task #29239886

commit 18734958e9bfbc055805d110a38dc76307eba742 upstream

Modify the intel_idle driver to get the C-states information from ACPI
_CST if the processor model is not recognized by it.

The processor is still required to support MWAIT and the information
from ACPI _CST will only be used if all of the C-states listed by
_CST are of the ACPI_CSTATE_FFH type (which means that they are
expected to be entered via MWAIT).

Moreover, the driver assumes that the _CST information is the same
for all CPUs in the system, so it is sufficient to evaluate _CST for
one of them and extract the common list of C-states from there.
Also _CST is evaluated once at the system initialization time and
the driver does not respond to _CST change notifications (that can
be changed in the future).

The main functional difference between intel_idle with this change
and the ACPI processor driver is that the former sets the target
residency to be equal to the exit latency (provided by _CST) for
C1-type C-states and to 3 times the exit latency value for the other
C-state types, whereas the latter obtains the target residency by
multiplying the exit latency by the same number (2 by default) for
all C-state types.  Therefore it is expected that in general using
the former instead of the latter on the same system will lead to
improved energy-efficiency.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Nyjia <yingbao.jia@intel.com>
Signed-off-by: NErwei Deng <erwei@linux.alibaba.com>
Reviewed-by: NArtie Ding <artie.ding@linux.alibaba.com>

task #29239886

commit 9f3d6daf61e5156139cd05643f7f1c2a9b7b49b0 upstream

Move the C-state verification and checks from
intel_idle_cpuidle_driver_init() to a separate function,
intel_idle_verify_cstate(), and make the former call it after
checking the CPUIDLE_FLAG_UNUSABLE state flag.

Also combine the drv->states[] updates with the incrementation of
drv->state_count.

No intentional functional impact.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Nyjia <yingbao.jia@intel.com>
Signed-off-by: NErwei Deng <erwei@linux.alibaba.com>
Reviewed-by: NArtie Ding <artie.ding@linux.alibaba.com>

commit f2c4db1bd80720cd8cb2a5aa220d9bc9f374f04e upstream

Going primarily by:

  https://en.wikipedia.org/wiki/List_of_Intel_Atom_microprocessors

with additional information gleaned from other related pages; notably:

 - Bonnell shrink was called Saltwell
 - Moorefield is the Merriefield refresh which makes it Airmont

The general naming scheme is: FAM6_ATOM_UARCH_SOCTYPE

  for i in `git grep -l FAM6_ATOM` ; do
	sed -i  -e 's/ATOM_PINEVIEW/ATOM_BONNELL/g'		\
		-e 's/ATOM_LINCROFT/ATOM_BONNELL_MID/'		\
		-e 's/ATOM_PENWELL/ATOM_SALTWELL_MID/g'		\
		-e 's/ATOM_CLOVERVIEW/ATOM_SALTWELL_TABLET/g'	\
		-e 's/ATOM_CEDARVIEW/ATOM_SALTWELL/g'		\
		-e 's/ATOM_SILVERMONT1/ATOM_SILVERMONT/g'	\
		-e 's/ATOM_SILVERMONT2/ATOM_SILVERMONT_X/g'	\
		-e 's/ATOM_MERRIFIELD/ATOM_SILVERMONT_MID/g'	\
		-e 's/ATOM_MOOREFIELD/ATOM_AIRMONT_MID/g'	\
		-e 's/ATOM_DENVERTON/ATOM_GOLDMONT_X/g'		\
		-e 's/ATOM_GEMINI_LAKE/ATOM_GOLDMONT_PLUS/g' ${i}
  done
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: dave.hansen@linux.intel.com
Cc: len.brown@intel.com
Signed-off-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When MWAIT is disabled, intel_idle refuses to probe.
But it may mis-lead the user by blaming this on the model number:

intel_idle: does not run on family 6 modesl 79

So defer the check for MWAIT until after the model# white-list check succeeds,
and if the MWAIT check fails, tell the user how to fix it:

intel_idle: Please enable MWAIT in BIOS SETUP
Signed-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This reverts commit 43858b4f.

The reason I removed the leave_mm() calls in question is because the
heuristic wasn't needed after that patch.  With the original version
of my PCID series, we never flushed a "lazy cpu" (i.e. a CPU running
kernel thread) due a flush on the loaded mm.

Unfortunately, that caused architectural issues, so now I've
reinstated these flushes on non-PCID systems in:

    commit b956575b ("x86/mm: Flush more aggressively in lazy TLB mode").

That, in turn, gives us a power management and occasionally
performance regression as compared to old kernels: a process that
goes into a deep idle state on a given CPU and gets its mm flushed
due to activity on a different CPU will wake the idle CPU.

