed() does
thigs -- let it first execute the protection against CPU hotplug by
calling get_online_cpus() and obtain the cpuidle lock only after that (and
perform the symmentric change when allowing CPUs hotplug again and
dropping cpuidle lock).

Spotted by lockdep.
Signed-off-by: NJiri Kosina <jkosina@suse.cz>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

dev->state_count is now always equal to drv->state_count and
drv->state_count no longer can change during driver's lifetime so
the default dev->state_count initialization in cpuidle_enable_device()
(called from cpuidle_register_device()) can be used instead.
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

acpi_processor_hotplug() calls acpi_processor_setup_cpuidle_cx()
without calling acpi_processor_setup_cpuidle_states() first so it
is possible that dev->state_count becomes different from
drv->state_count (in case of SMP system with unsupported C2/C3
states + enabled CPU hotplug and num_online_cpus() becoming > 1).

The driver code assumes that cpuidle core will handle such cases
but currently this is untrue (dev->state_count is used only for
handling cpuidle state sysfs entries and drv->state_count is used
for all other cases) and will not be fixed in the future as
dev->state_count is planned to be removed.

Fix the issue by checking for the max supported idle state in
C2/C3 state's ->enter handler (acpi_idle_enter_simple() for C2/C3
and acpi_idle_enter_bm() for C3 + bm_check flag set) and setting
the C1 state (instead of higher states) when needed.

Also remove no longer needed max idle state checks from
acpi_processor_setup_cpuidle_[states,cx]().
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

People seem to delight in writing wrong and broken mwait idle routines;
collapse the lot.

This leaves mwait_play_dead() the sole remaining user of __mwait() and
new __mwait() users are probably doing it wrong.

Also remove __sti_mwait() as its unused.

Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jacob Jun Pan <jacob.jun.pan@linux.intel.com>
Cc: Mike Galbraith <bitbucket@online.de>
Cc: Len Brown <lenb@kernel.org>
Cc: Rui Zhang <rui.zhang@intel.com>
Acked-by: NRafael Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131212141654.616820819@infradead.orgSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

In acpi_processor_resume(), the variable resumed_bm_rld is being
used without being initialized, so initialize it.
Signed-off-by: NAl Stone <al.stone@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Minor cleanup: remove some extra trailing white space.
Signed-off-by: NAl Stone <al.stone@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Replace direct inclusions of <acpi/acpi.h>, <acpi/acpi_bus.h> and
<acpi/acpi_drivers.h>, which are incorrect, with <linux/acpi.h>
inclusions and remove some inclusions of those files that aren't
necessary.

First of all, <acpi/acpi.h>, <acpi/acpi_bus.h> and <acpi/acpi_drivers.h>
should not be included directly from any files that are built for
CONFIG_ACPI unset, because that generally leads to build warnings about
undefined symbols in !CONFIG_ACPI builds.  For CONFIG_ACPI set,
<linux/acpi.h> includes those files and for CONFIG_ACPI unset it
provides stub ACPI symbols to be used in that case.

Second, there are ordering dependencies between those files that always
have to be met.  Namely, it is required that <acpi/acpi_bus.h> be included
prior to <acpi/acpi_drivers.h> so that the acpi_pci_root declarations the
latter depends on are always there.  And <acpi/acpi.h> which provides
basic ACPICA type declarations should always be included prior to any other
ACPI headers in CONFIG_ACPI builds.  That also is taken care of including
<linux/acpi.h> as appropriate.
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> (drivers/pci stuff)
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> (Xen stuff)
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Mike reported that commit 7d1a9417 ("x86: Use generic idle loop")
regressed several workloads and caused excessive reschedule
interrupts.

The patch in question failed to notice that the x86 code had an
inverted sense of the polling state versus the new generic code (x86:
default polling, generic: default !polling).

Fix the two prominent x86 mwait based idle drivers and introduce a few
new generic polling helpers (fixing the wrong smp_mb__after_clear_bit
usage).

Also switch the idle routines to using tif_need_resched() which is an
immediate TIF_NEED_RESCHED test as opposed to need_resched which will
end up being slightly different.
Reported-by: NMike Galbraith <bitbucket@online.de>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: lenb@kernel.org
Cc: tglx@linutronix.de
Link: http://lkml.kernel.org/n/tip-nc03imb0etuefmzybzj7sprf@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

The only acpi_processor_get_power_info_fadt() user
(acpi_processor_get_power_info()) dereferences pr before calling
the function.

The only acpi_processor_hotplug() user (acpi_cpu_soft_notify())
checks for pr == NULL before calling the function.

The only acpi_processor_cst_has_changed() user (acpi_processor_notify())
checks for pr == NULL before calling the function.

The only acpi_processor_power_init() user (__acpi_processor_start())
dereferences pr before calling the function.

Thus remove superfluous pr == NULL checks from affected functions.

