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>

These different headers are not needed.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NLen Brown <len.brown@intel.com>

The different definitions are not used anywhere in the code.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NLen Brown <len.brown@intel.com>

acpi_processor_get_power_info() has to be called before
acpi_processor_setup_cpuidle_states() to have the latest
information available. This fixes the missing C-state information
after AC-->DC transition.
Signed-off-by: NThomas Schlichter <thomas.schlichter@web.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

If cpuidle is disabled, that means that:

	per_cpu(acpi_cpuidle_device, pr->id)

is set to NULL as the acpi_processor_power_init ends up failing at

	 retval = cpuidle_register_driver(&acpi_idle_driver)

(in acpi_processor_power_init) and never sets the per_cpu idle
device.  So when acpi_processor_hotplug on CPU online notification
tries to reference said device it crashes:

cpu 3 spinlock event irq 62
BUG: unable to handle kernel NULL pointer dereference at 0000000000000004
IP: [<ffffffff81381013>] acpi_processor_setup_cpuidle_cx+0x3f/0x105
PGD a259b067 PUD ab38b067 PMD 0
Oops: 0002 [#1] SMP
odules linked in: dm_multipath dm_mod xen_evtchn iscsi_boot_sysfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi libcrc32c crc32c nouveau mxm_wmi wmi radeon ttm sg sr_mod sd_mod cdrom ata_generic ata_piix libata crc32c_intel scsi_mod atl1c i915 fbcon tileblit font bitblit softcursor drm_kms_helper video xen_blkfront xen_netfront fb_sys_fops sysimgblt sysfillrect syscopyarea xenfs xen_privcmd mperf
CPU 1
Pid: 3047, comm: bash Not tainted 3.8.0-rc3upstream-00250-g165c029 #1 MSI MS-7680/H61M-P23 (MS-7680)
RIP: e030:[<ffffffff81381013>]  [<ffffffff81381013>] acpi_processor_setup_cpuidle_cx+0x3f/0x105
RSP: e02b:ffff88001742dca8  EFLAGS: 00010202
RAX: 0000000000010be9 RBX: ffff8800a0a61800 RCX: ffff880105380000
RDX: 0000000000000003 RSI: 0000000000000200 RDI: ffff8800a0a61800
RBP: ffff88001742dce8 R08: ffffffff81812360 R09: 0000000000000200
R10: aaaaaaaaaaaaaaaa R11: 0000000000000001 R12: ffff8800a0a61800
R13: 00000000ffffff01 R14: 0000000000000000 R15: ffffffff81a907a0
FS:  00007fd6942f7700(0000) GS:ffff880105280000(0000) knlGS:0000000000000000
CS:  e033 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000004 CR3: 00000000a6773000 CR4: 0000000000042660
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process bash (pid: 3047, threadinfo ffff88001742c000, task ffff880017944000)
Stack:
 0000000000000150 ffff880100f59e00 ffff88001742dcd8 ffff8800a0a61800
 0000000000000000 00000000ffffff01 0000000000000000 ffffffff81a907a0
 ffff88001742dd18 ffffffff813815b1 ffff88001742dd08 ffffffff810ae336
Call Trace:
 [<ffffffff813815b1>] acpi_processor_hotplug+0x7c/0x9f
 [<ffffffff810ae336>] ? schedule_delayed_work_on+0x16/0x20
 [<ffffffff8137ee8f>] acpi_cpu_soft_notify+0x90/0xca
 [<ffffffff8166023d>] notifier_call_chain+0x4d/0x70
 [<ffffffff810bc369>] __raw_notifier_call_chain+0x9/0x10
 [<ffffffff81094a4b>] __cpu_notify+0x1b/0x30
 [<ffffffff81652cf7>] _cpu_up+0x103/0x14b
 [<ffffffff81652e18>] cpu_up+0xd9/0xec
 [<ffffffff8164a254>] store_online+0x94/0xd0
 [<ffffffff814122fb>] dev_attr_store+0x1b/0x20
 [<ffffffff81216404>] sysfs_write_file+0xf4/0x170

This patch fixes it.
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Many cpuidle drivers measure their time spent in an idle state by
reading the wallclock time before and after idling and calculating the
difference. This leads to erroneous results when the wallclock time gets
updated by another processor in the meantime, adding that clock
adjustment to the idle state's time counter.