Reinstate the old ugly heuristic: if a CPU goes into ACPI C3 or an
intel_idle state that is likely to cause a TLB flush gets its mm
switched to init_mm before going idle.

FWIW, this heuristic is lousy.  Whether we should change CR3 before
idle isn't a good hint except insofar as the performance hit is a bit
lower if the TLB is getting flushed by the idle code anyway.  What we
really want to know is whether we anticipate being idle long enough
that the mm is likely to be flushed before we wake up.  This is more a
matter of the expected latency than the idle state that gets chosen.
This heuristic also completely fails on systems that don't know
whether the TLB will be flushed (e.g. AMD systems?).  OTOH it may be a
bit obsolete anyway -- PCID systems don't presently benefit from this
heuristic at all.

We also shouldn't do this callback from innermost bit of the idle code
due to the RCU nastiness it causes.  All the information need is
available before rcu_idle_enter() needs to happen.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 43858b4f "x86/mm: Stop calling leave_mm() in idle code"
Link: http://lkml.kernel.org/r/c513bbd4e653747213e05bc7062de000bf0202a5.1509793738.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

If the 'arat' cpu flag is set, then the conditionals in intel_idle() that
guard calling tick_broadcast_enter()/exit() will never be true. Use
static_cpu_has(X86_FEATURE_ARAT) to create a fast path to replace
the conditional.
Signed-off-by: NJason Baron <jbaron@akamai.com>
Acked-by: NJacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Make the drivers that want to include the polling state into their
states table initialize it explicitly and drop the initialization of
it (which in fact is conditional, but that is not obvious from the
code) from the core.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: NSudeep Holla <sudeep.holla@arm.com>
Acked-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

Rename the ->enter_freeze cpuidle driver callback to ->enter_s2idle
to make it clear that it is used for entering suspend-to-idle and
rename the related functions, variables and so on accordingly.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Now that lazy TLB suppresses all flush IPIs (as opposed to all but
the first), there's no need to leave_mm() when going idle.

This means we can get rid of the rcuidle hack in
switch_mm_irqs_off() and we can unexport leave_mm().

This also removes acpi_unlazy_tlb() from the x86 and ia64 headers,
since it has no callers any more.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Reviewed-by: NNadav Amit <nadav.amit@gmail.com>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/03c699cfd6021e467be650d6b73deaccfe4b4bd7.1498751203.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Remove #define PREFIX and add #define pr_fmt to use more common logging.

Miscellanea:

o Add missing newline to format
o Convert a single printk without KERN_<LEVEL> to pr_info
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NJacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Gemini Lake uses the same C-states as Broxton and also uses the
IRTL MSR's to determine maximum C-state latency.
Signed-off-by: NDavid E. Box <david.e.box@linux.intel.com>
Acked-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

previously known as  MSR_NHM_SNB_PKG_CST_CFG_CTL
Signed-off-by: NLen Brown <len.brown@intel.com>

Cosmetic only -- no functional change in this patch.

sysfs before:

state4/desc:MWAIT 0x20
state4/name:C6-HSW

sysfs after:

state4/desc:MWAIT 0x20
state4/name:C6

We remove the platform acronyms from the end of the state name
(-HSW in this case) for three reasonse.

 1. more consistency with acpi_idle, which prints C1, C2, C3 etc.

 2. users know what platform they are on already
    an acronym for the processor code name here
    seems to cause more confusion than clarity.

 3. less clutter in "cpupower monitor" output,
    which truncates the names to 4 columns.

The precise definition of the state continues to be available in "desc".
Reported-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Install the callbacks via the state machine and let the core invoke the
callbacks on the already online CPUs.

The two smp_call_function_single() invocations in intel_idle_cpu_init() have
been removed because intel_idle_cpu_init() is now invoked via the hotplug
callback which runs on the target CPU. The IRQ-off calling convention for
auto_demotion_disable() and c1e_promotion_disable() has not been preserved
because only those two modify the MSR during CPU intialization.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: NJacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Since commit 1cf4f629 ("cpu/hotplug: Move online calls to
hotplugged cpu") the CPU_ONLINE and CPU_DOWN_PREPARE notifiers are
always run on the hot plugged CPU, and as of commit 3b9d6da6
("cpu/hotplug: Fix rollback during error-out in __cpu_disable()") the
CPU_DOWN_FAILED notifier also runs on the hot plugged CPU. This patch
converts the SMP functional calls into direct calls.