Also:

While at it remove redundant brackets from acpi_processor_hotplug().
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

This removes all the drivers/acpi uses of the __cpuinit macros
from all C files.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: Len Brown <lenb@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: linux-acpi@vger.kernel.org
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Since acpi_processor_suspend() and acpi_processor_resume() need not
be visible outside of the file they are defined in, make them
static.

[rjw: Changelog]
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The system suspend routine of the ACPI processor driver saves
the BUS_MASTER_RLD register and its resume routine restores it.
However, there can be only one such register in the system and it
really should be saved after non-boot CPUs have been offlined and
restored before they are put back online during resume.

For this reason, move the saving and restoration of BUS_MASTER_RLD
to syscore suspend and syscore resume, respectively, and drop the no
longer necessary suspend/resume callbacks from the ACPI processor
driver.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The en_core_tk_irqen flag is set in all the cpuidle driver which
means it is not necessary to specify this flag.

Remove the flag and the code related to it.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>  # for mach-omap2/*
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit ac3ebafa "ACPI / idle: remove usage of the statedata"
changed the percpu processor cstate to a unified cstate in ACPI idle.
That caused all our NHM boxes to boot hang or panic.

2178751 Task dump for CPU 1:
	2178752 swapper/1       R  running task     6736     0      1 0x00000000
	2178753  ffff8801e8029dc8 ffffffff8101cf96 ffff8801e8029e28 ffffffff813d294b
	2178754  0000000000000f99 0000000000000003 00000000003cf654 0000000025c17d03
	2178755  ffff8801e8029e38 ffff8801e74fc000 00000002590dc5c4 ffffffff8163cdb0
	2178756 Call Trace:
	2178757  [<ffffffff8101cf96>] ? acpi_processor_ffh_cstate_enter+0x2d/0x2f
	2178758  [<ffffffff813d294b>] acpi_idle_enter_bm+0x1b1/0x236
	2178759  [<ffffffff8163cdb0>] ? disable_cpuidle+0x10/0x10
	2178760  [<ffffffff8163cdc2>] cpuidle_enter+0x12/0x14
	2178761  [<ffffffff8163d286>] cpuidle_wrap_enter+0x2f/0x6d
	2178762  [<ffffffff8163d2d4>] cpuidle_enter_tk+0x10/0x12
	2178763  [<ffffffff8163cdd6>] cpuidle_enter_state+0x12/0x3a
	2178764  [<ffffffff8163d4a7>] cpuidle_idle_call+0xe8/0x161
	2178765  [<ffffffff81008d99>] cpu_idle+0x5e/0xa4
	2178766  [<ffffffff8174c6c1>] start_secondary+0x1a9/0x1ad
	2178767 Task dump for CPU 2:

In fact, the ACPI idle is based on the assumption of difference percpu
cstate structures that are necessary for the implementation to work
cprrectly.  A unique acpi_processor_cx is not sifficient by far.

This patch is just a quick fix re-introducing the percpu cstates.

If someone really wants to unify the ACPI cstates, please make sure
that the whole software infrastructure is changed and take hardware
as well as many different kinds of BIOS settings into account.

[rjw: Changelog]
Reported-by: NLKP project <lkp@linux.intel.com>
Reported-by: NXie ChanglongX <changlongx.xie@intel.com>
Tested-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NAlex Shi <alex.shi@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

mwait_idle() is a C1-only idle loop intended to be more efficient
than HLT, starting on Pentium-4 HT-enabled processors.

But mwait_idle() has been replaced by the more general
mwait_idle_with_hints(), which handles both C1 and deeper C-states.
ACPI processor_idle and intel_idle use only mwait_idle_with_hints(),
and no longer use mwait_idle().

Here we simplify the x86 native idle code by removing mwait_idle(),
and the "idle=mwait" bootparam used to invoke it.

Since Linux 3.0 there has been a boot-time warning when "idle=mwait"
was invoked saying it would be removed in 2012.  This removal
was also noted in the (now removed:-) feature-removal-schedule.txt.

After this change, kernels configured with
(CONFIG_ACPI=n && CONFIG_INTEL_IDLE=n) when run on hardware
that supports MWAIT will simply use HLT.  If MWAIT is desired
on those systems, cpuidle and the cpuidle drivers above
can be enabled.
Signed-off-by: NLen Brown <len.brown@intel.com>
Cc: x86@kernel.org

Len Brown sent a patch to remove this field in the intel_idle driver.
The other user of this field is the davinci cpuidle driver and a
patch has been sent to remove the usage of it.

This patch removes the last user of this field.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NLen Brown <len.brown@intel.com>

The cpuidle_device is retrieved in the function by using directly
the global variable. But the caller of this function already have
this device and it can be passed as a parameter. That is one small
step to encapsulate the code more.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NLen Brown <len.brown@intel.com>