If the clock adjustment was negative, the result is even worse due to an
erroneous cast from int to unsigned long long of the last_residency
variable. The negative 32 bit integer will zero-extend and result in a
forward time jump of roughly four billion milliseconds or 1.3 hours on
the idle state residency counter.

This patch changes all affected cpuidle drivers to either use the
monotonic clock for their measurements or make use of the generic time
measurement wrapper in cpuidle.c, which was already working correctly.
Some superfluous CLIs/STIs in the ACPI code are removed (interrupts
should always already be disabled before entering the idle function, and
not get reenabled until the generic wrapper has performed its second
measurement). It also removes the erroneous cast, making sure that
negative residency values are applied correctly even though they should
not appear anymore.
Signed-off-by: NJulius Werner <jwerner@chromium.org>
Reviewed-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
Tested-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The dereference should be moved below the NULL test.

dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch)
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NLen Brown <len.brown@intel.com>

Currently we have the cpuidle_device field in the acpi_processor_power structure.
This adds a dependency between processor.h and cpuidle.h

Although it is not a real problem, removing this dependency has the benefit of
separating a bit more the cpuidle code from the rest of the acpi code.
Also, the compilation should be a bit improved because we do no longer
include cpuidle.h in processor.h. The preprocessor was generating 30418 loc
and with this patch it generates 30256 loc for processor_thermal.c, a file
which is not concerned at all by cpuidle, like processor_perflib.c and
processor_throttling.c.

That may sound ridiculous, but "small streams make big rivers" :P

This patch moves this field into a static global per cpu variable like what is
done in the intel_idle driver.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

The 'device' parameter is not used neither in acpi_processor_power_init
and acpi_processor_power_exit. This patch removes it.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Remove the unused power field from struct struct acpi_processor_cx.

[rjw: Modified changelog.]
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Remove the time field as it is not used.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Remove the usage field as it is not used.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Remove the latency_ticks field as it is not used.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Fixes issues like this:

i_aSL -> iASL
00-7_f -> 00-7F
local_fADT -> local_FADT
execute_oSI -> execute_OSI

Also, in function headers, the parameters are now translated to
lower case (with underscores if necessary.)
Signed-off-by: NBob Moore <robert.moore@intel.com>
Signed-off-by: NLin Ming <ming.m.lin@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

On certain bios, resume hangs if cpus are allowed to enter idle states
during suspend [1].

This was fixed in apci idle driver [2].But intel_idle driver does not
have this fix. Thus instead of replicating the fix in both the idle
drivers, or in more platform specific idle drivers if needed, the
more general cpuidle infrastructure could handle this.

A suspend callback in cpuidle_driver could handle this fix. But
a cpuidle_driver provides only basic functionalities like platform idle
state detection capability and mechanisms to support entry and exit
into CPU idle states. All other cpuidle functions are found in the
cpuidle generic infrastructure for good reason that all cpuidle
drivers, irrepective of their platforms will support these functions.

One option therefore would be to register a suspend callback in cpuidle
which handles this fix. This could be called through a PM_SUSPEND_PREPARE
notifier. But this is too generic a notfier for a driver to handle.

Also, ideally the job of cpuidle is not to handle side effects of suspend.
It should expose the interfaces which "handle cpuidle 'during' suspend"
or any other operation, which the subsystems call during that respective
operation.

The fix demands that during suspend, no cpus should be allowed to enter
deep C-states. The interface cpuidle_uninstall_idle_handler() in cpuidle
ensures that. Not just that it also kicks all the cpus which are already
in idle out of their idle states which was being done during cpu hotplug
through a CPU_DYING_FROZEN callbacks.

Now the question arises about when during suspend should
cpuidle_uninstall_idle_handler() be called. Since we are dealing with
drivers it seems best to call this function during dpm_suspend().
Delaying the call till dpm_suspend_noirq() does no harm, as long as it is
before cpu_hotplug_begin() to avoid race conditions with cpu hotpulg
operations. In dpm_suspend_noirq(), it would be wise to place this call
before suspend_device_irqs() to avoid ugly interactions with the same.

Ananlogously, during resume.