smp_function_call_single() executes the function with interrupts
disabled. This calling convention is not preserved, because
tick_broadcast_enable() and tick_braodcast_disable() handle
interrupts themselves.
Signed-off-by: NAnna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: NJacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Add Knights Mill (KNM) to the list of CPUIDs supported by intel_idle.
Signed-off-by: NPiotr Luc <piotr.luc@intel.com>
Reviewed-by: NDave Hansen <dave.hansen@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Add CPU ID for Atom Z34xx processors. Datasheets indicate support for this,
detailed information about potential quirks or limitations are missing, though.
So we just reuse the definition from official BSP code.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

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>

Commit 5dcef694 ("intel_idle: add BXT support") added an 8-element
lookup array with just a 2-bit value used for lookups. As per the SDM
that bit field is really 3 bits wide. While this is supposedly benign
here, future re-use of the code for other CPUs might expose the issue.
Signed-off-by: NJan Beulich <jbeulich@suse.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Since irtl_ns_units[] has itself zero entries, make sure the caller
recognized those cases along with the MSR read returning zero, as zero
is not a valid value for exit_latency and target_residency.
Signed-off-by: NJan Beulich <jbeulich@suse.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Len Brown noticed something was amiss in our INTEL_FAM6_*
definitions.  It seems like model 0x1F was a Nehalem part,
marketed as "Intel Core i7 and i5 Processors" (according to the
SDM).  But, although it was a Nehalem 0x1F had some uncore events
which were shared with Westmere.

Len also mentioned he thought it was called "Havendale", which
Wikipedia says was graphics-oriented and canceled:

	https://en.wikipedia.org/wiki/Nehalem_(microarchitecture)

So either way, it's probably not imporant what we call it, but
call it Nehalem to be accurate, and add a "G" since it seems
graphics-related.  If it were canceled that would be a good reason
why it's so sparsely and inconsistently referred to in the code.
Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160629192737.949C41A8@viggo.jf.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Denverton is an Intel Atom based micro server which shares the same
Goldmont architecture as Broxton. The available C-states on
Denverton is a subset of Broxton with only C1, C1e, and C6.
Signed-off-by: NJacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The Kconfig for this driver is currently declared with:

config INTEL_IDLE
        bool "Cpuidle Driver for Intel Processors"

...meaning that it currently is not being built as a module by anyone.

This was done in commit 6ce9cd86
("intel_idle: disable module support") since "...the module capability
is cauing more trouble than it is worth."

This was done over 5y ago, and Daniel adds that:

    ...the modular support has been removed from almost all the cpuidle
    drivers and the cpuidle framework is no longer assuming driver could
    be unloaded.

    Removing the modular dead code in the driver makes sense as this
    what have been done in the others drivers.

So lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.  At a
later date we might want to consider whether subsys_init or another
init category seems more appropriate than device_init.

We replace module.h with moduleparam.h since the file does declare
some module parameters, and leaving them as such is currently the
easiest way to remain compatible with existing boot arg use cases.

Note that MODULE_DEVICE_TABLE is a no-op for non-modular code.

Also note that we can't remove intel_idle_cpuidle_devices_uninit() as
that is still used for unwind purposes if the init fails.

We also delete the MODULE_LICENSE tag etc. since all that information
is already contained at the top of the file in the comments.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Use the new INTEL_FAM6_* macros for intel_idle.c.  Also fix up
some of the macros to be consistent with how some of the
intel_idle code refers to the model.

There's on oddity here: model 0x1F is uniquely referred to here
and nowhere else that I could find.  0x1E/0x1F are just spelled
out as "Intel Core i7 and i5 Processors" in the SDM or as "Intel
processors based on the Nehalem, Westmere microarchitectures" in
the RDPMC section.  Comments between tables 19-19 and 19-20 in
the SDM seem to point to 0x1F being some kind of Westmere, so
let's call it "WESTMERE2".
Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: jacob.jun.pan@intel.com
Cc: linux-pm@vger.kernel.org
Link: http://lkml.kernel.org/r/20160603001932.EE978EB9@viggo.jf.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Broxton has all the HSW C-states, except C3.
BXT C-state timing is slightly different.

Here we trust the IRTL MSRs as authority
on maximum C-state latency, and override the driver's tables
with the values found in the associated IRTL MSRs.
Further we set the target_residency to 1x maximum latency,
trusting the hardware demotion logic.
Signed-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

KBL is similar to SKL
Signed-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

SKX is similar to BDX
Signed-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This driver registers cpuidle devices when a CPU comes online, but it
leaves the registrations in place when a CPU goes offline.  The module
exit code only unregisters the currently online CPUs, leaving the
devices for offline CPUs dangling.

This patch changes the driver to clean up all registrations on exit,
even those from CPUs that are offline.
Signed-off-by: NRichard Cochran <rcochran@linutronix.de>
Signed-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

If a cpuidle registration error occurs during the hot plug notifier
callback, we should really inform the hot plug machinery instead of
just ignoring the error.  This patch changes the callback to properly
return on error.
Signed-off-by: NRichard Cochran <rcochran@linutronix.de>
Signed-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The helper function, intel_idle_cpu_init, registers one new device
with the cpuidle layer.  If the registration should fail, that
function immediately calls intel_idle_cpuidle_devices_uninit() to
unregister every last CPU's device.  However, it makes no sense to do
so, when called from the hot plug notifier callback.

This patch moves the call to intel_idle_cpuidle_devices_uninit()
outside of the helper function to the one call site that actually
needs to perform the de-registrations.
Signed-off-by: NRichard Cochran <rcochran@linutronix.de>
Signed-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This driver sets the broadcast tick quite early on during probe and does
not clean up again in cast of failure.  This patch moves the setup call
after the registration, placing the on_each_cpu() calls within the global
CPU lock region.
Signed-off-by: NRichard Cochran <rcochran@linutronix.de>
Signed-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The helper function, intel_idle_cpuidle_devices_uninit, frees the
globally allocated per-CPU data.  However, this function is invoked
from the hot plug notifier callback at a time when freeing that data
is not safe.

If the call to cpuidle_register_driver() should fail (say, due to lack
of memory), then the driver will free its per-CPU region.  On the
*next* CPU_ONLINE event, the driver will happily use the region again
and even free it again if the failure repeats.

This patch fixes the issue by moving the call to free_percpu() outside
of the helper function at the two call sites that actually need to
free the per-CPU data.
Signed-off-by: NRichard Cochran <rcochran@linutronix.de>
Signed-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

In the module_init() method, if the per-CPU allocation fails, then the
active cpuidle registration is not cleaned up.  This patch fixes the
issue by attempting the allocation before registration, and then
cleaning it up again on registration failure.
Signed-off-by: NRichard Cochran <rcochran@linutronix.de>
Signed-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

In the module_exit() method, this driver first frees its per-CPU
pointer, then unregisters a callback making use of the pointer.
Furthermore, the function, intel_idle_cpuidle_devices_uninit, is racy
against CPU hot plugging as it calls for_each_online_cpu().

This patch corrects the issues by unregistering first on the exit path
while holding the hot plug lock.
Signed-off-by: NRichard Cochran <rcochran@linutronix.de>
Signed-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The function, intel_idle_cpuidle_driver_init, makes calls on each CPU
to auto_demotion_disable() and c1e_promotion_disable().  These calls
are redundant, as intel_idle_cpu_init() does the same calls just a bit
later on.  They are also premature, as the driver registration may yet
fail.

This patch removes the redundant code.
Signed-off-by: NRichard Cochran <rcochran@linutronix.de>
Signed-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The function, intel_idle_cpuidle_driver_init, delivers no error codes
at all.  This patch changes the function to return 'void' instead of
returning zero.
Signed-off-by: NRichard Cochran <rcochran@linutronix.de>
Signed-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Signed-off-by: NRichard Cochran <rcochran@linutronix.de>
Signed-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Enables "Intel(R) Xeon Phi(TM) Processor x200 Product Family" support,
formerly code-named KNL. It is based on modified Intel Atom Silvermont
microarchitecture.
Signed-off-by: NDasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com>
[micah.barany@intel.com: adjusted values of residency and latency]
Signed-off-by: NMicah Barany <micah.barany@intel.com>
[hubert.chrzaniuk@intel.com: removed deprecated CPUIDLE_FLAG_TIME_VALID flag]
Signed-off-by: NHubert Chrzaniuk <hubert.chrzaniuk@intel.com>
Signed-off-by: NPawel Karczewski <pawel.karczewski@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Some SKL-H configurations require "intel_idle.max_cstate=7" to boot.
While that is an effective workaround, it disables C10.

This patch detects the problematic configuration,
and disables C8 and C9, keeping C10 enabled.

Note that enabling SGX in BIOS SETUP can also prevent this issue,
if the system BIOS provides that option.

https://bugzilla.kernel.org/show_bug.cgi?id=109081
"Freezes with Intel i7 6700HQ (Skylake), unless intel_idle.max_cstate=7"
Signed-off-by: NLen Brown <len.brown@intel.com>
Cc: stable@vger.kernel.org

Addition of PC9 state, and minor tweaks to existing PC6 and PC8 states.
Signed-off-by: NLen Brown <len.brown@intel.com>