References:
[1] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/674075.
[2] http://marc.info/?l=linux-pm&m=133958534231884&w=2Reported-and-tested-by: NDave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
Reviewed-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Make the ACPI processor driver define its PM callbacks through
a struct dev_pm_ops object rather than by using legacy PM hooks
in struct acpi_device_ops.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

None of the drivers implementing the ACPI device suspend callback
uses the pm_message_t argument of it, so this argument may be dropped
entirely from that callback.  This will simplify switching the ACPI
bus type to PM handling based on struct dev_pm_ops.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Commit e978aa7d ( cpuidle: Move
dev->last_residency update to driver enter routine; remove dev->last_state)
was  breaking suspend on laptops, as reported in the below link
	- https://lkml.org/lkml/2011/11/11/164

This was fixed in commit 3439a8da
(ACPI / cpuidle: Remove acpi_idle_suspend (to fix suspend regression)
by removing acpi_idle_suspend flag.
	- https://lkml.org/lkml/2011/11/14/74

But this did fix did not work on all systems
as Suspend/resume regression was reported on Lenovo S10-3
recently by Dave.
	- https://lkml.org/lkml/2012/5/27/115
It looked like with commit e978aa7d broke suspend and
with commit 3439a8da resume was not working with acpi_idle driver.

This patch fixes the regression that caused this issue
in the first place. acpi_idle_suspend flag is essential on
some x86 systems to prevent the cpus from going to deeper C-states
when suspend is triggered ( commit b04e7bdb )
So reverting the commit 3439a8da is essential.

By default, irqs are disabled in cpu_idle arch specific call
and re-enabled in idle state return path . During suspend,
the acpi_idle_suspend flag is set, which
prevents the cpus from going to deeper idle states,
it is essential to enabling the irqs in this return path too.

To address the suspend issue,
we were not re-enabling the interrupts while returning from
acpi_idle_enter_bm() routine if acpi_idle_suspend flag is set.
and this caused suspend failure.

In addition to the above, to improve the readability of the code,
return of -ENIVAL is replaced with -EBUSY in acpi_idle_suspend
return path. Implying that the system is currently busy when suspend
is in progress, which prevents the cpus from entering deeper C-states.
Reported-and-Tested-by: NDav Hansen <dave@linux.vnet.ibm.com>
Tested-by: NPreeti Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: NDeepthi Dharwar <deepthi@linux.vnet.ibm.com>
Reviewed-by: NSrivatsa S Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

ACPI code is shared by arch/x86 and arch/ia64. ia64 doesn't provide a plain
"halt()" function.  Use safe_halt() instead.
Signed-off-by: NTony Luck <tony.luck@intel.com>
Tested-by: NBoris Ostrovsky <boris.ostrovsky@amd.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

The acpi_processor_cst_has_changed() function is invoked from a
CPU_ONLINE or CPU_DEAD function, which might well execute on CPU 0
even though the CPU being hotplugged is some other CPU.  In addition,
acpi_processor_cst_has_changed() invokes smp_processor_id() without
protection, resulting in splats when onlining CPUs.

This commit therefore changes the smp_processor_id() to pr->id, as is
used elsewhere in the code, for example, in acpi_processor_add().
Signed-off-by: NPaul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Tested-by: NYong Zhang <yong.zhang0@gmail.com>
Acked-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NLen Brown <len.brown@intel.com>

Currently when a CPU is off-lined it enters either MWAIT-based idle or,
if MWAIT is not desired or supported, HLT-based idle (which places the
processor in C1 state). This patch allows processors without MWAIT
support to stay in states deeper than C1.
Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@amd.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

After commit e978aa7d ("cpuidle: Move dev->last_residency update to
driver enter routine; remove dev->last_state") setting acpi_idle_suspend
to 1 by acpi_processor_suspend() causes the ACPI cpuidle routines to
return error codes continuously, which in turn causes cpuidle to lock up
(hard).

However, acpi_idle_suspend doesn't appear to be useful for any
particular purpose (it's racy and doesn't really provide any real
protection), so it can be removed, which makes the problem go away.
Reported-and-tested-by: NTomas M. <tmezzadra@gmail.com>
Reported-and-tested-by: NFerenc Wagner <wferi@niif.hu>
Tested-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch makes the cpuidle_states structure global (single copy)
instead of per-cpu. The statistics needed on per-cpu basis
by the governor are kept per-cpu. This simplifies the cpuidle
subsystem as state registration is done by single cpu only.
Having single copy of cpuidle_states saves memory. Rare case
of asymmetric C-states can be handled within the cpuidle driver
and architectures such as POWER do not have asymmetric C-states.

Having single/global registration of all the idle states,
dynamic C-state transitions on x86 are handled by
the boot cpu. Here, the boot cpu  would disable all the devices,
re-populate the states and later enable all the devices,
irrespective of the cpu that would receive the notification first.

Reference:
https://lkml.org/lkml/2011/4/25/83Signed-off-by: NDeepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: NTrinabh Gupta <g.trinabh@gmail.com>
Tested-by: NJean Pihet <j-pihet@ti.com>
Reviewed-by: NKevin Hilman <khilman@ti.com>
Acked-by: NArjan van de Ven <arjan@linux.intel.com>
Acked-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

This is the first step towards global registration of cpuidle
states. The statistics used primarily by the governor are per-cpu
and have to be split from rest of the fields inside cpuidle_state,
which would be made global i.e. single copy. The driver_data field
is also per-cpu and moved.
Signed-off-by: NDeepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: NTrinabh Gupta <g.trinabh@gmail.com>
Tested-by: NJean Pihet <j-pihet@ti.com>
Reviewed-by: NKevin Hilman <khilman@ti.com>
Acked-by: NArjan van de Ven <arjan@linux.intel.com>
Acked-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Cpuidle governor only suggests the state to enter using the
governor->select() interface, but allows the low level driver to
override the recommended state. The actual entered state
may be different because of software or hardware demotion. Software
demotion is done by the back-end cpuidle driver and can be accounted
correctly. Current cpuidle code uses last_state field to capture the
actual state entered and based on that updates the statistics for the
state entered.

Ideally the driver enter routine should update the counters,
and it should return the state actually entered rather than the time
spent there. The generic cpuidle code should simply handle where
the counters live in the sysfs namespace, not updating the counters.

Reference:
https://lkml.org/lkml/2011/3/25/52Signed-off-by: NDeepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: NTrinabh Gupta <g.trinabh@gmail.com>
Tested-by: NJean Pihet <j-pihet@ti.com>
Reviewed-by: NKevin Hilman <khilman@ti.com>
Acked-by: NArjan van de Ven <arjan@linux.intel.com>
Acked-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

We cannot preempt this lock on -rt as we are in an
interrupt disabled region and about to go into deep sleep.

In mainline this change documents the low level nature of
the lock - otherwise there's no functional difference. Lockdep
and Sparse checking will work as usual.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Len Brown <len.brown@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The PM QoS implementation files are better named
kernel/power/qos.c and include/linux/pm_qos.h.

The PM QoS support is compiled under the CONFIG_PM option.
Signed-off-by: NJean Pihet <j-pihet@ti.com>
Acked-by: Nmarkgross <markgross@thegnar.org>
Reviewed-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

The workaround for AMD erratum 400 uses the term "c1e" falsely suggesting:
1. Intel C1E is somehow involved
2. All AMD processors with C1E are involved

Use the string "amd_c1e" instead of simply "c1e" to clarify that
this workaround is specific to AMD's version of C1E.
Use the string "e400" to clarify that the workaround is specific
to AMD processors with Erratum 400.

This patch is text-substitution only, with no functional change.

cc: x86@kernel.org
Acked-by: NBorislav Petkov <borislav.petkov@amd.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

CPUIDLE_FLAG_SHALLOW
CPUIDLE_FLAG_BALANCED
CPUIDLE_FLAG_DEEP
CPUIDLE_FLAG_CHECK_BM

were set by acpi_processor_setup_cpuidle(),
but never used by cpuidle or by acpi_idle.
So stop setting them.
Signed-off-by: NLen Brown <len.brown@intel.com>

Having four variables for the same thing:
  idle_halt, idle_nomwait, force_mwait and boot_option_idle_overrides
is rather confusing and unnecessary complex.

if idle= boot param is passed, only set up one variable:
boot_option_idle_overrides

Introduces following functional changes/fixes:
  - intel_idle driver does not register if any idle=xy
    boot param is passed.
  - processor_idle.c will also not register a cpuidle driver
    and get active if idle=halt is passed.
    Before a cpuidle driver with one (C1, halt) state got registered
    Now the default_idle function will be used which finally uses
    the same idle call to enter sleep state (safe_halt()), but
    without registering a whole cpuidle driver.

That means idle= param will always avoid cpuidle drivers to register
with one exception (same behavior as before):
idle=nomwait
may still register acpi_idle cpuidle driver, but C1 will not use
mwait, but hlt. This can be a workaround for IO based deeper sleep
states where C1 mwait causes problems.
Signed-off-by: NThomas Renninger <trenn@suse.de>
cc: x86@kernel.org
Signed-off-by: NLen Brown <len.brown@intel.com>

__get_cpu_var() can be replaced with this_cpu_read and will then use a single
read instruction with implied address calculation to access the correct per cpu
instance.

However, the address of a per cpu variable passed to __this_cpu_read() cannot be
determed (since its an implied address conversion through segment prefixes).
Therefore apply this only to uses of __get_cpu_var where the addres of the
variable is not used.

V3->V4:
	- Move one instance of this_cpu_inc_return to a later patch
	  so that this one can go in without percpu infrastructrure
	  changes.

Sedat: fixed compile failure caused by an extra ')'.

Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

The mW data in this field comes from AML _CST,
which was typed in by a BIOS writer, and is thus
considered unreliable.

Linux does not use it for making any decisions.
We do display it in sysfs where somebody might
read it and assume it is meaningful, so delete it.
Signed-off-by: NLen Brown <len.brown@intel.com>

Looks like a left over from /proc/acpi/processor/*/power which got removed
Signed-off-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

Some minor improvements in error handling, but overall it was mostly dead
code.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLen Brown <len.brown@intel.com>

Remove deprecated ACPI processor procfs I/F, including:
/proc/acpi/processor/CPUX/power
/proc/acpi/processor/CPUX/limit
/proc/acpi/processor/CPUX/info

/proc/acpi/processor/CPUX/throttling still exists,
as we don't have sysfs I/F available for now.
Signed-off-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Accomodate the original C1E-aware idle routine to the different times
during boot when the BIOS enables C1E. While at it, remove the synthetic
CPUID flag in favor of a single global setting which denotes C1E status
on the system.

[ hpa: changed c1e_enabled to be a bool; clarified cpu bit 3:21 comment ]
Signed-off-by: NMichal Schmidt <mschmidt@redhat.com>
LKML-Reference: <20100727165335.GA11630@aftab>
Signed-off-by: NBorislav Petkov <borislav.petkov@amd.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>

Now that all arches have been converted over to use generic time via
clocksources or arch_gettimeoffset(), we can remove the GENERIC_TIME
config option and simplify the generic code.
Signed-off-by: NJohn Stultz <johnstul@us.ibm.com>
LKML-Reference: <1279068988-21864-4-git-send-email-johnstul@us.ibm.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

processor.bm_check_disable=1" prevents Linux from checking BM_STS
before entering C3-type cpu power states.

This may be useful for a system running acpi_idle
where the BIOS exports FADT C-states, _CST IO C-states,
or _CST FFH C-states with the BM_STS bit set;
while configuring the chipset to set BM_STS
more frequently than perhaps is optimal.

Note that such systems may have been developed
using a tickful OS that would quickly clear BM_STS,
rather than a tickless OS that may go for some time
between checking and clearing BM_STS.

Note also that an alternative for newer systems
is to use the intel_idle driver, which always
ignores BM_STS, relying Linux device drivers
to register constraints explicitly via PM_QOS.

https://bugzilla.kernel.org/show_bug.cgi?id=15886Signed-off-by: NLen Brown <len.brown@intel.com>

It turns out that there is a bit in the _CST for Intel FFH C3
that tells the OS if we should be checking BM_STS or not.

Linux has been unconditionally checking BM_STS.
If the chip-set is configured to enable BM_STS,
it can retard or completely prevent entry into
deep C-states -- as illustrated by turbostat:

http://userweb.kernel.org/~lenb/acpi/utils/pmtools/turbostat/

ref: Intel Processor Vendor-Specific ACPI Interface Specification
table 4 "_CST FFH GAS Field Encoding"
Bit 1: Set to 1 if OSPM should use Bus Master avoidance for this C-state

https://bugzilla.kernel.org/show_bug.cgi?id=15886Signed-off-by: NLen Brown <len.brown@intel.com>